drivers/firmware/dcdbas.c

   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) 1995-2005 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/init.h>
  27 #include <linux/kernel.h>
  28 #include <linux/mc146818rtc.h>
  29 #include <linux/module.h>
  30 #include <linux/reboot.h>
  31 #include <linux/sched.h>
  32 #include <linux/smp.h>
  33 #include <linux/spinlock.h>
  34 #include <linux/string.h>
  35 #include <linux/types.h>
  36 #include <asm/io.h>
  37 #include <asm/semaphore.h>
  38
  39 #include "dcdbas.h"
  40
  41 #define DRIVER_NAME             "dcdbas"
  42 #define DRIVER_VERSION          "5.6.0-2"
  43 #define DRIVER_DESCRIPTION      "Dell Systems Management Base Driver"
  44
  45 static struct platform_device *dcdbas_pdev;
  46
  47 static u8 *smi_data_buf;
  48 static dma_addr_t smi_data_buf_handle;
  49 static unsigned long smi_data_buf_size;
  50 static u32 smi_data_buf_phys_addr;
  51 static DECLARE_MUTEX(smi_data_lock);
  52
  53 static unsigned int host_control_action;
  54 static unsigned int host_control_smi_type;
  55 static unsigned int host_control_on_shutdown;
  56
  57 /**
  58  * smi_data_buf_free: free SMI data buffer
  59  */
  60 static void smi_data_buf_free(void)
  61 {
  62         if (!smi_data_buf)
  63                 return;
  64
  65         dev_dbg(&dcdbas_pdev->dev, "%s: phys: %x size: %lu\n",
  66                 __FUNCTION__, smi_data_buf_phys_addr, smi_data_buf_size);
  67
  68         dma_free_coherent(&dcdbas_pdev->dev, smi_data_buf_size, smi_data_buf,
  69                           smi_data_buf_handle);
  70         smi_data_buf = NULL;
  71         smi_data_buf_handle = 0;
  72         smi_data_buf_phys_addr = 0;
  73         smi_data_buf_size = 0;
  74 }
  75
  76 /**
  77  * smi_data_buf_realloc: grow SMI data buffer if needed
  78  */
  79 static int smi_data_buf_realloc(unsigned long size)
  80 {
  81         void *buf;
  82         dma_addr_t handle;
  83
  84         if (smi_data_buf_size >= size)
  85                 return 0;
  86
  87         if (size > MAX_SMI_DATA_BUF_SIZE)
  88                 return -EINVAL;
  89
  90         /* new buffer is needed */
  91         buf = dma_alloc_coherent(&dcdbas_pdev->dev, size, &handle, GFP_KERNEL);
  92         if (!buf) {
  93                 dev_dbg(&dcdbas_pdev->dev,
  94                         "%s: failed to allocate memory size %lu\n",
  95                         __FUNCTION__, size);
  96                 return -ENOMEM;
  97         }
  98         /* memory zeroed by dma_alloc_coherent */
  99
 100         if (smi_data_buf)
 101                 memcpy(buf, smi_data_buf, smi_data_buf_size);
 102
 103         /* free any existing buffer */
 104         smi_data_buf_free();
 105
 106         /* set up new buffer for use */
 107         smi_data_buf = buf;
 108         smi_data_buf_handle = handle;
 109         smi_data_buf_phys_addr = (u32) virt_to_phys(buf);
 110         smi_data_buf_size = size;
 111
 112         dev_dbg(&dcdbas_pdev->dev, "%s: phys: %x size: %lu\n",
 113                 __FUNCTION__, smi_data_buf_phys_addr, smi_data_buf_size);
 114
 115         return 0;
 116 }
 117
 118 static ssize_t smi_data_buf_phys_addr_show(struct device *dev,
 119                                            struct device_attribute *attr,
 120                                            char *buf)
 121 {
 122         return sprintf(buf, "%x\n", smi_data_buf_phys_addr);
 123 }
 124
 125 static ssize_t smi_data_buf_size_show(struct device *dev,
 126                                       struct device_attribute *attr,
 127                                       char *buf)
 128 {
 129         return sprintf(buf, "%lu\n", smi_data_buf_size);
 130 }
 131
 132 static ssize_t smi_data_buf_size_store(struct device *dev,
 133                                        struct device_attribute *attr,
 134                                        const char *buf, size_t count)
 135 {
 136         unsigned long buf_size;
 137         ssize_t ret;
 138
 139         buf_size = simple_strtoul(buf, NULL, 10);
 140
 141         /* make sure SMI data buffer is at least buf_size */
 142         down(&smi_data_lock);
 143         ret = smi_data_buf_realloc(buf_size);
 144         up(&smi_data_lock);
 145         if (ret)
 146                 return ret;
 147
 148         return count;
 149 }
 150
 151 static ssize_t smi_data_read(struct kobject *kobj, char *buf, loff_t pos,
