drivers/char/ipmi/ipmi_ssif.c

   1 // SPDX-License-Identifier: GPL-2.0+
   2 /*
   3  * ipmi_ssif.c
   4  *
   5  * The interface to the IPMI driver for SMBus access to a SMBus
   6  * compliant device.  Called SSIF by the IPMI spec.
   7  *
   8  * Author: Intel Corporation
   9  *         Todd Davis <todd.c.davis@intel.com>
  10  *
  11  * Rewritten by Corey Minyard <minyard@acm.org> to support the
  12  * non-blocking I2C interface, add support for multi-part
  13  * transactions, add PEC support, and general clenaup.
  14  *
  15  * Copyright 2003 Intel Corporation
  16  * Copyright 2005 MontaVista Software
  17  */
  18
  19 /*
  20  * This file holds the "policy" for the interface to the SSIF state
  21  * machine.  It does the configuration, handles timers and interrupts,
  22  * and drives the real SSIF state machine.
  23  */
  24
  25 /*
  26  * TODO: Figure out how to use SMB alerts.  This will require a new
  27  * interface into the I2C driver, I believe.
  28  */
  29
  30 #define pr_fmt(fmt) "ipmi_ssif: " fmt
  31 #define dev_fmt(fmt) "ipmi_ssif: " fmt
  32
  33 #if defined(MODVERSIONS)
  34 #include <linux/modversions.h>
  35 #endif
  36
  37 #include <linux/module.h>
  38 #include <linux/moduleparam.h>
  39 #include <linux/sched.h>
  40 #include <linux/seq_file.h>
  41 #include <linux/timer.h>
  42 #include <linux/delay.h>
  43 #include <linux/errno.h>
  44 #include <linux/spinlock.h>
  45 #include <linux/slab.h>
  46 #include <linux/list.h>
  47 #include <linux/i2c.h>
  48 #include <linux/ipmi_smi.h>
  49 #include <linux/init.h>
  50 #include <linux/dmi.h>
  51 #include <linux/kthread.h>
  52 #include <linux/acpi.h>
  53 #include <linux/ctype.h>
  54 #include <linux/time64.h>
  55 #include "ipmi_dmi.h"
  56
  57 #define DEVICE_NAME "ipmi_ssif"
  58
  59 #define IPMI_GET_SYSTEM_INTERFACE_CAPABILITIES_CMD      0x57
  60
  61 #define SSIF_IPMI_REQUEST                       2
  62 #define SSIF_IPMI_MULTI_PART_REQUEST_START      6
  63 #define SSIF_IPMI_MULTI_PART_REQUEST_MIDDLE     7
  64 #define SSIF_IPMI_MULTI_PART_REQUEST_END        8
  65 #define SSIF_IPMI_RESPONSE                      3
  66 #define SSIF_IPMI_MULTI_PART_RESPONSE_MIDDLE    9
  67
  68 /* ssif_debug is a bit-field
  69  *      SSIF_DEBUG_MSG -        commands and their responses
  70  *      SSIF_DEBUG_STATES -     message states
  71  *      SSIF_DEBUG_TIMING -      Measure times between events in the driver
  72  */
  73 #define SSIF_DEBUG_TIMING       4
  74 #define SSIF_DEBUG_STATE        2
  75 #define SSIF_DEBUG_MSG          1
  76 #define SSIF_NODEBUG            0
  77 #define SSIF_DEFAULT_DEBUG      (SSIF_NODEBUG)
  78
  79 /*
  80  * Timer values
  81  */
  82 #define SSIF_MSG_USEC           20000   /* 20ms between message tries. */
  83 #define SSIF_MSG_PART_USEC      5000    /* 5ms for a message part */
  84
  85 /* How many times to we retry sending/receiving the message. */
  86 #define SSIF_SEND_RETRIES       5
  87 #define SSIF_RECV_RETRIES       250
  88
  89 #define SSIF_MSG_MSEC           (SSIF_MSG_USEC / 1000)
  90 #define SSIF_MSG_JIFFIES        ((SSIF_MSG_USEC * 1000) / TICK_NSEC)
  91 #define SSIF_MSG_PART_JIFFIES   ((SSIF_MSG_PART_USEC * 1000) / TICK_NSEC)
  92
  93 /*
  94  * Timeout for the watch, only used for get flag timer.
  95  */
  96 #define SSIF_WATCH_MSG_TIMEOUT          msecs_to_jiffies(10)
  97 #define SSIF_WATCH_WATCHDOG_TIMEOUT     msecs_to_jiffies(250)
  98
  99 enum ssif_intf_state {
 100         SSIF_NORMAL,
 101         SSIF_GETTING_FLAGS,
 102         SSIF_GETTING_EVENTS,
 103         SSIF_CLEARING_FLAGS,
 104         SSIF_GETTING_MESSAGES,
 105         /* FIXME - add watchdog stuff. */
 106 };
 107
 108 #define SSIF_IDLE(ssif)  ((ssif)->ssif_state == SSIF_NORMAL \
 109                           && (ssif)->curr_msg == NULL)
 110
 111 /*
 112  * Indexes into stats[] in ssif_info below.
 113  */
 114 enum ssif_stat_indexes {
 115         /* Number of total messages sent. */
 116         SSIF_STAT_sent_messages = 0,
 117
 118         /*
 119          * Number of message parts sent.  Messages may be broken into
 120          * parts if they are long.
 121          */
 122         SSIF_STAT_sent_messages_parts,
 123
 124         /*
 125          * Number of time a message was retried.
 126          */
 127         SSIF_STAT_send_retries,
 128
 129         /*
 130          * Number of times the send of a message failed.
 131          */
 132         SSIF_STAT_send_errors,
 133
 134         /*
 135          * Number of message responses received.
 136          */
 137         SSIF_STAT_received_messages,
 138
 139         /*
 140          * Number of message fragments received.
 141          */
 142         SSIF_STAT_received_message_parts,
 143
 144         /*
 145          * Number of times the receive of a message was retried.
 146          */
 147         SSIF_STAT_receive_retries,
 148
 149         /*
 150          * Number of errors receiving messages.
 151          */
 152         SSIF_STAT_receive_errors,
 153
 154         /*
 155          * Number of times a flag fetch was requested.
 156          */
 157         SSIF_STAT_flag_fetches,
 158
 159         /*
 160          * Number of times the hardware didn't follow the state machine.
 161          */
 162         SSIF_STAT_hosed,
 163
 164         /*
 165          * Number of received events.
 166          */
 167         SSIF_STAT_events,
 168
 169         /* Number of asyncronous messages received. */
 170         SSIF_STAT_incoming_messages,
 171
 172         /* Number of watchdog pretimeouts. */
 173         SSIF_STAT_watchdog_pretimeouts,
 174
 175         /* Number of alers received. */
 176         SSIF_STAT_alerts,
 177
 178         /* Always add statistics before this value, it must be last. */
 179         SSIF_NUM_STATS
 180 };
 181
 182 struct ssif_addr_info {
 183         struct i2c_board_info binfo;
 184         char *adapter_name;
 185         int debug;
 186         int slave_addr;
 187         enum ipmi_addr_src addr_src;
 188         union ipmi_smi_info_union addr_info;
 189         struct device *dev;
 190         struct i2c_client *client;
 191
 192         struct i2c_client *added_client;
 193
 194         struct mutex clients_mutex;
 195         struct list_head clients;
 196
 197         struct list_head link;
 198 };
 199
 200 struct ssif_info;
 201
 202 typedef void (*ssif_i2c_done)(struct ssif_info *ssif_info, int result,
 203                              unsigned char *data, unsigned int len);
 204
 205 struct ssif_info {
 206         struct ipmi_smi     *intf;
 207         spinlock_t          lock;
 208         struct ipmi_smi_msg *waiting_msg;
 209         struct ipmi_smi_msg *curr_msg;
 210         enum ssif_intf_state ssif_state;
 211         unsigned long       ssif_debug;
 212
 213         struct ipmi_smi_handlers handlers;
 214
 215         enum ipmi_addr_src addr_source; /* ACPI, PCI, SMBIOS, hardcode, etc. */
 216         union ipmi_smi_info_union addr_info;
 217
 218         /*
 219          * Flags from the last GET_MSG_FLAGS command, used when an ATTN
 220          * is set to hold the flags until we are done handling everything
 221          * from the flags.
 222          */
 223 #define RECEIVE_MSG_AVAIL       0x01
 224 #define EVENT_MSG_BUFFER_FULL   0x02
 225 #define WDT_PRE_TIMEOUT_INT     0x08
 226         unsigned char       msg_flags;
 227
 228         u8                  global_enables;
 229         bool                has_event_buffer;
 230         bool                supports_alert;
 231
 232         /*
 233          * Used to tell what we should do with alerts.  If we are
 234          * waiting on a response, read the data immediately.
 235          */
 236         bool                got_alert;
 237         bool                waiting_alert;
 238
 239         /*
 240          * If set to true, this will request events the next time the
 241          * state machine is idle.
 242          */
 243         bool                req_events;
 244
 245         /*
 246          * If set to true, this will request flags the next time the
 247          * state machine is idle.
 248          */
 249         bool                req_flags;
 250
 251         /*
 252          * Used to perform timer operations when run-to-completion
 253          * mode is on.  This is a countdown timer.
