drivers/char/ipmi/ipmi_ssif.c

   1 /*
   2  * ipmi_ssif.c
   3  *
   4  * The interface to the IPMI driver for SMBus access to a SMBus
   5  * compliant device.  Called SSIF by the IPMI spec.
   6  *
   7  * Author: Intel Corporation
   8  *         Todd Davis <todd.c.davis@intel.com>
   9  *
  10  * Rewritten by Corey Minyard <minyard@acm.org> to support the
  11  * non-blocking I2C interface, add support for multi-part
  12  * transactions, add PEC support, and general clenaup.
  13  *
  14  * Copyright 2003 Intel Corporation
  15  * Copyright 2005 MontaVista Software
  16  *
  17  *  This program is free software; you can redistribute it and/or modify it
  18  *  under the terms of the GNU General Public License as published by the
  19  *  Free Software Foundation; either version 2 of the License, or (at your
  20  *  option) any later version.
  21  */
  22
  23 /*
  24  * This file holds the "policy" for the interface to the SSIF state
  25  * machine.  It does the configuration, handles timers and interrupts,
  26  * and drives the real SSIF state machine.
  27  */
  28
  29 /*
  30  * TODO: Figure out how to use SMB alerts.  This will require a new
  31  * interface into the I2C driver, I believe.
  32  */
  33
  34 #if defined(MODVERSIONS)
  35 #include <linux/modversions.h>
  36 #endif
  37
  38 #include <linux/module.h>
  39 #include <linux/moduleparam.h>
  40 #include <linux/sched.h>
  41 #include <linux/seq_file.h>
  42 #include <linux/timer.h>
  43 #include <linux/delay.h>
  44 #include <linux/errno.h>
  45 #include <linux/spinlock.h>
  46 #include <linux/slab.h>
  47 #include <linux/list.h>
  48 #include <linux/i2c.h>
  49 #include <linux/ipmi_smi.h>
  50 #include <linux/init.h>
  51 #include <linux/dmi.h>
  52 #include <linux/kthread.h>
  53 #include <linux/acpi.h>
  54 #include <linux/ctype.h>
  55 #include <linux/time64.h>
  56
  57 #define PFX "ipmi_ssif: "
  58 #define DEVICE_NAME "ipmi_ssif"
  59
  60 #define IPMI_GET_SYSTEM_INTERFACE_CAPABILITIES_CMD      0x57
  61
  62 #define SSIF_IPMI_REQUEST                       2
  63 #define SSIF_IPMI_MULTI_PART_REQUEST_START      6
  64 #define SSIF_IPMI_MULTI_PART_REQUEST_MIDDLE     7
  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 enum ssif_intf_state {
  94         SSIF_NORMAL,
  95         SSIF_GETTING_FLAGS,
  96         SSIF_GETTING_EVENTS,
  97         SSIF_CLEARING_FLAGS,
  98         SSIF_GETTING_MESSAGES,
  99         /* FIXME - add watchdog stuff. */
 100 };
 101
 102 #define SSIF_IDLE(ssif)  ((ssif)->ssif_state == SSIF_NORMAL \
 103                           && (ssif)->curr_msg == NULL)
 104
 105 /*
 106  * Indexes into stats[] in ssif_info below.
 107  */
 108 enum ssif_stat_indexes {
 109         /* Number of total messages sent. */
 110         SSIF_STAT_sent_messages = 0,
 111
 112         /*
 113          * Number of message parts sent.  Messages may be broken into
 114          * parts if they are long.
 115          */
 116         SSIF_STAT_sent_messages_parts,
 117
 118         /*
 119          * Number of time a message was retried.
 120          */
 121         SSIF_STAT_send_retries,
 122
 123         /*
 124          * Number of times the send of a message failed.
 125          */
 126         SSIF_STAT_send_errors,
 127
 128         /*
 129          * Number of message responses received.
 130          */
 131         SSIF_STAT_received_messages,
 132
 133         /*
 134          * Number of message fragments received.
 135          */
 136         SSIF_STAT_received_message_parts,
 137
 138         /*
 139          * Number of times the receive of a message was retried.
 140          */
 141         SSIF_STAT_receive_retries,
 142
 143         /*
 144          * Number of errors receiving messages.
 145          */
 146         SSIF_STAT_receive_errors,
 147
 148         /*
 149          * Number of times a flag fetch was requested.
 150          */
 151         SSIF_STAT_flag_fetches,
 152
 153         /*
 154          * Number of times the hardware didn't follow the state machine.
 155          */
 156         SSIF_STAT_hosed,
 157
 158         /*
 159          * Number of received events.
 160          */
 161         SSIF_STAT_events,
 162
 163         /* Number of asyncronous messages received. */
 164         SSIF_STAT_incoming_messages,
 165
 166         /* Number of watchdog pretimeouts. */
 167         SSIF_STAT_watchdog_pretimeouts,
 168
 169         /* Number of alers received. */
 170         SSIF_STAT_alerts,
 171
 172         /* Always add statistics before this value, it must be last. */
 173         SSIF_NUM_STATS
 174 };
 175
 176 struct ssif_addr_info {
 177         struct i2c_board_info binfo;
 178         char *adapter_name;
 179         int debug;
 180         int slave_addr;
 181         enum ipmi_addr_src addr_src;
 182         union ipmi_smi_info_union addr_info;
 183
 184         struct mutex clients_mutex;
 185         struct list_head clients;
 186
 187         struct list_head link;
 188 };
 189
 190 struct ssif_info;
 191
 192 typedef void (*ssif_i2c_done)(struct ssif_info *ssif_info, int result,
 193                              unsigned char *data, unsigned int len);
 194
 195 struct ssif_info {
 196         ipmi_smi_t          intf;
 197         int                 intf_num;
 198         spinlock_t          lock;
 199         struct ipmi_smi_msg *waiting_msg;
 200         struct ipmi_smi_msg *curr_msg;
 201         enum ssif_intf_state ssif_state;
 202         unsigned long       ssif_debug;
 203
 204         struct ipmi_smi_handlers handlers;
 205
 206         enum ipmi_addr_src addr_source; /* ACPI, PCI, SMBIOS, hardcode, etc. */
 207         union ipmi_smi_info_union addr_info;
 208
 209         /*
 210          * Flags from the last GET_MSG_FLAGS command, used when an ATTN
 211          * is set to hold the flags until we are done handling everything
 212          * from the flags.
 213          */
 214 #define RECEIVE_MSG_AVAIL       0x01
 215 #define EVENT_MSG_BUFFER_FULL   0x02
 216 #define WDT_PRE_TIMEOUT_INT     0x08
 217         unsigned char       msg_flags;
 218
 219         u8                  global_enables;
 220         bool                has_event_buffer;
 221         bool                supports_alert;
 222
 223         /*
 224          * Used to tell what we should do with alerts.  If we are
 225          * waiting on a response, read the data immediately.
 226          */
 227         bool                got_alert;
 228         bool                waiting_alert;
 229
 230         /*
 231          * If set to true, this will request events the next time the
 232          * state machine is idle.
 233          */
 234         bool                req_events;
 235
 236         /*
 237          * If set to true, this will request flags the next time the
 238          * state machine is idle.
 239          */
 240         bool                req_flags;
 241
 242         /*
 243          * Used to perform timer operations when run-to-completion
 244          * mode is on.  This is a countdown timer.
 245          */
 246         int                 rtc_us_timer;
 247
 248         /* Used for sending/receiving data.  +1 for the length. */
 249         unsigned char data[IPMI_MAX_MSG_LENGTH + 1];
 250         unsigned int  data_len;
 251
 252         /* Temp receive buffer, gets copied into data. */
 253         unsigned char recv[I2C_SMBUS_BLOCK_MAX];
 254
 255         struct i2c_client *client;
 256         ssif_i2c_done done_handler;
 257
 258         /* Thread interface handling */
 259         struct task_struct *thread;
 260         struct completion wake_thread;
 261         bool stopping;
 262         int i2c_read_write;
 263         int i2c_command;
 264         unsigned char *i2c_data;
 265         unsigned int i2c_size;
 266
 267         /* From the device id response. */
 268         struct ipmi_device_id device_id;
 269
 270         struct timer_list retry_timer;
 271         int retries_left;
 272
 273         /* Info from SSIF cmd */
 274         unsigned char max_xmit_msg_size;
 275         unsigned char max_recv_msg_size;
 276         unsigned int  multi_support;
 277         int           supports_pec;
 278
 279 #define SSIF_NO_MULTI           0
 280 #define SSIF_MULTI_2_PART       1
 281 #define SSIF_MULTI_n_PART       2
 282         unsigned char *multi_data;
 283         unsigned int  multi_len;
 284         unsigned int  multi_pos;
 285
 286         atomic_t stats[SSIF_NUM_STATS];
 287 };
 288
 289 #define ssif_inc_stat(ssif, stat) \
 290         atomic_inc(&(ssif)->stats[SSIF_STAT_ ## stat])
 291 #define ssif_get_stat(ssif, stat) \
 292         ((unsigned int) atomic_read(&(ssif)->stats[SSIF_STAT_ ## stat]))
 293
 294 static bool initialized;
 295
 296 static atomic_t next_intf = ATOMIC_INIT(0);
 297
 298 static void return_hosed_msg(struct ssif_info *ssif_info,
 299                              struct ipmi_smi_msg *msg);
 300 static void start_next_msg(struct ssif_info *ssif_info, unsigned long *flags);
 301 static int start_send(struct ssif_info *ssif_info,
 302                       unsigned char   *data,
 303                       unsigned int    len);
 304
 305 static unsigned long *ipmi_ssif_lock_cond(struct ssif_info *ssif_info,
 306                                           unsigned long *flags)
 307 {
 308         spin_lock_irqsave(&ssif_info->lock, *flags);
 309         return flags;
 310 }
 311
 312 static void ipmi_ssif_unlock_cond(struct ssif_info *ssif_info,
 313                                   unsigned long *flags)
 314 {
 315         spin_unlock_irqrestore(&ssif_info->lock, *flags);
 316 }
 317
 318 static void deliver_recv_msg(struct ssif_info *ssif_info,
 319                              struct ipmi_smi_msg *msg)
 320 {
 321         ipmi_smi_t    intf = ssif_info->intf;
 322
 323         if (!intf) {
 324                 ipmi_free_smi_msg(msg);
 325         } else if (msg->rsp_size < 0) {
 326                 return_hosed_msg(ssif_info, msg);
 327                 pr_err(PFX
 328                        "Malformed message in deliver_recv_msg: rsp_size = %d\n",
 329                        msg->rsp_size);
 330         } else {
 331                 ipmi_smi_msg_received(intf, msg);
 332         }
 333 }
 334
 335 static void return_hosed_msg(struct ssif_info *ssif_info,
 336                              struct ipmi_smi_msg *msg)
 337 {
 338         ssif_inc_stat(ssif_info, hosed);
 339
 340         /* Make it a response */
 341         msg->rsp[0] = msg->data[0] | 4;
 342         msg->rsp[1] = msg->data[1];
 343         msg->rsp[2] = 0xFF; /* Unknown error. */
 344         msg->rsp_size = 3;
 345
 346         deliver_recv_msg(ssif_info, msg);
 347 }
 348
 349 /*
 350  * Must be called with the message lock held.  This will release the
 351  * message lock.  Note that the caller will check SSIF_IDLE and start a
 352  * new operation, so there is no need to check for new messages to
 353  * start in here.
