drivers/acpi/apei/ghes.c

   1 /*
   2  * APEI Generic Hardware Error Source support
   3  *
   4  * Generic Hardware Error Source provides a way to report platform
   5  * hardware errors (such as that from chipset). It works in so called
   6  * "Firmware First" mode, that is, hardware errors are reported to
   7  * firmware firstly, then reported to Linux by firmware. This way,
   8  * some non-standard hardware error registers or non-standard hardware
   9  * link can be checked by firmware to produce more hardware error
  10  * information for Linux.
  11  *
  12  * For more information about Generic Hardware Error Source, please
  13  * refer to ACPI Specification version 4.0, section 17.3.2.6
  14  *
  15  * Copyright 2010,2011 Intel Corp.
  16  *   Author: Huang Ying <ying.huang@intel.com>
  17  *
  18  * This program is free software; you can redistribute it and/or
  19  * modify it under the terms of the GNU General Public License version
  20  * 2 as published by the Free Software Foundation;
  21  *
  22  * This program is distributed in the hope that it will be useful,
  23  * but WITHOUT ANY WARRANTY; without even the implied warranty of
  24  * MERCHANTABILITY or FITNESS FOR A PARTICULAR PURPOSE.  See the
  25  * GNU General Public License for more details.
  26  *
  27  * You should have received a copy of the GNU General Public License
  28  * along with this program; if not, write to the Free Software
  29  * Foundation, Inc., 59 Temple Place, Suite 330, Boston, MA  02111-1307  USA
  30  */
  31
  32 #include <linux/kernel.h>
  33 #include <linux/module.h>
  34 #include <linux/init.h>
  35 #include <linux/acpi.h>
  36 #include <linux/io.h>
  37 #include <linux/interrupt.h>
  38 #include <linux/timer.h>
  39 #include <linux/cper.h>
  40 #include <linux/kdebug.h>
  41 #include <linux/platform_device.h>
  42 #include <linux/mutex.h>
  43 #include <linux/ratelimit.h>
  44 #include <linux/vmalloc.h>
  45 #include <linux/irq_work.h>
  46 #include <linux/llist.h>
  47 #include <linux/genalloc.h>
  48 #include <acpi/apei.h>
  49 #include <acpi/atomicio.h>
  50 #include <acpi/hed.h>
  51 #include <asm/mce.h>
  52 #include <asm/tlbflush.h>
  53
  54 #include "apei-internal.h"
  55
  56 #define GHES_PFX        "GHES: "
  57
  58 #define GHES_ESTATUS_MAX_SIZE           65536
  59 #define GHES_ESOURCE_PREALLOC_MAX_SIZE  65536
  60
  61 #define GHES_ESTATUS_POOL_MIN_ALLOC_ORDER 3
  62
  63 /* This is just an estimation for memory pool allocation */
  64 #define GHES_ESTATUS_CACHE_AVG_SIZE     512
  65
  66 #define GHES_ESTATUS_CACHES_SIZE        4
  67
  68 #define GHES_ESTATUS_IN_CACHE_MAX_NSEC  10000000000ULL
  69 /* Prevent too many caches are allocated because of RCU */
  70 #define GHES_ESTATUS_CACHE_ALLOCED_MAX  (GHES_ESTATUS_CACHES_SIZE * 3 / 2)
  71
  72 #define GHES_ESTATUS_CACHE_LEN(estatus_len)                     \
  73         (sizeof(struct ghes_estatus_cache) + (estatus_len))
  74 #define GHES_ESTATUS_FROM_CACHE(estatus_cache)                  \
  75         ((struct acpi_hest_generic_status *)                    \
  76          ((struct ghes_estatus_cache *)(estatus_cache) + 1))
  77
  78 #define GHES_ESTATUS_NODE_LEN(estatus_len)                      \
  79         (sizeof(struct ghes_estatus_node) + (estatus_len))
  80 #define GHES_ESTATUS_FROM_NODE(estatus_node)                            \
  81         ((struct acpi_hest_generic_status *)                            \
  82          ((struct ghes_estatus_node *)(estatus_node) + 1))
  83
  84 /*
  85  * One struct ghes is created for each generic hardware error source.
  86  * It provides the context for APEI hardware error timer/IRQ/SCI/NMI
  87  * handler.
  88  *
  89  * estatus: memory buffer for error status block, allocated during
  90  * HEST parsing.
  91  */
  92 #define GHES_TO_CLEAR           0x0001
  93 #define GHES_EXITING            0x0002
  94
  95 struct ghes {
  96         struct acpi_hest_generic *generic;
  97         struct acpi_hest_generic_status *estatus;
  98         u64 buffer_paddr;
  99         unsigned long flags;
 100         union {
 101                 struct list_head list;
 102                 struct timer_list timer;
 103                 unsigned int irq;
 104         };
 105 };
 106
 107 struct ghes_estatus_node {
 108         struct llist_node llnode;
 109         struct acpi_hest_generic *generic;
 110 };
 111
 112 struct ghes_estatus_cache {
 113         u32 estatus_len;
 114         atomic_t count;
 115         struct acpi_hest_generic *generic;
 116         unsigned long long time_in;
 117         struct rcu_head rcu;
 118 };
 119
 120 int ghes_disable;
 121 module_param_named(disable, ghes_disable, bool, 0);
 122
 123 static int ghes_panic_timeout   __read_mostly = 30;
 124
 125 /*
 126  * All error sources notified with SCI shares one notifier function,
 127  * so they need to be linked and checked one by one.  This is applied
 128  * to NMI too.
