drivers/acpi/apei/erst.c

   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
  23 #include <linux/kernel.h>
  24 #include <linux/module.h>
  25 #include <linux/init.h>
  26 #include <linux/delay.h>
  27 #include <linux/io.h>
  28 #include <linux/acpi.h>
  29 #include <linux/uaccess.h>
  30 #include <linux/cper.h>
  31 #include <linux/nmi.h>
  32 #include <linux/hardirq.h>
  33 #include <linux/pstore.h>
  34 #include <linux/vmalloc.h>
  35 #include <linux/mm.h> /* kvfree() */
  36 #include <acpi/apei.h>
  37
  38 #include "apei-internal.h"
  39
  40 #undef pr_fmt
  41 #define pr_fmt(fmt) "ERST: " fmt
  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 milliseconds */
  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_RAW_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_warn(FW_WARN "Firmware does not respond in time.\n");
 112                 return 1;
 113         }
 114         *t -= spin_unit;
 115         ndelay(spin_unit);
 116         touch_nmi_watchdog();
 117         return 0;
 118 }
 119
 120 static int erst_exec_load_var1(struct apei_exec_context *ctx,
 121                                struct acpi_whea_header *entry)
 122 {
 123         return __apei_exec_read_register(entry, &ctx->var1);
 124 }
 125
 126 static int erst_exec_load_var2(struct apei_exec_context *ctx,
 127                                struct acpi_whea_header *entry)
 128 {
 129         return __apei_exec_read_register(entry, &ctx->var2);
 130 }
 131
 132 static int erst_exec_store_var1(struct apei_exec_context *ctx,
 133                                 struct acpi_whea_header *entry)
 134 {
 135         return __apei_exec_write_register(entry, ctx->var1);
 136 }
 137
 138 static int erst_exec_add(struct apei_exec_context *ctx,
 139                          struct acpi_whea_header *entry)
 140 {
 141         ctx->var1 += ctx->var2;
 142         return 0;
 143 }
 144
 145 static int erst_exec_subtract(struct apei_exec_context *ctx,
 146                               struct acpi_whea_header *entry)
 147 {
 148         ctx->var1 -= ctx->var2;
 149         return 0;
 150 }
 151
 152 static int erst_exec_add_value(struct apei_exec_context *ctx,
 153                                struct acpi_whea_header *entry)
 154 {
 155         int rc;
 156         u64 val;
 157
 158         rc = __apei_exec_read_register(entry, &val);
 159         if (rc)
 160                 return rc;
 161         val += ctx->value;
 162         rc = __apei_exec_write_register(entry, val);
 163         return rc;
 164 }
 165
 166 static int erst_exec_subtract_value(struct apei_exec_context *ctx,
 167                                     struct acpi_whea_header *entry)
 168 {
 169         int rc;
 170         u64 val;
 171
 172         rc = __apei_exec_read_register(entry, &val);
 173         if (rc)
 174                 return rc;
 175         val -= ctx->value;
 176         rc = __apei_exec_write_register(entry, val);
 177         return rc;
 178 }
 179
 180 static int erst_exec_stall(struct apei_exec_context *ctx,
 181                            struct acpi_whea_header *entry)
 182 {
 183         u64 stall_time;
 184
 185         if (ctx->value > FIRMWARE_MAX_STALL) {
 186                 if (!in_nmi())
 187                         pr_warn(FW_WARN
 188                         "Too long stall time for stall instruction: 0x%llx.\n",
 189                                    ctx->value);
 190                 stall_time = FIRMWARE_MAX_STALL;
 191         } else
 192                 stall_time = ctx->value;
 193         udelay(stall_time);
 194         return 0;
 195 }
 196
 197 static int erst_exec_stall_while_true(struct apei_exec_context *ctx,
 198                                       struct acpi_whea_header *entry)
 199 {
 200         int rc;
 201         u64 val;
 202         u64 timeout = FIRMWARE_TIMEOUT;
 203         u64 stall_time;
 204
 205         if (ctx->var1 > FIRMWARE_MAX_STALL) {
 206                 if (!in_nmi())
 207                         pr_warn(FW_WARN
 208                 "Too long stall time for stall while true instruction: 0x%llx.\n",
 209                                    ctx->var1);
 210                 stall_time = FIRMWARE_MAX_STALL;
 211         } else
 212                 stall_time = ctx->var1;
 213
 214         for (;;) {
 215                 rc = __apei_exec_read_register(entry, &val);
 216                 if (rc)
 217                         return rc;
 218                 if (val != ctx->value)
 219                         break;
 220                 if (erst_timedout(&timeout, stall_time * NSEC_PER_USEC))