 354  */
 355 static void start_clear_flags(struct ssif_info *ssif_info, unsigned long *flags)
 356 {
 357         unsigned char msg[3];
 358
 359         ssif_info->msg_flags &= ~WDT_PRE_TIMEOUT_INT;
 360         ssif_info->ssif_state = SSIF_CLEARING_FLAGS;
 361         ipmi_ssif_unlock_cond(ssif_info, flags);
 362
 363         /* Make sure the watchdog pre-timeout flag is not set at startup. */
 364         msg[0] = (IPMI_NETFN_APP_REQUEST << 2);
 365         msg[1] = IPMI_CLEAR_MSG_FLAGS_CMD;
 366         msg[2] = WDT_PRE_TIMEOUT_INT;
 367
 368         if (start_send(ssif_info, msg, 3) != 0) {
 369                 /* Error, just go to normal state. */
 370                 ssif_info->ssif_state = SSIF_NORMAL;
 371         }
 372 }
 373
 374 static void start_flag_fetch(struct ssif_info *ssif_info, unsigned long *flags)
 375 {
 376         unsigned char mb[2];
 377
 378         ssif_info->req_flags = false;
 379         ssif_info->ssif_state = SSIF_GETTING_FLAGS;
 380         ipmi_ssif_unlock_cond(ssif_info, flags);
 381
 382         mb[0] = (IPMI_NETFN_APP_REQUEST << 2);
 383         mb[1] = IPMI_GET_MSG_FLAGS_CMD;
 384         if (start_send(ssif_info, mb, 2) != 0)
 385                 ssif_info->ssif_state = SSIF_NORMAL;
 386 }
 387
 388 static void check_start_send(struct ssif_info *ssif_info, unsigned long *flags,
 389                              struct ipmi_smi_msg *msg)
 390 {
 391         if (start_send(ssif_info, msg->data, msg->data_size) != 0) {
 392                 unsigned long oflags;
 393
 394                 flags = ipmi_ssif_lock_cond(ssif_info, &oflags);
 395                 ssif_info->curr_msg = NULL;
 396                 ssif_info->ssif_state = SSIF_NORMAL;
 397                 ipmi_ssif_unlock_cond(ssif_info, flags);
 398                 ipmi_free_smi_msg(msg);
 399         }
 400 }
 401
 402 static void start_event_fetch(struct ssif_info *ssif_info, unsigned long *flags)
 403 {
 404         struct ipmi_smi_msg *msg;
 405
 406         ssif_info->req_events = false;
 407
 408         msg = ipmi_alloc_smi_msg();
 409         if (!msg) {
 410                 ssif_info->ssif_state = SSIF_NORMAL;
 411                 return;
 412         }
 413
 414         ssif_info->curr_msg = msg;
 415         ssif_info->ssif_state = SSIF_GETTING_EVENTS;
 416         ipmi_ssif_unlock_cond(ssif_info, flags);
 417
 418         msg->data[0] = (IPMI_NETFN_APP_REQUEST << 2);
 419         msg->data[1] = IPMI_READ_EVENT_MSG_BUFFER_CMD;
 420         msg->data_size = 2;
 421
 422         check_start_send(ssif_info, flags, msg);
 423 }
 424
 425 static void start_recv_msg_fetch(struct ssif_info *ssif_info,
 426                                  unsigned long *flags)
 427 {
 428         struct ipmi_smi_msg *msg;
 429
 430         msg = ipmi_alloc_smi_msg();
 431         if (!msg) {
 432                 ssif_info->ssif_state = SSIF_NORMAL;
 433                 return;
 434         }
 435
 436         ssif_info->curr_msg = msg;
 437         ssif_info->ssif_state = SSIF_GETTING_MESSAGES;
 438         ipmi_ssif_unlock_cond(ssif_info, flags);
 439
 440         msg->data[0] = (IPMI_NETFN_APP_REQUEST << 2);
 441         msg->data[1] = IPMI_GET_MSG_CMD;
 442         msg->data_size = 2;
 443
 444         check_start_send(ssif_info, flags, msg);
 445 }
 446
 447 /*
 448  * Must be called with the message lock held.  This will release the
 449  * message lock.  Note that the caller will check SSIF_IDLE and start a
 450  * new operation, so there is no need to check for new messages to
 451  * start in here.
 452  */
 453 static void handle_flags(struct ssif_info *ssif_info, unsigned long *flags)
 454 {
 455         if (ssif_info->msg_flags & WDT_PRE_TIMEOUT_INT) {
 456                 ipmi_smi_t intf = ssif_info->intf;
 457                 /* Watchdog pre-timeout */
 458                 ssif_inc_stat(ssif_info, watchdog_pretimeouts);
 459                 start_clear_flags(ssif_info, flags);
 460                 if (intf)
 461                         ipmi_smi_watchdog_pretimeout(intf);
 462         } else if (ssif_info->msg_flags & RECEIVE_MSG_AVAIL)
 463                 /* Messages available. */
 464                 start_recv_msg_fetch(ssif_info, flags);
 465         else if (ssif_info->msg_flags & EVENT_MSG_BUFFER_FULL)
 466                 /* Events available. */
 467                 start_event_fetch(ssif_info, flags);
 468         else {
 469                 ssif_info->ssif_state = SSIF_NORMAL;
 470                 ipmi_ssif_unlock_cond(ssif_info, flags);
 471         }
 472 }
 473
 474 static int ipmi_ssif_thread(void *data)
 475 {
 476         struct ssif_info *ssif_info = data;
 477
 478         while (!kthread_should_stop()) {
 479                 int result;
 480
 481                 /* Wait for something to do */
 482                 result = wait_for_completion_interruptible(
 483                                                 &ssif_info->wake_thread);
 484                 if (ssif_info->stopping)
 485                         break;
 486                 if (result == -ERESTARTSYS)
 487                         continue;
 488                 init_completion(&ssif_info->wake_thread);
 489
 490                 if (ssif_info->i2c_read_write == I2C_SMBUS_WRITE) {
 491                         result = i2c_smbus_write_block_data(
 492                                 ssif_info->client, ssif_info->i2c_command,
 493                                 ssif_info->i2c_data[0],
 494                                 ssif_info->i2c_data + 1);
 495                         ssif_info->done_handler(ssif_info, result, NULL, 0);
 496                 } else {
 497                         result = i2c_smbus_read_block_data(
 498                                 ssif_info->client, ssif_info->i2c_command,
 499                                 ssif_info->i2c_data);
 500                         if (result < 0)
 501                                 ssif_info->done_handler(ssif_info, result,
 502                                                         NULL, 0);
 503                         else
 504                                 ssif_info->done_handler(ssif_info, 0,
 505                                                         ssif_info->i2c_data,
 506                                                         result);
 507                 }
 508         }
 509
 510         return 0;
 511 }
 512
 513 static int ssif_i2c_send(struct ssif_info *ssif_info,
 514                         ssif_i2c_done handler,
 515                         int read_write, int command,
 516                         unsigned char *data, unsigned int size)
 517 {
 518         ssif_info->done_handler = handler;
 519
 520         ssif_info->i2c_read_write = read_write;
 521         ssif_info->i2c_command = command;
 522         ssif_info->i2c_data = data;
 523         ssif_info->i2c_size = size;
 524         complete(&ssif_info->wake_thread);
 525         return 0;
 526 }
 527
 528
 529 static void msg_done_handler(struct ssif_info *ssif_info, int result,
 530                              unsigned char *data, unsigned int len);
 531
 532 static void start_get(struct ssif_info *ssif_info)
 533 {
 534         int rv;
 535
 536         ssif_info->rtc_us_timer = 0;
 537         ssif_info->multi_pos = 0;
 538
 539         rv = ssif_i2c_send(ssif_info, msg_done_handler, I2C_SMBUS_READ,
 540                           SSIF_IPMI_RESPONSE,
 541                           ssif_info->recv, I2C_SMBUS_BLOCK_DATA);
 542         if (rv < 0) {
 543                 /* request failed, just return the error. */
 544                 if (ssif_info->ssif_debug & SSIF_DEBUG_MSG)
 545                         pr_info("Error from i2c_non_blocking_op(5)\n");
 546
 547                 msg_done_handler(ssif_info, -EIO, NULL, 0);
 548         }
 549 }
 550
 551 static void retry_timeout(unsigned long data)
 552 {
 553         struct ssif_info *ssif_info = (void *) data;
 554         unsigned long oflags, *flags;
 555         bool waiting;
 556
 557         if (ssif_info->stopping)
 558                 return;
 559
 560         flags = ipmi_ssif_lock_cond(ssif_info, &oflags);
 561         waiting = ssif_info->waiting_alert;
 562         ssif_info->waiting_alert = false;
 563         ipmi_ssif_unlock_cond(ssif_info, flags);
 564
 565         if (waiting)
 566                 start_get(ssif_info);
 567 }
 568
 569
 570 static void ssif_alert(struct i2c_client *client, enum i2c_alert_protocol type,
 571                        unsigned int data)
 572 {
 573         struct ssif_info *ssif_info = i2c_get_clientdata(client);
 574         unsigned long oflags, *flags;
 575         bool do_get = false;
 576
 577         if (type != I2C_PROTOCOL_SMBUS_ALERT)
 578                 return;
 579
 580         ssif_inc_stat(ssif_info, alerts);
 581
 582         flags = ipmi_ssif_lock_cond(ssif_info, &oflags);
 583         if (ssif_info->waiting_alert) {
 584                 ssif_info->waiting_alert = false;
 585                 del_timer(&ssif_info->retry_timer);
 586                 do_get = true;
 587         } else if (ssif_info->curr_msg) {
 588                 ssif_info->got_alert = true;
 589         }
 590         ipmi_ssif_unlock_cond(ssif_info, flags);
 591         if (do_get)
 592                 start_get(ssif_info);
 593 }
 594
 595 static int start_resend(struct ssif_info *ssif_info);
 596
 597 static void msg_done_handler(struct ssif_info *ssif_info, int result,
 598                              unsigned char *data, unsigned int len)
 599 {
 600         struct ipmi_smi_msg *msg;
 601         unsigned long oflags, *flags;
 602         int rv;
 603
 604         /*
 605          * We are single-threaded here, so no need for a lock until we
 606          * start messing with driver states or the queues.
