drivers/acpi/apei/erst.c

   1 // SPDX-License-Identifier: GPL-2.0-only
   2 /*
   3  * APEI Error Record Serialization Table support
   4  *
   5  * ERST is a way provided by APEI to save and retrieve hardware error
   6  * information to and from a persistent store.
   7  *
   8  * For more information about ERST, please refer to ACPI Specification
   9  * version 4.0, section 17.4.
  10  *
  11  * Copyright 2010 Intel Corp.
  12  *   Author: Huang Ying <ying.huang@intel.com>
  13  */
  14
  15 #include <linux/kernel.h>
  16 #include <linux/module.h>
  17 #include <linux/init.h>
  18 #include <linux/delay.h>
  19 #include <linux/io.h>
  20 #include <linux/acpi.h>
  21 #include <linux/uaccess.h>
  22 #include <linux/cper.h>
  23 #include <linux/nmi.h>
  24 #include <linux/hardirq.h>
  25 #include <linux/pstore.h>
  26 #include <linux/vmalloc.h>
  27 #include <linux/mm.h> /* kvfree() */
  28 #include <acpi/apei.h>
  29
  30 #include "apei-internal.h"
  31
  32 #undef pr_fmt
  33 #define pr_fmt(fmt) "ERST: " fmt
  34
  35 /* ERST command status */
  36 #define ERST_STATUS_SUCCESS                     0x0
  37 #define ERST_STATUS_NOT_ENOUGH_SPACE            0x1
  38 #define ERST_STATUS_HARDWARE_NOT_AVAILABLE      0x2
  39 #define ERST_STATUS_FAILED                      0x3
  40 #define ERST_STATUS_RECORD_STORE_EMPTY          0x4
  41 #define ERST_STATUS_RECORD_NOT_FOUND            0x5
  42
  43 #define ERST_TAB_ENTRY(tab)                                             \
  44         ((struct acpi_whea_header *)((char *)(tab) +                    \
  45                                      sizeof(struct acpi_table_erst)))
  46
  47 #define SPIN_UNIT               100                     /* 100ns */
  48 /* Firmware should respond within 1 milliseconds */
  49 #define FIRMWARE_TIMEOUT        (1 * NSEC_PER_MSEC)
  50 #define FIRMWARE_MAX_STALL      50                      /* 50us */
  51
  52 int erst_disable;
  53 EXPORT_SYMBOL_GPL(erst_disable);
  54
  55 static struct acpi_table_erst *erst_tab;
  56
  57 /* ERST Error Log Address Range atrributes */
  58 #define ERST_RANGE_RESERVED     0x0001
  59 #define ERST_RANGE_NVRAM        0x0002
  60 #define ERST_RANGE_SLOW         0x0004
  61
  62 /*
  63  * ERST Error Log Address Range, used as buffer for reading/writing
  64  * error records.
  65  */
  66 static struct erst_erange {
  67         u64 base;
  68         u64 size;
  69         void __iomem *vaddr;
  70         u32 attr;
  71 } erst_erange;
  72
  73 /*
  74  * Prevent ERST interpreter to run simultaneously, because the
  75  * corresponding firmware implementation may not work properly when
  76  * invoked simultaneously.
  77  *
  78  * It is used to provide exclusive accessing for ERST Error Log
  79  * Address Range too.
  80  */
  81 static DEFINE_RAW_SPINLOCK(erst_lock);
  82
  83 static inline int erst_errno(int command_status)
  84 {
  85         switch (command_status) {
  86         case ERST_STATUS_SUCCESS:
  87                 return 0;
  88         case ERST_STATUS_HARDWARE_NOT_AVAILABLE:
  89                 return -ENODEV;
  90         case ERST_STATUS_NOT_ENOUGH_SPACE:
  91                 return -ENOSPC;
  92         case ERST_STATUS_RECORD_STORE_EMPTY:
  93         case ERST_STATUS_RECORD_NOT_FOUND:
  94                 return -ENOENT;
  95         default:
  96                 return -EINVAL;
  97         }
  98 }
  99
 100 static int erst_timedout(u64 *t, u64 spin_unit)
 101 {
 102         if ((s64)*t < spin_unit) {
 103                 pr_warn(FW_WARN "Firmware does not respond in time.\n");
 104                 return 1;
 105         }
 106         *t -= spin_unit;
 107         ndelay(spin_unit);
 108         touch_nmi_watchdog();
 109         return 0;
 110 }
 111
 112 static int erst_exec_load_var1(struct apei_exec_context *ctx,
 113                                struct acpi_whea_header *entry)
 114 {
 115         return __apei_exec_read_register(entry, &ctx->var1);
 116 }
 117
 118 static int erst_exec_load_var2(struct apei_exec_context *ctx,
 119                                struct acpi_whea_header *entry)
 120 {
 121         return __apei_exec_read_register(entry, &ctx->var2);
 122 }
 123
 124 static int erst_exec_store_var1(struct apei_exec_context *ctx,
 125                                 struct acpi_whea_header *entry)
 126 {
 127         return __apei_exec_write_register(entry, ctx->var1);
 128 }
 129
 130 static int erst_exec_add(struct apei_exec_context *ctx,
 131                          struct acpi_whea_header *entry)
 132 {
 133         ctx->var1 += ctx->var2;
 134         return 0;
 135 }
 136
 137 static int erst_exec_subtract(struct apei_exec_context *ctx,
 138                               struct acpi_whea_header *entry)
 139 {
 140         ctx->var1 -= ctx->var2;
 141         return 0;
 142 }
 143
 144 static int erst_exec_add_value(struct apei_exec_context *ctx,
 145                                struct acpi_whea_header *entry)
 146 {
 147         int rc;
 148         u64 val;
 149
 150         rc = __apei_exec_read_register(entry, &val);
 151         if (rc)
 152                 return rc;
 153         val += ctx->value;
 154         rc = __apei_exec_write_register(entry, val);
 155         return rc;
 156 }
 157
 158 static int erst_exec_subtract_value(struct apei_exec_context *ctx,
