drivers/s390/block/dasd.c

/* [<][>][^][v][top][bottom][index][help] */
This source file includes following definitions.
dasd_alloc_device
dasd_free_device
dasd_alloc_block
dasd_free_block
dasd_state_new_to_known
dasd_state_known_to_new
dasd_debugfs_setup
dasd_state_known_to_basic
dasd_state_basic_to_known
dasd_state_basic_to_ready
_wait_for_empty_queues
dasd_state_ready_to_basic
dasd_state_unfmt_to_basic
dasd_state_ready_to_online
dasd_state_online_to_ready
dasd_increase_state
dasd_decrease_state
dasd_change_state
do_kick_device
dasd_kick_device
do_reload_device
dasd_reload_device
do_restore_device
dasd_restore_device
dasd_set_target_state
_wait_for_device
dasd_enable_device
dasd_profile_start
dasd_profile_end_add_data
dasd_profile_end
dasd_profile_reset
dasd_profile_on
dasd_profile_off
dasd_get_user_string
dasd_stats_write
dasd_stats_array
dasd_stats_seq_print
dasd_stats_show
dasd_stats_open
dasd_profile_init
dasd_profile_exit
dasd_statistics_removeroot
dasd_statistics_createroot
dasd_statistics_createroot
dasd_statistics_removeroot
dasd_stats_generic_show
dasd_profile_init
dasd_profile_exit
dasd_profile_on
dasd_hosts_show
dasd_hosts_exit
dasd_hosts_init
dasd_smalloc_request
dasd_fmalloc_request
dasd_sfree_request
dasd_ffree_request
dasd_check_cqr
dasd_term_IO
dasd_start_IO
dasd_device_timeout
dasd_device_set_timer
dasd_device_clear_timer
dasd_handle_killed_request
dasd_generic_handle_state_change
dasd_check_hpf_error
dasd_ese_needs_format
dasd_ese_oos_cond
dasd_int_handler
dasd_generic_uc_handler
__dasd_device_recovery
__dasd_device_process_ccw_queue
__dasd_process_cqr
__dasd_device_process_final_queue
__dasd_device_check_expire
__dasd_device_is_unusable
__dasd_device_start_head
__dasd_device_check_path_events
dasd_flush_device_queue
dasd_device_tasklet
dasd_schedule_device_bh
dasd_device_set_stop_bits
dasd_device_remove_stop_bits
dasd_add_request_head
dasd_add_request_tail
dasd_wakeup_cb
_wait_for_wakeup
__dasd_sleep_on_erp
__dasd_sleep_on_loop_condition
_dasd_sleep_on
_wait_for_wakeup_queue
_dasd_sleep_on_queue
dasd_sleep_on
dasd_sleep_on_queue
dasd_sleep_on_queue_interruptible
dasd_sleep_on_interruptible
_dasd_term_running_cqr
dasd_sleep_on_immediatly
__dasd_cancel_req
dasd_cancel_req
dasd_block_timeout
dasd_block_set_timer
dasd_block_clear_timer
__dasd_process_erp
__dasd_cleanup_cqr
__dasd_process_block_ccw_queue
dasd_return_cqr_cb
__dasd_block_start_head
dasd_block_tasklet
_dasd_wake_block_flush_cb
_dasd_requeue_request
dasd_flush_block_queue
dasd_schedule_block_bh
do_dasd_request
dasd_times_out
dasd_init_hctx
dasd_exit_hctx
dasd_request_done
dasd_alloc_queue
dasd_free_queue
dasd_open
dasd_release
dasd_getgeo
dasd_exit
dasd_device_is_ro
dasd_generic_auto_online
dasd_generic_probe
dasd_generic_free_discipline
dasd_generic_remove
dasd_generic_set_online
dasd_generic_set_offline
dasd_generic_last_path_gone
dasd_generic_path_operational
dasd_generic_notify
dasd_generic_path_event
dasd_generic_verify_path
dasd_generic_space_exhaust
dasd_generic_space_avail
dasd_generic_requeue_all_requests
do_requeue_requests
dasd_schedule_requeue
dasd_generic_pm_freeze
dasd_generic_restore_device
dasd_generic_build_rdc
dasd_generic_read_dev_chars
dasd_get_sense
dasd_generic_shutdown
dasd_init
   1 // SPDX-License-Identifier: GPL-2.0
   2 /*
   3  * Author(s)......: Holger Smolinski <Holger.Smolinski@de.ibm.com>
   4  *                  Horst Hummel <Horst.Hummel@de.ibm.com>
   5  *                  Carsten Otte <Cotte@de.ibm.com>
   6  *                  Martin Schwidefsky <schwidefsky@de.ibm.com>
   7  * Bugreports.to..: <Linux390@de.ibm.com>
   8  * Copyright IBM Corp. 1999, 2009
   9  */
  10 
  11 #define KMSG_COMPONENT "dasd"
  12 #define pr_fmt(fmt) KMSG_COMPONENT ": " fmt
  13 
  14 #include <linux/kmod.h>
  15 #include <linux/init.h>
  16 #include <linux/interrupt.h>
  17 #include <linux/ctype.h>
  18 #include <linux/major.h>
  19 #include <linux/slab.h>
  20 #include <linux/hdreg.h>
  21 #include <linux/async.h>
  22 #include <linux/mutex.h>
  23 #include <linux/debugfs.h>
  24 #include <linux/seq_file.h>
  25 #include <linux/vmalloc.h>
  26 
  27 #include <asm/ccwdev.h>
  28 #include <asm/ebcdic.h>
  29 #include <asm/idals.h>
  30 #include <asm/itcw.h>
  31 #include <asm/diag.h>
  32 
  33 /* This is ugly... */
  34 #define PRINTK_HEADER "dasd:"
  35 
  36 #include "dasd_int.h"
  37 /*
  38  * SECTION: Constant definitions to be used within this file
  39  */
  40 #define DASD_CHANQ_MAX_SIZE 4
  41 
  42 #define DASD_DIAG_MOD           "dasd_diag_mod"
  43 
  44 static unsigned int queue_depth = 32;
  45 static unsigned int nr_hw_queues = 4;
  46 
  47 module_param(queue_depth, uint, 0444);
  48 MODULE_PARM_DESC(queue_depth, "Default queue depth for new DASD devices");
  49 
  50 module_param(nr_hw_queues, uint, 0444);
  51 MODULE_PARM_DESC(nr_hw_queues, "Default number of hardware queues for new DASD devices");
  52 
  53 /*
  54  * SECTION: exported variables of dasd.c
  55  */
  56 debug_info_t *dasd_debug_area;
  57 EXPORT_SYMBOL(dasd_debug_area);
  58 static struct dentry *dasd_debugfs_root_entry;
  59 struct dasd_discipline *dasd_diag_discipline_pointer;
  60 EXPORT_SYMBOL(dasd_diag_discipline_pointer);
  61 void dasd_int_handler(struct ccw_device *, unsigned long, struct irb *);
  62 
  63 MODULE_AUTHOR("Holger Smolinski <Holger.Smolinski@de.ibm.com>");
  64 MODULE_DESCRIPTION("Linux on S/390 DASD device driver,"
  65                    " Copyright IBM Corp. 2000");
  66 MODULE_SUPPORTED_DEVICE("dasd");
  67 MODULE_LICENSE("GPL");
  68 
  69 /*
  70  * SECTION: prototypes for static functions of dasd.c
  71  */
  72 static int  dasd_alloc_queue(struct dasd_block *);
  73 static void dasd_free_queue(struct dasd_block *);
  74 static int dasd_flush_block_queue(struct dasd_block *);
  75 static void dasd_device_tasklet(unsigned long);
  76 static void dasd_block_tasklet(unsigned long);
  77 static void do_kick_device(struct work_struct *);
  78 static void do_restore_device(struct work_struct *);
  79 static void do_reload_device(struct work_struct *);
  80 static void do_requeue_requests(struct work_struct *);
  81 static void dasd_return_cqr_cb(struct dasd_ccw_req *, void *);
  82 static void dasd_device_timeout(struct timer_list *);
  83 static void dasd_block_timeout(struct timer_list *);
  84 static void __dasd_process_erp(struct dasd_device *, struct dasd_ccw_req *);
  85 static void dasd_profile_init(struct dasd_profile *, struct dentry *);
  86 static void dasd_profile_exit(struct dasd_profile *);
  87 static void dasd_hosts_init(struct dentry *, struct dasd_device *);
  88 static void dasd_hosts_exit(struct dasd_device *);
  89 
  90 /*
  91  * SECTION: Operations on the device structure.
  92  */
  93 static wait_queue_head_t dasd_init_waitq;
  94 static wait_queue_head_t dasd_flush_wq;
  95 static wait_queue_head_t generic_waitq;
  96 static wait_queue_head_t shutdown_waitq;
  97 
  98 /*
  99  * Allocate memory for a new device structure.
 100  */
 101 struct dasd_device *dasd_alloc_device(void)
 102 {
 103         struct dasd_device *device;
 104 
 105         device = kzalloc(sizeof(struct dasd_device), GFP_ATOMIC);
 106         if (!device)
 107                 return ERR_PTR(-ENOMEM);
 108 
 109         /* Get two pages for normal block device operations. */
 110         device->ccw_mem = (void *) __get_free_pages(GFP_ATOMIC | GFP_DMA, 1);
 111         if (!device->ccw_mem) {
 112                 kfree(device);
 113                 return ERR_PTR(-ENOMEM);
 114         }
 115         /* Get one page for error recovery. */
 116         device->erp_mem = (void *) get_zeroed_page(GFP_ATOMIC | GFP_DMA);
 117         if (!device->erp_mem) {
 118                 free_pages((unsigned long) device->ccw_mem, 1);
 119                 kfree(device);
 120                 return ERR_PTR(-ENOMEM);
 121         }
 122         /* Get two pages for ese format. */
 123         device->ese_mem = (void *)__get_free_pages(GFP_ATOMIC | GFP_DMA, 1);
 124         if (!device->ese_mem) {
 125                 free_page((unsigned long) device->erp_mem);
 126                 free_pages((unsigned long) device->ccw_mem, 1);
 127                 kfree(device);
 128                 return ERR_PTR(-ENOMEM);
 129         }
 130 
 131         dasd_init_chunklist(&device->ccw_chunks, device->ccw_mem, PAGE_SIZE*2);
 132         dasd_init_chunklist(&device->erp_chunks, device->erp_mem, PAGE_SIZE);
 133         dasd_init_chunklist(&device->ese_chunks, device->ese_mem, PAGE_SIZE * 2);
 134         spin_lock_init(&device->mem_lock);
 135         atomic_set(&device->tasklet_scheduled, 0);
 136         tasklet_init(&device->tasklet, dasd_device_tasklet,
 137                      (unsigned long) device);
 138         INIT_LIST_HEAD(&device->ccw_queue);
 139         timer_setup(&device->timer, dasd_device_timeout, 0);
 140         INIT_WORK(&device->kick_work, do_kick_device);
 141         INIT_WORK(&device->restore_device, do_restore_device);
 142         INIT_WORK(&device->reload_device, do_reload_device);
 143         INIT_WORK(&device->requeue_requests, do_requeue_requests);
 144         device->state = DASD_STATE_NEW;
 145         device->target = DASD_STATE_NEW;
 146         mutex_init(&device->state_mutex);
 147         spin_lock_init(&device->profile.lock);
 148         return device;
 149 }
 150 
 151 /*
 152  * Free memory of a device structure.
 153  */
 154 void dasd_free_device(struct dasd_device *device)
 155 {
 156         kfree(device->private);
 157         free_pages((unsigned long) device->ese_mem, 1);
 158         free_page((unsigned long) device->erp_mem);
 159         free_pages((unsigned long) device->ccw_mem, 1);
 160         kfree(device);
 161 }
 162 
 163 /*
 164  * Allocate memory for a new device structure.
 165  */
 166 struct dasd_block *dasd_alloc_block(void)
 167 {
 168         struct dasd_block *block;
 169 
 170         block = kzalloc(sizeof(*block), GFP_ATOMIC);
 171         if (!block)
 172                 return ERR_PTR(-ENOMEM);
 173         /* open_count = 0 means device online but not in use */
 174         atomic_set(&block->open_count, -1);
 175 
 176         atomic_set(&block->tasklet_scheduled, 0);
 177         tasklet_init(&block->tasklet, dasd_block_tasklet,
 178                      (unsigned long) block);
 179         INIT_LIST_HEAD(&block->ccw_queue);
 180         spin_lock_init(&block->queue_lock);
 181         INIT_LIST_HEAD(&block->format_list);
 182         spin_lock_init(&block->format_lock);
 183         timer_setup(&block->timer, dasd_block_timeout, 0);
 184         spin_lock_init(&block->profile.lock);
 185 
 186         return block;
 187 }
 188 EXPORT_SYMBOL_GPL(dasd_alloc_block);
 189 
 190 /*
 191  * Free memory of a device structure.
 192  */
 193 void dasd_free_block(struct dasd_block *block)
 194 {
 195         kfree(block);
 196 }
 197 EXPORT_SYMBOL_GPL(dasd_free_block);
 198 
 199 /*
 200  * Make a new device known to the system.
 201  */
 202 static int dasd_state_new_to_known(struct dasd_device *device)
 203 {
 204         int rc;
 205 
 206         /*
 207          * As long as the device is not in state DASD_STATE_NEW we want to
 208          * keep the reference count > 0.
 209          */
 210         dasd_get_device(device);
 211 
 212         if (device->block) {
 213                 rc = dasd_alloc_queue(device->block);
 214                 if (rc) {
 215                         dasd_put_device(device);
 216                         return rc;
 217                 }
 218         }
 219         device->state = DASD_STATE_KNOWN;
 220         return 0;
 221 }
 222 
 223 /*
 224  * Let the system forget about a device.
 225  */
 226 static int dasd_state_known_to_new(struct dasd_device *device)
 227 {
 228         /* Disable extended error reporting for this device. */
 229         dasd_eer_disable(device);
 230         device->state = DASD_STATE_NEW;
 231 
 232         if (device->block)
 233                 dasd_free_queue(device->block);
 234 
 235         /* Give up reference we took in dasd_state_new_to_known. */
 236         dasd_put_device(device);
 237         return 0;
 238 }
 239 
 240 static struct dentry *dasd_debugfs_setup(const char *name,
 241                                          struct dentry *base_dentry)
 242 {
 243         struct dentry *pde;
 244 
 245         if (!base_dentry)
 246                 return NULL;
 247         pde = debugfs_create_dir(name, base_dentry);
 248         if (!pde || IS_ERR(pde))
 249                 return NULL;
 250         return pde;
 251 }
 252 
 253 /*
 254  * Request the irq line for the device.
 255  */
 256 static int dasd_state_known_to_basic(struct dasd_device *device)
 257 {
 258         struct dasd_block *block = device->block;
 259         int rc = 0;
 260 
 261         /* Allocate and register gendisk structure. */
 262         if (block) {
 263                 rc = dasd_gendisk_alloc(block);
 264                 if (rc)
 265                         return rc;
 266                 block->debugfs_dentry =
 267                         dasd_debugfs_setup(block->gdp->disk_name,
 268                                            dasd_debugfs_root_entry);
 269                 dasd_profile_init(&block->profile, block->debugfs_dentry);
 270                 if (dasd_global_profile_level == DASD_PROFILE_ON)
 271                         dasd_profile_on(&device->block->profile);
 272         }
 273         device->debugfs_dentry =
 274                 dasd_debugfs_setup(dev_name(&device->cdev->dev),
 275                                    dasd_debugfs_root_entry);
 276         dasd_profile_init(&device->profile, device->debugfs_dentry);
 277         dasd_hosts_init(device->debugfs_dentry, device);
 278 
 279         /* register 'device' debug area, used for all DBF_DEV_XXX calls */
 280         device->debug_area = debug_register(dev_name(&device->cdev->dev), 4, 1,
 281                                             8 * sizeof(long));
 282         debug_register_view(device->debug_area, &debug_sprintf_view);
 283         debug_set_level(device->debug_area, DBF_WARNING);
 284         DBF_DEV_EVENT(DBF_EMERG, device, "%s", "debug area created");
 285 
 286         device->state = DASD_STATE_BASIC;
 287 
 288         return rc;
 289 }
 290 
 291 /*
 292  * Release the irq line for the device. Terminate any running i/o.
 293  */
 294 static int dasd_state_basic_to_known(struct dasd_device *device)
 295 {
 296         int rc;
 297 
 298         if (device->discipline->basic_to_known) {
 299                 rc = device->discipline->basic_to_known(device);
 300                 if (rc)
 301                         return rc;
 302         }
 303 
 304         if (device->block) {
 305                 dasd_profile_exit(&device->block->profile);
 306                 debugfs_remove(device->block->debugfs_dentry);
 307                 dasd_gendisk_free(device->block);
 308                 dasd_block_clear_timer(device->block);
 309         }
 310         rc = dasd_flush_device_queue(device);
 311         if (rc)
 312                 return rc;
 313         dasd_device_clear_timer(device);
 314         dasd_profile_exit(&device->profile);
 315         dasd_hosts_exit(device);
 316         debugfs_remove(device->debugfs_dentry);
 317         DBF_DEV_EVENT(DBF_EMERG, device, "%p debug area deleted", device);
 318         if (device->debug_area != NULL) {
 319                 debug_unregister(device->debug_area);
 320                 device->debug_area = NULL;
 321         }
 322         device->state = DASD_STATE_KNOWN;
 323         return 0;
 324 }
 325 
 326 /*
 327  * Do the initial analysis. The do_analysis function may return
 328  * -EAGAIN in which case the device keeps the state DASD_STATE_BASIC
 329  * until the discipline decides to continue the startup sequence
 330  * by calling the function dasd_change_state. The eckd disciplines
 331  * uses this to start a ccw that detects the format. The completion
 332  * interrupt for this detection ccw uses the kernel event daemon to
 333  * trigger the call to dasd_change_state. All this is done in the
 334  * discipline code, see dasd_eckd.c.
 335  * After the analysis ccw is done (do_analysis returned 0) the block
 336  * device is setup.
 337  * In case the analysis returns an error, the device setup is stopped
 338  * (a fake disk was already added to allow formatting).
 339  */
 340 static int dasd_state_basic_to_ready(struct dasd_device *device)
 341 {
 342         int rc;
 343         struct dasd_block *block;
 344         struct gendisk *disk;
 345 
 346         rc = 0;
 347         block = device->block;
 348         /* make disk known with correct capacity */
 349         if (block) {
 350                 if (block->base->discipline->do_analysis != NULL)
 351                         rc = block->base->discipline->do_analysis(block);
 352                 if (rc) {
 353                         if (rc != -EAGAIN) {
 354                                 device->state = DASD_STATE_UNFMT;
 355                                 disk = device->block->gdp;
 356                                 kobject_uevent(&disk_to_dev(disk)->kobj,
 357                                                KOBJ_CHANGE);
 358                                 goto out;
 359                         }
 360                         return rc;
 361                 }
 362                 if (device->discipline->setup_blk_queue)
 363                         device->discipline->setup_blk_queue(block);
 364                 set_capacity(block->gdp,
 365                              block->blocks << block->s2b_shift);
 366                 device->state = DASD_STATE_READY;
 367                 rc = dasd_scan_partitions(block);
 368                 if (rc) {
 369                         device->state = DASD_STATE_BASIC;
 370                         return rc;
 371                 }
 372         } else {
 373                 device->state = DASD_STATE_READY;
 374         }
 375 out:
 376         if (device->discipline->basic_to_ready)
 377                 rc = device->discipline->basic_to_ready(device);
 378         return rc;
 379 }
 380 
 381 static inline
 382 int _wait_for_empty_queues(struct dasd_device *device)
 383 {
 384         if (device->block)
 385                 return list_empty(&device->ccw_queue) &&
 386                         list_empty(&device->block->ccw_queue);
 387         else
 388                 return list_empty(&device->ccw_queue);
 389 }
 390 
 391 /*
 392  * Remove device from block device layer. Destroy dirty buffers.
 393  * Forget format information. Check if the target level is basic
 394  * and if it is create fake disk for formatting.
 395  */
 396 static int dasd_state_ready_to_basic(struct dasd_device *device)
 397 {
 398         int rc;
 399 
 400         device->state = DASD_STATE_BASIC;
 401         if (device->block) {
 402                 struct dasd_block *block = device->block;
 403                 rc = dasd_flush_block_queue(block);
 404                 if (rc) {
 405                         device->state = DASD_STATE_READY;
 406                         return rc;
 407                 }
 408                 dasd_destroy_partitions(block);
 409                 block->blocks = 0;
 410                 block->bp_block = 0;
 411                 block->s2b_shift = 0;
 412         }
 413         return 0;
 414 }
 415 
 416 /*
 417  * Back to basic.
 418  */
 419 static int dasd_state_unfmt_to_basic(struct dasd_device *device)
 420 {
 421         device->state = DASD_STATE_BASIC;
 422         return 0;
 423 }
 424 
 425 /*
 426  * Make the device online and schedule the bottom half to start
 427  * the requeueing of requests from the linux request queue to the
 428  * ccw queue.
 429  */
 430 static int
 431 dasd_state_ready_to_online(struct dasd_device * device)
 432 {
 433         struct gendisk *disk;
 434         struct disk_part_iter piter;
 435         struct hd_struct *part;
 436 
 437         device->state = DASD_STATE_ONLINE;
 438         if (device->block) {
 439                 dasd_schedule_block_bh(device->block);
 440                 if ((device->features & DASD_FEATURE_USERAW)) {
 441                         disk = device->block->gdp;
 442                         kobject_uevent(&disk_to_dev(disk)->kobj, KOBJ_CHANGE);
 443                         return 0;
 444                 }
 445                 disk = device->block->bdev->bd_disk;
 446                 disk_part_iter_init(&piter, disk, DISK_PITER_INCL_PART0);
 447                 while ((part = disk_part_iter_next(&piter)))
 448                         kobject_uevent(&part_to_dev(part)->kobj, KOBJ_CHANGE);
 449                 disk_part_iter_exit(&piter);
 450         }
 451         return 0;
 452 }
 453 
 454 /*
 455  * Stop the requeueing of requests again.
