drivers/char/ipmi/ipmi_si

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This source file includes following definitions.
debug_timestamp
register_xaction_notifier
deliver_recv_msg
return_hosed_msg
start_next_msg
smi_mod_timer
start_new_msg
start_check_enables
start_clear_flags
start_getting_msg_queue
start_getting_events
disable_si_irq
enable_si_irq
alloc_msg_handle_irq
handle_flags
current_global_enables
check_bt_irq
handle_transaction_done
smi_event_handler
check_start_timer_thread
flush_messages
sender
set_run_to_completion
ipmi_si_set_not_busy
ipmi_si_is_busy
ipmi_thread_busy_wait
ipmi_thread
poll
request_events
set_need_watch
smi_timeout
ipmi_si_irq_handler
smi_start_processing
get_smi_info
set_maintenance_mode
ipmi_irq_finish_setup
ipmi_irq_start_cleanup
std_irq_cleanup
ipmi_std_irq_setup
wait_for_msg_done
try_get_dev_id
get_global_enables
set_global_enables
check_clr_rcv_irq
check_set_rcv_irq
try_enable_event_buffer
type_show
interrupts_enabled_show
params_show
oem_data_avail_to_receive_msg_avail
setup_dell_poweredge_oem_data_handler
return_hosed_msg_badsize
dell_poweredge_bt_xaction_handler
setup_dell_poweredge_bt_xaction_handler
setup_oem_data_handler
setup_xaction_handlers
check_for_broken_irqs
stop_timer_and_thread
find_dup_si
ipmi_si_add_smi
try_smi_init
init_ipmi_si
shutdown_smi
cleanup_one_si
ipmi_si_remove_by_dev
ipmi_si_remove_by_data
cleanup_ipmi_si
   1 // SPDX-License-Identifier: GPL-2.0+
   2 /*
   3  * ipmi_si.c
   4  *
   5  * The interface to the IPMI driver for the system interfaces (KCS, SMIC,
   6  * BT).
   7  *
   8  * Author: MontaVista Software, Inc.
   9  *         Corey Minyard <minyard@mvista.com>
  10  *         source@mvista.com
  11  *
  12  * Copyright 2002 MontaVista Software Inc.
  13  * Copyright 2006 IBM Corp., Christian Krafft <krafft@de.ibm.com>
  14  */
  15 
  16 /*
  17  * This file holds the "policy" for the interface to the SMI state
  18  * machine.  It does the configuration, handles timers and interrupts,
  19  * and drives the real SMI state machine.
  20  */
  21 
  22 #define pr_fmt(fmt) "ipmi_si: " fmt
  23 
  24 #include <linux/module.h>
  25 #include <linux/moduleparam.h>
  26 #include <linux/sched.h>
  27 #include <linux/seq_file.h>
  28 #include <linux/timer.h>
  29 #include <linux/errno.h>
  30 #include <linux/spinlock.h>
  31 #include <linux/slab.h>
  32 #include <linux/delay.h>
  33 #include <linux/list.h>
  34 #include <linux/notifier.h>
  35 #include <linux/mutex.h>
  36 #include <linux/kthread.h>
  37 #include <asm/irq.h>
  38 #include <linux/interrupt.h>
  39 #include <linux/rcupdate.h>
  40 #include <linux/ipmi.h>
  41 #include <linux/ipmi_smi.h>
  42 #include "ipmi_si.h"
  43 #include "ipmi_si_sm.h"
  44 #include <linux/string.h>
  45 #include <linux/ctype.h>
  46 
  47 /* Measure times between events in the driver. */
  48 #undef DEBUG_TIMING
  49 
  50 /* Call every 10 ms. */
  51 #define SI_TIMEOUT_TIME_USEC    10000
  52 #define SI_USEC_PER_JIFFY       (1000000/HZ)
  53 #define SI_TIMEOUT_JIFFIES      (SI_TIMEOUT_TIME_USEC/SI_USEC_PER_JIFFY)
  54 #define SI_SHORT_TIMEOUT_USEC  250 /* .25ms when the SM request a
  55                                       short timeout */
  56 
  57 enum si_intf_state {
  58         SI_NORMAL,
  59         SI_GETTING_FLAGS,
  60         SI_GETTING_EVENTS,
  61         SI_CLEARING_FLAGS,
  62         SI_GETTING_MESSAGES,
  63         SI_CHECKING_ENABLES,
  64         SI_SETTING_ENABLES
  65         /* FIXME - add watchdog stuff. */
  66 };
  67 
  68 /* Some BT-specific defines we need here. */
  69 #define IPMI_BT_INTMASK_REG             2
  70 #define IPMI_BT_INTMASK_CLEAR_IRQ_BIT   2
  71 #define IPMI_BT_INTMASK_ENABLE_IRQ_BIT  1
  72 
  73 static const char * const si_to_str[] = { "invalid", "kcs", "smic", "bt" };
  74 
  75 static bool initialized;
  76 
  77 /*
  78  * Indexes into stats[] in smi_info below.
  79  */
  80 enum si_stat_indexes {
  81         /*
  82          * Number of times the driver requested a timer while an operation
  83          * was in progress.
  84          */
  85         SI_STAT_short_timeouts = 0,
  86 
  87         /*
  88          * Number of times the driver requested a timer while nothing was in
  89          * progress.
  90          */
  91         SI_STAT_long_timeouts,
  92 
  93         /* Number of times the interface was idle while being polled. */
  94         SI_STAT_idles,
  95 
  96         /* Number of interrupts the driver handled. */
  97         SI_STAT_interrupts,
  98 
  99         /* Number of time the driver got an ATTN from the hardware. */
 100         SI_STAT_attentions,
 101 
 102         /* Number of times the driver requested flags from the hardware. */
 103         SI_STAT_flag_fetches,
 104 
 105         /* Number of times the hardware didn't follow the state machine. */
 106         SI_STAT_hosed_count,
 107 
 108         /* Number of completed messages. */
 109         SI_STAT_complete_transactions,
 110 
 111         /* Number of IPMI events received from the hardware. */
 112         SI_STAT_events,
 113 
 114         /* Number of watchdog pretimeouts. */
 115         SI_STAT_watchdog_pretimeouts,
 116 
 117         /* Number of asynchronous messages received. */
 118         SI_STAT_incoming_messages,
 119 
 120 
 121         /* This *must* remain last, add new values above this. */
 122         SI_NUM_STATS
 123 };
 124 
 125 struct smi_info {
 126         int                    si_num;
 127         struct ipmi_smi        *intf;
 128         struct si_sm_data      *si_sm;
 129         const struct si_sm_handlers *handlers;
 130         spinlock_t             si_lock;
 131         struct ipmi_smi_msg    *waiting_msg;
 132         struct ipmi_smi_msg    *curr_msg;
 133         enum si_intf_state     si_state;
 134 
 135         /*
 136          * Used to handle the various types of I/O that can occur with
 137          * IPMI
 138          */
 139         struct si_sm_io io;
 140 
 141         /*
 142          * Per-OEM handler, called from handle_flags().  Returns 1
 143          * when handle_flags() needs to be re-run or 0 indicating it
 144          * set si_state itself.
 145          */
 146         int (*oem_data_avail_handler)(struct smi_info *smi_info);
 147 
 148         /*
 149          * Flags from the last GET_MSG_FLAGS command, used when an ATTN
 150          * is set to hold the flags until we are done handling everything
 151          * from the flags.
 152          */
 153 #define RECEIVE_MSG_AVAIL       0x01
 154 #define EVENT_MSG_BUFFER_FULL   0x02
 155 #define WDT_PRE_TIMEOUT_INT     0x08
 156 #define OEM0_DATA_AVAIL     0x20
 157 #define OEM1_DATA_AVAIL     0x40
 158 #define OEM2_DATA_AVAIL     0x80
 159 #define OEM_DATA_AVAIL      (OEM0_DATA_AVAIL | \
 160                              OEM1_DATA_AVAIL | \
 161                              OEM2_DATA_AVAIL)
 162         unsigned char       msg_flags;
 163 
 164         /* Does the BMC have an event buffer? */
 165         bool                has_event_buffer;
 166 
 167         /*
 168          * If set to true, this will request events the next time the
 169          * state machine is idle.
 170          */
 171         atomic_t            req_events;
 172 
 173         /*
 174          * If true, run the state machine to completion on every send
 175          * call.  Generally used after a panic to make sure stuff goes
 176          * out.
 177          */
 178         bool                run_to_completion;
 179 
 180         /* The timer for this si. */
 181         struct timer_list   si_timer;
 182 
 183         /* This flag is set, if the timer can be set */
 184         bool                timer_can_start;
 185 
 186         /* This flag is set, if the timer is running (timer_pending() isn't enough) */
 187         bool                timer_running;
 188 
 189         /* The time (in jiffies) the last timeout occurred at. */
 190         unsigned long       last_timeout_jiffies;
 191 
 192         /* Are we waiting for the events, pretimeouts, received msgs? */
 193         atomic_t            need_watch;
 194 
 195         /*
 196          * The driver will disable interrupts when it gets into a
 197          * situation where it cannot handle messages due to lack of
 198          * memory.  Once that situation clears up, it will re-enable
 199          * interrupts.
 200          */
 201         bool interrupt_disabled;
 202 
 203         /*
 204          * Does the BMC support events?
 205          */
 206         bool supports_event_msg_buff;
 207 
 208         /*
 209          * Can we disable interrupts the global enables receive irq
 210          * bit?  There are currently two forms of brokenness, some
 211          * systems cannot disable the bit (which is technically within
 212          * the spec but a bad idea) and some systems have the bit
 213          * forced to zero even though interrupts work (which is
 214          * clearly outside the spec).  The next bool tells which form
 215          * of brokenness is present.
 216          */
 217         bool cannot_disable_irq;
 218 
 219         /*
 220          * Some systems are broken and cannot set the irq enable
 221          * bit, even if they support interrupts.
 222          */
 223         bool irq_enable_broken;
 224 
 225         /* Is the driver in maintenance mode? */
 226         bool in_maintenance_mode;
 227 
 228         /*
 229          * Did we get an attention that we did not handle?
