1/* 2 * core function to access sclp interface 3 * 4 * Copyright IBM Corp. 1999, 2009 5 * 6 * Author(s): Martin Peschke <mpeschke@de.ibm.com> 7 * Martin Schwidefsky <schwidefsky@de.ibm.com> 8 */ 9 10#include <linux/kernel_stat.h> 11#include <linux/module.h> 12#include <linux/err.h> 13#include <linux/spinlock.h> 14#include <linux/interrupt.h> 15#include <linux/timer.h> 16#include <linux/reboot.h> 17#include <linux/jiffies.h> 18#include <linux/init.h> 19#include <linux/suspend.h> 20#include <linux/completion.h> 21#include <linux/platform_device.h> 22#include <asm/types.h> 23#include <asm/irq.h> 24 25#include "sclp.h" 26 27#define SCLP_HEADER "sclp: " 28 29/* Lock to protect internal data consistency. */ 30static DEFINE_SPINLOCK(sclp_lock); 31 32/* Mask of events that we can send to the sclp interface. */ 33static sccb_mask_t sclp_receive_mask; 34 35/* Mask of events that we can receive from the sclp interface. */ 36static sccb_mask_t sclp_send_mask; 37 38/* List of registered event listeners and senders. */ 39static struct list_head sclp_reg_list; 40 41/* List of queued requests. */ 42static struct list_head sclp_req_queue; 43 44/* Data for read and and init requests. */ 45static struct sclp_req sclp_read_req; 46static struct sclp_req sclp_init_req; 47static char sclp_read_sccb[PAGE_SIZE] __attribute__((__aligned__(PAGE_SIZE))); 48static char sclp_init_sccb[PAGE_SIZE] __attribute__((__aligned__(PAGE_SIZE))); 49 50/* Suspend request */ 51static DECLARE_COMPLETION(sclp_request_queue_flushed); 52 53/* Number of console pages to allocate, used by sclp_con.c and sclp_vt220.c */ 54int sclp_console_pages = SCLP_CONSOLE_PAGES; 55/* Flag to indicate if buffer pages are dropped on buffer full condition */ 56int sclp_console_drop = 0; 57/* Number of times the console dropped buffer pages */ 58unsigned long sclp_console_full; 59 60static void sclp_suspend_req_cb(struct sclp_req *req, void *data) 61{ 62 complete(&sclp_request_queue_flushed); 63} 64 65static int __init sclp_setup_console_pages(char *str) 66{ 67 int pages, rc; 68 69 rc = kstrtoint(str, 0, &pages); 70 if (!rc && pages >= SCLP_CONSOLE_PAGES) 71 sclp_console_pages = pages; 72 return 1; 73} 74 75__setup("sclp_con_pages=", sclp_setup_console_pages); 76 77static int __init sclp_setup_console_drop(char *str) 78{ 79 int drop, rc; 80 81 rc = kstrtoint(str, 0, &drop); 82 if (!rc && drop) 83 sclp_console_drop = 1; 84 return 1; 85} 86 87__setup("sclp_con_drop=", sclp_setup_console_drop); 88 89static struct sclp_req sclp_suspend_req; 90 91/* Timer for request retries. */ 92static struct timer_list sclp_request_timer; 93 94/* Timer for queued requests. */ 95static struct timer_list sclp_queue_timer; 96 97/* Internal state: is the driver initialized? */ 98static volatile enum sclp_init_state_t { 99 sclp_init_state_uninitialized, 100 sclp_init_state_initializing, 101 sclp_init_state_initialized 102} sclp_init_state = sclp_init_state_uninitialized; 103 104/* Internal state: is a request active at the sclp? */ 105static volatile enum sclp_running_state_t { 106 sclp_running_state_idle, 107 sclp_running_state_running, 108 sclp_running_state_reset_pending 109} sclp_running_state = sclp_running_state_idle; 110 111/* Internal state: is a read request pending? */ 112static volatile enum sclp_reading_state_t { 113 sclp_reading_state_idle, 114 sclp_reading_state_reading 115} sclp_reading_state = sclp_reading_state_idle; 116 117/* Internal state: is the driver currently serving requests? */ 118static volatile enum sclp_activation_state_t { 119 sclp_activation_state_active, 120 sclp_activation_state_deactivating, 121 sclp_activation_state_inactive, 122 sclp_activation_state_activating 123} sclp_activation_state = sclp_activation_state_active; 124 125/* Internal state: is an init mask request pending? */ 126static volatile enum sclp_mask_state_t { 127 sclp_mask_state_idle, 128 sclp_mask_state_initializing 129} sclp_mask_state = sclp_mask_state_idle; 130 131/* Internal state: is the driver suspended? */ 132static enum sclp_suspend_state_t { 133 sclp_suspend_state_running, 134 sclp_suspend_state_suspended, 135} sclp_suspend_state = sclp_suspend_state_running; 136 137/* Maximum retry counts */ 138#define SCLP_INIT_RETRY 3 139#define SCLP_MASK_RETRY 3 140 141/* Timeout intervals in seconds.