drivers/char/ipmi/ipmi_si_intf.c

   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 timespec64 t;
 269
 270         ktime_get_ts64(&t);
 271         pr_debug("**%s: %lld.%9.9ld\n", msg, 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 as a special constant to tell that we are spinning in kipmid
 939  * looking for something and not delaying between checks
 940  */
 941 #define IPMI_TIME_NOT_BUSY ns_to_ktime(-1ull)
 942 static inline bool ipmi_thread_busy_wait(enum si_sm_result smi_result,
 943                                          const struct smi_info *smi_info,
 944                                          ktime_t *busy_until)
 945 {
 946         unsigned int max_busy_us = 0;
 947
 948         if (smi_info->si_num < num_max_busy_us)
 949                 max_busy_us = kipmid_max_busy_us[smi_info->si_num];
 950         if (max_busy_us == 0 || smi_result != SI_SM_CALL_WITH_DELAY)
 951                 *busy_until = IPMI_TIME_NOT_BUSY;
 952         else if (*busy_until == IPMI_TIME_NOT_BUSY) {
 953                 *busy_until = ktime_get() + max_busy_us * NSEC_PER_USEC;
 954         } else {
 955                 if (unlikely(ktime_get() > *busy_until)) {
 956                         *busy_until = IPMI_TIME_NOT_BUSY;
 957                         return false;
 958                 }
 959         }
 960         return true;
 961 }
 962
 963
 964 /*
 965  * A busy-waiting loop for speeding up IPMI operation.
 966  *
 967  * Lousy hardware makes this hard.  This is only enabled for systems
 968  * that are not BT and do not have interrupts.  It starts spinning
 969  * when an operation is complete or until max_busy tells it to stop
 970  * (if that is enabled).  See the paragraph on kimid_max_busy_us in
 971  * Documentation/driver-api/ipmi.rst for details.
 972  */
 973 static int ipmi_thread(void *data)
 974 {
 975         struct smi_info *smi_info = data;
 976         unsigned long flags;
 977         enum si_sm_result smi_result;
 978         ktime_t busy_until = IPMI_TIME_NOT_BUSY;
 979
 980         set_user_nice(current, MAX_NICE);
 981         while (!kthread_should_stop()) {
 982                 int busy_wait;
 983
 984                 spin_lock_irqsave(&(smi_info->si_lock), flags);
 985                 smi_result = smi_event_handler(smi_info, 0);
 986
 987                 /*
 988                  * If the driver is doing something, there is a possible
 989                  * race with the timer.  If the timer handler see idle,
 990                  * and the thread here sees something else, the timer
 991                  * handler won't restart the timer even though it is
 992                  * required.  So start it here if necessary.
 993                  */
 994                 if (smi_result != SI_SM_IDLE && !smi_info->timer_running)
 995                         smi_mod_timer(smi_info, jiffies + SI_TIMEOUT_JIFFIES);
 996
 997                 spin_unlock_irqrestore(&(smi_info->si_lock), flags);
 998                 busy_wait = ipmi_thread_busy_wait(smi_result, smi_info,
 999                                                   &busy_until);
1000                 if (smi_result == SI_SM_CALL_WITHOUT_DELAY) {
1001                         ; /* do nothing */
1002                 } else if (smi_result == SI_SM_CALL_WITH_DELAY && busy_wait) {
1003                         /*
1004                          * In maintenance mode we run as fast as
1005                          * possible to allow firmware updates to
1006                          * complete as fast as possible, but normally
1007                          * don't bang on the scheduler.
1008                          */
1009                         if (smi_info->in_maintenance_mode)
1010                                 schedule();
1011                         else
1012                                 usleep_range(100, 200);
1013                 } else if (smi_result == SI_SM_IDLE) {
1014                         if (atomic_read(&smi_info->need_watch)) {
1015                                 schedule_timeout_interruptible(100);
1016                         } else {
1017                                 /* Wait to be woken up when we are needed. */
1018                                 __set_current_state(TASK_INTERRUPTIBLE);
1019                                 schedule();
1020                         }
1021                 } else {
1022                         schedule_timeout_interruptible(1);
1023                 }
1024         }
1025         return 0;
1026 }
1027
1028
1029 static void poll(void *send_info)
1030 {
1031         struct smi_info *smi_info = send_info;
1032         unsigned long flags = 0;
1033         bool run_to_completion = smi_info->run_to_completion;
1034
1035         /*
1036          * Make sure there is some delay in the poll loop so we can
1037          * drive time forward and timeout things.
1038          */
1039         udelay(10);
1040         if (!run_to_completion)
1041                 spin_lock_irqsave(&smi_info->si_lock, flags);
1042         smi_event_handler(smi_info, 10);
1043         if (!run_to_completion)
1044                 spin_unlock_irqrestore(&smi_info->si_lock, flags);
1045 }
1046
1047 static void request_events(void *send_info)
1048 {
1049         struct smi_info *smi_info = send_info;
1050
1051         if (!smi_info->has_event_buffer)
1052                 return;
1053
1054         atomic_set(&smi_info->req_events, 1);
1055 }
1056
1057 static void set_need_watch(void *send_info, unsigned int watch_mask)
1058 {
1059         struct smi_info *smi_info = send_info;
1060         unsigned long flags;
1061         int enable;
1062
1063         enable = !!watch_mask;
1064
1065         atomic_set(&smi_info->need_watch, enable);
1066         spin_lock_irqsave(&smi_info->si_lock, flags);
1067         check_start_timer_thread(smi_info);
1068         spin_unlock_irqrestore(&smi_info->si_lock, flags);
1069 }
1070
1071 static void smi_timeout(struct timer_list *t)
1072 {
1073         struct smi_info   *smi_info = from_timer(smi_info, t, si_timer);
1074         enum si_sm_result smi_result;
1075         unsigned long     flags;
1076         unsigned long     jiffies_now;
1077         long              time_diff;
1078         long              timeout;
1079
1080         spin_lock_irqsave(&(smi_info->si_lock), flags);
1081         debug_timestamp("Timer");
1082
1083         jiffies_now = jiffies;
1084         time_diff = (((long)jiffies_now - (long)smi_info->last_timeout_jiffies)
1085                      * SI_USEC_PER_JIFFY);
1086         smi_result = smi_event_handler(smi_info, time_diff);
1087
1088         if ((smi_info->io.irq) && (!smi_info->interrupt_disabled)) {
1089                 /* Running with interrupts, only do long timeouts. */
1090                 timeout = jiffies + SI_TIMEOUT_JIFFIES;
1091                 smi_inc_stat(smi_info, long_timeouts);
1092                 goto do_mod_timer;
1093         }
1094
1095         /*
1096          * If the state machine asks for a short delay, then shorten
1097          * the timer timeout.
