drivers/edac/ghes_edac.c

   1 // SPDX-License-Identifier: GPL-2.0-only
   2 /*
   3  * GHES/EDAC Linux driver
   4  *
   5  * Copyright (c) 2013 by Mauro Carvalho Chehab
   6  *
   7  * Red Hat Inc. https://www.redhat.com
   8  */
   9
  10 #define pr_fmt(fmt) KBUILD_MODNAME ": " fmt
  11
  12 #include <acpi/ghes.h>
  13 #include <linux/edac.h>
  14 #include <linux/dmi.h>
  15 #include "edac_module.h"
  16 #include <ras/ras_event.h>
  17
  18 struct ghes_pvt {
  19         struct mem_ctl_info *mci;
  20
  21         /* Buffers for the error handling routine */
  22         char other_detail[400];
  23         char msg[80];
  24 };
  25
  26 static refcount_t ghes_refcount = REFCOUNT_INIT(0);
  27
  28 /*
  29  * Access to ghes_pvt must be protected by ghes_lock. The spinlock
  30  * also provides the necessary (implicit) memory barrier for the SMP
  31  * case to make the pointer visible on another CPU.
  32  */
  33 static struct ghes_pvt *ghes_pvt;
  34
  35 /*
  36  * This driver's representation of the system hardware, as collected
  37  * from DMI.
  38  */
  39 struct ghes_hw_desc {
  40         int num_dimms;
  41         struct dimm_info *dimms;
  42 } ghes_hw;
  43
  44 /* GHES registration mutex */
  45 static DEFINE_MUTEX(ghes_reg_mutex);
  46
  47 /*
  48  * Sync with other, potentially concurrent callers of
  49  * ghes_edac_report_mem_error(). We don't know what the
  50  * "inventive" firmware would do.
  51  */
  52 static DEFINE_SPINLOCK(ghes_lock);
  53
  54 /* "ghes_edac.force_load=1" skips the platform check */
  55 static bool __read_mostly force_load;
  56 module_param(force_load, bool, 0);
  57
  58 static bool system_scanned;
  59
  60 /* Memory Device - Type 17 of SMBIOS spec */
  61 struct memdev_dmi_entry {
  62         u8 type;
  63         u8 length;
  64         u16 handle;
  65         u16 phys_mem_array_handle;
  66         u16 mem_err_info_handle;
  67         u16 total_width;
  68         u16 data_width;
  69         u16 size;
  70         u8 form_factor;
  71         u8 device_set;
  72         u8 device_locator;
  73         u8 bank_locator;
  74         u8 memory_type;
  75         u16 type_detail;
  76         u16 speed;
  77         u8 manufacturer;
  78         u8 serial_number;
  79         u8 asset_tag;
  80         u8 part_number;
  81         u8 attributes;
  82         u32 extended_size;
  83         u16 conf_mem_clk_speed;
  84 } __attribute__((__packed__));
  85
  86 static struct dimm_info *find_dimm_by_handle(struct mem_ctl_info *mci, u16 handle)
  87 {
  88         struct dimm_info *dimm;
  89
  90         mci_for_each_dimm(mci, dimm) {
  91                 if (dimm->smbios_handle == handle)
  92                         return dimm;
  93         }
  94
  95         return NULL;
  96 }
  97
  98 static void dimm_setup_label(struct dimm_info *dimm, u16 handle)
  99 {
 100         const char *bank = NULL, *device = NULL;
 101
 102         dmi_memdev_name(handle, &bank, &device);
 103
 104         /*
 105          * Set to a NULL string when both bank and device are zero. In this case,
 106          * the label assigned by default will be preserved.
