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Linux/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 <linux/pci.h>
 49 #include <linux/aer.h>
 50 
 51 #include <acpi/ghes.h>
 52 #include <asm/mce.h>
 53 #include <asm/tlbflush.h>
 54 #include <asm/nmi.h>
 55 
 56 #include "apei-internal.h"
 57 
 58 #define GHES_PFX        "GHES: "
 59 
 60 #define GHES_ESTATUS_MAX_SIZE           65536
 61 #define GHES_ESOURCE_PREALLOC_MAX_SIZE  65536
 62 
 63 #define GHES_ESTATUS_POOL_MIN_ALLOC_ORDER 3
 64 
 65 /* This is just an estimation for memory pool allocation */
 66 #define GHES_ESTATUS_CACHE_AVG_SIZE     512
 67 
 68 #define GHES_ESTATUS_CACHES_SIZE        4
 69 
 70 #define GHES_ESTATUS_IN_CACHE_MAX_NSEC  10000000000ULL
 71 /* Prevent too many caches are allocated because of RCU */
 72 #define GHES_ESTATUS_CACHE_ALLOCED_MAX  (GHES_ESTATUS_CACHES_SIZE * 3 / 2)
 73 
 74 #define GHES_ESTATUS_CACHE_LEN(estatus_len)                     \
 75         (sizeof(struct ghes_estatus_cache) + (estatus_len))
 76 #define GHES_ESTATUS_FROM_CACHE(estatus_cache)                  \
 77         ((struct acpi_generic_status *)                         \
 78          ((struct ghes_estatus_cache *)(estatus_cache) + 1))
 79 
 80 #define GHES_ESTATUS_NODE_LEN(estatus_len)                      \
 81         (sizeof(struct ghes_estatus_node) + (estatus_len))
 82 #define GHES_ESTATUS_FROM_NODE(estatus_node)                    \
 83         ((struct acpi_generic_status *)                         \
 84          ((struct ghes_estatus_node *)(estatus_node) + 1))
 85 
 86 bool ghes_disable;
 87 module_param_named(disable, ghes_disable, bool, 0);
 88 
 89 static int ghes_panic_timeout   __read_mostly = 30;
 90 
 91 /*
 92  * All error sources notified with SCI shares one notifier function,
 93  * so they need to be linked and checked one by one.  This is applied
 94  * to NMI too.
 95  *
 96  * RCU is used for these lists, so ghes_list_mutex is only used for
 97  * list changing, not for traversing.
 98  */
 99 static LIST_HEAD(ghes_sci);
100 static LIST_HEAD(ghes_nmi);
101 static DEFINE_MUTEX(ghes_list_mutex);
102 
103 /*
104  * NMI may be triggered on any CPU, so ghes_nmi_lock is used for
105  * mutual exclusion.
106  */
107 static DEFINE_RAW_SPINLOCK(ghes_nmi_lock);
108 
109 /*
110  * Because the memory area used to transfer hardware error information
111  * from BIOS to Linux can be determined only in NMI, IRQ or timer
112  * handler, but general ioremap can not be used in atomic context, so
113  * a special version of atomic ioremap is implemented for that.
114  */
115 
116 /*
117  * Two virtual pages are used, one for NMI context, the other for
118  * IRQ/PROCESS context
119  */
120 #define GHES_IOREMAP_PAGES              2
121 #define GHES_IOREMAP_NMI_PAGE(base)     (base)
122 #define GHES_IOREMAP_IRQ_PAGE(base)     ((base) + PAGE_SIZE)
123 
124 /* virtual memory area for atomic ioremap */
125 static struct vm_struct *ghes_ioremap_area;
126 /*
127  * These 2 spinlock is used to prevent atomic ioremap virtual memory
128  * area from being mapped simultaneously.
129  */
130 static DEFINE_RAW_SPINLOCK(ghes_ioremap_lock_nmi);
131 static DEFINE_SPINLOCK(ghes_ioremap_lock_irq);
132 
133 /*
134  * printk is not safe in NMI context.  So in NMI handler, we allocate
135  * required memory from lock-less memory allocator
136  * (ghes_estatus_pool), save estatus into it, put them into lock-less
137  * list (ghes_estatus_llist), then delay printk into IRQ context via
138  * irq_work (ghes_proc_irq_work).  ghes_estatus_size_request record
139  * required pool size by all NMI error source.
