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) 1995-2006 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/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 <linux/mutex.h>
  37 #include <asm/io.h>
  38 #include <asm/semaphore.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
  46 static struct platform_device *dcdbas_pdev;
  47
  48 static u8 *smi_data_buf;
  49 static dma_addr_t smi_data_buf_handle;
  50 static unsigned long smi_data_buf_size;
  51 static u32 smi_data_buf_phys_addr;
  52 static DEFINE_MUTEX(smi_data_lock);
  53
  54 static unsigned int host_control_action;
  55 static unsigned int host_control_smi_type;
  56 static unsigned int host_control_on_shutdown;
  57
  58 /**
  59  * smi_data_buf_free: free SMI data buffer
  60  */
  61 static 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                 __FUNCTION__, 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  */
  80 static 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                         __FUNCTION__, 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                 __FUNCTION__, smi_data_buf_phys_addr, smi_data_buf_size);
 115
 116         return 0;
 117 }
 118
 119 static 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
 126 static 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
 133 static 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
 152 static ssize_t smi_data_read(struct kobject *kobj,
 153                              struct bin_attribute *bin_attr,
 154                              char *buf, loff_t pos, size_t count)
 155 {
 156         size_t max_read;
 157         ssize_t ret;
 158
 159         mutex_lock(&smi_data_lock);
 160
 161         if (pos >= smi_data_buf_size) {
 162                 ret = 0;
 163                 goto out;
 164         }
 165
 166         max_read = smi_data_buf_size - pos;
 167         ret = min(max_read, count);
 168         memcpy(buf, smi_data_buf + pos, ret);
 169 out:
 170         mutex_unlock(&smi_data_lock);
 171         return ret;
 172 }
 173
 174 static ssize_t smi_data_write(struct kobject *kobj,
 175                               struct bin_attribute *bin_attr,
 176                               char *buf, loff_t pos, size_t count)
 177 {
 178         ssize_t ret;
 179
 180         if ((pos + count) > MAX_SMI_DATA_BUF_SIZE)
 181                 return -EINVAL;
 182
 183         mutex_lock(&smi_data_lock);
 184
 185         ret = smi_data_buf_realloc(pos + count);
 186         if (ret)
 187                 goto out;
 188
 189         memcpy(smi_data_buf + pos, buf, count);
 190         ret = count;
 191 out:
 192         mutex_unlock(&smi_data_lock);
 193         return ret;
 194 }
 195
 196 static ssize_t host_control_action_show(struct device *dev,
 197                                         struct device_attribute *attr,
 198                                         char *buf)
 199 {
 200         return sprintf(buf, "%u\n", host_control_action);
 201 }
 202
 203 static ssize_t host_control_action_store(struct device *dev,
 204                                          struct device_attribute *attr,
 205                                          const char *buf, size_t count)
 206 {
 207         ssize_t ret;
 208
 209         /* make sure buffer is available for host control command */
 210         mutex_lock(&smi_data_lock);
 211         ret = smi_data_buf_realloc(sizeof(struct apm_cmd));
 212         mutex_unlock(&smi_data_lock);
 213         if (ret)
 214                 return ret;
 215
 216         host_control_action = simple_strtoul(buf, NULL, 10);
 217         return count;
 218 }
 219
 220 static ssize_t host_control_smi_type_show(struct device *dev,
 221                                           struct device_attribute *attr,
 222                                           char *buf)
 223 {
 224         return sprintf(buf, "%u\n", host_control_smi_type);
 225 }
 226
 227 static ssize_t host_control_smi_type_store(struct device *dev,
 228                                            struct device_attribute *attr,
 229                                            const char *buf, size_t count)
 230 {
 231         host_control_smi_type = simple_strtoul(buf, NULL, 10);
 232         return count;
 233 }
 234
 235 static ssize_t host_control_on_shutdown_show(struct device *dev,
 236                                              struct device_attribute *attr,
 237                                              char *buf)
 238 {
 239         return sprintf(buf, "%u\n", host_control_on_shutdown);
 240 }
 241
 242 static ssize_t host_control_on_shutdown_store(struct device *dev,
 243                                               struct device_attribute *attr,
 244                                               const char *buf, size_t count)
 245 {
 246         host_control_on_shutdown = simple_strtoul(buf, NULL, 10);
 247         return count;
 248 }
 249
 250 /**
 251  * smi_request: generate SMI request
 252  *
 253  * Called with smi_data_lock.
