1 // SPDX-License-Identifier: GPL-2.0-only 2 /* 3 * dcdbas.c: Dell Systems Management Base Driver 4 * 5 * The Dell Systems Management Base Driver provides a sysfs interface for 6 * systems management software to perform System Management Interrupts (SMIs) 7 * and Host Control Actions (power cycle or power off after OS shutdown) on 8 * Dell systems. 9 * 10 * See Documentation/driver-api/dcdbas.rst for more information. 11 * 12 * Copyright (C) 1995-2006 Dell Inc. 13 */ 14 15 #include <linux/platform_device.h> 16 #include <linux/acpi.h> 17 #include <linux/dma-mapping.h> 18 #include <linux/dmi.h> 19 #include <linux/errno.h> 20 #include <linux/cpu.h> 21 #include <linux/gfp.h> 22 #include <linux/init.h> 23 #include <linux/io.h> 24 #include <linux/kernel.h> 25 #include <linux/mc146818rtc.h> 26 #include <linux/module.h> 27 #include <linux/reboot.h> 28 #include <linux/sched.h> 29 #include <linux/smp.h> 30 #include <linux/spinlock.h> 31 #include <linux/string.h> 32 #include <linux/types.h> 33 #include <linux/mutex.h> 34 35 #include "dcdbas.h" 36 37 #define DRIVER_NAME "dcdbas" 38 #define DRIVER_VERSION "5.6.0-3.4" 39 #define DRIVER_DESCRIPTION "Dell Systems Management Base Driver" 40 41 static struct platform_device *dcdbas_pdev; 42 43 static unsigned long max_smi_data_buf_size = MAX_SMI_DATA_BUF_SIZE; 44 static DEFINE_MUTEX(smi_data_lock); 45 static u8 *bios_buffer; 46 static struct smi_buffer smi_buf; 47 48 static unsigned int host_control_action; 49 static unsigned int host_control_smi_type; 50 static unsigned int host_control_on_shutdown; 51 52 static bool wsmt_enabled; 53 54 int dcdbas_smi_alloc(struct smi_buffer *smi_buffer, unsigned long size) 55 { 56 smi_buffer->virt = dma_alloc_coherent(&dcdbas_pdev->dev, size, 57 &smi_buffer->dma, GFP_KERNEL); 58 if (!smi_buffer->virt) { 59 dev_dbg(&dcdbas_pdev->dev, 60 "%s: failed to allocate memory size %lu\n", 61 __func__, size); 62 return -ENOMEM; 63 } 64 smi_buffer->size = size; 65 66 dev_dbg(&dcdbas_pdev->dev, "%s: phys: %x size: %lu\n", 67 __func__, (u32)smi_buffer->dma, smi_buffer->size); 68 69 return 0; 70 } 71 EXPORT_SYMBOL_GPL(dcdbas_smi_alloc); 72 73 void dcdbas_smi_free(struct smi_buffer *smi_buffer) 74 { 75 if (!smi_buffer->virt) 76 return; 77 78 dev_dbg(&dcdbas_pdev->dev, "%s: phys: %x size: %lu\n", 79 __func__, (u32)smi_buffer->dma, smi_buffer->size); 80 dma_free_coherent(&dcdbas_pdev->dev, smi_buffer->size, 81 smi_buffer->virt, smi_buffer->dma); 82 smi_buffer->virt = NULL; 83 smi_buffer->dma = 0; 84 smi_buffer->size = 0; 85 } 86 EXPORT_SYMBOL_GPL(dcdbas_smi_free); 87 88 /** 89 * smi_data_buf_free: free SMI data buffer 90 */ 91 static void smi_data_buf_free(void) 92 { 93 if (!smi_buf.virt || wsmt_enabled) 94 return; 95 96 dcdbas_smi_free(&smi_buf); 97 } 98 99 /** 100 * smi_data_buf_realloc: grow SMI data buffer if needed 101 */ 102 static int smi_data_buf_realloc(unsigned long size) 103 { 104 struct smi_buffer tmp; 105 int ret; 106 107 if (smi_buf.size >= size) 108 return 0; 109 110 if (size > max_smi_data_buf_size) 111 return -EINVAL; 112 113 /* new buffer is needed */ 114 ret = dcdbas_smi_alloc(&tmp, size); 115 if (ret) 116 return ret; 117 118 /* memory zeroed by dma_alloc_coherent */ 119 if (smi_buf.virt) 120 memcpy(tmp.virt, smi_buf.virt, smi_buf.size); 121 122 /* free any existing buffer */ 123 smi_data_buf_free(); 124 125 /* set up new buffer for use */ 126 smi_buf = tmp; 127 128 return 0; 129 } 130 131 static ssize_t smi_data_buf_phys_addr_show(struct device *dev, 132 struct device_attribute *attr, 133 char *buf) 134 { 135 return sprintf(buf, "%x\n", (u32)smi_buf.dma); 136 } 137 138 static ssize_t smi_data_buf_size_show(struct device *dev, 139 struct device_attribute *attr, 140 char *buf) 141 { 142 return sprintf(buf, "%lu\n", smi_buf.size); 143 } 144 145 static ssize_t smi_data_buf_size_store(struct device *dev, 146 struct device_attribute *attr, 147 const char *buf, size_t count) 148 { 149 unsigned long buf_size; 150 ssize_t ret; 151 152 buf_size = simple_strtoul(buf, NULL, 10); 153 154 /* make sure SMI data buffer is at least buf_size */ 155 mutex_lock(&smi_data_lock); 156 ret = smi_data_buf_realloc(buf_size); 157 mutex_unlock(&smi_data_lock); 158 if (ret) 159 return ret; 160 161 return count; 162 } 163 164 static ssize_t smi_data_read(struct file *filp, struct kobject *kobj, 165 struct bin_attribute *bin_attr, 166 char *buf, loff_t pos, size_t count) 167 { 168 ssize_t ret; 169 170 mutex_lock(&smi_data_lock); 171 ret = memory_read_from_buffer(buf, count, &pos, smi_buf.virt, 172 smi_buf.size); 173 mutex_unlock(&smi_data_lock); 174 return ret; 175 } 176 177 static ssize_t smi_data_write(struct file *filp, struct kobject *kobj, 178 struct bin_attribute *bin_attr, 179 char *buf, loff_t pos, size_t count) 180 { 181 ssize_t ret; 182 183 if ((pos + count) > max_smi_data_buf_size) 184 return -EINVAL; 185 186 mutex_lock(&smi_data_lock); 187 188 ret = smi_data_buf_realloc(pos + count); 189 if (ret) 190 goto out; 191 192 memcpy(smi_buf.virt + pos, buf, count); 193 ret = count; 194 out: 195 mutex_unlock(&smi_data_lock); 196 return ret; 197 } 198 199 static ssize_t host_control_action_show(struct device *dev, 200 struct device_attribute *attr, 201 char *buf) 202 { 203 return sprintf(buf, "%u\n", host_control_action); 204 } 205 206 static ssize_t host_control_action_store(struct device *dev, 207 struct device_attribute *attr, 208 const char *buf, size_t count) 209 { 210 ssize_t ret; 211 212 /* make sure buffer is available for host control command */ 213 mutex_lock(&smi_data_lock); 214 ret = smi_data_buf_realloc(sizeof(struct apm_cmd)); 215 mutex_unlock(&smi_data_lock); 216 if (ret) 217 return ret; 218 219 host_control_action = simple_strtoul(buf, NULL, 10); 220 return count; 221 } 222 223 static ssize_t host_control_smi_type_show(struct device *dev, 224 struct device_attribute *attr, 225 char *buf) 226 { 227 return sprintf(buf, "%u\n", host_control_smi_type); 228 } 229 230 static ssize_t host_control_smi_type_store(struct device *dev, 231 struct