linux/drivers/firmware/dcdbas.c
<<
>>
Prefs
   1/*
   2 *  dcdbas.c: Dell Systems Management Base Driver
   3 *
   4 *  The Dell Systems Management Base Driver provides a sysfs interface for
   5 *  systems management software to perform System Management Interrupts (SMIs)
   6 *  and Host Control Actions (power cycle or power off after OS shutdown) on
   7 *  Dell systems.
   8 *
   9 *  See Documentation/dcdbas.txt for more information.
  10 *
  11 *  Copyright (C) 1995-2006 Dell Inc.
  12 *
  13 *  This program is free software; you can redistribute it and/or modify
  14 *  it under the terms of the GNU General Public License v2.0 as published by
  15 *  the Free Software Foundation.
  16 *
  17 *  This program is distributed in the hope that it will be useful,
  18 *  but WITHOUT ANY WARRANTY; without even the implied warranty of
  19 *  MERCHANTABILITY or FITNESS FOR A PARTICULAR PURPOSE.  See the
  20 *  GNU General Public License for more details.
  21 */
  22
  23#include <linux/platform_device.h>
  24#include <linux/dma-mapping.h>
  25#include <linux/errno.h>
  26#include <linux/gfp.h>
  27#include <linux/init.h>
  28#include <linux/kernel.h>
  29#include <linux/mc146818rtc.h>
  30#include <linux/module.h>
  31#include <linux/reboot.h>
  32#include <linux/sched.h>
  33#include <linux/smp.h>
  34#include <linux/spinlock.h>
  35#include <linux/string.h>
  36#include <linux/types.h>
  37#include <linux/mutex.h>
  38#include <asm/io.h>
  39
  40#include "dcdbas.h"
  41
  42#define DRIVER_NAME             "dcdbas"
  43#define DRIVER_VERSION          "5.6.0-3.2"
  44#define DRIVER_DESCRIPTION      "Dell Systems Management Base Driver"
  45
  46static struct platform_device *dcdbas_pdev;
  47
  48static u8 *smi_data_buf;
  49static dma_addr_t smi_data_buf_handle;
  50static unsigned long smi_data_buf_size;
  51static u32 smi_data_buf_phys_addr;
  52static DEFINE_MUTEX(smi_data_lock);
  53
  54static unsigned int host_control_action;
  55static unsigned int host_control_smi_type;
  56static unsigned int host_control_on_shutdown;
  57
  58/**
  59 * smi_data_buf_free: free SMI data buffer
  60 */
  61static void smi_data_buf_free(void)
  62{
  63        if (!smi_data_buf)
  64                return;
  65
  66        dev_dbg(&dcdbas_pdev->dev, "%s: phys: %x size: %lu\n",
  67                __func__, smi_data_buf_phys_addr, smi_data_buf_size);
  68
  69        dma_free_coherent(&dcdbas_pdev->dev, smi_data_buf_size, smi_data_buf,
  70                          smi_data_buf_handle);
  71        smi_data_buf = NULL;
  72        smi_data_buf_handle = 0;
  73        smi_data_buf_phys_addr = 0;
  74        smi_data_buf_size = 0;
  75}
  76
  77/**
  78 * smi_data_buf_realloc: grow SMI data buffer if needed
  79 */
  80static int smi_data_buf_realloc(unsigned long size)
  81{
  82        void *buf;
  83        dma_addr_t handle;
  84
  85        if (smi_data_buf_size >= size)
  86                return 0;
  87
  88        if (size > MAX_SMI_DATA_BUF_SIZE)
  89                return -EINVAL;
  90
  91        /* new buffer is needed */
  92        buf = dma_alloc_coherent(&dcdbas_pdev->dev, size, &handle, GFP_KERNEL);
  93        if (!buf) {
  94                dev_dbg(&dcdbas_pdev->dev,
  95                        "%s: failed to allocate memory size %lu\n",
  96                        __func__, size);
  97                return -ENOMEM;
  98        }
  99        /* memory zeroed by dma_alloc_coherent */
 100
 101        if (smi_data_buf)
 102                memcpy(buf, smi_data_buf, smi_data_buf_size);
 103
 104        /* free any existing buffer */
 105        smi_data_buf_free();
 106
 107        /* set up new buffer for use */
 108        smi_data_buf = buf;
 109        smi_data_buf_handle = handle;
 110        smi_data_buf_phys_addr = (u32) virt_to_phys(buf);
 111        smi_data_buf_size = size;
 112
 113        dev_dbg(&dcdbas_pdev->dev, "%s: phys: %x size: %lu\n",
 114                __func__, smi_data_buf_phys_addr, smi_data_buf_size);
 115
 116        return 0;
 117}
 118
 119static ssize_t smi_data_buf_phys_addr_show(struct device *dev,
 120                                           struct device_attribute *attr,
 121                                           char *buf)
 122{
 123        return sprintf(buf, "%x\n", smi_data_buf_phys_addr);