1098          */
1099         if (smi_result == SI_SM_CALL_WITH_DELAY) {
1100                 smi_inc_stat(smi_info, short_timeouts);
1101                 timeout = jiffies + 1;
1102         } else {
1103                 smi_inc_stat(smi_info, long_timeouts);
1104                 timeout = jiffies + SI_TIMEOUT_JIFFIES;
1105         }
1106
1107 do_mod_timer:
1108         if (smi_result != SI_SM_IDLE)
1109                 smi_mod_timer(smi_info, timeout);
1110         else
1111                 smi_info->timer_running = false;
1112         spin_unlock_irqrestore(&(smi_info->si_lock), flags);
1113 }
1114
1115 irqreturn_t ipmi_si_irq_handler(int irq, void *data)
1116 {
1117         struct smi_info *smi_info = data;
1118         unsigned long   flags;
1119
1120         if (smi_info->io.si_type == SI_BT)
1121                 /* We need to clear the IRQ flag for the BT interface. */
1122                 smi_info->io.outputb(&smi_info->io, IPMI_BT_INTMASK_REG,
1123                                      IPMI_BT_INTMASK_CLEAR_IRQ_BIT
1124                                      | IPMI_BT_INTMASK_ENABLE_IRQ_BIT);
1125
1126         spin_lock_irqsave(&(smi_info->si_lock), flags);
1127
1128         smi_inc_stat(smi_info, interrupts);
1129
1130         debug_timestamp("Interrupt");
1131
1132         smi_event_handler(smi_info, 0);
1133         spin_unlock_irqrestore(&(smi_info->si_lock), flags);
1134         return IRQ_HANDLED;
1135 }
1136
1137 static int smi_start_processing(void            *send_info,
1138                                 struct ipmi_smi *intf)
1139 {
1140         struct smi_info *new_smi = send_info;
1141         int             enable = 0;
1142
1143         new_smi->intf = intf;
1144
1145         /* Set up the timer that drives the interface. */
1146         timer_setup(&new_smi->si_timer, smi_timeout, 0);
1147         new_smi->timer_can_start = true;
1148         smi_mod_timer(new_smi, jiffies + SI_TIMEOUT_JIFFIES);
1149
1150         /* Try to claim any interrupts. */
1151         if (new_smi->io.irq_setup) {
1152                 new_smi->io.irq_handler_data = new_smi;
1153                 new_smi->io.irq_setup(&new_smi->io);
1154         }
1155
1156         /*
1157          * Check if the user forcefully enabled the daemon.
1158          */
1159         if (new_smi->si_num < num_force_kipmid)
1160                 enable = force_kipmid[new_smi->si_num];
1161         /*
1162          * The BT interface is efficient enough to not need a thread,
1163          * and there is no need for a thread if we have interrupts.
1164          */
1165         else if ((new_smi->io.si_type != SI_BT) && (!new_smi->io.irq))
1166                 enable = 1;
1167
1168         if (enable) {
1169                 new_smi->thread = kthread_run(ipmi_thread, new_smi,
1170                                               "kipmi%d", new_smi->si_num);
1171                 if (IS_ERR(new_smi->thread)) {
1172                         dev_notice(new_smi->io.dev, "Could not start"
1173                                    " kernel thread due to error %ld, only using"
1174                                    " timers to drive the interface\n",
1175                                    PTR_ERR(new_smi->thread));
1176                         new_smi->thread = NULL;
1177                 }
1178         }
1179
1180         return 0;
1181 }
1182
1183 static int get_smi_info(void *send_info, struct ipmi_smi_info *data)
1184 {
1185         struct smi_info *smi = send_info;
1186
1187         data->addr_src = smi->io.addr_source;
1188         data->dev = smi->io.dev;
1189         data->addr_info = smi->io.addr_info;
1190         get_device(smi->io.dev);
1191
1192         return 0;
1193 }
1194
1195 static void set_maintenance_mode(void *send_info, bool enable)
1196 {
1197         struct smi_info   *smi_info = send_info;
1198
1199         if (!enable)
1200                 atomic_set(&smi_info->req_events, 0);
1201         smi_info->in_maintenance_mode = enable;
1202 }
1203
1204 static void shutdown_smi(void *send_info);
1205 static const struct ipmi_smi_handlers handlers = {
1206         .owner                  = THIS_MODULE,
1207         .start_processing       = smi_start_processing,
1208         .shutdown               = shutdown_smi,
1209         .get_smi_info           = get_smi_info,
1210         .sender                 = sender,
1211         .request_events         = request_events,
1212         .set_need_watch         = set_need_watch,
1213         .set_maintenance_mode   = set_maintenance_mode,
1214         .set_run_to_completion  = set_run_to_completion,
1215         .flush_messages         = flush_messages,
1216         .poll                   = poll,
1217 };
1218
1219 static LIST_HEAD(smi_infos);
1220 static DEFINE_MUTEX(smi_infos_lock);
1221 static int smi_num; /* Used to sequence the SMIs */
1222
1223 static const char * const addr_space_to_str[] = { "i/o", "mem" };
1224
1225 module_param_array(force_kipmid, int, &num_force_kipmid, 0);
1226 MODULE_PARM_DESC(force_kipmid, "Force the kipmi daemon to be enabled (1) or"
1227                  " disabled(0).  Normally the IPMI driver auto-detects"
1228                  " this, but the value may be overridden by this parm.");
1229 module_param(unload_when_empty, bool, 0);
1230 MODULE_PARM_DESC(unload_when_empty, "Unload the module if no interfaces are"
1231                  " specified or found, default is 1.  Setting to 0"
1232                  " is useful for hot add of devices using hotmod.");
1233 module_param_array(kipmid_max_busy_us, uint, &num_max_busy_us, 0644);
1234 MODULE_PARM_DESC(kipmid_max_busy_us,
1235                  "Max time (in microseconds) to busy-wait for IPMI data before"
1236                  " sleeping. 0 (default) means to wait forever. Set to 100-500"
1237                  " if kipmid is using up a lot of CPU time.");
1238
1239 void ipmi_irq_finish_setup(struct si_sm_io *io)
1240 {
1241         if (io->si_type == SI_BT)
1242                 /* Enable the interrupt in the BT interface. */
1243                 io->outputb(io, IPMI_BT_INTMASK_REG,
1244                             IPMI_BT_INTMASK_ENABLE_IRQ_BIT);
1245 }
1246
1247 void ipmi_irq_start_cleanup(struct si_sm_io *io)
1248 {
1249         if (io->si_type == SI_BT)
1250                 /* Disable the interrupt in the BT interface. */
1251                 io->outputb(io, IPMI_BT_INTMASK_REG, 0);
1252 }
1253
1254 static void std_irq_cleanup(struct si_sm_io *io)
1255 {
1256         ipmi_irq_start_cleanup(io);
1257         free_irq(io->irq, io->irq_handler_data);
1258 }
1259
1260 int ipmi_std_irq_setup(struct si_sm_io *io)
1261 {
1262         int rv;
1263
1264         if (!io->irq)
1265                 return 0;
1266
1267         rv = request_irq(io->irq,
1268                          ipmi_si_irq_handler,
1269                          IRQF_SHARED,
1270                          SI_DEVICE_NAME,
1271                          io->irq_handler_data);
1272         if (rv) {
1273                 dev_warn(io->dev, "%s unable to claim interrupt %d,"
1274                          " running polled\n",
1275                          SI_DEVICE_NAME, io->irq);
1276                 io->irq = 0;
1277         } else {
1278                 io->irq_cleanup = std_irq_cleanup;
1279                 ipmi_irq_finish_setup(io);
1280                 dev_info(io->dev, "Using irq %d\n", io->irq);
1281         }
1282
1283         return rv;
1284 }
1285
1286 static int wait_for_msg_done(struct smi_info *smi_info)
1287 {
1288         enum si_sm_result     smi_result;
1289
1290         smi_result = smi_info->handlers->event(smi_info->si_sm, 0);
1291         for (;;) {
1292                 if (smi_result == SI_SM_CALL_WITH_DELAY ||
1293                     smi_result == SI_SM_CALL_WITH_TICK_DELAY) {
1294                         schedule_timeout_uninterruptible(1);
1295                         smi_result = smi_info->handlers->event(
1296                                 smi_info->si_sm, jiffies_to_usecs(1));
1297                 } else if (smi_result == SI_SM_CALL_WITHOUT_DELAY) {
1298                         smi_result = smi_info->handlers->event(
1299                                 smi_info->si_sm, 0);
1300                 } else
1301                         break;
1302         }
1303         if (smi_result == SI_SM_HOSED)
1304                 /*
1305                  * We couldn't get the state machine to run, so whatever's at
1306                  * the port is probably not an IPMI SMI interface.
