drivers/acpi/apei/apei-base.c

   1 /*
   2  * apei-base.c - ACPI Platform Error Interface (APEI) supporting
   3  * infrastructure
   4  *
   5  * APEI allows to report errors (for example from the chipset) to the
   6  * the operating system. This improves NMI handling especially. In
   7  * addition it supports error serialization and error injection.
   8  *
   9  * For more information about APEI, please refer to ACPI Specification
  10  * version 4.0, chapter 17.
  11  *
  12  * This file has Common functions used by more than one APEI table,
  13  * including framework of interpreter for ERST and EINJ; resource
  14  * management for APEI registers.
  15  *
  16  * Copyright (C) 2009, Intel Corp.
  17  *      Author: Huang Ying <ying.huang@intel.com>
  18  *
  19  * This program is free software; you can redistribute it and/or
  20  * modify it under the terms of the GNU General Public License version
  21  * 2 as published by the Free Software Foundation.
  22  *
  23  * This program is distributed in the hope that it will be useful,
  24  * but WITHOUT ANY WARRANTY; without even the implied warranty of
  25  * MERCHANTABILITY or FITNESS FOR A PARTICULAR PURPOSE.  See the
  26  * GNU General Public License for more details.
  27  *
  28  * You should have received a copy of the GNU General Public License
  29  * along with this program; if not, write to the Free Software
  30  * Foundation, Inc., 59 Temple Place, Suite 330, Boston, MA  02111-1307  USA
  31  */
  32
  33 #include <linux/kernel.h>
  34 #include <linux/module.h>
  35 #include <linux/init.h>
  36 #include <linux/acpi.h>
  37 #include <linux/slab.h>
  38 #include <linux/io.h>
  39 #include <linux/kref.h>
  40 #include <linux/rculist.h>
  41 #include <linux/interrupt.h>
  42 #include <linux/debugfs.h>
  43 #include <acpi/atomicio.h>
  44
  45 #include "apei-internal.h"
  46
  47 #define APEI_PFX "APEI: "
  48
  49 /*
  50  * APEI ERST (Error Record Serialization Table) and EINJ (Error
  51  * INJection) interpreter framework.
  52  */
  53
  54 #define APEI_EXEC_PRESERVE_REGISTER     0x1
  55
  56 void apei_exec_ctx_init(struct apei_exec_context *ctx,
  57                         struct apei_exec_ins_type *ins_table,
  58                         u32 instructions,
  59                         struct acpi_whea_header *action_table,
  60                         u32 entries)
  61 {
  62         ctx->ins_table = ins_table;
  63         ctx->instructions = instructions;
  64         ctx->action_table = action_table;
  65         ctx->entries = entries;
  66 }
  67 EXPORT_SYMBOL_GPL(apei_exec_ctx_init);
  68
  69 int __apei_exec_read_register(struct acpi_whea_header *entry, u64 *val)
  70 {
  71         int rc;
  72
  73         rc = acpi_atomic_read(val, &entry->register_region);
  74         if (rc)
  75                 return rc;
  76         *val >>= entry->register_region.bit_offset;
  77         *val &= entry->mask;
  78
  79         return 0;
  80 }
  81
  82 int apei_exec_read_register(struct apei_exec_context *ctx,
  83                             struct acpi_whea_header *entry)
  84 {
  85         int rc;
  86         u64 val = 0;
  87
  88         rc = __apei_exec_read_register(entry, &val);
  89         if (rc)
  90                 return rc;
  91         ctx->value = val;
  92
  93         return 0;
  94 }
  95 EXPORT_SYMBOL_GPL(apei_exec_read_register);
  96
  97 int apei_exec_read_register_value(struct apei_exec_context *ctx,
  98                                   struct acpi_whea_header *entry)
  99 {
 100         int rc;
 101
 102         rc = apei_exec_read_register(ctx, entry);
 103         if (rc)
 104                 return rc;
 105         ctx->value = (ctx->value == entry->value);
 106
 107         return 0;
 108 }
 109 EXPORT_SYMBOL_GPL(apei_exec_read_register_value);
 110
 111 int __apei_exec_write_register(struct acpi_whea_header *entry, u64 val)
 112 {
 113         int rc;
 114
 115         val &= entry->mask;
 116         val <<= entry->register_region.bit_offset;
 117         if (entry->flags & APEI_EXEC_PRESERVE_REGISTER) {
 118                 u64 valr = 0;
 119                 rc = acpi_atomic_read(&valr, &entry->register_region);
 120                 if (rc)
 121                         return rc;
 122                 valr &= ~(entry->mask << entry->register_region.bit_offset);
 123                 val |= valr;
 124         }
 125         rc = acpi_atomic_write(val, &entry->register_region);
 126
 127         return rc;
 128 }
 129
 130 int apei_exec_write_register(struct apei_exec_context *ctx,
