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/gfp.h>
  27 #include <linux/init.h>
  28 #include <linux/kernel.h>
  29 #include <linux/mc146818rtc.h>
  30 #include <linux/module.h>
  31 #include <linux/reboot.h>
  32 #include <linux/sched.h>
  33 #include <linux/smp.h>
  34 #include <linux/spinlock.h>
  35 #include <linux/string.h>
  36 #include <linux/types.h>
  37 #include <linux/mutex.h>
  38 #include <asm/io.h>
  39
  40 #include "dcdbas.h"
  41
  42 #define DRIVER_NAME             "dcdbas"
  43 #define DRIVER_VERSION          "5.6.0-3.2"
  44 #define DRIVER_DESCRIPTION      "Dell Systems Management Base Driver"
  45
  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                 __func__, smi_data_buf_phys_addr, smi_data_buf_size);
  68
  69         dma_free_coherent(&dcdbas_pdev->dev, smi_data_buf_size, smi_data_buf,
  70                           smi_data_buf_handle);
  71         smi_data_buf = NULL;
  72         smi_data_buf_handle = 0;
  73         smi_data_buf_phys_addr = 0;
  74         smi_data_buf_size = 0;
  75 }
  76
  77 /**
  78  * smi_data_buf_realloc: grow SMI data buffer if needed
  79  */
  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                         __func__, size);
  97                 return -ENOMEM;
  98         }
  99         /* memory zeroed by dma_alloc_coherent */
 100
 101         if (smi_data_buf)
 102                 memcpy(buf, smi_data_buf, smi_data_buf_size);
 103
 104         /* free any existing buffer */
 105         smi_data_buf_free();
 106
 107         /* set up new buffer for use */
 108         smi_data_buf = buf;
 109         smi_data_buf_handle = handle;
 110         smi_data_buf_phys_addr = (u32) virt_to_phys(buf);
 111         smi_data_buf_size = size;
 112
 113         dev_dbg(&dcdbas_pdev->dev, "%s: phys: %x size: %lu\n",
 114                 __func__, smi_data_buf_phys_addr, smi_data_buf_size);
 115
 116         return 0;
 117 }
 118
 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 file *filp, struct kobject *kobj,
 153                              struct bin_attribute *bin_attr,
 154                              char *buf, loff_t pos, size_t count)
 155 {
 156         ssize_t ret;
 157
 158         mutex_lock(&smi_data_lock);
 159         ret = memory_read_from_buffer(buf, count, &pos, smi_data_buf,
 160                                         smi_data_buf_size);
 161         mutex_unlock(&smi_data_lock);
 162         return ret;
 163 }
 164
 165 static ssize_t smi_data_write(struct file *filp, struct kobject *kobj,
 166                               struct bin_attribute *bin_attr,
 167                               char *buf, loff_t pos, size_t count)
 168 {
 169         ssize_t ret;
 170
 171         if ((pos + count) > MAX_SMI_DATA_BUF_SIZE)
 172                 return -EINVAL;
 173
 174         mutex_lock(&smi_data_lock);
 175
 176         ret = smi_data_buf_realloc(pos + count);
 177         if (ret)
 178                 goto out;
 179
 180         memcpy(smi_data_buf + pos, buf, count);
 181         ret = count;
 182 out:
 183         mutex_unlock(&smi_data_lock);
 184         return ret;
 185 }
 186
 187 static ssize_t host_control_action_show(struct device *dev,
 188                                         struct device_attribute *attr,
 189                                         char *buf)
 190 {
 191         return sprintf(buf, "%u\n", host_control_action);
 192 }
 193
 194 static ssize_t host_control_action_store(struct device *dev,
 195                                          struct device_attribute *attr,
 196                                          const char *buf, size_t count)
 197 {
 198         ssize_t ret;
 199
 200         /* make sure buffer is available for host control command */
 201         mutex_lock(&smi_data_lock);
 202         ret = smi_data_buf_realloc(sizeof(struct apm_cmd));
 203         mutex_unlock(&smi_data_lock);
 204         if (ret)
 205                 return ret;
 206
 207         host_control_action = simple_strtoul(buf, NULL, 10);
 208         return count;
 209 }
 210
 211 static ssize_t host_control_smi_type_show(struct device *dev,
 212                                           struct device_attribute *attr,
 213                                           char *buf)
 214 {
 215         return sprintf(buf, "%u\n", host_control_smi_type);
 216 }
 217
 218 static ssize_t host_control_smi_type_store(struct device *dev,
 219                                            struct device_attribute *attr,
 220                                            const char *buf, size_t count)
 221 {
 222         host_control_smi_type = simple_strtoul(buf, NULL, 10);
 223         return count;
 224 }
 225
 226 static ssize_t host_control_on_shutdown_show(struct device *dev,
 227                                              struct device_attribute *attr,
 228                                              char *buf)
 229 {
 230         return sprintf(buf, "%u\n", host_control_on_shutdown);
 231 }
 232
 233 static ssize_t host_control_on_shutdown_store(struct device *dev,
 234                                               struct device_attribute *attr,
 235                                               const char *buf, size_t count)
 236 {
 237         host_control_on_shutdown = simple_strtoul(buf, NULL, 10);
 238         return count;
 239 }
 240
 241 /**
 242  * dcdbas_smi_request: generate SMI request
 243  *
 244  * Called with smi_data_lock.