 254  */
 255 static int smi_request(struct smi_cmd *smi_cmd)
 256 {
 257         cpumask_t old_mask;
 258         int ret = 0;
 259
 260         if (smi_cmd->magic != SMI_CMD_MAGIC) {
 261                 dev_info(&dcdbas_pdev->dev, "%s: invalid magic value\n",
 262                          __FUNCTION__);
 263                 return -EBADR;
 264         }
 265
 266         /* SMI requires CPU 0 */
 267         old_mask = current->cpus_allowed;
 268         set_cpus_allowed(current, cpumask_of_cpu(0));
 269         if (smp_processor_id() != 0) {
 270                 dev_dbg(&dcdbas_pdev->dev, "%s: failed to get CPU 0\n",
 271                         __FUNCTION__);
 272                 ret = -EBUSY;
 273                 goto out;
 274         }
 275
 276         /* generate SMI */
 277         asm volatile (
 278                 "outb %b0,%w1"
 279                 : /* no output args */
 280                 : "a" (smi_cmd->command_code),
 281                   "d" (smi_cmd->command_address),
 282                   "b" (smi_cmd->ebx),
 283                   "c" (smi_cmd->ecx)
 284                 : "memory"
 285         );
 286
 287 out:
 288         set_cpus_allowed(current, old_mask);
 289         return ret;
 290 }
 291
 292 /**
 293  * smi_request_store:
 294  *
 295  * The valid values are:
 296  * 0: zero SMI data buffer
 297  * 1: generate calling interface SMI
 298  * 2: generate raw SMI
 299  *
 300  * User application writes smi_cmd to smi_data before telling driver
 301  * to generate SMI.
 302  */
 303 static ssize_t smi_request_store(struct device *dev,
 304                                  struct device_attribute *attr,
 305                                  const char *buf, size_t count)
 306 {
 307         struct smi_cmd *smi_cmd;
 308         unsigned long val = simple_strtoul(buf, NULL, 10);
 309         ssize_t ret;
 310
 311         mutex_lock(&smi_data_lock);
 312
 313         if (smi_data_buf_size < sizeof(struct smi_cmd)) {
 314                 ret = -ENODEV;
 315                 goto out;
 316         }
 317         smi_cmd = (struct smi_cmd *)smi_data_buf;
 318
 319         switch (val) {
 320         case 2:
 321                 /* Raw SMI */
 322                 ret = smi_request(smi_cmd);
 323                 if (!ret)
 324                         ret = count;
 325                 break;
 326         case 1:
 327                 /* Calling Interface SMI */
 328                 smi_cmd->ebx = (u32) virt_to_phys(smi_cmd->command_buffer);
 329                 ret = smi_request(smi_cmd);
 330                 if (!ret)
 331                         ret = count;
 332                 break;
 333         case 0:
 334                 memset(smi_data_buf, 0, smi_data_buf_size);
 335                 ret = count;
 336                 break;
 337         default:
 338                 ret = -EINVAL;
 339                 break;
 340         }
 341
 342 out:
 343         mutex_unlock(&smi_data_lock);
 344         return ret;
 345 }
 346
 347 /**
 348  * host_control_smi: generate host control SMI
 349  *
 350  * Caller must set up the host control command in smi_data_buf.
