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/cpu.h>
  27 #include <linux/gfp.h>
  28 #include <linux/init.h>
  29 #include <linux/kernel.h>
  30 #include <linux/mc146818rtc.h>
  31 #include <linux/module.h>
  32 #include <linux/reboot.h>
  33 #include <linux/sched.h>
  34 #include <linux/smp.h>
  35 #include <linux/spinlock.h>
  36 #include <linux/string.h>
  37 #include <linux/types.h>
  38 #include <linux/mutex.h>
  39 #include <asm/io.h>
  40
  41 #include "dcdbas.h"
  42
  43 #define DRIVER_NAME             "dcdbas"
  44 #define DRIVER_VERSION          "5.6.0-3.2"
  45 #define DRIVER_DESCRIPTION      "Dell Systems Management Base Driver"
  46
  47 static struct platform_device *dcdbas_pdev;
  48
  49 static u8 *smi_data_buf;
  50 static dma_addr_t smi_data_buf_handle;
  51 static unsigned long smi_data_buf_size;
  52 static u32 smi_data_buf_phys_addr;
  53 static DEFINE_MUTEX(smi_data_lock);
  54
  55 static unsigned int host_control_action;
  56 static unsigned int host_control_smi_type;
  57 static unsigned int host_control_on_shutdown;
  58
  59 /**
  60  * smi_data_buf_free: free SMI data buffer
  61  */
  62 static void smi_data_buf_free(void)
  63 {
  64         if (!smi_data_buf)
  65                 return;
  66
  67         dev_dbg(&dcdbas_pdev->dev, "%s: phys: %x size: %lu\n",
  68                 __func__, smi_data_buf_phys_addr, smi_data_buf_size);
  69
  70         dma_free_coherent(&dcdbas_pdev->dev, smi_data_buf_size, smi_data_buf,
  71                           smi_data_buf_handle);
  72         smi_data_buf = NULL;
  73         smi_data_buf_handle = 0;
  74         smi_data_buf_phys_addr = 0;
  75         smi_data_buf_size = 0;
  76 }
  77
  78 /**
  79  * smi_data_buf_realloc: grow SMI data buffer if needed
  80  */
  81 static int smi_data_buf_realloc(unsigned long size)
  82 {
  83         void *buf;
  84         dma_addr_t handle;
  85
  86         if (smi_data_buf_size >= size)
  87                 return 0;
  88
  89         if (size > MAX_SMI_DATA_BUF_SIZE)
  90                 return -EINVAL;
  91
  92         /* new buffer is needed */
  93         buf = dma_alloc_coherent(&dcdbas_pdev->dev, size, &handle, GFP_KERNEL);
  94         if (!buf) {
  95                 dev_dbg(&dcdbas_pdev->dev,
  96                         "%s: failed to allocate memory size %lu\n",
  97                         __func__, size);
  98                 return -ENOMEM;
  99         }
 100         /* memory zeroed by dma_alloc_coherent */
 101
 102         if (smi_data_buf)
 103                 memcpy(buf, smi_data_buf, smi_data_buf_size);
 104
 105         /* free any existing buffer */
 106         smi_data_buf_free();
 107
 108         /* set up new buffer for use */
 109         smi_data_buf = buf;
 110         smi_data_buf_handle = handle;
 111         smi_data_buf_phys_addr = (u32) virt_to_phys(buf);
 112         smi_data_buf_size = size;
 113
 114         dev_dbg(&dcdbas_pdev->dev, "%s: phys: %x size: %lu\n",
 115                 __func__, smi_data_buf_phys_addr, smi_data_buf_size);
 116
 117         return 0;
 118 }
 119
 120 static ssize_t smi_data_buf_phys_addr_show(struct device *dev,
 121                                            struct device_attribute *attr,
 122                                            char *buf)
 123 {
 124         return sprintf(buf, "%x\n", smi_data_buf_phys_addr);
 125 }
 126
 127 static ssize_t smi_data_buf_size_show(struct device *dev,
 128                                       struct device_attribute *attr,
 129                                       char *buf)
 130 {
 131         return sprintf(buf, "%lu\n", smi_data_buf_size);
 132 }
 133
 134 static ssize_t smi_data_buf_size_store(struct device *dev,
 135                                        struct device_attribute *attr,
 136                                        const char *buf, size_t count)
 137 {
 138         unsigned long buf_size;
 139         ssize_t ret;
 140
 141         buf_size = simple_strtoul(buf, NULL, 10);
 142
 143         /* make sure SMI data buffer is at least buf_size */
 144         mutex_lock(&smi_data_lock);
 145         ret = smi_data_buf_realloc(buf_size);
 146         mutex_unlock(&smi_data_lock);
 147         if (ret)
 148                 return ret;
 149
 150         return count;
 151 }
 152