 254          */
 255         int                 rtc_us_timer;
 256
 257         /* Used for sending/receiving data.  +1 for the length. */
 258         unsigned char data[IPMI_MAX_MSG_LENGTH + 1];
 259         unsigned int  data_len;
 260
 261         /* Temp receive buffer, gets copied into data. */
 262         unsigned char recv[I2C_SMBUS_BLOCK_MAX];
 263
 264         struct i2c_client *client;
 265         ssif_i2c_done done_handler;
 266
 267         /* Thread interface handling */
 268         struct task_struct *thread;
 269         struct completion wake_thread;
 270         bool stopping;
 271         int i2c_read_write;
 272         int i2c_command;
 273         unsigned char *i2c_data;
 274         unsigned int i2c_size;
 275
 276         struct timer_list retry_timer;
 277         int retries_left;
 278
 279         long watch_timeout;             /* Timeout for flags check, 0 if off. */
 280         struct timer_list watch_timer;  /* Flag fetch timer. */
 281
 282         /* Info from SSIF cmd */
 283         unsigned char max_xmit_msg_size;
 284         unsigned char max_recv_msg_size;
 285         bool cmd8_works; /* See test_multipart_messages() for details. */
 286         unsigned int  multi_support;
 287         int           supports_pec;
 288
 289 #define SSIF_NO_MULTI           0
 290 #define SSIF_MULTI_2_PART       1
 291 #define SSIF_MULTI_n_PART       2
 292         unsigned char *multi_data;
 293         unsigned int  multi_len;
 294         unsigned int  multi_pos;
 295
 296         atomic_t stats[SSIF_NUM_STATS];
 297 };
 298
 299 #define ssif_inc_stat(ssif, stat) \
 300         atomic_inc(&(ssif)->stats[SSIF_STAT_ ## stat])
 301 #define ssif_get_stat(ssif, stat) \
 302         ((unsigned int) atomic_read(&(ssif)->stats[SSIF_STAT_ ## stat]))
 303
 304 static bool initialized;
 305 static bool platform_registered;
 306
 307 static void return_hosed_msg(struct ssif_info *ssif_info,
 308                              struct ipmi_smi_msg *msg);
 309 static void start_next_msg(struct ssif_info *ssif_info, unsigned long *flags);
 310 static int start_send(struct ssif_info *ssif_info,
 311                       unsigned char   *data,
 312                       unsigned int    len);
 313
 314 static unsigned long *ipmi_ssif_lock_cond(struct ssif_info *ssif_info,
 315                                           unsigned long *flags)
 316         __acquires(&ssif_info->lock)
 317 {
 318         spin_lock_irqsave(&ssif_info->lock, *flags);
 319         return flags;
 320 }
 321
 322 static void ipmi_ssif_unlock_cond(struct ssif_info *ssif_info,
 323                                   unsigned long *flags)
 324         __releases(&ssif_info->lock)
 325 {
 326         spin_unlock_irqrestore(&ssif_info->lock, *flags);
 327 }
 328
 329 static void deliver_recv_msg(struct ssif_info *ssif_info,
 330                              struct ipmi_smi_msg *msg)
 331 {
 332         if (msg->rsp_size < 0) {
 333                 return_hosed_msg(ssif_info, msg);
 334                 dev_err(&ssif_info->client->dev,
 335                         "%s: Malformed message: rsp_size = %d\n",
 336                        __func__, msg->rsp_size);
 337         } else {
 338                 ipmi_smi_msg_received(ssif_info->intf, msg);
 339         }
 340 }
 341
 342 static void return_hosed_msg(struct ssif_info *ssif_info,
 343                              struct ipmi_smi_msg *msg)
 344 {
 345         ssif_inc_stat(ssif_info, hosed);
 346
 347         /* Make it a response */
 348         msg->rsp[0] = msg->data[0] | 4;
 349         msg->rsp[1] = msg->data[1];
 350         msg->rsp[2] = 0xFF; /* Unknown error. */
 351         msg->rsp_size = 3;
 352
 353         deliver_recv_msg(ssif_info, msg);
 354 }
 355
 356 /*
 357  * Must be called with the message lock held.  This will release the
 358  * message lock.  Note that the caller will check SSIF_IDLE and start a
 359  * new operation, so there is no need to check for new messages to
 360  * start in here.
 361  */
 362 static void start_clear_flags(struct ssif_info *ssif_info, unsigned long *flags)
 363 {
 364         unsigned char msg[3];
 365
 366         ssif_info->msg_flags &= ~WDT_PRE_TIMEOUT_INT;
 367         ssif_info->ssif_state = SSIF_CLEARING_FLAGS;
 368         ipmi_ssif_unlock_cond(ssif_info, flags);
 369
 370         /* Make sure the watchdog pre-timeout flag is not set at startup. */
 371         msg[0] = (IPMI_NETFN_APP_REQUEST << 2);
 372         msg[1] = IPMI_CLEAR_MSG_FLAGS_CMD;
 373         msg[2] = WDT_PRE_TIMEOUT_INT;
 374
 375         if (start_send(ssif_info, msg, 3) != 0) {
 376                 /* Error, just go to normal state. */
 377                 ssif_info->ssif_state = SSIF_NORMAL;
 378         }
 379 }
 380
 381 static void start_flag_fetch(struct ssif_info *ssif_info, unsigned long *flags)
 382 {
 383         unsigned char mb[2];
 384
 385         ssif_info->req_flags = false;
 386         ssif_info->ssif_state = SSIF_GETTING_FLAGS;
 387         ipmi_ssif_unlock_cond(ssif_info, flags);
 388
 389         mb[0] = (IPMI_NETFN_APP_REQUEST << 2);
 390         mb[1] = IPMI_GET_MSG_FLAGS_CMD;
 391         if (start_send(ssif_info, mb, 2) != 0)
 392                 ssif_info->ssif_state = SSIF_NORMAL;
 393 }
 394
 395 static void check_start_send(struct ssif_info *ssif_info, unsigned long *flags,
 396                              struct ipmi_smi_msg *msg)
 397 {
 398         if (start_send(ssif_info, msg->data, msg->data_size) != 0) {
 399                 unsigned long oflags;
 400
 401                 flags = ipmi_ssif_lock_cond(ssif_info, &oflags);
 402                 ssif_info->curr_msg = NULL;
 403                 ssif_info->ssif_state = SSIF_NORMAL;
 404                 ipmi_ssif_unlock_cond(ssif_info, flags);
 405                 ipmi_free_smi_msg(msg);
 406         }
 407 }
 408
 409 static void start_event_fetch(struct ssif_info *ssif_info, unsigned long *flags)
 410 {
 411         struct ipmi_smi_msg *msg;
 412
 413         ssif_info->req_events = false;
 414
 415         msg = ipmi_alloc_smi_msg();
 416         if (!msg) {
 417                 ssif_info->ssif_state = SSIF_NORMAL;
 418                 ipmi_ssif_unlock_cond(ssif_info, flags);
 419                 return;
 420         }
 421
 422         ssif_info->curr_msg = msg;
 423         ssif_info->ssif_state = SSIF_GETTING_EVENTS;
 424         ipmi_ssif_unlock_cond(ssif_info, flags);
 425
 426         msg->data[0] = (IPMI_NETFN_APP_REQUEST << 2);
 427         msg->data[1] = IPMI_READ_EVENT_MSG_BUFFER_CMD;
 428         msg->data_size = 2;
 429
 430         check_start_send(ssif_info, flags, msg);
 431 }
 432
 433 static void start_recv_msg_fetch(struct ssif_info *ssif_info,
 434                                  unsigned long *flags)
 435 {
 436         struct ipmi_smi_msg *msg;
 437
 438         msg = ipmi_alloc_smi_msg();
 439         if (!msg) {
 440                 ssif_info->ssif_state = SSIF_NORMAL;
 441                 ipmi_ssif_unlock_cond(ssif_info, flags);
 442                 return;
 443         }
 444
 445         ssif_info->curr_msg = msg;
 446         ssif_info->ssif_state = SSIF_GETTING_MESSAGES;
 447         ipmi_ssif_unlock_cond(ssif_info, flags);
 448
 449         msg->data[0] = (IPMI_NETFN_APP_REQUEST << 2);
 450         msg->data[1] = IPMI_GET_MSG_CMD;
 451         msg->data_size = 2;
 452
 453         check_start_send(ssif_info, flags, msg);
 454 }
 455
 456 /*
 457  * Must be called with the message lock held.  This will release the
 458  * message lock.  Note that the caller will check SSIF_IDLE and start a
 459  * new operation, so there is no need to check for new messages to
 460  * start in here.
 461  */
 462 static void handle_flags(struct ssif_info *ssif_info, unsigned long *flags)
 463 {
 464         if (ssif_info->msg_flags & WDT_PRE_TIMEOUT_INT) {
 465                 /* Watchdog pre-timeout */
 466                 ssif_inc_stat(ssif_info, watchdog_pretimeouts);
 467                 start_clear_flags(ssif_info, flags);
 468                 ipmi_smi_watchdog_pretimeout(ssif_info->intf);
 469         } else if (ssif_info->msg_flags & RECEIVE_MSG_AVAIL)
 470                 /* Messages available. */
 471                 start_recv_msg_fetch(ssif_info, flags);
 472         else if (ssif_info->msg_flags & EVENT_MSG_BUFFER_FULL)
 473                 /* Events available. */
 474                 start_event_fetch(ssif_info, flags);
 475         else {
 476                 ssif_info->ssif_state = SSIF_NORMAL;
 477                 ipmi_ssif_unlock_cond(ssif_info, flags);
 478         }
 479 }
 480
 481 static int ipmi_ssif_thread(void *data)
 482 {
 483         struct ssif_info *ssif_info = data;
 484
 485         while (!kthread_should_stop()) {
 486                 int result;
 487
 488                 /* Wait for something to do */
 489                 result = wait_for_completion_interruptible(
 490                                                 &ssif_info->wake_thread);
 491                 if (ssif_info->stopping)
 492                         break;
 493                 if (result == -ERESTARTSYS)
 494                         continue;
 495                 init_completion(&ssif_info->wake_thread);
 496
 497                 if (ssif_info->i2c_read_write == I2C_SMBUS_WRITE) {
 498                         result = i2c_smbus_write_block_data(
 499                                 ssif_info->client, ssif_info->i2c_command,
 500                                 ssif_info->i2c_data[0],
 501                                 ssif_info->i2c_data + 1);
 502                         ssif_info->done_handler(ssif_info, result, NULL, 0);
 503                 } else {
 504                         result = i2c_smbus_read_block_data(
 505                                 ssif_info->client, ssif_info->i2c_command,
 506                                 ssif_info->i2c_data);
 507                         if (result < 0)
 508                                 ssif_info->done_handler(ssif_info, result,
 509                                                         NULL, 0);
 510                         else
 511                                 ssif_info->done_handler(ssif_info, 0,
 512                                                         ssif_info->i2c_data,
 513                                                         result);
 514                 }
 515         }
 516
 517         return 0;
 518 }
 519
 520 static int ssif_i2c_send(struct ssif_info *ssif_info,
 521                         ssif_i2c_done handler,
 522                         int read_write, int command,
 523                         unsigned char *data, unsigned int size)
 524 {
 525         ssif_info->done_handler = handler;
 526
 527         ssif_info->i2c_read_write = read_write;
 528         ssif_info->i2c_command = command;
 529         ssif_info->i2c_data = data;
 530         ssif_info->i2c_size = size;
 531         complete(&ssif_info->wake_thread);
 532         return 0;
 533 }
 534
 535
 536 static void msg_done_handler(struct ssif_info *ssif_info, int result,
 537                              unsigned char *data, unsigned int len);
 538
 539 static void start_get(struct ssif_info *ssif_info)
 540 {
 541         int rv;
 542
 543         ssif_info->rtc_us_timer = 0;
 544         ssif_info->multi_pos = 0;
 545
 546         rv = ssif_i2c_send(ssif_info, msg_done_handler, I2C_SMBUS_READ,
 547                           SSIF_IPMI_RESPONSE,
 548                           ssif_info->recv, I2C_SMBUS_BLOCK_DATA);
 549         if (rv < 0) {
 550                 /* request failed, just return the error. */
 551                 if (ssif_info->ssif_debug & SSIF_DEBUG_MSG)
 552                         dev_dbg(&ssif_info->client->dev,
 553                                 "Error from i2c_non_blocking_op(5)\n");
 554
 555                 msg_done_handler(ssif_info, -EIO, NULL, 0);
 556         }
 557 }
 558
 559 static void retry_timeout(struct timer_list *t)
 560 {
 561         struct ssif_info *ssif_info = from_timer(ssif_info, t, retry_timer);
 562         unsigned long oflags, *flags;
 563         bool waiting;
 564
 565         if (ssif_info->stopping)
 566                 return;
 567
 568         flags = ipmi_ssif_lock_cond(ssif_info, &oflags);
 569         waiting = ssif_info->waiting_alert;
 570         ssif_info->waiting_alert = false;
 571         ipmi_ssif_unlock_cond(ssif_info, flags);
 572
 573         if (waiting)
 574                 start_get(ssif_info);
 575 }
 576
 577 static void watch_timeout(struct timer_list *t)
 578 {
 579         struct ssif_info *ssif_info = from_timer(ssif_info, t, watch_timer);
 580         unsigned long oflags, *flags;
 581
 582         if (ssif_info->stopping)
 583                 return;
 584
 585         flags = ipmi_ssif_lock_cond(ssif_info, &oflags);
 586         if (ssif_info->watch_timeout) {
 587                 mod_timer(&ssif_info->watch_timer,
 588                           jiffies + ssif_info->watch_timeout);
 589                 if (SSIF_IDLE(ssif_info)) {
 590                         start_flag_fetch(ssif_info, flags); /* Releases lock */
 591                         return;
 592                 }
 593                 ssif_info->req_flags = true;
 594         }
 595         ipmi_ssif_unlock_cond(ssif_info, flags);
 596 }
 597
 598 static void ssif_alert(struct i2c_client *client, enum i2c_alert_protocol type,
 599                        unsigned int data)
 600 {
 601         struct ssif_info *ssif_info = i2c_get_clientdata(client);
 602         unsigned long oflags, *flags;
 603         bool do_get = false;
 604
 605         if (type != I2C_PROTOCOL_SMBUS_ALERT)
 606                 return;
 607
 608         ssif_inc_stat(ssif_info, alerts);
 609
 610         flags = ipmi_ssif_lock_cond(ssif_info, &oflags);
 611         if (ssif_info->waiting_alert) {
 612                 ssif_info->waiting_alert = false;
 613                 del_timer(&ssif_info->retry_timer);
 614                 do_get = true;
 615         } else if (ssif_info->curr_msg) {
 616                 ssif_info->got_alert = true;
 617         }
 618         ipmi_ssif_unlock_cond(ssif_info, flags);
 619         if (do_get)
 620                 start_get(ssif_info);
 621 }
 622
 623 static int start_resend(struct ssif_info *ssif_info);
 624
 625 static void msg_done_handler(struct ssif_info *ssif_info, int result,
 626                              unsigned char *data, unsigned int len)
 627 {
 628         struct ipmi_smi_msg *msg;
 629         unsigned long oflags, *flags;
 630         int rv;
 631
 632         /*
 633          * We are single-threaded here, so no need for a lock until we
 634          * start messing with driver states or the queues.
