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v3.1
   1/*
   2 * APEI Error Record Serialization Table support
   3 *
   4 * ERST is a way provided by APEI to save and retrieve hardware error
   5 * information to and from a persistent store.
   6 *
   7 * For more information about ERST, please refer to ACPI Specification
   8 * version 4.0, section 17.4.
   9 *
  10 * Copyright 2010 Intel Corp.
  11 *   Author: Huang Ying <ying.huang@intel.com>
  12 *
  13 * This program is free software; you can redistribute it and/or
  14 * modify it under the terms of the GNU General Public License version
  15 * 2 as published by the Free Software Foundation.
  16 *
  17 * This program is distributed in the hope that it will be useful,
  18 * but WITHOUT ANY WARRANTY; without even the implied warranty of
  19 * MERCHANTABILITY or FITNESS FOR A PARTICULAR PURPOSE.  See the
  20 * GNU General Public License for more details.
  21 *
  22 * You should have received a copy of the GNU General Public License
  23 * along with this program; if not, write to the Free Software
  24 * Foundation, Inc., 59 Temple Place, Suite 330, Boston, MA  02111-1307  USA
  25 */
  26
  27#include <linux/kernel.h>
  28#include <linux/module.h>
  29#include <linux/init.h>
  30#include <linux/delay.h>
  31#include <linux/io.h>
  32#include <linux/acpi.h>
  33#include <linux/uaccess.h>
  34#include <linux/cper.h>
  35#include <linux/nmi.h>
  36#include <linux/hardirq.h>
  37#include <linux/pstore.h>
  38#include <acpi/apei.h>
  39
  40#include "apei-internal.h"
  41
  42#define ERST_PFX "ERST: "
 
  43
  44/* ERST command status */
  45#define ERST_STATUS_SUCCESS			0x0
  46#define ERST_STATUS_NOT_ENOUGH_SPACE		0x1
  47#define ERST_STATUS_HARDWARE_NOT_AVAILABLE	0x2
  48#define ERST_STATUS_FAILED			0x3
  49#define ERST_STATUS_RECORD_STORE_EMPTY		0x4
  50#define ERST_STATUS_RECORD_NOT_FOUND		0x5
  51
  52#define ERST_TAB_ENTRY(tab)						\
  53	((struct acpi_whea_header *)((char *)(tab) +			\
  54				     sizeof(struct acpi_table_erst)))
  55
  56#define SPIN_UNIT		100			/* 100ns */
  57/* Firmware should respond within 1 milliseconds */
  58#define FIRMWARE_TIMEOUT	(1 * NSEC_PER_MSEC)
  59#define FIRMWARE_MAX_STALL	50			/* 50us */
  60
  61int erst_disable;
  62EXPORT_SYMBOL_GPL(erst_disable);
  63
  64static struct acpi_table_erst *erst_tab;
  65
  66/* ERST Error Log Address Range atrributes */
  67#define ERST_RANGE_RESERVED	0x0001
  68#define ERST_RANGE_NVRAM	0x0002
  69#define ERST_RANGE_SLOW		0x0004
  70
  71/*
  72 * ERST Error Log Address Range, used as buffer for reading/writing
  73 * error records.
  74 */
  75static struct erst_erange {
  76	u64 base;
  77	u64 size;
  78	void __iomem *vaddr;
  79	u32 attr;
  80} erst_erange;
  81
  82/*
  83 * Prevent ERST interpreter to run simultaneously, because the
  84 * corresponding firmware implementation may not work properly when
  85 * invoked simultaneously.
  86 *
  87 * It is used to provide exclusive accessing for ERST Error Log
  88 * Address Range too.
  89 */
  90static DEFINE_RAW_SPINLOCK(erst_lock);
  91
  92static inline int erst_errno(int command_status)
  93{
  94	switch (command_status) {
  95	case ERST_STATUS_SUCCESS:
  96		return 0;
  97	case ERST_STATUS_HARDWARE_NOT_AVAILABLE:
  98		return -ENODEV;
  99	case ERST_STATUS_NOT_ENOUGH_SPACE:
 100		return -ENOSPC;
 101	case ERST_STATUS_RECORD_STORE_EMPTY:
 102	case ERST_STATUS_RECORD_NOT_FOUND:
 103		return -ENOENT;
 104	default:
 105		return -EINVAL;
 106	}
 107}
 108
 109static int erst_timedout(u64 *t, u64 spin_unit)
 110{
 111	if ((s64)*t < spin_unit) {
 112		pr_warning(FW_WARN ERST_PFX
 113			   "Firmware does not respond in time\n");
 114		return 1;
 115	}
 116	*t -= spin_unit;
 117	ndelay(spin_unit);
 118	touch_nmi_watchdog();
 119	return 0;
 120}
 121
 122static int erst_exec_load_var1(struct apei_exec_context *ctx,
 123			       struct acpi_whea_header *entry)
 124{
 125	return __apei_exec_read_register(entry, &ctx->var1);
 126}
 127
 128static int erst_exec_load_var2(struct apei_exec_context *ctx,
 129			       struct acpi_whea_header *entry)
 130{
 131	return __apei_exec_read_register(entry, &ctx->var2);
 132}
 133
 134static int erst_exec_store_var1(struct apei_exec_context *ctx,
 135				struct acpi_whea_header *entry)
 136{
 137	return __apei_exec_write_register(entry, ctx->var1);
 138}
 139
 140static int erst_exec_add(struct apei_exec_context *ctx,
 141			 struct acpi_whea_header *entry)
 142{
 143	ctx->var1 += ctx->var2;
 144	return 0;
 145}
 146
 147static int erst_exec_subtract(struct apei_exec_context *ctx,
 148			      struct acpi_whea_header *entry)
 149{
 150	ctx->var1 -= ctx->var2;
 151	return 0;
 152}
 153
 154static int erst_exec_add_value(struct apei_exec_context *ctx,
 155			       struct acpi_whea_header *entry)
 156{
 157	int rc;
 158	u64 val;
 159
 160	rc = __apei_exec_read_register(entry, &val);
 161	if (rc)
 162		return rc;
 163	val += ctx->value;
 164	rc = __apei_exec_write_register(entry, val);
 165	return rc;
 166}
 167
 168static int erst_exec_subtract_value(struct apei_exec_context *ctx,
 169				    struct acpi_whea_header *entry)
 170{
 171	int rc;
 172	u64 val;
 173
 174	rc = __apei_exec_read_register(entry, &val);
 175	if (rc)
 176		return rc;
 177	val -= ctx->value;
 178	rc = __apei_exec_write_register(entry, val);
 179	return rc;
 180}
 181
 182static int erst_exec_stall(struct apei_exec_context *ctx,
 183			   struct acpi_whea_header *entry)
 184{
 185	u64 stall_time;
 186
 187	if (ctx->value > FIRMWARE_MAX_STALL) {
 188		if (!in_nmi())
 189			pr_warning(FW_WARN ERST_PFX
 190			"Too long stall time for stall instruction: %llx.\n",
 191				   ctx->value);
 192		stall_time = FIRMWARE_MAX_STALL;
 193	} else
 194		stall_time = ctx->value;
 195	udelay(stall_time);
 196	return 0;
 197}
 198
 199static int erst_exec_stall_while_true(struct apei_exec_context *ctx,
 200				      struct acpi_whea_header *entry)
 201{
 202	int rc;
 203	u64 val;
 204	u64 timeout = FIRMWARE_TIMEOUT;
 205	u64 stall_time;
 206
 207	if (ctx->var1 > FIRMWARE_MAX_STALL) {
 208		if (!in_nmi())
 209			pr_warning(FW_WARN ERST_PFX
 210		"Too long stall time for stall while true instruction: %llx.\n",
 211				   ctx->var1);
 212		stall_time = FIRMWARE_MAX_STALL;
 213	} else
 214		stall_time = ctx->var1;
 215
 216	for (;;) {
 217		rc = __apei_exec_read_register(entry, &val);
 218		if (rc)
 219			return rc;
 220		if (val != ctx->value)
 221			break;
 222		if (erst_timedout(&timeout, stall_time * NSEC_PER_USEC))
 223			return -EIO;
 224	}
 225	return 0;
 226}
 227
 228static int erst_exec_skip_next_instruction_if_true(
 229	struct apei_exec_context *ctx,
 230	struct acpi_whea_header *entry)
 231{
 232	int rc;
 233	u64 val;
 234
 235	rc = __apei_exec_read_register(entry, &val);
 236	if (rc)
 237		return rc;
 238	if (val == ctx->value) {
 239		ctx->ip += 2;
 240		return APEI_EXEC_SET_IP;
 241	}
 242
 243	return 0;
 244}
 245
 246static int erst_exec_goto(struct apei_exec_context *ctx,
 247			  struct acpi_whea_header *entry)
 248{
 249	ctx->ip = ctx->value;
 250	return APEI_EXEC_SET_IP;
 251}
 252
 253static int erst_exec_set_src_address_base(struct apei_exec_context *ctx,
 254					  struct acpi_whea_header *entry)
 255{
 256	return __apei_exec_read_register(entry, &ctx->src_base);
 257}
 258
 259static int erst_exec_set_dst_address_base(struct apei_exec_context *ctx,
 260					  struct acpi_whea_header *entry)
 261{
 262	return __apei_exec_read_register(entry, &ctx->dst_base);
 263}
 264
 265static int erst_exec_move_data(struct apei_exec_context *ctx,
 266			       struct acpi_whea_header *entry)
 267{
 268	int rc;
 269	u64 offset;
 270	void *src, *dst;
 271
 272	/* ioremap does not work in interrupt context */
 273	if (in_interrupt()) {
 274		pr_warning(ERST_PFX
 275			   "MOVE_DATA can not be used in interrupt context");
 276		return -EBUSY;
 277	}
 278
 279	rc = __apei_exec_read_register(entry, &offset);
 280	if (rc)
 281		return rc;
 282
 283	src = ioremap(ctx->src_base + offset, ctx->var2);
 284	if (!src)
 285		return -ENOMEM;
 286	dst = ioremap(ctx->dst_base + offset, ctx->var2);
 287	if (!dst)
 
 288		return -ENOMEM;
 