140  */
141 static struct gen_pool *ghes_estatus_pool;
142 static unsigned long ghes_estatus_pool_size_request;
143 static struct llist_head ghes_estatus_llist;
144 static struct irq_work ghes_proc_irq_work;
145 
146 struct ghes_estatus_cache *ghes_estatus_caches[GHES_ESTATUS_CACHES_SIZE];
147 static atomic_t ghes_estatus_cache_alloced;
148 
149 static int ghes_ioremap_init(void)
150 {
151         ghes_ioremap_area = __get_vm_area(PAGE_SIZE * GHES_IOREMAP_PAGES,
152                 VM_IOREMAP, VMALLOC_START, VMALLOC_END);
153         if (!ghes_ioremap_area) {
154                 pr_err(GHES_PFX "Failed to allocate virtual memory area for atomic ioremap.\n");
155                 return -ENOMEM;
156         }
157 
158         return 0;
159 }
160 
161 static void ghes_ioremap_exit(void)
162 {
163         free_vm_area(ghes_ioremap_area);
164 }
165 
166 static void __iomem *ghes_ioremap_pfn_nmi(u64 pfn)
167 {
168         unsigned long vaddr;
169 
170         vaddr = (unsigned long)GHES_IOREMAP_NMI_PAGE(ghes_ioremap_area->addr);
171         ioremap_page_range(vaddr, vaddr + PAGE_SIZE,
172                            pfn << PAGE_SHIFT, PAGE_KERNEL);
173 
174         return (void __iomem *)vaddr;
175 }
176 
177 static void __iomem *ghes_ioremap_pfn_irq(u64 pfn)
178 {
179         unsigned long vaddr;
180 
181         vaddr = (unsigned long)GHES_IOREMAP_IRQ_PAGE(ghes_ioremap_area->addr);
182         ioremap_page_range(vaddr, vaddr + PAGE_SIZE,
183                            pfn << PAGE_SHIFT, PAGE_KERNEL);
184 
185         return (void __iomem *)vaddr;
186 }
187 
188 static void ghes_iounmap_nmi(void __iomem *vaddr_ptr)
189 {
190         unsigned long vaddr = (unsigned long __force)vaddr_ptr;
191         void *base = ghes_ioremap_area->addr;
192 
193         BUG_ON(vaddr != (unsigned long)GHES_IOREMAP_NMI_PAGE(base));
194         unmap_kernel_range_noflush(vaddr, PAGE_SIZE);
195         __flush_tlb_one(vaddr);
196 }
197 
198 static void ghes_iounmap_irq(void __iomem *vaddr_ptr)
199 {
200         unsigned long vaddr = (unsigned long __force)vaddr_ptr;
201         void *base = ghes_ioremap_area->addr;
202 
203         BUG_ON(vaddr != (unsigned long)GHES_IOREMAP_IRQ_PAGE(base));
204         unmap_kernel_range_noflush(vaddr, PAGE_SIZE);
205         __flush_tlb_one(vaddr);
206 }
207 
208 static int ghes_estatus_pool_init(void)
209 {
210         ghes_estatus_pool = gen_pool_create(GHES_ESTATUS_POOL_MIN_ALLOC_ORDER, -1);
211         if (!ghes_estatus_pool)
212                 return -ENOMEM;
213         return 0;
214 }
215 
216 static void ghes_estatus_pool_free_chunk_page(struct gen_pool *pool,
217                                               struct gen_pool_chunk *chunk,
218                                               void *data)
219 {
220         free_page(chunk->start_addr);
221 }
222 
223 static void ghes_estatus_pool_exit(void)
224 {
225         gen_pool_for_each_chunk(ghes_estatus_pool,
226                                 ghes_estatus_pool_free_chunk_page, NULL);
227         gen_pool_destroy(ghes_estatus_pool);
228 }
229 
230 static int ghes_estatus_pool_expand(unsigned long len)
231 {
232         unsigned long i, pages, size, addr;
233         int ret;
234 
235         ghes_estatus_pool_size_request += PAGE_ALIGN(len);
236         size = gen_pool_size(ghes_estatus_pool);
237         if (size >= ghes_estatus_pool_size_request)
238                 return 0;
239         pages = (ghes_estatus_pool_size_request - size) / PAGE_SIZE;
240         for (i = 0; i < pages; i++) {
241                 addr = __get_free_page(GFP_KERNEL);
242                 if (!addr)
243                         return -ENOMEM;
244                 ret = gen_pool_add(ghes_estatus_pool, addr, PAGE_SIZE, -1);
245                 if (ret)
246                         return ret;
247         }
248 
249         return 0;
250 }
251 
252 static void ghes_estatus_pool_shrink(unsigned long len)
253 {
254         ghes_estatus_pool_size_request -= PAGE_ALIGN(len);
255 }
256 
257 static struct ghes *ghes_new(struct acpi_hest_generic *generic)
258 {
259         struct ghes *ghes;
260         unsigned int error_block_length;
261         int rc;
262 
263         ghes = kzalloc(sizeof(*ghes), GFP_KERNEL);
264         if (!ghes)
265                 return ERR_PTR(-ENOMEM);
266         ghes->generic = generic;
267         rc = apei_map_generic_address(&generic->error_status_address);
268         if (rc)
269                 goto err_free;
270         error_block_length = generic->error_block_length;
271         if (error_block_length > GHES_ESTATUS_MAX_SIZE) {
272                 pr_warning(FW_WARN GHES_PFX
273                            "Error status block length is too long: %u for "
274                            "generic hardware error source: %d.\n",
275                            error_block_length, generic->header.source_id);
276                 error_block_length = GHES_ESTATUS_MAX_SIZE;
277         }
278         ghes->estatus = kmalloc(error_block_length, GFP_KERNEL);
279         if (!ghes->estatus) {
280                 rc = -ENOMEM;
281                 goto err_unmap;
282         }
283 
284         return ghes;
285 
286 err_unmap:
287         apei_unmap_generic_address(&generic->error_status_address);
288 err_free:
289         kfree(ghes);
