1 /* 2 * APEI Error Record Serialization Table support 3 * 4 * ERST is a way provided by APEI to save and retrieve hardware error 5 * information to and from a persistent store. 6 * 7 * For more information about ERST, please refer to ACPI Specification 8 * version 4.0, section 17.4. 9 * 10 * Copyright 2010 Intel Corp. 11 * Author: Huang Ying <ying.huang@intel.com> 12 * 13 * This program is free software; you can redistribute it and/or 14 * modify it under the terms of the GNU General Public License version 15 * 2 as published by 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 * You should have received a copy of the GNU General Public License 23 * along with this program; if not, write to the Free Software 24 * Foundation, Inc., 59 Temple Place, Suite 330, Boston, MA 02111-1307 USA 25 */ 26 27 #include <linux/kernel.h> 28 #include <linux/module.h> 29 #include <linux/init.h> 30 #include <linux/delay.h> 31 #include <linux/io.h> 32 #include <linux/acpi.h> 33 #include <linux/uaccess.h> 34 #include <linux/cper.h> 35 #include <linux/nmi.h> 36 #include <linux/hardirq.h> 37 #include <acpi/apei.h> 38 39 #include "apei-internal.h" 40 41 #define ERST_PFX "ERST: " 42 43 /* ERST command status */ 44 #define ERST_STATUS_SUCCESS 0x0 45 #define ERST_STATUS_NOT_ENOUGH_SPACE 0x1 46 #define ERST_STATUS_HARDWARE_NOT_AVAILABLE 0x2 47 #define ERST_STATUS_FAILED 0x3 48 #define ERST_STATUS_RECORD_STORE_EMPTY 0x4 49 #define ERST_STATUS_RECORD_NOT_FOUND 0x5 50 51 #define ERST_TAB_ENTRY(tab) \ 52 ((struct acpi_whea_header *)((char *)(tab) + \ 53 sizeof(struct acpi_table_erst))) 54 55 #define SPIN_UNIT 100 /* 100ns */ 56 /* Firmware should respond within 1 miliseconds */ 57 #define FIRMWARE_TIMEOUT (1 * NSEC_PER_MSEC) 58 #define FIRMWARE_MAX_STALL 50 /* 50us */ 59 60 int erst_disable; 61 EXPORT_SYMBOL_GPL(erst_disable); 62 63 static struct acpi_table_erst *erst_tab; 64 65 /* ERST Error Log Address Range atrributes */ 66 #define ERST_RANGE_RESERVED 0x0001 67 #define ERST_RANGE_NVRAM 0x0002 68 #define ERST_RANGE_SLOW 0x0004 69 70 /* 71 * ERST Error Log Address Range, used as buffer for reading/writing 72 * error records. 73 */ 74 static struct erst_erange { 75 u64 base; 76 u64 size; 77 void __iomem *vaddr; 78 u32 attr; 79 } erst_erange; 80 81 /* 82 * Prevent ERST interpreter to run simultaneously, because the 83 * corresponding firmware implementation may not work properly when 84 * invoked simultaneously. 85 * 86 * It is used to provide exclusive accessing for ERST Error Log 87 * Address Range too. 88 */ 89 static DEFINE_SPINLOCK(erst_lock); 90 91 static inline int erst_errno(int command_status) 92 { 93 switch (command_status) { 94 case ERST_STATUS_SUCCESS: 95 return 0; 96 case ERST_STATUS_HARDWARE_NOT_AVAILABLE: 97 return -ENODEV; 98 case ERST_STATUS_NOT_ENOUGH_SPACE: 99 return -ENOSPC; 100 case ERST_STATUS_RECORD_STORE_EMPTY: 101 case ERST_STATUS_RECORD_NOT_FOUND: 102 return -ENOENT; 103 default: 104 return -EINVAL; 105 } 106 } 107 108 static int erst_timedout(u64 *t, u64 spin_unit) 109 { 110 if ((s64)*t < spin_unit) { 111 pr_warning(FW_WARN ERST_PFX 112 "Firmware does not respond in time\n"); 113 return 1; 114 } 115 *t -= spin_unit; 116 ndelay(spin_unit); 117 touch_nmi_watchdog(); 