[linux-block.git] / drivers / firmware / efi / efi-pstore.c

#include <linux/efi.h>
#include <linux/module.h>
#include <linux/pstore.h>
#include <linux/slab.h>
#include <linux/ucs2_string.h>

#define DUMP_NAME_LEN 52

static bool efivars_pstore_disable =
	IS_ENABLED(CONFIG_EFI_VARS_PSTORE_DEFAULT_DISABLE);

module_param_named(pstore_disable, efivars_pstore_disable, bool, 0644);

#define PSTORE_EFI_ATTRIBUTES \
	(EFI_VARIABLE_NON_VOLATILE | \
	 EFI_VARIABLE_BOOTSERVICE_ACCESS | \
	 EFI_VARIABLE_RUNTIME_ACCESS)

static int efi_pstore_open(struct pstore_info *psi)
{
	psi->data = NULL;
	return 0;
}

static int efi_pstore_close(struct pstore_info *psi)
{
	psi->data = NULL;
	return 0;
}

static inline u64 generic_id(unsigned long timestamp,
			     unsigned int part, int count)
{
	return ((u64) timestamp * 100 + part) * 1000 + count;
}

static int efi_pstore_read_func(struct efivar_entry *entry,
				struct pstore_record *record)
{
	efi_guid_t vendor = LINUX_EFI_CRASH_GUID;
	char name[DUMP_NAME_LEN], data_type;
	int i;
	int cnt;
	unsigned int part;
	unsigned long time, size;

	if (efi_guidcmp(entry->var.VendorGuid, vendor))
		return 0;

	for (i = 0; i < DUMP_NAME_LEN; i++)
		name[i] = entry->var.VariableName[i];

	if (sscanf(name, "dump-type%u-%u-%d-%lu-%c",
		   &record->type, &part, &cnt, &time, &data_type) == 5) {
		record->id = generic_id(time, part, cnt);
		record->count = cnt;
		record->time.tv_sec = time;
		record->time.tv_nsec = 0;
		if (data_type == 'C')
			record->compressed = true;
		else
			record->compressed = false;
		record->ecc_notice_size = 0;
	} else if (sscanf(name, "dump-type%u-%u-%d-%lu",
		   &record->type, &part, &cnt, &time) == 4) {
		record->id = generic_id(time, part, cnt);
		record->count = cnt;
		record->time.tv_sec = time;
		record->time.tv_nsec = 0;
		record->compressed = false;
		record->ecc_notice_size = 0;
	} else if (sscanf(name, "dump-type%u-%u-%lu",
			  &record->type, &part, &time) == 3) {
		/*
		 * Check if an old format,
		 * which doesn't support holding
		 * multiple logs, remains.
		 */
		record->id = generic_id(time, part, 0);
		record->count = 0;
		record->time.tv_sec = time;
		record->time.tv_nsec = 0;
		record->compressed = false;
		record->ecc_notice_size = 0;
	} else
		return 0;

	entry->var.DataSize = 1024;
	__efivar_entry_get(entry, &entry->var.Attributes,
			   &entry->var.DataSize, entry->var.Data);
	size = entry->var.DataSize;
	memcpy(record->buf, entry->var.Data,
	       (size_t)min_t(unsigned long, EFIVARS_DATA_SIZE_MAX, size));

	return size;
}

/**
 * efi_pstore_scan_sysfs_enter
 * @pos: scanning entry
 * @next: next entry
 * @head: list head
 */
static void efi_pstore_scan_sysfs_enter(struct efivar_entry *pos,
					struct efivar_entry *next,
					struct list_head *head)
{
	pos->scanning = true;
	if (&next->list != head)
		next->scanning = true;
}

/**
 * __efi_pstore_scan_sysfs_exit
 * @entry: deleting entry
 * @turn_off_scanning: Check if a scanning flag should be turned off
 */
static inline int __efi_pstore_scan_sysfs_exit(struct efivar_entry *entry,
						bool turn_off_scanning)
{
	if (entry->deleting) {
		list_del(&entry->list);
		efivar_entry_iter_end();
		efivar_unregister(entry);
		if (efivar_entry_iter_begin())
			return -EINTR;
	} else if (turn_off_scanning)
		entry->scanning = false;

	return 0;
}

/**
 * efi_pstore_scan_sysfs_exit
 * @pos: scanning entry
 * @next: next entry
 * @head: list head
 * @stop: a flag checking if scanning will stop
 */
static int efi_pstore_scan_sysfs_exit(struct efivar_entry *pos,
				       struct efivar_entry *next,
				       struct list_head *head, bool stop)
{
	int ret = __efi_pstore_scan_sysfs_exit(pos, true);

	if (ret)
		return ret;

	if (stop)
		ret = __efi_pstore_scan_sysfs_exit(next, &next->list != head);
	return ret;
}

