drivers/acpi/acpi_ipmi.c

   1 /*
   2  *  acpi_ipmi.c - ACPI IPMI opregion
   3  *
   4  *  Copyright (C) 2010 Intel Corporation
   5  *  Copyright (C) 2010 Zhao Yakui <yakui.zhao@intel.com>
   6  *
   7  * ~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~
   8  *
   9  *  This program is free software; you can redistribute it and/or modify
  10  *  it under the terms of the GNU General Public License as published by
  11  *  the Free Software Foundation; either version 2 of the License, or (at
  12  *  your option) any later version.
  13  *
  14  *  This program is distributed in the hope that it will be useful, but
  15  *  WITHOUT ANY WARRANTY; without even the implied warranty of
  16  *  MERCHANTABILITY or FITNESS FOR A PARTICULAR PURPOSE.  See the GNU
  17  *  General Public License for more details.
  18  *
  19  *  You should have received a copy of the GNU General Public License along
  20  *  with this program; if not, write to the Free Software Foundation, Inc.,
  21  *  59 Temple Place, Suite 330, Boston, MA 02111-1307 USA.
  22  *
  23  * ~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~
  24  */
  25
  26 #include <linux/kernel.h>
  27 #include <linux/module.h>
  28 #include <linux/init.h>
  29 #include <linux/types.h>
  30 #include <linux/delay.h>
  31 #include <linux/proc_fs.h>
  32 #include <linux/seq_file.h>
  33 #include <linux/interrupt.h>
  34 #include <linux/list.h>
  35 #include <linux/spinlock.h>
  36 #include <linux/io.h>
  37 #include <acpi/acpi_bus.h>
  38 #include <acpi/acpi_drivers.h>
  39 #include <linux/ipmi.h>
  40 #include <linux/device.h>
  41 #include <linux/pnp.h>
  42 #include <linux/spinlock.h>
  43
  44 MODULE_AUTHOR("Zhao Yakui");
  45 MODULE_DESCRIPTION("ACPI IPMI Opregion driver");
  46 MODULE_LICENSE("GPL");
  47
  48 #define IPMI_FLAGS_HANDLER_INSTALL      0
  49
  50 #define ACPI_IPMI_OK                    0
  51 #define ACPI_IPMI_TIMEOUT               0x10
  52 #define ACPI_IPMI_UNKNOWN               0x07
  53 /* the IPMI timeout is 5s */
  54 #define IPMI_TIMEOUT                    (5 * HZ)
  55
  56 struct acpi_ipmi_device {
  57         /* the device list attached to driver_data.ipmi_devices */
  58         struct list_head head;
  59         /* the IPMI request message list */
  60         struct list_head tx_msg_list;
  61         spinlock_t      tx_msg_lock;
  62         acpi_handle handle;
  63         struct pnp_dev *pnp_dev;
  64         ipmi_user_t     user_interface;
  65         int ipmi_ifnum; /* IPMI interface number */
  66         long curr_msgid;
  67         unsigned long flags;
  68         struct ipmi_smi_info smi_data;
  69 };
  70
  71 struct ipmi_driver_data {
  72         struct list_head        ipmi_devices;
  73         struct ipmi_smi_watcher bmc_events;
  74         struct ipmi_user_hndl   ipmi_hndlrs;
  75         struct mutex            ipmi_lock;
  76 };
  77
  78 struct acpi_ipmi_msg {
  79         struct list_head head;
  80         /*
  81          * General speaking the addr type should be SI_ADDR_TYPE. And
  82          * the addr channel should be BMC.
  83          * In fact it can also be IPMB type. But we will have to
  84          * parse it from the Netfn command buffer. It is so complex
  85          * that it is skipped.