 289
 290	memmove(dst, src, ctx->var2);
 291
 292	iounmap(src);
 293	iounmap(dst);
 294
 295	return 0;
 296}
 297
 298static struct apei_exec_ins_type erst_ins_type[] = {
 299	[ACPI_ERST_READ_REGISTER] = {
 300		.flags = APEI_EXEC_INS_ACCESS_REGISTER,
 301		.run = apei_exec_read_register,
 302	},
 303	[ACPI_ERST_READ_REGISTER_VALUE] = {
 304		.flags = APEI_EXEC_INS_ACCESS_REGISTER,
 305		.run = apei_exec_read_register_value,
 306	},
 307	[ACPI_ERST_WRITE_REGISTER] = {
 308		.flags = APEI_EXEC_INS_ACCESS_REGISTER,
 309		.run = apei_exec_write_register,
 310	},
 311	[ACPI_ERST_WRITE_REGISTER_VALUE] = {
 312		.flags = APEI_EXEC_INS_ACCESS_REGISTER,
 313		.run = apei_exec_write_register_value,
 314	},
 315	[ACPI_ERST_NOOP] = {
 316		.flags = 0,
 317		.run = apei_exec_noop,
 318	},
 319	[ACPI_ERST_LOAD_VAR1] = {
 320		.flags = APEI_EXEC_INS_ACCESS_REGISTER,
 321		.run = erst_exec_load_var1,
 322	},
 323	[ACPI_ERST_LOAD_VAR2] = {
 324		.flags = APEI_EXEC_INS_ACCESS_REGISTER,
 325		.run = erst_exec_load_var2,
 326	},
 327	[ACPI_ERST_STORE_VAR1] = {
 328		.flags = APEI_EXEC_INS_ACCESS_REGISTER,
 329		.run = erst_exec_store_var1,
 330	},
 331	[ACPI_ERST_ADD] = {
 332		.flags = 0,
 333		.run = erst_exec_add,
 334	},
 335	[ACPI_ERST_SUBTRACT] = {
 336		.flags = 0,
 337		.run = erst_exec_subtract,
 338	},
 339	[ACPI_ERST_ADD_VALUE] = {
 340		.flags = APEI_EXEC_INS_ACCESS_REGISTER,
 341		.run = erst_exec_add_value,
 342	},
 343	[ACPI_ERST_SUBTRACT_VALUE] = {
 344		.flags = APEI_EXEC_INS_ACCESS_REGISTER,
 345		.run = erst_exec_subtract_value,
 346	},
 347	[ACPI_ERST_STALL] = {
 348		.flags = 0,
 349		.run = erst_exec_stall,
 350	},
 351	[ACPI_ERST_STALL_WHILE_TRUE] = {
 352		.flags = APEI_EXEC_INS_ACCESS_REGISTER,
 353		.run = erst_exec_stall_while_true,
 354	},
 355	[ACPI_ERST_SKIP_NEXT_IF_TRUE] = {
 356		.flags = APEI_EXEC_INS_ACCESS_REGISTER,
 357		.run = erst_exec_skip_next_instruction_if_true,
 358	},
 359	[ACPI_ERST_GOTO] = {
 360		.flags = 0,
 361		.run = erst_exec_goto,
 362	},
 363	[ACPI_ERST_SET_SRC_ADDRESS_BASE] = {
 364		.flags = APEI_EXEC_INS_ACCESS_REGISTER,
 365		.run = erst_exec_set_src_address_base,
 366	},
 367	[ACPI_ERST_SET_DST_ADDRESS_BASE] = {
 368		.flags = APEI_EXEC_INS_ACCESS_REGISTER,
 369		.run = erst_exec_set_dst_address_base,
 370	},
 371	[ACPI_ERST_MOVE_DATA] = {
 372		.flags = APEI_EXEC_INS_ACCESS_REGISTER,
 373		.run = erst_exec_move_data,
 374	},
 375};
 376
 377static inline void erst_exec_ctx_init(struct apei_exec_context *ctx)
 378{
 379	apei_exec_ctx_init(ctx, erst_ins_type, ARRAY_SIZE(erst_ins_type),
 380			   ERST_TAB_ENTRY(erst_tab), erst_tab->entries);
 381}
 382
 383static int erst_get_erange(struct erst_erange *range)
 384{
 385	struct apei_exec_context ctx;
 386	int rc;
 387
 388	erst_exec_ctx_init(&ctx);
 389	rc = apei_exec_run(&ctx, ACPI_ERST_GET_ERROR_RANGE);
 390	if (rc)
 391		return rc;
 392	range->base = apei_exec_ctx_get_output(&ctx);
 393	rc = apei_exec_run(&ctx, ACPI_ERST_GET_ERROR_LENGTH);
 394	if (rc)
 395		return rc;
 396	range->size = apei_exec_ctx_get_output(&ctx);
 397	rc = apei_exec_run(&ctx, ACPI_ERST_GET_ERROR_ATTRIBUTES);
 398	if (rc)
 399		return rc;
 400	range->attr = apei_exec_ctx_get_output(&ctx);
 401
 402	return 0;
 403}
 404
 405static ssize_t __erst_get_record_count(void)
 406{
 407	struct apei_exec_context ctx;
 408	int rc;
 409
 410	erst_exec_ctx_init(&ctx);
 411	rc = apei_exec_run(&ctx, ACPI_ERST_GET_RECORD_COUNT);
 412	if (rc)
 413		return rc;
 414	return apei_exec_ctx_get_output(&ctx);
 415}
 416
 417ssize_t erst_get_record_count(void)
 418{
 419	ssize_t count;
 420	unsigned long flags;
 421
 422	if (erst_disable)
 423		return -ENODEV;
 424
 425	raw_spin_lock_irqsave(&erst_lock, flags);
 426	count = __erst_get_record_count();
 427	raw_spin_unlock_irqrestore(&erst_lock, flags);
 428
 429	return count;
 430}
 431EXPORT_SYMBOL_GPL(erst_get_record_count);
 432
 433#define ERST_RECORD_ID_CACHE_SIZE_MIN	16
 434#define ERST_RECORD_ID_CACHE_SIZE_MAX	1024
 435
 436struct erst_record_id_cache {
 437	struct mutex lock;
 438	u64 *entries;
 439	int len;
 440	int size;
 441	int refcount;
 442};
 443
 444static struct erst_record_id_cache erst_record_id_cache = {
 445	.lock = __MUTEX_INITIALIZER(erst_record_id_cache.lock),
 446	.refcount = 0,
 447};
 448
 449static int __erst_get_next_record_id(u64 *record_id)
 450{
 451	struct apei_exec_context ctx;
 452	int rc;
 453
 454	erst_exec_ctx_init(&ctx);
 455	rc = apei_exec_run(&ctx, ACPI_ERST_GET_RECORD_ID);
 456	if (rc)
 457		return rc;
 458	*record_id = apei_exec_ctx_get_output(&ctx);
 459
 460	return 0;
 461}
 462
 463int erst_get_record_id_begin(int *pos)
 464{
 465	int rc;
 466
 467	if (erst_disable)
 468		return -ENODEV;
 469
 470	rc = mutex_lock_interruptible(&erst_record_id_cache.lock);
 471	if (rc)
 472		return rc;
 473	erst_record_id_cache.refcount++;
 474	mutex_unlock(&erst_record_id_cache.lock);
 475
 476	*pos = 0;
 477
 478	return 0;
 479}
 480EXPORT_SYMBOL_GPL(erst_get_record_id_begin);
 481
 482/* erst_record_id_cache.lock must be held by caller */
 483static int __erst_record_id_cache_add_one(void)
 484{
 485	u64 id, prev_id, first_id;
 486	int i, rc;
 487	u64 *entries;
 488	unsigned long flags;
 489
 490	id = prev_id = first_id = APEI_ERST_INVALID_RECORD_ID;
 491retry:
 492	raw_spin_lock_irqsave(&erst_lock, flags);
 493	rc = __erst_get_next_record_id(&id);
 494	raw_spin_unlock_irqrestore(&erst_lock, flags);
 495	if (rc == -ENOENT)
 496		return 0;
 497	if (rc)
 498		return rc;
 499	if (id == APEI_ERST_INVALID_RECORD_ID)
 500		return 0;
 501	/* can not skip current ID, or loop back to first ID */
 502	if (id == prev_id || id == first_id)
 503		return 0;
 504	if (first_id == APEI_ERST_INVALID_RECORD_ID)
 505		first_id = id;
 506	prev_id = id;
 507
 508	entries = erst_record_id_cache.entries;
 509	for (i = 0; i < erst_record_id_cache.len; i++) {
 510		if (entries[i] == id)
 511			break;
 512	}
 513	/* record id already in cache, try next */
 514	if (i < erst_record_id_cache.len)
 515		goto retry;
 516	if (erst_record_id_cache.len >= erst_record_id_cache.size) {
 517		int new_size, alloc_size;
 518		u64 *new_entries;
 519
 520		new_size = erst_record_id_cache.size * 2;
 521		new_size = clamp_val(new_size, ERST_RECORD_ID_CACHE_SIZE_MIN,
 522				     ERST_RECORD_ID_CACHE_SIZE_MAX);
 523		if (new_size <= erst_record_id_cache.size) {
 524			if (printk_ratelimit())
 525				pr_warning(FW_WARN ERST_PFX
 526					   "too many record ID!\n");
 527			return 0;
 528		}
 529		alloc_size = new_size * sizeof(entries[0]);
 530		if (alloc_size < PAGE_SIZE)
 531			new_entries = kmalloc(alloc_size, GFP_KERNEL);
 532		else
 533			new_entries = vmalloc(alloc_size);
 534		if (!new_entries)
 535			return -ENOMEM;
 536		memcpy(new_entries, entries,
 537		       erst_record_id_cache.len * sizeof(entries[0]));
 538		if (erst_record_id_cache.size < PAGE_SIZE)
 539			kfree(entries);
 540		else
 541			vfree(entries);
 542		erst_record_id_cache.entries = entries = new_entries;
 543		erst_record_id_cache.size = new_size;
 544	}
 545	entries[i] = id;
 546	erst_record_id_cache.len++;
 547
 548	return 1;
 549}
 550
 551/*
 552 * Get the record ID of an existing error record on the persistent
 553 * storage. If there is no error record on the persistent storage, the
 554 * returned record_id is APEI_ERST_INVALID_RECORD_ID.
 555 */
 556int erst_get_record_id_next(int *pos, u64 *record_id)
 557{
 558	int rc = 0;
 559	u64 *entries;
 560
 561	if (erst_disable)
 562		return -ENODEV;
 563
 564	/* must be enclosed by erst_get_record_id_begin/end */
 565	BUG_ON(!erst_record_id_cache.refcount);
 566	BUG_ON(*pos < 0 || *pos > erst_record_id_cache.len);
 567
 568	mutex_lock(&erst_record_id_cache.lock);
 569	entries = erst_record_id_cache.entries;
 570	for (; *pos < erst_record_id_cache.len; (*pos)++)
 571		if (entries[*pos] != APEI_ERST_INVALID_RECORD_ID)
 572			break;
 573	/* found next record id in cache */
 574	if (*pos < erst_record_id_cache.len) {
 575		*record_id = entries[*pos];
 576		(*pos)++;
 577		goto out_unlock;
 578	}
 579
 580	/* Try to add one more record ID to cache */
 581	rc = __erst_record_id_cache_add_one();
 582	if (rc < 0)
 583		goto out_unlock;
 584	/* successfully add one new ID */
 585	if (rc == 1) {
 586		*record_id = erst_record_id_cache.entries[*pos];
 587		(*pos)++;
 588		rc = 0;
 589	} else {
 590		*pos = -1;
 591		*record_id = APEI_ERST_INVALID_RECORD_ID;
 592	}
 593out_unlock:
 594	mutex_unlock(&erst_record_id_cache.lock);
 595
 596	return rc;
 597}
 598EXPORT_SYMBOL_GPL(erst_get_record_id_next);
 599
 600/* erst_record_id_cache.lock must be held by caller */
 601static void __erst_record_id_cache_compact(void)
 602{
 603	int i, wpos = 0;
 604	u64 *entries;
 605
 606	if (erst_record_id_cache.refcount)
 607		return;
 608
 609	entries = erst_record_id_cache.entries;
 610	for (i = 0; i < erst_record_id_cache.len; i++) {
 611		if (entries[i] == APEI_ERST_INVALID_RECORD_ID)
 612			continue;
 613		if (wpos != i)