290         return ERR_PTR(rc);
291 }
292 
293 static void ghes_fini(struct ghes *ghes)
294 {
295         kfree(ghes->estatus);
296         apei_unmap_generic_address(&ghes->generic->error_status_address);
297 }
298 
299 static inline int ghes_severity(int severity)
300 {
301         switch (severity) {
302         case CPER_SEV_INFORMATIONAL:
303                 return GHES_SEV_NO;
304         case CPER_SEV_CORRECTED:
305                 return GHES_SEV_CORRECTED;
306         case CPER_SEV_RECOVERABLE:
307                 return GHES_SEV_RECOVERABLE;
308         case CPER_SEV_FATAL:
309                 return GHES_SEV_PANIC;
310         default:
311                 /* Unknown, go panic */
312                 return GHES_SEV_PANIC;
313         }
314 }
315 
316 static void ghes_copy_tofrom_phys(void *buffer, u64 paddr, u32 len,
317                                   int from_phys)
318 {
319         void __iomem *vaddr;
320         unsigned long flags = 0;
321         int in_nmi = in_nmi();
322         u64 offset;
323         u32 trunk;
324 
325         while (len > 0) {
326                 offset = paddr - (paddr & PAGE_MASK);
327                 if (in_nmi) {
328                         raw_spin_lock(&ghes_ioremap_lock_nmi);
329                         vaddr = ghes_ioremap_pfn_nmi(paddr >> PAGE_SHIFT);
330                 } else {
331                         spin_lock_irqsave(&ghes_ioremap_lock_irq, flags);
332                         vaddr = ghes_ioremap_pfn_irq(paddr >> PAGE_SHIFT);
333                 }
334                 trunk = PAGE_SIZE - offset;
335                 trunk = min(trunk, len);
336                 if (from_phys)
337                         memcpy_fromio(buffer, vaddr + offset, trunk);
338                 else
339                         memcpy_toio(vaddr + offset, buffer, trunk);
340                 len -= trunk;
341                 paddr += trunk;
342                 buffer += trunk;
343                 if (in_nmi) {
344                         ghes_iounmap_nmi(vaddr);
345                         raw_spin_unlock(&ghes_ioremap_lock_nmi);
346                 } else {
347                         ghes_iounmap_irq(vaddr);
348                         spin_unlock_irqrestore(&ghes_ioremap_lock_irq, flags);
349                 }
350         }
351 }
352 
353 static int ghes_read_estatus(struct ghes *ghes, int silent)
354 {
355         struct acpi_hest_generic *g = ghes->generic;
356         u64 buf_paddr;
357         u32 len;
358         int rc;
359 
360         rc = apei_read(&buf_paddr, &g->error_status_address);
361         if (rc) {
362                 if (!silent && printk_ratelimit())
363                         pr_warning(FW_WARN GHES_PFX
364 "Failed to read error status block address for hardware error source: %d.\n",
365                                    g->header.source_id);
366                 return -EIO;
367         }
368         if (!buf_paddr)
369                 return -ENOENT;
370 
371         ghes_copy_tofrom_phys(ghes->estatus, buf_paddr,
372                               sizeof(*ghes->estatus), 1);
373         if (!ghes->estatus->block_status)
374                 return -ENOENT;
375 
376         ghes->buffer_paddr = buf_paddr;
377         ghes->flags |= GHES_TO_CLEAR;
378 
379         rc = -EIO;
380         len = cper_estatus_len(ghes->estatus);
381         if (len < sizeof(*ghes->estatus))
382                 goto err_read_block;
383         if (len > ghes->generic->error_block_length)
384                 goto err_read_block;
385         if (cper_estatus_check_header(ghes->estatus))
386                 goto err_read_block;
387         ghes_copy_tofrom_phys(ghes->estatus + 1,
388                               buf_paddr + sizeof(*ghes->estatus),
389                               len - sizeof(*ghes->estatus), 1);
390         if (cper_estatus_check(ghes->estatus))
391                 goto err_read_block;
392         rc = 0;
393 
394 err_read_block:
395         if (rc && !silent && printk_ratelimit())
396                 pr_warning(FW_WARN GHES_PFX
397                            "Failed to read error status block!\n");
398         return rc;
399 }
400 
401 static void ghes_clear_estatus(struct ghes *ghes)
402 {
403         ghes->estatus->block_status = 0;
404         if (!(ghes->flags & GHES_TO_CLEAR))
405                 return;
406         ghes_copy_tofrom_phys(ghes->estatus, ghes->buffer_paddr,
407                               sizeof(ghes->estatus->block_status), 0);
408         ghes->flags &= ~GHES_TO_CLEAR;
409 }
410 
411 static void ghes_handle_memory_failure(struct acpi_generic_data *gdata, int sev)
412 {
413 #ifdef CONFIG_ACPI_APEI_MEMORY_FAILURE
414         unsigned long pfn;
415         int flags = -1;
416         int sec_sev = ghes_severity(gdata->error_severity);
417         struct cper_sec_mem_err *mem_err;
418         mem_err = (struct cper_sec_mem_err *)(gdata + 1);
419 
420         if (!(mem_err->validation_bits & CPER_MEM_VALID_PA))
421                 return;
422 
423         pfn = mem_err->physical_addr >> PAGE_SHIFT;
424         if (!pfn_valid(pfn)) {
425                 pr_warn_ratelimited(FW_WARN GHES_PFX
426                 "Invalid address in generic error data: %#llx\n",
427                 mem_err->physical_addr);
428                 return;