  86          */
  87         struct ipmi_addr addr;
  88         long tx_msgid;
  89         /* it is used to track whether the IPMI message is finished */
  90         struct completion tx_complete;
  91         struct kernel_ipmi_msg tx_message;
  92         int     msg_done;
  93         /* tx data . And copy it from ACPI object buffer */
  94         u8      tx_data[64];
  95         int     tx_len;
  96         u8      rx_data[64];
  97         int     rx_len;
  98         struct acpi_ipmi_device *device;
  99 };
 100
 101 /* IPMI request/response buffer per ACPI 4.0, sec 5.5.2.4.3.2 */
 102 struct acpi_ipmi_buffer {
 103         u8 status;
 104         u8 length;
 105         u8 data[64];
 106 };
 107
 108 static void ipmi_register_bmc(int iface, struct device *dev);
 109 static void ipmi_bmc_gone(int iface);
 110 static void ipmi_msg_handler(struct ipmi_recv_msg *msg, void *user_msg_data);
 111 static void acpi_add_ipmi_device(struct acpi_ipmi_device *ipmi_device);
 112 static void acpi_remove_ipmi_device(struct acpi_ipmi_device *ipmi_device);
 113
 114 static struct ipmi_driver_data driver_data = {
 115         .ipmi_devices = LIST_HEAD_INIT(driver_data.ipmi_devices),
 116         .bmc_events = {
 117                 .owner = THIS_MODULE,
 118                 .new_smi = ipmi_register_bmc,
 119                 .smi_gone = ipmi_bmc_gone,
 120         },
 121         .ipmi_hndlrs = {
 122                 .ipmi_recv_hndl = ipmi_msg_handler,
 123         },
 124 };
 125
 126 static struct acpi_ipmi_msg *acpi_alloc_ipmi_msg(struct acpi_ipmi_device *ipmi)
 127 {
 128         struct acpi_ipmi_msg *ipmi_msg;
 129         struct pnp_dev *pnp_dev = ipmi->pnp_dev;
 130
 131         ipmi_msg = kzalloc(sizeof(struct acpi_ipmi_msg), GFP_KERNEL);
 132         if (!ipmi_msg)  {
 133                 dev_warn(&pnp_dev->dev, "Can't allocate memory for ipmi_msg\n");
 134                 return NULL;
 135         }
 136         init_completion(&ipmi_msg->tx_complete);
 137         INIT_LIST_HEAD(&ipmi_msg->head);
 138         ipmi_msg->device = ipmi;
 139         return ipmi_msg;
 140 }
 141
 142 #define         IPMI_OP_RGN_NETFN(offset)       ((offset >> 8) & 0xff)
 143 #define         IPMI_OP_RGN_CMD(offset)         (offset & 0xff)
 144 static void acpi_format_ipmi_msg(struct acpi_ipmi_msg *tx_msg,
 145                                 acpi_physical_address address,
 146                                 acpi_integer *value)
 147 {
 148         struct kernel_ipmi_msg *msg;
 149         struct acpi_ipmi_buffer *buffer;
 150         struct acpi_ipmi_device *device;
 151         unsigned long flags;
 152
 153         msg = &tx_msg->tx_message;
 154         /*
 155          * IPMI network function and command are encoded in the address
 156          * within the IPMI OpRegion; see ACPI 4.0, sec 5.5.2.4.3.
 157          */
 158         msg->netfn = IPMI_OP_RGN_NETFN(address);
 159         msg->cmd = IPMI_OP_RGN_CMD(address);
 160         msg->data = tx_msg->tx_data;
 161         /*
 162          * value is the parameter passed by the IPMI opregion space handler.
 163          * It points to the IPMI request message buffer
 164          */
 165         buffer = (struct acpi_ipmi_buffer *)value;
 166         /* copy the tx message data */
 167         msg->data_len = buffer->length;
 168         memcpy(tx_msg->tx_data, buffer->data, msg->data_len);
 169         /*
 170          * now the default type is SYSTEM_INTERFACE and channel type is BMC.
 171          * If the netfn is APP_REQUEST and the cmd is SEND_MESSAGE,
 172          * the addr type should be changed to IPMB. Then we will have to parse
 173          * the IPMI request message buffer to get the IPMB address.
 174          * If so, please fix me.
 175          */
 176         tx_msg->addr.addr_type = IPMI_SYSTEM_INTERFACE_ADDR_TYPE;
 177         tx_msg->addr.channel = IPMI_BMC_CHANNEL;
 178         tx_msg->addr.data[0] = 0;
 179
 180         /* Get the msgid */
 181         device = tx_msg->device;
 182         spin_lock_irqsave(&device->tx_msg_lock, flags);
 183         device->curr_msgid++;
 184         tx_msg->tx_msgid = device->curr_msgid;
 185         spin_unlock_irqrestore(&device->tx_msg_lock, flags);
 186 }
 187
 188 static void acpi_format_ipmi_response(struct acpi_ipmi_msg *msg,
 189                 acpi_integer *value, int rem_time)
 190 {
 191         struct acpi_ipmi_buffer *buffer;
 192
 193         /*
 194          * value is also used as output parameter. It represents the response
 195          * IPMI message returned by IPMI command.
 196          */
 197         buffer = (struct acpi_ipmi_buffer *)value;
 198         if (!rem_time && !msg->msg_done) {
 199                 buffer->status = ACPI_IPMI_TIMEOUT;
 200                 return;
 201         }
 202         /*
 203          * If the flag of msg_done is not set or the recv length is zero, it
 204          * means that the IPMI command is not executed correctly.
