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 #include <linux/version.h>
  35 #if defined(MODVERSIONS)
  36 #include <linux/modversions.h>
  37 #endif
  38
  39 #include <linux/module.h>
  40 #include <linux/moduleparam.h>
  41 #include <linux/sched.h>
  42 #include <linux/seq_file.h>
  43 #include <linux/timer.h>
  44 #include <linux/delay.h>
  45 #include <linux/errno.h>
  46 #include <linux/spinlock.h>
  47 #include <linux/slab.h>
  48 #include <linux/list.h>
  49 #include <linux/i2c.h>
  50 #include <linux/ipmi_smi.h>
  51 #include <linux/init.h>
  52 #include <linux/dmi.h>
  53 #include <linux/kthread.h>
  54 #include <linux/acpi.h>
  55
  56 #define PFX "ipmi_ssif: "
  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_RESPONSE                      3
  65 #define SSIF_IPMI_MULTI_PART_RESPONSE_MIDDLE    9
  66
  67 /* ssif_debug is a bit-field
  68  *      SSIF_DEBUG_MSG -        commands and their responses
  69  *      SSIF_DEBUG_STATES -     message states
  70  *      SSIF_DEBUG_TIMING -      Measure times between events in the driver
  71  */
  72 #define SSIF_DEBUG_TIMING       4
  73 #define SSIF_DEBUG_STATE        2
  74 #define SSIF_DEBUG_MSG          1
  75 #define SSIF_NODEBUG            0
  76 #define SSIF_DEFAULT_DEBUG      (SSIF_NODEBUG)
  77
  78 /*
  79  * Timer values
  80  */
  81 #define SSIF_MSG_USEC           20000   /* 20ms between message tries. */
  82 #define SSIF_MSG_PART_USEC      5000    /* 5ms for a message part */
  83
  84 /* How many times to we retry sending/receiving the message. */
  85 #define SSIF_SEND_RETRIES       5
  86 #define SSIF_RECV_RETRIES       250
  87
  88 #define SSIF_MSG_MSEC           (SSIF_MSG_USEC / 1000)
  89 #define SSIF_MSG_JIFFIES        ((SSIF_MSG_USEC * 1000) / TICK_NSEC)
  90 #define SSIF_MSG_PART_JIFFIES   ((SSIF_MSG_PART_USEC * 1000) / TICK_NSEC)
  91
  92 enum ssif_intf_state {
  93         SSIF_NORMAL,
  94         SSIF_GETTING_FLAGS,
  95         SSIF_GETTING_EVENTS,
  96         SSIF_CLEARING_FLAGS,
  97         SSIF_GETTING_MESSAGES,
  98         /* FIXME - add watchdog stuff. */
  99 };
 100
 101 #define SSIF_IDLE(ssif)  ((ssif)->ssif_state == SSIF_NORMAL \
 102                           && (ssif)->curr_msg == NULL)
 103
 104 /*
 105  * Indexes into stats[] in ssif_info below.
 106  */
 107 enum ssif_stat_indexes {
 108         /* Number of total messages sent. */
 109         SSIF_STAT_sent_messages = 0,
 110
 111         /*
 112          * Number of message parts sent.  Messages may be broken into
 113          * parts if they are long.
 114          */
 115         SSIF_STAT_sent_messages_parts,
 116
 117         /*
 118          * Number of time a message was retried.
 119          */
 120         SSIF_STAT_send_retries,
 121
 122         /*
 123          * Number of times the send of a message failed.
 124          */
 125         SSIF_STAT_send_errors,
 126
 127         /*
 128          * Number of message responses received.
 129          */
 130         SSIF_STAT_received_messages,
 131
 132         /*
 133          * Number of message fragments received.
 134          */
 135         SSIF_STAT_received_message_parts,
 136
 137         /*
 138          * Number of times the receive of a message was retried.
 139          */
 140         SSIF_STAT_receive_retries,
 141
 142         /*
 143          * Number of errors receiving messages.
 144          */
 145         SSIF_STAT_receive_errors,
 146
 147         /*
 148          * Number of times a flag fetch was requested.
 149          */
 150         SSIF_STAT_flag_fetches,
 151
 152         /*
 153          * Number of times the hardware didn't follow the state machine.
 154          */
 155         SSIF_STAT_hosed,
 156
 157         /*
 158          * Number of received events.
 159          */
 160         SSIF_STAT_events,
 161
 162         /* Number of asyncronous messages received. */
 163         SSIF_STAT_incoming_messages,
 164
 165         /* Number of watchdog pretimeouts. */
 166         SSIF_STAT_watchdog_pretimeouts,
 167
 168         /* Always add statistics before this value, it must be last. */
 169         SSIF_NUM_STATS
 170 };
 171
 172 struct ssif_addr_info {
 173         unsigned short addr;
 174         struct i2c_board_info binfo;
 175         char *adapter_name;
 176         int debug;
 177         int slave_addr;
 178         enum ipmi_addr_src addr_src;
 179         union ipmi_smi_info_union addr_info;
 180
 181         struct mutex clients_mutex;
 182         struct list_head clients;
 183
 184         struct list_head link;
 185 };
 186
 187 struct ssif_info;
 188
 189 typedef void (*ssif_i2c_done)(struct ssif_info *ssif_info, int result,
 190                              unsigned char *data, unsigned int len);
 191
 192 struct ssif_info {
 193         ipmi_smi_t          intf;
 194         int                 intf_num;
 195         spinlock_t          lock;
 196         struct ipmi_smi_msg *waiting_msg;
 197         struct ipmi_smi_msg *curr_msg;
 198         enum ssif_intf_state ssif_state;
 199         unsigned long       ssif_debug;
 200
 201         struct ipmi_smi_handlers handlers;
 202
 203         enum ipmi_addr_src addr_source; /* ACPI, PCI, SMBIOS, hardcode, etc. */
 204         union ipmi_smi_info_union addr_info;
 205
 206         /*
 207          * Flags from the last GET_MSG_FLAGS command, used when an ATTN
 208          * is set to hold the flags until we are done handling everything
 209          * from the flags.
 210          */
 211 #define RECEIVE_MSG_AVAIL       0x01
 212 #define EVENT_MSG_BUFFER_FULL   0x02
 213 #define WDT_PRE_TIMEOUT_INT     0x08
 214         unsigned char       msg_flags;
 215
 216         bool                has_event_buffer;
 217
 218         /*
 219          * If set to true, this will request events the next time the
 220          * state machine is idle.
 221          */
 222         bool                req_events;
 223
 224         /*
 225          * If set to true, this will request flags the next time the
 226          * state machine is idle.
 227          */
 228         bool                req_flags;
 229
 230         /*
 231          * Used to perform timer operations when run-to-completion
 232          * mode is on.  This is a countdown timer.
 233          */
 234         int                 rtc_us_timer;
 235
 236         /* Used for sending/receiving data.  +1 for the length. */
 237         unsigned char data[IPMI_MAX_MSG_LENGTH + 1];
 238         unsigned int  data_len;
 239
 240         /* Temp receive buffer, gets copied into data. */
 241         unsigned char recv[I2C_SMBUS_BLOCK_MAX];
 242
 243         struct i2c_client *client;
 244         ssif_i2c_done done_handler;
 245
 246         /* Thread interface handling */
 247         struct task_struct *thread;
 248         struct completion wake_thread;
 249         bool stopping;
 250         int i2c_read_write;
 251         int i2c_command;
 252         unsigned char *i2c_data;
 253         unsigned int i2c_size;
 254
 255         /* From the device id response. */
 256         struct ipmi_device_id device_id;
 257
 258         struct timer_list retry_timer;
 259         int retries_left;
 260
 261         /* Info from SSIF cmd */
 262         unsigned char max_xmit_msg_size;
 263         unsigned char max_recv_msg_size;
 264         unsigned int  multi_support;
 265         int           supports_pec;
 266
 267 #define SSIF_NO_MULTI           0
 268 #define SSIF_MULTI_2_PART       1
 269 #define SSIF_MULTI_n_PART       2
 270         unsigned char *multi_data;
 271         unsigned int  multi_len;
 272         unsigned int  multi_pos;
 273
 274         atomic_t stats[SSIF_NUM_STATS];
 275 };
 276
 277 #define ssif_inc_stat(ssif, stat) \
 278         atomic_inc(&(ssif)->stats[SSIF_STAT_ ## stat])
 279 #define ssif_get_stat(ssif, stat) \
 280         ((unsigned int) atomic_read(&(ssif)->stats[SSIF_STAT_ ## stat]))
 281
 282 static bool initialized;
 283
 284 static atomic_t next_intf = ATOMIC_INIT(0);
 285
 286 static void return_hosed_msg(struct ssif_info *ssif_info,
 287                              struct ipmi_smi_msg *msg);
 288 static void start_next_msg(struct ssif_info *ssif_info, unsigned long *flags);
 289 static int start_send(struct ssif_info *ssif_info,
 290                       unsigned char   *data,
 291                       unsigned int    len);
 292
 293 static unsigned long *ipmi_ssif_lock_cond(struct ssif_info *ssif_info,
 294                                           unsigned long *flags)
 295 {
 296         spin_lock_irqsave(&ssif_info->lock, *flags);
 297         return flags;
 298 }
 299
 300 static void ipmi_ssif_unlock_cond(struct ssif_info *ssif_info,
 301                                   unsigned long *flags)
 302 {
 303         spin_unlock_irqrestore(&ssif_info->lock, *flags);
 304 }
 305
 306 static void deliver_recv_msg(struct ssif_info *ssif_info,
 307                              struct ipmi_smi_msg *msg)
 308 {
 309         ipmi_smi_t    intf = ssif_info->intf;
 310
 311         if (!intf) {
 312                 ipmi_free_smi_msg(msg);
 313         } else if (msg->rsp_size < 0) {
 314                 return_hosed_msg(ssif_info, msg);
 315                 pr_err(PFX
 316                        "Malformed message in deliver_recv_msg: rsp_size = %d\n",
 317                        msg->rsp_size);
 318         } else {
 319                 ipmi_smi_msg_received(intf, msg);
 320         }
 321 }
 322
 323 static void return_hosed_msg(struct ssif_info *ssif_info,
 324                              struct ipmi_smi_msg *msg)
 325 {
 326         ssif_inc_stat(ssif_info, hosed);
 327
 328         /* Make it a response */
 329         msg->rsp[0] = msg->data[0] | 4;
 330         msg->rsp[1] = msg->data[1];
 331         msg->rsp[2] = 0xFF; /* Unknown error. */
 332         msg->rsp_size = 3;
 333
 334         deliver_recv_msg(ssif_info, msg);
 335 }
 336
 337 /*
 338  * Must be called with the message lock held.  This will release the
 339  * message lock.  Note that the caller will check SSIF_IDLE and start a
 340  * new operation, so there is no need to check for new messages to
 341  * start in here.