 153 static ssize_t smi_data_read(struct file *filp, struct kobject *kobj,
 154                              struct bin_attribute *bin_attr,
 155                              char *buf, loff_t pos, size_t count)
 156 {
 157         ssize_t ret;
 158
 159         mutex_lock(&smi_data_lock);
 160         ret = memory_read_from_buffer(buf, count, &pos, smi_data_buf,
 161                                         smi_data_buf_size);
 162         mutex_unlock(&smi_data_lock);
 163         return ret;
 164 }
 165
 166 static ssize_t smi_data_write(struct file *filp, struct kobject *kobj,
 167                               struct bin_attribute *bin_attr,
 168                               char *buf, loff_t pos, size_t count)
 169 {
 170         ssize_t ret;
 171
 172         if ((pos + count) > MAX_SMI_DATA_BUF_SIZE)
 173                 return -EINVAL;
 174
 175         mutex_lock(&smi_data_lock);
 176
 177         ret = smi_data_buf_realloc(pos + count);
 178         if (ret)
 179                 goto out;
 180
 181         memcpy(smi_data_buf + pos, buf, count);
 182         ret = count;
 183 out:
 184         mutex_unlock(&smi_data_lock);
 185         return ret;
 186 }
 187
 188 static ssize_t host_control_action_show(struct device *dev,
 189                                         struct device_attribute *attr,
 190                                         char *buf)
 191 {
 192         return sprintf(buf, "%u\n", host_control_action);
 193 }
 194
 195 static ssize_t host_control_action_store(struct device *dev,
 196                                          struct device_attribute *attr,
 197                                          const char *buf, size_t count)
 198 {
 199         ssize_t ret;
 200
 201         /* make sure buffer is available for host control command */
 202         mutex_lock(&smi_data_lock);
 203         ret = smi_data_buf_realloc(sizeof(struct apm_cmd));
 204         mutex_unlock(&smi_data_lock);
 205         if (ret)
 206                 return ret;
 207
 208         host_control_action = simple_strtoul(buf, NULL, 10);
 209         return count;
 210 }
 211
 212 static ssize_t host_control_smi_type_show(struct device *dev,
 213                                           struct device_attribute *attr,
 214                                           char *buf)
 215 {
 216         return sprintf(buf, "%u\n", host_control_smi_type);
 217 }
 218
 219 static ssize_t host_control_smi_type_store(struct device *dev,
 220                                            struct device_attribute *attr,
 221                                            const char *buf, size_t count)
 222 {
 223         host_control_smi_type = simple_strtoul(buf, NULL, 10);
 224         return count;
 225 }
 226
 227 static ssize_t host_control_on_shutdown_show(struct device *dev,
 228                                              struct device_attribute *attr,
 229                                              char *buf)
 230 {
 231         return sprintf(buf, "%u\n", host_control_on_shutdown);
 232 }
 233
 234 static ssize_t host_control_on_shutdown_store(struct device *dev,
 235                                               struct device_attribute *attr,
 236                                               const char *buf, size_t count)
 237 {
 238         host_control_on_shutdown = simple_strtoul(buf, NULL, 10);
 239         return count;
 240 }
 241
 242 static int raise_smi(void *par)
 243 {
 244         struct smi_cmd *smi_cmd = par;
 245
 246         if (smp_processor_id() != 0) {
 247                 dev_dbg(&dcdbas_pdev->dev, "%s: failed to get CPU 0\n",
 248                         __func__);
 249                 return -EBUSY;
 250         }
 251
 252         /* generate SMI */
 253         /* inb to force posted write through and make SMI happen now */
 254         asm volatile (
 255                 "outb %b0,%w1\n"
 256                 "inb %w1"
 257                 : /* no output args */
 258                 : "a" (smi_cmd->command_code),
 259                   "d" (smi_cmd->command_address),
 260                   "b" (smi_cmd->ebx),
 261                   "c" (smi_cmd->ecx)
 262                 : "memory"
 263         );
 264
 265         return 0;
 266 }
 267 /**
 268  * dcdbas_smi_request: generate SMI request
 269  *
 270  * Called with smi_data_lock.