*/ 142#define SCLP_BUSY_INTERVAL 10 143#define SCLP_RETRY_INTERVAL 30 144 145static void sclp_process_queue(void); 146static void __sclp_make_read_req(void); 147static int sclp_init_mask(int calculate); 148static int sclp_init(void); 149 150/* Perform service call. Return 0 on success, non-zero otherwise. */ 151int 152sclp_service_call(sclp_cmdw_t command, void *sccb) 153{ 154 int cc = 4; /* Initialize for program check handling */ 155 156 asm volatile( 157 "0: .insn rre,0xb2200000,%1,%2\n" /* servc %1,%2 */ 158 "1: ipm %0\n" 159 " srl %0,28\n" 160 "2:\n" 161 EX_TABLE(0b, 2b) 162 EX_TABLE(1b, 2b) 163 : "+&d" (cc) : "d" (command), "a" (__pa(sccb)) 164 : "cc", "memory"); 165 if (cc == 4) 166 return -EINVAL; 167 if (cc == 3) 168 return -EIO; 169 if (cc == 2) 170 return -EBUSY; 171 return 0; 172} 173 174 175static void 176__sclp_queue_read_req(void) 177{ 178 if (sclp_reading_state == sclp_reading_state_idle) { 179 sclp_reading_state = sclp_reading_state_reading; 180 __sclp_make_read_req(); 181 /* Add request to head of queue */ 182 list_add(&sclp_read_req.list, &sclp_req_queue); 183 } 184} 185 186/* Set up request retry timer. Called while sclp_lock is locked. */ 187static inline void 188__sclp_set_request_timer(unsigned long time, void (*function)(unsigned long), 189 unsigned long data) 190{ 191 del_timer(&sclp_request_timer); 192 sclp_request_timer.function = function; 193 sclp_request_timer.data = data; 194 sclp_request_timer.expires = jiffies + time; 195 add_timer(&sclp_request_timer); 196} 197 198/* Request timeout handler. Restart the request queue. If DATA is non-zero, 199 * force restart of running request. */ 200static void 201sclp_request_timeout(unsigned long data) 202{ 203 unsigned long flags; 204 205 spin_lock_irqsave(&sclp_lock, flags); 206 if (data) { 207 if (sclp_running_state == sclp_running_state_running) { 208 /* Break running state and queue NOP read event request 209 * to get a defined interface state. */ 210 __sclp_queue_read_req(); 211 sclp_running_state = sclp_running_state_idle; 212 } 213 } else { 214 __sclp_set_request_timer(SCLP_BUSY_INTERVAL * HZ, 215 sclp_request_timeout, 0); 216 } 217 spin_unlock_irqrestore(&sclp_lock, flags); 218 sclp_process_queue(); 219} 220 221/* 222 * Returns the expire value in jiffies of the next pending request timeout, 223 * if any. Needs to be called with sclp_lock. 224 */ 225static unsigned long __sclp_req_queue_find_next_timeout(void) 226{ 227 unsigned long expires_next = 0; 228 struct sclp_req *req; 229 230 list_for_each_entry(req, &sclp_req_queue, list) { 231 if (!req->queue_expires) 232 continue; 233 if (!expires_next || 234 (time_before(req->queue_expires, expires_next))) 235 expires_next = req->queue_expires; 236 } 237 return expires_next; 238} 239 240/* 241 * Returns expired request, if any, and removes it from the list. 242 */ 243static struct sclp_req *__sclp_req_queue_remove_expired_req(void) 244{ 245 unsigned long flags, now; 246 struct sclp_req *req; 247 248 spin_lock_irqsave(&sclp_lock, flags); 249 now = jiffies; 250 /* Don't need list_for_each_safe because we break out after list_del */ 251 list_for_each_entry(req, &sclp_req_queue, list) { 252 if (!req->queue_expires) 253 continue; 254 if (time_before_eq(req->queue_expires, now)) { 255 if (req->status == SCLP_REQ_QUEUED) { 256 req->status = SCLP_REQ_QUEUED_TIMEOUT; 257 list_del(&req->list); 258 goto out; 259 } 260 } 261 } 262 req = NULL; 263out: 264 spin_unlock_irqrestore(&sclp_lock, flags); 265 return req; 266} 267 268/* 269 * Timeout handler for queued requests. Removes request from list and 270 * invokes callback. This timer can be set per request in situations where 271 * waiting too long would be harmful to the system, e.g. during SE reboot. 272 */ 273static void sclp_req_queue_timeout(unsigned long data) 274{ 275 unsigned long flags, expires_next; 276 struct sclp_req *req; 277 278 do { 279 req = __sclp_req_queue_remove_expired_req(); 280 if (req && req->callback) 281 req->callback(req, req->callback_data); 282 } while (req); 283 284 spin_lock_irqsave(&sclp_lock, flags); 285 expires_next = __sclp_req_queue_find_next_timeout(); 286 if (expires_next) 287 mod_timer(&sclp_queue_timer, expires_next); 288 spin_unlock_irqrestore(&sclp_lock, flags); 289} 290 291/* Try to start a request. Return zero if the request was successfully 292 * started or if it will be started at a later time. Return non-zero otherwise. 293 * Called while sclp_lock is locked. */ 294static int 295__sclp_start_request(struct sclp_req *req) 296{ 297 int rc; 298 299 if (sclp_running_state != sclp_running_state_idle) 300 return 0; 301 del_timer(&sclp_request_timer); 302 rc = sclp_service_call(req->command, req->sccb); 303 req->start_count++; 304 305 if (rc == 0) { 306 /* Successfully started request */ 307 req->status = SCLP_REQ_RUNNING; 308 sclp_running_state = sclp_running_state_running; 309 __sclp_set_request_timer(SCLP_RETRY_INTERVAL * HZ, 310 sclp_request_timeout, 1); 311 return 0; 312 } else if (rc == -EBUSY) { 313 /* Try again later */ 314 __sclp_set_request_timer(SCLP_BUSY_INTERVAL * HZ, 315 sclp_request_timeout, 0); 316 return 0; 317 } 318 /* Request failed */ 319 req->status = SCLP_REQ_FAILED; 320 return rc; 321} 322 