 129  *
 130  * RCU is used for these lists, so ghes_list_mutex is only used for
 131  * list changing, not for traversing.
 132  */
 133 static LIST_HEAD(ghes_sci);
 134 static LIST_HEAD(ghes_nmi);
 135 static DEFINE_MUTEX(ghes_list_mutex);
 136
 137 /*
 138  * NMI may be triggered on any CPU, so ghes_nmi_lock is used for
 139  * mutual exclusion.
 140  */
 141 static DEFINE_RAW_SPINLOCK(ghes_nmi_lock);
 142
 143 /*
 144  * Because the memory area used to transfer hardware error information
 145  * from BIOS to Linux can be determined only in NMI, IRQ or timer
 146  * handler, but general ioremap can not be used in atomic context, so
 147  * a special version of atomic ioremap is implemented for that.
 148  */
 149
 150 /*
 151  * Two virtual pages are used, one for NMI context, the other for
 152  * IRQ/PROCESS context
 153  */
 154 #define GHES_IOREMAP_PAGES              2
 155 #define GHES_IOREMAP_NMI_PAGE(base)     (base)
 156 #define GHES_IOREMAP_IRQ_PAGE(base)     ((base) + PAGE_SIZE)
 157
 158 /* virtual memory area for atomic ioremap */
 159 static struct vm_struct *ghes_ioremap_area;
 160 /*
 161  * These 2 spinlock is used to prevent atomic ioremap virtual memory
 162  * area from being mapped simultaneously.
 163  */
 164 static DEFINE_RAW_SPINLOCK(ghes_ioremap_lock_nmi);
 165 static DEFINE_SPINLOCK(ghes_ioremap_lock_irq);
 166
 167 /*
 168  * printk is not safe in NMI context.  So in NMI handler, we allocate
 169  * required memory from lock-less memory allocator
 170  * (ghes_estatus_pool), save estatus into it, put them into lock-less
 171  * list (ghes_estatus_llist), then delay printk into IRQ context via
 172  * irq_work (ghes_proc_irq_work).  ghes_estatus_size_request record
 173  * required pool size by all NMI error source.
 174  */
 175 static struct gen_pool *ghes_estatus_pool;
 176 static unsigned long ghes_estatus_pool_size_request;
 177 static struct llist_head ghes_estatus_llist;
 178 static struct irq_work ghes_proc_irq_work;
 179
 180 struct ghes_estatus_cache *ghes_estatus_caches[GHES_ESTATUS_CACHES_SIZE];
 181 static atomic_t ghes_estatus_cache_alloced;
 182
 183 static int ghes_ioremap_init(void)
 184 {
 185         ghes_ioremap_area = __get_vm_area(PAGE_SIZE * GHES_IOREMAP_PAGES,
 186                 VM_IOREMAP, VMALLOC_START, VMALLOC_END);
 187         if (!ghes_ioremap_area) {
 188                 pr_err(GHES_PFX "Failed to allocate virtual memory area for atomic ioremap.\n");
 189                 return -ENOMEM;
 190         }
 191
 192         return 0;
 193 }
 194
 195 static void ghes_ioremap_exit(void)
 196 {
 197         free_vm_area(ghes_ioremap_area);
 198 }
 199
 200 static void __iomem *ghes_ioremap_pfn_nmi(u64 pfn)
 201 {
 202         unsigned long vaddr;
 203
 204         vaddr = (unsigned long)GHES_IOREMAP_NMI_PAGE(ghes_ioremap_area->addr);
 205         ioremap_page_range(vaddr, vaddr + PAGE_SIZE,
 206                            pfn << PAGE_SHIFT, PAGE_KERNEL);
 207
 208         return (void __iomem *)vaddr;
 209 }
 210
 211 static void __iomem *ghes_ioremap_pfn_irq(u64 pfn)
 212 {
 213         unsigned long vaddr;
 214
 215         vaddr = (unsigned long)GHES_IOREMAP_IRQ_PAGE(ghes_ioremap_area->addr);
 216         ioremap_page_range(vaddr, vaddr + PAGE_SIZE,
 217                            pfn << PAGE_SHIFT, PAGE_KERNEL);
 218
 219         return (void __iomem *)vaddr;
 220 }
 221
 222 static void ghes_iounmap_nmi(void __iomem *vaddr_ptr)
 223 {
 224         unsigned long vaddr = (unsigned long __force)vaddr_ptr;
 225         void *base = ghes_ioremap_area->addr;
 226
 227         BUG_ON(vaddr != (unsigned long)GHES_IOREMAP_NMI_PAGE(base));
 228         unmap_kernel_range_noflush(vaddr, PAGE_SIZE);
 229         __flush_tlb_one(vaddr);
 230 }
 231
 232 static void ghes_iounmap_irq(void __iomem *vaddr_ptr)
 233 {
 234         unsigned long vaddr = (unsigned long __force)vaddr_ptr;
 235         void *base = ghes_ioremap_area->addr;
 236
 237         BUG_ON(vaddr != (unsigned long)GHES_IOREMAP_IRQ_PAGE(base));
 238         unmap_kernel_range_noflush(vaddr, PAGE_SIZE);
 239         __flush_tlb_one(vaddr);
 240 }
 241
 242 static int ghes_estatus_pool_init(void)
 243 {
 244         ghes_estatus_pool = gen_pool_create(GHES_ESTATUS_POOL_MIN_ALLOC_ORDER, -1);
 245         if (!ghes_estatus_pool)
 246                 return -ENOMEM;
 247         return 0;
 248 }
 249
 250 static void ghes_estatus_pool_free_chunk_page(struct gen_pool *pool,
 251                                               struct gen_pool_chunk *chunk,
 252                                               void *data)
 253 {
 254         free_page(chunk->start_addr);
 255 }
 256
 257 static void ghes_estatus_pool_exit(void)
 258 {
 259         gen_pool_for_each_chunk(ghes_estatus_pool,
 260                                 ghes_estatus_pool_free_chunk_page, NULL);
 261         gen_pool_destroy(ghes_estatus_pool);
 262 }
 263
 264 static int ghes_estatus_pool_expand(unsigned long len)
 265 {
 266         unsigned long i, pages, size, addr;
