drivers/char/ipmi/ipmi

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This source file includes following definitions.
ipmi_ssif_lock_cond
ipmi_ssif_unlock_cond
deliver_recv_msg
return_hosed_msg
start_clear_flags
start_flag_fetch
check_start_send
start_event_fetch
start_recv_msg_fetch
handle_flags
ipmi_ssif_thread
ssif_i2c_send
start_get
retry_timeout
watch_timeout
ssif_alert
msg_done_handler
msg_written_handler
start_resend
start_send
start_next_msg
sender
get_smi_info
request_events
ssif_set_need_watch
ssif_start_processing
ipmi_type_show
shutdown_ssif
ssif_remove
read_response
do_cmd
ssif_detect
strcmp_nospace
ssif_info_find
check_acpi
find_slave_address
start_multipart_test
test_multipart_messages
ssif_remove_dup
ssif_add_infos
ssif_check_and_remove
ssif_probe
ssif_adapter_handler
new_ssif_client
free_ssif_clients
ssif_address_list
dmi_ipmi_probe
dmi_ipmi_probe
ssif_platform_probe
ssif_platform_remove
init_ipmi_ssif
cleanup_ipmi_ssif
   1 // SPDX-License-Identifier: GPL-2.0+
   2 /*
   3  * ipmi_ssif.c
   4  *
   5  * The interface to the IPMI driver for SMBus access to a SMBus
   6  * compliant device.  Called SSIF by the IPMI spec.
   7  *
   8  * Author: Intel Corporation
   9  *         Todd Davis <todd.c.davis@intel.com>
  10  *
  11  * Rewritten by Corey Minyard <minyard@acm.org> to support the
  12  * non-blocking I2C interface, add support for multi-part
  13  * transactions, add PEC support, and general clenaup.
  14  *
  15  * Copyright 2003 Intel Corporation
  16  * Copyright 2005 MontaVista Software
  17  */
  18 
  19 /*
  20  * This file holds the "policy" for the interface to the SSIF state
  21  * machine.  It does the configuration, handles timers and interrupts,
  22  * and drives the real SSIF state machine.
  23  */
  24 
  25 /*
  26  * TODO: Figure out how to use SMB alerts.  This will require a new
  27  * interface into the I2C driver, I believe.
  28  */
  29 
  30 #define pr_fmt(fmt) "ipmi_ssif: " fmt
  31 #define dev_fmt(fmt) "ipmi_ssif: " fmt
  32 
  33 #if defined(MODVERSIONS)
  34 #include <linux/modversions.h>
  35 #endif
  36 
  37 #include <linux/module.h>
  38 #include <linux/moduleparam.h>
  39 #include <linux/sched.h>
  40 #include <linux/seq_file.h>
  41 #include <linux/timer.h>
  42 #include <linux/delay.h>
  43 #include <linux/errno.h>
  44 #include <linux/spinlock.h>
  45 #include <linux/slab.h>
  46 #include <linux/list.h>
  47 #include <linux/i2c.h>
  48 #include <linux/ipmi_smi.h>
  49 #include <linux/init.h>
  50 #include <linux/dmi.h>
  51 #include <linux/kthread.h>
  52 #include <linux/acpi.h>
  53 #include <linux/ctype.h>
  54 #include <linux/time64.h>
  55 #include "ipmi_dmi.h"
  56 
  57 #define DEVICE_NAME "ipmi_ssif"
  58 
  59 #define IPMI_GET_SYSTEM_INTERFACE_CAPABILITIES_CMD      0x57
  60 
  61 #define SSIF_IPMI_REQUEST                       2
  62 #define SSIF_IPMI_MULTI_PART_REQUEST_START      6
  63 #define SSIF_IPMI_MULTI_PART_REQUEST_MIDDLE     7
  64 #define SSIF_IPMI_MULTI_PART_REQUEST_END        8
  65 #define SSIF_IPMI_RESPONSE                      3
  66 #define SSIF_IPMI_MULTI_PART_RESPONSE_MIDDLE    9
  67 
  68 /* ssif_debug is a bit-field
  69  *      SSIF_DEBUG_MSG -        commands and their responses
  70  *      SSIF_DEBUG_STATES -     message states
  71  *      SSIF_DEBUG_TIMING -      Measure times between events in the driver
  72  */
  73 #define SSIF_DEBUG_TIMING       4
  74 #define SSIF_DEBUG_STATE        2
  75 #define SSIF_DEBUG_MSG          1
  76 #define SSIF_NODEBUG            0
  77 #define SSIF_DEFAULT_DEBUG      (SSIF_NODEBUG)
  78 
  79 /*
  80  * Timer values
  81  */
  82 #define SSIF_MSG_USEC           20000   /* 20ms between message tries. */
  83 #define SSIF_MSG_PART_USEC      5000    /* 5ms for a message part */
  84 
  85 /* How many times to we retry sending/receiving the message. */
  86 #define SSIF_SEND_RETRIES       5
  87 #define SSIF_RECV_RETRIES       250
  88 
  89 #define SSIF_MSG_MSEC           (SSIF_MSG_USEC / 1000)
  90 #define SSIF_MSG_JIFFIES        ((SSIF_MSG_USEC * 1000) / TICK_NSEC)
  91 #define SSIF_MSG_PART_JIFFIES   ((SSIF_MSG_PART_USEC * 1000) / TICK_NSEC)
  92 
  93 /*
  94  * Timeout for the watch, only used for get flag timer.