 221                         return -EIO;
 222         }
 223         return 0;
 224 }
 225
 226 static int erst_exec_skip_next_instruction_if_true(
 227         struct apei_exec_context *ctx,
 228         struct acpi_whea_header *entry)
 229 {
 230         int rc;
 231         u64 val;
 232
 233         rc = __apei_exec_read_register(entry, &val);
 234         if (rc)
 235                 return rc;
 236         if (val == ctx->value) {
 237                 ctx->ip += 2;
 238                 return APEI_EXEC_SET_IP;
 239         }
 240
 241         return 0;
 242 }
 243
 244 static int erst_exec_goto(struct apei_exec_context *ctx,
 245                           struct acpi_whea_header *entry)
 246 {
 247         ctx->ip = ctx->value;
 248         return APEI_EXEC_SET_IP;
 249 }
 250
 251 static int erst_exec_set_src_address_base(struct apei_exec_context *ctx,
 252                                           struct acpi_whea_header *entry)
 253 {
 254         return __apei_exec_read_register(entry, &ctx->src_base);
 255 }
 256
 257 static int erst_exec_set_dst_address_base(struct apei_exec_context *ctx,
 258                                           struct acpi_whea_header *entry)
 259 {
 260         return __apei_exec_read_register(entry, &ctx->dst_base);
 261 }
 262
 263 static int erst_exec_move_data(struct apei_exec_context *ctx,
 264                                struct acpi_whea_header *entry)
 265 {
 266         int rc;
 267         u64 offset;
 268         void *src, *dst;
 269
 270         /* ioremap does not work in interrupt context */
 271         if (in_interrupt()) {
 272                 pr_warn("MOVE_DATA can not be used in interrupt context.\n");
 273                 return -EBUSY;
 274         }
 275
 276         rc = __apei_exec_read_register(entry, &offset);
 277         if (rc)
 278                 return rc;
 279
 280         src = ioremap(ctx->src_base + offset, ctx->var2);
 281         if (!src)
 282                 return -ENOMEM;
 283         dst = ioremap(ctx->dst_base + offset, ctx->var2);
 284         if (!dst) {
 285                 iounmap(src);
 286                 return -ENOMEM;
 287         }
 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         raw_spin_lock_irqsave(&erst_lock, flags);
 425         count = __erst_get_record_count();
 426         raw_spin_unlock_irqrestore(&erst_lock, flags);
 427
 428         return count;
 429 }
 430 EXPORT_SYMBOL_GPL(erst_get_record_count);
 431
 432 #define ERST_RECORD_ID_CACHE_SIZE_MIN   16
 433 #define ERST_RECORD_ID_CACHE_SIZE_MAX   1024
 434
 435 struct erst_record_id_cache {
 436         struct mutex lock;
 437         u64 *entries;
 438         int len;
 439         int size;
 440         int refcount;
 441 };
 442
 443 static struct erst_record_id_cache erst_record_id_cache = {
 444         .lock = __MUTEX_INITIALIZER(erst_record_id_cache.lock),
 445         .refcount = 0,
 446 };
 447
 448 static int __erst_get_next_record_id(u64 *record_id)
 449 {
 450         struct apei_exec_context ctx;
 451         int rc;
 452
 453         erst_exec_ctx_init(&ctx);
 454         rc = apei_exec_run(&ctx, ACPI_ERST_GET_RECORD_ID);
 455         if (rc)
 456                 return rc;
 457         *record_id = apei_exec_ctx_get_output(&ctx);
 458
 459         return 0;
 460 }
 461
 462 int erst_get_record_id_begin(int *pos)
 463 {
 464         int rc;
 465
 466         if (erst_disable)
 467                 return -ENODEV;
 468
 469         rc = mutex_lock_interruptible(&erst_record_id_cache.lock);
 470         if (rc)
 471                 return rc;
 472         erst_record_id_cache.refcount++;
 473         mutex_unlock(&erst_record_id_cache.lock);
 474
 475         *pos = 0;
 476
 477         return 0;
 478 }
 479 EXPORT_SYMBOL_GPL(erst_get_record_id_begin);
 480
 481 /* erst_record_id_cache.lock must be held by caller */
 482 static int __erst_record_id_cache_add_one(void)
 483 {
 484         u64 id, prev_id, first_id;
 485         int i, rc;
 486         u64 *entries;
 487         unsigned long flags;
 488
 489         id = prev_id = first_id = APEI_ERST_INVALID_RECORD_ID;
 490 retry:
 491         raw_spin_lock_irqsave(&erst_lock, flags);
 492         rc = __erst_get_next_record_id(&id);
 493         raw_spin_unlock_irqrestore(&erst_lock, flags);
 494         if (rc == -ENOENT)
 495                 return 0;
 496         if (rc)
 497                 return rc;
 498         if (id == APEI_ERST_INVALID_RECORD_ID)
 499                 return 0;
 500         /* can not skip current ID, or loop back to first ID */