/**
 * efi_pstore_sysfs_entry_iter
 *
 * @record: pstore record to pass to callback
 * @pos: entry to begin iterating from
 *
 * You MUST call efivar_enter_iter_begin() before this function, and
 * efivar_entry_iter_end() afterwards.
 *
 * It is possible to begin iteration from an arbitrary entry within
 * the list by passing @pos. @pos is updated on return to point to
 * the next entry of the last one passed to efi_pstore_read_func().
 * To begin iterating from the beginning of the list @pos must be %NULL.
 */
static int efi_pstore_sysfs_entry_iter(struct pstore_record *record,
				       struct efivar_entry **pos)
{
	struct efivar_entry *entry, *n;
	struct list_head *head = &efivar_sysfs_list;
	int size = 0;
	int ret;

	if (!*pos) {
		list_for_each_entry_safe(entry, n, head, list) {
			efi_pstore_scan_sysfs_enter(entry, n, head);

			size = efi_pstore_read_func(entry, record);
			ret = efi_pstore_scan_sysfs_exit(entry, n, head,
							 size < 0);
			if (ret)
				return ret;
			if (size)
				break;
		}
		*pos = n;
		return size;
	}

	list_for_each_entry_safe_from((*pos), n, head, list) {
		efi_pstore_scan_sysfs_enter((*pos), n, head);

		size = efi_pstore_read_func((*pos), record);
		ret = efi_pstore_scan_sysfs_exit((*pos), n, head, size < 0);
		if (ret)
			return ret;
		if (size)
			break;
	}
	*pos = n;
	return size;
}

/**
 * efi_pstore_read
 *
 * This function returns a size of NVRAM entry logged via efi_pstore_write().
 * The meaning and behavior of efi_pstore/pstore are as below.
 *
 * size > 0: Got data of an entry logged via efi_pstore_write() successfully,
 *           and pstore filesystem will continue reading subsequent entries.
 * size == 0: Entry was not logged via efi_pstore_write(),
 *            and efi_pstore driver will continue reading subsequent entries.
 * size < 0: Failed to get data of entry logging via efi_pstore_write(),
 *           and pstore will stop reading entry.
 */
static ssize_t efi_pstore_read(struct pstore_record *record)
{
	struct efivar_entry *entry = (struct efivar_entry *)record->psi->data;
	ssize_t size;

	record->buf = kzalloc(EFIVARS_DATA_SIZE_MAX, GFP_KERNEL);
	if (!record->buf)
		return -ENOMEM;

	if (efivar_entry_iter_begin()) {
		size = -EINTR;
		goto out;
	}
	size = efi_pstore_sysfs_entry_iter(record, &entry);
	efivar_entry_iter_end();

out:
	if (size <= 0) {
		kfree(record->buf);
		record->buf = NULL;
	}
	return size;
}

static int efi_pstore_write(struct pstore_record *record)
{
	char name[DUMP_NAME_LEN];
	efi_char16_t efi_name[DUMP_NAME_LEN];
	efi_guid_t vendor = LINUX_EFI_CRASH_GUID;
	int i, ret = 0;

	snprintf(name, sizeof(name), "dump-type%u-%u-%d-%lu-%c",
		 record->type, record->part, record->count,
		 get_seconds(), record->compressed ? 'C' : 'D');

	for (i = 0; i < DUMP_NAME_LEN; i++)
		efi_name[i] = name[i];

	efivar_entry_set_safe(efi_name, vendor, PSTORE_EFI_ATTRIBUTES,
			      !pstore_cannot_block_path(record->reason),
			      record->size, record->psi->buf);

	if (record->reason == KMSG_DUMP_OOPS)
		efivar_run_worker();

	record->id = record->part;
	return ret;
};

struct pstore_erase_data {
	u64 id;
	enum pstore_type_id type;
	int count;
	struct timespec time;
	efi_char16_t *name;
};