 107          */
 108         snprintf(dimm->label, sizeof(dimm->label), "%s%s%s",
 109                  (bank && *bank) ? bank : "",
 110                  (bank && *bank && device && *device) ? " " : "",
 111                  (device && *device) ? device : "");
 112 }
 113
 114 static void assign_dmi_dimm_info(struct dimm_info *dimm, struct memdev_dmi_entry *entry)
 115 {
 116         u16 rdr_mask = BIT(7) | BIT(13);
 117
 118         if (entry->size == 0xffff) {
 119                 pr_info("Can't get DIMM%i size\n", dimm->idx);
 120                 dimm->nr_pages = MiB_TO_PAGES(32);/* Unknown */
 121         } else if (entry->size == 0x7fff) {
 122                 dimm->nr_pages = MiB_TO_PAGES(entry->extended_size);
 123         } else {
 124                 if (entry->size & BIT(15))
 125                         dimm->nr_pages = MiB_TO_PAGES((entry->size & 0x7fff) << 10);
 126                 else
 127                         dimm->nr_pages = MiB_TO_PAGES(entry->size);
 128         }
 129
 130         switch (entry->memory_type) {
 131         case 0x12:
 132                 if (entry->type_detail & BIT(13))
 133                         dimm->mtype = MEM_RDDR;
 134                 else
 135                         dimm->mtype = MEM_DDR;
 136                 break;
 137         case 0x13:
 138                 if (entry->type_detail & BIT(13))
 139                         dimm->mtype = MEM_RDDR2;
 140                 else
 141                         dimm->mtype = MEM_DDR2;
 142                 break;
 143         case 0x14:
 144                 dimm->mtype = MEM_FB_DDR2;
 145                 break;
 146         case 0x18:
 147                 if (entry->type_detail & BIT(12))
 148                         dimm->mtype = MEM_NVDIMM;
 149                 else if (entry->type_detail & BIT(13))
 150                         dimm->mtype = MEM_RDDR3;
 151                 else
 152                         dimm->mtype = MEM_DDR3;
 153                 break;
 154         case 0x1a:
 155                 if (entry->type_detail & BIT(12))
 156                         dimm->mtype = MEM_NVDIMM;
 157                 else if (entry->type_detail & BIT(13))
 158                         dimm->mtype = MEM_RDDR4;
 159                 else
 160                         dimm->mtype = MEM_DDR4;
 161                 break;
 162         default:
 163                 if (entry->type_detail & BIT(6))
 164                         dimm->mtype = MEM_RMBS;
 165                 else if ((entry->type_detail & rdr_mask) == rdr_mask)
 166                         dimm->mtype = MEM_RDR;
 167                 else if (entry->type_detail & BIT(7))
 168                         dimm->mtype = MEM_SDR;
 169                 else if (entry->type_detail & BIT(9))
 170                         dimm->mtype = MEM_EDO;
 171                 else
 172                         dimm->mtype = MEM_UNKNOWN;
 173         }
 174
 175         /*
 176          * Actually, we can only detect if the memory has bits for
 177          * checksum or not
 178          */
 179         if (entry->total_width == entry->data_width)
 180                 dimm->edac_mode = EDAC_NONE;
 181         else
 182                 dimm->edac_mode = EDAC_SECDED;
 183
 184         dimm->dtype = DEV_UNKNOWN;
 185         dimm->grain = 128;              /* Likely, worse case */
 186
 187         dimm_setup_label(dimm, entry->handle);
 188
 189         if (dimm->nr_pages) {
 190                 edac_dbg(1, "DIMM%i: %s size = %d MB%s\n",
 191                         dimm->idx, edac_mem_types[dimm->mtype],
 192                         PAGES_TO_MiB(dimm->nr_pages),
 193                         (dimm->edac_mode != EDAC_NONE) ? "(ECC)" : "");
 194                 edac_dbg(2, "\ttype %d, detail 0x%02x, width %d(total %d)\n",
 195                         entry->memory_type, entry->type_detail,
 196                         entry->total_width, entry->data_width);
 197         }
 198
 199         dimm->smbios_handle = entry->handle;
 200 }
 201
 202 static void enumerate_dimms(const struct dmi_header *dh, void *arg)
 203 {
 204         struct memdev_dmi_entry *entry = (struct memdev_dmi_entry *)dh;
 205         struct ghes_hw_desc *hw = (struct ghes_hw_desc *)arg;
 206         struct dimm_info *d;
 207
 208         if (dh->type != DMI_ENTRY_MEM_DEVICE)
 209                 return;
 210
 211         /* Enlarge the array with additional 16 */
 212         if (!hw->num_dimms || !(hw->num_dimms % 16)) {
 213                 struct dimm_info *new;
 214
 215                 new = krealloc(hw->dimms, (hw->num_dimms + 16) * sizeof(struct dimm_info),
 216                                 GFP_KERNEL);
 217                 if (!new) {
 218                         WARN_ON_ONCE(1);
 219                         return;
 220                 }
 221
 222                 hw->dimms = new;
 223         }
 224
 225         d = &hw->dimms[hw->num_dimms];
 226         d->idx = hw->num_dimms;
 227
 228         assign_dmi_dimm_info(d, entry);
 229
 230         hw->num_dimms++;
 231 }
 232
 233 static void ghes_scan_system(void)
 234 {
 235         if (system_scanned)
 236                 return;
 237
 238         dmi_walk(enumerate_dimms, &ghes_hw);
 239
 240         system_scanned = true;
 241 }
 242
 243 void ghes_edac_report_mem_error(int sev, struct cper_sec_mem_err *mem_err)
 244 {
 245         struct edac_raw_error_desc *e;
 246         struct mem_ctl_info *mci;
 247         struct ghes_pvt *pvt;
 248         unsigned long flags;
 249         char *p;
 250
 251         /*
 252          * We can do the locking below because GHES defers error processing
 253          * from NMI to IRQ context. Whenever that changes, we'd at least
 254          * know.
