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 #include <linux/notifier.h>
  18
  19 #define OTHER_DETAIL_LEN        400
  20
  21 struct ghes_pvt {
  22         struct mem_ctl_info *mci;
  23
  24         /* Buffers for the error handling routine */
  25         char other_detail[OTHER_DETAIL_LEN];
  26         char msg[80];
  27 };
  28
  29 static refcount_t ghes_refcount = REFCOUNT_INIT(0);
  30
  31 /*
  32  * Access to ghes_pvt must be protected by ghes_lock. The spinlock
  33  * also provides the necessary (implicit) memory barrier for the SMP
  34  * case to make the pointer visible on another CPU.
  35  */
  36 static struct ghes_pvt *ghes_pvt;
  37
  38 /*
  39  * This driver's representation of the system hardware, as collected
  40  * from DMI.
  41  */
  42 static struct ghes_hw_desc {
  43         int num_dimms;
  44         struct dimm_info *dimms;
  45 } ghes_hw;
  46
  47 /* GHES registration mutex */
  48 static DEFINE_MUTEX(ghes_reg_mutex);
  49
  50 /*
  51  * Sync with other, potentially concurrent callers of
  52  * ghes_edac_report_mem_error(). We don't know what the
  53  * "inventive" firmware would do.
  54  */
  55 static DEFINE_SPINLOCK(ghes_lock);
  56
  57 static bool system_scanned;
  58
  59 static struct list_head *ghes_devs;
  60
  61 /* Memory Device - Type 17 of SMBIOS spec */
  62 struct memdev_dmi_entry {
  63         u8 type;
  64         u8 length;
  65         u16 handle;
  66         u16 phys_mem_array_handle;
  67         u16 mem_err_info_handle;
  68         u16 total_width;
  69         u16 data_width;
  70         u16 size;
  71         u8 form_factor;
  72         u8 device_set;
  73         u8 device_locator;
  74         u8 bank_locator;
  75         u8 memory_type;
  76         u16 type_detail;
  77         u16 speed;
  78         u8 manufacturer;
  79         u8 serial_number;
  80         u8 asset_tag;
  81         u8 part_number;
  82         u8 attributes;
  83         u32 extended_size;
  84         u16 conf_mem_clk_speed;
  85 } __attribute__((__packed__));
  86
  87 static struct dimm_info *find_dimm_by_handle(struct mem_ctl_info *mci, u16 handle)
  88 {
  89         struct dimm_info *dimm;
  90
  91         mci_for_each_dimm(mci, dimm) {
  92                 if (dimm->smbios_handle == handle)
  93                         return dimm;
  94         }
  95
  96         return NULL;
  97 }
  98
  99 static void dimm_setup_label(struct dimm_info *dimm, u16 handle)
 100 {
 101         const char *bank = NULL, *device = NULL;
 102
 103         dmi_memdev_name(handle, &bank, &device);
 104
 105         /*
 106          * Set to a NULL string when both bank and device are zero. In this case,
 107          * the label assigned by default will be preserved.