 267         int ret;
 268
 269         ghes_estatus_pool_size_request += PAGE_ALIGN(len);
 270         size = gen_pool_size(ghes_estatus_pool);
 271         if (size >= ghes_estatus_pool_size_request)
 272                 return 0;
 273         pages = (ghes_estatus_pool_size_request - size) / PAGE_SIZE;
 274         for (i = 0; i < pages; i++) {
 275                 addr = __get_free_page(GFP_KERNEL);
 276                 if (!addr)
 277                         return -ENOMEM;
 278                 ret = gen_pool_add(ghes_estatus_pool, addr, PAGE_SIZE, -1);
 279                 if (ret)
 280                         return ret;
 281         }
 282
 283         return 0;
 284 }
 285
 286 static void ghes_estatus_pool_shrink(unsigned long len)
 287 {
 288         ghes_estatus_pool_size_request -= PAGE_ALIGN(len);
 289 }
 290
 291 static struct ghes *ghes_new(struct acpi_hest_generic *generic)
 292 {
 293         struct ghes *ghes;
 294         unsigned int error_block_length;
 295         int rc;
 296
 297         ghes = kzalloc(sizeof(*ghes), GFP_KERNEL);
 298         if (!ghes)
 299                 return ERR_PTR(-ENOMEM);
 300         ghes->generic = generic;
 301         rc = acpi_pre_map_gar(&generic->error_status_address);
 302         if (rc)
 303                 goto err_free;
 304         error_block_length = generic->error_block_length;
 305         if (error_block_length > GHES_ESTATUS_MAX_SIZE) {
 306                 pr_warning(FW_WARN GHES_PFX
 307                            "Error status block length is too long: %u for "
 308                            "generic hardware error source: %d.\n",
 309                            error_block_length, generic->header.source_id);
 310                 error_block_length = GHES_ESTATUS_MAX_SIZE;
 311         }
 312         ghes->estatus = kmalloc(error_block_length, GFP_KERNEL);
 313         if (!ghes->estatus) {
 314                 rc = -ENOMEM;
 315                 goto err_unmap;
 316         }
 317
 318         return ghes;
 319
 320 err_unmap:
 321         acpi_post_unmap_gar(&generic->error_status_address);
 322 err_free:
 323         kfree(ghes);
 324         return ERR_PTR(rc);
 325 }
 326
 327 static void ghes_fini(struct ghes *ghes)
 328 {
 329         kfree(ghes->estatus);
 330         acpi_post_unmap_gar(&ghes->generic->error_status_address);
 331 }
 332
 333 enum {
 334         GHES_SEV_NO = 0x0,
 335         GHES_SEV_CORRECTED = 0x1,
 336         GHES_SEV_RECOVERABLE = 0x2,
 337         GHES_SEV_PANIC = 0x3,
 338 };
 339
 340 static inline int ghes_severity(int severity)
 341 {
 342         switch (severity) {
 343         case CPER_SEV_INFORMATIONAL:
 344                 return GHES_SEV_NO;
 345         case CPER_SEV_CORRECTED:
 346                 return GHES_SEV_CORRECTED;
 347         case CPER_SEV_RECOVERABLE:
 348                 return GHES_SEV_RECOVERABLE;
 349         case CPER_SEV_FATAL:
 350                 return GHES_SEV_PANIC;
 351         default:
 352                 /* Unknown, go panic */
 353                 return GHES_SEV_PANIC;
 354         }
 355 }
 356
 357 static void ghes_copy_tofrom_phys(void *buffer, u64 paddr, u32 len,
 358                                   int from_phys)
 359 {
 360         void __iomem *vaddr;
 361         unsigned long flags = 0;
 362         int in_nmi = in_nmi();
 363         u64 offset;
 364         u32 trunk;
 365
 366         while (len > 0) {
 367                 offset = paddr - (paddr & PAGE_MASK);
 368                 if (in_nmi) {
 369                         raw_spin_lock(&ghes_ioremap_lock_nmi);
 370                         vaddr = ghes_ioremap_pfn_nmi(paddr >> PAGE_SHIFT);
 371                 } else {
 372                         spin_lock_irqsave(&ghes_ioremap_lock_irq, flags);
 373                         vaddr = ghes_ioremap_pfn_irq(paddr >> PAGE_SHIFT);
 374                 }
 375                 trunk = PAGE_SIZE - offset;
 376                 trunk = min(trunk, len);
 377                 if (from_phys)
 378                         memcpy_fromio(buffer, vaddr + offset, trunk);
 379                 else
 380                         memcpy_toio(vaddr + offset, buffer, trunk);
 381                 len -= trunk;
 382                 paddr += trunk;
 383                 buffer += trunk;
 384                 if (in_nmi) {
 385                         ghes_iounmap_nmi(vaddr);
 386                         raw_spin_unlock(&ghes_ioremap_lock_nmi);
 387                 } else {
 388                         ghes_iounmap_irq(vaddr);
 389                         spin_unlock_irqrestore(&ghes_ioremap_lock_irq, flags);
 390                 }
 391         }
 392 }
 393
 394 static int ghes_read_estatus(struct ghes *ghes, int silent)
 395 {
 396         struct acpi_hest_generic *g = ghes->generic;
 397         u64 buf_paddr;
 398         u32 len;
 399         int rc;
 400
 401         rc = acpi_atomic_read(&buf_paddr, &g->error_status_address);
 402         if (rc) {
 403                 if (!silent && printk_ratelimit())