 635          */
 636
 637         if (result < 0) {
 638                 ssif_info->retries_left--;
 639                 if (ssif_info->retries_left > 0) {
 640                         ssif_inc_stat(ssif_info, receive_retries);
 641
 642                         flags = ipmi_ssif_lock_cond(ssif_info, &oflags);
 643                         ssif_info->waiting_alert = true;
 644                         ssif_info->rtc_us_timer = SSIF_MSG_USEC;
 645                         if (!ssif_info->stopping)
 646                                 mod_timer(&ssif_info->retry_timer,
 647                                           jiffies + SSIF_MSG_JIFFIES);
 648                         ipmi_ssif_unlock_cond(ssif_info, flags);
 649                         return;
 650                 }
 651
 652                 ssif_inc_stat(ssif_info, receive_errors);
 653
 654                 if  (ssif_info->ssif_debug & SSIF_DEBUG_MSG)
 655                         dev_dbg(&ssif_info->client->dev,
 656                                 "%s: Error %d\n", __func__, result);
 657                 len = 0;
 658                 goto continue_op;
 659         }
 660
 661         if ((len > 1) && (ssif_info->multi_pos == 0)
 662                                 && (data[0] == 0x00) && (data[1] == 0x01)) {
 663                 /* Start of multi-part read.  Start the next transaction. */
 664                 int i;
 665
 666                 ssif_inc_stat(ssif_info, received_message_parts);
 667
 668                 /* Remove the multi-part read marker. */
 669                 len -= 2;
 670                 data += 2;
 671                 for (i = 0; i < len; i++)
 672                         ssif_info->data[i] = data[i];
 673                 ssif_info->multi_len = len;
 674                 ssif_info->multi_pos = 1;
 675
 676                 rv = ssif_i2c_send(ssif_info, msg_done_handler, I2C_SMBUS_READ,
 677                                   SSIF_IPMI_MULTI_PART_RESPONSE_MIDDLE,
 678                                   ssif_info->recv, I2C_SMBUS_BLOCK_DATA);
 679                 if (rv < 0) {
 680                         if (ssif_info->ssif_debug & SSIF_DEBUG_MSG)
 681                                 dev_dbg(&ssif_info->client->dev,
 682                                         "Error from i2c_non_blocking_op(1)\n");
 683
 684                         result = -EIO;
 685                 } else
 686                         return;
 687         } else if (ssif_info->multi_pos) {
 688                 /* Middle of multi-part read.  Start the next transaction. */
 689                 int i;
 690                 unsigned char blocknum;
 691
 692                 if (len == 0) {
 693                         result = -EIO;
 694                         if (ssif_info->ssif_debug & SSIF_DEBUG_MSG)
 695                                 dev_dbg(&ssif_info->client->dev,
 696                                         "Middle message with no data\n");
 697
 698                         goto continue_op;
 699                 }
 700
 701                 blocknum = data[0];
 702                 len--;
 703                 data++;
 704
 705                 if (blocknum != 0xff && len != 31) {
 706                     /* All blocks but the last must have 31 data bytes. */
 707                         result = -EIO;
 708                         if (ssif_info->ssif_debug & SSIF_DEBUG_MSG)
 709                                 dev_dbg(&ssif_info->client->dev,
 710                                         "Received middle message <31\n");
 711
 712                         goto continue_op;
 713                 }
 714
 715                 if (ssif_info->multi_len + len > IPMI_MAX_MSG_LENGTH) {
 716                         /* Received message too big, abort the operation. */
 717                         result = -E2BIG;
 718                         if (ssif_info->ssif_debug & SSIF_DEBUG_MSG)
 719                                 dev_dbg(&ssif_info->client->dev,
 720                                         "Received message too big\n");
 721
 722                         goto continue_op;
 723                 }
 724
 725                 for (i = 0; i < len; i++)
 726                         ssif_info->data[i + ssif_info->multi_len] = data[i];
 727                 ssif_info->multi_len += len;
 728                 if (blocknum == 0xff) {
 729                         /* End of read */
 730                         len = ssif_info->multi_len;
 731                         data = ssif_info->data;
 732                 } else if (blocknum + 1 != ssif_info->multi_pos) {
 733                         /*
 734                          * Out of sequence block, just abort.  Block
 735                          * numbers start at zero for the second block,
 736                          * but multi_pos starts at one, so the +1.
 737                          */
 738                         if (ssif_info->ssif_debug & SSIF_DEBUG_MSG)
 739                                 dev_dbg(&ssif_info->client->dev,
 740                                         "Received message out of sequence, expected %u, got %u\n",
 741                                         ssif_info->multi_pos - 1, blocknum);
 742                         result = -EIO;
 743                 } else {
 744                         ssif_inc_stat(ssif_info, received_message_parts);
 745
 746                         ssif_info->multi_pos++;
 747
 748                         rv = ssif_i2c_send(ssif_info, msg_done_handler,
 749                                            I2C_SMBUS_READ,
 750                                            SSIF_IPMI_MULTI_PART_RESPONSE_MIDDLE,
 751                                            ssif_info->recv,
 752                                            I2C_SMBUS_BLOCK_DATA);
 753                         if (rv < 0) {
 754                                 if (ssif_info->ssif_debug & SSIF_DEBUG_MSG)
 755                                         dev_dbg(&ssif_info->client->dev,
 756                                                 "Error from ssif_i2c_send\n");
 757
 758                                 result = -EIO;
 759                         } else
 760                                 return;
 761                 }
 762         }
 763
 764  continue_op:
 765         if (result < 0) {
 766                 ssif_inc_stat(ssif_info, receive_errors);
 767         } else {
 768                 ssif_inc_stat(ssif_info, received_messages);
 769                 ssif_inc_stat(ssif_info, received_message_parts);
 770         }
 771
 772         if (ssif_info->ssif_debug & SSIF_DEBUG_STATE)
 773                 dev_dbg(&ssif_info->client->dev,
 774                         "DONE 1: state = %d, result=%d\n",
 775                         ssif_info->ssif_state, result);
 776
 777         flags = ipmi_ssif_lock_cond(ssif_info, &oflags);
 778         msg = ssif_info->curr_msg;
 779         if (msg) {
 780                 if (data) {
 781                         if (len > IPMI_MAX_MSG_LENGTH)
 782                                 len = IPMI_MAX_MSG_LENGTH;
 783                         memcpy(msg->rsp, data, len);
 784                 } else {
 785                         len = 0;
 786                 }
 787                 msg->rsp_size = len;
 788                 ssif_info->curr_msg = NULL;
 789         }
 790
 791         switch (ssif_info->ssif_state) {
 792         case SSIF_NORMAL:
 793                 ipmi_ssif_unlock_cond(ssif_info, flags);
 794                 if (!msg)
 795                         break;
 796
 797                 if (result < 0)
 798                         return_hosed_msg(ssif_info, msg);
 799                 else
 800                         deliver_recv_msg(ssif_info, msg);
 801                 break;
 802
 803         case SSIF_GETTING_FLAGS:
 804                 /* We got the flags from the SSIF, now handle them. */
 805                 if ((result < 0) || (len < 4) || (data[2] != 0)) {
 806                         /*
 807                          * Error fetching flags, or invalid length,
 808                          * just give up for now.
 809                          */
 810                         ssif_info->ssif_state = SSIF_NORMAL;
 811                         ipmi_ssif_unlock_cond(ssif_info, flags);
 812                         dev_warn(&ssif_info->client->dev,
 813                                  "Error getting flags: %d %d, %x\n",
 814                                  result, len, (len >= 3) ? data[2] : 0);
 815                 } else if (data[0] != (IPMI_NETFN_APP_REQUEST | 1) << 2
 816                            || data[1] != IPMI_GET_MSG_FLAGS_CMD) {
 817                         /*
 818                          * Don't abort here, maybe it was a queued
 819                          * response to a previous command.
