drivers/firmware/dcdbas.c

   1 /*
   2  *  dcdbas.c: Dell Systems Management Base Driver
   3  *
   4  *  The Dell Systems Management Base Driver provides a sysfs interface for
   5  *  systems management software to perform System Management Interrupts (SMIs)
   6  *  and Host Control Actions (power cycle or power off after OS shutdown) on
   7  *  Dell systems.
   8  *
   9  *  See Documentation/dcdbas.txt for more information.
  10  *
  11  *  Copyright (C) 1995-2005 Dell Inc.
  12  *
  13  *  This program is free software; you can redistribute it and/or modify
  14  *  it under the terms of the GNU General Public License v2.0 as published by
  15  *  the Free Software Foundation.
  16  *
  17  *  This program is distributed in the hope that it will be useful,
  18  *  but WITHOUT ANY WARRANTY; without even the implied warranty of
  19  *  MERCHANTABILITY or FITNESS FOR A PARTICULAR PURPOSE.  See the
  20  *  GNU General Public License for more details.
  21  */
  22
  23 #include <linux/platform_device.h>
  24 #include <linux/dma-mapping.h>
  25 #include <linux/errno.h>
  26 #include <linux/init.h>
  27 #include <linux/kernel.h>
  28 #include <linux/mc146818rtc.h>
  29 #include <linux/module.h>
  30 #include <linux/reboot.h>
  31 #include <linux/sched.h>
  32 #include <linux/smp.h>
  33 #include <linux/spinlock.h>
  34 #include <linux/string.h>
  35 #include <linux/types.h>
  36 #include <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          "5.6.0-2"
  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, char *buf, loff_t pos,
 153                              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, char *buf, loff_t pos,
 174                               size_t count)
 175 {
 176         ssize_t ret;
 177
 178         mutex_lock(&smi_data_lock);
 179
 180         ret = smi_data_buf_realloc(pos + count);
 181         if (ret)
 182                 goto out;
 183
 184         memcpy(smi_data_buf + pos, buf, count);
 185         ret = count;
 186 out:
 187         mutex_unlock(&smi_data_lock);
 188         return ret;
 189 }
 190
 191 static ssize_t host_control_action_show(struct device *dev,
 192                                         struct device_attribute *attr,
 193                                         char *buf)
 194 {
 195         return sprintf(buf, "%u\n", host_control_action);
 196 }
 197
 198 static ssize_t host_control_action_store(struct device *dev,
 199                                          struct device_attribute *attr,
 200                                          const char *buf, size_t count)
 201 {
 202         ssize_t ret;
 203
 204         /* make sure buffer is available for host control command */
 205         mutex_lock(&smi_data_lock);
 206         ret = smi_data_buf_realloc(sizeof(struct apm_cmd));
 207         mutex_unlock(&smi_data_lock);
 208         if (ret)
 209                 return ret;
 210
 211         host_control_action = simple_strtoul(buf, NULL, 10);
 212         return count;
 213 }
 214
 215 static ssize_t host_control_smi_type_show(struct device *dev,
 216                                           struct device_attribute *attr,
 217                                           char *buf)
 218 {
 219         return sprintf(buf, "%u\n", host_control_smi_type);
 220 }
 221
 222 static ssize_t host_control_smi_type_store(struct device *dev,
 223                                            struct device_attribute *attr,
 224                                            const char *buf, size_t count)
 225 {
 226         host_control_smi_type = simple_strtoul(buf, NULL, 10);
 227         return count;
 228 }
 229
 230 static ssize_t host_control_on_shutdown_show(struct device *dev,
 231                                              struct device_attribute *attr,
 232                                              char *buf)
 233 {
 234         return sprintf(buf, "%u\n", host_control_on_shutdown);
 235 }
 236
 237 static ssize_t host_control_on_shutdown_store(struct device *dev,
 238                                               struct device_attribute *attr,
 239                                               const char *buf, size_t count)
 240 {
 241         host_control_on_shutdown = simple_strtoul(buf, NULL, 10);
 242         return count;
 243 }
 244
 245 /**
 246  * smi_request: generate SMI request
 247  *
 248  * Called with smi_data_lock.