118 return 0; 119 } 120 121 static int erst_exec_load_var1(struct apei_exec_context *ctx, 122 struct acpi_whea_header *entry) 123 { 124 return __apei_exec_read_register(entry, &ctx->var1); 125 } 126 127 static int erst_exec_load_var2(struct apei_exec_context *ctx, 128 struct acpi_whea_header *entry) 129 { 130 return __apei_exec_read_register(entry, &ctx->var2); 131 } 132 133 static int erst_exec_store_var1(struct apei_exec_context *ctx, 134 struct acpi_whea_header *entry) 135 { 136 return __apei_exec_write_register(entry, ctx->var1); 137 } 138 139 static int erst_exec_add(struct apei_exec_context *ctx, 140 struct acpi_whea_header *entry) 141 { 142 ctx->var1 += ctx->var2; 143 return 0; 144 } 145 146 static int erst_exec_subtract(struct apei_exec_context *ctx, 147 struct acpi_whea_header *entry) 148 { 149 ctx->var1 -= ctx->var2; 150 return 0; 151 } 152 153 static int erst_exec_add_value(struct apei_exec_context *ctx, 154 struct acpi_whea_header *entry) 155 { 156 int rc; 157 u64 val; 158 159 rc = __apei_exec_read_register(entry, &val); 160 if (rc) 161 return rc; 162 val += ctx->value; 163 rc = __apei_exec_write_register(entry, val); 164 return rc; 165 } 166 167 static int erst_exec_subtract_value(struct apei_exec_context *ctx, 168 struct acpi_whea_header *entry) 169 { 170 int rc; 171 u64 val; 172 173 rc = __apei_exec_read_register(entry, &val); 174 if (rc) 175 return rc; 176 val -= ctx->value; 177 rc = __apei_exec_write_register(entry, val); 178 return rc; 179 } 180 181 static int erst_exec_stall(struct apei_exec_context *ctx, 182 struct acpi_whea_header *entry) 183 { 184 u64 stall_time; 185 186 if (ctx->value > FIRMWARE_MAX_STALL) { 187 if (!in_nmi()) 188 pr_warning(FW_WARN ERST_PFX 189 "Too long stall time for stall instruction: %llx.\n", 190 ctx->value); 191 stall_time = FIRMWARE_MAX_STALL; 192 } else 193 stall_time = ctx->value; 194 udelay(stall_time); 195 return 0; 196 } 197 198 static int erst_exec_stall_while_true(struct apei_exec_context *ctx, 199 struct acpi_whea_header *entry) 200 { 201 int rc; 202 u64 val; 203 u64 timeout = FIRMWARE_TIMEOUT; 204 u64 stall_time; 205 206 if (ctx->var1 > FIRMWARE_MAX_STALL) { 207 if (!in_nmi()) 208 pr_warning(FW_WARN ERST_PFX 209 "Too long stall time for stall while true instruction: %llx.\n", 210 ctx->var1); 211 stall_time = FIRMWARE_MAX_STALL; 212 } else 213 stall_time = ctx->var1; 214 215 for (;;) { 216 rc = __apei_exec_read_register(entry, &val); 217 if (rc) 218 return rc; 219 if (val != ctx->value) 220 break; 221 if (erst_timedout(&timeout, stall_time * NSEC_PER_USEC)) 222 return -EIO; 223 } 224 return 0; 225 } 226 227 static int erst_exec_skip_next_instruction_if_true( 228 struct apei_exec_context *ctx, 229 struct acpi_whea_header *entry) 230 { 231 int rc; 232 u64 val; 233 234 rc = __apei_exec_read_register(entry, &val); 235 if (rc) 236 return rc; 237 if (val == ctx->value) { 238 ctx->ip += 2; 239 return APEI_EXEC_SET_IP; 240 } 241 242 return 0; 243 } 244 245 static int erst_exec_goto(struct apei_exec_context *ctx, 246 struct acpi_whea_header *entry) 247 { 248 ctx->ip = ctx->value; 249 return APEI_EXEC_SET_IP; 250 } 251 252 static int erst_exec_set_src_address_base(struct apei_exec_context *ctx, 