device_attribute *attr, 232 const char *buf, size_t count) 233 { 234 host_control_smi_type = simple_strtoul(buf, NULL, 10); 235 return count; 236 } 237 238 static ssize_t host_control_on_shutdown_show(struct device *dev, 239 struct device_attribute *attr, 240 char *buf) 241 { 242 return sprintf(buf, "%u\n", host_control_on_shutdown); 243 } 244 245 static ssize_t host_control_on_shutdown_store(struct device *dev, 246 struct device_attribute *attr, 247 const char *buf, size_t count) 248 { 249 host_control_on_shutdown = simple_strtoul(buf, NULL, 10); 250 return count; 251 } 252 253 static int raise_smi(void *par) 254 { 255 struct smi_cmd *smi_cmd = par; 256 257 if (smp_processor_id() != 0) { 258 dev_dbg(&dcdbas_pdev->dev, "%s: failed to get CPU 0\n", 259 __func__); 260 return -EBUSY; 261 } 262 263 /* generate SMI */ 264 /* inb to force posted write through and make SMI happen now */ 265 asm volatile ( 266 "outb %b0,%w1\n" 267 "inb %w1" 268 : /* no output args */ 269 : "a" (smi_cmd->command_code), 270 "d" (smi_cmd->command_address), 271 "b" (smi_cmd->ebx), 272 "c" (smi_cmd->ecx) 273 : "memory" 274 ); 275 276 return 0; 277 } 278 /** 279 * dcdbas_smi_request: generate SMI request 280 * 281 * Called with smi_data_lock. 282 */ 283 int dcdbas_smi_request(struct smi_cmd *smi_cmd) 284 { 285 int ret; 286 287 if (smi_cmd->magic != SMI_CMD_MAGIC) { 288 dev_info(&dcdbas_pdev->dev, "%s: invalid magic value\n", 289 __func__); 290 return -EBADR; 291 } 292 293 /* SMI requires CPU 0 */ 294 cpus_read_lock(); 295 ret = smp_call_on_cpu(0, raise_smi, smi_cmd, true); 296 cpus_read_unlock(); 297 298 return ret; 299 } 300 EXPORT_SYMBOL(dcdbas_smi_request); 301 302 /** 303 * smi_request_store: 304 * 305 * The valid values are: 306 * 0: zero SMI data buffer 307 * 1: generate calling interface SMI 308 * 2: generate raw SMI 309 * 310 * User application writes smi_cmd to smi_data before telling driver 311 * to generate SMI. 312 */ 313 static ssize_t smi_request_store(struct device *dev, 314 struct device_attribute *attr, 315 const char *buf, size_t count) 316 { 317 struct smi_cmd *smi_cmd; 318 unsigned long val = simple_strtoul(buf, NULL, 10); 319 ssize_t ret; 320 321 mutex_lock(&smi_data_lock); 322 323 if (smi_buf.size < sizeof(struct smi_cmd)) { 324 ret = -ENODEV; 325 goto out; 326 } 327 smi_cmd = (struct smi_cmd *)smi_buf.virt; 328 329 switch (val) { 330 case 2: 331 /* Raw SMI */ 332 ret = dcdbas_smi_request(smi_cmd); 333 if (!ret) 334 ret = count; 335 break; 336 case 1: 337 /* 338 * Calling Interface SMI 339 * 340 * Provide physical address of command buffer field within 341 * the struct smi_cmd to BIOS. 342 * 343 * Because the address that smi_cmd (smi_buf.virt) points to 344 * will be from memremap() of a non-memory address if WSMT 345 * is present, we can't use virt_to_phys() on smi_cmd, so 346 * we have to use the physical address that was saved when 347 * the virtual address for smi_cmd was received. 