 159                                     struct acpi_whea_header *entry)
 160 {
 161         int rc;
 162         u64 val;
 163
 164         rc = __apei_exec_read_register(entry, &val);
 165         if (rc)
 166                 return rc;
 167         val -= ctx->value;
 168         rc = __apei_exec_write_register(entry, val);
 169         return rc;
 170 }
 171
 172 static int erst_exec_stall(struct apei_exec_context *ctx,
 173                            struct acpi_whea_header *entry)
 174 {
 175         u64 stall_time;
 176
 177         if (ctx->value > FIRMWARE_MAX_STALL) {
 178                 if (!in_nmi())
 179                         pr_warn(FW_WARN
 180                         "Too long stall time for stall instruction: 0x%llx.\n",
 181                                    ctx->value);
 182                 stall_time = FIRMWARE_MAX_STALL;
 183         } else
 184                 stall_time = ctx->value;
 185         udelay(stall_time);
 186         return 0;
 187 }
 188
 189 static int erst_exec_stall_while_true(struct apei_exec_context *ctx,
 190                                       struct acpi_whea_header *entry)
 191 {
 192         int rc;
 193         u64 val;
 194         u64 timeout = FIRMWARE_TIMEOUT;
 195         u64 stall_time;
 196
 197         if (ctx->var1 > FIRMWARE_MAX_STALL) {
 198                 if (!in_nmi())
 199                         pr_warn(FW_WARN
 200                 "Too long stall time for stall while true instruction: 0x%llx.\n",
 201                                    ctx->var1);
 202                 stall_time = FIRMWARE_MAX_STALL;
 203         } else
 204                 stall_time = ctx->var1;
 205
 206         for (;;) {
 207                 rc = __apei_exec_read_register(entry, &val);
 208                 if (rc)
 209                         return rc;
 210                 if (val != ctx->value)
 211                         break;
 212                 if (erst_timedout(&timeout, stall_time * NSEC_PER_USEC))
 213                         return -EIO;
 214         }
 215         return 0;
 216 }
 217
 218 static int erst_exec_skip_next_instruction_if_true(
 219         struct apei_exec_context *ctx,
 220         struct acpi_whea_header *entry)
 221 {
 222         int rc;
 223         u64 val;
 224
 225         rc = __apei_exec_read_register(entry, &val);
 226         if (rc)
 227                 return rc;
 228         if (val == ctx->value) {
 229                 ctx->ip += 2;
 230                 return APEI_EXEC_SET_IP;
 231         }
 232
 233         return 0;
 234 }
 235
 236 static int erst_exec_goto(struct apei_exec_context *ctx,
 237                           struct acpi_whea_header *entry)
 238 {
 239         ctx->ip = ctx->value;
 240         return APEI_EXEC_SET_IP;
 241 }
 242
 243 static int erst_exec_set_src_address_base(struct apei_exec_context *ctx,
 244                                           struct acpi_whea_header *entry)
 245 {
 246         return __apei_exec_read_register(entry, &ctx->src_base);
 247 }
 248
 249 static int erst_exec_set_dst_address_base(struct apei_exec_context *ctx,
 250                                           struct acpi_whea_header *entry)
 251 {
 252         return __apei_exec_read_register(entry, &ctx->dst_base);
 253 }
 254
 255 static int erst_exec_move_data(struct apei_exec_context *ctx,
 256                                struct acpi_whea_header *entry)
 257 {
 258         int rc;
 259         u64 offset;
 260         void *src, *dst;
 261
 262         /* ioremap does not work in interrupt context */
 263         if (in_interrupt()) {
 264                 pr_warn("MOVE_DATA can not be used in interrupt context.\n");
 265                 return -EBUSY;
 266         }
 267
 268         rc = __apei_exec_read_register(entry, &offset);
 269         if (rc)
 270                 return rc;
 271
 272         src = ioremap(ctx->src_base + offset, ctx->var2);
 273         if (!src)
 274                 return -ENOMEM;
 275         dst = ioremap(ctx->dst_base + offset, ctx->var2);
 276         if (!dst) {
 277                 iounmap(src);
 278                 return -ENOMEM;
 279         }
 280
 281         memmove(dst, src, ctx->var2);
 282
 283         iounmap(src);
 284         iounmap(dst);
 285
 286         return 0;
 287 }
 288
 289 static struct apei_exec_ins_type erst_ins_type[] = {
 290         [ACPI_ERST_READ_REGISTER] = {
 291                 .flags = APEI_EXEC_INS_ACCESS_REGISTER,
 292                 .run = apei_exec_read_register,
 293         },
 294         [ACPI_ERST_READ_REGISTER_VALUE] = {
 295                 .flags = APEI_EXEC_INS_ACCESS_REGISTER,
 296                 .run = apei_exec_read_register_value,
 297         },
 298         [ACPI_ERST_WRITE_REGISTER] = {
 299                 .flags = APEI_EXEC_INS_ACCESS_REGISTER,
 300                 .run = apei_exec_write_register,
 301         },
 302         [ACPI_ERST_WRITE_REGISTER_VALUE] = {
 303                 .flags = APEI_EXEC_INS_ACCESS_REGISTER,
 304                 .run = apei_exec_write_register_value,
 305         },
 306         [ACPI_ERST_NOOP] = {
 307                 .flags = 0,
 308                 .run = apei_exec_noop,
 309         },
 310         [ACPI_ERST_LOAD_VAR1] = {
 311                 .flags = APEI_EXEC_INS_ACCESS_REGISTER,