 230          */
 231         bool got_attn;
 232 
 233         /* From the get device id response... */
 234         struct ipmi_device_id device_id;
 235 
 236         /* Have we added the device group to the device? */
 237         bool dev_group_added;
 238 
 239         /* Counters and things for the proc filesystem. */
 240         atomic_t stats[SI_NUM_STATS];
 241 
 242         struct task_struct *thread;
 243 
 244         struct list_head link;
 245 };
 246 
 247 #define smi_inc_stat(smi, stat) \
 248         atomic_inc(&(smi)->stats[SI_STAT_ ## stat])
 249 #define smi_get_stat(smi, stat) \
 250         ((unsigned int) atomic_read(&(smi)->stats[SI_STAT_ ## stat]))
 251 
 252 #define IPMI_MAX_INTFS 4
 253 static int force_kipmid[IPMI_MAX_INTFS];
 254 static int num_force_kipmid;
 255 
 256 static unsigned int kipmid_max_busy_us[IPMI_MAX_INTFS];
 257 static int num_max_busy_us;
 258 
 259 static bool unload_when_empty = true;
 260 
 261 static int try_smi_init(struct smi_info *smi);
 262 static void cleanup_one_si(struct smi_info *smi_info);
 263 static void cleanup_ipmi_si(void);
 264 
 265 #ifdef DEBUG_TIMING
 266 void debug_timestamp(char *msg)
 267 {
 268         struct timespec t;
 269 
 270         ktime_get_ts(&t);
 271         pr_debug("**%s: %ld.%9.9ld\n", msg, (long) t.tv_sec, t.tv_nsec);
 272 }
 273 #else
 274 #define debug_timestamp(x)
 275 #endif
 276 
 277 static ATOMIC_NOTIFIER_HEAD(xaction_notifier_list);
 278 static int register_xaction_notifier(struct notifier_block *nb)
 279 {
 280         return atomic_notifier_chain_register(&xaction_notifier_list, nb);
 281 }
 282 
 283 static void deliver_recv_msg(struct smi_info *smi_info,
 284                              struct ipmi_smi_msg *msg)
 285 {
 286         /* Deliver the message to the upper layer. */
 287         ipmi_smi_msg_received(smi_info->intf, msg);
 288 }
 289 
 290 static void return_hosed_msg(struct smi_info *smi_info, int cCode)
 291 {
 292         struct ipmi_smi_msg *msg = smi_info->curr_msg;
 293 
 294         if (cCode < 0 || cCode > IPMI_ERR_UNSPECIFIED)
 295                 cCode = IPMI_ERR_UNSPECIFIED;
 296         /* else use it as is */
 297 
 298         /* Make it a response */
 299         msg->rsp[0] = msg->data[0] | 4;
 300         msg->rsp[1] = msg->data[1];
 301         msg->rsp[2] = cCode;
 302         msg->rsp_size = 3;
 303 
 304         smi_info->curr_msg = NULL;
 305         deliver_recv_msg(smi_info, msg);
 306 }
 307 
 308 static enum si_sm_result start_next_msg(struct smi_info *smi_info)
 309 {
 310         int              rv;
 311 
 312         if (!smi_info->waiting_msg) {
 313                 smi_info->curr_msg = NULL;
 314                 rv = SI_SM_IDLE;
 315         } else {
 316                 int err;
 317 
 318                 smi_info->curr_msg = smi_info->waiting_msg;
 319                 smi_info->waiting_msg = NULL;
 320                 debug_timestamp("Start2");
 321                 err = atomic_notifier_call_chain(&xaction_notifier_list,
 322                                 0, smi_info);
 323                 if (err & NOTIFY_STOP_MASK) {
 324                         rv = SI_SM_CALL_WITHOUT_DELAY;
 325                         goto out;
 326                 }
 327                 err = smi_info->handlers->start_transaction(
 328                         smi_info->si_sm,
 329                         smi_info->curr_msg->data,
 330                         smi_info->curr_msg->data_size);
 331                 if (err)
 332                         return_hosed_msg(smi_info, err);
 333 
 334                 rv = SI_SM_CALL_WITHOUT_DELAY;
 335         }
 336 out:
 337         return rv;
 338 }
 339 
 340 static void smi_mod_timer(struct smi_info *smi_info, unsigned long new_val)
 341 {
 342         if (!smi_info->timer_can_start)
 343                 return;
 344         smi_info->last_timeout_jiffies = jiffies;
 345         mod_timer(&smi_info->si_timer, new_val);
 346         smi_info->timer_running = true;
 347 }
 348 
 349 /*
 350  * Start a new message and (re)start the timer and thread.
 351  */
 352 static void start_new_msg(struct smi_info *smi_info, unsigned char *msg,
 353                           unsigned int size)
 354 {
 355         smi_mod_timer(smi_info, jiffies + SI_TIMEOUT_JIFFIES);
 356 
 357         if (smi_info->thread)
 358                 wake_up_process(smi_info->thread);
 359 
 360         smi_info->handlers->start_transaction(smi_info->si_sm, msg, size);
 361 }
 362 
 363 static void start_check_enables(struct smi_info *smi_info)
 364 {
 365         unsigned char msg[2];
 366 
 367         msg[0] = (IPMI_NETFN_APP_REQUEST << 2);
 368         msg[1] = IPMI_GET_BMC_GLOBAL_ENABLES_CMD;
 369 
 370         start_new_msg(smi_info, msg, 2);
 371         smi_info->si_state = SI_CHECKING_ENABLES;
 372 }
 373 
 374 static void start_clear_flags(struct smi_info *smi_info)
 375 {
 376         unsigned char msg[3];
 377 
 378         /* Make sure the watchdog pre-timeout flag is not set at startup. */
 379         msg[0] = (IPMI_NETFN_APP_REQUEST << 2);
 380         msg[1] = IPMI_CLEAR_MSG_FLAGS_CMD;
 381         msg[2] = WDT_PRE_TIMEOUT_INT;
 382 
 383         start_new_msg(smi_info, msg, 3);
 384         smi_info->si_state = SI_CLEARING_FLAGS;
 385 }
 386 
 387 static void start_getting_msg_queue(struct smi_info *smi_info)
 388 {
 389         smi_info->curr_msg->data[0] = (IPMI_NETFN_APP_REQUEST << 2);
 390         smi_info->curr_msg->data[1] = IPMI_GET_MSG_CMD;
 391         smi_info->curr_msg->data_size = 2;
 392 
 393         start_new_msg(smi_info, smi_info->curr_msg->data,
 394                       smi_info->curr_msg->data_size);
 395         smi_info->si_state = SI_GETTING_MESSAGES;
 396 }
 397 
 398 static void start_getting_events(struct smi_info *smi_info)
 399 {
 400         smi_info->curr_msg->data[0] = (IPMI_NETFN_APP_REQUEST << 2);
 401         smi_info->curr_msg->data[1] = IPMI_READ_EVENT_MSG_BUFFER_CMD;
 402         smi_info->curr_msg->data_size = 2;
 403 
 404         start_new_msg(smi_info, smi_info->curr_msg->data,
 405                       smi_info->curr_msg->data_size);
 406         smi_info->si_state = SI_GETTING_EVENTS;
 407 }
 408 
 409 /*
 410  * When we have a situtaion where we run out of memory and cannot
 411  * allocate messages, we just leave them in the BMC and run the system
 412  * polled until we can allocate some memory.  Once we have some
 413  * memory, we will re-enable the interrupt.
 414  *
 415  * Note that we cannot just use disable_irq(), since the interrupt may
 416  * be shared.
 417  */
 418 static inline bool disable_si_irq(struct smi_info *smi_info)
 419 {
 420         if ((smi_info->io.irq) && (!smi_info->interrupt_disabled)) {
 421                 smi_info->interrupt_disabled = true;
 422                 start_check_enables(smi_info);
 423                 return true;
 424         }
 425         return false;
 426 }
 427 
 428 static inline bool enable_si_irq(struct smi_info *smi_info)
 429 {
 430         if ((smi_info->io.irq) && (smi_info->interrupt_disabled)) {
 431                 smi_info->interrupt_disabled = false;
 432                 start_check_enables(smi_info);
 433                 return true;
 434         }
 435         return false;
 436 }
 437 
 438 /*
 439  * Allocate a message.  If unable to allocate, start the interrupt
 440  * disable process and return NULL.  If able to allocate but
 441  * interrupts are disabled, free the message and return NULL after
 442  * starting the interrupt enable process.
 443  */
 444 static struct ipmi_smi_msg *alloc_msg_handle_irq(struct smi_info *smi_info)
 445 {
 446         struct ipmi_smi_msg *msg;
 447 
 448         msg = ipmi_alloc_smi_msg();
 449         if (!msg) {
 450                 if (!disable_si_irq(smi_info))
 451                         smi_info->si_state = SI_NORMAL;
 452         } else if (enable_si_irq(smi_info)) {
 453                 ipmi_free_smi_msg(msg);
 454                 msg = NULL;
 455         }
 456         return msg;
 457 }
 458 
 459 static void handle_flags(struct smi_info *smi_info)
 460 {
 461 retry:
 462         if (smi_info->msg_flags & WDT_PRE_TIMEOUT_INT) {
 463                 /* Watchdog pre-timeout */
 464                 smi_inc_stat(smi_info, watchdog_pretimeouts);
 465 
 466                 start_clear_flags(smi_info);
 467                 smi_info->msg_flags &= ~WDT_PRE_TIMEOUT_INT;
 468                 ipmi_smi_watchdog_pretimeout(smi_info->intf);
 469         } else if (smi_info->msg_flags & RECEIVE_MSG_AVAIL) {
 470                 /* Messages available. */
 471                 smi_info->curr_msg = alloc_msg_handle_irq(smi_info);
 472                 if (!smi_info->curr_msg)
 473                         return;
 474 
 475                 start_getting_msg_queue(smi_info);
 476         } else if (smi_info->msg_flags & EVENT_MSG_BUFFER_FULL) {
 477                 /* Events available. */
 478                 smi_info->curr_msg = alloc_msg_handle_irq(smi_info);
 479                 if (!smi_info->curr_msg)
 480                         return;
 481 
 482                 start_getting_events(smi_info);
 483         } else if (smi_info->msg_flags & OEM_DATA_AVAIL &&
 484                    smi_info->oem_data_avail_handler) {
 485                 if (smi_info->oem_data_avail_handler(smi_info))
 486                         goto retry;
 487         } else
 488                 smi_info->si_state = SI_NORMAL;
 489 }
 490 
 491 /*
 492  * Global enables we care about.
 493  */
 494 #define GLOBAL_ENABLES_MASK (IPMI_BMC_EVT_MSG_BUFF | IPMI_BMC_RCV_MSG_INTR | \
 495                              IPMI_BMC_EVT_MSG_INTR)
 496 
 497 static u8 current_global_enables(struct smi_info *smi_info, u8 base,
 498                                  bool *irq_on)
 499 {
 500         u8 enables = 0;
 501 
 502         if (smi_info->supports_event_msg_buff)
 503                 enables |= IPMI_BMC_EVT_MSG_BUFF;
 504 
 505         if (((smi_info->io.irq && !smi_info->interrupt_disabled) ||
 506              smi_info->cannot_disable_irq) &&
 507             !smi_info->irq_enable_broken)
 508                 enables |= IPMI_BMC_RCV_MSG_INTR;
 509 
 510         if (smi_info->supports_event_msg_buff &&
 511             smi_info->io.irq && !smi_info->interrupt_disabled &&
 512             !smi_info->irq_enable_broken)
 513                 enables |= IPMI_BMC_EVT_MSG_INTR;
 514 
 515         *irq_on = enables & (IPMI_BMC_EVT_MSG_INTR | IPMI_BMC_RCV_MSG_INTR);
 516 
 517         return enables;
 518 }
 519 
 520 static void check_bt_irq(struct smi_info *smi_info, bool irq_on)
 521 {
 522         u8 irqstate = smi_info->io.inputb(&smi_info->io, IPMI_BT_INTMASK_REG);
 523 
 524         irqstate &= IPMI_BT_INTMASK_ENABLE_IRQ_BIT;
 525 
 526         if ((bool)irqstate == irq_on)
 527                 return;
 528 
 529         if (irq_on)
 530                 smi_info->io.outputb(&smi_info->io, IPMI_BT_INTMASK_REG,
 531                                      IPMI_BT_INTMASK_ENABLE_IRQ_BIT);
 532         else
 533                 smi_info->io.outputb(&smi_info->io, IPMI_BT_INTMASK_REG, 0);
 534 }
 535 
 536 static void handle_transaction_done(struct smi_info *smi_info)
 537 {
 538         struct ipmi_smi_msg *msg;
 539 
 540         debug_timestamp("Done");
 541         switch (smi_info->si_state) {
 542         case SI_NORMAL:
 543                 if (!smi_info->curr_msg)
 544                         break;
 545 
 546                 smi_info->curr_msg->rsp_size
 547                         = smi_info->handlers->get_result(
 548                                 smi_info->si_sm,
 549                                 smi_info->curr_msg->rsp,
 550                                 IPMI_MAX_MSG_LENGTH);
 551 
 552                 /*
 553                  * Do this here becase deliver_recv_msg() releases the
 554                  * lock, and a new message can be put in during the
 555                  * time the lock is released.