253 struct acpi_whea_header *entry) 254 { 255 return __apei_exec_read_register(entry, &ctx->src_base); 256 } 257 258 static int erst_exec_set_dst_address_base(struct apei_exec_context *ctx, 259 struct acpi_whea_header *entry) 260 { 261 return __apei_exec_read_register(entry, &ctx->dst_base); 262 } 263 264 static int erst_exec_move_data(struct apei_exec_context *ctx, 265 struct acpi_whea_header *entry) 266 { 267 int rc; 268 u64 offset; 269 void *src, *dst; 270 271 /* ioremap does not work in interrupt context */ 272 if (in_interrupt()) { 273 pr_warning(ERST_PFX 274 "MOVE_DATA can not be used in interrupt context"); 275 return -EBUSY; 276 } 277 278 rc = __apei_exec_read_register(entry, &offset); 279 if (rc) 280 return rc; 281 282 src = ioremap(ctx->src_base + offset, ctx->var2); 283 if (!src) 284 return -ENOMEM; 285 dst = ioremap(ctx->dst_base + offset, ctx->var2); 286 if (!dst) 287 return -ENOMEM; 288 289 memmove(dst, src, ctx->var2); 290 291 iounmap(src); 292 iounmap(dst); 293 294 return 0; 295 } 296 297 static struct apei_exec_ins_type erst_ins_type[] = { 298 [ACPI_ERST_READ_REGISTER] = { 299 .flags = APEI_EXEC_INS_ACCESS_REGISTER, 300 .run = apei_exec_read_register, 301 }, 302 [ACPI_ERST_READ_REGISTER_VALUE] = { 303 .flags = APEI_EXEC_INS_ACCESS_REGISTER, 304 .run = apei_exec_read_register_value, 305 }, 306 [ACPI_ERST_WRITE_REGISTER] = { 307 .flags = APEI_EXEC_INS_ACCESS_REGISTER, 308 .run = apei_exec_write_register, 309 }, 310 [ACPI_ERST_WRITE_REGISTER_VALUE] = { 311 .flags = APEI_EXEC_INS_ACCESS_REGISTER, 312 .run = apei_exec_write_register_value, 313 }, 314 [ACPI_ERST_NOOP] = { 315 .flags = 0, 316 .run = apei_exec_noop, 317 }, 318 [ACPI_ERST_LOAD_VAR1] = { 319 .flags = APEI_EXEC_INS_ACCESS_REGISTER, 320 .run = erst_exec_load_var1, 321 }, 322 [ACPI_ERST_LOAD_VAR2] = { 323 .flags = APEI_EXEC_INS_ACCESS_REGISTER, 324 .run = erst_exec_load_var2, 325 }, 326 [ACPI_ERST_STORE_VAR1] = { 327 .flags = APEI_EXEC_INS_ACCESS_REGISTER, 328 .run = erst_exec_store_var1, 329 }, 330 [ACPI_ERST_ADD] = { 331 .flags = 0, 332 .run = erst_exec_add, 333 }, 334 [ACPI_ERST_SUBTRACT] = { 335 .flags = 0, 336 .run = erst_exec_subtract, 337 }, 338 [ACPI_ERST_ADD_VALUE] = { 339 .flags = APEI_EXEC_INS_ACCESS_REGISTER, 340 .run = erst_exec_add_value, 341 }, 342 [ACPI_ERST_SUBTRACT_VALUE] = { 343 .flags = APEI_EXEC_INS_ACCESS_REGISTER, 344 .run = erst_exec_subtract_value, 345 }, 346 [ACPI_ERST_STALL] = { 347 .flags = 0, 348 .run = erst_exec_stall, 349 }, 350 [ACPI_ERST_STALL_WHILE_TRUE] = { 351 .flags = APEI_EXEC_INS_ACCESS_REGISTER, 352 .run = erst_exec_stall_while_true, 353 }, 354 [ACPI_ERST_SKIP_NEXT_IF_TRUE] = { 355 .flags = APEI_EXEC_INS_ACCESS_REGISTER, 356 .run = erst_exec_skip_next_instruction_if_true, 357 }, 358 [ACPI_ERST_GOTO] = { 359 .flags = 0, 360 .run = erst_exec_goto, 361 }, 362 [ACPI_ERST_SET_SRC_ADDRESS_BASE] = { 363 .flags = APEI_EXEC_INS_ACCESS_REGISTER, 364 .run = erst_exec_set_src_address_base, 365 }, 366 [ACPI_ERST_SET_DST_ADDRESS_BASE] = { 367 .flags = APEI_EXEC_INS_ACCESS_REGISTER, 368 .run = erst_exec_set_dst_address_base, 369 }, 370 [ACPI_ERST_MOVE_DATA] = { 371 .flags = APEI_EXEC_INS_ACCESS_REGISTER, 372 .run = erst_exec_move_data, 373 }, 374 }; 375 376 