 124}
 125
 126static ssize_t smi_data_buf_size_show(struct device *dev,
 127                                      struct device_attribute *attr,
 128                                      char *buf)
 129{
 130        return sprintf(buf, "%lu\n", smi_data_buf_size);
 131}
 132
 133static ssize_t smi_data_buf_size_store(struct device *dev,
 134                                       struct device_attribute *attr,
 135                                       const char *buf, size_t count)
 136{
 137        unsigned long buf_size;
 138        ssize_t ret;
 139
 140        buf_size = simple_strtoul(buf, NULL, 10);
 141
 142        /* make sure SMI data buffer is at least buf_size */
 143        mutex_lock(&smi_data_lock);
 144        ret = smi_data_buf_realloc(buf_size);
 145        mutex_unlock(&smi_data_lock);
 146        if (ret)
 147                return ret;
 148
 149        return count;
 150}
 151
 152static ssize_t smi_data_read(struct file *filp, struct kobject *kobj,
 153                             struct bin_attribute *bin_attr,
 154                             char *buf, loff_t pos, size_t count)
 155{
 156        ssize_t ret;
 157
 158        mutex_lock(&smi_data_lock);
 159        ret = memory_read_from_buffer(buf, count, &pos, smi_data_buf,
 160                                        smi_data_buf_size);
 161        mutex_unlock(&smi_data_lock);
 162        return ret;
 163}
 164
 165static ssize_t smi_data_write(struct file *filp, struct kobject *kobj,
 166                              struct bin_attribute *bin_attr,
 167                              char *buf, loff_t pos, size_t count)
 168{
 169        ssize_t ret;
 170
 171        if ((pos + count) > MAX_SMI_DATA_BUF_SIZE)
 172                return -EINVAL;
 173
 174        mutex_lock(&smi_data_lock);
 175
 176        ret = smi_data_buf_realloc(pos + count);
 177        if (ret)
 178                goto out;
 179
 180        memcpy(smi_data_buf + pos, buf, count);
 181        ret = count;
 182out:
 183        mutex_unlock(&smi_data_lock);
 184        return ret;
 185}
 186
 187static ssize_t host_control_action_show(struct device *dev,
 188                                        struct device_attribute *attr,
 189                                        char *buf)
 190{
 191        return sprintf(buf, "%u\n", host_control_action);
 192}
 193
 194static ssize_t host_control_action_store(struct device *dev,
 195                                         struct device_attribute *attr,
 196                                         const char *buf, size_t count)
 197{
 198        ssize_t ret;
 199
 200        /* make sure buffer is available for host control command */
 201        mutex_lock(&smi_data_lock);
 202        ret = smi_data_buf_realloc(sizeof(struct apm_cmd));
 203        mutex_unlock(&smi_data_lock);
 204        if (ret)
 205                return ret;
 206
 207        host_control_action = simple_strtoul(buf, NULL, 10);
 208        return count;
 209}
 210
 211static ssize_t host_control_smi_type_show(struct device *dev,
 212                                          struct device_attribute *attr,
 213                                          char *buf)
 214{
 215        return sprintf(buf, "%u\n", host_control_smi_type);
 216}
 217
 218static ssize_t host_control_smi_type_store(struct device *dev,
 219                                           struct device_attribute *attr,
 220                                           const char *buf, size_t count)
 221{
 222        host_control_smi_type = simple_strtoul(buf, NULL, 10);
 223        return count;
 224}
 225
 226static ssize_t host_control_on_shutdown_show(struct device *dev,
 227                                             struct device_attribute *attr,
 228                                             char *buf)
 229{
 230        return sprintf(buf, "%u\n", host_control_on_shutdown);
 231}
 232
 233static ssize_t host_control_on_shutdown_store(struct device *dev,
 234                                              struct device_attribute *attr,
 235                                              const char *buf, size_t count)
 236{
 237        host_control_on_shutdown = simple_strtoul(buf, NULL, 10);
 238        return count;
 239}
 240
 241/**
 242 * dcdbas_smi_request: generate SMI request
 243 *
 244 * Called with smi_data_lock.