1307                  */
1308                 return -ENODEV;
1309
1310         return 0;
1311 }
1312
1313 static int try_get_dev_id(struct smi_info *smi_info)
1314 {
1315         unsigned char         msg[2];
1316         unsigned char         *resp;
1317         unsigned long         resp_len;
1318         int                   rv = 0;
1319         unsigned int          retry_count = 0;
1320
1321         resp = kmalloc(IPMI_MAX_MSG_LENGTH, GFP_KERNEL);
1322         if (!resp)
1323                 return -ENOMEM;
1324
1325         /*
1326          * Do a Get Device ID command, since it comes back with some
1327          * useful info.
1328          */
1329         msg[0] = IPMI_NETFN_APP_REQUEST << 2;
1330         msg[1] = IPMI_GET_DEVICE_ID_CMD;
1331
1332 retry:
1333         smi_info->handlers->start_transaction(smi_info->si_sm, msg, 2);
1334
1335         rv = wait_for_msg_done(smi_info);
1336         if (rv)
1337                 goto out;
1338
1339         resp_len = smi_info->handlers->get_result(smi_info->si_sm,
1340                                                   resp, IPMI_MAX_MSG_LENGTH);
1341
1342         /* Check and record info from the get device id, in case we need it. */
1343         rv = ipmi_demangle_device_id(resp[0] >> 2, resp[1],
1344                         resp + 2, resp_len - 2, &smi_info->device_id);
1345         if (rv) {
1346                 /* record completion code */
1347                 unsigned char cc = *(resp + 2);
1348
1349                 if (cc != IPMI_CC_NO_ERROR &&
1350                     ++retry_count <= GET_DEVICE_ID_MAX_RETRY) {
1351                         dev_warn(smi_info->io.dev,
1352                             "BMC returned 0x%2.2x, retry get bmc device id\n",
1353                             cc);
1354                         goto retry;
1355                 }
1356         }
1357
1358 out:
1359         kfree(resp);
1360         return rv;
1361 }
1362
1363 static int get_global_enables(struct smi_info *smi_info, u8 *enables)
1364 {
1365         unsigned char         msg[3];
1366         unsigned char         *resp;
1367         unsigned long         resp_len;
1368         int                   rv;
1369
1370         resp = kmalloc(IPMI_MAX_MSG_LENGTH, GFP_KERNEL);
1371         if (!resp)
1372                 return -ENOMEM;
1373
1374         msg[0] = IPMI_NETFN_APP_REQUEST << 2;
1375         msg[1] = IPMI_GET_BMC_GLOBAL_ENABLES_CMD;
1376         smi_info->handlers->start_transaction(smi_info->si_sm, msg, 2);
1377
1378         rv = wait_for_msg_done(smi_info);
1379         if (rv) {
1380                 dev_warn(smi_info->io.dev,
1381                          "Error getting response from get global enables command: %d\n",
1382                          rv);
1383                 goto out;
1384         }
1385
1386         resp_len = smi_info->handlers->get_result(smi_info->si_sm,
1387                                                   resp, IPMI_MAX_MSG_LENGTH);
1388
1389         if (resp_len < 4 ||
1390                         resp[0] != (IPMI_NETFN_APP_REQUEST | 1) << 2 ||
1391                         resp[1] != IPMI_GET_BMC_GLOBAL_ENABLES_CMD   ||
1392                         resp[2] != 0) {
1393                 dev_warn(smi_info->io.dev,
1394                          "Invalid return from get global enables command: %ld %x %x %x\n",
1395                          resp_len, resp[0], resp[1], resp[2]);
1396                 rv = -EINVAL;
1397                 goto out;
1398         } else {
1399                 *enables = resp[3];
1400         }
1401
1402 out:
1403         kfree(resp);
1404         return rv;
1405 }
1406
1407 /*
1408  * Returns 1 if it gets an error from the command.
1409  */
1410 static int set_global_enables(struct smi_info *smi_info, u8 enables)
1411 {
1412         unsigned char         msg[3];
1413         unsigned char         *resp;
1414         unsigned long         resp_len;
1415         int                   rv;
1416
1417         resp = kmalloc(IPMI_MAX_MSG_LENGTH, GFP_KERNEL);
1418         if (!resp)
1419                 return -ENOMEM;
1420
1421         msg[0] = IPMI_NETFN_APP_REQUEST << 2;
1422         msg[1] = IPMI_SET_BMC_GLOBAL_ENABLES_CMD;
1423         msg[2] = enables;
1424         smi_info->handlers->start_transaction(smi_info->si_sm, msg, 3);
1425
1426         rv = wait_for_msg_done(smi_info);
1427         if (rv) {
1428                 dev_warn(smi_info->io.dev,
1429                          "Error getting response from set global enables command: %d\n",
1430                          rv);
1431                 goto out;
1432         }
1433
1434         resp_len = smi_info->handlers->get_result(smi_info->si_sm,
1435                                                   resp, IPMI_MAX_MSG_LENGTH);
1436
1437         if (resp_len < 3 ||
1438                         resp[0] != (IPMI_NETFN_APP_REQUEST | 1) << 2 ||
1439                         resp[1] != IPMI_SET_BMC_GLOBAL_ENABLES_CMD) {
1440                 dev_warn(smi_info->io.dev,
1441                          "Invalid return from set global enables command: %ld %x %x\n",
1442                          resp_len, resp[0], resp[1]);
1443                 rv = -EINVAL;
1444                 goto out;
1445         }
1446
1447         if (resp[2] != 0)
1448                 rv = 1;
1449
1450 out:
1451         kfree(resp);
1452         return rv;
1453 }
1454
1455 /*
1456  * Some BMCs do not support clearing the receive irq bit in the global
1457  * enables (even if they don't support interrupts on the BMC).  Check
1458  * for this and handle it properly.