 245  */
 246 int dcdbas_smi_request(struct smi_cmd *smi_cmd)
 247 {
 248         cpumask_var_t old_mask;
 249         int ret = 0;
 250
 251         if (smi_cmd->magic != SMI_CMD_MAGIC) {
 252                 dev_info(&dcdbas_pdev->dev, "%s: invalid magic value\n",
 253                          __func__);
 254                 return -EBADR;
 255         }
 256
 257         /* SMI requires CPU 0 */
 258         if (!alloc_cpumask_var(&old_mask, GFP_KERNEL))
 259                 return -ENOMEM;
 260
 261         cpumask_copy(old_mask, &current->cpus_allowed);
 262         set_cpus_allowed_ptr(current, cpumask_of(0));
 263         if (smp_processor_id() != 0) {
 264                 dev_dbg(&dcdbas_pdev->dev, "%s: failed to get CPU 0\n",
 265                         __func__);
 266                 ret = -EBUSY;
 267                 goto out;
 268         }
 269
 270         /* generate SMI */
 271         /* inb to force posted write through and make SMI happen now */
 272         asm volatile (
 273                 "outb %b0,%w1\n"
 274                 "inb %w1"
 275                 : /* no output args */
 276                 : "a" (smi_cmd->command_code),
 277                   "d" (smi_cmd->command_address),
 278                   "b" (smi_cmd->ebx),
 279                   "c" (smi_cmd->ecx)
 280                 : "memory"
 281         );
 282
 283 out:
 284         set_cpus_allowed_ptr(current, old_mask);
 285         free_cpumask_var(old_mask);
 286         return ret;
 287 }
 288
 289 /**
 290  * smi_request_store:
 291  *
 292  * The valid values are:
 293  * 0: zero SMI data buffer
 294  * 1: generate calling interface SMI
 295  * 2: generate raw SMI
 296  *
 297  * User application writes smi_cmd to smi_data before telling driver
 298  * to generate SMI.
 299  */
 300 static ssize_t smi_request_store(struct device *dev,
 301                                  struct device_attribute *attr,
 302                                  const char *buf, size_t count)
 303 {
 304         struct smi_cmd *smi_cmd;
 305         unsigned long val = simple_strtoul(buf, NULL, 10);
 306         ssize_t ret;
 307
 308         mutex_lock(&smi_data_lock);
 309
 310         if (smi_data_buf_size < sizeof(struct smi_cmd)) {
 311                 ret = -ENODEV;
 312                 goto out;
 313         }
 314         smi_cmd = (struct smi_cmd *)smi_data_buf;
 315
 316         switch (val) {
 317         case 2:
 318                 /* Raw SMI */
 319                 ret = dcdbas_smi_request(smi_cmd);
 320                 if (!ret)
 321                         ret = count;
 322                 break;
 323         case 1:
 324                 /* Calling Interface SMI */
 325                 smi_cmd->ebx = (u32) virt_to_phys(smi_cmd->command_buffer);
 326                 ret = dcdbas_smi_request(smi_cmd);
 327                 if (!ret)
 328                         ret = count;
 329                 break;
 330         case 0:
 331                 memset(smi_data_buf, 0, smi_data_buf_size);
 332                 ret = count;
 333                 break;
 334         default:
 335                 ret = -EINVAL;
 336                 break;
 337         }
 338
 339 out:
 340         mutex_unlock(&smi_data_lock);
 341         return ret;
 342 }
 343 EXPORT_SYMBOL(dcdbas_smi_request);
 344
 345 /**
 346  * host_control_smi: generate host control SMI
 347  *
 348  * Caller must set up the host control command in smi_data_buf.