429         }
430 
431         /* iff following two events can be handled properly by now */
432         if (sec_sev == GHES_SEV_CORRECTED &&
433             (gdata->flags & CPER_SEC_ERROR_THRESHOLD_EXCEEDED))
434                 flags = MF_SOFT_OFFLINE;
435         if (sev == GHES_SEV_RECOVERABLE && sec_sev == GHES_SEV_RECOVERABLE)
436                 flags = 0;
437 
438         if (flags != -1)
439                 memory_failure_queue(pfn, 0, flags);
440 #endif
441 }
442 
443 static void ghes_do_proc(struct ghes *ghes,
444                          const struct acpi_generic_status *estatus)
445 {
446         int sev, sec_sev;
447         struct acpi_generic_data *gdata;
448 
449         sev = ghes_severity(estatus->error_severity);
450         apei_estatus_for_each_section(estatus, gdata) {
451                 sec_sev = ghes_severity(gdata->error_severity);
452                 if (!uuid_le_cmp(*(uuid_le *)gdata->section_type,
453                                  CPER_SEC_PLATFORM_MEM)) {
454                         struct cper_sec_mem_err *mem_err;
455                         mem_err = (struct cper_sec_mem_err *)(gdata+1);
456                         ghes_edac_report_mem_error(ghes, sev, mem_err);
457 
458 #ifdef CONFIG_X86_MCE
459                         apei_mce_report_mem_error(sev, mem_err);
460 #endif
461                         ghes_handle_memory_failure(gdata, sev);
462                 }
463 #ifdef CONFIG_ACPI_APEI_PCIEAER
464                 else if (!uuid_le_cmp(*(uuid_le *)gdata->section_type,
465                                       CPER_SEC_PCIE)) {
466                         struct cper_sec_pcie *pcie_err;
467                         pcie_err = (struct cper_sec_pcie *)(gdata+1);
468                         if (sev == GHES_SEV_RECOVERABLE &&
469                             sec_sev == GHES_SEV_RECOVERABLE &&
470                             pcie_err->validation_bits & CPER_PCIE_VALID_DEVICE_ID &&
471                             pcie_err->validation_bits & CPER_PCIE_VALID_AER_INFO) {
472                                 unsigned int devfn;
473                                 int aer_severity;
474 
475                                 devfn = PCI_DEVFN(pcie_err->device_id.device,
476                                                   pcie_err->device_id.function);
477                                 aer_severity = cper_severity_to_aer(sev);
478 
479                                 /*
480                                  * If firmware reset the component to contain
481                                  * the error, we must reinitialize it before
482                                  * use, so treat it as a fatal AER error.
483                                  */
484                                 if (gdata->flags & CPER_SEC_RESET)
485                                         aer_severity = AER_FATAL;
486 
487                                 aer_recover_queue(pcie_err->device_id.segment,
488                                                   pcie_err->device_id.bus,
489                                                   devfn, aer_severity,
490                                                   (struct aer_capability_regs *)
491                                                   pcie_err->aer_info);
492                         }
493 
494                 }
495 #endif
496         }
497 }
498 
499 static void __ghes_print_estatus(const char *pfx,
500                                  const struct acpi_hest_generic *generic,
501                                  const struct acpi_generic_status *estatus)
502 {
503         static atomic_t seqno;
504         unsigned int curr_seqno;
505         char pfx_seq[64];
506 
507         if (pfx == NULL) {
508                 if (ghes_severity(estatus->error_severity) <=
509                     GHES_SEV_CORRECTED)
510                         pfx = KERN_WARNING;
511                 else
512                         pfx = KERN_ERR;
513         }
514         curr_seqno = atomic_inc_return(&seqno);
515         snprintf(pfx_seq, sizeof(pfx_seq), "%s{%u}" HW_ERR, pfx, curr_seqno);
516         printk("%s""Hardware error from APEI Generic Hardware Error Source: %d\n",
517                pfx_seq, generic->header.source_id);
518         cper_estatus_print(pfx_seq, estatus);
519 }
520 
521 static int ghes_print_estatus(const char *pfx,
522                               const struct acpi_hest_generic *generic,
523                               const struct acpi_generic_status *estatus)
524 {
525         /* Not more than 2 messages every 5 seconds */
526         static DEFINE_RATELIMIT_STATE(ratelimit_corrected, 5*HZ, 2);
527         static DEFINE_RATELIMIT_STATE(ratelimit_uncorrected, 5*HZ, 2);
528         struct ratelimit_state *ratelimit;
529 
530         if (ghes_severity(estatus->error_severity) <= GHES_SEV_CORRECTED)
531                 ratelimit = &ratelimit_corrected;
532         else
533                 ratelimit = &ratelimit_uncorrected;
534         if (__ratelimit(ratelimit)) {
535                 __ghes_print_estatus(pfx, generic, estatus);
536                 return 1;
537         }
538         return 0;
539 }
540 
541 /*
542  * GHES error status reporting throttle, to report more kinds of
543  * errors, instead of just most frequently occurred errors.