1459  */
1460 static void check_clr_rcv_irq(struct smi_info *smi_info)
1461 {
1462         u8 enables = 0;
1463         int rv;
1464
1465         rv = get_global_enables(smi_info, &enables);
1466         if (!rv) {
1467                 if ((enables & IPMI_BMC_RCV_MSG_INTR) == 0)
1468                         /* Already clear, should work ok. */
1469                         return;
1470
1471                 enables &= ~IPMI_BMC_RCV_MSG_INTR;
1472                 rv = set_global_enables(smi_info, enables);
1473         }
1474
1475         if (rv < 0) {
1476                 dev_err(smi_info->io.dev,
1477                         "Cannot check clearing the rcv irq: %d\n", rv);
1478                 return;
1479         }
1480
1481         if (rv) {
1482                 /*
1483                  * An error when setting the event buffer bit means
1484                  * clearing the bit is not supported.
1485                  */
1486                 dev_warn(smi_info->io.dev,
1487                          "The BMC does not support clearing the recv irq bit, compensating, but the BMC needs to be fixed.\n");
1488                 smi_info->cannot_disable_irq = true;
1489         }
1490 }
1491
1492 /*
1493  * Some BMCs do not support setting the interrupt bits in the global
1494  * enables even if they support interrupts.  Clearly bad, but we can
1495  * compensate.
1496  */
1497 static void check_set_rcv_irq(struct smi_info *smi_info)
1498 {
1499         u8 enables = 0;
1500         int rv;
1501
1502         if (!smi_info->io.irq)
1503                 return;
1504
1505         rv = get_global_enables(smi_info, &enables);
1506         if (!rv) {
1507                 enables |= IPMI_BMC_RCV_MSG_INTR;
1508                 rv = set_global_enables(smi_info, enables);
1509         }
1510
1511         if (rv < 0) {
1512                 dev_err(smi_info->io.dev,
1513                         "Cannot check setting the rcv irq: %d\n", rv);
1514                 return;
1515         }
1516
1517         if (rv) {
1518                 /*
1519                  * An error when setting the event buffer bit means
1520                  * setting the bit is not supported.
1521                  */
1522                 dev_warn(smi_info->io.dev,
1523                          "The BMC does not support setting the recv irq bit, compensating, but the BMC needs to be fixed.\n");
1524                 smi_info->cannot_disable_irq = true;
1525                 smi_info->irq_enable_broken = true;
1526         }
1527 }
1528
1529 static int try_enable_event_buffer(struct smi_info *smi_info)
1530 {
1531         unsigned char         msg[3];
1532         unsigned char         *resp;
1533         unsigned long         resp_len;
1534         int                   rv = 0;
1535
1536         resp = kmalloc(IPMI_MAX_MSG_LENGTH, GFP_KERNEL);
1537         if (!resp)
1538                 return -ENOMEM;
1539
1540         msg[0] = IPMI_NETFN_APP_REQUEST << 2;
1541         msg[1] = IPMI_GET_BMC_GLOBAL_ENABLES_CMD;
1542         smi_info->handlers->start_transaction(smi_info->si_sm, msg, 2);
1543
1544         rv = wait_for_msg_done(smi_info);
1545         if (rv) {
1546                 pr_warn("Error getting response from get global enables command, the event buffer is not enabled\n");
1547                 goto out;
1548         }
1549
1550         resp_len = smi_info->handlers->get_result(smi_info->si_sm,
1551                                                   resp, IPMI_MAX_MSG_LENGTH);
1552
1553         if (resp_len < 4 ||
1554                         resp[0] != (IPMI_NETFN_APP_REQUEST | 1) << 2 ||
1555                         resp[1] != IPMI_GET_BMC_GLOBAL_ENABLES_CMD   ||
1556                         resp[2] != 0) {
1557                 pr_warn("Invalid return from get global enables command, cannot enable the event buffer\n");
1558                 rv = -EINVAL;
1559                 goto out;
1560         }
1561
1562         if (resp[3] & IPMI_BMC_EVT_MSG_BUFF) {
1563                 /* buffer is already enabled, nothing to do. */
1564                 smi_info->supports_event_msg_buff = true;
1565                 goto out;
1566         }
1567
1568         msg[0] = IPMI_NETFN_APP_REQUEST << 2;
1569         msg[1] = IPMI_SET_BMC_GLOBAL_ENABLES_CMD;
1570         msg[2] = resp[3] | IPMI_BMC_EVT_MSG_BUFF;
1571         smi_info->handlers->start_transaction(smi_info->si_sm, msg, 3);
1572
1573         rv = wait_for_msg_done(smi_info);
1574         if (rv) {
1575                 pr_warn("Error getting response from set global, enables command, the event buffer is not enabled\n");
1576                 goto out;
1577         }
1578
1579         resp_len = smi_info->handlers->get_result(smi_info->si_sm,
1580                                                   resp, IPMI_MAX_MSG_LENGTH);
1581
1582         if (resp_len < 3 ||
1583                         resp[0] != (IPMI_NETFN_APP_REQUEST | 1) << 2 ||
1584                         resp[1] != IPMI_SET_BMC_GLOBAL_ENABLES_CMD) {
1585                 pr_warn("Invalid return from get global, enables command, not enable the event buffer\n");
1586                 rv = -EINVAL;
1587                 goto out;
1588         }
1589
1590         if (resp[2] != 0)
1591                 /*
1592                  * An error when setting the event buffer bit means
1593                  * that the event buffer is not supported.