 205          * The status code will be ACPI_IPMI_UNKNOWN.
 206          */
 207         if (!msg->msg_done || !msg->rx_len) {
 208                 buffer->status = ACPI_IPMI_UNKNOWN;
 209                 return;
 210         }
 211         /*
 212          * If the IPMI response message is obtained correctly, the status code
 213          * will be ACPI_IPMI_OK
 214          */
 215         buffer->status = ACPI_IPMI_OK;
 216         buffer->length = msg->rx_len;
 217         memcpy(buffer->data, msg->rx_data, msg->rx_len);
 218 }
 219
 220 static void ipmi_flush_tx_msg(struct acpi_ipmi_device *ipmi)
 221 {
 222         struct acpi_ipmi_msg *tx_msg, *temp;
 223         int count = HZ / 10;
 224         struct pnp_dev *pnp_dev = ipmi->pnp_dev;
 225
 226         list_for_each_entry_safe(tx_msg, temp, &ipmi->tx_msg_list, head) {
 227                 /* wake up the sleep thread on the Tx msg */
 228                 complete(&tx_msg->tx_complete);
 229         }
 230
 231         /* wait for about 100ms to flush the tx message list */
 232         while (count--) {
 233                 if (list_empty(&ipmi->tx_msg_list))
 234                         break;
 235                 schedule_timeout(1);
 236         }
 237         if (!list_empty(&ipmi->tx_msg_list))
 238                 dev_warn(&pnp_dev->dev, "tx msg list is not NULL\n");
 239 }
 240
 241 static void ipmi_msg_handler(struct ipmi_recv_msg *msg, void *user_msg_data)
 242 {
 243         struct acpi_ipmi_device *ipmi_device = user_msg_data;
 244         int msg_found = 0;
 245         struct acpi_ipmi_msg *tx_msg;
 246         struct pnp_dev *pnp_dev = ipmi_device->pnp_dev;
 247         unsigned long flags;
 248
 249         if (msg->user != ipmi_device->user_interface) {
 250                 dev_warn(&pnp_dev->dev, "Unexpected response is returned. "
 251                         "returned user %p, expected user %p\n",
 252                         msg->user, ipmi_device->user_interface);
 253                 ipmi_free_recv_msg(msg);
 254                 return;
 255         }
 256         spin_lock_irqsave(&ipmi_device->tx_msg_lock, flags);
 257         list_for_each_entry(tx_msg, &ipmi_device->tx_msg_list, head) {
 258                 if (msg->msgid == tx_msg->tx_msgid) {
 259                         msg_found = 1;
 260                         break;
 261                 }
 262         }
 263
 264         spin_unlock_irqrestore(&ipmi_device->tx_msg_lock, flags);
 265         if (!msg_found) {
 266                 dev_warn(&pnp_dev->dev, "Unexpected response (msg id %ld) is "
 267                         "returned.\n", msg->msgid);
 268                 ipmi_free_recv_msg(msg);
 269                 return;
 270         }
 271
 272         if (msg->msg.data_len) {
 273                 /* copy the response data to Rx_data buffer */
 274                 memcpy(tx_msg->rx_data, msg->msg_data, msg->msg.data_len);
 275                 tx_msg->rx_len = msg->msg.data_len;
 276                 tx_msg->msg_done = 1;
 277         }
 278         complete(&tx_msg->tx_complete);
 279         ipmi_free_recv_msg(msg);
 280 };
 281
 282 static void ipmi_register_bmc(int iface, struct device *dev)
 283 {
 284         struct acpi_ipmi_device *ipmi_device, *temp;
 285         struct pnp_dev *pnp_dev;
 286         ipmi_user_t             user;
 287         int err;
 288         struct ipmi_smi_info smi_data;
 289         acpi_handle handle;
 290
 291         err = ipmi_get_smi_info(iface, &smi_data);
 292
 293         if (err)
 294                 return;
 295
 296         if (smi_data.addr_src != SI_ACPI) {
 297                 put_device(smi_data.dev);
 298                 return;
 299         }
 300
 301         handle = smi_data.addr_info.acpi_info.acpi_handle;
 302
 303         mutex_lock(&driver_data.ipmi_lock);
 304         list_for_each_entry(temp, &driver_data.ipmi_devices, head) {
 305                 /*
 306                  * if the corresponding ACPI handle is already added
 307                  * to the device list, don't add it again.