  95  */
  96 #define SSIF_WATCH_MSG_TIMEOUT          msecs_to_jiffies(10)
  97 #define SSIF_WATCH_WATCHDOG_TIMEOUT     msecs_to_jiffies(250)
  98 
  99 enum ssif_intf_state {
 100         SSIF_NORMAL,
 101         SSIF_GETTING_FLAGS,
 102         SSIF_GETTING_EVENTS,
 103         SSIF_CLEARING_FLAGS,
 104         SSIF_GETTING_MESSAGES,
 105         /* FIXME - add watchdog stuff. */
 106 };
 107 
 108 #define SSIF_IDLE(ssif)  ((ssif)->ssif_state == SSIF_NORMAL \
 109                           && (ssif)->curr_msg == NULL)
 110 
 111 /*
 112  * Indexes into stats[] in ssif_info below.
 113  */
 114 enum ssif_stat_indexes {
 115         /* Number of total messages sent. */
 116         SSIF_STAT_sent_messages = 0,
 117 
 118         /*
 119          * Number of message parts sent.  Messages may be broken into
 120          * parts if they are long.
 121          */
 122         SSIF_STAT_sent_messages_parts,
 123 
 124         /*
 125          * Number of time a message was retried.
 126          */
 127         SSIF_STAT_send_retries,
 128 
 129         /*
 130          * Number of times the send of a message failed.
 131          */
 132         SSIF_STAT_send_errors,
 133 
 134         /*
 135          * Number of message responses received.
 136          */
 137         SSIF_STAT_received_messages,
 138 
 139         /*
 140          * Number of message fragments received.
 141          */
 142         SSIF_STAT_received_message_parts,
 143 
 144         /*
 145          * Number of times the receive of a message was retried.
 146          */
 147         SSIF_STAT_receive_retries,
 148 
 149         /*
 150          * Number of errors receiving messages.
 151          */
 152         SSIF_STAT_receive_errors,
 153 
 154         /*
 155          * Number of times a flag fetch was requested.
 156          */
 157         SSIF_STAT_flag_fetches,
 158 
 159         /*
 160          * Number of times the hardware didn't follow the state machine.
 161          */
 162         SSIF_STAT_hosed,
 163 
 164         /*
 165          * Number of received events.
 166          */
 167         SSIF_STAT_events,
 168 
 169         /* Number of asyncronous messages received. */
 170         SSIF_STAT_incoming_messages,
 171 
 172         /* Number of watchdog pretimeouts. */
 173         SSIF_STAT_watchdog_pretimeouts,
 174 
 175         /* Number of alers received. */
 176         SSIF_STAT_alerts,
 177 
 178         /* Always add statistics before this value, it must be last. */
 179         SSIF_NUM_STATS
 180 };
 181 
 182 struct ssif_addr_info {
 183         struct i2c_board_info binfo;
 184         char *adapter_name;
 185         int debug;
 186         int slave_addr;
 187         enum ipmi_addr_src addr_src;
 188         union ipmi_smi_info_union addr_info;
 189         struct device *dev;
 190         struct i2c_client *client;
 191 
 192         struct i2c_client *added_client;
 193 
 194         struct mutex clients_mutex;
 195         struct list_head clients;
 196 
 197         struct list_head link;
 198 };
 199 
 200 struct ssif_info;
 201 
 202 typedef void (*ssif_i2c_done)(struct ssif_info *ssif_info, int result,
 203                              unsigned char *data, unsigned int len);
 204 
 205 struct ssif_info {
 206         struct ipmi_smi     *intf;
 207         spinlock_t          lock;
 208         struct ipmi_smi_msg *waiting_msg;
 209         struct ipmi_smi_msg *curr_msg;
 210         enum ssif_intf_state ssif_state;
 211         unsigned long       ssif_debug;
 212 
 213         struct ipmi_smi_handlers handlers;
 214 
 215         enum ipmi_addr_src addr_source; /* ACPI, PCI, SMBIOS, hardcode, etc. */
 216         union ipmi_smi_info_union addr_info;
 217 
 218         /*
 219          * Flags from the last GET_MSG_FLAGS command, used when an ATTN
 220          * is set to hold the flags until we are done handling everything
 221          * from the flags.
 222          */
 223 #define RECEIVE_MSG_AVAIL       0x01
 224 #define EVENT_MSG_BUFFER_FULL   0x02
 225 #define WDT_PRE_TIMEOUT_INT     0x08
 226         unsigned char       msg_flags;
 227 
 228         u8                  global_enables;
 229         bool                has_event_buffer;
 230         bool                supports_alert;
 231 
 232         /*
 233          * Used to tell what we should do with alerts.  If we are
 234          * waiting on a response, read the data immediately.
 235          */
 236         bool                got_alert;
 237         bool                waiting_alert;
 238 
 239         /*
 240          * If set to true, this will request events the next time the
 241          * state machine is idle.
 242          */
 243         bool                req_events;
 244 
 245         /*
 246          * If set to true, this will request flags the next time the
 247          * state machine is idle.
 248          */
 249         bool                req_flags;
 250 
 251         /*
 252          * Used to perform timer operations when run-to-completion
 253          * mode is on.  This is a countdown timer.