 351  */
 352 static int host_control_smi(void)
 353 {
 354         struct apm_cmd *apm_cmd;
 355         u8 *data;
 356         unsigned long flags;
 357         u32 num_ticks;
 358         s8 cmd_status;
 359         u8 index;
 360
 361         apm_cmd = (struct apm_cmd *)smi_data_buf;
 362         apm_cmd->status = ESM_STATUS_CMD_UNSUCCESSFUL;
 363
 364         switch (host_control_smi_type) {
 365         case HC_SMITYPE_TYPE1:
 366                 spin_lock_irqsave(&rtc_lock, flags);
 367                 /* write SMI data buffer physical address */
 368                 data = (u8 *)&smi_data_buf_phys_addr;
 369                 for (index = PE1300_CMOS_CMD_STRUCT_PTR;
 370                      index < (PE1300_CMOS_CMD_STRUCT_PTR + 4);
 371                      index++, data++) {
 372                         outb(index,
 373                              (CMOS_BASE_PORT + CMOS_PAGE2_INDEX_PORT_PIIX4));
 374                         outb(*data,
 375                              (CMOS_BASE_PORT + CMOS_PAGE2_DATA_PORT_PIIX4));
 376                 }
 377
 378                 /* first set status to -1 as called by spec */
 379                 cmd_status = ESM_STATUS_CMD_UNSUCCESSFUL;
 380                 outb((u8) cmd_status, PCAT_APM_STATUS_PORT);
 381
 382                 /* generate SMM call */
 383                 outb(ESM_APM_CMD, PCAT_APM_CONTROL_PORT);
 384                 spin_unlock_irqrestore(&rtc_lock, flags);
 385
 386                 /* wait a few to see if it executed */
 387                 num_ticks = TIMEOUT_USEC_SHORT_SEMA_BLOCKING;
 388                 while ((cmd_status = inb(PCAT_APM_STATUS_PORT))
 389                        == ESM_STATUS_CMD_UNSUCCESSFUL) {
 390                         num_ticks--;
 391                         if (num_ticks == EXPIRED_TIMER)
 392                                 return -ETIME;
 393                 }
 394                 break;
 395
 396         case HC_SMITYPE_TYPE2:
 397         case HC_SMITYPE_TYPE3:
 398                 spin_lock_irqsave(&rtc_lock, flags);
 399                 /* write SMI data buffer physical address */
 400                 data = (u8 *)&smi_data_buf_phys_addr;
 401                 for (index = PE1400_CMOS_CMD_STRUCT_PTR;
 402                      index < (PE1400_CMOS_CMD_STRUCT_PTR + 4);
 403                      index++, data++) {
 404                         outb(index, (CMOS_BASE_PORT + CMOS_PAGE1_INDEX_PORT));
 405                         outb(*data, (CMOS_BASE_PORT + CMOS_PAGE1_DATA_PORT));
 406                 }
 407
 408                 /* generate SMM call */
 409                 if (host_control_smi_type == HC_SMITYPE_TYPE3)
 410                         outb(ESM_APM_CMD, PCAT_APM_CONTROL_PORT);
 411                 else
 412                         outb(ESM_APM_CMD, PE1400_APM_CONTROL_PORT);
 413
 414                 /* restore RTC index pointer since it was written to above */
 415                 CMOS_READ(RTC_REG_C);
 416                 spin_unlock_irqrestore(&rtc_lock, flags);
 417
 418                 /* read control port back to serialize write */
 419                 cmd_status = inb(PE1400_APM_CONTROL_PORT);
 420
 421                 /* wait a few to see if it executed */
 422                 num_ticks = TIMEOUT_USEC_SHORT_SEMA_BLOCKING;
 423                 while (apm_cmd->status == ESM_STATUS_CMD_UNSUCCESSFUL) {
 424                         num_ticks--;
 425                         if (num_ticks == EXPIRED_TIMER)
 426                                 return -ETIME;
 427                 }
 428                 break;
 429
 430         default:
 431                 dev_dbg(&dcdbas_pdev->dev, "%s: invalid SMI type %u\n",
 432                         __FUNCTION__, host_control_smi_type);
 433                 return -ENOSYS;
 434         }
 435
 436         return 0;
 437 }
 438
 439 /**
 440  * dcdbas_host_control: initiate host control
 441  *
 442  * This function is called by the driver after the system has
 443  * finished shutting down if the user application specified a
 444  * host control action to perform on shutdown.  It is safe to
 445  * use smi_data_buf at this point because the system has finished
 446  * shutting down and no userspace apps are running.
