linux/drivers/firmware/dcdbas.c
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   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        /* inb to force posted write through and make SMI happen now */
 272        asm volatile (
 273                "outb %b0,%w1\n"
 274                "inb %w1"
 275                : /* no output args */
 276                : "a" (smi_cmd->command_code),
 277                  "d" (smi_cmd->command_address),
 278                  "b" (smi_cmd->ebx),
 279                  "c" (smi_cmd->ecx)
 280                : "memory"
 281        );
 282
 283out:
 284        set_cpus_allowed_ptr(current, old_mask);
 285        free_cpumask_var(old_mask);
 286        return ret;
 287}
 288
 289/**
 290 * smi_request_store:
 291 *
 292 * The valid values are:
 293 * 0: zero SMI data buffer
 294 * 1: generate calling interface SMI
 295 * 2: generate raw SMI
 296 *
 297 * User application writes smi_cmd to smi_data before telling driver
 298 * to generate SMI.
 299 */
 300static ssize_t smi_request_store(struct device *dev,
 301                                 struct device_attribute *attr,
 302                                 const char *buf, size_t count)
 303{
 304        struct smi_cmd *smi_cmd;
 305        unsigned long val = simple_strtoul(buf, NULL, 10);
 306        ssize_t ret;
 307
 308        mutex_lock(&smi_data_lock);
 309
 310        if (smi_data_buf_size < sizeof(struct smi_cmd)) {
 311                ret = -ENODEV;
 312                goto out;
 313        }
 314        smi_cmd = (struct smi_cmd *)smi_data_buf;
 315
 316        switch (val) {
 317        case 2:
 318                /* Raw SMI */
 319                ret = dcdbas_smi_request(smi_cmd);
 320                if (!ret)
 321                        ret = count;
 322                break;
 323        case 1:
 324                /* Calling Interface SMI */
 325                smi_cmd->ebx = (u32) virt_to_phys(smi_cmd->command_buffer);
 326                ret = dcdbas_smi_request(smi_cmd);
 327                if (!ret)
 328                        ret = count;
 329                break;
 330        case 0:
 331                memset(smi_data_buf, 0, smi_data_buf_size);
 332                ret = count;
 333                break;
 334        default:
 335                ret = -EINVAL;
 336                break;
 337        }
 338
 339out:
 340        mutex_unlock(&smi_data_lock);
 341        return ret;
 342}
 343EXPORT_SYMBOL(dcdbas_smi_request);
 344
 345/**
 346 * host_control_smi: generate host control SMI
 347 *
 348 * Caller must set up the host control command in smi_data_buf.
 349 */
 350static int host_control_smi(void)
 351{
 352        struct apm_cmd *apm_cmd;
 353        u8 *data;
 354        unsigned long flags;
 355        u32 num_ticks;
 356        s8 cmd_status;
 357        u8 index;
 358
 359        apm_cmd = (struct apm_cmd *)smi_data_buf;
 360        apm_cmd->status = ESM_STATUS_CMD_UNSUCCESSFUL;
 361
 362        switch (host_control_smi_type) {
 363        case HC_SMITYPE_TYPE1:
 364                spin_lock_irqsave(&rtc_lock, flags);
 365                /* write SMI data buffer physical address */
 366                data = (u8 *)&smi_data_buf_phys_addr;
 367                for (index = PE1300_CMOS_CMD_STRUCT_PTR;
 368                     index < (PE1300_CMOS_CMD_STRUCT_PTR + 4);
 369                     index++, data++) {
 370                        outb(index,
 371                             (CMOS_BASE_PORT + CMOS_PAGE2_INDEX_PORT_PIIX4));
 372                        outb(*data,
 373                             (CMOS_BASE_PORT + CMOS_PAGE2_DATA_PORT_PIIX4));
 374                }
 375
 376                /* first set status to -1 as called by spec */
 377                cmd_status = ESM_STATUS_CMD_UNSUCCESSFUL;
 378                outb((u8) cmd_status, PCAT_APM_STATUS_PORT);
 379
 380                /* generate SMM call */
 381                outb(ESM_APM_CMD, PCAT_APM_CONTROL_PORT);
 382                spin_unlock_irqrestore(&rtc_lock, flags);
 383
 384                /* wait a few to see if it executed */
 385                num_ticks = TIMEOUT_USEC_SHORT_SEMA_BLOCKING;
 386                while ((cmd_status = inb(PCAT_APM_STATUS_PORT))
 387                       == ESM_STATUS_CMD_UNSUCCESSFUL) {
 388                        num_ticks--;
 389                        if (num_ticks == EXPIRED_TIMER)
 390                                return -ETIME;
 391                }
 392                break;
 393
 394        case HC_SMITYPE_TYPE2:
 395        case HC_SMITYPE_TYPE3:
 396                spin_lock_irqsave(&rtc_lock, flags);
 397                /* write SMI data buffer physical address */
 398                data = (u8 *)&smi_data_buf_phys_addr;
 399                for (index = PE1400_CMOS_CMD_STRUCT_PTR;
 400                     index < (PE1400_CMOS_CMD_STRUCT_PTR + 4);
 401                     index++, data++) {
 402                        outb(index, (CMOS_BASE_PORT + CMOS_PAGE1_INDEX_PORT));
 403                        outb(*data, (CMOS_BASE_PORT + CMOS_PAGE1_DATA_PORT));
 404                }
 405
 406                /* generate SMM call */