 501         if (id == prev_id || id == first_id)
 502                 return 0;
 503         if (first_id == APEI_ERST_INVALID_RECORD_ID)
 504                 first_id = id;
 505         prev_id = id;
 506
 507         entries = erst_record_id_cache.entries;
 508         for (i = 0; i < erst_record_id_cache.len; i++) {
 509                 if (entries[i] == id)
 510                         break;
 511         }
 512         /* record id already in cache, try next */
 513         if (i < erst_record_id_cache.len)
 514                 goto retry;
 515         if (erst_record_id_cache.len >= erst_record_id_cache.size) {
 516                 int new_size;
 517                 u64 *new_entries;
 518
 519                 new_size = erst_record_id_cache.size * 2;
 520                 new_size = clamp_val(new_size, ERST_RECORD_ID_CACHE_SIZE_MIN,
 521                                      ERST_RECORD_ID_CACHE_SIZE_MAX);
 522                 if (new_size <= erst_record_id_cache.size) {
 523                         if (printk_ratelimit())
 524                                 pr_warn(FW_WARN "too many record IDs!\n");
 525                         return 0;
 526                 }
 527                 new_entries = kvmalloc_array(new_size, sizeof(entries[0]),
 528                                              GFP_KERNEL);
 529                 if (!new_entries)
 530                         return -ENOMEM;
 531                 memcpy(new_entries, entries,
 532                        erst_record_id_cache.len * sizeof(entries[0]));
 533                 kvfree(entries);
 534                 erst_record_id_cache.entries = entries = new_entries;
 535                 erst_record_id_cache.size = new_size;
 536         }
 537         entries[i] = id;
 538         erst_record_id_cache.len++;
 539
 540         return 1;
 541 }
 542
 543 /*
 544  * Get the record ID of an existing error record on the persistent
 545  * storage. If there is no error record on the persistent storage, the
 546  * returned record_id is APEI_ERST_INVALID_RECORD_ID.
 547  */
 548 int erst_get_record_id_next(int *pos, u64 *record_id)
 549 {
 550         int rc = 0;
 551         u64 *entries;
 552
 553         if (erst_disable)
 554                 return -ENODEV;
 555
 556         /* must be enclosed by erst_get_record_id_begin/end */
 557         BUG_ON(!erst_record_id_cache.refcount);
 558         BUG_ON(*pos < 0 || *pos > erst_record_id_cache.len);
 559
 560         mutex_lock(&erst_record_id_cache.lock);
 561         entries = erst_record_id_cache.entries;
 562         for (; *pos < erst_record_id_cache.len; (*pos)++)
 563                 if (entries[*pos] != APEI_ERST_INVALID_RECORD_ID)
 564                         break;
 565         /* found next record id in cache */
 566         if (*pos < erst_record_id_cache.len) {
 567                 *record_id = entries[*pos];
 568                 (*pos)++;
 569                 goto out_unlock;
 570         }
 571
 572         /* Try to add one more record ID to cache */
 573         rc = __erst_record_id_cache_add_one();
 574         if (rc < 0)
 575                 goto out_unlock;
 576         /* successfully add one new ID */
 577         if (rc == 1) {
 578                 *record_id = erst_record_id_cache.entries[*pos];
 579                 (*pos)++;
 580                 rc = 0;
 581         } else {
 582                 *pos = -1;
 583                 *record_id = APEI_ERST_INVALID_RECORD_ID;
 584         }
 585 out_unlock:
 586         mutex_unlock(&erst_record_id_cache.lock);
 587
 588         return rc;
 589 }
 590 EXPORT_SYMBOL_GPL(erst_get_record_id_next);
 591
 592 /* erst_record_id_cache.lock must be held by caller */
 593 static void __erst_record_id_cache_compact(void)
 594 {
 595         int i, wpos = 0;
 596         u64 *entries;
 597
 598         if (erst_record_id_cache.refcount)
 599                 return;
 600
 601         entries = erst_record_id_cache.entries;
 602         for (i = 0; i < erst_record_id_cache.len; i++) {
 603                 if (entries[i] == APEI_ERST_INVALID_RECORD_ID)
 604                         continue;
 605                 if (wpos != i)
 606                         entries[wpos] = entries[i];
 607                 wpos++;
 608         }
 609         erst_record_id_cache.len = wpos;
 610 }
 611
 612 void erst_get_record_id_end(void)
 613 {
 614         /*
 615          * erst_disable != 0 should be detected by invoker via the
 616          * return value of erst_get_record_id_begin/next, so this
 617          * function should not be called for erst_disable != 0.