 254          */
 255         int                 rtc_us_timer;
 256 
 257         /* Used for sending/receiving data.  +1 for the length. */
 258         unsigned char data[IPMI_MAX_MSG_LENGTH + 1];
 259         unsigned int  data_len;
 260 
 261         /* Temp receive buffer, gets copied into data. */
 262         unsigned char recv[I2C_SMBUS_BLOCK_MAX];
 263 
 264         struct i2c_client *client;
 265         ssif_i2c_done done_handler;
 266 
 267         /* Thread interface handling */
 268         struct task_struct *thread;
 269         struct completion wake_thread;
 270         bool stopping;
 271         int i2c_read_write;
 272         int i2c_command;
 273         unsigned char *i2c_data;
 274         unsigned int i2c_size;
 275 
 276         struct timer_list retry_timer;
 277         int retries_left;
 278 
 279         long watch_timeout;             /* Timeout for flags check, 0 if off. */
 280         struct timer_list watch_timer;  /* Flag fetch timer. */
 281 
 282         /* Info from SSIF cmd */
 283         unsigned char max_xmit_msg_size;
 284         unsigned char max_recv_msg_size;
 285         bool cmd8_works; /* See test_multipart_messages() for details. */
 286         unsigned int  multi_support;
 287         int           supports_pec;
 288 
 289 #define SSIF_NO_MULTI           0
 290 #define SSIF_MULTI_2_PART       1
 291 #define SSIF_MULTI_n_PART       2
 292         unsigned char *multi_data;
 293         unsigned int  multi_len;
 294         unsigned int  multi_pos;
 295 
 296         atomic_t stats[SSIF_NUM_STATS];
 297 };
 298 
 299 #define ssif_inc_stat(ssif, stat) \
 300         atomic_inc(&(ssif)->stats[SSIF_STAT_ ## stat])
 301 #define ssif_get_stat(ssif, stat) \
 302         ((unsigned int) atomic_read(&(ssif)->stats[SSIF_STAT_ ## stat]))
 303 
 304 static bool initialized;
 305 static bool platform_registered;
 306 
 307 static void return_hosed_msg(struct ssif_info *ssif_info,
 308                              struct ipmi_smi_msg *msg);
 309 static void start_next_msg(struct ssif_info *ssif_info, unsigned long *flags);
 310 static int start_send(struct ssif_info *ssif_info,
 311                       unsigned char   *data,
 312                       unsigned int    len);
 313 
 314 static unsigned long *ipmi_ssif_lock_cond(struct ssif_info *ssif_info,
 315                                           unsigned long *flags)
 316 {
 317         spin_lock_irqsave(&ssif_info->lock, *flags);
 318         return flags;
 319 }
 320 
 321 static void ipmi_ssif_unlock_cond(struct ssif_info *ssif_info,
 322                                   unsigned long *flags)
 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                 return true;
1474         }
1475 #endif
1476         return false;
1477 }
1478 
1479 static int find_slave_address(struct i2c_client *client, int slave_addr)
1480 {
1481 #ifdef CONFIG_IPMI_DMI_DECODE
1482         if (!slave_addr)
1483                 slave_addr = ipmi_dmi_get_slave_addr(
1484                         SI_TYPE_INVALID,
1485                         i2c_adapter_id(client->adapter),
1486                         client->addr);
1487 #endif
1488 
1489         return slave_addr;
1490 }
1491 
1492 static int start_multipart_test(struct i2c_client *client,
1493                                 unsigned char *msg, bool do_middle)
1494 {
1495         int retry_cnt = SSIF_SEND_RETRIES, ret;
1496 
1497 retry_write:
1498         ret = i2c_smbus_write_block_data(client,
1499                                          SSIF_IPMI_MULTI_PART_REQUEST_START,
1500                                          32, msg);
1501         if (ret) {
1502                 retry_cnt--;
1503                 if (retry_cnt > 0)
1504                         goto retry_write;
1505                 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");
1506                 return ret;
1507         }
1508 
1509         if (!do_middle)
1510                 return 0;
1511 
1512         ret = i2c_smbus_write_block_data(client,
1513                                          SSIF_IPMI_MULTI_PART_REQUEST_MIDDLE,
1514                                          32, msg + 32);
1515         if (ret) {
1516                 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");
1517                 return ret;
1518         }
1519 
1520         return 0;
1521 }
1522 
1523 static void test_multipart_messages(struct i2c_client *client,
1524                                     struct ssif_info *ssif_info,
1525                                     unsigned char *resp)
1526 {
1527         unsigned char msg[65];
1528         int ret;
1529         bool do_middle;
1530 
1531         if (ssif_info->max_xmit_msg_size <= 32)
1532                 return;
1533 
1534         do_middle = ssif_info->max_xmit_msg_size > 63;
1535 
1536         memset(msg, 0, sizeof(msg));
1537         msg[0] = IPMI_NETFN_APP_REQUEST << 2;
1538         msg[1] = IPMI_GET_DEVICE_ID_CMD;
1539 
1540         /*
1541          * The specification is all messed up dealing with sending
1542          * multi-part messages.  Per what the specification says, it
1543          * is impossible to send a message that is a multiple of 32
1544          * bytes, except for 32 itself.  It talks about a "start"
1545          * transaction (cmd=6) that must be 32 bytes, "middle"
1546          * transaction (cmd=7) that must be 32 bytes, and an "end"
1547          * transaction.  The "end" transaction is shown as cmd=7 in
1548          * the text, but if that's the case there is no way to
1549          * differentiate between a middle and end part except the
1550          * length being less than 32.  But there is a table at the far
1551          * end of the section (that I had never noticed until someone
1552          * pointed it out to me) that mentions it as cmd=8.