 342  */
 343 static void start_clear_flags(struct ssif_info *ssif_info, unsigned long *flags)
 344 {
 345         unsigned char msg[3];
 346
 347         ssif_info->msg_flags &= ~WDT_PRE_TIMEOUT_INT;
 348         ssif_info->ssif_state = SSIF_CLEARING_FLAGS;
 349         ipmi_ssif_unlock_cond(ssif_info, flags);
 350
 351         /* Make sure the watchdog pre-timeout flag is not set at startup. */
 352         msg[0] = (IPMI_NETFN_APP_REQUEST << 2);
 353         msg[1] = IPMI_CLEAR_MSG_FLAGS_CMD;
 354         msg[2] = WDT_PRE_TIMEOUT_INT;
 355
 356         if (start_send(ssif_info, msg, 3) != 0) {
 357                 /* Error, just go to normal state. */
 358                 ssif_info->ssif_state = SSIF_NORMAL;
 359         }
 360 }
 361
 362 static void start_flag_fetch(struct ssif_info *ssif_info, unsigned long *flags)
 363 {
 364         unsigned char mb[2];
 365
 366         ssif_info->req_flags = false;
 367         ssif_info->ssif_state = SSIF_GETTING_FLAGS;
 368         ipmi_ssif_unlock_cond(ssif_info, flags);
 369
 370         mb[0] = (IPMI_NETFN_APP_REQUEST << 2);
 371         mb[1] = IPMI_GET_MSG_FLAGS_CMD;
 372         if (start_send(ssif_info, mb, 2) != 0)
 373                 ssif_info->ssif_state = SSIF_NORMAL;
 374 }
 375
 376 static void check_start_send(struct ssif_info *ssif_info, unsigned long *flags,
 377                              struct ipmi_smi_msg *msg)
 378 {
 379         if (start_send(ssif_info, msg->data, msg->data_size) != 0) {
 380                 unsigned long oflags;
 381
 382                 flags = ipmi_ssif_lock_cond(ssif_info, &oflags);
 383                 ssif_info->curr_msg = NULL;
 384                 ssif_info->ssif_state = SSIF_NORMAL;
 385                 ipmi_ssif_unlock_cond(ssif_info, flags);
 386                 ipmi_free_smi_msg(msg);
 387         }
 388 }
 389
 390 static void start_event_fetch(struct ssif_info *ssif_info, unsigned long *flags)
 391 {
 392         struct ipmi_smi_msg *msg;
 393
 394         ssif_info->req_events = false;
 395
 396         msg = ipmi_alloc_smi_msg();
 397         if (!msg) {
 398                 ssif_info->ssif_state = SSIF_NORMAL;
 399                 return;
 400         }
 401
 402         ssif_info->curr_msg = msg;
 403         ssif_info->ssif_state = SSIF_GETTING_EVENTS;
 404         ipmi_ssif_unlock_cond(ssif_info, flags);
 405
 406         msg->data[0] = (IPMI_NETFN_APP_REQUEST << 2);
 407         msg->data[1] = IPMI_READ_EVENT_MSG_BUFFER_CMD;
 408         msg->data_size = 2;
 409
 410         check_start_send(ssif_info, flags, msg);
 411 }
 412
 413 static void start_recv_msg_fetch(struct ssif_info *ssif_info,
 414                                  unsigned long *flags)
 415 {
 416         struct ipmi_smi_msg *msg;
 417
 418         msg = ipmi_alloc_smi_msg();
 419         if (!msg) {
 420                 ssif_info->ssif_state = SSIF_NORMAL;
 421                 return;
 422         }
 423
 424         ssif_info->curr_msg = msg;
 425         ssif_info->ssif_state = SSIF_GETTING_MESSAGES;
 426         ipmi_ssif_unlock_cond(ssif_info, flags);
 427
 428         msg->data[0] = (IPMI_NETFN_APP_REQUEST << 2);
 429         msg->data[1] = IPMI_GET_MSG_CMD;
 430         msg->data_size = 2;
 431
 432         check_start_send(ssif_info, flags, msg);
 433 }
 434
 435 /*
 436  * Must be called with the message lock held.  This will release the
 437  * message lock.  Note that the caller will check SSIF_IDLE and start a
 438  * new operation, so there is no need to check for new messages to
 439  * start in here.
 440  */
 441 static void handle_flags(struct ssif_info *ssif_info, unsigned long *flags)
 442 {
 443         if (ssif_info->msg_flags & WDT_PRE_TIMEOUT_INT) {
 444                 ipmi_smi_t intf = ssif_info->intf;
 445                 /* Watchdog pre-timeout */
 446                 ssif_inc_stat(ssif_info, watchdog_pretimeouts);
 447                 start_clear_flags(ssif_info, flags);
 448                 if (intf)
 449                         ipmi_smi_watchdog_pretimeout(intf);
 450         } else if (ssif_info->msg_flags & RECEIVE_MSG_AVAIL)
 451                 /* Messages available. */
 452                 start_recv_msg_fetch(ssif_info, flags);
 453         else if (ssif_info->msg_flags & EVENT_MSG_BUFFER_FULL)
 454                 /* Events available. */
 455                 start_event_fetch(ssif_info, flags);
 456         else {
 457                 ssif_info->ssif_state = SSIF_NORMAL;
 458                 ipmi_ssif_unlock_cond(ssif_info, flags);
 459         }
 460 }
 461
 462 static int ipmi_ssif_thread(void *data)
 463 {
 464         struct ssif_info *ssif_info = data;
 465
 466         while (!kthread_should_stop()) {
 467                 int result;
 468
 469                 /* Wait for something to do */
 470                 wait_for_completion(&ssif_info->wake_thread);
 471                 init_completion(&ssif_info->wake_thread);
 472
 473                 if (ssif_info->stopping)
 474                         break;
 475
 476                 if (ssif_info->i2c_read_write == I2C_SMBUS_WRITE) {
 477                         result = i2c_smbus_write_block_data(
 478                                 ssif_info->client, SSIF_IPMI_REQUEST,
 479                                 ssif_info->i2c_data[0],
 480                                 ssif_info->i2c_data + 1);
 481                         ssif_info->done_handler(ssif_info, result, NULL, 0);
 482                 } else {
 483                         result = i2c_smbus_read_block_data(
 484                                 ssif_info->client, SSIF_IPMI_RESPONSE,
 485                                 ssif_info->i2c_data);
 486                         if (result < 0)
 487                                 ssif_info->done_handler(ssif_info, result,
 488                                                         NULL, 0);
 489                         else
 490                                 ssif_info->done_handler(ssif_info, 0,
 491                                                         ssif_info->i2c_data,
 492                                                         result);
 493                 }
 494         }
 495
 496         return 0;
 497 }
 498
 499 static int ssif_i2c_send(struct ssif_info *ssif_info,
 500                         ssif_i2c_done handler,
 501                         int read_write, int command,
 502                         unsigned char *data, unsigned int size)
 503 {
 504         ssif_info->done_handler = handler;
 505
 506         ssif_info->i2c_read_write = read_write;
 507         ssif_info->i2c_command = command;
 508         ssif_info->i2c_data = data;
 509         ssif_info->i2c_size = size;
 510         complete(&ssif_info->wake_thread);
 511         return 0;
 512 }
 513
 514
 515 static void msg_done_handler(struct ssif_info *ssif_info, int result,
 516                              unsigned char *data, unsigned int len);
 517
 518 static void retry_timeout(unsigned long data)
 519 {
 520         struct ssif_info *ssif_info = (void *) data;
 521         int rv;
 522
 523         if (ssif_info->stopping)
 524                 return;
 525
 526         ssif_info->rtc_us_timer = 0;
 527
 528         rv = ssif_i2c_send(ssif_info, msg_done_handler, I2C_SMBUS_READ,
 529                           SSIF_IPMI_RESPONSE,
 530                           ssif_info->recv, I2C_SMBUS_BLOCK_DATA);
 531         if (rv < 0) {
 532                 /* request failed, just return the error. */
 533                 if (ssif_info->ssif_debug & SSIF_DEBUG_MSG)
 534                         pr_info("Error from i2c_non_blocking_op(5)\n");
 535
 536                 msg_done_handler(ssif_info, -EIO, NULL, 0);
 537         }
 538 }
 539
 540 static int start_resend(struct ssif_info *ssif_info);
 541
 542 static void msg_done_handler(struct ssif_info *ssif_info, int result,
 543                              unsigned char *data, unsigned int len)
 544 {
 545         struct ipmi_smi_msg *msg;
 546         unsigned long oflags, *flags;
 547         int rv;
 548
 549         /*
 550          * We are single-threaded here, so no need for a lock until we
 551          * start messing with driver states or the queues.