323/* Try to start queued requests. */ 324static void 325sclp_process_queue(void) 326{ 327 struct sclp_req *req; 328 int rc; 329 unsigned long flags; 330 331 spin_lock_irqsave(&sclp_lock, flags); 332 if (sclp_running_state != sclp_running_state_idle) { 333 spin_unlock_irqrestore(&sclp_lock, flags); 334 return; 335 } 336 del_timer(&sclp_request_timer); 337 while (!list_empty(&sclp_req_queue)) { 338 req = list_entry(sclp_req_queue.next, struct sclp_req, list); 339 if (!req->sccb) 340 goto do_post; 341 rc = __sclp_start_request(req); 342 if (rc == 0) 343 break; 344 /* Request failed */ 345 if (req->start_count > 1) { 346 /* Cannot abort already submitted request - could still 347 * be active at the SCLP */ 348 __sclp_set_request_timer(SCLP_BUSY_INTERVAL * HZ, 349 sclp_request_timeout, 0); 350 break; 351 } 352do_post: 353 /* Post-processing for aborted request */ 354 list_del(&req->list); 355 if (req->callback) { 356 spin_unlock_irqrestore(&sclp_lock, flags); 357 req->callback(req, req->callback_data); 358 spin_lock_irqsave(&sclp_lock, flags); 359 } 360 } 361 spin_unlock_irqrestore(&sclp_lock, flags); 362} 363 364static int __sclp_can_add_request(struct sclp_req *req) 365{ 366 if (req == &sclp_suspend_req || req == &sclp_init_req) 367 return 1; 368 if (sclp_suspend_state != sclp_suspend_state_running) 369 return 0; 370 if (sclp_init_state != sclp_init_state_initialized) 371 return 0; 372 if (sclp_activation_state != sclp_activation_state_active) 373 return 0; 374 return 1; 375} 376 377/* Queue a new request. Return zero on success, non-zero otherwise. */ 378int 379sclp_add_request(struct sclp_req *req) 380{ 381 unsigned long flags; 382 int rc; 383 384 spin_lock_irqsave(&sclp_lock, flags); 385 if (!__sclp_can_add_request(req)) { 386 spin_unlock_irqrestore(&sclp_lock, flags); 387 return -EIO; 388 } 389 req->status = SCLP_REQ_QUEUED; 390 req->start_count = 0; 391 list_add_tail(&req->list, &sclp_req_queue); 392 rc = 0; 393 if (req->queue_timeout) { 394 req->queue_expires = jiffies + req->queue_timeout * HZ; 395 if (!timer_pending(&sclp_queue_timer) || 396 time_after(sclp_queue_timer.expires, req->queue_expires)) 397 mod_timer(&sclp_queue_timer, req->queue_expires); 398 } else 399 req->queue_expires = 0; 400 /* Start if request is first in list */ 401 if (sclp_running_state == sclp_running_state_idle && 402 req->list.prev == &sclp_req_queue) { 403 if (!req->sccb) { 404 list_del(&req->list); 405 rc = -ENODATA; 406 goto out; 407 } 408 rc = __sclp_start_request(req); 409 if (rc) 410 list_del(&req->list); 411 } 412out: 413 spin_unlock_irqrestore(&sclp_lock, flags); 414 return rc; 415} 416 417EXPORT_SYMBOL(sclp_add_request); 418 419/* Dispatch events found in request buffer to registered listeners. Return 0 420 * if all events were dispatched, non-zero otherwise. */ 421static int 422sclp_dispatch_evbufs(struct sccb_header *sccb) 423{ 424 unsigned long flags; 425 struct evbuf_header *evbuf; 426 struct list_head *l; 427 struct sclp_register *reg; 428 int offset; 429 int rc; 430 431 spin_lock_irqsave(&sclp_lock, flags); 432 rc = 0; 433 for (offset = sizeof(struct sccb_header); offset < sccb->length; 434 offset += evbuf->length) { 435 evbuf = (struct evbuf_header *) ((addr_t) sccb + offset); 436 /* Check for malformed hardware response */ 437 if (evbuf->length == 0) 438 break; 439 /* Search for event handler */ 440 reg = NULL; 441 list_for_each(l, &sclp_reg_list) { 442 reg = list_entry(l, struct sclp_register, list); 443 if (reg->receive_mask & (1 << (32 - evbuf->type))) 444 break; 445 else 446 reg = NULL; 447 } 448 if (reg && reg->receiver_fn) { 449 spin_unlock_irqrestore(&sclp_lock, flags); 450 reg->receiver_fn(evbuf); 451 spin_lock_irqsave(&sclp_lock, flags); 452 } else if (reg == NULL) 453 rc = -EOPNOTSUPP; 454 } 455 spin_unlock_irqrestore(&sclp_lock, flags); 456 return rc; 457} 458 459/* Read event data request callback. */ 460static void 461sclp_read_cb(struct sclp_req *req, void *data) 462{ 463 unsigned long flags; 464 struct sccb_header *sccb; 465 466 sccb = (struct sccb_header *) req->sccb; 467 if (req->status == SCLP_REQ_DONE && (sccb->response_code == 0x20 || 468 sccb->response_code == 0x220)) 469 sclp_dispatch_evbufs(sccb); 470 spin_lock_irqsave(&sclp_lock, flags); 471 sclp_reading_state = sclp_reading_state_idle; 472 spin_unlock_irqrestore(&sclp_lock, flags); 473} 474 475/* Prepare read event data request. Called while sclp_lock is locked. */ 476static void __sclp_make_read_req(void) 477{ 478 struct sccb_header *sccb; 479 480 sccb = (struct sccb_header *) sclp_read_sccb; 481 clear_page(sccb); 482 memset(&sclp_read_req, 0, sizeof(struct sclp_req)); 483 sclp_read_req.command = SCLP_CMDW_READ_EVENT_DATA; 484 sclp_read_req.status = SCLP_REQ_QUEUED; 485 sclp_read_req.start_count = 0; 486 sclp_read_req.callback = sclp_read_cb; 487 sclp_read_req.sccb = sccb; 488 sccb->length = PAGE_SIZE; 489 sccb->function_code = 0; 490 sccb->control_mask[2] = 0x80; 491} 492 493/* Search request list for request with matching sccb. Return request if found, 494 * NULL otherwise. Called while sclp_lock is locked. */ 495static inline struct sclp_req * 496__sclp_find_req(u32 sccb) 497{ 498 struct list_head *l; 499 struct sclp_req *req; 500 501 list_for_each(l, &sclp_req_queue) { 502 req = list_entry(l, struct sclp_req, list); 503 if (sccb == (u32) (addr_t) req->sccb) 504 return req; 505 } 506 return NULL; 507} 508 509/* Handler for external interruption. Perform request post-processing. 