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
  39 #include "dcdbas.h"
  40
  41 #define DRIVER_NAME             "dcdbas"
  42 #define DRIVER_VERSION          "5.6.0-3.2"
  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 DEFINE_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                 __func__, 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                         __func__, 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                 __func__, 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         mutex_lock(&smi_data_lock);
 143         ret = smi_data_buf_realloc(buf_size);
 144         mutex_unlock(&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,
 152                              struct bin_attribute *bin_attr,
 153                              char *buf, loff_t pos, size_t count)
 154 {
 155         size_t max_read;
 156         ssize_t ret;
 157
 158         mutex_lock(&smi_data_lock);
 159
 160         if (pos >= smi_data_buf_size) {
 161                 ret = 0;
 162                 goto out;
 163         }
 164
 165         max_read = smi_data_buf_size - pos;
 166         ret = min(max_read, count);
 167         memcpy(buf, smi_data_buf + pos, ret);
 168 out:
 169         mutex_unlock(&smi_data_lock);
 170         return ret;
 171 }
 172
 173 static ssize_t smi_data_write(struct kobject *kobj,
 174                               struct bin_attribute *bin_attr,
 175                               char *buf, loff_t pos, size_t count)
 176 {
 177         ssize_t ret;
 178
 179         if ((pos + count) > MAX_SMI_DATA_BUF_SIZE)
 180                 return -EINVAL;
 181
 182         mutex_lock(&smi_data_lock);
 183
 184         ret = smi_data_buf_realloc(pos + count);
 185         if (ret)
 186                 goto out;
 187
 188         memcpy(smi_data_buf + pos, buf, count);
 189         ret = count;
 190 out:
 191         mutex_unlock(&smi_data_lock);
 192         return ret;
 193 }
 194
 195 static ssize_t host_control_action_show(struct device *dev,
 196                                         struct device_attribute *attr,
 197                                         char *buf)
 198 {
 199         return sprintf(buf, "%u\n", host_control_action);
 200 }
 201
 202 static ssize_t host_control_action_store(struct device *dev,
 203                                          struct device_attribute *attr,
 204                                          const char *buf, size_t count)
 205 {
 206         ssize_t ret;
 207
 208         /* make sure buffer is available for host control command */
 209         mutex_lock(&smi_data_lock);
 210         ret = smi_data_buf_realloc(sizeof(struct apm_cmd));
 211         mutex_unlock(&smi_data_lock);
 212         if (ret)
 213                 return ret;
 214
 215         host_control_action = simple_strtoul(buf, NULL, 10);
 216         return count;
 217 }
 218
 219 static ssize_t host_control_smi_type_show(struct device *dev,
 220                                           struct device_attribute *attr,
 221                                           char *buf)
 222 {
 223         return sprintf(buf, "%u\n", host_control_smi_type);
 224 }
 225
 226 static ssize_t host_control_smi_type_store(struct device *dev,
 227                                            struct device_attribute *attr,
 228                                            const char *buf, size_t count)
 229 {
 230         host_control_smi_type = simple_strtoul(buf, NULL, 10);
 231         return count;
 232 }
 233
 234 static ssize_t host_control_on_shutdown_show(struct device *dev,
 235                                              struct device_attribute *attr,
 236                                              char *buf)
 237 {
 238         return sprintf(buf, "%u\n", host_control_on_shutdown);
 239 }
 240
 241 static ssize_t host_control_on_shutdown_store(struct device *dev,
 242                                               struct device_attribute *attr,
 243                                               const char *buf, size_t count)
 244 {
 245         host_control_on_shutdown = simple_strtoul(buf, NULL, 10);
 246         return count;
 247 }
 248
 249 /**
 250  * smi_request: generate SMI request
 251  *
 252  * Called with smi_data_lock.