 614			memcpy(&entries[wpos], &entries[i], sizeof(entries[i]));
 615		wpos++;
 616	}
 617	erst_record_id_cache.len = wpos;
 618}
 619
 620void erst_get_record_id_end(void)
 621{
 622	/*
 623	 * erst_disable != 0 should be detected by invoker via the
 624	 * return value of erst_get_record_id_begin/next, so this
 625	 * function should not be called for erst_disable != 0.
 626	 */
 627	BUG_ON(erst_disable);
 628
 629	mutex_lock(&erst_record_id_cache.lock);
 630	erst_record_id_cache.refcount--;
 631	BUG_ON(erst_record_id_cache.refcount < 0);
 632	__erst_record_id_cache_compact();
 633	mutex_unlock(&erst_record_id_cache.lock);
 634}
 635EXPORT_SYMBOL_GPL(erst_get_record_id_end);
 636
 637static int __erst_write_to_storage(u64 offset)
 638{
 639	struct apei_exec_context ctx;
 640	u64 timeout = FIRMWARE_TIMEOUT;
 641	u64 val;
 642	int rc;
 643
 644	erst_exec_ctx_init(&ctx);
 645	rc = apei_exec_run_optional(&ctx, ACPI_ERST_BEGIN_WRITE);
 646	if (rc)
 647		return rc;
 648	apei_exec_ctx_set_input(&ctx, offset);
 649	rc = apei_exec_run(&ctx, ACPI_ERST_SET_RECORD_OFFSET);
 650	if (rc)
 651		return rc;
 652	rc = apei_exec_run(&ctx, ACPI_ERST_EXECUTE_OPERATION);
 653	if (rc)
 654		return rc;
 655	for (;;) {
 656		rc = apei_exec_run(&ctx, ACPI_ERST_CHECK_BUSY_STATUS);
 657		if (rc)
 658			return rc;
 659		val = apei_exec_ctx_get_output(&ctx);
 660		if (!val)
 661			break;
 662		if (erst_timedout(&timeout, SPIN_UNIT))
 663			return -EIO;
 664	}
 665	rc = apei_exec_run(&ctx, ACPI_ERST_GET_COMMAND_STATUS);
 666	if (rc)
 667		return rc;
 668	val = apei_exec_ctx_get_output(&ctx);
 669	rc = apei_exec_run_optional(&ctx, ACPI_ERST_END);
 670	if (rc)
 671		return rc;
 672
 673	return erst_errno(val);
 674}
 675
 676static int __erst_read_from_storage(u64 record_id, u64 offset)
 677{
 678	struct apei_exec_context ctx;
 679	u64 timeout = FIRMWARE_TIMEOUT;
 680	u64 val;
 681	int rc;
 682
 683	erst_exec_ctx_init(&ctx);
 684	rc = apei_exec_run_optional(&ctx, ACPI_ERST_BEGIN_READ);
 685	if (rc)
 686		return rc;
 687	apei_exec_ctx_set_input(&ctx, offset);
 688	rc = apei_exec_run(&ctx, ACPI_ERST_SET_RECORD_OFFSET);
 689	if (rc)
 690		return rc;
 691	apei_exec_ctx_set_input(&ctx, record_id);
 692	rc = apei_exec_run(&ctx, ACPI_ERST_SET_RECORD_ID);
 693	if (rc)
 694		return rc;
 695	rc = apei_exec_run(&ctx, ACPI_ERST_EXECUTE_OPERATION);
 696	if (rc)
 697		return rc;
 698	for (;;) {
 699		rc = apei_exec_run(&ctx, ACPI_ERST_CHECK_BUSY_STATUS);
 700		if (rc)
 701			return rc;
 702		val = apei_exec_ctx_get_output(&ctx);
 703		if (!val)
 704			break;
 705		if (erst_timedout(&timeout, SPIN_UNIT))
 706			return -EIO;
 707	};
 708	rc = apei_exec_run(&ctx, ACPI_ERST_GET_COMMAND_STATUS);
 709	if (rc)
 710		return rc;
 711	val = apei_exec_ctx_get_output(&ctx);
 712	rc = apei_exec_run_optional(&ctx, ACPI_ERST_END);
 713	if (rc)
 714		return rc;
 715
 716	return erst_errno(val);
 717}
 718
 719static int __erst_clear_from_storage(u64 record_id)
 720{
 721	struct apei_exec_context ctx;
 722	u64 timeout = FIRMWARE_TIMEOUT;
 723	u64 val;
 724	int rc;
 725
 726	erst_exec_ctx_init(&ctx);
 727	rc = apei_exec_run_optional(&ctx, ACPI_ERST_BEGIN_CLEAR);
 728	if (rc)
 729		return rc;
 730	apei_exec_ctx_set_input(&ctx, record_id);
 731	rc = apei_exec_run(&ctx, ACPI_ERST_SET_RECORD_ID);
 732	if (rc)
 733		return rc;
 734	rc = apei_exec_run(&ctx, ACPI_ERST_EXECUTE_OPERATION);
 735	if (rc)
 736		return rc;
 737	for (;;) {
 738		rc = apei_exec_run(&ctx, ACPI_ERST_CHECK_BUSY_STATUS);
 739		if (rc)
 740			return rc;
 741		val = apei_exec_ctx_get_output(&ctx);
 742		if (!val)
 743			break;
 744		if (erst_timedout(&timeout, SPIN_UNIT))
 745			return -EIO;
 746	}
 747	rc = apei_exec_run(&ctx, ACPI_ERST_GET_COMMAND_STATUS);
 748	if (rc)
 749		return rc;
 750	val = apei_exec_ctx_get_output(&ctx);
 751	rc = apei_exec_run_optional(&ctx, ACPI_ERST_END);
 752	if (rc)
 753		return rc;
 754
 755	return erst_errno(val);
 756}
 757
 758/* NVRAM ERST Error Log Address Range is not supported yet */
 759static void pr_unimpl_nvram(void)
 760{
 761	if (printk_ratelimit())
 762		pr_warning(ERST_PFX
 763		"NVRAM ERST Log Address Range is not implemented yet\n");
 764}
 765
 766static int __erst_write_to_nvram(const struct cper_record_header *record)
 767{
 768	/* do not print message, because printk is not safe for NMI */
 769	return -ENOSYS;
 770}
 771
 772static int __erst_read_to_erange_from_nvram(u64 record_id, u64 *offset)
 773{
 774	pr_unimpl_nvram();
 775	return -ENOSYS;
 776}
 777
 778static int __erst_clear_from_nvram(u64 record_id)
 779{
 780	pr_unimpl_nvram();
 781	return -ENOSYS;
 782}
 783
 784int erst_write(const struct cper_record_header *record)
 785{
 786	int rc;
 787	unsigned long flags;
 788	struct cper_record_header *rcd_erange;
 789
 790	if (erst_disable)
 791		return -ENODEV;
 792
 793	if (memcmp(record->signature, CPER_SIG_RECORD, CPER_SIG_SIZE))
 794		return -EINVAL;
 795
 796	if (erst_erange.attr & ERST_RANGE_NVRAM) {
 797		if (!raw_spin_trylock_irqsave(&erst_lock, flags))
 798			return -EBUSY;
 799		rc = __erst_write_to_nvram(record);
 800		raw_spin_unlock_irqrestore(&erst_lock, flags);
 801		return rc;
 802	}
 803
 804	if (record->record_length > erst_erange.size)
 805		return -EINVAL;
 806
 807	if (!raw_spin_trylock_irqsave(&erst_lock, flags))
 808		return -EBUSY;
 809	memcpy(erst_erange.vaddr, record, record->record_length);
 810	rcd_erange = erst_erange.vaddr;
 811	/* signature for serialization system */
 812	memcpy(&rcd_erange->persistence_information, "ER", 2);
 813
 814	rc = __erst_write_to_storage(0);
 815	raw_spin_unlock_irqrestore(&erst_lock, flags);
 816
 817	return rc;
 818}
 819EXPORT_SYMBOL_GPL(erst_write);
 820
 821static int __erst_read_to_erange(u64 record_id, u64 *offset)
 822{
 823	int rc;
 824
 825	if (erst_erange.attr & ERST_RANGE_NVRAM)
 826		return __erst_read_to_erange_from_nvram(
 827			record_id, offset);
 828
 829	rc = __erst_read_from_storage(record_id, 0);
 830	if (rc)
 831		return rc;
 832	*offset = 0;
 833
 834	return 0;
 835}
 836
 837static ssize_t __erst_read(u64 record_id, struct cper_record_header *record,
 838			   size_t buflen)
 839{
 840	int rc;
 841	u64 offset, len = 0;
 842	struct cper_record_header *rcd_tmp;
 843
 844	rc = __erst_read_to_erange(record_id, &offset);
 845	if (rc)
 846		return rc;
 847	rcd_tmp = erst_erange.vaddr + offset;
 848	len = rcd_tmp->record_length;
 849	if (len <= buflen)
 850		memcpy(record, rcd_tmp, len);
 851
 852	return len;
 853}
 854
 855/*
 856 * If return value > buflen, the buffer size is not big enough,
 857 * else if return value < 0, something goes wrong,
 858 * else everything is OK, and return value is record length
 859 */
 860ssize_t erst_read(u64 record_id, struct cper_record_header *record,
 861		  size_t buflen)
 862{
 863	ssize_t len;
 864	unsigned long flags;
 865
 866	if (erst_disable)
 867		return -ENODEV;
 868
 869	raw_spin_lock_irqsave(&erst_lock, flags);
 870	len = __erst_read(record_id, record, buflen);
 871	raw_spin_unlock_irqrestore(&erst_lock, flags);
 872	return len;
 873}
 874EXPORT_SYMBOL_GPL(erst_read);
 875
 876int erst_clear(u64 record_id)
 877{
 878	int rc, i;
 879	unsigned long flags;
 880	u64 *entries;
 881
 882	if (erst_disable)
 883		return -ENODEV;
 884
 885	rc = mutex_lock_interruptible(&erst_record_id_cache.lock);
 886	if (rc)
 887		return rc;
 888	raw_spin_lock_irqsave(&erst_lock, flags);
 889	if (erst_erange.attr & ERST_RANGE_NVRAM)
 890		rc = __erst_clear_from_nvram(record_id);
 891	else
 892		rc = __erst_clear_from_storage(record_id);
 893	raw_spin_unlock_irqrestore(&erst_lock, flags);
 894	if (rc)
 895		goto out;
 896	entries = erst_record_id_cache.entries;
 897	for (i = 0; i < erst_record_id_cache.len; i++) {
 898		if (entries[i] == record_id)
 899			entries[i] = APEI_ERST_INVALID_RECORD_ID;
 900	}
 901	__erst_record_id_cache_compact();
 902out:
 903	mutex_unlock(&erst_record_id_cache.lock);
 904	return rc;
 905}
 906EXPORT_SYMBOL_GPL(erst_clear);
 907
 908static int __init setup_erst_disable(char *str)
 909{
 910	erst_disable = 1;
 911	return 0;
 912}
 913
 914__setup("erst_disable", setup_erst_disable);
 915
 916static int erst_check_table(struct acpi_table_erst *erst_tab)
 917{
 918	if ((erst_tab->header_length !=
 919	     (sizeof(struct acpi_table_erst) - sizeof(erst_tab->header)))
 920	    && (erst_tab->header_length != sizeof(struct acpi_table_einj)))
 921		return -EINVAL;
 922	if (erst_tab->header.length < sizeof(struct acpi_table_erst))
 923		return -EINVAL;
 924	if (erst_tab->entries !=
 925	    (erst_tab->header.length - sizeof(struct acpi_table_erst)) /
 926	    sizeof(struct acpi_erst_entry))
 927		return -EINVAL;
 928
 929	return 0;
 930}
 931
 932static int erst_open_pstore(struct pstore_info *psi);
 933static int erst_close_pstore(struct pstore_info *psi);
 934static ssize_t erst_reader(u64 *id, enum pstore_type_id *type,
 935			   struct timespec *time, struct pstore_info *psi);
 936static u64 erst_writer(enum pstore_type_id type, unsigned int part,
 