544  */
545 static int ghes_estatus_cached(struct acpi_generic_status *estatus)
546 {
547         u32 len;
548         int i, cached = 0;
549         unsigned long long now;
550         struct ghes_estatus_cache *cache;
551         struct acpi_generic_status *cache_estatus;
552 
553         len = cper_estatus_len(estatus);
554         rcu_read_lock();
555         for (i = 0; i < GHES_ESTATUS_CACHES_SIZE; i++) {
556                 cache = rcu_dereference(ghes_estatus_caches[i]);
557                 if (cache == NULL)
558                         continue;
559                 if (len != cache->estatus_len)
560                         continue;
561                 cache_estatus = GHES_ESTATUS_FROM_CACHE(cache);
562                 if (memcmp(estatus, cache_estatus, len))
563                         continue;
564                 atomic_inc(&cache->count);
565                 now = sched_clock();
566                 if (now - cache->time_in < GHES_ESTATUS_IN_CACHE_MAX_NSEC)
567                         cached = 1;
568                 break;
569         }
570         rcu_read_unlock();
571         return cached;
572 }
573 
574 static struct ghes_estatus_cache *ghes_estatus_cache_alloc(
575         struct acpi_hest_generic *generic,
576         struct acpi_generic_status *estatus)
577 {
578         int alloced;
579         u32 len, cache_len;
580         struct ghes_estatus_cache *cache;
581         struct acpi_generic_status *cache_estatus;
582 
583         alloced = atomic_add_return(1, &ghes_estatus_cache_alloced);
584         if (alloced > GHES_ESTATUS_CACHE_ALLOCED_MAX) {
585                 atomic_dec(&ghes_estatus_cache_alloced);
586                 return NULL;
587         }
588         len = cper_estatus_len(estatus);
589         cache_len = GHES_ESTATUS_CACHE_LEN(len);
590         cache = (void *)gen_pool_alloc(ghes_estatus_pool, cache_len);
591         if (!cache) {
592                 atomic_dec(&ghes_estatus_cache_alloced);
593                 return NULL;
594         }
595         cache_estatus = GHES_ESTATUS_FROM_CACHE(cache);
596         memcpy(cache_estatus, estatus, len);
597         cache->estatus_len = len;
598         atomic_set(&cache->count, 0);
599         cache->generic = generic;
600         cache->time_in = sched_clock();
601         return cache;
602 }
603 
604 static void ghes_estatus_cache_free(struct ghes_estatus_cache *cache)
605 {
606         u32 len;
607 
608         len = cper_estatus_len(GHES_ESTATUS_FROM_CACHE(cache));
609         len = GHES_ESTATUS_CACHE_LEN(len);
610         gen_pool_free(ghes_estatus_pool, (unsigned long)cache, len);
611         atomic_dec(&ghes_estatus_cache_alloced);
612 }
613 
614 static void ghes_estatus_cache_rcu_free(struct rcu_head *head)
615 {
616         struct ghes_estatus_cache *cache;
617 
618         cache = container_of(head, struct ghes_estatus_cache, rcu);
619         ghes_estatus_cache_free(cache);
620 }
621 
622 static void ghes_estatus_cache_add(
623         struct acpi_hest_generic *generic,
624         struct acpi_generic_status *estatus)
625 {
626         int i, slot = -1, count;
627         unsigned long long now, duration, period, max_period = 0;
628         struct ghes_estatus_cache *cache, *slot_cache = NULL, *new_cache;
629 
630         new_cache = ghes_estatus_cache_alloc(generic, estatus);
631         if (new_cache == NULL)
632                 return;
633         rcu_read_lock();
634         now = sched_clock();
635         for (i = 0; i < GHES_ESTATUS_CACHES_SIZE; i++) {
636                 cache = rcu_dereference(ghes_estatus_caches[i]);
637                 if (cache == NULL) {
638                         slot = i;
639                         slot_cache = NULL;
640                         break;
641                 }
642                 duration = now - cache->time_in;
643                 if (duration >= GHES_ESTATUS_IN_CACHE_MAX_NSEC) {
644                         slot = i;
645                         slot_cache = cache;
646                         break;
647                 }
648                 count = atomic_read(&cache->count);
649                 period = duration;
650                 do_div(period, (count + 1));
651                 if (period > max_period) {
652                         max_period = period;
653                         slot = i;
654                         slot_cache = cache;
655                 }
656         }
657         /* new_cache must be put into array after its contents are written */
658         smp_wmb();
659         if (slot != -1 && cmpxchg(ghes_estatus_caches + slot,
660                                   slot_cache, new_cache) == slot_cache) {
661                 if (slot_cache)
662                         call_rcu(&slot_cache->rcu, ghes_estatus_cache_rcu_free);
663         } else
664                 ghes_estatus_cache_free(new_cache);
665         rcu_read_unlock();
666 }
667 
668 static int ghes_proc(struct ghes *ghes)
669 {
670         int rc;
671 
672         rc = ghes_read_estatus(ghes, 0);
673         if (rc)
674                 goto out;
675         if (!ghes_estatus_cached(ghes->estatus)) {
676                 if (ghes_print_estatus(NULL, ghes->generic, ghes->estatus))
677                         ghes_estatus_cache_add(ghes->generic, ghes->estatus);
678         }
679         ghes_do_proc(ghes, ghes->estatus);
680 out:
681         ghes_clear_estatus(ghes);
682         return 0;
683 }
684 
685 static void ghes_add_timer(struct ghes *ghes)
686 {
687         struct acpi_hest_generic *g = ghes->generic;
688         unsigned long expire;
689 
690         if (!g->notify.poll_interval) {
691                 pr_warning(FW_WARN GHES_PFX "Poll interval is 0 for generic hardware error source: %d, disabled.\n",
692                            g->header.source_id);
693                 return;
694         }
695         expire = jiffies + msecs_to_jiffies(g->notify.poll_interval);
696         ghes->timer.expires = round_jiffies_relative(expire);
697         add_timer(&ghes->timer);
698 }
699 
700 static void ghes_poll_func(unsigned long data)
701 {
702         struct ghes *ghes = (void *)data;
703 
704         ghes_proc(ghes);
705         if (!(ghes->flags & GHES_EXITING))
706                 ghes_add_timer(ghes);
707 }
708 
709 static irqreturn_t ghes_irq_func(int irq, void *data)
710 {
711         struct ghes *ghes = data;
712         int rc;
713 
714         rc = ghes_proc(ghes);
715         if (rc)
716                 return IRQ_NONE;
717 
718         return IRQ_HANDLED;
719 }
720 
721 static int ghes_notify_sci(struct notifier_block *this,
722                                   unsigned long event, void *data)
723 {
724         struct ghes *ghes;
725         int ret = NOTIFY_DONE;
726 
727         rcu_read_lock();
728         list_for_each_entry_rcu(ghes, &ghes_sci, list) {
729                 if (!ghes_proc(ghes))
730                         ret = NOTIFY_OK;
731         }
732         rcu_read_unlock();
733 
734         return ret;
735 }
736 
737 static struct llist_node *llist_nodes_reverse(struct llist_node *llnode)
738 {
739         struct llist_node *next, *tail = NULL;
740 
741         while (llnode) {
742                 next = llnode->next;
743                 llnode->next = tail;
744                 tail = llnode;
745                 llnode = next;
746         }
747 
748         return tail;
749 }
750 
751 static void ghes_proc_in_irq(struct irq_work *irq_work)
752 {
753         struct llist_node *llnode, *next;
754         struct ghes_estatus_node *estatus_node;
755         struct acpi_hest_generic *generic;
756         struct acpi_generic_status *estatus;
757         u32 len, node_len;
758 
759         llnode = llist_del_all(&ghes_estatus_llist);
760         /*
761          * Because the time order of estatus in list is reversed,
762          * revert it back to proper order.