1553          *
1554          * After some thought, I think the example is wrong and the
1555          * end transaction should be cmd=8.  But some systems don't
1556          * implement cmd=8, they use a zero-length end transaction,
1557          * even though that violates the SMBus specification.
1558          *
1559          * So, to work around this, this code tests if cmd=8 works.
1560          * If it does, then we use that.  If not, it tests zero-
1561          * byte end transactions.  If that works, good.  If not,
1562          * we only allow 63-byte transactions max.
1563          */
1564 
1565         ret = start_multipart_test(client, msg, do_middle);
1566         if (ret)
1567                 goto out_no_multi_part;
1568 
1569         ret = i2c_smbus_write_block_data(client,
1570                                          SSIF_IPMI_MULTI_PART_REQUEST_END,
1571                                          1, msg + 64);
1572 
1573         if (!ret)
1574                 ret = read_response(client, resp);
1575 
1576         if (ret > 0) {
1577                 /* End transactions work, we are good. */
1578                 ssif_info->cmd8_works = true;
1579                 return;
1580         }
1581 
1582         ret = start_multipart_test(client, msg, do_middle);
1583         if (ret) {
1584                 dev_err(&client->dev, "Second multipart test failed.\n");
1585                 goto out_no_multi_part;
1586         }
1587 
1588         ret = i2c_smbus_write_block_data(client,
1589                                          SSIF_IPMI_MULTI_PART_REQUEST_MIDDLE,
1590                                          0, msg + 64);
1591         if (!ret)
1592                 ret = read_response(client, resp);
1593         if (ret > 0)
1594                 /* Zero-size end parts work, use those. */
1595                 return;
1596 
1597         /* Limit to 63 bytes and use a short middle command to mark the end. */
1598         if (ssif_info->max_xmit_msg_size > 63)
1599                 ssif_info->max_xmit_msg_size = 63;
1600         return;
1601 
1602 out_no_multi_part:
1603         ssif_info->max_xmit_msg_size = 32;
1604         return;
1605 }
1606 
1607 /*
1608  * Global enables we care about.
1609  */
1610 #define GLOBAL_ENABLES_MASK (IPMI_BMC_EVT_MSG_BUFF | IPMI_BMC_RCV_MSG_INTR | \
1611                              IPMI_BMC_EVT_MSG_INTR)
1612 
1613 static void ssif_remove_dup(struct i2c_client *client)
1614 {
1615         struct ssif_info *ssif_info = i2c_get_clientdata(client);
1616 
1617         ipmi_unregister_smi(ssif_info->intf);
1618         kfree(ssif_info);
1619 }
1620 
1621 static int ssif_add_infos(struct i2c_client *client)
1622 {
1623         struct ssif_addr_info *info;
1624 
1625         info = kzalloc(sizeof(*info), GFP_KERNEL);
1626         if (!info)
1627                 return -ENOMEM;
1628         info->addr_src = SI_ACPI;
1629         info->client = client;
1630         info->adapter_name = kstrdup(client->adapter->name, GFP_KERNEL);
1631         info->binfo.addr = client->addr;
1632         list_add_tail(&info->link, &ssif_infos);
1633         return 0;
1634 }
1635 
1636 /*
1637  * Prefer ACPI over SMBIOS, if both are available.
1638  * So if we get an ACPI interface and have already registered a SMBIOS
1639  * interface at the same address, remove the SMBIOS and add the ACPI one.