 249  */
 250 static int smi_request(struct smi_cmd *smi_cmd)
 251 {
 252         cpumask_t old_mask;
 253         int ret = 0;
 254
 255         if (smi_cmd->magic != SMI_CMD_MAGIC) {
 256                 dev_info(&dcdbas_pdev->dev, "%s: invalid magic value\n",
 257                          __FUNCTION__);
 258                 return -EBADR;
 259         }
 260
 261         /* SMI requires CPU 0 */
 262         old_mask = current->cpus_allowed;
 263         set_cpus_allowed(current, cpumask_of_cpu(0));
 264         if (smp_processor_id() != 0) {
 265                 dev_dbg(&dcdbas_pdev->dev, "%s: failed to get CPU 0\n",
 266                         __FUNCTION__);
 267                 ret = -EBUSY;
 268                 goto out;
 269         }
 270
 271         /* generate SMI */
 272         asm volatile (
 273                 "outb %b0,%w1"
 274                 : /* no output args */
 275                 : "a" (smi_cmd->command_code),
 276                   "d" (smi_cmd->command_address),
 277                   "b" (smi_cmd->ebx),
 278                   "c" (smi_cmd->ecx)
 279                 : "memory"
 280         );
 281
 282 out:
 283         set_cpus_allowed(current, old_mask);
 284         return ret;
 285 }
 286
 287 /**
 288  * smi_request_store:
 289  *
 290  * The valid values are:
 291  * 0: zero SMI data buffer
 292  * 1: generate calling interface SMI
 293  * 2: generate raw SMI
 294  *
 295  * User application writes smi_cmd to smi_data before telling driver
 296  * to generate SMI.
 297  */
 298 static ssize_t smi_request_store(struct device *dev,
 299                                  struct device_attribute *attr,
 300                                  const char *buf, size_t count)
 301 {
 302         struct smi_cmd *smi_cmd;
 303         unsigned long val = simple_strtoul(buf, NULL, 10);
 304         ssize_t ret;
 305
 306         mutex_lock(&smi_data_lock);
 307
 308         if (smi_data_buf_size < sizeof(struct smi_cmd)) {
 309                 ret = -ENODEV;
 310                 goto out;
 311         }
 312         smi_cmd = (struct smi_cmd *)smi_data_buf;
 313
 314         switch (val) {
 315         case 2:
 316                 /* Raw SMI */
 317                 ret = smi_request(smi_cmd);
 318                 if (!ret)
 319                         ret = count;
 320                 break;
 321         case 1:
 322                 /* Calling Interface SMI */
 323                 smi_cmd->ebx = (u32) virt_to_phys(smi_cmd->command_buffer);
 324                 ret = smi_request(smi_cmd);
 325                 if (!ret)
 326                         ret = count;
 327                 break;
 328         case 0:
 329                 memset(smi_data_buf, 0, smi_data_buf_size);
 330                 ret = count;
 331                 break;
 332         default:
 333                 ret = -EINVAL;
 334                 break;
 335         }
 336
 337 out:
 338         mutex_unlock(&smi_data_lock);
 339         return ret;
 340 }
 341
 342 /**
 343  * host_control_smi: generate host control SMI
 344  *
 345  * Caller must set up the host control command in smi_data_buf.