 618          */
 619         BUG_ON(erst_disable);
 620
 621         mutex_lock(&erst_record_id_cache.lock);
 622         erst_record_id_cache.refcount--;
 623         BUG_ON(erst_record_id_cache.refcount < 0);
 624         __erst_record_id_cache_compact();
 625         mutex_unlock(&erst_record_id_cache.lock);
 626 }
 627 EXPORT_SYMBOL_GPL(erst_get_record_id_end);
 628
 629 static int __erst_write_to_storage(u64 offset)
 630 {
 631         struct apei_exec_context ctx;
 632         u64 timeout = FIRMWARE_TIMEOUT;
 633         u64 val;
 634         int rc;
 635
 636         erst_exec_ctx_init(&ctx);
 637         rc = apei_exec_run_optional(&ctx, ACPI_ERST_BEGIN_WRITE);
 638         if (rc)
 639                 return rc;
 640         apei_exec_ctx_set_input(&ctx, offset);
 641         rc = apei_exec_run(&ctx, ACPI_ERST_SET_RECORD_OFFSET);
 642         if (rc)
 643                 return rc;
 644         rc = apei_exec_run(&ctx, ACPI_ERST_EXECUTE_OPERATION);
 645         if (rc)
 646                 return rc;
 647         for (;;) {
 648                 rc = apei_exec_run(&ctx, ACPI_ERST_CHECK_BUSY_STATUS);
 649                 if (rc)
 650                         return rc;
 651                 val = apei_exec_ctx_get_output(&ctx);
 652                 if (!val)
 653                         break;
 654                 if (erst_timedout(&timeout, SPIN_UNIT))
 655                         return -EIO;
 656         }
 657         rc = apei_exec_run(&ctx, ACPI_ERST_GET_COMMAND_STATUS);
 658         if (rc)
 659                 return rc;
 660         val = apei_exec_ctx_get_output(&ctx);
 661         rc = apei_exec_run_optional(&ctx, ACPI_ERST_END);
 662         if (rc)
 663                 return rc;
 664
 665         return erst_errno(val);
 666 }
 667
 668 static int __erst_read_from_storage(u64 record_id, u64 offset)
 669 {
 670         struct apei_exec_context ctx;
 671         u64 timeout = FIRMWARE_TIMEOUT;
 672         u64 val;
 673         int rc;
 674
 675         erst_exec_ctx_init(&ctx);
 676         rc = apei_exec_run_optional(&ctx, ACPI_ERST_BEGIN_READ);
 677         if (rc)
 678                 return rc;
 679         apei_exec_ctx_set_input(&ctx, offset);
 680         rc = apei_exec_run(&ctx, ACPI_ERST_SET_RECORD_OFFSET);
 681         if (rc)
 682                 return rc;
 683         apei_exec_ctx_set_input(&ctx, record_id);
 684         rc = apei_exec_run(&ctx, ACPI_ERST_SET_RECORD_ID);
 685         if (rc)
 686                 return rc;
 687         rc = apei_exec_run(&ctx, ACPI_ERST_EXECUTE_OPERATION);
 688         if (rc)
 689                 return rc;
 690         for (;;) {
 691                 rc = apei_exec_run(&ctx, ACPI_ERST_CHECK_BUSY_STATUS);
 692                 if (rc)
 693                         return rc;
 694                 val = apei_exec_ctx_get_output(&ctx);
 695                 if (!val)
 696                         break;
 697                 if (erst_timedout(&timeout, SPIN_UNIT))
 698                         return -EIO;
 699         };
 700         rc = apei_exec_run(&ctx, ACPI_ERST_GET_COMMAND_STATUS);
 701         if (rc)
 702                 return rc;
 703         val = apei_exec_ctx_get_output(&ctx);
 704         rc = apei_exec_run_optional(&ctx, ACPI_ERST_END);
 705         if (rc)
 706                 return rc;
 707
 708         return erst_errno(val);
 709 }
 710
 711 static int __erst_clear_from_storage(u64 record_id)
 712 {
 713         struct apei_exec_context ctx;
 714         u64 timeout = FIRMWARE_TIMEOUT;
 715         u64 val;
 716         int rc;
 717
 718         erst_exec_ctx_init(&ctx);
 719         rc = apei_exec_run_optional(&ctx, ACPI_ERST_BEGIN_CLEAR);
 720         if (rc)
 721                 return rc;
 722         apei_exec_ctx_set_input(&ctx, record_id);
 723         rc = apei_exec_run(&ctx, ACPI_ERST_SET_RECORD_ID);
 724         if (rc)
 725                 return rc;
 726         rc = apei_exec_run(&ctx, ACPI_ERST_EXECUTE_OPERATION);
 727         if (rc)
 728                 return rc;
 729         for (;;) {
 730                 rc = apei_exec_run(&ctx, ACPI_ERST_CHECK_BUSY_STATUS);
 731                 if (rc)
 732                         return rc;
 733                 val = apei_exec_ctx_get_output(&ctx);
 734                 if (!val)
 735                         break;
 736                 if (erst_timedout(&timeout, SPIN_UNIT))