1594                  */
1595                 rv = -ENOENT;
1596         else
1597                 smi_info->supports_event_msg_buff = true;
1598
1599 out:
1600         kfree(resp);
1601         return rv;
1602 }
1603
1604 #define IPMI_SI_ATTR(name) \
1605 static ssize_t name##_show(struct device *dev,                  \
1606                            struct device_attribute *attr,               \
1607                            char *buf)                                   \
1608 {                                                                       \
1609         struct smi_info *smi_info = dev_get_drvdata(dev);               \
1610                                                                         \
1611         return snprintf(buf, 10, "%u\n", smi_get_stat(smi_info, name)); \
1612 }                                                                       \
1613 static DEVICE_ATTR(name, 0444, name##_show, NULL)
1614
1615 static ssize_t type_show(struct device *dev,
1616                          struct device_attribute *attr,
1617                          char *buf)
1618 {
1619         struct smi_info *smi_info = dev_get_drvdata(dev);
1620
1621         return snprintf(buf, 10, "%s\n", si_to_str[smi_info->io.si_type]);
1622 }
1623 static DEVICE_ATTR(type, 0444, type_show, NULL);
1624
1625 static ssize_t interrupts_enabled_show(struct device *dev,
1626                                        struct device_attribute *attr,
1627                                        char *buf)
1628 {
1629         struct smi_info *smi_info = dev_get_drvdata(dev);
1630         int enabled = smi_info->io.irq && !smi_info->interrupt_disabled;
1631
1632         return snprintf(buf, 10, "%d\n", enabled);
1633 }
1634 static DEVICE_ATTR(interrupts_enabled, 0444,
1635                    interrupts_enabled_show, NULL);
1636
1637 IPMI_SI_ATTR(short_timeouts);
1638 IPMI_SI_ATTR(long_timeouts);
1639 IPMI_SI_ATTR(idles);
1640 IPMI_SI_ATTR(interrupts);
1641 IPMI_SI_ATTR(attentions);
1642 IPMI_SI_ATTR(flag_fetches);
1643 IPMI_SI_ATTR(hosed_count);
1644 IPMI_SI_ATTR(complete_transactions);
1645 IPMI_SI_ATTR(events);
1646 IPMI_SI_ATTR(watchdog_pretimeouts);
1647 IPMI_SI_ATTR(incoming_messages);
1648
1649 static ssize_t params_show(struct device *dev,
1650                            struct device_attribute *attr,
1651                            char *buf)
1652 {
1653         struct smi_info *smi_info = dev_get_drvdata(dev);
1654
1655         return snprintf(buf, 200,
1656                         "%s,%s,0x%lx,rsp=%d,rsi=%d,rsh=%d,irq=%d,ipmb=%d\n",
1657                         si_to_str[smi_info->io.si_type],
1658                         addr_space_to_str[smi_info->io.addr_space],
1659                         smi_info->io.addr_data,
1660                         smi_info->io.regspacing,
1661                         smi_info->io.regsize,
1662                         smi_info->io.regshift,
1663                         smi_info->io.irq,
1664                         smi_info->io.slave_addr);
1665 }
1666 static DEVICE_ATTR(params, 0444, params_show, NULL);
1667
1668 static struct attribute *ipmi_si_dev_attrs[] = {
1669         &dev_attr_type.attr,
1670         &dev_attr_interrupts_enabled.attr,
1671         &dev_attr_short_timeouts.attr,
1672         &dev_attr_long_timeouts.attr,
1673         &dev_attr_idles.attr,
1674         &dev_attr_interrupts.attr,
1675         &dev_attr_attentions.attr,
1676         &dev_attr_flag_fetches.attr,
1677         &dev_attr_hosed_count.attr,
1678         &dev_attr_complete_transactions.attr,
1679         &dev_attr_events.attr,
1680         &dev_attr_watchdog_pretimeouts.attr,
1681         &dev_attr_incoming_messages.attr,
1682         &dev_attr_params.attr,
1683         NULL
1684 };
1685
1686 static const struct attribute_group ipmi_si_dev_attr_group = {
1687         .attrs          = ipmi_si_dev_attrs,
1688 };
1689
1690 /*
1691  * oem_data_avail_to_receive_msg_avail
1692  * @info - smi_info structure with msg_flags set
1693  *
1694  * Converts flags from OEM_DATA_AVAIL to RECEIVE_MSG_AVAIL
1695  * Returns 1 indicating need to re-run handle_flags().
1696  */
1697 static int oem_data_avail_to_receive_msg_avail(struct smi_info *smi_info)
1698 {
1699         smi_info->msg_flags = ((smi_info->msg_flags & ~OEM_DATA_AVAIL) |
1700                                RECEIVE_MSG_AVAIL);
1701         return 1;
1702 }
1703
1704 /*
1705  * setup_dell_poweredge_oem_data_handler
1706  * @info - smi_info.device_id must be populated
1707  *
1708  * Systems that match, but have firmware version < 1.40 may assert
1709  * OEM0_DATA_AVAIL on their own, without being told via Set Flags that
1710  * it's safe to do so.  Such systems will de-assert OEM1_DATA_AVAIL
1711  * upon receipt of IPMI_GET_MSG_CMD, so we should treat these flags
1712  * as RECEIVE_MSG_AVAIL instead.
1713  *
1714  * As Dell has no plans to release IPMI 1.5 firmware that *ever*
1715  * assert the OEM[012] bits, and if it did, the driver would have to
1716  * change to handle that properly, we don't actually check for the
1717  * firmware version.
1718  * Device ID = 0x20                BMC on PowerEdge 8G servers
1719  * Device Revision = 0x80
1720  * Firmware Revision1 = 0x01       BMC version 1.40
1721  * Firmware Revision2 = 0x40       BCD encoded
1722  * IPMI Version = 0x51             IPMI 1.5
1723  * Manufacturer ID = A2 02 00      Dell IANA
1724  *
1725  * Additionally, PowerEdge systems with IPMI < 1.5 may also assert
1726  * OEM0_DATA_AVAIL and needs to be treated as RECEIVE_MSG_AVAIL.
1727  *
1728  */
1729 #define DELL_POWEREDGE_8G_BMC_DEVICE_ID  0x20
1730 #define DELL_POWEREDGE_8G_BMC_DEVICE_REV 0x80
1731 #define DELL_POWEREDGE_8G_BMC_IPMI_VERSION 0x51
1732 #define DELL_IANA_MFR_ID 0x0002a2
1733 static void setup_dell_poweredge_oem_data_handler(struct smi_info *smi_info)
1734 {
1735         struct ipmi_device_id *id = &smi_info->device_id;
1736         if (id->manufacturer_id == DELL_IANA_MFR_ID) {
1737                 if (id->device_id       == DELL_POWEREDGE_8G_BMC_DEVICE_ID  &&
1738                     id->device_revision == DELL_POWEREDGE_8G_BMC_DEVICE_REV &&
1739                     id->ipmi_version   == DELL_POWEREDGE_8G_BMC_IPMI_VERSION) {
1740                         smi_info->oem_data_avail_handler =
1741                                 oem_data_avail_to_receive_msg_avail;
1742                 } else if (ipmi_version_major(id) < 1 ||
1743                            (ipmi_version_major(id) == 1 &&
1744                             ipmi_version_minor(id) < 5)) {
1745                         smi_info->oem_data_avail_handler =
1746                                 oem_data_avail_to_receive_msg_avail;
1747                 }
1748         }
1749 }
1750
1751 #define CANNOT_RETURN_REQUESTED_LENGTH 0xCA
1752 static void return_hosed_msg_badsize(struct smi_info *smi_info)
1753 {
1754         struct ipmi_smi_msg *msg = smi_info->curr_msg;
1755
1756         /* Make it a response */
1757         msg->rsp[0] = msg->data[0] | 4;
1758         msg->rsp[1] = msg->data[1];
1759         msg->rsp[2] = CANNOT_RETURN_REQUESTED_LENGTH;
1760         msg->rsp_size = 3;
1761         smi_info->curr_msg = NULL;
1762         deliver_recv_msg(smi_info, msg);
1763 }
1764
1765 /*
1766  * dell_poweredge_bt_xaction_handler
1767  * @info - smi_info.device_id must be populated
1768  *
1769  * Dell PowerEdge servers with the BT interface (x6xx and 1750) will
1770  * not respond to a Get SDR command if the length of the data
1771  * requested is exactly 0x3A, which leads to command timeouts and no
1772  * data returned.  This intercepts such commands, and causes userspace
1773  * callers to try again with a different-sized buffer, which succeeds.