 552          */
 553
 554         if (result < 0) {
 555                 ssif_info->retries_left--;
 556                 if (ssif_info->retries_left > 0) {
 557                         ssif_inc_stat(ssif_info, receive_retries);
 558
 559                         mod_timer(&ssif_info->retry_timer,
 560                                   jiffies + SSIF_MSG_JIFFIES);
 561                         ssif_info->rtc_us_timer = SSIF_MSG_USEC;
 562                         return;
 563                 }
 564
 565                 ssif_inc_stat(ssif_info, receive_errors);
 566
 567                 if  (ssif_info->ssif_debug & SSIF_DEBUG_MSG)
 568                         pr_info("Error in msg_done_handler: %d\n", result);
 569                 len = 0;
 570                 goto continue_op;
 571         }
 572
 573         if ((len > 1) && (ssif_info->multi_pos == 0)
 574                                 && (data[0] == 0x00) && (data[1] == 0x01)) {
 575                 /* Start of multi-part read.  Start the next transaction. */
 576                 int i;
 577
 578                 ssif_inc_stat(ssif_info, received_message_parts);
 579
 580                 /* Remove the multi-part read marker. */
 581                 for (i = 0; i < (len-2); i++)
 582                         ssif_info->data[i] = data[i+2];
 583                 len -= 2;
 584                 ssif_info->multi_len = len;
 585                 ssif_info->multi_pos = 1;
 586
 587                 rv = ssif_i2c_send(ssif_info, msg_done_handler, I2C_SMBUS_READ,
 588                                   SSIF_IPMI_MULTI_PART_RESPONSE_MIDDLE,
 589                                   ssif_info->recv, I2C_SMBUS_BLOCK_DATA);
 590                 if (rv < 0) {
 591                         if (ssif_info->ssif_debug & SSIF_DEBUG_MSG)
 592                                 pr_info("Error from i2c_non_blocking_op(1)\n");
 593
 594                         result = -EIO;
 595                 } else
 596                         return;
 597         } else if (ssif_info->multi_pos) {
 598                 /* Middle of multi-part read.  Start the next transaction. */
 599                 int i;
 600                 unsigned char blocknum;
 601
 602                 if (len == 0) {
 603                         result = -EIO;
 604                         if (ssif_info->ssif_debug & SSIF_DEBUG_MSG)
 605                                 pr_info(PFX "Middle message with no data\n");
 606
 607                         goto continue_op;
 608                 }
 609
 610                 blocknum = data[ssif_info->multi_len];
 611
 612                 if (ssif_info->multi_len+len-1 > IPMI_MAX_MSG_LENGTH) {
 613                         /* Received message too big, abort the operation. */
 614                         result = -E2BIG;
 615                         if (ssif_info->ssif_debug & SSIF_DEBUG_MSG)
 616                                 pr_info("Received message too big\n");
 617
 618                         goto continue_op;
 619                 }
 620
 621                 /* Remove the blocknum from the data. */
 622                 for (i = 0; i < (len-1); i++)
 623                         ssif_info->data[i+ssif_info->multi_len] = data[i+1];
 624                 len--;
 625                 ssif_info->multi_len += len;
 626                 if (blocknum == 0xff) {
 627                         /* End of read */
 628                         len = ssif_info->multi_len;
 629                         data = ssif_info->data;
 630                 } else if ((blocknum+1) != ssif_info->multi_pos) {
 631                         /*
 632                          * Out of sequence block, just abort.  Block
 633                          * numbers start at zero for the second block,
 634                          * but multi_pos starts at one, so the +1.
 635                          */
 636                         result = -EIO;
 637                 } else {
 638                         ssif_inc_stat(ssif_info, received_message_parts);
 639
 640                         ssif_info->multi_pos++;
 641
 642                         rv = ssif_i2c_send(ssif_info, msg_done_handler,
 643                                            I2C_SMBUS_READ,
 644                                            SSIF_IPMI_MULTI_PART_RESPONSE_MIDDLE,
 645                                            ssif_info->recv,
 646                                            I2C_SMBUS_BLOCK_DATA);
 647                         if (rv < 0) {
 648                                 if (ssif_info->ssif_debug & SSIF_DEBUG_MSG)
 649                                         pr_info(PFX
 650                                                 "Error from i2c_non_blocking_op(2)\n");
 651
 652                                 result = -EIO;
 653                         } else
 654                                 return;
 655                 }
 656         }
 657
 658         if (result < 0) {
 659                 ssif_inc_stat(ssif_info, receive_errors);
 660         } else {
 661                 ssif_inc_stat(ssif_info, received_messages);
 662                 ssif_inc_stat(ssif_info, received_message_parts);
 663         }
 664
 665
 666  continue_op:
 667         if (ssif_info->ssif_debug & SSIF_DEBUG_STATE)
 668                 pr_info(PFX "DONE 1: state = %d, result=%d.\n",
 669                         ssif_info->ssif_state, result);
 670
 671         flags = ipmi_ssif_lock_cond(ssif_info, &oflags);
 672         msg = ssif_info->curr_msg;
 673         if (msg) {
 674                 msg->rsp_size = len;
 675                 if (msg->rsp_size > IPMI_MAX_MSG_LENGTH)
 676                         msg->rsp_size = IPMI_MAX_MSG_LENGTH;
 677                 memcpy(msg->rsp, data, msg->rsp_size);
 678                 ssif_info->curr_msg = NULL;
 679         }
 680
 681         switch (ssif_info->ssif_state) {
 682         case SSIF_NORMAL:
 683                 ipmi_ssif_unlock_cond(ssif_info, flags);
 684                 if (!msg)
 685                         break;
 686
 687                 if (result < 0)
 688                         return_hosed_msg(ssif_info, msg);
 689                 else
 690                         deliver_recv_msg(ssif_info, msg);
 691                 break;
 692
 693         case SSIF_GETTING_FLAGS:
 694                 /* We got the flags from the SSIF, now handle them. */
 695                 if ((result < 0) || (len < 4) || (data[2] != 0)) {
 696                         /*
 697                          * Error fetching flags, or invalid length,
 698                          * just give up for now.