 349  */
 350 static int host_control_smi(void)
 351 {
 352         struct apm_cmd *apm_cmd;
 353         u8 *data;
 354         unsigned long flags;
 355         u32 num_ticks;
 356         s8 cmd_status;
 357         u8 index;
 358
 359         apm_cmd = (struct apm_cmd *)smi_data_buf;
 360         apm_cmd->status = ESM_STATUS_CMD_UNSUCCESSFUL;
 361
 362         switch (host_control_smi_type) {
 363         case HC_SMITYPE_TYPE1:
 364                 spin_lock_irqsave(&rtc_lock, flags);
 365                 /* write SMI data buffer physical address */
 366                 data = (u8 *)&smi_data_buf_phys_addr;
 367                 for (index = PE1300_CMOS_CMD_STRUCT_PTR;
 368                      index < (PE1300_CMOS_CMD_STRUCT_PTR + 4);
 369                      index++, data++) {
 370                         outb(index,
 371                              (CMOS_BASE_PORT + CMOS_PAGE2_INDEX_PORT_PIIX4));
 372                         outb(*data,
 373                              (CMOS_BASE_PORT + CMOS_PAGE2_DATA_PORT_PIIX4));
 374                 }
 375
 376                 /* first set status to -1 as called by spec */
 377                 cmd_status = ESM_STATUS_CMD_UNSUCCESSFUL;
 378                 outb((u8) cmd_status, PCAT_APM_STATUS_PORT);
 379
 380                 /* generate SMM call */
 381                 outb(ESM_APM_CMD, PCAT_APM_CONTROL_PORT);
 382                 spin_unlock_irqrestore(&rtc_lock, flags);
 383
 384                 /* wait a few to see if it executed */
 385                 num_ticks = TIMEOUT_USEC_SHORT_SEMA_BLOCKING;
 386                 while ((cmd_status = inb(PCAT_APM_STATUS_PORT))
 387                        == ESM_STATUS_CMD_UNSUCCESSFUL) {
 388                         num_ticks--;
 389                         if (num_ticks == EXPIRED_TIMER)
 390                                 return -ETIME;
 391                 }
 392                 break;
 393
 394         case HC_SMITYPE_TYPE2:
 395         case HC_SMITYPE_TYPE3:
 396                 spin_lock_irqsave(&rtc_lock, flags);
 397                 /* write SMI data buffer physical address */
 398                 data = (u8 *)&smi_data_buf_phys_addr;
 399                 for (index = PE1400_CMOS_CMD_STRUCT_PTR;
 400                      index < (PE1400_CMOS_CMD_STRUCT_PTR + 4);
 401                      index++, data++) {
 402                         outb(index, (CMOS_BASE_PORT + CMOS_PAGE1_INDEX_PORT));
 403                         outb(*data, (CMOS_BASE_PORT + CMOS_PAGE1_DATA_PORT));
 404                 }
 405
 406                 /* generate SMM call */
 407                 if (host_control_smi_type == HC_SMITYPE_TYPE3)
 408                         outb(ESM_APM_CMD, PCAT_APM_CONTROL_PORT);
 409                 else
 410                         outb(ESM_APM_CMD, PE1400_APM_CONTROL_PORT);
 411
 412                 /* restore RTC index pointer since it was written to above */
 413                 CMOS_READ(RTC_REG_C);
 414                 spin_unlock_irqrestore(&rtc_lock, flags);
 415
 416                 /* read control port back to serialize write */
 417                 cmd_status = inb(PE1400_APM_CONTROL_PORT);
 418
 419                 /* wait a few to see if it executed */
 420                 num_ticks = TIMEOUT_USEC_SHORT_SEMA_BLOCKING;
 421                 while (apm_cmd->status == ESM_STATUS_CMD_UNSUCCESSFUL) {
 422                         num_ticks--;
 423                         if (num_ticks == EXPIRED_TIMER)
 424                                 return -ETIME;
 425                 }
 426                 break;
 427
 428         default:
 429                 dev_dbg(&dcdbas_pdev->dev, "%s: invalid SMI type %u\n",
 430                         __func__, host_control_smi_type);
 431                 return -ENOSYS;
 432         }
 433
 434         return 0;
 435 }
 436
 437 /**
 438  * dcdbas_host_control: initiate host control
 439  *
 440  * This function is called by the driver after the system has
 441  * finished shutting down if the user application specified a
 442  * host control action to perform on shutdown.  It is safe to
 443  * use smi_data_buf at this point because the system has finished
 444  * shutting down and no userspace apps are running.