 556                  */
 557                 msg = smi_info->curr_msg;
 558                 smi_info->curr_msg = NULL;
 559                 deliver_recv_msg(smi_info, msg);
 560                 break;
 561 
 562         case SI_GETTING_FLAGS:
 563         {
 564                 unsigned char msg[4];
 565                 unsigned int  len;
 566 
 567                 /* We got the flags from the SMI, now handle them. */
 568                 len = smi_info->handlers->get_result(smi_info->si_sm, msg, 4);
 569                 if (msg[2] != 0) {
 570                         /* Error fetching flags, just give up for now. */
 571                         smi_info->si_state = SI_NORMAL;
 572                 } else if (len < 4) {
 573                         /*
 574                          * Hmm, no flags.  That's technically illegal, but
 575                          * don't use uninitialized data.
 576                          */
 577                         smi_info->si_state = SI_NORMAL;
 578                 } else {
 579                         smi_info->msg_flags = msg[3];
 580                         handle_flags(smi_info);
 581                 }
 582                 break;
 583         }
 584 
 585         case SI_CLEARING_FLAGS:
 586         {
 587                 unsigned char msg[3];
 588 
 589                 /* We cleared the flags. */
 590                 smi_info->handlers->get_result(smi_info->si_sm, msg, 3);
 591                 if (msg[2] != 0) {
 592                         /* Error clearing flags */
 593                         dev_warn(smi_info->io.dev,
 594                                  "Error clearing flags: %2.2x\n", msg[2]);
 595                 }
 596                 smi_info->si_state = SI_NORMAL;
 597                 break;
 598         }
 599 
 600         case SI_GETTING_EVENTS:
 601         {
 602                 smi_info->curr_msg->rsp_size
 603                         = smi_info->handlers->get_result(
 604                                 smi_info->si_sm,
 605                                 smi_info->curr_msg->rsp,
 606                                 IPMI_MAX_MSG_LENGTH);
 607 
 608                 /*
 609                  * Do this here becase deliver_recv_msg() releases the
 610                  * lock, and a new message can be put in during the
 611                  * time the lock is released.
 612                  */
 613                 msg = smi_info->curr_msg;
 614                 smi_info->curr_msg = NULL;
 615                 if (msg->rsp[2] != 0) {
 616                         /* Error getting event, probably done. */
 617                         msg->done(msg);
 618 
 619                         /* Take off the event flag. */
 620                         smi_info->msg_flags &= ~EVENT_MSG_BUFFER_FULL;
 621                         handle_flags(smi_info);
 622                 } else {
 623                         smi_inc_stat(smi_info, events);
 624 
 625                         /*
 626                          * Do this before we deliver the message
 627                          * because delivering the message releases the
 628                          * lock and something else can mess with the
 629                          * state.
 630                          */
 631                         handle_flags(smi_info);
 632 
 633                         deliver_recv_msg(smi_info, msg);
 634                 }
 635                 break;
 636         }
 637 
 638         case SI_GETTING_MESSAGES:
 639         {
 640                 smi_info->curr_msg->rsp_size
 641                         = smi_info->handlers->get_result(
 642                                 smi_info->si_sm,
 643                                 smi_info->curr_msg->rsp,
 644                                 IPMI_MAX_MSG_LENGTH);
 645 
 646                 /*
 647                  * Do this here becase deliver_recv_msg() releases the
 648                  * lock, and a new message can be put in during the
 649                  * time the lock is released.
 650                  */
 651                 msg = smi_info->curr_msg;
 652                 smi_info->curr_msg = NULL;
 653                 if (msg->rsp[2] != 0) {
 654                         /* Error getting event, probably done. */
 655                         msg->done(msg);
 656 
 657                         /* Take off the msg flag. */
 658                         smi_info->msg_flags &= ~RECEIVE_MSG_AVAIL;
 659                         handle_flags(smi_info);
 660                 } else {
 661                         smi_inc_stat(smi_info, incoming_messages);
 662 
 663                         /*
 664                          * Do this before we deliver the message
 665                          * because delivering the message releases the
 666                          * lock and something else can mess with the
 667                          * state.
 668                          */
 669                         handle_flags(smi_info);
 670 
 671                         deliver_recv_msg(smi_info, msg);
 672                 }
 673                 break;
 674         }
 675 
 676         case SI_CHECKING_ENABLES:
 677         {
 678                 unsigned char msg[4];
 679                 u8 enables;
 680                 bool irq_on;
 681 
 682                 /* We got the flags from the SMI, now handle them. */
 683                 smi_info->handlers->get_result(smi_info->si_sm, msg, 4);
 684                 if (msg[2] != 0) {
 685                         dev_warn(smi_info->io.dev,
 686                                  "Couldn't get irq info: %x.\n", msg[2]);
 687                         dev_warn(smi_info->io.dev,
 688                                  "Maybe ok, but ipmi might run very slowly.\n");
 689                         smi_info->si_state = SI_NORMAL;
 690                         break;
 691                 }
 692                 enables = current_global_enables(smi_info, 0, &irq_on);
 693                 if (smi_info->io.si_type == SI_BT)
 694                         /* BT has its own interrupt enable bit. */
 695                         check_bt_irq(smi_info, irq_on);
 696                 if (enables != (msg[3] & GLOBAL_ENABLES_MASK)) {
 697                         /* Enables are not correct, fix them. */
 698                         msg[0] = (IPMI_NETFN_APP_REQUEST << 2);
 699                         msg[1] = IPMI_SET_BMC_GLOBAL_ENABLES_CMD;
 700                         msg[2] = enables | (msg[3] & ~GLOBAL_ENABLES_MASK);
 701                         smi_info->handlers->start_transaction(
 702                                 smi_info->si_sm, msg, 3);
 703                         smi_info->si_state = SI_SETTING_ENABLES;
 704                 } else if (smi_info->supports_event_msg_buff) {
 705                         smi_info->curr_msg = ipmi_alloc_smi_msg();
 706                         if (!smi_info->curr_msg) {
 707                                 smi_info->si_state = SI_NORMAL;
 708                                 break;
 709                         }
 710                         start_getting_events(smi_info);
 711                 } else {
 712                         smi_info->si_state = SI_NORMAL;
 713                 }
 714                 break;
 715         }
 716 
 717         case SI_SETTING_ENABLES:
 718         {
 719                 unsigned char msg[4];
 720 
 721                 smi_info->handlers->get_result(smi_info->si_sm, msg, 4);
 722                 if (msg[2] != 0)
 723                         dev_warn(smi_info->io.dev,
 724                                  "Could not set the global enables: 0x%x.\n",
 725                                  msg[2]);
 726 
 727                 if (smi_info->supports_event_msg_buff) {
 728                         smi_info->curr_msg = ipmi_alloc_smi_msg();
 729                         if (!smi_info->curr_msg) {
 730                                 smi_info->si_state = SI_NORMAL;
 731                                 break;
 732                         }
 733                         start_getting_events(smi_info);
 734                 } else {
 735                         smi_info->si_state = SI_NORMAL;
 736                 }
 737                 break;
 738         }
 739         }
 740 }
 741 
 742 /*
 743  * Called on timeouts and events.  Timeouts should pass the elapsed
 744  * time, interrupts should pass in zero.  Must be called with
 745  * si_lock held and interrupts disabled.
 746  */
 747 static enum si_sm_result smi_event_handler(struct smi_info *smi_info,
 748                                            int time)
 749 {
 750         enum si_sm_result si_sm_result;
 751 
 752 restart:
 753         /*
 754          * There used to be a loop here that waited a little while
 755          * (around 25us) before giving up.  That turned out to be
 756          * pointless, the minimum delays I was seeing were in the 300us
 757          * range, which is far too long to wait in an interrupt.  So
 758          * we just run until the state machine tells us something
 759          * happened or it needs a delay.
 760          */
 761         si_sm_result = smi_info->handlers->event(smi_info->si_sm, time);
 762         time = 0;
 763         while (si_sm_result == SI_SM_CALL_WITHOUT_DELAY)
 764                 si_sm_result = smi_info->handlers->event(smi_info->si_sm, 0);
 765 
 766         if (si_sm_result == SI_SM_TRANSACTION_COMPLETE) {
 767                 smi_inc_stat(smi_info, complete_transactions);
 768 
 769                 handle_transaction_done(smi_info);
 770                 goto restart;
 771         } else if (si_sm_result == SI_SM_HOSED) {
 772                 smi_inc_stat(smi_info, hosed_count);
 773 
 774                 /*
 775                  * Do the before return_hosed_msg, because that
 776                  * releases the lock.
 777                  */
 778                 smi_info->si_state = SI_NORMAL;
 779                 if (smi_info->curr_msg != NULL) {
 780                         /*
 781                          * If we were handling a user message, format
 782                          * a response to send to the upper layer to
 783                          * tell it about the error.
 784                          */
 785                         return_hosed_msg(smi_info, IPMI_ERR_UNSPECIFIED);
 786                 }
 787                 goto restart;
 788         }
 789 
 790         /*
 791          * We prefer handling attn over new messages.  But don't do
 792          * this if there is not yet an upper layer to handle anything.
 793          */
 794         if (si_sm_result == SI_SM_ATTN || smi_info->got_attn) {
 795                 unsigned char msg[2];
 796 
 797                 if (smi_info->si_state != SI_NORMAL) {
 798                         /*
 799                          * We got an ATTN, but we are doing something else.
 800                          * Handle the ATTN later.
 801                          */
 802                         smi_info->got_attn = true;
 803                 } else {
 804                         smi_info->got_attn = false;
 805                         smi_inc_stat(smi_info, attentions);
 806 
 807                         /*
 808                          * Got a attn, send down a get message flags to see
 809                          * what's causing it.  It would be better to handle
 810                          * this in the upper layer, but due to the way
 811                          * interrupts work with the SMI, that's not really
 812                          * possible.
 813                          */
 814                         msg[0] = (IPMI_NETFN_APP_REQUEST << 2);
 815                         msg[1] = IPMI_GET_MSG_FLAGS_CMD;
 816 
 817                         start_new_msg(smi_info, msg, 2);
 818                         smi_info->si_state = SI_GETTING_FLAGS;
 819                         goto restart;
 820                 }
 821         }
 822 
 823         /* If we are currently idle, try to start the next message. */
 824         if (si_sm_result == SI_SM_IDLE) {
 825                 smi_inc_stat(smi_info, idles);
 826 
 827                 si_sm_result = start_next_msg(smi_info);
 828                 if (si_sm_result != SI_SM_IDLE)
 829                         goto restart;
 830         }
 831 
 832         if ((si_sm_result == SI_SM_IDLE)
 833             && (atomic_read(&smi_info->req_events))) {
 834                 /*
 835                  * We are idle and the upper layer requested that I fetch
 836                  * events, so do so.
 837                  */
 838                 atomic_set(&smi_info->req_events, 0);
 839 
 840                 /*
 841                  * Take this opportunity to check the interrupt and
 842                  * message enable state for the BMC.  The BMC can be
 843                  * asynchronously reset, and may thus get interrupts
 844                  * disable and messages disabled.