/*
 * Clean up an entry with the same name
 */
static int efi_pstore_erase_func(struct efivar_entry *entry, void *data)
{
	struct pstore_erase_data *ed = data;
	efi_guid_t vendor = LINUX_EFI_CRASH_GUID;
	efi_char16_t efi_name_old[DUMP_NAME_LEN];
	efi_char16_t *efi_name = ed->name;
	unsigned long ucs2_len = ucs2_strlen(ed->name);
	char name_old[DUMP_NAME_LEN];
	int i;

	if (efi_guidcmp(entry->var.VendorGuid, vendor))
		return 0;

	if (ucs2_strncmp(entry->var.VariableName,
			  efi_name, (size_t)ucs2_len)) {
		/*
		 * Check if an old format, which doesn't support
		 * holding multiple logs, remains.
		 */
		sprintf(name_old, "dump-type%u-%u-%lu", ed->type,
			(unsigned int)ed->id, ed->time.tv_sec);

		for (i = 0; i < DUMP_NAME_LEN; i++)
			efi_name_old[i] = name_old[i];

		if (ucs2_strncmp(entry->var.VariableName, efi_name_old,
				  ucs2_strlen(efi_name_old)))
			return 0;
	}

	if (entry->scanning) {
		/*
		 * Skip deletion because this entry will be deleted
		 * after scanning is completed.
		 */
		entry->deleting = true;
	} else
		list_del(&entry->list);

	/* found */
	__efivar_entry_delete(entry);

	return 1;
}

static int efi_pstore_erase(enum pstore_type_id type, u64 id, int count,
			    struct timespec time, struct pstore_info *psi)
{
	struct pstore_erase_data edata;
	struct efivar_entry *entry = NULL;
	char name[DUMP_NAME_LEN];
	efi_char16_t efi_name[DUMP_NAME_LEN];
	int found, i;
	unsigned int part;

	do_div(id, 1000);
	part = do_div(id, 100);
	sprintf(name, "dump-type%u-%u-%d-%lu", type, part, count, time.tv_sec);

	for (i = 0; i < DUMP_NAME_LEN; i++)
		efi_name[i] = name[i];

	edata.id = part;
	edata.type = type;
	edata.count = count;
	edata.time = time;
	edata.name = efi_name;

	if (efivar_entry_iter_begin())
		return -EINTR;
	found = __efivar_entry_iter(efi_pstore_erase_func, &efivar_sysfs_list, &edata, &entry);

	if (found && !entry->scanning) {
		efivar_entry_iter_end();
		efivar_unregister(entry);
	} else
		efivar_entry_iter_end();

	return 0;
}

static struct pstore_info efi_pstore_info = {
	.owner		= THIS_MODULE,
	.name		= "efi",
	.flags		= PSTORE_FLAGS_DMESG,
	.open		= efi_pstore_open,
	.close		= efi_pstore_close,
	.read		= efi_pstore_read,
	.write		= efi_pstore_write,
	.erase		= efi_pstore_erase,
};

static __init int efivars_pstore_init(void)
{
	if (!efi_enabled(EFI_RUNTIME_SERVICES))
		return 0;

	if (!efivars_kobject())
		return 0;

	if (efivars_pstore_disable)
		return 0;

	efi_pstore_info.buf = kmalloc(4096, GFP_KERNEL);
	if (!efi_pstore_info.buf)
		return -ENOMEM;

	efi_pstore_info.bufsize = 1024;
	spin_lock_init(&efi_pstore_info.buf_lock);

	if (pstore_register(&efi_pstore_info)) {
		kfree(efi_pstore_info.buf);
		efi_pstore_info.buf = NULL;
		efi_pstore_info.bufsize = 0;
	}

	return 0;
}

static __exit void efivars_pstore_exit(void)
{
	if (!efi_pstore_info.bufsize)
		return;

	pstore_unregister(&efi_pstore_info);
	kfree(efi_pstore_info.buf);
	efi_pstore_info.buf = NULL;
	efi_pstore_info.bufsize = 0;
}

module_init(efivars_pstore_init);
module_exit(efivars_pstore_exit);

