linux/drivers/acpi/apei/erst.c
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   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
  52int erst_disable;
  53EXPORT_SYMBOL_GPL(erst_disable);
  54
  55static struct acpi_table_erst *erst_tab;
  56
  57/* ERST Error Log Address Range attributes */
  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 */
  66static 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 */
  81static DEFINE_RAW_SPINLOCK(erst_lock);
  82
  83static 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
 100static 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
 112static 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
 118static 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
 124static 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
 130static 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
 137static 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
 144static 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
 158static 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
 172static 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
 189static 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
 218static 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
 236static 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
 243static 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
 249static 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
 255static 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
 289static 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
 368static 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
 374static 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
 396static 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
 408ssize_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}
 422EXPORT_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
 427struct erst_record_id_cache {
 428        struct mutex lock;
 429        u64 *entries;
 430        int len;
 431        int size;
 432        int refcount;
 433};
 434
 435static struct erst_record_id_cache erst_record_id_cache = {
 436        .lock = __MUTEX_INITIALIZER(erst_record_id_cache.lock),
 437        .refcount = 0,
 438};
 439
 440static 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
 454int 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}
 471EXPORT_SYMBOL_GPL(erst_get_record_id_begin);
 472
 473/* erst_record_id_cache.lock must be held by caller */
 474static 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;
 482retry:
 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 */
 540int 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        }
 577out_unlock:
 578        mutex_unlock(&erst_record_id_cache.lock);
 579
 580        return rc;
 581}
 582EXPORT_SYMBOL_GPL(erst_get_record_id_next);
 583
 584/* erst_record_id_cache.lock must be held by caller */
 585static 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
 604void 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}
 619EXPORT_SYMBOL_GPL(erst_get_record_id_end);
 620
 621static 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
 660static 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
 703static 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 */
 743static void pr_unimpl_nvram(void)
 744{
 745        if (printk_ratelimit())
 746                pr_warn("NVRAM ERST Log Address Range not implemented yet.\n");
 747}
 748
 749static 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
 755static int __erst_read_to_erange_from_nvram(u64 record_id, u64 *offset)
 756{
 757        pr_unimpl_nvram();
 758        return -ENOSYS;
 759}
 760
 761static int __erst_clear_from_nvram(u64 record_id)
 762{
 763        pr_unimpl_nvram();
 764        return -ENOSYS;
 765}
 766
 767int 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}
 802EXPORT_SYMBOL_GPL(erst_write);
 803
 804static 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
 820static 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 */
 843ssize_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}
 857EXPORT_SYMBOL_GPL(erst_read);
 858
 859int 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();
 885out:
 886        mutex_unlock(&erst_record_id_cache.lock);
 887        return rc;
 888}
 889EXPORT_SYMBOL_GPL(erst_clear);
 890
 891static 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
 899static 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
 915static int erst_open_pstore(struct pstore_info *psi);
 916static int erst_close_pstore(struct pstore_info *psi);
 917static ssize_t erst_reader(struct pstore_record *record);
 918static int erst_writer(struct pstore_record *record);
 919static int erst_clearer(struct pstore_record *record);
 920
 921static 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
 945struct cper_pstore_record {
 946        struct cper_record_header hdr;
 947        struct cper_section_descriptor sec_hdr;
 948        char data[];
 949} __packed;
 950
 951static int reader_pos;
 952
 953static 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
 965static int erst_close_pstore(struct pstore_info *psi)
 966{
 967        erst_get_record_id_end();
 968
 969        return 0;
 970}
 971
 972static 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        }
 988skip:
 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
1035out:
1036        kfree(rcd);
1037        return (rc < 0) ? rc : (len - sizeof(*rcd));
1038}
1039
1040static 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
1088static int erst_clearer(struct pstore_record *record)
1089{
1090        return erst_clear(record->id);
1091}
1092
1093static 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
1191err_release_erange:
1192        release_mem_region(erst_erange.base, erst_erange.size);
1193err_unmap_reg:
1194        apei_exec_post_unmap_gars(&ctx);
1195err_release:
1196        apei_resources_release(&erst_resources);
1197err_fini:
1198        apei_resources_fini(&erst_resources);
1199err_put_erst_tab:
1200        acpi_put_table((struct acpi_table_header *)erst_tab);
1201err:
1202        erst_disable = 1;
1203        return rc;
1204}
1205
1206device_initcall(erst_init);
1207