 845                  */
 846                 if (smi_info->supports_event_msg_buff || smi_info->io.irq) {
 847                         start_check_enables(smi_info);
 848                 } else {
 849                         smi_info->curr_msg = alloc_msg_handle_irq(smi_info);
 850                         if (!smi_info->curr_msg)
 851                                 goto out;
 852 
 853                         start_getting_events(smi_info);
 854                 }
 855                 goto restart;
 856         }
 857 
 858         if (si_sm_result == SI_SM_IDLE && smi_info->timer_running) {
 859                 /* Ok it if fails, the timer will just go off. */
 860                 if (del_timer(&smi_info->si_timer))
 861                         smi_info->timer_running = false;
 862         }
 863 
 864 out:
 865         return si_sm_result;
 866 }
 867 
 868 static void check_start_timer_thread(struct smi_info *smi_info)
 869 {
 870         if (smi_info->si_state == SI_NORMAL && smi_info->curr_msg == NULL) {
 871                 smi_mod_timer(smi_info, jiffies + SI_TIMEOUT_JIFFIES);
 872 
 873                 if (smi_info->thread)
 874                         wake_up_process(smi_info->thread);
 875 
 876                 start_next_msg(smi_info);
 877                 smi_event_handler(smi_info, 0);
 878         }
 879 }
 880 
 881 static void flush_messages(void *send_info)
 882 {
 883         struct smi_info *smi_info = send_info;
 884         enum si_sm_result result;
 885 
 886         /*
 887          * Currently, this function is called only in run-to-completion
 888          * mode.  This means we are single-threaded, no need for locks.
 889          */
 890         result = smi_event_handler(smi_info, 0);
 891         while (result != SI_SM_IDLE) {
 892                 udelay(SI_SHORT_TIMEOUT_USEC);
 893                 result = smi_event_handler(smi_info, SI_SHORT_TIMEOUT_USEC);
 894         }
 895 }
 896 
 897 static void sender(void                *send_info,
 898                    struct ipmi_smi_msg *msg)
 899 {
 900         struct smi_info   *smi_info = send_info;
 901         unsigned long     flags;
 902 
 903         debug_timestamp("Enqueue");
 904 
 905         if (smi_info->run_to_completion) {
 906                 /*
 907                  * If we are running to completion, start it.  Upper
 908                  * layer will call flush_messages to clear it out.
 909                  */
 910                 smi_info->waiting_msg = msg;
 911                 return;
 912         }
 913 
 914         spin_lock_irqsave(&smi_info->si_lock, flags);
 915         /*
 916          * The following two lines don't need to be under the lock for
 917          * the lock's sake, but they do need SMP memory barriers to
 918          * avoid getting things out of order.  We are already claiming
 919          * the lock, anyway, so just do it under the lock to avoid the
 920          * ordering problem.
 921          */
 922         BUG_ON(smi_info->waiting_msg);
 923         smi_info->waiting_msg = msg;
 924         check_start_timer_thread(smi_info);
 925         spin_unlock_irqrestore(&smi_info->si_lock, flags);
 926 }
 927 
 928 static void set_run_to_completion(void *send_info, bool i_run_to_completion)
 929 {
 930         struct smi_info   *smi_info = send_info;
 931 
 932         smi_info->run_to_completion = i_run_to_completion;
 933         if (i_run_to_completion)
 934                 flush_messages(smi_info);
 935 }
 936 
 937 /*
 938  * Use -1 in the nsec value of the busy waiting timespec to tell that
 939  * we are spinning in kipmid looking for something and not delaying
 940  * between checks
 941  */
 942 static inline void ipmi_si_set_not_busy(struct timespec *ts)
 943 {
 944         ts->tv_nsec = -1;
 945 }
 946 static inline int ipmi_si_is_busy(struct timespec *ts)
 947 {
 948         return ts->tv_nsec != -1;
 949 }
 950 
 951 static inline bool ipmi_thread_busy_wait(enum si_sm_result smi_result,
 952                                          const struct smi_info *smi_info,
 953                                          struct timespec *busy_until)
 954 {
 955         unsigned int max_busy_us = 0;
 956 
 957         if (smi_info->si_num < num_max_busy_us)
 958                 max_busy_us = kipmid_max_busy_us[smi_info->si_num];
 959         if (max_busy_us == 0 || smi_result != SI_SM_CALL_WITH_DELAY)
 960                 ipmi_si_set_not_busy(busy_until);
 961         else if (!ipmi_si_is_busy(busy_until)) {
 962                 ktime_get_ts(busy_until);
 963                 timespec_add_ns(busy_until, max_busy_us * NSEC_PER_USEC);
 964         } else {
 965                 struct timespec now;
 966 
 967                 ktime_get_ts(&now);
 968                 if (unlikely(timespec_compare(&now, busy_until) > 0)) {
 969                         ipmi_si_set_not_busy(busy_until);
 970                         return false;
 971                 }
 972         }
 973         return true;
 974 }
 975 
 976 
 977 /*
 978  * A busy-waiting loop for speeding up IPMI operation.
 979  *
 980  * Lousy hardware makes this hard.  This is only enabled for systems
 981  * that are not BT and do not have interrupts.  It starts spinning
 982  * when an operation is complete or until max_busy tells it to stop
 983  * (if that is enabled).  See the paragraph on kimid_max_busy_us in
 984  * Documentation/IPMI.txt for details.
 985  */
 986 static int ipmi_thread(void *data)
 987 {
 988         struct smi_info *smi_info = data;
 989         unsigned long flags;
 990         enum si_sm_result smi_result;
 991         struct timespec busy_until = { 0, 0 };
 992 
 993         ipmi_si_set_not_busy(&busy_until);
 994         set_user_nice(current, MAX_NICE);
 995         while (!kthread_should_stop()) {
 996                 int busy_wait;
 997 
 998                 spin_lock_irqsave(&(smi_info->si_lock), flags);
 999                 smi_result = smi_event_handler(smi_info, 0);
1000 
1001                 /*
1002                  * If the driver is doing something, there is a possible
1003                  * race with the timer.  If the timer handler see idle,
1004                  * and the thread here sees something else, the timer
1005                  * handler won't restart the timer even though it is
1006                  * required.  So start it here if necessary.
1007                  */
1008                 if (smi_result != SI_SM_IDLE && !smi_info->timer_running)
1009                         smi_mod_timer(smi_info, jiffies + SI_TIMEOUT_JIFFIES);
1010 
1011                 spin_unlock_irqrestore(&(smi_info->si_lock), flags);
1012                 busy_wait = ipmi_thread_busy_wait(smi_result, smi_info,
1013                                                   &busy_until);
1014                 if (smi_result == SI_SM_CALL_WITHOUT_DELAY) {
1015                         ; /* do nothing */
1016                 } else if (smi_result == SI_SM_CALL_WITH_DELAY && busy_wait) {
1017                         /*
1018                          * In maintenance mode we run as fast as
1019                          * possible to allow firmware updates to
1020                          * complete as fast as possible, but normally
1021                          * don't bang on the scheduler.
1022                          */
1023                         if (smi_info->in_maintenance_mode)
1024                                 schedule();
1025                         else
1026                                 usleep_range(100, 200);
1027                 } else if (smi_result == SI_SM_IDLE) {
1028                         if (atomic_read(&smi_info->need_watch)) {
1029                                 schedule_timeout_interruptible(100);
1030                         } else {
1031                                 /* Wait to be woken up when we are needed. */
1032                                 __set_current_state(TASK_INTERRUPTIBLE);
1033                                 schedule();
1034                         }
1035                 } else {
1036                         schedule_timeout_interruptible(1);
1037                 }
1038         }
1039         return 0;
1040 }
1041 
1042 
1043 static void poll(void *send_info)
1044 {
1045         struct smi_info *smi_info = send_info;
1046         unsigned long flags = 0;
1047         bool run_to_completion = smi_info->run_to_completion;
1048 
1049         /*
1050          * Make sure there is some delay in the poll loop so we can
1051          * drive time forward and timeout things.
1052          */
1053         udelay(10);
1054         if (!run_to_completion)
1055                 spin_lock_irqsave(&smi_info->si_lock, flags);
1056         smi_event_handler(smi_info, 10);
1057         if (!run_to_completion)
1058                 spin_unlock_irqrestore(&smi_info->si_lock, flags);
1059 }
1060 
1061 static void request_events(void *send_info)
1062 {
1063         struct smi_info *smi_info = send_info;
1064 
1065         if (!smi_info->has_event_buffer)
1066                 return;
1067 
1068         atomic_set(&smi_info->req_events, 1);
1069 }
1070 
1071 static void set_need_watch(void *send_info, unsigned int watch_mask)
1072 {
1073         struct smi_info *smi_info = send_info;
1074         unsigned long flags;
1075         int enable;
1076 
1077         enable = !!watch_mask;
1078 
1079         atomic_set(&smi_info->need_watch, enable);
1080         spin_lock_irqsave(&smi_info->si_lock, flags);
1081         check_start_timer_thread(smi_info);
1082         spin_unlock_irqrestore(&smi_info->si_lock, flags);
1083 }
1084 
1085 static void smi_timeout(struct timer_list *t)
1086 {
1087         struct smi_info   *smi_info = from_timer(smi_info, t, si_timer);
1088         enum si_sm_result smi_result;
1089         unsigned long     flags;
1090         unsigned long     jiffies_now;
1091         long              time_diff;
1092         long              timeout;
1093 
1094         spin_lock_irqsave(&(smi_info->si_lock), flags);
1095         debug_timestamp("Timer");
1096 
1097         jiffies_now = jiffies;
1098         time_diff = (((long)jiffies_now - (long)smi_info->last_timeout_jiffies)
1099                      * SI_USEC_PER_JIFFY);
1100         smi_result = smi_event_handler(smi_info, time_diff);
1101 
1102         if ((smi_info->io.irq) && (!smi_info->interrupt_disabled)) {
1103                 /* Running with interrupts, only do long timeouts. */
1104                 timeout = jiffies + SI_TIMEOUT_JIFFIES;
1105                 smi_inc_stat(smi_info, long_timeouts);
1106                 goto do_mod_timer;
1107         }
1108 
1109         /*
1110          * If the state machine asks for a short delay, then shorten
1111          * the timer timeout.
1112          */
1113         if (smi_result == SI_SM_CALL_WITH_DELAY) {
1114                 smi_inc_stat(smi_info, short_timeouts);
1115                 timeout = jiffies + 1;
1116         } else {
1117                 smi_inc_stat(smi_info, long_timeouts);
1118                 timeout = jiffies + SI_TIMEOUT_JIFFIES;
1119         }
1120 
1121 do_mod_timer:
1122         if (smi_result != SI_SM_IDLE)
1123                 smi_mod_timer(smi_info, timeout);
1124         else
1125                 smi_info->timer_running = false;
1126         spin_unlock_irqrestore(&(smi_info->si_lock), flags);
1127 }
1128 
1129 irqreturn_t ipmi_si_irq_handler(int irq, void *data)
1130 {
1131         struct smi_info *smi_info = data;
1132         unsigned long   flags;
1133 
1134         if (smi_info->io.si_type == SI_BT)
1135                 /* We need to clear the IRQ flag for the BT interface. */
1136                 smi_info->io.outputb(&smi_info->io, IPMI_BT_INTMASK_REG,
1137                                      IPMI_BT_INTMASK_CLEAR_IRQ_BIT
1138                                      | IPMI_BT_INTMASK_ENABLE_IRQ_BIT);
1139 
1140         spin_lock_irqsave(&(smi_info->si_lock), flags);
1141 
1142         smi_inc_stat(smi_info, interrupts);
1143 
1144         debug_timestamp("Interrupt");
1145 
1146         smi_event_handler(smi_info, 0);
1147         spin_unlock_irqrestore(&(smi_info->si_lock), flags);
1148         return IRQ_HANDLED;
1149 }
1150 
1151 static int smi_start_processing(void            *send_info,
1152                                 struct ipmi_smi *intf)
1153 {
1154         struct smi_info *new_smi = send_info;
1155         int             enable = 0;
1156 
1157         new_smi->intf = intf;
1158 
1159         /* Set up the timer that drives the interface. */
1160         timer_setup(&new_smi->si_timer, smi_timeout, 0);
1161         new_smi->timer_can_start = true;
1162         smi_mod_timer(new_smi, jiffies + SI_TIMEOUT_JIFFIES);
1163 
1164         /* Try to claim any interrupts. */
1165         if (new_smi->io.irq_setup) {
1166                 new_smi->io.irq_handler_data = new_smi;
1167                 new_smi->io.irq_setup(&new_smi->io);
1168         }
1169 
1170         /*
1171          * Check if the user forcefully enabled the daemon.