510 * Prepare read event data request if necessary. Start processing of next 511 * request on queue. */ 512static void sclp_interrupt_handler(struct ext_code ext_code, 513 unsigned int param32, unsigned long param64) 514{ 515 struct sclp_req *req; 516 u32 finished_sccb; 517 u32 evbuf_pending; 518 519 inc_irq_stat(IRQEXT_SCP); 520 spin_lock(&sclp_lock); 521 finished_sccb = param32 & 0xfffffff8; 522 evbuf_pending = param32 & 0x3; 523 if (finished_sccb) { 524 del_timer(&sclp_request_timer); 525 sclp_running_state = sclp_running_state_reset_pending; 526 req = __sclp_find_req(finished_sccb); 527 if (req) { 528 /* Request post-processing */ 529 list_del(&req->list); 530 req->status = SCLP_REQ_DONE; 531 if (req->callback) { 532 spin_unlock(&sclp_lock); 533 req->callback(req, req->callback_data); 534 spin_lock(&sclp_lock); 535 } 536 } 537 sclp_running_state = sclp_running_state_idle; 538 } 539 if (evbuf_pending && 540 sclp_activation_state == sclp_activation_state_active) 541 __sclp_queue_read_req(); 542 spin_unlock(&sclp_lock); 543 sclp_process_queue(); 544} 545 546/* Convert interval in jiffies to TOD ticks. */ 547static inline u64 548sclp_tod_from_jiffies(unsigned long jiffies) 549{ 550 return (u64) (jiffies / HZ) << 32; 551} 552 553/* Wait until a currently running request finished. Note: while this function 554 * is running, no timers are served on the calling CPU. */ 555void 556sclp_sync_wait(void) 557{ 558 unsigned long long old_tick; 559 unsigned long flags; 560 unsigned long cr0, cr0_sync; 561 u64 timeout; 562 int irq_context; 563 564 /* We'll be disabling timer interrupts, so we need a custom timeout 565 * mechanism */ 566 timeout = 0; 567 if (timer_pending(&sclp_request_timer)) { 568 /* Get timeout TOD value */ 569 timeout = get_tod_clock_fast() + 570 sclp_tod_from_jiffies(sclp_request_timer.expires - 571 jiffies); 572 } 573 local_irq_save(flags); 574 /* Prevent bottom half from executing once we force interrupts open */ 575 irq_context = in_interrupt(); 576 if (!irq_context) 577 local_bh_disable(); 578 /* Enable service-signal interruption, disable timer interrupts */ 579 old_tick = local_tick_disable(); 580 trace_hardirqs_on(); 581 __ctl_store(cr0, 0, 0); 582 cr0_sync = cr0; 583 cr0_sync &= 0xffff00a0; 584 cr0_sync |= 0x00000200; 585 __ctl_load(cr0_sync, 0, 0); 586 __arch_local_irq_stosm(0x01); 587 /* Loop until driver state indicates finished request */ 588 while (sclp_running_state != sclp_running_state_idle) { 589 /* Check for expired request timer */ 590 if (timer_pending(&sclp_request_timer) && 591 get_tod_clock_fast() > timeout && 592 del_timer(&sclp_request_timer)) 593 sclp_request_timer.function(sclp_request_timer.data); 594 cpu_relax(); 595 } 596 local_irq_disable(); 597 __ctl_load(cr0, 0, 0); 598 if (!irq_context) 599 _local_bh_enable(); 600 local_tick_enable(old_tick); 601 local_irq_restore(flags); 602} 603EXPORT_SYMBOL(sclp_sync_wait); 604 605/* Dispatch changes in send and receive mask to registered listeners. */ 606static void 607sclp_dispatch_state_change(void) 608{ 609 struct list_head *l; 610 struct sclp_register *reg; 611 unsigned long flags; 612 sccb_mask_t receive_mask; 613 sccb_mask_t send_mask; 614 615 do { 616 spin_lock_irqsave(&sclp_lock, flags); 617 reg = NULL; 618 list_for_each(l, &sclp_reg_list) { 619 reg = list_entry(l, struct sclp_register, list); 620 receive_mask = reg->send_mask & sclp_receive_mask; 621 send_mask = reg->receive_mask & sclp_send_mask; 622 if (reg->sclp_receive_mask != receive_mask || 623 reg->sclp_send_mask != send_mask) { 624 reg->sclp_receive_mask = receive_mask; 625 reg->sclp_send_mask = send_mask; 626 break; 627 } else 628 reg = NULL; 629 } 630 spin_unlock_irqrestore(&sclp_lock, flags); 631 if (reg && reg->state_change_fn) 632 reg->state_change_fn(reg); 633 } while (reg); 634} 635 636struct sclp_statechangebuf { 637 struct evbuf_header header; 638 u8 validity_sclp_active_facility_mask : 1; 639 u8 validity_sclp_receive_mask : 1; 640 u8 validity_sclp_send_mask : 1; 641 u8 validity_read_data_function_mask : 1; 642 