 312                 .run = erst_exec_load_var1,
 313         },
 314         [ACPI_ERST_LOAD_VAR2] = {
 315                 .flags = APEI_EXEC_INS_ACCESS_REGISTER,
 316                 .run = erst_exec_load_var2,
 317         },
 318         [ACPI_ERST_STORE_VAR1] = {
 319                 .flags = APEI_EXEC_INS_ACCESS_REGISTER,
 320                 .run = erst_exec_store_var1,
 321         },
 322         [ACPI_ERST_ADD] = {
 323                 .flags = 0,
 324                 .run = erst_exec_add,
 325         },
 326         [ACPI_ERST_SUBTRACT] = {
 327                 .flags = 0,
 328                 .run = erst_exec_subtract,
 329         },
 330         [ACPI_ERST_ADD_VALUE] = {
 331                 .flags = APEI_EXEC_INS_ACCESS_REGISTER,
 332                 .run = erst_exec_add_value,
 333         },
 334         [ACPI_ERST_SUBTRACT_VALUE] = {
 335                 .flags = APEI_EXEC_INS_ACCESS_REGISTER,
 336                 .run = erst_exec_subtract_value,
 337         },
 338         [ACPI_ERST_STALL] = {
 339                 .flags = 0,
 340                 .run = erst_exec_stall,
 341         },
 342         [ACPI_ERST_STALL_WHILE_TRUE] = {
 343                 .flags = APEI_EXEC_INS_ACCESS_REGISTER,
 344                 .run = erst_exec_stall_while_true,
 345         },
 346         [ACPI_ERST_SKIP_NEXT_IF_TRUE] = {
 347                 .flags = APEI_EXEC_INS_ACCESS_REGISTER,
 348                 .run = erst_exec_skip_next_instruction_if_true,
 349         },
 350         [ACPI_ERST_GOTO] = {
 351                 .flags = 0,
 352                 .run = erst_exec_goto,
 353         },
 354         [ACPI_ERST_SET_SRC_ADDRESS_BASE] = {
 355                 .flags = APEI_EXEC_INS_ACCESS_REGISTER,
 356                 .run = erst_exec_set_src_address_base,
 357         },
 358         [ACPI_ERST_SET_DST_ADDRESS_BASE] = {
 359                 .flags = APEI_EXEC_INS_ACCESS_REGISTER,
 360                 .run = erst_exec_set_dst_address_base,
 361         },
 362         [ACPI_ERST_MOVE_DATA] = {
 363                 .flags = APEI_EXEC_INS_ACCESS_REGISTER,
 364                 .run = erst_exec_move_data,
 365         },
 366 };
 367
 368 static inline void erst_exec_ctx_init(struct apei_exec_context *ctx)
 369 {
 370         apei_exec_ctx_init(ctx, erst_ins_type, ARRAY_SIZE(erst_ins_type),
 371                            ERST_TAB_ENTRY(erst_tab), erst_tab->entries);
 372 }
 373
 374 static int erst_get_erange(struct erst_erange *range)
 375 {
 376         struct apei_exec_context ctx;
 377         int rc;
 378
 379         erst_exec_ctx_init(&ctx);
 380         rc = apei_exec_run(&ctx, ACPI_ERST_GET_ERROR_RANGE);
 381         if (rc)
 382                 return rc;
 383         range->base = apei_exec_ctx_get_output(&ctx);
 384         rc = apei_exec_run(&ctx, ACPI_ERST_GET_ERROR_LENGTH);
 385         if (rc)
 386                 return rc;
 387         range->size = apei_exec_ctx_get_output(&ctx);
 388         rc = apei_exec_run(&ctx, ACPI_ERST_GET_ERROR_ATTRIBUTES);
 389         if (rc)
 390                 return rc;
 391         range->attr = apei_exec_ctx_get_output(&ctx);
 392
 393         return 0;
 394 }
 395
 396 static ssize_t __erst_get_record_count(void)
 397 {
 398         struct apei_exec_context ctx;
 399         int rc;
 400
 401         erst_exec_ctx_init(&ctx);
 402         rc = apei_exec_run(&ctx, ACPI_ERST_GET_RECORD_COUNT);
 403         if (rc)
 404                 return rc;
 405         return apei_exec_ctx_get_output(&ctx);
 406 }
 407
 408 ssize_t erst_get_record_count(void)
 409 {
 410         ssize_t count;
 411         unsigned long flags;
 412
 413         if (erst_disable)
 414                 return -ENODEV;
 415
 416         raw_spin_lock_irqsave(&erst_lock, flags);
 417         count = __erst_get_record_count();
 418         raw_spin_unlock_irqrestore(&erst_lock, flags);
 419
 420         return count;
 421 }
 422 EXPORT_SYMBOL_GPL(erst_get_record_count);
 423
 424 #define ERST_RECORD_ID_CACHE_SIZE_MIN   16
 425 #define ERST_RECORD_ID_CACHE_SIZE_MAX   1024
 426
 427 struct erst_record_id_cache {
 428         struct mutex lock;
 429         u64 *entries;
 430         int len;
 431         int size;
 432         int refcount;
 433 };
 434
 435 static struct erst_record_id_cache erst_record_id_cache = {
 436         .lock = __MUTEX_INITIALIZER(erst_record_id_cache.lock),
 437         .refcount = 0,
 438 };
 439
 440 static int __erst_get_next_record_id(u64 *record_id)
 441 {
 442         struct apei_exec_context ctx;
 443         int rc;
 444
 445         erst_exec_ctx_init(&ctx);
 446         rc = apei_exec_run(&ctx, ACPI_ERST_GET_RECORD_ID);
 447         if (rc)
 448                 return rc;
 449         *record_id = apei_exec_ctx_get_output(&ctx);
 450
 451         return 0;
 452 }
 453
 454 int erst_get_record_id_begin(int *pos)
 455 {
 456         int rc;
 457
 458         if (erst_disable)
 459                 return -ENODEV;
 460
 461         rc = mutex_lock_interruptible(&erst_record_id_cache.lock);
 462         if (rc)
 463                 return rc;
 464         erst_record_id_cache.refcount++;
 465         mutex_unlock(&erst_record_id_cache.lock);
 466
 467         *pos = 0;
 468
 469         return 0;
 470 }
 471 EXPORT_SYMBOL_GPL(erst_get_record_id_begin);
 472
 473 /* erst_record_id_cache.lock must be held by caller */