1172          */
1173         if (new_smi->si_num < num_force_kipmid)
1174                 enable = force_kipmid[new_smi->si_num];
1175         /*
1176          * The BT interface is efficient enough to not need a thread,
1177          * and there is no need for a thread if we have interrupts.
1178          */
1179         else if ((new_smi->io.si_type != SI_BT) && (!new_smi->io.irq))
1180                 enable = 1;
1181 
1182         if (enable) {
1183                 new_smi->thread = kthread_run(ipmi_thread, new_smi,
1184                                               "kipmi%d", new_smi->si_num);
1185                 if (IS_ERR(new_smi->thread)) {
1186                         dev_notice(new_smi->io.dev, "Could not start"
1187                                    " kernel thread due to error %ld, only using"
1188                                    " timers to drive the interface\n",
1189                                    PTR_ERR(new_smi->thread));
1190                         new_smi->thread = NULL;
1191                 }
1192         }
1193 
1194         return 0;
1195 }
1196 
1197 static int get_smi_info(void *send_info, struct ipmi_smi_info *data)
1198 {
1199         struct smi_info *smi = send_info;
1200 
1201         data->addr_src = smi->io.addr_source;
1202         data->dev = smi->io.dev;
1203         data->addr_info = smi->io.addr_info;
1204         get_device(smi->io.dev);
1205 
1206         return 0;
1207 }
1208 
1209 static void set_maintenance_mode(void *send_info, bool enable)
1210 {
1211         struct smi_info   *smi_info = send_info;
1212 
1213         if (!enable)
1214                 atomic_set(&smi_info->req_events, 0);
1215         smi_info->in_maintenance_mode = enable;
1216 }
1217 
1218 static void shutdown_smi(void *send_info);
1219 static const struct ipmi_smi_handlers handlers = {
1220         .owner                  = THIS_MODULE,
1221         .start_processing       = smi_start_processing,
1222         .shutdown               = shutdown_smi,
1223         .get_smi_info           = get_smi_info,
1224         .sender                 = sender,
1225         .request_events         = request_events,
1226         .set_need_watch         = set_need_watch,
1227         .set_maintenance_mode   = set_maintenance_mode,
1228         .set_run_to_completion  = set_run_to_completion,
1229         .flush_messages         = flush_messages,
1230         .poll                   = poll,
1231 };
1232 
1233 static LIST_HEAD(smi_infos);
1234 static DEFINE_MUTEX(smi_infos_lock);
1235 static int smi_num; /* Used to sequence the SMIs */
1236 
1237 static const char * const addr_space_to_str[] = { "i/o", "mem" };
1238 
1239 module_param_array(force_kipmid, int, &num_force_kipmid, 0);
1240 MODULE_PARM_DESC(force_kipmid, "Force the kipmi daemon to be enabled (1) or"
1241                  " disabled(0).  Normally the IPMI driver auto-detects"
1242                  " this, but the value may be overridden by this parm.");
1243 module_param(unload_when_empty, bool, 0);
1244 MODULE_PARM_DESC(unload_when_empty, "Unload the module if no interfaces are"
1245                  " specified or found, default is 1.  Setting to 0"
1246                  " is useful for hot add of devices using hotmod.");
1247 module_param_array(kipmid_max_busy_us, uint, &num_max_busy_us, 0644);
1248 MODULE_PARM_DESC(kipmid_max_busy_us,
1249                  "Max time (in microseconds) to busy-wait for IPMI data before"
1250                  " sleeping. 0 (default) means to wait forever. Set to 100-500"
1251                  " if kipmid is using up a lot of CPU time.");
1252 
1253 void ipmi_irq_finish_setup(struct si_sm_io *io)
1254 {
1255         if (io->si_type == SI_BT)
1256                 /* Enable the interrupt in the BT interface. */
1257                 io->outputb(io, IPMI_BT_INTMASK_REG,
1258                             IPMI_BT_INTMASK_ENABLE_IRQ_BIT);
1259 }
1260 
1261 void ipmi_irq_start_cleanup(struct si_sm_io *io)
1262 {
1263         if (io->si_type == SI_BT)
1264                 /* Disable the interrupt in the BT interface. */
1265                 io->outputb(io, IPMI_BT_INTMASK_REG, 0);
1266 }
1267 
1268 static void std_irq_cleanup(struct si_sm_io *io)
1269 {
1270         ipmi_irq_start_cleanup(io);
1271         free_irq(io->irq, io->irq_handler_data);
1272 }
1273 
1274 int ipmi_std_irq_setup(struct si_sm_io *io)
1275 {
1276         int rv;
1277 
1278         if (!io->irq)
1279                 return 0;
1280 
1281         rv = request_irq(io->irq,
1282                          ipmi_si_irq_handler,
1283                          IRQF_SHARED,
1284                          SI_DEVICE_NAME,
1285                          io->irq_handler_data);
1286         if (rv) {
1287                 dev_warn(io->dev, "%s unable to claim interrupt %d,"
1288                          " running polled\n",
1289                          SI_DEVICE_NAME, io->irq);
1290                 io->irq = 0;
1291         } else {
1292                 io->irq_cleanup = std_irq_cleanup;
1293                 ipmi_irq_finish_setup(io);
1294                 dev_info(io->dev, "Using irq %d\n", io->irq);
1295         }
1296 
1297         return rv;
1298 }
1299 
1300 static int wait_for_msg_done(struct smi_info *smi_info)
1301 {
1302         enum si_sm_result     smi_result;
1303 
1304         smi_result = smi_info->handlers->event(smi_info->si_sm, 0);
1305         for (;;) {
1306                 if (smi_result == SI_SM_CALL_WITH_DELAY ||
1307                     smi_result == SI_SM_CALL_WITH_TICK_DELAY) {
1308                         schedule_timeout_uninterruptible(1);
1309                         smi_result = smi_info->handlers->event(
1310                                 smi_info->si_sm, jiffies_to_usecs(1));
1311                 } else if (smi_result == SI_SM_CALL_WITHOUT_DELAY) {
1312                         smi_result = smi_info->handlers->event(
1313                                 smi_info->si_sm, 0);
1314                 } else
1315                         break;
1316         }
1317         if (smi_result == SI_SM_HOSED)
1318                 /*
1319                  * We couldn't get the state machine to run, so whatever's at
1320                  * the port is probably not an IPMI SMI interface.
1321                  */
1322                 return -ENODEV;
1323 
1324         return 0;
1325 }
1326 
1327 static int try_get_dev_id(struct smi_info *smi_info)
1328 {
1329         unsigned char         msg[2];
1330         unsigned char         *resp;
1331         unsigned long         resp_len;
1332         int                   rv = 0;
1333 
1334         resp = kmalloc(IPMI_MAX_MSG_LENGTH, GFP_KERNEL);
1335         if (!resp)
1336                 return -ENOMEM;
1337 
1338         /*
1339          * Do a Get Device ID command, since it comes back with some
1340          * useful info.
1341          */
1342         msg[0] = IPMI_NETFN_APP_REQUEST << 2;
1343         msg[1] = IPMI_GET_DEVICE_ID_CMD;
1344         smi_info->handlers->start_transaction(smi_info->si_sm, msg, 2);
1345 
1346         rv = wait_for_msg_done(smi_info);
1347         if (rv)
1348                 goto out;
1349 
1350         resp_len = smi_info->handlers->get_result(smi_info->si_sm,
1351                                                   resp, IPMI_MAX_MSG_LENGTH);
1352 
1353         /* Check and record info from the get device id, in case we need it. */
1354         rv = ipmi_demangle_device_id(resp[0] >> 2, resp[1],
1355                         resp + 2, resp_len - 2, &smi_info->device_id);
1356 
1357 out:
1358         kfree(resp);
1359         return rv;
1360 }
1361 
1362 static int get_global_enables(struct smi_info *smi_info, u8 *enables)
1363 {
1364         unsigned char         msg[3];
1365         unsigned char         *resp;
1366         unsigned long         resp_len;
1367         int                   rv;
1368 
1369         resp = kmalloc(IPMI_MAX_MSG_LENGTH, GFP_KERNEL);
1370         if (!resp)
1371                 return -ENOMEM;
1372 
1373         msg[0] = IPMI_NETFN_APP_REQUEST << 2;
1374         msg[1] = IPMI_GET_BMC_GLOBAL_ENABLES_CMD;
1375         smi_info->handlers->start_transaction(smi_info->si_sm, msg, 2);
1376 
1377         rv = wait_for_msg_done(smi_info);
1378         if (rv) {
1379                 dev_warn(smi_info->io.dev,
1380                          "Error getting response from get global enables command: %d\n",
1381                          rv);
1382                 goto out;
1383         }
1384 
1385         resp_len = smi_info->handlers->get_result(smi_info->si_sm,
1386                                                   resp, IPMI_MAX_MSG_LENGTH);
1387 
1388         if (resp_len < 4 ||
1389                         resp[0] != (IPMI_NETFN_APP_REQUEST | 1) << 2 ||
1390                         resp[1] != IPMI_GET_BMC_GLOBAL_ENABLES_CMD   ||
1391                         resp[2] != 0) {
1392                 dev_warn(smi_info->io.dev,
1393                          "Invalid return from get global enables command: %ld %x %x %x\n",
1394                          resp_len, resp[0], resp[1], resp[2]);
1395                 rv = -EINVAL;
1396                 goto out;
1397         } else {
1398                 *enables = resp[3];
1399         }
1400 
1401 out:
1402         kfree(resp);
1403         return rv;
1404 }
1405 
1406 /*
1407  * Returns 1 if it gets an error from the command.
1408  */
1409 static int set_global_enables(struct smi_info *smi_info, u8 enables)
1410 {
1411         unsigned char         msg[3];
1412         unsigned char         *resp;
1413         unsigned long         resp_len;
1414         int                   rv;
1415 
1416         resp = kmalloc(IPMI_MAX_MSG_LENGTH, GFP_KERNEL);
1417         if (!resp)
1418                 return -ENOMEM;
1419 
1420         msg[0] = IPMI_NETFN_APP_REQUEST << 2;
1421         msg[1] = IPMI_SET_BMC_GLOBAL_ENABLES_CMD;
1422         msg[2] = enables;
1423         smi_info->handlers->start_transaction(smi_info->si_sm, msg, 3);
1424 
1425         rv = wait_for_msg_done(smi_info);
1426         if (rv) {
1427                 dev_warn(smi_info->io.dev,
1428                          "Error getting response from set global enables command: %d\n",
1429                          rv);
1430                 goto out;
1431         }
1432 
1433         resp_len = smi_info->handlers->get_result(smi_info->si_sm,
1434                                                   resp, IPMI_MAX_MSG_LENGTH);
1435 
1436         if (resp_len < 3 ||
1437                         resp[0] != (IPMI_NETFN_APP_REQUEST | 1) << 2 ||
1438                         resp[1] != IPMI_SET_BMC_GLOBAL_ENABLES_CMD) {
1439                 dev_warn(smi_info->io.dev,
1440                          "Invalid return from set global enables command: %ld %x %x\n",
1441                          resp_len, resp[0], resp[1]);
1442                 rv = -EINVAL;
1443                 goto out;
1444         }
1445 
1446         if (resp[2] != 0)
1447                 rv = 1;
1448 
1449 out:
1450         kfree(resp);
1451         return rv;
1452 }
1453 
1454 /*
1455  * Some BMCs do not support clearing the receive irq bit in the global
1456  * enables (even if they don't support interrupts on the BMC).  Check
1457  * for this and handle it properly.