 
 937		       size_t size, struct pstore_info *psi);
 938static int erst_clearer(enum pstore_type_id type, u64 id,
 939			struct pstore_info *psi);
 940
 941static struct pstore_info erst_info = {
 942	.owner		= THIS_MODULE,
 943	.name		= "erst",
 
 944	.open		= erst_open_pstore,
 945	.close		= erst_close_pstore,
 946	.read		= erst_reader,
 947	.write		= erst_writer,
 948	.erase		= erst_clearer
 949};
 950
 951#define CPER_CREATOR_PSTORE						\
 952	UUID_LE(0x75a574e3, 0x5052, 0x4b29, 0x8a, 0x8e, 0xbe, 0x2c,	\
 953		0x64, 0x90, 0xb8, 0x9d)
 954#define CPER_SECTION_TYPE_DMESG						\
 955	UUID_LE(0xc197e04e, 0xd545, 0x4a70, 0x9c, 0x17, 0xa5, 0x54,	\
 956		0x94, 0x19, 0xeb, 0x12)
 
 
 
 957#define CPER_SECTION_TYPE_MCE						\
 958	UUID_LE(0xfe08ffbe, 0x95e4, 0x4be7, 0xbc, 0x73, 0x40, 0x96,	\
 959		0x04, 0x4a, 0x38, 0xfc)
 960
 961struct cper_pstore_record {
 962	struct cper_record_header hdr;
 963	struct cper_section_descriptor sec_hdr;
 964	char data[];
 965} __packed;
 966
 967static int reader_pos;
 968
 969static int erst_open_pstore(struct pstore_info *psi)
 970{
 971	int rc;
 972
 973	if (erst_disable)
 974		return -ENODEV;
 975
 976	rc = erst_get_record_id_begin(&reader_pos);
 977
 978	return rc;
 979}
 980
 981static int erst_close_pstore(struct pstore_info *psi)
 982{
 983	erst_get_record_id_end();
 984
 985	return 0;
 986}
 987
 988static ssize_t erst_reader(u64 *id, enum pstore_type_id *type,
 989			   struct timespec *time, struct pstore_info *psi)
 
 990{
 991	int rc;
 992	ssize_t len = 0;
 993	u64 record_id;
 994	struct cper_pstore_record *rcd = (struct cper_pstore_record *)
 995					(erst_info.buf - sizeof(*rcd));
 996
 997	if (erst_disable)
 998		return -ENODEV;
 999
 
 
 
 
 
1000skip:
1001	rc = erst_get_record_id_next(&reader_pos, &record_id);
1002	if (rc)
1003		goto out;
1004
1005	/* no more record */
1006	if (record_id == APEI_ERST_INVALID_RECORD_ID) {
1007		rc = -1;
1008		goto out;
1009	}
1010
1011	len = erst_read(record_id, &rcd->hdr, sizeof(*rcd) +
1012			erst_info.bufsize);
1013	/* The record may be cleared by others, try read next record */
1014	if (len == -ENOENT)
1015		goto skip;
1016	else if (len < 0) {
1017		rc = -1;
1018		goto out;
1019	}
1020	if (uuid_le_cmp(rcd->hdr.creator_id, CPER_CREATOR_PSTORE) != 0)
1021		goto skip;
1022
 
 
 
 
 
 
1023	*id = record_id;
 
1024	if (uuid_le_cmp(rcd->sec_hdr.section_type,
 
 
 
 
1025			CPER_SECTION_TYPE_DMESG) == 0)
1026		*type = PSTORE_TYPE_DMESG;
1027	else if (uuid_le_cmp(rcd->sec_hdr.section_type,
1028			     CPER_SECTION_TYPE_MCE) == 0)
1029		*type = PSTORE_TYPE_MCE;
1030	else
1031		*type = PSTORE_TYPE_UNKNOWN;
1032
1033	if (rcd->hdr.validation_bits & CPER_VALID_TIMESTAMP)
1034		time->tv_sec = rcd->hdr.timestamp;
1035	else
1036		time->tv_sec = 0;
1037	time->tv_nsec = 0;
1038
1039out:
 
1040	return (rc < 0) ? rc : (len - sizeof(*rcd));
1041}
1042
1043static u64 erst_writer(enum pstore_type_id type, unsigned int part,
 
1044		       size_t size, struct pstore_info *psi)
1045{
1046	struct cper_pstore_record *rcd = (struct cper_pstore_record *)
1047					(erst_info.buf - sizeof(*rcd));
 
1048
1049	memset(rcd, 0, sizeof(*rcd));
1050	memcpy(rcd->hdr.signature, CPER_SIG_RECORD, CPER_SIG_SIZE);
1051	rcd->hdr.revision = CPER_RECORD_REV;
1052	rcd->hdr.signature_end = CPER_SIG_END;
1053	rcd->hdr.section_count = 1;
1054	rcd->hdr.error_severity = CPER_SEV_FATAL;
1055	/* timestamp valid. platform_id, partition_id are invalid */
1056	rcd->hdr.validation_bits = CPER_VALID_TIMESTAMP;
1057	rcd->hdr.timestamp = get_seconds();
1058	rcd->hdr.record_length = sizeof(*rcd) + size;
1059	rcd->hdr.creator_id = CPER_CREATOR_PSTORE;
1060	rcd->hdr.notification_type = CPER_NOTIFY_MCE;
1061	rcd->hdr.record_id = cper_next_record_id();
1062	rcd->hdr.flags = CPER_HW_ERROR_FLAGS_PREVERR;
1063
1064	rcd->sec_hdr.section_offset = sizeof(*rcd);
1065	rcd->sec_hdr.section_length = size;
1066	rcd->sec_hdr.revision = CPER_SEC_REV;
1067	/* fru_id and fru_text is invalid */
1068	rcd->sec_hdr.validation_bits = 0;
1069	rcd->sec_hdr.flags = CPER_SEC_PRIMARY;
1070	switch (type) {
1071	case PSTORE_TYPE_DMESG:
1072		rcd->sec_hdr.section_type = CPER_SECTION_TYPE_DMESG;
 
 
 
1073		break;
1074	case PSTORE_TYPE_MCE:
1075		rcd->sec_hdr.section_type = CPER_SECTION_TYPE_MCE;
1076		break;
1077	default:
1078		return -EINVAL;
1079	}
1080	rcd->sec_hdr.section_severity = CPER_SEV_FATAL;
1081
1082	erst_write(&rcd->hdr);
 
1083
1084	return rcd->hdr.record_id;
1085}
1086
1087static int erst_clearer(enum pstore_type_id type, u64 id,
1088			struct pstore_info *psi)
1089{
1090	return erst_clear(id);
1091}
1092
1093static int __init erst_init(void)
1094{
1095	int rc = 0;
1096	acpi_status status;
1097	struct apei_exec_context ctx;
1098	struct apei_resources erst_resources;
1099	struct resource *r;
1100	char *buf;
1101
1102	if (acpi_disabled)
1103		goto err;
1104
1105	if (erst_disable) {
1106		pr_info(ERST_PFX
1107	"Error Record Serialization Table (ERST) support is disabled.\n");
1108		goto err;
1109	}
1110
1111	status = acpi_get_table(ACPI_SIG_ERST, 0,
1112				(struct acpi_table_header **)&erst_tab);
1113	if (status == AE_NOT_FOUND) {
1114		pr_info(ERST_PFX "Table is not found!\n");
1115		goto err;
1116	} else if (ACPI_FAILURE(status)) {
1117		const char *msg = acpi_format_exception(status);
1118		pr_err(ERST_PFX "Failed to get table, %s\n", msg);
1119		rc = -EINVAL;
1120		goto err;
1121	}
1122
1123	rc = erst_check_table(erst_tab);
1124	if (rc) {
1125		pr_err(FW_BUG ERST_PFX "ERST table is invalid\n");
1126		goto err;
1127	}
1128
1129	apei_resources_init(&erst_resources);
1130	erst_exec_ctx_init(&ctx);
1131	rc = apei_exec_collect_resources(&ctx, &erst_resources);
1132	if (rc)
1133		goto err_fini;
1134	rc = apei_resources_request(&erst_resources, "APEI ERST");
1135	if (rc)
1136		goto err_fini;
1137	rc = apei_exec_pre_map_gars(&ctx);
1138	if (rc)
1139		goto err_release;
1140	rc = erst_get_erange(&erst_erange);
1141	if (rc) {
1142		if (rc == -ENODEV)
1143			pr_info(ERST_PFX
1144	"The corresponding hardware device or firmware implementation "
1145	"is not available.\n");
1146		else
1147			pr_err(ERST_PFX
1148			       "Failed to get Error Log Address Range.\n");
1149		goto err_unmap_reg;
1150	}
1151
1152	r = request_mem_region(erst_erange.base, erst_erange.size, "APEI ERST");
1153	if (!r) {
1154		pr_err(ERST_PFX
1155		"Can not request iomem region <0x%16llx-0x%16llx> for ERST.\n",
1156		(unsigned long long)erst_erange.base,
1157		(unsigned long long)erst_erange.base + erst_erange.size);
1158		rc = -EIO;
1159		goto err_unmap_reg;
1160	}
1161	rc = -ENOMEM;
1162	erst_erange.vaddr = ioremap_cache(erst_erange.base,
1163					  erst_erange.size);
1164	if (!erst_erange.vaddr)
1165		goto err_release_erange;
1166
 
 
 
1167	buf = kmalloc(erst_erange.size, GFP_KERNEL);
1168	mutex_init(&erst_info.buf_mutex);
1169	if (buf) {
1170		erst_info.buf = buf + sizeof(struct cper_pstore_record);
1171		erst_info.bufsize = erst_erange.size -
1172				    sizeof(struct cper_pstore_record);
1173		if (pstore_register(&erst_info)) {
1174			pr_info(ERST_PFX "Could not register with persistent store\n");
 
 
 
 
 