 820                          */
 821                         ipmi_ssif_unlock_cond(ssif_info, flags);
 822                         dev_warn(&ssif_info->client->dev,
 823                                  "Invalid response getting flags: %x %x\n",
 824                                  data[0], data[1]);
 825                 } else {
 826                         ssif_inc_stat(ssif_info, flag_fetches);
 827                         ssif_info->msg_flags = data[3];
 828                         handle_flags(ssif_info, flags);
 829                 }
 830                 break;
 831
 832         case SSIF_CLEARING_FLAGS:
 833                 /* We cleared the flags. */
 834                 if ((result < 0) || (len < 3) || (data[2] != 0)) {
 835                         /* Error clearing flags */
 836                         dev_warn(&ssif_info->client->dev,
 837                                  "Error clearing flags: %d %d, %x\n",
 838                                  result, len, (len >= 3) ? data[2] : 0);
 839                 } else if (data[0] != (IPMI_NETFN_APP_REQUEST | 1) << 2
 840                            || data[1] != IPMI_CLEAR_MSG_FLAGS_CMD) {
 841                         dev_warn(&ssif_info->client->dev,
 842                                  "Invalid response clearing flags: %x %x\n",
 843                                  data[0], data[1]);
 844                 }
 845                 ssif_info->ssif_state = SSIF_NORMAL;
 846                 ipmi_ssif_unlock_cond(ssif_info, flags);
 847                 break;
 848
 849         case SSIF_GETTING_EVENTS:
 850                 if ((result < 0) || (len < 3) || (msg->rsp[2] != 0)) {
 851                         /* Error getting event, probably done. */
 852                         msg->done(msg);
 853
 854                         /* Take off the event flag. */
 855                         ssif_info->msg_flags &= ~EVENT_MSG_BUFFER_FULL;
 856                         handle_flags(ssif_info, flags);
 857                 } else if (msg->rsp[0] != (IPMI_NETFN_APP_REQUEST | 1) << 2
 858                            || msg->rsp[1] != IPMI_READ_EVENT_MSG_BUFFER_CMD) {
 859                         dev_warn(&ssif_info->client->dev,
 860                                  "Invalid response getting events: %x %x\n",
 861                                  msg->rsp[0], msg->rsp[1]);
 862                         msg->done(msg);
 863                         /* Take off the event flag. */
 864                         ssif_info->msg_flags &= ~EVENT_MSG_BUFFER_FULL;
 865                         handle_flags(ssif_info, flags);
 866                 } else {
 867                         handle_flags(ssif_info, flags);
 868                         ssif_inc_stat(ssif_info, events);
 869                         deliver_recv_msg(ssif_info, msg);
 870                 }
 871                 break;
 872
 873         case SSIF_GETTING_MESSAGES:
 874                 if ((result < 0) || (len < 3) || (msg->rsp[2] != 0)) {
 875                         /* Error getting event, probably done. */
 876                         msg->done(msg);
 877
 878                         /* Take off the msg flag. */
 879                         ssif_info->msg_flags &= ~RECEIVE_MSG_AVAIL;
 880                         handle_flags(ssif_info, flags);
 881                 } else if (msg->rsp[0] != (IPMI_NETFN_APP_REQUEST | 1) << 2
 882                            || msg->rsp[1] != IPMI_GET_MSG_CMD) {
 883                         dev_warn(&ssif_info->client->dev,
 884                                  "Invalid response clearing flags: %x %x\n",
 885                                  msg->rsp[0], msg->rsp[1]);
 886                         msg->done(msg);
 887
 888                         /* Take off the msg flag. */
 889                         ssif_info->msg_flags &= ~RECEIVE_MSG_AVAIL;
 890                         handle_flags(ssif_info, flags);
 891                 } else {
 892                         ssif_inc_stat(ssif_info, incoming_messages);
 893                         handle_flags(ssif_info, flags);
 894                         deliver_recv_msg(ssif_info, msg);
 895                 }
 896                 break;
 897         }
 898
 899         flags = ipmi_ssif_lock_cond(ssif_info, &oflags);
 900         if (SSIF_IDLE(ssif_info) && !ssif_info->stopping) {
 901                 if (ssif_info->req_events)
 902                         start_event_fetch(ssif_info, flags);
 903                 else if (ssif_info->req_flags)
 904                         start_flag_fetch(ssif_info, flags);
 905                 else
 906                         start_next_msg(ssif_info, flags);
 907         } else
 908                 ipmi_ssif_unlock_cond(ssif_info, flags);
 909
 910         if (ssif_info->ssif_debug & SSIF_DEBUG_STATE)
 911                 dev_dbg(&ssif_info->client->dev,
 912                         "DONE 2: state = %d.\n", ssif_info->ssif_state);
 913 }
 914
 915 static void msg_written_handler(struct ssif_info *ssif_info, int result,
 916                                 unsigned char *data, unsigned int len)
 917 {
 918         int rv;
 919
 920         /* We are single-threaded here, so no need for a lock. */
 921         if (result < 0) {
 922                 ssif_info->retries_left--;
 923                 if (ssif_info->retries_left > 0) {
 924                         if (!start_resend(ssif_info)) {
 925                                 ssif_inc_stat(ssif_info, send_retries);
 926                                 return;
 927                         }
 928                         /* request failed, just return the error. */
 929                         ssif_inc_stat(ssif_info, send_errors);
 930
 931                         if (ssif_info->ssif_debug & SSIF_DEBUG_MSG)
 932                                 dev_dbg(&ssif_info->client->dev,
 933                                         "%s: Out of retries\n", __func__);
 934                         msg_done_handler(ssif_info, -EIO, NULL, 0);
 935                         return;
 936                 }
 937
 938                 ssif_inc_stat(ssif_info, send_errors);
 939
 940                 /*
 941                  * Got an error on transmit, let the done routine
 942                  * handle it.
 943                  */
 944                 if (ssif_info->ssif_debug & SSIF_DEBUG_MSG)
 945                         dev_dbg(&ssif_info->client->dev,
 946                                 "%s: Error  %d\n", __func__, result);
 947
 948                 msg_done_handler(ssif_info, result, NULL, 0);
 949                 return;
 950         }
 951
 952         if (ssif_info->multi_data) {
 953                 /*
 954                  * In the middle of a multi-data write.  See the comment
 955                  * in the SSIF_MULTI_n_PART case in the probe function
 956                  * for details on the intricacies of this.
 957                  */
 958                 int left, to_write;
 959                 unsigned char *data_to_send;
 960                 unsigned char cmd;
 961
 962                 ssif_inc_stat(ssif_info, sent_messages_parts);
 963
 964                 left = ssif_info->multi_len - ssif_info->multi_pos;
 965                 to_write = left;
 966                 if (to_write > 32)
 967                         to_write = 32;
 968                 /* Length byte. */
 969                 ssif_info->multi_data[ssif_info->multi_pos] = to_write;
 970                 data_to_send = ssif_info->multi_data + ssif_info->multi_pos;
 971                 ssif_info->multi_pos += to_write;
 972                 cmd = SSIF_IPMI_MULTI_PART_REQUEST_MIDDLE;
 973                 if (ssif_info->cmd8_works) {
 974                         if (left == to_write) {
 975                                 cmd = SSIF_IPMI_MULTI_PART_REQUEST_END;
 976                                 ssif_info->multi_data = NULL;
 977                         }
 978                 } else if (to_write < 32) {
 979                         ssif_info->multi_data = NULL;
 980                 }
 981
 982                 rv = ssif_i2c_send(ssif_info, msg_written_handler,
 983                                    I2C_SMBUS_WRITE, cmd,
 984                                    data_to_send, I2C_SMBUS_BLOCK_DATA);
 985                 if (rv < 0) {
 986                         /* request failed, just return the error. */
 987                         ssif_inc_stat(ssif_info, send_errors);
 988
 989                         if (ssif_info->ssif_debug & SSIF_DEBUG_MSG)
 990                                 dev_dbg(&ssif_info->client->dev,
 991                                         "Error from i2c_non_blocking_op(3)\n");
 992                         msg_done_handler(ssif_info, -EIO, NULL, 0);
 993                 }
 994         } else {
 995                 /* Ready to request the result. */
 996                 unsigned long oflags, *flags;
 997
 998                 ssif_inc_stat(ssif_info, sent_messages);
 999                 ssif_inc_stat(ssif_info, sent_messages_parts);
1000
1001                 flags = ipmi_ssif_lock_cond(ssif_info, &oflags);
1002                 if (ssif_info->got_alert) {
1003                         /* The result is already ready, just start it. */
1004                         ssif_info->got_alert = false;
1005                         ipmi_ssif_unlock_cond(ssif_info, flags);
1006                         start_get(ssif_info);
1007                 } else {
1008                         /* Wait a jiffie then request the next message */
1009                         ssif_info->waiting_alert = true;
1010                         ssif_info->retries_left = SSIF_RECV_RETRIES;
1011                         ssif_info->rtc_us_timer = SSIF_MSG_PART_USEC;
1012                         if (!ssif_info->stopping)
1013                                 mod_timer(&ssif_info->retry_timer,
1014                                           jiffies + SSIF_MSG_PART_JIFFIES);
1015                         ipmi_ssif_unlock_cond(ssif_info, flags);
1016                 }
1017         }
1018 }
1019
1020 static int start_resend(struct ssif_info *ssif_info)
1021 {
1022         int rv;
1023         int command;
1024
1025         ssif_info->got_alert = false;
1026
1027         if (ssif_info->data_len > 32) {
1028                 command = SSIF_IPMI_MULTI_PART_REQUEST_START;
1029                 ssif_info->multi_data = ssif_info->data;
1030                 ssif_info->multi_len = ssif_info->data_len;
1031                 /*
1032                  * Subtle thing, this is 32, not 33, because we will
1033                  * overwrite the thing at position 32 (which was just
1034                  * transmitted) with the new length.