 404                         pr_warning(FW_WARN GHES_PFX
 405 "Failed to read error status block address for hardware error source: %d.\n",
 406                                    g->header.source_id);
 407                 return -EIO;
 408         }
 409         if (!buf_paddr)
 410                 return -ENOENT;
 411
 412         ghes_copy_tofrom_phys(ghes->estatus, buf_paddr,
 413                               sizeof(*ghes->estatus), 1);
 414         if (!ghes->estatus->block_status)
 415                 return -ENOENT;
 416
 417         ghes->buffer_paddr = buf_paddr;
 418         ghes->flags |= GHES_TO_CLEAR;
 419
 420         rc = -EIO;
 421         len = apei_estatus_len(ghes->estatus);
 422         if (len < sizeof(*ghes->estatus))
 423                 goto err_read_block;
 424         if (len > ghes->generic->error_block_length)
 425                 goto err_read_block;
 426         if (apei_estatus_check_header(ghes->estatus))
 427                 goto err_read_block;
 428         ghes_copy_tofrom_phys(ghes->estatus + 1,
 429                               buf_paddr + sizeof(*ghes->estatus),
 430                               len - sizeof(*ghes->estatus), 1);
 431         if (apei_estatus_check(ghes->estatus))
 432                 goto err_read_block;
 433         rc = 0;
 434
 435 err_read_block:
 436         if (rc && !silent && printk_ratelimit())
 437                 pr_warning(FW_WARN GHES_PFX
 438                            "Failed to read error status block!\n");
 439         return rc;
 440 }
 441
 442 static void ghes_clear_estatus(struct ghes *ghes)
 443 {
 444         ghes->estatus->block_status = 0;
 445         if (!(ghes->flags & GHES_TO_CLEAR))
 446                 return;
 447         ghes_copy_tofrom_phys(ghes->estatus, ghes->buffer_paddr,
 448                               sizeof(ghes->estatus->block_status), 0);
 449         ghes->flags &= ~GHES_TO_CLEAR;
 450 }
 451
 452 static void ghes_do_proc(const struct acpi_hest_generic_status *estatus)
 453 {
 454         int sev, sec_sev;
 455         struct acpi_hest_generic_data *gdata;
 456
 457         sev = ghes_severity(estatus->error_severity);
 458         apei_estatus_for_each_section(estatus, gdata) {
 459                 sec_sev = ghes_severity(gdata->error_severity);
 460                 if (!uuid_le_cmp(*(uuid_le *)gdata->section_type,
 461                                  CPER_SEC_PLATFORM_MEM)) {
 462                         struct cper_sec_mem_err *mem_err;
 463                         mem_err = (struct cper_sec_mem_err *)(gdata+1);
 464 #ifdef CONFIG_X86_MCE
 465                         apei_mce_report_mem_error(sev == GHES_SEV_CORRECTED,
 466                                                   mem_err);
 467 #endif
 468 #ifdef CONFIG_ACPI_APEI_MEMORY_FAILURE
 469                         if (sev == GHES_SEV_RECOVERABLE &&
 470                             sec_sev == GHES_SEV_RECOVERABLE &&
 471                             mem_err->validation_bits & CPER_MEM_VALID_PHYSICAL_ADDRESS) {
 472                                 unsigned long pfn;
 473                                 pfn = mem_err->physical_addr >> PAGE_SHIFT;
 474                                 memory_failure_queue(pfn, 0, 0);
 475                         }
 476 #endif
 477                 }
 478         }
 479 }
 480
 481 static void __ghes_print_estatus(const char *pfx,
 482                                  const struct acpi_hest_generic *generic,
 483                                  const struct acpi_hest_generic_status *estatus)
 484 {
 485         if (pfx == NULL) {
 486                 if (ghes_severity(estatus->error_severity) <=
 487                     GHES_SEV_CORRECTED)
 488                         pfx = KERN_WARNING HW_ERR;
 489                 else
 490                         pfx = KERN_ERR HW_ERR;
 491         }
 492         printk("%s""Hardware error from APEI Generic Hardware Error Source: %d\n",
 493                pfx, generic->header.source_id);
 494         apei_estatus_print(pfx, estatus);
 495 }
 496
 497 static int ghes_print_estatus(const char *pfx,
 498                               const struct acpi_hest_generic *generic,
 499                               const struct acpi_hest_generic_status *estatus)
 500 {
 501         /* Not more than 2 messages every 5 seconds */
 502         static DEFINE_RATELIMIT_STATE(ratelimit_corrected, 5*HZ, 2);
 503         static DEFINE_RATELIMIT_STATE(ratelimit_uncorrected, 5*HZ, 2);
 504         struct ratelimit_state *ratelimit;
 505
 506         if (ghes_severity(estatus->error_severity) <= GHES_SEV_CORRECTED)
 507                 ratelimit = &ratelimit_corrected;
 508         else
 509                 ratelimit = &ratelimit_uncorrected;
 510         if (__ratelimit(ratelimit)) {
 511                 __ghes_print_estatus(pfx, generic, estatus);
 512                 return 1;
 513         }
 514         return 0;
 515 }
 516
 517 /*
 518  * GHES error status reporting throttle, to report more kinds of
 519  * errors, instead of just most frequently occurred errors.