 737                         return -EIO;
 738         }
 739         rc = apei_exec_run(&ctx, ACPI_ERST_GET_COMMAND_STATUS);
 740         if (rc)
 741                 return rc;
 742         val = apei_exec_ctx_get_output(&ctx);
 743         rc = apei_exec_run_optional(&ctx, ACPI_ERST_END);
 744         if (rc)
 745                 return rc;
 746
 747         return erst_errno(val);
 748 }
 749
 750 /* NVRAM ERST Error Log Address Range is not supported yet */
 751 static void pr_unimpl_nvram(void)
 752 {
 753         if (printk_ratelimit())
 754                 pr_warn("NVRAM ERST Log Address Range not implemented yet.\n");
 755 }
 756
 757 static int __erst_write_to_nvram(const struct cper_record_header *record)
 758 {
 759         /* do not print message, because printk is not safe for NMI */
 760         return -ENOSYS;
 761 }
 762
 763 static int __erst_read_to_erange_from_nvram(u64 record_id, u64 *offset)
 764 {
 765         pr_unimpl_nvram();
 766         return -ENOSYS;
 767 }
 768
 769 static int __erst_clear_from_nvram(u64 record_id)
 770 {
 771         pr_unimpl_nvram();
 772         return -ENOSYS;
 773 }
 774
 775 int erst_write(const struct cper_record_header *record)
 776 {
 777         int rc;
 778         unsigned long flags;
 779         struct cper_record_header *rcd_erange;
 780
 781         if (erst_disable)
 782                 return -ENODEV;
 783
 784         if (memcmp(record->signature, CPER_SIG_RECORD, CPER_SIG_SIZE))
 785                 return -EINVAL;
 786
 787         if (erst_erange.attr & ERST_RANGE_NVRAM) {
 788                 if (!raw_spin_trylock_irqsave(&erst_lock, flags))
 789                         return -EBUSY;
 790                 rc = __erst_write_to_nvram(record);
 791                 raw_spin_unlock_irqrestore(&erst_lock, flags);
 792                 return rc;
 793         }
 794
 795         if (record->record_length > erst_erange.size)
 796                 return -EINVAL;
 797
 798         if (!raw_spin_trylock_irqsave(&erst_lock, flags))
 799                 return -EBUSY;
 800         memcpy(erst_erange.vaddr, record, record->record_length);
 801         rcd_erange = erst_erange.vaddr;
 802         /* signature for serialization system */
 803         memcpy(&rcd_erange->persistence_information, "ER", 2);
 804
 805         rc = __erst_write_to_storage(0);
 806         raw_spin_unlock_irqrestore(&erst_lock, flags);
 807
 808         return rc;
 809 }
 810 EXPORT_SYMBOL_GPL(erst_write);
 811
 812 static int __erst_read_to_erange(u64 record_id, u64 *offset)
 813 {
 814         int rc;
 815
 816         if (erst_erange.attr & ERST_RANGE_NVRAM)
 817                 return __erst_read_to_erange_from_nvram(
 818                         record_id, offset);
 819
 820         rc = __erst_read_from_storage(record_id, 0);
 821         if (rc)
 822                 return rc;
 823         *offset = 0;
 824
 825         return 0;
 826 }
 827
 828 static ssize_t __erst_read(u64 record_id, struct cper_record_header *record,
 829                            size_t buflen)
 830 {
 831         int rc;
 832         u64 offset, len = 0;
 833         struct cper_record_header *rcd_tmp;
 834
 835         rc = __erst_read_to_erange(record_id, &offset);
 836         if (rc)
 837                 return rc;
 838         rcd_tmp = erst_erange.vaddr + offset;
 839         len = rcd_tmp->record_length;
 840         if (len <= buflen)
 841                 memcpy(record, rcd_tmp, len);
 842
 843         return len;
 844 }
 845
 846 /*
 847  * If return value > buflen, the buffer size is not big enough,
 848  * else if return value < 0, something goes wrong,
 849  * else everything is OK, and return value is record length
 850  */
 851 ssize_t erst_read(u64 record_id, struct cper_record_header *record,
 852                   size_t buflen)
 853 {
 854         ssize_t len;
 855         unsigned long flags;
 856
 857         if (erst_disable)
 858                 return -ENODEV;
 859
 860         raw_spin_lock_irqsave(&erst_lock, flags);
 861         len = __erst_read(record_id, record, buflen);
 862         raw_spin_unlock_irqrestore(&erst_lock, flags);
 863         return len;
 864 }
 865 EXPORT_SYMBOL_GPL(erst_read);
 866
 867 int erst_clear(u64 record_id)
 868 {
 869         int rc, i;
 870         unsigned long flags;