348 */ 349 smi_cmd->ebx = (u32)smi_buf.dma + 350 offsetof(struct smi_cmd, command_buffer); 351 ret = dcdbas_smi_request(smi_cmd); 352 if (!ret) 353 ret = count; 354 break; 355 case 0: 356 memset(smi_buf.virt, 0, smi_buf.size); 357 ret = count; 358 break; 359 default: 360 ret = -EINVAL; 361 break; 362 } 363 364 out: 365 mutex_unlock(&smi_data_lock); 366 return ret; 367 } 368 369 /** 370 * host_control_smi: generate host control SMI 371 * 372 * Caller must set up the host control command in smi_buf.virt. 373 */ 374 static int host_control_smi(void) 375 { 376 struct apm_cmd *apm_cmd; 377 u8 *data; 378 unsigned long flags; 379 u32 num_ticks; 380 s8 cmd_status; 381 u8 index; 382 383 apm_cmd = (struct apm_cmd *)smi_buf.virt; 384 apm_cmd->status = ESM_STATUS_CMD_UNSUCCESSFUL; 385 386 switch (host_control_smi_type) { 387 case HC_SMITYPE_TYPE1: 388 spin_lock_irqsave(&rtc_lock, flags); 389 /* write SMI data buffer physical address */ 390 data = (u8 *)&smi_buf.dma; 391 for (index = PE1300_CMOS_CMD_STRUCT_PTR; 392 index < (PE1300_CMOS_CMD_STRUCT_PTR + 4); 393 index++, data++) { 394 outb(index, 395 (CMOS_BASE_PORT + CMOS_PAGE2_INDEX_PORT_PIIX4)); 396 outb(*data, 397 (CMOS_BASE_PORT + CMOS_PAGE2_DATA_PORT_PIIX4)); 398 } 399 400 /* first set status to -1 as called by spec */ 401 cmd_status = ESM_STATUS_CMD_UNSUCCESSFUL; 402 outb((u8) cmd_status, PCAT_APM_STATUS_PORT); 403 404 /* generate SMM call */ 405 outb(ESM_APM_CMD, PCAT_APM_CONTROL_PORT); 406 spin_unlock_irqrestore(&rtc_lock, flags); 407 408 /* wait a few to see if it executed */ 409 num_ticks = TIMEOUT_USEC_SHORT_SEMA_BLOCKING; 410 while ((s8)inb(PCAT_APM_STATUS_PORT) == ESM_STATUS_CMD_UNSUCCESSFUL) { 411 num_ticks--; 412 if (num_ticks == EXPIRED_TIMER) 413 return -ETIME; 414 } 415 break; 416 417 case HC_SMITYPE_TYPE2: 418 case HC_SMITYPE_TYPE3: 419 spin_lock_irqsave(&rtc_lock, flags); 420 /* write SMI data buffer physical address */ 421 data = (u8 *)&smi_buf.dma; 422 for (index = PE1400_CMOS_CMD_STRUCT_PTR; 423 index < (PE1400_CMOS_CMD_STRUCT_PTR + 4); 424 index++, data++) { 425 outb(index, (CMOS_BASE_PORT + CMOS_PAGE1_INDEX_PORT)); 426 outb(*data, (CMOS_BASE_PORT + CMOS_PAGE1_DATA_PORT)); 427 } 428 429 /* generate SMM call */ 430 if (host_control_smi_type == HC_SMITYPE_TYPE3) 431 outb(ESM_APM_CMD, PCAT_APM_CONTROL_PORT); 432 else 433 outb(ESM_APM_CMD, PE1400_APM_CONTROL_PORT); 434 435 /* restore RTC index pointer since it was written to above */ 436 CMOS_READ(RTC_REG_C); 437 spin_unlock_irqrestore(&rtc_lock, flags); 438 439 /* read control port back to serialize write */ 440 cmd_status = inb(PE1400_APM_CONTROL_PORT); 441 442 /* wait a few to see if it executed */ 443 num_ticks = TIMEOUT_USEC_SHORT_SEMA_BLOCKING; 444 while (apm_cmd->status == ESM_STATUS_CMD_UNSUCCESSFUL) { 445 num_ticks--; 446 if (num_ticks == EXPIRED_TIMER) 447 return -ETIME; 448 } 449 break; 450 451 default: 452 dev_dbg(&dcdbas_pdev->dev, "%s: invalid SMI type %u\n", 453 __func__, host_control_smi_type); 454 return -ENOSYS; 455 } 456 457 return 0; 458 } 459 460 /** 461 * dcdbas_host_control: initiate host control 462 * 463 * This function is called by the driver after the system has 464 * finished shutting down if the user application specified a 465 * host control action to perform on shutdown. It is safe to 466 * use smi_buf.virt at this point because the system has finished 467 * shutting down and no userspace apps are running. 