 308                  */
 309                 if (temp->handle == handle)
 310                         goto out;
 311         }
 312
 313         ipmi_device = kzalloc(sizeof(*ipmi_device), GFP_KERNEL);
 314
 315         if (!ipmi_device)
 316                 goto out;
 317
 318         pnp_dev = to_pnp_dev(smi_data.dev);
 319         ipmi_device->handle = handle;
 320         ipmi_device->pnp_dev = pnp_dev;
 321
 322         err = ipmi_create_user(iface, &driver_data.ipmi_hndlrs,
 323                                         ipmi_device, &user);
 324         if (err) {
 325                 dev_warn(&pnp_dev->dev, "Can't create IPMI user interface\n");
 326                 kfree(ipmi_device);
 327                 goto out;
 328         }
 329         acpi_add_ipmi_device(ipmi_device);
 330         ipmi_device->user_interface = user;
 331         ipmi_device->ipmi_ifnum = iface;
 332         mutex_unlock(&driver_data.ipmi_lock);
 333         memcpy(&ipmi_device->smi_data, &smi_data, sizeof(struct ipmi_smi_info));
 334         return;
 335
 336 out:
 337         mutex_unlock(&driver_data.ipmi_lock);
 338         put_device(smi_data.dev);
 339         return;
 340 }
 341
 342 static void ipmi_bmc_gone(int iface)
 343 {
 344         struct acpi_ipmi_device *ipmi_device, *temp;
 345
 346         mutex_lock(&driver_data.ipmi_lock);
 347         list_for_each_entry_safe(ipmi_device, temp,
 348                                 &driver_data.ipmi_devices, head) {
 349                 if (ipmi_device->ipmi_ifnum != iface)
 350                         continue;
 351
 352                 acpi_remove_ipmi_device(ipmi_device);
 353                 put_device(ipmi_device->smi_data.dev);
 354                 kfree(ipmi_device);
 355                 break;
 356         }
 357         mutex_unlock(&driver_data.ipmi_lock);
 358 }
 359 /* --------------------------------------------------------------------------
 360  *                      Address Space Management
 361  * -------------------------------------------------------------------------- */
 362 /*
 363  * This is the IPMI opregion space handler.
 364  * @function: indicates the read/write. In fact as the IPMI message is driven
 365  * by command, only write is meaningful.
 366  * @address: This contains the netfn/command of IPMI request message.
 367  * @bits   : not used.
 368  * @value  : it is an in/out parameter. It points to the IPMI message buffer.
 369  *           Before the IPMI message is sent, it represents the actual request
 370  *           IPMI message. After the IPMI message is finished, it represents
 371  *           the response IPMI message returned by IPMI command.
 372  * @handler_context: IPMI device context.
 373  */
 374
 375 static acpi_status
 376 acpi_ipmi_space_handler(u32 function, acpi_physical_address address,
 377                       u32 bits, acpi_integer *value,
 378                       void *handler_context, void *region_context)
 379 {
 380         struct acpi_ipmi_msg *tx_msg;
 381         struct acpi_ipmi_device *ipmi_device = handler_context;
 382         int err, rem_time;
 383         acpi_status status;
 384         unsigned long flags;
 385         /*
 386          * IPMI opregion message.
 387          * IPMI message is firstly written to the BMC and system software
 388          * can get the respsonse. So it is unmeaningful for the read access
 389          * of IPMI opregion.