u16 _zeros : 12; 643 u16 mask_length; 644 u64 sclp_active_facility_mask; 645 sccb_mask_t sclp_receive_mask; 646 sccb_mask_t sclp_send_mask; 647 u32 read_data_function_mask; 648} __attribute__((packed)); 649 650 651/* State change event callback. Inform listeners of changes. */ 652static void 653sclp_state_change_cb(struct evbuf_header *evbuf) 654{ 655 unsigned long flags; 656 struct sclp_statechangebuf *scbuf; 657 658 scbuf = (struct sclp_statechangebuf *) evbuf; 659 if (scbuf->mask_length != sizeof(sccb_mask_t)) 660 return; 661 spin_lock_irqsave(&sclp_lock, flags); 662 if (scbuf->validity_sclp_receive_mask) 663 sclp_receive_mask = scbuf->sclp_receive_mask; 664 if (scbuf->validity_sclp_send_mask) 665 sclp_send_mask = scbuf->sclp_send_mask; 666 spin_unlock_irqrestore(&sclp_lock, flags); 667 if (scbuf->validity_sclp_active_facility_mask) 668 sclp_facilities = scbuf->sclp_active_facility_mask; 669 sclp_dispatch_state_change(); 670} 671 672static struct sclp_register sclp_state_change_event = { 673 .receive_mask = EVTYP_STATECHANGE_MASK, 674 .receiver_fn = sclp_state_change_cb 675}; 676 677/* Calculate receive and send mask of currently registered listeners. 678 * Called while sclp_lock is locked. */ 679static inline void 680__sclp_get_mask(sccb_mask_t *receive_mask, sccb_mask_t *send_mask) 681{ 682 struct list_head *l; 683 struct sclp_register *t; 684 685 *receive_mask = 0; 686 *send_mask = 0; 687 list_for_each(l, &sclp_reg_list) { 688 t = list_entry(l, struct sclp_register, list); 689 *receive_mask |= t->receive_mask; 690 *send_mask |= t->send_mask; 691 } 692} 693 694/* Register event listener. Return 0 on success, non-zero otherwise. */ 695int 696sclp_register(struct sclp_register *reg) 697{ 698 unsigned long flags; 699 sccb_mask_t receive_mask; 700 sccb_mask_t send_mask; 701 int rc; 702 703 rc = sclp_init(); 704 if (rc) 705 return rc; 706 spin_lock_irqsave(&sclp_lock, flags); 707 /* Check event mask for collisions */ 708 __sclp_get_mask(&receive_mask, &send_mask); 709 if (reg->receive_mask & receive_mask || reg->send_mask & send_mask) { 710 spin_unlock_irqrestore(&sclp_lock, flags); 711 return -EBUSY; 712 } 713 /* Trigger initial state change callback */ 714 reg->sclp_receive_mask = 0; 715 reg->sclp_send_mask = 0; 716 reg->pm_event_posted = 0; 717 list_add(®->list, &sclp_reg_list); 718 spin_unlock_irqrestore(&sclp_lock, flags); 719 rc = sclp_init_mask(1); 720 if (rc) { 721 spin_lock_irqsave(&sclp_lock, flags); 722 list_del(®->list); 723 spin_unlock_irqrestore(&sclp_lock, flags); 724 } 725 return rc; 726} 727 728EXPORT_SYMBOL(sclp_register); 729 730/* Unregister event listener. */ 731void 732sclp_unregister(struct sclp_register *reg) 733{ 734 unsigned long flags; 735 736 spin_lock_irqsave(&sclp_lock, flags); 737 list_del(®->list); 738 spin_unlock_irqrestore(&sclp_lock, flags); 739 sclp_init_mask(1); 740} 741 742EXPORT_SYMBOL(sclp_unregister); 743 744/* Remove event buffers which are marked processed. Return the number of 745 * remaining event buffers. */ 746int 747sclp_remove_processed(struct sccb_header *sccb) 748{ 749 struct evbuf_header *evbuf; 750 int unprocessed; 751 u16 remaining; 752 753 evbuf = (struct evbuf_header *) (sccb + 1); 754 unprocessed = 0; 755 remaining = sccb->length - sizeof(struct sccb_header); 756 while (remaining > 0) { 757 remaining -= evbuf->length; 758 if (evbuf->flags & 0x80) { 759 sccb->length -= evbuf->length; 760 memcpy(evbuf, (void *) ((addr_t) evbuf + evbuf->length), 761 remaining); 762 } else { 763 unprocessed++; 764 evbuf = (struct evbuf_header *) 765 ((addr_t) evbuf + evbuf->length); 766 } 767 } 768 return unprocessed; 769} 770 771EXPORT_SYMBOL(sclp_remove_processed); 772 773/* Prepare init mask request. Called while sclp_lock is locked. */ 774static inline void 775__sclp_make_init_req(u32 receive_mask, u32 send_mask) 776{ 777 struct init_sccb *sccb; 778 779 sccb = (struct init_sccb *) sclp_init_sccb; 780 clear_page(sccb); 781 memset(&sclp_init_req, 0, sizeof(struct sclp_req)); 782 sclp_init_req.command = SCLP_CMDW_WRITE_EVENT_MASK; 783 sclp_init_req.status = SCLP_REQ_FILLED; 784 sclp_init_req.start_count = 0; 785 sclp_init_req.callback = NULL; 786 sclp_init_req.callback_data = NULL; 787 sclp_init_req.sccb = sccb; 788 sccb->header.length = sizeof(struct init_sccb); 789 sccb->mask_length = sizeof(sccb_mask_t); 790 sccb->receive_mask = receive_mask; 791 sccb->send_mask = send_mask; 792 sccb->sclp_receive_mask = 0; 793 sccb->sclp_send_mask = 0; 794} 795 796/* Start init mask request. If calculate is non-zero, calculate the mask as 797 * requested by registered listeners. Use zero mask otherwise. Return 0 on 798 * success, non-zero otherwise. */ 799static int 800sclp_init_mask(int calculate) 801{ 802 unsigned long flags; 803 