 474 static int __erst_record_id_cache_add_one(void)
 475 {
 476         u64 id, prev_id, first_id;
 477         int i, rc;
 478         u64 *entries;
 479         unsigned long flags;
 480
 481         id = prev_id = first_id = APEI_ERST_INVALID_RECORD_ID;
 482 retry:
 483         raw_spin_lock_irqsave(&erst_lock, flags);
 484         rc = __erst_get_next_record_id(&id);
 485         raw_spin_unlock_irqrestore(&erst_lock, flags);
 486         if (rc == -ENOENT)
 487                 return 0;
 488         if (rc)
 489                 return rc;
 490         if (id == APEI_ERST_INVALID_RECORD_ID)
 491                 return 0;
 492         /* can not skip current ID, or loop back to first ID */
 493         if (id == prev_id || id == first_id)
 494                 return 0;
 495         if (first_id == APEI_ERST_INVALID_RECORD_ID)
 496                 first_id = id;
 497         prev_id = id;
 498
 499         entries = erst_record_id_cache.entries;
 500         for (i = 0; i < erst_record_id_cache.len; i++) {
 501                 if (entries[i] == id)
 502                         break;
 503         }
 504         /* record id already in cache, try next */
 505         if (i < erst_record_id_cache.len)
 506                 goto retry;
 507         if (erst_record_id_cache.len >= erst_record_id_cache.size) {
 508                 int new_size;
 509                 u64 *new_entries;
 510
 511                 new_size = erst_record_id_cache.size * 2;
 512                 new_size = clamp_val(new_size, ERST_RECORD_ID_CACHE_SIZE_MIN,
 513                                      ERST_RECORD_ID_CACHE_SIZE_MAX);
 514                 if (new_size <= erst_record_id_cache.size) {
 515                         if (printk_ratelimit())
 516                                 pr_warn(FW_WARN "too many record IDs!\n");
 517                         return 0;
 518                 }
 519                 new_entries = kvmalloc_array(new_size, sizeof(entries[0]),
 520                                              GFP_KERNEL);
 521                 if (!new_entries)
 522                         return -ENOMEM;
 523                 memcpy(new_entries, entries,
 524                        erst_record_id_cache.len * sizeof(entries[0]));
 525                 kvfree(entries);
 526                 erst_record_id_cache.entries = entries = new_entries;
 527                 erst_record_id_cache.size = new_size;
 528         }
 529         entries[i] = id;
 530         erst_record_id_cache.len++;
 531
 532         return 1;
 533 }
 534
 535 /*
 536  * Get the record ID of an existing error record on the persistent
 537  * storage. If there is no error record on the persistent storage, the
 538  * returned record_id is APEI_ERST_INVALID_RECORD_ID.
 539  */
 540 int erst_get_record_id_next(int *pos, u64 *record_id)
 541 {
 542         int rc = 0;
 543         u64 *entries;
 544
 545         if (erst_disable)
 546                 return -ENODEV;
 547
 548         /* must be enclosed by erst_get_record_id_begin/end */
 549         BUG_ON(!erst_record_id_cache.refcount);
 550         BUG_ON(*pos < 0 || *pos > erst_record_id_cache.len);
 551
 552         mutex_lock(&erst_record_id_cache.lock);
 553         entries = erst_record_id_cache.entries;
 554         for (; *pos < erst_record_id_cache.len; (*pos)++)
 555                 if (entries[*pos] != APEI_ERST_INVALID_RECORD_ID)
 556                         break;
 557         /* found next record id in cache */
 558         if (*pos < erst_record_id_cache.len) {
 559                 *record_id = entries[*pos];
 560                 (*pos)++;
 561                 goto out_unlock;
 562         }
 563
 564         /* Try to add one more record ID to cache */
 565         rc = __erst_record_id_cache_add_one();
 566         if (rc < 0)
 567                 goto out_unlock;
 568         /* successfully add one new ID */
 569         if (rc == 1) {
 570                 *record_id = erst_record_id_cache.entries[*pos];
 571                 (*pos)++;
 572                 rc = 0;
 573         } else {
 574                 *pos = -1;
 575                 *record_id = APEI_ERST_INVALID_RECORD_ID;
 576         }
 577 out_unlock:
 578         mutex_unlock(&erst_record_id_cache.lock);
 579
 580         return rc;
 581 }
 582 EXPORT_SYMBOL_GPL(erst_get_record_id_next);
 583
 584 /* erst_record_id_cache.lock must be held by caller */
 585 static void __erst_record_id_cache_compact(void)
 586 {
 587         int i, wpos = 0;
 588         u64 *entries;
 589
 590         if (erst_record_id_cache.refcount)
 591                 return;
 592
 593         entries = erst_record_id_cache.entries;
 594         for (i = 0; i < erst_record_id_cache.len; i++) {
 595                 if (entries[i] == APEI_ERST_INVALID_RECORD_ID)
 596                         continue;
 597                 if (wpos != i)
 598                         entries[wpos] = entries[i];
 599                 wpos++;
 600         }
 601         erst_record_id_cache.len = wpos;
 602 }
 603
 604 void erst_get_record_id_end(void)
 605 {
 606         /*
 607          * erst_disable != 0 should be detected by invoker via the
 608          * return value of erst_get_record_id_begin/next, so this
 609          * function should not be called for erst_disable != 0.