 456  */
 457 static int dasd_state_online_to_ready(struct dasd_device *device)
 458 {
 459         int rc;
 460         struct gendisk *disk;
 461         struct disk_part_iter piter;
 462         struct hd_struct *part;
 463 
 464         if (device->discipline->online_to_ready) {
 465                 rc = device->discipline->online_to_ready(device);
 466                 if (rc)
 467                         return rc;
 468         }
 469 
 470         device->state = DASD_STATE_READY;
 471         if (device->block && !(device->features & DASD_FEATURE_USERAW)) {
 472                 disk = device->block->bdev->bd_disk;
 473                 disk_part_iter_init(&piter, disk, DISK_PITER_INCL_PART0);
 474                 while ((part = disk_part_iter_next(&piter)))
 475                         kobject_uevent(&part_to_dev(part)->kobj, KOBJ_CHANGE);
 476                 disk_part_iter_exit(&piter);
 477         }
 478         return 0;
 479 }
 480 
 481 /*
 482  * Device startup state changes.
 483  */
 484 static int dasd_increase_state(struct dasd_device *device)
 485 {
 486         int rc;
 487 
 488         rc = 0;
 489         if (device->state == DASD_STATE_NEW &&
 490             device->target >= DASD_STATE_KNOWN)
 491                 rc = dasd_state_new_to_known(device);
 492 
 493         if (!rc &&
 494             device->state == DASD_STATE_KNOWN &&
 495             device->target >= DASD_STATE_BASIC)
 496                 rc = dasd_state_known_to_basic(device);
 497 
 498         if (!rc &&
 499             device->state == DASD_STATE_BASIC &&
 500             device->target >= DASD_STATE_READY)
 501                 rc = dasd_state_basic_to_ready(device);
 502 
 503         if (!rc &&
 504             device->state == DASD_STATE_UNFMT &&
 505             device->target > DASD_STATE_UNFMT)
 506                 rc = -EPERM;
 507 
 508         if (!rc &&
 509             device->state == DASD_STATE_READY &&
 510             device->target >= DASD_STATE_ONLINE)
 511                 rc = dasd_state_ready_to_online(device);
 512 
 513         return rc;
 514 }
 515 
 516 /*
 517  * Device shutdown state changes.
 518  */
 519 static int dasd_decrease_state(struct dasd_device *device)
 520 {
 521         int rc;
 522 
 523         rc = 0;
 524         if (device->state == DASD_STATE_ONLINE &&
 525             device->target <= DASD_STATE_READY)
 526                 rc = dasd_state_online_to_ready(device);
 527 
 528         if (!rc &&
 529             device->state == DASD_STATE_READY &&
 530             device->target <= DASD_STATE_BASIC)
 531                 rc = dasd_state_ready_to_basic(device);
 532 
 533         if (!rc &&
 534             device->state == DASD_STATE_UNFMT &&
 535             device->target <= DASD_STATE_BASIC)
 536                 rc = dasd_state_unfmt_to_basic(device);
 537 
 538         if (!rc &&
 539             device->state == DASD_STATE_BASIC &&
 540             device->target <= DASD_STATE_KNOWN)
 541                 rc = dasd_state_basic_to_known(device);
 542 
 543         if (!rc &&
 544             device->state == DASD_STATE_KNOWN &&
 545             device->target <= DASD_STATE_NEW)
 546                 rc = dasd_state_known_to_new(device);
 547 
 548         return rc;
 549 }
 550 
 551 /*
 552  * This is the main startup/shutdown routine.
 553  */
 554 static void dasd_change_state(struct dasd_device *device)
 555 {
 556         int rc;
 557 
 558         if (device->state == device->target)
 559                 /* Already where we want to go today... */
 560                 return;
 561         if (device->state < device->target)
 562                 rc = dasd_increase_state(device);
 563         else
 564                 rc = dasd_decrease_state(device);
 565         if (rc == -EAGAIN)
 566                 return;
 567         if (rc)
 568                 device->target = device->state;
 569 
 570         /* let user-space know that the device status changed */
 571         kobject_uevent(&device->cdev->dev.kobj, KOBJ_CHANGE);
 572 
 573         if (device->state == device->target)
 574                 wake_up(&dasd_init_waitq);
 575 }
 576 
 577 /*
 578  * Kick starter for devices that did not complete the startup/shutdown
 579  * procedure or were sleeping because of a pending state.
 580  * dasd_kick_device will schedule a call do do_kick_device to the kernel
 581  * event daemon.
 582  */
 583 static void do_kick_device(struct work_struct *work)
 584 {
 585         struct dasd_device *device = container_of(work, struct dasd_device, kick_work);
 586         mutex_lock(&device->state_mutex);
 587         dasd_change_state(device);
 588         mutex_unlock(&device->state_mutex);
 589         dasd_schedule_device_bh(device);
 590         dasd_put_device(device);
 591 }
 592 
 593 void dasd_kick_device(struct dasd_device *device)
 594 {
 595         dasd_get_device(device);
 596         /* queue call to dasd_kick_device to the kernel event daemon. */
 597         if (!schedule_work(&device->kick_work))
 598                 dasd_put_device(device);
 599 }
 600 EXPORT_SYMBOL(dasd_kick_device);
 601 
 602 /*
 603  * dasd_reload_device will schedule a call do do_reload_device to the kernel
 604  * event daemon.
 605  */
 606 static void do_reload_device(struct work_struct *work)
 607 {
 608         struct dasd_device *device = container_of(work, struct dasd_device,
 609                                                   reload_device);
 610         device->discipline->reload(device);
 611         dasd_put_device(device);
 612 }
 613 
 614 void dasd_reload_device(struct dasd_device *device)
 615 {
 616         dasd_get_device(device);
 617         /* queue call to dasd_reload_device to the kernel event daemon. */
 618         if (!schedule_work(&device->reload_device))
 619                 dasd_put_device(device);
 620 }
 621 EXPORT_SYMBOL(dasd_reload_device);
 622 
 623 /*
 624  * dasd_restore_device will schedule a call do do_restore_device to the kernel
 625  * event daemon.
 626  */
 627 static void do_restore_device(struct work_struct *work)
 628 {
 629         struct dasd_device *device = container_of(work, struct dasd_device,
 630                                                   restore_device);
 631         device->cdev->drv->restore(device->cdev);
 632         dasd_put_device(device);
 633 }
 634 
 635 void dasd_restore_device(struct dasd_device *device)
 636 {
 637         dasd_get_device(device);
 638         /* queue call to dasd_restore_device to the kernel event daemon. */
 639         if (!schedule_work(&device->restore_device))
 640                 dasd_put_device(device);
 641 }
 642 
 643 /*
 644  * Set the target state for a device and starts the state change.
 645  */
 646 void dasd_set_target_state(struct dasd_device *device, int target)
 647 {
 648         dasd_get_device(device);
 649         mutex_lock(&device->state_mutex);
 650         /* If we are in probeonly mode stop at DASD_STATE_READY. */
 651         if (dasd_probeonly && target > DASD_STATE_READY)
 652                 target = DASD_STATE_READY;
 653         if (device->target != target) {
 654                 if (device->state == target)
 655                         wake_up(&dasd_init_waitq);
 656                 device->target = target;
 657         }
 658         if (device->state != device->target)
 659                 dasd_change_state(device);
 660         mutex_unlock(&device->state_mutex);
 661         dasd_put_device(device);
 662 }
 663 EXPORT_SYMBOL(dasd_set_target_state);
 664 
 665 /*
 666  * Enable devices with device numbers in [from..to].
 667  */
 668 static inline int _wait_for_device(struct dasd_device *device)
 669 {
 670         return (device->state == device->target);
 671 }
 672 
 673 void dasd_enable_device(struct dasd_device *device)
 674 {
 675         dasd_set_target_state(device, DASD_STATE_ONLINE);
 676         if (device->state <= DASD_STATE_KNOWN)
 677                 /* No discipline for device found. */
 678                 dasd_set_target_state(device, DASD_STATE_NEW);
 679         /* Now wait for the devices to come up. */
 680         wait_event(dasd_init_waitq, _wait_for_device(device));
 681 
 682         dasd_reload_device(device);
 683         if (device->discipline->kick_validate)
 684                 device->discipline->kick_validate(device);
 685 }
 686 EXPORT_SYMBOL(dasd_enable_device);
 687 
 688 /*
 689  * SECTION: device operation (interrupt handler, start i/o, term i/o ...)
 690  */
 691 
 692 unsigned int dasd_global_profile_level = DASD_PROFILE_OFF;
 693 
 694 #ifdef CONFIG_DASD_PROFILE
 695 struct dasd_profile dasd_global_profile = {
 696         .lock = __SPIN_LOCK_UNLOCKED(dasd_global_profile.lock),
 697 };
 698 static struct dentry *dasd_debugfs_global_entry;
 699 
 700 /*
 701  * Add profiling information for cqr before execution.
 702  */
 703 static void dasd_profile_start(struct dasd_block *block,
 704                                struct dasd_ccw_req *cqr,
 705                                struct request *req)
 706 {
 707         struct list_head *l;
 708         unsigned int counter;
 709         struct dasd_device *device;
 710 
 711         /* count the length of the chanq for statistics */
 712         counter = 0;
 713         if (dasd_global_profile_level || block->profile.data)
 714                 list_for_each(l, &block->ccw_queue)
 715                         if (++counter >= 31)
 716                                 break;
 717 
 718         spin_lock(&dasd_global_profile.lock);
 719         if (dasd_global_profile.data) {
 720                 dasd_global_profile.data->dasd_io_nr_req[counter]++;
 721                 if (rq_data_dir(req) == READ)
 722                         dasd_global_profile.data->dasd_read_nr_req[counter]++;
 723         }
 724         spin_unlock(&dasd_global_profile.lock);
 725 
 726         spin_lock(&block->profile.lock);
 727         if (block->profile.data) {
 728                 block->profile.data->dasd_io_nr_req[counter]++;
 729                 if (rq_data_dir(req) == READ)
 730                         block->profile.data->dasd_read_nr_req[counter]++;
 731         }
 732         spin_unlock(&block->profile.lock);
 733 
 734         /*
 735          * We count the request for the start device, even though it may run on
 736          * some other device due to error recovery. This way we make sure that
 737          * we count each request only once.
 738          */
 739         device = cqr->startdev;
 740         if (device->profile.data) {
 741                 counter = 1; /* request is not yet queued on the start device */
 742                 list_for_each(l, &device->ccw_queue)
 743                         if (++counter >= 31)
 744                                 break;
 745         }
 746         spin_lock(&device->profile.lock);
 747         if (device->profile.data) {
 748                 device->profile.data->dasd_io_nr_req[counter]++;
 749                 if (rq_data_dir(req) == READ)
 750                         device->profile.data->dasd_read_nr_req[counter]++;
 751         }
 752         spin_unlock(&device->profile.lock);
 753 }
 754 
 755 /*
 756  * Add profiling information for cqr after execution.
 757  */
 758 
 759 #define dasd_profile_counter(value, index)                         \
 760 {                                                                  \
 761         for (index = 0; index < 31 && value >> (2+index); index++) \
 762                 ;                                                  \
 763 }
 764 
 765 static void dasd_profile_end_add_data(struct dasd_profile_info *data,
 766                                       int is_alias,
 767                                       int is_tpm,
 768                                       int is_read,
 769                                       long sectors,
 770                                       int sectors_ind,
 771                                       int tottime_ind,
 772                                       int tottimeps_ind,
 773                                       int strtime_ind,
 774                                       int irqtime_ind,
 775                                       int irqtimeps_ind,
 776                                       int endtime_ind)
 777 {
 778         /* in case of an overflow, reset the whole profile */
 779         if (data->dasd_io_reqs == UINT_MAX) {
 780                         memset(data, 0, sizeof(*data));
 781                         ktime_get_real_ts64(&data->starttod);
 782         }
 783         data->dasd_io_reqs++;
 784         data->dasd_io_sects += sectors;
 785         if (is_alias)
 786                 data->dasd_io_alias++;
 787         if (is_tpm)
 788                 data->dasd_io_tpm++;
 789 
 790         data->dasd_io_secs[sectors_ind]++;
 791         data->dasd_io_times[tottime_ind]++;
 792         data->dasd_io_timps[tottimeps_ind]++;
 793         data->dasd_io_time1[strtime_ind]++;
 794         data->dasd_io_time2[irqtime_ind]++;
 795         data->dasd_io_time2ps[irqtimeps_ind]++;
 796         data->dasd_io_time3[endtime_ind]++;
 797 
 798         if (is_read) {
 799                 data->dasd_read_reqs++;
 800                 data->dasd_read_sects += sectors;
 801                 if (is_alias)
 802                         data->dasd_read_alias++;
 803                 if (is_tpm)
 804                         data->dasd_read_tpm++;
 805                 data->dasd_read_secs[sectors_ind]++;
 806                 data->dasd_read_times[tottime_ind]++;
 807                 data->dasd_read_time1[strtime_ind]++;
 808                 data->dasd_read_time2[irqtime_ind]++;
 809                 data->dasd_read_time3[endtime_ind]++;
 810         }
 811 }
 812 
 813 static void dasd_profile_end(struct dasd_block *block,
 814                              struct dasd_ccw_req *cqr,
 815                              struct request *req)
 816 {
 817         unsigned long strtime, irqtime, endtime, tottime;
 818         unsigned long tottimeps, sectors;
 819         struct dasd_device *device;
 820         int sectors_ind, tottime_ind, tottimeps_ind, strtime_ind;
 821         int irqtime_ind, irqtimeps_ind, endtime_ind;
 822         struct dasd_profile_info *data;
 823 
 824         device = cqr->startdev;
 825         if (!(dasd_global_profile_level ||
 826               block->profile.data ||
 827               device->profile.data))
 828                 return;
 829 
 830         sectors = blk_rq_sectors(req);
 831         if (!cqr->buildclk || !cqr->startclk ||
 832             !cqr->stopclk || !cqr->endclk ||
 833             !sectors)
 834                 return;
 835 
 836         strtime = ((cqr->startclk - cqr->buildclk) >> 12);
 837         irqtime = ((cqr->stopclk - cqr->startclk) >> 12);
 838         endtime = ((cqr->endclk - cqr->stopclk) >> 12);
 839         tottime = ((cqr->endclk - cqr->buildclk) >> 12);
 840         tottimeps = tottime / sectors;
 841 
 842         dasd_profile_counter(sectors, sectors_ind);
 843         dasd_profile_counter(tottime, tottime_ind);
 844         dasd_profile_counter(tottimeps, tottimeps_ind);
 845         dasd_profile_counter(strtime, strtime_ind);
 846         dasd_profile_counter(irqtime, irqtime_ind);
 847         dasd_profile_counter(irqtime / sectors, irqtimeps_ind);
 848         dasd_profile_counter(endtime, endtime_ind);
 849 
 850         spin_lock(&dasd_global_profile.lock);
 851         if (dasd_global_profile.data) {
 852                 data = dasd_global_profile.data;
 853                 data->dasd_sum_times += tottime;
 854                 data->dasd_sum_time_str += strtime;
 855                 data->dasd_sum_time_irq += irqtime;
 856                 data->dasd_sum_time_end += endtime;
 857                 dasd_profile_end_add_data(dasd_global_profile.data,
 858                                           cqr->startdev != block->base,
 859                                           cqr->cpmode == 1,
 860                                           rq_data_dir(req) == READ,
 861                                           sectors, sectors_ind, tottime_ind,
 862                                           tottimeps_ind, strtime_ind,
 863                                           irqtime_ind, irqtimeps_ind,
 864                                           endtime_ind);
 865         }
 866         spin_unlock(&dasd_global_profile.lock);
 867 
 868         spin_lock(&block->profile.lock);
 869         if (block->profile.data) {
 870                 data = block->profile.data;
 871                 data->dasd_sum_times += tottime;
 872                 data->dasd_sum_time_str += strtime;
 873                 data->dasd_sum_time_irq += irqtime;
 874                 data->dasd_sum_time_end += endtime;
 875                 dasd_profile_end_add_data(block->profile.data,
 876                                           cqr->startdev != block->base,
 877                                           cqr->cpmode == 1,
 878                                           rq_data_dir(req) == READ,
 879                                           sectors, sectors_ind, tottime_ind,
 880                                           tottimeps_ind, strtime_ind,
 881                                           irqtime_ind, irqtimeps_ind,
 882                                           endtime_ind);
 883         }
 884         spin_unlock(&block->profile.lock);
 885 
 886         spin_lock(&device->profile.lock);
 887         if (device->profile.data) {
 888                 data = device->profile.data;
 889                 data->dasd_sum_times += tottime;
 890                 data->dasd_sum_time_str += strtime;
 891                 data->dasd_sum_time_irq += irqtime;
 892                 data->dasd_sum_time_end += endtime;
 893                 dasd_profile_end_add_data(device->profile.data,
 894                                           cqr->startdev != block->base,
 895                                           cqr->cpmode == 1,
 896                                           rq_data_dir(req) == READ,
 897                                           sectors, sectors_ind, tottime_ind,
 898                                           tottimeps_ind, strtime_ind,
 899                                           irqtime_ind, irqtimeps_ind,
 900                                           endtime_ind);
 901         }
 902         spin_unlock(&device->profile.lock);
 903 }
 904 
 905 void dasd_profile_reset(struct dasd_profile *profile)
 906 {
 907         struct dasd_profile_info *data;
 908 
 909         spin_lock_bh(&profile->lock);
 910         data = profile->data;
 911         if (!data) {
 912                 spin_unlock_bh(&profile->lock);
 913                 return;
 914         }
 915         memset(data, 0, sizeof(*data));
 916         ktime_get_real_ts64(&data->starttod);
 917         spin_unlock_bh(&profile->lock);
 918 }
 919 
 920 int dasd_profile_on(struct dasd_profile *profile)
 921 {
 922         struct dasd_profile_info *data;
 923 
 924         data = kzalloc(sizeof(*data), GFP_KERNEL);
 925         if (!data)
 926                 return -ENOMEM;
 927         spin_lock_bh(&profile->lock);
 928         if (profile->data) {
 929                 spin_unlock_bh(&profile->lock);
 930                 kfree(data);
 931                 return 0;
 932         }
 933         ktime_get_real_ts64(&data->starttod);
 934         profile->data = data;
 935         spin_unlock_bh(&profile->lock);
 936         return 0;
 937 }
 938 
 939 void dasd_profile_off(struct dasd_profile *profile)
 940 {
 941         spin_lock_bh(&profile->lock);
 942         kfree(profile->data);
 943         profile->data = NULL;
 944         spin_unlock_bh(&profile->lock);
 945 }
 946 
 947 char *dasd_get_user_string(const char __user *user_buf, size_t user_len)
 948 {
 949         char *buffer;
 950 
 951         buffer = vmalloc(user_len + 1);
 952         if (buffer == NULL)
 953                 return ERR_PTR(-ENOMEM);
 954         if (copy_from_user(buffer, user_buf, user_len) != 0) {
 955                 vfree(buffer);
 956                 return ERR_PTR(-EFAULT);
 957         }
 958         /* got the string, now strip linefeed. */
 959         if (buffer[user_len - 1] == '\n')
 960                 buffer[user_len - 1] = 0;
 961         else
 962                 buffer[user_len] = 0;
 963         return buffer;
 964 }
 965 
 966 static ssize_t dasd_stats_write(struct file *file,
 967                                 const char __user *user_buf,
 968                                 size_t user_len, loff_t *pos)
 969 {
 970         char *buffer, *str;
 971         int rc;
 972         struct seq_file *m = (struct seq_file *)file->private_data;
 973         struct dasd_profile *prof = m->private;
 974 
 975         if (user_len > 65536)
 976                 user_len = 65536;
 977         buffer = dasd_get_user_string(user_buf, user_len);
 978         if (IS_ERR(buffer))
 979                 return PTR_ERR(buffer);
 980 
 981         str = skip_spaces(buffer);
 982         rc = user_len;
 983         if (strncmp(str, "reset", 5) == 0) {
 984                 dasd_profile_reset(prof);
 985         } else if (strncmp(str, "on", 2) == 0) {
 986                 rc = dasd_profile_on(prof);
 987                 if (rc)
 988                         goto out;
 989                 rc = user_len;
 990                 if (prof == &dasd_global_profile) {
 991                         dasd_profile_reset(prof);
 992                         dasd_global_profile_level = DASD_PROFILE_GLOBAL_ONLY;
 993                 }
 994         } else if (strncmp(str, "off", 3) == 0) {
 995                 if (prof == &dasd_global_profile)
 996                         dasd_global_profile_level = DASD_PROFILE_OFF;
 997                 dasd_profile_off(prof);
 998         } else
 999                 rc = -EINVAL;
1000 out:
1001         vfree(buffer);
1002         return rc;
1003 }
1004 
1005 static void dasd_stats_array(struct seq_file *m, unsigned int *array)
1006 {
1007         int i;
1008 
1009         for (i = 0; i < 32; i++)
1010                 seq_printf(m, "%u ", array[i]);
1011         seq_putc(m, '\n');
1012 }
1013 
1014 static void dasd_stats_seq_print(struct seq_file *m,
1015                                  struct dasd_profile_info *data)
1016 {
1017         seq_printf(m, "start_time %lld.%09ld\n",
1018                    (s64)data->starttod.tv_sec, data->starttod.tv_nsec);
1019         seq_printf(m, "total_requests %u\n", data->dasd_io_reqs);
1020         seq_printf(m, "total_sectors %u\n", data->dasd_io_sects);
1021         seq_printf(m, "total_pav %u\n", data->dasd_io_alias);
1022         seq_printf(m, "total_hpf %u\n", data->dasd_io_tpm);
1023         seq_printf(m, "avg_total %lu\n", data->dasd_io_reqs ?