 255          */
 256         if (WARN_ON_ONCE(in_nmi()))
 257                 return;
 258
 259         spin_lock_irqsave(&ghes_lock, flags);
 260
 261         pvt = ghes_pvt;
 262         if (!pvt)
 263                 goto unlock;
 264
 265         mci = pvt->mci;
 266         e = &mci->error_desc;
 267
 268         /* Cleans the error report buffer */
 269         memset(e, 0, sizeof (*e));
 270         e->error_count = 1;
 271         e->grain = 1;
 272         e->msg = pvt->msg;
 273         e->other_detail = pvt->other_detail;
 274         e->top_layer = -1;
 275         e->mid_layer = -1;
 276         e->low_layer = -1;
 277         *pvt->other_detail = '\0';
 278         *pvt->msg = '\0';
 279
 280         switch (sev) {
 281         case GHES_SEV_CORRECTED:
 282                 e->type = HW_EVENT_ERR_CORRECTED;
 283                 break;
 284         case GHES_SEV_RECOVERABLE:
 285                 e->type = HW_EVENT_ERR_UNCORRECTED;
 286                 break;
 287         case GHES_SEV_PANIC:
 288                 e->type = HW_EVENT_ERR_FATAL;
 289                 break;
 290         default:
 291         case GHES_SEV_NO:
 292                 e->type = HW_EVENT_ERR_INFO;
 293         }
 294
 295         edac_dbg(1, "error validation_bits: 0x%08llx\n",
 296                  (long long)mem_err->validation_bits);
 297
 298         /* Error type, mapped on e->msg */
 299         if (mem_err->validation_bits & CPER_MEM_VALID_ERROR_TYPE) {
 300                 p = pvt->msg;
 301                 switch (mem_err->error_type) {
 302                 case 0:
 303                         p += sprintf(p, "Unknown");
 304                         break;
 305                 case 1:
 306                         p += sprintf(p, "No error");
 307                         break;
 308                 case 2:
 309                         p += sprintf(p, "Single-bit ECC");
 310                         break;
 311                 case 3:
 312                         p += sprintf(p, "Multi-bit ECC");
 313                         break;
 314                 case 4:
 315                         p += sprintf(p, "Single-symbol ChipKill ECC");
 316                         break;
 317                 case 5:
 318                         p += sprintf(p, "Multi-symbol ChipKill ECC");
 319                         break;
 320                 case 6:
 321                         p += sprintf(p, "Master abort");
 322                         break;
 323                 case 7:
 324                         p += sprintf(p, "Target abort");
 325                         break;
 326                 case 8:
 327                         p += sprintf(p, "Parity Error");
 328                         break;
 329                 case 9:
 330                         p += sprintf(p, "Watchdog timeout");
 331                         break;
 332                 case 10:
 333                         p += sprintf(p, "Invalid address");
 334                         break;
 335                 case 11:
 336                         p += sprintf(p, "Mirror Broken");
 337                         break;
 338                 case 12:
 339                         p += sprintf(p, "Memory Sparing");
 340                         break;
 341                 case 13:
 342                         p += sprintf(p, "Scrub corrected error");
 343                         break;
 344                 case 14:
 345                         p += sprintf(p, "Scrub uncorrected error");
 346                         break;
 347                 case 15:
 348                         p += sprintf(p, "Physical Memory Map-out event");
 349                         break;
 350                 default:
 351                         p += sprintf(p, "reserved error (%d)",
 352                                      mem_err->error_type);
 353                 }
 354         } else {
 355                 strcpy(pvt->msg, "unknown error");
 356         }
 357
 358         /* Error address */
 359         if (mem_err->validation_bits & CPER_MEM_VALID_PA) {
 360                 e->page_frame_number = PHYS_PFN(mem_err->physical_addr);
 361                 e->offset_in_page = offset_in_page(mem_err->physical_addr);