 607          */
 608
 609         if (result < 0) {
 610                 ssif_info->retries_left--;
 611                 if (ssif_info->retries_left > 0) {
 612                         ssif_inc_stat(ssif_info, receive_retries);
 613
 614                         flags = ipmi_ssif_lock_cond(ssif_info, &oflags);
 615                         ssif_info->waiting_alert = true;
 616                         ssif_info->rtc_us_timer = SSIF_MSG_USEC;
 617                         mod_timer(&ssif_info->retry_timer,
 618                                   jiffies + SSIF_MSG_JIFFIES);
 619                         ipmi_ssif_unlock_cond(ssif_info, flags);
 620                         return;
 621                 }
 622
 623                 ssif_inc_stat(ssif_info, receive_errors);
 624
 625                 if  (ssif_info->ssif_debug & SSIF_DEBUG_MSG)
 626                         pr_info("Error in msg_done_handler: %d\n", result);
 627                 len = 0;
 628                 goto continue_op;
 629         }
 630
 631         if ((len > 1) && (ssif_info->multi_pos == 0)
 632                                 && (data[0] == 0x00) && (data[1] == 0x01)) {
 633                 /* Start of multi-part read.  Start the next transaction. */
 634                 int i;
 635
 636                 ssif_inc_stat(ssif_info, received_message_parts);
 637
 638                 /* Remove the multi-part read marker. */
 639                 len -= 2;
 640                 for (i = 0; i < len; i++)
 641                         ssif_info->data[i] = data[i+2];
 642                 ssif_info->multi_len = len;
 643                 ssif_info->multi_pos = 1;
 644
 645                 rv = ssif_i2c_send(ssif_info, msg_done_handler, I2C_SMBUS_READ,
 646                                   SSIF_IPMI_MULTI_PART_RESPONSE_MIDDLE,
 647                                   ssif_info->recv, I2C_SMBUS_BLOCK_DATA);
 648                 if (rv < 0) {
 649                         if (ssif_info->ssif_debug & SSIF_DEBUG_MSG)
 650                                 pr_info("Error from i2c_non_blocking_op(1)\n");
 651
 652                         result = -EIO;
 653                 } else
 654                         return;
 655         } else if (ssif_info->multi_pos) {
 656                 /* Middle of multi-part read.  Start the next transaction. */
 657                 int i;
 658                 unsigned char blocknum;
 659
 660                 if (len == 0) {
 661                         result = -EIO;
 662                         if (ssif_info->ssif_debug & SSIF_DEBUG_MSG)
 663                                 pr_info(PFX "Middle message with no data\n");
 664
 665                         goto continue_op;
 666                 }
 667
 668                 blocknum = data[0];
 669
 670                 if (ssif_info->multi_len + len - 1 > IPMI_MAX_MSG_LENGTH) {
 671                         /* Received message too big, abort the operation. */
 672                         result = -E2BIG;
 673                         if (ssif_info->ssif_debug & SSIF_DEBUG_MSG)
 674                                 pr_info("Received message too big\n");
 675
 676                         goto continue_op;
 677                 }
 678
 679                 /* Remove the blocknum from the data. */
 680                 len--;
 681                 for (i = 0; i < len; i++)
 682                         ssif_info->data[i + ssif_info->multi_len] = data[i + 1];
 683                 ssif_info->multi_len += len;
 684                 if (blocknum == 0xff) {
 685                         /* End of read */
 686                         len = ssif_info->multi_len;
 687                         data = ssif_info->data;
 688                 } else if (blocknum + 1 != ssif_info->multi_pos) {
 689                         /*
 690                          * Out of sequence block, just abort.  Block
 691                          * numbers start at zero for the second block,
 692                          * but multi_pos starts at one, so the +1.
 693                          */
 694                         result = -EIO;
 695                 } else {
 696                         ssif_inc_stat(ssif_info, received_message_parts);
 697
 698                         ssif_info->multi_pos++;
 699
 700                         rv = ssif_i2c_send(ssif_info, msg_done_handler,
 701                                            I2C_SMBUS_READ,
 702                                            SSIF_IPMI_MULTI_PART_RESPONSE_MIDDLE,
 703                                            ssif_info->recv,
 704                                            I2C_SMBUS_BLOCK_DATA);
 705                         if (rv < 0) {
 706                                 if (ssif_info->ssif_debug & SSIF_DEBUG_MSG)
 707                                         pr_info(PFX
 708                                                 "Error from ssif_i2c_send\n");
 709
 710                                 result = -EIO;
 711                         } else
 712                                 return;
 713                 }
 714         }
 715
 716         if (result < 0) {
 717                 ssif_inc_stat(ssif_info, receive_errors);
 718         } else {
 719                 ssif_inc_stat(ssif_info, received_messages);
 720                 ssif_inc_stat(ssif_info, received_message_parts);
 721         }
 722
 723
 724  continue_op:
 725         if (ssif_info->ssif_debug & SSIF_DEBUG_STATE)
 726                 pr_info(PFX "DONE 1: state = %d, result=%d.\n",
 727                         ssif_info->ssif_state, result);
 728
 729         flags = ipmi_ssif_lock_cond(ssif_info, &oflags);
 730         msg = ssif_info->curr_msg;
 731         if (msg) {
 732                 msg->rsp_size = len;
 733                 if (msg->rsp_size > IPMI_MAX_MSG_LENGTH)
 734                         msg->rsp_size = IPMI_MAX_MSG_LENGTH;
 735                 memcpy(msg->rsp, data, msg->rsp_size);
 736                 ssif_info->curr_msg = NULL;
 737         }
 738
 739         switch (ssif_info->ssif_state) {
 740         case SSIF_NORMAL:
 741                 ipmi_ssif_unlock_cond(ssif_info, flags);
 742                 if (!msg)
 743                         break;
 744
 745                 if (result < 0)
 746                         return_hosed_msg(ssif_info, msg);
 747                 else
 748                         deliver_recv_msg(ssif_info, msg);
 749                 break;
 750
 751         case SSIF_GETTING_FLAGS:
 752                 /* We got the flags from the SSIF, now handle them. */
 753                 if ((result < 0) || (len < 4) || (data[2] != 0)) {
 754                         /*
 755                          * Error fetching flags, or invalid length,
 756                          * just give up for now.