 447  */
 448 static void dcdbas_host_control(void)
 449 {
 450         struct apm_cmd *apm_cmd;
 451         u8 action;
 452
 453         if (host_control_action == HC_ACTION_NONE)
 454                 return;
 455
 456         action = host_control_action;
 457         host_control_action = HC_ACTION_NONE;
 458
 459         if (!smi_data_buf) {
 460                 dev_dbg(&dcdbas_pdev->dev, "%s: no SMI buffer\n", __FUNCTION__);
 461                 return;
 462         }
 463
 464         if (smi_data_buf_size < sizeof(struct apm_cmd)) {
 465                 dev_dbg(&dcdbas_pdev->dev, "%s: SMI buffer too small\n",
 466                         __FUNCTION__);
 467                 return;
 468         }
 469
 470         apm_cmd = (struct apm_cmd *)smi_data_buf;
 471
 472         /* power off takes precedence */
 473         if (action & HC_ACTION_HOST_CONTROL_POWEROFF) {
 474                 apm_cmd->command = ESM_APM_POWER_CYCLE;
 475                 apm_cmd->reserved = 0;
 476                 *((s16 *)&apm_cmd->parameters.shortreq.parm[0]) = (s16) 0;
 477                 host_control_smi();
 478         } else if (action & HC_ACTION_HOST_CONTROL_POWERCYCLE) {
 479                 apm_cmd->command = ESM_APM_POWER_CYCLE;
 480                 apm_cmd->reserved = 0;
 481                 *((s16 *)&apm_cmd->parameters.shortreq.parm[0]) = (s16) 20;
 482                 host_control_smi();
 483         }
 484 }
 485
 486 /**
 487  * dcdbas_reboot_notify: handle reboot notification for host control
 488  */
 489 static int dcdbas_reboot_notify(struct notifier_block *nb, unsigned long code,
 490                                 void *unused)
 491 {
 492         switch (code) {
 493         case SYS_DOWN:
 494         case SYS_HALT:
 495         case SYS_POWER_OFF:
 496                 if (host_control_on_shutdown) {
 497                         /* firmware is going to perform host control action */
 498                         printk(KERN_WARNING "Please wait for shutdown "
 499                                "action to complete...\n");
 500                         dcdbas_host_control();
 501                 }
 502                 break;
 503         }
 504
 505         return NOTIFY_DONE;
 506 }
 507
 508 static struct notifier_block dcdbas_reboot_nb = {
 509         .notifier_call = dcdbas_reboot_notify,
 510         .next = NULL,
 511         .priority = INT_MIN
 512 };
 513
 514 static DCDBAS_BIN_ATTR_RW(smi_data);
 515
 516 static struct bin_attribute *dcdbas_bin_attrs[] = {
 517         &bin_attr_smi_data,
 518         NULL
 519 };
 520
 521 static DCDBAS_DEV_ATTR_RW(smi_data_buf_size);
 522 static DCDBAS_DEV_ATTR_RO(smi_data_buf_phys_addr);
 523 static DCDBAS_DEV_ATTR_WO(smi_request);
 524 static DCDBAS_DEV_ATTR_RW(host_control_action);
 525 static DCDBAS_DEV_ATTR_RW(host_control_smi_type);
 526 static DCDBAS_DEV_ATTR_RW(host_control_on_shutdown);
 527
 528 static struct attribute *dcdbas_dev_attrs[] = {
 529         &dev_attr_smi_data_buf_size.attr,
 530         &dev_attr_smi_data_buf_phys_addr.attr,
 531         &dev_attr_smi_request.attr,
 532         &dev_attr_host_control_action.attr,
 533         &dev_attr_host_control_smi_type.attr,
 534         &dev_attr_host_control_on_shutdown.attr,
 535         NULL
 536 };
 537
 538 static struct attribute_group dcdbas_attr_group = {
 539         .attrs = dcdbas_dev_attrs,
 540 };
 541
 542 static int __devinit dcdbas_probe(struct platform_device *dev)
 543 {
 544         int i, error;
 545
 546         host_control_action = HC_ACTION_NONE;
 547         host_control_smi_type = HC_SMITYPE_NONE;
 548
 549         /*
 550          * BIOS SMI calls require buffer addresses be in 32-bit address space.