struct init_sccb *sccb = (struct init_sccb *) sclp_init_sccb; 804 sccb_mask_t receive_mask; 805 sccb_mask_t send_mask; 806 int retry; 807 int rc; 808 unsigned long wait; 809 810 spin_lock_irqsave(&sclp_lock, flags); 811 /* Check if interface is in appropriate state */ 812 if (sclp_mask_state != sclp_mask_state_idle) { 813 spin_unlock_irqrestore(&sclp_lock, flags); 814 return -EBUSY; 815 } 816 if (sclp_activation_state == sclp_activation_state_inactive) { 817 spin_unlock_irqrestore(&sclp_lock, flags); 818 return -EINVAL; 819 } 820 sclp_mask_state = sclp_mask_state_initializing; 821 /* Determine mask */ 822 if (calculate) 823 __sclp_get_mask(&receive_mask, &send_mask); 824 else { 825 receive_mask = 0; 826 send_mask = 0; 827 } 828 rc = -EIO; 829 for (retry = 0; retry <= SCLP_MASK_RETRY; retry++) { 830 /* Prepare request */ 831 __sclp_make_init_req(receive_mask, send_mask); 832 spin_unlock_irqrestore(&sclp_lock, flags); 833 if (sclp_add_request(&sclp_init_req)) { 834 /* Try again later */ 835 wait = jiffies + SCLP_BUSY_INTERVAL * HZ; 836 while (time_before(jiffies, wait)) 837 sclp_sync_wait(); 838 spin_lock_irqsave(&sclp_lock, flags); 839 continue; 840 } 841 while (sclp_init_req.status != SCLP_REQ_DONE && 842 sclp_init_req.status != SCLP_REQ_FAILED) 843 sclp_sync_wait(); 844 spin_lock_irqsave(&sclp_lock, flags); 845 if (sclp_init_req.status == SCLP_REQ_DONE && 846 sccb->header.response_code == 0x20) { 847 /* Successful request */ 848 if (calculate) { 849 sclp_receive_mask = sccb->sclp_receive_mask; 850 sclp_send_mask = sccb->sclp_send_mask; 851 } else { 852 sclp_receive_mask = 0; 853 sclp_send_mask = 0; 854 } 855 spin_unlock_irqrestore(&sclp_lock, flags); 856 sclp_dispatch_state_change(); 857 spin_lock_irqsave(&sclp_lock, flags); 858 rc = 0; 859 break; 860 } 861 } 862 sclp_mask_state = sclp_mask_state_idle; 863 spin_unlock_irqrestore(&sclp_lock, flags); 864 return rc; 865} 866 867/* Deactivate SCLP interface. On success, new requests will be rejected, 868 * events will no longer be dispatched. Return 0 on success, non-zero 869 * otherwise. */ 870int 871sclp_deactivate(void) 872{ 873 unsigned long flags; 874 int rc; 875 876 spin_lock_irqsave(&sclp_lock, flags); 877 /* Deactivate can only be called when active */ 878 if (sclp_activation_state != sclp_activation_state_active) { 879 spin_unlock_irqrestore(&sclp_lock, flags); 880 return -EINVAL; 881 } 882 sclp_activation_state = sclp_activation_state_deactivating; 883 spin_unlock_irqrestore(&sclp_lock, flags); 884 rc = sclp_init_mask(0); 885 spin_lock_irqsave(&sclp_lock, flags); 886 if (rc == 0) 887 sclp_activation_state = sclp_activation_state_inactive; 888 else 889 sclp_activation_state = sclp_activation_state_active; 890 spin_unlock_irqrestore(&sclp_lock, flags); 891 return rc; 892} 893 894EXPORT_SYMBOL(sclp_deactivate); 895 896/* Reactivate SCLP interface after sclp_deactivate. On success, new 897 * requests will be accepted, events will be dispatched again. Return 0 on 898 * success, non-zero otherwise. */ 899int 900sclp_reactivate(void) 901{ 902 unsigned long flags; 903 int rc; 904 905 spin_lock_irqsave(&sclp_lock, flags); 906 /* Reactivate can only be called when inactive */ 907 if (sclp_activation_state != sclp_activation_state_inactive) { 908 spin_unlock_irqrestore(&sclp_lock, flags); 909 return -EINVAL; 910 } 911 sclp_activation_state = sclp_activation_state_activating; 912 spin_unlock_irqrestore(&sclp_lock, flags); 913 rc = sclp_init_mask(1); 914 spin_lock_irqsave(&sclp_lock, flags); 915 if (rc == 0) 916 sclp_activation_state = sclp_activation_state_active; 917 else 918 sclp_activation_state = sclp_activation_state_inactive; 919 spin_unlock_irqrestore(&sclp_lock, flags); 920 return rc; 921} 922 923EXPORT_SYMBOL(sclp_reactivate); 924 925/* Handler for external interruption used during initialization. Modify 926 * request state to done. */ 927static void sclp_check_handler(struct ext_code ext_code, 928 unsigned int param32, unsigned long param64) 929{ 930 u32 finished_sccb; 931 932 inc_irq_stat(IRQEXT_SCP); 933 finished_sccb = param32 & 0xfffffff8; 934 /* Is this the interrupt we are waiting for? */ 935 if (finished_sccb == 0) 936 return; 937 if (finished_sccb != (u32) (addr_t) sclp_init_sccb) 938 panic("sclp: unsolicited interrupt for buffer at 0x%x\n", 939 finished_sccb); 940 spin_lock(&sclp_lock); 941 if (sclp_running_state == sclp_running_state_running) { 942 sclp_init_req.status = SCLP_REQ_DONE; 943 sclp_running_state = sclp_running_state_idle; 944 } 945 spin_unlock(&sclp_lock); 946} 947 948/* Initial init mask request timed out. Modify request state to failed. */ 949static void 950sclp_check_timeout(unsigned long data) 951{ 952 unsigned long flags; 953 954 spin_lock_irqsave(&sclp_lock, flags); 955 if (sclp_running_state == sclp_running_state_running) { 956 sclp_init_req.status = SCLP_REQ_FAILED; 957 sclp_running_state = sclp_running_state_idle; 958 } 959 spin_unlock_irqrestore(&sclp_lock, flags); 960} 961 962/* Perform a check of the SCLP interface. Return zero if the interface is 963 * available and there are no pending requests from a previous instance. 