1024                    data->dasd_sum_times / data->dasd_io_reqs : 0UL);
1025         seq_printf(m, "avg_build_to_ssch %lu\n", data->dasd_io_reqs ?
1026                    data->dasd_sum_time_str / data->dasd_io_reqs : 0UL);
1027         seq_printf(m, "avg_ssch_to_irq %lu\n", data->dasd_io_reqs ?
1028                    data->dasd_sum_time_irq / data->dasd_io_reqs : 0UL);
1029         seq_printf(m, "avg_irq_to_end %lu\n", data->dasd_io_reqs ?
1030                    data->dasd_sum_time_end / data->dasd_io_reqs : 0UL);
1031         seq_puts(m, "histogram_sectors ");
1032         dasd_stats_array(m, data->dasd_io_secs);
1033         seq_puts(m, "histogram_io_times ");
1034         dasd_stats_array(m, data->dasd_io_times);
1035         seq_puts(m, "histogram_io_times_weighted ");
1036         dasd_stats_array(m, data->dasd_io_timps);
1037         seq_puts(m, "histogram_time_build_to_ssch ");
1038         dasd_stats_array(m, data->dasd_io_time1);
1039         seq_puts(m, "histogram_time_ssch_to_irq ");
1040         dasd_stats_array(m, data->dasd_io_time2);
1041         seq_puts(m, "histogram_time_ssch_to_irq_weighted ");
1042         dasd_stats_array(m, data->dasd_io_time2ps);
1043         seq_puts(m, "histogram_time_irq_to_end ");
1044         dasd_stats_array(m, data->dasd_io_time3);
1045         seq_puts(m, "histogram_ccw_queue_length ");
1046         dasd_stats_array(m, data->dasd_io_nr_req);
1047         seq_printf(m, "total_read_requests %u\n", data->dasd_read_reqs);
1048         seq_printf(m, "total_read_sectors %u\n", data->dasd_read_sects);
1049         seq_printf(m, "total_read_pav %u\n", data->dasd_read_alias);
1050         seq_printf(m, "total_read_hpf %u\n", data->dasd_read_tpm);
1051         seq_puts(m, "histogram_read_sectors ");
1052         dasd_stats_array(m, data->dasd_read_secs);
1053         seq_puts(m, "histogram_read_times ");
1054         dasd_stats_array(m, data->dasd_read_times);
1055         seq_puts(m, "histogram_read_time_build_to_ssch ");
1056         dasd_stats_array(m, data->dasd_read_time1);
1057         seq_puts(m, "histogram_read_time_ssch_to_irq ");
1058         dasd_stats_array(m, data->dasd_read_time2);
1059         seq_puts(m, "histogram_read_time_irq_to_end ");
1060         dasd_stats_array(m, data->dasd_read_time3);
1061         seq_puts(m, "histogram_read_ccw_queue_length ");
1062         dasd_stats_array(m, data->dasd_read_nr_req);
1063 }
1064 
1065 static int dasd_stats_show(struct seq_file *m, void *v)
1066 {
1067         struct dasd_profile *profile;
1068         struct dasd_profile_info *data;
1069 
1070         profile = m->private;
1071         spin_lock_bh(&profile->lock);
1072         data = profile->data;
1073         if (!data) {
1074                 spin_unlock_bh(&profile->lock);
1075                 seq_puts(m, "disabled\n");
1076                 return 0;
1077         }
1078         dasd_stats_seq_print(m, data);
1079         spin_unlock_bh(&profile->lock);
1080         return 0;
1081 }
1082 
1083 static int dasd_stats_open(struct inode *inode, struct file *file)
1084 {
1085         struct dasd_profile *profile = inode->i_private;
1086         return single_open(file, dasd_stats_show, profile);
1087 }
1088 
1089 static const struct file_operations dasd_stats_raw_fops = {
1090         .owner          = THIS_MODULE,
1091         .open           = dasd_stats_open,
1092         .read           = seq_read,
1093         .llseek         = seq_lseek,
1094         .release        = single_release,
1095         .write          = dasd_stats_write,
1096 };
1097 
1098 static void dasd_profile_init(struct dasd_profile *profile,
1099                               struct dentry *base_dentry)
1100 {
1101         umode_t mode;
1102         struct dentry *pde;
1103 
1104         if (!base_dentry)
1105                 return;
1106         profile->dentry = NULL;
1107         profile->data = NULL;
1108         mode = (S_IRUSR | S_IWUSR | S_IFREG);
1109         pde = debugfs_create_file("statistics", mode, base_dentry,
1110                                   profile, &dasd_stats_raw_fops);
1111         if (pde && !IS_ERR(pde))
1112                 profile->dentry = pde;
1113         return;
1114 }
1115 
1116 static void dasd_profile_exit(struct dasd_profile *profile)
1117 {
1118         dasd_profile_off(profile);
1119         debugfs_remove(profile->dentry);
1120         profile->dentry = NULL;
1121 }
1122 
1123 static void dasd_statistics_removeroot(void)
1124 {
1125         dasd_global_profile_level = DASD_PROFILE_OFF;
1126         dasd_profile_exit(&dasd_global_profile);
1127         debugfs_remove(dasd_debugfs_global_entry);
1128         debugfs_remove(dasd_debugfs_root_entry);
1129 }
1130 
1131 static void dasd_statistics_createroot(void)
1132 {
1133         struct dentry *pde;
1134 
1135         dasd_debugfs_root_entry = NULL;
1136         pde = debugfs_create_dir("dasd", NULL);
1137         if (!pde || IS_ERR(pde))
1138                 goto error;
1139         dasd_debugfs_root_entry = pde;
1140         pde = debugfs_create_dir("global", dasd_debugfs_root_entry);
1141         if (!pde || IS_ERR(pde))
1142                 goto error;
1143         dasd_debugfs_global_entry = pde;
1144         dasd_profile_init(&dasd_global_profile, dasd_debugfs_global_entry);
1145         return;
1146 
1147 error:
1148         DBF_EVENT(DBF_ERR, "%s",
1149                   "Creation of the dasd debugfs interface failed");
1150         dasd_statistics_removeroot();
1151         return;
1152 }
1153 
1154 #else
1155 #define dasd_profile_start(block, cqr, req) do {} while (0)
1156 #define dasd_profile_end(block, cqr, req) do {} while (0)
1157 
1158 static void dasd_statistics_createroot(void)
1159 {
1160         return;
1161 }
1162 
1163 static void dasd_statistics_removeroot(void)
1164 {
1165         return;
1166 }
1167 
1168 int dasd_stats_generic_show(struct seq_file *m, void *v)
1169 {
1170         seq_puts(m, "Statistics are not activated in this kernel\n");
1171         return 0;
1172 }
1173 
1174 static void dasd_profile_init(struct dasd_profile *profile,
1175                               struct dentry *base_dentry)
1176 {
1177         return;
1178 }
1179 
1180 static void dasd_profile_exit(struct dasd_profile *profile)
1181 {
1182         return;
1183 }
1184 
1185 int dasd_profile_on(struct dasd_profile *profile)
1186 {
1187         return 0;
1188 }
1189 
1190 #endif                          /* CONFIG_DASD_PROFILE */
1191 
1192 static int dasd_hosts_show(struct seq_file *m, void *v)
1193 {
1194         struct dasd_device *device;
1195         int rc = -EOPNOTSUPP;
1196 
1197         device = m->private;
1198         dasd_get_device(device);
1199 
1200         if (device->discipline->hosts_print)
1201                 rc = device->discipline->hosts_print(device, m);
1202 
1203         dasd_put_device(device);
1204         return rc;
1205 }
1206 
1207 DEFINE_SHOW_ATTRIBUTE(dasd_hosts);
1208 
1209 static void dasd_hosts_exit(struct dasd_device *device)
1210 {
1211         debugfs_remove(device->hosts_dentry);
1212         device->hosts_dentry = NULL;
1213 }
1214 
1215 static void dasd_hosts_init(struct dentry *base_dentry,
1216                             struct dasd_device *device)
1217 {
1218         struct dentry *pde;
1219         umode_t mode;
1220 
1221         if (!base_dentry)
1222                 return;
1223 
1224         mode = S_IRUSR | S_IFREG;
1225         pde = debugfs_create_file("host_access_list", mode, base_dentry,
1226                                   device, &dasd_hosts_fops);
1227         if (pde && !IS_ERR(pde))
1228                 device->hosts_dentry = pde;
1229 }
1230 
1231 struct dasd_ccw_req *dasd_smalloc_request(int magic, int cplength, int datasize,
1232                                           struct dasd_device *device,
1233                                           struct dasd_ccw_req *cqr)
1234 {
1235         unsigned long flags;
1236         char *data, *chunk;
1237         int size = 0;
1238 
1239         if (cplength > 0)
1240                 size += cplength * sizeof(struct ccw1);
1241         if (datasize > 0)
1242                 size += datasize;
1243         if (!cqr)
1244                 size += (sizeof(*cqr) + 7L) & -8L;
1245 
1246         spin_lock_irqsave(&device->mem_lock, flags);
1247         data = chunk = dasd_alloc_chunk(&device->ccw_chunks, size);
1248         spin_unlock_irqrestore(&device->mem_lock, flags);
1249         if (!chunk)
1250                 return ERR_PTR(-ENOMEM);
1251         if (!cqr) {
1252                 cqr = (void *) data;
1253                 data += (sizeof(*cqr) + 7L) & -8L;
1254         }
1255         memset(cqr, 0, sizeof(*cqr));
1256         cqr->mem_chunk = chunk;
1257         if (cplength > 0) {
1258                 cqr->cpaddr = data;
1259                 data += cplength * sizeof(struct ccw1);
1260                 memset(cqr->cpaddr, 0, cplength * sizeof(struct ccw1));
1261         }
1262         if (datasize > 0) {
1263                 cqr->data = data;
1264                 memset(cqr->data, 0, datasize);
1265         }
1266         cqr->magic = magic;
1267         set_bit(DASD_CQR_FLAGS_USE_ERP, &cqr->flags);
1268         dasd_get_device(device);
1269         return cqr;
1270 }
1271 EXPORT_SYMBOL(dasd_smalloc_request);
1272 
1273 struct dasd_ccw_req *dasd_fmalloc_request(int magic, int cplength,
1274                                           int datasize,
1275                                           struct dasd_device *device)
1276 {
1277         struct dasd_ccw_req *cqr;
1278         unsigned long flags;
1279         int size, cqr_size;
1280         char *data;
1281 
1282         cqr_size = (sizeof(*cqr) + 7L) & -8L;
1283         size = cqr_size;
1284         if (cplength > 0)
1285                 size += cplength * sizeof(struct ccw1);
1286         if (datasize > 0)
1287                 size += datasize;
1288 
1289         spin_lock_irqsave(&device->mem_lock, flags);
1290         cqr = dasd_alloc_chunk(&device->ese_chunks, size);
1291         spin_unlock_irqrestore(&device->mem_lock, flags);
1292         if (!cqr)
1293                 return ERR_PTR(-ENOMEM);
1294         memset(cqr, 0, sizeof(*cqr));
1295         data = (char *)cqr + cqr_size;
1296         cqr->cpaddr = NULL;
1297         if (cplength > 0) {
1298                 cqr->cpaddr = data;
1299                 data += cplength * sizeof(struct ccw1);
1300                 memset(cqr->cpaddr, 0, cplength * sizeof(struct ccw1));
1301         }
1302         cqr->data = NULL;
1303         if (datasize > 0) {
1304                 cqr->data = data;
1305                 memset(cqr->data, 0, datasize);
1306         }
1307 
1308         cqr->magic = magic;
1309         set_bit(DASD_CQR_FLAGS_USE_ERP, &cqr->flags);
1310         dasd_get_device(device);
1311 
1312         return cqr;
1313 }
1314 EXPORT_SYMBOL(dasd_fmalloc_request);
1315 
1316 void dasd_sfree_request(struct dasd_ccw_req *cqr, struct dasd_device *device)
1317 {
1318         unsigned long flags;
1319 
1320         spin_lock_irqsave(&device->mem_lock, flags);
1321         dasd_free_chunk(&device->ccw_chunks, cqr->mem_chunk);
1322         spin_unlock_irqrestore(&device->mem_lock, flags);
1323         dasd_put_device(device);
1324 }
1325 EXPORT_SYMBOL(dasd_sfree_request);
1326 
1327 void dasd_ffree_request(struct dasd_ccw_req *cqr, struct dasd_device *device)
1328 {
1329         unsigned long flags;
1330 
1331         spin_lock_irqsave(&device->mem_lock, flags);
1332         dasd_free_chunk(&device->ese_chunks, cqr);
1333         spin_unlock_irqrestore(&device->mem_lock, flags);
1334         dasd_put_device(device);
1335 }
1336 EXPORT_SYMBOL(dasd_ffree_request);
1337 
1338 /*
1339  * Check discipline magic in cqr.
1340  */
1341 static inline int dasd_check_cqr(struct dasd_ccw_req *cqr)
1342 {
1343         struct dasd_device *device;
1344 
1345         if (cqr == NULL)
1346                 return -EINVAL;
1347         device = cqr->startdev;
1348         if (strncmp((char *) &cqr->magic, device->discipline->ebcname, 4)) {
1349                 DBF_DEV_EVENT(DBF_WARNING, device,
1350                             " dasd_ccw_req 0x%08x magic doesn't match"
1351                             " discipline 0x%08x",
1352                             cqr->magic,
1353                             *(unsigned int *) device->discipline->name);
1354                 return -EINVAL;
1355         }
1356         return 0;
1357 }
1358 
1359 /*
1360  * Terminate the current i/o and set the request to clear_pending.
1361  * Timer keeps device runnig.
1362  * ccw_device_clear can fail if the i/o subsystem
1363  * is in a bad mood.
1364  */
1365 int dasd_term_IO(struct dasd_ccw_req *cqr)
1366 {
1367         struct dasd_device *device;
1368         int retries, rc;
1369         char errorstring[ERRORLENGTH];
1370 
1371         /* Check the cqr */
1372         rc = dasd_check_cqr(cqr);
1373         if (rc)
1374                 return rc;
1375         retries = 0;
1376         device = (struct dasd_device *) cqr->startdev;
1377         while ((retries < 5) && (cqr->status == DASD_CQR_IN_IO)) {
1378                 rc = ccw_device_clear(device->cdev, (long) cqr);
1379                 switch (rc) {
1380                 case 0: /* termination successful */
1381                         cqr->status = DASD_CQR_CLEAR_PENDING;
1382                         cqr->stopclk = get_tod_clock();
1383                         cqr->starttime = 0;
1384                         DBF_DEV_EVENT(DBF_DEBUG, device,
1385                                       "terminate cqr %p successful",
1386                                       cqr);
1387                         break;
1388                 case -ENODEV:
1389                         DBF_DEV_EVENT(DBF_ERR, device, "%s",
1390                                       "device gone, retry");
1391                         break;
1392                 case -EINVAL:
1393                         /*
1394                          * device not valid so no I/O could be running
1395                          * handle CQR as termination successful
1396                          */
1397                         cqr->status = DASD_CQR_CLEARED;
1398                         cqr->stopclk = get_tod_clock();
1399                         cqr->starttime = 0;
1400                         /* no retries for invalid devices */
1401                         cqr->retries = -1;
1402                         DBF_DEV_EVENT(DBF_ERR, device, "%s",
1403                                       "EINVAL, handle as terminated");
1404                         /* fake rc to success */
1405                         rc = 0;
1406                         break;
1407                 default:
1408                         /* internal error 10 - unknown rc*/
1409                         snprintf(errorstring, ERRORLENGTH, "10 %d", rc);
1410                         dev_err(&device->cdev->dev, "An error occurred in the "
1411                                 "DASD device driver, reason=%s\n", errorstring);
1412                         BUG();
1413                         break;
1414                 }
1415                 retries++;
1416         }
1417         dasd_schedule_device_bh(device);
1418         return rc;
1419 }
1420 EXPORT_SYMBOL(dasd_term_IO);
1421 
1422 /*
1423  * Start the i/o. This start_IO can fail if the channel is really busy.
1424  * In that case set up a timer to start the request later.
1425  */
1426 int dasd_start_IO(struct dasd_ccw_req *cqr)
1427 {
1428         struct dasd_device *device;
1429         int rc;
1430         char errorstring[ERRORLENGTH];
1431 
1432         /* Check the cqr */
1433         rc = dasd_check_cqr(cqr);
1434         if (rc) {
1435                 cqr->intrc = rc;
1436                 return rc;
1437         }
1438         device = (struct dasd_device *) cqr->startdev;
1439         if (((cqr->block &&
1440               test_bit(DASD_FLAG_LOCK_STOLEN, &cqr->block->base->flags)) ||
1441              test_bit(DASD_FLAG_LOCK_STOLEN, &device->flags)) &&
1442             !test_bit(DASD_CQR_ALLOW_SLOCK, &cqr->flags)) {
1443                 DBF_DEV_EVENT(DBF_DEBUG, device, "start_IO: return request %p "
1444                               "because of stolen lock", cqr);
1445                 cqr->status = DASD_CQR_ERROR;
1446                 cqr->intrc = -EPERM;
1447                 return -EPERM;
1448         }
1449         if (cqr->retries < 0) {
1450                 /* internal error 14 - start_IO run out of retries */
1451                 sprintf(errorstring, "14 %p", cqr);
1452                 dev_err(&device->cdev->dev, "An error occurred in the DASD "
1453                         "device driver, reason=%s\n", errorstring);
1454                 cqr->status = DASD_CQR_ERROR;
1455                 return -EIO;
1456         }
1457         cqr->startclk = get_tod_clock();
1458         cqr->starttime = jiffies;
1459         cqr->retries--;
1460         if (!test_bit(DASD_CQR_VERIFY_PATH, &cqr->flags)) {
1461                 cqr->lpm &= dasd_path_get_opm(device);
1462                 if (!cqr->lpm)
1463                         cqr->lpm = dasd_path_get_opm(device);
1464         }
1465         if (cqr->cpmode == 1) {
1466                 rc = ccw_device_tm_start(device->cdev, cqr->cpaddr,
1467                                          (long) cqr, cqr->lpm);
1468         } else {
1469                 rc = ccw_device_start(device->cdev, cqr->cpaddr,
1470                                       (long) cqr, cqr->lpm, 0);
1471         }
1472         switch (rc) {
1473         case 0:
1474                 cqr->status = DASD_CQR_IN_IO;
1475                 break;
1476         case -EBUSY:
1477                 DBF_DEV_EVENT(DBF_WARNING, device, "%s",
1478                               "start_IO: device busy, retry later");
1479                 break;
1480         case -EACCES:
1481                 /* -EACCES indicates that the request used only a subset of the
1482                  * available paths and all these paths are gone. If the lpm of
1483                  * this request was only a subset of the opm (e.g. the ppm) then
1484                  * we just do a retry with all available paths.
1485                  * If we already use the full opm, something is amiss, and we
1486                  * need a full path verification.
1487                  */
1488                 if (test_bit(DASD_CQR_VERIFY_PATH, &cqr->flags)) {
1489                         DBF_DEV_EVENT(DBF_WARNING, device,
1490                                       "start_IO: selected paths gone (%x)",
1491                                       cqr->lpm);
1492                 } else if (cqr->lpm != dasd_path_get_opm(device)) {
1493                         cqr->lpm = dasd_path_get_opm(device);
1494                         DBF_DEV_EVENT(DBF_DEBUG, device, "%s",
1495                                       "start_IO: selected paths gone,"
1496                                       " retry on all paths");
1497                 } else {
1498                         DBF_DEV_EVENT(DBF_WARNING, device, "%s",
1499                                       "start_IO: all paths in opm gone,"
1500                                       " do path verification");
1501                         dasd_generic_last_path_gone(device);
1502                         dasd_path_no_path(device);
1503                         dasd_path_set_tbvpm(device,
1504                                           ccw_device_get_path_mask(
1505                                                   device->cdev));
1506                 }
1507                 break;
1508         case -ENODEV:
1509                 DBF_DEV_EVENT(DBF_WARNING, device, "%s",
1510                               "start_IO: -ENODEV device gone, retry");
1511                 break;
1512         case -EIO:
1513                 DBF_DEV_EVENT(DBF_WARNING, device, "%s",
1514                               "start_IO: -EIO device gone, retry");
1515                 break;
1516         case -EINVAL:
1517                 /* most likely caused in power management context */
1518                 DBF_DEV_EVENT(DBF_WARNING, device, "%s",
1519                               "start_IO: -EINVAL device currently "
1520                               "not accessible");
1521                 break;
1522         default:
1523                 /* internal error 11 - unknown rc */
1524                 snprintf(errorstring, ERRORLENGTH, "11 %d", rc);
1525                 dev_err(&device->cdev->dev,
1526                         "An error occurred in the DASD device driver, "
1527                         "reason=%s\n", errorstring);
1528                 BUG();
1529                 break;
1530         }
1531         cqr->intrc = rc;
1532         return rc;
1533 }
1534 EXPORT_SYMBOL(dasd_start_IO);
1535 
1536 /*
1537  * Timeout function for dasd devices. This is used for different purposes
1538  *  1) missing interrupt handler for normal operation
1539  *  2) delayed start of request where start_IO failed with -EBUSY
1540  *  3) timeout for missing state change interrupts
1541  * The head of the ccw queue will have status DASD_CQR_IN_IO for 1),
1542  * DASD_CQR_QUEUED for 2) and 3).