 520  */
 521 static int ghes_estatus_cached(struct acpi_hest_generic_status *estatus)
 522 {
 523         u32 len;
 524         int i, cached = 0;
 525         unsigned long long now;
 526         struct ghes_estatus_cache *cache;
 527         struct acpi_hest_generic_status *cache_estatus;
 528
 529         len = apei_estatus_len(estatus);
 530         rcu_read_lock();
 531         for (i = 0; i < GHES_ESTATUS_CACHES_SIZE; i++) {
 532                 cache = rcu_dereference(ghes_estatus_caches[i]);
 533                 if (cache == NULL)
 534                         continue;
 535                 if (len != cache->estatus_len)
 536                         continue;
 537                 cache_estatus = GHES_ESTATUS_FROM_CACHE(cache);
 538                 if (memcmp(estatus, cache_estatus, len))
 539                         continue;
 540                 atomic_inc(&cache->count);
 541                 now = sched_clock();
 542                 if (now - cache->time_in < GHES_ESTATUS_IN_CACHE_MAX_NSEC)
 543                         cached = 1;
 544                 break;
 545         }
 546         rcu_read_unlock();
 547         return cached;
 548 }
 549
 550 static struct ghes_estatus_cache *ghes_estatus_cache_alloc(
 551         struct acpi_hest_generic *generic,
 552         struct acpi_hest_generic_status *estatus)
 553 {
 554         int alloced;
 555         u32 len, cache_len;
 556         struct ghes_estatus_cache *cache;
 557         struct acpi_hest_generic_status *cache_estatus;
 558
 559         alloced = atomic_add_return(1, &ghes_estatus_cache_alloced);
 560         if (alloced > GHES_ESTATUS_CACHE_ALLOCED_MAX) {
 561                 atomic_dec(&ghes_estatus_cache_alloced);
 562                 return NULL;
 563         }
 564         len = apei_estatus_len(estatus);
 565         cache_len = GHES_ESTATUS_CACHE_LEN(len);
 566         cache = (void *)gen_pool_alloc(ghes_estatus_pool, cache_len);
 567         if (!cache) {
 568                 atomic_dec(&ghes_estatus_cache_alloced);
 569                 return NULL;
 570         }
 571         cache_estatus = GHES_ESTATUS_FROM_CACHE(cache);
 572         memcpy(cache_estatus, estatus, len);
 573         cache->estatus_len = len;
 574         atomic_set(&cache->count, 0);
 575         cache->generic = generic;
 576         cache->time_in = sched_clock();
 577         return cache;
 578 }
 579
 580 static void ghes_estatus_cache_free(struct ghes_estatus_cache *cache)
 581 {
 582         u32 len;
 583
 584         len = apei_estatus_len(GHES_ESTATUS_FROM_CACHE(cache));
 585         len = GHES_ESTATUS_CACHE_LEN(len);
 586         gen_pool_free(ghes_estatus_pool, (unsigned long)cache, len);
 587         atomic_dec(&ghes_estatus_cache_alloced);
 588 }
 589
 590 static void ghes_estatus_cache_rcu_free(struct rcu_head *head)
 591 {
 592         struct ghes_estatus_cache *cache;
 593
 594         cache = container_of(head, struct ghes_estatus_cache, rcu);
 595         ghes_estatus_cache_free(cache);
 596 }
 597
 598 static void ghes_estatus_cache_add(
 599         struct acpi_hest_generic *generic,
 600         struct acpi_hest_generic_status *estatus)
 601 {
 602         int i, slot = -1, count;
 603         unsigned long long now, duration, period, max_period = 0;
 604         struct ghes_estatus_cache *cache, *slot_cache = NULL, *new_cache;
 605
 606         new_cache = ghes_estatus_cache_alloc(generic, estatus);
 607         if (new_cache == NULL)
 608                 return;
 609         rcu_read_lock();
 610         now = sched_clock();
 611         for (i = 0; i < GHES_ESTATUS_CACHES_SIZE; i++) {
 612                 cache = rcu_dereference(ghes_estatus_caches[i]);
 613                 if (cache == NULL) {
 614                         slot = i;
 615                         slot_cache = NULL;
 616                         break;
 617                 }
 618                 duration = now - cache->time_in;
 619                 if (duration >= GHES_ESTATUS_IN_CACHE_MAX_NSEC) {
 620                         slot = i;
 621                         slot_cache = cache;
 622                         break;
 623                 }
 624                 count = atomic_read(&cache->count);
 625                 period = duration;
 626                 do_div(period, (count + 1));
 627                 if (period > max_period) {
 628                         max_period = period;
 629                         slot = i;
 630                         slot_cache = cache;
 631                 }
 632         }
 633         /* new_cache must be put into array after its contents are written */
 634         smp_wmb();
 635         if (slot != -1 && cmpxchg(ghes_estatus_caches + slot,
 636                                   slot_cache, new_cache) == slot_cache) {
 637                 if (slot_cache)
 638                         call_rcu(&slot_cache->rcu, ghes_estatus_cache_rcu_free);
 639         } else
 640                 ghes_estatus_cache_free(new_cache);
 641         rcu_read_unlock();
 642 }
 643
 644 static int ghes_proc(struct ghes *ghes)
 645 {
 646         int rc;
 647
 648         rc = ghes_read_estatus(ghes, 0);
 649         if (rc)
 650                 goto out;
 651         if (!ghes_estatus_cached(ghes->estatus)) {
 652                 if (ghes_print_estatus(NULL, ghes->generic, ghes->estatus))