964 * Return non-zero otherwise. */ 965static int 966sclp_check_interface(void) 967{ 968 struct init_sccb *sccb; 969 unsigned long flags; 970 int retry; 971 int rc; 972 973 spin_lock_irqsave(&sclp_lock, flags); 974 /* Prepare init mask command */ 975 rc = register_external_irq(EXT_IRQ_SERVICE_SIG, sclp_check_handler); 976 if (rc) { 977 spin_unlock_irqrestore(&sclp_lock, flags); 978 return rc; 979 } 980 for (retry = 0; retry <= SCLP_INIT_RETRY; retry++) { 981 __sclp_make_init_req(0, 0); 982 sccb = (struct init_sccb *) sclp_init_req.sccb; 983 rc = sclp_service_call(sclp_init_req.command, sccb); 984 if (rc == -EIO) 985 break; 986 sclp_init_req.status = SCLP_REQ_RUNNING; 987 sclp_running_state = sclp_running_state_running; 988 __sclp_set_request_timer(SCLP_RETRY_INTERVAL * HZ, 989 sclp_check_timeout, 0); 990 spin_unlock_irqrestore(&sclp_lock, flags); 991 /* Enable service-signal interruption - needs to happen 992 * with IRQs enabled. */ 993 irq_subclass_register(IRQ_SUBCLASS_SERVICE_SIGNAL); 994 /* Wait for signal from interrupt or timeout */ 995 sclp_sync_wait(); 996 /* Disable service-signal interruption - needs to happen 997 * with IRQs enabled. */ 998 irq_subclass_unregister(IRQ_SUBCLASS_SERVICE_SIGNAL); 999 spin_lock_irqsave(&sclp_lock, flags); 1000 del_timer(&sclp_request_timer); 1001 if (sclp_init_req.status == SCLP_REQ_DONE && 1002 sccb->header.response_code == 0x20) { 1003 rc = 0; 1004 break; 1005 } else 1006 rc = -EBUSY; 1007 } 1008 unregister_external_irq(EXT_IRQ_SERVICE_SIG, sclp_check_handler); 1009 spin_unlock_irqrestore(&sclp_lock, flags); 1010 return rc; 1011} 1012 1013/* Reboot event handler. Reset send and receive mask to prevent pending SCLP 1014 * events from interfering with rebooted system. */ 1015static int 1016sclp_reboot_event(struct notifier_block *this, unsigned long event, void *ptr) 1017{ 1018 sclp_deactivate(); 1019 return NOTIFY_DONE; 1020} 1021 1022static struct notifier_block sclp_reboot_notifier = { 1023 .notifier_call = sclp_reboot_event 1024}; 1025 1026/* 1027 * Suspend/resume SCLP notifier implementation 1028 */ 1029 1030static void sclp_pm_event(enum sclp_pm_event sclp_pm_event, int rollback) 1031{ 1032 struct sclp_register *reg; 1033 unsigned long flags; 1034 1035 if (!rollback) { 1036 spin_lock_irqsave(&sclp_lock, flags); 1037 list_for_each_entry(reg, &sclp_reg_list, list) 1038 reg->pm_event_posted = 0; 1039 spin_unlock_irqrestore(&sclp_lock, flags); 1040 } 1041 do { 1042 spin_lock_irqsave(&sclp_lock, flags); 1043 list_for_each_entry(reg, &sclp_reg_list, list) { 1044 if (rollback && reg->pm_event_posted) 1045 goto found; 1046 if (!rollback && !reg->pm_event_posted) 1047 goto found; 1048 } 1049 spin_unlock_irqrestore(&sclp_lock, flags); 1050 return; 1051found: 1052 spin_unlock_irqrestore(&sclp_lock, flags); 1053 if (reg->pm_event_fn) 1054 reg->pm_event_fn(reg, sclp_pm_event); 1055 reg->pm_event_posted = rollback ? 0 : 1; 1056 } while (1); 1057} 1058 1059/* 1060 * Susend/resume callbacks for platform device 1061 */ 1062 1063static int sclp_freeze(struct device *dev) 1064{ 1065 unsigned long flags; 1066 int rc; 1067 1068 sclp_pm_event(SCLP_PM_EVENT_FREEZE, 0); 1069 1070 spin_lock_irqsave(&sclp_lock, flags); 1071 sclp_suspend_state = sclp_suspend_state_suspended; 1072 spin_unlock_irqrestore(&sclp_lock, flags); 1073 1074 /* Init supend data */ 1075 memset(&sclp_suspend_req, 0, sizeof(sclp_suspend_req)); 1076 sclp_suspend_req.callback = sclp_suspend_req_cb; 1077 sclp_suspend_req.status = SCLP_REQ_FILLED; 1078 init_completion(&sclp_request_queue_flushed); 1079 1080 rc = sclp_add_request(&sclp_suspend_req); 1081 if (rc == 0) 1082 wait_for_completion(&sclp_request_queue_flushed); 1083 else if (rc != -ENODATA) 1084 goto fail_thaw; 1085 1086 rc = sclp_deactivate(); 1087 if (rc) 1088 goto fail_thaw; 1089 return 0; 1090 1091fail_thaw: 1092 spin_lock_irqsave(&sclp_lock, flags); 1093 sclp_suspend_state = sclp_suspend_state_running; 1094 spin_unlock_irqrestore(&sclp_lock, flags); 1095 sclp_pm_event(SCLP_PM_EVENT_THAW, 1); 1096 return rc; 1097} 1098 1099static int sclp_undo_suspend(enum sclp_pm_event event) 1100{ 1101 unsigned long flags; 1102 int rc; 1103 1104 rc = sclp_reactivate(); 1105 if (rc) 1106 return rc; 1107 1108 spin_lock_irqsave(&sclp_lock, flags); 1109 sclp_suspend_state = sclp_suspend_state_running; 1110 spin_unlock_irqrestore(&sclp_lock, flags); 1111 1112 sclp_pm_event(event, 