1543  */
1544 static void dasd_device_timeout(struct timer_list *t)
1545 {
1546         unsigned long flags;
1547         struct dasd_device *device;
1548 
1549         device = from_timer(device, t, timer);
1550         spin_lock_irqsave(get_ccwdev_lock(device->cdev), flags);
1551         /* re-activate request queue */
1552         dasd_device_remove_stop_bits(device, DASD_STOPPED_PENDING);
1553         spin_unlock_irqrestore(get_ccwdev_lock(device->cdev), flags);
1554         dasd_schedule_device_bh(device);
1555 }
1556 
1557 /*
1558  * Setup timeout for a device in jiffies.
1559  */
1560 void dasd_device_set_timer(struct dasd_device *device, int expires)
1561 {
1562         if (expires == 0)
1563                 del_timer(&device->timer);
1564         else
1565                 mod_timer(&device->timer, jiffies + expires);
1566 }
1567 EXPORT_SYMBOL(dasd_device_set_timer);
1568 
1569 /*
1570  * Clear timeout for a device.
1571  */
1572 void dasd_device_clear_timer(struct dasd_device *device)
1573 {
1574         del_timer(&device->timer);
1575 }
1576 EXPORT_SYMBOL(dasd_device_clear_timer);
1577 
1578 static void dasd_handle_killed_request(struct ccw_device *cdev,
1579                                        unsigned long intparm)
1580 {
1581         struct dasd_ccw_req *cqr;
1582         struct dasd_device *device;
1583 
1584         if (!intparm)
1585                 return;
1586         cqr = (struct dasd_ccw_req *) intparm;
1587         if (cqr->status != DASD_CQR_IN_IO) {
1588                 DBF_EVENT_DEVID(DBF_DEBUG, cdev,
1589                                 "invalid status in handle_killed_request: "
1590                                 "%02x", cqr->status);
1591                 return;
1592         }
1593 
1594         device = dasd_device_from_cdev_locked(cdev);
1595         if (IS_ERR(device)) {
1596                 DBF_EVENT_DEVID(DBF_DEBUG, cdev, "%s",
1597                                 "unable to get device from cdev");
1598                 return;
1599         }
1600 
1601         if (!cqr->startdev ||
1602             device != cqr->startdev ||
1603             strncmp(cqr->startdev->discipline->ebcname,
1604                     (char *) &cqr->magic, 4)) {
1605                 DBF_EVENT_DEVID(DBF_DEBUG, cdev, "%s",
1606                                 "invalid device in request");
1607                 dasd_put_device(device);
1608                 return;
1609         }
1610 
1611         /* Schedule request to be retried. */
1612         cqr->status = DASD_CQR_QUEUED;
1613 
1614         dasd_device_clear_timer(device);
1615         dasd_schedule_device_bh(device);
1616         dasd_put_device(device);
1617 }
1618 
1619 void dasd_generic_handle_state_change(struct dasd_device *device)
1620 {
1621         /* First of all start sense subsystem status request. */
1622         dasd_eer_snss(device);
1623 
1624         dasd_device_remove_stop_bits(device, DASD_STOPPED_PENDING);
1625         dasd_schedule_device_bh(device);
1626         if (device->block) {
1627                 dasd_schedule_block_bh(device->block);
1628                 if (device->block->request_queue)
1629                         blk_mq_run_hw_queues(device->block->request_queue,
1630                                              true);
1631         }
1632 }
1633 EXPORT_SYMBOL_GPL(dasd_generic_handle_state_change);
1634 
1635 static int dasd_check_hpf_error(struct irb *irb)
1636 {
1637         return (scsw_tm_is_valid_schxs(&irb->scsw) &&
1638             (irb->scsw.tm.sesq == SCSW_SESQ_DEV_NOFCX ||
1639              irb->scsw.tm.sesq == SCSW_SESQ_PATH_NOFCX));
1640 }
1641 
1642 static int dasd_ese_needs_format(struct dasd_block *block, struct irb *irb)
1643 {
1644         struct dasd_device *device = NULL;
1645         u8 *sense = NULL;
1646 
1647         if (!block)
1648                 return 0;
1649         device = block->base;
1650         if (!device || !device->discipline->is_ese)
1651                 return 0;
1652         if (!device->discipline->is_ese(device))
1653                 return 0;
1654 
1655         sense = dasd_get_sense(irb);
1656         if (!sense)
1657                 return 0;
1658 
1659         return !!(sense[1] & SNS1_NO_REC_FOUND) ||
1660                 !!(sense[1] & SNS1_FILE_PROTECTED) ||
1661                 scsw_cstat(&irb->scsw) == SCHN_STAT_INCORR_LEN;
1662 }
1663 
1664 static int dasd_ese_oos_cond(u8 *sense)
1665 {
1666         return sense[0] & SNS0_EQUIPMENT_CHECK &&
1667                 sense[1] & SNS1_PERM_ERR &&
1668                 sense[1] & SNS1_WRITE_INHIBITED &&
1669                 sense[25] == 0x01;
1670 }
1671 
1672 /*
1673  * Interrupt handler for "normal" ssch-io based dasd devices.
1674  */
1675 void dasd_int_handler(struct ccw_device *cdev, unsigned long intparm,
1676                       struct irb *irb)
1677 {
1678         struct dasd_ccw_req *cqr, *next, *fcqr;
1679         struct dasd_device *device;
1680         unsigned long now;
1681         int nrf_suppressed = 0;
1682         int fp_suppressed = 0;
1683         u8 *sense = NULL;
1684         int expires;
1685 
1686         cqr = (struct dasd_ccw_req *) intparm;
1687         if (IS_ERR(irb)) {
1688                 switch (PTR_ERR(irb)) {
1689                 case -EIO:
1690                         if (cqr && cqr->status == DASD_CQR_CLEAR_PENDING) {
1691                                 device = cqr->startdev;
1692                                 cqr->status = DASD_CQR_CLEARED;
1693                                 dasd_device_clear_timer(device);
1694                                 wake_up(&dasd_flush_wq);
1695                                 dasd_schedule_device_bh(device);
1696                                 return;
1697                         }
1698                         break;
1699                 case -ETIMEDOUT:
1700                         DBF_EVENT_DEVID(DBF_WARNING, cdev, "%s: "
1701                                         "request timed out\n", __func__);
1702                         break;
1703                 default:
1704                         DBF_EVENT_DEVID(DBF_WARNING, cdev, "%s: "
1705                                         "unknown error %ld\n", __func__,
1706                                         PTR_ERR(irb));
1707                 }
1708                 dasd_handle_killed_request(cdev, intparm);
1709                 return;
1710         }
1711 
1712         now = get_tod_clock();
1713         /* check for conditions that should be handled immediately */
1714         if (!cqr ||
1715             !(scsw_dstat(&irb->scsw) == (DEV_STAT_CHN_END | DEV_STAT_DEV_END) &&
1716               scsw_cstat(&irb->scsw) == 0)) {
1717                 if (cqr)
1718                         memcpy(&cqr->irb, irb, sizeof(*irb));
1719                 device = dasd_device_from_cdev_locked(cdev);
1720                 if (IS_ERR(device))
1721                         return;
1722                 /* ignore unsolicited interrupts for DIAG discipline */
1723                 if (device->discipline == dasd_diag_discipline_pointer) {
1724                         dasd_put_device(device);
1725                         return;
1726                 }
1727 
1728                 /*
1729                  * In some cases 'File Protected' or 'No Record Found' errors
1730                  * might be expected and debug log messages for the
1731                  * corresponding interrupts shouldn't be written then.
1732                  * Check if either of the according suppress bits is set.
1733                  */
1734                 sense = dasd_get_sense(irb);
1735                 if (sense) {
1736                         fp_suppressed = (sense[1] & SNS1_FILE_PROTECTED) &&
1737                                 test_bit(DASD_CQR_SUPPRESS_FP, &cqr->flags);
1738                         nrf_suppressed = (sense[1] & SNS1_NO_REC_FOUND) &&
1739                                 test_bit(DASD_CQR_SUPPRESS_NRF, &cqr->flags);
1740 
1741                         /*
1742                          * Extent pool probably out-of-space.
1743                          * Stop device and check exhaust level.
1744                          */
1745                         if (dasd_ese_oos_cond(sense)) {
1746                                 dasd_generic_space_exhaust(device, cqr);
1747                                 device->discipline->ext_pool_exhaust(device, cqr);
1748                                 dasd_put_device(device);
1749                                 return;
1750                         }
1751                 }
1752                 if (!(fp_suppressed || nrf_suppressed))
1753                         device->discipline->dump_sense_dbf(device, irb, "int");
1754 
1755                 if (device->features & DASD_FEATURE_ERPLOG)
1756                         device->discipline->dump_sense(device, cqr, irb);
1757                 device->discipline->check_for_device_change(device, cqr, irb);
1758                 dasd_put_device(device);
1759         }
1760 
1761         /* check for for attention message */
1762         if (scsw_dstat(&irb->scsw) & DEV_STAT_ATTENTION) {
1763                 device = dasd_device_from_cdev_locked(cdev);
1764                 if (!IS_ERR(device)) {
1765                         device->discipline->check_attention(device,
1766                                                             irb->esw.esw1.lpum);
1767                         dasd_put_device(device);
1768                 }
1769         }
1770 
1771         if (!cqr)
1772                 return;
1773 
1774         device = (struct dasd_device *) cqr->startdev;
1775         if (!device ||
1776             strncmp(device->discipline->ebcname, (char *) &cqr->magic, 4)) {
1777                 DBF_EVENT_DEVID(DBF_DEBUG, cdev, "%s",
1778                                 "invalid device in request");
1779                 return;
1780         }
1781 
1782         if (dasd_ese_needs_format(cqr->block, irb)) {
1783                 if (rq_data_dir((struct request *)cqr->callback_data) == READ) {
1784                         device->discipline->ese_read(cqr, irb);
1785                         cqr->status = DASD_CQR_SUCCESS;
1786                         cqr->stopclk = now;
1787                         dasd_device_clear_timer(device);
1788                         dasd_schedule_device_bh(device);
1789                         return;
1790                 }
1791                 fcqr = device->discipline->ese_format(device, cqr, irb);
1792                 if (IS_ERR(fcqr)) {
1793                         if (PTR_ERR(fcqr) == -EINVAL) {
1794                                 cqr->status = DASD_CQR_ERROR;
1795                                 return;
1796                         }
1797                         /*
1798                          * If we can't format now, let the request go
1799                          * one extra round. Maybe we can format later.
1800                          */
1801                         cqr->status = DASD_CQR_QUEUED;
1802                         dasd_schedule_device_bh(device);
1803                         return;
1804                 } else {
1805                         fcqr->status = DASD_CQR_QUEUED;
1806                         cqr->status = DASD_CQR_QUEUED;
1807                         list_add(&fcqr->devlist, &device->ccw_queue);
1808                         dasd_schedule_device_bh(device);
1809                         return;
1810                 }
1811         }
1812 
1813         /* Check for clear pending */
1814         if (cqr->status == DASD_CQR_CLEAR_PENDING &&
1815             scsw_fctl(&irb->scsw) & SCSW_FCTL_CLEAR_FUNC) {
1816                 cqr->status = DASD_CQR_CLEARED;
1817                 dasd_device_clear_timer(device);
1818                 wake_up(&dasd_flush_wq);
1819                 dasd_schedule_device_bh(device);
1820                 return;
1821         }
1822 
1823         /* check status - the request might have been killed by dyn detach */
1824         if (cqr->status != DASD_CQR_IN_IO) {
1825                 DBF_DEV_EVENT(DBF_DEBUG, device, "invalid status: bus_id %s, "
1826                               "status %02x", dev_name(&cdev->dev), cqr->status);
1827                 return;
1828         }
1829 
1830         next = NULL;
1831         expires = 0;
1832         if (scsw_dstat(&irb->scsw) == (DEV_STAT_CHN_END | DEV_STAT_DEV_END) &&
1833             scsw_cstat(&irb->scsw) == 0) {
1834                 /* request was completed successfully */
1835                 cqr->status = DASD_CQR_SUCCESS;
1836                 cqr->stopclk = now;
1837                 /* Start first request on queue if possible -> fast_io. */
1838                 if (cqr->devlist.next != &device->ccw_queue) {
1839                         next = list_entry(cqr->devlist.next,
1840                                           struct dasd_ccw_req, devlist);
1841                 }
1842         } else {  /* error */
1843                 /* check for HPF error
1844                  * call discipline function to requeue all requests
1845                  * and disable HPF accordingly
1846                  */
1847                 if (cqr->cpmode && dasd_check_hpf_error(irb) &&
1848                     device->discipline->handle_hpf_error)
1849                         device->discipline->handle_hpf_error(device, irb);
1850                 /*
1851                  * If we don't want complex ERP for this request, then just
1852                  * reset this and retry it in the fastpath
1853                  */
1854                 if (!test_bit(DASD_CQR_FLAGS_USE_ERP, &cqr->flags) &&
1855                     cqr->retries > 0) {
1856                         if (cqr->lpm == dasd_path_get_opm(device))
1857                                 DBF_DEV_EVENT(DBF_DEBUG, device,
1858                                               "default ERP in fastpath "
1859                                               "(%i retries left)",
1860                                               cqr->retries);
1861                         if (!test_bit(DASD_CQR_VERIFY_PATH, &cqr->flags))
1862                                 cqr->lpm = dasd_path_get_opm(device);
1863                         cqr->status = DASD_CQR_QUEUED;
1864                         next = cqr;
1865                 } else
1866                         cqr->status = DASD_CQR_ERROR;
1867         }
1868         if (next && (next->status == DASD_CQR_QUEUED) &&
1869             (!device->stopped)) {
1870                 if (device->discipline->start_IO(next) == 0)
1871                         expires = next->expires;
1872         }
1873         if (expires != 0)
1874                 dasd_device_set_timer(device, expires);
1875         else
1876                 dasd_device_clear_timer(device);
1877         dasd_schedule_device_bh(device);
1878 }
1879 EXPORT_SYMBOL(dasd_int_handler);
1880 
1881 enum uc_todo dasd_generic_uc_handler(struct ccw_device *cdev, struct irb *irb)
1882 {
1883         struct dasd_device *device;
1884 
1885         device = dasd_device_from_cdev_locked(cdev);
1886 
1887         if (IS_ERR(device))
1888                 goto out;
1889         if (test_bit(DASD_FLAG_OFFLINE, &device->flags) ||
1890            device->state != device->target ||
1891            !device->discipline->check_for_device_change){
1892                 dasd_put_device(device);
1893                 goto out;
1894         }
1895         if (device->discipline->dump_sense_dbf)
1896                 device->discipline->dump_sense_dbf(device, irb, "uc");
1897         device->discipline->check_for_device_change(device, NULL, irb);
1898         dasd_put_device(device);
1899 out:
1900         return UC_TODO_RETRY;
1901 }
1902 EXPORT_SYMBOL_GPL(dasd_generic_uc_handler);
1903 
1904 /*
1905  * If we have an error on a dasd_block layer request then we cancel
1906  * and return all further requests from the same dasd_block as well.
1907  */
1908 static void __dasd_device_recovery(struct dasd_device *device,
1909                                    struct dasd_ccw_req *ref_cqr)
1910 {
1911         struct list_head *l, *n;
1912         struct dasd_ccw_req *cqr;
1913 
1914         /*
1915          * only requeue request that came from the dasd_block layer
1916          */
1917         if (!ref_cqr->block)
1918                 return;
1919 
1920         list_for_each_safe(l, n, &device->ccw_queue) {
1921                 cqr = list_entry(l, struct dasd_ccw_req, devlist);
1922                 if (cqr->status == DASD_CQR_QUEUED &&
1923                     ref_cqr->block == cqr->block) {
1924                         cqr->status = DASD_CQR_CLEARED;
1925                 }
1926         }
1927 };
1928 
1929 /*
1930  * Remove those ccw requests from the queue that need to be returned
1931  * to the upper layer.
1932  */
1933 static void __dasd_device_process_ccw_queue(struct dasd_device *device,
1934                                             struct list_head *final_queue)
1935 {
1936         struct list_head *l, *n;
1937         struct dasd_ccw_req *cqr;
1938 
1939         /* Process request with final status. */
1940         list_for_each_safe(l, n, &device->ccw_queue) {
1941                 cqr = list_entry(l, struct dasd_ccw_req, devlist);
1942 
1943                 /* Skip any non-final request. */
1944                 if (cqr->status == DASD_CQR_QUEUED ||
1945                     cqr->status == DASD_CQR_IN_IO ||
1946                     cqr->status == DASD_CQR_CLEAR_PENDING)
1947                         continue;
1948                 if (cqr->status == DASD_CQR_ERROR) {
1949                         __dasd_device_recovery(device, cqr);
1950                 }
1951                 /* Rechain finished requests to final queue */
1952                 list_move_tail(&cqr->devlist, final_queue);
1953         }
1954 }
1955 
1956 static void __dasd_process_cqr(struct dasd_device *device,
1957                                struct dasd_ccw_req *cqr)
1958 {
1959         char errorstring[ERRORLENGTH];
1960 
1961         switch (cqr->status) {
1962         case DASD_CQR_SUCCESS:
1963                 cqr->status = DASD_CQR_DONE;
1964                 break;
1965         case DASD_CQR_ERROR:
1966                 cqr->status = DASD_CQR_NEED_ERP;
1967                 break;
1968         case DASD_CQR_CLEARED:
1969                 cqr->status = DASD_CQR_TERMINATED;
1970                 break;
1971         default:
1972                 /* internal error 12 - wrong cqr status*/
1973                 snprintf(errorstring, ERRORLENGTH, "12 %p %x02", cqr, cqr->status);
1974                 dev_err(&device->cdev->dev,
1975                         "An error occurred in the DASD device driver, "
1976                         "reason=%s\n", errorstring);
1977                 BUG();
1978         }
1979         if (cqr->callback)
1980                 cqr->callback(cqr, cqr->callback_data);
1981 }
1982 
1983 /*
1984  * the cqrs from the final queue are returned to the upper layer
1985  * by setting a dasd_block state and calling the callback function
1986  */
1987 static void __dasd_device_process_final_queue(struct dasd_device *device,
1988                                               struct list_head *final_queue)
1989 {
1990         struct list_head *l, *n;
1991         struct dasd_ccw_req *cqr;
1992         struct dasd_block *block;
1993 
1994         list_for_each_safe(l, n, final_queue) {
1995                 cqr = list_entry(l, struct dasd_ccw_req, devlist);
1996                 list_del_init(&cqr->devlist);
1997                 block = cqr->block;
1998                 if (!block) {
1999                         __dasd_process_cqr(device, cqr);
2000                 } else {
2001                         spin_lock_bh(&block->queue_lock);
2002                         __dasd_process_cqr(device, cqr);
2003                         spin_unlock_bh(&block->queue_lock);
2004                 }
2005         }
2006 }
2007 
2008 /*
2009  * Take a look at the first request on the ccw queue and check
2010  * if it reached its expire time. If so, terminate the IO.
2011  */
2012 static void __dasd_device_check_expire(struct dasd_device *device)
2013 {
2014         struct dasd_ccw_req *cqr;
2015 
2016         if (list_empty(&device->ccw_queue))
2017                 return;
2018         cqr = list_entry(device->ccw_queue.next, struct dasd_ccw_req, devlist);
2019         if ((cqr->status == DASD_CQR_IN_IO && cqr->expires != 0) &&
2020             (time_after_eq(jiffies, cqr->expires + cqr->starttime))) {
2021                 if (test_bit(DASD_FLAG_SAFE_OFFLINE_RUNNING, &device->flags)) {
2022                         /*
2023                          * IO in safe offline processing should not
2024                          * run out of retries
2025                          */
2026                         cqr->retries++;
2027                 }
2028                 if (device->discipline->term_IO(cqr) != 0) {
2029                         /* Hmpf, try again in 5 sec */
2030                         dev_err(&device->cdev->dev,
2031                                 "cqr %p timed out (%lus) but cannot be "
2032                                 "ended, retrying in 5 s\n",
2033                                 cqr, (cqr->expires/HZ));
2034                         cqr->expires += 5*HZ;
2035                         dasd_device_set_timer(device, 5*HZ);
2036                 } else {
2037                         dev_err(&device->cdev->dev,
2038                                 "cqr %p timed out (%lus), %i retries "
2039                                 "remaining\n", cqr, (cqr->expires/HZ),
2040                                 cqr->retries);
2041                 }
2042         }
2043 }
2044 
2045 /*
2046  * return 1 when device is not eligible for IO
2047  */
2048 static int __dasd_device_is_unusable(struct dasd_device *device,
2049                                      struct dasd_ccw_req *cqr)
2050 {
2051         int mask = ~(DASD_STOPPED_DC_WAIT | DASD_UNRESUMED_PM | DASD_STOPPED_NOSPC);
2052 
2053         if (test_bit(DASD_FLAG_OFFLINE, &device->flags) &&
2054             !test_bit(DASD_FLAG_SAFE_OFFLINE_RUNNING, &device->flags)) {
2055                 /*
2056                  * dasd is being set offline
2057                  * but it is no safe offline where we have to allow I/O
2058                  */
2059                 return 1;
2060         }
2061         if (device->stopped) {
2062                 if (device->stopped & mask) {
2063                         /* stopped and CQR will not change that. */
2064                         return 1;
2065                 }
2066                 if (!test_bit(DASD_CQR_VERIFY_PATH, &cqr->flags)) {
2067                         /* CQR is not able to change device to
2068                          * operational. */
2069                         return 1;
2070                 }
2071                 /* CQR required to get device operational. */
2072         }
2073         return 0;
2074 }
2075 
2076 /*
2077  * Take a look at the first request on the ccw queue and check
2078  * if it needs to be started.
