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v3.5.6
   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#include <acpi/apei.h>
 
  52#include <acpi/hed.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/*
  88 * One struct ghes is created for each generic hardware error source.
  89 * It provides the context for APEI hardware error timer/IRQ/SCI/NMI
  90 * handler.
  91 *
  92 * estatus: memory buffer for error status block, allocated during
  93 * HEST parsing.
  94 */
  95#define GHES_TO_CLEAR		0x0001
  96#define GHES_EXITING		0x0002
  97
  98struct ghes {
  99	struct acpi_hest_generic *generic;
 100	struct acpi_hest_generic_status *estatus;
 101	u64 buffer_paddr;
 102	unsigned long flags;
 103	union {
 104		struct list_head list;
 105		struct timer_list timer;
 106		unsigned int irq;
 107	};
 108};
 109
 110struct ghes_estatus_node {
 111	struct llist_node llnode;
 112	struct acpi_hest_generic *generic;
 113};
 114
 115struct ghes_estatus_cache {
 116	u32 estatus_len;
 117	atomic_t count;
 118	struct acpi_hest_generic *generic;
 119	unsigned long long time_in;
 120	struct rcu_head rcu;
 121};
 122
 123bool ghes_disable;
 124module_param_named(disable, ghes_disable, bool, 0);
 125
 126static int ghes_panic_timeout	__read_mostly = 30;
 127
 128/*
 129 * All error sources notified with SCI shares one notifier function,
 130 * so they need to be linked and checked one by one.  This is applied
 131 * to NMI too.
 132 *
 133 * RCU is used for these lists, so ghes_list_mutex is only used for
 134 * list changing, not for traversing.
 135 */
 136static LIST_HEAD(ghes_sci);
 137static LIST_HEAD(ghes_nmi);
 138static DEFINE_MUTEX(ghes_list_mutex);
 139
 140/*
 141 * NMI may be triggered on any CPU, so ghes_nmi_lock is used for
 142 * mutual exclusion.
 143 */
 144static DEFINE_RAW_SPINLOCK(ghes_nmi_lock);
 145
 146/*
 147 * Because the memory area used to transfer hardware error information
 148 * from BIOS to Linux can be determined only in NMI, IRQ or timer
 149 * handler, but general ioremap can not be used in atomic context, so
 150 * a special version of atomic ioremap is implemented for that.
 151 */
 152
 153/*
 154 * Two virtual pages are used, one for NMI context, the other for
 155 * IRQ/PROCESS context
 156 */
 157#define GHES_IOREMAP_PAGES		2
 158#define GHES_IOREMAP_NMI_PAGE(base)	(base)
 159#define GHES_IOREMAP_IRQ_PAGE(base)	((base) + PAGE_SIZE)
 160
 161/* virtual memory area for atomic ioremap */
 162static struct vm_struct *ghes_ioremap_area;
 163/*
 164 * These 2 spinlock is used to prevent atomic ioremap virtual memory
 165 * area from being mapped simultaneously.
 166 */
 167static DEFINE_RAW_SPINLOCK(ghes_ioremap_lock_nmi);
 168static DEFINE_SPINLOCK(ghes_ioremap_lock_irq);
 169
 170/*
 171 * printk is not safe in NMI context.  So in NMI handler, we allocate
 172 * required memory from lock-less memory allocator
 173 * (ghes_estatus_pool), save estatus into it, put them into lock-less
 174 * list (ghes_estatus_llist), then delay printk into IRQ context via
 175 * irq_work (ghes_proc_irq_work).  ghes_estatus_size_request record
 176 * required pool size by all NMI error source.
 177 */
 178static struct gen_pool *ghes_estatus_pool;
 179static unsigned long ghes_estatus_pool_size_request;
 180static struct llist_head ghes_estatus_llist;
 181static struct irq_work ghes_proc_irq_work;
 182
 183struct ghes_estatus_cache *ghes_estatus_caches[GHES_ESTATUS_CACHES_SIZE];
 184static atomic_t ghes_estatus_cache_alloced;
 185
 186static int ghes_ioremap_init(void)
 187{
 188	ghes_ioremap_area = __get_vm_area(PAGE_SIZE * GHES_IOREMAP_PAGES,
 189		VM_IOREMAP, VMALLOC_START, VMALLOC_END);
 190	if (!ghes_ioremap_area) {
 191		pr_err(GHES_PFX "Failed to allocate virtual memory area for atomic ioremap.\n");
 192		return -ENOMEM;
 193	}
 194
 195	return 0;
 196}
 197
 198static void ghes_ioremap_exit(void)
 199{
 200	free_vm_area(ghes_ioremap_area);
 201}
 202
 203static void __iomem *ghes_ioremap_pfn_nmi(u64 pfn)
 204{
 205	unsigned long vaddr;
 206
 207	vaddr = (unsigned long)GHES_IOREMAP_NMI_PAGE(ghes_ioremap_area->addr);
 208	ioremap_page_range(vaddr, vaddr + PAGE_SIZE,
 209			   pfn << PAGE_SHIFT, PAGE_KERNEL);
 210
 211	return (void __iomem *)vaddr;
 212}
 213
 214static void __iomem *ghes_ioremap_pfn_irq(u64 pfn)
 215{
 216	unsigned long vaddr;
 217
 218	vaddr = (unsigned long)GHES_IOREMAP_IRQ_PAGE(ghes_ioremap_area->addr);
 219	ioremap_page_range(vaddr, vaddr + PAGE_SIZE,
 220			   pfn << PAGE_SHIFT, PAGE_KERNEL);
 221
 222	return (void __iomem *)vaddr;
 223}
 224
 225static void ghes_iounmap_nmi(void __iomem *vaddr_ptr)
 226{
 227	unsigned long vaddr = (unsigned long __force)vaddr_ptr;
 228	void *base = ghes_ioremap_area->addr;
 229
 230	BUG_ON(vaddr != (unsigned long)GHES_IOREMAP_NMI_PAGE(base));
 231	unmap_kernel_range_noflush(vaddr, PAGE_SIZE);
 232	__flush_tlb_one(vaddr);
 233}
 234
 235static void ghes_iounmap_irq(void __iomem *vaddr_ptr)
 236{
 237	unsigned long vaddr = (unsigned long __force)vaddr_ptr;
 238	void *base = ghes_ioremap_area->addr;
 239
 240	BUG_ON(vaddr != (unsigned long)GHES_IOREMAP_IRQ_PAGE(base));
 241	unmap_kernel_range_noflush(vaddr, PAGE_SIZE);
 242	__flush_tlb_one(vaddr);