 757                          */
 758                         ssif_info->ssif_state = SSIF_NORMAL;
 759                         ipmi_ssif_unlock_cond(ssif_info, flags);
 760                         pr_warn(PFX "Error getting flags: %d %d, %x\n",
 761                                result, len, data[2]);
 762                 } else if (data[0] != (IPMI_NETFN_APP_REQUEST | 1) << 2
 763                            || data[1] != IPMI_GET_MSG_FLAGS_CMD) {
 764                         pr_warn(PFX "Invalid response getting flags: %x %x\n",
 765                                 data[0], data[1]);
 766                 } else {
 767                         ssif_inc_stat(ssif_info, flag_fetches);
 768                         ssif_info->msg_flags = data[3];
 769                         handle_flags(ssif_info, flags);
 770                 }
 771                 break;
 772
 773         case SSIF_CLEARING_FLAGS:
 774                 /* We cleared the flags. */
 775                 if ((result < 0) || (len < 3) || (data[2] != 0)) {
 776                         /* Error clearing flags */
 777                         pr_warn(PFX "Error clearing flags: %d %d, %x\n",
 778                                result, len, data[2]);
 779                 } else if (data[0] != (IPMI_NETFN_APP_REQUEST | 1) << 2
 780                            || data[1] != IPMI_CLEAR_MSG_FLAGS_CMD) {
 781                         pr_warn(PFX "Invalid response clearing flags: %x %x\n",
 782                                 data[0], data[1]);
 783                 }
 784                 ssif_info->ssif_state = SSIF_NORMAL;
 785                 ipmi_ssif_unlock_cond(ssif_info, flags);
 786                 break;
 787
 788         case SSIF_GETTING_EVENTS:
 789                 if ((result < 0) || (len < 3) || (msg->rsp[2] != 0)) {
 790                         /* Error getting event, probably done. */
 791                         msg->done(msg);
 792
 793                         /* Take off the event flag. */
 794                         ssif_info->msg_flags &= ~EVENT_MSG_BUFFER_FULL;
 795                         handle_flags(ssif_info, flags);
 796                 } else if (msg->rsp[0] != (IPMI_NETFN_APP_REQUEST | 1) << 2
 797                            || msg->rsp[1] != IPMI_READ_EVENT_MSG_BUFFER_CMD) {
 798                         pr_warn(PFX "Invalid response getting events: %x %x\n",
 799                                 msg->rsp[0], msg->rsp[1]);
 800                         msg->done(msg);
 801                         /* Take off the event flag. */
 802                         ssif_info->msg_flags &= ~EVENT_MSG_BUFFER_FULL;
 803                         handle_flags(ssif_info, flags);
 804                 } else {
 805                         handle_flags(ssif_info, flags);
 806                         ssif_inc_stat(ssif_info, events);
 807                         deliver_recv_msg(ssif_info, msg);
 808                 }
 809                 break;
 810
 811         case SSIF_GETTING_MESSAGES:
 812                 if ((result < 0) || (len < 3) || (msg->rsp[2] != 0)) {
 813                         /* Error getting event, probably done. */
 814                         msg->done(msg);
 815
 816                         /* Take off the msg flag. */
 817                         ssif_info->msg_flags &= ~RECEIVE_MSG_AVAIL;
 818                         handle_flags(ssif_info, flags);
 819                 } else if (msg->rsp[0] != (IPMI_NETFN_APP_REQUEST | 1) << 2
 820                            || msg->rsp[1] != IPMI_GET_MSG_CMD) {
 821                         pr_warn(PFX "Invalid response clearing flags: %x %x\n",
 822                                 msg->rsp[0], msg->rsp[1]);
 823                         msg->done(msg);
 824
 825                         /* Take off the msg flag. */
 826                         ssif_info->msg_flags &= ~RECEIVE_MSG_AVAIL;
 827                         handle_flags(ssif_info, flags);
 828                 } else {
 829                         ssif_inc_stat(ssif_info, incoming_messages);
 830                         handle_flags(ssif_info, flags);
 831                         deliver_recv_msg(ssif_info, msg);
 832                 }
 833                 break;
 834         }
 835
 836         flags = ipmi_ssif_lock_cond(ssif_info, &oflags);
 837         if (SSIF_IDLE(ssif_info) && !ssif_info->stopping) {
 838                 if (ssif_info->req_events)
 839                         start_event_fetch(ssif_info, flags);
 840                 else if (ssif_info->req_flags)
 841                         start_flag_fetch(ssif_info, flags);
 842                 else
 843                         start_next_msg(ssif_info, flags);
 844         } else
 845                 ipmi_ssif_unlock_cond(ssif_info, flags);
 846
 847         if (ssif_info->ssif_debug & SSIF_DEBUG_STATE)
 848                 pr_info(PFX "DONE 2: state = %d.\n", ssif_info->ssif_state);
 849 }
 850
 851 static void msg_written_handler(struct ssif_info *ssif_info, int result,
 852                                 unsigned char *data, unsigned int len)
 853 {
 854         int rv;
 855
 856         /* We are single-threaded here, so no need for a lock. */
 857         if (result < 0) {
 858                 ssif_info->retries_left--;
 859                 if (ssif_info->retries_left > 0) {
 860                         if (!start_resend(ssif_info)) {
 861                                 ssif_inc_stat(ssif_info, send_retries);
 862                                 return;
 863                         }
 864                         /* request failed, just return the error. */
 865                         ssif_inc_stat(ssif_info, send_errors);
 866
 867                         if (ssif_info->ssif_debug & SSIF_DEBUG_MSG)
 868                                 pr_info(PFX
 869                                         "Out of retries in msg_written_handler\n");
 870                         msg_done_handler(ssif_info, -EIO, NULL, 0);
 871                         return;
 872                 }
 873
 874                 ssif_inc_stat(ssif_info, send_errors);
 875
 876                 /*
 877                  * Got an error on transmit, let the done routine
 878                  * handle it.
 879                  */
 880                 if (ssif_info->ssif_debug & SSIF_DEBUG_MSG)
 881                         pr_info("Error in msg_written_handler: %d\n", result);
 882
 883                 msg_done_handler(ssif_info, result, NULL, 0);
 884                 return;
 885         }
 886
 887         if (ssif_info->multi_data) {
 888                 /*
 889                  * In the middle of a multi-data write.  See the comment
 890                  * in the SSIF_MULTI_n_PART case in the probe function
 891                  * for details on the intricacies of this.
 892                  */
 893                 int left;
 894
 895                 ssif_inc_stat(ssif_info, sent_messages_parts);
 896
 897                 left = ssif_info->multi_len - ssif_info->multi_pos;
 898                 if (left > 32)
 899                         left = 32;
 900                 /* Length byte. */
 901                 ssif_info->multi_data[ssif_info->multi_pos] = left;
 902                 ssif_info->multi_pos += left;
 903                 if (left < 32)
 904                         /*
 905                          * Write is finished.  Note that we must end
 906                          * with a write of less than 32 bytes to
 907                          * complete the transaction, even if it is
 908                          * zero bytes.
 909                          */
 910                         ssif_info->multi_data = NULL;
 911
 912                 rv = ssif_i2c_send(ssif_info, msg_written_handler,
 913                                   I2C_SMBUS_WRITE,
 914                                   SSIF_IPMI_MULTI_PART_REQUEST_MIDDLE,
 915                                   ssif_info->multi_data + ssif_info->multi_pos,
 916                                   I2C_SMBUS_BLOCK_DATA);
 917                 if (rv < 0) {
 918                         /* request failed, just return the error. */
 919                         ssif_inc_stat(ssif_info, send_errors);
 920
 921                         if (ssif_info->ssif_debug & SSIF_DEBUG_MSG)
 922                                 pr_info("Error from i2c_non_blocking_op(3)\n");
 923                         msg_done_handler(ssif_info, -EIO, NULL, 0);
 924                 }
 925         } else {
 926                 /* Ready to request the result. */
 927                 unsigned long oflags, *flags;
 928
 929                 ssif_inc_stat(ssif_info, sent_messages);
 930                 ssif_inc_stat(ssif_info, sent_messages_parts);
 931
 932                 flags = ipmi_ssif_lock_cond(ssif_info, &oflags);
 933                 if (ssif_info->got_alert) {
 934                         /* The result is already ready, just start it. */
 935                         ssif_info->got_alert = false;
 936                         ipmi_ssif_unlock_cond(ssif_info, flags);
 937                         start_get(ssif_info);
 938                 } else {
 939                         /* Wait a jiffie then request the next message */
 940                         ssif_info->waiting_alert = true;
 941                         ssif_info->retries_left = SSIF_RECV_RETRIES;
 942                         ssif_info->rtc_us_timer = SSIF_MSG_PART_USEC;
 943                         mod_timer(&ssif_info->retry_timer,
 944                                   jiffies + SSIF_MSG_PART_JIFFIES);
 945                         ipmi_ssif_unlock_cond(ssif_info, flags);
 946                 }
 947         }
 948 }
 949
 950 static int start_resend(struct ssif_info *ssif_info)
 951 {
 952         int rv;
 953         int command;
 954
 955         ssif_info->got_alert = false;
 956
 957         if (ssif_info->data_len > 32) {
 958                 command = SSIF_IPMI_MULTI_PART_REQUEST_START;
 959                 ssif_info->multi_data = ssif_info->data;
 960                 ssif_info->multi_len = ssif_info->data_len;
 961                 /*
 962                  * Subtle thing, this is 32, not 33, because we will
 963                  * overwrite the thing at position 32 (which was just
 964                  * transmitted) with the new length.