 871         u64 *entries;
 872
 873         if (erst_disable)
 874                 return -ENODEV;
 875
 876         rc = mutex_lock_interruptible(&erst_record_id_cache.lock);
 877         if (rc)
 878                 return rc;
 879         raw_spin_lock_irqsave(&erst_lock, flags);
 880         if (erst_erange.attr & ERST_RANGE_NVRAM)
 881                 rc = __erst_clear_from_nvram(record_id);
 882         else
 883                 rc = __erst_clear_from_storage(record_id);
 884         raw_spin_unlock_irqrestore(&erst_lock, flags);
 885         if (rc)
 886                 goto out;
 887         entries = erst_record_id_cache.entries;
 888         for (i = 0; i < erst_record_id_cache.len; i++) {
 889                 if (entries[i] == record_id)
 890                         entries[i] = APEI_ERST_INVALID_RECORD_ID;
 891         }
 892         __erst_record_id_cache_compact();
 893 out:
 894         mutex_unlock(&erst_record_id_cache.lock);
 895         return rc;
 896 }
 897 EXPORT_SYMBOL_GPL(erst_clear);
 898
 899 static int __init setup_erst_disable(char *str)
 900 {
 901         erst_disable = 1;
 902         return 0;
 903 }
 904
 905 __setup("erst_disable", setup_erst_disable);
 906
 907 static int erst_check_table(struct acpi_table_erst *erst_tab)
 908 {
 909         if ((erst_tab->header_length !=
 910              (sizeof(struct acpi_table_erst) - sizeof(erst_tab->header)))
 911             && (erst_tab->header_length != sizeof(struct acpi_table_erst)))
 912                 return -EINVAL;
 913         if (erst_tab->header.length < sizeof(struct acpi_table_erst))
 914                 return -EINVAL;
 915         if (erst_tab->entries !=
 916             (erst_tab->header.length - sizeof(struct acpi_table_erst)) /
 917             sizeof(struct acpi_erst_entry))
 918                 return -EINVAL;
 919
 920         return 0;
 921 }
 922
 923 static int erst_open_pstore(struct pstore_info *psi);
 924 static int erst_close_pstore(struct pstore_info *psi);
 925 static ssize_t erst_reader(struct pstore_record *record);
 926 static int erst_writer(struct pstore_record *record);
 927 static int erst_clearer(struct pstore_record *record);
 928
 929 static struct pstore_info erst_info = {
 930         .owner          = THIS_MODULE,
 931         .name           = "erst",
 932         .flags          = PSTORE_FLAGS_DMESG,
 933         .open           = erst_open_pstore,
 934         .close          = erst_close_pstore,
 935         .read           = erst_reader,
 936         .write          = erst_writer,
 937         .erase          = erst_clearer
 938 };
 939
 940 #define CPER_CREATOR_PSTORE                                             \
 941         GUID_INIT(0x75a574e3, 0x5052, 0x4b29, 0x8a, 0x8e, 0xbe, 0x2c,   \
 942                   0x64, 0x90, 0xb8, 0x9d)
 943 #define CPER_SECTION_TYPE_DMESG                                         \
 944         GUID_INIT(0xc197e04e, 0xd545, 0x4a70, 0x9c, 0x17, 0xa5, 0x54,   \
 945                   0x94, 0x19, 0xeb, 0x12)
 946 #define CPER_SECTION_TYPE_DMESG_Z                                       \
 947         GUID_INIT(0x4f118707, 0x04dd, 0x4055, 0xb5, 0xdd, 0x95, 0x6d,   \
 948                   0x34, 0xdd, 0xfa, 0xc6)
 949 #define CPER_SECTION_TYPE_MCE                                           \
 950         GUID_INIT(0xfe08ffbe, 0x95e4, 0x4be7, 0xbc, 0x73, 0x40, 0x96,   \
 951                   0x04, 0x4a, 0x38, 0xfc)
 952
 953 struct cper_pstore_record {
 954         struct cper_record_header hdr;
 955         struct cper_section_descriptor sec_hdr;
 956         char data[];
 957 } __packed;
 958
 959 static int reader_pos;
 960
 961 static int erst_open_pstore(struct pstore_info *psi)
 962 {
 963         int rc;
 964
 965         if (erst_disable)
 966                 return -ENODEV;
 967
 968         rc = erst_get_record_id_begin(&reader_pos);
 969
 970         return rc;
 971 }
 972
 973 static int erst_close_pstore(struct pstore_info *psi)
 974 {
 975         erst_get_record_id_end();
 976
 977         return 0;
 978 }
 979
 980 static ssize_t erst_reader(struct pstore_record *record)
 981 {
 982         int rc;
 983         ssize_t len = 0;
 984         u64 record_id;
 985         struct cper_pstore_record *rcd;
 986         size_t rcd_len = sizeof(*rcd) + erst_info.bufsize;
 987
 988         if (erst_disable)
 989                 return -ENODEV;