static inline void erst_exec_ctx_init(struct apei_exec_context *ctx) 377 { 378 apei_exec_ctx_init(ctx, erst_ins_type, ARRAY_SIZE(erst_ins_type), 379 ERST_TAB_ENTRY(erst_tab), erst_tab->entries); 380 } 381 382 static int erst_get_erange(struct erst_erange *range) 383 { 384 struct apei_exec_context ctx; 385 int rc; 386 387 erst_exec_ctx_init(&ctx); 388 rc = apei_exec_run(&ctx, ACPI_ERST_GET_ERROR_RANGE); 389 if (rc) 390 return rc; 391 range->base = apei_exec_ctx_get_output(&ctx); 392 rc = apei_exec_run(&ctx, ACPI_ERST_GET_ERROR_LENGTH); 393 if (rc) 394 return rc; 395 range->size = apei_exec_ctx_get_output(&ctx); 396 rc = apei_exec_run(&ctx, ACPI_ERST_GET_ERROR_ATTRIBUTES); 397 if (rc) 398 return rc; 399 range->attr = apei_exec_ctx_get_output(&ctx); 400 401 return 0; 402 } 403 404 static ssize_t __erst_get_record_count(void) 405 { 406 struct apei_exec_context ctx; 407 int rc; 408 409 erst_exec_ctx_init(&ctx); 410 rc = apei_exec_run(&ctx, ACPI_ERST_GET_RECORD_COUNT); 411 if (rc) 412 return rc; 413 return apei_exec_ctx_get_output(&ctx); 414 } 415 416 ssize_t erst_get_record_count(void) 417 { 418 ssize_t count; 419 unsigned long flags; 420 421 if (erst_disable) 422 return -ENODEV; 423 424 spin_lock_irqsave(&erst_lock, flags); 425 count = __erst_get_record_count(); 426 spin_unlock_irqrestore(&erst_lock, flags); 427 428 return count; 429 } 430 EXPORT_SYMBOL_GPL(erst_get_record_count); 431 432 static int __erst_get_next_record_id(u64 *record_id) 433 { 434 struct apei_exec_context ctx; 435 int rc; 436 437 erst_exec_ctx_init(&ctx); 438 rc = apei_exec_run(&ctx, ACPI_ERST_GET_RECORD_ID); 439 if (rc) 440 return rc; 441 *record_id = apei_exec_ctx_get_output(&ctx); 442 443 return 0; 444 } 445 446 /* 447 * Get the record ID of an existing error record on the persistent 448 * storage. If there is no error record on the persistent storage, the 449 * returned record_id is APEI_ERST_INVALID_RECORD_ID. 450 */ 451 int erst_get_next_record_id(u64 *record_id) 452 { 453 int rc; 454 unsigned long flags; 455 456 if (erst_disable) 457 return -ENODEV; 458 459 spin_lock_irqsave(&erst_lock, flags); 460 rc = __erst_get_next_record_id(record_id); 461 spin_unlock_irqrestore(&erst_lock, flags); 462 463 return rc; 464 } 465 EXPORT_SYMBOL_GPL(erst_get_next_record_id); 466 467 static int __erst_write_to_storage(u64 offset) 468 { 469 struct apei_exec_context ctx; 470 u64 timeout = FIRMWARE_TIMEOUT; 471 u64 val; 472 int rc; 473 474 erst_exec_ctx_init(&ctx); 475 rc = apei_exec_run(&ctx, ACPI_ERST_BEGIN_WRITE); 476 if (rc) 477 return rc; 478 apei_exec_ctx_set_input(&ctx, offset); 479 rc = apei_exec_run(&ctx, ACPI_ERST_SET_RECORD_OFFSET); 480 if (rc) 481 return rc; 482 rc = apei_exec_run(&ctx, ACPI_ERST_EXECUTE_OPERATION); 483 if (rc) 484 return rc; 485 for (;;) { 486 rc = apei_exec_run(&ctx, ACPI_ERST_CHECK_BUSY_STATUS); 487 if (rc) 488 return rc; 489 val = apei_exec_ctx_get_output(&ctx); 490 if (!val) 491 break; 492 if (erst_timedout(&timeout, SPIN_UNIT)) 493 return -EIO; 494 } 495 rc = apei_exec_run(&ctx, ACPI_ERST_GET_COMMAND_STATUS); 496 if (rc) 497 return rc; 498 val = apei_exec_ctx_get_output(&ctx); 499 rc = apei_exec_run(&ctx, ACPI_ERST_END); 500 if (rc) 501 return rc; 502 503 return