 131                              struct acpi_whea_header *entry)
 132 {
 133         return __apei_exec_write_register(entry, ctx->value);
 134 }
 135 EXPORT_SYMBOL_GPL(apei_exec_write_register);
 136
 137 int apei_exec_write_register_value(struct apei_exec_context *ctx,
 138                                    struct acpi_whea_header *entry)
 139 {
 140         int rc;
 141
 142         ctx->value = entry->value;
 143         rc = apei_exec_write_register(ctx, entry);
 144
 145         return rc;
 146 }
 147 EXPORT_SYMBOL_GPL(apei_exec_write_register_value);
 148
 149 int apei_exec_noop(struct apei_exec_context *ctx,
 150                    struct acpi_whea_header *entry)
 151 {
 152         return 0;
 153 }
 154 EXPORT_SYMBOL_GPL(apei_exec_noop);
 155
 156 /*
 157  * Interpret the specified action. Go through whole action table,
 158  * execute all instructions belong to the action.
 159  */
 160 int apei_exec_run(struct apei_exec_context *ctx, u8 action)
 161 {
 162         int rc;
 163         u32 i, ip;
 164         struct acpi_whea_header *entry;
 165         apei_exec_ins_func_t run;
 166
 167         ctx->ip = 0;
 168
 169         /*
 170          * "ip" is the instruction pointer of current instruction,
 171          * "ctx->ip" specifies the next instruction to executed,
 172          * instruction "run" function may change the "ctx->ip" to
 173          * implement "goto" semantics.
 174          */
 175 rewind:
 176         ip = 0;
 177         for (i = 0; i < ctx->entries; i++) {
 178                 entry = &ctx->action_table[i];
 179                 if (entry->action != action)
 180                         continue;
 181                 if (ip == ctx->ip) {
 182                         if (entry->instruction >= ctx->instructions ||
 183                             !ctx->ins_table[entry->instruction].run) {
 184                                 pr_warning(FW_WARN APEI_PFX
 185                         "Invalid action table, unknown instruction type: %d\n",
 186                                            entry->instruction);
 187                                 return -EINVAL;
 188                         }
 189                         run = ctx->ins_table[entry->instruction].run;
 190                         rc = run(ctx, entry);
 191                         if (rc < 0)
 192                                 return rc;
 193                         else if (rc != APEI_EXEC_SET_IP)
 194                                 ctx->ip++;
 195                 }
 196                 ip++;
 197                 if (ctx->ip < ip)
 198                         goto rewind;
 199         }
 200
 201         return 0;
 202 }
 203 EXPORT_SYMBOL_GPL(apei_exec_run);
 204
 205 typedef int (*apei_exec_entry_func_t)(struct apei_exec_context *ctx,
 206                                       struct acpi_whea_header *entry,
 207                                       void *data);
 208
 209 static int apei_exec_for_each_entry(struct apei_exec_context *ctx,
 210                                     apei_exec_entry_func_t func,
 211                                     void *data,
 212                                     int *end)
 213 {
 214         u8 ins;
 215         int i, rc;
 216         struct acpi_whea_header *entry;
 217         struct apei_exec_ins_type *ins_table = ctx->ins_table;
 218
 219         for (i = 0; i < ctx->entries; i++) {
 220                 entry = ctx->action_table + i;
 221                 ins = entry->instruction;
 222                 if (end)
 223                         *end = i;
 224                 if (ins >= ctx->instructions || !ins_table[ins].run) {
 225                         pr_warning(FW_WARN APEI_PFX
 226                         "Invalid action table, unknown instruction type: %d\n",
 227                                    ins);
 228                         return -EINVAL;
 229                 }
 230                 rc = func(ctx, entry, data);
 231                 if (rc)
 232                         return rc;
 233         }
 234
 235         return 0;
 236 }
 237
 238 static int pre_map_gar_callback(struct apei_exec_context *ctx,
 239                                 struct acpi_whea_header *entry,
 240                                 void *data)
 241 {
 242         u8 ins = entry->instruction;
 243
 244         if (ctx->ins_table[ins].flags & APEI_EXEC_INS_ACCESS_REGISTER)
 245                 return acpi_pre_map_gar(&entry->register_region);
 246
 247         return 0;
 248 }
 249
 250 /*
 251  * Pre-map all GARs in action table to make it possible to access them
 252  * in NMI handler.