 346  */
 347 static int host_control_smi(void)
 348 {
 349         struct apm_cmd *apm_cmd;
 350         u8 *data;
 351         unsigned long flags;
 352         u32 num_ticks;
 353         s8 cmd_status;
 354         u8 index;
 355
 356         apm_cmd = (struct apm_cmd *)smi_data_buf;
 357         apm_cmd->status = ESM_STATUS_CMD_UNSUCCESSFUL;
 358
 359         switch (host_control_smi_type) {
 360         case HC_SMITYPE_TYPE1:
 361                 spin_lock_irqsave(&rtc_lock, flags);
 362                 /* write SMI data buffer physical address */
 363                 data = (u8 *)&smi_data_buf_phys_addr;
 364                 for (index = PE1300_CMOS_CMD_STRUCT_PTR;
 365                      index < (PE1300_CMOS_CMD_STRUCT_PTR + 4);
 366                      index++, data++) {
 367                         outb(index,
 368                              (CMOS_BASE_PORT + CMOS_PAGE2_INDEX_PORT_PIIX4));
 369                         outb(*data,
 370                              (CMOS_BASE_PORT + CMOS_PAGE2_DATA_PORT_PIIX4));
 371                 }
 372
 373                 /* first set status to -1 as called by spec */
 374                 cmd_status = ESM_STATUS_CMD_UNSUCCESSFUL;
 375                 outb((u8) cmd_status, PCAT_APM_STATUS_PORT);
 376
 377                 /* generate SMM call */
 378                 outb(ESM_APM_CMD, PCAT_APM_CONTROL_PORT);
 379                 spin_unlock_irqrestore(&rtc_lock, flags);
 380
 381                 /* wait a few to see if it executed */
 382                 num_ticks = TIMEOUT_USEC_SHORT_SEMA_BLOCKING;
 383                 while ((cmd_status = inb(PCAT_APM_STATUS_PORT))
 384                        == ESM_STATUS_CMD_UNSUCCESSFUL) {
 385                         num_ticks--;
 386                         if (num_ticks == EXPIRED_TIMER)
 387                                 return -ETIME;
 388                 }
 389                 break;
 390
 391         case HC_SMITYPE_TYPE2:
 392         case HC_SMITYPE_TYPE3:
 393                 spin_lock_irqsave(&rtc_lock, flags);
 394                 /* write SMI data buffer physical address */
 395                 data = (u8 *)&smi_data_buf_phys_addr;
 396                 for (index = PE1400_CMOS_CMD_STRUCT_PTR;
 397                      index < (PE1400_CMOS_CMD_STRUCT_PTR + 4);
 398                      index++, data++) {
 399                         outb(index, (CMOS_BASE_PORT + CMOS_PAGE1_INDEX_PORT));
 400                         outb(*data, (CMOS_BASE_PORT + CMOS_PAGE1_DATA_PORT));
 401                 }
 402
 403                 /* generate SMM call */
 404                 if (host_control_smi_type == HC_SMITYPE_TYPE3)
 405                         outb(ESM_APM_CMD, PCAT_APM_CONTROL_PORT);
 406                 else
 407                         outb(ESM_APM_CMD, PE1400_APM_CONTROL_PORT);
 408
 409                 /* restore RTC index pointer since it was written to above */
 410                 CMOS_READ(RTC_REG_C);
 411                 spin_unlock_irqrestore(&rtc_lock, flags);
 412
 413                 /* read control port back to serialize write */
 414                 cmd_status = inb(PE1400_APM_CONTROL_PORT);
 415
 416                 /* wait a few to see if it executed */
 417                 num_ticks = TIMEOUT_USEC_SHORT_SEMA_BLOCKING;
 418                 while (apm_cmd->status == ESM_STATUS_CMD_UNSUCCESSFUL) {
 419                         num_ticks--;
 420                         if (num_ticks == EXPIRED_TIMER)
 421                                 return -ETIME;
 422                 }
 423                 break;
 424
 425         default:
 426                 dev_dbg(&dcdbas_pdev->dev, "%s: invalid SMI type %u\n",
 427                         __FUNCTION__, host_control_smi_type);
 428                 return -ENOSYS;
 429         }
 430
 431         return 0;
 432 }
 433
 434 /**
 435  * dcdbas_host_control: initiate host control
 436  *
 437  * This function is called by the driver after the system has
 438  * finished shutting down if the user application specified a
 439  * host control action to perform on shutdown.  It is safe to
 440  * use smi_data_buf at this point because the system has finished
 441  * shutting down and no userspace apps are running.