MODULE_DESCRIPTION("EFI variable backend for pstore");
MODULE_LICENSE("GPL");
MODULE_ALIAS("platform:efivars");
Commit	Line	Data
04851772 MF	1	#include <linux/efi.h>
	2	#include <linux/module.h>
	3	#include <linux/pstore.h>
20b4fb48	4	#include <linux/slab.h>
a614e192	5	#include <linux/ucs2_string.h>
04851772 MF	6
	7	#define DUMP_NAME_LEN 52
	8
	9	static bool efivars_pstore_disable =
	10	IS_ENABLED(CONFIG_EFI_VARS_PSTORE_DEFAULT_DISABLE);
	11
	12	module_param_named(pstore_disable, efivars_pstore_disable, bool, 0644);
	13
	14	#define PSTORE_EFI_ATTRIBUTES \
	15	(EFI_VARIABLE_NON_VOLATILE \| \
	16	EFI_VARIABLE_BOOTSERVICE_ACCESS \| \
	17	EFI_VARIABLE_RUNTIME_ACCESS)
	18
	19	static int efi_pstore_open(struct pstore_info *psi)
	20	{
04851772 MF	21	psi->data = NULL;
	22	return 0;
	23	}
	24
	25	static int efi_pstore_close(struct pstore_info *psi)
	26	{
04851772 MF	27	psi->data = NULL;
	28	return 0;
	29	}
	30
fdeadb43 MX	31	static inline u64 generic_id(unsigned long timestamp,
	32	unsigned int part, int count)
	33	{
783ee431	34	return ((u64) timestamp * 100 + part) * 1000 + count;
fdeadb43 MX	35	}
fdeadb43 MX	36
125cc42b KC	37	static int efi_pstore_read_func(struct efivar_entry *entry,
125cc42b KC	38	struct pstore_record *record)
04851772 MF	39	{
04851772 MF	40	efi_guid_t vendor = LINUX_EFI_CRASH_GUID;
f8c62f34	41	char name[DUMP_NAME_LEN], data_type;
04851772 MF	42	int i;
	43	int cnt;
	44	unsigned int part;
	45	unsigned long time, size;
	46
	47	if (efi_guidcmp(entry->var.VendorGuid, vendor))
	48	return 0;
	49
	50	for (i = 0; i < DUMP_NAME_LEN; i++)
	51	name[i] = entry->var.VariableName[i];
	52
f8c62f34	53	if (sscanf(name, "dump-type%u-%u-%d-%lu-%c",
125cc42b KC	54	&record->type, &part, &cnt, &time, &data_type) == 5) {
	55	record->id = generic_id(time, part, cnt);
	56	record->count = cnt;
	57	record->time.tv_sec = time;
	58	record->time.tv_nsec = 0;
f8c62f34	59	if (data_type == 'C')
125cc42b	60	record->compressed = true;
f8c62f34	61	else
125cc42b KC	62	record->compressed = false;
125cc42b KC	63	record->ecc_notice_size = 0;
f8c62f34	64	} else if (sscanf(name, "dump-type%u-%u-%d-%lu",
125cc42b KC	65	&record->type, &part, &cnt, &time) == 4) {
	66	record->id = generic_id(time, part, cnt);
	67	record->count = cnt;
	68	record->time.tv_sec = time;
	69	record->time.tv_nsec = 0;
	70	record->compressed = false;
	71	record->ecc_notice_size = 0;
04851772	72	} else if (sscanf(name, "dump-type%u-%u-%lu",
125cc42b	73	&record->type, &part, &time) == 3) {
04851772 MF	74	/*
	75	* Check if an old format,
	76	* which doesn't support holding
	77	* multiple logs, remains.
	78	*/
125cc42b KC	79	record->id = generic_id(time, part, 0);
	80	record->count = 0;
	81	record->time.tv_sec = time;
	82	record->time.tv_nsec = 0;
	83	record->compressed = false;
	84	record->ecc_notice_size = 0;
04851772 MF	85	} else
	86	return 0;
	87
8a415b8c MF	88	entry->var.DataSize = 1024;
	89	__efivar_entry_get(entry, &entry->var.Attributes,
	90	&entry->var.DataSize, entry->var.Data);
	91	size = entry->var.DataSize;
125cc42b	92	memcpy(record->buf, entry->var.Data,
e0d59733	93	(size_t)min_t(unsigned long, EFIVARS_DATA_SIZE_MAX, size));
8a415b8c	94
04851772 MF	95	return size;
	96	}
	97
e0d59733 SA	98	/**
e0d59733 SA	99	* efi_pstore_scan_sysfs_enter