2079  */
2080 static void __dasd_device_start_head(struct dasd_device *device)
2081 {
2082         struct dasd_ccw_req *cqr;
2083         int rc;
2084 
2085         if (list_empty(&device->ccw_queue))
2086                 return;
2087         cqr = list_entry(device->ccw_queue.next, struct dasd_ccw_req, devlist);
2088         if (cqr->status != DASD_CQR_QUEUED)
2089                 return;
2090         /* if device is not usable return request to upper layer */
2091         if (__dasd_device_is_unusable(device, cqr)) {
2092                 cqr->intrc = -EAGAIN;
2093                 cqr->status = DASD_CQR_CLEARED;
2094                 dasd_schedule_device_bh(device);
2095                 return;
2096         }
2097 
2098         rc = device->discipline->start_IO(cqr);
2099         if (rc == 0)
2100                 dasd_device_set_timer(device, cqr->expires);
2101         else if (rc == -EACCES) {
2102                 dasd_schedule_device_bh(device);
2103         } else
2104                 /* Hmpf, try again in 1/2 sec */
2105                 dasd_device_set_timer(device, 50);
2106 }
2107 
2108 static void __dasd_device_check_path_events(struct dasd_device *device)
2109 {
2110         int rc;
2111 
2112         if (!dasd_path_get_tbvpm(device))
2113                 return;
2114 
2115         if (device->stopped &
2116             ~(DASD_STOPPED_DC_WAIT | DASD_UNRESUMED_PM))
2117                 return;
2118         rc = device->discipline->verify_path(device,
2119                                              dasd_path_get_tbvpm(device));
2120         if (rc)
2121                 dasd_device_set_timer(device, 50);
2122         else
2123                 dasd_path_clear_all_verify(device);
2124 };
2125 
2126 /*
2127  * Go through all request on the dasd_device request queue,
2128  * terminate them on the cdev if necessary, and return them to the
2129  * submitting layer via callback.
2130  * Note:
2131  * Make sure that all 'submitting layers' still exist when
2132  * this function is called!. In other words, when 'device' is a base
2133  * device then all block layer requests must have been removed before
2134  * via dasd_flush_block_queue.
2135  */
2136 int dasd_flush_device_queue(struct dasd_device *device)
2137 {
2138         struct dasd_ccw_req *cqr, *n;
2139         int rc;
2140         struct list_head flush_queue;
2141 
2142         INIT_LIST_HEAD(&flush_queue);
2143         spin_lock_irq(get_ccwdev_lock(device->cdev));
2144         rc = 0;
2145         list_for_each_entry_safe(cqr, n, &device->ccw_queue, devlist) {
2146                 /* Check status and move request to flush_queue */
2147                 switch (cqr->status) {
2148                 case DASD_CQR_IN_IO:
2149                         rc = device->discipline->term_IO(cqr);
2150                         if (rc) {
2151                                 /* unable to terminate requeust */
2152                                 dev_err(&device->cdev->dev,
2153                                         "Flushing the DASD request queue "
2154                                         "failed for request %p\n", cqr);
2155                                 /* stop flush processing */
2156                                 goto finished;
2157                         }
2158                         break;
2159                 case DASD_CQR_QUEUED:
2160                         cqr->stopclk = get_tod_clock();
2161                         cqr->status = DASD_CQR_CLEARED;
2162                         break;
2163                 default: /* no need to modify the others */
2164                         break;
2165                 }
2166                 list_move_tail(&cqr->devlist, &flush_queue);
2167         }
2168 finished:
2169         spin_unlock_irq(get_ccwdev_lock(device->cdev));
2170         /*
2171          * After this point all requests must be in state CLEAR_PENDING,
2172          * CLEARED, SUCCESS or ERROR. Now wait for CLEAR_PENDING to become
2173          * one of the others.
2174          */
2175         list_for_each_entry_safe(cqr, n, &flush_queue, devlist)
2176                 wait_event(dasd_flush_wq,
2177                            (cqr->status != DASD_CQR_CLEAR_PENDING));
2178         /*
2179          * Now set each request back to TERMINATED, DONE or NEED_ERP
2180          * and call the callback function of flushed requests
2181          */
2182         __dasd_device_process_final_queue(device, &flush_queue);
2183         return rc;
2184 }
2185 EXPORT_SYMBOL_GPL(dasd_flush_device_queue);
2186 
2187 /*
2188  * Acquire the device lock and process queues for the device.
2189  */
2190 static void dasd_device_tasklet(unsigned long data)
2191 {
2192         struct dasd_device *device = (struct dasd_device *) data;
2193         struct list_head final_queue;
2194 
2195         atomic_set (&device->tasklet_scheduled, 0);
2196         INIT_LIST_HEAD(&final_queue);
2197         spin_lock_irq(get_ccwdev_lock(device->cdev));
2198         /* Check expire time of first request on the ccw queue. */
2199         __dasd_device_check_expire(device);
2200         /* find final requests on ccw queue */
2201         __dasd_device_process_ccw_queue(device, &final_queue);
2202         __dasd_device_check_path_events(device);
2203         spin_unlock_irq(get_ccwdev_lock(device->cdev));
2204         /* Now call the callback function of requests with final status */
2205         __dasd_device_process_final_queue(device, &final_queue);
2206         spin_lock_irq(get_ccwdev_lock(device->cdev));
2207         /* Now check if the head of the ccw queue needs to be started. */
2208         __dasd_device_start_head(device);
2209         spin_unlock_irq(get_ccwdev_lock(device->cdev));
2210         if (waitqueue_active(&shutdown_waitq))
2211                 wake_up(&shutdown_waitq);
2212         dasd_put_device(device);
2213 }
2214 
2215 /*
2216  * Schedules a call to dasd_tasklet over the device tasklet.
2217  */
2218 void dasd_schedule_device_bh(struct dasd_device *device)
2219 {
2220         /* Protect against rescheduling. */
2221         if (atomic_cmpxchg (&device->tasklet_scheduled, 0, 1) != 0)
2222                 return;
2223         dasd_get_device(device);
2224         tasklet_hi_schedule(&device->tasklet);
2225 }
2226 EXPORT_SYMBOL(dasd_schedule_device_bh);
2227 
2228 void dasd_device_set_stop_bits(struct dasd_device *device, int bits)
2229 {
2230         device->stopped |= bits;
2231 }
2232 EXPORT_SYMBOL_GPL(dasd_device_set_stop_bits);
2233 
2234 void dasd_device_remove_stop_bits(struct dasd_device *device, int bits)
2235 {
2236         device->stopped &= ~bits;
2237         if (!device->stopped)
2238                 wake_up(&generic_waitq);
2239 }
2240 EXPORT_SYMBOL_GPL(dasd_device_remove_stop_bits);
2241 
2242 /*
2243  * Queue a request to the head of the device ccw_queue.
2244  * Start the I/O if possible.
2245  */
2246 void dasd_add_request_head(struct dasd_ccw_req *cqr)
2247 {
2248         struct dasd_device *device;
2249         unsigned long flags;
2250 
2251         device = cqr->startdev;
2252         spin_lock_irqsave(get_ccwdev_lock(device->cdev), flags);
2253         cqr->status = DASD_CQR_QUEUED;
2254         list_add(&cqr->devlist, &device->ccw_queue);
2255         /* let the bh start the request to keep them in order */
2256         dasd_schedule_device_bh(device);
2257         spin_unlock_irqrestore(get_ccwdev_lock(device->cdev), flags);
2258 }
2259 EXPORT_SYMBOL(dasd_add_request_head);
2260 
2261 /*
2262  * Queue a request to the tail of the device ccw_queue.
2263  * Start the I/O if possible.
2264  */
2265 void dasd_add_request_tail(struct dasd_ccw_req *cqr)
2266 {
2267         struct dasd_device *device;
2268         unsigned long flags;
2269 
2270         device = cqr->startdev;
2271         spin_lock_irqsave(get_ccwdev_lock(device->cdev), flags);
2272         cqr->status = DASD_CQR_QUEUED;
2273         list_add_tail(&cqr->devlist, &device->ccw_queue);
2274         /* let the bh start the request to keep them in order */
2275         dasd_schedule_device_bh(device);
2276         spin_unlock_irqrestore(get_ccwdev_lock(device->cdev), flags);
2277 }
2278 EXPORT_SYMBOL(dasd_add_request_tail);
2279 
2280 /*
2281  * Wakeup helper for the 'sleep_on' functions.
2282  */
2283 void dasd_wakeup_cb(struct dasd_ccw_req *cqr, void *data)
2284 {
2285         spin_lock_irq(get_ccwdev_lock(cqr->startdev->cdev));
2286         cqr->callback_data = DASD_SLEEPON_END_TAG;
2287         spin_unlock_irq(get_ccwdev_lock(cqr->startdev->cdev));
2288         wake_up(&generic_waitq);
2289 }
2290 EXPORT_SYMBOL_GPL(dasd_wakeup_cb);
2291 
2292 static inline int _wait_for_wakeup(struct dasd_ccw_req *cqr)
2293 {
2294         struct dasd_device *device;
2295         int rc;
2296 
2297         device = cqr->startdev;
2298         spin_lock_irq(get_ccwdev_lock(device->cdev));
2299         rc = (cqr->callback_data == DASD_SLEEPON_END_TAG);
2300         spin_unlock_irq(get_ccwdev_lock(device->cdev));
2301         return rc;
2302 }
2303 
2304 /*
2305  * checks if error recovery is necessary, returns 1 if yes, 0 otherwise.
2306  */
2307 static int __dasd_sleep_on_erp(struct dasd_ccw_req *cqr)
2308 {
2309         struct dasd_device *device;
2310         dasd_erp_fn_t erp_fn;
2311 
2312         if (cqr->status == DASD_CQR_FILLED)
2313                 return 0;
2314         device = cqr->startdev;
2315         if (test_bit(DASD_CQR_FLAGS_USE_ERP, &cqr->flags)) {
2316                 if (cqr->status == DASD_CQR_TERMINATED) {
2317                         device->discipline->handle_terminated_request(cqr);
2318                         return 1;
2319                 }
2320                 if (cqr->status == DASD_CQR_NEED_ERP) {
2321                         erp_fn = device->discipline->erp_action(cqr);
2322                         erp_fn(cqr);
2323                         return 1;
2324                 }
2325                 if (cqr->status == DASD_CQR_FAILED)
2326                         dasd_log_sense(cqr, &cqr->irb);
2327                 if (cqr->refers) {
2328                         __dasd_process_erp(device, cqr);
2329                         return 1;
2330                 }
2331         }
2332         return 0;
2333 }
2334 
2335 static int __dasd_sleep_on_loop_condition(struct dasd_ccw_req *cqr)
2336 {
2337         if (test_bit(DASD_CQR_FLAGS_USE_ERP, &cqr->flags)) {
2338                 if (cqr->refers) /* erp is not done yet */
2339                         return 1;
2340                 return ((cqr->status != DASD_CQR_DONE) &&
2341                         (cqr->status != DASD_CQR_FAILED));
2342         } else
2343                 return (cqr->status == DASD_CQR_FILLED);
2344 }
2345 
2346 static int _dasd_sleep_on(struct dasd_ccw_req *maincqr, int interruptible)
2347 {
2348         struct dasd_device *device;
2349         int rc;
2350         struct list_head ccw_queue;
2351         struct dasd_ccw_req *cqr;
2352 
2353         INIT_LIST_HEAD(&ccw_queue);
2354         maincqr->status = DASD_CQR_FILLED;
2355         device = maincqr->startdev;
2356         list_add(&maincqr->blocklist, &ccw_queue);
2357         for (cqr = maincqr;  __dasd_sleep_on_loop_condition(cqr);
2358              cqr = list_first_entry(&ccw_queue,
2359                                     struct dasd_ccw_req, blocklist)) {
2360 
2361                 if (__dasd_sleep_on_erp(cqr))
2362                         continue;
2363                 if (cqr->status != DASD_CQR_FILLED) /* could be failed */
2364                         continue;
2365                 if (test_bit(DASD_FLAG_LOCK_STOLEN, &device->flags) &&
2366                     !test_bit(DASD_CQR_ALLOW_SLOCK, &cqr->flags)) {
2367                         cqr->status = DASD_CQR_FAILED;
2368                         cqr->intrc = -EPERM;
2369                         continue;
2370                 }
2371                 /* Non-temporary stop condition will trigger fail fast */
2372                 if (device->stopped & ~DASD_STOPPED_PENDING &&
2373                     test_bit(DASD_CQR_FLAGS_FAILFAST, &cqr->flags) &&
2374                     (!dasd_eer_enabled(device))) {
2375                         cqr->status = DASD_CQR_FAILED;
2376                         cqr->intrc = -ENOLINK;
2377                         continue;
2378                 }
2379                 /*
2380                  * Don't try to start requests if device is in
2381                  * offline processing, it might wait forever
2382                  */
2383                 if (test_bit(DASD_FLAG_OFFLINE, &device->flags)) {
2384                         cqr->status = DASD_CQR_FAILED;
2385                         cqr->intrc = -ENODEV;
2386                         continue;
2387                 }
2388                 /*
2389                  * Don't try to start requests if device is stopped
2390                  * except path verification requests
2391                  */
2392                 if (!test_bit(DASD_CQR_VERIFY_PATH, &cqr->flags)) {
2393                         if (interruptible) {
2394                                 rc = wait_event_interruptible(
2395                                         generic_waitq, !(device->stopped));
2396                                 if (rc == -ERESTARTSYS) {
2397                                         cqr->status = DASD_CQR_FAILED;
2398                                         maincqr->intrc = rc;
2399                                         continue;
2400                                 }
2401                         } else
2402                                 wait_event(generic_waitq, !(device->stopped));
2403                 }
2404                 if (!cqr->callback)
2405                         cqr->callback = dasd_wakeup_cb;
2406 
2407                 cqr->callback_data = DASD_SLEEPON_START_TAG;
2408                 dasd_add_request_tail(cqr);
2409                 if (interruptible) {
2410                         rc = wait_event_interruptible(
2411                                 generic_waitq, _wait_for_wakeup(cqr));
2412                         if (rc == -ERESTARTSYS) {
2413                                 dasd_cancel_req(cqr);
2414                                 /* wait (non-interruptible) for final status */
2415                                 wait_event(generic_waitq,
2416                                            _wait_for_wakeup(cqr));
2417                                 cqr->status = DASD_CQR_FAILED;
2418                                 maincqr->intrc = rc;
2419                                 continue;
2420                         }
2421                 } else
2422                         wait_event(generic_waitq, _wait_for_wakeup(cqr));
2423         }
2424 
2425         maincqr->endclk = get_tod_clock();
2426         if ((maincqr->status != DASD_CQR_DONE) &&
2427             (maincqr->intrc != -ERESTARTSYS))
2428                 dasd_log_sense(maincqr, &maincqr->irb);
2429         if (maincqr->status == DASD_CQR_DONE)
2430                 rc = 0;
2431         else if (maincqr->intrc)
2432                 rc = maincqr->intrc;
2433         else
2434                 rc = -EIO;
2435         return rc;
2436 }
2437 
2438 static inline int _wait_for_wakeup_queue(struct list_head *ccw_queue)
2439 {
2440         struct dasd_ccw_req *cqr;
2441 
2442         list_for_each_entry(cqr, ccw_queue, blocklist) {
2443                 if (cqr->callback_data != DASD_SLEEPON_END_TAG)
2444                         return 0;
2445         }
2446 
2447         return 1;
2448 }
2449 
2450 static int _dasd_sleep_on_queue(struct list_head *ccw_queue, int interruptible)
2451 {
2452         struct dasd_device *device;
2453         struct dasd_ccw_req *cqr, *n;
2454         u8 *sense = NULL;
2455         int rc;
2456 
2457 retry:
2458         list_for_each_entry_safe(cqr, n, ccw_queue, blocklist) {
2459                 device = cqr->startdev;
2460                 if (cqr->status != DASD_CQR_FILLED) /*could be failed*/
2461                         continue;
2462 
2463                 if (test_bit(DASD_FLAG_LOCK_STOLEN, &device->flags) &&
2464                     !test_bit(DASD_CQR_ALLOW_SLOCK, &cqr->flags)) {
2465                         cqr->status = DASD_CQR_FAILED;
2466                         cqr->intrc = -EPERM;
2467                         continue;
2468                 }
2469                 /*Non-temporary stop condition will trigger fail fast*/
2470                 if (device->stopped & ~DASD_STOPPED_PENDING &&
2471                     test_bit(DASD_CQR_FLAGS_FAILFAST, &cqr->flags) &&
2472                     !dasd_eer_enabled(device)) {
2473                         cqr->status = DASD_CQR_FAILED;
2474                         cqr->intrc = -EAGAIN;
2475                         continue;
2476                 }
2477 
2478                 /*Don't try to start requests if device is stopped*/
2479                 if (interruptible) {
2480                         rc = wait_event_interruptible(
2481                                 generic_waitq, !device->stopped);
2482                         if (rc == -ERESTARTSYS) {
2483                                 cqr->status = DASD_CQR_FAILED;
2484                                 cqr->intrc = rc;
2485                                 continue;
2486                         }
2487                 } else
2488                         wait_event(generic_waitq, !(device->stopped));
2489 
2490                 if (!cqr->callback)
2491                         cqr->callback = dasd_wakeup_cb;
2492                 cqr->callback_data = DASD_SLEEPON_START_TAG;
2493                 dasd_add_request_tail(cqr);
2494         }
2495 
2496         wait_event(generic_waitq, _wait_for_wakeup_queue(ccw_queue));
2497 
2498         rc = 0;
2499         list_for_each_entry_safe(cqr, n, ccw_queue, blocklist) {
2500                 /*
2501                  * In some cases the 'File Protected' or 'Incorrect Length'
2502                  * error might be expected and error recovery would be
2503                  * unnecessary in these cases.  Check if the according suppress
2504                  * bit is set.
2505                  */
2506                 sense = dasd_get_sense(&cqr->irb);
2507                 if (sense && sense[1] & SNS1_FILE_PROTECTED &&
2508                     test_bit(DASD_CQR_SUPPRESS_FP, &cqr->flags))
2509                         continue;
2510                 if (scsw_cstat(&cqr->irb.scsw) == 0x40 &&
2511                     test_bit(DASD_CQR_SUPPRESS_IL, &cqr->flags))
2512                         continue;
2513 
2514                 /*
2515                  * for alias devices simplify error recovery and
2516                  * return to upper layer
2517                  * do not skip ERP requests
2518                  */
2519                 if (cqr->startdev != cqr->basedev && !cqr->refers &&
2520                     (cqr->status == DASD_CQR_TERMINATED ||
2521                      cqr->status == DASD_CQR_NEED_ERP))
2522                         return -EAGAIN;
2523 
2524                 /* normal recovery for basedev IO */
2525                 if (__dasd_sleep_on_erp(cqr))
2526                         /* handle erp first */
2527                         goto retry;
2528         }
2529 
2530         return 0;
2531 }
2532 
2533 /*
2534  * Queue a request to the tail of the device ccw_queue and wait for
2535  * it's completion.
2536  */
2537 int dasd_sleep_on(struct dasd_ccw_req *cqr)
2538 {
2539         return _dasd_sleep_on(cqr, 0);
2540 }
2541 EXPORT_SYMBOL(dasd_sleep_on);
2542 
2543 /*
2544  * Start requests from a ccw_queue and wait for their completion.
2545  */
2546 int dasd_sleep_on_queue(struct list_head *ccw_queue)
2547 {
2548         return _dasd_sleep_on_queue(ccw_queue, 0);
2549 }
2550 EXPORT_SYMBOL(dasd_sleep_on_queue);
2551 
2552 /*
2553  * Start requests from a ccw_queue and wait interruptible for their completion.
2554  */
2555 int dasd_sleep_on_queue_interruptible(struct list_head *ccw_queue)
2556 {
2557         return _dasd_sleep_on_queue(ccw_queue, 1);
2558 }
2559 EXPORT_SYMBOL(dasd_sleep_on_queue_interruptible);
2560 
2561 /*
2562  * Queue a request to the tail of the device ccw_queue and wait
2563  * interruptible for it's completion.
2564  */
2565 int dasd_sleep_on_interruptible(struct dasd_ccw_req *cqr)
2566 {
2567         return _dasd_sleep_on(cqr, 1);
2568 }
2569 EXPORT_SYMBOL(dasd_sleep_on_interruptible);
2570 
2571 /*
2572  * Whoa nelly now it gets really hairy. For some functions (e.g. steal lock
2573  * for eckd devices) the currently running request has to be terminated
2574  * and be put back to status queued, before the special request is added
2575  * to the head of the queue. Then the special request is waited on normally.
2576  */
2577 static inline int _dasd_term_running_cqr(struct dasd_device *device)
2578 {
2579         struct dasd_ccw_req *cqr;
2580         int rc;
2581 
2582         if (list_empty(&device->ccw_queue))
2583                 return 0;
2584         cqr = list_entry(device->ccw_queue.next, struct dasd_ccw_req, devlist);
2585         rc = device->discipline->term_IO(cqr);
2586         if (!rc)
2587                 /*
2588                  * CQR terminated because a more important request is pending.
2589                  * Undo decreasing of retry counter because this is
2590                  * not an error case.