763          */
764         llnode = llist_nodes_reverse(llnode);
765         while (llnode) {
766                 next = llnode->next;
767                 estatus_node = llist_entry(llnode, struct ghes_estatus_node,
768                                            llnode);
769                 estatus = GHES_ESTATUS_FROM_NODE(estatus_node);
770                 len = cper_estatus_len(estatus);
771                 node_len = GHES_ESTATUS_NODE_LEN(len);
772                 ghes_do_proc(estatus_node->ghes, estatus);
773                 if (!ghes_estatus_cached(estatus)) {
774                         generic = estatus_node->generic;
775                         if (ghes_print_estatus(NULL, generic, estatus))
776                                 ghes_estatus_cache_add(generic, estatus);
777                 }
778                 gen_pool_free(ghes_estatus_pool, (unsigned long)estatus_node,
779                               node_len);
780                 llnode = next;
781         }
782 }
783 
784 static void ghes_print_queued_estatus(void)
785 {
786         struct llist_node *llnode;
787         struct ghes_estatus_node *estatus_node;
788         struct acpi_hest_generic *generic;
789         struct acpi_generic_status *estatus;
790         u32 len, node_len;
791 
792         llnode = llist_del_all(&ghes_estatus_llist);
793         /*
794          * Because the time order of estatus in list is reversed,
795          * revert it back to proper order.
796          */
797         llnode = llist_nodes_reverse(llnode);
798         while (llnode) {
799                 estatus_node = llist_entry(llnode, struct ghes_estatus_node,
800                                            llnode);
801                 estatus = GHES_ESTATUS_FROM_NODE(estatus_node);
802                 len = cper_estatus_len(estatus);
803                 node_len = GHES_ESTATUS_NODE_LEN(len);
804                 generic = estatus_node->generic;
805                 ghes_print_estatus(NULL, generic, estatus);
806                 llnode = llnode->next;
807         }
808 }
809 
810 static int ghes_notify_nmi(unsigned int cmd, struct pt_regs *regs)
811 {
812         struct ghes *ghes, *ghes_global = NULL;
813         int sev, sev_global = -1;
814         int ret = NMI_DONE;
815 
816         raw_spin_lock(&ghes_nmi_lock);
817         list_for_each_entry_rcu(ghes, &ghes_nmi, list) {
818                 if (ghes_read_estatus(ghes, 1)) {
819                         ghes_clear_estatus(ghes);
820                         continue;
821                 }
822                 sev = ghes_severity(ghes->estatus->error_severity);
823                 if (sev > sev_global) {
824                         sev_global = sev;
825                         ghes_global = ghes;
826                 }
827                 ret = NMI_HANDLED;
828         }
829 
830         if (ret == NMI_DONE)
831                 goto out;
832 
833         if (sev_global >= GHES_SEV_PANIC) {
834                 oops_begin();
835                 ghes_print_queued_estatus();
836                 __ghes_print_estatus(KERN_EMERG, ghes_global->generic,
837                                      ghes_global->estatus);
838                 /* reboot to log the error! */
839                 if (panic_timeout == 0)
840                         panic_timeout = ghes_panic_timeout;
841                 panic("Fatal hardware error!");
842         }
843 
844         list_for_each_entry_rcu(ghes, &ghes_nmi, list) {
845 #ifdef CONFIG_ARCH_HAVE_NMI_SAFE_CMPXCHG
846                 u32 len, node_len;
847                 struct ghes_estatus_node *estatus_node;
848                 struct acpi_generic_status *estatus;
849 #endif
850                 if (!(ghes->flags & GHES_TO_CLEAR))
851                         continue;
852 #ifdef CONFIG_ARCH_HAVE_NMI_SAFE_CMPXCHG
853                 if (ghes_estatus_cached(ghes->estatus))
854                         goto next;
855                 /* Save estatus for further processing in IRQ context */
856                 len = cper_estatus_len(ghes->estatus);
857                 node_len = GHES_ESTATUS_NODE_LEN(len);
858                 estatus_node = (void *)gen_pool_alloc(ghes_estatus_pool,
859                                                       node_len);
860                 if (estatus_node) {
861                         estatus_node->ghes = ghes;
862                         estatus_node->generic = ghes->generic;
863                         estatus = GHES_ESTATUS_FROM_NODE(estatus_node);
864                         memcpy(estatus, ghes->estatus, len);
865                         llist_add(&estatus_node->llnode, &ghes_estatus_llist);
866                 }
867 next:
868 #endif
869                 ghes_clear_estatus(ghes);
870         }
871 #ifdef CONFIG_ARCH_HAVE_NMI_SAFE_CMPXCHG
872         irq_work_queue(&ghes_proc_irq_work);
873 #endif
874 
875 out:
876         raw_spin_unlock(&ghes_nmi_lock);
877         return ret;
878 }
879 
880 static struct notifier_block ghes_notifier_sci = {
881         .notifier_call = ghes_notify_sci,
882 };
883 
884 static unsigned long ghes_esource_prealloc_size(
885         const struct acpi_hest_generic *generic)
886 {
887         unsigned long block_length, prealloc_records, prealloc_size;
888 
889         block_length = min_t(unsigned long, generic->error_block_length,
890                              GHES_ESTATUS_MAX_SIZE);
891         prealloc_records = max_t(unsigned long,
892                                  generic->records_to_preallocate, 1);
893         prealloc_size = min_t(unsigned long, block_length * prealloc_records,
894                               GHES_ESOURCE_PREALLOC_MAX_SIZE);
895 
896         return prealloc_size;
897 }
898 
899 static int ghes_probe(struct platform_device *ghes_dev)
900 {
901         struct acpi_hest_generic *generic;
902         struct ghes *ghes = NULL;
903         unsigned long len;
904         int rc = -EINVAL;
905 
906         generic = *(struct acpi_hest_generic **)ghes_dev->dev.platform_data;
907         if (!generic->enabled)
908                 return -ENODEV;
909 
910         switch (generic->notify.type) {
911         case ACPI_HEST_NOTIFY_POLLED:
912         case ACPI_HEST_NOTIFY_EXTERNAL:
913         case ACPI_HEST_NOTIFY_SCI:
914         case ACPI_HEST_NOTIFY_NMI:
915                 break;
916         case ACPI_HEST_NOTIFY_LOCAL:
917                 pr_warning(GHES_PFX "Generic hardware error source: %d notified via local interrupt is not supported!\n",
918                            generic->header.source_id);
919                 goto err;
920         default:
921                 pr_warning(FW_WARN GHES_PFX "Unknown notification type: %u for generic hardware error source: %d\n",
922                            generic->notify.type, generic->header.source_id);
923                 goto err;
924         }
925 
926         rc = -EIO;
927         if (generic->error_block_length <
928             sizeof(struct acpi_generic_status)) {
929                 pr_warning(FW_BUG GHES_PFX "Invalid error block length: %u for generic hardware error source: %d\n",
930                            generic->error_block_length,
931                            generic->header.source_id);
932                 goto err;
933         }
934         ghes = ghes_new(generic);
935         if (IS_ERR(ghes)) {
936                 rc = PTR_ERR(ghes);
937                 ghes = NULL;
938                 goto err;
939         }
940 
941         rc = ghes_edac_register(ghes, &ghes_dev->dev);
942         if (rc < 0)
943                 goto err;
944 
945         switch (generic->notify.type) {
946         case ACPI_HEST_NOTIFY_POLLED:
947                 ghes->timer.function = ghes_poll_func;
948                 ghes->timer.data = (unsigned long)ghes;
949                 init_timer_deferrable(&ghes->timer);
950                 ghes_add_timer(ghes);
951                 break;
952         case ACPI_HEST_NOTIFY_EXTERNAL:
953                 /* External interrupt vector is GSI */
954                 rc = acpi_gsi_to_irq(generic->notify.vector, &ghes->irq);
955                 if (rc) {
956                         pr_err(GHES_PFX "Failed to map GSI to IRQ for generic hardware error source: %d\n",
957                                generic->header.source_id);
958                         goto err_edac_unreg;
959                 }
960                 rc = request_irq(ghes->irq, ghes_irq_func, 0, "GHES IRQ", ghes);
961                 if (rc) {
962                         pr_err(GHES_PFX "Failed to register IRQ for generic hardware error source: %d\n",
963                                generic->header.source_id);
964                         goto err_edac_unreg;
965                 }
966                 break;
967         case ACPI_HEST_NOTIFY_SCI:
968                 mutex_lock(&ghes_list_mutex);
969                 if (list_empty(&ghes_sci))
970                         register_acpi_hed_notifier(&ghes_notifier_sci);
971                 list_add_rcu(&ghes->list, &ghes_sci);
972                 mutex_unlock(&ghes_list_mutex);
973                 break;
974         case ACPI_HEST_NOTIFY_NMI:
975                 len = ghes_esource_prealloc_size(generic);
976                 ghes_estatus_pool_expand(len);
977                 mutex_lock(&ghes_list_mutex);
978                 if (list_empty(&ghes_nmi))
979                         register_nmi_handler(NMI_LOCAL, ghes_notify_nmi, 0,
980                                                 "ghes");
981                 list_add_rcu(&ghes->list, &ghes_nmi);
982                 mutex_unlock(&ghes_list_mutex);
983                 break;
984         default:
985                 BUG();
986         }
987         platform_set_drvdata(ghes_dev, ghes);