erst_errno(val); 504 } 505 506 static int __erst_read_from_storage(u64 record_id, u64 offset) 507 { 508 struct apei_exec_context ctx; 509 u64 timeout = FIRMWARE_TIMEOUT; 510 u64 val; 511 int rc; 512 513 erst_exec_ctx_init(&ctx); 514 rc = apei_exec_run(&ctx, ACPI_ERST_BEGIN_READ); 515 if (rc) 516 return rc; 517 apei_exec_ctx_set_input(&ctx, offset); 518 rc = apei_exec_run(&ctx, ACPI_ERST_SET_RECORD_OFFSET); 519 if (rc) 520 return rc; 521 apei_exec_ctx_set_input(&ctx, record_id); 522 rc = apei_exec_run(&ctx, ACPI_ERST_SET_RECORD_ID); 523 if (rc) 524 return rc; 525 rc = apei_exec_run(&ctx, ACPI_ERST_EXECUTE_OPERATION); 526 if (rc) 527 return rc; 528 for (;;) { 529 rc = apei_exec_run(&ctx, ACPI_ERST_CHECK_BUSY_STATUS); 530 if (rc) 531 return rc; 532 val = apei_exec_ctx_get_output(&ctx); 533 if (!val) 534 break; 535 if (erst_timedout(&timeout, SPIN_UNIT)) 536 return -EIO; 537 }; 538 rc = apei_exec_run(&ctx, ACPI_ERST_GET_COMMAND_STATUS); 539 if (rc) 540 return rc; 541 val = apei_exec_ctx_get_output(&ctx); 542 rc = apei_exec_run(&ctx, ACPI_ERST_END); 543 if (rc) 544 return rc; 545 546 return erst_errno(val); 547 } 548 549 static int __erst_clear_from_storage(u64 record_id) 550 { 551 struct apei_exec_context ctx; 552 u64 timeout = FIRMWARE_TIMEOUT; 553 u64 val; 554 int rc; 555 556 erst_exec_ctx_init(&ctx); 557 rc = apei_exec_run(&ctx, ACPI_ERST_BEGIN_CLEAR); 558 if (rc) 559 return rc; 560 apei_exec_ctx_set_input(&ctx, record_id); 561 rc = apei_exec_run(&ctx, ACPI_ERST_SET_RECORD_ID); 562 if (rc) 563 return rc; 564 rc = apei_exec_run(&ctx, ACPI_ERST_EXECUTE_OPERATION); 565 if (rc) 566 return rc; 567 for (;;) { 568 rc = apei_exec_run(&ctx, ACPI_ERST_CHECK_BUSY_STATUS); 569 if (rc) 570 return rc; 571 val = apei_exec_ctx_get_output(&ctx); 572 if (!val) 573 break; 574 if (erst_timedout(&timeout, SPIN_UNIT)) 575 return -EIO; 576 } 577 rc = apei_exec_run(&ctx, ACPI_ERST_GET_COMMAND_STATUS); 578 if (rc) 579 return rc; 580 val = apei_exec_ctx_get_output(&ctx); 581 rc = apei_exec_run(&ctx, ACPI_ERST_END); 582 if (rc) 583 return rc; 584 585 return erst_errno(val); 586 } 587 588 /* NVRAM ERST Error Log Address Range is not supported yet */ 589 static void pr_unimpl_nvram(void) 590 { 591 if (printk_ratelimit()) 592 pr_warning(ERST_PFX 593 "NVRAM ERST Log Address Range is not implemented yet\n"); 594 } 595 596 static int __erst_write_to_nvram(const struct cper_record_header *record) 597 { 598 /* do not print message, because printk is not safe for NMI */ 599 return -ENOSYS; 600 } 601 602 static int __erst_read_to_erange_from_nvram(u64 record_id, u64 *offset) 603 { 604 pr_unimpl_nvram(); 605 return -ENOSYS; 606 } 607 608 static int __erst_clear_from_nvram(u64 record_id) 609 { 610 pr_unimpl_nvram(); 611 return -ENOSYS; 612 } 613 614 int erst_write(const struct cper_record_header *record) 615 { 616 int rc; 617 unsigned long flags; 618 struct cper_record_header *rcd_erange; 619 620 if (erst_disable) 621 return -ENODEV; 622 623 if (memcmp(record->signature, CPER_SIG_RECORD, CPER_SIG_SIZE)) 624 return -EINVAL; 625 626 if (erst_erange.attr & ERST_RANGE_NVRAM) { 627 if (!spin_trylock_irqsave(&erst_lock, flags)) 628 return -EBUSY; 629 rc = __erst_write_to_nvram(record); 630 