 108          */
 109         snprintf(dimm->label, sizeof(dimm->label), "%s%s%s",
 110                  (bank && *bank) ? bank : "",
 111                  (bank && *bank && device && *device) ? " " : "",
 112                  (device && *device) ? device : "");
 113 }
 114
 115 static void assign_dmi_dimm_info(struct dimm_info *dimm, struct memdev_dmi_entry *entry)
 116 {
 117         u16 rdr_mask = BIT(7) | BIT(13);
 118
 119         if (entry->size == 0xffff) {
 120                 pr_info("Can't get DIMM%i size\n", dimm->idx);
 121                 dimm->nr_pages = MiB_TO_PAGES(32);/* Unknown */
 122         } else if (entry->size == 0x7fff) {
 123                 dimm->nr_pages = MiB_TO_PAGES(entry->extended_size);
 124         } else {
 125                 if (entry->size & BIT(15))
 126                         dimm->nr_pages = MiB_TO_PAGES((entry->size & 0x7fff) << 10);
 127                 else
 128                         dimm->nr_pages = MiB_TO_PAGES(entry->size);
 129         }
 130
 131         switch (entry->memory_type) {
 132         case 0x12:
 133                 if (entry->type_detail & BIT(13))
 134                         dimm->mtype = MEM_RDDR;
 135                 else
 136                         dimm->mtype = MEM_DDR;
 137                 break;
 138         case 0x13:
 139                 if (entry->type_detail & BIT(13))
 140                         dimm->mtype = MEM_RDDR2;
 141                 else
 142                         dimm->mtype = MEM_DDR2;
 143                 break;
 144         case 0x14:
 145                 dimm->mtype = MEM_FB_DDR2;
 146                 break;
 147         case 0x18:
 148                 if (entry->type_detail & BIT(12))
 149                         dimm->mtype = MEM_NVDIMM;
 150                 else if (entry->type_detail & BIT(13))
 151                         dimm->mtype = MEM_RDDR3;
 152                 else
 153                         dimm->mtype = MEM_DDR3;
 154                 break;
 155         case 0x1a:
 156                 if (entry->type_detail & BIT(12))
 157                         dimm->mtype = MEM_NVDIMM;
 158                 else if (entry->type_detail & BIT(13))
 159                         dimm->mtype = MEM_RDDR4;
 160                 else
 161                         dimm->mtype = MEM_DDR4;
 162                 break;
 163         default:
 164                 if (entry->type_detail & BIT(6))
 165                         dimm->mtype = MEM_RMBS;
 166                 else if ((entry->type_detail & rdr_mask) == rdr_mask)
 167                         dimm->mtype = MEM_RDR;
 168                 else if (entry->type_detail & BIT(7))
 169                         dimm->mtype = MEM_SDR;
 170                 else if (entry->type_detail & BIT(9))
 171                         dimm->mtype = MEM_EDO;
 172                 else
 173                         dimm->mtype = MEM_UNKNOWN;
 174         }
 175
 176         /*
 177          * Actually, we can only detect if the memory has bits for
 178          * checksum or not
 179          */
 180         if (entry->total_width == entry->data_width)
 181                 dimm->edac_mode = EDAC_NONE;
 182         else
 183                 dimm->edac_mode = EDAC_SECDED;
 184
 185         dimm->dtype = DEV_UNKNOWN;
 186         dimm->grain = 128;              /* Likely, worse case */
 187
 188         dimm_setup_label(dimm, entry->handle);
 189
 190         if (dimm->nr_pages) {
 191                 edac_dbg(1, "DIMM%i: %s size = %d MB%s\n",
 192                         dimm->idx, edac_mem_types[dimm->mtype],
 193                         PAGES_TO_MiB(dimm->nr_pages),
 194                         (dimm->edac_mode != EDAC_NONE) ? "(ECC)" : "");
 195                 edac_dbg(2, "\ttype %d, detail 0x%02x, width %d(total %d)\n",
 196                         entry->memory_type, entry->type_detail,
 197                         entry->total_width, entry->data_width);
 198         }
 199
 200         dimm->smbios_handle = entry->handle;
 201 }
 202
 203 static void enumerate_dimms(const struct dmi_header *dh, void *arg)
 204 {
 205         struct memdev_dmi_entry *entry = (struct memdev_dmi_entry *)dh;
 206         struct ghes_hw_desc *hw = (struct ghes_hw_desc *)arg;
 207         struct dimm_info *d;
 208
 209         if (dh->type != DMI_ENTRY_MEM_DEVICE)
 210                 return;
 211
 212         /* Enlarge the array with additional 16 */