 653                         ghes_estatus_cache_add(ghes->generic, ghes->estatus);
 654         }
 655         ghes_do_proc(ghes->estatus);
 656 out:
 657         ghes_clear_estatus(ghes);
 658         return 0;
 659 }
 660
 661 static void ghes_add_timer(struct ghes *ghes)
 662 {
 663         struct acpi_hest_generic *g = ghes->generic;
 664         unsigned long expire;
 665
 666         if (!g->notify.poll_interval) {
 667                 pr_warning(FW_WARN GHES_PFX "Poll interval is 0 for generic hardware error source: %d, disabled.\n",
 668                            g->header.source_id);
 669                 return;
 670         }
 671         expire = jiffies + msecs_to_jiffies(g->notify.poll_interval);
 672         ghes->timer.expires = round_jiffies_relative(expire);
 673         add_timer(&ghes->timer);
 674 }
 675
 676 static void ghes_poll_func(unsigned long data)
 677 {
 678         struct ghes *ghes = (void *)data;
 679
 680         ghes_proc(ghes);
 681         if (!(ghes->flags & GHES_EXITING))
 682                 ghes_add_timer(ghes);
 683 }
 684
 685 static irqreturn_t ghes_irq_func(int irq, void *data)
 686 {
 687         struct ghes *ghes = data;
 688         int rc;
 689
 690         rc = ghes_proc(ghes);
 691         if (rc)
 692                 return IRQ_NONE;
 693
 694         return IRQ_HANDLED;
 695 }
 696
 697 static int ghes_notify_sci(struct notifier_block *this,
 698                                   unsigned long event, void *data)
 699 {
 700         struct ghes *ghes;
 701         int ret = NOTIFY_DONE;
 702
 703         rcu_read_lock();
 704         list_for_each_entry_rcu(ghes, &ghes_sci, list) {
 705                 if (!ghes_proc(ghes))
 706                         ret = NOTIFY_OK;
 707         }
 708         rcu_read_unlock();
 709
 710         return ret;
 711 }
 712
 713 static void ghes_proc_in_irq(struct irq_work *irq_work)
 714 {
 715         struct llist_node *llnode, *next, *tail = NULL;
 716         struct ghes_estatus_node *estatus_node;
 717         struct acpi_hest_generic *generic;
 718         struct acpi_hest_generic_status *estatus;
 719         u32 len, node_len;
 720
 721         /*
 722          * Because the time order of estatus in list is reversed,
 723          * revert it back to proper order.
 724          */
 725         llnode = llist_del_all(&ghes_estatus_llist);
 726         while (llnode) {
 727                 next = llnode->next;
 728                 llnode->next = tail;
 729                 tail = llnode;
 730                 llnode = next;
 731         }
 732         llnode = tail;
 733         while (llnode) {
 734                 next = llnode->next;
 735                 estatus_node = llist_entry(llnode, struct ghes_estatus_node,
 736                                            llnode);
 737                 estatus = GHES_ESTATUS_FROM_NODE(estatus_node);
 738                 len = apei_estatus_len(estatus);
 739                 node_len = GHES_ESTATUS_NODE_LEN(len);
 740                 ghes_do_proc(estatus);
 741                 if (!ghes_estatus_cached(estatus)) {
 742                         generic = estatus_node->generic;
 743                         if (ghes_print_estatus(NULL, generic, estatus))
 744                                 ghes_estatus_cache_add(generic, estatus);
 745                 }
 746                 gen_pool_free(ghes_estatus_pool, (unsigned long)estatus_node,
 747                               node_len);
 748                 llnode = next;
 749         }
 750 }
 751
 752 static int ghes_notify_nmi(struct notifier_block *this,
 753                                   unsigned long cmd, void *data)
 754 {
 755         struct ghes *ghes, *ghes_global = NULL;
 756         int sev, sev_global = -1;
 757         int ret = NOTIFY_DONE;
 758
 759         if (cmd != DIE_NMI)
 760                 return ret;
 761
 762         raw_spin_lock(&ghes_nmi_lock);
 763         list_for_each_entry_rcu(ghes, &ghes_nmi, list) {
 764                 if (ghes_read_estatus(ghes, 1)) {
 765                         ghes_clear_estatus(ghes);
 766                         continue;
 767                 }
 768                 sev = ghes_severity(ghes->estatus->error_severity);
 769                 if (sev > sev_global) {
 770                         sev_global = sev;
 771                         ghes_global = ghes;
 772                 }
 773                 ret = NOTIFY_STOP;
 774         }
 775
 776         if (ret == NOTIFY_DONE)
 777                 goto out;
 778
 779         if (sev_global >= GHES_SEV_PANIC) {
 780                 oops_begin();
 781                 __ghes_print_estatus(KERN_EMERG HW_ERR, ghes_global->generic,
 782                                      ghes_global->estatus);
 783                 /* reboot to log the error! */
 784                 if (panic_timeout == 0)
 785                         panic_timeout = ghes_panic_timeout;
 786                 panic("Fatal hardware error!");
 787         }
 788
 789         list_for_each_entry_rcu(ghes, &ghes_nmi, list) {
 790 #ifdef CONFIG_ARCH_HAVE_NMI_SAFE_CMPXCHG
 791                 u32 len, node_len;
 792                 struct ghes_estatus_node *estatus_node;
 793                 struct acpi_hest_generic_status *estatus;
 794 #endif
 795                 if (!(ghes->flags & GHES_TO_CLEAR))