468 */ 469 static void dcdbas_host_control(void) 470 { 471 struct apm_cmd *apm_cmd; 472 u8 action; 473 474 if (host_control_action == HC_ACTION_NONE) 475 return; 476 477 action = host_control_action; 478 host_control_action = HC_ACTION_NONE; 479 480 if (!smi_buf.virt) { 481 dev_dbg(&dcdbas_pdev->dev, "%s: no SMI buffer\n", __func__); 482 return; 483 } 484 485 if (smi_buf.size < sizeof(struct apm_cmd)) { 486 dev_dbg(&dcdbas_pdev->dev, "%s: SMI buffer too small\n", 487 __func__); 488 return; 489 } 490 491 apm_cmd = (struct apm_cmd *)smi_buf.virt; 492 493 /* power off takes precedence */ 494 if (action & HC_ACTION_HOST_CONTROL_POWEROFF) { 495 apm_cmd->command = ESM_APM_POWER_CYCLE; 496 apm_cmd->reserved = 0; 497 *((s16 *)&apm_cmd->parameters.shortreq.parm[0]) = (s16) 0; 498 host_control_smi(); 499 } else if (action & HC_ACTION_HOST_CONTROL_POWERCYCLE) { 500 apm_cmd->command = ESM_APM_POWER_CYCLE; 501 apm_cmd->reserved = 0; 502 *((s16 *)&apm_cmd->parameters.shortreq.parm[0]) = (s16) 20; 503 host_control_smi(); 504 } 505 } 506 507 /* WSMT */ 508 509 static u8 checksum(u8 *buffer, u8 length) 510 { 511 u8 sum = 0; 512 u8 *end = buffer + length; 513 514 while (buffer < end) 515 sum += *buffer++; 516 return sum; 517 } 518 519 static inline struct smm_eps_table *check_eps_table(u8 *addr) 520 { 521 struct smm_eps_table *eps = (struct smm_eps_table *)addr; 522 523 if (strncmp(eps->smm_comm_buff_anchor, SMM_EPS_SIG, 4) != 0) 524 return NULL; 525 526 if (checksum(addr, eps->length) != 0) 527 return NULL; 528 529 return eps; 530 } 531 532 static int dcdbas_check_wsmt(void) 533 { 534 const struct dmi_device *dev = NULL; 535 struct acpi_table_wsmt *wsmt = NULL; 536 struct smm_eps_table *eps = NULL; 537 u64 bios_buf_paddr; 538 u64 remap_size; 539 u8 *addr; 540 541 acpi_get_table(ACPI_SIG_WSMT, 0, (struct acpi_table_header **)&wsmt); 542 if (!wsmt) 543 return 0; 544 545 /* Check if WSMT ACPI table shows that protection is enabled */ 546 if (!(wsmt->protection_flags & ACPI_WSMT_FIXED_COMM_BUFFERS) || 547 !(wsmt->protection_flags & ACPI_WSMT_COMM_BUFFER_NESTED_PTR_PROTECTION)) 548 return 0; 549 550 /* 551 * BIOS could provide the address/size of the protected buffer 552 * in an SMBIOS string or in an EPS structure in 0xFxxxx. 553 */ 554 555 /* Check SMBIOS for buffer address */ 556 while ((dev = dmi_find_device(DMI_DEV_TYPE_OEM_STRING, NULL, dev))) 557 if (sscanf(dev->name, "30[%16llx;%8llx]", &bios_buf_paddr, 558 &remap_size) == 2) 559 goto remap; 560 561 /* Scan for EPS (entry point structure) */ 562 for (addr = (u8 *)__va(0xf0000); 563 addr < (u8 *)__va(0x100000 - sizeof(struct smm_eps_table)); 564 addr += 16) { 565 eps = check_eps_table(addr); 566 if (eps) 567 break; 568 } 569 570 if (!eps) { 571 dev_dbg(&dcdbas_pdev->dev, "found WSMT, but no firmware buffer found\n"); 572 return -ENODEV; 573 } 574 bios_buf_paddr = eps->smm_comm_buff_addr; 575 remap_size = eps->num_of_4k_pages * PAGE_SIZE; 576 577 remap: 578 /* 579 * Get physical address of buffer and map to virtual address. 