1774  */
1775
1776 #define STORAGE_NETFN 0x0A
1777 #define STORAGE_CMD_GET_SDR 0x23
1778 static int dell_poweredge_bt_xaction_handler(struct notifier_block *self,
1779                                              unsigned long unused,
1780                                              void *in)
1781 {
1782         struct smi_info *smi_info = in;
1783         unsigned char *data = smi_info->curr_msg->data;
1784         unsigned int size   = smi_info->curr_msg->data_size;
1785         if (size >= 8 &&
1786             (data[0]>>2) == STORAGE_NETFN &&
1787             data[1] == STORAGE_CMD_GET_SDR &&
1788             data[7] == 0x3A) {
1789                 return_hosed_msg_badsize(smi_info);
1790                 return NOTIFY_STOP;
1791         }
1792         return NOTIFY_DONE;
1793 }
1794
1795 static struct notifier_block dell_poweredge_bt_xaction_notifier = {
1796         .notifier_call  = dell_poweredge_bt_xaction_handler,
1797 };
1798
1799 /*
1800  * setup_dell_poweredge_bt_xaction_handler
1801  * @info - smi_info.device_id must be filled in already
1802  *
1803  * Fills in smi_info.device_id.start_transaction_pre_hook
1804  * when we know what function to use there.
1805  */
1806 static void
1807 setup_dell_poweredge_bt_xaction_handler(struct smi_info *smi_info)
1808 {
1809         struct ipmi_device_id *id = &smi_info->device_id;
1810         if (id->manufacturer_id == DELL_IANA_MFR_ID &&
1811             smi_info->io.si_type == SI_BT)
1812                 register_xaction_notifier(&dell_poweredge_bt_xaction_notifier);
1813 }
1814
1815 /*
1816  * setup_oem_data_handler
1817  * @info - smi_info.device_id must be filled in already
1818  *
1819  * Fills in smi_info.device_id.oem_data_available_handler
1820  * when we know what function to use there.
1821  */
1822
1823 static void setup_oem_data_handler(struct smi_info *smi_info)
1824 {
1825         setup_dell_poweredge_oem_data_handler(smi_info);
1826 }
1827
1828 static void setup_xaction_handlers(struct smi_info *smi_info)
1829 {
1830         setup_dell_poweredge_bt_xaction_handler(smi_info);
1831 }
1832
1833 static void check_for_broken_irqs(struct smi_info *smi_info)
1834 {
1835         check_clr_rcv_irq(smi_info);
1836         check_set_rcv_irq(smi_info);
1837 }
1838
1839 static inline void stop_timer_and_thread(struct smi_info *smi_info)
1840 {
1841         if (smi_info->thread != NULL) {
1842                 kthread_stop(smi_info->thread);
1843                 smi_info->thread = NULL;
1844         }
1845
1846         smi_info->timer_can_start = false;
1847         del_timer_sync(&smi_info->si_timer);
1848 }
1849
1850 static struct smi_info *find_dup_si(struct smi_info *info)
1851 {
1852         struct smi_info *e;
1853
1854         list_for_each_entry(e, &smi_infos, link) {
1855                 if (e->io.addr_space != info->io.addr_space)
1856                         continue;
1857                 if (e->io.addr_data == info->io.addr_data) {
1858                         /*
1859                          * This is a cheap hack, ACPI doesn't have a defined
1860                          * slave address but SMBIOS does.  Pick it up from
1861                          * any source that has it available.
1862                          */
1863                         if (info->io.slave_addr && !e->io.slave_addr)
1864                                 e->io.slave_addr = info->io.slave_addr;
1865                         return e;
1866                 }
1867         }
1868
1869         return NULL;
1870 }
1871
1872 int ipmi_si_add_smi(struct si_sm_io *io)
1873 {
1874         int rv = 0;
1875         struct smi_info *new_smi, *dup;
1876
1877         /*
1878          * If the user gave us a hard-coded device at the same
1879          * address, they presumably want us to use it and not what is
1880          * in the firmware.
1881          */
1882         if (io->addr_source != SI_HARDCODED && io->addr_source != SI_HOTMOD &&
1883             ipmi_si_hardcode_match(io->addr_space, io->addr_data)) {
1884                 dev_info(io->dev,
1885                          "Hard-coded device at this address already exists");
1886                 return -ENODEV;
1887         }
1888
1889         if (!io->io_setup) {
1890                 if (io->addr_space == IPMI_IO_ADDR_SPACE) {
1891                         io->io_setup = ipmi_si_port_setup;
1892                 } else if (io->addr_space == IPMI_MEM_ADDR_SPACE) {
1893                         io->io_setup = ipmi_si_mem_setup;
1894                 } else {
1895                         return -EINVAL;
1896                 }
1897         }
1898
1899         new_smi = kzalloc(sizeof(*new_smi), GFP_KERNEL);
1900         if (!new_smi)
1901                 return -ENOMEM;
1902         spin_lock_init(&new_smi->si_lock);
1903
1904         new_smi->io = *io;
1905
1906         mutex_lock(&smi_infos_lock);
1907         dup = find_dup_si(new_smi);
1908         if (dup) {
1909                 if (new_smi->io.addr_source == SI_ACPI &&
1910                     dup->io.addr_source == SI_SMBIOS) {
1911                         /* We prefer ACPI over SMBIOS. */
1912                         dev_info(dup->io.dev,
1913                                  "Removing SMBIOS-specified %s state machine in favor of ACPI\n",
1914                                  si_to_str[new_smi->io.si_type]);
1915                         cleanup_one_si(dup);
1916                 } else {
1917                         dev_info(new_smi->io.dev,
1918                                  "%s-specified %s state machine: duplicate\n",
1919                                  ipmi_addr_src_to_str(new_smi->io.addr_source),
1920                                  si_to_str[new_smi->io.si_type]);
1921                         rv = -EBUSY;
1922                         kfree(new_smi);
1923                         goto out_err;
1924                 }
1925         }
1926
1927         pr_info("Adding %s-specified %s state machine\n",
1928                 ipmi_addr_src_to_str(new_smi->io.addr_source),
1929                 si_to_str[new_smi->io.si_type]);
1930
1931         list_add_tail(&new_smi->link, &smi_infos);
1932
1933         if (initialized)
1934                 rv = try_smi_init(new_smi);
1935 out_err:
1936         mutex_unlock(&smi_infos_lock);
1937         return rv;
1938 }
1939
1940 /*
1941  * Try to start up an interface.  Must be called with smi_infos_lock
1942  * held, primarily to keep smi_num consistent, we only one to do these
1943  * one at a time.