 243}
 244
 245static int ghes_estatus_pool_init(void)
 246{
 247	ghes_estatus_pool = gen_pool_create(GHES_ESTATUS_POOL_MIN_ALLOC_ORDER, -1);
 248	if (!ghes_estatus_pool)
 249		return -ENOMEM;
 250	return 0;
 251}
 252
 253static void ghes_estatus_pool_free_chunk_page(struct gen_pool *pool,
 254					      struct gen_pool_chunk *chunk,
 255					      void *data)
 256{
 257	free_page(chunk->start_addr);
 258}
 259
 260static void ghes_estatus_pool_exit(void)
 261{
 262	gen_pool_for_each_chunk(ghes_estatus_pool,
 263				ghes_estatus_pool_free_chunk_page, NULL);
 264	gen_pool_destroy(ghes_estatus_pool);
 265}
 266
 267static int ghes_estatus_pool_expand(unsigned long len)
 268{
 269	unsigned long i, pages, size, addr;
 270	int ret;
 271
 272	ghes_estatus_pool_size_request += PAGE_ALIGN(len);
 273	size = gen_pool_size(ghes_estatus_pool);
 274	if (size >= ghes_estatus_pool_size_request)
 275		return 0;
 276	pages = (ghes_estatus_pool_size_request - size) / PAGE_SIZE;
 277	for (i = 0; i < pages; i++) {
 278		addr = __get_free_page(GFP_KERNEL);
 279		if (!addr)
 280			return -ENOMEM;
 281		ret = gen_pool_add(ghes_estatus_pool, addr, PAGE_SIZE, -1);
 282		if (ret)
 283			return ret;
 284	}
 285
 286	return 0;
 287}
 288
 289static void ghes_estatus_pool_shrink(unsigned long len)
 290{
 291	ghes_estatus_pool_size_request -= PAGE_ALIGN(len);
 292}
 293
 294static struct ghes *ghes_new(struct acpi_hest_generic *generic)
 295{
 296	struct ghes *ghes;
 297	unsigned int error_block_length;
 298	int rc;
 299
 300	ghes = kzalloc(sizeof(*ghes), GFP_KERNEL);
 301	if (!ghes)
 302		return ERR_PTR(-ENOMEM);
 303	ghes->generic = generic;
 304	rc = apei_map_generic_address(&generic->error_status_address);
 305	if (rc)
 306		goto err_free;
 307	error_block_length = generic->error_block_length;
 308	if (error_block_length > GHES_ESTATUS_MAX_SIZE) {
 309		pr_warning(FW_WARN GHES_PFX
 310			   "Error status block length is too long: %u for "
 311			   "generic hardware error source: %d.\n",
 312			   error_block_length, generic->header.source_id);
 313		error_block_length = GHES_ESTATUS_MAX_SIZE;
 314	}
 315	ghes->estatus = kmalloc(error_block_length, GFP_KERNEL);
 316	if (!ghes->estatus) {
 317		rc = -ENOMEM;
 318		goto err_unmap;
 319	}
 320
 321	return ghes;
 322
 323err_unmap:
 324	apei_unmap_generic_address(&generic->error_status_address);
 325err_free:
 326	kfree(ghes);
 327	return ERR_PTR(rc);
 328}
 329
 330static void ghes_fini(struct ghes *ghes)
 331{
 332	kfree(ghes->estatus);
 333	apei_unmap_generic_address(&ghes->generic->error_status_address);
 334}
 335
 336enum {
 337	GHES_SEV_NO = 0x0,
 338	GHES_SEV_CORRECTED = 0x1,
 339	GHES_SEV_RECOVERABLE = 0x2,
 340	GHES_SEV_PANIC = 0x3,
 341};
 342
 343static inline int ghes_severity(int severity)
 344{
 345	switch (severity) {
 346	case CPER_SEV_INFORMATIONAL:
 347		return GHES_SEV_NO;
 348	case CPER_SEV_CORRECTED:
 349		return GHES_SEV_CORRECTED;
 350	case CPER_SEV_RECOVERABLE:
 351		return GHES_SEV_RECOVERABLE;
 352	case CPER_SEV_FATAL:
 353		return GHES_SEV_PANIC;
 354	default:
 355		/* Unknown, go panic */
 356		return GHES_SEV_PANIC;
 357	}
 358}
 359
 360static void ghes_copy_tofrom_phys(void *buffer, u64 paddr, u32 len,
 361				  int from_phys)
 362{
 363	void __iomem *vaddr;
 364	unsigned long flags = 0;
 365	int in_nmi = in_nmi();
 366	u64 offset;
 367	u32 trunk;
 368
 369	while (len > 0) {
 370		offset = paddr - (paddr & PAGE_MASK);
 371		if (in_nmi) {
 372			raw_spin_lock(&ghes_ioremap_lock_nmi);
 373			vaddr = ghes_ioremap_pfn_nmi(paddr >> PAGE_SHIFT);
 374		} else {
 375			spin_lock_irqsave(&ghes_ioremap_lock_irq, flags);
 376			vaddr = ghes_ioremap_pfn_irq(paddr >> PAGE_SHIFT);
 377		}
 378		trunk = PAGE_SIZE - offset;
 379		trunk = min(trunk, len);
 380		if (from_phys)
 381			memcpy_fromio(buffer, vaddr + offset, trunk);
 382		else
 383			memcpy_toio(vaddr + offset, buffer, trunk);
 384		len -= trunk;
 385		paddr += trunk;
 386		buffer += trunk;
 387		if (in_nmi) {
 388			ghes_iounmap_nmi(vaddr);
 389			raw_spin_unlock(&ghes_ioremap_lock_nmi);
 390		} else {
 391			ghes_iounmap_irq(vaddr);
 392			spin_unlock_irqrestore(&ghes_ioremap_lock_irq, flags);
 393		}
 394	}
 395}
 396
 397static int ghes_read_estatus(struct ghes *ghes, int silent)
 398{
 399	struct acpi_hest_generic *g = ghes->generic;
 400	u64 buf_paddr;
 401	u32 len;
 402	int rc;
 403
 404	rc = apei_read(&buf_paddr, &g->error_status_address);
 405	if (rc) {
 406		if (!silent && printk_ratelimit())
 407			pr_warning(FW_WARN GHES_PFX
 408"Failed to read error status block address for hardware error source: %d.\n",
 409				   g->header.source_id);
 410		return -EIO;
 411	}
 412	if (!buf_paddr)
 413		return -ENOENT;
 414
 415	ghes_copy_tofrom_phys(ghes->estatus, buf_paddr,
 416			      sizeof(*ghes->estatus), 1);
 417	if (!ghes->estatus->block_status)
 418		return -ENOENT;
 419
 420	ghes->buffer_paddr = buf_paddr;
 421	ghes->flags |= GHES_TO_CLEAR;
 422
 423	rc = -EIO;
 424	len = apei_estatus_len(ghes->estatus);
 425	if (len < sizeof(*ghes->estatus))
 426		goto err_read_block;
 427	if (len > ghes->generic->error_block_length)
 428		goto err_read_block;
 429	if (apei_estatus_check_header(ghes->estatus))