1175			kfree(buf);
1176		}
1177	}
1178
1179	pr_info(ERST_PFX
1180	"Error Record Serialization Table (ERST) support is initialized.\n");
1181
1182	return 0;
1183
1184err_release_erange:
1185	release_mem_region(erst_erange.base, erst_erange.size);
1186err_unmap_reg:
1187	apei_exec_post_unmap_gars(&ctx);
1188err_release:
1189	apei_resources_release(&erst_resources);
1190err_fini:
1191	apei_resources_fini(&erst_resources);
1192err:
1193	erst_disable = 1;
1194	return rc;
1195}
1196
1197device_initcall(erst_init);
v3.15
   1/*
   2 * APEI Error Record Serialization Table support
   3 *
   4 * ERST is a way provided by APEI to save and retrieve hardware error
   5 * information to and from a persistent store.
   6 *
   7 * For more information about ERST, please refer to ACPI Specification
   8 * version 4.0, section 17.4.
   9 *
  10 * Copyright 2010 Intel Corp.
  11 *   Author: Huang Ying <ying.huang@intel.com>
  12 *
  13 * This program is free software; you can redistribute it and/or
  14 * modify it under the terms of the GNU General Public License version
  15 * 2 as published by the Free Software Foundation.
  16 *
  17 * This program is distributed in the hope that it will be useful,
  18 * but WITHOUT ANY WARRANTY; without even the implied warranty of
  19 * MERCHANTABILITY or FITNESS FOR A PARTICULAR PURPOSE.  See the
  20 * GNU General Public License for more details.
  21 *
  22 * You should have received a copy of the GNU General Public License
  23 * along with this program; if not, write to the Free Software
  24 * Foundation, Inc., 59 Temple Place, Suite 330, Boston, MA  02111-1307  USA
  25 */
  26
  27#include <linux/kernel.h>
  28#include <linux/module.h>
  29#include <linux/init.h>
  30#include <linux/delay.h>
  31#include <linux/io.h>
  32#include <linux/acpi.h>
  33#include <linux/uaccess.h>
  34#include <linux/cper.h>
  35#include <linux/nmi.h>
  36#include <linux/hardirq.h>
  37#include <linux/pstore.h>
  38#include <acpi/apei.h>
  39
  40#include "apei-internal.h"
  41
  42#undef pr_fmt
  43#define pr_fmt(fmt) "ERST: " fmt
  44
  45/* ERST command status */
  46#define ERST_STATUS_SUCCESS			0x0
  47#define ERST_STATUS_NOT_ENOUGH_SPACE		0x1
  48#define ERST_STATUS_HARDWARE_NOT_AVAILABLE	0x2
  49#define ERST_STATUS_FAILED			0x3
  50#define ERST_STATUS_RECORD_STORE_EMPTY		0x4
  51#define ERST_STATUS_RECORD_NOT_FOUND		0x5
  52
  53#define ERST_TAB_ENTRY(tab)						\
  54	((struct acpi_whea_header *)((char *)(tab) +			\
  55				     sizeof(struct acpi_table_erst)))
  56
  57#define SPIN_UNIT		100			/* 100ns */
  58/* Firmware should respond within 1 milliseconds */
  59#define FIRMWARE_TIMEOUT	(1 * NSEC_PER_MSEC)
  60#define FIRMWARE_MAX_STALL	50			/* 50us */
  61
  62int erst_disable;
  63EXPORT_SYMBOL_GPL(erst_disable);
  64
  65static struct acpi_table_erst *erst_tab;
  66
  67/* ERST Error Log Address Range atrributes */
  68#define ERST_RANGE_RESERVED	0x0001
  69#define ERST_RANGE_NVRAM	0x0002
  70#define ERST_RANGE_SLOW		0x0004
  71
  72/*
  73 * ERST Error Log Address Range, used as buffer for reading/writing
  74 * error records.
  75 */
  76static struct erst_erange {
  77	u64 base;
  78	u64 size;
  79	void __iomem *vaddr;
  80	u32 attr;
  81} erst_erange;
  82
  83/*
  84 * Prevent ERST interpreter to run simultaneously, because the
  85 * corresponding firmware implementation may not work properly when
  86 * invoked simultaneously.
  87 *
  88 * It is used to provide exclusive accessing for ERST Error Log
  89 * Address Range too.
  90 */
  91static DEFINE_RAW_SPINLOCK(erst_lock);
  92
  93static inline int erst_errno(int command_status)
  94{
  95	switch (command_status) {
  96	case ERST_STATUS_SUCCESS:
  97		return 0;
  98	case ERST_STATUS_HARDWARE_NOT_AVAILABLE:
  99		return -ENODEV;
 100	case ERST_STATUS_NOT_ENOUGH_SPACE:
 101		return -ENOSPC;
 102	case ERST_STATUS_RECORD_STORE_EMPTY:
 103	case ERST_STATUS_RECORD_NOT_FOUND:
 104		return -ENOENT;
 105	default:
 106		return -EINVAL;
 107	}
 108}
 109
 110static int erst_timedout(u64 *t, u64 spin_unit)
 111{
 112	if ((s64)*t < spin_unit) {
 113		pr_warn(FW_WARN "Firmware does not respond in time.\n");
 
 114		return 1;
 115	}
 116	*t -= spin_unit;
 117	ndelay(spin_unit);
 118	touch_nmi_watchdog();
 119	return 0;
 120}
 121
 122static int erst_exec_load_var1(struct apei_exec_context *ctx,
 123			       struct acpi_whea_header *entry)
 124{
 125	return __apei_exec_read_register(entry, &ctx->var1);
 126}
 127
 128static int erst_exec_load_var2(struct apei_exec_context *ctx,
 129			       struct acpi_whea_header *entry)
 130{
 131	return __apei_exec_read_register(entry, &ctx->var2);
 132}
 133
 134static int erst_exec_store_var1(struct apei_exec_context *ctx,
 135				struct acpi_whea_header *entry)
 136{
 137	return __apei_exec_write_register(entry, ctx->var1);
 138}
 139
 140static int erst_exec_add(struct apei_exec_context *ctx,
 141			 struct acpi_whea_header *entry)
 142{
 143	ctx->var1 += ctx->var2;
 144	return 0;
 145}
 146
 147static int erst_exec_subtract(struct apei_exec_context *ctx,
 148			      struct acpi_whea_header *entry)
 149{
 150	ctx->var1 -= ctx->var2;
 151	return 0;
 152}
 153
 154static int erst_exec_add_value(struct apei_exec_context *ctx,
 155			       struct acpi_whea_header *entry)
 156{
 157	int rc;
 158	u64 val;
 159
 160	rc = __apei_exec_read_register(entry, &val);
 161	if (rc)
 162		return rc;
 163	val += ctx->value;
 164	rc = __apei_exec_write_register(entry, val);
 165	return rc;
 166}
 167
 168static int erst_exec_subtract_value(struct apei_exec_context *ctx,
 169				    struct acpi_whea_header *entry)
 170{
 171	int rc;
 172	u64 val;
 173
 174	rc = __apei_exec_read_register(entry, &val);
 175	if (rc)
 176		return rc;
 177	val -= ctx->value;
 178	rc = __apei_exec_write_register(entry, val);
 179	return rc;
 180}
 181
 182static int erst_exec_stall(struct apei_exec_context *ctx,
 183			   struct acpi_whea_header *entry)
 184{
 185	u64 stall_time;
 186
 187	if (ctx->value > FIRMWARE_MAX_STALL) {
 188		if (!in_nmi())
 189			pr_warn(FW_WARN
 190			"Too long stall time for stall instruction: 0x%llx.\n",
 191				   ctx->value);
 192		stall_time = FIRMWARE_MAX_STALL;
 193	} else
 194		stall_time = ctx->value;
 195	udelay(stall_time);
 196	return 0;
 197}
 198
 199static int erst_exec_stall_while_true(struct apei_exec_context *ctx,
 200				      struct acpi_whea_header *entry)
 201{
 202	int rc;
 203	u64 val;
 204	u64 timeout = FIRMWARE_TIMEOUT;
 205	u64 stall_time;
 206
 207	if (ctx->var1 > FIRMWARE_MAX_STALL) {
 208		if (!in_nmi())
 209			pr_warn(FW_WARN
 210		"Too long stall time for stall while true instruction: 0x%llx.\n",
 211				   ctx->var1);
 212		stall_time = FIRMWARE_MAX_STALL;
 213	} else
 214		stall_time = ctx->var1;
 215
 216	for (;;) {
 217		rc = __apei_exec_read_register(entry, &val);
 218		if (rc)
 219			return rc;
 220		if (val != ctx->value)
 221			break;
 222		if (erst_timedout(&timeout, stall_time * NSEC_PER_USEC))
 223			return -EIO;
 224	}
 225	return 0;
 226}
 227
 228static int erst_exec_skip_next_instruction_if_true(
 229	struct apei_exec_context *ctx,
 230	struct acpi_whea_header *entry)
 231{
 232	int rc;
 233	u64 val;
 234
 235	rc = __apei_exec_read_register(entry, &val);
 236	if (rc)
 237		return rc;
 238	if (val == ctx->value) {
 239		ctx->ip += 2;
 240		return APEI_EXEC_SET_IP;
 241	}
 242
 243	return 0;
 244}
 245
 246static int erst_exec_goto(struct apei_exec_context *ctx,
 247			  struct acpi_whea_header *entry)
 248{
 249	ctx->ip = ctx->value;
 250	return APEI_EXEC_SET_IP;
 251}
 252
 253static int erst_exec_set_src_address_base(struct apei_exec_context *ctx,
 254					  struct acpi_whea_header *entry)
 255{
 256	return __apei_exec_read_register(entry, &ctx->src_base);
 257}
 258
 259static int erst_exec_set_dst_address_base(struct apei_exec_context *ctx,
 260					  struct acpi_whea_header *entry)
 261{
 262	return __apei_exec_read_register(entry, &ctx->dst_base);
 263}
 264
 265static int erst_exec_move_data(struct apei_exec_context *ctx,
 266			       struct acpi_whea_header *entry)
 267{
 268	int rc;
 269	u64 offset;
 270	void *src, *dst;
 271
 272	/* ioremap does not work in interrupt context */
 273	if (in_interrupt()) {
 274		pr_warn("MOVE_DATA can not be used in interrupt context.\n");
 