spin_unlock_irqrestore(&erst_lock, flags); 631 return rc; 632 } 633 634 if (record->record_length > erst_erange.size) 635 return -EINVAL; 636 637 if (!spin_trylock_irqsave(&erst_lock, flags)) 638 return -EBUSY; 639 memcpy(erst_erange.vaddr, record, record->record_length); 640 rcd_erange = erst_erange.vaddr; 641 /* signature for serialization system */ 642 memcpy(&rcd_erange->persistence_information, "ER", 2); 643 644 rc = __erst_write_to_storage(0); 645 spin_unlock_irqrestore(&erst_lock, flags); 646 647 return rc; 648 } 649 EXPORT_SYMBOL_GPL(erst_write); 650 651 static int __erst_read_to_erange(u64 record_id, u64 *offset) 652 { 653 int rc; 654 655 if (erst_erange.attr & ERST_RANGE_NVRAM) 656 return __erst_read_to_erange_from_nvram( 657 record_id, offset); 658 659 rc = __erst_read_from_storage(record_id, 0); 660 if (rc) 661 return rc; 662 *offset = 0; 663 664 return 0; 665 } 666 667 static ssize_t __erst_read(u64 record_id, struct cper_record_header *record, 668 size_t buflen) 669 { 670 int rc; 671 u64 offset, len = 0; 672 struct cper_record_header *rcd_tmp; 673 674 rc = __erst_read_to_erange(record_id, &offset); 675 if (rc) 676 return rc; 677 rcd_tmp = erst_erange.vaddr + offset; 678 len = rcd_tmp->record_length; 679 if (len <= buflen) 680 memcpy(record, rcd_tmp, len); 681 682 return len; 683 } 684 685 /* 686 * If return value > buflen, the buffer size is not big enough, 687 * else if return value < 0, something goes wrong, 688 * else everything is OK, and return value is record length 689 */ 690 ssize_t erst_read(u64 record_id, struct cper_record_header *record, 691 size_t buflen) 692 { 693 ssize_t len; 694 unsigned long flags; 695 696 if (erst_disable) 697 return -ENODEV; 698 699 spin_lock_irqsave(&erst_lock, flags); 700 len = __erst_read(record_id, record, buflen); 701 spin_unlock_irqrestore(&erst_lock, flags); 702 return len; 703 } 704 EXPORT_SYMBOL_GPL(erst_read); 705 706 /* 707 * If return value > buflen, the buffer size is not big enough, 708 * else if return value = 0, there is no more record to read, 709 * else if return value < 0, something goes wrong, 710 * else everything is OK, and return value is record length 711 */ 712 ssize_t erst_read_next(struct cper_record_header *record, size_t buflen) 713 { 714 int rc; 715 ssize_t len; 716 unsigned long flags; 717 u64 record_id; 718 719 if (erst_disable) 720 return -ENODEV; 721 722 spin_lock_irqsave(&erst_lock, flags); 723 rc = __erst_get_next_record_id(&record_id); 724 if (rc) { 725 spin_unlock_irqrestore(&erst_lock, flags); 726 return rc; 727 } 728 /* no more record */ 729 if (record_id == APEI_ERST_INVALID_RECORD_ID) { 730 spin_unlock_irqrestore(&erst_lock, flags); 731 return 0; 732 } 733 734 len = __erst_read(record_id, record, buflen); 735 spin_unlock_irqrestore(&erst_lock, flags); 736 737 return len; 738 } 739 EXPORT_SYMBOL_GPL(erst_read_next); 740 741 int erst_clear(u64 record_id) 742 { 743 int rc; 744 unsigned long flags; 745 746 if (erst_disable) 747 return -ENODEV; 748 749 spin_lock_irqsave(&erst_lock, flags); 750 if (erst_erange.attr & ERST_RANGE_NVRAM) 751 rc = __erst_clear_from_nvram(record_id); 752 else 753 rc = __erst_clear_from_storage(record_id); 754 spin_unlock_irqrestore(&erst_lock, flags); 