1944  */
1945 static int try_smi_init(struct smi_info *new_smi)
1946 {
1947         int rv = 0;
1948         int i;
1949
1950         pr_info("Trying %s-specified %s state machine at %s address 0x%lx, slave address 0x%x, irq %d\n",
1951                 ipmi_addr_src_to_str(new_smi->io.addr_source),
1952                 si_to_str[new_smi->io.si_type],
1953                 addr_space_to_str[new_smi->io.addr_space],
1954                 new_smi->io.addr_data,
1955                 new_smi->io.slave_addr, new_smi->io.irq);
1956
1957         switch (new_smi->io.si_type) {
1958         case SI_KCS:
1959                 new_smi->handlers = &kcs_smi_handlers;
1960                 break;
1961
1962         case SI_SMIC:
1963                 new_smi->handlers = &smic_smi_handlers;
1964                 break;
1965
1966         case SI_BT:
1967                 new_smi->handlers = &bt_smi_handlers;
1968                 break;
1969
1970         default:
1971                 /* No support for anything else yet. */
1972                 rv = -EIO;
1973                 goto out_err;
1974         }
1975
1976         new_smi->si_num = smi_num;
1977
1978         /* Do this early so it's available for logs. */
1979         if (!new_smi->io.dev) {
1980                 pr_err("IPMI interface added with no device\n");
1981                 rv = -EIO;
1982                 goto out_err;
1983         }
1984
1985         /* Allocate the state machine's data and initialize it. */
1986         new_smi->si_sm = kmalloc(new_smi->handlers->size(), GFP_KERNEL);
1987         if (!new_smi->si_sm) {
1988                 rv = -ENOMEM;
1989                 goto out_err;
1990         }
1991         new_smi->io.io_size = new_smi->handlers->init_data(new_smi->si_sm,
1992                                                            &new_smi->io);
1993
1994         /* Now that we know the I/O size, we can set up the I/O. */
1995         rv = new_smi->io.io_setup(&new_smi->io);
1996         if (rv) {
1997                 dev_err(new_smi->io.dev, "Could not set up I/O space\n");
1998                 goto out_err;
1999         }
2000
2001         /* Do low-level detection first. */
2002         if (new_smi->handlers->detect(new_smi->si_sm)) {
2003                 if (new_smi->io.addr_source)
2004                         dev_err(new_smi->io.dev,
2005                                 "Interface detection failed\n");
2006                 rv = -ENODEV;
2007                 goto out_err;
2008         }
2009
2010         /*
2011          * Attempt a get device id command.  If it fails, we probably
2012          * don't have a BMC here.
2013          */
2014         rv = try_get_dev_id(new_smi);
2015         if (rv) {
2016                 if (new_smi->io.addr_source)
2017                         dev_err(new_smi->io.dev,
2018                                "There appears to be no BMC at this location\n");
2019                 goto out_err;
2020         }
2021
2022         setup_oem_data_handler(new_smi);
2023         setup_xaction_handlers(new_smi);
2024         check_for_broken_irqs(new_smi);
2025
2026         new_smi->waiting_msg = NULL;
2027         new_smi->curr_msg = NULL;
2028         atomic_set(&new_smi->req_events, 0);
2029         new_smi->run_to_completion = false;
2030         for (i = 0; i < SI_NUM_STATS; i++)
2031                 atomic_set(&new_smi->stats[i], 0);
2032
2033         new_smi->interrupt_disabled = true;
2034         atomic_set(&new_smi->need_watch, 0);
2035
2036         rv = try_enable_event_buffer(new_smi);
2037         if (rv == 0)
2038                 new_smi->has_event_buffer = true;
2039
2040         /*
2041          * Start clearing the flags before we enable interrupts or the
2042          * timer to avoid racing with the timer.
2043          */
2044         start_clear_flags(new_smi);
2045
2046         /*
2047          * IRQ is defined to be set when non-zero.  req_events will
2048          * cause a global flags check that will enable interrupts.
2049          */
2050         if (new_smi->io.irq) {
2051                 new_smi->interrupt_disabled = false;
2052                 atomic_set(&new_smi->req_events, 1);
2053         }
2054
2055         dev_set_drvdata(new_smi->io.dev, new_smi);
2056         rv = device_add_group(new_smi->io.dev, &ipmi_si_dev_attr_group);
2057         if (rv) {
2058                 dev_err(new_smi->io.dev,
2059                         "Unable to add device attributes: error %d\n",
2060                         rv);
2061                 goto out_err;
2062         }
2063         new_smi->dev_group_added = true;
2064
2065         rv = ipmi_register_smi(&handlers,
2066                                new_smi,
2067                                new_smi->io.dev,
2068                                new_smi->io.slave_addr);
2069         if (rv) {
2070                 dev_err(new_smi->io.dev,
2071                         "Unable to register device: error %d\n",
2072                         rv);
2073                 goto out_err;
2074         }
2075
2076         /* Don't increment till we know we have succeeded. */
2077         smi_num++;
2078
2079         dev_info(new_smi->io.dev, "IPMI %s interface initialized\n",
2080                  si_to_str[new_smi->io.si_type]);
2081
2082         WARN_ON(new_smi->io.dev->init_name != NULL);
2083
2084  out_err:
2085         if (rv && new_smi->io.io_cleanup) {
2086                 new_smi->io.io_cleanup(&new_smi->io);
2087                 new_smi->io.io_cleanup = NULL;
2088         }
2089
2090         return rv;
2091 }
2092
2093 static int __init init_ipmi_si(void)
2094 {
2095         struct smi_info *e;
2096         enum ipmi_addr_src type = SI_INVALID;
2097
2098         if (initialized)
2099                 return 0;
2100
2101         ipmi_hardcode_init();
2102
2103         pr_info("IPMI System Interface driver\n");
2104
2105         ipmi_si_platform_init();
2106
2107         ipmi_si_pci_init();
2108
2109         ipmi_si_parisc_init();
2110
2111         /* We prefer devices with interrupts, but in the case of a machine
2112            with multiple BMCs we assume that there will be several instances
2113            of a given type so if we succeed in registering a type then also
2114            try to register everything else of the same type */
2115         mutex_lock(&smi_infos_lock);
2116         list_for_each_entry(e, &smi_infos, link) {
2117                 /* Try to register a device if it has an IRQ and we either
2118                    haven't successfully registered a device yet or this