 965                  */
 966                 ssif_info->multi_pos = 32;
 967                 ssif_info->data[0] = 32;
 968         } else {
 969                 ssif_info->multi_data = NULL;
 970                 command = SSIF_IPMI_REQUEST;
 971                 ssif_info->data[0] = ssif_info->data_len;
 972         }
 973
 974         rv = ssif_i2c_send(ssif_info, msg_written_handler, I2C_SMBUS_WRITE,
 975                           command, ssif_info->data, I2C_SMBUS_BLOCK_DATA);
 976         if (rv && (ssif_info->ssif_debug & SSIF_DEBUG_MSG))
 977                 pr_info("Error from i2c_non_blocking_op(4)\n");
 978         return rv;
 979 }
 980
 981 static int start_send(struct ssif_info *ssif_info,
 982                       unsigned char   *data,
 983                       unsigned int    len)
 984 {
 985         if (len > IPMI_MAX_MSG_LENGTH)
 986                 return -E2BIG;
 987         if (len > ssif_info->max_xmit_msg_size)
 988                 return -E2BIG;
 989
 990         ssif_info->retries_left = SSIF_SEND_RETRIES;
 991         memcpy(ssif_info->data + 1, data, len);
 992         ssif_info->data_len = len;
 993         return start_resend(ssif_info);
 994 }
 995
 996 /* Must be called with the message lock held. */
 997 static void start_next_msg(struct ssif_info *ssif_info, unsigned long *flags)
 998 {
 999         struct ipmi_smi_msg *msg;
1000         unsigned long oflags;
1001
1002  restart:
1003         if (!SSIF_IDLE(ssif_info)) {
1004                 ipmi_ssif_unlock_cond(ssif_info, flags);
1005                 return;
1006         }
1007
1008         if (!ssif_info->waiting_msg) {
1009                 ssif_info->curr_msg = NULL;
1010                 ipmi_ssif_unlock_cond(ssif_info, flags);
1011         } else {
1012                 int rv;
1013
1014                 ssif_info->curr_msg = ssif_info->waiting_msg;
1015                 ssif_info->waiting_msg = NULL;
1016                 ipmi_ssif_unlock_cond(ssif_info, flags);
1017                 rv = start_send(ssif_info,
1018                                 ssif_info->curr_msg->data,
1019                                 ssif_info->curr_msg->data_size);
1020                 if (rv) {
1021                         msg = ssif_info->curr_msg;
1022                         ssif_info->curr_msg = NULL;
1023                         return_hosed_msg(ssif_info, msg);
1024                         flags = ipmi_ssif_lock_cond(ssif_info, &oflags);
1025                         goto restart;
1026                 }
1027         }
1028 }
1029
1030 static void sender(void                *send_info,
1031                    struct ipmi_smi_msg *msg)
1032 {
1033         struct ssif_info *ssif_info = (struct ssif_info *) send_info;
1034         unsigned long oflags, *flags;
1035
1036         BUG_ON(ssif_info->waiting_msg);
1037         ssif_info->waiting_msg = msg;
1038
1039         flags = ipmi_ssif_lock_cond(ssif_info, &oflags);
1040         start_next_msg(ssif_info, flags);
1041
1042         if (ssif_info->ssif_debug & SSIF_DEBUG_TIMING) {
1043                 struct timespec64 t;
1044
1045                 ktime_get_real_ts64(&t);
1046                 pr_info("**Enqueue %02x %02x: %lld.%6.6ld\n",
1047                        msg->data[0], msg->data[1],
1048                        (long long) t.tv_sec, (long) t.tv_nsec / NSEC_PER_USEC);
1049         }
1050 }
1051
1052 static int get_smi_info(void *send_info, struct ipmi_smi_info *data)
1053 {
1054         struct ssif_info *ssif_info = send_info;
1055
1056         data->addr_src = ssif_info->addr_source;
1057         data->dev = &ssif_info->client->dev;
1058         data->addr_info = ssif_info->addr_info;
1059         get_device(data->dev);
1060
1061         return 0;
1062 }
1063
1064 /*
1065  * Instead of having our own timer to periodically check the message
1066  * flags, we let the message handler drive us.
1067  */
1068 static void request_events(void *send_info)
1069 {
1070         struct ssif_info *ssif_info = (struct ssif_info *) send_info;
1071         unsigned long oflags, *flags;
1072
1073         if (!ssif_info->has_event_buffer)
1074                 return;
1075
1076         flags = ipmi_ssif_lock_cond(ssif_info, &oflags);
1077         /*
1078          * Request flags first, not events, because the lower layer
1079          * doesn't have a way to send an attention.  But make sure
1080          * event checking still happens.
1081          */
1082         ssif_info->req_events = true;
1083         if (SSIF_IDLE(ssif_info))
1084                 start_flag_fetch(ssif_info, flags);
1085         else {
1086                 ssif_info->req_flags = true;
1087                 ipmi_ssif_unlock_cond(ssif_info, flags);
1088         }
1089 }
1090
1091 static int inc_usecount(void *send_info)
1092 {
1093         struct ssif_info *ssif_info = send_info;
1094
1095         if (!i2c_get_adapter(ssif_info->client->adapter->nr))
1096                 return -ENODEV;
1097
1098         i2c_use_client(ssif_info->client);
1099         return 0;
1100 }
1101
1102 static void dec_usecount(void *send_info)
1103 {
1104         struct ssif_info *ssif_info = send_info;
1105
1106         i2c_release_client(ssif_info->client);
1107         i2c_put_adapter(ssif_info->client->adapter);
1108 }
1109
1110 static int ssif_start_processing(void *send_info,
1111                                  ipmi_smi_t intf)
1112 {
1113         struct ssif_info *ssif_info = send_info;
1114
1115         ssif_info->intf = intf;
1116
1117         return 0;
1118 }
1119
1120 #define MAX_SSIF_BMCS 4
1121
1122 static unsigned short addr[MAX_SSIF_BMCS];
1123 static int num_addrs;
1124 module_param_array(addr, ushort, &num_addrs, 0);
1125 MODULE_PARM_DESC(addr, "The addresses to scan for IPMI BMCs on the SSIFs.");
1126
1127 static char *adapter_name[MAX_SSIF_BMCS];
1128 static int num_adapter_names;
1129 module_param_array(adapter_name, charp, &num_adapter_names, 0);
1130 MODULE_PARM_DESC(adapter_name, "The string name of the I2C device that has the BMC.  By default all devices are scanned.");
1131
1132 static int slave_addrs[MAX_SSIF_BMCS];
1133 static int num_slave_addrs;
1134 module_param_array(slave_addrs, int, &num_slave_addrs, 0);
1135 MODULE_PARM_DESC(slave_addrs,
1136                  "The default IPMB slave address for the controller.");
1137
1138 static bool alerts_broken;
1139 module_param(alerts_broken, bool, 0);
1140 MODULE_PARM_DESC(alerts_broken, "Don't enable alerts for the controller.");
1141
1142 /*
1143  * Bit 0 enables message debugging, bit 1 enables state debugging, and
1144  * bit 2 enables timing debugging.  This is an array indexed by
1145  * interface number"
1146  */
1147 static int dbg[MAX_SSIF_BMCS];
1148 static int num_dbg;
1149 module_param_array(dbg, int, &num_dbg, 0);
1150 MODULE_PARM_DESC(dbg, "Turn on debugging.");
1151
1152 static bool ssif_dbg_probe;
1153 module_param_named(dbg_probe, ssif_dbg_probe, bool, 0);
1154 MODULE_PARM_DESC(dbg_probe, "Enable debugging of probing of adapters.");
1155
1156 static bool ssif_tryacpi = true;
1157 module_param_named(tryacpi, ssif_tryacpi, bool, 0);
1158 MODULE_PARM_DESC(tryacpi, "Setting this to zero will disable the default scan of the interfaces identified via ACPI");
1159
1160 static bool ssif_trydmi = true;
1161 module_param_named(trydmi, ssif_trydmi, bool, 0);
1162 MODULE_PARM_DESC(trydmi, "Setting this to zero will disable the default scan of the interfaces identified via DMI (SMBIOS)");
1163
1164 static DEFINE_MUTEX(ssif_infos_mutex);
1165 static LIST_HEAD(ssif_infos);
1166
1167 static int ssif_remove(struct i2c_client *client)
1168 {
1169         struct ssif_info *ssif_info = i2c_get_clientdata(client);
1170         int rv;
1171
1172         if (!ssif_info)
1173                 return 0;
1174
1175         /*
1176          * After this point, we won't deliver anything asychronously
1177          * to the message handler.  We can unregister ourself.
1178          */
1179         rv = ipmi_unregister_smi(ssif_info->intf);
1180         if (rv) {
1181                 pr_err(PFX "Unable to unregister device: errno=%d\n", rv);
1182                 return rv;
1183         }
1184         ssif_info->intf = NULL;
1185
1186         /* make sure the driver is not looking for flags any more. */
1187         while (ssif_info->ssif_state != SSIF_NORMAL)
1188                 schedule_timeout(1);
1189
1190         ssif_info->stopping = true;
1191         del_timer_sync(&ssif_info->retry_timer);
1192         if (ssif_info->thread) {
1193                 complete(&ssif_info->wake_thread);
1194                 kthread_stop(ssif_info->thread);
1195         }
1196
1197         /*
1198          * No message can be outstanding now, we have removed the
1199          * upper layer and it permitted us to do so.