1035                  */
1036                 ssif_info->multi_pos = 32;
1037                 ssif_info->data[0] = 32;
1038         } else {
1039                 ssif_info->multi_data = NULL;
1040                 command = SSIF_IPMI_REQUEST;
1041                 ssif_info->data[0] = ssif_info->data_len;
1042         }
1043
1044         rv = ssif_i2c_send(ssif_info, msg_written_handler, I2C_SMBUS_WRITE,
1045                           command, ssif_info->data, I2C_SMBUS_BLOCK_DATA);
1046         if (rv && (ssif_info->ssif_debug & SSIF_DEBUG_MSG))
1047                 dev_dbg(&ssif_info->client->dev,
1048                         "Error from i2c_non_blocking_op(4)\n");
1049         return rv;
1050 }
1051
1052 static int start_send(struct ssif_info *ssif_info,
1053                       unsigned char   *data,
1054                       unsigned int    len)
1055 {
1056         if (len > IPMI_MAX_MSG_LENGTH)
1057                 return -E2BIG;
1058         if (len > ssif_info->max_xmit_msg_size)
1059                 return -E2BIG;
1060
1061         ssif_info->retries_left = SSIF_SEND_RETRIES;
1062         memcpy(ssif_info->data + 1, data, len);
1063         ssif_info->data_len = len;
1064         return start_resend(ssif_info);
1065 }
1066
1067 /* Must be called with the message lock held. */
1068 static void start_next_msg(struct ssif_info *ssif_info, unsigned long *flags)
1069 {
1070         struct ipmi_smi_msg *msg;
1071         unsigned long oflags;
1072
1073  restart:
1074         if (!SSIF_IDLE(ssif_info)) {
1075                 ipmi_ssif_unlock_cond(ssif_info, flags);
1076                 return;
1077         }
1078
1079         if (!ssif_info->waiting_msg) {
1080                 ssif_info->curr_msg = NULL;
1081                 ipmi_ssif_unlock_cond(ssif_info, flags);
1082         } else {
1083                 int rv;
1084
1085                 ssif_info->curr_msg = ssif_info->waiting_msg;
1086                 ssif_info->waiting_msg = NULL;
1087                 ipmi_ssif_unlock_cond(ssif_info, flags);
1088                 rv = start_send(ssif_info,
1089                                 ssif_info->curr_msg->data,
1090                                 ssif_info->curr_msg->data_size);
1091                 if (rv) {
1092                         msg = ssif_info->curr_msg;
1093                         ssif_info->curr_msg = NULL;
1094                         return_hosed_msg(ssif_info, msg);
1095                         flags = ipmi_ssif_lock_cond(ssif_info, &oflags);
1096                         goto restart;
1097                 }
1098         }
1099 }
1100
1101 static void sender(void                *send_info,
1102                    struct ipmi_smi_msg *msg)
1103 {
1104         struct ssif_info *ssif_info = (struct ssif_info *) send_info;
1105         unsigned long oflags, *flags;
1106
1107         BUG_ON(ssif_info->waiting_msg);
1108         ssif_info->waiting_msg = msg;
1109
1110         flags = ipmi_ssif_lock_cond(ssif_info, &oflags);
1111         start_next_msg(ssif_info, flags);
1112
1113         if (ssif_info->ssif_debug & SSIF_DEBUG_TIMING) {
1114                 struct timespec64 t;
1115
1116                 ktime_get_real_ts64(&t);
1117                 dev_dbg(&ssif_info->client->dev,
1118                         "**Enqueue %02x %02x: %lld.%6.6ld\n",
1119                         msg->data[0], msg->data[1],
1120                         (long long)t.tv_sec, (long)t.tv_nsec / NSEC_PER_USEC);
1121         }
1122 }
1123
1124 static int get_smi_info(void *send_info, struct ipmi_smi_info *data)
1125 {
1126         struct ssif_info *ssif_info = send_info;
1127
1128         data->addr_src = ssif_info->addr_source;
1129         data->dev = &ssif_info->client->dev;
1130         data->addr_info = ssif_info->addr_info;
1131         get_device(data->dev);
1132
1133         return 0;
1134 }
1135
1136 /*
1137  * Upper layer wants us to request events.
1138  */
1139 static void request_events(void *send_info)
1140 {
1141         struct ssif_info *ssif_info = (struct ssif_info *) send_info;
1142         unsigned long oflags, *flags;
1143
1144         if (!ssif_info->has_event_buffer)
1145                 return;
1146
1147         flags = ipmi_ssif_lock_cond(ssif_info, &oflags);
1148         ssif_info->req_events = true;
1149         ipmi_ssif_unlock_cond(ssif_info, flags);
1150 }
1151
1152 /*
1153  * Upper layer is changing the flag saying whether we need to request
1154  * flags periodically or not.
1155  */
1156 static void ssif_set_need_watch(void *send_info, unsigned int watch_mask)
1157 {
1158         struct ssif_info *ssif_info = (struct ssif_info *) send_info;
1159         unsigned long oflags, *flags;
1160         long timeout = 0;
1161
1162         if (watch_mask & IPMI_WATCH_MASK_CHECK_MESSAGES)
1163                 timeout = SSIF_WATCH_MSG_TIMEOUT;
1164         else if (watch_mask)
1165                 timeout = SSIF_WATCH_WATCHDOG_TIMEOUT;
1166
1167         flags = ipmi_ssif_lock_cond(ssif_info, &oflags);
1168         if (timeout != ssif_info->watch_timeout) {
1169                 ssif_info->watch_timeout = timeout;
1170                 if (ssif_info->watch_timeout)
1171                         mod_timer(&ssif_info->watch_timer,
1172                                   jiffies + ssif_info->watch_timeout);
1173         }
1174         ipmi_ssif_unlock_cond(ssif_info, flags);
1175 }
1176
1177 static int ssif_start_processing(void            *send_info,
1178                                  struct ipmi_smi *intf)
1179 {
1180         struct ssif_info *ssif_info = send_info;
1181
1182         ssif_info->intf = intf;
1183
1184         return 0;
1185 }
1186
1187 #define MAX_SSIF_BMCS 4
1188
1189 static unsigned short addr[MAX_SSIF_BMCS];
1190 static int num_addrs;
1191 module_param_array(addr, ushort, &num_addrs, 0);
1192 MODULE_PARM_DESC(addr, "The addresses to scan for IPMI BMCs on the SSIFs.");
1193
1194 static char *adapter_name[MAX_SSIF_BMCS];
1195 static int num_adapter_names;
1196 module_param_array(adapter_name, charp, &num_adapter_names, 0);
1197 MODULE_PARM_DESC(adapter_name, "The string name of the I2C device that has the BMC.  By default all devices are scanned.");
1198
1199 static int slave_addrs[MAX_SSIF_BMCS];
1200 static int num_slave_addrs;
1201 module_param_array(slave_addrs, int, &num_slave_addrs, 0);
1202 MODULE_PARM_DESC(slave_addrs,
1203                  "The default IPMB slave address for the controller.");
1204
1205 static bool alerts_broken;
1206 module_param(alerts_broken, bool, 0);
1207 MODULE_PARM_DESC(alerts_broken, "Don't enable alerts for the controller.");
1208
1209 /*
1210  * Bit 0 enables message debugging, bit 1 enables state debugging, and
1211  * bit 2 enables timing debugging.  This is an array indexed by
1212  * interface number"
1213  */
1214 static int dbg[MAX_SSIF_BMCS];
1215 static int num_dbg;
1216 module_param_array(dbg, int, &num_dbg, 0);
1217 MODULE_PARM_DESC(dbg, "Turn on debugging.");
1218
1219 static bool ssif_dbg_probe;
1220 module_param_named(dbg_probe, ssif_dbg_probe, bool, 0);
1221 MODULE_PARM_DESC(dbg_probe, "Enable debugging of probing of adapters.");
1222
1223 static bool ssif_tryacpi = true;
1224 module_param_named(tryacpi, ssif_tryacpi, bool, 0);
1225 MODULE_PARM_DESC(tryacpi, "Setting this to zero will disable the default scan of the interfaces identified via ACPI");
1226
1227 static bool ssif_trydmi = true;
1228 module_param_named(trydmi, ssif_trydmi, bool, 0);
1229 MODULE_PARM_DESC(trydmi, "Setting this to zero will disable the default scan of the interfaces identified via DMI (SMBIOS)");
1230
1231 static DEFINE_MUTEX(ssif_infos_mutex);
1232 static LIST_HEAD(ssif_infos);
1233
1234 #define IPMI_SSIF_ATTR(name) \
1235 static ssize_t ipmi_##name##_show(struct device *dev,                   \
1236                                   struct device_attribute *attr,        \
1237                                   char *buf)                            \
1238 {                                                                       \
1239         struct ssif_info *ssif_info = dev_get_drvdata(dev);             \
1240                                                                         \
1241         return snprintf(buf, 10, "%u\n", ssif_get_stat(ssif_info, name));\
1242 }                                                                       \
1243 static DEVICE_ATTR(name, S_IRUGO, ipmi_##name##_show, NULL)
1244
1245 static ssize_t ipmi_type_show(struct device *dev,
1246                               struct device_attribute *attr,
1247                               char *buf)
1248 {
1249         return snprintf(buf, 10, "ssif\n");
1250 }
1251 static DEVICE_ATTR(type, S_IRUGO, ipmi_type_show, NULL);
1252
1253 IPMI_SSIF_ATTR(sent_messages);
1254 IPMI_SSIF_ATTR(sent_messages_parts);
1255 IPMI_SSIF_ATTR(send_retries);
1256 IPMI_SSIF_ATTR(send_errors);
1257 IPMI_SSIF_ATTR(received_messages);
1258 IPMI_SSIF_ATTR(received_message_parts);
1259 IPMI_SSIF_ATTR(receive_retries);
1260 IPMI_SSIF_ATTR(receive_errors);
1261 IPMI_SSIF_ATTR(flag_fetches);
1262 IPMI_SSIF_ATTR(hosed);
1263 IPMI_SSIF_ATTR(events);
1264 IPMI_SSIF_ATTR(watchdog_pretimeouts);
1265 IPMI_SSIF_ATTR(alerts);
1266
1267 static struct attribute *ipmi_ssif_dev_attrs[] = {
1268         &dev_attr_type.attr,
1269         &dev_attr_sent_messages.attr,
1270         &dev_attr_sent_messages_parts.attr,
1271         &dev_attr_send_retries.attr,
1272         &dev_attr_send_errors.attr,
1273         &dev_attr_received_messages.attr,
1274         &dev_attr_received_message_parts.attr,
1275         &dev_attr_receive_retries.attr,
1276         &dev_attr_receive_errors.attr,
1277         &dev_attr_flag_fetches.attr,
1278         &dev_attr_hosed.attr,
1279         &dev_attr_events.attr,
1280         &dev_attr_watchdog_pretimeouts.attr,
1281         &dev_attr_alerts.attr,
1282         NULL
1283 };
1284
1285 static const struct attribute_group ipmi_ssif_dev_attr_group = {
1286         .attrs          = ipmi_ssif_dev_attrs,
1287 };
1288
1289 static void shutdown_ssif(void *send_info)
1290 {
1291         struct ssif_info *ssif_info = send_info;
1292
1293         device_remove_group(&ssif_info->client->dev, &ipmi_ssif_dev_attr_group);
1294         dev_set_drvdata(&ssif_info->client->dev, NULL);
1295
1296         /* make sure the driver is not looking for flags any more. */
1297         while (ssif_info->ssif_state != SSIF_NORMAL)
1298                 schedule_timeout(1);
1299
1300         ssif_info->stopping = true;
1301         del_timer_sync(&ssif_info->watch_timer);
1302         del_timer_sync(&ssif_info->retry_timer);
1303         if (ssif_info->thread) {
1304                 complete(&ssif_info->wake_thread);
1305                 kthread_stop(ssif_info->thread);
1306         }
1307 }
1308
1309 static int ssif_remove(struct i2c_client *client)
1310 {
1311         struct ssif_info *ssif_info = i2c_get_clientdata(client);
1312         struct ssif_addr_info *addr_info;
1313
1314         if (!ssif_info)
1315                 return 0;
1316
1317         /*
1318          * After this point, we won't deliver anything asychronously
1319          * to the message handler.  We can unregister ourself.