 152                              size_t count)
 153 {
 154         size_t max_read;
 155         ssize_t ret;
 156
 157         down(&smi_data_lock);
 158
 159         if (pos >= smi_data_buf_size) {
 160                 ret = 0;
 161                 goto out;
 162         }
 163
 164         max_read = smi_data_buf_size - pos;
 165         ret = min(max_read, count);
 166         memcpy(buf, smi_data_buf + pos, ret);
 167 out:
 168         up(&smi_data_lock);
 169         return ret;
 170 }
 171
 172 static ssize_t smi_data_write(struct kobject *kobj, char *buf, loff_t pos,
 173                               size_t count)
 174 {
 175         ssize_t ret;
 176
 177         down(&smi_data_lock);
 178
 179         ret = smi_data_buf_realloc(pos + count);
 180         if (ret)
 181                 goto out;
 182
 183         memcpy(smi_data_buf + pos, buf, count);
 184         ret = count;
 185 out:
 186         up(&smi_data_lock);
 187         return ret;
 188 }
 189
 190 static ssize_t host_control_action_show(struct device *dev,
 191                                         struct device_attribute *attr,
 192                                         char *buf)
 193 {
 194         return sprintf(buf, "%u\n", host_control_action);
 195 }
 196
 197 static ssize_t host_control_action_store(struct device *dev,
 198                                          struct device_attribute *attr,
 199                                          const char *buf, size_t count)
 200 {
 201         ssize_t ret;
 202
 203         /* make sure buffer is available for host control command */
 204         down(&smi_data_lock);
 205         ret = smi_data_buf_realloc(sizeof(struct apm_cmd));
 206         up(&smi_data_lock);
 207         if (ret)
 208                 return ret;
 209
 210         host_control_action = simple_strtoul(buf, NULL, 10);
 211         return count;
 212 }
 213
 214 static ssize_t host_control_smi_type_show(struct device *dev,
 215                                           struct device_attribute *attr,
 216                                           char *buf)
 217 {
 218         return sprintf(buf, "%u\n", host_control_smi_type);
 219 }
 220
 221 static ssize_t host_control_smi_type_store(struct device *dev,
 222                                            struct device_attribute *attr,
 223                                            const char *buf, size_t count)
 224 {
 225         host_control_smi_type = simple_strtoul(buf, NULL, 10);
 226         return count;
 227 }
 228
 229 static ssize_t host_control_on_shutdown_show(struct device *dev,
 230                                              struct device_attribute *attr,
 231                                              char *buf)
 232 {
 233         return sprintf(buf, "%u\n", host_control_on_shutdown);
 234 }
 235
 236 static ssize_t host_control_on_shutdown_store(struct device *dev,
 237                                               struct device_attribute *attr,
 238                                               const char *buf, size_t count)
 239 {
 240         host_control_on_shutdown = simple_strtoul(buf, NULL, 10);
 241         return count;
 242 }
 243
 244 /**
 245  * smi_request: generate SMI request
 246  *
 247  * Called with smi_data_lock.
 248  */
 249 static int smi_request(struct smi_cmd *smi_cmd)
 250 {
 251         cpumask_t old_mask;
 252         int ret = 0;
 253
 254         if (smi_cmd->magic != SMI_CMD_MAGIC) {
 255                 dev_info(&dcdbas_pdev->dev, "%s: invalid magic value\n",
 256                          __FUNCTION__);
 257                 return -EBADR;
 258         }
 259
 260         /* SMI requires CPU 0 */
 261         old_mask = current->cpus_allowed;
 262         set_cpus_allowed(current, cpumask_of_cpu(0));
 263         if (smp_processor_id() != 0) {
 264                 dev_dbg(&dcdbas_pdev->dev, "%s: failed to get CPU 0\n",
 265                         __FUNCTION__);
 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
 281 out:
 282         set_cpus_allowed(current, old_mask);
 283         return ret;
 284 }
 285
 286 /**
 287  * smi_request_store:
 288  *
 289  * The valid values are:
 290  * 0: zero SMI data buffer
 291  * 1: generate calling interface SMI
 292  * 2: generate raw SMI
 293  *
 294  * User application writes smi_cmd to smi_data before telling driver
 295  * to generate SMI.