 245 */
 246int dcdbas_smi_request(struct smi_cmd *smi_cmd)
 247{
 248        cpumask_var_t old_mask;
 249        int ret = 0;
 250
 251        if (smi_cmd->magic != SMI_CMD_MAGIC) {
 252                dev_info(&dcdbas_pdev->dev, "%s: invalid magic value\n",
 253                         __func__);
 254                return -EBADR;
 255        }
 256
 257        /* SMI requires CPU 0 */
 258        if (!alloc_cpumask_var(&old_mask, GFP_KERNEL))
 259                return -ENOMEM;
 260
 261        cpumask_copy(old_mask, &current->cpus_allowed);
 262        set_cpus_allowed_ptr(current, cpumask_of(0));
 263        if (smp_processor_id() != 0) {
 264                dev_dbg(&dcdbas_pdev->dev, "%s: failed to get CPU 0\n",
 265                        __func__);
 266                ret = -EBUSY;
 267                goto out;
 268        }
 269
 270        /* generate SMI */
 271        asm volatile (
 272                "outb %b0,%w1"
 273                : /* no output args */
 274                : "a" (smi_cmd->command_code),
 275                  "d" (smi_cmd->command_address),
 276                  "b" (smi_cmd->ebx),
 277                  "c" (smi_cmd->ecx)
 278                : "memory"
 279        );
 280
 281out:
 282        set_cpus_allowed_ptr(current, old_mask);
 283        free_cpumask_var(old_mask);
 284        return ret;
 285}
 286
 287/**
 288 * smi_request_store:
 289 *
 290 * The valid values are:
 291 * 0: zero SMI data buffer
 292 * 1: generate calling interface SMI
 293 * 2: generate raw SMI
 294 *
 295 * User application writes smi_cmd to smi_data before telling driver
 296 * to generate SMI.
 297 */
 298static ssize_t smi_request_store(struct device *dev,
 299                                 struct device_attribute *attr,
 300                                 const char *buf, size_t count)
 301{
 302        struct smi_cmd *smi_cmd;
 303        unsigned long val = simple_strtoul(buf, NULL, 10);
 304        ssize_t ret;
 305
 306        mutex_lock(&smi_data_lock);
 307
 308        if (smi_data_buf_size < sizeof(struct smi_cmd)) {
 309                ret = -ENODEV;
 310                goto out;
 311        }
 312        smi_cmd = (struct smi_cmd *)smi_data_buf;
 313
 314        switch (val) {
 315        case 2:
 316                /* Raw SMI */
 317                ret = dcdbas_smi_request(smi_cmd);
 318                if (!ret)
 319                        ret = count;
 320                break;
 321        case 1:
 322                /* Calling Interface SMI */
 323                smi_cmd->ebx = (u32) virt_to_phys(smi_cmd->command_buffer);
 324                ret = dcdbas_smi_request(smi_cmd);
 325                if (!ret)
 326                        ret = count;
 327                break;
 328        case 0:
 329                memset(smi_data_buf, 0, smi_data_buf_size);
 330                ret = count;
 331                break;
 332        default:
 333                ret = -EINVAL;
 334                break;
 335        }
 336
 337out:
 338        mutex_unlock(&smi_data_lock);
 339        return ret;
 340}
 341EXPORT_SYMBOL(dcdbas_smi_request);
 342
 343/**
 344 * host_control_smi: generate host control SMI
 345 *
 346 * Caller must set up the host control command in smi_data_buf.