988 
989         return 0;
990 err_edac_unreg:
991         ghes_edac_unregister(ghes);
992 err:
993         if (ghes) {
994                 ghes_fini(ghes);
995                 kfree(ghes);
996         }
997         return rc;
998 }
999 
1000 static int ghes_remove(struct platform_device *ghes_dev)
1001 {
1002         struct ghes *ghes;
1003         struct acpi_hest_generic *generic;
1004         unsigned long len;
1005 
1006         ghes = platform_get_drvdata(ghes_dev);
1007         generic = ghes->generic;
1008 
1009         ghes->flags |= GHES_EXITING;
1010         switch (generic->notify.type) {
1011         case ACPI_HEST_NOTIFY_POLLED:
1012                 del_timer_sync(&ghes->timer);
1013                 break;
1014         case ACPI_HEST_NOTIFY_EXTERNAL:
1015                 free_irq(ghes->irq, ghes);
1016                 break;
1017         case ACPI_HEST_NOTIFY_SCI:
1018                 mutex_lock(&ghes_list_mutex);
1019                 list_del_rcu(&ghes->list);
1020                 if (list_empty(&ghes_sci))
1021                         unregister_acpi_hed_notifier(&ghes_notifier_sci);
1022                 mutex_unlock(&ghes_list_mutex);
1023                 break;
1024         case ACPI_HEST_NOTIFY_NMI:
1025                 mutex_lock(&ghes_list_mutex);
1026                 list_del_rcu(&ghes->list);
1027                 if (list_empty(&ghes_nmi))
1028                         unregister_nmi_handler(NMI_LOCAL, "ghes");
1029                 mutex_unlock(&ghes_list_mutex);
1030                 /*
1031                  * To synchronize with NMI handler, ghes can only be
1032                  * freed after NMI handler finishes.
1033                  */
1034                 synchronize_rcu();
1035                 len = ghes_esource_prealloc_size(generic);
1036                 ghes_estatus_pool_shrink(len);
1037                 break;
1038         default:
1039                 BUG();
1040                 break;
1041         }
1042 
1043         ghes_fini(ghes);
1044 
1045         ghes_edac_unregister(ghes);
1046 
1047         kfree(ghes);
1048 
1049         platform_set_drvdata(ghes_dev, NULL);
1050 
1051         return 0;
1052 }
1053 
1054 static struct platform_driver ghes_platform_driver = {
1055         .driver         = {
1056                 .name   = "GHES",
1057                 .owner  = THIS_MODULE,
1058         },
1059         .probe          = ghes_probe,
1060         .remove         = ghes_remove,
1061 };
1062 
1063 static int __init ghes_init(void)
1064 {
1065         int rc;
1066 
1067         if (acpi_disabled)
1068                 return -ENODEV;
1069 
1070         if (hest_disable) {
1071                 pr_info(GHES_PFX "HEST is not enabled!\n");
1072                 return -EINVAL;
1073         }
1074 
1075         if (ghes_disable) {
1076                 pr_info(GHES_PFX "GHES is not enabled!\n");
1077                 return -EINVAL;
1078         }
1079 
1080         init_irq_work(&ghes_proc_irq_work, ghes_proc_in_irq);
1081 
1082         rc = ghes_ioremap_init();
1083         if (rc)
1084                 goto err;
1085 
1086         rc = ghes_estatus_pool_init();
1087         if (rc)
1088                 goto err_ioremap_exit;
1089 
1090         rc = ghes_estatus_pool_expand(GHES_ESTATUS_CACHE_AVG_SIZE *
1091                                       GHES_ESTATUS_CACHE_ALLOCED_MAX);
1092         if (rc)
1093                 goto err_pool_exit;
1094 
1095         rc = platform_driver_register(&ghes_platform_driver);
1096         if (rc)
1097                 goto err_pool_exit;
1098 
1099         rc = apei_osc_setup();
1100         if (rc == 0 && osc_sb_apei_support_acked)
1101                 pr_info(GHES_PFX "APEI firmware first mode is enabled by APEI bit and WHEA _OSC.\n");
1102         else if (rc == 0 && !osc_sb_apei_support_acked)
1103                 pr_info(GHES_PFX "APEI firmware first mode is enabled by WHEA _OSC.\n");
1104         else if (rc && osc_sb_apei_support_acked)
1105                 pr_info(GHES_PFX "APEI firmware first mode is enabled by APEI bit.\n");
1106         else
1107                 pr_info(GHES_PFX "Failed to enable APEI firmware first mode.\n");
1108 
1109         return 0;
1110 err_pool_exit:
1111         ghes_estatus_pool_exit();
1112 err_ioremap_exit:
1113         ghes_ioremap_exit();
1114 err:
1115         return rc;
1116 }
1117 
1118 static void __exit ghes_exit(void)
1119 {
1120         platform_driver_unregister(&ghes_platform_driver);
1121         ghes_estatus_pool_exit();
1122         ghes_ioremap_exit();
1123 }
1124 
1125 module_init(ghes_init);
1126 module_exit(ghes_exit);
1127 
1128 MODULE_AUTHOR("Huang Ying");
1129 MODULE_DESCRIPTION("APEI Generic Hardware Error Source support");
1130 MODULE_LICENSE("GPL");
1131 MODULE_ALIAS("platform:GHES");
1132 

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