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 find_dimm_by_handle(struct mem_ctl_info * mci,u16 handle)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 dimm_setup_label(struct dimm_info * dimm,u16 handle)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 assign_dmi_dimm_info(struct dimm_info * dimm,struct memdev_dmi_entry * entry)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 enumerate_dimms(const struct dmi_header * dh,void * arg)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 ghes_scan_system(void)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 print_mem_error_other_detail(const struct cper_sec_mem_err * mem,char * msg,const char * location,unsigned int len)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 ghes_edac_report_mem_error(struct notifier_block * nb,unsigned long val,void * data)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 ghes_edac_register(struct device * dev)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 ghes_edac_unregister(struct ghes * ghes)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 ghes_edac_init(void)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 ghes_edac_exit(void)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"); 574