 347 */
 348static int host_control_smi(void)
 349{
 350        struct apm_cmd *apm_cmd;
 351        u8 *data;
 352        unsigned long flags;
 353        u32 num_ticks;
 354        s8 cmd_status;
 355        u8 index;
 356
 357        apm_cmd = (struct apm_cmd *)smi_data_buf;
 358        apm_cmd->status = ESM_STATUS_CMD_UNSUCCESSFUL;
 359
 360        switch (host_control_smi_type) {
 361        case HC_SMITYPE_TYPE1:
 362                spin_lock_irqsave(&rtc_lock, flags);
 363                /* write SMI data buffer physical address */
 364                data = (u8 *)&smi_data_buf_phys_addr;
 365                for (index = PE1300_CMOS_CMD_STRUCT_PTR;
 366                     index < (PE1300_CMOS_CMD_STRUCT_PTR + 4);
 367                     index++, data++) {
 368                        outb(index,
 369                             (CMOS_BASE_PORT + CMOS_PAGE2_INDEX_PORT_PIIX4));
 370                        outb(*data,
 371                             (CMOS_BASE_PORT + CMOS_PAGE2_DATA_PORT_PIIX4));
 372                }
 373
 374                /* first set status to -1 as called by spec */
 375                cmd_status = ESM_STATUS_CMD_UNSUCCESSFUL;
 376                outb((u8) cmd_status, PCAT_APM_STATUS_PORT);
 377
 378                /* generate SMM call */
 379                outb(ESM_APM_CMD, PCAT_APM_CONTROL_PORT);
 380                spin_unlock_irqrestore(&rtc_lock, flags);
 381
 382                /* wait a few to see if it executed */
 383                num_ticks = TIMEOUT_USEC_SHORT_SEMA_BLOCKING;
 384                while ((cmd_status = inb(PCAT_APM_STATUS_PORT))
 385                       == ESM_STATUS_CMD_UNSUCCESSFUL) {
 386                        num_ticks--;
 387                        if (num_ticks == EXPIRED_TIMER)
 388                                return -ETIME;
 389                }
 390                break;
 391
 392        case HC_SMITYPE_TYPE2:
 393        case HC_SMITYPE_TYPE3:
 394                spin_lock_irqsave(&rtc_lock, flags);
 395                /* write SMI data buffer physical address */
 396                data = (u8 *)&smi_data_buf_phys_addr;
 397                for (index = PE1400_CMOS_CMD_STRUCT_PTR;
 398                     index < (PE1400_CMOS_CMD_STRUCT_PTR + 4);
 399                     index++, data++) {
 400                        outb(index, (CMOS_BASE_PORT + CMOS_PAGE1_INDEX_PORT));
 401                        outb(*data, (CMOS_BASE_PORT + CMOS_PAGE1_DATA_PORT));
 402                }
 403
 404                /* generate SMM call */
 405                if (host_control_smi_type == HC_SMITYPE_TYPE3)
 406                        outb(ESM_APM_CMD, PCAT_APM_CONTROL_PORT);
 407                else
 408                        outb(ESM_APM_CMD, PE1400_APM_CONTROL_PORT);
 409
 410                /* restore RTC index pointer since it was written to above */
 411                CMOS_READ(RTC_REG_C);
 412                spin_unlock_irqrestore(&rtc_lock, flags);
 413
 414                /* read control port back to serialize write */
 415                cmd_status = inb(PE1400_APM_CONTROL_PORT);
 416
 417                /* wait a few to see if it executed */
 418                num_ticks = TIMEOUT_USEC_SHORT_SEMA_BLOCKING;
 419                while (apm_cmd->status == ESM_STATUS_CMD_UNSUCCESSFUL) {
 420                        num_ticks--;
 421                        if (num_ticks == EXPIRED_TIMER)
 422                                return -ETIME;
 423                }
 424                break;
 425
 426        default:
 427                dev_dbg(&dcdbas_pdev->dev, "%s: invalid SMI type %u\n",
 428                        __func__, host_control_smi_type);
 429                return -ENOSYS;
 430        }
 431
 432        return 0;
 433}
 434
 435/**
 436 * dcdbas_host_control: initiate host control
 437 *
 438 * This function is called by the driver after the system has
 439 * finished shutting down if the user application specified a
 440 * host control action to perform on shutdown.  It is safe to
 441 * use smi_data_buf at this point because the system has finished
 442 * shutting down and no userspace apps are running.
