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