 610          */
 611         BUG_ON(erst_disable);
 612
 613         mutex_lock(&erst_record_id_cache.lock);
 614         erst_record_id_cache.refcount--;
 615         BUG_ON(erst_record_id_cache.refcount < 0);
 616         __erst_record_id_cache_compact();
 617         mutex_unlock(&erst_record_id_cache.lock);
 618 }
 619 EXPORT_SYMBOL_GPL(erst_get_record_id_end);
 620
 621 static int __erst_write_to_storage(u64 offset)
 622 {
 623         struct apei_exec_context ctx;
 624         u64 timeout = FIRMWARE_TIMEOUT;
 625         u64 val;
 626         int rc;
 627
 628         erst_exec_ctx_init(&ctx);
 629         rc = apei_exec_run_optional(&ctx, ACPI_ERST_BEGIN_WRITE);
 630         if (rc)
 631                 return rc;
 632         apei_exec_ctx_set_input(&ctx, offset);
 633         rc = apei_exec_run(&ctx, ACPI_ERST_SET_RECORD_OFFSET);
 634         if (rc)
 635                 return rc;
 636         rc = apei_exec_run(&ctx, ACPI_ERST_EXECUTE_OPERATION);
 637         if (rc)
 638                 return rc;
 639         for (;;) {
 640                 rc = apei_exec_run(&ctx, ACPI_ERST_CHECK_BUSY_STATUS);
 641                 if (rc)
 642                         return rc;
 643                 val = apei_exec_ctx_get_output(&ctx);
 644                 if (!val)
 645                         break;
 646                 if (erst_timedout(&timeout, SPIN_UNIT))
 647                         return -EIO;
 648         }
 649         rc = apei_exec_run(&ctx, ACPI_ERST_GET_COMMAND_STATUS);
 650         if (rc)
 651                 return rc;
 652         val = apei_exec_ctx_get_output(&ctx);
 653         rc = apei_exec_run_optional(&ctx, ACPI_ERST_END);
 654         if (rc)
 655                 return rc;
 656
 657         return erst_errno(val);
 658 }
 659
 660 static int __erst_read_from_storage(u64 record_id, u64 offset)
 661 {
 662         struct apei_exec_context ctx;
 663         u64 timeout = FIRMWARE_TIMEOUT;
 664         u64 val;
 665         int rc;
 666
 667         erst_exec_ctx_init(&ctx);
 668         rc = apei_exec_run_optional(&ctx, ACPI_ERST_BEGIN_READ);
 669         if (rc)
 670                 return rc;
 671         apei_exec_ctx_set_input(&ctx, offset);
 672         rc = apei_exec_run(&ctx, ACPI_ERST_SET_RECORD_OFFSET);
 673         if (rc)
 674                 return rc;
 675         apei_exec_ctx_set_input(&ctx, record_id);
 676         rc = apei_exec_run(&ctx, ACPI_ERST_SET_RECORD_ID);
 677         if (rc)
 678                 return rc;
 679         rc = apei_exec_run(&ctx, ACPI_ERST_EXECUTE_OPERATION);
 680         if (rc)
 681                 return rc;
 682         for (;;) {
 683                 rc = apei_exec_run(&ctx, ACPI_ERST_CHECK_BUSY_STATUS);
 684                 if (rc)
 685                         return rc;
 686                 val = apei_exec_ctx_get_output(&ctx);
 687                 if (!val)
 688                         break;
 689                 if (erst_timedout(&timeout, SPIN_UNIT))
 690                         return -EIO;
 691         };
 692         rc = apei_exec_run(&ctx, ACPI_ERST_GET_COMMAND_STATUS);
 693         if (rc)
 694                 return rc;
 695         val = apei_exec_ctx_get_output(&ctx);
 696         rc = apei_exec_run_optional(&ctx, ACPI_ERST_END);
 697         if (rc)
 698                 return rc;
 699
 700         return erst_errno(val);
 701 }
 702
 703 static int __erst_clear_from_storage(u64 record_id)
 704 {
 705         struct apei_exec_context ctx;
 706         u64 timeout = FIRMWARE_TIMEOUT;
 707         u64 val;
 708         int rc;
 709
 710         erst_exec_ctx_init(&ctx);
 711         rc = apei_exec_run_optional(&ctx, ACPI_ERST_BEGIN_CLEAR);
 712         if (rc)
 713                 return rc;
 714         apei_exec_ctx_set_input(&ctx, record_id);
 715         rc = apei_exec_run(&ctx, ACPI_ERST_SET_RECORD_ID);
 716         if (rc)
 717                 return rc;
 718         rc = apei_exec_run(&ctx, ACPI_ERST_EXECUTE_OPERATION);
 719         if (rc)
 720                 return rc;
 721         for (;;) {
 722                 rc = apei_exec_run(&ctx, ACPI_ERST_CHECK_BUSY_STATUS);
 723                 if (rc)
 724                         return rc;
 725                 val = apei_exec_ctx_get_output(&ctx);
 726                 if (!val)
 727                         break;
 728                 if (erst_timedout(&timeout, SPIN_UNIT))
 729                         return -EIO;
 730         }
 731         rc = apei_exec_run(&ctx, ACPI_ERST_GET_COMMAND_STATUS);
 732         if (rc)
 733                 return rc;
 734         val = apei_exec_ctx_get_output(&ctx);
 735         rc = apei_exec_run_optional(&ctx, ACPI_ERST_END);
 736         if (rc)
 737                 return rc;
 738
 739         return erst_errno(val);
 740 }
 741
 742 /* NVRAM ERST Error Log Address Range is not supported yet */
 743 static void pr_unimpl_nvram(void)
 744 {
 745         if (printk_ratelimit())
 746                 pr_warn("NVRAM ERST Log Address Range not implemented yet.\n");
 747 }
 748
 749 static int __erst_write_to_nvram(const struct cper_record_header *record)
 750 {
 751         /* do not print message, because printk is not safe for NMI */
 752         return -ENOSYS;
 753 }
 754
 755 static int __erst_read_to_erange_from_nvram(u64 record_id, u64 *offset)
 756 {
 757         pr_unimpl_nvram();
 758         return -ENOSYS;
 759 }
 760
 761 static int __erst_clear_from_nvram(u64 record_id)
 762 {
 763         pr_unimpl_nvram();