 253  */
 254 static int smi_request(struct smi_cmd *smi_cmd)
 255 {
 256         cpumask_t old_mask;
 257         int ret = 0;
 258
 259         if (smi_cmd->magic != SMI_CMD_MAGIC) {
 260                 dev_info(&dcdbas_pdev->dev, "%s: invalid magic value\n",
 261                          __func__);
 262                 return -EBADR;
 263         }
 264
 265         /* SMI requires CPU 0 */
 266         old_mask = current->cpus_allowed;
 267         set_cpus_allowed_ptr(current, &cpumask_of_cpu(0));
 268         if (smp_processor_id() != 0) {
 269                 dev_dbg(&dcdbas_pdev->dev, "%s: failed to get CPU 0\n",
 270                         __func__);
 271                 ret = -EBUSY;
 272                 goto out;
 273         }
 274
 275         /* generate SMI */
 276         asm volatile (
 277                 "outb %b0,%w1"
 278                 : /* no output args */
 279                 : "a" (smi_cmd->command_code),
 280                   "d" (smi_cmd->command_address),
 281                   "b" (smi_cmd->ebx),
 282                   "c" (smi_cmd->ecx)
 283                 : "memory"
 284         );
 285
 286 out:
 287         set_cpus_allowed_ptr(current, &old_mask);
 288         return ret;
 289 }
 290
 291 /**
 292  * smi_request_store:
 293  *
 294  * The valid values are:
 295  * 0: zero SMI data buffer
 296  * 1: generate calling interface SMI
 297  * 2: generate raw SMI
 298  *
 299  * User application writes smi_cmd to smi_data before telling driver
 300  * to generate SMI.
 301  */
 302 static ssize_t smi_request_store(struct device *dev,
 303                                  struct device_attribute *attr,
 304                                  const char *buf, size_t count)
 305 {
 306         struct smi_cmd *smi_cmd;
 307         unsigned long val = simple_strtoul(buf, NULL, 10);
 308         ssize_t ret;
 309
 310         mutex_lock(&smi_data_lock);
 311
 312         if (smi_data_buf_size < sizeof(struct smi_cmd)) {
 313                 ret = -ENODEV;
 314                 goto out;
 315         }
 316         smi_cmd = (struct smi_cmd *)smi_data_buf;
 317
 318         switch (val) {
 319         case 2:
 320                 /* Raw SMI */
 321                 ret = smi_request(smi_cmd);
 322                 if (!ret)
 323                         ret = count;
 324                 break;
 325         case 1:
 326                 /* Calling Interface SMI */
 327                 smi_cmd->ebx = (u32) virt_to_phys(smi_cmd->command_buffer);
 328                 ret = smi_request(smi_cmd);
 329                 if (!ret)
 330                         ret = count;
 331                 break;
 332         case 0:
 333                 memset(smi_data_buf, 0, smi_data_buf_size);
 334                 ret = count;
 335                 break;
 336         default:
 337                 ret = -EINVAL;
 338                 break;
 339         }
 340
 341 out:
 342         mutex_unlock(&smi_data_lock);
 343         return ret;
 344 }
 345
 346 /**
 347  * host_control_smi: generate host control SMI
 348  *
 349  * Caller must set up the host control command in smi_data_buf.