 275		return -EBUSY;
 276	}
 277
 278	rc = __apei_exec_read_register(entry, &offset);
 279	if (rc)
 280		return rc;
 281
 282	src = ioremap(ctx->src_base + offset, ctx->var2);
 283	if (!src)
 284		return -ENOMEM;
 285	dst = ioremap(ctx->dst_base + offset, ctx->var2);
 286	if (!dst) {
 287		iounmap(src);
 288		return -ENOMEM;
 289	}
 290
 291	memmove(dst, src, ctx->var2);
 292
 293	iounmap(src);
 294	iounmap(dst);
 295
 296	return 0;
 297}
 298
 299static struct apei_exec_ins_type erst_ins_type[] = {
 300	[ACPI_ERST_READ_REGISTER] = {
 301		.flags = APEI_EXEC_INS_ACCESS_REGISTER,
 302		.run = apei_exec_read_register,
 303	},
 304	[ACPI_ERST_READ_REGISTER_VALUE] = {
 305		.flags = APEI_EXEC_INS_ACCESS_REGISTER,
 306		.run = apei_exec_read_register_value,
 307	},
 308	[ACPI_ERST_WRITE_REGISTER] = {
 309		.flags = APEI_EXEC_INS_ACCESS_REGISTER,
 310		.run = apei_exec_write_register,
 311	},
 312	[ACPI_ERST_WRITE_REGISTER_VALUE] = {
 313		.flags = APEI_EXEC_INS_ACCESS_REGISTER,
 314		.run = apei_exec_write_register_value,
 315	},
 316	[ACPI_ERST_NOOP] = {
 317		.flags = 0,
 318		.run = apei_exec_noop,
 319	},
 320	[ACPI_ERST_LOAD_VAR1] = {
 321		.flags = APEI_EXEC_INS_ACCESS_REGISTER,
 322		.run = erst_exec_load_var1,
 323	},
 324	[ACPI_ERST_LOAD_VAR2] = {
 325		.flags = APEI_EXEC_INS_ACCESS_REGISTER,
 326		.run = erst_exec_load_var2,
 327	},
 328	[ACPI_ERST_STORE_VAR1] = {
 329		.flags = APEI_EXEC_INS_ACCESS_REGISTER,
 330		.run = erst_exec_store_var1,
 331	},
 332	[ACPI_ERST_ADD] = {
 333		.flags = 0,
 334		.run = erst_exec_add,
 335	},
 336	[ACPI_ERST_SUBTRACT] = {
 337		.flags = 0,
 338		.run = erst_exec_subtract,
 339	},
 340	[ACPI_ERST_ADD_VALUE] = {
 341		.flags = APEI_EXEC_INS_ACCESS_REGISTER,
 342		.run = erst_exec_add_value,
 343	},
 344	[ACPI_ERST_SUBTRACT_VALUE] = {
 345		.flags = APEI_EXEC_INS_ACCESS_REGISTER,
 346		.run = erst_exec_subtract_value,
 347	},
 348	[ACPI_ERST_STALL] = {
 349		.flags = 0,
 350		.run = erst_exec_stall,
 351	},
 352	[ACPI_ERST_STALL_WHILE_TRUE] = {
 353		.flags = APEI_EXEC_INS_ACCESS_REGISTER,
 354		.run = erst_exec_stall_while_true,
 355	},
 356	[ACPI_ERST_SKIP_NEXT_IF_TRUE] = {
 357		.flags = APEI_EXEC_INS_ACCESS_REGISTER,
 358		.run = erst_exec_skip_next_instruction_if_true,
 359	},
 360	[ACPI_ERST_GOTO] = {
 361		.flags = 0,
 362		.run = erst_exec_goto,
 363	},
 364	[ACPI_ERST_SET_SRC_ADDRESS_BASE] = {
 365		.flags = APEI_EXEC_INS_ACCESS_REGISTER,
 366		.run = erst_exec_set_src_address_base,
 367	},
 368	[ACPI_ERST_SET_DST_ADDRESS_BASE] = {
 369		.flags = APEI_EXEC_INS_ACCESS_REGISTER,
 370		.run = erst_exec_set_dst_address_base,
 371	},
 372	[ACPI_ERST_MOVE_DATA] = {
 373		.flags = APEI_EXEC_INS_ACCESS_REGISTER,
 374		.run = erst_exec_move_data,
 375	},
 376};
 377
 378static inline void erst_exec_ctx_init(struct apei_exec_context *ctx)
 379{
 380	apei_exec_ctx_init(ctx, erst_ins_type, ARRAY_SIZE(erst_ins_type),
 381			   ERST_TAB_ENTRY(erst_tab), erst_tab->entries);
 382}
 383
 384static int erst_get_erange(struct erst_erange *range)
 385{
 386	struct apei_exec_context ctx;
 387	int rc;
 388
 389	erst_exec_ctx_init(&ctx);
 390	rc = apei_exec_run(&ctx, ACPI_ERST_GET_ERROR_RANGE);
 391	if (rc)
 392		return rc;
 393	range->base = apei_exec_ctx_get_output(&ctx);
 394	rc = apei_exec_run(&ctx, ACPI_ERST_GET_ERROR_LENGTH);
 395	if (rc)
 396		return rc;
 397	range->size = apei_exec_ctx_get_output(&ctx);
 398	rc = apei_exec_run(&ctx, ACPI_ERST_GET_ERROR_ATTRIBUTES);
 399	if (rc)
 400		return rc;
 401	range->attr = apei_exec_ctx_get_output(&ctx);
 402
 403	return 0;
 404}
 405
 406static ssize_t __erst_get_record_count(void)
 407{
 408	struct apei_exec_context ctx;
 409	int rc;
 410
 411	erst_exec_ctx_init(&ctx);
 412	rc = apei_exec_run(&ctx, ACPI_ERST_GET_RECORD_COUNT);
 413	if (rc)
 414		return rc;
 415	return apei_exec_ctx_get_output(&ctx);
 416}
 417
 418ssize_t erst_get_record_count(void)
 419{
 420	ssize_t count;
 421	unsigned long flags;
 422
 423	if (erst_disable)
 424		return -ENODEV;
 425
 426	raw_spin_lock_irqsave(&erst_lock, flags);
 427	count = __erst_get_record_count();
 428	raw_spin_unlock_irqrestore(&erst_lock, flags);
 429
 430	return count;
 431}
 432EXPORT_SYMBOL_GPL(erst_get_record_count);
 433
 434#define ERST_RECORD_ID_CACHE_SIZE_MIN	16
 435#define ERST_RECORD_ID_CACHE_SIZE_MAX	1024
 436
 437struct erst_record_id_cache {
 438	struct mutex lock;
 439	u64 *entries;
 440	int len;
 441	int size;
 442	int refcount;
 443};
 444
 445static struct erst_record_id_cache erst_record_id_cache = {
 446	.lock = __MUTEX_INITIALIZER(erst_record_id_cache.lock),
 447	.refcount = 0,
 448};
 449
 450static int __erst_get_next_record_id(u64 *record_id)
 451{
 452	struct apei_exec_context ctx;
 453	int rc;
 454
 455	erst_exec_ctx_init(&ctx);
 456	rc = apei_exec_run(&ctx, ACPI_ERST_GET_RECORD_ID);
 457	if (rc)
 458		return rc;
 459	*record_id = apei_exec_ctx_get_output(&ctx);
 460
 461	return 0;
 462}
 463
 464int erst_get_record_id_begin(int *pos)
 465{
 466	int rc;
 467
 468	if (erst_disable)
 469		return -ENODEV;
 470
 471	rc = mutex_lock_interruptible(&erst_record_id_cache.lock);
 472	if (rc)
 473		return rc;
 474	erst_record_id_cache.refcount++;
 475	mutex_unlock(&erst_record_id_cache.lock);
 476
 477	*pos = 0;
 478
 479	return 0;
 480}
 481EXPORT_SYMBOL_GPL(erst_get_record_id_begin);
 482
 483/* erst_record_id_cache.lock must be held by caller */
 484static int __erst_record_id_cache_add_one(void)
 485{
 486	u64 id, prev_id, first_id;
 487	int i, rc;
 488	u64 *entries;
 489	unsigned long flags;
 490
 491	id = prev_id = first_id = APEI_ERST_INVALID_RECORD_ID;
 492retry:
 493	raw_spin_lock_irqsave(&erst_lock, flags);
 494	rc = __erst_get_next_record_id(&id);
 495	raw_spin_unlock_irqrestore(&erst_lock, flags);
 496	if (rc == -ENOENT)
 497		return 0;
 498	if (rc)
 499		return rc;
 500	if (id == APEI_ERST_INVALID_RECORD_ID)
 501		return 0;
 502	/* can not skip current ID, or loop back to first ID */
 503	if (id == prev_id || id == first_id)
 504		return 0;
 505	if (first_id == APEI_ERST_INVALID_RECORD_ID)
 506		first_id = id;
 507	prev_id = id;
 508
 509	entries = erst_record_id_cache.entries;
 510	for (i = 0; i < erst_record_id_cache.len; i++) {
 511		if (entries[i] == id)
 512			break;
 513	}
 514	/* record id already in cache, try next */
 515	if (i < erst_record_id_cache.len)
 516		goto retry;
 517	if (erst_record_id_cache.len >= erst_record_id_cache.size) {
 518		int new_size, alloc_size;
 519		u64 *new_entries;
 520
 521		new_size = erst_record_id_cache.size * 2;
 522		new_size = clamp_val(new_size, ERST_RECORD_ID_CACHE_SIZE_MIN,
 523				     ERST_RECORD_ID_CACHE_SIZE_MAX);
 524		if (new_size <= erst_record_id_cache.size) {
 525			if (printk_ratelimit())
 526				pr_warn(FW_WARN "too many record IDs!\n");
 