 430		goto err_read_block;
 431	ghes_copy_tofrom_phys(ghes->estatus + 1,
 432			      buf_paddr + sizeof(*ghes->estatus),
 433			      len - sizeof(*ghes->estatus), 1);
 434	if (apei_estatus_check(ghes->estatus))
 435		goto err_read_block;
 436	rc = 0;
 437
 438err_read_block:
 439	if (rc && !silent && printk_ratelimit())
 440		pr_warning(FW_WARN GHES_PFX
 441			   "Failed to read error status block!\n");
 442	return rc;
 443}
 444
 445static void ghes_clear_estatus(struct ghes *ghes)
 446{
 447	ghes->estatus->block_status = 0;
 448	if (!(ghes->flags & GHES_TO_CLEAR))
 449		return;
 450	ghes_copy_tofrom_phys(ghes->estatus, ghes->buffer_paddr,
 451			      sizeof(ghes->estatus->block_status), 0);
 452	ghes->flags &= ~GHES_TO_CLEAR;
 453}
 454
 455static void ghes_do_proc(const struct acpi_hest_generic_status *estatus)
 456{
 457	int sev, sec_sev;
 458	struct acpi_hest_generic_data *gdata;
 459
 460	sev = ghes_severity(estatus->error_severity);
 461	apei_estatus_for_each_section(estatus, gdata) {
 462		sec_sev = ghes_severity(gdata->error_severity);
 463		if (!uuid_le_cmp(*(uuid_le *)gdata->section_type,
 464				 CPER_SEC_PLATFORM_MEM)) {
 465			struct cper_sec_mem_err *mem_err;
 466			mem_err = (struct cper_sec_mem_err *)(gdata+1);
 467#ifdef CONFIG_X86_MCE
 468			apei_mce_report_mem_error(sev == GHES_SEV_CORRECTED,
 469						  mem_err);
 470#endif
 471#ifdef CONFIG_ACPI_APEI_MEMORY_FAILURE
 472			if (sev == GHES_SEV_RECOVERABLE &&
 473			    sec_sev == GHES_SEV_RECOVERABLE &&
 474			    mem_err->validation_bits & CPER_MEM_VALID_PHYSICAL_ADDRESS) {
 475				unsigned long pfn;
 476				pfn = mem_err->physical_addr >> PAGE_SHIFT;
 477				memory_failure_queue(pfn, 0, 0);
 478			}
 479#endif
 480		}
 481#ifdef CONFIG_ACPI_APEI_PCIEAER
 482		else if (!uuid_le_cmp(*(uuid_le *)gdata->section_type,
 483				      CPER_SEC_PCIE)) {
 484			struct cper_sec_pcie *pcie_err;
 485			pcie_err = (struct cper_sec_pcie *)(gdata+1);
 486			if (sev == GHES_SEV_RECOVERABLE &&
 487			    sec_sev == GHES_SEV_RECOVERABLE &&
 488			    pcie_err->validation_bits & CPER_PCIE_VALID_DEVICE_ID &&
 489			    pcie_err->validation_bits & CPER_PCIE_VALID_AER_INFO) {
 490				unsigned int devfn;
 491				int aer_severity;
 492				devfn = PCI_DEVFN(pcie_err->device_id.device,
 493						  pcie_err->device_id.function);
 494				aer_severity = cper_severity_to_aer(sev);
 495				aer_recover_queue(pcie_err->device_id.segment,
 496						  pcie_err->device_id.bus,
 497						  devfn, aer_severity);
 498			}
 499
 500		}
 501#endif
 502	}
 503}
 504
 505static void __ghes_print_estatus(const char *pfx,
 506				 const struct acpi_hest_generic *generic,
 507				 const struct acpi_hest_generic_status *estatus)
 508{
 509	static atomic_t seqno;
 510	unsigned int curr_seqno;
 511	char pfx_seq[64];
 512
 513	if (pfx == NULL) {
 514		if (ghes_severity(estatus->error_severity) <=
 515		    GHES_SEV_CORRECTED)
 516			pfx = KERN_WARNING;
 517		else
 518			pfx = KERN_ERR;
 519	}
 520	curr_seqno = atomic_inc_return(&seqno);
 521	snprintf(pfx_seq, sizeof(pfx_seq), "%s{%u}" HW_ERR, pfx, curr_seqno);
 522	printk("%s""Hardware error from APEI Generic Hardware Error Source: %d\n",
 523	       pfx_seq, generic->header.source_id);
 524	apei_estatus_print(pfx_seq, estatus);
 525}
 526
 527static int ghes_print_estatus(const char *pfx,
 528			      const struct acpi_hest_generic *generic,
 529			      const struct acpi_hest_generic_status *estatus)
 530{
 531	/* Not more than 2 messages every 5 seconds */
 532	static DEFINE_RATELIMIT_STATE(ratelimit_corrected, 5*HZ, 2);
 533	static DEFINE_RATELIMIT_STATE(ratelimit_uncorrected, 5*HZ, 2);
 534	struct ratelimit_state *ratelimit;
 535
 536	if (ghes_severity(estatus->error_severity) <= GHES_SEV_CORRECTED)
 537		ratelimit = &ratelimit_corrected;
 538	else
 539		ratelimit = &ratelimit_uncorrected;
 540	if (__ratelimit(ratelimit)) {
 541		__ghes_print_estatus(pfx, generic, estatus);
 542		return 1;
 543	}
 544	return 0;
 545}
 546
 547/*
 548 * GHES error status reporting throttle, to report more kinds of
 549 * errors, instead of just most frequently occurred errors.
 550 */
 551static int ghes_estatus_cached(struct acpi_hest_generic_status *estatus)
 552{
 553	u32 len;
 554	int i, cached = 0;
 555	unsigned long long now;
 556	struct ghes_estatus_cache *cache;
 557	struct acpi_hest_generic_status *cache_estatus;
 558
 559	len = apei_estatus_len(estatus);
 560	rcu_read_lock();
 561	for (i = 0; i < GHES_ESTATUS_CACHES_SIZE; i++) {
 562		cache = rcu_dereference(ghes_estatus_caches[i]);
 563		if (cache == NULL)
 564			continue;
 565		if (len != cache->estatus_len)
 566			continue;
 567		cache_estatus = GHES_ESTATUS_FROM_CACHE(cache);
 568		if (memcmp(estatus, cache_estatus, len))
 569			continue;
 570		atomic_inc(&cache->count);
 571		now = sched_clock();
 572		if (now - cache->time_in < GHES_ESTATUS_IN_CACHE_MAX_NSEC)
 573			cached = 1;
 574		break;
 575	}
 576	rcu_read_unlock();
 577	return cached;
 578}
 579
 580static struct ghes_estatus_cache *ghes_estatus_cache_alloc(
 581	struct acpi_hest_generic *generic,
 582	struct acpi_hest_generic_status *estatus)
 583{
 584	int alloced;
 585	u32 len, cache_len;
 586	struct ghes_estatus_cache *cache;