 764         return -ENOSYS;
 765 }
 766
 767 int erst_write(const struct cper_record_header *record)
 768 {
 769         int rc;
 770         unsigned long flags;
 771         struct cper_record_header *rcd_erange;
 772
 773         if (erst_disable)
 774                 return -ENODEV;
 775
 776         if (memcmp(record->signature, CPER_SIG_RECORD, CPER_SIG_SIZE))
 777                 return -EINVAL;
 778
 779         if (erst_erange.attr & ERST_RANGE_NVRAM) {
 780                 if (!raw_spin_trylock_irqsave(&erst_lock, flags))
 781                         return -EBUSY;
 782                 rc = __erst_write_to_nvram(record);
 783                 raw_spin_unlock_irqrestore(&erst_lock, flags);
 784                 return rc;
 785         }
 786
 787         if (record->record_length > erst_erange.size)
 788                 return -EINVAL;
 789
 790         if (!raw_spin_trylock_irqsave(&erst_lock, flags))
 791                 return -EBUSY;
 792         memcpy(erst_erange.vaddr, record, record->record_length);
 793         rcd_erange = erst_erange.vaddr;
 794         /* signature for serialization system */
 795         memcpy(&rcd_erange->persistence_information, "ER", 2);
 796
 797         rc = __erst_write_to_storage(0);
 798         raw_spin_unlock_irqrestore(&erst_lock, flags);
 799
 800         return rc;
 801 }
 802 EXPORT_SYMBOL_GPL(erst_write);
 803
 804 static int __erst_read_to_erange(u64 record_id, u64 *offset)
 805 {
 806         int rc;
 807
 808         if (erst_erange.attr & ERST_RANGE_NVRAM)
 809                 return __erst_read_to_erange_from_nvram(
 810                         record_id, offset);
 811
 812         rc = __erst_read_from_storage(record_id, 0);
 813         if (rc)
 814                 return rc;
 815         *offset = 0;
 816
 817         return 0;
 818 }
 819
 820 static ssize_t __erst_read(u64 record_id, struct cper_record_header *record,
 821                            size_t buflen)
 822 {
 823         int rc;
 824         u64 offset, len = 0;
 825         struct cper_record_header *rcd_tmp;
 826
 827         rc = __erst_read_to_erange(record_id, &offset);
 828         if (rc)
 829                 return rc;
 830         rcd_tmp = erst_erange.vaddr + offset;
 831         len = rcd_tmp->record_length;
 832         if (len <= buflen)
 833                 memcpy(record, rcd_tmp, len);
 834
 835         return len;
 836 }
 837
 838 /*
 839  * If return value > buflen, the buffer size is not big enough,
 840  * else if return value < 0, something goes wrong,
 841  * else everything is OK, and return value is record length
 842  */
 843 ssize_t erst_read(u64 record_id, struct cper_record_header *record,
 844                   size_t buflen)
 845 {
 846         ssize_t len;
 847         unsigned long flags;
 848
 849         if (erst_disable)
 850                 return -ENODEV;
 851
 852         raw_spin_lock_irqsave(&erst_lock, flags);
 853         len = __erst_read(record_id, record, buflen);
 854         raw_spin_unlock_irqrestore(&erst_lock, flags);
 855         return len;
 856 }
 857 EXPORT_SYMBOL_GPL(erst_read);
 858
 859 int erst_clear(u64 record_id)
 860 {
 861         int rc, i;
 862         unsigned long flags;
 863         u64 *entries;
 864
 865         if (erst_disable)
 866                 return -ENODEV;
 867
 868         rc = mutex_lock_interruptible(&erst_record_id_cache.lock);
 869         if (rc)
 870                 return rc;
 871         raw_spin_lock_irqsave(&erst_lock, flags);
 872         if (erst_erange.attr & ERST_RANGE_NVRAM)
 873                 rc = __erst_clear_from_nvram(record_id);
 874         else
 875                 rc = __erst_clear_from_storage(record_id);
 876         raw_spin_unlock_irqrestore(&erst_lock, flags);
 877         if (rc)
 878                 goto out;
 879         entries = erst_record_id_cache.entries;
 880         for (i = 0; i < erst_record_id_cache.len; i++) {
 881                 if (entries[i] == record_id)
 882                         entries[i] = APEI_ERST_INVALID_RECORD_ID;
 883         }
 884         __erst_record_id_cache_compact();
 885 out:
 886         mutex_unlock(&erst_record_id_cache.lock);
 887         return rc;
 888 }
 889 EXPORT_SYMBOL_GPL(erst_clear);
 890
 891 static int __init setup_erst_disable(char *str)
 892 {
 893         erst_disable = 1;
 894         return 0;
 895 }
 896
 897 __setup("erst_disable", setup_erst_disable);
 898
 899 static int erst_check_table(struct acpi_table_erst *erst_tab)
 900 {
 901         if ((erst_tab->header_length !=
 902              (sizeof(struct acpi_table_erst) - sizeof(erst_tab->header)))
 903             && (erst_tab->header_length != sizeof(struct acpi_table_erst)))
 904                 return -EINVAL;
 905         if (erst_tab->header.length < sizeof(struct acpi_table_erst))
 906                 return -EINVAL;
 907         if (erst_tab->entries !=
 908             (erst_tab->header.length - sizeof(struct acpi_table_erst)) /
 909             sizeof(struct acpi_erst_entry))
 910                 return -EINVAL;
 911
 912         return 0;
 913 }
 914
 915 static int erst_open_pstore(struct pstore_info *psi);
 916 static int erst_close_pstore(struct pstore_info *psi);
 917 static ssize_t erst_reader(struct pstore_record *record);
 918 static int erst_writer(struct pstore_record *record);
 919 static int erst_clearer(struct pstore_record *record);
 920
 921 static struct pstore_info erst_info = {