1200          */
1201         kfree(ssif_info);
1202         return 0;
1203 }
1204
1205 static int do_cmd(struct i2c_client *client, int len, unsigned char *msg,
1206                   int *resp_len, unsigned char *resp)
1207 {
1208         int retry_cnt;
1209         int ret;
1210
1211         retry_cnt = SSIF_SEND_RETRIES;
1212  retry1:
1213         ret = i2c_smbus_write_block_data(client, SSIF_IPMI_REQUEST, len, msg);
1214         if (ret) {
1215                 retry_cnt--;
1216                 if (retry_cnt > 0)
1217                         goto retry1;
1218                 return -ENODEV;
1219         }
1220
1221         ret = -ENODEV;
1222         retry_cnt = SSIF_RECV_RETRIES;
1223         while (retry_cnt > 0) {
1224                 ret = i2c_smbus_read_block_data(client, SSIF_IPMI_RESPONSE,
1225                                                 resp);
1226                 if (ret > 0)
1227                         break;
1228                 msleep(SSIF_MSG_MSEC);
1229                 retry_cnt--;
1230                 if (retry_cnt <= 0)
1231                         break;
1232         }
1233
1234         if (ret > 0) {
1235                 /* Validate that the response is correct. */
1236                 if (ret < 3 ||
1237                     (resp[0] != (msg[0] | (1 << 2))) ||
1238                     (resp[1] != msg[1]))
1239                         ret = -EINVAL;
1240                 else {
1241                         *resp_len = ret;
1242                         ret = 0;
1243                 }
1244         }
1245
1246         return ret;
1247 }
1248
1249 static int ssif_detect(struct i2c_client *client, struct i2c_board_info *info)
1250 {
1251         unsigned char *resp;
1252         unsigned char msg[3];
1253         int           rv;
1254         int           len;
1255
1256         resp = kmalloc(IPMI_MAX_MSG_LENGTH, GFP_KERNEL);
1257         if (!resp)
1258                 return -ENOMEM;
1259
1260         /* Do a Get Device ID command, since it is required. */
1261         msg[0] = IPMI_NETFN_APP_REQUEST << 2;
1262         msg[1] = IPMI_GET_DEVICE_ID_CMD;
1263         rv = do_cmd(client, 2, msg, &len, resp);
1264         if (rv)
1265                 rv = -ENODEV;
1266         else
1267                 strlcpy(info->type, DEVICE_NAME, I2C_NAME_SIZE);
1268         kfree(resp);
1269         return rv;
1270 }
1271
1272 static int smi_type_proc_show(struct seq_file *m, void *v)
1273 {
1274         seq_puts(m, "ssif\n");
1275
1276         return 0;
1277 }
1278
1279 static int smi_type_proc_open(struct inode *inode, struct file *file)
1280 {
1281         return single_open(file, smi_type_proc_show, inode->i_private);
1282 }
1283
1284 static const struct file_operations smi_type_proc_ops = {
1285         .open           = smi_type_proc_open,
1286         .read           = seq_read,
1287         .llseek         = seq_lseek,
1288         .release        = single_release,
1289 };
1290
1291 static int smi_stats_proc_show(struct seq_file *m, void *v)
1292 {
1293         struct ssif_info *ssif_info = m->private;
1294
1295         seq_printf(m, "sent_messages:          %u\n",
1296                    ssif_get_stat(ssif_info, sent_messages));
1297         seq_printf(m, "sent_messages_parts:    %u\n",
1298                    ssif_get_stat(ssif_info, sent_messages_parts));
1299         seq_printf(m, "send_retries:           %u\n",
1300                    ssif_get_stat(ssif_info, send_retries));
1301         seq_printf(m, "send_errors:            %u\n",
1302                    ssif_get_stat(ssif_info, send_errors));
1303         seq_printf(m, "received_messages:      %u\n",
1304                    ssif_get_stat(ssif_info, received_messages));
1305         seq_printf(m, "received_message_parts: %u\n",
1306                    ssif_get_stat(ssif_info, received_message_parts));
1307         seq_printf(m, "receive_retries:        %u\n",
1308                    ssif_get_stat(ssif_info, receive_retries));
1309         seq_printf(m, "receive_errors:         %u\n",
1310                    ssif_get_stat(ssif_info, receive_errors));
1311         seq_printf(m, "flag_fetches:           %u\n",
1312                    ssif_get_stat(ssif_info, flag_fetches));
1313         seq_printf(m, "hosed:                  %u\n",
1314                    ssif_get_stat(ssif_info, hosed));
1315         seq_printf(m, "events:                 %u\n",
1316                    ssif_get_stat(ssif_info, events));
1317         seq_printf(m, "watchdog_pretimeouts:   %u\n",
1318                    ssif_get_stat(ssif_info, watchdog_pretimeouts));
1319         seq_printf(m, "alerts:                 %u\n",
1320                    ssif_get_stat(ssif_info, alerts));
1321         return 0;
1322 }
1323
1324 static int smi_stats_proc_open(struct inode *inode, struct file *file)
1325 {
1326         return single_open(file, smi_stats_proc_show, PDE_DATA(inode));
1327 }
1328
1329 static const struct file_operations smi_stats_proc_ops = {
1330         .open           = smi_stats_proc_open,
1331         .read           = seq_read,
1332         .llseek         = seq_lseek,
1333         .release        = single_release,
1334 };
1335
1336 static int strcmp_nospace(char *s1, char *s2)
1337 {
1338         while (*s1 && *s2) {
1339                 while (isspace(*s1))
1340                         s1++;
1341                 while (isspace(*s2))
1342                         s2++;
1343                 if (*s1 > *s2)
1344                         return 1;
1345                 if (*s1 < *s2)
1346                         return -1;
1347                 s1++;
1348                 s2++;
1349         }
1350         return 0;
1351 }
1352
1353 static struct ssif_addr_info *ssif_info_find(unsigned short addr,
1354                                              char *adapter_name,
1355                                              bool match_null_name)
1356 {
1357         struct ssif_addr_info *info, *found = NULL;
1358
1359 restart:
1360         list_for_each_entry(info, &ssif_infos, link) {
1361                 if (info->binfo.addr == addr) {
1362                         if (info->adapter_name || adapter_name) {
1363                                 if (!info->adapter_name != !adapter_name) {
1364                                         /* One is NULL and one is not */
1365                                         continue;
1366                                 }
1367                                 if (adapter_name &&
1368                                     strcmp_nospace(info->adapter_name,
1369                                                    adapter_name))
1370                                         /* Names do not match */
1371                                         continue;
1372                         }
1373                         found = info;
1374                         break;
1375                 }
1376         }
1377
1378         if (!found && match_null_name) {
1379                 /* Try to get an exact match first, then try with a NULL name */
1380                 adapter_name = NULL;
1381                 match_null_name = false;
1382                 goto restart;
1383         }
1384
1385         return found;
1386 }
1387
1388 static bool check_acpi(struct ssif_info *ssif_info, struct device *dev)
1389 {
1390 #ifdef CONFIG_ACPI
1391         acpi_handle acpi_handle;
1392
1393         acpi_handle = ACPI_HANDLE(dev);
1394         if (acpi_handle) {
1395                 ssif_info->addr_source = SI_ACPI;
1396                 ssif_info->addr_info.acpi_info.acpi_handle = acpi_handle;
1397                 return true;
1398         }
1399 #endif
1400         return false;
1401 }
1402
1403 static int find_slave_address(struct i2c_client *client, int slave_addr)
1404 {
1405         struct ssif_addr_info *info;
1406
1407         if (slave_addr)
1408                 return slave_addr;
1409
1410         /*
1411          * Came in without a slave address, search around to see if
1412          * the other sources have a slave address.  This lets us pick
1413          * up an SMBIOS slave address when using ACPI.
1414          */
1415         list_for_each_entry(info, &ssif_infos, link) {
1416                 if (info->binfo.addr != client->addr)
1417                         continue;
1418                 if (info->adapter_name && client->adapter->name &&
1419                     strcmp_nospace(info->adapter_name,
1420                                    client->adapter->name))
1421                         continue;
1422                 if (info->slave_addr) {
1423                         slave_addr = info->slave_addr;
1424                         break;
1425                 }
1426         }
1427
1428         return slave_addr;
1429 }
1430
1431 /*
1432  * Global enables we care about.
1433  */
1434 #define GLOBAL_ENABLES_MASK (IPMI_BMC_EVT_MSG_BUFF | IPMI_BMC_RCV_MSG_INTR | \
1435                              IPMI_BMC_EVT_MSG_INTR)
1436
1437 static int ssif_probe(struct i2c_client *client, const struct i2c_device_id *id)
1438 {
1439         unsigned char     msg[3];
1440         unsigned char     *resp;
1441         struct ssif_info   *ssif_info;
1442         int               rv = 0;
1443         int               len;
1444         int               i;
1445         u8                slave_addr = 0;
1446         struct ssif_addr_info *addr_info = NULL;
1447
1448
1449         resp = kmalloc(IPMI_MAX_MSG_LENGTH, GFP_KERNEL);
1450         if (!resp)
1451                 return -ENOMEM;
1452
1453         ssif_info = kzalloc(sizeof(*ssif_info), GFP_KERNEL);
1454         if (!ssif_info) {
1455                 kfree(resp);
1456                 return -ENOMEM;
1457         }
1458
1459         if (!check_acpi(ssif_info, &client->dev)) {
1460                 addr_info = ssif_info_find(client->addr, client->adapter->name,
1461                                            true);
1462                 if (!addr_info) {
1463                         /* Must have come in through sysfs. */
1464                         ssif_info->addr_source = SI_HOTMOD;
1465                 } else {
1466                         ssif_info->addr_source = addr_info->addr_src;
1467                         ssif_info->ssif_debug = addr_info->debug;
1468                         ssif_info->addr_info = addr_info->addr_info;
1469                         slave_addr = addr_info->slave_addr;
1470                 }
1471         }
1472
1473         slave_addr = find_slave_address(client, slave_addr);
1474
1475         pr_info(PFX "Trying %s-specified SSIF interface at i2c address 0x%x, adapter %s, slave address 0x%x\n",
1476                ipmi_addr_src_to_str(ssif_info->addr_source),
1477                client->addr, client->adapter->name, slave_addr);
1478
1479         /*
1480          * Do a Get Device ID command, since it comes back with some
1481          * useful info.
1482          */
1483         msg[0] = IPMI_NETFN_APP_REQUEST << 2;
1484         msg[1] = IPMI_GET_DEVICE_ID_CMD;
1485         rv = do_cmd(client, 2, msg, &len, resp);
1486         if (rv)
1487                 goto out;
1488
1489         rv = ipmi_demangle_device_id(resp, len, &ssif_info->device_id);
1490         if (rv)
1491                 goto out;
1492
1493         ssif_info->client = client;
1494         i2c_set_clientdata(client, ssif_info);
1495
1496         /* Now check for system interface capabilities */
1497         msg[0] = IPMI_NETFN_APP_REQUEST << 2;
1498         msg[1] = IPMI_GET_SYSTEM_INTERFACE_CAPABILITIES_CMD;
1499         msg[2] = 0; /* SSIF */
1500         rv = do_cmd(client, 3, msg, &len, resp);
1501         if (!rv && (len >= 3) && (resp[2] == 0)) {
1502                 if (len < 7) {
1503                         if (ssif_dbg_probe)
1504                                 pr_info(PFX "SSIF info too short: %d\n", len);
1505                         goto no_support;
1506                 }
1507
1508                 /* Got a good SSIF response, handle it. */
1509                 ssif_info->max_xmit_msg_size = resp[5];
1510                 ssif_info->max_recv_msg_size = resp[6];
1511                 ssif_info->multi_support = (resp[4] >> 6) & 0x3;
1512                 ssif_info->supports_pec = (resp[4] >> 3) & 0x1;
1513
1514                 /* Sanitize the data */
1515                 switch (ssif_info->multi_support) {
1516                 case SSIF_NO_MULTI:
1517                         if (ssif_info->max_xmit_msg_size > 32)
1518                                 ssif_info->max_xmit_msg_size = 32;
1519                         if (ssif_info->max_recv_msg_size > 32)
1520                                 ssif_info->max_recv_msg_size = 32;
1521                         break;
1522
1523                 case SSIF_MULTI_2_PART:
1524                         if (ssif_info->max_xmit_msg_size > 63)
1525                                 ssif_info->max_xmit_msg_size = 63;
1526                         if (ssif_info->max_recv_msg_size > 62)
1527                                 ssif_info->max_recv_msg_size = 62;
1528                         break;
1529
1530                 case SSIF_MULTI_n_PART:
1531                         /*
1532                          * The specification is rather confusing at
1533                          * this point, but I think I understand what
1534                          * is meant.  At least I have a workable
1535                          * solution.  With multi-part messages, you
1536                          * cannot send a message that is a multiple of
1537                          * 32-bytes in length, because the start and
1538                          * middle messages are 32-bytes and the end
1539                          * message must be at least one byte.  You
1540                          * can't fudge on an extra byte, that would
1541                          * screw up things like fru data writes.  So
1542                          * we limit the length to 63 bytes.  That way
1543                          * a 32-byte message gets sent as a single
1544                          * part.  A larger message will be a 32-byte
1545                          * start and the next message is always going
1546                          * to be 1-31 bytes in length.  Not ideal, but
1547                          * it should work.