 407                if (host_control_smi_type == HC_SMITYPE_TYPE3)
 408                        outb(ESM_APM_CMD, PCAT_APM_CONTROL_PORT);
 409                else
 410                        outb(ESM_APM_CMD, PE1400_APM_CONTROL_PORT);
 411
 412                /* restore RTC index pointer since it was written to above */
 413                CMOS_READ(RTC_REG_C);
 414                spin_unlock_irqrestore(&rtc_lock, flags);
 415
 416                /* read control port back to serialize write */
 417                cmd_status = inb(PE1400_APM_CONTROL_PORT);
 418
 419                /* wait a few to see if it executed */
 420                num_ticks = TIMEOUT_USEC_SHORT_SEMA_BLOCKING;
 421                while (apm_cmd->status == ESM_STATUS_CMD_UNSUCCESSFUL) {
 422                        num_ticks--;
 423                        if (num_ticks == EXPIRED_TIMER)
 424                                return -ETIME;
 425                }
 426                break;
 427
 428        default:
 429                dev_dbg(&dcdbas_pdev->dev, "%s: invalid SMI type %u\n",
 430                        __func__, host_control_smi_type);
 431                return -ENOSYS;
 432        }
 433
 434        return 0;
 435}
 436
 437/**
 438 * dcdbas_host_control: initiate host control
 439 *
 440 * This function is called by the driver after the system has
 441 * finished shutting down if the user application specified a
 442 * host control action to perform on shutdown.  It is safe to
 443 * use smi_data_buf at this point because the system has finished
 444 * shutting down and no userspace apps are running.
 445 */
 446static void dcdbas_host_control(void)
 447{
 448        struct apm_cmd *apm_cmd;
 449        u8 action;
 450
 451        if (host_control_action == HC_ACTION_NONE)
 452                return;
 453
 454        action = host_control_action;
 455        host_control_action = HC_ACTION_NONE;
 456
 457        if (!smi_data_buf) {
 458                dev_dbg(&dcdbas_pdev->dev, "%s: no SMI buffer\n", __func__);
 459                return;
 460        }
 461
 462        if (smi_data_buf_size < sizeof(struct apm_cmd)) {
 463                dev_dbg(&dcdbas_pdev->dev, "%s: SMI buffer too small\n",
 464                        __func__);
 465                return;
 466        }
 467
 468        apm_cmd = (struct apm_cmd *)smi_data_buf;
 469
 470        /* power off takes precedence */
 471        if (action & HC_ACTION_HOST_CONTROL_POWEROFF) {
 472                apm_cmd->command = ESM_APM_POWER_CYCLE;
 473                apm_cmd->reserved = 0;
 474                *((s16 *)&apm_cmd->parameters.shortreq.parm[0]) = (s16) 0;
 475                host_control_smi();
 476        } else if (action & HC_ACTION_HOST_CONTROL_POWERCYCLE) {
 477                apm_cmd->command = ESM_APM_POWER_CYCLE;
 478                apm_cmd->reserved = 0;
 479                *((s16 *)&apm_cmd->parameters.shortreq.parm[0]) = (s16) 20;
 480                host_control_smi();
 481        }
 482}
 483
 484/**
 485 * dcdbas_reboot_notify: handle reboot notification for host control
 486 */
 487static int dcdbas_reboot_notify(struct notifier_block *nb, unsigned long code,
 488                                void *unused)
 489{
 490        switch (code) {
 491        case SYS_DOWN:
 492        case SYS_HALT:
 493        case SYS_POWER_OFF:
 494                if (host_control_on_shutdown) {
 495                        /* firmware is going to perform host control action */
 496                        printk(KERN_WARNING "Please wait for shutdown "
 497                               "action to complete...\n");
 498                        dcdbas_host_control();
 499                }
 500                break;
 501        }
 502
 503        return NOTIFY_DONE;
 504}
 505
 506static struct notifier_block dcdbas_reboot_nb = {
 507        .notifier_call = dcdbas_reboot_notify,
 508        .next = NULL,
 509        .priority = INT_MIN
 510};
 511
 512static DCDBAS_BIN_ATTR_RW(smi_data);
 513
 514static struct bin_attribute *dcdbas_bin_attrs[] = {
 515        &bin_attr_smi_data,
 516        NULL
 517};
 518
 519static DCDBAS_DEV_ATTR_RW(smi_data_buf_size);
 520static DCDBAS_DEV_ATTR_RO(smi_data_buf_phys_addr);
 521static DCDBAS_DEV_ATTR_WO(smi_request);
 522static DCDBAS_DEV_ATTR_RW(host_control_action);
 523static DCDBAS_DEV_ATTR_RW(host_control_smi_type);
 524static DCDBAS_DEV_ATTR_RW(host_control_on_shutdown);
 525
 526static struct attribute *dcdbas_dev_attrs[] = {
 527        &dev_attr_smi_data_buf_size.attr,
 528        &dev_attr_smi_data_buf_phys_addr.attr,
 529        &dev_attr_smi_request.attr,
 530        &dev_attr_host_control_action.attr,
 531        &dev_attr_host_control_smi_type.attr,
 532        &dev_attr_host_control_on_shutdown.attr,
 533        NULL
 534};
 535
 536static struct attribute_group dcdbas_attr_group = {
 537        .attrs = dcdbas_dev_attrs,
 538};
 539
 540static int dcdbas_probe(struct platform_device *dev)
 541{
 542        int i, error;
 543
 544        host_control_action = HC_ACTION_NONE;
 545        host_control_smi_type = HC_SMITYPE_NONE;
 546
 547        /*
 548         * BIOS SMI calls require buffer addresses be in 32-bit address space.