a07e7449	100	* @pos: scanning entry
e0d59733 SA	101	* @next: next entry
	102	* @head: list head
	103	*/
	104	static void efi_pstore_scan_sysfs_enter(struct efivar_entry *pos,
	105	struct efivar_entry *next,
	106	struct list_head *head)
	107	{
	108	pos->scanning = true;
	109	if (&next->list != head)
	110	next->scanning = true;
	111	}
	112
	113	/**
	114	* __efi_pstore_scan_sysfs_exit
	115	* @entry: deleting entry
	116	* @turn_off_scanning: Check if a scanning flag should be turned off
	117	*/
21b3ddd3	118	static inline int __efi_pstore_scan_sysfs_exit(struct efivar_entry *entry,
e0d59733 SA	119	bool turn_off_scanning)
	120	{
	121	if (entry->deleting) {
	122	list_del(&entry->list);
	123	efivar_entry_iter_end();
	124	efivar_unregister(entry);
21b3ddd3 SC	125	if (efivar_entry_iter_begin())
21b3ddd3 SC	126	return -EINTR;
e0d59733 SA	127	} else if (turn_off_scanning)
e0d59733 SA	128	entry->scanning = false;
21b3ddd3 SC	129
21b3ddd3 SC	130	return 0;
e0d59733 SA	131	}
	132
	133	/**
	134	* efi_pstore_scan_sysfs_exit
	135	* @pos: scanning entry
	136	* @next: next entry
	137	* @head: list head
	138	* @stop: a flag checking if scanning will stop
	139	*/
21b3ddd3	140	static int efi_pstore_scan_sysfs_exit(struct efivar_entry *pos,
e0d59733 SA	141	struct efivar_entry *next,
	142	struct list_head *head, bool stop)
	143	{
21b3ddd3 SC	144	int ret = __efi_pstore_scan_sysfs_exit(pos, true);
	145
	146	if (ret)
	147	return ret;
	148
e0d59733	149	if (stop)
21b3ddd3 SC	150	ret = __efi_pstore_scan_sysfs_exit(next, &next->list != head);
21b3ddd3 SC	151	return ret;
e0d59733 SA	152	}
	153
	154	/**
	155	* efi_pstore_sysfs_entry_iter
	156	*
125cc42b	157	* @record: pstore record to pass to callback
e0d59733 SA	158	* @pos: entry to begin iterating from
	159	*
	160	* You MUST call efivar_enter_iter_begin() before this function, and
	161	* efivar_entry_iter_end() afterwards.
	162	*
	163	* It is possible to begin iteration from an arbitrary entry within
	164	* the list by passing @pos. @pos is updated on return to point to
	165	* the next entry of the last one passed to efi_pstore_read_func().
	166	* To begin iterating from the beginning of the list @pos must be %NULL.
	167	*/
125cc42b KC	168	static int efi_pstore_sysfs_entry_iter(struct pstore_record *record,
125cc42b KC	169	struct efivar_entry **pos)
e0d59733 SA	170	{
	171	struct efivar_entry entry, n;
	172	struct list_head *head = &efivar_sysfs_list;
	173	int size = 0;
21b3ddd3	174	int ret;
e0d59733 SA	175
	176	if (!*pos) {
	177	list_for_each_entry_safe(entry, n, head, list) {
	178	efi_pstore_scan_sysfs_enter(entry, n, head);
	179
125cc42b	180	size = efi_pstore_read_func(entry, record);
21b3ddd3 SC	181	ret = efi_pstore_scan_sysfs_exit(entry, n, head,
	182	size < 0);
	183	if (ret)
	184	return ret;
e0d59733 SA	185	if (size)
	186	break;
	187	}
	188	*pos = n;
	189	return size;
	190	}
	191
	192	list_for_each_entry_safe_from((*pos), n, head, list) {
	193	efi_pstore_scan_sysfs_enter((*pos), n, head);
	194
125cc42b	195	size = efi_pstore_read_func((*pos), record);
21b3ddd3 SC	196	ret = efi_pstore_scan_sysfs_exit((*pos), n, head, size < 0);
	197	if (ret)
	198	return ret;
e0d59733 SA	199	if (size)
	200	break;
	201	}
	202	*pos = n;
	203	return size;