1458  */
1459 static void check_clr_rcv_irq(struct smi_info *smi_info)
1460 {
1461         u8 enables = 0;
1462         int rv;
1463 
1464         rv = get_global_enables(smi_info, &enables);
1465         if (!rv) {
1466                 if ((enables & IPMI_BMC_RCV_MSG_INTR) == 0)
1467                         /* Already clear, should work ok. */
1468                         return;
1469 
1470                 enables &= ~IPMI_BMC_RCV_MSG_INTR;
1471                 rv = set_global_enables(smi_info, enables);
1472         }
1473 
1474         if (rv < 0) {
1475                 dev_err(smi_info->io.dev,
1476                         "Cannot check clearing the rcv irq: %d\n", rv);
1477                 return;
1478         }
1479 
1480         if (rv) {
1481                 /*
1482                  * An error when setting the event buffer bit means
1483                  * clearing the bit is not supported.
1484                  */
1485                 dev_warn(smi_info->io.dev,
1486                          "The BMC does not support clearing the recv irq bit, compensating, but the BMC needs to be fixed.\n");
1487                 smi_info->cannot_disable_irq = true;
1488         }
1489 }
1490 
1491 /*
1492  * Some BMCs do not support setting the interrupt bits in the global
1493  * enables even if they support interrupts.  Clearly bad, but we can
1494  * compensate.
1495  */
1496 static void check_set_rcv_irq(struct smi_info *smi_info)
1497 {
1498         u8 enables = 0;
1499         int rv;
1500 
1501         if (!smi_info->io.irq)
1502                 return;
1503 
1504         rv = get_global_enables(smi_info, &enables);
1505         if (!rv) {
1506                 enables |= IPMI_BMC_RCV_MSG_INTR;
1507                 rv = set_global_enables(smi_info, enables);
1508         }
1509 
1510         if (rv < 0) {
1511                 dev_err(smi_info->io.dev,
1512                         "Cannot check setting the rcv irq: %d\n", rv);
1513                 return;
1514         }
1515 
1516         if (rv) {
1517                 /*
1518                  * An error when setting the event buffer bit means
1519                  * setting the bit is not supported.
1520                  */
1521                 dev_warn(smi_info->io.dev,
1522                          "The BMC does not support setting the recv irq bit, compensating, but the BMC needs to be fixed.\n");
1523                 smi_info->cannot_disable_irq = true;
1524                 smi_info->irq_enable_broken = true;
1525         }
1526 }
1527 
1528 static int try_enable_event_buffer(struct smi_info *smi_info)
1529 {
1530         unsigned char         msg[3];
1531         unsigned char         *resp;
1532         unsigned long         resp_len;
1533         int                   rv = 0;
1534 
1535         resp = kmalloc(IPMI_MAX_MSG_LENGTH, GFP_KERNEL);
1536         if (!resp)
1537                 return -ENOMEM;
1538 
1539         msg[0] = IPMI_NETFN_APP_REQUEST << 2;
1540         msg[1] = IPMI_GET_BMC_GLOBAL_ENABLES_CMD;
1541         smi_info->handlers->start_transaction(smi_info->si_sm, msg, 2);
1542 
1543         rv = wait_for_msg_done(smi_info);
1544         if (rv) {
1545                 pr_warn("Error getting response from get global enables command, the event buffer is not enabled\n");
1546                 goto out;
1547         }
1548 
1549         resp_len = smi_info->handlers->get_result(smi_info->si_sm,
1550                                                   resp, IPMI_MAX_MSG_LENGTH);
1551 
1552         if (resp_len < 4 ||
1553                         resp[0] != (IPMI_NETFN_APP_REQUEST | 1) << 2 ||
1554                         resp[1] != IPMI_GET_BMC_GLOBAL_ENABLES_CMD   ||
1555                         resp[2] != 0) {
1556                 pr_warn("Invalid return from get global enables command, cannot enable the event buffer\n");
1557                 rv = -EINVAL;
1558                 goto out;
1559         }
1560 
1561         if (resp[3] & IPMI_BMC_EVT_MSG_BUFF) {
1562                 /* buffer is already enabled, nothing to do. */
1563                 smi_info->supports_event_msg_buff = true;
1564                 goto out;
1565         }
1566 
1567         msg[0] = IPMI_NETFN_APP_REQUEST << 2;
1568         msg[1] = IPMI_SET_BMC_GLOBAL_ENABLES_CMD;
1569         msg[2] = resp[3] | IPMI_BMC_EVT_MSG_BUFF;
1570         smi_info->handlers->start_transaction(smi_info->si_sm, msg, 3);
1571 
1572         rv = wait_for_msg_done(smi_info);
1573         if (rv) {
1574                 pr_warn("Error getting response from set global, enables command, the event buffer is not enabled\n");
1575                 goto out;
1576         }
1577 
1578         resp_len = smi_info->handlers->get_result(smi_info->si_sm,
1579                                                   resp, IPMI_MAX_MSG_LENGTH);
1580 
1581         if (resp_len < 3 ||
1582                         resp[0] != (IPMI_NETFN_APP_REQUEST | 1) << 2 ||
1583                         resp[1] != IPMI_SET_BMC_GLOBAL_ENABLES_CMD) {
1584                 pr_warn("Invalid return from get global, enables command, not enable the event buffer\n");
1585                 rv = -EINVAL;
1586                 goto out;
1587         }
1588 
1589         if (resp[2] != 0)
1590                 /*
1591                  * An error when setting the event buffer bit means
1592                  * that the event buffer is not supported.
1593                  */
1594                 rv = -ENOENT;
1595         else
1596                 smi_info->supports_event_msg_buff = true;
1597 
1598 out:
1599         kfree(resp);
1600         return rv;
1601 }
1602 
1603 #define IPMI_SI_ATTR(name) \
1604 static ssize_t name##_show(struct device *dev,                  \
1605                            struct device_attribute *attr,               \
1606                            char *buf)                                   \
1607 {                                                                       \
1608         struct smi_info *smi_info = dev_get_drvdata(dev);               \
1609                                                                         \
1610         return snprintf(buf, 10, "%u\n", smi_get_stat(smi_info, name)); \
1611 }                                                                       \
1612 static DEVICE_ATTR(name, 0444, name##_show, NULL)
1613 
1614 static ssize_t type_show(struct device *dev,
1615                          struct device_attribute *attr,
1616                          char *buf)
1617 {
1618         struct smi_info *smi_info = dev_get_drvdata(dev);
1619 
1620         return snprintf(buf, 10, "%s\n", si_to_str[smi_info->io.si_type]);
1621 }
1622 static DEVICE_ATTR(type, 0444, type_show, NULL);
1623 
1624 static ssize_t interrupts_enabled_show(struct device *dev,
1625                                        struct device_attribute *attr,
1626                                        char *buf)
1627 {
1628         struct smi_info *smi_info = dev_get_drvdata(dev);
1629         int enabled = smi_info->io.irq && !smi_info->interrupt_disabled;
1630 
1631         return snprintf(buf, 10, "%d\n", enabled);
1632 }
1633 static DEVICE_ATTR(interrupts_enabled, 0444,
1634                    interrupts_enabled_show, NULL);
1635 
1636 IPMI_SI_ATTR(short_timeouts);
1637 IPMI_SI_ATTR(long_timeouts);
1638 IPMI_SI_ATTR(idles);
1639 IPMI_SI_ATTR(interrupts);
1640 IPMI_SI_ATTR(attentions);
1641 IPMI_SI_ATTR(flag_fetches);
1642 IPMI_SI_ATTR(hosed_count);
1643 IPMI_SI_ATTR(complete_transactions);
1644 IPMI_SI_ATTR(events);
1645 IPMI_SI_ATTR(watchdog_pretimeouts);
1646 IPMI_SI_ATTR(incoming_messages);
1647 
1648 static ssize_t params_show(struct device *dev,
1649                            struct device_attribute *attr,
1650                            char *buf)
1651 {
1652         struct smi_info *smi_info = dev_get_drvdata(dev);
1653 
1654         return snprintf(buf, 200,
1655                         "%s,%s,0x%lx,rsp=%d,rsi=%d,rsh=%d,irq=%d,ipmb=%d\n",
1656                         si_to_str[smi_info->io.si_type],
1657                         addr_space_to_str[smi_info->io.addr_space],
1658                         smi_info->io.addr_data,
1659                         smi_info->io.regspacing,
1660                         smi_info->io.regsize,
1661                         smi_info->io.regshift,
1662                         smi_info->io.irq,
1663                         smi_info->io.slave_addr);
1664 }
1665 static DEVICE_ATTR(params, 0444, params_show, NULL);
1666 
1667 static struct attribute *ipmi_si_dev_attrs[] = {
1668         &dev_attr_type.attr,
1669         &dev_attr_interrupts_enabled.attr,
1670         &dev_attr_short_timeouts.attr,
1671         &dev_attr_long_timeouts.attr,
1672         &dev_attr_idles.attr,
1673         &dev_attr_interrupts.attr,
1674         &dev_attr_attentions.attr,
1675         &dev_attr_flag_fetches.attr,
1676         &dev_attr_hosed_count.attr,
1677         &dev_attr_complete_transactions.attr,
1678         &dev_attr_events.attr,
1679         &dev_attr_watchdog_pretimeouts.attr,
1680         &dev_attr_incoming_messages.attr,
1681         &dev_attr_params.attr,
1682         NULL
1683 };
1684 
1685 static const struct attribute_group ipmi_si_dev_attr_group = {
1686         .attrs          = ipmi_si_dev_attrs,
1687 };
1688 
1689 /*
1690  * oem_data_avail_to_receive_msg_avail
1691  * @info - smi_info structure with msg_flags set
1692  *
1693  * Converts flags from OEM_DATA_AVAIL to RECEIVE_MSG_AVAIL
1694  * Returns 1 indicating need to re-run handle_flags().
1695  */
1696 static int oem_data_avail_to_receive_msg_avail(struct smi_info *smi_info)
1697 {
1698         smi_info->msg_flags = ((smi_info->msg_flags & ~OEM_DATA_AVAIL) |
1699                                RECEIVE_MSG_AVAIL);
1700         return 1;
1701 }
1702 
1703 /*
1704  * setup_dell_poweredge_oem_data_handler
1705  * @info - smi_info.device_id must be populated
1706  *
1707  * Systems that match, but have firmware version < 1.40 may assert
1708  * OEM0_DATA_AVAIL on their own, without being told via Set Flags that
1709  * it's safe to do so.  Such systems will de-assert OEM1_DATA_AVAIL
1710  * upon receipt of IPMI_GET_MSG_CMD, so we should treat these flags
1711  * as RECEIVE_MSG_AVAIL instead.