2591                  */
2592                 cqr->retries++;
2593         return rc;
2594 }
2595 
2596 int dasd_sleep_on_immediatly(struct dasd_ccw_req *cqr)
2597 {
2598         struct dasd_device *device;
2599         int rc;
2600 
2601         device = cqr->startdev;
2602         if (test_bit(DASD_FLAG_LOCK_STOLEN, &device->flags) &&
2603             !test_bit(DASD_CQR_ALLOW_SLOCK, &cqr->flags)) {
2604                 cqr->status = DASD_CQR_FAILED;
2605                 cqr->intrc = -EPERM;
2606                 return -EIO;
2607         }
2608         spin_lock_irq(get_ccwdev_lock(device->cdev));
2609         rc = _dasd_term_running_cqr(device);
2610         if (rc) {
2611                 spin_unlock_irq(get_ccwdev_lock(device->cdev));
2612                 return rc;
2613         }
2614         cqr->callback = dasd_wakeup_cb;
2615         cqr->callback_data = DASD_SLEEPON_START_TAG;
2616         cqr->status = DASD_CQR_QUEUED;
2617         /*
2618          * add new request as second
2619          * first the terminated cqr needs to be finished
2620          */
2621         list_add(&cqr->devlist, device->ccw_queue.next);
2622 
2623         /* let the bh start the request to keep them in order */
2624         dasd_schedule_device_bh(device);
2625 
2626         spin_unlock_irq(get_ccwdev_lock(device->cdev));
2627 
2628         wait_event(generic_waitq, _wait_for_wakeup(cqr));
2629 
2630         if (cqr->status == DASD_CQR_DONE)
2631                 rc = 0;
2632         else if (cqr->intrc)
2633                 rc = cqr->intrc;
2634         else
2635                 rc = -EIO;
2636 
2637         /* kick tasklets */
2638         dasd_schedule_device_bh(device);
2639         if (device->block)
2640                 dasd_schedule_block_bh(device->block);
2641 
2642         return rc;
2643 }
2644 EXPORT_SYMBOL(dasd_sleep_on_immediatly);
2645 
2646 /*
2647  * Cancels a request that was started with dasd_sleep_on_req.
2648  * This is useful to timeout requests. The request will be
2649  * terminated if it is currently in i/o.
2650  * Returns 0 if request termination was successful
2651  *         negative error code if termination failed
2652  * Cancellation of a request is an asynchronous operation! The calling
2653  * function has to wait until the request is properly returned via callback.
2654  */
2655 static int __dasd_cancel_req(struct dasd_ccw_req *cqr)
2656 {
2657         struct dasd_device *device = cqr->startdev;
2658         int rc = 0;
2659 
2660         switch (cqr->status) {
2661         case DASD_CQR_QUEUED:
2662                 /* request was not started - just set to cleared */
2663                 cqr->status = DASD_CQR_CLEARED;
2664                 break;
2665         case DASD_CQR_IN_IO:
2666                 /* request in IO - terminate IO and release again */
2667                 rc = device->discipline->term_IO(cqr);
2668                 if (rc) {
2669                         dev_err(&device->cdev->dev,
2670                                 "Cancelling request %p failed with rc=%d\n",
2671                                 cqr, rc);
2672                 } else {
2673                         cqr->stopclk = get_tod_clock();
2674                 }
2675                 break;
2676         default: /* already finished or clear pending - do nothing */
2677                 break;
2678         }
2679         dasd_schedule_device_bh(device);
2680         return rc;
2681 }
2682 
2683 int dasd_cancel_req(struct dasd_ccw_req *cqr)
2684 {
2685         struct dasd_device *device = cqr->startdev;
2686         unsigned long flags;
2687         int rc;
2688 
2689         spin_lock_irqsave(get_ccwdev_lock(device->cdev), flags);
2690         rc = __dasd_cancel_req(cqr);
2691         spin_unlock_irqrestore(get_ccwdev_lock(device->cdev), flags);
2692         return rc;
2693 }
2694 
2695 /*
2696  * SECTION: Operations of the dasd_block layer.
2697  */
2698 
2699 /*
2700  * Timeout function for dasd_block. This is used when the block layer
2701  * is waiting for something that may not come reliably, (e.g. a state
2702  * change interrupt)
2703  */
2704 static void dasd_block_timeout(struct timer_list *t)
2705 {
2706         unsigned long flags;
2707         struct dasd_block *block;
2708 
2709         block = from_timer(block, t, timer);
2710         spin_lock_irqsave(get_ccwdev_lock(block->base->cdev), flags);
2711         /* re-activate request queue */
2712         dasd_device_remove_stop_bits(block->base, DASD_STOPPED_PENDING);
2713         spin_unlock_irqrestore(get_ccwdev_lock(block->base->cdev), flags);
2714         dasd_schedule_block_bh(block);
2715         blk_mq_run_hw_queues(block->request_queue, true);
2716 }
2717 
2718 /*
2719  * Setup timeout for a dasd_block in jiffies.
2720  */
2721 void dasd_block_set_timer(struct dasd_block *block, int expires)
2722 {
2723         if (expires == 0)
2724                 del_timer(&block->timer);
2725         else
2726                 mod_timer(&block->timer, jiffies + expires);
2727 }
2728 EXPORT_SYMBOL(dasd_block_set_timer);
2729 
2730 /*
2731  * Clear timeout for a dasd_block.
2732  */
2733 void dasd_block_clear_timer(struct dasd_block *block)
2734 {
2735         del_timer(&block->timer);
2736 }
2737 EXPORT_SYMBOL(dasd_block_clear_timer);
2738 
2739 /*
2740  * Process finished error recovery ccw.
2741  */
2742 static void __dasd_process_erp(struct dasd_device *device,
2743                                struct dasd_ccw_req *cqr)
2744 {
2745         dasd_erp_fn_t erp_fn;
2746 
2747         if (cqr->status == DASD_CQR_DONE)
2748                 DBF_DEV_EVENT(DBF_NOTICE, device, "%s", "ERP successful");
2749         else
2750                 dev_err(&device->cdev->dev, "ERP failed for the DASD\n");
2751         erp_fn = device->discipline->erp_postaction(cqr);
2752         erp_fn(cqr);
2753 }
2754 
2755 static void __dasd_cleanup_cqr(struct dasd_ccw_req *cqr)
2756 {
2757         struct request *req;
2758         blk_status_t error = BLK_STS_OK;
2759         unsigned int proc_bytes;
2760         int status;
2761 
2762         req = (struct request *) cqr->callback_data;
2763         dasd_profile_end(cqr->block, cqr, req);
2764 
2765         proc_bytes = cqr->proc_bytes;
2766         status = cqr->block->base->discipline->free_cp(cqr, req);
2767         if (status < 0)
2768                 error = errno_to_blk_status(status);
2769         else if (status == 0) {
2770                 switch (cqr->intrc) {
2771                 case -EPERM:
2772                         error = BLK_STS_NEXUS;
2773                         break;
2774                 case -ENOLINK:
2775                         error = BLK_STS_TRANSPORT;
2776                         break;
2777                 case -ETIMEDOUT:
2778                         error = BLK_STS_TIMEOUT;
2779                         break;
2780                 default:
2781                         error = BLK_STS_IOERR;
2782                         break;
2783                 }
2784         }
2785 
2786         /*
2787          * We need to take care for ETIMEDOUT errors here since the
2788          * complete callback does not get called in this case.
2789          * Take care of all errors here and avoid additional code to
2790          * transfer the error value to the complete callback.
2791          */
2792         if (error) {
2793                 blk_mq_end_request(req, error);
2794                 blk_mq_run_hw_queues(req->q, true);
2795         } else {
2796                 /*
2797                  * Partial completed requests can happen with ESE devices.
2798                  * During read we might have gotten a NRF error and have to
2799                  * complete a request partially.
2800                  */
2801                 if (proc_bytes) {
2802                         blk_update_request(req, BLK_STS_OK,
2803                                            blk_rq_bytes(req) - proc_bytes);
2804                         blk_mq_requeue_request(req, true);
2805                 } else {
2806                         blk_mq_complete_request(req);
2807                 }
2808         }
2809 }
2810 
2811 /*
2812  * Process ccw request queue.
2813  */
2814 static void __dasd_process_block_ccw_queue(struct dasd_block *block,
2815                                            struct list_head *final_queue)
2816 {
2817         struct list_head *l, *n;
2818         struct dasd_ccw_req *cqr;
2819         dasd_erp_fn_t erp_fn;
2820         unsigned long flags;
2821         struct dasd_device *base = block->base;
2822 
2823 restart:
2824         /* Process request with final status. */
2825         list_for_each_safe(l, n, &block->ccw_queue) {
2826                 cqr = list_entry(l, struct dasd_ccw_req, blocklist);
2827                 if (cqr->status != DASD_CQR_DONE &&
2828                     cqr->status != DASD_CQR_FAILED &&
2829                     cqr->status != DASD_CQR_NEED_ERP &&
2830                     cqr->status != DASD_CQR_TERMINATED)
2831                         continue;
2832 
2833                 if (cqr->status == DASD_CQR_TERMINATED) {
2834                         base->discipline->handle_terminated_request(cqr);
2835                         goto restart;
2836                 }
2837 
2838                 /*  Process requests that may be recovered */
2839                 if (cqr->status == DASD_CQR_NEED_ERP) {
2840                         erp_fn = base->discipline->erp_action(cqr);
2841                         if (IS_ERR(erp_fn(cqr)))
2842                                 continue;
2843                         goto restart;
2844                 }
2845 
2846                 /* log sense for fatal error */
2847                 if (cqr->status == DASD_CQR_FAILED) {
2848                         dasd_log_sense(cqr, &cqr->irb);
2849                 }
2850 
2851                 /* First of all call extended error reporting. */
2852                 if (dasd_eer_enabled(base) &&
2853                     cqr->status == DASD_CQR_FAILED) {
2854                         dasd_eer_write(base, cqr, DASD_EER_FATALERROR);
2855 
2856                         /* restart request  */
2857                         cqr->status = DASD_CQR_FILLED;
2858                         cqr->retries = 255;
2859                         spin_lock_irqsave(get_ccwdev_lock(base->cdev), flags);
2860                         dasd_device_set_stop_bits(base, DASD_STOPPED_QUIESCE);
2861                         spin_unlock_irqrestore(get_ccwdev_lock(base->cdev),
2862                                                flags);
2863                         goto restart;
2864                 }
2865 
2866                 /* Process finished ERP request. */
2867                 if (cqr->refers) {
2868                         __dasd_process_erp(base, cqr);
2869                         goto restart;
2870                 }
2871 
2872                 /* Rechain finished requests to final queue */
2873                 cqr->endclk = get_tod_clock();
2874                 list_move_tail(&cqr->blocklist, final_queue);
2875         }
2876 }
2877 
2878 static void dasd_return_cqr_cb(struct dasd_ccw_req *cqr, void *data)
2879 {
2880         dasd_schedule_block_bh(cqr->block);
2881 }
2882 
2883 static void __dasd_block_start_head(struct dasd_block *block)
2884 {
2885         struct dasd_ccw_req *cqr;
2886 
2887         if (list_empty(&block->ccw_queue))
2888                 return;
2889         /* We allways begin with the first requests on the queue, as some
2890          * of previously started requests have to be enqueued on a
2891          * dasd_device again for error recovery.
2892          */
2893         list_for_each_entry(cqr, &block->ccw_queue, blocklist) {
2894                 if (cqr->status != DASD_CQR_FILLED)
2895                         continue;
2896                 if (test_bit(DASD_FLAG_LOCK_STOLEN, &block->base->flags) &&
2897                     !test_bit(DASD_CQR_ALLOW_SLOCK, &cqr->flags)) {
2898                         cqr->status = DASD_CQR_FAILED;
2899                         cqr->intrc = -EPERM;
2900                         dasd_schedule_block_bh(block);
2901                         continue;
2902                 }
2903                 /* Non-temporary stop condition will trigger fail fast */
2904                 if (block->base->stopped & ~DASD_STOPPED_PENDING &&
2905                     test_bit(DASD_CQR_FLAGS_FAILFAST, &cqr->flags) &&
2906                     (!dasd_eer_enabled(block->base))) {
2907                         cqr->status = DASD_CQR_FAILED;
2908                         cqr->intrc = -ENOLINK;
2909                         dasd_schedule_block_bh(block);
2910                         continue;
2911                 }
2912                 /* Don't try to start requests if device is stopped */
2913                 if (block->base->stopped)
2914                         return;
2915 
2916                 /* just a fail safe check, should not happen */
2917                 if (!cqr->startdev)
2918                         cqr->startdev = block->base;
2919 
2920                 /* make sure that the requests we submit find their way back */
2921                 cqr->callback = dasd_return_cqr_cb;
2922 
2923                 dasd_add_request_tail(cqr);
2924         }
2925 }
2926 
2927 /*
2928  * Central dasd_block layer routine. Takes requests from the generic
2929  * block layer request queue, creates ccw requests, enqueues them on
2930  * a dasd_device and processes ccw requests that have been returned.
2931  */
2932 static void dasd_block_tasklet(unsigned long data)
2933 {
2934         struct dasd_block *block = (struct dasd_block *) data;
2935         struct list_head final_queue;
2936         struct list_head *l, *n;
2937         struct dasd_ccw_req *cqr;
2938         struct dasd_queue *dq;
2939 
2940         atomic_set(&block->tasklet_scheduled, 0);
2941         INIT_LIST_HEAD(&final_queue);
2942         spin_lock_irq(&block->queue_lock);
2943         /* Finish off requests on ccw queue */
2944         __dasd_process_block_ccw_queue(block, &final_queue);
2945         spin_unlock_irq(&block->queue_lock);
2946 
2947         /* Now call the callback function of requests with final status */
2948         list_for_each_safe(l, n, &final_queue) {
2949                 cqr = list_entry(l, struct dasd_ccw_req, blocklist);
2950                 dq = cqr->dq;
2951                 spin_lock_irq(&dq->lock);
2952                 list_del_init(&cqr->blocklist);
2953                 __dasd_cleanup_cqr(cqr);
2954                 spin_unlock_irq(&dq->lock);
2955         }
2956 
2957         spin_lock_irq(&block->queue_lock);
2958         /* Now check if the head of the ccw queue needs to be started. */
2959         __dasd_block_start_head(block);
2960         spin_unlock_irq(&block->queue_lock);
2961 
2962         if (waitqueue_active(&shutdown_waitq))
2963                 wake_up(&shutdown_waitq);
2964         dasd_put_device(block->base);
2965 }
2966 
2967 static void _dasd_wake_block_flush_cb(struct dasd_ccw_req *cqr, void *data)
2968 {
2969         wake_up(&dasd_flush_wq);
2970 }
2971 
2972 /*
2973  * Requeue a request back to the block request queue
2974  * only works for block requests
2975  */
2976 static int _dasd_requeue_request(struct dasd_ccw_req *cqr)
2977 {
2978         struct dasd_block *block = cqr->block;
2979         struct request *req;
2980 
2981         if (!block)
2982                 return -EINVAL;
2983         spin_lock_irq(&cqr->dq->lock);
2984         req = (struct request *) cqr->callback_data;
2985         blk_mq_requeue_request(req, false);
2986         spin_unlock_irq(&cqr->dq->lock);
2987 
2988         return 0;
2989 }
2990 
2991 /*
2992  * Go through all request on the dasd_block request queue, cancel them
2993  * on the respective dasd_device, and return them to the generic
2994  * block layer.
2995  */
2996 static int dasd_flush_block_queue(struct dasd_block *block)
2997 {
2998         struct dasd_ccw_req *cqr, *n;
2999         int rc, i;
3000         struct list_head flush_queue;
3001         unsigned long flags;
3002 
3003         INIT_LIST_HEAD(&flush_queue);
3004         spin_lock_bh(&block->queue_lock);
3005         rc = 0;
3006 restart:
3007         list_for_each_entry_safe(cqr, n, &block->ccw_queue, blocklist) {
3008                 /* if this request currently owned by a dasd_device cancel it */
3009                 if (cqr->status >= DASD_CQR_QUEUED)
3010                         rc = dasd_cancel_req(cqr);
3011                 if (rc < 0)
3012                         break;
3013                 /* Rechain request (including erp chain) so it won't be
3014                  * touched by the dasd_block_tasklet anymore.
3015                  * Replace the callback so we notice when the request
3016                  * is returned from the dasd_device layer.
3017                  */
3018                 cqr->callback = _dasd_wake_block_flush_cb;
3019                 for (i = 0; cqr != NULL; cqr = cqr->refers, i++)
3020                         list_move_tail(&cqr->blocklist, &flush_queue);
3021                 if (i > 1)
3022                         /* moved more than one request - need to restart */
3023                         goto restart;
3024         }
3025         spin_unlock_bh(&block->queue_lock);
3026         /* Now call the callback function of flushed requests */
3027 restart_cb:
3028         list_for_each_entry_safe(cqr, n, &flush_queue, blocklist) {
3029                 wait_event(dasd_flush_wq, (cqr->status < DASD_CQR_QUEUED));
3030                 /* Process finished ERP request. */
3031                 if (cqr->refers) {
3032                         spin_lock_bh(&block->queue_lock);
3033                         __dasd_process_erp(block->base, cqr);
3034                         spin_unlock_bh(&block->queue_lock);
3035                         /* restart list_for_xx loop since dasd_process_erp
3036                          * might remove multiple elements */
3037                         goto restart_cb;
3038                 }
3039                 /* call the callback function */
3040                 spin_lock_irqsave(&cqr->dq->lock, flags);
3041                 cqr->endclk = get_tod_clock();
3042                 list_del_init(&cqr->blocklist);
3043                 __dasd_cleanup_cqr(cqr);
3044                 spin_unlock_irqrestore(&cqr->dq->lock, flags);
3045         }
3046         return rc;
3047 }
3048 
3049 /*
3050  * Schedules a call to dasd_tasklet over the device tasklet.
3051  */
3052 void dasd_schedule_block_bh(struct dasd_block *block)
3053 {
3054         /* Protect against rescheduling. */
3055         if (atomic_cmpxchg(&block->tasklet_scheduled, 0, 1) != 0)
3056                 return;
3057         /* life cycle of block is bound to it's base device */
3058         dasd_get_device(block->base);
3059         tasklet_hi_schedule(&block->tasklet);
3060 }
3061 EXPORT_SYMBOL(dasd_schedule_block_bh);
3062 
3063 
3064 /*
3065  * SECTION: external block device operations
3066  * (request queue handling, open, release, etc.)
3067  */
3068 
3069 /*
3070  * Dasd request queue function. Called from ll_rw_blk.c
3071  */
3072 static blk_status_t do_dasd_request(struct blk_mq_hw_ctx *hctx,
3073                                     const struct blk_mq_queue_data *qd)
3074 {
3075         struct dasd_block *block = hctx->queue->queuedata;
3076         struct dasd_queue *dq = hctx->driver_data;
3077         struct request *req = qd->rq;
3078         struct dasd_device *basedev;
3079         struct dasd_ccw_req *cqr;
3080         blk_status_t rc = BLK_STS_OK;
3081 
3082         basedev = block->base;
3083         spin_lock_irq(&dq->lock);
3084         if (basedev->state < DASD_STATE_READY) {
3085                 DBF_DEV_EVENT(DBF_ERR, basedev,
3086                               "device not ready for request %p", req);
3087                 rc = BLK_STS_IOERR;
3088                 goto out;
3089         }
3090 
3091         /*
3092          * if device is stopped do not fetch new requests
3093          * except failfast is active which will let requests fail
3094          * immediately in __dasd_block_start_head()
3095          */
3096         if (basedev->stopped && !(basedev->features & DASD_FEATURE_FAILFAST)) {
3097                 DBF_DEV_EVENT(DBF_ERR, basedev,
3098                               "device stopped request %p", req);
3099                 rc = BLK_STS_RESOURCE;
3100                 goto out;
3101         }
3102 
3103         if (basedev->features & DASD_FEATURE_READONLY &&
3104             rq_data_dir(req) == WRITE) {
3105                 DBF_DEV_EVENT(DBF_ERR, basedev,
3106                               "Rejecting write request %p", req);
3107                 rc = BLK_STS_IOERR;
3108                 goto out;
3109         }
3110 
3111         if (test_bit(DASD_FLAG_ABORTALL, &basedev->flags) &&
3112             (basedev->features & DASD_FEATURE_FAILFAST ||
3113              blk_noretry_request(req))) {
3114                 DBF_DEV_EVENT(DBF_ERR, basedev,
3115                               "Rejecting failfast request %p", req);
3116                 rc = BLK_STS_IOERR;
3117                 goto out;
3118         }
3119 
3120         cqr = basedev->discipline->build_cp(basedev, block, req);
3121         if (IS_ERR(cqr)) {
3122                 if (PTR_ERR(cqr) == -EBUSY ||
3123                     PTR_ERR(cqr) == -ENOMEM ||
3124                     PTR_ERR(cqr) == -EAGAIN) {
3125                         rc = BLK_STS_RESOURCE;
3126                         goto out;
3127                 }
3128                 DBF_DEV_EVENT(DBF_ERR, basedev,
3129                               "CCW creation failed (rc=%ld) on request %p",
3130                               PTR_ERR(cqr), req);
3131                 rc = BLK_STS_IOERR;
3132                 goto out;
3133         }
3134         /*
3135          *  Note: callback is set to dasd_return_cqr_cb in
3136          * __dasd_block_start_head to cover erp requests as well
3137          */
3138         cqr->callback_data = req;
3139         cqr->status = DASD_CQR_FILLED;
3140         cqr->dq = dq;
3141 
3142         blk_mq_start_request(req);
3143         spin_lock(&block->queue_lock);
3144         list_add_tail(&cqr->blocklist, &block->ccw_queue);
3145         INIT_LIST_HEAD(&cqr->devlist);
3146         dasd_profile_start(block, cqr, req);
3147         dasd_schedule_block_bh(block);
3148         spin_unlock(&block->queue_lock);
3149 
3150 out:
3151         spin_unlock_irq(&dq->lock);
3152         return rc;
3153 }
3154 
3155 /*
3156  * Block timeout callback, called from the block layer
3157  *
3158  * Return values:
3159  * BLK_EH_RESET_TIMER if the request should be left running
3160  * BLK_EH_DONE if the request is handled or terminated
3161  *                    by the driver.