 213         if (!hw->num_dimms || !(hw->num_dimms % 16)) {
 214                 struct dimm_info *new;
 215
 216                 new = krealloc_array(hw->dimms, hw->num_dimms + 16,
 217                                      sizeof(struct dimm_info), GFP_KERNEL);
 218                 if (!new) {
 219                         WARN_ON_ONCE(1);
 220                         return;
 221                 }
 222
 223                 hw->dimms = new;
 224         }
 225
 226         d = &hw->dimms[hw->num_dimms];
 227         d->idx = hw->num_dimms;
 228
 229         assign_dmi_dimm_info(d, entry);
 230
 231         hw->num_dimms++;
 232 }
 233
 234 static void ghes_scan_system(void)
 235 {
 236         if (system_scanned)
 237                 return;
 238
 239         dmi_walk(enumerate_dimms, &ghes_hw);
 240
 241         system_scanned = true;
 242 }
 243
 244 static int print_mem_error_other_detail(const struct cper_sec_mem_err *mem, char *msg,
 245                                         const char *location, unsigned int len)
 246 {
 247         u32 n;
 248
 249         if (!msg)
 250                 return 0;
 251
 252         n = 0;
 253         len -= 1;
 254
 255         n += scnprintf(msg + n, len - n, "APEI location: %s ", location);
 256
 257         if (!(mem->validation_bits & CPER_MEM_VALID_ERROR_STATUS))
 258                 goto out;
 259
 260         n += scnprintf(msg + n, len - n, "status(0x%016llx): ", mem->error_status);
 261         n += scnprintf(msg + n, len - n, "%s ", cper_mem_err_status_str(mem->error_status));
 262
 263 out:
 264         msg[n] = '\0';
 265
 266         return n;
 267 }
 268
 269 static int ghes_edac_report_mem_error(struct notifier_block *nb,
 270                                       unsigned long val, void *data)
 271 {
 272         struct cper_sec_mem_err *mem_err = (struct cper_sec_mem_err *)data;
 273         struct cper_mem_err_compact cmem;
 274         struct edac_raw_error_desc *e;
 275         struct mem_ctl_info *mci;
 276         unsigned long sev = val;
 277         struct ghes_pvt *pvt;
 278         unsigned long flags;
 279         char *p;
 280
 281         /*
 282          * We can do the locking below because GHES defers error processing
 283          * from NMI to IRQ context. Whenever that changes, we'd at least
 284          * know.
 285          */
 286         if (WARN_ON_ONCE(in_nmi()))
 287                 return NOTIFY_OK;
 288
 289         spin_lock_irqsave(&ghes_lock, flags);
 290
 291         pvt = ghes_pvt;
 292         if (!pvt)
 293                 goto unlock;
 294
 295         mci = pvt->mci;
 296         e = &mci->error_desc;
 297
 298         /* Cleans the error report buffer */
 299         memset(e, 0, sizeof (*e));
 300         e->error_count = 1;
 301         e->grain = 1;
 302         e->msg = pvt->msg;
 303         e->other_detail = pvt->other_detail;
 304         e->top_layer = -1;
 305         e->mid_layer = -1;
 306         e->low_layer = -1;
 307         *pvt->other_detail = '\0';
 308         *pvt->msg = '\0';
 309
 310         switch (sev) {
 311         case GHES_SEV_CORRECTED:
 312                 e->type = HW_EVENT_ERR_CORRECTED;
 313                 break;
 314         case GHES_SEV_RECOVERABLE:
 315                 e->type = HW_EVENT_ERR_UNCORRECTED;
 316                 break;
 317         case GHES_SEV_PANIC:
 318                 e->type = HW_EVENT_ERR_FATAL;
 319                 break;
 320         default:
 321         case GHES_SEV_NO:
 322                 e->type = HW_EVENT_ERR_INFO;
 323         }
 324
 325         edac_dbg(1, "error validation_bits: 0x%08llx\n",
 326                  (long long)mem_err->validation_bits);
 327
 328         /* Error type, mapped on e->msg */
 329         if (mem_err->validation_bits & CPER_MEM_VALID_ERROR_TYPE) {
 330                 u8 etype = mem_err->error_type;
 331
 332                 p = pvt->msg;
 333                 p += snprintf(p, sizeof(pvt->msg), "%s", cper_mem_err_type_str(etype));
 334         } else {
 335                 strcpy(pvt->msg, "unknown error");
 336         }
 337
 338         /* Error address */
 339         if (mem_err->validation_bits & CPER_MEM_VALID_PA) {
 340                 e->page_frame_number = PHYS_PFN(mem_err->physical_addr);
 341                 e->offset_in_page = offset_in_page(mem_err->physical_addr);
 342         }
 343
 344         /* Error grain */
 345         if (mem_err->validation_bits & CPER_MEM_VALID_PA_MASK)