1712  *
1713  * As Dell has no plans to release IPMI 1.5 firmware that *ever*
1714  * assert the OEM[012] bits, and if it did, the driver would have to
1715  * change to handle that properly, we don't actually check for the
1716  * firmware version.
1717  * Device ID = 0x20                BMC on PowerEdge 8G servers
1718  * Device Revision = 0x80
1719  * Firmware Revision1 = 0x01       BMC version 1.40
1720  * Firmware Revision2 = 0x40       BCD encoded
1721  * IPMI Version = 0x51             IPMI 1.5
1722  * Manufacturer ID = A2 02 00      Dell IANA
1723  *
1724  * Additionally, PowerEdge systems with IPMI < 1.5 may also assert
1725  * OEM0_DATA_AVAIL and needs to be treated as RECEIVE_MSG_AVAIL.
1726  *
1727  */
1728 #define DELL_POWEREDGE_8G_BMC_DEVICE_ID  0x20
1729 #define DELL_POWEREDGE_8G_BMC_DEVICE_REV 0x80
1730 #define DELL_POWEREDGE_8G_BMC_IPMI_VERSION 0x51
1731 #define DELL_IANA_MFR_ID 0x0002a2
1732 static void setup_dell_poweredge_oem_data_handler(struct smi_info *smi_info)
1733 {
1734         struct ipmi_device_id *id = &smi_info->device_id;
1735         if (id->manufacturer_id == DELL_IANA_MFR_ID) {
1736                 if (id->device_id       == DELL_POWEREDGE_8G_BMC_DEVICE_ID  &&
1737                     id->device_revision == DELL_POWEREDGE_8G_BMC_DEVICE_REV &&
1738                     id->ipmi_version   == DELL_POWEREDGE_8G_BMC_IPMI_VERSION) {
1739                         smi_info->oem_data_avail_handler =
1740                                 oem_data_avail_to_receive_msg_avail;
1741                 } else if (ipmi_version_major(id) < 1 ||
1742                            (ipmi_version_major(id) == 1 &&
1743                             ipmi_version_minor(id) < 5)) {
1744                         smi_info->oem_data_avail_handler =
1745                                 oem_data_avail_to_receive_msg_avail;
1746                 }
1747         }
1748 }
1749 
1750 #define CANNOT_RETURN_REQUESTED_LENGTH 0xCA
1751 static void return_hosed_msg_badsize(struct smi_info *smi_info)
1752 {
1753         struct ipmi_smi_msg *msg = smi_info->curr_msg;
1754 
1755         /* Make it a response */
1756         msg->rsp[0] = msg->data[0] | 4;
1757         msg->rsp[1] = msg->data[1];
1758         msg->rsp[2] = CANNOT_RETURN_REQUESTED_LENGTH;
1759         msg->rsp_size = 3;
1760         smi_info->curr_msg = NULL;
1761         deliver_recv_msg(smi_info, msg);
1762 }
1763 
1764 /*
1765  * dell_poweredge_bt_xaction_handler
1766  * @info - smi_info.device_id must be populated
1767  *
1768  * Dell PowerEdge servers with the BT interface (x6xx and 1750) will
1769  * not respond to a Get SDR command if the length of the data
1770  * requested is exactly 0x3A, which leads to command timeouts and no
1771  * data returned.  This intercepts such commands, and causes userspace
1772  * callers to try again with a different-sized buffer, which succeeds.
1773  */
1774 
1775 #define STORAGE_NETFN 0x0A
1776 #define STORAGE_CMD_GET_SDR 0x23
1777 static int dell_poweredge_bt_xaction_handler(struct notifier_block *self,
1778                                              unsigned long unused,
1779                                              void *in)
1780 {
1781         struct smi_info *smi_info = in;
1782         unsigned char *data = smi_info->curr_msg->data;
1783         unsigned int size   = smi_info->curr_msg->data_size;
1784         if (size >= 8 &&
1785             (data[0]>>2) == STORAGE_NETFN &&
1786             data[1] == STORAGE_CMD_GET_SDR &&
1787             data[7] == 0x3A) {
1788                 return_hosed_msg_badsize(smi_info);
1789                 return NOTIFY_STOP;
1790         }
1791         return NOTIFY_DONE;
1792 }
1793 
1794 static struct notifier_block dell_poweredge_bt_xaction_notifier = {
1795         .notifier_call  = dell_poweredge_bt_xaction_handler,
1796 };
1797 
1798 /*
1799  * setup_dell_poweredge_bt_xaction_handler
1800  * @info - smi_info.device_id must be filled in already
1801  *
1802  * Fills in smi_info.device_id.start_transaction_pre_hook
1803  * when we know what function to use there.
1804  */
1805 static void
1806 setup_dell_poweredge_bt_xaction_handler(struct smi_info *smi_info)
1807 {
1808         struct ipmi_device_id *id = &smi_info->device_id;
1809         if (id->manufacturer_id == DELL_IANA_MFR_ID &&
1810             smi_info->io.si_type == SI_BT)
1811                 register_xaction_notifier(&dell_poweredge_bt_xaction_notifier);
1812 }
1813 
1814 /*
1815  * setup_oem_data_handler
1816  * @info - smi_info.device_id must be filled in already
1817  *
1818  * Fills in smi_info.device_id.oem_data_available_handler
1819  * when we know what function to use there.
1820  */
1821 
1822 static void setup_oem_data_handler(struct smi_info *smi_info)
1823 {
1824         setup_dell_poweredge_oem_data_handler(smi_info);
1825 }
1826 
1827 static void setup_xaction_handlers(struct smi_info *smi_info)
1828 {
1829         setup_dell_poweredge_bt_xaction_handler(smi_info);
1830 }
1831 
1832 static void check_for_broken_irqs(struct smi_info *smi_info)
1833 {
1834         check_clr_rcv_irq(smi_info);
1835         check_set_rcv_irq(smi_info);
1836 }
1837 
1838 static inline void stop_timer_and_thread(struct smi_info *smi_info)
1839 {
1840         if (smi_info->thread != NULL) {
1841                 kthread_stop(smi_info->thread);
1842                 smi_info->thread = NULL;
1843         }
1844 
1845         smi_info->timer_can_start = false;
1846         del_timer_sync(&smi_info->si_timer);
1847 }
1848 
1849 static struct smi_info *find_dup_si(struct smi_info *info)
1850 {
1851         struct smi_info *e;
1852 
1853         list_for_each_entry(e, &smi_infos, link) {
1854                 if (e->io.addr_space != info->io.addr_space)
1855                         continue;
1856                 if (e->io.addr_data == info->io.addr_data) {
1857                         /*
1858                          * This is a cheap hack, ACPI doesn't have a defined
1859                          * slave address but SMBIOS does.  Pick it up from
1860                          * any source that has it available.
1861                          */
1862                         if (info->io.slave_addr && !e->io.slave_addr)
1863                                 e->io.slave_addr = info->io.slave_addr;
1864                         return e;
1865                 }
1866         }
1867 
1868         return NULL;
1869 }
1870 
1871 int ipmi_si_add_smi(struct si_sm_io *io)
1872 {
1873         int rv = 0;
1874         struct smi_info *new_smi, *dup;
1875 
1876         /*
1877          * If the user gave us a hard-coded device at the same
1878          * address, they presumably want us to use it and not what is
1879          * in the firmware.
1880          */
1881         if (io->addr_source != SI_HARDCODED && io->addr_source != SI_HOTMOD &&
1882             ipmi_si_hardcode_match(io->addr_space, io->addr_data)) {
1883                 dev_info(io->dev,
1884                          "Hard-coded device at this address already exists");
1885                 return -ENODEV;
1886         }
1887 
1888         if (!io->io_setup) {
1889                 if (io->addr_space == IPMI_IO_ADDR_SPACE) {
1890                         io->io_setup = ipmi_si_port_setup;
1891                 } else if (io->addr_space == IPMI_MEM_ADDR_SPACE) {
1892                         io->io_setup = ipmi_si_mem_setup;
1893                 } else {
1894                         return -EINVAL;
1895                 }
1896         }
1897 
1898         new_smi = kzalloc(sizeof(*new_smi), GFP_KERNEL);
1899         if (!new_smi)
1900                 return -ENOMEM;
1901         spin_lock_init(&new_smi->si_lock);
1902 
1903         new_smi->io = *io;
1904 
1905         mutex_lock(&smi_infos_lock);
1906         dup = find_dup_si(new_smi);
1907         if (dup) {
1908                 if (new_smi->io.addr_source == SI_ACPI &&
1909                     dup->io.addr_source == SI_SMBIOS) {
1910                         /* We prefer ACPI over SMBIOS. */
1911                         dev_info(dup->io.dev,
1912                                  "Removing SMBIOS-specified %s state machine in favor of ACPI\n",
1913                                  si_to_str[new_smi->io.si_type]);
1914                         cleanup_one_si(dup);
1915                 } else {
1916                         dev_info(new_smi->io.dev,
1917                                  "%s-specified %s state machine: duplicate\n",
1918                                  ipmi_addr_src_to_str(new_smi->io.addr_source),
1919                                  si_to_str[new_smi->io.si_type]);
1920                         rv = -EBUSY;
1921                         kfree(new_smi);
1922                         goto out_err;
1923                 }
1924         }
1925 
1926         pr_info("Adding %s-specified %s state machine\n",
1927                 ipmi_addr_src_to_str(new_smi->io.addr_source),
1928                 si_to_str[new_smi->io.si_type]);
1929 
1930         list_add_tail(&new_smi->link, &smi_infos);
1931 
1932         if (initialized)
1933                 rv = try_smi_init(new_smi);
1934 out_err:
1935         mutex_unlock(&smi_infos_lock);
1936         return rv;
1937 }
1938 
1939 /*
1940  * Try to start up an interface.  Must be called with smi_infos_lock
1941  * held, primarily to keep smi_num consistent, we only one to do these
1942  * one at a time.
1943  */
1944 static int try_smi_init(struct smi_info *new_smi)
1945 {
1946         int rv = 0;
1947         int i;
1948 
1949         pr_info("Trying %s-specified %s state machine at %s address 0x%lx, slave address 0x%x, irq %d\n",
1950                 ipmi_addr_src_to_str(new_smi->io.addr_source),
1951                 si_to_str[new_smi->io.si_type],
1952                 addr_space_to_str[new_smi->io.addr_space],
1953                 new_smi->io.addr_data,
1954                 new_smi->io.slave_addr, new_smi->io.irq);
1955 
1956         switch (new_smi->io.si_type) {
1957         case SI_KCS:
1958                 new_smi->handlers = &kcs_smi_handlers;
1959                 break;
1960 
1961         case SI_SMIC:
1962                 new_smi->handlers = &smic_smi_handlers;
1963                 break;
1964 
1965         case SI_BT:
1966                 new_smi->handlers = &bt_smi_handlers;
1967                 break;
1968 
1969         default:
1970                 /* No support for anything else yet. */
1971                 rv = -EIO;
1972                 goto out_err;
1973         }
1974 
1975         new_smi->si_num = smi_num;
1976 
1977         /* Do this early so it's available for logs. */
1978         if (!new_smi->io.dev) {
1979                 pr_err("IPMI interface added with no device\n");
1980                 rv = EIO;
1981                 goto out_err;
1982         }
1983 
1984         /* Allocate the state machine's data and initialize it. */
1985         new_smi->si_sm = kmalloc(new_smi->handlers->size(), GFP_KERNEL);
1986         if (!new_smi->si_sm) {
1987                 rv = -ENOMEM;
1988                 goto out_err;
1989         }
1990         new_smi->io.io_size = new_smi->handlers->init_data(new_smi->si_sm,
1991                                                            &new_smi->io);
1992 
1993         /* Now that we know the I/O size, we can set up the I/O. */
1994         rv = new_smi->io.io_setup(&new_smi->io);
1995         if (rv) {
1996                 dev_err(new_smi->io.dev, "Could not set up I/O space\n");
1997                 goto out_err;
1998         }
1999 
2000         /* Do low-level detection first. */
2001         if (new_smi->handlers->detect(new_smi->si_sm)) {
2002                 if (new_smi->io.addr_source)
2003                         dev_err(new_smi->io.dev,
2004                                 "Interface detection failed\n");
2005                 rv = -ENODEV;
2006                 goto out_err;
2007         }
2008 
2009         /*
2010          * Attempt a get device id command.  If it fails, we probably
2011          * don't have a BMC here.