 990
 991         rcd = kmalloc(rcd_len, GFP_KERNEL);
 992         if (!rcd) {
 993                 rc = -ENOMEM;
 994                 goto out;
 995         }
 996 skip:
 997         rc = erst_get_record_id_next(&reader_pos, &record_id);
 998         if (rc)
 999                 goto out;
1000
1001         /* no more record */
1002         if (record_id == APEI_ERST_INVALID_RECORD_ID) {
1003                 rc = -EINVAL;
1004                 goto out;
1005         }
1006
1007         len = erst_read(record_id, &rcd->hdr, rcd_len);
1008         /* The record may be cleared by others, try read next record */
1009         if (len == -ENOENT)
1010                 goto skip;
1011         else if (len < 0 || len < sizeof(*rcd)) {
1012                 rc = -EIO;
1013                 goto out;
1014         }
1015         if (!guid_equal(&rcd->hdr.creator_id, &CPER_CREATOR_PSTORE))
1016                 goto skip;
1017
1018         record->buf = kmalloc(len, GFP_KERNEL);
1019         if (record->buf == NULL) {
1020                 rc = -ENOMEM;
1021                 goto out;
1022         }
1023         memcpy(record->buf, rcd->data, len - sizeof(*rcd));
1024         record->id = record_id;
1025         record->compressed = false;
1026         record->ecc_notice_size = 0;
1027         if (guid_equal(&rcd->sec_hdr.section_type, &CPER_SECTION_TYPE_DMESG_Z)) {
1028                 record->type = PSTORE_TYPE_DMESG;
1029                 record->compressed = true;
1030         } else if (guid_equal(&rcd->sec_hdr.section_type, &CPER_SECTION_TYPE_DMESG))
1031                 record->type = PSTORE_TYPE_DMESG;
1032         else if (guid_equal(&rcd->sec_hdr.section_type, &CPER_SECTION_TYPE_MCE))
1033                 record->type = PSTORE_TYPE_MCE;
1034         else
1035                 record->type = PSTORE_TYPE_MAX;
1036
1037         if (rcd->hdr.validation_bits & CPER_VALID_TIMESTAMP)
1038                 record->time.tv_sec = rcd->hdr.timestamp;
1039         else
1040                 record->time.tv_sec = 0;
1041         record->time.tv_nsec = 0;
1042
1043 out:
1044         kfree(rcd);
1045         return (rc < 0) ? rc : (len - sizeof(*rcd));
1046 }
1047
1048 static int erst_writer(struct pstore_record *record)
1049 {
1050         struct cper_pstore_record *rcd = (struct cper_pstore_record *)
1051                                         (erst_info.buf - sizeof(*rcd));
1052         int ret;
1053
1054         memset(rcd, 0, sizeof(*rcd));
1055         memcpy(rcd->hdr.signature, CPER_SIG_RECORD, CPER_SIG_SIZE);
1056         rcd->hdr.revision = CPER_RECORD_REV;
1057         rcd->hdr.signature_end = CPER_SIG_END;
1058         rcd->hdr.section_count = 1;
1059         rcd->hdr.error_severity = CPER_SEV_FATAL;
1060         /* timestamp valid. platform_id, partition_id are invalid */
1061         rcd->hdr.validation_bits = CPER_VALID_TIMESTAMP;
1062         rcd->hdr.timestamp = ktime_get_real_seconds();
1063         rcd->hdr.record_length = sizeof(*rcd) + record->size;
1064         rcd->hdr.creator_id = CPER_CREATOR_PSTORE;
1065         rcd->hdr.notification_type = CPER_NOTIFY_MCE;
1066         rcd->hdr.record_id = cper_next_record_id();
1067         rcd->hdr.flags = CPER_HW_ERROR_FLAGS_PREVERR;
1068
1069         rcd->sec_hdr.section_offset = sizeof(*rcd);
1070         rcd->sec_hdr.section_length = record->size;
1071         rcd->sec_hdr.revision = CPER_SEC_REV;
1072         /* fru_id and fru_text is invalid */
1073         rcd->sec_hdr.validation_bits = 0;
1074         rcd->sec_hdr.flags = CPER_SEC_PRIMARY;
1075         switch (record->type) {
1076         case PSTORE_TYPE_DMESG:
1077                 if (record->compressed)
1078                         rcd->sec_hdr.section_type = CPER_SECTION_TYPE_DMESG_Z;
1079                 else
1080                         rcd->sec_hdr.section_type = CPER_SECTION_TYPE_DMESG;
1081                 break;
1082         case PSTORE_TYPE_MCE:
1083                 rcd->sec_hdr.section_type = CPER_SECTION_TYPE_MCE;
1084                 break;
1085         default:
1086                 return -EINVAL;
1087         }
1088         rcd->sec_hdr.section_severity = CPER_SEV_FATAL;
1089
1090         ret = erst_write(&rcd->hdr);
1091         record->id = rcd->hdr.record_id;
1092
1093         return ret;
1094 }
1095
1096 static int erst_clearer(struct pstore_record *record)