 443 */
 444static void dcdbas_host_control(void)
 445{
 446        struct apm_cmd *apm_cmd;
 447        u8 action;
 448
 449        if (host_control_action == HC_ACTION_NONE)
 450                return;
 451
 452        action = host_control_action;
 453        host_control_action = HC_ACTION_NONE;
 454
 455        if (!smi_data_buf) {
 456                dev_dbg(&dcdbas_pdev->dev, "%s: no SMI buffer\n", __func__);
 457                return;
 458        }
 459
 460        if (smi_data_buf_size < sizeof(struct apm_cmd)) {
 461                dev_dbg(&dcdbas_pdev->dev, "%s: SMI buffer too small\n",
 462                        __func__);
 463                return;
 464        }
 465
 466        apm_cmd = (struct apm_cmd *)smi_data_buf;
 467
 468        /* power off takes precedence */
 469        if (action & HC_ACTION_HOST_CONTROL_POWEROFF) {
 470                apm_cmd->command = ESM_APM_POWER_CYCLE;
 471                apm_cmd->reserved = 0;
 472                *((s16 *)&apm_cmd->parameters.shortreq.parm[0]) = (s16) 0;
 473                host_control_smi();
 474        } else if (action & HC_ACTION_HOST_CONTROL_POWERCYCLE) {
 475                apm_cmd->command = ESM_APM_POWER_CYCLE;
 476                apm_cmd->reserved = 0;
 477                *((s16 *)&apm_cmd->parameters.shortreq.parm[0]) = (s16) 20;
 478                host_control_smi();
 479        }
 480}
 481
 482/**
 483 * dcdbas_reboot_notify: handle reboot notification for host control
 484 */
 485static int dcdbas_reboot_notify(struct notifier_block *nb, unsigned long code,
 486                                void *unused)
 487{
 488        switch (code) {
 489        case SYS_DOWN:
 490        case SYS_HALT:
 491        case SYS_POWER_OFF:
 492                if (host_control_on_shutdown) {
 493                        /* firmware is going to perform host control action */
 494                        printk(KERN_WARNING "Please wait for shutdown "
 495                               "action to complete...\n");
 496                        dcdbas_host_control();
 497                }
 498                break;
 499        }
 500
 501        return NOTIFY_DONE;
 502}
 503
 504static struct notifier_block dcdbas_reboot_nb = {
 505        .notifier_call = dcdbas_reboot_notify,
 506        .next = NULL,
 507        .priority = INT_MIN
 508};
 509
 510static DCDBAS_BIN_ATTR_RW(smi_data);
 511
 512static struct bin_attribute *dcdbas_bin_attrs[] = {
 513        &bin_attr_smi_data,
 514        NULL
 515};
 516
 517static DCDBAS_DEV_ATTR_RW(smi_data_buf_size);
 518static DCDBAS_DEV_ATTR_RO(smi_data_buf_phys_addr);
 519static DCDBAS_DEV_ATTR_WO(smi_request);
 520static DCDBAS_DEV_ATTR_RW(host_control_action);
 521static DCDBAS_DEV_ATTR_RW(host_control_smi_type);
 522static DCDBAS_DEV_ATTR_RW(host_control_on_shutdown);
 523
 524static struct attribute *dcdbas_dev_attrs[] = {
 525        &dev_attr_smi_data_buf_size.attr,
 526        &dev_attr_smi_data_buf_phys_addr.attr,
 527        &dev_attr_smi_request.attr,
 528        &dev_attr_host_control_action.attr,
 529        &dev_attr_host_control_smi_type.attr,
 530        &dev_attr_host_control_on_shutdown.attr,
 531        NULL
 532};
 533
 534static struct attribute_group dcdbas_attr_group = {
 535        .attrs = dcdbas_dev_attrs,
 536};
 537
 538static int __devinit dcdbas_probe(struct platform_device *dev)
 539{
 540        int i, error;
 541
 542        host_control_action = HC_ACTION_NONE;
 543        host_control_smi_type = HC_SMITYPE_NONE;
 544
 545        /*
 546         * BIOS SMI calls require buffer addresses be in 32-bit address space.