1640  */
1641 static int ssif_check_and_remove(struct i2c_client *client,
1642                               struct ssif_info *ssif_info)
1643 {
1644         struct ssif_addr_info *info;
1645 
1646         list_for_each_entry(info, &ssif_infos, link) {
1647                 if (!info->client)
1648                         return 0;
1649                 if (!strcmp(info->adapter_name, client->adapter->name) &&
1650                     info->binfo.addr == client->addr) {
1651                         if (info->addr_src == SI_ACPI)
1652                                 return -EEXIST;
1653 
1654                         if (ssif_info->addr_source == SI_ACPI &&
1655                             info->addr_src == SI_SMBIOS) {
1656                                 dev_info(&client->dev,
1657                                          "Removing %s-specified SSIF interface in favor of ACPI\n",
1658                                          ipmi_addr_src_to_str(info->addr_src));
1659                                 ssif_remove_dup(info->client);
1660                                 return 0;
1661                         }
1662                 }
1663         }
1664         return 0;
1665 }
1666 
1667 static int ssif_probe(struct i2c_client *client, const struct i2c_device_id *id)
1668 {
1669         unsigned char     msg[3];
1670         unsigned char     *resp;
1671         struct ssif_info   *ssif_info;
1672         int               rv = 0;
1673         int               len;
1674         int               i;
1675         u8                slave_addr = 0;
1676         struct ssif_addr_info *addr_info = NULL;
1677 
1678         mutex_lock(&ssif_infos_mutex);
1679         resp = kmalloc(IPMI_MAX_MSG_LENGTH, GFP_KERNEL);
1680         if (!resp) {
1681                 mutex_unlock(&ssif_infos_mutex);
1682                 return -ENOMEM;
1683         }
1684 
1685         ssif_info = kzalloc(sizeof(*ssif_info), GFP_KERNEL);
1686         if (!ssif_info) {
1687                 kfree(resp);
1688                 mutex_unlock(&ssif_infos_mutex);
1689                 return -ENOMEM;
1690         }
1691 
1692         if (!check_acpi(ssif_info, &client->dev)) {
1693                 addr_info = ssif_info_find(client->addr, client->adapter->name,
1694                                            true);
1695                 if (!addr_info) {
1696                         /* Must have come in through sysfs. */
1697                         ssif_info->addr_source = SI_HOTMOD;
1698                 } else {
1699                         ssif_info->addr_source = addr_info->addr_src;
1700                         ssif_info->ssif_debug = addr_info->debug;
1701                         ssif_info->addr_info = addr_info->addr_info;
1702                         addr_info->client = client;
1703                         slave_addr = addr_info->slave_addr;
1704                 }
1705         }
1706 
1707         rv = ssif_check_and_remove(client, ssif_info);
1708         /* If rv is 0 and addr source is not SI_ACPI, continue probing */
1709         if (!rv && ssif_info->addr_source == SI_ACPI) {
1710                 rv = ssif_add_infos(client);
1711                 if (rv) {
1712                         dev_err(&client->dev, "Out of memory!, exiting ..\n");
1713                         goto out;
1714                 }
1715         } else if (rv) {
1716                 dev_err(&client->dev, "Not probing, Interface already present\n");
1717                 goto out;
1718         }
1719 
1720         slave_addr = find_slave_address(client, slave_addr);
1721 
1722         dev_info(&client->dev,
1723                  "Trying %s-specified SSIF interface at i2c address 0x%x, adapter %s, slave address 0x%x\n",
1724                 ipmi_addr_src_to_str(ssif_info->addr_source),
1725                 client->addr, client->adapter->name, slave_addr);
1726 
1727         ssif_info->client = client;
1728         i2c_set_clientdata(client, ssif_info);
1729 
1730         /* Now check for system interface capabilities */
1731         msg[0] = IPMI_NETFN_APP_REQUEST << 2;
1732         msg[1] = IPMI_GET_SYSTEM_INTERFACE_CAPABILITIES_CMD;
1733         msg[2] = 0; /* SSIF */
1734         rv = do_cmd(client, 3, msg, &len, resp);
1735         if (!rv && (len >= 3) && (resp[2] == 0)) {
1736                 if (len < 7) {
1737                         if (ssif_dbg_probe)
1738                                 dev_dbg(&ssif_info->client->dev,
1739                                         "SSIF info too short: %d\n", len);
1740                         goto no_support;
1741                 }
1742 
1743                 /* Got a good SSIF response, handle it. */
1744                 ssif_info->max_xmit_msg_size = resp[5];
1745                 ssif_info->max_recv_msg_size = resp[6];
1746                 ssif_info->multi_support = (resp[4] >> 6) & 0x3;
1747                 ssif_info->supports_pec = (resp[4] >> 3) & 0x1;
1748 
1749                 /* Sanitize the data */
1750                 switch (ssif_info->multi_support) {
1751                 case SSIF_NO_MULTI:
1752                         if (ssif_info->max_xmit_msg_size > 32)
1753                                 ssif_info->max_xmit_msg_size = 32;
1754                         if (ssif_info->max_recv_msg_size > 32)
1755                                 ssif_info->max_recv_msg_size = 32;
1756                         break;
1757 
1758                 case SSIF_MULTI_2_PART:
1759                         if (ssif_info->max_xmit_msg_size > 63)
1760                                 ssif_info->max_xmit_msg_size = 63;