 587	struct acpi_hest_generic_status *cache_estatus;
 588
 589	alloced = atomic_add_return(1, &ghes_estatus_cache_alloced);
 590	if (alloced > GHES_ESTATUS_CACHE_ALLOCED_MAX) {
 591		atomic_dec(&ghes_estatus_cache_alloced);
 592		return NULL;
 593	}
 594	len = apei_estatus_len(estatus);
 595	cache_len = GHES_ESTATUS_CACHE_LEN(len);
 596	cache = (void *)gen_pool_alloc(ghes_estatus_pool, cache_len);
 597	if (!cache) {
 598		atomic_dec(&ghes_estatus_cache_alloced);
 599		return NULL;
 600	}
 601	cache_estatus = GHES_ESTATUS_FROM_CACHE(cache);
 602	memcpy(cache_estatus, estatus, len);
 603	cache->estatus_len = len;
 604	atomic_set(&cache->count, 0);
 605	cache->generic = generic;
 606	cache->time_in = sched_clock();
 607	return cache;
 608}
 609
 610static void ghes_estatus_cache_free(struct ghes_estatus_cache *cache)
 611{
 612	u32 len;
 613
 614	len = apei_estatus_len(GHES_ESTATUS_FROM_CACHE(cache));
 615	len = GHES_ESTATUS_CACHE_LEN(len);
 616	gen_pool_free(ghes_estatus_pool, (unsigned long)cache, len);
 617	atomic_dec(&ghes_estatus_cache_alloced);
 618}
 619
 620static void ghes_estatus_cache_rcu_free(struct rcu_head *head)
 621{
 622	struct ghes_estatus_cache *cache;
 623
 624	cache = container_of(head, struct ghes_estatus_cache, rcu);
 625	ghes_estatus_cache_free(cache);
 626}
 627
 628static void ghes_estatus_cache_add(
 629	struct acpi_hest_generic *generic,
 630	struct acpi_hest_generic_status *estatus)
 631{
 632	int i, slot = -1, count;
 633	unsigned long long now, duration, period, max_period = 0;
 634	struct ghes_estatus_cache *cache, *slot_cache = NULL, *new_cache;
 635
 636	new_cache = ghes_estatus_cache_alloc(generic, estatus);
 637	if (new_cache == NULL)
 638		return;
 639	rcu_read_lock();
 640	now = sched_clock();
 641	for (i = 0; i < GHES_ESTATUS_CACHES_SIZE; i++) {
 642		cache = rcu_dereference(ghes_estatus_caches[i]);
 643		if (cache == NULL) {
 644			slot = i;
 645			slot_cache = NULL;
 646			break;
 647		}
 648		duration = now - cache->time_in;
 649		if (duration >= GHES_ESTATUS_IN_CACHE_MAX_NSEC) {
 650			slot = i;
 651			slot_cache = cache;
 652			break;
 653		}
 654		count = atomic_read(&cache->count);
 655		period = duration;
 656		do_div(period, (count + 1));
 657		if (period > max_period) {
 658			max_period = period;
 659			slot = i;
 660			slot_cache = cache;
 661		}
 662	}
 663	/* new_cache must be put into array after its contents are written */
 664	smp_wmb();
 665	if (slot != -1 && cmpxchg(ghes_estatus_caches + slot,
 666				  slot_cache, new_cache) == slot_cache) {
 667		if (slot_cache)
 668			call_rcu(&slot_cache->rcu, ghes_estatus_cache_rcu_free);
 669	} else
 670		ghes_estatus_cache_free(new_cache);
 671	rcu_read_unlock();
 672}
 673
 674static int ghes_proc(struct ghes *ghes)
 675{
 676	int rc;
 677
 678	rc = ghes_read_estatus(ghes, 0);
 679	if (rc)
 680		goto out;
 681	if (!ghes_estatus_cached(ghes->estatus)) {
 682		if (ghes_print_estatus(NULL, ghes->generic, ghes->estatus))
 683			ghes_estatus_cache_add(ghes->generic, ghes->estatus);
 684	}
 685	ghes_do_proc(ghes->estatus);
 686out:
 687	ghes_clear_estatus(ghes);
 688	return 0;
 689}
 690
 691static void ghes_add_timer(struct ghes *ghes)
 692{
 693	struct acpi_hest_generic *g = ghes->generic;
 694	unsigned long expire;
 695
 696	if (!g->notify.poll_interval) {
 697		pr_warning(FW_WARN GHES_PFX "Poll interval is 0 for generic hardware error source: %d, disabled.\n",
 698			   g->header.source_id);
 699		return;
 700	}
 701	expire = jiffies + msecs_to_jiffies(g->notify.poll_interval);
 702	ghes->timer.expires = round_jiffies_relative(expire);
 703	add_timer(&ghes->timer);
 704}
 705
 706static void ghes_poll_func(unsigned long data)
 707{
 708	struct ghes *ghes = (void *)data;
 709
 710	ghes_proc(ghes);
 711	if (!(ghes->flags & GHES_EXITING))
 712		ghes_add_timer(ghes);
 713}
 714
 715static irqreturn_t ghes_irq_func(int irq, void *data)
 716{
 717	struct ghes *ghes = data;
 718	int rc;
 719
 720	rc = ghes_proc(ghes);
 721	if (rc)
 722		return IRQ_NONE;
 723
 724	return IRQ_HANDLED;
 725}
 726
 727static int ghes_notify_sci(struct notifier_block *this,
 728				  unsigned long event, void *data)
 729{
 730	struct ghes *ghes;
 731	int ret = NOTIFY_DONE;
 732
 733	rcu_read_lock();
 734	list_for_each_entry_rcu(ghes, &ghes_sci, list) {
 735		if (!ghes_proc(ghes))
 736			ret = NOTIFY_OK;
 737	}
 738	rcu_read_unlock();
 739
 740	return ret;
 741}
 742
 743static struct llist_node *llist_nodes_reverse(struct llist_node *llnode)
 744{
 745	struct llist_node *next, *tail = NULL;
 746
 747	while (llnode) {
 748		next = llnode->next;
 749		llnode->next = tail;
 750		tail = llnode;
 751		llnode = next;
 752	}
 753
 754	return tail;
 755}
 756
 757static void ghes_proc_in_irq(struct irq_work *irq_work)
 758{
 759	struct llist_node *llnode, *next;
 760	struct ghes_estatus_node *estatus_node;
 761	struct acpi_hest_generic *generic;
 762	struct acpi_hest_generic_status *estatus;
 763	u32 len, node_len;
 764
 765	llnode = llist_del_all(&ghes_estatus_llist);
 766	/*
 767	 * Because the time order of estatus in list is reversed,
 768	 * revert it back to proper order.
 769	 */
 770	llnode = llist_nodes_reverse(llnode);
 