1320          */
1321         ipmi_unregister_smi(ssif_info->intf);
1322
1323         list_for_each_entry(addr_info, &ssif_infos, link) {
1324                 if (addr_info->client == client) {
1325                         addr_info->client = NULL;
1326                         break;
1327                 }
1328         }
1329
1330         kfree(ssif_info);
1331
1332         return 0;
1333 }
1334
1335 static int read_response(struct i2c_client *client, unsigned char *resp)
1336 {
1337         int ret = -ENODEV, retry_cnt = SSIF_RECV_RETRIES;
1338
1339         while (retry_cnt > 0) {
1340                 ret = i2c_smbus_read_block_data(client, SSIF_IPMI_RESPONSE,
1341                                                 resp);
1342                 if (ret > 0)
1343                         break;
1344                 msleep(SSIF_MSG_MSEC);
1345                 retry_cnt--;
1346                 if (retry_cnt <= 0)
1347                         break;
1348         }
1349
1350         return ret;
1351 }
1352
1353 static int do_cmd(struct i2c_client *client, int len, unsigned char *msg,
1354                   int *resp_len, unsigned char *resp)
1355 {
1356         int retry_cnt;
1357         int ret;
1358
1359         retry_cnt = SSIF_SEND_RETRIES;
1360  retry1:
1361         ret = i2c_smbus_write_block_data(client, SSIF_IPMI_REQUEST, len, msg);
1362         if (ret) {
1363                 retry_cnt--;
1364                 if (retry_cnt > 0)
1365                         goto retry1;
1366                 return -ENODEV;
1367         }
1368
1369         ret = read_response(client, resp);
1370         if (ret > 0) {
1371                 /* Validate that the response is correct. */
1372                 if (ret < 3 ||
1373                     (resp[0] != (msg[0] | (1 << 2))) ||
1374                     (resp[1] != msg[1]))
1375                         ret = -EINVAL;
1376                 else if (ret > IPMI_MAX_MSG_LENGTH) {
1377                         ret = -E2BIG;
1378                 } else {
1379                         *resp_len = ret;
1380                         ret = 0;
1381                 }
1382         }
1383
1384         return ret;
1385 }
1386
1387 static int ssif_detect(struct i2c_client *client, struct i2c_board_info *info)
1388 {
1389         unsigned char *resp;
1390         unsigned char msg[3];
1391         int           rv;
1392         int           len;
1393
1394         resp = kmalloc(IPMI_MAX_MSG_LENGTH, GFP_KERNEL);
1395         if (!resp)
1396                 return -ENOMEM;
1397
1398         /* Do a Get Device ID command, since it is required. */
1399         msg[0] = IPMI_NETFN_APP_REQUEST << 2;
1400         msg[1] = IPMI_GET_DEVICE_ID_CMD;
1401         rv = do_cmd(client, 2, msg, &len, resp);
1402         if (rv)
1403                 rv = -ENODEV;
1404         else
1405                 strlcpy(info->type, DEVICE_NAME, I2C_NAME_SIZE);
1406         kfree(resp);
1407         return rv;
1408 }
1409
1410 static int strcmp_nospace(char *s1, char *s2)
1411 {
1412         while (*s1 && *s2) {
1413                 while (isspace(*s1))
1414                         s1++;
1415                 while (isspace(*s2))
1416                         s2++;
1417                 if (*s1 > *s2)
1418                         return 1;
1419                 if (*s1 < *s2)
1420                         return -1;
1421                 s1++;
1422                 s2++;
1423         }
1424         return 0;
1425 }
1426
1427 static struct ssif_addr_info *ssif_info_find(unsigned short addr,
1428                                              char *adapter_name,
1429                                              bool match_null_name)
1430 {
1431         struct ssif_addr_info *info, *found = NULL;
1432
1433 restart:
1434         list_for_each_entry(info, &ssif_infos, link) {
1435                 if (info->binfo.addr == addr) {
1436                         if (info->addr_src == SI_SMBIOS)
1437                                 info->adapter_name = kstrdup(adapter_name,
1438                                                              GFP_KERNEL);
1439
1440                         if (info->adapter_name || adapter_name) {
1441                                 if (!info->adapter_name != !adapter_name) {
1442                                         /* One is NULL and one is not */
1443                                         continue;
1444                                 }
1445                                 if (adapter_name &&
1446                                     strcmp_nospace(info->adapter_name,
1447                                                    adapter_name))
1448                                         /* Names do not match */
1449                                         continue;
1450                         }
1451                         found = info;
1452                         break;
1453                 }
1454         }
1455
1456         if (!found && match_null_name) {
1457                 /* Try to get an exact match first, then try with a NULL name */
1458                 adapter_name = NULL;
1459                 match_null_name = false;
1460                 goto restart;
1461         }
1462
1463         return found;
1464 }
1465
1466 static bool check_acpi(struct ssif_info *ssif_info, struct device *dev)
1467 {
1468 #ifdef CONFIG_ACPI
1469         acpi_handle acpi_handle;
1470
1471         acpi_handle = ACPI_HANDLE(dev);
1472         if (acpi_handle) {
1473                 ssif_info->addr_source = SI_ACPI;
1474                 ssif_info->addr_info.acpi_info.acpi_handle = acpi_handle;
1475                 return true;
1476         }
1477 #endif
1478         return false;
1479 }
1480
1481 static int find_slave_address(struct i2c_client *client, int slave_addr)
1482 {
1483 #ifdef CONFIG_IPMI_DMI_DECODE
1484         if (!slave_addr)
1485                 slave_addr = ipmi_dmi_get_slave_addr(
1486                         SI_TYPE_INVALID,
1487                         i2c_adapter_id(client->adapter),
1488                         client->addr);
1489 #endif
1490
1491         return slave_addr;
1492 }
1493
1494 static int start_multipart_test(struct i2c_client *client,
1495                                 unsigned char *msg, bool do_middle)
1496 {
1497         int retry_cnt = SSIF_SEND_RETRIES, ret;
1498
1499 retry_write:
1500         ret = i2c_smbus_write_block_data(client,
1501                                          SSIF_IPMI_MULTI_PART_REQUEST_START,
1502                                          32, msg);
1503         if (ret) {
1504                 retry_cnt--;
1505                 if (retry_cnt > 0)
1506                         goto retry_write;
1507                 dev_err(&client->dev, "Could not write multi-part start, though the BMC said it could handle it.  Just limit sends to one part.\n");
1508                 return ret;
1509         }
1510
1511         if (!do_middle)
1512                 return 0;
1513
1514         ret = i2c_smbus_write_block_data(client,
1515                                          SSIF_IPMI_MULTI_PART_REQUEST_MIDDLE,
1516                                          32, msg + 32);
1517         if (ret) {
1518                 dev_err(&client->dev, "Could not write multi-part middle, though the BMC said it could handle it.  Just limit sends to one part.\n");
1519                 return ret;
1520         }
1521
1522         return 0;
1523 }
1524
1525 static void test_multipart_messages(struct i2c_client *client,
1526                                     struct ssif_info *ssif_info,
1527                                     unsigned char *resp)
1528 {
1529         unsigned char msg[65];
1530         int ret;
1531         bool do_middle;
1532
1533         if (ssif_info->max_xmit_msg_size <= 32)
1534                 return;
1535
1536         do_middle = ssif_info->max_xmit_msg_size > 63;
1537
1538         memset(msg, 0, sizeof(msg));
1539         msg[0] = IPMI_NETFN_APP_REQUEST << 2;
1540         msg[1] = IPMI_GET_DEVICE_ID_CMD;
1541
1542         /*
1543          * The specification is all messed up dealing with sending
1544          * multi-part messages.  Per what the specification says, it
1545          * is impossible to send a message that is a multiple of 32
1546          * bytes, except for 32 itself.  It talks about a "start"
1547          * transaction (cmd=6) that must be 32 bytes, "middle"
1548          * transaction (cmd=7) that must be 32 bytes, and an "end"
1549          * transaction.  The "end" transaction is shown as cmd=7 in
1550          * the text, but if that's the case there is no way to
1551          * differentiate between a middle and end part except the
1552          * length being less than 32.  But there is a table at the far
1553          * end of the section (that I had never noticed until someone
1554          * pointed it out to me) that mentions it as cmd=8.
1555          *
1556          * After some thought, I think the example is wrong and the
1557          * end transaction should be cmd=8.  But some systems don't
1558          * implement cmd=8, they use a zero-length end transaction,
1559          * even though that violates the SMBus specification.
1560          *
1561          * So, to work around this, this code tests if cmd=8 works.
1562          * If it does, then we use that.  If not, it tests zero-
1563          * byte end transactions.  If that works, good.  If not,
1564          * we only allow 63-byte transactions max.
1565          */
1566
1567         ret = start_multipart_test(client, msg, do_middle);
1568         if (ret)
1569                 goto out_no_multi_part;
1570
1571         ret = i2c_smbus_write_block_data(client,
1572                                          SSIF_IPMI_MULTI_PART_REQUEST_END,
1573                                          1, msg + 64);
1574
1575         if (!ret)
1576                 ret = read_response(client, resp);
1577
1578         if (ret > 0) {
1579                 /* End transactions work, we are good. */
1580                 ssif_info->cmd8_works = true;
1581                 return;
1582         }
1583
1584         ret = start_multipart_test(client, msg, do_middle);
1585         if (ret) {
1586                 dev_err(&client->dev, "Second multipart test failed.\n");
1587                 goto out_no_multi_part;
1588         }
1589
1590         ret = i2c_smbus_write_block_data(client,
1591                                          SSIF_IPMI_MULTI_PART_REQUEST_MIDDLE,
1592                                          0, msg + 64);
1593         if (!ret)
1594                 ret = read_response(client, resp);
1595         if (ret > 0)
1596                 /* Zero-size end parts work, use those. */
1597                 return;
1598
1599         /* Limit to 63 bytes and use a short middle command to mark the end. */
1600         if (ssif_info->max_xmit_msg_size > 63)
1601                 ssif_info->max_xmit_msg_size = 63;
1602         return;
1603
1604 out_no_multi_part:
1605         ssif_info->max_xmit_msg_size = 32;
1606         return;
1607 }
1608
1609 /*
1610  * Global enables we care about.
1611  */
1612 #define GLOBAL_ENABLES_MASK (IPMI_BMC_EVT_MSG_BUFF | IPMI_BMC_RCV_MSG_INTR | \
1613                              IPMI_BMC_EVT_MSG_INTR)
1614
1615 static void ssif_remove_dup(struct i2c_client *client)
1616 {
1617         struct ssif_info *ssif_info = i2c_get_clientdata(client);
1618
1619         ipmi_unregister_smi(ssif_info->intf);
1620         kfree(ssif_info);
1621 }
1622
1623 static int ssif_add_infos(struct i2c_client *client)
1624 {
1625         struct ssif_addr_info *info;
1626
1627         info = kzalloc(sizeof(*info), GFP_KERNEL);
1628         if (!info)
1629                 return -ENOMEM;
1630         info->addr_src = SI_ACPI;
1631         info->client = client;
1632         info->adapter_name = kstrdup(client->adapter->name, GFP_KERNEL);
1633         info->binfo.addr = client->addr;
1634         list_add_tail(&info->link, &ssif_infos);
1635         return 0;
1636 }
1637
1638 /*
1639  * Prefer ACPI over SMBIOS, if both are available.
1640  * So if we get an ACPI interface and have already registered a SMBIOS
1641  * interface at the same address, remove the SMBIOS and add the ACPI one.