1548                          */
1549                         if (ssif_info->max_xmit_msg_size > 63)
1550                                 ssif_info->max_xmit_msg_size = 63;
1551                         break;
1552
1553                 default:
1554                         /* Data is not sane, just give up. */
1555                         goto no_support;
1556                 }
1557         } else {
1558  no_support:
1559                 /* Assume no multi-part or PEC support */
1560                 pr_info(PFX "Error fetching SSIF: %d %d %2.2x, your system probably doesn't support this command so using defaults\n",
1561                        rv, len, resp[2]);
1562
1563                 ssif_info->max_xmit_msg_size = 32;
1564                 ssif_info->max_recv_msg_size = 32;
1565                 ssif_info->multi_support = SSIF_NO_MULTI;
1566                 ssif_info->supports_pec = 0;
1567         }
1568
1569         /* Make sure the NMI timeout is cleared. */
1570         msg[0] = IPMI_NETFN_APP_REQUEST << 2;
1571         msg[1] = IPMI_CLEAR_MSG_FLAGS_CMD;
1572         msg[2] = WDT_PRE_TIMEOUT_INT;
1573         rv = do_cmd(client, 3, msg, &len, resp);
1574         if (rv || (len < 3) || (resp[2] != 0))
1575                 pr_warn(PFX "Unable to clear message flags: %d %d %2.2x\n",
1576                         rv, len, resp[2]);
1577
1578         /* Attempt to enable the event buffer. */
1579         msg[0] = IPMI_NETFN_APP_REQUEST << 2;
1580         msg[1] = IPMI_GET_BMC_GLOBAL_ENABLES_CMD;
1581         rv = do_cmd(client, 2, msg, &len, resp);
1582         if (rv || (len < 4) || (resp[2] != 0)) {
1583                 pr_warn(PFX "Error getting global enables: %d %d %2.2x\n",
1584                         rv, len, resp[2]);
1585                 rv = 0; /* Not fatal */
1586                 goto found;
1587         }
1588
1589         ssif_info->global_enables = resp[3];
1590
1591         if (resp[3] & IPMI_BMC_EVT_MSG_BUFF) {
1592                 ssif_info->has_event_buffer = true;
1593                 /* buffer is already enabled, nothing to do. */
1594                 goto found;
1595         }
1596
1597         msg[0] = IPMI_NETFN_APP_REQUEST << 2;
1598         msg[1] = IPMI_SET_BMC_GLOBAL_ENABLES_CMD;
1599         msg[2] = ssif_info->global_enables | IPMI_BMC_EVT_MSG_BUFF;
1600         rv = do_cmd(client, 3, msg, &len, resp);
1601         if (rv || (len < 2)) {
1602                 pr_warn(PFX "Error setting global enables: %d %d %2.2x\n",
1603                         rv, len, resp[2]);
1604                 rv = 0; /* Not fatal */
1605                 goto found;
1606         }
1607
1608         if (resp[2] == 0) {
1609                 /* A successful return means the event buffer is supported. */
1610                 ssif_info->has_event_buffer = true;
1611                 ssif_info->global_enables |= IPMI_BMC_EVT_MSG_BUFF;
1612         }
1613
1614         /* Some systems don't behave well if you enable alerts. */
1615         if (alerts_broken)
1616                 goto found;
1617
1618         msg[0] = IPMI_NETFN_APP_REQUEST << 2;
1619         msg[1] = IPMI_SET_BMC_GLOBAL_ENABLES_CMD;
1620         msg[2] = ssif_info->global_enables | IPMI_BMC_RCV_MSG_INTR;
1621         rv = do_cmd(client, 3, msg, &len, resp);
1622         if (rv || (len < 2)) {
1623                 pr_warn(PFX "Error setting global enables: %d %d %2.2x\n",
1624                         rv, len, resp[2]);
1625                 rv = 0; /* Not fatal */
1626                 goto found;
1627         }
1628
1629         if (resp[2] == 0) {
1630                 /* A successful return means the alert is supported. */
1631                 ssif_info->supports_alert = true;
1632                 ssif_info->global_enables |= IPMI_BMC_RCV_MSG_INTR;
1633         }
1634
1635  found:
1636         ssif_info->intf_num = atomic_inc_return(&next_intf);
1637
1638         if (ssif_dbg_probe) {
1639                 pr_info("ssif_probe: i2c_probe found device at i2c address %x\n",
1640                         client->addr);
1641         }
1642
1643         spin_lock_init(&ssif_info->lock);
1644         ssif_info->ssif_state = SSIF_NORMAL;
1645         init_timer(&ssif_info->retry_timer);
1646         ssif_info->retry_timer.data = (unsigned long) ssif_info;
1647         ssif_info->retry_timer.function = retry_timeout;
1648
1649         for (i = 0; i < SSIF_NUM_STATS; i++)
1650                 atomic_set(&ssif_info->stats[i], 0);
1651
1652         if (ssif_info->supports_pec)
1653                 ssif_info->client->flags |= I2C_CLIENT_PEC;
1654
1655         ssif_info->handlers.owner = THIS_MODULE;
1656         ssif_info->handlers.start_processing = ssif_start_processing;
1657         ssif_info->handlers.get_smi_info = get_smi_info;
1658         ssif_info->handlers.sender = sender;
1659         ssif_info->handlers.request_events = request_events;
1660         ssif_info->handlers.inc_usecount = inc_usecount;
1661         ssif_info->handlers.dec_usecount = dec_usecount;
1662
1663         {
1664                 unsigned int thread_num;
1665
1666                 thread_num = ((ssif_info->client->adapter->nr << 8) |
1667                               ssif_info->client->addr);
1668                 init_completion(&ssif_info->wake_thread);
1669                 ssif_info->thread = kthread_run(ipmi_ssif_thread, ssif_info,
1670                                                "kssif%4.4x", thread_num);
1671                 if (IS_ERR(ssif_info->thread)) {
1672                         rv = PTR_ERR(ssif_info->thread);
1673                         dev_notice(&ssif_info->client->dev,
1674                                    "Could not start kernel thread: error %d\n",
1675                                    rv);
1676                         goto out;
1677                 }
1678         }
1679
1680         rv = ipmi_register_smi(&ssif_info->handlers,
1681                                ssif_info,
1682                                &ssif_info->device_id,
1683                                &ssif_info->client->dev,
1684                                slave_addr);
1685          if (rv) {
1686                 pr_err(PFX "Unable to register device: error %d\n", rv);
1687                 goto out;
1688         }
1689
1690         rv = ipmi_smi_add_proc_entry(ssif_info->intf, "type",
1691                                      &smi_type_proc_ops,
1692                                      ssif_info);
1693         if (rv) {
1694                 pr_err(PFX "Unable to create proc entry: %d\n", rv);
1695                 goto out_err_unreg;
1696         }
1697
1698         rv = ipmi_smi_add_proc_entry(ssif_info->intf, "ssif_stats",
1699                                      &smi_stats_proc_ops,
1700                                      ssif_info);
1701         if (rv) {
1702                 pr_err(PFX "Unable to create proc entry: %d\n", rv);
1703                 goto out_err_unreg;
1704         }
1705
1706  out:
1707         if (rv)
1708                 kfree(ssif_info);
1709         kfree(resp);
1710         return rv;
1711
1712  out_err_unreg:
1713         ipmi_unregister_smi(ssif_info->intf);
1714         goto out;
1715 }
1716
1717 static int ssif_adapter_handler(struct device *adev, void *opaque)
1718 {
1719         struct ssif_addr_info *addr_info = opaque;
1720
1721         if (adev->type != &i2c_adapter_type)
1722                 return 0;
1723
1724         i2c_new_device(to_i2c_adapter(adev), &addr_info->binfo);
1725
1726         if (!addr_info->adapter_name)
1727                 return 1; /* Only try the first I2C adapter by default. */
1728         return 0;
1729 }
1730
1731 static int new_ssif_client(int addr, char *adapter_name,
1732                            int debug, int slave_addr,
1733                            enum ipmi_addr_src addr_src)
1734 {
1735         struct ssif_addr_info *addr_info;
1736         int rv = 0;
1737
1738         mutex_lock(&ssif_infos_mutex);
1739         if (ssif_info_find(addr, adapter_name, false)) {
1740                 rv = -EEXIST;
1741                 goto out_unlock;
1742         }
1743
1744         addr_info = kzalloc(sizeof(*addr_info), GFP_KERNEL);
1745         if (!addr_info) {
1746                 rv = -ENOMEM;
1747                 goto out_unlock;
1748         }
1749
1750         if (adapter_name) {
1751                 addr_info->adapter_name = kstrdup(adapter_name, GFP_KERNEL);
1752                 if (!addr_info->adapter_name) {
1753                         kfree(addr_info);
1754                         rv = -ENOMEM;
1755                         goto out_unlock;
1756                 }
1757         }
1758
1759         strncpy(addr_info->binfo.type, DEVICE_NAME,
1760                 sizeof(addr_info->binfo.type));
1761         addr_info->binfo.addr = addr;
1762         addr_info->binfo.platform_data = addr_info;
1763         addr_info->debug = debug;
1764         addr_info->slave_addr = slave_addr;
1765         addr_info->addr_src = addr_src;
1766
1767         list_add_tail(&addr_info->link, &ssif_infos);
1768
1769         if (initialized)
1770                 i2c_for_each_dev(addr_info, ssif_adapter_handler);
1771         /* Otherwise address list will get it */
1772
1773 out_unlock:
1774         mutex_unlock(&ssif_infos_mutex);
1775         return rv;
1776 }
1777
1778 static void free_ssif_clients(void)
1779 {
1780         struct ssif_addr_info *info, *tmp;
1781
1782         mutex_lock(&ssif_infos_mutex);
1783         list_for_each_entry_safe(info, tmp, &ssif_infos, link) {
1784                 list_del(&info->link);
1785                 kfree(info->adapter_name);
1786                 kfree(info);
1787         }
1788         mutex_unlock(&ssif_infos_mutex);
1789 }
1790
1791 static unsigned short *ssif_address_list(void)
1792 {
1793         struct ssif_addr_info *info;
1794         unsigned int count = 0, i;
1795         unsigned short *address_list;
1796
1797         list_for_each_entry(info, &ssif_infos, link)
1798                 count++;
1799
1800         address_list = kzalloc(sizeof(*address_list) * (count + 1), GFP_KERNEL);
1801         if (!address_list)
1802                 return NULL;
1803
1804         i = 0;
1805         list_for_each_entry(info, &ssif_infos, link) {
1806                 unsigned short addr = info->binfo.addr;
1807                 int j;
1808
1809                 for (j = 0; j < i; j++) {
1810                         if (address_list[j] == addr)
1811                                 goto skip_addr;
1812                 }
1813                 address_list[i] = addr;
1814 skip_addr:
1815                 i++;
1816         }
1817         address_list[i] = I2C_CLIENT_END;
1818
1819         return address_list;
1820 }
1821
1822 #ifdef CONFIG_ACPI
1823 static const struct acpi_device_id ssif_acpi_match[] = {
1824         { "IPI0001", 0 },
1825         { },
1826 };
1827 MODULE_DEVICE_TABLE(acpi, ssif_acpi_match);
1828
1829 /*
1830  * Once we get an ACPI failure, we don't try any more, because we go
1831  * through the tables sequentially.  Once we don't find a table, there
1832  * are no more.