 699                          */
 700                         ssif_info->ssif_state = SSIF_NORMAL;
 701                         ipmi_ssif_unlock_cond(ssif_info, flags);
 702                         pr_warn(PFX "Error getting flags: %d %d, %x\n",
 703                                result, len, data[2]);
 704                 } else if (data[0] != (IPMI_NETFN_APP_REQUEST | 1) << 2
 705                            || data[1] != IPMI_GET_MSG_FLAGS_CMD) {
 706                         pr_warn(PFX "Invalid response getting flags: %x %x\n",
 707                                 data[0], data[1]);
 708                 } else {
 709                         ssif_inc_stat(ssif_info, flag_fetches);
 710                         ssif_info->msg_flags = data[3];
 711                         handle_flags(ssif_info, flags);
 712                 }
 713                 break;
 714
 715         case SSIF_CLEARING_FLAGS:
 716                 /* We cleared the flags. */
 717                 if ((result < 0) || (len < 3) || (data[2] != 0)) {
 718                         /* Error clearing flags */
 719                         pr_warn(PFX "Error clearing flags: %d %d, %x\n",
 720                                result, len, data[2]);
 721                 } else if (data[0] != (IPMI_NETFN_APP_REQUEST | 1) << 2
 722                            || data[1] != IPMI_CLEAR_MSG_FLAGS_CMD) {
 723                         pr_warn(PFX "Invalid response clearing flags: %x %x\n",
 724                                 data[0], data[1]);
 725                 }
 726                 ssif_info->ssif_state = SSIF_NORMAL;
 727                 ipmi_ssif_unlock_cond(ssif_info, flags);
 728                 break;
 729
 730         case SSIF_GETTING_EVENTS:
 731                 if ((result < 0) || (len < 3) || (msg->rsp[2] != 0)) {
 732                         /* Error getting event, probably done. */
 733                         msg->done(msg);
 734
 735                         /* Take off the event flag. */
 736                         ssif_info->msg_flags &= ~EVENT_MSG_BUFFER_FULL;
 737                         handle_flags(ssif_info, flags);
 738                 } else if (msg->rsp[0] != (IPMI_NETFN_APP_REQUEST | 1) << 2
 739                            || msg->rsp[1] != IPMI_READ_EVENT_MSG_BUFFER_CMD) {
 740                         pr_warn(PFX "Invalid response getting events: %x %x\n",
 741                                 msg->rsp[0], msg->rsp[1]);
 742                         msg->done(msg);
 743                         /* Take off the event flag. */
 744                         ssif_info->msg_flags &= ~EVENT_MSG_BUFFER_FULL;
 745                         handle_flags(ssif_info, flags);
 746                 } else {
 747                         handle_flags(ssif_info, flags);
 748                         ssif_inc_stat(ssif_info, events);
 749                         deliver_recv_msg(ssif_info, msg);
 750                 }
 751                 break;
 752
 753         case SSIF_GETTING_MESSAGES:
 754                 if ((result < 0) || (len < 3) || (msg->rsp[2] != 0)) {
 755                         /* Error getting event, probably done. */
 756                         msg->done(msg);
 757
 758                         /* Take off the msg flag. */
 759                         ssif_info->msg_flags &= ~RECEIVE_MSG_AVAIL;
 760                         handle_flags(ssif_info, flags);
 761                 } else if (msg->rsp[0] != (IPMI_NETFN_APP_REQUEST | 1) << 2
 762                            || msg->rsp[1] != IPMI_GET_MSG_CMD) {
 763                         pr_warn(PFX "Invalid response clearing flags: %x %x\n",
 764                                 msg->rsp[0], msg->rsp[1]);
 765                         msg->done(msg);
 766
 767                         /* Take off the msg flag. */
 768                         ssif_info->msg_flags &= ~RECEIVE_MSG_AVAIL;
 769                         handle_flags(ssif_info, flags);
 770                 } else {
 771                         ssif_inc_stat(ssif_info, incoming_messages);
 772                         handle_flags(ssif_info, flags);
 773                         deliver_recv_msg(ssif_info, msg);
 774                 }
 775                 break;
 776         }
 777
 778         flags = ipmi_ssif_lock_cond(ssif_info, &oflags);
 779         if (SSIF_IDLE(ssif_info) && !ssif_info->stopping) {
 780                 if (ssif_info->req_events)
 781                         start_event_fetch(ssif_info, flags);
 782                 else if (ssif_info->req_flags)
 783                         start_flag_fetch(ssif_info, flags);
 784                 else
 785                         start_next_msg(ssif_info, flags);
 786         } else
 787                 ipmi_ssif_unlock_cond(ssif_info, flags);
 788
 789         if (ssif_info->ssif_debug & SSIF_DEBUG_STATE)
 790                 pr_info(PFX "DONE 2: state = %d.\n", ssif_info->ssif_state);
 791 }
 792
 793 static void msg_written_handler(struct ssif_info *ssif_info, int result,
 794                                 unsigned char *data, unsigned int len)
 795 {
 796         int rv;
 797
 798         /* We are single-threaded here, so no need for a lock. */
 799         if (result < 0) {
 800                 ssif_info->retries_left--;
 801                 if (ssif_info->retries_left > 0) {
 802                         if (!start_resend(ssif_info)) {
 803                                 ssif_inc_stat(ssif_info, send_retries);
 804                                 return;
 805                         }
 806                         /* request failed, just return the error. */
 807                         ssif_inc_stat(ssif_info, send_errors);
 808
 809                         if (ssif_info->ssif_debug & SSIF_DEBUG_MSG)
 810                                 pr_info(PFX
 811                                         "Out of retries in msg_written_handler\n");
 812                         msg_done_handler(ssif_info, -EIO, NULL, 0);
 813                         return;
 814                 }
 815
 816                 ssif_inc_stat(ssif_info, send_errors);
 817
 818                 /*
 819                  * Got an error on transmit, let the done routine
 820                  * handle it.
 821                  */
 822                 if (ssif_info->ssif_debug & SSIF_DEBUG_MSG)
 823                         pr_info("Error in msg_written_handler: %d\n", result);
 824
 825                 msg_done_handler(ssif_info, result, NULL, 0);
 826                 return;
 827         }
 828
 829         if (ssif_info->multi_data) {
 830                 /* In the middle of a multi-data write. */
 831                 int left;
 832
 833                 ssif_inc_stat(ssif_info, sent_messages_parts);
 834
 835                 left = ssif_info->multi_len - ssif_info->multi_pos;
 836                 if (left > 32)
 837                         left = 32;
 838                 /* Length byte. */
 839                 ssif_info->multi_data[ssif_info->multi_pos] = left;
 840                 ssif_info->multi_pos += left;
 841                 if (left < 32)
 842                         /*
 843                          * Write is finished.  Note that we must end
 844                          * with a write of less than 32 bytes to
 845                          * complete the transaction, even if it is
 846                          * zero bytes.
 847                          */
 848                         ssif_info->multi_data = NULL;
 849
 850                 rv = ssif_i2c_send(ssif_info, msg_written_handler,
 851                                   I2C_SMBUS_WRITE,
 852                                   SSIF_IPMI_MULTI_PART_REQUEST_MIDDLE,
 853                                   ssif_info->multi_data + ssif_info->multi_pos,
 854                                   I2C_SMBUS_BLOCK_DATA);
 855                 if (rv < 0) {
 856                         /* request failed, just return the error. */
 857                         ssif_inc_stat(ssif_info, send_errors);
 858
 859                         if (ssif_info->ssif_debug & SSIF_DEBUG_MSG)
 860                                 pr_info("Error from i2c_non_blocking_op(3)\n");
 861                         msg_done_handler(ssif_info, -EIO, NULL, 0);
 862                 }
 863         } else {
 864                 ssif_inc_stat(ssif_info, sent_messages);
 865                 ssif_inc_stat(ssif_info, sent_messages_parts);
 866
 867                 /* Wait a jiffie then request the next message */
 868                 ssif_info->retries_left = SSIF_RECV_RETRIES;
 869                 ssif_info->rtc_us_timer = SSIF_MSG_PART_USEC;
 870                 mod_timer(&ssif_info->retry_timer,
 871                           jiffies + SSIF_MSG_PART_JIFFIES);
 872                 return;
 873         }
 874 }
 875
 876 static int start_resend(struct ssif_info *ssif_info)
 877 {
 878         int rv;
 879         int command;
 880
 881         if (ssif_info->data_len > 32) {
 882                 command = SSIF_IPMI_MULTI_PART_REQUEST_START;
 883                 ssif_info->multi_data = ssif_info->data;
 884                 ssif_info->multi_len = ssif_info->data_len;
 885                 /*
 886                  * Subtle thing, this is 32, not 33, because we will
 887                  * overwrite the thing at position 32 (which was just
 888                  * transmitted) with the new length.