 
 
 
 
 
 
 771	while (llnode) {
 772		next = llnode->next;
 773		estatus_node = llist_entry(llnode, struct ghes_estatus_node,
 774					   llnode);
 775		estatus = GHES_ESTATUS_FROM_NODE(estatus_node);
 776		len = apei_estatus_len(estatus);
 777		node_len = GHES_ESTATUS_NODE_LEN(len);
 778		ghes_do_proc(estatus);
 779		if (!ghes_estatus_cached(estatus)) {
 780			generic = estatus_node->generic;
 781			if (ghes_print_estatus(NULL, generic, estatus))
 782				ghes_estatus_cache_add(generic, estatus);
 783		}
 784		gen_pool_free(ghes_estatus_pool, (unsigned long)estatus_node,
 785			      node_len);
 786		llnode = next;
 787	}
 788}
 789
 790static void ghes_print_queued_estatus(void)
 791{
 792	struct llist_node *llnode;
 793	struct ghes_estatus_node *estatus_node;
 794	struct acpi_hest_generic *generic;
 795	struct acpi_hest_generic_status *estatus;
 796	u32 len, node_len;
 797
 798	llnode = llist_del_all(&ghes_estatus_llist);
 799	/*
 800	 * Because the time order of estatus in list is reversed,
 801	 * revert it back to proper order.
 802	 */
 803	llnode = llist_nodes_reverse(llnode);
 804	while (llnode) {
 805		estatus_node = llist_entry(llnode, struct ghes_estatus_node,
 806					   llnode);
 807		estatus = GHES_ESTATUS_FROM_NODE(estatus_node);
 808		len = apei_estatus_len(estatus);
 809		node_len = GHES_ESTATUS_NODE_LEN(len);
 810		generic = estatus_node->generic;
 811		ghes_print_estatus(NULL, generic, estatus);
 812		llnode = llnode->next;
 813	}
 814}
 815
 816static int ghes_notify_nmi(unsigned int cmd, struct pt_regs *regs)
 817{
 818	struct ghes *ghes, *ghes_global = NULL;
 819	int sev, sev_global = -1;
 820	int ret = NMI_DONE;
 
 
 
 821
 822	raw_spin_lock(&ghes_nmi_lock);
 823	list_for_each_entry_rcu(ghes, &ghes_nmi, list) {
 824		if (ghes_read_estatus(ghes, 1)) {
 825			ghes_clear_estatus(ghes);
 826			continue;
 827		}
 828		sev = ghes_severity(ghes->estatus->error_severity);
 829		if (sev > sev_global) {
 830			sev_global = sev;
 831			ghes_global = ghes;
 832		}
 833		ret = NMI_HANDLED;
 834	}
 835
 836	if (ret == NMI_DONE)
 837		goto out;
 838
 839	if (sev_global >= GHES_SEV_PANIC) {
 840		oops_begin();
 841		ghes_print_queued_estatus();
 842		__ghes_print_estatus(KERN_EMERG, ghes_global->generic,
 843				     ghes_global->estatus);
 844		/* reboot to log the error! */
 845		if (panic_timeout == 0)
 846			panic_timeout = ghes_panic_timeout;
 847		panic("Fatal hardware error!");
 848	}
 849
 850	list_for_each_entry_rcu(ghes, &ghes_nmi, list) {
 851#ifdef CONFIG_ARCH_HAVE_NMI_SAFE_CMPXCHG
 852		u32 len, node_len;
 853		struct ghes_estatus_node *estatus_node;
 854		struct acpi_hest_generic_status *estatus;
 855#endif
 856		if (!(ghes->flags & GHES_TO_CLEAR))
 857			continue;
 858#ifdef CONFIG_ARCH_HAVE_NMI_SAFE_CMPXCHG
 859		if (ghes_estatus_cached(ghes->estatus))
 860			goto next;
 861		/* Save estatus for further processing in IRQ context */
 862		len = apei_estatus_len(ghes->estatus);
 863		node_len = GHES_ESTATUS_NODE_LEN(len);
 864		estatus_node = (void *)gen_pool_alloc(ghes_estatus_pool,
 865						      node_len);
 866		if (estatus_node) {
 867			estatus_node->generic = ghes->generic;
 868			estatus = GHES_ESTATUS_FROM_NODE(estatus_node);
 869			memcpy(estatus, ghes->estatus, len);
 870			llist_add(&estatus_node->llnode, &ghes_estatus_llist);
 871		}
 872next:
 873#endif
 874		ghes_clear_estatus(ghes);
 875	}
 876#ifdef CONFIG_ARCH_HAVE_NMI_SAFE_CMPXCHG
 877	irq_work_queue(&ghes_proc_irq_work);
 878#endif
 879
 880out:
 881	raw_spin_unlock(&ghes_nmi_lock);
 882	return ret;
 883}
 884
 885static struct notifier_block ghes_notifier_sci = {
 886	.notifier_call = ghes_notify_sci,
 887};
 888
 
 
 