 362         }
 363
 364         /* Error grain */
 365         if (mem_err->validation_bits & CPER_MEM_VALID_PA_MASK)
 366                 e->grain = ~mem_err->physical_addr_mask + 1;
 367
 368         /* Memory error location, mapped on e->location */
 369         p = e->location;
 370         if (mem_err->validation_bits & CPER_MEM_VALID_NODE)
 371                 p += sprintf(p, "node:%d ", mem_err->node);
 372         if (mem_err->validation_bits & CPER_MEM_VALID_CARD)
 373                 p += sprintf(p, "card:%d ", mem_err->card);
 374         if (mem_err->validation_bits & CPER_MEM_VALID_MODULE)
 375                 p += sprintf(p, "module:%d ", mem_err->module);
 376         if (mem_err->validation_bits & CPER_MEM_VALID_RANK_NUMBER)
 377                 p += sprintf(p, "rank:%d ", mem_err->rank);
 378         if (mem_err->validation_bits & CPER_MEM_VALID_BANK)
 379                 p += sprintf(p, "bank:%d ", mem_err->bank);
 380         if (mem_err->validation_bits & CPER_MEM_VALID_BANK_GROUP)
 381                 p += sprintf(p, "bank_group:%d ",
 382                              mem_err->bank >> CPER_MEM_BANK_GROUP_SHIFT);
 383         if (mem_err->validation_bits & CPER_MEM_VALID_BANK_ADDRESS)
 384                 p += sprintf(p, "bank_address:%d ",
 385                              mem_err->bank & CPER_MEM_BANK_ADDRESS_MASK);
 386         if (mem_err->validation_bits & (CPER_MEM_VALID_ROW | CPER_MEM_VALID_ROW_EXT)) {
 387                 u32 row = mem_err->row;
 388
 389                 row |= cper_get_mem_extension(mem_err->validation_bits, mem_err->extended);
 390                 p += sprintf(p, "row:%d ", row);
 391         }
 392         if (mem_err->validation_bits & CPER_MEM_VALID_COLUMN)
 393                 p += sprintf(p, "col:%d ", mem_err->column);
 394         if (mem_err->validation_bits & CPER_MEM_VALID_BIT_POSITION)
 395                 p += sprintf(p, "bit_pos:%d ", mem_err->bit_pos);
 396         if (mem_err->validation_bits & CPER_MEM_VALID_MODULE_HANDLE) {
 397                 const char *bank = NULL, *device = NULL;
 398                 struct dimm_info *dimm;
 399
 400                 dmi_memdev_name(mem_err->mem_dev_handle, &bank, &device);
 401                 if (bank != NULL && device != NULL)
 402                         p += sprintf(p, "DIMM location:%s %s ", bank, device);
 403                 else
 404                         p += sprintf(p, "DIMM DMI handle: 0x%.4x ",
 405                                      mem_err->mem_dev_handle);
 406
 407                 dimm = find_dimm_by_handle(mci, mem_err->mem_dev_handle);
 408                 if (dimm) {
 409                         e->top_layer = dimm->idx;
 410                         strcpy(e->label, dimm->label);
 411                 }
 412         }
 413         if (mem_err->validation_bits & CPER_MEM_VALID_CHIP_ID)
 414                 p += sprintf(p, "chipID: %d ",
 415                              mem_err->extended >> CPER_MEM_CHIP_ID_SHIFT);
 416         if (p > e->location)
 417                 *(p - 1) = '\0';
 418
 419         if (!*e->label)
 420                 strcpy(e->label, "unknown memory");
 421
 422         /* All other fields are mapped on e->other_detail */
 423         p = pvt->other_detail;
 424         p += snprintf(p, sizeof(pvt->other_detail),
 425                 "APEI location: %s ", e->location);
 426         if (mem_err->validation_bits & CPER_MEM_VALID_ERROR_STATUS) {
 427                 u64 status = mem_err->error_status;
 428
 429                 p += sprintf(p, "status(0x%016llx): ", (long long)status);
 430                 switch ((status >> 8) & 0xff) {
 431                 case 1:
 432                         p += sprintf(p, "Error detected internal to the component ");
 433                         break;
 434                 case 16:
 435                         p += sprintf(p, "Error detected in the bus ");
 436                         break;
 437                 case 4:
 438                         p += sprintf(p, "Storage error in DRAM memory ");
 439                         break;
 440                 case 5:
 441                         p += sprintf(p, "Storage error in TLB ");