755 756 return rc; 757 } 758 EXPORT_SYMBOL_GPL(erst_clear); 759 760 static int __init setup_erst_disable(char *str) 761 { 762 erst_disable = 1; 763 return 0; 764 } 765 766 __setup("erst_disable", setup_erst_disable); 767 768 static int erst_check_table(struct acpi_table_erst *erst_tab) 769 { 770 if ((erst_tab->header_length != 771 (sizeof(struct acpi_table_erst) - sizeof(erst_tab->header))) 772 && (erst_tab->header_length != sizeof(struct acpi_table_einj))) 773 return -EINVAL; 774 if (erst_tab->header.length < sizeof(struct acpi_table_erst)) 775 return -EINVAL; 776 if (erst_tab->entries != 777 (erst_tab->header.length - sizeof(struct acpi_table_erst)) / 778 sizeof(struct acpi_erst_entry)) 779 return -EINVAL; 780 781 return 0; 782 } 783 784 static int __init erst_init(void) 785 { 786 int rc = 0; 787 acpi_status status; 788 struct apei_exec_context ctx; 789 struct apei_resources erst_resources; 790 struct resource *r; 791 792 if (acpi_disabled) 793 goto err; 794 795 if (erst_disable) { 796 pr_info(ERST_PFX 797 "Error Record Serialization Table (ERST) support is disabled.\n"); 798 goto err; 799 } 800 801 status = acpi_get_table(ACPI_SIG_ERST, 0, 802 (struct acpi_table_header **)&erst_tab); 803 if (status == AE_NOT_FOUND) { 804 pr_info(ERST_PFX "Table is not found!\n"); 805 goto err; 806 } else if (ACPI_FAILURE(status)) { 807 const char *msg = acpi_format_exception(status); 808 pr_err(ERST_PFX "Failed to get table, %s\n", msg); 809 rc = -EINVAL; 810 goto err; 811 } 812 813 rc = erst_check_table(erst_tab); 814 if (rc) { 815 pr_err(FW_BUG ERST_PFX "ERST table is invalid\n"); 816 goto err; 817 } 818 819 apei_resources_init(&erst_resources); 820 erst_exec_ctx_init(&ctx); 821 rc = apei_exec_collect_resources(&ctx, &erst_resources); 822 if (rc) 823 goto err_fini; 824 rc = apei_resources_request(&erst_resources, "APEI ERST"); 825 if (rc) 826 goto err_fini; 827 rc = apei_exec_pre_map_gars(&ctx); 828 if (rc) 829 goto err_release; 830 rc = erst_get_erange(&erst_erange); 831 if (rc) { 832 if (rc == -ENODEV) 833 pr_info(ERST_PFX 834 "The corresponding hardware device or firmware implementation " 835 "is not available.\n"); 836 else 837 pr_err(ERST_PFX 838 "Failed to get Error Log Address Range.\n"); 839 goto err_unmap_reg; 840 } 841 842 r = request_mem_region(erst_erange.base, erst_erange.size, "APEI ERST"); 843 if (!r) { 844 pr_err(ERST_PFX 845 "Can not request iomem region <0x%16llx-0x%16llx> for ERST.\n", 846 (unsigned long long)erst_erange.base, 847 (unsigned long long)erst_erange.base + erst_erange.size); 848 rc = -EIO; 849 goto err_unmap_reg; 850 } 851 rc = -ENOMEM; 852 erst_erange.vaddr = ioremap_cache(erst_erange.base, 853 erst_erange.size); 854 if (!erst_erange.vaddr) 855 goto err_release_erange; 856 857 pr_info(ERST_PFX 858 "Error Record Serialization Table (ERST) support is initialized.\n"); 859 860 return 0; 861 862 err_release_erange: 863 release_mem_region(erst_erange.base, erst_erange.size); 864 err_unmap_reg: 865 apei_exec_post_unmap_gars(&ctx); 866 err_release: 867 apei_resources_release(&erst_resources); 868 err_fini: 869 apei_resources_fini(&erst_resources); 870 err: 871 erst_disable = 1; 872 return rc; 873 } 874 875 device_initcall(erst_init); 876