 922         .owner          = THIS_MODULE,
 923         .name           = "erst",
 924         .flags          = PSTORE_FLAGS_DMESG,
 925         .open           = erst_open_pstore,
 926         .close          = erst_close_pstore,
 927         .read           = erst_reader,
 928         .write          = erst_writer,
 929         .erase          = erst_clearer
 930 };
 931
 932 #define CPER_CREATOR_PSTORE                                             \
 933         GUID_INIT(0x75a574e3, 0x5052, 0x4b29, 0x8a, 0x8e, 0xbe, 0x2c,   \
 934                   0x64, 0x90, 0xb8, 0x9d)
 935 #define CPER_SECTION_TYPE_DMESG                                         \
 936         GUID_INIT(0xc197e04e, 0xd545, 0x4a70, 0x9c, 0x17, 0xa5, 0x54,   \
 937                   0x94, 0x19, 0xeb, 0x12)
 938 #define CPER_SECTION_TYPE_DMESG_Z                                       \
 939         GUID_INIT(0x4f118707, 0x04dd, 0x4055, 0xb5, 0xdd, 0x95, 0x6d,   \
 940                   0x34, 0xdd, 0xfa, 0xc6)
 941 #define CPER_SECTION_TYPE_MCE                                           \
 942         GUID_INIT(0xfe08ffbe, 0x95e4, 0x4be7, 0xbc, 0x73, 0x40, 0x96,   \
 943                   0x04, 0x4a, 0x38, 0xfc)
 944
 945 struct cper_pstore_record {
 946         struct cper_record_header hdr;
 947         struct cper_section_descriptor sec_hdr;
 948         char data[];
 949 } __packed;
 950
 951 static int reader_pos;
 952
 953 static int erst_open_pstore(struct pstore_info *psi)
 954 {
 955         int rc;
 956
 957         if (erst_disable)
 958                 return -ENODEV;
 959
 960         rc = erst_get_record_id_begin(&reader_pos);
 961
 962         return rc;
 963 }
 964
 965 static int erst_close_pstore(struct pstore_info *psi)
 966 {
 967         erst_get_record_id_end();
 968
 969         return 0;
 970 }
 971
 972 static ssize_t erst_reader(struct pstore_record *record)
 973 {
 974         int rc;
 975         ssize_t len = 0;
 976         u64 record_id;
 977         struct cper_pstore_record *rcd;
 978         size_t rcd_len = sizeof(*rcd) + erst_info.bufsize;
 979
 980         if (erst_disable)
 981                 return -ENODEV;
 982
 983         rcd = kmalloc(rcd_len, GFP_KERNEL);
 984         if (!rcd) {
 985                 rc = -ENOMEM;
 986                 goto out;
 987         }
 988 skip:
 989         rc = erst_get_record_id_next(&reader_pos, &record_id);
 990         if (rc)
 991                 goto out;
 992
 993         /* no more record */
 994         if (record_id == APEI_ERST_INVALID_RECORD_ID) {
 995                 rc = -EINVAL;
 996                 goto out;
 997         }
 998
 999         len = erst_read(record_id, &rcd->hdr, rcd_len);
1000         /* The record may be cleared by others, try read next record */
1001         if (len == -ENOENT)
1002                 goto skip;
1003         else if (len < 0 || len < sizeof(*rcd)) {
1004                 rc = -EIO;
1005                 goto out;
1006         }
1007         if (!guid_equal(&rcd->hdr.creator_id, &CPER_CREATOR_PSTORE))
1008                 goto skip;
1009
1010         record->buf = kmalloc(len, GFP_KERNEL);
1011         if (record->buf == NULL) {
1012                 rc = -ENOMEM;
1013                 goto out;
1014         }
1015         memcpy(record->buf, rcd->data, len - sizeof(*rcd));
1016         record->id = record_id;
1017         record->compressed = false;
1018         record->ecc_notice_size = 0;
1019         if (guid_equal(&rcd->sec_hdr.section_type, &CPER_SECTION_TYPE_DMESG_Z)) {
1020                 record->type = PSTORE_TYPE_DMESG;
1021                 record->compressed = true;
1022         } else if (guid_equal(&rcd->sec_hdr.section_type, &CPER_SECTION_TYPE_DMESG))
1023                 record->type = PSTORE_TYPE_DMESG;
1024         else if (guid_equal(&rcd->sec_hdr.section_type, &CPER_SECTION_TYPE_MCE))
1025                 record->type = PSTORE_TYPE_MCE;
1026         else
1027                 record->type = PSTORE_TYPE_MAX;
1028
1029         if (rcd->hdr.validation_bits & CPER_VALID_TIMESTAMP)
1030                 record->time.tv_sec = rcd->hdr.timestamp;
1031         else
1032                 record->time.tv_sec = 0;
1033         record->time.tv_nsec = 0;
1034
1035 out:
1036         kfree(rcd);
1037         return (rc < 0) ? rc : (len - sizeof(*rcd));
1038 }
1039
1040 static int erst_writer(struct pstore_record *record)
1041 {
1042         struct cper_pstore_record *rcd = (struct cper_pstore_record *)
1043                                         (erst_info.buf - sizeof(*rcd));
1044         int ret;
1045
1046         memset(rcd, 0, sizeof(*rcd));
1047         memcpy(rcd->hdr.signature, CPER_SIG_RECORD, CPER_SIG_SIZE);
1048         rcd->hdr.revision = CPER_RECORD_REV;
1049         rcd->hdr.signature_end = CPER_SIG_END;
1050         rcd->hdr.section_count = 1;
1051         rcd->hdr.error_severity = CPER_SEV_FATAL;
1052         /* timestamp valid. platform_id, partition_id are invalid */
1053         rcd->hdr.validation_bits = CPER_VALID_TIMESTAMP;
1054         rcd->hdr.timestamp = ktime_get_real_seconds();
1055         rcd->hdr.record_length = sizeof(*rcd) + record->size;
1056         rcd->hdr.creator_id = CPER_CREATOR_PSTORE;
1057         rcd->hdr.notification_type = CPER_NOTIFY_MCE;
1058         rcd->hdr.record_id = cper_next_record_id();
1059         rcd->hdr.flags = CPER_HW_ERROR_FLAGS_PREVERR;
1060
1061         rcd->sec_hdr.section_offset = sizeof(*rcd);
1062         rcd->sec_hdr.section_length = record->size;