 271  */
 272 int dcdbas_smi_request(struct smi_cmd *smi_cmd)
 273 {
 274         int ret;
 275
 276         if (smi_cmd->magic != SMI_CMD_MAGIC) {
 277                 dev_info(&dcdbas_pdev->dev, "%s: invalid magic value\n",
 278                          __func__);
 279                 return -EBADR;
 280         }
 281
 282         /* SMI requires CPU 0 */
 283         get_online_cpus();
 284         ret = smp_call_on_cpu(0, raise_smi, smi_cmd, true);
 285         put_online_cpus();
 286
 287         return ret;
 288 }
 289
 290 /**
 291  * smi_request_store:
 292  *
 293  * The valid values are:
 294  * 0: zero SMI data buffer
 295  * 1: generate calling interface SMI
 296  * 2: generate raw SMI
 297  *
 298  * User application writes smi_cmd to smi_data before telling driver
 299  * to generate SMI.
 300  */
 301 static ssize_t smi_request_store(struct device *dev,
 302                                  struct device_attribute *attr,
 303                                  const char *buf, size_t count)
 304 {
 305         struct smi_cmd *smi_cmd;
 306         unsigned long val = simple_strtoul(buf, NULL, 10);
 307         ssize_t ret;
 308
 309         mutex_lock(&smi_data_lock);
 310
 311         if (smi_data_buf_size < sizeof(struct smi_cmd)) {
 312                 ret = -ENODEV;
 313                 goto out;
 314         }
 315         smi_cmd = (struct smi_cmd *)smi_data_buf;
 316
 317         switch (val) {
 318         case 2:
 319                 /* Raw SMI */
 320                 ret = dcdbas_smi_request(smi_cmd);
 321                 if (!ret)
 322                         ret = count;
 323                 break;
 324         case 1:
 325                 /* Calling Interface SMI */
 326                 smi_cmd->ebx = (u32) virt_to_phys(smi_cmd->command_buffer);
 327                 ret = dcdbas_smi_request(smi_cmd);
 328                 if (!ret)
 329                         ret = count;
 330                 break;
 331         case 0:
 332                 memset(smi_data_buf, 0, smi_data_buf_size);
 333                 ret = count;
 334                 break;
 335         default:
 336                 ret = -EINVAL;
 337                 break;
 338         }
 339
 340 out:
 341         mutex_unlock(&smi_data_lock);
 342         return ret;
 343 }
 344 EXPORT_SYMBOL(dcdbas_smi_request);
 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 const struct attribute_group dcdbas_attr_group = {
 538         .attrs = dcdbas_dev_attrs,
 539         .bin_attrs = dcdbas_bin_attrs,
 540 };
 541
 542 static int dcdbas_probe(struct platform_device *dev)
 543 {
 544         int error;
 545
 546         host_control_action = HC_ACTION_NONE;
 547         host_control_smi_type = HC_SMITYPE_NONE;
 548
 549         dcdbas_pdev = dev;
 550
 551         /*
 552          * BIOS SMI calls require buffer addresses be in 32-bit address space.