3162  */
3163 enum blk_eh_timer_return dasd_times_out(struct request *req, bool reserved)
3164 {
3165         struct dasd_block *block = req->q->queuedata;
3166         struct dasd_device *device;
3167         struct dasd_ccw_req *cqr;
3168         unsigned long flags;
3169         int rc = 0;
3170 
3171         cqr = blk_mq_rq_to_pdu(req);
3172         if (!cqr)
3173                 return BLK_EH_DONE;
3174 
3175         spin_lock_irqsave(&cqr->dq->lock, flags);
3176         device = cqr->startdev ? cqr->startdev : block->base;
3177         if (!device->blk_timeout) {
3178                 spin_unlock_irqrestore(&cqr->dq->lock, flags);
3179                 return BLK_EH_RESET_TIMER;
3180         }
3181         DBF_DEV_EVENT(DBF_WARNING, device,
3182                       " dasd_times_out cqr %p status %x",
3183                       cqr, cqr->status);
3184 
3185         spin_lock(&block->queue_lock);
3186         spin_lock(get_ccwdev_lock(device->cdev));
3187         cqr->retries = -1;
3188         cqr->intrc = -ETIMEDOUT;
3189         if (cqr->status >= DASD_CQR_QUEUED) {
3190                 rc = __dasd_cancel_req(cqr);
3191         } else if (cqr->status == DASD_CQR_FILLED ||
3192                    cqr->status == DASD_CQR_NEED_ERP) {
3193                 cqr->status = DASD_CQR_TERMINATED;
3194         } else if (cqr->status == DASD_CQR_IN_ERP) {
3195                 struct dasd_ccw_req *searchcqr, *nextcqr, *tmpcqr;
3196 
3197                 list_for_each_entry_safe(searchcqr, nextcqr,
3198                                          &block->ccw_queue, blocklist) {
3199                         tmpcqr = searchcqr;
3200                         while (tmpcqr->refers)
3201                                 tmpcqr = tmpcqr->refers;
3202                         if (tmpcqr != cqr)
3203                                 continue;
3204                         /* searchcqr is an ERP request for cqr */
3205                         searchcqr->retries = -1;
3206                         searchcqr->intrc = -ETIMEDOUT;
3207                         if (searchcqr->status >= DASD_CQR_QUEUED) {
3208                                 rc = __dasd_cancel_req(searchcqr);
3209                         } else if ((searchcqr->status == DASD_CQR_FILLED) ||
3210                                    (searchcqr->status == DASD_CQR_NEED_ERP)) {
3211                                 searchcqr->status = DASD_CQR_TERMINATED;
3212                                 rc = 0;
3213                         } else if (searchcqr->status == DASD_CQR_IN_ERP) {
3214                                 /*
3215                                  * Shouldn't happen; most recent ERP
3216                                  * request is at the front of queue
3217                                  */
3218                                 continue;
3219                         }
3220                         break;
3221                 }
3222         }
3223         spin_unlock(get_ccwdev_lock(device->cdev));
3224         dasd_schedule_block_bh(block);
3225         spin_unlock(&block->queue_lock);
3226         spin_unlock_irqrestore(&cqr->dq->lock, flags);
3227 
3228         return rc ? BLK_EH_RESET_TIMER : BLK_EH_DONE;
3229 }
3230 
3231 static int dasd_init_hctx(struct blk_mq_hw_ctx *hctx, void *data,
3232                           unsigned int idx)
3233 {
3234         struct dasd_queue *dq = kzalloc(sizeof(*dq), GFP_KERNEL);
3235 
3236         if (!dq)
3237                 return -ENOMEM;
3238 
3239         spin_lock_init(&dq->lock);
3240         hctx->driver_data = dq;
3241 
3242         return 0;
3243 }
3244 
3245 static void dasd_exit_hctx(struct blk_mq_hw_ctx *hctx, unsigned int idx)
3246 {
3247         kfree(hctx->driver_data);
3248         hctx->driver_data = NULL;
3249 }
3250 
3251 static void dasd_request_done(struct request *req)
3252 {
3253         blk_mq_end_request(req, 0);
3254         blk_mq_run_hw_queues(req->q, true);
3255 }
3256 
3257 static struct blk_mq_ops dasd_mq_ops = {
3258         .queue_rq = do_dasd_request,
3259         .complete = dasd_request_done,
3260         .timeout = dasd_times_out,
3261         .init_hctx = dasd_init_hctx,
3262         .exit_hctx = dasd_exit_hctx,
3263 };
3264 
3265 /*
3266  * Allocate and initialize request queue and default I/O scheduler.
3267  */
3268 static int dasd_alloc_queue(struct dasd_block *block)
3269 {
3270         int rc;
3271 
3272         block->tag_set.ops = &dasd_mq_ops;
3273         block->tag_set.cmd_size = sizeof(struct dasd_ccw_req);
3274         block->tag_set.nr_hw_queues = nr_hw_queues;
3275         block->tag_set.queue_depth = queue_depth;
3276         block->tag_set.flags = BLK_MQ_F_SHOULD_MERGE;
3277         block->tag_set.numa_node = NUMA_NO_NODE;
3278 
3279         rc = blk_mq_alloc_tag_set(&block->tag_set);
3280         if (rc)
3281                 return rc;
3282 
3283         block->request_queue = blk_mq_init_queue(&block->tag_set);
3284         if (IS_ERR(block->request_queue))
3285                 return PTR_ERR(block->request_queue);
3286 
3287         block->request_queue->queuedata = block;
3288 
3289         return 0;
3290 }
3291 
3292 /*
3293  * Deactivate and free request queue.
3294  */
3295 static void dasd_free_queue(struct dasd_block *block)
3296 {
3297         if (block->request_queue) {
3298                 blk_cleanup_queue(block->request_queue);
3299                 blk_mq_free_tag_set(&block->tag_set);
3300                 block->request_queue = NULL;
3301         }
3302 }
3303 
3304 static int dasd_open(struct block_device *bdev, fmode_t mode)
3305 {
3306         struct dasd_device *base;
3307         int rc;
3308 
3309         base = dasd_device_from_gendisk(bdev->bd_disk);
3310         if (!base)
3311                 return -ENODEV;
3312 
3313         atomic_inc(&base->block->open_count);
3314         if (test_bit(DASD_FLAG_OFFLINE, &base->flags)) {
3315                 rc = -ENODEV;
3316                 goto unlock;
3317         }
3318 
3319         if (!try_module_get(base->discipline->owner)) {
3320                 rc = -EINVAL;
3321                 goto unlock;
3322         }
3323 
3324         if (dasd_probeonly) {
3325                 dev_info(&base->cdev->dev,
3326                          "Accessing the DASD failed because it is in "
3327                          "probeonly mode\n");
3328                 rc = -EPERM;
3329                 goto out;
3330         }
3331 
3332         if (base->state <= DASD_STATE_BASIC) {
3333                 DBF_DEV_EVENT(DBF_ERR, base, " %s",
3334                               " Cannot open unrecognized device");
3335                 rc = -ENODEV;
3336                 goto out;
3337         }
3338 
3339         if ((mode & FMODE_WRITE) &&
3340             (test_bit(DASD_FLAG_DEVICE_RO, &base->flags) ||
3341              (base->features & DASD_FEATURE_READONLY))) {
3342                 rc = -EROFS;
3343                 goto out;
3344         }
3345 
3346         dasd_put_device(base);
3347         return 0;
3348 
3349 out:
3350         module_put(base->discipline->owner);
3351 unlock:
3352         atomic_dec(&base->block->open_count);
3353         dasd_put_device(base);
3354         return rc;
3355 }
3356 
3357 static void dasd_release(struct gendisk *disk, fmode_t mode)
3358 {
3359         struct dasd_device *base = dasd_device_from_gendisk(disk);
3360         if (base) {
3361                 atomic_dec(&base->block->open_count);
3362                 module_put(base->discipline->owner);
3363                 dasd_put_device(base);
3364         }
3365 }
3366 
3367 /*
3368  * Return disk geometry.
3369  */
3370 static int dasd_getgeo(struct block_device *bdev, struct hd_geometry *geo)
3371 {
3372         struct dasd_device *base;
3373 
3374         base = dasd_device_from_gendisk(bdev->bd_disk);
3375         if (!base)
3376                 return -ENODEV;
3377 
3378         if (!base->discipline ||
3379             !base->discipline->fill_geometry) {
3380                 dasd_put_device(base);
3381                 return -EINVAL;
3382         }
3383         base->discipline->fill_geometry(base->block, geo);
3384         geo->start = get_start_sect(bdev) >> base->block->s2b_shift;
3385         dasd_put_device(base);
3386         return 0;
3387 }
3388 
3389 const struct block_device_operations
3390 dasd_device_operations = {
3391         .owner          = THIS_MODULE,
3392         .open           = dasd_open,
3393         .release        = dasd_release,
3394         .ioctl          = dasd_ioctl,
3395         .compat_ioctl   = dasd_ioctl,
3396         .getgeo         = dasd_getgeo,
3397 };
3398 
3399 /*******************************************************************************
3400  * end of block device operations
3401  */
3402 
3403 static void
3404 dasd_exit(void)
3405 {
3406 #ifdef CONFIG_PROC_FS
3407         dasd_proc_exit();
3408 #endif
3409         dasd_eer_exit();
3410         kmem_cache_destroy(dasd_page_cache);
3411         dasd_page_cache = NULL;
3412         dasd_gendisk_exit();
3413         dasd_devmap_exit();
3414         if (dasd_debug_area != NULL) {
3415                 debug_unregister(dasd_debug_area);
3416                 dasd_debug_area = NULL;
3417         }
3418         dasd_statistics_removeroot();
3419 }
3420 
3421 /*
3422  * SECTION: common functions for ccw_driver use
3423  */
3424 
3425 /*
3426  * Is the device read-only?
3427  * Note that this function does not report the setting of the
3428  * readonly device attribute, but how it is configured in z/VM.
3429  */
3430 int dasd_device_is_ro(struct dasd_device *device)
3431 {
3432         struct ccw_dev_id dev_id;
3433         struct diag210 diag_data;
3434         int rc;
3435 
3436         if (!MACHINE_IS_VM)
3437                 return 0;
3438         ccw_device_get_id(device->cdev, &dev_id);
3439         memset(&diag_data, 0, sizeof(diag_data));
3440         diag_data.vrdcdvno = dev_id.devno;
3441         diag_data.vrdclen = sizeof(diag_data);
3442         rc = diag210(&diag_data);
3443         if (rc == 0 || rc == 2) {
3444                 return diag_data.vrdcvfla & 0x80;
3445         } else {
3446                 DBF_EVENT(DBF_WARNING, "diag210 failed for dev=%04x with rc=%d",
3447                           dev_id.devno, rc);
3448                 return 0;
3449         }
3450 }
3451 EXPORT_SYMBOL_GPL(dasd_device_is_ro);
3452 
3453 static void dasd_generic_auto_online(void *data, async_cookie_t cookie)
3454 {
3455         struct ccw_device *cdev = data;
3456         int ret;
3457 
3458         ret = ccw_device_set_online(cdev);
3459         if (ret)
3460                 pr_warn("%s: Setting the DASD online failed with rc=%d\n",
3461                         dev_name(&cdev->dev), ret);
3462 }
3463 
3464 /*
3465  * Initial attempt at a probe function. this can be simplified once
3466  * the other detection code is gone.
3467  */
3468 int dasd_generic_probe(struct ccw_device *cdev,
3469                        struct dasd_discipline *discipline)
3470 {
3471         int ret;
3472 
3473         ret = dasd_add_sysfs_files(cdev);
3474         if (ret) {
3475                 DBF_EVENT_DEVID(DBF_WARNING, cdev, "%s",
3476                                 "dasd_generic_probe: could not add "
3477                                 "sysfs entries");
3478                 return ret;
3479         }
3480         cdev->handler = &dasd_int_handler;
3481 
3482         /*
3483          * Automatically online either all dasd devices (dasd_autodetect)
3484          * or all devices specified with dasd= parameters during
3485          * initial probe.
3486          */
3487         if ((dasd_get_feature(cdev, DASD_FEATURE_INITIAL_ONLINE) > 0 ) ||
3488             (dasd_autodetect && dasd_busid_known(dev_name(&cdev->dev)) != 0))
3489                 async_schedule(dasd_generic_auto_online, cdev);
3490         return 0;
3491 }
3492 EXPORT_SYMBOL_GPL(dasd_generic_probe);
3493 
3494 void dasd_generic_free_discipline(struct dasd_device *device)
3495 {
3496         /* Forget the discipline information. */
3497         if (device->discipline) {
3498                 if (device->discipline->uncheck_device)
3499                         device->discipline->uncheck_device(device);
3500                 module_put(device->discipline->owner);
3501                 device->discipline = NULL;
3502         }
3503         if (device->base_discipline) {
3504                 module_put(device->base_discipline->owner);
3505                 device->base_discipline = NULL;
3506         }
3507 }
3508 EXPORT_SYMBOL_GPL(dasd_generic_free_discipline);
3509 
3510 /*
3511  * This will one day be called from a global not_oper handler.
3512  * It is also used by driver_unregister during module unload.
3513  */
3514 void dasd_generic_remove(struct ccw_device *cdev)
3515 {
3516         struct dasd_device *device;
3517         struct dasd_block *block;
3518 
3519         cdev->handler = NULL;
3520 
3521         device = dasd_device_from_cdev(cdev);
3522         if (IS_ERR(device)) {
3523                 dasd_remove_sysfs_files(cdev);
3524                 return;
3525         }
3526         if (test_and_set_bit(DASD_FLAG_OFFLINE, &device->flags) &&
3527             !test_bit(DASD_FLAG_SAFE_OFFLINE_RUNNING, &device->flags)) {
3528                 /* Already doing offline processing */
3529                 dasd_put_device(device);
3530                 dasd_remove_sysfs_files(cdev);
3531                 return;
3532         }
3533         /*
3534          * This device is removed unconditionally. Set offline
3535          * flag to prevent dasd_open from opening it while it is
3536          * no quite down yet.
3537          */
3538         dasd_set_target_state(device, DASD_STATE_NEW);
3539         /* dasd_delete_device destroys the device reference. */
3540         block = device->block;
3541         dasd_delete_device(device);
3542         /*
3543          * life cycle of block is bound to device, so delete it after
3544          * device was safely removed
3545          */
3546         if (block)
3547                 dasd_free_block(block);
3548 
3549         dasd_remove_sysfs_files(cdev);
3550 }
3551 EXPORT_SYMBOL_GPL(dasd_generic_remove);
3552 
3553 /*
3554  * Activate a device. This is called from dasd_{eckd,fba}_probe() when either
3555  * the device is detected for the first time and is supposed to be used
3556  * or the user has started activation through sysfs.
3557  */
3558 int dasd_generic_set_online(struct ccw_device *cdev,
3559                             struct dasd_discipline *base_discipline)
3560 {
3561         struct dasd_discipline *discipline;
3562         struct dasd_device *device;
3563         int rc;
3564 
3565         /* first online clears initial online feature flag */
3566         dasd_set_feature(cdev, DASD_FEATURE_INITIAL_ONLINE, 0);
3567         device = dasd_create_device(cdev);
3568         if (IS_ERR(device))
3569                 return PTR_ERR(device);
3570 
3571         discipline = base_discipline;
3572         if (device->features & DASD_FEATURE_USEDIAG) {
3573                 if (!dasd_diag_discipline_pointer) {
3574                         /* Try to load the required module. */
3575                         rc = request_module(DASD_DIAG_MOD);
3576                         if (rc) {
3577                                 pr_warn("%s Setting the DASD online failed "
3578                                         "because the required module %s "
3579                                         "could not be loaded (rc=%d)\n",
3580                                         dev_name(&cdev->dev), DASD_DIAG_MOD,
3581                                         rc);
3582                                 dasd_delete_device(device);
3583                                 return -ENODEV;
3584                         }
3585                 }
3586                 /* Module init could have failed, so check again here after
3587                  * request_module(). */
3588                 if (!dasd_diag_discipline_pointer) {
3589                         pr_warn("%s Setting the DASD online failed because of missing DIAG discipline\n",
3590                                 dev_name(&cdev->dev));
3591                         dasd_delete_device(device);
3592                         return -ENODEV;
3593                 }
3594                 discipline = dasd_diag_discipline_pointer;
3595         }
3596         if (!try_module_get(base_discipline->owner)) {
3597                 dasd_delete_device(device);
3598                 return -EINVAL;
3599         }
3600         if (!try_module_get(discipline->owner)) {
3601                 module_put(base_discipline->owner);
3602                 dasd_delete_device(device);
3603                 return -EINVAL;
3604         }
3605         device->base_discipline = base_discipline;
3606         device->discipline = discipline;
3607 
3608         /* check_device will allocate block device if necessary */
3609         rc = discipline->check_device(device);
3610         if (rc) {
3611                 pr_warn("%s Setting the DASD online with discipline %s failed with rc=%i\n",
3612                         dev_name(&cdev->dev), discipline->name, rc);
3613                 module_put(discipline->owner);
3614                 module_put(base_discipline->owner);
3615                 dasd_delete_device(device);
3616                 return rc;
3617         }
3618 
3619         dasd_set_target_state(device, DASD_STATE_ONLINE);
3620         if (device->state <= DASD_STATE_KNOWN) {
3621                 pr_warn("%s Setting the DASD online failed because of a missing discipline\n",
3622                         dev_name(&cdev->dev));
3623                 rc = -ENODEV;
3624                 dasd_set_target_state(device, DASD_STATE_NEW);
3625                 if (device->block)
3626                         dasd_free_block(device->block);
3627                 dasd_delete_device(device);
3628         } else
3629                 pr_debug("dasd_generic device %s found\n",
3630                                 dev_name(&cdev->dev));
3631 
3632         wait_event(dasd_init_waitq, _wait_for_device(device));
3633 
3634         dasd_put_device(device);
3635         return rc;
3636 }
3637 EXPORT_SYMBOL_GPL(dasd_generic_set_online);
3638 
3639 int dasd_generic_set_offline(struct ccw_device *cdev)
3640 {
3641         struct dasd_device *device;
3642         struct dasd_block *block;
3643         int max_count, open_count, rc;
3644         unsigned long flags;
3645 
3646         rc = 0;
3647         spin_lock_irqsave(get_ccwdev_lock(cdev), flags);
3648         device = dasd_device_from_cdev_locked(cdev);
3649         if (IS_ERR(device)) {
3650                 spin_unlock_irqrestore(get_ccwdev_lock(cdev), flags);
3651                 return PTR_ERR(device);
3652         }
3653 
3654         /*
3655          * We must make sure that this device is currently not in use.
3656          * The open_count is increased for every opener, that includes
3657          * the blkdev_get in dasd_scan_partitions. We are only interested
3658          * in the other openers.
3659          */
3660         if (device->block) {
3661                 max_count = device->block->bdev ? 0 : -1;
3662                 open_count = atomic_read(&device->block->open_count);
3663                 if (open_count > max_count) {
3664                         if (open_count > 0)
3665                                 pr_warn("%s: The DASD cannot be set offline with open count %i\n",
3666                                         dev_name(&cdev->dev), open_count);
3667                         else
3668                                 pr_warn("%s: The DASD cannot be set offline while it is in use\n",
3669                                         dev_name(&cdev->dev));
3670                         rc = -EBUSY;
3671                         goto out_err;
3672                 }
3673         }
3674 
3675         /*
3676          * Test if the offline processing is already running and exit if so.