 549         * This is done by setting the DMA mask below.
 550         */
 551        dcdbas_pdev->dev.coherent_dma_mask = DMA_BIT_MASK(32);
 552        dcdbas_pdev->dev.dma_mask = &dcdbas_pdev->dev.coherent_dma_mask;
 553
 554        error = sysfs_create_group(&dev->dev.kobj, &dcdbas_attr_group);
 555        if (error)
 556                return error;
 557
 558        for (i = 0; dcdbas_bin_attrs[i]; i++) {
 559                error = sysfs_create_bin_file(&dev->dev.kobj,
 560                                              dcdbas_bin_attrs[i]);
 561                if (error) {
 562                        while (--i >= 0)
 563                                sysfs_remove_bin_file(&dev->dev.kobj,
 564                                                      dcdbas_bin_attrs[i]);
 565                        sysfs_remove_group(&dev->dev.kobj, &dcdbas_attr_group);
 566                        return error;
 567                }
 568        }
 569
 570        register_reboot_notifier(&dcdbas_reboot_nb);
 571
 572        dev_info(&dev->dev, "%s (version %s)\n",
 573                 DRIVER_DESCRIPTION, DRIVER_VERSION);
 574
 575        return 0;
 576}
 577
 578static int dcdbas_remove(struct platform_device *dev)
 579{
 580        int i;
 581
 582        unregister_reboot_notifier(&dcdbas_reboot_nb);
 583        for (i = 0; dcdbas_bin_attrs[i]; i++)
 584                sysfs_remove_bin_file(&dev->dev.kobj, dcdbas_bin_attrs[i]);
 585        sysfs_remove_group(&dev->dev.kobj, &dcdbas_attr_group);
 586
 587        return 0;
 588}
 589
 590static struct platform_driver dcdbas_driver = {
 591        .driver         = {
 592                .name   = DRIVER_NAME,
 593                .owner  = THIS_MODULE,
 594        },
 595        .probe          = dcdbas_probe,
 596        .remove         = dcdbas_remove,
 597};
 598
 599/**
 600 * dcdbas_init: initialize driver
 601 */
 602static int __init dcdbas_init(void)
 603{
 604        int error;
 605
 606        error = platform_driver_register(&dcdbas_driver);
 607        if (error)
 608                return error;
 609
 610        dcdbas_pdev = platform_device_alloc(DRIVER_NAME, -1);
 611        if (!dcdbas_pdev) {
 612                error = -ENOMEM;
 613                goto err_unregister_driver;
 614        }
 615
 616        error = platform_device_add(dcdbas_pdev);
 617        if (error)
 618                goto err_free_device;
 619
 620        return 0;
 621
 622 err_free_device:
 623        platform_device_put(dcdbas_pdev);
 624 err_unregister_driver:
 625        platform_driver_unregister(&dcdbas_driver);
 626        return error;
 627}
 628
 629/**
 630 * dcdbas_exit: perform driver cleanup
 631 */
 632static void __exit dcdbas_exit(void)
 633{
 634        /*
 635         * make sure functions that use dcdbas_pdev are called
 636         * before platform_device_unregister
 637         */
 638        unregister_reboot_notifier(&dcdbas_reboot_nb);
 639
 640        /*
 641         * We have to free the buffer here instead of dcdbas_remove
 642         * because only in module exit function we can be sure that
 643         * all sysfs attributes belonging to this module have been
 644         * released.
 645         */
 646        smi_data_buf_free();
 647        platform_device_unregister(dcdbas_pdev);
 648        platform_driver_unregister(&dcdbas_driver);
 649}
 650
 651module_init(dcdbas_init);
 652module_exit(dcdbas_exit);
 653
 654MODULE_DESCRIPTION(DRIVER_DESCRIPTION " (version " DRIVER_VERSION ")");
 655MODULE_VERSION(DRIVER_VERSION);
 656MODULE_AUTHOR("Dell Inc.");
 657MODULE_LICENSE("GPL");
 658/* Any System or BIOS claiming to be by Dell */
 659MODULE_ALIAS("dmi:*:[bs]vnD[Ee][Ll][Ll]*:*");
 660
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