	204	}
	205
	206	/**
	207	* efi_pstore_read
	208	*
	209	* This function returns a size of NVRAM entry logged via efi_pstore_write().
	210	* The meaning and behavior of efi_pstore/pstore are as below.
	211	*
	212	* size > 0: Got data of an entry logged via efi_pstore_write() successfully,
	213	* and pstore filesystem will continue reading subsequent entries.
	214	* size == 0: Entry was not logged via efi_pstore_write(),
	215	* and efi_pstore driver will continue reading subsequent entries.
	216	* size < 0: Failed to get data of entry logging via efi_pstore_write(),
	217	* and pstore will stop reading entry.
	218	*/
125cc42b	219	static ssize_t efi_pstore_read(struct pstore_record *record)
04851772	220	{
125cc42b	221	struct efivar_entry entry = (struct efivar_entry )record->psi->data;
e0d59733	222	ssize_t size;
04851772	223
125cc42b KC	224	record->buf = kzalloc(EFIVARS_DATA_SIZE_MAX, GFP_KERNEL);
125cc42b KC	225	if (!record->buf)
e0d59733 SA	226	return -ENOMEM;
e0d59733 SA	227
21b3ddd3	228	if (efivar_entry_iter_begin()) {
125cc42b KC	229	size = -EINTR;
125cc42b KC	230	goto out;
21b3ddd3	231	}
125cc42b	232	size = efi_pstore_sysfs_entry_iter(record, &entry);
e0d59733	233	efivar_entry_iter_end();
125cc42b KC	234
	235	out:
	236	if (size <= 0) {
	237	kfree(record->buf);
	238	record->buf = NULL;
	239	}
e0d59733	240	return size;
04851772 MF	241	}
04851772 MF	242
76cc9580	243	static int efi_pstore_write(struct pstore_record *record)
04851772 MF	244	{
	245	char name[DUMP_NAME_LEN];
	246	efi_char16_t efi_name[DUMP_NAME_LEN];
	247	efi_guid_t vendor = LINUX_EFI_CRASH_GUID;
	248	int i, ret = 0;
	249
76cc9580 KC	250	snprintf(name, sizeof(name), "dump-type%u-%u-%d-%lu-%c",
	251	record->type, record->part, record->count,
	252	get_seconds(), record->compressed ? 'C' : 'D');
04851772 MF	253
	254	for (i = 0; i < DUMP_NAME_LEN; i++)
	255	efi_name[i] = name[i];
	256
	257	efivar_entry_set_safe(efi_name, vendor, PSTORE_EFI_ATTRIBUTES,
76cc9580 KC	258	!pstore_cannot_block_path(record->reason),
76cc9580 KC	259	record->size, record->psi->buf);
04851772	260
76cc9580	261	if (record->reason == KMSG_DUMP_OOPS)
04851772 MF	262	efivar_run_worker();
04851772 MF	263
76cc9580	264	record->id = record->part;
04851772 MF	265	return ret;
	266	};
	267
	268	struct pstore_erase_data {
	269	u64 id;
	270	enum pstore_type_id type;
	271	int count;
	272	struct timespec time;
	273	efi_char16_t *name;
	274	};
	275
	276	/*
	277	* Clean up an entry with the same name
	278	*/
	279	static int efi_pstore_erase_func(struct efivar_entry entry, void data)
	280	{
	281	struct pstore_erase_data *ed = data;
	282	efi_guid_t vendor = LINUX_EFI_CRASH_GUID;
	283	efi_char16_t efi_name_old[DUMP_NAME_LEN];
	284	efi_char16_t *efi_name = ed->name;
a614e192	285	unsigned long ucs2_len = ucs2_strlen(ed->name);
04851772 MF	286	char name_old[DUMP_NAME_LEN];
	287	int i;
	288
	289	if (efi_guidcmp(entry->var.VendorGuid, vendor))
	290	return 0;
	291
a614e192 MF	292	if (ucs2_strncmp(entry->var.VariableName,
a614e192 MF	293	efi_name, (size_t)ucs2_len)) {
04851772 MF	294	/*
	295	* Check if an old format, which doesn't support
	296	* holding multiple logs, remains.
	297	*/
	298	sprintf(name_old, "dump-type%u-%u-%lu", ed->type,
	299	(unsigned int)ed->id, ed->time.tv_sec);