 547         * This is done by setting the DMA mask below.
 548         */
 549        dcdbas_pdev->dev.coherent_dma_mask = DMA_BIT_MASK(32);
 550        dcdbas_pdev->dev.dma_mask = &dcdbas_pdev->dev.coherent_dma_mask;
 551
 552        error = sysfs_create_group(&dev->dev.kobj, &dcdbas_attr_group);
 553        if (error)
 554                return error;
 555
 556        for (i = 0; dcdbas_bin_attrs[i]; i++) {
 557                error = sysfs_create_bin_file(&dev->dev.kobj,
 558                                              dcdbas_bin_attrs[i]);
 559                if (error) {
 560                        while (--i >= 0)
 561                                sysfs_remove_bin_file(&dev->dev.kobj,
 562                                                      dcdbas_bin_attrs[i]);
 563                        sysfs_remove_group(&dev->dev.kobj, &dcdbas_attr_group);
 564                        return error;
 565                }
 566        }
 567
 568        register_reboot_notifier(&dcdbas_reboot_nb);
 569
 570        dev_info(&dev->dev, "%s (version %s)\n",
 571                 DRIVER_DESCRIPTION, DRIVER_VERSION);
 572
 573        return 0;
 574}
 575
 576static int __devexit dcdbas_remove(struct platform_device *dev)
 577{
 578        int i;
 579
 580        unregister_reboot_notifier(&dcdbas_reboot_nb);
 581        for (i = 0; dcdbas_bin_attrs[i]; i++)
 582                sysfs_remove_bin_file(&dev->dev.kobj, dcdbas_bin_attrs[i]);
 583        sysfs_remove_group(&dev->dev.kobj, &dcdbas_attr_group);
 584
 585        return 0;
 586}
 587
 588static struct platform_driver dcdbas_driver = {
 589        .driver         = {
 590                .name   = DRIVER_NAME,
 591                .owner  = THIS_MODULE,
 592        },
 593        .probe          = dcdbas_probe,
 594        .remove         = __devexit_p(dcdbas_remove),
 595};
 596
 597/**
 598 * dcdbas_init: initialize driver
 599 */
 600static int __init dcdbas_init(void)
 601{
 602        int error;
 603
 604        error = platform_driver_register(&dcdbas_driver);
 605        if (error)
 606                return error;
 607
 608        dcdbas_pdev = platform_device_alloc(DRIVER_NAME, -1);
 609        if (!dcdbas_pdev) {
 610                error = -ENOMEM;
 611                goto err_unregister_driver;
 612        }
 613
 614        error = platform_device_add(dcdbas_pdev);
 615        if (error)
 616                goto err_free_device;
 617
 618        return 0;
 619
 620 err_free_device:
 621        platform_device_put(dcdbas_pdev);
 622 err_unregister_driver:
 623        platform_driver_unregister(&dcdbas_driver);
 624        return error;
 625}
 626
 627/**
 628 * dcdbas_exit: perform driver cleanup
 629 */
 630static void __exit dcdbas_exit(void)
 631{
 632        /*
 633         * make sure functions that use dcdbas_pdev are called
 634         * before platform_device_unregister
 635         */
 636        unregister_reboot_notifier(&dcdbas_reboot_nb);
 637
 638        /*
 639         * We have to free the buffer here instead of dcdbas_remove
 640         * because only in module exit function we can be sure that
 641         * all sysfs attributes belonging to this module have been
 642         * released.
 643         */
 644        smi_data_buf_free();
 645        platform_device_unregister(dcdbas_pdev);
 646        platform_driver_unregister(&dcdbas_driver);
 647}
 648
 649module_init(dcdbas_init);
 650module_exit(dcdbas_exit);
 651
 652MODULE_DESCRIPTION(DRIVER_DESCRIPTION " (version " DRIVER_VERSION ")");
 653MODULE_VERSION(DRIVER_VERSION);
 654MODULE_AUTHOR("Dell Inc.");
 655MODULE_LICENSE("GPL");
 656/* Any System or BIOS claiming to be by Dell */
 657MODULE_ALIAS("dmi:*:[bs]vnD[Ee][Ll][Ll]*:*");
 658