 
 889static unsigned long ghes_esource_prealloc_size(
 890	const struct acpi_hest_generic *generic)
 891{
 892	unsigned long block_length, prealloc_records, prealloc_size;
 893
 894	block_length = min_t(unsigned long, generic->error_block_length,
 895			     GHES_ESTATUS_MAX_SIZE);
 896	prealloc_records = max_t(unsigned long,
 897				 generic->records_to_preallocate, 1);
 898	prealloc_size = min_t(unsigned long, block_length * prealloc_records,
 899			      GHES_ESOURCE_PREALLOC_MAX_SIZE);
 900
 901	return prealloc_size;
 902}
 903
 904static int __devinit ghes_probe(struct platform_device *ghes_dev)
 905{
 906	struct acpi_hest_generic *generic;
 907	struct ghes *ghes = NULL;
 908	unsigned long len;
 909	int rc = -EINVAL;
 910
 911	generic = *(struct acpi_hest_generic **)ghes_dev->dev.platform_data;
 912	if (!generic->enabled)
 913		return -ENODEV;
 914
 915	switch (generic->notify.type) {
 916	case ACPI_HEST_NOTIFY_POLLED:
 917	case ACPI_HEST_NOTIFY_EXTERNAL:
 918	case ACPI_HEST_NOTIFY_SCI:
 919	case ACPI_HEST_NOTIFY_NMI:
 920		break;
 921	case ACPI_HEST_NOTIFY_LOCAL:
 922		pr_warning(GHES_PFX "Generic hardware error source: %d notified via local interrupt is not supported!\n",
 923			   generic->header.source_id);
 924		goto err;
 925	default:
 926		pr_warning(FW_WARN GHES_PFX "Unknown notification type: %u for generic hardware error source: %d\n",
 927			   generic->notify.type, generic->header.source_id);
 928		goto err;
 929	}
 930
 931	rc = -EIO;
 932	if (generic->error_block_length <
 933	    sizeof(struct acpi_hest_generic_status)) {
 934		pr_warning(FW_BUG GHES_PFX "Invalid error block length: %u for generic hardware error source: %d\n",
 935			   generic->error_block_length,
 936			   generic->header.source_id);
 937		goto err;
 938	}
 939	ghes = ghes_new(generic);
 940	if (IS_ERR(ghes)) {
 941		rc = PTR_ERR(ghes);
 942		ghes = NULL;
 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		if (acpi_gsi_to_irq(generic->notify.vector, &ghes->irq)) {
 955			pr_err(GHES_PFX "Failed to map GSI to IRQ for generic hardware error source: %d\n",
 956			       generic->header.source_id);
 957			goto err;
 958		}
 959		if (request_irq(ghes->irq, ghes_irq_func,
 960				0, "GHES IRQ", ghes)) {
 961			pr_err(GHES_PFX "Failed to register IRQ for generic hardware error source: %d\n",
 962			       generic->header.source_id);
 963			goto err;
 964		}
 965		break;
 966	case ACPI_HEST_NOTIFY_SCI:
 967		mutex_lock(&ghes_list_mutex);
 968		if (list_empty(&ghes_sci))
 969			register_acpi_hed_notifier(&ghes_notifier_sci);
 970		list_add_rcu(&ghes->list, &ghes_sci);
 971		mutex_unlock(&ghes_list_mutex);
 972		break;
 973	case ACPI_HEST_NOTIFY_NMI:
 974		len = ghes_esource_prealloc_size(generic);
 975		ghes_estatus_pool_expand(len);
 976		mutex_lock(&ghes_list_mutex);
 977		if (list_empty(&ghes_nmi))
 978			register_nmi_handler(NMI_LOCAL, ghes_notify_nmi, 0,
 979						"ghes");
 980		list_add_rcu(&ghes->list, &ghes_nmi);
 981		mutex_unlock(&ghes_list_mutex);
 982		break;
 983	default:
 984		BUG();
 985	}
 986	platform_set_drvdata(ghes_dev, ghes);
 987
 988	return 0;
 989err:
 990	if (ghes) {
 991		ghes_fini(ghes);
 992		kfree(ghes);
 993	}
 994	return rc;
 995}
 996
 997static int __devexit ghes_remove(struct platform_device *ghes_dev)
 998{
 999	struct ghes *ghes;
1000	struct acpi_hest_generic *generic;
1001	unsigned long len;
1002
1003	ghes = platform_get_drvdata(ghes_dev);
1004	generic = ghes->generic;
1005
1006	ghes->flags |= GHES_EXITING;
1007	switch (generic->notify.type) {
1008	case ACPI_HEST_NOTIFY_POLLED:
1009		del_timer_sync(&ghes->timer);
1010		break;
1011	case ACPI_HEST_NOTIFY_EXTERNAL:
1012		free_irq(ghes->irq, ghes);
1013		break;
1014	case ACPI_HEST_NOTIFY_SCI:
1015		mutex_lock(&ghes_list_mutex);
1016		list_del_rcu(&ghes->list);
1017		if (list_empty(&ghes_sci))
1018			unregister_acpi_hed_notifier(&ghes_notifier_sci);
1019		mutex_unlock(&ghes_list_mutex);
1020		break;
1021	case ACPI_HEST_NOTIFY_NMI:
1022		mutex_lock(&ghes_list_mutex);
1023		list_del_rcu(&ghes->list);
1024		if (list_empty(&ghes_nmi))
1025			unregister_nmi_handler(NMI_LOCAL, "ghes");
1026		mutex_unlock(&ghes_list_mutex);
1027		/*
1028		 * To synchronize with NMI handler, ghes can only be
1029		 * freed after NMI handler finishes.
1030		 */
1031		synchronize_rcu();
1032		len = ghes_esource_prealloc_size(generic);
1033		ghes_estatus_pool_shrink(len);
1034		break;
1035	default:
1036		BUG();
1037		break;
1038	}
1039
1040	ghes_fini(ghes);
1041	kfree(ghes);
1042
1043	platform_set_drvdata(ghes_dev, NULL);
1044
1045	return 0;
1046}
1047
1048static struct platform_driver ghes_platform_driver = {
1049	.driver		= {
1050		.name	= "GHES",
1051		.owner	= THIS_MODULE,
1052	},
1053	.probe		= ghes_probe,
1054	.remove		= ghes_remove,
1055};
1056
1057static int __init ghes_init(void)
1058{
1059	int rc;
1060
1061	if (acpi_disabled)
1062		return -ENODEV;
1063
1064	if (hest_disable) {
1065		pr_info(GHES_PFX "HEST is not enabled!\n");
1066		return -EINVAL;
1067	}
1068
1069	if (ghes_disable) {
1070		pr_info(GHES_PFX "GHES is not enabled!\n");
1071		return -EINVAL;
1072	}
1073
1074	init_irq_work(&ghes_proc_irq_work, ghes_proc_in_irq);
1075