 350  */
 351 static int host_control_smi(void)
 352 {
 353         struct apm_cmd *apm_cmd;
 354         u8 *data;
 355         unsigned long flags;
 356         u32 num_ticks;
 357         s8 cmd_status;
 358         u8 index;
 359
 360         apm_cmd = (struct apm_cmd *)smi_data_buf;
 361         apm_cmd->status = ESM_STATUS_CMD_UNSUCCESSFUL;
 362
 363         switch (host_control_smi_type) {
 364         case HC_SMITYPE_TYPE1:
 365                 spin_lock_irqsave(&rtc_lock, flags);
 366                 /* write SMI data buffer physical address */
 367                 data = (u8 *)&smi_data_buf_phys_addr;
 368                 for (index = PE1300_CMOS_CMD_STRUCT_PTR;
 369                      index < (PE1300_CMOS_CMD_STRUCT_PTR + 4);
 370                      index++, data++) {
 371                         outb(index,
 372                              (CMOS_BASE_PORT + CMOS_PAGE2_INDEX_PORT_PIIX4));
 373                         outb(*data,
 374                              (CMOS_BASE_PORT + CMOS_PAGE2_DATA_PORT_PIIX4));
 375                 }
 376
 377                 /* first set status to -1 as called by spec */
 378                 cmd_status = ESM_STATUS_CMD_UNSUCCESSFUL;
 379                 outb((u8) cmd_status, PCAT_APM_STATUS_PORT);
 380
 381                 /* generate SMM call */
 382                 outb(ESM_APM_CMD, PCAT_APM_CONTROL_PORT);
 383                 spin_unlock_irqrestore(&rtc_lock, flags);
 384
 385                 /* wait a few to see if it executed */
 386                 num_ticks = TIMEOUT_USEC_SHORT_SEMA_BLOCKING;
 387                 while ((cmd_status = inb(PCAT_APM_STATUS_PORT))
 388                        == ESM_STATUS_CMD_UNSUCCESSFUL) {
 389                         num_ticks--;
 390                         if (num_ticks == EXPIRED_TIMER)
 391                                 return -ETIME;
 392                 }
 393                 break;
 394
 395         case HC_SMITYPE_TYPE2:
 396         case HC_SMITYPE_TYPE3:
 397                 spin_lock_irqsave(&rtc_lock, flags);
 398                 /* write SMI data buffer physical address */
 399                 data = (u8 *)&smi_data_buf_phys_addr;
 400                 for (index = PE1400_CMOS_CMD_STRUCT_PTR;
 401                      index < (PE1400_CMOS_CMD_STRUCT_PTR + 4);
 402                      index++, data++) {
 403                         outb(index, (CMOS_BASE_PORT + CMOS_PAGE1_INDEX_PORT));
 404                         outb(*data, (CMOS_BASE_PORT + CMOS_PAGE1_DATA_PORT));
 405                 }
 406
 407                 /* generate SMM call */
 408                 if (host_control_smi_type == HC_SMITYPE_TYPE3)
 409                         outb(ESM_APM_CMD, PCAT_APM_CONTROL_PORT);
 410                 else
 411                         outb(ESM_APM_CMD, PE1400_APM_CONTROL_PORT);
 412
 413                 /* restore RTC index pointer since it was written to above */
 414                 CMOS_READ(RTC_REG_C);
 415                 spin_unlock_irqrestore(&rtc_lock, flags);
 416
 417                 /* read control port back to serialize write */
 418                 cmd_status = inb(PE1400_APM_CONTROL_PORT);
 419
 420                 /* wait a few to see if it executed */
 421                 num_ticks = TIMEOUT_USEC_SHORT_SEMA_BLOCKING;
 422                 while (apm_cmd->status == ESM_STATUS_CMD_UNSUCCESSFUL) {
 423                         num_ticks--;
 424                         if (num_ticks == EXPIRED_TIMER)
 425                                 return -ETIME;
 426                 }
 427                 break;
 428
 429         default:
 430                 dev_dbg(&dcdbas_pdev->dev, "%s: invalid SMI type %u\n",
 431                         __func__, host_control_smi_type);
 432                 return -ENOSYS;
 433         }
 434
 435         return 0;
 436 }
 437
 438 /**
 439  * dcdbas_host_control: initiate host control
 440  *
 441  * This function is called by the driver after the system has
 442  * finished shutting down if the user application specified a
 443  * host control action to perform on shutdown.  It is safe to
 444  * use smi_data_buf at this point because the system has finished
 445  * shutting down and no userspace apps are running.