 445  */
 446 static void dcdbas_host_control(void)
 447 {
 448         struct apm_cmd *apm_cmd;
 449         u8 action;
 450
 451         if (host_control_action == HC_ACTION_NONE)
 452                 return;
 453
 454         action = host_control_action;
 455         host_control_action = HC_ACTION_NONE;
 456
 457         if (!smi_data_buf) {
 458                 dev_dbg(&dcdbas_pdev->dev, "%s: no SMI buffer\n", __func__);
 459                 return;
 460         }
 461
 462         if (smi_data_buf_size < sizeof(struct apm_cmd)) {
 463                 dev_dbg(&dcdbas_pdev->dev, "%s: SMI buffer too small\n",
 464                         __func__);
 465                 return;
 466         }
 467
 468         apm_cmd = (struct apm_cmd *)smi_data_buf;
 469
 470         /* power off takes precedence */
 471         if (action & HC_ACTION_HOST_CONTROL_POWEROFF) {
 472                 apm_cmd->command = ESM_APM_POWER_CYCLE;
 473                 apm_cmd->reserved = 0;
 474                 *((s16 *)&apm_cmd->parameters.shortreq.parm[0]) = (s16) 0;
 475                 host_control_smi();
 476         } else if (action & HC_ACTION_HOST_CONTROL_POWERCYCLE) {
 477                 apm_cmd->command = ESM_APM_POWER_CYCLE;
 478                 apm_cmd->reserved = 0;
 479                 *((s16 *)&apm_cmd->parameters.shortreq.parm[0]) = (s16) 20;
 480                 host_control_smi();
 481         }
 482 }
 483
 484 /**
 485  * dcdbas_reboot_notify: handle reboot notification for host control
 486  */
 487 static int dcdbas_reboot_notify(struct notifier_block *nb, unsigned long code,
 488                                 void *unused)
 489 {
 490         switch (code) {
 491         case SYS_DOWN:
 492         case SYS_HALT:
 493         case SYS_POWER_OFF:
 494                 if (host_control_on_shutdown) {
 495                         /* firmware is going to perform host control action */
 496                         printk(KERN_WARNING "Please wait for shutdown "
 497                                "action to complete...\n");
 498                         dcdbas_host_control();
 499                 }
 500                 break;
 501         }
 502
 503         return NOTIFY_DONE;
 504 }
 505
 506 static struct notifier_block dcdbas_reboot_nb = {
 507         .notifier_call = dcdbas_reboot_notify,
 508         .next = NULL,
 509         .priority = INT_MIN
 510 };
 511
 512 static DCDBAS_BIN_ATTR_RW(smi_data);
 513
 514 static struct bin_attribute *dcdbas_bin_attrs[] = {
 515         &bin_attr_smi_data,
 516         NULL
 517 };
 518
 519 static DCDBAS_DEV_ATTR_RW(smi_data_buf_size);
 520 static DCDBAS_DEV_ATTR_RO(smi_data_buf_phys_addr);
 521 static DCDBAS_DEV_ATTR_WO(smi_request);
 522 static DCDBAS_DEV_ATTR_RW(host_control_action);
 523 static DCDBAS_DEV_ATTR_RW(host_control_smi_type);
 524 static DCDBAS_DEV_ATTR_RW(host_control_on_shutdown);
 525
 526 static struct attribute *dcdbas_dev_attrs[] = {
 527         &dev_attr_smi_data_buf_size.attr,
 528         &dev_attr_smi_data_buf_phys_addr.attr,
 529         &dev_attr_smi_request.attr,
 530         &dev_attr_host_control_action.attr,
 531         &dev_attr_host_control_smi_type.attr,
 532         &dev_attr_host_control_on_shutdown.attr,
 533         NULL
 534 };
 535
 536 static struct attribute_group dcdbas_attr_group = {
 537         .attrs = dcdbas_dev_attrs,
 538         .bin_attrs = dcdbas_bin_attrs,
 539 };
 540
 541 static int dcdbas_probe(struct platform_device *dev)
 542 {
 543         int error;
 544
 545         host_control_action = HC_ACTION_NONE;
 546         host_control_smi_type = HC_SMITYPE_NONE;
 547
 548         dcdbas_pdev = dev;
 549
 550         /*
 551          * BIOS SMI calls require buffer addresses be in 32-bit address space.