 527			return 0;
 528		}
 529		alloc_size = new_size * sizeof(entries[0]);
 530		if (alloc_size < PAGE_SIZE)
 531			new_entries = kmalloc(alloc_size, GFP_KERNEL);
 532		else
 533			new_entries = vmalloc(alloc_size);
 534		if (!new_entries)
 535			return -ENOMEM;
 536		memcpy(new_entries, entries,
 537		       erst_record_id_cache.len * sizeof(entries[0]));
 538		if (erst_record_id_cache.size < PAGE_SIZE)
 539			kfree(entries);
 540		else
 541			vfree(entries);
 542		erst_record_id_cache.entries = entries = new_entries;
 543		erst_record_id_cache.size = new_size;
 544	}
 545	entries[i] = id;
 546	erst_record_id_cache.len++;
 547
 548	return 1;
 549}
 550
 551/*
 552 * Get the record ID of an existing error record on the persistent
 553 * storage. If there is no error record on the persistent storage, the
 554 * returned record_id is APEI_ERST_INVALID_RECORD_ID.
 555 */
 556int erst_get_record_id_next(int *pos, u64 *record_id)
 557{
 558	int rc = 0;
 559	u64 *entries;
 560
 561	if (erst_disable)
 562		return -ENODEV;
 563
 564	/* must be enclosed by erst_get_record_id_begin/end */
 565	BUG_ON(!erst_record_id_cache.refcount);
 566	BUG_ON(*pos < 0 || *pos > erst_record_id_cache.len);
 567
 568	mutex_lock(&erst_record_id_cache.lock);
 569	entries = erst_record_id_cache.entries;
 570	for (; *pos < erst_record_id_cache.len; (*pos)++)
 571		if (entries[*pos] != APEI_ERST_INVALID_RECORD_ID)
 572			break;
 573	/* found next record id in cache */
 574	if (*pos < erst_record_id_cache.len) {
 575		*record_id = entries[*pos];
 576		(*pos)++;
 577		goto out_unlock;
 578	}
 579
 580	/* Try to add one more record ID to cache */
 581	rc = __erst_record_id_cache_add_one();
 582	if (rc < 0)
 583		goto out_unlock;
 584	/* successfully add one new ID */
 585	if (rc == 1) {
 586		*record_id = erst_record_id_cache.entries[*pos];
 587		(*pos)++;
 588		rc = 0;
 589	} else {
 590		*pos = -1;
 591		*record_id = APEI_ERST_INVALID_RECORD_ID;
 592	}
 593out_unlock:
 594	mutex_unlock(&erst_record_id_cache.lock);
 595
 596	return rc;
 597}
 598EXPORT_SYMBOL_GPL(erst_get_record_id_next);
 599
 600/* erst_record_id_cache.lock must be held by caller */
 601static void __erst_record_id_cache_compact(void)
 602{
 603	int i, wpos = 0;
 604	u64 *entries;
 605
 606	if (erst_record_id_cache.refcount)
 607		return;
 608
 609	entries = erst_record_id_cache.entries;
 610	for (i = 0; i < erst_record_id_cache.len; i++) {
 611		if (entries[i] == APEI_ERST_INVALID_RECORD_ID)
 612			continue;
 613		if (wpos != i)
 614			entries[wpos] = entries[i];
 615		wpos++;
 616	}
 617	erst_record_id_cache.len = wpos;
 618}
 619
 620void erst_get_record_id_end(void)
 621{
 622	/*
 623	 * erst_disable != 0 should be detected by invoker via the
 624	 * return value of erst_get_record_id_begin/next, so this
 625	 * function should not be called for erst_disable != 0.
 626	 */
 627	BUG_ON(erst_disable);
 628
 629	mutex_lock(&erst_record_id_cache.lock);
 630	erst_record_id_cache.refcount--;
 631	BUG_ON(erst_record_id_cache.refcount < 0);
 632	__erst_record_id_cache_compact();
 633	mutex_unlock(&erst_record_id_cache.lock);
 634}
 635EXPORT_SYMBOL_GPL(erst_get_record_id_end);
 636
 637static int __erst_write_to_storage(u64 offset)
 638{
 639	struct apei_exec_context ctx;
 640	u64 timeout = FIRMWARE_TIMEOUT;
 641	u64 val;
 642	int rc;
 643
 644	erst_exec_ctx_init(&ctx);
 645	rc = apei_exec_run_optional(&ctx, ACPI_ERST_BEGIN_WRITE);
 646	if (rc)
 647		return rc;
 648	apei_exec_ctx_set_input(&ctx, offset);
 649	rc = apei_exec_run(&ctx, ACPI_ERST_SET_RECORD_OFFSET);
 650	if (rc)
 651		return rc;
 652	rc = apei_exec_run(&ctx, ACPI_ERST_EXECUTE_OPERATION);
 653	if (rc)
 654		return rc;
 655	for (;;) {
 656		rc = apei_exec_run(&ctx, ACPI_ERST_CHECK_BUSY_STATUS);
 657		if (rc)
 658			return rc;
 659		val = apei_exec_ctx_get_output(&ctx);
 660		if (!val)
 661			break;
 662		if (erst_timedout(&timeout, SPIN_UNIT))
 663			return -EIO;
 664	}
 665	rc = apei_exec_run(&ctx, ACPI_ERST_GET_COMMAND_STATUS);
 666	if (rc)
 667		return rc;
 668	val = apei_exec_ctx_get_output(&ctx);
 669	rc = apei_exec_run_optional(&ctx, ACPI_ERST_END);
 670	if (rc)
 671		return rc;
 672
 673	return erst_errno(val);
 674}
 675
 676static int __erst_read_from_storage(u64 record_id, u64 offset)
 677{
 678	struct apei_exec_context ctx;
 679	u64 timeout = FIRMWARE_TIMEOUT;
 680	u64 val;
 681	int rc;
 682
 683	erst_exec_ctx_init(&ctx);
 684	rc = apei_exec_run_optional(&ctx, ACPI_ERST_BEGIN_READ);
 685	if (rc)
 686		return rc;
 687	apei_exec_ctx_set_input(&ctx, offset);
 688	rc = apei_exec_run(&ctx, ACPI_ERST_SET_RECORD_OFFSET);
 689	if (rc)
 690		return rc;
 691	apei_exec_ctx_set_input(&ctx, record_id);
 692	rc = apei_exec_run(&ctx, ACPI_ERST_SET_RECORD_ID);
 693	if (rc)
 694		return rc;
 695	rc = apei_exec_run(&ctx, ACPI_ERST_EXECUTE_OPERATION);
 696	if (rc)
 697		return rc;
 698	for (;;) {
 699		rc = apei_exec_run(&ctx, ACPI_ERST_CHECK_BUSY_STATUS);
 700		if (rc)
 701			return rc;
 702		val = apei_exec_ctx_get_output(&ctx);
 703		if (!val)
 704			break;
 705		if (erst_timedout(&timeout, SPIN_UNIT))
 706			return -EIO;
 707	};
 708	rc = apei_exec_run(&ctx, ACPI_ERST_GET_COMMAND_STATUS);
 709	if (rc)
 710		return rc;
 711	val = apei_exec_ctx_get_output(&ctx);
 712	rc = apei_exec_run_optional(&ctx, ACPI_ERST_END);
 713	if (rc)
 714		return rc;
 715
 716	return erst_errno(val);
 717}
 718
 719static int __erst_clear_from_storage(u64 record_id)
 720{
 721	struct apei_exec_context ctx;
 722	u64 timeout = FIRMWARE_TIMEOUT;
 723	u64 val;
 724	int rc;
 725
 726	erst_exec_ctx_init(&ctx);
 727	rc = apei_exec_run_optional(&ctx, ACPI_ERST_BEGIN_CLEAR);
 728	if (rc)
 729		return rc;
 730	apei_exec_ctx_set_input(&ctx, record_id);
 731	rc = apei_exec_run(&ctx, ACPI_ERST_SET_RECORD_ID);
 732	if (rc)
 733		return rc;
 734	rc = apei_exec_run(&ctx, ACPI_ERST_EXECUTE_OPERATION);
 735	if (rc)
 736		return rc;
 737	for (;;) {
 738		rc = apei_exec_run(&ctx, ACPI_ERST_CHECK_BUSY_STATUS);
 739		if (rc)
 740			return rc;
 741		val = apei_exec_ctx_get_output(&ctx);
 742		if (!val)
 743			break;
 744		if (erst_timedout(&timeout, SPIN_UNIT))
 745			return -EIO;
 746	}
 747	rc = apei_exec_run(&ctx, ACPI_ERST_GET_COMMAND_STATUS);
 748	if (rc)
 749		return rc;
 750	val = apei_exec_ctx_get_output(&ctx);
 751	rc = apei_exec_run_optional(&ctx, ACPI_ERST_END);
 752	if (rc)
 753		return rc;
 754
 755	return erst_errno(val);
 756}
 757
 758/* NVRAM ERST Error Log Address Range is not supported yet */
 759static void pr_unimpl_nvram(void)
 760{
 761	if (printk_ratelimit())
 762		pr_warn("NVRAM ERST Log Address Range not implemented yet.\n");
 
 763}
 764
 765static int __erst_write_to_nvram(const struct cper_record_header *record)
 766{
 767	/* do not print message, because printk is not safe for NMI */
 768	return -ENOSYS;
 769}
 770
 771static int __erst_read_to_erange_from_nvram(u64 record_id, u64 *offset)
 772{
 773	pr_unimpl_nvram();
 774	return -ENOSYS;
 775}
 776
 777static int __erst_clear_from_nvram(u64 record_id)
 778{
 779	pr_unimpl_nvram();
 780	return -ENOSYS;
 781}
 782
 783int erst_write(const struct cper_record_header *record)
 784{
 785	int rc;
 786	unsigned long flags;
 787	struct cper_record_header *rcd_erange;
 788
 789	if (erst_disable)
 790		return -ENODEV;
 791
 792	if (memcmp(record->signature, CPER_SIG_RECORD, CPER_SIG_SIZE))
 793		return -EINVAL;
 794
 795	if (erst_erange.attr & ERST_RANGE_NVRAM) {
 796		if (!raw_spin_trylock_irqsave(&erst_lock, flags))
 797			return -EBUSY;
 798		rc = __erst_write_to_nvram(record);
 799		raw_spin_unlock_irqrestore(&erst_lock, flags);
 800		return rc;
 801	}
 802
 803	if (record->record_length > erst_erange.size)
 804		return -EINVAL;
 805
 806	if (!raw_spin_trylock_irqsave(&erst_lock, flags))
 807		return -EBUSY;
 808	memcpy(erst_erange.vaddr, record, record->record_length);
 809	rcd_erange = erst_erange.vaddr;
 810	/* signature for serialization system */
 811	memcpy(&rcd_erange->persistence_information, "ER", 2);
 812
 813	rc = __erst_write_to_storage(0);
 814	raw_spin_unlock_irqrestore(&erst_lock, flags);
 815
 816	return rc;
 817}
 818EXPORT_SYMBOL_GPL(erst_write);
 819
 820static int __erst_read_to_erange(u64 record_id, u64 *offset)
 821{
 822	int rc;
 823
 824	if (erst_erange.attr & ERST_RANGE_NVRAM)
 825		return __erst_read_to_erange_from_nvram(
 826			record_id, offset);
 827
 828	rc = __erst_read_from_storage(record_id, 0);
 829	if (rc)
 830		return rc;
 831	*offset = 0;
 832
 833	return 0;
 834}
 835
 836static ssize_t __erst_read(u64 record_id, struct cper_record_header *record,
 837			   size_t buflen)
 838{
 839	int rc;
 840	u64 offset, len = 0;
 841	struct cper_record_header *rcd_tmp;
 842
 843	rc = __erst_read_to_erange(record_id, &offset);
 844	if (rc)
 845		return rc;
 846	rcd_tmp = erst_erange.vaddr + offset;
 847	len = rcd_tmp->record_length;
 848	if (len <= buflen)
 849		memcpy(record, rcd_tmp, len);
 850
 851	return len;
 852}
 853
 854/*
 855 * If return value > buflen, the buffer size is not big enough,
 856 * else if return value < 0, something goes wrong,
 857 * else everything is OK, and return value is record length
 858 */
 859ssize_t erst_read(u64 record_id, struct cper_record_header *record,
 860		  size_t buflen)
 861{
 862	ssize_t len;
 863	unsigned long flags;
 864
 865	if (erst_disable)
 866		return -ENODEV;
 867
 868	raw_spin_lock_irqsave(&erst_lock, flags);
 869	len = __erst_read(record_id, record, buflen);
 870	raw_spin_unlock_irqrestore(&erst_lock, flags);
 871	return len;
 872}
 873EXPORT_SYMBOL_GPL(erst_read);
 874
 875int erst_clear(u64 record_id)
 876{
 877	int rc, i;
 878	unsigned long flags;
 879	u64 *entries;
 880
 881	if (erst_disable)
 882		return -ENODEV;
 883
 884	rc = mutex_lock_interruptible(&erst_record_id_cache.lock);
 885	if (rc)
 886		return rc;
 887	raw_spin_lock_irqsave(&erst_lock, flags);
 888	if (erst_erange.attr & ERST_RANGE_NVRAM)
 889		rc = __erst_clear_from_nvram(record_id);
 890	else
 891		rc = __erst_clear_from_storage(record_id);
 892	raw_spin_unlock_irqrestore(&erst_lock, flags);
 893	if (rc)
 894		goto out;
 895	entries = erst_record_id_cache.entries;
 896	for (i = 0; i < erst_record_id_cache.len; i++) {
 897		if (entries[i] == record_id)
 898			entries[i] = APEI_ERST_INVALID_RECORD_ID;
 899	}
 900	__erst_record_id_cache_compact();
 901out:
 902	mutex_unlock(&erst_record_id_cache.lock);
 903	return rc;
 904}
 905EXPORT_SYMBOL_GPL(erst_clear);
 906
 907static int __init setup_erst_disable(char *str)
 908{
 909	erst_disable = 1;
 910	return 0;
 911}
 912
 913__setup("erst_disable", setup_erst_disable);
 914
 915static int erst_check_table(struct acpi_table_erst *erst_tab)
 916{
 917	if ((erst_tab->header_length !=
 918	     (sizeof(struct acpi_table_erst) - sizeof(erst_tab->header)))
 919	    && (erst_tab->header_length != sizeof(struct acpi_table_erst)))
 920		return -EINVAL;
 921	if (erst_tab->header.length < sizeof(struct acpi_table_erst))
 922		return -EINVAL;
 923	if (erst_tab->entries !=
 924	    (erst_tab->header.length - sizeof(struct acpi_table_erst)) /
 925	    sizeof(struct acpi_erst_entry))
 926		return -EINVAL;
 927
 928	return 0;
 929}
 930
 931static int erst_open_pstore(struct pstore_info *psi);
 932static int erst_close_pstore(struct pstore_info *psi);
 933static ssize_t erst_reader(u64 *id, enum pstore_type_id *type, int *count,
 934			   struct timespec *time, char **buf,
 935			   bool *compressed, struct pstore_info *psi);
 936static int erst_writer(enum pstore_type_id type, enum kmsg_dump_reason reason,
 937		       u64 *id, unsigned int part, int count, bool compressed,
 938		       size_t size, struct pstore_info *psi);
 939static int erst_clearer(enum pstore_type_id type, u64 id, int count,
 940			struct timespec time, struct pstore_info *psi);
 941
 942static struct pstore_info erst_info = {
 943	.owner		= THIS_MODULE,
 944	.name		= "erst",
 945	.flags		= PSTORE_FLAGS_FRAGILE,
 946	.open		= erst_open_pstore,
 947	.close		= erst_close_pstore,
 948	.read		= erst_reader,
 949	.write		= erst_writer,
 950	.erase		= erst_clearer
 951};
 952
 953#define CPER_CREATOR_PSTORE						\
 954	UUID_LE(0x75a574e3, 0x5052, 0x4b29, 0x8a, 0x8e, 0xbe, 0x2c,	\
 955		0x64, 0x90, 0xb8, 0x9d)
 956#define CPER_SECTION_TYPE_DMESG						\
 957	UUID_LE(0xc197e04e, 0xd545, 0x4a70, 0x9c, 0x17, 0xa5, 0x54,	\
 958		0x94, 0x19, 0xeb, 0x12)
 959#define CPER_SECTION_TYPE_DMESG_Z					\
 960	UUID_LE(0x4f118707, 0x04dd, 0x4055, 0xb5, 0xdd, 0x95, 0x6d,	\
 961		0x34, 0xdd, 0xfa, 0xc6)
 962#define CPER_SECTION_TYPE_MCE						\
 963	UUID_LE(0xfe08ffbe, 0x95e4, 0x4be7, 0xbc, 0x73, 0x40, 0x96,	\
 964		0x04, 0x4a, 0x38, 0xfc)
 965
 966struct cper_pstore_record {
 967	struct cper_record_header hdr;
 968	struct cper_section_descriptor sec_hdr;
 969	char data[];
 970} __packed;
 971
 972static int reader_pos;
 973
 974static int erst_open_pstore(struct pstore_info *psi)
 975{
 976	int rc;
 977
 978	if (erst_disable)
 979		return -ENODEV;
 980
 981	rc = erst_get_record_id_begin(&reader_pos);
 982
 983	return rc;
 984}
 985
 986static int erst_close_pstore(struct pstore_info *psi)
 987{
 988	erst_get_record_id_end();
 989
 990	return 0;
 991}
 992
 993static ssize_t erst_reader(u64 *id, enum pstore_type_id *type, int *count,
 994			   struct timespec *time, char **buf,
 995			   bool *compressed, struct pstore_info *psi)
 996{
 997	int rc;
 998	ssize_t len = 0;
 999	u64 record_id;
1000	struct cper_pstore_record *rcd;
1001	size_t rcd_len = sizeof(*rcd) + erst_info.bufsize;
1002
1003	if (erst_disable)
1004		return -ENODEV;
1005
1006	rcd = kmalloc(rcd_len, GFP_KERNEL);
1007	if (!rcd) {
1008		rc = -ENOMEM;
1009		goto out;
1010	}
1011skip:
1012	rc = erst_get_record_id_next(&reader_pos, &record_id);
1013	if (rc)
1014		goto out;
1015
1016	/* no more record */
1017	if (record_id == APEI_ERST_INVALID_RECORD_ID) {
1018		rc = -EINVAL;
1019		goto out;
1020	}
1021
1022	len = erst_read(record_id, &rcd->hdr, rcd_len);
 