 796                         continue;
 797 #ifdef CONFIG_ARCH_HAVE_NMI_SAFE_CMPXCHG
 798                 if (ghes_estatus_cached(ghes->estatus))
 799                         goto next;
 800                 /* Save estatus for further processing in IRQ context */
 801                 len = apei_estatus_len(ghes->estatus);
 802                 node_len = GHES_ESTATUS_NODE_LEN(len);
 803                 estatus_node = (void *)gen_pool_alloc(ghes_estatus_pool,
 804                                                       node_len);
 805                 if (estatus_node) {
 806                         estatus_node->generic = ghes->generic;
 807                         estatus = GHES_ESTATUS_FROM_NODE(estatus_node);
 808                         memcpy(estatus, ghes->estatus, len);
 809                         llist_add(&estatus_node->llnode, &ghes_estatus_llist);
 810                 }
 811 next:
 812 #endif
 813                 ghes_clear_estatus(ghes);
 814         }
 815 #ifdef CONFIG_ARCH_HAVE_NMI_SAFE_CMPXCHG
 816         irq_work_queue(&ghes_proc_irq_work);
 817 #endif
 818
 819 out:
 820         raw_spin_unlock(&ghes_nmi_lock);
 821         return ret;
 822 }
 823
 824 static struct notifier_block ghes_notifier_sci = {
 825         .notifier_call = ghes_notify_sci,
 826 };
 827
 828 static struct notifier_block ghes_notifier_nmi = {
 829         .notifier_call = ghes_notify_nmi,
 830 };
 831
 832 static unsigned long ghes_esource_prealloc_size(
 833         const struct acpi_hest_generic *generic)
 834 {
 835         unsigned long block_length, prealloc_records, prealloc_size;
 836
 837         block_length = min_t(unsigned long, generic->error_block_length,
 838                              GHES_ESTATUS_MAX_SIZE);
 839         prealloc_records = max_t(unsigned long,
 840                                  generic->records_to_preallocate, 1);
 841         prealloc_size = min_t(unsigned long, block_length * prealloc_records,
 842                               GHES_ESOURCE_PREALLOC_MAX_SIZE);
 843
 844         return prealloc_size;
 845 }
 846
 847 static int __devinit ghes_probe(struct platform_device *ghes_dev)
 848 {
 849         struct acpi_hest_generic *generic;
 850         struct ghes *ghes = NULL;
 851         unsigned long len;
 852         int rc = -EINVAL;
 853
 854         generic = *(struct acpi_hest_generic **)ghes_dev->dev.platform_data;
 855         if (!generic->enabled)
 856                 return -ENODEV;
 857
 858         switch (generic->notify.type) {
 859         case ACPI_HEST_NOTIFY_POLLED:
 860         case ACPI_HEST_NOTIFY_EXTERNAL:
 861         case ACPI_HEST_NOTIFY_SCI:
 862         case ACPI_HEST_NOTIFY_NMI:
 863                 break;
 864         case ACPI_HEST_NOTIFY_LOCAL:
 865                 pr_warning(GHES_PFX "Generic hardware error source: %d notified via local interrupt is not supported!\n",
 866                            generic->header.source_id);
 867                 goto err;
 868         default:
 869                 pr_warning(FW_WARN GHES_PFX "Unknown notification type: %u for generic hardware error source: %d\n",
 870                            generic->notify.type, generic->header.source_id);
 871                 goto err;
 872         }
 873
 874         rc = -EIO;
 875         if (generic->error_block_length <
 876             sizeof(struct acpi_hest_generic_status)) {
 877                 pr_warning(FW_BUG GHES_PFX "Invalid error block length: %u for generic hardware error source: %d\n",
 878                            generic->error_block_length,
 879                            generic->header.source_id);
 880                 goto err;
 881         }
 882         ghes = ghes_new(generic);
 883         if (IS_ERR(ghes)) {
 884                 rc = PTR_ERR(ghes);
 885                 ghes = NULL;
 886                 goto err;
 887         }
 888         switch (generic->notify.type) {
 889         case ACPI_HEST_NOTIFY_POLLED:
 890                 ghes->timer.function = ghes_poll_func;
 891                 ghes->timer.data = (unsigned long)ghes;
 892                 init_timer_deferrable(&ghes->timer);
 893                 ghes_add_timer(ghes);
 894                 break;
 895         case ACPI_HEST_NOTIFY_EXTERNAL:
 896                 /* External interrupt vector is GSI */
 897                 if (acpi_gsi_to_irq(generic->notify.vector, &ghes->irq)) {
 898                         pr_err(GHES_PFX "Failed to map GSI to IRQ for generic hardware error source: %d\n",
 899                                generic->header.source_id);
 900                         goto err;
 901                 }
 902                 if (request_irq(ghes->irq, ghes_irq_func,
 903                                 0, "GHES IRQ", ghes)) {
 904                         pr_err(GHES_PFX "Failed to register IRQ for generic hardware error source: %d\n",
 905                                generic->header.source_id);
 906                         goto err;
 907                 }
 908                 break;
 909         case ACPI_HEST_NOTIFY_SCI:
 910                 mutex_lock(&ghes_list_mutex);
 911                 if (list_empty(&ghes_sci))
 912                         register_acpi_hed_notifier(&ghes_notifier_sci);
 913                 list_add_rcu(&ghes->list, &ghes_sci);