 889                  */
 890                 ssif_info->multi_pos = 32;
 891                 ssif_info->data[0] = 32;
 892         } else {
 893                 ssif_info->multi_data = NULL;
 894                 command = SSIF_IPMI_REQUEST;
 895                 ssif_info->data[0] = ssif_info->data_len;
 896         }
 897
 898         rv = ssif_i2c_send(ssif_info, msg_written_handler, I2C_SMBUS_WRITE,
 899                           command, ssif_info->data, I2C_SMBUS_BLOCK_DATA);
 900         if (rv && (ssif_info->ssif_debug & SSIF_DEBUG_MSG))
 901                 pr_info("Error from i2c_non_blocking_op(4)\n");
 902         return rv;
 903 }
 904
 905 static int start_send(struct ssif_info *ssif_info,
 906                       unsigned char   *data,
 907                       unsigned int    len)
 908 {
 909         if (len > IPMI_MAX_MSG_LENGTH)
 910                 return -E2BIG;
 911         if (len > ssif_info->max_xmit_msg_size)
 912                 return -E2BIG;
 913
 914         ssif_info->retries_left = SSIF_SEND_RETRIES;
 915         memcpy(ssif_info->data+1, data, len);
 916         ssif_info->data_len = len;
 917         return start_resend(ssif_info);
 918 }
 919
 920 /* Must be called with the message lock held. */
 921 static void start_next_msg(struct ssif_info *ssif_info, unsigned long *flags)
 922 {
 923         struct ipmi_smi_msg *msg;
 924         unsigned long oflags;
 925
 926  restart:
 927         if (!SSIF_IDLE(ssif_info)) {
 928                 ipmi_ssif_unlock_cond(ssif_info, flags);
 929                 return;
 930         }
 931
 932         if (!ssif_info->waiting_msg) {
 933                 ssif_info->curr_msg = NULL;
 934                 ipmi_ssif_unlock_cond(ssif_info, flags);
 935         } else {
 936                 int rv;
 937
 938                 ssif_info->curr_msg = ssif_info->waiting_msg;
 939                 ssif_info->waiting_msg = NULL;
 940                 ipmi_ssif_unlock_cond(ssif_info, flags);
 941                 rv = start_send(ssif_info,
 942                                 ssif_info->curr_msg->data,
 943                                 ssif_info->curr_msg->data_size);
 944                 if (rv) {
 945                         msg = ssif_info->curr_msg;
 946                         ssif_info->curr_msg = NULL;
 947                         return_hosed_msg(ssif_info, msg);
 948                         flags = ipmi_ssif_lock_cond(ssif_info, &oflags);
 949                         goto restart;
 950                 }
 951         }
 952 }
 953
 954 static void sender(void                *send_info,
 955                    struct ipmi_smi_msg *msg)
 956 {
 957         struct ssif_info *ssif_info = (struct ssif_info *) send_info;
 958         unsigned long oflags, *flags;
 959
 960         BUG_ON(ssif_info->waiting_msg);
 961         ssif_info->waiting_msg = msg;
 962
 963         flags = ipmi_ssif_lock_cond(ssif_info, &oflags);
 964         start_next_msg(ssif_info, flags);
 965
 966         if (ssif_info->ssif_debug & SSIF_DEBUG_TIMING) {
 967                 struct timeval t;
 968
 969                 do_gettimeofday(&t);
 970                 pr_info("**Enqueue %02x %02x: %ld.%6.6ld\n",
 971                        msg->data[0], msg->data[1], t.tv_sec, t.tv_usec);
 972         }
 973 }
 974
 975 static int get_smi_info(void *send_info, struct ipmi_smi_info *data)
 976 {
 977         struct ssif_info *ssif_info = send_info;
 978
 979         data->addr_src = ssif_info->addr_source;
 980         data->dev = &ssif_info->client->dev;
 981         data->addr_info = ssif_info->addr_info;
 982         get_device(data->dev);
 983
 984         return 0;
 985 }
 986
 987 /*
 988  * Instead of having our own timer to periodically check the message
 989  * flags, we let the message handler drive us.
 990  */
 991 static void request_events(void *send_info)
 992 {
 993         struct ssif_info *ssif_info = (struct ssif_info *) send_info;
 994         unsigned long oflags, *flags;
 995
 996         if (!ssif_info->has_event_buffer)
 997                 return;
 998
 999         flags = ipmi_ssif_lock_cond(ssif_info, &oflags);
1000         /*
1001          * Request flags first, not events, because the lower layer
1002          * doesn't have a way to send an attention.  But make sure
1003          * event checking still happens.
1004          */
1005         ssif_info->req_events = true;
1006         if (SSIF_IDLE(ssif_info))
1007                 start_flag_fetch(ssif_info, flags);
1008         else {
1009                 ssif_info->req_flags = true;
1010                 ipmi_ssif_unlock_cond(ssif_info, flags);
1011         }
1012 }
1013
1014 static int inc_usecount(void *send_info)
1015 {
1016         struct ssif_info *ssif_info = send_info;
1017
1018         if (!i2c_get_adapter(ssif_info->client->adapter->nr))
1019                 return -ENODEV;
1020
1021         i2c_use_client(ssif_info->client);
1022         return 0;
1023 }
1024
1025 static void dec_usecount(void *send_info)
1026 {
1027         struct ssif_info *ssif_info = send_info;
1028
1029         i2c_release_client(ssif_info->client);
1030         i2c_put_adapter(ssif_info->client->adapter);
1031 }
1032
1033 static int ssif_start_processing(void *send_info,
1034                                  ipmi_smi_t intf)
1035 {
1036         struct ssif_info *ssif_info = send_info;
1037
1038         ssif_info->intf = intf;
1039
1040         return 0;
1041 }
1042
1043 #define MAX_SSIF_BMCS 4
1044
1045 static unsigned short addr[MAX_SSIF_BMCS];
1046 static int num_addrs;
1047 module_param_array(addr, ushort, &num_addrs, 0);
1048 MODULE_PARM_DESC(addr, "The addresses to scan for IPMI BMCs on the SSIFs.");
1049
1050 static char *adapter_name[MAX_SSIF_BMCS];
1051 static int num_adapter_names;
1052 module_param_array(adapter_name, charp, &num_adapter_names, 0);
1053 MODULE_PARM_DESC(adapter_name, "The string name of the I2C device that has the BMC.  By default all devices are scanned.");
1054
1055 static int slave_addrs[MAX_SSIF_BMCS];
1056 static int num_slave_addrs;
1057 module_param_array(slave_addrs, int, &num_slave_addrs, 0);
1058 MODULE_PARM_DESC(slave_addrs,
1059                  "The default IPMB slave address for the controller.");
1060
1061 /*
1062  * Bit 0 enables message debugging, bit 1 enables state debugging, and
1063  * bit 2 enables timing debugging.  This is an array indexed by
1064  * interface number"
1065  */
1066 static int dbg[MAX_SSIF_BMCS];
1067 static int num_dbg;
1068 module_param_array(dbg, int, &num_dbg, 0);
1069 MODULE_PARM_DESC(dbg, "Turn on debugging.");
1070
1071 static bool ssif_dbg_probe;
1072 module_param_named(dbg_probe, ssif_dbg_probe, bool, 0);
1073 MODULE_PARM_DESC(dbg_probe, "Enable debugging of probing of adapters.");
1074
1075 static int use_thread;
1076 module_param(use_thread, int, 0);
1077 MODULE_PARM_DESC(use_thread, "Use the thread interface.");
1078
1079 static bool ssif_tryacpi = 1;
1080 module_param_named(tryacpi, ssif_tryacpi, bool, 0);
1081 MODULE_PARM_DESC(tryacpi, "Setting this to zero will disable the default scan of the interfaces identified via ACPI");
1082
1083 static bool ssif_trydmi = 1;
1084 module_param_named(trydmi, ssif_trydmi, bool, 0);
1085 MODULE_PARM_DESC(trydmi, "Setting this to zero will disable the default scan of the interfaces identified via DMI (SMBIOS)");
1086
1087 static DEFINE_MUTEX(ssif_infos_mutex);
1088 static LIST_HEAD(ssif_infos);
1089
1090 static int ssif_remove(struct i2c_client *client)
1091 {
1092         struct ssif_info *ssif_info = i2c_get_clientdata(client);
1093         int rv;
1094
1095         if (!ssif_info)
1096                 return 0;
1097
1098         i2c_set_clientdata(client, NULL);
1099
1100         /*
1101          * After this point, we won't deliver anything asychronously
1102          * to the message handler.  We can unregister ourself.
1103          */
1104         rv = ipmi_unregister_smi(ssif_info->intf);
1105         if (rv) {
1106                 pr_err(PFX "Unable to unregister device: errno=%d\n", rv);
1107                 return rv;
1108         }
1109         ssif_info->intf = NULL;
1110
1111         /* make sure the driver is not looking for flags any more. */
1112         while (ssif_info->ssif_state != SSIF_NORMAL)
1113                 schedule_timeout(1);
1114
1115         ssif_info->stopping = true;
1116         del_timer_sync(&ssif_info->retry_timer);
1117         if (ssif_info->thread) {
1118                 complete(&ssif_info->wake_thread);
1119                 kthread_stop(ssif_info->thread);
1120         }
1121
1122         /*
1123          * No message can be outstanding now, we have removed the
1124          * upper layer and it permitted us to do so.