 296  */
 297 static ssize_t smi_request_store(struct device *dev,
 298                                  struct device_attribute *attr,
 299                                  const char *buf, size_t count)
 300 {
 301         struct smi_cmd *smi_cmd;
 302         unsigned long val = simple_strtoul(buf, NULL, 10);
 303         ssize_t ret;
 304
 305         down(&smi_data_lock);
 306
 307         if (smi_data_buf_size < sizeof(struct smi_cmd)) {
 308                 ret = -ENODEV;
 309                 goto out;
 310         }
 311         smi_cmd = (struct smi_cmd *)smi_data_buf;
 312
 313         switch (val) {
 314         case 2:
 315                 /* Raw SMI */
 316                 ret = smi_request(smi_cmd);
 317                 if (!ret)
 318                         ret = count;
 319                 break;
 320         case 1:
 321                 /* Calling Interface SMI */
 322                 smi_cmd->ebx = (u32) virt_to_phys(smi_cmd->command_buffer);
 323                 ret = smi_request(smi_cmd);
 324                 if (!ret)
 325                         ret = count;
 326                 break;
 327         case 0:
 328                 memset(smi_data_buf, 0, smi_data_buf_size);
 329                 ret = count;
 330                 break;
 331         default:
 332                 ret = -EINVAL;
 333                 break;
 334         }
 335
 336 out:
 337         up(&smi_data_lock);
 338         return ret;
 339 }
 340
 341 /**
 342  * host_control_smi: generate host control SMI
 343  *
 344  * Caller must set up the host control command in smi_data_buf.
 345  */
 346 static int host_control_smi(void)
 347 {
 348         struct apm_cmd *apm_cmd;
 349         u8 *data;
 350         unsigned long flags;
 351         u32 num_ticks;
 352         s8 cmd_status;
 353         u8 index;
 354
 355         apm_cmd = (struct apm_cmd *)smi_data_buf;
 356         apm_cmd->status = ESM_STATUS_CMD_UNSUCCESSFUL;
 357
 358         switch (host_control_smi_type) {
 359         case HC_SMITYPE_TYPE1:
 360                 spin_lock_irqsave(&rtc_lock, flags);
 361                 /* write SMI data buffer physical address */
 362                 data = (u8 *)&smi_data_buf_phys_addr;
 363                 for (index = PE1300_CMOS_CMD_STRUCT_PTR;
 364                      index < (PE1300_CMOS_CMD_STRUCT_PTR + 4);
 365                      index++, data++) {
 366                         outb(index,
 367                              (CMOS_BASE_PORT + CMOS_PAGE2_INDEX_PORT_PIIX4));
 368                         outb(*data,
 369                              (CMOS_BASE_PORT + CMOS_PAGE2_DATA_PORT_PIIX4));
 370                 }
 371
 372                 /* first set status to -1 as called by spec */
 373                 cmd_status = ESM_STATUS_CMD_UNSUCCESSFUL;
 374                 outb((u8) cmd_status, PCAT_APM_STATUS_PORT);
 375
 376                 /* generate SMM call */
 377                 outb(ESM_APM_CMD, PCAT_APM_CONTROL_PORT);
 378                 spin_unlock_irqrestore(&rtc_lock, flags);
 379
 380                 /* wait a few to see if it executed */
 381                 num_ticks = TIMEOUT_USEC_SHORT_SEMA_BLOCKING;
 382                 while ((cmd_status = inb(PCAT_APM_STATUS_PORT))
 383                        == ESM_STATUS_CMD_UNSUCCESSFUL) {
 384                         num_ticks--;
 385                         if (num_ticks == EXPIRED_TIMER)
 386                                 return -ETIME;
 387                 }
 388                 break;
 389
 390         case HC_SMITYPE_TYPE2:
 391         case HC_SMITYPE_TYPE3:
 392                 spin_lock_irqsave(&rtc_lock, flags);
 393                 /* write SMI data buffer physical address */
 394                 data = (u8 *)&smi_data_buf_phys_addr;