3677          * If a safe offline is being processed this could only be a normal
3678          * offline that should be able to overtake the safe offline and
3679          * cancel any I/O we do not want to wait for any longer
3680          */
3681         if (test_bit(DASD_FLAG_OFFLINE, &device->flags)) {
3682                 if (test_bit(DASD_FLAG_SAFE_OFFLINE_RUNNING, &device->flags)) {
3683                         clear_bit(DASD_FLAG_SAFE_OFFLINE_RUNNING,
3684                                   &device->flags);
3685                 } else {
3686                         rc = -EBUSY;
3687                         goto out_err;
3688                 }
3689         }
3690         set_bit(DASD_FLAG_OFFLINE, &device->flags);
3691 
3692         /*
3693          * if safe_offline is called set safe_offline_running flag and
3694          * clear safe_offline so that a call to normal offline
3695          * can overrun safe_offline processing
3696          */
3697         if (test_and_clear_bit(DASD_FLAG_SAFE_OFFLINE, &device->flags) &&
3698             !test_and_set_bit(DASD_FLAG_SAFE_OFFLINE_RUNNING, &device->flags)) {
3699                 /* need to unlock here to wait for outstanding I/O */
3700                 spin_unlock_irqrestore(get_ccwdev_lock(cdev), flags);
3701                 /*
3702                  * If we want to set the device safe offline all IO operations
3703                  * should be finished before continuing the offline process
3704                  * so sync bdev first and then wait for our queues to become
3705                  * empty
3706                  */
3707                 if (device->block) {
3708                         rc = fsync_bdev(device->block->bdev);
3709                         if (rc != 0)
3710                                 goto interrupted;
3711                 }
3712                 dasd_schedule_device_bh(device);
3713                 rc = wait_event_interruptible(shutdown_waitq,
3714                                               _wait_for_empty_queues(device));
3715                 if (rc != 0)
3716                         goto interrupted;
3717 
3718                 /*
3719                  * check if a normal offline process overtook the offline
3720                  * processing in this case simply do nothing beside returning
3721                  * that we got interrupted
3722                  * otherwise mark safe offline as not running any longer and
3723                  * continue with normal offline
3724                  */
3725                 spin_lock_irqsave(get_ccwdev_lock(cdev), flags);
3726                 if (!test_bit(DASD_FLAG_SAFE_OFFLINE_RUNNING, &device->flags)) {
3727                         rc = -ERESTARTSYS;
3728                         goto out_err;
3729                 }
3730                 clear_bit(DASD_FLAG_SAFE_OFFLINE_RUNNING, &device->flags);
3731         }
3732         spin_unlock_irqrestore(get_ccwdev_lock(cdev), flags);
3733 
3734         dasd_set_target_state(device, DASD_STATE_NEW);
3735         /* dasd_delete_device destroys the device reference. */
3736         block = device->block;
3737         dasd_delete_device(device);
3738         /*
3739          * life cycle of block is bound to device, so delete it after
3740          * device was safely removed
3741          */
3742         if (block)
3743                 dasd_free_block(block);
3744 
3745         return 0;
3746 
3747 interrupted:
3748         /* interrupted by signal */
3749         spin_lock_irqsave(get_ccwdev_lock(cdev), flags);
3750         clear_bit(DASD_FLAG_SAFE_OFFLINE_RUNNING, &device->flags);
3751         clear_bit(DASD_FLAG_OFFLINE, &device->flags);
3752 out_err:
3753         dasd_put_device(device);
3754         spin_unlock_irqrestore(get_ccwdev_lock(cdev), flags);
3755         return rc;
3756 }
3757 EXPORT_SYMBOL_GPL(dasd_generic_set_offline);
3758 
3759 int dasd_generic_last_path_gone(struct dasd_device *device)
3760 {
3761         struct dasd_ccw_req *cqr;
3762 
3763         dev_warn(&device->cdev->dev, "No operational channel path is left "
3764                  "for the device\n");
3765         DBF_DEV_EVENT(DBF_WARNING, device, "%s", "last path gone");
3766         /* First of all call extended error reporting. */
3767         dasd_eer_write(device, NULL, DASD_EER_NOPATH);
3768 
3769         if (device->state < DASD_STATE_BASIC)
3770                 return 0;
3771         /* Device is active. We want to keep it. */
3772         list_for_each_entry(cqr, &device->ccw_queue, devlist)
3773                 if ((cqr->status == DASD_CQR_IN_IO) ||
3774                     (cqr->status == DASD_CQR_CLEAR_PENDING)) {
3775                         cqr->status = DASD_CQR_QUEUED;
3776                         cqr->retries++;
3777                 }
3778         dasd_device_set_stop_bits(device, DASD_STOPPED_DC_WAIT);
3779         dasd_device_clear_timer(device);
3780         dasd_schedule_device_bh(device);
3781         return 1;
3782 }
3783 EXPORT_SYMBOL_GPL(dasd_generic_last_path_gone);
3784 
3785 int dasd_generic_path_operational(struct dasd_device *device)
3786 {
3787         dev_info(&device->cdev->dev, "A channel path to the device has become "
3788                  "operational\n");
3789         DBF_DEV_EVENT(DBF_WARNING, device, "%s", "path operational");
3790         dasd_device_remove_stop_bits(device, DASD_STOPPED_DC_WAIT);
3791         if (device->stopped & DASD_UNRESUMED_PM) {
3792                 dasd_device_remove_stop_bits(device, DASD_UNRESUMED_PM);
3793                 dasd_restore_device(device);
3794                 return 1;
3795         }
3796         dasd_schedule_device_bh(device);
3797         if (device->block) {
3798                 dasd_schedule_block_bh(device->block);
3799                 if (device->block->request_queue)
3800                         blk_mq_run_hw_queues(device->block->request_queue,
3801                                              true);
3802                 }
3803 
3804         if (!device->stopped)
3805                 wake_up(&generic_waitq);
3806 
3807         return 1;
3808 }
3809 EXPORT_SYMBOL_GPL(dasd_generic_path_operational);
3810 
3811 int dasd_generic_notify(struct ccw_device *cdev, int event)
3812 {
3813         struct dasd_device *device;
3814         int ret;
3815 
3816         device = dasd_device_from_cdev_locked(cdev);
3817         if (IS_ERR(device))
3818                 return 0;
3819         ret = 0;
3820         switch (event) {
3821         case CIO_GONE:
3822         case CIO_BOXED:
3823         case CIO_NO_PATH:
3824                 dasd_path_no_path(device);
3825                 ret = dasd_generic_last_path_gone(device);
3826                 break;
3827         case CIO_OPER:
3828                 ret = 1;
3829                 if (dasd_path_get_opm(device))
3830                         ret = dasd_generic_path_operational(device);
3831                 break;
3832         }
3833         dasd_put_device(device);
3834         return ret;
3835 }
3836 EXPORT_SYMBOL_GPL(dasd_generic_notify);
3837 
3838 void dasd_generic_path_event(struct ccw_device *cdev, int *path_event)
3839 {
3840         struct dasd_device *device;
3841         int chp, oldopm, hpfpm, ifccpm;
3842 
3843         device = dasd_device_from_cdev_locked(cdev);
3844         if (IS_ERR(device))
3845                 return;
3846 
3847         oldopm = dasd_path_get_opm(device);
3848         for (chp = 0; chp < 8; chp++) {
3849                 if (path_event[chp] & PE_PATH_GONE) {
3850                         dasd_path_notoper(device, chp);
3851                 }
3852                 if (path_event[chp] & PE_PATH_AVAILABLE) {
3853                         dasd_path_available(device, chp);
3854                         dasd_schedule_device_bh(device);
3855                 }
3856                 if (path_event[chp] & PE_PATHGROUP_ESTABLISHED) {
3857                         if (!dasd_path_is_operational(device, chp) &&
3858                             !dasd_path_need_verify(device, chp)) {
3859                                 /*
3860                                  * we can not establish a pathgroup on an
3861                                  * unavailable path, so trigger a path
3862                                  * verification first
3863                                  */
3864                         dasd_path_available(device, chp);
3865                         dasd_schedule_device_bh(device);
3866                         }
3867                         DBF_DEV_EVENT(DBF_WARNING, device, "%s",
3868                                       "Pathgroup re-established\n");
3869                         if (device->discipline->kick_validate)
3870                                 device->discipline->kick_validate(device);
3871                 }
3872         }
3873         hpfpm = dasd_path_get_hpfpm(device);
3874         ifccpm = dasd_path_get_ifccpm(device);
3875         if (!dasd_path_get_opm(device) && hpfpm) {
3876                 /*
3877                  * device has no operational paths but at least one path is
3878                  * disabled due to HPF errors
3879                  * disable HPF at all and use the path(s) again
3880                  */
3881                 if (device->discipline->disable_hpf)
3882                         device->discipline->disable_hpf(device);
3883                 dasd_device_set_stop_bits(device, DASD_STOPPED_NOT_ACC);
3884                 dasd_path_set_tbvpm(device, hpfpm);
3885                 dasd_schedule_device_bh(device);
3886                 dasd_schedule_requeue(device);
3887         } else if (!dasd_path_get_opm(device) && ifccpm) {
3888                 /*
3889                  * device has no operational paths but at least one path is
3890                  * disabled due to IFCC errors
3891                  * trigger path verification on paths with IFCC errors
3892                  */
3893                 dasd_path_set_tbvpm(device, ifccpm);
3894                 dasd_schedule_device_bh(device);
3895         }
3896         if (oldopm && !dasd_path_get_opm(device) && !hpfpm && !ifccpm) {
3897                 dev_warn(&device->cdev->dev,
3898                          "No verified channel paths remain for the device\n");
3899                 DBF_DEV_EVENT(DBF_WARNING, device,
3900                               "%s", "last verified path gone");
3901                 dasd_eer_write(device, NULL, DASD_EER_NOPATH);
3902                 dasd_device_set_stop_bits(device,
3903                                           DASD_STOPPED_DC_WAIT);
3904         }
3905         dasd_put_device(device);
3906 }
3907 EXPORT_SYMBOL_GPL(dasd_generic_path_event);
3908 
3909 int dasd_generic_verify_path(struct dasd_device *device, __u8 lpm)
3910 {
3911         if (!dasd_path_get_opm(device) && lpm) {
3912                 dasd_path_set_opm(device, lpm);
3913                 dasd_generic_path_operational(device);
3914         } else
3915                 dasd_path_add_opm(device, lpm);
3916         return 0;
3917 }
3918 EXPORT_SYMBOL_GPL(dasd_generic_verify_path);
3919 
3920 void dasd_generic_space_exhaust(struct dasd_device *device,
3921                                 struct dasd_ccw_req *cqr)
3922 {
3923         dasd_eer_write(device, NULL, DASD_EER_NOSPC);
3924 
3925         if (device->state < DASD_STATE_BASIC)
3926                 return;
3927 
3928         if (cqr->status == DASD_CQR_IN_IO ||
3929             cqr->status == DASD_CQR_CLEAR_PENDING) {
3930                 cqr->status = DASD_CQR_QUEUED;
3931                 cqr->retries++;
3932         }
3933         dasd_device_set_stop_bits(device, DASD_STOPPED_NOSPC);
3934         dasd_device_clear_timer(device);
3935         dasd_schedule_device_bh(device);
3936 }
3937 EXPORT_SYMBOL_GPL(dasd_generic_space_exhaust);
3938 
3939 void dasd_generic_space_avail(struct dasd_device *device)
3940 {
3941         dev_info(&device->cdev->dev, "Extent pool space is available\n");
3942         DBF_DEV_EVENT(DBF_WARNING, device, "%s", "space available");
3943 
3944         dasd_device_remove_stop_bits(device, DASD_STOPPED_NOSPC);
3945         dasd_schedule_device_bh(device);
3946 
3947         if (device->block) {
3948                 dasd_schedule_block_bh(device->block);
3949                 if (device->block->request_queue)
3950                         blk_mq_run_hw_queues(device->block->request_queue, true);
3951         }
3952         if (!device->stopped)
3953                 wake_up(&generic_waitq);
3954 }
3955 EXPORT_SYMBOL_GPL(dasd_generic_space_avail);
3956 
3957 /*
3958  * clear active requests and requeue them to block layer if possible
3959  */
3960 static int dasd_generic_requeue_all_requests(struct dasd_device *device)
3961 {
3962         struct list_head requeue_queue;
3963         struct dasd_ccw_req *cqr, *n;
3964         struct dasd_ccw_req *refers;
3965         int rc;
3966 
3967         INIT_LIST_HEAD(&requeue_queue);
3968         spin_lock_irq(get_ccwdev_lock(device->cdev));
3969         rc = 0;
3970         list_for_each_entry_safe(cqr, n, &device->ccw_queue, devlist) {
3971                 /* Check status and move request to flush_queue */
3972                 if (cqr->status == DASD_CQR_IN_IO) {
3973                         rc = device->discipline->term_IO(cqr);
3974                         if (rc) {
3975                                 /* unable to terminate requeust */
3976                                 dev_err(&device->cdev->dev,
3977                                         "Unable to terminate request %p "
3978                                         "on suspend\n", cqr);
3979                                 spin_unlock_irq(get_ccwdev_lock(device->cdev));
3980                                 dasd_put_device(device);
3981                                 return rc;
3982                         }
3983                 }
3984                 list_move_tail(&cqr->devlist, &requeue_queue);
3985         }
3986         spin_unlock_irq(get_ccwdev_lock(device->cdev));
3987 
3988         list_for_each_entry_safe(cqr, n, &requeue_queue, devlist) {
3989                 wait_event(dasd_flush_wq,
3990                            (cqr->status != DASD_CQR_CLEAR_PENDING));
3991 
3992                 /*
3993                  * requeue requests to blocklayer will only work
3994                  * for block device requests
3995                  */
3996                 if (_dasd_requeue_request(cqr))
3997                         continue;
3998 
3999                 /* remove requests from device and block queue */
4000                 list_del_init(&cqr->devlist);
4001                 while (cqr->refers != NULL) {
4002                         refers = cqr->refers;
4003                         /* remove the request from the block queue */
4004                         list_del(&cqr->blocklist);
4005                         /* free the finished erp request */
4006                         dasd_free_erp_request(cqr, cqr->memdev);
4007                         cqr = refers;
4008                 }
4009 
4010                 /*
4011                  * _dasd_requeue_request already checked for a valid
4012                  * blockdevice, no need to check again
4013                  * all erp requests (cqr->refers) have a cqr->block
4014                  * pointer copy from the original cqr
4015                  */
4016                 list_del_init(&cqr->blocklist);
4017                 cqr->block->base->discipline->free_cp(
4018                         cqr, (struct request *) cqr->callback_data);
4019         }
4020 
4021         /*
4022          * if requests remain then they are internal request
4023          * and go back to the device queue
4024          */
4025         if (!list_empty(&requeue_queue)) {
4026                 /* move freeze_queue to start of the ccw_queue */
4027                 spin_lock_irq(get_ccwdev_lock(device->cdev));
4028                 list_splice_tail(&requeue_queue, &device->ccw_queue);
4029                 spin_unlock_irq(get_ccwdev_lock(device->cdev));
4030         }
4031         dasd_schedule_device_bh(device);
4032         return rc;
4033 }
4034 
4035 static void do_requeue_requests(struct work_struct *work)
4036 {
4037         struct dasd_device *device = container_of(work, struct dasd_device,
4038                                                   requeue_requests);
4039         dasd_generic_requeue_all_requests(device);
4040         dasd_device_remove_stop_bits(device, DASD_STOPPED_NOT_ACC);
4041         if (device->block)
4042                 dasd_schedule_block_bh(device->block);
4043         dasd_put_device(device);
4044 }
4045 
4046 void dasd_schedule_requeue(struct dasd_device *device)
4047 {
4048         dasd_get_device(device);
4049         /* queue call to dasd_reload_device to the kernel event daemon. */
4050         if (!schedule_work(&device->requeue_requests))
4051                 dasd_put_device(device);
4052 }
4053 EXPORT_SYMBOL(dasd_schedule_requeue);
4054 
4055 int dasd_generic_pm_freeze(struct ccw_device *cdev)
4056 {
4057         struct dasd_device *device = dasd_device_from_cdev(cdev);
4058 
4059         if (IS_ERR(device))
4060                 return PTR_ERR(device);
4061 
4062         /* mark device as suspended */
4063         set_bit(DASD_FLAG_SUSPENDED, &device->flags);
4064 
4065         if (device->discipline->freeze)
4066                 device->discipline->freeze(device);
4067 
4068         /* disallow new I/O  */
4069         dasd_device_set_stop_bits(device, DASD_STOPPED_PM);
4070 
4071         return dasd_generic_requeue_all_requests(device);
4072 }
4073 EXPORT_SYMBOL_GPL(dasd_generic_pm_freeze);
4074 
4075 int dasd_generic_restore_device(struct ccw_device *cdev)
4076 {
4077         struct dasd_device *device = dasd_device_from_cdev(cdev);
4078         int rc = 0;
4079 
4080         if (IS_ERR(device))
4081                 return PTR_ERR(device);
4082 
4083         /* allow new IO again */
4084         dasd_device_remove_stop_bits(device,
4085                                      (DASD_STOPPED_PM | DASD_UNRESUMED_PM));
4086 
4087         dasd_schedule_device_bh(device);
4088 
4089         /*
4090          * call discipline restore function
4091          * if device is stopped do nothing e.g. for disconnected devices
4092          */
4093         if (device->discipline->restore && !(device->stopped))
4094                 rc = device->discipline->restore(device);
4095         if (rc || device->stopped)
4096                 /*
4097                  * if the resume failed for the DASD we put it in
4098                  * an UNRESUMED stop state
4099                  */
4100                 device->stopped |= DASD_UNRESUMED_PM;
4101 
4102         if (device->block) {
4103                 dasd_schedule_block_bh(device->block);
4104                 if (device->block->request_queue)
4105                         blk_mq_run_hw_queues(device->block->request_queue,
4106                                              true);
4107         }
4108 
4109         clear_bit(DASD_FLAG_SUSPENDED, &device->flags);
4110         dasd_put_device(device);
4111         return 0;
4112 }
4113 EXPORT_SYMBOL_GPL(dasd_generic_restore_device);
4114 
4115 static struct dasd_ccw_req *dasd_generic_build_rdc(struct dasd_device *device,
4116                                                    int rdc_buffer_size,
4117                                                    int magic)
4118 {
4119         struct dasd_ccw_req *cqr;
4120         struct ccw1 *ccw;
4121 
4122         cqr = dasd_smalloc_request(magic, 1 /* RDC */, rdc_buffer_size, device,
4123                                    NULL);
4124 
4125         if (IS_ERR(cqr)) {
4126                 /* internal error 13 - Allocating the RDC request failed*/
4127                 dev_err(&device->cdev->dev,
4128                          "An error occurred in the DASD device driver, "
4129                          "reason=%s\n", "13");
4130                 return cqr;
4131         }
4132 
4133         ccw = cqr->cpaddr;
4134         ccw->cmd_code = CCW_CMD_RDC;
4135         ccw->cda = (__u32)(addr_t) cqr->data;
4136         ccw->flags = 0;
4137         ccw->count = rdc_buffer_size;
4138         cqr->startdev = device;
4139         cqr->memdev = device;
4140         cqr->expires = 10*HZ;
4141         cqr->retries = 256;
4142         cqr->buildclk = get_tod_clock();
4143         cqr->status = DASD_CQR_FILLED;
4144         return cqr;
4145 }
4146 
4147 
4148 int dasd_generic_read_dev_chars(struct dasd_device *device, int magic,
4149                                 void *rdc_buffer, int rdc_buffer_size)
4150 {
4151         int ret;
4152         struct dasd_ccw_req *cqr;
4153 
4154         cqr = dasd_generic_build_rdc(device, rdc_buffer_size, magic);
4155         if (IS_ERR(cqr))
4156                 return PTR_ERR(cqr);
4157 
4158         ret = dasd_sleep_on(cqr);
4159         if (ret == 0)
4160                 memcpy(rdc_buffer, cqr->data, rdc_buffer_size);
4161         dasd_sfree_request(cqr, cqr->memdev);
4162         return ret;
4163 }
4164 EXPORT_SYMBOL_GPL(dasd_generic_read_dev_chars);
4165 
4166 /*
4167  *   In command mode and transport mode we need to look for sense
4168  *   data in different places. The sense data itself is allways
4169  *   an array of 32 bytes, so we can unify the sense data access
4170  *   for both modes.
4171  */
4172 char *dasd_get_sense(struct irb *irb)
4173 {
4174         struct tsb *tsb = NULL;
4175         char *sense = NULL;
4176 
4177         if (scsw_is_tm(&irb->scsw) && (irb->scsw.tm.fcxs == 0x01)) {
4178                 if (irb->scsw.tm.tcw)
4179                         tsb = tcw_get_tsb((struct tcw *)(unsigned long)
4180                                           irb->scsw.tm.tcw);
4181                 if (tsb && tsb->length == 64 && tsb->flags)
4182                         switch (tsb->flags & 0x07) {
4183                         case 1: /* tsa_iostat */
4184                                 sense = tsb->tsa.iostat.sense;
4185                                 break;
4186                         case 2: /* tsa_ddpc */
4187                                 sense = tsb->tsa.ddpc.sense;
4188                                 break;
4189                         default:
4190                                 /* currently we don't use interrogate data */
4191                                 break;
4192                         }
4193         } else if (irb->esw.esw0.erw.cons) {
4194                 sense = irb->ecw;
4195         }
4196         return sense;
4197 }
4198 EXPORT_SYMBOL_GPL(dasd_get_sense);
4199 
4200 void dasd_generic_shutdown(struct ccw_device *cdev)
4201 {
4202         struct dasd_device *device;
4203 
4204         device = dasd_device_from_cdev(cdev);
4205         if (IS_ERR(device))
4206                 return;
4207 
4208         if (device->block)
4209                 dasd_schedule_block_bh(device->block);
4210 
4211         dasd_schedule_device_bh(device);
4212 
4213         wait_event(shutdown_waitq, _wait_for_empty_queues(device));
4214 }
4215 EXPORT_SYMBOL_GPL(dasd_generic_shutdown);
4216 
4217 static int __init dasd_init(void)
4218 {
4219         int rc;
4220 
4221         init_waitqueue_head(&dasd_init_waitq);
4222         init_waitqueue_head(&dasd_flush_wq);
4223         init_waitqueue_head(&generic_waitq);
4224         init_waitqueue_head(&shutdown_waitq);
4225 
4226         /* register 'common' DASD debug area, used for all DBF_XXX calls */
4227         dasd_debug_area = debug_register("dasd", 1, 1, 8 * sizeof(long));
4228         if (dasd_debug_area == NULL) {
4229                 rc = -ENOMEM;
4230                 goto failed;
4231         }
4232         debug_register_view(dasd_debug_area, &debug_sprintf_view);
4233         debug_set_level(dasd_debug_area, DBF_WARNING);
4234 
4235         DBF_EVENT(DBF_EMERG, "%s", "debug area created");
4236 
4237         dasd_diag_discipline_pointer = NULL;
4238 
4239         dasd_statistics_createroot();
4240 
4241         rc = dasd_devmap_init();
4242         if (rc)
4243                 goto failed;
4244         rc = dasd_gendisk_init();
4245         if (rc)
4246                 goto failed;
4247         rc = dasd_parse();
4248         if (rc)
4249                 goto failed;
4250         rc = dasd_eer_init();
4251         if (rc)
4252                 goto failed;
4253 #ifdef CONFIG_PROC_FS
4254         rc = dasd_proc_init();
4255         if (rc)
4256                 goto failed;
4257 #endif
4258 
4259         return 0;
4260 failed:
4261         pr_info("The DASD device driver could not be initialized\n");
4262         dasd_exit();
4263         return rc;
4264 }
4265 
4266 module_init(dasd_init);
4267 module_exit(dasd_exit);
/* [<][>][^][v][top][bottom][index][help] */
root/drivers/s390/block/dasd.c

DEFINITIONS