1076	rc = ghes_ioremap_init();
1077	if (rc)
1078		goto err;
1079
1080	rc = ghes_estatus_pool_init();
1081	if (rc)
1082		goto err_ioremap_exit;
1083
1084	rc = ghes_estatus_pool_expand(GHES_ESTATUS_CACHE_AVG_SIZE *
1085				      GHES_ESTATUS_CACHE_ALLOCED_MAX);
1086	if (rc)
1087		goto err_pool_exit;
1088
1089	rc = platform_driver_register(&ghes_platform_driver);
1090	if (rc)
1091		goto err_pool_exit;
1092
1093	rc = apei_osc_setup();
1094	if (rc == 0 && osc_sb_apei_support_acked)
1095		pr_info(GHES_PFX "APEI firmware first mode is enabled by APEI bit and WHEA _OSC.\n");
1096	else if (rc == 0 && !osc_sb_apei_support_acked)
1097		pr_info(GHES_PFX "APEI firmware first mode is enabled by WHEA _OSC.\n");
1098	else if (rc && osc_sb_apei_support_acked)
1099		pr_info(GHES_PFX "APEI firmware first mode is enabled by APEI bit.\n");
1100	else
1101		pr_info(GHES_PFX "Failed to enable APEI firmware first mode.\n");
1102
1103	return 0;
1104err_pool_exit:
1105	ghes_estatus_pool_exit();
1106err_ioremap_exit:
1107	ghes_ioremap_exit();
1108err:
1109	return rc;
1110}
1111
1112static void __exit ghes_exit(void)
1113{
1114	platform_driver_unregister(&ghes_platform_driver);
1115	ghes_estatus_pool_exit();
1116	ghes_ioremap_exit();
1117}
1118
1119module_init(ghes_init);
1120module_exit(ghes_exit);
1121
1122MODULE_AUTHOR("Huang Ying");
1123MODULE_DESCRIPTION("APEI Generic Hardware Error Source support");
1124MODULE_LICENSE("GPL");
1125MODULE_ALIAS("platform:GHES");
v3.1
   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
  95struct 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
 107struct ghes_estatus_node {
 108	struct llist_node llnode;
 109	struct acpi_hest_generic *generic;
 110};
 111
 112struct 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
 120int ghes_disable;
 121module_param_named(disable, ghes_disable, bool, 0);
 122
 123static 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 */
 133static LIST_HEAD(ghes_sci);
 134static LIST_HEAD(ghes_nmi);
 135static 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 */
 141static 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 */
 159static 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 */
 164static DEFINE_RAW_SPINLOCK(ghes_ioremap_lock_nmi);
 165static 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 */
 175static struct gen_pool *ghes_estatus_pool;
 176static unsigned long ghes_estatus_pool_size_request;
 177static struct llist_head ghes_estatus_llist;
 178static struct irq_work ghes_proc_irq_work;
 179
 180struct ghes_estatus_cache *ghes_estatus_caches[GHES_ESTATUS_CACHES_SIZE];
 181static atomic_t ghes_estatus_cache_alloced;
 182
 183static 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
 195static void ghes_ioremap_exit(void)
 196{
 197	free_vm_area(ghes_ioremap_area);
 198}
 199
 200static 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
 211static 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
 222static 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
 232static 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
 242static 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
 250static 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
 257static 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
 264static 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
 286static void ghes_estatus_pool_shrink(unsigned long len)
 287{
 288	ghes_estatus_pool_size_request -= PAGE_ALIGN(len);
 289}
 290
 291static 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
 320err_unmap:
 321	acpi_post_unmap_gar(&generic->error_status_address);
 322err_free:
 323	kfree(ghes);
 324	return ERR_PTR(rc);
 325}
 326
 327static void ghes_fini(struct ghes *ghes)
 328{
 329	kfree(ghes->estatus);
 330	acpi_post_unmap_gar(&ghes->generic->error_status_address);
 331}
 332
 333enum {
 334	GHES_SEV_NO = 0x0,
 335	GHES_SEV_CORRECTED = 0x1,
 336	GHES_SEV_RECOVERABLE = 0x2,
 337	GHES_SEV_PANIC = 0x3,
 338};
 339
 340static 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
 357static 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
 394static 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
 435err_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
 442static 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
 452static 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
 481static 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
 497static 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 */
 521static 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
 550static 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
 580static 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
 590static 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
 598static 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
 644static 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);
 656out:
 657	ghes_clear_estatus(ghes);
 658	return 0;
 659}
 660
 661static 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
 676static 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
 685static 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
 697static 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
 