580 * Table gives size in 4K pages, regardless of actual system page size. 581 */ 582 if (upper_32_bits(bios_buf_paddr + 8)) { 583 dev_warn(&dcdbas_pdev->dev, "found WSMT, but buffer address is above 4GB\n"); 584 return -EINVAL; 585 } 586 /* 587 * Limit remap size to MAX_SMI_DATA_BUF_SIZE + 8 (since the first 8 588 * bytes are used for a semaphore, not the data buffer itself). 589 */ 590 if (remap_size > MAX_SMI_DATA_BUF_SIZE + 8) 591 remap_size = MAX_SMI_DATA_BUF_SIZE + 8; 592 593 bios_buffer = memremap(bios_buf_paddr, remap_size, MEMREMAP_WB); 594 if (!bios_buffer) { 595 dev_warn(&dcdbas_pdev->dev, "found WSMT, but failed to map buffer\n"); 596 return -ENOMEM; 597 } 598 599 /* First 8 bytes is for a semaphore, not part of the smi_buf.virt */ 600 smi_buf.dma = bios_buf_paddr + 8; 601 smi_buf.virt = bios_buffer + 8; 602 smi_buf.size = remap_size - 8; 603 max_smi_data_buf_size = smi_buf.size; 604 wsmt_enabled = true; 605 dev_info(&dcdbas_pdev->dev, 606 "WSMT found, using firmware-provided SMI buffer.\n"); 607 return 1; 608 } 609 610 /** 611 * dcdbas_reboot_notify: handle reboot notification for host control 612 */ 613 static int dcdbas_reboot_notify(struct notifier_block *nb, unsigned long code, 614 void *unused) 615 { 616 switch (code) { 617 case SYS_DOWN: 618 case SYS_HALT: 619 case SYS_POWER_OFF: 620 if (host_control_on_shutdown) { 621 /* firmware is going to perform host control action */ 622 printk(KERN_WARNING "Please wait for shutdown " 623 "action to complete...\n"); 624 dcdbas_host_control(); 625 } 626 break; 627 } 628 629 return NOTIFY_DONE; 630 } 631 632 static struct notifier_block dcdbas_reboot_nb = { 633 .notifier_call = dcdbas_reboot_notify, 634 .next = NULL, 635 .priority = INT_MIN 636 }; 637 638 static DCDBAS_BIN_ATTR_RW(smi_data); 639 640 static struct bin_attribute *dcdbas_bin_attrs[] = { 641 &bin_attr_smi_data, 642 NULL 643 }; 644 645 static DCDBAS_DEV_ATTR_RW(smi_data_buf_size); 646 static DCDBAS_DEV_ATTR_RO(smi_data_buf_phys_addr); 647 static DCDBAS_DEV_ATTR_WO(smi_request); 648 static DCDBAS_DEV_ATTR_RW(host_control_action); 649 static DCDBAS_DEV_ATTR_RW(host_control_smi_type); 650 static DCDBAS_DEV_ATTR_RW(host_control_on_shutdown); 651 652 static struct attribute *dcdbas_dev_attrs[] = { 653 &dev_attr_smi_data_buf_size.attr, 654 &dev_attr_smi_data_buf_phys_addr.attr, 655 &dev_attr_smi_request.attr, 656 &dev_attr_host_control_action.attr, 657 &dev_attr_host_control_smi_type.attr, 658 &dev_attr_host_control_on_shutdown.attr, 659 NULL 660 }; 661 662 static const struct attribute_group dcdbas_attr_group = { 663 .attrs = dcdbas_dev_attrs, 664 .bin_attrs = dcdbas_bin_attrs, 665 }; 666 667 static int dcdbas_probe(struct platform_device *dev) 668 { 669 int error; 670 671 host_control_action = HC_ACTION_NONE; 672 host_control_smi_type = HC_SMITYPE_NONE; 673 674 dcdbas_pdev = dev; 675 676 /* Check if ACPI WSMT table specifies protected SMI buffer address */ 677 error = dcdbas_check_wsmt(); 678 if (error < 0) 679 return error; 680 681 /* 682 * BIOS SMI calls require buffer addresses be in 32-bit address space. 