 553          * This is done by setting the DMA mask below.
 554          */
 555         error = dma_set_coherent_mask(&dcdbas_pdev->dev, DMA_BIT_MASK(32));
 556         if (error)
 557                 return error;
 558
 559         error = sysfs_create_group(&dev->dev.kobj, &dcdbas_attr_group);
 560         if (error)
 561                 return error;
 562
 563         register_reboot_notifier(&dcdbas_reboot_nb);
 564
 565         dev_info(&dev->dev, "%s (version %s)\n",
 566                  DRIVER_DESCRIPTION, DRIVER_VERSION);
 567
 568         return 0;
 569 }
 570
 571 static int dcdbas_remove(struct platform_device *dev)
 572 {
 573         unregister_reboot_notifier(&dcdbas_reboot_nb);
 574         sysfs_remove_group(&dev->dev.kobj, &dcdbas_attr_group);
 575
 576         return 0;
 577 }
 578
 579 static struct platform_driver dcdbas_driver = {
 580         .driver         = {
 581                 .name   = DRIVER_NAME,
 582         },
 583         .probe          = dcdbas_probe,
 584         .remove         = dcdbas_remove,
 585 };
 586
 587 static const struct platform_device_info dcdbas_dev_info __initconst = {
 588         .name           = DRIVER_NAME,
 589         .id             = -1,
 590         .dma_mask       = DMA_BIT_MASK(32),
 591 };
 592
 593 static struct platform_device *dcdbas_pdev_reg;
 594
 595 /**
 596  * dcdbas_init: initialize driver
 597  */
 598 static int __init dcdbas_init(void)
 599 {
 600         int error;
 601
 602         error = platform_driver_register(&dcdbas_driver);
 603         if (error)
 604                 return error;
 605
 606         dcdbas_pdev_reg = platform_device_register_full(&dcdbas_dev_info);
 607         if (IS_ERR(dcdbas_pdev_reg)) {
 608                 error = PTR_ERR(dcdbas_pdev_reg);
 609                 goto err_unregister_driver;
 610         }
 611
 612         return 0;
 613
 614  err_unregister_driver:
 615         platform_driver_unregister(&dcdbas_driver);
 616         return error;
 617 }
 618
 619 /**
 620  * dcdbas_exit: perform driver cleanup
 621  */
 622 static void __exit dcdbas_exit(void)
 623 {
 624         /*
 625          * make sure functions that use dcdbas_pdev are called
 626          * before platform_device_unregister
 627          */
 628         unregister_reboot_notifier(&dcdbas_reboot_nb);
 629
 630         /*
 631          * We have to free the buffer here instead of dcdbas_remove
 632          * because only in module exit function we can be sure that
 633          * all sysfs attributes belonging to this module have been
 634          * released.
 635          */
 636         if (dcdbas_pdev)
 637                 smi_data_buf_free();
 638         platform_device_unregister(dcdbas_pdev_reg);
 639         platform_driver_unregister(&dcdbas_driver);
 640 }
 641
 642 module_init(dcdbas_init);
 643 module_exit(dcdbas_exit);
 644
 645 MODULE_DESCRIPTION(DRIVER_DESCRIPTION " (version " DRIVER_VERSION ")");
 646 MODULE_VERSION(DRIVER_VERSION);
 647 MODULE_AUTHOR("Dell Inc.");
 648 MODULE_LICENSE("GPL");
 649 /* Any System or BIOS claiming to be by Dell */
 650 MODULE_ALIAS("dmi:*:[bs]vnD[Ee][Ll][Ll]*:*");