linux/drivers/acpi/acpi_ipmi.c
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   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
  44MODULE_AUTHOR("Zhao Yakui");
  45MODULE_DESCRIPTION("ACPI IPMI Opregion driver");
  46MODULE_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
  56struct 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
  71struct 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
  78struct 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 */
 102struct acpi_ipmi_buffer {
 103        u8 status;
 104        u8 length;
 105        u8 data[64];
 106};
 107
 108static void ipmi_register_bmc(int iface, struct device *dev);
 109static void ipmi_bmc_gone(int iface);
 110static void ipmi_msg_handler(struct ipmi_recv_msg *msg, void *user_msg_data);
 111static void acpi_add_ipmi_device(struct acpi_ipmi_device *ipmi_device);
 112static void acpi_remove_ipmi_device(struct acpi_ipmi_device *ipmi_device);
 113
 114static 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
 126static 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)
 144static 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
 188static 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
 220static 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
 241static 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
 282static 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
 336out:
 337        mutex_unlock(&driver_data.ipmi_lock);
 338        put_device(smi_data.dev);
 339        return;
 340}
 341
 342static 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
 375static acpi_status
 376acpi_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
 419end_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
 427static 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
 438static 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
 459static 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
 471static 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
 489static 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
 503static 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
 528module_init(acpi_ipmi_init);
 529module_exit(acpi_ipmi_exit);
 530
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