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