683 * This is done by setting the DMA mask below. 684 */ 685 error = dma_set_coherent_mask(&dcdbas_pdev->dev, DMA_BIT_MASK(32)); 686 if (error) 687 return error; 688 689 error = sysfs_create_group(&dev->dev.kobj, &dcdbas_attr_group); 690 if (error) 691 return error; 692 693 register_reboot_notifier(&dcdbas_reboot_nb); 694 695 dev_info(&dev->dev, "%s (version %s)\n", 696 DRIVER_DESCRIPTION, DRIVER_VERSION); 697 698 return 0; 699 } 700 701 static int dcdbas_remove(struct platform_device *dev) 702 { 703 unregister_reboot_notifier(&dcdbas_reboot_nb); 704 sysfs_remove_group(&dev->dev.kobj, &dcdbas_attr_group); 705 706 return 0; 707 } 708 709 static struct platform_driver dcdbas_driver = { 710 .driver = { 711 .name = DRIVER_NAME, 712 }, 713 .probe = dcdbas_probe, 714 .remove = dcdbas_remove, 715 }; 716 717 static const struct platform_device_info dcdbas_dev_info __initconst = { 718 .name = DRIVER_NAME, 719 .id = -1, 720 .dma_mask = DMA_BIT_MASK(32), 721 }; 722 723 static struct platform_device *dcdbas_pdev_reg; 724 725 /** 726 * dcdbas_init: initialize driver 727 */ 728 static int __init dcdbas_init(void) 729 { 730 int error; 731 732 error = platform_driver_register(&dcdbas_driver); 733 if (error) 734 return error; 735 736 dcdbas_pdev_reg = platform_device_register_full(&dcdbas_dev_info); 737 if (IS_ERR(dcdbas_pdev_reg)) { 738 error = PTR_ERR(dcdbas_pdev_reg); 739 goto err_unregister_driver; 740 } 741 742 return 0; 743 744 err_unregister_driver: 745 platform_driver_unregister(&dcdbas_driver); 746 return error; 747 } 748 749 /** 750 * dcdbas_exit: perform driver cleanup 751 */ 752 static void __exit dcdbas_exit(void) 753 { 754 /* 755 * make sure functions that use dcdbas_pdev are called 756 * before platform_device_unregister 757 */ 758 unregister_reboot_notifier(&dcdbas_reboot_nb); 759 760 /* 761 * We have to free the buffer here instead of dcdbas_remove 762 * because only in module exit function we can be sure that 763 * all sysfs attributes belonging to this module have been 764 * released. 765 */ 766 if (dcdbas_pdev) 767 smi_data_buf_free(); 768 if (bios_buffer) 769 memunmap(bios_buffer); 770 platform_device_unregister(dcdbas_pdev_reg); 771 platform_driver_unregister(&dcdbas_driver); 772 } 773 774 subsys_initcall_sync(dcdbas_init); 775 module_exit(dcdbas_exit); 776 777 MODULE_DESCRIPTION(DRIVER_DESCRIPTION " (version " DRIVER_VERSION ")"); 778 MODULE_VERSION(DRIVER_VERSION); 779 MODULE_AUTHOR("Dell Inc."); 780 MODULE_LICENSE("GPL"); 781 /* Any System or BIOS claiming to be by Dell */ 782 MODULE_ALIAS("dmi:*:[bs]vnD[Ee][Ll][Ll]*:*"); 783