 446  */
 447 static void dcdbas_host_control(void)
 448 {
 449         struct apm_cmd *apm_cmd;
 450         u8 action;
 451
 452         if (host_control_action == HC_ACTION_NONE)
 453                 return;
 454
 455         action = host_control_action;
 456         host_control_action = HC_ACTION_NONE;
 457
 458         if (!smi_data_buf) {
 459                 dev_dbg(&dcdbas_pdev->dev, "%s: no SMI buffer\n", __func__);
 460                 return;
 461         }
 462
 463         if (smi_data_buf_size < sizeof(struct apm_cmd)) {
 464                 dev_dbg(&dcdbas_pdev->dev, "%s: SMI buffer too small\n",
 465                         __func__);
 466                 return;
 467         }
 468
 469         apm_cmd = (struct apm_cmd *)smi_data_buf;
 470
 471         /* power off takes precedence */
 472         if (action & HC_ACTION_HOST_CONTROL_POWEROFF) {
 473                 apm_cmd->command = ESM_APM_POWER_CYCLE;
 474                 apm_cmd->reserved = 0;
 475                 *((s16 *)&apm_cmd->parameters.shortreq.parm[0]) = (s16) 0;
 476                 host_control_smi();
 477         } else if (action & HC_ACTION_HOST_CONTROL_POWERCYCLE) {
 478                 apm_cmd->command = ESM_APM_POWER_CYCLE;
 479                 apm_cmd->reserved = 0;
 480                 *((s16 *)&apm_cmd->parameters.shortreq.parm[0]) = (s16) 20;
 481                 host_control_smi();
 482         }
 483 }
 484
 485 /**
 486  * dcdbas_reboot_notify: handle reboot notification for host control
 487  */
 488 static int dcdbas_reboot_notify(struct notifier_block *nb, unsigned long code,
 489                                 void *unused)
 490 {
 491         switch (code) {
 492         case SYS_DOWN:
 493         case SYS_HALT:
 494         case SYS_POWER_OFF:
 495                 if (host_control_on_shutdown) {
 496                         /* firmware is going to perform host control action */
 497                         printk(KERN_WARNING "Please wait for shutdown "
 498                                "action to complete...\n");
 499                         dcdbas_host_control();
 500                 }
 501                 break;
 502         }
 503
 504         return NOTIFY_DONE;
 505 }
 506
 507 static struct notifier_block dcdbas_reboot_nb = {
 508         .notifier_call = dcdbas_reboot_notify,
 509         .next = NULL,
 510         .priority = INT_MIN
 511 };
 512
 513 static DCDBAS_BIN_ATTR_RW(smi_data);
 514
 515 static struct bin_attribute *dcdbas_bin_attrs[] = {
 516         &bin_attr_smi_data,
 517         NULL
 518 };
 519
 520 static DCDBAS_DEV_ATTR_RW(smi_data_buf_size);
 521 static DCDBAS_DEV_ATTR_RO(smi_data_buf_phys_addr);
 522 static DCDBAS_DEV_ATTR_WO(smi_request);
 523 static DCDBAS_DEV_ATTR_RW(host_control_action);
 524 static DCDBAS_DEV_ATTR_RW(host_control_smi_type);
 525 static DCDBAS_DEV_ATTR_RW(host_control_on_shutdown);
 526
 527 static struct attribute *dcdbas_dev_attrs[] = {
 528         &dev_attr_smi_data_buf_size.attr,
 529         &dev_attr_smi_data_buf_phys_addr.attr,
 530         &dev_attr_smi_request.attr,
 531         &dev_attr_host_control_action.attr,
 532         &dev_attr_host_control_smi_type.attr,
 533         &dev_attr_host_control_on_shutdown.attr,
 534         NULL
 535 };
 536
 537 static struct attribute_group dcdbas_attr_group = {
 538         .attrs = dcdbas_dev_attrs,
 539 };
 540
 541 static int __devinit dcdbas_probe(struct platform_device *dev)
 542 {
 543         int i, error;
 544
 545         host_control_action = HC_ACTION_NONE;
 546         host_control_smi_type = HC_SMITYPE_NONE;
 547
 548         /*
 549          * BIOS SMI calls require buffer addresses be in 32-bit address space.
 550          * This is done by setting the DMA mask below.