1761                         if (ssif_info->max_recv_msg_size > 62)
1762                                 ssif_info->max_recv_msg_size = 62;
1763                         break;
1764 
1765                 case SSIF_MULTI_n_PART:
1766                         /* We take whatever size given, but do some testing. */
1767                         break;
1768 
1769                 default:
1770                         /* Data is not sane, just give up. */
1771                         goto no_support;
1772                 }
1773         } else {
1774  no_support:
1775                 /* Assume no multi-part or PEC support */
1776                 dev_info(&ssif_info->client->dev,
1777                          "Error fetching SSIF: %d %d %2.2x, your system probably doesn't support this command so using defaults\n",
1778                         rv, len, resp[2]);
1779 
1780                 ssif_info->max_xmit_msg_size = 32;
1781                 ssif_info->max_recv_msg_size = 32;
1782                 ssif_info->multi_support = SSIF_NO_MULTI;
1783                 ssif_info->supports_pec = 0;
1784         }
1785 
1786         test_multipart_messages(client, ssif_info, resp);
1787 
1788         /* Make sure the NMI timeout is cleared. */
1789         msg[0] = IPMI_NETFN_APP_REQUEST << 2;
1790         msg[1] = IPMI_CLEAR_MSG_FLAGS_CMD;
1791         msg[2] = WDT_PRE_TIMEOUT_INT;
1792         rv = do_cmd(client, 3, msg, &len, resp);
1793         if (rv || (len < 3) || (resp[2] != 0))
1794                 dev_warn(&ssif_info->client->dev,
1795                          "Unable to clear message flags: %d %d %2.2x\n",
1796                          rv, len, resp[2]);
1797 
1798         /* Attempt to enable the event buffer. */
1799         msg[0] = IPMI_NETFN_APP_REQUEST << 2;
1800         msg[1] = IPMI_GET_BMC_GLOBAL_ENABLES_CMD;
1801         rv = do_cmd(client, 2, msg, &len, resp);
1802         if (rv || (len < 4) || (resp[2] != 0)) {
1803                 dev_warn(&ssif_info->client->dev,
1804                          "Error getting global enables: %d %d %2.2x\n",
1805                          rv, len, resp[2]);
1806                 rv = 0; /* Not fatal */
1807                 goto found;
1808         }
1809 
1810         ssif_info->global_enables = resp[3];
1811 
1812         if (resp[3] & IPMI_BMC_EVT_MSG_BUFF) {
1813                 ssif_info->has_event_buffer = true;
1814                 /* buffer is already enabled, nothing to do. */
1815                 goto found;
1816         }
1817 
1818         msg[0] = IPMI_NETFN_APP_REQUEST << 2;
1819         msg[1] = IPMI_SET_BMC_GLOBAL_ENABLES_CMD;
1820         msg[2] = ssif_info->global_enables | IPMI_BMC_EVT_MSG_BUFF;
1821         rv = do_cmd(client, 3, msg, &len, resp);
1822         if (rv || (len < 2)) {
1823                 dev_warn(&ssif_info->client->dev,
1824                          "Error setting global enables: %d %d %2.2x\n",
1825                          rv, len, resp[2]);
1826                 rv = 0; /* Not fatal */
1827                 goto found;
1828         }
1829 
1830         if (resp[2] == 0) {
1831                 /* A successful return means the event buffer is supported. */
1832                 ssif_info->has_event_buffer = true;
1833                 ssif_info->global_enables |= IPMI_BMC_EVT_MSG_BUFF;
1834         }
1835 
1836         /* Some systems don't behave well if you enable alerts. */
1837         if (alerts_broken)
1838                 goto found;
1839 
1840         msg[0] = IPMI_NETFN_APP_REQUEST << 2;
1841         msg[1] = IPMI_SET_BMC_GLOBAL_ENABLES_CMD;
1842         msg[2] = ssif_info->global_enables | IPMI_BMC_RCV_MSG_INTR;
1843         rv = do_cmd(client, 3, msg, &len, resp);
1844         if (rv || (len < 2)) {
1845                 dev_warn(&ssif_info->client->dev,
1846                          "Error setting global enables: %d %d %2.2x\n",
1847                          rv, len, resp[2]);
1848                 rv = 0; /* Not fatal */
1849                 goto found;
1850         }
1851 
1852         if (resp[2] == 0) {
1853                 /* A successful return means the alert is supported. */
1854                 ssif_info->supports_alert = true;
1855                 ssif_info->global_enables |= IPMI_BMC_RCV_MSG_INTR;
1856         }
1857 
1858  found:
1859         if (ssif_dbg_probe) {
1860                 dev_dbg(&ssif_info->client->dev,
1861                        "%s: i2c_probe found device at i2c address %x\n",
1862                        __func__, client->addr);
1863         }
1864 
1865         spin_lock_init(&ssif_info->lock);
1866         ssif_info->ssif_state = SSIF_NORMAL;
1867         timer_setup(&ssif_info->retry_timer, retry_timeout, 0);
1868         timer_setup(&ssif_info->watch_timer, watch_timeout, 0);
1869 
1870         for (i = 0; i < SSIF_NUM_STATS; i++)
1871                 atomic_set(&ssif_info->stats[i], 0);
1872 
1873         if (ssif_info->supports_pec)
1874                 ssif_info->client->flags |= I2C_CLIENT_PEC;
1875 
1876         ssif_info->handlers.owner = THIS_MODULE;
1877         ssif_info->handlers.start_processing = ssif_start_processing;
1878         ssif_info->handlers.shutdown = shutdown_ssif;
1879         ssif_info->handlers.get_smi_info = get_smi_info;
1880         ssif_info->handlers.sender = sender;
1881         ssif_info->handlers.request_events = request_events;
1882         ssif_info->handlers.set_need_watch = ssif_set_need_watch;
1883 
1884         {
1885                 unsigned int thread_num;
1886 