1063         rcd->sec_hdr.revision = CPER_SEC_REV;
1064         /* fru_id and fru_text is invalid */
1065         rcd->sec_hdr.validation_bits = 0;
1066         rcd->sec_hdr.flags = CPER_SEC_PRIMARY;
1067         switch (record->type) {
1068         case PSTORE_TYPE_DMESG:
1069                 if (record->compressed)
1070                         rcd->sec_hdr.section_type = CPER_SECTION_TYPE_DMESG_Z;
1071                 else
1072                         rcd->sec_hdr.section_type = CPER_SECTION_TYPE_DMESG;
1073                 break;
1074         case PSTORE_TYPE_MCE:
1075                 rcd->sec_hdr.section_type = CPER_SECTION_TYPE_MCE;
1076                 break;
1077         default:
1078                 return -EINVAL;
1079         }
1080         rcd->sec_hdr.section_severity = CPER_SEV_FATAL;
1081
1082         ret = erst_write(&rcd->hdr);
1083         record->id = rcd->hdr.record_id;
1084
1085         return ret;
1086 }
1087
1088 static int erst_clearer(struct pstore_record *record)
1089 {
1090         return erst_clear(record->id);
1091 }
1092
1093 static int __init erst_init(void)
1094 {
1095         int rc = 0;
1096         acpi_status status;
1097         struct apei_exec_context ctx;
1098         struct apei_resources erst_resources;
1099         struct resource *r;
1100         char *buf;
1101
1102         if (acpi_disabled)
1103                 goto err;
1104
1105         if (erst_disable) {
1106                 pr_info(
1107         "Error Record Serialization Table (ERST) support is disabled.\n");
1108                 goto err;
1109         }
1110
1111         status = acpi_get_table(ACPI_SIG_ERST, 0,
1112                                 (struct acpi_table_header **)&erst_tab);
1113         if (status == AE_NOT_FOUND)
1114                 goto err;
1115         else if (ACPI_FAILURE(status)) {
1116                 const char *msg = acpi_format_exception(status);
1117                 pr_err("Failed to get table, %s\n", msg);
1118                 rc = -EINVAL;
1119                 goto err;
1120         }
1121
1122         rc = erst_check_table(erst_tab);
1123         if (rc) {
1124                 pr_err(FW_BUG "ERST table is invalid.\n");
1125                 goto err_put_erst_tab;
1126         }
1127
1128         apei_resources_init(&erst_resources);
1129         erst_exec_ctx_init(&ctx);
1130         rc = apei_exec_collect_resources(&ctx, &erst_resources);
1131         if (rc)
1132                 goto err_fini;
1133         rc = apei_resources_request(&erst_resources, "APEI ERST");
1134         if (rc)
1135                 goto err_fini;
1136         rc = apei_exec_pre_map_gars(&ctx);
1137         if (rc)
1138                 goto err_release;
1139         rc = erst_get_erange(&erst_erange);
1140         if (rc) {
1141                 if (rc == -ENODEV)
1142                         pr_info(
1143         "The corresponding hardware device or firmware implementation "
1144         "is not available.\n");
1145                 else
1146                         pr_err("Failed to get Error Log Address Range.\n");
1147                 goto err_unmap_reg;
1148         }
1149
1150         r = request_mem_region(erst_erange.base, erst_erange.size, "APEI ERST");
1151         if (!r) {
1152                 pr_err("Can not request [mem %#010llx-%#010llx] for ERST.\n",
1153                        (unsigned long long)erst_erange.base,
1154                        (unsigned long long)erst_erange.base + erst_erange.size - 1);
1155                 rc = -EIO;
1156                 goto err_unmap_reg;
1157         }
1158         rc = -ENOMEM;
1159         erst_erange.vaddr = ioremap_cache(erst_erange.base,
1160                                           erst_erange.size);
1161         if (!erst_erange.vaddr)
1162                 goto err_release_erange;
1163
1164         pr_info(
1165         "Error Record Serialization Table (ERST) support is initialized.\n");
1166
1167         buf = kmalloc(erst_erange.size, GFP_KERNEL);
1168         if (buf) {
1169                 erst_info.buf = buf + sizeof(struct cper_pstore_record);
1170                 erst_info.bufsize = erst_erange.size -
1171                                     sizeof(struct cper_pstore_record);
1172                 rc = pstore_register(&erst_info);
1173                 if (rc) {
1174                         if (rc != -EPERM)
1175                                 pr_info(
1176                                 "Could not register with persistent store.\n");
1177                         erst_info.buf = NULL;
1178                         erst_info.bufsize = 0;
1179                         kfree(buf);
1180                 }
1181         } else
1182                 pr_err(
1183                 "Failed to allocate %lld bytes for persistent store error log.\n",
1184                 erst_erange.size);
1185
1186         /* Cleanup ERST Resources */
1187         apei_resources_fini(&erst_resources);
1188
1189         return 0;
1190
1191 err_release_erange:
1192         release_mem_region(erst_erange.base, erst_erange.size);
1193 err_unmap_reg:
1194         apei_exec_post_unmap_gars(&ctx);
1195 err_release:
1196         apei_resources_release(&erst_resources);
1197 err_fini:
1198         apei_resources_fini(&erst_resources);
1199 err_put_erst_tab:
1200         acpi_put_table((struct acpi_table_header *)erst_tab);
1201 err:
1202         erst_disable = 1;
1203         return rc;
1204 }
1205
1206 device_initcall(erst_init);