 552          * This is done by setting the DMA mask below.
 553          */
 554         error = dma_set_coherent_mask(&dcdbas_pdev->dev, DMA_BIT_MASK(32));
 555         if (error)
 556                 return error;
 557
 558         error = sysfs_create_group(&dev->dev.kobj, &dcdbas_attr_group);
 559         if (error)
 560                 return error;
 561
 562         register_reboot_notifier(&dcdbas_reboot_nb);
 563
 564         dev_info(&dev->dev, "%s (version %s)\n",
 565                  DRIVER_DESCRIPTION, DRIVER_VERSION);
 566
 567         return 0;
 568 }
 569
 570 static int dcdbas_remove(struct platform_device *dev)
 571 {
 572         unregister_reboot_notifier(&dcdbas_reboot_nb);
 573         sysfs_remove_group(&dev->dev.kobj, &dcdbas_attr_group);
 574
 575         return 0;
 576 }
 577
 578 static struct platform_driver dcdbas_driver = {
 579         .driver         = {
 580                 .name   = DRIVER_NAME,
 581         },
 582         .probe          = dcdbas_probe,
 583         .remove         = dcdbas_remove,
 584 };
 585
 586 static const struct platform_device_info dcdbas_dev_info __initconst = {
 587         .name           = DRIVER_NAME,
 588         .id             = -1,
 589         .dma_mask       = DMA_BIT_MASK(32),
 590 };
 591
 592 static struct platform_device *dcdbas_pdev_reg;
 593
 594 /**
 595  * dcdbas_init: initialize driver
 596  */
 597 static int __init dcdbas_init(void)
 598 {
 599         int error;
 600
 601         error = platform_driver_register(&dcdbas_driver);
 602         if (error)
 603                 return error;
 604
 605         dcdbas_pdev_reg = platform_device_register_full(&dcdbas_dev_info);
 606         if (IS_ERR(dcdbas_pdev_reg)) {
 607                 error = PTR_ERR(dcdbas_pdev_reg);
 608                 goto err_unregister_driver;
 609         }
 610
 611         return 0;
 612
 613  err_unregister_driver:
 614         platform_driver_unregister(&dcdbas_driver);
 615         return error;
 616 }
 617
 618 /**
 619  * dcdbas_exit: perform driver cleanup
 620  */
 621 static void __exit dcdbas_exit(void)
 622 {
 623         /*
 624          * make sure functions that use dcdbas_pdev are called
 625          * before platform_device_unregister
 626          */
 627         unregister_reboot_notifier(&dcdbas_reboot_nb);
 628
 629         /*
 630          * We have to free the buffer here instead of dcdbas_remove
 631          * because only in module exit function we can be sure that
 632          * all sysfs attributes belonging to this module have been
 633          * released.
 634          */
 635         if (dcdbas_pdev)
 636                 smi_data_buf_free();
 637         platform_device_unregister(dcdbas_pdev_reg);
 638         platform_driver_unregister(&dcdbas_driver);
 639 }
 640
 641 module_init(dcdbas_init);
 642 module_exit(dcdbas_exit);
 643
 644 MODULE_DESCRIPTION(DRIVER_DESCRIPTION " (version " DRIVER_VERSION ")");
 645 MODULE_VERSION(DRIVER_VERSION);
 646 MODULE_AUTHOR("Dell Inc.");
 647 MODULE_LICENSE("GPL");
 648 /* Any System or BIOS claiming to be by Dell */
 649 MODULE_ALIAS("dmi:*:[bs]vnD[Ee][Ll][Ll]*:*");