1887                 thread_num = ((i2c_adapter_id(ssif_info->client->adapter)
1888                                << 8) |
1889                               ssif_info->client->addr);
1890                 init_completion(&ssif_info->wake_thread);
1891                 ssif_info->thread = kthread_run(ipmi_ssif_thread, ssif_info,
1892                                                "kssif%4.4x", thread_num);
1893                 if (IS_ERR(ssif_info->thread)) {
1894                         rv = PTR_ERR(ssif_info->thread);
1895                         dev_notice(&ssif_info->client->dev,
1896                                    "Could not start kernel thread: error %d\n",
1897                                    rv);
1898                         goto out;
1899                 }
1900         }
1901 
1902         dev_set_drvdata(&ssif_info->client->dev, ssif_info);
1903         rv = device_add_group(&ssif_info->client->dev,
1904                               &ipmi_ssif_dev_attr_group);
1905         if (rv) {
1906                 dev_err(&ssif_info->client->dev,
1907                         "Unable to add device attributes: error %d\n",
1908                         rv);
1909                 goto out;
1910         }
1911 
1912         rv = ipmi_register_smi(&ssif_info->handlers,
1913                                ssif_info,
1914                                &ssif_info->client->dev,
1915                                slave_addr);
1916         if (rv) {
1917                 dev_err(&ssif_info->client->dev,
1918                         "Unable to register device: error %d\n", rv);
1919                 goto out_remove_attr;
1920         }
1921 
1922  out:
1923         if (rv) {
1924                 if (addr_info)
1925                         addr_info->client = NULL;
1926 
1927                 dev_err(&ssif_info->client->dev,
1928                         "Unable to start IPMI SSIF: %d\n", rv);
1929                 kfree(ssif_info);
1930         }
1931         kfree(resp);
1932         mutex_unlock(&ssif_infos_mutex);
1933         return rv;
1934 
1935 out_remove_attr:
1936         device_remove_group(&ssif_info->client->dev, &ipmi_ssif_dev_attr_group);
1937         dev_set_drvdata(&ssif_info->client->dev, NULL);
1938         goto out;
1939 }
1940 
1941 static int ssif_adapter_handler(struct device *adev, void *opaque)
1942 {
1943         struct ssif_addr_info *addr_info = opaque;
1944 
1945         if (adev->type != &i2c_adapter_type)
1946                 return 0;
1947 
1948         addr_info->added_client = i2c_new_device(to_i2c_adapter(adev),
1949                                                  &addr_info->binfo);
1950 
1951         if (!addr_info->adapter_name)
1952                 return 1; /* Only try the first I2C adapter by default. */
1953         return 0;
1954 }
1955 
1956 static int new_ssif_client(int addr, char *adapter_name,
1957                            int debug, int slave_addr,
1958                            enum ipmi_addr_src addr_src,
1959                            struct device *dev)
1960 {
1961         struct ssif_addr_info *addr_info;
1962         int rv = 0;
1963 
1964         mutex_lock(&ssif_infos_mutex);
1965         if (ssif_info_find(addr, adapter_name, false)) {
1966                 rv = -EEXIST;
1967                 goto out_unlock;
1968         }
1969 
1970         addr_info = kzalloc(sizeof(*addr_info), GFP_KERNEL);
1971         if (!addr_info) {
1972                 rv = -ENOMEM;
1973                 goto out_unlock;
1974         }
1975 
1976         if (adapter_name) {
1977                 addr_info->adapter_name = kstrdup(adapter_name, GFP_KERNEL);
1978                 if (!addr_info->adapter_name) {
1979                         kfree(addr_info);
1980                         rv = -ENOMEM;
1981                         goto out_unlock;
1982                 }
1983         }
1984 
1985         strncpy(addr_info->binfo.type, DEVICE_NAME,
1986                 sizeof(addr_info->binfo.type));
1987         addr_info->binfo.addr = addr;
1988         addr_info->binfo.platform_data = addr_info;
1989         addr_info->debug = debug;
1990         addr_info->slave_addr = slave_addr;
1991         addr_info->addr_src = addr_src;
1992         addr_info->dev = dev;
1993 
1994         if (dev)
1995                 dev_set_drvdata(dev, addr_info);
1996 
1997         list_add_tail(&addr_info->link, &ssif_infos);
1998 
1999         if (initialized)
2000                 i2c_for_each_dev(addr_info, ssif_adapter_handler);
2001         /* Otherwise address list will get it */
2002 
2003 out_unlock:
2004         mutex_unlock(&ssif_infos_mutex);
2005         return rv;
2006 }
2007 
2008 static void free_ssif_clients(void)
2009 {
2010         struct ssif_addr_info *info, *tmp;
2011 
2012         mutex_lock(&ssif_infos_mutex);
2013         list_for_each_entry_safe(info, tmp, &ssif_infos, link) {
2014                 list_del(&info->link);
2015                 kfree(info->adapter_name);
2016                 kfree(info);
2017         }
2018         mutex_unlock(&ssif_infos_mutex);
2019 }
2020 
2021 static unsigned short *ssif_address_list(void)
2022 {
2023         struct ssif_addr_info *info;
2024         unsigned int count = 0, i = 0;
2025         unsigned short *address_list;
2026 
2027         list_for_each_entry(info, &ssif_infos, link)
2028                 count++;
2029 
2030         address_list = kcalloc(count + 1, sizeof(*address_list),
2031                                GFP_KERNEL);
2032         if (!address_list)
2033                 return NULL;
2034 