1833  */
1834 static int acpi_failure;
1835
1836 /*
1837  * Defined in the IPMI 2.0 spec.
1838  */
1839 struct SPMITable {
1840         s8      Signature[4];
1841         u32     Length;
1842         u8      Revision;
1843         u8      Checksum;
1844         s8      OEMID[6];
1845         s8      OEMTableID[8];
1846         s8      OEMRevision[4];
1847         s8      CreatorID[4];
1848         s8      CreatorRevision[4];
1849         u8      InterfaceType;
1850         u8      IPMIlegacy;
1851         s16     SpecificationRevision;
1852
1853         /*
1854          * Bit 0 - SCI interrupt supported
1855          * Bit 1 - I/O APIC/SAPIC
1856          */
1857         u8      InterruptType;
1858
1859         /*
1860          * If bit 0 of InterruptType is set, then this is the SCI
1861          * interrupt in the GPEx_STS register.
1862          */
1863         u8      GPE;
1864
1865         s16     Reserved;
1866
1867         /*
1868          * If bit 1 of InterruptType is set, then this is the I/O
1869          * APIC/SAPIC interrupt.
1870          */
1871         u32     GlobalSystemInterrupt;
1872
1873         /* The actual register address. */
1874         struct acpi_generic_address addr;
1875
1876         u8      UID[4];
1877
1878         s8      spmi_id[1]; /* A '\0' terminated array starts here. */
1879 };
1880
1881 static int try_init_spmi(struct SPMITable *spmi)
1882 {
1883         unsigned short myaddr;
1884
1885         if (num_addrs >= MAX_SSIF_BMCS)
1886                 return -1;
1887
1888         if (spmi->IPMIlegacy != 1) {
1889                 pr_warn("IPMI: Bad SPMI legacy: %d\n", spmi->IPMIlegacy);
1890                 return -ENODEV;
1891         }
1892
1893         if (spmi->InterfaceType != 4)
1894                 return -ENODEV;
1895
1896         if (spmi->addr.space_id != ACPI_ADR_SPACE_SMBUS) {
1897                 pr_warn(PFX "Invalid ACPI SSIF I/O Address type: %d\n",
1898                         spmi->addr.space_id);
1899                 return -EIO;
1900         }
1901
1902         myaddr = spmi->addr.address & 0x7f;
1903
1904         return new_ssif_client(myaddr, NULL, 0, 0, SI_SPMI);
1905 }
1906
1907 static void spmi_find_bmc(void)
1908 {
1909         acpi_status      status;
1910         struct SPMITable *spmi;
1911         int              i;
1912
1913         if (acpi_disabled)
1914                 return;
1915
1916         if (acpi_failure)
1917                 return;
1918
1919         for (i = 0; ; i++) {
1920                 status = acpi_get_table(ACPI_SIG_SPMI, i+1,
1921                                         (struct acpi_table_header **)&spmi);
1922                 if (status != AE_OK)
1923                         return;
1924
1925                 try_init_spmi(spmi);
1926         }
1927 }
1928 #else
1929 static void spmi_find_bmc(void) { }
1930 #endif
1931
1932 #ifdef CONFIG_DMI
1933 static int decode_dmi(const struct dmi_device *dmi_dev)
1934 {
1935         struct dmi_header *dm = dmi_dev->device_data;
1936         u8             *data = (u8 *) dm;
1937         u8             len = dm->length;
1938         unsigned short myaddr;
1939         int            slave_addr;
1940
1941         if (num_addrs >= MAX_SSIF_BMCS)
1942                 return -1;
1943
1944         if (len < 9)
1945                 return -1;
1946
1947         if (data[0x04] != 4) /* Not SSIF */
1948                 return -1;
1949
1950         if ((data[8] >> 1) == 0) {
1951                 /*
1952                  * Some broken systems put the I2C address in
1953                  * the slave address field.  We try to
1954                  * accommodate them here.
1955                  */
1956                 myaddr = data[6] >> 1;
1957                 slave_addr = 0;
1958         } else {
1959                 myaddr = data[8] >> 1;
1960                 slave_addr = data[6];
1961         }
1962
1963         return new_ssif_client(myaddr, NULL, 0, slave_addr, SI_SMBIOS);
1964 }
1965
1966 static void dmi_iterator(void)
1967 {
1968         const struct dmi_device *dev = NULL;
1969
1970         while ((dev = dmi_find_device(DMI_DEV_TYPE_IPMI, NULL, dev)))
1971                 decode_dmi(dev);
1972 }
1973 #else
1974 static void dmi_iterator(void) { }
1975 #endif
1976
1977 static const struct i2c_device_id ssif_id[] = {
1978         { DEVICE_NAME, 0 },
1979         { }
1980 };
1981 MODULE_DEVICE_TABLE(i2c, ssif_id);
1982
1983 static struct i2c_driver ssif_i2c_driver = {
1984         .class          = I2C_CLASS_HWMON,
1985         .driver         = {
1986                 .name                   = DEVICE_NAME
1987         },
1988         .probe          = ssif_probe,
1989         .remove         = ssif_remove,
1990         .alert          = ssif_alert,
1991         .id_table       = ssif_id,
1992         .detect         = ssif_detect
1993 };
1994
1995 static int init_ipmi_ssif(void)
1996 {
1997         int i;
1998         int rv;
1999
2000         if (initialized)
2001                 return 0;
2002
2003         pr_info("IPMI SSIF Interface driver\n");
2004
2005         /* build list for i2c from addr list */
2006         for (i = 0; i < num_addrs; i++) {
2007                 rv = new_ssif_client(addr[i], adapter_name[i],
2008                                      dbg[i], slave_addrs[i],
2009                                      SI_HARDCODED);
2010                 if (rv)
2011                         pr_err(PFX
2012                                "Couldn't add hardcoded device at addr 0x%x\n",
2013                                addr[i]);
2014         }
2015
2016         if (ssif_tryacpi)
2017                 ssif_i2c_driver.driver.acpi_match_table =
2018                         ACPI_PTR(ssif_acpi_match);
2019         if (ssif_trydmi)
2020                 dmi_iterator();
2021         if (ssif_tryacpi)
2022                 spmi_find_bmc();
2023
2024         ssif_i2c_driver.address_list = ssif_address_list();
2025
2026         rv = i2c_add_driver(&ssif_i2c_driver);
2027         if (!rv)
2028                 initialized = true;
2029
2030         return rv;
2031 }
2032 module_init(init_ipmi_ssif);
2033
2034 static void cleanup_ipmi_ssif(void)
2035 {
2036         if (!initialized)
2037                 return;
2038
2039         initialized = false;
2040
2041         i2c_del_driver(&ssif_i2c_driver);
2042
2043         free_ssif_clients();
2044 }
2045 module_exit(cleanup_ipmi_ssif);
2046
2047 MODULE_AUTHOR("Todd C Davis <todd.c.davis@intel.com>, Corey Minyard <minyard@acm.org>");
2048 MODULE_DESCRIPTION("IPMI driver for management controllers on a SMBus");
2049 MODULE_LICENSE("GPL");