 551          * This is done by setting the DMA mask below.
 552          */
 553         dcdbas_pdev->dev.coherent_dma_mask = DMA_32BIT_MASK;
 554         dcdbas_pdev->dev.dma_mask = &dcdbas_pdev->dev.coherent_dma_mask;
 555
 556         error = sysfs_create_group(&dev->dev.kobj, &dcdbas_attr_group);
 557         if (error)
 558                 return error;
 559
 560         for (i = 0; dcdbas_bin_attrs[i]; i++) {
 561                 error = sysfs_create_bin_file(&dev->dev.kobj,
 562                                               dcdbas_bin_attrs[i]);
 563                 if (error) {
 564                         while (--i >= 0)
 565                                 sysfs_remove_bin_file(&dev->dev.kobj,
 566                                                       dcdbas_bin_attrs[i]);
 567                         sysfs_remove_group(&dev->dev.kobj, &dcdbas_attr_group);
 568                         return error;
 569                 }
 570         }
 571
 572         register_reboot_notifier(&dcdbas_reboot_nb);
 573
 574         dev_info(&dev->dev, "%s (version %s)\n",
 575                  DRIVER_DESCRIPTION, DRIVER_VERSION);
 576
 577         return 0;
 578 }
 579
 580 static int __devexit dcdbas_remove(struct platform_device *dev)
 581 {
 582         int i;
 583
 584         unregister_reboot_notifier(&dcdbas_reboot_nb);
 585         for (i = 0; dcdbas_bin_attrs[i]; i++)
 586                 sysfs_remove_bin_file(&dev->dev.kobj, dcdbas_bin_attrs[i]);
 587         sysfs_remove_group(&dev->dev.kobj, &dcdbas_attr_group);
 588
 589         return 0;
 590 }
 591
 592 static struct platform_driver dcdbas_driver = {
 593         .driver         = {
 594                 .name   = DRIVER_NAME,
 595                 .owner  = THIS_MODULE,
 596         },
 597         .probe          = dcdbas_probe,
 598         .remove         = __devexit_p(dcdbas_remove),
 599 };
 600
 601 /**
 602  * dcdbas_init: initialize driver
 603  */
 604 static int __init dcdbas_init(void)
 605 {
 606         int error;
 607
 608         error = platform_driver_register(&dcdbas_driver);
 609         if (error)
 610                 return error;
 611
 612         dcdbas_pdev = platform_device_alloc(DRIVER_NAME, -1);
 613         if (!dcdbas_pdev) {
 614                 error = -ENOMEM;
 615                 goto err_unregister_driver;
 616         }
 617
 618         error = platform_device_add(dcdbas_pdev);
 619         if (error)
 620                 goto err_free_device;
 621
 622         return 0;
 623
 624  err_free_device:
 625         platform_device_put(dcdbas_pdev);
 626  err_unregister_driver:
 627         platform_driver_unregister(&dcdbas_driver);
 628         return error;
 629 }
 630
 631 /**
 632  * dcdbas_exit: perform driver cleanup
 633  */
 634 static void __exit dcdbas_exit(void)
 635 {
 636         /*
 637          * make sure functions that use dcdbas_pdev are called
 638          * before platform_device_unregister
 639          */
 640         unregister_reboot_notifier(&dcdbas_reboot_nb);
 641         smi_data_buf_free();
 642         platform_device_unregister(dcdbas_pdev);
 643         platform_driver_unregister(&dcdbas_driver);
 644
 645         /*
 646          * We have to free the buffer here instead of dcdbas_remove
 647          * because only in module exit function we can be sure that
 648          * all sysfs attributes belonging to this module have been
 649          * released.
 650          */
 651         smi_data_buf_free();
 652 }
 653
 654 module_init(dcdbas_init);
 655 module_exit(dcdbas_exit);
 656
 657 MODULE_DESCRIPTION(DRIVER_DESCRIPTION " (version " DRIVER_VERSION ")");
 658 MODULE_VERSION(DRIVER_VERSION);
 659 MODULE_AUTHOR("Dell Inc.");
 660 MODULE_LICENSE("GPL");
 661