1642  */
1643 static int ssif_check_and_remove(struct i2c_client *client,
1644                               struct ssif_info *ssif_info)
1645 {
1646         struct ssif_addr_info *info;
1647
1648         list_for_each_entry(info, &ssif_infos, link) {
1649                 if (!info->client)
1650                         return 0;
1651                 if (!strcmp(info->adapter_name, client->adapter->name) &&
1652                     info->binfo.addr == client->addr) {
1653                         if (info->addr_src == SI_ACPI)
1654                                 return -EEXIST;
1655
1656                         if (ssif_info->addr_source == SI_ACPI &&
1657                             info->addr_src == SI_SMBIOS) {
1658                                 dev_info(&client->dev,
1659                                          "Removing %s-specified SSIF interface in favor of ACPI\n",
1660                                          ipmi_addr_src_to_str(info->addr_src));
1661                                 ssif_remove_dup(info->client);
1662                                 return 0;
1663                         }
1664                 }
1665         }
1666         return 0;
1667 }
1668
1669 static int ssif_probe(struct i2c_client *client, const struct i2c_device_id *id)
1670 {
1671         unsigned char     msg[3];
1672         unsigned char     *resp;
1673         struct ssif_info   *ssif_info;
1674         int               rv = 0;
1675         int               len;
1676         int               i;
1677         u8                slave_addr = 0;
1678         struct ssif_addr_info *addr_info = NULL;
1679
1680         mutex_lock(&ssif_infos_mutex);
1681         resp = kmalloc(IPMI_MAX_MSG_LENGTH, GFP_KERNEL);
1682         if (!resp) {
1683                 mutex_unlock(&ssif_infos_mutex);
1684                 return -ENOMEM;
1685         }
1686
1687         ssif_info = kzalloc(sizeof(*ssif_info), GFP_KERNEL);
1688         if (!ssif_info) {
1689                 kfree(resp);
1690                 mutex_unlock(&ssif_infos_mutex);
1691                 return -ENOMEM;
1692         }
1693
1694         if (!check_acpi(ssif_info, &client->dev)) {
1695                 addr_info = ssif_info_find(client->addr, client->adapter->name,
1696                                            true);
1697                 if (!addr_info) {
1698                         /* Must have come in through sysfs. */
1699                         ssif_info->addr_source = SI_HOTMOD;
1700                 } else {
1701                         ssif_info->addr_source = addr_info->addr_src;
1702                         ssif_info->ssif_debug = addr_info->debug;
1703                         ssif_info->addr_info = addr_info->addr_info;
1704                         addr_info->client = client;
1705                         slave_addr = addr_info->slave_addr;
1706                 }
1707         }
1708
1709         rv = ssif_check_and_remove(client, ssif_info);
1710         /* If rv is 0 and addr source is not SI_ACPI, continue probing */
1711         if (!rv && ssif_info->addr_source == SI_ACPI) {
1712                 rv = ssif_add_infos(client);
1713                 if (rv) {
1714                         dev_err(&client->dev, "Out of memory!, exiting ..\n");
1715                         goto out;
1716                 }
1717         } else if (rv) {
1718                 dev_err(&client->dev, "Not probing, Interface already present\n");
1719                 goto out;
1720         }
1721
1722         slave_addr = find_slave_address(client, slave_addr);
1723
1724         dev_info(&client->dev,
1725                  "Trying %s-specified SSIF interface at i2c address 0x%x, adapter %s, slave address 0x%x\n",
1726                 ipmi_addr_src_to_str(ssif_info->addr_source),
1727                 client->addr, client->adapter->name, slave_addr);
1728
1729         ssif_info->client = client;
1730         i2c_set_clientdata(client, ssif_info);
1731
1732         /* Now check for system interface capabilities */
1733         msg[0] = IPMI_NETFN_APP_REQUEST << 2;
1734         msg[1] = IPMI_GET_SYSTEM_INTERFACE_CAPABILITIES_CMD;
1735         msg[2] = 0; /* SSIF */
1736         rv = do_cmd(client, 3, msg, &len, resp);
1737         if (!rv && (len >= 3) && (resp[2] == 0)) {
1738                 if (len < 7) {
1739                         if (ssif_dbg_probe)
1740                                 dev_dbg(&ssif_info->client->dev,
1741                                         "SSIF info too short: %d\n", len);
1742                         goto no_support;
1743                 }
1744
1745                 /* Got a good SSIF response, handle it. */
1746                 ssif_info->max_xmit_msg_size = resp[5];
1747                 ssif_info->max_recv_msg_size = resp[6];
1748                 ssif_info->multi_support = (resp[4] >> 6) & 0x3;
1749                 ssif_info->supports_pec = (resp[4] >> 3) & 0x1;
1750
1751                 /* Sanitize the data */
1752                 switch (ssif_info->multi_support) {
1753                 case SSIF_NO_MULTI:
1754                         if (ssif_info->max_xmit_msg_size > 32)
1755                                 ssif_info->max_xmit_msg_size = 32;
1756                         if (ssif_info->max_recv_msg_size > 32)
1757                                 ssif_info->max_recv_msg_size = 32;
1758                         break;
1759
1760                 case SSIF_MULTI_2_PART:
1761                         if (ssif_info->max_xmit_msg_size > 63)
1762                                 ssif_info->max_xmit_msg_size = 63;
1763                         if (ssif_info->max_recv_msg_size > 62)
1764                                 ssif_info->max_recv_msg_size = 62;
1765                         break;
1766
1767                 case SSIF_MULTI_n_PART:
1768                         /* We take whatever size given, but do some testing. */
1769                         break;
1770
1771                 default:
1772                         /* Data is not sane, just give up. */
1773                         goto no_support;
1774                 }
1775         } else {
1776  no_support:
1777                 /* Assume no multi-part or PEC support */
1778                 dev_info(&ssif_info->client->dev,
1779                          "Error fetching SSIF: %d %d %2.2x, your system probably doesn't support this command so using defaults\n",
1780                         rv, len, resp[2]);
1781
1782                 ssif_info->max_xmit_msg_size = 32;
1783                 ssif_info->max_recv_msg_size = 32;
1784                 ssif_info->multi_support = SSIF_NO_MULTI;
1785                 ssif_info->supports_pec = 0;
1786         }
1787
1788         test_multipart_messages(client, ssif_info, resp);
1789
1790         /* Make sure the NMI timeout is cleared. */
1791         msg[0] = IPMI_NETFN_APP_REQUEST << 2;
1792         msg[1] = IPMI_CLEAR_MSG_FLAGS_CMD;
1793         msg[2] = WDT_PRE_TIMEOUT_INT;
1794         rv = do_cmd(client, 3, msg, &len, resp);
1795         if (rv || (len < 3) || (resp[2] != 0))
1796                 dev_warn(&ssif_info->client->dev,
1797                          "Unable to clear message flags: %d %d %2.2x\n",
1798                          rv, len, resp[2]);
1799
1800         /* Attempt to enable the event buffer. */
1801         msg[0] = IPMI_NETFN_APP_REQUEST << 2;
1802         msg[1] = IPMI_GET_BMC_GLOBAL_ENABLES_CMD;
1803         rv = do_cmd(client, 2, msg, &len, resp);
1804         if (rv || (len < 4) || (resp[2] != 0)) {
1805                 dev_warn(&ssif_info->client->dev,
1806                          "Error getting global enables: %d %d %2.2x\n",
1807                          rv, len, resp[2]);
1808                 rv = 0; /* Not fatal */
1809                 goto found;
1810         }
1811
1812         ssif_info->global_enables = resp[3];
1813
1814         if (resp[3] & IPMI_BMC_EVT_MSG_BUFF) {
1815                 ssif_info->has_event_buffer = true;
1816                 /* buffer is already enabled, nothing to do. */
1817                 goto found;
1818         }
1819
1820         msg[0] = IPMI_NETFN_APP_REQUEST << 2;
1821         msg[1] = IPMI_SET_BMC_GLOBAL_ENABLES_CMD;
1822         msg[2] = ssif_info->global_enables | IPMI_BMC_EVT_MSG_BUFF;
1823         rv = do_cmd(client, 3, msg, &len, resp);
1824         if (rv || (len < 2)) {
1825                 dev_warn(&ssif_info->client->dev,
1826                          "Error setting global enables: %d %d %2.2x\n",
1827                          rv, len, resp[2]);
1828                 rv = 0; /* Not fatal */
1829                 goto found;
1830         }
1831
1832         if (resp[2] == 0) {
1833                 /* A successful return means the event buffer is supported. */
1834                 ssif_info->has_event_buffer = true;
1835                 ssif_info->global_enables |= IPMI_BMC_EVT_MSG_BUFF;
1836         }
1837
1838         /* Some systems don't behave well if you enable alerts. */
1839         if (alerts_broken)
1840                 goto found;
1841
1842         msg[0] = IPMI_NETFN_APP_REQUEST << 2;
1843         msg[1] = IPMI_SET_BMC_GLOBAL_ENABLES_CMD;
1844         msg[2] = ssif_info->global_enables | IPMI_BMC_RCV_MSG_INTR;
1845         rv = do_cmd(client, 3, msg, &len, resp);
1846         if (rv || (len < 2)) {
1847                 dev_warn(&ssif_info->client->dev,
1848                          "Error setting global enables: %d %d %2.2x\n",
1849                          rv, len, resp[2]);
1850                 rv = 0; /* Not fatal */
1851                 goto found;
1852         }
1853
1854         if (resp[2] == 0) {
1855                 /* A successful return means the alert is supported. */
1856                 ssif_info->supports_alert = true;
1857                 ssif_info->global_enables |= IPMI_BMC_RCV_MSG_INTR;
1858         }
1859
1860  found:
1861         if (ssif_dbg_probe) {
1862                 dev_dbg(&ssif_info->client->dev,
1863                        "%s: i2c_probe found device at i2c address %x\n",
1864                        __func__, client->addr);
1865         }
1866
1867         spin_lock_init(&ssif_info->lock);
1868         ssif_info->ssif_state = SSIF_NORMAL;
1869         timer_setup(&ssif_info->retry_timer, retry_timeout, 0);
1870         timer_setup(&ssif_info->watch_timer, watch_timeout, 0);
1871
1872         for (i = 0; i < SSIF_NUM_STATS; i++)
1873                 atomic_set(&ssif_info->stats[i], 0);
1874
1875         if (ssif_info->supports_pec)
1876                 ssif_info->client->flags |= I2C_CLIENT_PEC;
1877
1878         ssif_info->handlers.owner = THIS_MODULE;
1879         ssif_info->handlers.start_processing = ssif_start_processing;
1880         ssif_info->handlers.shutdown = shutdown_ssif;
1881         ssif_info->handlers.get_smi_info = get_smi_info;
1882         ssif_info->handlers.sender = sender;
1883         ssif_info->handlers.request_events = request_events;
1884         ssif_info->handlers.set_need_watch = ssif_set_need_watch;
1885
1886         {
1887                 unsigned int thread_num;