 914                 mutex_unlock(&ghes_list_mutex);
 915                 break;
 916         case ACPI_HEST_NOTIFY_NMI:
 917                 len = ghes_esource_prealloc_size(generic);
 918                 ghes_estatus_pool_expand(len);
 919                 mutex_lock(&ghes_list_mutex);
 920                 if (list_empty(&ghes_nmi))
 921                         register_die_notifier(&ghes_notifier_nmi);
 922                 list_add_rcu(&ghes->list, &ghes_nmi);
 923                 mutex_unlock(&ghes_list_mutex);
 924                 break;
 925         default:
 926                 BUG();
 927         }
 928         platform_set_drvdata(ghes_dev, ghes);
 929
 930         return 0;
 931 err:
 932         if (ghes) {
 933                 ghes_fini(ghes);
 934                 kfree(ghes);
 935         }
 936         return rc;
 937 }
 938
 939 static int __devexit ghes_remove(struct platform_device *ghes_dev)
 940 {
 941         struct ghes *ghes;
 942         struct acpi_hest_generic *generic;
 943         unsigned long len;
 944
 945         ghes = platform_get_drvdata(ghes_dev);
 946         generic = ghes->generic;
 947
 948         ghes->flags |= GHES_EXITING;
 949         switch (generic->notify.type) {
 950         case ACPI_HEST_NOTIFY_POLLED:
 951                 del_timer_sync(&ghes->timer);
 952                 break;
 953         case ACPI_HEST_NOTIFY_EXTERNAL:
 954                 free_irq(ghes->irq, ghes);
 955                 break;
 956         case ACPI_HEST_NOTIFY_SCI:
 957                 mutex_lock(&ghes_list_mutex);
 958                 list_del_rcu(&ghes->list);
 959                 if (list_empty(&ghes_sci))
 960                         unregister_acpi_hed_notifier(&ghes_notifier_sci);
 961                 mutex_unlock(&ghes_list_mutex);
 962                 break;
 963         case ACPI_HEST_NOTIFY_NMI:
 964                 mutex_lock(&ghes_list_mutex);
 965                 list_del_rcu(&ghes->list);
 966                 if (list_empty(&ghes_nmi))
 967                         unregister_die_notifier(&ghes_notifier_nmi);
 968                 mutex_unlock(&ghes_list_mutex);
 969                 /*
 970                  * To synchronize with NMI handler, ghes can only be
 971                  * freed after NMI handler finishes.
 972                  */
 973                 synchronize_rcu();
 974                 len = ghes_esource_prealloc_size(generic);
 975                 ghes_estatus_pool_shrink(len);
 976                 break;
 977         default:
 978                 BUG();
 979                 break;
 980         }
 981
 982         ghes_fini(ghes);
 983         kfree(ghes);
 984
 985         platform_set_drvdata(ghes_dev, NULL);
 986
 987         return 0;
 988 }
 989
 990 static struct platform_driver ghes_platform_driver = {
 991         .driver         = {
 992                 .name   = "GHES",
 993                 .owner  = THIS_MODULE,
 994         },
 995         .probe          = ghes_probe,
 996         .remove         = ghes_remove,
 997 };
 998
 999 static int __init ghes_init(void)
1000 {
1001         int rc;
1002
1003         if (acpi_disabled)
1004                 return -ENODEV;
1005
1006         if (hest_disable) {
1007                 pr_info(GHES_PFX "HEST is not enabled!\n");
1008                 return -EINVAL;
1009         }
1010
1011         if (ghes_disable) {
1012                 pr_info(GHES_PFX "GHES is not enabled!\n");
1013                 return -EINVAL;
1014         }
1015
1016         init_irq_work(&ghes_proc_irq_work, ghes_proc_in_irq);
1017
1018         rc = ghes_ioremap_init();
1019         if (rc)
1020                 goto err;
1021
1022         rc = ghes_estatus_pool_init();
1023         if (rc)
1024                 goto err_ioremap_exit;
1025
1026         rc = ghes_estatus_pool_expand(GHES_ESTATUS_CACHE_AVG_SIZE *
1027                                       GHES_ESTATUS_CACHE_ALLOCED_MAX);
1028         if (rc)
1029                 goto err_pool_exit;
1030
1031         rc = platform_driver_register(&ghes_platform_driver);
1032         if (rc)
1033                 goto err_pool_exit;
1034
1035         rc = apei_osc_setup();
1036         if (rc == 0 && osc_sb_apei_support_acked)
1037                 pr_info(GHES_PFX "APEI firmware first mode is enabled by APEI bit and WHEA _OSC.\n");
1038         else if (rc == 0 && !osc_sb_apei_support_acked)
1039                 pr_info(GHES_PFX "APEI firmware first mode is enabled by WHEA _OSC.\n");
1040         else if (rc && osc_sb_apei_support_acked)
1041                 pr_info(GHES_PFX "APEI firmware first mode is enabled by APEI bit.\n");
1042         else
1043                 pr_info(GHES_PFX "Failed to enable APEI firmware first mode.\n");
1044
1045         return 0;
1046 err_pool_exit:
1047         ghes_estatus_pool_exit();
1048 err_ioremap_exit:
1049         ghes_ioremap_exit();
1050 err:
1051         return rc;
1052 }
1053
1054 static void __exit ghes_exit(void)
1055 {
1056         platform_driver_unregister(&ghes_platform_driver);
1057         ghes_estatus_pool_exit();
1058         ghes_ioremap_exit();
1059 }
1060
1061 module_init(ghes_init);
1062 module_exit(ghes_exit);
1063
1064 MODULE_AUTHOR("Huang Ying");
1065 MODULE_DESCRIPTION("APEI Generic Hardware Error Source support");
1066 MODULE_LICENSE("GPL");
1067 MODULE_ALIAS("platform:GHES");