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