	300
	301	for (i = 0; i < DUMP_NAME_LEN; i++)
	302	efi_name_old[i] = name_old[i];
	303
a614e192 MF	304	if (ucs2_strncmp(entry->var.VariableName, efi_name_old,
a614e192 MF	305	ucs2_strlen(efi_name_old)))
04851772 MF	306	return 0;
	307	}
	308
e0d59733 SA	309	if (entry->scanning) {
	310	/*
	311	* Skip deletion because this entry will be deleted
	312	* after scanning is completed.
	313	*/
	314	entry->deleting = true;
	315	} else
	316	list_del(&entry->list);
	317
04851772 MF	318	/* found */
04851772 MF	319	__efivar_entry_delete(entry);
12abcfde	320
04851772 MF	321	return 1;
	322	}
	323
	324	static int efi_pstore_erase(enum pstore_type_id type, u64 id, int count,
	325	struct timespec time, struct pstore_info *psi)
	326	{
	327	struct pstore_erase_data edata;
4ee39e97	328	struct efivar_entry *entry = NULL;
04851772 MF	329	char name[DUMP_NAME_LEN];
	330	efi_char16_t efi_name[DUMP_NAME_LEN];
	331	int found, i;
fdeadb43	332	unsigned int part;
04851772	333
fdeadb43 MX	334	do_div(id, 1000);
	335	part = do_div(id, 100);
	336	sprintf(name, "dump-type%u-%u-%d-%lu", type, part, count, time.tv_sec);
04851772 MF	337
	338	for (i = 0; i < DUMP_NAME_LEN; i++)
	339	efi_name[i] = name[i];
	340
fdeadb43	341	edata.id = part;
04851772 MF	342	edata.type = type;
	343	edata.count = count;
	344	edata.time = time;
	345	edata.name = efi_name;
	346
21b3ddd3 SC	347	if (efivar_entry_iter_begin())
21b3ddd3 SC	348	return -EINTR;
04851772	349	found = __efivar_entry_iter(efi_pstore_erase_func, &efivar_sysfs_list, &edata, &entry);
04851772	350
e0d59733 SA	351	if (found && !entry->scanning) {
e0d59733 SA	352	efivar_entry_iter_end();
04851772	353	efivar_unregister(entry);
e0d59733 SA	354	} else
e0d59733 SA	355	efivar_entry_iter_end();
04851772 MF	356
	357	return 0;
	358	}
	359
	360	static struct pstore_info efi_pstore_info = {
	361	.owner = THIS_MODULE,
	362	.name = "efi",
c950fd6f	363	.flags = PSTORE_FLAGS_DMESG,
04851772 MF	364	.open = efi_pstore_open,
	365	.close = efi_pstore_close,
	366	.read = efi_pstore_read,
	367	.write = efi_pstore_write,
	368	.erase = efi_pstore_erase,
	369	};
	370
	371	static __init int efivars_pstore_init(void)
	372	{
	373	if (!efi_enabled(EFI_RUNTIME_SERVICES))
	374	return 0;
	375
	376	if (!efivars_kobject())
	377	return 0;
	378
	379	if (efivars_pstore_disable)
	380	return 0;
	381
	382	efi_pstore_info.buf = kmalloc(4096, GFP_KERNEL);
	383	if (!efi_pstore_info.buf)
	384	return -ENOMEM;
	385
	386	efi_pstore_info.bufsize = 1024;
	387	spin_lock_init(&efi_pstore_info.buf_lock);
	388
0d838347 LS	389	if (pstore_register(&efi_pstore_info)) {
	390	kfree(efi_pstore_info.buf);
	391	efi_pstore_info.buf = NULL;
	392	efi_pstore_info.bufsize = 0;
	393	}
04851772 MF	394
	395	return 0;
	396	}
	397
	398	static __exit void efivars_pstore_exit(void)
	399	{
cae73167 GT	400	if (!efi_pstore_info.bufsize)
	401	return;
	402
	403	pstore_unregister(&efi_pstore_info);
	404	kfree(efi_pstore_info.buf);
	405	efi_pstore_info.buf = NULL;
	406	efi_pstore_info.bufsize = 0;
04851772 MF	407	}
	408
	409	module_init(efivars_pstore_init);
	410	module_exit(efivars_pstore_exit);
	411
	412	MODULE_DESCRIPTION("EFI variable backend for pstore");
	413	MODULE_LICENSE("GPL");
9ac4d5ab	414	MODULE_ALIAS("platform:efivars");