 
 
 
 
 
 
 
 
 
 
 
 
 
 713static 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
 752static 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		}
 811next:
 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
 819out:
 820	raw_spin_unlock(&ghes_nmi_lock);
 821	return ret;
 822}
 823
 824static struct notifier_block ghes_notifier_sci = {
 825	.notifier_call = ghes_notify_sci,
 826};
 827
 828static struct notifier_block ghes_notifier_nmi = {
 829	.notifier_call = ghes_notify_nmi,
 830};
 831
 832static 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
 847static 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;
 931err:
 932	if (ghes) {
 933		ghes_fini(ghes);
 934		kfree(ghes);
 935	}
 936	return rc;
 937}
 938
 939static 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
 990static 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
 999static 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;
1046err_pool_exit:
1047	ghes_estatus_pool_exit();
1048err_ioremap_exit:
1049	ghes_ioremap_exit();
1050err:
1051	return rc;
1052}
1053
1054static void __exit ghes_exit(void)
1055{
1056	platform_driver_unregister(&ghes_platform_driver);
1057	ghes_estatus_pool_exit();
1058	ghes_ioremap_exit();
1059}
1060
1061module_init(ghes_init);
1062module_exit(ghes_exit);
1063
1064MODULE_AUTHOR("Huang Ying");
1065MODULE_DESCRIPTION("APEI Generic Hardware Error Source support");
1066MODULE_LICENSE("GPL");
1067MODULE_ALIAS("platform:GHES");