 253  */
 254 int apei_exec_pre_map_gars(struct apei_exec_context *ctx)
 255 {
 256         int rc, end;
 257
 258         rc = apei_exec_for_each_entry(ctx, pre_map_gar_callback,
 259                                       NULL, &end);
 260         if (rc) {
 261                 struct apei_exec_context ctx_unmap;
 262                 memcpy(&ctx_unmap, ctx, sizeof(*ctx));
 263                 ctx_unmap.entries = end;
 264                 apei_exec_post_unmap_gars(&ctx_unmap);
 265         }
 266
 267         return rc;
 268 }
 269 EXPORT_SYMBOL_GPL(apei_exec_pre_map_gars);
 270
 271 static int post_unmap_gar_callback(struct apei_exec_context *ctx,
 272                                    struct acpi_whea_header *entry,
 273                                    void *data)
 274 {
 275         u8 ins = entry->instruction;
 276
 277         if (ctx->ins_table[ins].flags & APEI_EXEC_INS_ACCESS_REGISTER)
 278                 acpi_post_unmap_gar(&entry->register_region);
 279
 280         return 0;
 281 }
 282
 283 /* Post-unmap all GAR in action table. */
 284 int apei_exec_post_unmap_gars(struct apei_exec_context *ctx)
 285 {
 286         return apei_exec_for_each_entry(ctx, post_unmap_gar_callback,
 287                                         NULL, NULL);
 288 }
 289 EXPORT_SYMBOL_GPL(apei_exec_post_unmap_gars);
 290
 291 /*
 292  * Resource management for GARs in APEI
 293  */
 294 struct apei_res {
 295         struct list_head list;
 296         unsigned long start;
 297         unsigned long end;
 298 };
 299
 300 /* Collect all resources requested, to avoid conflict */
 301 struct apei_resources apei_resources_all = {
 302         .iomem = LIST_HEAD_INIT(apei_resources_all.iomem),
 303         .ioport = LIST_HEAD_INIT(apei_resources_all.ioport),
 304 };
 305
 306 static int apei_res_add(struct list_head *res_list,
 307                         unsigned long start, unsigned long size)
 308 {
 309         struct apei_res *res, *resn, *res_ins = NULL;
 310         unsigned long end = start + size;
 311
 312         if (end <= start)
 313                 return 0;
 314 repeat:
 315         list_for_each_entry_safe(res, resn, res_list, list) {
 316                 if (res->start > end || res->end < start)
 317                         continue;
 318                 else if (end <= res->end && start >= res->start) {
 319                         kfree(res_ins);
 320                         return 0;
 321                 }
 322                 list_del(&res->list);
 323                 res->start = start = min(res->start, start);
 324                 res->end = end = max(res->end, end);
 325                 kfree(res_ins);
 326                 res_ins = res;
 327                 goto repeat;
 328         }
 329
 330         if (res_ins)
 331                 list_add(&res_ins->list, res_list);
 332         else {
 333                 res_ins = kmalloc(sizeof(*res), GFP_KERNEL);
 334                 if (!res_ins)
 335                         return -ENOMEM;
 336                 res_ins->start = start;
 337                 res_ins->end = end;
 338                 list_add(&res_ins->list, res_list);
 339         }
 340
 341         return 0;
 342 }
 343
 344 static int apei_res_sub(struct list_head *res_list1,
 345                         struct list_head *res_list2)
 346 {
 347         struct apei_res *res1, *resn1, *res2, *res;
 348         res1 = list_entry(res_list1->next, struct apei_res, list);
 349         resn1 = list_entry(res1->list.next, struct apei_res, list);
 350         while (&res1->list != res_list1) {
 351                 list_for_each_entry(res2, res_list2, list) {
 352                         if (res1->start >= res2->end ||
 353                             res1->end <= res2->start)
 354                                 continue;
 355                         else if (res1->end <= res2->end &&
 356                                  res1->start >= res2->start) {
 357                                 list_del(&res1->list);
 358                                 kfree(res1);
 359                                 break;
 360                         } else if (res1->end > res2->end &&
 361                                    res1->start < res2->start) {
 362                                 res = kmalloc(sizeof(*res), GFP_KERNEL);
 363                                 if (!res)
 364                                         return -ENOMEM;
 365                                 res->start = res2->end;
 366                                 res->end = res1->end;