1097 {
1098         return erst_clear(record->id);
1099 }
1100
1101 static int __init erst_init(void)
1102 {
1103         int rc = 0;
1104         acpi_status status;
1105         struct apei_exec_context ctx;
1106         struct apei_resources erst_resources;
1107         struct resource *r;
1108         char *buf;
1109
1110         if (acpi_disabled)
1111                 goto err;
1112
1113         if (erst_disable) {
1114                 pr_info(
1115         "Error Record Serialization Table (ERST) support is disabled.\n");
1116                 goto err;
1117         }
1118
1119         status = acpi_get_table(ACPI_SIG_ERST, 0,
1120                                 (struct acpi_table_header **)&erst_tab);
1121         if (status == AE_NOT_FOUND)
1122                 goto err;
1123         else if (ACPI_FAILURE(status)) {
1124                 const char *msg = acpi_format_exception(status);
1125                 pr_err("Failed to get table, %s\n", msg);
1126                 rc = -EINVAL;
1127                 goto err;
1128         }
1129
1130         rc = erst_check_table(erst_tab);
1131         if (rc) {
1132                 pr_err(FW_BUG "ERST table is invalid.\n");
1133                 goto err;
1134         }
1135
1136         apei_resources_init(&erst_resources);
1137         erst_exec_ctx_init(&ctx);
1138         rc = apei_exec_collect_resources(&ctx, &erst_resources);
1139         if (rc)
1140                 goto err_fini;
1141         rc = apei_resources_request(&erst_resources, "APEI ERST");
1142         if (rc)
1143                 goto err_fini;
1144         rc = apei_exec_pre_map_gars(&ctx);
1145         if (rc)
1146                 goto err_release;
1147         rc = erst_get_erange(&erst_erange);
1148         if (rc) {
1149                 if (rc == -ENODEV)
1150                         pr_info(
1151         "The corresponding hardware device or firmware implementation "
1152         "is not available.\n");
1153                 else
1154                         pr_err("Failed to get Error Log Address Range.\n");
1155                 goto err_unmap_reg;
1156         }
1157
1158         r = request_mem_region(erst_erange.base, erst_erange.size, "APEI ERST");
1159         if (!r) {
1160                 pr_err("Can not request [mem %#010llx-%#010llx] for ERST.\n",
1161                        (unsigned long long)erst_erange.base,
1162                        (unsigned long long)erst_erange.base + erst_erange.size - 1);
1163                 rc = -EIO;
1164                 goto err_unmap_reg;
1165         }
1166         rc = -ENOMEM;
1167         erst_erange.vaddr = ioremap_cache(erst_erange.base,
1168                                           erst_erange.size);
1169         if (!erst_erange.vaddr)
1170                 goto err_release_erange;
1171
1172         pr_info(
1173         "Error Record Serialization Table (ERST) support is initialized.\n");
1174
1175         buf = kmalloc(erst_erange.size, GFP_KERNEL);
1176         if (buf) {
1177                 erst_info.buf = buf + sizeof(struct cper_pstore_record);
1178                 erst_info.bufsize = erst_erange.size -
1179                                     sizeof(struct cper_pstore_record);
1180                 rc = pstore_register(&erst_info);
1181                 if (rc) {
1182                         if (rc != -EPERM)
1183                                 pr_info(
1184                                 "Could not register with persistent store.\n");
1185                         erst_info.buf = NULL;
1186                         erst_info.bufsize = 0;
1187                         kfree(buf);
1188                 }
1189         } else
1190                 pr_err(
1191                 "Failed to allocate %lld bytes for persistent store error log.\n",
1192                 erst_erange.size);
1193
1194         /* Cleanup ERST Resources */
1195         apei_resources_fini(&erst_resources);
1196
1197         return 0;
1198
1199 err_release_erange:
1200         release_mem_region(erst_erange.base, erst_erange.size);
1201 err_unmap_reg:
1202         apei_exec_post_unmap_gars(&ctx);
1203 err_release:
1204         apei_resources_release(&erst_resources);
1205 err_fini:
1206         apei_resources_fini(&erst_resources);
1207 err:
1208         erst_disable = 1;
1209         return rc;
1210 }
1211
1212 device_initcall(erst_init);