 442                         break;
 443                 case 6:
 444                         p += sprintf(p, "Storage error in cache ");
 445                         break;
 446                 case 7:
 447                         p += sprintf(p, "Error in one or more functional units ");
 448                         break;
 449                 case 8:
 450                         p += sprintf(p, "component failed self test ");
 451                         break;
 452                 case 9:
 453                         p += sprintf(p, "Overflow or undervalue of internal queue ");
 454                         break;
 455                 case 17:
 456                         p += sprintf(p, "Virtual address not found on IO-TLB or IO-PDIR ");
 457                         break;
 458                 case 18:
 459                         p += sprintf(p, "Improper access error ");
 460                         break;
 461                 case 19:
 462                         p += sprintf(p, "Access to a memory address which is not mapped to any component ");
 463                         break;
 464                 case 20:
 465                         p += sprintf(p, "Loss of Lockstep ");
 466                         break;
 467                 case 21:
 468                         p += sprintf(p, "Response not associated with a request ");
 469                         break;
 470                 case 22:
 471                         p += sprintf(p, "Bus parity error - must also set the A, C, or D Bits ");
 472                         break;
 473                 case 23:
 474                         p += sprintf(p, "Detection of a PATH_ERROR ");
 475                         break;
 476                 case 25:
 477                         p += sprintf(p, "Bus operation timeout ");
 478                         break;
 479                 case 26:
 480                         p += sprintf(p, "A read was issued to data that has been poisoned ");
 481                         break;
 482                 default:
 483                         p += sprintf(p, "reserved ");
 484                         break;
 485                 }
 486         }
 487         if (mem_err->validation_bits & CPER_MEM_VALID_REQUESTOR_ID)
 488                 p += sprintf(p, "requestorID: 0x%016llx ",
 489                              (long long)mem_err->requestor_id);
 490         if (mem_err->validation_bits & CPER_MEM_VALID_RESPONDER_ID)
 491                 p += sprintf(p, "responderID: 0x%016llx ",
 492                              (long long)mem_err->responder_id);
 493         if (mem_err->validation_bits & CPER_MEM_VALID_TARGET_ID)
 494                 p += sprintf(p, "targetID: 0x%016llx ",
 495                              (long long)mem_err->responder_id);
 496         if (p > pvt->other_detail)
 497                 *(p - 1) = '\0';
 498
 499         edac_raw_mc_handle_error(e);
 500
 501 unlock:
 502         spin_unlock_irqrestore(&ghes_lock, flags);
 503 }
 504
 505 /*
 506  * Known systems that are safe to enable this module.
 507  */
 508 static struct acpi_platform_list plat_list[] = {
 509         {"HPE   ", "Server  ", 0, ACPI_SIG_FADT, all_versions},
 510         { } /* End */
 511 };
 512
 513 int ghes_edac_register(struct ghes *ghes, struct device *dev)
 514 {
 515         bool fake = false;
 516         struct mem_ctl_info *mci;
 517         struct ghes_pvt *pvt;
 518         struct edac_mc_layer layers[1];
 519         unsigned long flags;
 520         int idx = -1;
 521         int rc = 0;
 522
 523         if (IS_ENABLED(CONFIG_X86)) {
 524                 /* Check if safe to enable on this system */
 525                 idx = acpi_match_platform_list(plat_list);
 526                 if (!force_load && idx < 0)
 527                         return -ENODEV;
 528         } else {
 529                 force_load = true;
 530                 idx = 0;
 531         }
 532
 533         /* finish another registration/unregistration instance first */
 534         mutex_lock(&ghes_reg_mutex);
 535
 536         /*
 537          * We have only one logical memory controller to which all DIMMs belong.