 367                                 res1->end = res2->start;
 368                                 list_add(&res->list, &res1->list);
 369                                 resn1 = res;
 370                         } else {
 371                                 if (res1->start < res2->start)
 372                                         res1->end = res2->start;
 373                                 else
 374                                         res1->start = res2->end;
 375                         }
 376                 }
 377                 res1 = resn1;
 378                 resn1 = list_entry(resn1->list.next, struct apei_res, list);
 379         }
 380
 381         return 0;
 382 }
 383
 384 static void apei_res_clean(struct list_head *res_list)
 385 {
 386         struct apei_res *res, *resn;
 387
 388         list_for_each_entry_safe(res, resn, res_list, list) {
 389                 list_del(&res->list);
 390                 kfree(res);
 391         }
 392 }
 393
 394 void apei_resources_fini(struct apei_resources *resources)
 395 {
 396         apei_res_clean(&resources->iomem);
 397         apei_res_clean(&resources->ioport);
 398 }
 399 EXPORT_SYMBOL_GPL(apei_resources_fini);
 400
 401 static int apei_resources_merge(struct apei_resources *resources1,
 402                                 struct apei_resources *resources2)
 403 {
 404         int rc;
 405         struct apei_res *res;
 406
 407         list_for_each_entry(res, &resources2->iomem, list) {
 408                 rc = apei_res_add(&resources1->iomem, res->start,
 409                                   res->end - res->start);
 410                 if (rc)
 411                         return rc;
 412         }
 413         list_for_each_entry(res, &resources2->ioport, list) {
 414                 rc = apei_res_add(&resources1->ioport, res->start,
 415                                   res->end - res->start);
 416                 if (rc)
 417                         return rc;
 418         }
 419
 420         return 0;
 421 }
 422
 423 /*
 424  * EINJ has two groups of GARs (EINJ table entry and trigger table
 425  * entry), so common resources are subtracted from the trigger table
 426  * resources before the second requesting.
 427  */
 428 int apei_resources_sub(struct apei_resources *resources1,
 429                        struct apei_resources *resources2)
 430 {
 431         int rc;
 432
 433         rc = apei_res_sub(&resources1->iomem, &resources2->iomem);
 434         if (rc)
 435                 return rc;
 436         return apei_res_sub(&resources1->ioport, &resources2->ioport);
 437 }
 438 EXPORT_SYMBOL_GPL(apei_resources_sub);
 439
 440 /*
 441  * IO memory/port rersource management mechanism is used to check
 442  * whether memory/port area used by GARs conflicts with normal memory
 443  * or IO memory/port of devices.
 444  */
 445 int apei_resources_request(struct apei_resources *resources,
 446                            const char *desc)
 447 {
 448         struct apei_res *res, *res_bak = NULL;
 449         struct resource *r;
 450         int rc;
 451
 452         rc = apei_resources_sub(resources, &apei_resources_all);
 453         if (rc)
 454                 return rc;
 455
 456         rc = -EINVAL;
 457         list_for_each_entry(res, &resources->iomem, list) {
 458                 r = request_mem_region(res->start, res->end - res->start,
 459                                        desc);
 460                 if (!r) {
 461                         pr_err(APEI_PFX
 462                 "Can not request iomem region <%016llx-%016llx> for GARs.\n",
 463                                (unsigned long long)res->start,
 464                                (unsigned long long)res->end);
 465                         res_bak = res;
 466                         goto err_unmap_iomem;
 467                 }
 468         }
 469
 470         list_for_each_entry(res, &resources->ioport, list) {
 471                 r = request_region(res->start, res->end - res->start, desc);
 472                 if (!r) {
 473                         pr_err(APEI_PFX
 474                 "Can not request ioport region <%016llx-%016llx> for GARs.\n",
 475                                (unsigned long long)res->start,
 476                                (unsigned long long)res->end);
 477                         res_bak = res;
 478                         goto err_unmap_ioport;
 479                 }
 480         }
 481
 482         rc = apei_resources_merge(&apei_resources_all, resources);
 483         if (rc) {