0); 1113 return 0; 1114} 1115 1116static int sclp_thaw(struct device *dev) 1117{ 1118 return sclp_undo_suspend(SCLP_PM_EVENT_THAW); 1119} 1120 1121static int sclp_restore(struct device *dev) 1122{ 1123 return sclp_undo_suspend(SCLP_PM_EVENT_RESTORE); 1124} 1125 1126static const struct dev_pm_ops sclp_pm_ops = { 1127 .freeze = sclp_freeze, 1128 .thaw = sclp_thaw, 1129 .restore = sclp_restore, 1130}; 1131 1132static ssize_t sclp_show_console_pages(struct device_driver *dev, char *buf) 1133{ 1134 return sprintf(buf, "%i\n", sclp_console_pages); 1135} 1136 1137static DRIVER_ATTR(con_pages, S_IRUSR, sclp_show_console_pages, NULL); 1138 1139static ssize_t sclp_show_con_drop(struct device_driver *dev, char *buf) 1140{ 1141 return sprintf(buf, "%i\n", sclp_console_drop); 1142} 1143 1144static DRIVER_ATTR(con_drop, S_IRUSR, sclp_show_con_drop, NULL); 1145 1146static ssize_t sclp_show_console_full(struct device_driver *dev, char *buf) 1147{ 1148 return sprintf(buf, "%lu\n", sclp_console_full); 1149} 1150 1151static DRIVER_ATTR(con_full, S_IRUSR, sclp_show_console_full, NULL); 1152 1153static struct attribute *sclp_drv_attrs[] = { 1154 &driver_attr_con_pages.attr, 1155 &driver_attr_con_drop.attr, 1156 &driver_attr_con_full.attr, 1157 NULL, 1158}; 1159static struct attribute_group sclp_drv_attr_group = { 1160 .attrs = sclp_drv_attrs, 1161}; 1162static const struct attribute_group *sclp_drv_attr_groups[] = { 1163 &sclp_drv_attr_group, 1164 NULL, 1165}; 1166 1167static struct platform_driver sclp_pdrv = { 1168 .driver = { 1169 .name = "sclp", 1170 .pm = &sclp_pm_ops, 1171 .groups = sclp_drv_attr_groups, 1172 }, 1173}; 1174 1175static struct platform_device *sclp_pdev; 1176 1177/* Initialize SCLP driver. Return zero if driver is operational, non-zero 1178 * otherwise. */ 1179static int 1180sclp_init(void) 1181{ 1182 unsigned long flags; 1183 int rc = 0; 1184 1185 spin_lock_irqsave(&sclp_lock, flags); 1186 /* Check for previous or running initialization */ 1187 if (sclp_init_state != sclp_init_state_uninitialized) 1188 goto fail_unlock; 1189 sclp_init_state = sclp_init_state_initializing; 1190 /* Set up variables */ 1191 INIT_LIST_HEAD(&sclp_req_queue); 1192 INIT_LIST_HEAD(&sclp_reg_list); 1193 list_add(&sclp_state_change_event.list, &sclp_reg_list); 1194 init_timer(&sclp_request_timer); 1195 init_timer(&sclp_queue_timer); 1196 sclp_queue_timer.function = sclp_req_queue_timeout; 1197 /* Check interface */ 1198 spin_unlock_irqrestore(&sclp_lock, flags); 1199 rc = sclp_check_interface(); 1200 spin_lock_irqsave(&sclp_lock, flags); 1201 if (rc) 1202 goto fail_init_state_uninitialized; 1203 /* Register reboot handler */ 1204 rc = register_reboot_notifier(&sclp_reboot_notifier); 1205 if (rc) 1206 goto fail_init_state_uninitialized; 1207 /* Register interrupt handler */ 1208 rc = register_external_irq(EXT_IRQ_SERVICE_SIG, sclp_interrupt_handler); 1209 if (rc) 1210 goto fail_unregister_reboot_notifier; 1211 sclp_init_state = sclp_init_state_initialized; 1212 spin_unlock_irqrestore(&sclp_lock, flags); 1213 /* Enable service-signal external interruption - needs to happen with 1214 * IRQs enabled. */ 1215 irq_subclass_register(IRQ_SUBCLASS_SERVICE_SIGNAL); 1216 sclp_init_mask(1); 1217 return 0; 1218 1219fail_unregister_reboot_notifier: 1220 unregister_reboot_notifier(&sclp_reboot_notifier); 1221fail_init_state_uninitialized: 1222 sclp_init_state = sclp_init_state_uninitialized; 1223fail_unlock: 1224 spin_unlock_irqrestore(&sclp_lock, flags); 1225 return rc; 1226} 1227 1228/* 1229 * SCLP panic notifier: If we are suspended, we thaw SCLP in order to be able 1230 * to print the panic message. 1231 */ 1232static int sclp_panic_notify(struct notifier_block *self, 1233 unsigned long event, void *data) 1234{ 1235 if (sclp_suspend_state == sclp_suspend_state_suspended) 1236 sclp_undo_suspend(SCLP_PM_EVENT_THAW); 1237 return NOTIFY_OK; 1238} 1239 1240static struct notifier_block sclp_on_panic_nb = { 1241 .notifier_call = sclp_panic_notify, 1242 .priority = SCLP_PANIC_PRIO, 1243}; 1244 1245static __init int sclp_initcall(void) 1246{ 1247 int rc; 1248 1249 rc = platform_driver_register(&sclp_pdrv); 1250 if (rc) 1251 return rc; 1252 1253 sclp_pdev = platform_device_register_simple("sclp", -1, NULL, 0); 1254 rc = PTR_ERR_OR_ZERO(sclp_pdev); 1255 if (rc) 1256 goto fail_platform_driver_unregister; 1257 1258 rc = atomic_notifier_chain_register(&panic_notifier_list, 1259 &sclp_on_panic_nb); 1260 if (rc) 1261 goto fail_platform_device_unregister; 1262 1263 return sclp_init(); 1264 1265fail_platform_device_unregister: 1266 platform_device_unregister(sclp_pdev); 1267fail_platform_driver_unregister: 1268 platform_driver_unregister(&sclp_pdrv); 1269 return rc; 1270} 1271 1272arch_initcall(sclp_initcall); 1273