 538          */
 539         if (refcount_inc_not_zero(&ghes_refcount))
 540                 goto unlock;
 541
 542         ghes_scan_system();
 543
 544         /* Check if we've got a bogus BIOS */
 545         if (!ghes_hw.num_dimms) {
 546                 fake = true;
 547                 ghes_hw.num_dimms = 1;
 548         }
 549
 550         layers[0].type = EDAC_MC_LAYER_ALL_MEM;
 551         layers[0].size = ghes_hw.num_dimms;
 552         layers[0].is_virt_csrow = true;
 553
 554         mci = edac_mc_alloc(0, ARRAY_SIZE(layers), layers, sizeof(struct ghes_pvt));
 555         if (!mci) {
 556                 pr_info("Can't allocate memory for EDAC data\n");
 557                 rc = -ENOMEM;
 558                 goto unlock;
 559         }
 560
 561         pvt             = mci->pvt_info;
 562         pvt->mci        = mci;
 563
 564         mci->pdev = dev;
 565         mci->mtype_cap = MEM_FLAG_EMPTY;
 566         mci->edac_ctl_cap = EDAC_FLAG_NONE;
 567         mci->edac_cap = EDAC_FLAG_NONE;
 568         mci->mod_name = "ghes_edac.c";
 569         mci->ctl_name = "ghes_edac";
 570         mci->dev_name = "ghes";
 571
 572         if (fake) {
 573                 pr_info("This system has a very crappy BIOS: It doesn't even list the DIMMS.\n");
 574                 pr_info("Its SMBIOS info is wrong. It is doubtful that the error report would\n");
 575                 pr_info("work on such system. Use this driver with caution\n");
 576         } else if (idx < 0) {
 577                 pr_info("This EDAC driver relies on BIOS to enumerate memory and get error reports.\n");
 578                 pr_info("Unfortunately, not all BIOSes reflect the memory layout correctly.\n");
 579                 pr_info("So, the end result of using this driver varies from vendor to vendor.\n");
 580                 pr_info("If you find incorrect reports, please contact your hardware vendor\n");
 581                 pr_info("to correct its BIOS.\n");
 582                 pr_info("This system has %d DIMM sockets.\n", ghes_hw.num_dimms);
 583         }
 584
 585         if (!fake) {
 586                 struct dimm_info *src, *dst;
 587                 int i = 0;
 588
 589                 mci_for_each_dimm(mci, dst) {
 590                         src = &ghes_hw.dimms[i];
 591
 592                         dst->idx           = src->idx;
 593                         dst->smbios_handle = src->smbios_handle;
 594                         dst->nr_pages      = src->nr_pages;
 595                         dst->mtype         = src->mtype;
 596                         dst->edac_mode     = src->edac_mode;
 597                         dst->dtype         = src->dtype;
 598                         dst->grain         = src->grain;
 599
 600                         /*
 601                          * If no src->label, preserve default label assigned
 602                          * from EDAC core.
 603                          */
 604                         if (strlen(src->label))
 605                                 memcpy(dst->label, src->label, sizeof(src->label));
 606
 607                         i++;
 608                 }
 609
 610         } else {
 611                 struct dimm_info *dimm = edac_get_dimm(mci, 0, 0, 0);
 612
 613                 dimm->nr_pages = 1;
 614                 dimm->grain = 128;
 615                 dimm->mtype = MEM_UNKNOWN;
 616                 dimm->dtype = DEV_UNKNOWN;
 617                 dimm->edac_mode = EDAC_SECDED;
 618         }
 619
 620         rc = edac_mc_add_mc(mci);
 621         if (rc < 0) {
 622                 pr_info("Can't register with the EDAC core\n");
 623                 edac_mc_free(mci);
 624                 rc = -ENODEV;
 625                 goto unlock;
 626         }
 627
 628         spin_lock_irqsave(&ghes_lock, flags);
 629         ghes_pvt = pvt;
 630         spin_unlock_irqrestore(&ghes_lock, flags);
 631
 632         /* only set on success */
 633         refcount_set(&ghes_refcount, 1);
 634
 635 unlock:
 636
 637         /* Not needed anymore */
 638         kfree(ghes_hw.dimms);
 639         ghes_hw.dimms = NULL;
 640
 641         mutex_unlock(&ghes_reg_mutex);
 642
 643         return rc;
 644 }
 645
 646 void ghes_edac_unregister(struct ghes *ghes)
 647 {
 648         struct mem_ctl_info *mci;
 649         unsigned long flags;
 650
 651         if (!force_load)
 652                 return;
 653
 654         mutex_lock(&ghes_reg_mutex);
 655
 656         system_scanned = false;
 657         memset(&ghes_hw, 0, sizeof(struct ghes_hw_desc));
 658
 659         if (!refcount_dec_and_test(&ghes_refcount))
 660                 goto unlock;
 661
 662         /*
 663          * Wait for the irq handler being finished.
 664          */
 665         spin_lock_irqsave(&ghes_lock, flags);
 666         mci = ghes_pvt ? ghes_pvt->mci : NULL;
 667         ghes_pvt = NULL;
 668         spin_unlock_irqrestore(&ghes_lock, flags);
 669
 670         if (!mci)
 671                 goto unlock;
 672
 673         mci = edac_mc_del_mc(mci->pdev);
 674         if (mci)
 675                 edac_mc_free(mci);
 676
 677 unlock:
 678         mutex_unlock(&ghes_reg_mutex);
 679 }