2012          */
2013         rv = try_get_dev_id(new_smi);
2014         if (rv) {
2015                 if (new_smi->io.addr_source)
2016                         dev_err(new_smi->io.dev,
2017                                "There appears to be no BMC at this location\n");
2018                 goto out_err;
2019         }
2020 
2021         setup_oem_data_handler(new_smi);
2022         setup_xaction_handlers(new_smi);
2023         check_for_broken_irqs(new_smi);
2024 
2025         new_smi->waiting_msg = NULL;
2026         new_smi->curr_msg = NULL;
2027         atomic_set(&new_smi->req_events, 0);
2028         new_smi->run_to_completion = false;
2029         for (i = 0; i < SI_NUM_STATS; i++)
2030                 atomic_set(&new_smi->stats[i], 0);
2031 
2032         new_smi->interrupt_disabled = true;
2033         atomic_set(&new_smi->need_watch, 0);
2034 
2035         rv = try_enable_event_buffer(new_smi);
2036         if (rv == 0)
2037                 new_smi->has_event_buffer = true;
2038 
2039         /*
2040          * Start clearing the flags before we enable interrupts or the
2041          * timer to avoid racing with the timer.
2042          */
2043         start_clear_flags(new_smi);
2044 
2045         /*
2046          * IRQ is defined to be set when non-zero.  req_events will
2047          * cause a global flags check that will enable interrupts.
2048          */
2049         if (new_smi->io.irq) {
2050                 new_smi->interrupt_disabled = false;
2051                 atomic_set(&new_smi->req_events, 1);
2052         }
2053 
2054         dev_set_drvdata(new_smi->io.dev, new_smi);
2055         rv = device_add_group(new_smi->io.dev, &ipmi_si_dev_attr_group);
2056         if (rv) {
2057                 dev_err(new_smi->io.dev,
2058                         "Unable to add device attributes: error %d\n",
2059                         rv);
2060                 goto out_err;
2061         }
2062         new_smi->dev_group_added = true;
2063 
2064         rv = ipmi_register_smi(&handlers,
2065                                new_smi,
2066                                new_smi->io.dev,
2067                                new_smi->io.slave_addr);
2068         if (rv) {
2069                 dev_err(new_smi->io.dev,
2070                         "Unable to register device: error %d\n",
2071                         rv);
2072                 goto out_err;
2073         }
2074 
2075         /* Don't increment till we know we have succeeded. */
2076         smi_num++;
2077 
2078         dev_info(new_smi->io.dev, "IPMI %s interface initialized\n",
2079                  si_to_str[new_smi->io.si_type]);
2080 
2081         WARN_ON(new_smi->io.dev->init_name != NULL);
2082 
2083  out_err:
2084         if (rv && new_smi->io.io_cleanup) {
2085                 new_smi->io.io_cleanup(&new_smi->io);
2086                 new_smi->io.io_cleanup = NULL;
2087         }
2088 
2089         return rv;
2090 }
2091 
2092 static int __init init_ipmi_si(void)
2093 {
2094         struct smi_info *e;
2095         enum ipmi_addr_src type = SI_INVALID;
2096 
2097         if (initialized)
2098                 return 0;
2099 
2100         ipmi_hardcode_init();
2101 
2102         pr_info("IPMI System Interface driver\n");
2103 
2104         ipmi_si_platform_init();
2105 
2106         ipmi_si_pci_init();
2107 
2108         ipmi_si_parisc_init();
2109 
2110         /* We prefer devices with interrupts, but in the case of a machine
2111            with multiple BMCs we assume that there will be several instances
2112            of a given type so if we succeed in registering a type then also
2113            try to register everything else of the same type */
2114         mutex_lock(&smi_infos_lock);
2115         list_for_each_entry(e, &smi_infos, link) {
2116                 /* Try to register a device if it has an IRQ and we either
2117                    haven't successfully registered a device yet or this
2118                    device has the same type as one we successfully registered */
2119                 if (e->io.irq && (!type || e->io.addr_source == type)) {
2120                         if (!try_smi_init(e)) {
2121                                 type = e->io.addr_source;
2122                         }
2123                 }
2124         }
2125 
2126         /* type will only have been set if we successfully registered an si */
2127         if (type)
2128                 goto skip_fallback_noirq;
2129 
2130         /* Fall back to the preferred device */
2131 
2132         list_for_each_entry(e, &smi_infos, link) {
2133                 if (!e->io.irq && (!type || e->io.addr_source == type)) {
2134                         if (!try_smi_init(e)) {
2135                                 type = e->io.addr_source;
2136                         }
2137                 }
2138         }
2139 
2140 skip_fallback_noirq:
2141         initialized = true;
2142         mutex_unlock(&smi_infos_lock);
2143 
2144         if (type)
2145                 return 0;
2146 
2147         mutex_lock(&smi_infos_lock);
2148         if (unload_when_empty && list_empty(&smi_infos)) {
2149                 mutex_unlock(&smi_infos_lock);
2150                 cleanup_ipmi_si();
2151                 pr_warn("Unable to find any System Interface(s)\n");
2152                 return -ENODEV;
2153         } else {
2154                 mutex_unlock(&smi_infos_lock);
2155                 return 0;
2156         }
2157 }
2158 module_init(init_ipmi_si);
2159 
2160 static void shutdown_smi(void *send_info)
2161 {
2162         struct smi_info *smi_info = send_info;
2163 
2164         if (smi_info->dev_group_added) {
2165                 device_remove_group(smi_info->io.dev, &ipmi_si_dev_attr_group);
2166                 smi_info->dev_group_added = false;
2167         }
2168         if (smi_info->io.dev)
2169                 dev_set_drvdata(smi_info->io.dev, NULL);
2170 
2171         /*
2172          * Make sure that interrupts, the timer and the thread are
2173          * stopped and will not run again.
2174          */
2175         smi_info->interrupt_disabled = true;
2176         if (smi_info->io.irq_cleanup) {
2177                 smi_info->io.irq_cleanup(&smi_info->io);
2178                 smi_info->io.irq_cleanup = NULL;
2179         }
2180         stop_timer_and_thread(smi_info);
2181 
2182         /*
2183          * Wait until we know that we are out of any interrupt
2184          * handlers might have been running before we freed the
2185          * interrupt.
2186          */
2187         synchronize_rcu();
2188 
2189         /*
2190          * Timeouts are stopped, now make sure the interrupts are off
2191          * in the BMC.  Note that timers and CPU interrupts are off,
2192          * so no need for locks.
2193          */
2194         while (smi_info->curr_msg || (smi_info->si_state != SI_NORMAL)) {
2195                 poll(smi_info);
2196                 schedule_timeout_uninterruptible(1);
2197         }
2198         if (smi_info->handlers)
2199                 disable_si_irq(smi_info);
2200         while (smi_info->curr_msg || (smi_info->si_state != SI_NORMAL)) {
2201                 poll(smi_info);
2202                 schedule_timeout_uninterruptible(1);
2203         }
2204         if (smi_info->handlers)
2205                 smi_info->handlers->cleanup(smi_info->si_sm);
2206 
2207         if (smi_info->io.addr_source_cleanup) {
2208                 smi_info->io.addr_source_cleanup(&smi_info->io);
2209                 smi_info->io.addr_source_cleanup = NULL;
2210         }
2211         if (smi_info->io.io_cleanup) {
2212                 smi_info->io.io_cleanup(&smi_info->io);
2213                 smi_info->io.io_cleanup = NULL;
2214         }
2215 
2216         kfree(smi_info->si_sm);
2217         smi_info->si_sm = NULL;
2218 
2219         smi_info->intf = NULL;
2220 }
2221 
2222 /*
2223  * Must be called with smi_infos_lock held, to serialize the
2224  * smi_info->intf check.
2225  */
2226 static void cleanup_one_si(struct smi_info *smi_info)
2227 {
2228         if (!smi_info)
2229                 return;
2230 
2231         list_del(&smi_info->link);
2232 
2233         if (smi_info->intf)
2234                 ipmi_unregister_smi(smi_info->intf);
2235 
2236         kfree(smi_info);
2237 }
2238 
2239 int ipmi_si_remove_by_dev(struct device *dev)
2240 {
2241         struct smi_info *e;
2242         int rv = -ENOENT;
2243 
2244         mutex_lock(&smi_infos_lock);
2245         list_for_each_entry(e, &smi_infos, link) {
2246                 if (e->io.dev == dev) {
2247                         cleanup_one_si(e);
2248                         rv = 0;
2249                         break;
2250                 }
2251         }
2252         mutex_unlock(&smi_infos_lock);
2253 
2254         return rv;
2255 }
2256 
2257 struct device *ipmi_si_remove_by_data(int addr_space, enum si_type si_type,
2258                                       unsigned long addr)
2259 {
2260         /* remove */
2261         struct smi_info *e, *tmp_e;
2262         struct device *dev = NULL;
2263 
2264         mutex_lock(&smi_infos_lock);
2265         list_for_each_entry_safe(e, tmp_e, &smi_infos, link) {
2266                 if (e->io.addr_space != addr_space)
2267                         continue;
2268                 if (e->io.si_type != si_type)
2269                         continue;
2270                 if (e->io.addr_data == addr) {
2271                         dev = get_device(e->io.dev);
2272                         cleanup_one_si(e);
2273                 }
2274         }
2275         mutex_unlock(&smi_infos_lock);
2276 
2277         return dev;
2278 }
2279 
2280 static void cleanup_ipmi_si(void)
2281 {
2282         struct smi_info *e, *tmp_e;
2283 
2284         if (!initialized)
2285                 return;
2286 
2287         ipmi_si_pci_shutdown();
2288 
2289         ipmi_si_parisc_shutdown();
2290 
2291         ipmi_si_platform_shutdown();
2292 
2293         mutex_lock(&smi_infos_lock);
2294         list_for_each_entry_safe(e, tmp_e, &smi_infos, link)
2295                 cleanup_one_si(e);
2296         mutex_unlock(&smi_infos_lock);
2297 
2298         ipmi_si_hardcode_exit();
2299         ipmi_si_hotmod_exit();
2300 }
2301 module_exit(cleanup_ipmi_si);
2302 
2303 MODULE_ALIAS("platform:dmi-ipmi-si");
2304 MODULE_LICENSE("GPL");
2305 MODULE_AUTHOR("Corey Minyard <minyard@mvista.com>");
2306 MODULE_DESCRIPTION("Interface to the IPMI driver for the KCS, SMIC, and BT"
2307                    " system interfaces.");
/* [<][>][^][v][top][bottom][index][help] */
root/drivers/char/ipmi/ipmi_si_intf.c

DEFINITIONS