 395                 for (index = PE1400_CMOS_CMD_STRUCT_PTR;
 396                      index < (PE1400_CMOS_CMD_STRUCT_PTR + 4);
 397                      index++, data++) {
 398                         outb(index, (CMOS_BASE_PORT + CMOS_PAGE1_INDEX_PORT));
 399                         outb(*data, (CMOS_BASE_PORT + CMOS_PAGE1_DATA_PORT));
 400                 }
 401
 402                 /* generate SMM call */
 403                 if (host_control_smi_type == HC_SMITYPE_TYPE3)
 404                         outb(ESM_APM_CMD, PCAT_APM_CONTROL_PORT);
 405                 else
 406                         outb(ESM_APM_CMD, PE1400_APM_CONTROL_PORT);
 407
 408                 /* restore RTC index pointer since it was written to above */
 409                 CMOS_READ(RTC_REG_C);
 410                 spin_unlock_irqrestore(&rtc_lock, flags);
 411
 412                 /* read control port back to serialize write */
 413                 cmd_status = inb(PE1400_APM_CONTROL_PORT);
 414
 415                 /* wait a few to see if it executed */
 416                 num_ticks = TIMEOUT_USEC_SHORT_SEMA_BLOCKING;
 417                 while (apm_cmd->status == ESM_STATUS_CMD_UNSUCCESSFUL) {
 418                         num_ticks--;
 419                         if (num_ticks == EXPIRED_TIMER)
 420                                 return -ETIME;
 421                 }
 422                 break;
 423
 424         default:
 425                 dev_dbg(&dcdbas_pdev->dev, "%s: invalid SMI type %u\n",
 426                         __FUNCTION__, host_control_smi_type);
 427                 return -ENOSYS;
 428         }
 429
 430         return 0;
 431 }
 432
 433 /**
 434  * dcdbas_host_control: initiate host control
 435  *
 436  * This function is called by the driver after the system has
 437  * finished shutting down if the user application specified a
 438  * host control action to perform on shutdown.  It is safe to
 439  * use smi_data_buf at this point because the system has finished
 440  * shutting down and no userspace apps are running.
 441  */
 442 static void dcdbas_host_control(void)
 443 {
 444         struct apm_cmd *apm_cmd;
 445         u8 action;
 446
 447         if (host_control_action == HC_ACTION_NONE)
 448                 return;
 449
 450         action = host_control_action;
 451         host_control_action = HC_ACTION_NONE;
 452
 453         if (!smi_data_buf) {
 454                 dev_dbg(&dcdbas_pdev->dev, "%s: no SMI buffer\n", __FUNCTION__);
 455                 return;
 456         }
 457
 458         if (smi_data_buf_size < sizeof(struct apm_cmd)) {
 459                 dev_dbg(&dcdbas_pdev->dev, "%s: SMI buffer too small\n",
 460                         __FUNCTION__);
 461                 return;
 462         }
 463
 464         apm_cmd = (struct apm_cmd *)smi_data_buf;
 465
 466         /* power off takes precedence */
 467         if (action & HC_ACTION_HOST_CONTROL_POWEROFF) {
 468                 apm_cmd->command = ESM_APM_POWER_CYCLE;
 469                 apm_cmd->reserved = 0;
 470                 *((s16 *)&apm_cmd->parameters.shortreq.parm[0]) = (s16) 0;
 471                 host_control_smi();
 472         } else if (action & HC_ACTION_HOST_CONTROL_POWERCYCLE) {
 473                 apm_cmd->command = ESM_APM_POWER_CYCLE;
 474                 apm_cmd->reserved = 0;
 475                 *((s16 *)&apm_cmd->parameters.shortreq.parm[0]) = (s16) 20;
 476                 host_control_smi();
 477         }
 478 }
 479
 480 /**
 481  * dcdbas_reboot_notify: handle reboot notification for host control
 482  */
 483 static int dcdbas_reboot_notify(struct notifier_block *nb, unsigned long code,
 484                                 void *unused)
 485 {
 486         static unsigned int notify_cnt = 0;