 390          */
 391         if ((function & ACPI_IO_MASK) == ACPI_READ)
 392                 return AE_TYPE;
 393
 394         if (!ipmi_device->user_interface)
 395                 return AE_NOT_EXIST;
 396
 397         tx_msg = acpi_alloc_ipmi_msg(ipmi_device);
 398         if (!tx_msg)
 399                 return AE_NO_MEMORY;
 400
 401         acpi_format_ipmi_msg(tx_msg, address, value);
 402         spin_lock_irqsave(&ipmi_device->tx_msg_lock, flags);
 403         list_add_tail(&tx_msg->head, &ipmi_device->tx_msg_list);
 404         spin_unlock_irqrestore(&ipmi_device->tx_msg_lock, flags);
 405         err = ipmi_request_settime(ipmi_device->user_interface,
 406                                         &tx_msg->addr,
 407                                         tx_msg->tx_msgid,
 408                                         &tx_msg->tx_message,
 409                                         NULL, 0, 0, 0);
 410         if (err) {
 411                 status = AE_ERROR;
 412                 goto end_label;
 413         }
 414         rem_time = wait_for_completion_timeout(&tx_msg->tx_complete,
 415                                         IPMI_TIMEOUT);
 416         acpi_format_ipmi_response(tx_msg, value, rem_time);
 417         status = AE_OK;
 418
 419 end_label:
 420         spin_lock_irqsave(&ipmi_device->tx_msg_lock, flags);
 421         list_del(&tx_msg->head);
 422         spin_unlock_irqrestore(&ipmi_device->tx_msg_lock, flags);
 423         kfree(tx_msg);
 424         return status;
 425 }
 426
 427 static void ipmi_remove_space_handler(struct acpi_ipmi_device *ipmi)
 428 {
 429         if (!test_bit(IPMI_FLAGS_HANDLER_INSTALL, &ipmi->flags))
 430                 return;
 431
 432         acpi_remove_address_space_handler(ipmi->handle,
 433                                 ACPI_ADR_SPACE_IPMI, &acpi_ipmi_space_handler);
 434
 435         clear_bit(IPMI_FLAGS_HANDLER_INSTALL, &ipmi->flags);
 436 }
 437
 438 static int ipmi_install_space_handler(struct acpi_ipmi_device *ipmi)
 439 {
 440         acpi_status status;
 441
 442         if (test_bit(IPMI_FLAGS_HANDLER_INSTALL, &ipmi->flags))
 443                 return 0;
 444
 445         status = acpi_install_address_space_handler(ipmi->handle,
 446                                                     ACPI_ADR_SPACE_IPMI,
 447                                                     &acpi_ipmi_space_handler,
 448                                                     NULL, ipmi);
 449         if (ACPI_FAILURE(status)) {
 450                 struct pnp_dev *pnp_dev = ipmi->pnp_dev;
 451                 dev_warn(&pnp_dev->dev, "Can't register IPMI opregion space "
 452                         "handle\n");
 453                 return -EINVAL;
 454         }
 455         set_bit(IPMI_FLAGS_HANDLER_INSTALL, &ipmi->flags);
 456         return 0;
 457 }
 458
 459 static void acpi_add_ipmi_device(struct acpi_ipmi_device *ipmi_device)
 460 {
 461
 462         INIT_LIST_HEAD(&ipmi_device->head);
 463
 464         spin_lock_init(&ipmi_device->tx_msg_lock);
 465         INIT_LIST_HEAD(&ipmi_device->tx_msg_list);
 466         ipmi_install_space_handler(ipmi_device);
 467
 468         list_add_tail(&ipmi_device->head, &driver_data.ipmi_devices);
 469 }
 470
 471 static void acpi_remove_ipmi_device(struct acpi_ipmi_device *ipmi_device)
 472 {
 473         /*
 474          * If the IPMI user interface is created, it should be
 475          * destroyed.
 476          */
 477         if (ipmi_device->user_interface) {
 478                 ipmi_destroy_user(ipmi_device->user_interface);
 479                 ipmi_device->user_interface = NULL;
 480         }
 481         /* flush the Tx_msg list */
 482         if (!list_empty(&ipmi_device->tx_msg_list))
 483                 ipmi_flush_tx_msg(ipmi_device);
 484
 485         list_del(&ipmi_device->head);
 486         ipmi_remove_space_handler(ipmi_device);
 487 }
 488
 489 static int __init acpi_ipmi_init(void)
 490 {
 491         int result = 0;
 492
 493         if (acpi_disabled)
 494                 return result;
 495
 496         mutex_init(&driver_data.ipmi_lock);
 497
 498         result = ipmi_smi_watcher_register(&driver_data.bmc_events);
 499
 500         return result;
 501 }
 502
 503 static void __exit acpi_ipmi_exit(void)
 504 {
 505         struct acpi_ipmi_device *ipmi_device, *temp;
 506
 507         if (acpi_disabled)
 508                 return;
 509
 510         ipmi_smi_watcher_unregister(&driver_data.bmc_events);
 511
 512         /*
 513          * When one smi_watcher is unregistered, it is only deleted
 514          * from the smi_watcher list. But the smi_gone callback function
 515          * is not called. So explicitly uninstall the ACPI IPMI oregion
 516          * handler and free it.
 517          */
 518         mutex_lock(&driver_data.ipmi_lock);
 519         list_for_each_entry_safe(ipmi_device, temp,
 520                                 &driver_data.ipmi_devices, head) {
 521                 acpi_remove_ipmi_device(ipmi_device);
 522                 put_device(ipmi_device->smi_data.dev);
 523                 kfree(ipmi_device);
 524         }
 525         mutex_unlock(&driver_data.ipmi_lock);
 526 }
 527
 528 module_init(acpi_ipmi_init);
 529 module_exit(acpi_ipmi_exit);