1125          */
1126         kfree(ssif_info);
1127         return 0;
1128 }
1129
1130 static int do_cmd(struct i2c_client *client, int len, unsigned char *msg,
1131                   int *resp_len, unsigned char *resp)
1132 {
1133         int retry_cnt;
1134         int ret;
1135
1136         retry_cnt = SSIF_SEND_RETRIES;
1137  retry1:
1138         ret = i2c_smbus_write_block_data(client, SSIF_IPMI_REQUEST, len, msg);
1139         if (ret) {
1140                 retry_cnt--;
1141                 if (retry_cnt > 0)
1142                         goto retry1;
1143                 return -ENODEV;
1144         }
1145
1146         ret = -ENODEV;
1147         retry_cnt = SSIF_RECV_RETRIES;
1148         while (retry_cnt > 0) {
1149                 ret = i2c_smbus_read_block_data(client, SSIF_IPMI_RESPONSE,
1150                                                 resp);
1151                 if (ret > 0)
1152                         break;
1153                 msleep(SSIF_MSG_MSEC);
1154                 retry_cnt--;
1155                 if (retry_cnt <= 0)
1156                         break;
1157         }
1158
1159         if (ret > 0) {
1160                 /* Validate that the response is correct. */
1161                 if (ret < 3 ||
1162                     (resp[0] != (msg[0] | (1 << 2))) ||
1163                     (resp[1] != msg[1]))
1164                         ret = -EINVAL;
1165                 else {
1166                         *resp_len = ret;
1167                         ret = 0;
1168                 }
1169         }
1170
1171         return ret;
1172 }
1173
1174 static int ssif_detect(struct i2c_client *client, struct i2c_board_info *info)
1175 {
1176         unsigned char *resp;
1177         unsigned char msg[3];
1178         int           rv;
1179         int           len;
1180
1181         resp = kmalloc(IPMI_MAX_MSG_LENGTH, GFP_KERNEL);
1182         if (!resp)
1183                 return -ENOMEM;
1184
1185         /* Do a Get Device ID command, since it is required. */
1186         msg[0] = IPMI_NETFN_APP_REQUEST << 2;
1187         msg[1] = IPMI_GET_DEVICE_ID_CMD;
1188         rv = do_cmd(client, 2, msg, &len, resp);
1189         if (rv)
1190                 rv = -ENODEV;
1191         else
1192                 strlcpy(info->type, DEVICE_NAME, I2C_NAME_SIZE);
1193         kfree(resp);
1194         return rv;
1195 }
1196
1197 static int smi_type_proc_show(struct seq_file *m, void *v)
1198 {
1199         return seq_puts(m, "ssif\n");
1200 }
1201
1202 static int smi_type_proc_open(struct inode *inode, struct file *file)
1203 {
1204         return single_open(file, smi_type_proc_show, inode->i_private);
1205 }
1206
1207 static const struct file_operations smi_type_proc_ops = {
1208         .open           = smi_type_proc_open,
1209         .read           = seq_read,
1210         .llseek         = seq_lseek,
1211         .release        = single_release,
1212 };
1213
1214 static int smi_stats_proc_show(struct seq_file *m, void *v)
1215 {
1216         struct ssif_info *ssif_info = m->private;
1217
1218         seq_printf(m, "sent_messages:          %u\n",
1219                    ssif_get_stat(ssif_info, sent_messages));
1220         seq_printf(m, "sent_messages_parts:    %u\n",
1221                    ssif_get_stat(ssif_info, sent_messages_parts));
1222         seq_printf(m, "send_retries:           %u\n",
1223                    ssif_get_stat(ssif_info, send_retries));
1224         seq_printf(m, "send_errors:            %u\n",
1225                    ssif_get_stat(ssif_info, send_errors));
1226         seq_printf(m, "received_messages:      %u\n",
1227                    ssif_get_stat(ssif_info, received_messages));
1228         seq_printf(m, "received_message_parts: %u\n",
1229                    ssif_get_stat(ssif_info, received_message_parts));
1230         seq_printf(m, "receive_retries:        %u\n",
1231                    ssif_get_stat(ssif_info, receive_retries));
1232         seq_printf(m, "receive_errors:         %u\n",
1233                    ssif_get_stat(ssif_info, receive_errors));
1234         seq_printf(m, "flag_fetches:           %u\n",
1235                    ssif_get_stat(ssif_info, flag_fetches));
1236         seq_printf(m, "hosed:                  %u\n",
1237                    ssif_get_stat(ssif_info, hosed));
1238         seq_printf(m, "events:                 %u\n",
1239                    ssif_get_stat(ssif_info, events));
1240         seq_printf(m, "watchdog_pretimeouts:   %u\n",
1241                    ssif_get_stat(ssif_info, watchdog_pretimeouts));
1242         return 0;
1243 }
1244
1245 static int smi_stats_proc_open(struct inode *inode, struct file *file)
1246 {
1247         return single_open(file, smi_stats_proc_show, PDE_DATA(inode));
1248 }
1249
1250 static const struct file_operations smi_stats_proc_ops = {
1251         .open           = smi_stats_proc_open,
1252         .read           = seq_read,
1253         .llseek         = seq_lseek,
1254         .release        = single_release,
1255 };
1256
1257 static struct ssif_addr_info *ssif_info_find(unsigned short addr,
1258                                              char *adapter_name,
1259                                              bool match_null_name)
1260 {
1261         struct ssif_addr_info *info, *found = NULL;
1262
1263 restart:
1264         list_for_each_entry(info, &ssif_infos, link) {
1265                 if (info->binfo.addr == addr) {
1266                         if (info->adapter_name || adapter_name) {
1267                                 if (!info->adapter_name != !adapter_name) {
1268                                         /* One is NULL and one is not */
1269                                         continue;
1270                                 }
1271                                 if (strcmp(info->adapter_name, adapter_name))
1272                                         /* Names to not match */
1273                                         continue;
1274                         }
1275                         found = info;
1276                         break;
1277                 }
1278         }
1279
1280         if (!found && match_null_name) {
1281                 /* Try to get an exact match first, then try with a NULL name */
1282                 adapter_name = NULL;
1283                 match_null_name = false;
1284                 goto restart;
1285         }
1286
1287         return found;
1288 }
1289
1290 static bool check_acpi(struct ssif_info *ssif_info, struct device *dev)
1291 {
1292 #ifdef CONFIG_ACPI
1293         acpi_handle acpi_handle;
1294
1295         acpi_handle = ACPI_HANDLE(dev);
1296         if (acpi_handle) {
1297                 ssif_info->addr_source = SI_ACPI;
1298                 ssif_info->addr_info.acpi_info.acpi_handle = acpi_handle;
1299                 return true;
1300         }
1301 #endif
1302         return false;
1303 }
1304
1305 static int ssif_probe(struct i2c_client *client, const struct i2c_device_id *id)
1306 {
1307         unsigned char     msg[3];
1308         unsigned char     *resp;
1309         struct ssif_info   *ssif_info;
1310         int               rv = 0;
1311         int               len;
1312         int               i;
1313         u8                slave_addr = 0;
1314         struct ssif_addr_info *addr_info = NULL;
1315
1316
1317         resp = kmalloc(IPMI_MAX_MSG_LENGTH, GFP_KERNEL);
1318         if (!resp)
1319                 return -ENOMEM;
1320
1321         ssif_info = kzalloc(sizeof(*ssif_info), GFP_KERNEL);
1322         if (!ssif_info) {
1323                 kfree(resp);
1324                 return -ENOMEM;
1325         }
1326
1327         if (!check_acpi(ssif_info, &client->dev)) {
1328                 addr_info = ssif_info_find(client->addr, client->adapter->name,
1329                                            true);
1330                 if (!addr_info) {
1331                         /* Must have come in through sysfs. */
1332                         ssif_info->addr_source = SI_HOTMOD;
1333                 } else {
1334                         ssif_info->addr_source = addr_info->addr_src;
1335                         ssif_info->ssif_debug = addr_info->debug;
1336                         ssif_info->addr_info = addr_info->addr_info;
1337                         slave_addr = addr_info->slave_addr;
1338                 }
1339         }
1340
1341         pr_info(PFX "Trying %s-specified SSIF interface at i2c address 0x%x, adapter %s, slave address 0x%x\n",
1342                ipmi_addr_src_to_str(ssif_info->addr_source),
1343                client->addr, client->adapter->name, slave_addr);
1344
1345         /*
1346          * Do a Get Device ID command, since it comes back with some
1347          * useful info.