 346                 e->grain = ~mem_err->physical_addr_mask + 1;
 347
 348         /* Memory error location, mapped on e->location */
 349         p = e->location;
 350         cper_mem_err_pack(mem_err, &cmem);
 351         p += cper_mem_err_location(&cmem, p);
 352
 353         if (mem_err->validation_bits & CPER_MEM_VALID_MODULE_HANDLE) {
 354                 struct dimm_info *dimm;
 355
 356                 p += cper_dimm_err_location(&cmem, p);
 357                 dimm = find_dimm_by_handle(mci, mem_err->mem_dev_handle);
 358                 if (dimm) {
 359                         e->top_layer = dimm->idx;
 360                         strcpy(e->label, dimm->label);
 361                 }
 362         }
 363         if (p > e->location)
 364                 *(p - 1) = '\0';
 365
 366         if (!*e->label)
 367                 strcpy(e->label, "unknown memory");
 368
 369         /* All other fields are mapped on e->other_detail */
 370         p = pvt->other_detail;
 371         p += print_mem_error_other_detail(mem_err, p, e->location, OTHER_DETAIL_LEN);
 372         if (p > pvt->other_detail)
 373                 *(p - 1) = '\0';
 374
 375         edac_raw_mc_handle_error(e);
 376
 377 unlock:
 378         spin_unlock_irqrestore(&ghes_lock, flags);
 379
 380         return NOTIFY_OK;
 381 }
 382
 383 static struct notifier_block ghes_edac_mem_err_nb = {
 384         .notifier_call  = ghes_edac_report_mem_error,
 385         .priority       = 0,
 386 };
 387
 388 static int ghes_edac_register(struct device *dev)
 389 {
 390         bool fake = false;
 391         struct mem_ctl_info *mci;
 392         struct ghes_pvt *pvt;
 393         struct edac_mc_layer layers[1];
 394         unsigned long flags;
 395         int rc = 0;
 396
 397         /* finish another registration/unregistration instance first */
 398         mutex_lock(&ghes_reg_mutex);
 399
 400         /*
 401          * We have only one logical memory controller to which all DIMMs belong.
 402          */
 403         if (refcount_inc_not_zero(&ghes_refcount))
 404                 goto unlock;
 405
 406         ghes_scan_system();
 407
 408         /* Check if we've got a bogus BIOS */
 409         if (!ghes_hw.num_dimms) {
 410                 fake = true;
 411                 ghes_hw.num_dimms = 1;
 412         }
 413
 414         layers[0].type = EDAC_MC_LAYER_ALL_MEM;
 415         layers[0].size = ghes_hw.num_dimms;
 416         layers[0].is_virt_csrow = true;
 417
 418         mci = edac_mc_alloc(0, ARRAY_SIZE(layers), layers, sizeof(struct ghes_pvt));
 419         if (!mci) {
 420                 pr_info("Can't allocate memory for EDAC data\n");
 421                 rc = -ENOMEM;
 422                 goto unlock;
 423         }
 424
 425         pvt             = mci->pvt_info;
 426         pvt->mci        = mci;
 427
 428         mci->pdev = dev;
 429         mci->mtype_cap = MEM_FLAG_EMPTY;
 430         mci->edac_ctl_cap = EDAC_FLAG_NONE;
 431         mci->edac_cap = EDAC_FLAG_NONE;
 432         mci->mod_name = "ghes_edac.c";
 433         mci->ctl_name = "ghes_edac";
 434         mci->dev_name = "ghes";
 435
 436         if (fake) {
 437                 pr_info("This system has a very crappy BIOS: It doesn't even list the DIMMS.\n");
 438                 pr_info("Its SMBIOS info is wrong. It is doubtful that the error report would\n");
 439                 pr_info("work on such system. Use this driver with caution\n");
 440         }
 441
 442         pr_info("This system has %d DIMM sockets.\n", ghes_hw.num_dimms);
 443
 444         if (!fake) {
 445                 struct dimm_info *src, *dst;
 446                 int i = 0;
 447
 448                 mci_for_each_dimm(mci, dst) {
 449                         src = &ghes_hw.dimms[i];
 450
 451                         dst->idx           = src->idx;
 452                         dst->smbios_handle = src->smbios_handle;
 453                         dst->nr_pages      = src->nr_pages;
 454                         dst->mtype         = src->mtype;
 455                         dst->edac_mode     = src->edac_mode;
 456                         dst->dtype         = src->dtype;
 457                         dst->grain         = src->grain;
 458
 459                         /*
 460                          * If no src->label, preserve default label assigned
 461                          * from EDAC core.