 442  */
 443 static void dcdbas_host_control(void)
 444 {
 445         struct apm_cmd *apm_cmd;
 446         u8 action;
 447
 448         if (host_control_action == HC_ACTION_NONE)
 449                 return;
 450
 451         action = host_control_action;
 452         host_control_action = HC_ACTION_NONE;
 453
 454         if (!smi_data_buf) {
 455                 dev_dbg(&dcdbas_pdev->dev, "%s: no SMI buffer\n", __FUNCTION__);
 456                 return;
 457         }
 458
 459         if (smi_data_buf_size < sizeof(struct apm_cmd)) {
 460                 dev_dbg(&dcdbas_pdev->dev, "%s: SMI buffer too small\n",
 461                         __FUNCTION__);
 462                 return;
 463         }
 464
 465         apm_cmd = (struct apm_cmd *)smi_data_buf;
 466
 467         /* power off takes precedence */
 468         if (action & HC_ACTION_HOST_CONTROL_POWEROFF) {
 469                 apm_cmd->command = ESM_APM_POWER_CYCLE;
 470                 apm_cmd->reserved = 0;
 471                 *((s16 *)&apm_cmd->parameters.shortreq.parm[0]) = (s16) 0;
 472                 host_control_smi();
 473         } else if (action & HC_ACTION_HOST_CONTROL_POWERCYCLE) {
 474                 apm_cmd->command = ESM_APM_POWER_CYCLE;
 475                 apm_cmd->reserved = 0;
 476                 *((s16 *)&apm_cmd->parameters.shortreq.parm[0]) = (s16) 20;
 477                 host_control_smi();
 478         }
 479 }
 480
 481 /**
 482  * dcdbas_reboot_notify: handle reboot notification for host control
 483  */
 484 static int dcdbas_reboot_notify(struct notifier_block *nb, unsigned long code,
 485                                 void *unused)
 486 {
 487         switch (code) {
 488         case SYS_DOWN:
 489         case SYS_HALT:
 490         case SYS_POWER_OFF:
 491                 if (host_control_on_shutdown) {
 492                         /* firmware is going to perform host control action */
 493                         printk(KERN_WARNING "Please wait for shutdown "
 494                                "action to complete...\n");
 495                         dcdbas_host_control();
 496                 }
 497                 break;
 498         }
 499
 500         return NOTIFY_DONE;
 501 }
 502
 503 static struct notifier_block dcdbas_reboot_nb = {
 504         .notifier_call = dcdbas_reboot_notify,
 505         .next = NULL,
 506         .priority = INT_MIN
 507 };
 508
 509 static DCDBAS_BIN_ATTR_RW(smi_data);
 510
 511 static struct bin_attribute *dcdbas_bin_attrs[] = {
 512         &bin_attr_smi_data,
 513         NULL
 514 };
 515
 516 static DCDBAS_DEV_ATTR_RW(smi_data_buf_size);
 517 static DCDBAS_DEV_ATTR_RO(smi_data_buf_phys_addr);
 518 static DCDBAS_DEV_ATTR_WO(smi_request);
 519 static DCDBAS_DEV_ATTR_RW(host_control_action);
 520 static DCDBAS_DEV_ATTR_RW(host_control_smi_type);
 521 static DCDBAS_DEV_ATTR_RW(host_control_on_shutdown);
 522
 523 static struct attribute *dcdbas_dev_attrs[] = {
 524         &dev_attr_smi_data_buf_size.attr,
 525         &dev_attr_smi_data_buf_phys_addr.attr,
 526         &dev_attr_smi_request.attr,
 527         &dev_attr_host_control_action.attr,
 528         &dev_attr_host_control_smi_type.attr,
 529         &dev_attr_host_control_on_shutdown.attr,
 530         NULL
 531 };
 532
 533 static struct attribute_group dcdbas_attr_group = {
 534         .attrs = dcdbas_dev_attrs,
 535 };
 536
 537 static int __devinit dcdbas_probe(struct platform_device *dev)
 538 {
 539         int i, error;
 540
 541         host_control_action = HC_ACTION_NONE;
 542         host_control_smi_type = HC_SMITYPE_NONE;
 543
 544         /*
 545          * BIOS SMI calls require buffer addresses be in 32-bit address space.
 546          * This is done by setting the DMA mask below.