 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                         if (++notify_cnt == 2) {
 495                                 printk(KERN_WARNING
 496                                        "Please wait for shutdown "
 497                                        "action to complete...\n");
 498                                 dcdbas_host_control();
 499                         }
 500                         /*
 501                          * register again and initiate the host control
 502                          * action on the second notification to allow
 503                          * everyone that registered to be notified
 504                          */
 505                         register_reboot_notifier(nb);
 506                 }
 507                 break;
 508         }
 509
 510         return NOTIFY_DONE;
 511 }
 512
 513 static struct notifier_block dcdbas_reboot_nb = {
 514         .notifier_call = dcdbas_reboot_notify,
 515         .next = NULL,
 516         .priority = 0
 517 };
 518
 519 static DCDBAS_BIN_ATTR_RW(smi_data);
 520
 521 static struct bin_attribute *dcdbas_bin_attrs[] = {
 522         &bin_attr_smi_data,
 523         NULL
 524 };
 525
 526 static DCDBAS_DEV_ATTR_RW(smi_data_buf_size);
 527 static DCDBAS_DEV_ATTR_RO(smi_data_buf_phys_addr);
 528 static DCDBAS_DEV_ATTR_WO(smi_request);
 529 static DCDBAS_DEV_ATTR_RW(host_control_action);
 530 static DCDBAS_DEV_ATTR_RW(host_control_smi_type);
 531 static DCDBAS_DEV_ATTR_RW(host_control_on_shutdown);
 532
 533 static struct device_attribute *dcdbas_dev_attrs[] = {
 534         &dev_attr_smi_data_buf_size,
 535         &dev_attr_smi_data_buf_phys_addr,
 536         &dev_attr_smi_request,
 537         &dev_attr_host_control_action,
 538         &dev_attr_host_control_smi_type,
 539         &dev_attr_host_control_on_shutdown,
 540         NULL
 541 };
 542
 543 /**
 544  * dcdbas_init: initialize driver
 545  */
 546 static int __init dcdbas_init(void)
 547 {
 548         int i;
 549
 550         host_control_action = HC_ACTION_NONE;
 551         host_control_smi_type = HC_SMITYPE_NONE;
 552
 553         dcdbas_pdev = platform_device_register_simple(DRIVER_NAME, -1, NULL, 0);
 554         if (IS_ERR(dcdbas_pdev))
 555                 return PTR_ERR(dcdbas_pdev);
 556
 557         /*
 558          * BIOS SMI calls require buffer addresses be in 32-bit address space.
 559          * This is done by setting the DMA mask below.
 560          */
 561         dcdbas_pdev->dev.coherent_dma_mask = DMA_32BIT_MASK;
 562         dcdbas_pdev->dev.dma_mask = &dcdbas_pdev->dev.coherent_dma_mask;
 563
 564         register_reboot_notifier(&dcdbas_reboot_nb);
 565
 566         for (i = 0; dcdbas_bin_attrs[i]; i++)
 567                 sysfs_create_bin_file(&dcdbas_pdev->dev.kobj,
 568                                       dcdbas_bin_attrs[i]);
 569
 570         for (i = 0; dcdbas_dev_attrs[i]; i++)
 571                 device_create_file(&dcdbas_pdev->dev, dcdbas_dev_attrs[i]);
 572
 573         dev_info(&dcdbas_pdev->dev, "%s (version %s)\n",
 574                  DRIVER_DESCRIPTION, DRIVER_VERSION);
 575
 576         return 0;
 577 }
 578
 579 /**
 580  * dcdbas_exit: perform driver cleanup
 581  */
 582 static void __exit dcdbas_exit(void)
 583 {
 584         /*
 585          * make sure functions that use dcdbas_pdev are called
 586          * before platform_device_unregister
 587          */
 588         unregister_reboot_notifier(&dcdbas_reboot_nb);
 589         smi_data_buf_free();
 590         platform_device_unregister(dcdbas_pdev);
 591 }
 592
 593 module_init(dcdbas_init);
 594 module_exit(dcdbas_exit);
 595
 596 MODULE_DESCRIPTION(DRIVER_DESCRIPTION " (version " DRIVER_VERSION ")");
 597 MODULE_VERSION(DRIVER_VERSION);
 598 MODULE_AUTHOR("Dell Inc.");
 599 MODULE_LICENSE("GPL");
 600