1888
1889                 thread_num = ((i2c_adapter_id(ssif_info->client->adapter)
1890                                << 8) |
1891                               ssif_info->client->addr);
1892                 init_completion(&ssif_info->wake_thread);
1893                 ssif_info->thread = kthread_run(ipmi_ssif_thread, ssif_info,
1894                                                "kssif%4.4x", thread_num);
1895                 if (IS_ERR(ssif_info->thread)) {
1896                         rv = PTR_ERR(ssif_info->thread);
1897                         dev_notice(&ssif_info->client->dev,
1898                                    "Could not start kernel thread: error %d\n",
1899                                    rv);
1900                         goto out;
1901                 }
1902         }
1903
1904         dev_set_drvdata(&ssif_info->client->dev, ssif_info);
1905         rv = device_add_group(&ssif_info->client->dev,
1906                               &ipmi_ssif_dev_attr_group);
1907         if (rv) {
1908                 dev_err(&ssif_info->client->dev,
1909                         "Unable to add device attributes: error %d\n",
1910                         rv);
1911                 goto out;
1912         }
1913
1914         rv = ipmi_register_smi(&ssif_info->handlers,
1915                                ssif_info,
1916                                &ssif_info->client->dev,
1917                                slave_addr);
1918         if (rv) {
1919                 dev_err(&ssif_info->client->dev,
1920                         "Unable to register device: error %d\n", rv);
1921                 goto out_remove_attr;
1922         }
1923
1924  out:
1925         if (rv) {
1926                 if (addr_info)
1927                         addr_info->client = NULL;
1928
1929                 dev_err(&ssif_info->client->dev,
1930                         "Unable to start IPMI SSIF: %d\n", rv);
1931                 kfree(ssif_info);
1932         }
1933         kfree(resp);
1934         mutex_unlock(&ssif_infos_mutex);
1935         return rv;
1936
1937 out_remove_attr:
1938         device_remove_group(&ssif_info->client->dev, &ipmi_ssif_dev_attr_group);
1939         dev_set_drvdata(&ssif_info->client->dev, NULL);
1940         goto out;
1941 }
1942
1943 static int ssif_adapter_handler(struct device *adev, void *opaque)
1944 {
1945         struct ssif_addr_info *addr_info = opaque;
1946
1947         if (adev->type != &i2c_adapter_type)
1948                 return 0;
1949
1950         addr_info->added_client = i2c_new_client_device(to_i2c_adapter(adev),
1951                                                         &addr_info->binfo);
1952
1953         if (!addr_info->adapter_name)
1954                 return 1; /* Only try the first I2C adapter by default. */
1955         return 0;
1956 }
1957
1958 static int new_ssif_client(int addr, char *adapter_name,
1959                            int debug, int slave_addr,
1960                            enum ipmi_addr_src addr_src,
1961                            struct device *dev)
1962 {
1963         struct ssif_addr_info *addr_info;
1964         int rv = 0;
1965
1966         mutex_lock(&ssif_infos_mutex);
1967         if (ssif_info_find(addr, adapter_name, false)) {
1968                 rv = -EEXIST;
1969                 goto out_unlock;
1970         }
1971
1972         addr_info = kzalloc(sizeof(*addr_info), GFP_KERNEL);
1973         if (!addr_info) {
1974                 rv = -ENOMEM;
1975                 goto out_unlock;
1976         }
1977
1978         if (adapter_name) {
1979                 addr_info->adapter_name = kstrdup(adapter_name, GFP_KERNEL);
1980                 if (!addr_info->adapter_name) {
1981                         kfree(addr_info);
1982                         rv = -ENOMEM;
1983                         goto out_unlock;
1984                 }
1985         }
1986
1987         strncpy(addr_info->binfo.type, DEVICE_NAME,
1988                 sizeof(addr_info->binfo.type));
1989         addr_info->binfo.addr = addr;
1990         addr_info->binfo.platform_data = addr_info;
1991         addr_info->debug = debug;
1992         addr_info->slave_addr = slave_addr;
1993         addr_info->addr_src = addr_src;
1994         addr_info->dev = dev;
1995
1996         if (dev)
1997                 dev_set_drvdata(dev, addr_info);
1998
1999         list_add_tail(&addr_info->link, &ssif_infos);
2000
2001         if (initialized)
2002                 i2c_for_each_dev(addr_info, ssif_adapter_handler);
2003         /* Otherwise address list will get it */
2004
2005 out_unlock:
2006         mutex_unlock(&ssif_infos_mutex);
2007         return rv;
2008 }
2009
2010 static void free_ssif_clients(void)
2011 {
2012         struct ssif_addr_info *info, *tmp;
2013
2014         mutex_lock(&ssif_infos_mutex);
2015         list_for_each_entry_safe(info, tmp, &ssif_infos, link) {
2016                 list_del(&info->link);
2017                 kfree(info->adapter_name);
2018                 kfree(info);
2019         }
2020         mutex_unlock(&ssif_infos_mutex);
2021 }
2022
2023 static unsigned short *ssif_address_list(void)
2024 {
2025         struct ssif_addr_info *info;
2026         unsigned int count = 0, i = 0;
2027         unsigned short *address_list;
2028
2029         list_for_each_entry(info, &ssif_infos, link)
2030                 count++;
2031
2032         address_list = kcalloc(count + 1, sizeof(*address_list),
2033                                GFP_KERNEL);
2034         if (!address_list)
2035                 return NULL;
2036
2037         list_for_each_entry(info, &ssif_infos, link) {
2038                 unsigned short addr = info->binfo.addr;
2039                 int j;
2040
2041                 for (j = 0; j < i; j++) {
2042                         if (address_list[j] == addr)
2043                                 /* Found a dup. */
2044                                 break;
2045                 }
2046                 if (j == i) /* Didn't find it in the list. */
2047                         address_list[i++] = addr;
2048         }
2049         address_list[i] = I2C_CLIENT_END;
2050
2051         return address_list;
2052 }
2053
2054 #ifdef CONFIG_ACPI
2055 static const struct acpi_device_id ssif_acpi_match[] = {
2056         { "IPI0001", 0 },
2057         { },
2058 };
2059 MODULE_DEVICE_TABLE(acpi, ssif_acpi_match);
2060 #endif
2061
2062 #ifdef CONFIG_DMI
2063 static int dmi_ipmi_probe(struct platform_device *pdev)
2064 {
2065         u8 slave_addr = 0;
2066         u16 i2c_addr;
2067         int rv;
2068
2069         if (!ssif_trydmi)
2070                 return -ENODEV;
2071
2072         rv = device_property_read_u16(&pdev->dev, "i2c-addr", &i2c_addr);
2073         if (rv) {
2074                 dev_warn(&pdev->dev, "No i2c-addr property\n");
2075                 return -ENODEV;
2076         }
2077
2078         rv = device_property_read_u8(&pdev->dev, "slave-addr", &slave_addr);
2079         if (rv)
2080                 slave_addr = 0x20;
2081
2082         return new_ssif_client(i2c_addr, NULL, 0,
2083                                slave_addr, SI_SMBIOS, &pdev->dev);
2084 }
2085 #else
2086 static int dmi_ipmi_probe(struct platform_device *pdev)
2087 {
2088         return -ENODEV;
2089 }
2090 #endif
2091
2092 static const struct i2c_device_id ssif_id[] = {
2093         { DEVICE_NAME, 0 },
2094         { }
2095 };
2096 MODULE_DEVICE_TABLE(i2c, ssif_id);
2097
2098 static struct i2c_driver ssif_i2c_driver = {
2099         .class          = I2C_CLASS_HWMON,
2100         .driver         = {
2101                 .name                   = DEVICE_NAME
2102         },
2103         .probe          = ssif_probe,
2104         .remove         = ssif_remove,
2105         .alert          = ssif_alert,
2106         .id_table       = ssif_id,
2107         .detect         = ssif_detect
2108 };
2109
2110 static int ssif_platform_probe(struct platform_device *dev)
2111 {
2112         return dmi_ipmi_probe(dev);
2113 }
2114
2115 static int ssif_platform_remove(struct platform_device *dev)
2116 {
2117         struct ssif_addr_info *addr_info = dev_get_drvdata(&dev->dev);
2118
2119         if (!addr_info)
2120                 return 0;
2121
2122         mutex_lock(&ssif_infos_mutex);
2123         i2c_unregister_device(addr_info->added_client);
2124
2125         list_del(&addr_info->link);
2126         kfree(addr_info);
2127         mutex_unlock(&ssif_infos_mutex);
2128         return 0;
2129 }
2130
2131 static const struct platform_device_id ssif_plat_ids[] = {
2132     { "dmi-ipmi-ssif", 0 },
2133     { }
2134 };
2135
2136 static struct platform_driver ipmi_driver = {
2137         .driver = {
2138                 .name = DEVICE_NAME,
2139         },
2140         .probe          = ssif_platform_probe,
2141         .remove         = ssif_platform_remove,
2142         .id_table       = ssif_plat_ids
2143 };
2144
2145 static int init_ipmi_ssif(void)
2146 {
2147         int i;
2148         int rv;
2149
2150         if (initialized)
2151                 return 0;
2152
2153         pr_info("IPMI SSIF Interface driver\n");
2154
2155         /* build list for i2c from addr list */
2156         for (i = 0; i < num_addrs; i++) {
2157                 rv = new_ssif_client(addr[i], adapter_name[i],
2158                                      dbg[i], slave_addrs[i],
2159                                      SI_HARDCODED, NULL);
2160                 if (rv)
2161                         pr_err("Couldn't add hardcoded device at addr 0x%x\n",
2162                                addr[i]);
2163         }
2164
2165         if (ssif_tryacpi)
2166                 ssif_i2c_driver.driver.acpi_match_table =
2167                         ACPI_PTR(ssif_acpi_match);
2168
2169         if (ssif_trydmi) {
2170                 rv = platform_driver_register(&ipmi_driver);
2171                 if (rv)
2172                         pr_err("Unable to register driver: %d\n", rv);
2173                 else
2174                         platform_registered = true;
2175         }
2176
2177         ssif_i2c_driver.address_list = ssif_address_list();
2178
2179         rv = i2c_add_driver(&ssif_i2c_driver);
2180         if (!rv)
2181                 initialized = true;
2182
2183         return rv;
2184 }
2185 module_init(init_ipmi_ssif);
2186
2187 static void cleanup_ipmi_ssif(void)
2188 {
2189         if (!initialized)
2190                 return;
2191
2192         initialized = false;
2193
2194         i2c_del_driver(&ssif_i2c_driver);
2195
2196         kfree(ssif_i2c_driver.address_list);
2197
2198         if (ssif_trydmi && platform_registered)
2199                 platform_driver_unregister(&ipmi_driver);
2200
2201         free_ssif_clients();
2202 }
2203 module_exit(cleanup_ipmi_ssif);
2204
2205 MODULE_ALIAS("platform:dmi-ipmi-ssif");
2206 MODULE_AUTHOR("Todd C Davis <todd.c.davis@intel.com>, Corey Minyard <minyard@acm.org>");
2207 MODULE_DESCRIPTION("IPMI driver for management controllers on a SMBus");
2208 MODULE_LICENSE("GPL");