 551          */
 552         dcdbas_pdev->dev.coherent_dma_mask = DMA_32BIT_MASK;
 553         dcdbas_pdev->dev.dma_mask = &dcdbas_pdev->dev.coherent_dma_mask;
 554
 555         error = sysfs_create_group(&dev->dev.kobj, &dcdbas_attr_group);
 556         if (error)
 557                 return error;
 558
 559         for (i = 0; dcdbas_bin_attrs[i]; i++) {
 560                 error = sysfs_create_bin_file(&dev->dev.kobj,
 561                                               dcdbas_bin_attrs[i]);
 562                 if (error) {
 563                         while (--i >= 0)
 564                                 sysfs_remove_bin_file(&dev->dev.kobj,
 565                                                       dcdbas_bin_attrs[i]);
 566                         sysfs_remove_group(&dev->dev.kobj, &dcdbas_attr_group);
 567                         return error;
 568                 }
 569         }
 570
 571         register_reboot_notifier(&dcdbas_reboot_nb);
 572
 573         dev_info(&dev->dev, "%s (version %s)\n",
 574                  DRIVER_DESCRIPTION, DRIVER_VERSION);
 575
 576         return 0;
 577 }
 578
 579 static int __devexit dcdbas_remove(struct platform_device *dev)
 580 {
 581         int i;
 582
 583         unregister_reboot_notifier(&dcdbas_reboot_nb);
 584         for (i = 0; dcdbas_bin_attrs[i]; i++)
 585                 sysfs_remove_bin_file(&dev->dev.kobj, dcdbas_bin_attrs[i]);
 586         sysfs_remove_group(&dev->dev.kobj, &dcdbas_attr_group);
 587
 588         return 0;
 589 }
 590
 591 static struct platform_driver dcdbas_driver = {
 592         .driver         = {
 593                 .name   = DRIVER_NAME,
 594                 .owner  = THIS_MODULE,
 595         },
 596         .probe          = dcdbas_probe,
 597         .remove         = __devexit_p(dcdbas_remove),
 598 };
 599
 600 /**
 601  * dcdbas_init: initialize driver
 602  */
 603 static int __init dcdbas_init(void)
 604 {
 605         int error;
 606
 607         error = platform_driver_register(&dcdbas_driver);
 608         if (error)
 609                 return error;
 610
 611         dcdbas_pdev = platform_device_alloc(DRIVER_NAME, -1);
 612         if (!dcdbas_pdev) {
 613                 error = -ENOMEM;
 614                 goto err_unregister_driver;
 615         }
 616
 617         error = platform_device_add(dcdbas_pdev);
 618         if (error)
 619                 goto err_free_device;
 620
 621         return 0;
 622
 623  err_free_device:
 624         platform_device_put(dcdbas_pdev);
 625  err_unregister_driver:
 626         platform_driver_unregister(&dcdbas_driver);
 627         return error;
 628 }
 629
 630 /**
 631  * dcdbas_exit: perform driver cleanup
 632  */
 633 static void __exit dcdbas_exit(void)
 634 {
 635         /*
 636          * make sure functions that use dcdbas_pdev are called
 637          * before platform_device_unregister
 638          */
 639         unregister_reboot_notifier(&dcdbas_reboot_nb);
 640         smi_data_buf_free();
 641         platform_device_unregister(dcdbas_pdev);
 642         platform_driver_unregister(&dcdbas_driver);
 643
 644         /*
 645          * We have to free the buffer here instead of dcdbas_remove
 646          * because only in module exit function we can be sure that
 647          * all sysfs attributes belonging to this module have been
 648          * released.
 649          */
 650         smi_data_buf_free();
 651 }
 652
 653 module_init(dcdbas_init);
 654 module_exit(dcdbas_exit);
 655
 656 MODULE_DESCRIPTION(DRIVER_DESCRIPTION " (version " DRIVER_VERSION ")");
 657 MODULE_VERSION(DRIVER_VERSION);
 658 MODULE_AUTHOR("Dell Inc.");
 659 MODULE_LICENSE("GPL");
 660 /* Any System or BIOS claiming to be by Dell */
 661 MODULE_ALIAS("dmi:*:[bs]vnD[Ee][Ll][Ll]*:*");