 484                 pr_err(APEI_PFX "Fail to merge resources!\n");
 485                 goto err_unmap_ioport;
 486         }
 487
 488         return 0;
 489 err_unmap_ioport:
 490         list_for_each_entry(res, &resources->ioport, list) {
 491                 if (res == res_bak)
 492                         break;
 493                 release_region(res->start, res->end - res->start);
 494         }
 495         res_bak = NULL;
 496 err_unmap_iomem:
 497         list_for_each_entry(res, &resources->iomem, list) {
 498                 if (res == res_bak)
 499                         break;
 500                 release_mem_region(res->start, res->end - res->start);
 501         }
 502         return rc;
 503 }
 504 EXPORT_SYMBOL_GPL(apei_resources_request);
 505
 506 void apei_resources_release(struct apei_resources *resources)
 507 {
 508         int rc;
 509         struct apei_res *res;
 510
 511         list_for_each_entry(res, &resources->iomem, list)
 512                 release_mem_region(res->start, res->end - res->start);
 513         list_for_each_entry(res, &resources->ioport, list)
 514                 release_region(res->start, res->end - res->start);
 515
 516         rc = apei_resources_sub(&apei_resources_all, resources);
 517         if (rc)
 518                 pr_err(APEI_PFX "Fail to sub resources!\n");
 519 }
 520 EXPORT_SYMBOL_GPL(apei_resources_release);
 521
 522 static int apei_check_gar(struct acpi_generic_address *reg, u64 *paddr)
 523 {
 524         u32 width, space_id;
 525
 526         width = reg->bit_width;
 527         space_id = reg->space_id;
 528         /* Handle possible alignment issues */
 529         memcpy(paddr, &reg->address, sizeof(*paddr));
 530         if (!*paddr) {
 531                 pr_warning(FW_BUG APEI_PFX
 532                            "Invalid physical address in GAR [0x%llx/%u/%u]\n",
 533                            *paddr, width, space_id);
 534                 return -EINVAL;
 535         }
 536
 537         if ((width != 8) && (width != 16) && (width != 32) && (width != 64)) {
 538                 pr_warning(FW_BUG APEI_PFX
 539                            "Invalid bit width in GAR [0x%llx/%u/%u]\n",
 540                            *paddr, width, space_id);
 541                 return -EINVAL;
 542         }
 543
 544         if (space_id != ACPI_ADR_SPACE_SYSTEM_MEMORY &&
 545             space_id != ACPI_ADR_SPACE_SYSTEM_IO) {
 546                 pr_warning(FW_BUG APEI_PFX
 547                            "Invalid address space type in GAR [0x%llx/%u/%u]\n",
 548                            *paddr, width, space_id);
 549                 return -EINVAL;
 550         }
 551
 552         return 0;
 553 }
 554
 555 static int collect_res_callback(struct apei_exec_context *ctx,
 556                                 struct acpi_whea_header *entry,
 557                                 void *data)
 558 {
 559         struct apei_resources *resources = data;
 560         struct acpi_generic_address *reg = &entry->register_region;
 561         u8 ins = entry->instruction;
 562         u64 paddr;
 563         int rc;
 564
 565         if (!(ctx->ins_table[ins].flags & APEI_EXEC_INS_ACCESS_REGISTER))
 566                 return 0;
 567
 568         rc = apei_check_gar(reg, &paddr);
 569         if (rc)
 570                 return rc;
 571
 572         switch (reg->space_id) {
 573         case ACPI_ADR_SPACE_SYSTEM_MEMORY:
 574                 return apei_res_add(&resources->iomem, paddr,
 575                                     reg->bit_width / 8);
 576         case ACPI_ADR_SPACE_SYSTEM_IO:
 577                 return apei_res_add(&resources->ioport, paddr,
 578                                     reg->bit_width / 8);
 579         default:
 580                 return -EINVAL;
 581         }
 582 }
 583
 584 /*
 585  * Same register may be used by multiple instructions in GARs, so
 586  * resources are collected before requesting.
 587  */
 588 int apei_exec_collect_resources(struct apei_exec_context *ctx,
 589                                 struct apei_resources *resources)
 590 {
 591         return apei_exec_for_each_entry(ctx, collect_res_callback,
 592                                         resources, NULL);
 593 }
 594 EXPORT_SYMBOL_GPL(apei_exec_collect_resources);
 595
 596 struct dentry *apei_get_debugfs_dir(void)
 597 {
 598         static struct dentry *dapei;
 599
 600         if (!dapei)
 601                 dapei = debugfs_create_dir("apei", NULL);
 602
 603         return dapei;
 604 }
 605 EXPORT_SYMBOL_GPL(apei_get_debugfs_dir);