2119                    device has the same type as one we successfully registered */
2120                 if (e->io.irq && (!type || e->io.addr_source == type)) {
2121                         if (!try_smi_init(e)) {
2122                                 type = e->io.addr_source;
2123                         }
2124                 }
2125         }
2126
2127         /* type will only have been set if we successfully registered an si */
2128         if (type)
2129                 goto skip_fallback_noirq;
2130
2131         /* Fall back to the preferred device */
2132
2133         list_for_each_entry(e, &smi_infos, link) {
2134                 if (!e->io.irq && (!type || e->io.addr_source == type)) {
2135                         if (!try_smi_init(e)) {
2136                                 type = e->io.addr_source;
2137                         }
2138                 }
2139         }
2140
2141 skip_fallback_noirq:
2142         initialized = true;
2143         mutex_unlock(&smi_infos_lock);
2144
2145         if (type)
2146                 return 0;
2147
2148         mutex_lock(&smi_infos_lock);
2149         if (unload_when_empty && list_empty(&smi_infos)) {
2150                 mutex_unlock(&smi_infos_lock);
2151                 cleanup_ipmi_si();
2152                 pr_warn("Unable to find any System Interface(s)\n");
2153                 return -ENODEV;
2154         } else {
2155                 mutex_unlock(&smi_infos_lock);
2156                 return 0;
2157         }
2158 }
2159 module_init(init_ipmi_si);
2160
2161 static void shutdown_smi(void *send_info)
2162 {
2163         struct smi_info *smi_info = send_info;
2164
2165         if (smi_info->dev_group_added) {
2166                 device_remove_group(smi_info->io.dev, &ipmi_si_dev_attr_group);
2167                 smi_info->dev_group_added = false;
2168         }
2169         if (smi_info->io.dev)
2170                 dev_set_drvdata(smi_info->io.dev, NULL);
2171
2172         /*
2173          * Make sure that interrupts, the timer and the thread are
2174          * stopped and will not run again.
2175          */
2176         smi_info->interrupt_disabled = true;
2177         if (smi_info->io.irq_cleanup) {
2178                 smi_info->io.irq_cleanup(&smi_info->io);
2179                 smi_info->io.irq_cleanup = NULL;
2180         }
2181         stop_timer_and_thread(smi_info);
2182
2183         /*
2184          * Wait until we know that we are out of any interrupt
2185          * handlers might have been running before we freed the
2186          * interrupt.
2187          */
2188         synchronize_rcu();
2189
2190         /*
2191          * Timeouts are stopped, now make sure the interrupts are off
2192          * in the BMC.  Note that timers and CPU interrupts are off,
2193          * so no need for locks.
2194          */
2195         while (smi_info->curr_msg || (smi_info->si_state != SI_NORMAL)) {
2196                 poll(smi_info);
2197                 schedule_timeout_uninterruptible(1);
2198         }
2199         if (smi_info->handlers)
2200                 disable_si_irq(smi_info);
2201         while (smi_info->curr_msg || (smi_info->si_state != SI_NORMAL)) {
2202                 poll(smi_info);
2203                 schedule_timeout_uninterruptible(1);
2204         }
2205         if (smi_info->handlers)
2206                 smi_info->handlers->cleanup(smi_info->si_sm);
2207
2208         if (smi_info->io.addr_source_cleanup) {
2209                 smi_info->io.addr_source_cleanup(&smi_info->io);
2210                 smi_info->io.addr_source_cleanup = NULL;
2211         }
2212         if (smi_info->io.io_cleanup) {
2213                 smi_info->io.io_cleanup(&smi_info->io);
2214                 smi_info->io.io_cleanup = NULL;
2215         }
2216
2217         kfree(smi_info->si_sm);
2218         smi_info->si_sm = NULL;
2219
2220         smi_info->intf = NULL;
2221 }
2222
2223 /*
2224  * Must be called with smi_infos_lock held, to serialize the
2225  * smi_info->intf check.
2226  */
2227 static void cleanup_one_si(struct smi_info *smi_info)
2228 {
2229         if (!smi_info)
2230                 return;
2231
2232         list_del(&smi_info->link);
2233
2234         if (smi_info->intf)
2235                 ipmi_unregister_smi(smi_info->intf);
2236
2237         kfree(smi_info);
2238 }
2239
2240 int ipmi_si_remove_by_dev(struct device *dev)
2241 {
2242         struct smi_info *e;
2243         int rv = -ENOENT;
2244
2245         mutex_lock(&smi_infos_lock);
2246         list_for_each_entry(e, &smi_infos, link) {
2247                 if (e->io.dev == dev) {
2248                         cleanup_one_si(e);
2249                         rv = 0;
2250                         break;
2251                 }
2252         }
2253         mutex_unlock(&smi_infos_lock);
2254
2255         return rv;
2256 }
2257
2258 struct device *ipmi_si_remove_by_data(int addr_space, enum si_type si_type,
2259                                       unsigned long addr)
2260 {
2261         /* remove */
2262         struct smi_info *e, *tmp_e;
2263         struct device *dev = NULL;
2264
2265         mutex_lock(&smi_infos_lock);
2266         list_for_each_entry_safe(e, tmp_e, &smi_infos, link) {
2267                 if (e->io.addr_space != addr_space)
2268                         continue;
2269                 if (e->io.si_type != si_type)
2270                         continue;
2271                 if (e->io.addr_data == addr) {
2272                         dev = get_device(e->io.dev);
2273                         cleanup_one_si(e);
2274                 }
2275         }
2276         mutex_unlock(&smi_infos_lock);
2277
2278         return dev;
2279 }
2280
2281 static void cleanup_ipmi_si(void)
2282 {
2283         struct smi_info *e, *tmp_e;
2284
2285         if (!initialized)
2286                 return;
2287
2288         ipmi_si_pci_shutdown();
2289
2290         ipmi_si_parisc_shutdown();
2291
2292         ipmi_si_platform_shutdown();
2293
2294         mutex_lock(&smi_infos_lock);
2295         list_for_each_entry_safe(e, tmp_e, &smi_infos, link)
2296                 cleanup_one_si(e);
2297         mutex_unlock(&smi_infos_lock);
2298
2299         ipmi_si_hardcode_exit();
2300         ipmi_si_hotmod_exit();
2301 }
2302 module_exit(cleanup_ipmi_si);
2303
2304 MODULE_ALIAS("platform:dmi-ipmi-si");
2305 MODULE_LICENSE("GPL");
2306 MODULE_AUTHOR("Corey Minyard <minyard@mvista.com>");
2307 MODULE_DESCRIPTION("Interface to the IPMI driver for the KCS, SMIC, and BT"
2308                    " system interfaces.");