1348          */
1349         msg[0] = IPMI_NETFN_APP_REQUEST << 2;
1350         msg[1] = IPMI_GET_DEVICE_ID_CMD;
1351         rv = do_cmd(client, 2, msg, &len, resp);
1352         if (rv)
1353                 goto out;
1354
1355         rv = ipmi_demangle_device_id(resp, len, &ssif_info->device_id);
1356         if (rv)
1357                 goto out;
1358
1359         ssif_info->client = client;
1360         i2c_set_clientdata(client, ssif_info);
1361
1362         /* Now check for system interface capabilities */
1363         msg[0] = IPMI_NETFN_APP_REQUEST << 2;
1364         msg[1] = IPMI_GET_SYSTEM_INTERFACE_CAPABILITIES_CMD;
1365         msg[2] = 0; /* SSIF */
1366         rv = do_cmd(client, 3, msg, &len, resp);
1367         if (!rv && (len >= 3) && (resp[2] == 0)) {
1368                 if (len < 7) {
1369                         if (ssif_dbg_probe)
1370                                 pr_info(PFX "SSIF info too short: %d\n", len);
1371                         goto no_support;
1372                 }
1373
1374                 /* Got a good SSIF response, handle it. */
1375                 ssif_info->max_xmit_msg_size = resp[5];
1376                 ssif_info->max_recv_msg_size = resp[6];
1377                 ssif_info->multi_support = (resp[4] >> 6) & 0x3;
1378                 ssif_info->supports_pec = (resp[4] >> 3) & 0x1;
1379
1380                 /* Sanitize the data */
1381                 switch (ssif_info->multi_support) {
1382                 case SSIF_NO_MULTI:
1383                         if (ssif_info->max_xmit_msg_size > 32)
1384                                 ssif_info->max_xmit_msg_size = 32;
1385                         if (ssif_info->max_recv_msg_size > 32)
1386                                 ssif_info->max_recv_msg_size = 32;
1387                         break;
1388
1389                 case SSIF_MULTI_2_PART:
1390                         if (ssif_info->max_xmit_msg_size > 64)
1391                                 ssif_info->max_xmit_msg_size = 64;
1392                         if (ssif_info->max_recv_msg_size > 62)
1393                                 ssif_info->max_recv_msg_size = 62;
1394                         break;
1395
1396                 case SSIF_MULTI_n_PART:
1397                         break;
1398
1399                 default:
1400                         /* Data is not sane, just give up. */
1401                         goto no_support;
1402                 }
1403         } else {
1404  no_support:
1405                 /* Assume no multi-part or PEC support */
1406                 pr_info(PFX "Error fetching SSIF: %d %d %2.2x, your system probably doesn't support this command so  using defaults\n",
1407                        rv, len, resp[2]);
1408
1409                 ssif_info->max_xmit_msg_size = 32;
1410                 ssif_info->max_recv_msg_size = 32;
1411                 ssif_info->multi_support = SSIF_NO_MULTI;
1412                 ssif_info->supports_pec = 0;
1413         }
1414
1415         /* Make sure the NMI timeout is cleared. */
1416         msg[0] = IPMI_NETFN_APP_REQUEST << 2;
1417         msg[1] = IPMI_CLEAR_MSG_FLAGS_CMD;
1418         msg[2] = WDT_PRE_TIMEOUT_INT;
1419         rv = do_cmd(client, 3, msg, &len, resp);
1420         if (rv || (len < 3) || (resp[2] != 0))
1421                 pr_warn(PFX "Unable to clear message flags: %d %d %2.2x\n",
1422                         rv, len, resp[2]);
1423
1424         /* Attempt to enable the event buffer. */
1425         msg[0] = IPMI_NETFN_APP_REQUEST << 2;
1426         msg[1] = IPMI_GET_BMC_GLOBAL_ENABLES_CMD;
1427         rv = do_cmd(client, 2, msg, &len, resp);
1428         if (rv || (len < 4) || (resp[2] != 0)) {
1429                 pr_warn(PFX "Error getting global enables: %d %d %2.2x\n",
1430                         rv, len, resp[2]);
1431                 rv = 0; /* Not fatal */
1432                 goto found;
1433         }
1434
1435         if (resp[3] & IPMI_BMC_EVT_MSG_BUFF) {
1436                 ssif_info->has_event_buffer = true;
1437                 /* buffer is already enabled, nothing to do. */
1438                 goto found;
1439         }
1440
1441         msg[0] = IPMI_NETFN_APP_REQUEST << 2;
1442         msg[1] = IPMI_SET_BMC_GLOBAL_ENABLES_CMD;
1443         msg[2] = resp[3] | IPMI_BMC_EVT_MSG_BUFF;
1444         rv = do_cmd(client, 3, msg, &len, resp);
1445         if (rv || (len < 2)) {
1446                 pr_warn(PFX "Error getting global enables: %d %d %2.2x\n",
1447                         rv, len, resp[2]);
1448                 rv = 0; /* Not fatal */
1449                 goto found;
1450         }
1451
1452         if (resp[2] == 0)
1453                 /* A successful return means the event buffer is supported. */
1454                 ssif_info->has_event_buffer = true;
1455
1456  found:
1457         ssif_info->intf_num = atomic_inc_return(&next_intf);
1458
1459         if (ssif_dbg_probe) {
1460                 pr_info("ssif_probe: i2c_probe found device at i2c address %x\n",
1461                         client->addr);
1462         }
1463
1464         spin_lock_init(&ssif_info->lock);
1465         ssif_info->ssif_state = SSIF_NORMAL;
1466         init_timer(&ssif_info->retry_timer);
1467         ssif_info->retry_timer.data = (unsigned long) ssif_info;
1468         ssif_info->retry_timer.function = retry_timeout;
1469
1470         for (i = 0; i < SSIF_NUM_STATS; i++)
1471                 atomic_set(&ssif_info->stats[i], 0);
1472
1473         if (ssif_info->supports_pec)
1474                 ssif_info->client->flags |= I2C_CLIENT_PEC;
1475
1476         ssif_info->handlers.owner = THIS_MODULE;
1477         ssif_info->handlers.start_processing = ssif_start_processing;
1478         ssif_info->handlers.get_smi_info = get_smi_info;
1479         ssif_info->handlers.sender = sender;
1480         ssif_info->handlers.request_events = request_events;
1481         ssif_info->handlers.inc_usecount = inc_usecount;
1482         ssif_info->handlers.dec_usecount = dec_usecount;
1483
1484         {
1485                 unsigned int thread_num;
1486
1487                 thread_num = ((ssif_info->client->adapter->nr << 8) |
1488                               ssif_info->client->addr);
1489                 init_completion(&ssif_info->wake_thread);
1490                 ssif_info->thread = kthread_run(ipmi_ssif_thread, ssif_info,
1491                                                "kssif%4.4x", thread_num);
1492                 if (IS_ERR(ssif_info->thread)) {
1493                         rv = PTR_ERR(ssif_info->thread);
1494                         dev_notice(&ssif_info->client->dev,
1495                                    "Could not start kernel thread: error %d\n",
1496                                    rv);
1497                         goto out;
1498                 }
1499         }
1500
1501         rv = ipmi_register_smi(&ssif_info->handlers,
1502                                ssif_info,
1503                                &ssif_info->device_id,
1504                                &ssif_info->client->dev,
1505                                slave_addr);
1506          if (rv) {
1507                 pr_err(PFX "Unable to register device: error %d\n", rv);
1508                 goto out;
1509         }
1510
1511         rv = ipmi_smi_add_proc_entry(ssif_info->intf, "type",
1512                                      &smi_type_proc_ops,
1513                                      ssif_info);
1514         if (rv) {
1515                 pr_err(PFX "Unable to create proc entry: %d\n", rv);
1516                 goto out_err_unreg;
1517         }
1518
1519         rv = ipmi_smi_add_proc_entry(ssif_info->intf, "ssif_stats",
1520                                      &smi_stats_proc_ops,
1521                                      ssif_info);
1522         if (rv) {
1523                 pr_err(PFX "Unable to create proc entry: %d\n", rv);
1524                 goto out_err_unreg;
1525         }
1526
1527  out:
1528         if (rv)
1529                 kfree(ssif_info);
1530         kfree(resp);
1531         return rv;
1532
1533  out_err_unreg:
1534         ipmi_unregister_smi(ssif_info->intf);
1535         goto out;
1536 }
1537
1538 static int ssif_adapter_handler(struct device *adev, void *opaque)
1539 {
1540         struct ssif_addr_info *addr_info = opaque;
1541
1542         if (adev->type != &i2c_adapter_type)
1543                 return 0;
1544
1545         i2c_new_device(to_i2c_adapter(adev), &addr_info->binfo);
1546
1547         if (!addr_info->adapter_name)
1548                 return 1; /* Only try the first I2C adapter by default. */
1549         return 0;
1550 }
1551
1552 static int new_ssif_client(int addr, char *adapter_name,
1553                            int debug, int slave_addr,
1554                            enum ipmi_addr_src addr_src)
1555 {
1556         struct ssif_addr_info *addr_info;
1557         int rv = 0;
1558
1559         mutex_lock(&ssif_infos_mutex);
1560         if (ssif_info_find(addr, adapter_name, false)) {
1561                 rv = -EEXIST;
1562                 goto out_unlock;
1563         }
1564
1565         addr_info = kzalloc(sizeof(*addr_info), GFP_KERNEL);
1566         if (!addr_info) {
1567                 rv = -ENOMEM;
1568                 goto out_unlock;
1569         }
1570
1571         if (adapter_name) {
1572                 addr_info->adapter_name = kstrdup(adapter_name, GFP_KERNEL);
1573                 if (!addr_info->adapter_name) {
1574                         kfree(addr_info);
1575                         rv = -ENOMEM;
1576                         goto out_unlock;
1577                 }
1578         }
1579
1580         strncpy(addr_info->binfo.type, DEVICE_NAME,
1581                 sizeof(addr_info->binfo.type));
1582         addr_info->binfo.addr = addr;
1583         addr_info->binfo.platform_data = addr_info;
1584         addr_info->debug = debug;
1585         addr_info->slave_addr = slave_addr;
1586         addr_info->addr_src = addr_src;
1587
1588         list_add_tail(&addr_info->link, &ssif_infos);
1589
1590         if (initialized)
1591                 i2c_for_each_dev(addr_info, ssif_adapter_handler);
1592         /* Otherwise address list will get it */
1593
1594 out_unlock:
1595         mutex_unlock(&ssif_infos_mutex);
1596         return rv;
1597 }
1598
1599 static void free_ssif_clients(void)
1600 {
1601         struct ssif_addr_info *info, *tmp;
1602
1603         mutex_lock(&ssif_infos_mutex);
1604         list_for_each_entry_safe(info, tmp, &ssif_infos, link) {
1605                 list_del(&info->link);
1606                 kfree(info->adapter_name);
1607                 kfree(info);
1608         }
1609         mutex_unlock(&ssif_infos_mutex);
1610 }
1611
1612 static unsigned short *ssif_address_list(void)
1613 {
1614         struct ssif_addr_info *info;
1615         unsigned int count = 0, i;
1616         unsigned short *address_list;
1617
1618         list_for_each_entry(info, &ssif_infos, link)
1619                 count++;
1620
1621         address_list = kzalloc(sizeof(*address_list) * (count + 1), GFP_KERNEL);
1622         if (!address_list)
1623                 return NULL;
1624
1625         i = 0;
1626         list_for_each_entry(info, &ssif_infos, link) {
1627                 unsigned short addr = info->binfo.addr;
1628                 int j;
1629
1630                 for (j = 0; j < i; j++) {
1631                         if (address_list[j] == addr)
1632                                 goto skip_addr;
1633                 }
1634                 address_list[i] = addr;
1635 skip_addr:
1636                 i++;
1637         }
1638         address_list[i] = I2C_CLIENT_END;
1639
1640         return address_list;
1641 }
1642
1643 #ifdef CONFIG_ACPI
1644 static struct acpi_device_id ssif_acpi_match[] = {
1645         { "IPI0001", 0 },
1646         { },
1647 };
1648 MODULE_DEVICE_TABLE(acpi, ssif_acpi_match);
1649
1650 /*
1651  * Once we get an ACPI failure, we don't try any more, because we go
1652  * through the tables sequentially.  Once we don't find a table, there
1653  * are no more.