 462                          */
 463                         if (strlen(src->label))
 464                                 memcpy(dst->label, src->label, sizeof(src->label));
 465
 466                         i++;
 467                 }
 468
 469         } else {
 470                 struct dimm_info *dimm = edac_get_dimm(mci, 0, 0, 0);
 471
 472                 dimm->nr_pages = 1;
 473                 dimm->grain = 128;
 474                 dimm->mtype = MEM_UNKNOWN;
 475                 dimm->dtype = DEV_UNKNOWN;
 476                 dimm->edac_mode = EDAC_SECDED;
 477         }
 478
 479         rc = edac_mc_add_mc(mci);
 480         if (rc < 0) {
 481                 pr_info("Can't register with the EDAC core\n");
 482                 edac_mc_free(mci);
 483                 rc = -ENODEV;
 484                 goto unlock;
 485         }
 486
 487         spin_lock_irqsave(&ghes_lock, flags);
 488         ghes_pvt = pvt;
 489         spin_unlock_irqrestore(&ghes_lock, flags);
 490
 491         ghes_register_report_chain(&ghes_edac_mem_err_nb);
 492
 493         /* only set on success */
 494         refcount_set(&ghes_refcount, 1);
 495
 496 unlock:
 497
 498         /* Not needed anymore */
 499         kfree(ghes_hw.dimms);
 500         ghes_hw.dimms = NULL;
 501
 502         mutex_unlock(&ghes_reg_mutex);
 503
 504         return rc;
 505 }
 506
 507 static void ghes_edac_unregister(struct ghes *ghes)
 508 {
 509         struct mem_ctl_info *mci;
 510         unsigned long flags;
 511
 512         mutex_lock(&ghes_reg_mutex);
 513
 514         system_scanned = false;
 515         memset(&ghes_hw, 0, sizeof(struct ghes_hw_desc));
 516
 517         if (!refcount_dec_and_test(&ghes_refcount))
 518                 goto unlock;
 519
 520         /*
 521          * Wait for the irq handler being finished.
 522          */
 523         spin_lock_irqsave(&ghes_lock, flags);
 524         mci = ghes_pvt ? ghes_pvt->mci : NULL;
 525         ghes_pvt = NULL;
 526         spin_unlock_irqrestore(&ghes_lock, flags);
 527
 528         if (!mci)
 529                 goto unlock;
 530
 531         mci = edac_mc_del_mc(mci->pdev);
 532         if (mci)
 533                 edac_mc_free(mci);
 534
 535         ghes_unregister_report_chain(&ghes_edac_mem_err_nb);
 536
 537 unlock:
 538         mutex_unlock(&ghes_reg_mutex);
 539 }
 540
 541 static int __init ghes_edac_init(void)
 542 {
 543         struct ghes *g, *g_tmp;
 544
 545         ghes_devs = ghes_get_devices();
 546         if (!ghes_devs)
 547                 return -ENODEV;
 548
 549         if (list_empty(ghes_devs)) {
 550                 pr_info("GHES probing device list is empty\n");
 551                 return -ENODEV;
 552         }
 553
 554         list_for_each_entry_safe(g, g_tmp, ghes_devs, elist) {
 555                 ghes_edac_register(g->dev);
 556         }
 557
 558         return 0;
 559 }
 560 module_init(ghes_edac_init);
 561
 562 static void __exit ghes_edac_exit(void)
 563 {
 564         struct ghes *g, *g_tmp;
 565
 566         list_for_each_entry_safe(g, g_tmp, ghes_devs, elist) {
 567                 ghes_edac_unregister(g);
 568         }
 569 }
 570 module_exit(ghes_edac_exit);
 571
 572 MODULE_LICENSE("GPL");
 573 MODULE_DESCRIPTION("Output ACPI APEI/GHES BIOS detected errors via EDAC");