1023	/* The record may be cleared by others, try read next record */
1024	if (len == -ENOENT)
1025		goto skip;
1026	else if (len < sizeof(*rcd)) {
1027		rc = -EIO;
1028		goto out;
1029	}
1030	if (uuid_le_cmp(rcd->hdr.creator_id, CPER_CREATOR_PSTORE) != 0)
1031		goto skip;
1032
1033	*buf = kmalloc(len, GFP_KERNEL);
1034	if (*buf == NULL) {
1035		rc = -ENOMEM;
1036		goto out;
1037	}
1038	memcpy(*buf, rcd->data, len - sizeof(*rcd));
1039	*id = record_id;
1040	*compressed = false;
1041	if (uuid_le_cmp(rcd->sec_hdr.section_type,
1042			CPER_SECTION_TYPE_DMESG_Z) == 0) {
1043		*type = PSTORE_TYPE_DMESG;
1044		*compressed = true;
1045	} else if (uuid_le_cmp(rcd->sec_hdr.section_type,
1046			CPER_SECTION_TYPE_DMESG) == 0)
1047		*type = PSTORE_TYPE_DMESG;
1048	else if (uuid_le_cmp(rcd->sec_hdr.section_type,
1049			     CPER_SECTION_TYPE_MCE) == 0)
1050		*type = PSTORE_TYPE_MCE;
1051	else
1052		*type = PSTORE_TYPE_UNKNOWN;
1053
1054	if (rcd->hdr.validation_bits & CPER_VALID_TIMESTAMP)
1055		time->tv_sec = rcd->hdr.timestamp;
1056	else
1057		time->tv_sec = 0;
1058	time->tv_nsec = 0;
1059
1060out:
1061	kfree(rcd);
1062	return (rc < 0) ? rc : (len - sizeof(*rcd));
1063}
1064
1065static int erst_writer(enum pstore_type_id type, enum kmsg_dump_reason reason,
1066		       u64 *id, unsigned int part, int count, bool compressed,
1067		       size_t size, struct pstore_info *psi)
1068{
1069	struct cper_pstore_record *rcd = (struct cper_pstore_record *)
1070					(erst_info.buf - sizeof(*rcd));
1071	int ret;
1072
1073	memset(rcd, 0, sizeof(*rcd));
1074	memcpy(rcd->hdr.signature, CPER_SIG_RECORD, CPER_SIG_SIZE);
1075	rcd->hdr.revision = CPER_RECORD_REV;
1076	rcd->hdr.signature_end = CPER_SIG_END;
1077	rcd->hdr.section_count = 1;
1078	rcd->hdr.error_severity = CPER_SEV_FATAL;
1079	/* timestamp valid. platform_id, partition_id are invalid */
1080	rcd->hdr.validation_bits = CPER_VALID_TIMESTAMP;
1081	rcd->hdr.timestamp = get_seconds();
1082	rcd->hdr.record_length = sizeof(*rcd) + size;
1083	rcd->hdr.creator_id = CPER_CREATOR_PSTORE;
1084	rcd->hdr.notification_type = CPER_NOTIFY_MCE;
1085	rcd->hdr.record_id = cper_next_record_id();
1086	rcd->hdr.flags = CPER_HW_ERROR_FLAGS_PREVERR;
1087
1088	rcd->sec_hdr.section_offset = sizeof(*rcd);
1089	rcd->sec_hdr.section_length = size;
1090	rcd->sec_hdr.revision = CPER_SEC_REV;
1091	/* fru_id and fru_text is invalid */
1092	rcd->sec_hdr.validation_bits = 0;
1093	rcd->sec_hdr.flags = CPER_SEC_PRIMARY;
1094	switch (type) {
1095	case PSTORE_TYPE_DMESG:
1096		if (compressed)
1097			rcd->sec_hdr.section_type = CPER_SECTION_TYPE_DMESG_Z;
1098		else
1099			rcd->sec_hdr.section_type = CPER_SECTION_TYPE_DMESG;
1100		break;
1101	case PSTORE_TYPE_MCE:
1102		rcd->sec_hdr.section_type = CPER_SECTION_TYPE_MCE;
1103		break;
1104	default:
1105		return -EINVAL;
1106	}
1107	rcd->sec_hdr.section_severity = CPER_SEV_FATAL;
1108
1109	ret = erst_write(&rcd->hdr);
1110	*id = rcd->hdr.record_id;
1111
1112	return ret;
1113}
1114
1115static int erst_clearer(enum pstore_type_id type, u64 id, int count,
1116			struct timespec time, struct pstore_info *psi)
1117{
1118	return erst_clear(id);
1119}
1120
1121static int __init erst_init(void)
1122{
1123	int rc = 0;
1124	acpi_status status;
1125	struct apei_exec_context ctx;
1126	struct apei_resources erst_resources;
1127	struct resource *r;
1128	char *buf;
1129
1130	if (acpi_disabled)
1131		goto err;
1132
1133	if (erst_disable) {
1134		pr_info(
1135	"Error Record Serialization Table (ERST) support is disabled.\n");
1136		goto err;
1137	}
1138
1139	status = acpi_get_table(ACPI_SIG_ERST, 0,
1140				(struct acpi_table_header **)&erst_tab);
1141	if (status == AE_NOT_FOUND)
 
1142		goto err;
1143	else if (ACPI_FAILURE(status)) {
1144		const char *msg = acpi_format_exception(status);
1145		pr_err("Failed to get table, %s\n", msg);
1146		rc = -EINVAL;
1147		goto err;
1148	}
1149
1150	rc = erst_check_table(erst_tab);
1151	if (rc) {
1152		pr_err(FW_BUG "ERST table is invalid.\n");
1153		goto err;
1154	}
1155
1156	apei_resources_init(&erst_resources);
1157	erst_exec_ctx_init(&ctx);
1158	rc = apei_exec_collect_resources(&ctx, &erst_resources);
1159	if (rc)
1160		goto err_fini;
1161	rc = apei_resources_request(&erst_resources, "APEI ERST");
1162	if (rc)
1163		goto err_fini;
1164	rc = apei_exec_pre_map_gars(&ctx);
1165	if (rc)
1166		goto err_release;
1167	rc = erst_get_erange(&erst_erange);
1168	if (rc) {
1169		if (rc == -ENODEV)
1170			pr_info(
1171	"The corresponding hardware device or firmware implementation "
1172	"is not available.\n");
1173		else
1174			pr_err("Failed to get Error Log Address Range.\n");
 
1175		goto err_unmap_reg;
1176	}
1177
1178	r = request_mem_region(erst_erange.base, erst_erange.size, "APEI ERST");
1179	if (!r) {
1180		pr_err("Can not request [mem %#010llx-%#010llx] for ERST.\n",
1181		       (unsigned long long)erst_erange.base,
1182		       (unsigned long long)erst_erange.base + erst_erange.size - 1);
 
1183		rc = -EIO;
1184		goto err_unmap_reg;
1185	}
1186	rc = -ENOMEM;
1187	erst_erange.vaddr = ioremap_cache(erst_erange.base,
1188					  erst_erange.size);
1189	if (!erst_erange.vaddr)
1190		goto err_release_erange;
1191
1192	pr_info(
1193	"Error Record Serialization Table (ERST) support is initialized.\n");
1194
1195	buf = kmalloc(erst_erange.size, GFP_KERNEL);
1196	spin_lock_init(&erst_info.buf_lock);
1197	if (buf) {
1198		erst_info.buf = buf + sizeof(struct cper_pstore_record);
1199		erst_info.bufsize = erst_erange.size -
1200				    sizeof(struct cper_pstore_record);
1201		rc = pstore_register(&erst_info);
1202		if (rc) {
1203			if (rc != -EPERM)
1204				pr_info(
1205				"Could not register with persistent store.\n");
1206			erst_info.buf = NULL;
1207			erst_info.bufsize = 0;
1208			kfree(buf);
1209		}
1210	} else
1211		pr_err(
1212		"Failed to allocate %lld bytes for persistent store error log.\n",
1213		erst_erange.size);
1214
1215	return 0;
1216
1217err_release_erange:
1218	release_mem_region(erst_erange.base, erst_erange.size);
1219err_unmap_reg:
1220	apei_exec_post_unmap_gars(&ctx);
1221err_release:
1222	apei_resources_release(&erst_resources);
1223err_fini:
1224	apei_resources_fini(&erst_resources);
1225err:
1226	erst_disable = 1;
1227	return rc;
1228}
1229
1230device_initcall(erst_init);