1654  */
1655 static int acpi_failure;
1656
1657 /*
1658  * Defined in the IPMI 2.0 spec.
1659  */
1660 struct SPMITable {
1661         s8      Signature[4];
1662         u32     Length;
1663         u8      Revision;
1664         u8      Checksum;
1665         s8      OEMID[6];
1666         s8      OEMTableID[8];
1667         s8      OEMRevision[4];
1668         s8      CreatorID[4];
1669         s8      CreatorRevision[4];
1670         u8      InterfaceType;
1671         u8      IPMIlegacy;
1672         s16     SpecificationRevision;
1673
1674         /*
1675          * Bit 0 - SCI interrupt supported
1676          * Bit 1 - I/O APIC/SAPIC
1677          */
1678         u8      InterruptType;
1679
1680         /*
1681          * If bit 0 of InterruptType is set, then this is the SCI
1682          * interrupt in the GPEx_STS register.
1683          */
1684         u8      GPE;
1685
1686         s16     Reserved;
1687
1688         /*
1689          * If bit 1 of InterruptType is set, then this is the I/O
1690          * APIC/SAPIC interrupt.
1691          */
1692         u32     GlobalSystemInterrupt;
1693
1694         /* The actual register address. */
1695         struct acpi_generic_address addr;
1696
1697         u8      UID[4];
1698
1699         s8      spmi_id[1]; /* A '\0' terminated array starts here. */
1700 };
1701
1702 static int try_init_spmi(struct SPMITable *spmi)
1703 {
1704         unsigned short myaddr;
1705
1706         if (num_addrs >= MAX_SSIF_BMCS)
1707                 return -1;
1708
1709         if (spmi->IPMIlegacy != 1) {
1710                 pr_warn("IPMI: Bad SPMI legacy: %d\n", spmi->IPMIlegacy);
1711                 return -ENODEV;
1712         }
1713
1714         if (spmi->InterfaceType != 4)
1715                 return -ENODEV;
1716
1717         if (spmi->addr.space_id != ACPI_ADR_SPACE_SMBUS) {
1718                 pr_warn(PFX "Invalid ACPI SSIF I/O Address type: %d\n",
1719                         spmi->addr.space_id);
1720                 return -EIO;
1721         }
1722
1723         myaddr = spmi->addr.address >> 1;
1724
1725         return new_ssif_client(myaddr, NULL, 0, 0, SI_SPMI);
1726 }
1727
1728 static void spmi_find_bmc(void)
1729 {
1730         acpi_status      status;
1731         struct SPMITable *spmi;
1732         int              i;
1733
1734         if (acpi_disabled)
1735                 return;
1736
1737         if (acpi_failure)
1738                 return;
1739
1740         for (i = 0; ; i++) {
1741                 status = acpi_get_table(ACPI_SIG_SPMI, i+1,
1742                                         (struct acpi_table_header **)&spmi);
1743                 if (status != AE_OK)
1744                         return;
1745
1746                 try_init_spmi(spmi);
1747         }
1748 }
1749 #else
1750 static void spmi_find_bmc(void) { }
1751 #endif
1752
1753 #ifdef CONFIG_DMI
1754 static int decode_dmi(const struct dmi_device *dmi_dev)
1755 {
1756         struct dmi_header *dm = dmi_dev->device_data;
1757         u8             *data = (u8 *) dm;
1758         u8             len = dm->length;
1759         unsigned short myaddr;
1760         int            slave_addr;
1761
1762         if (num_addrs >= MAX_SSIF_BMCS)
1763                 return -1;
1764
1765         if (len < 9)
1766                 return -1;
1767
1768         if (data[0x04] != 4) /* Not SSIF */
1769                 return -1;
1770
1771         if ((data[8] >> 1) == 0) {
1772                 /*
1773                  * Some broken systems put the I2C address in
1774                  * the slave address field.  We try to
1775                  * accommodate them here.
1776                  */
1777                 myaddr = data[6] >> 1;
1778                 slave_addr = 0;
1779         } else {
1780                 myaddr = data[8] >> 1;
1781                 slave_addr = data[6];
1782         }
1783
1784         return new_ssif_client(myaddr, NULL, 0, 0, SI_SMBIOS);
1785 }
1786
1787 static void dmi_iterator(void)
1788 {
1789         const struct dmi_device *dev = NULL;
1790
1791         while ((dev = dmi_find_device(DMI_DEV_TYPE_IPMI, NULL, dev)))
1792                 decode_dmi(dev);
1793 }
1794 #else
1795 static void dmi_iterator(void) { }
1796 #endif
1797
1798 static const struct i2c_device_id ssif_id[] = {
1799         { DEVICE_NAME, 0 },
1800         { }
1801 };
1802 MODULE_DEVICE_TABLE(i2c, ssif_id);
1803
1804 static struct i2c_driver ssif_i2c_driver = {
1805         .class          = I2C_CLASS_HWMON,
1806         .driver         = {
1807                 .owner                  = THIS_MODULE,
1808                 .name                   = DEVICE_NAME
1809         },
1810         .probe          = ssif_probe,
1811         .remove         = ssif_remove,
1812         .id_table       = ssif_id,
1813         .detect         = ssif_detect
1814 };
1815
1816 static int init_ipmi_ssif(void)
1817 {
1818         int i;
1819         int rv;
1820
1821         if (initialized)
1822                 return 0;
1823
1824         pr_info("IPMI SSIF Interface driver\n");
1825
1826         /* build list for i2c from addr list */
1827         for (i = 0; i < num_addrs; i++) {
1828                 rv = new_ssif_client(addr[i], adapter_name[i],
1829                                      dbg[i], slave_addrs[i],
1830                                      SI_HARDCODED);
1831                 if (!rv)
1832                         pr_err(PFX
1833                                "Couldn't add hardcoded device at addr 0x%x\n",
1834                                addr[i]);
1835         }
1836
1837         if (ssif_tryacpi)
1838                 ssif_i2c_driver.driver.acpi_match_table =
1839                         ACPI_PTR(ssif_acpi_match);
1840         if (ssif_trydmi)
1841                 dmi_iterator();
1842         if (ssif_tryacpi)
1843                 spmi_find_bmc();
1844
1845         ssif_i2c_driver.address_list = ssif_address_list();
1846
1847         rv = i2c_add_driver(&ssif_i2c_driver);
1848         if (!rv)
1849                 initialized = true;
1850
1851         return rv;
1852 }
1853 module_init(init_ipmi_ssif);
1854
1855 static void cleanup_ipmi_ssif(void)
1856 {
1857         if (!initialized)
1858                 return;
1859
1860         initialized = false;
1861
1862         i2c_del_driver(&ssif_i2c_driver);
1863
1864         free_ssif_clients();
1865 }
1866 module_exit(cleanup_ipmi_ssif);
1867
1868 MODULE_AUTHOR("Todd C Davis <todd.c.davis@intel.com>, Corey Minyard <minyard@acm.org>");
1869 MODULE_DESCRIPTION("IPMI driver for management controllers on a SMBus");
1870 MODULE_LICENSE("GPL");