 547          */
 548         dcdbas_pdev->dev.coherent_dma_mask = DMA_32BIT_MASK;
 549         dcdbas_pdev->dev.dma_mask = &dcdbas_pdev->dev.coherent_dma_mask;
 550
 551         error = sysfs_create_group(&dev->dev.kobj, &dcdbas_attr_group);
 552         if (error)
 553                 return error;
 554
 555         for (i = 0; dcdbas_bin_attrs[i]; i++) {
 556                 error = sysfs_create_bin_file(&dev->dev.kobj,
 557                                               dcdbas_bin_attrs[i]);
 558                 if (error) {
 559                         while (--i >= 0)
 560                                 sysfs_remove_bin_file(&dev->dev.kobj,
 561                                                       dcdbas_bin_attrs[i]);
 562                         sysfs_create_group(&dev->dev.kobj, &dcdbas_attr_group);
 563                         return error;
 564                 }
 565         }
 566
 567         register_reboot_notifier(&dcdbas_reboot_nb);
 568
 569         dev_info(&dev->dev, "%s (version %s)\n",
 570                  DRIVER_DESCRIPTION, DRIVER_VERSION);
 571
 572         return 0;
 573 }
 574
 575 static int __devexit dcdbas_remove(struct platform_device *dev)
 576 {
 577         int i;
 578
 579         unregister_reboot_notifier(&dcdbas_reboot_nb);
 580         for (i = 0; dcdbas_bin_attrs[i]; i++)
 581                 sysfs_remove_bin_file(&dev->dev.kobj, dcdbas_bin_attrs[i]);
 582         sysfs_remove_group(&dev->dev.kobj, &dcdbas_attr_group);
 583
 584         return 0;
 585 }
 586
 587 static struct platform_driver dcdbas_driver = {
 588         .driver         = {
 589                 .name   = DRIVER_NAME,
 590                 .owner  = THIS_MODULE,
 591         },
 592         .probe          = dcdbas_probe,
 593         .remove         = __devexit_p(dcdbas_remove),
 594 };
 595
 596 /**
 597  * dcdbas_init: initialize driver
 598  */
 599 static int __init dcdbas_init(void)
 600 {
 601         int error;
 602
 603         error = platform_driver_register(&dcdbas_driver);
 604         if (error)
 605                 return error;
 606
 607         dcdbas_pdev = platform_device_alloc(DRIVER_NAME, -1);
 608         if (!dcdbas_pdev) {
 609                 error = -ENOMEM;
 610                 goto err_unregister_driver;
 611         }
 612
 613         error = platform_device_add(dcdbas_pdev);
 614         if (error)
 615                 goto err_free_device;
 616
 617         return 0;
 618
 619  err_free_device:
 620         platform_device_put(dcdbas_pdev);
 621  err_unregister_driver:
 622         platform_driver_unregister(&dcdbas_driver);
 623         return error;
 624 }
 625
 626 /**
 627  * dcdbas_exit: perform driver cleanup
 628  */
 629 static void __exit dcdbas_exit(void)
 630 {
 631         /*
 632          * make sure functions that use dcdbas_pdev are called
 633          * before platform_device_unregister
 634          */
 635         unregister_reboot_notifier(&dcdbas_reboot_nb);
 636         smi_data_buf_free();
 637         platform_device_unregister(dcdbas_pdev);
 638         platform_driver_unregister(&dcdbas_driver);
 639
 640         /*
 641          * We have to free the buffer here instead of dcdbas_remove
 642          * because only in module exit function we can be sure that
 643          * all sysfs attributes belonging to this module have been
 644          * released.
 645          */
 646         smi_data_buf_free();
 647 }
 648
 649 module_init(dcdbas_init);
 650 module_exit(dcdbas_exit);
 651
 652 MODULE_DESCRIPTION(DRIVER_DESCRIPTION " (version " DRIVER_VERSION ")");
 653 MODULE_VERSION(DRIVER_VERSION);
 654 MODULE_AUTHOR("Dell Inc.");
 655 MODULE_LICENSE("GPL");
 656