2035         list_for_each_entry(info, &ssif_infos, link) {
2036                 unsigned short addr = info->binfo.addr;
2037                 int j;
2038 
2039                 for (j = 0; j < i; j++) {
2040                         if (address_list[j] == addr)
2041                                 /* Found a dup. */
2042                                 break;
2043                 }
2044                 if (j == i) /* Didn't find it in the list. */
2045                         address_list[i++] = addr;
2046         }
2047         address_list[i] = I2C_CLIENT_END;
2048 
2049         return address_list;
2050 }
2051 
2052 #ifdef CONFIG_ACPI
2053 static const struct acpi_device_id ssif_acpi_match[] = {
2054         { "IPI0001", 0 },
2055         { },
2056 };
2057 MODULE_DEVICE_TABLE(acpi, ssif_acpi_match);
2058 #endif
2059 
2060 #ifdef CONFIG_DMI
2061 static int dmi_ipmi_probe(struct platform_device *pdev)
2062 {
2063         u8 slave_addr = 0;
2064         u16 i2c_addr;
2065         int rv;
2066 
2067         if (!ssif_trydmi)
2068                 return -ENODEV;
2069 
2070         rv = device_property_read_u16(&pdev->dev, "i2c-addr", &i2c_addr);
2071         if (rv) {
2072                 dev_warn(&pdev->dev, "No i2c-addr property\n");
2073                 return -ENODEV;
2074         }
2075 
2076         rv = device_property_read_u8(&pdev->dev, "slave-addr", &slave_addr);
2077         if (rv)
2078                 slave_addr = 0x20;
2079 
2080         return new_ssif_client(i2c_addr, NULL, 0,
2081                                slave_addr, SI_SMBIOS, &pdev->dev);
2082 }
2083 #else
2084 static int dmi_ipmi_probe(struct platform_device *pdev)
2085 {
2086         return -ENODEV;
2087 }
2088 #endif
2089 
2090 static const struct i2c_device_id ssif_id[] = {
2091         { DEVICE_NAME, 0 },
2092         { }
2093 };
2094 MODULE_DEVICE_TABLE(i2c, ssif_id);
2095 
2096 static struct i2c_driver ssif_i2c_driver = {
2097         .class          = I2C_CLASS_HWMON,
2098         .driver         = {
2099                 .name                   = DEVICE_NAME
2100         },
2101         .probe          = ssif_probe,
2102         .remove         = ssif_remove,
2103         .alert          = ssif_alert,
2104         .id_table       = ssif_id,
2105         .detect         = ssif_detect
2106 };
2107 
2108 static int ssif_platform_probe(struct platform_device *dev)
2109 {
2110         return dmi_ipmi_probe(dev);
2111 }
2112 
2113 static int ssif_platform_remove(struct platform_device *dev)
2114 {
2115         struct ssif_addr_info *addr_info = dev_get_drvdata(&dev->dev);
2116 
2117         if (!addr_info)
2118                 return 0;
2119 
2120         mutex_lock(&ssif_infos_mutex);
2121         i2c_unregister_device(addr_info->added_client);
2122 
2123         list_del(&addr_info->link);
2124         kfree(addr_info);
2125         mutex_unlock(&ssif_infos_mutex);
2126         return 0;
2127 }
2128 
2129 static const struct platform_device_id ssif_plat_ids[] = {
2130     { "dmi-ipmi-ssif", 0 },
2131     { }
2132 };
2133 
2134 static struct platform_driver ipmi_driver = {
2135         .driver = {
2136                 .name = DEVICE_NAME,
2137         },
2138         .probe          = ssif_platform_probe,
2139         .remove         = ssif_platform_remove,
2140         .id_table       = ssif_plat_ids
2141 };
2142 
2143 static int init_ipmi_ssif(void)
2144 {
2145         int i;
2146         int rv;
2147 
2148         if (initialized)
2149                 return 0;
2150 
2151         pr_info("IPMI SSIF Interface driver\n");
2152 
2153         /* build list for i2c from addr list */
2154         for (i = 0; i < num_addrs; i++) {
2155                 rv = new_ssif_client(addr[i], adapter_name[i],
2156                                      dbg[i], slave_addrs[i],
2157                                      SI_HARDCODED, NULL);
2158                 if (rv)
2159                         pr_err("Couldn't add hardcoded device at addr 0x%x\n",
2160                                addr[i]);
2161         }
2162 
2163         if (ssif_tryacpi)
2164                 ssif_i2c_driver.driver.acpi_match_table =
2165                         ACPI_PTR(ssif_acpi_match);
2166 
2167         if (ssif_trydmi) {
2168                 rv = platform_driver_register(&ipmi_driver);
2169                 if (rv)
2170                         pr_err("Unable to register driver: %d\n", rv);
2171                 else
2172                         platform_registered = true;
2173         }
2174 
2175         ssif_i2c_driver.address_list = ssif_address_list();
2176 
2177         rv = i2c_add_driver(&ssif_i2c_driver);
2178         if (!rv)
2179                 initialized = true;
2180 
2181         return rv;
2182 }
2183 module_init(init_ipmi_ssif);
2184 
2185 static void cleanup_ipmi_ssif(void)
2186 {
2187         if (!initialized)
2188                 return;
2189 
2190         initialized = false;
2191 
2192         i2c_del_driver(&ssif_i2c_driver);
2193 
2194         kfree(ssif_i2c_driver.address_list);
2195 
2196         if (ssif_trydmi && platform_registered)
2197                 platform_driver_unregister(&ipmi_driver);
2198 
2199         free_ssif_clients();
2200 }
2201 module_exit(cleanup_ipmi_ssif);
2202 
2203 MODULE_ALIAS("platform:dmi-ipmi-ssif");
2204 MODULE_AUTHOR("Todd C Davis <todd.c.davis@intel.com>, Corey Minyard <minyard@acm.org>");
2205 MODULE_DESCRIPTION("IPMI driver for management controllers on a SMBus");
2206 MODULE_LICENSE("GPL");
/* [<][>][^][v][top][bottom][index][help] */
root/drivers/char/ipmi/ipmi_ssif.c

DEFINITIONS
