[linux-block.git] / include / linux / pstore.h

/*
 * Persistent Storage - pstore.h
 *
 * Copyright (C) 2010 Intel Corporation <tony.luck@intel.com>
 *
 * This code is the generic layer to export data records from platform
 * level persistent storage via a file system.
 *
 *  This program is free software; you can redistribute it and/or modify
 *  it under the terms of the GNU General Public License version 2 as
 *  published by the Free Software Foundation.
 *
 *  This program is distributed in the hope that it will be useful,
 *  but WITHOUT ANY WARRANTY; without even the implied warranty of
 *  MERCHANTABILITY or FITNESS FOR A PARTICULAR PURPOSE.  See the
 *  GNU General Public License for more details.
 *
 *  You should have received a copy of the GNU General Public License
 *  along with this program; if not, write to the Free Software
 *  Foundation, Inc., 59 Temple Place, Suite 330, Boston, MA  02111-1307  USA
 */
#ifndef _LINUX_PSTORE_H
#define _LINUX_PSTORE_H

#include <linux/compiler.h>
#include <linux/errno.h>
#include <linux/kmsg_dump.h>
#include <linux/mutex.h>
#include <linux/spinlock.h>
#include <linux/time.h>
#include <linux/types.h>

/* pstore record types (see fs/pstore/inode.c for filename templates) */
enum pstore_type_id {
	PSTORE_TYPE_DMESG	= 0,
	PSTORE_TYPE_MCE		= 1,
	PSTORE_TYPE_CONSOLE	= 2,
	PSTORE_TYPE_FTRACE	= 3,
	/* PPC64 partition types */
	PSTORE_TYPE_PPC_RTAS	= 4,
	PSTORE_TYPE_PPC_OF	= 5,
	PSTORE_TYPE_PPC_COMMON	= 6,
	PSTORE_TYPE_PMSG	= 7,
	PSTORE_TYPE_PPC_OPAL	= 8,
	PSTORE_TYPE_UNKNOWN	= 255
};

struct module;

/**
 * struct pstore_info - backend pstore driver structure
 *
 * @owner:	module which is repsonsible for this backend driver
 * @name:	name of the backend driver
 *
 * @buf_lock:	spinlock to serialize access to @buf
 * @buf:	preallocated crash dump buffer
 * @bufsize:	size of @buf available for crash dump writes
 *
 * @read_mutex:	serializes @open, @read, @close, and @erase callbacks
 * @flags:	bitfield of frontends the backend can accept writes for
 * @data:	backend-private pointer passed back during callbacks
 *
 * Callbacks:
 *
 * @open:
 *	Notify backend that pstore is starting a full read of backend
 *	records. Followed by one or more @read calls, and a final @close.
 *
 *	@psi:	in: pointer to the struct pstore_info for the backend
 *
 *	Returns 0 on success, and non-zero on error.
 *
 * @close:
 *	Notify backend that pstore has finished a full read of backend
 *	records. Always preceded by an @open call and one or more @read
 *	calls.
 *
 *	@psi:	in: pointer to the struct pstore_info for the backend
 *
 *	Returns 0 on success, and non-zero on error. (Though pstore will
 *	ignore the error.)
 *
 * @read:
 *	Read next available backend record. Called after a successful
 *	@open.
 *
 *	@id:	out: unique identifier for the record
 *	@type:	out: pstore record type
 *	@count: out: for PSTORE_TYPE_DMESG, the Oops count.
 *	@time:	out: timestamp for the record
 *	@buf:	out: kmalloc copy of record contents, to be freed by pstore
 *	@compressed:
 *		out: if the record contents are compressed
 *	@ecc_notice_size:
 *		out: ECC information
 *	@psi:	in: pointer to the struct pstore_info for the backend
 *
 *	Returns record size on success, zero when no more records are
 *	available, or negative on error.
 *
 * @write:
 *	Perform a frontend notification of a write to a backend record. The
 *	data to be stored has already been written to the registered @buf
 *	of the @psi structure.
 *
 *	@type:	in: pstore record type to write
 *	@reason:
 *		in: pstore write reason
 *	@id:	out: unique identifier for the record
 *	@part:	in: position in a multipart write
 *	@count:	in: increasing from 0 since boot, the number of this Oops
 *	@compressed:
 *		in: if the record is compressed
 *	@size:	in: size of the write
 *	@psi:	in: pointer to the struct pstore_info for the backend
 *
 *	Returns 0 on success, and non-zero on error.
 *
 * @write_buf:
 *	Perform a frontend write to a backend record, using a specified
 *	buffer. Unlike @write, this does not use the @psi @buf.
 *
 *	@type:	in: pstore record type to write
 *	@reason:
 *		in: pstore write reason
 *	@id:	out: unique identifier for the record
 *	@part:	in: position in a multipart write
 *	@buf:	in: pointer to contents to write to backend record
 *	@compressed:
 *		in: if the record is compressed
 *	@size:	in: size of the write
 *	@psi:	in: pointer to the struct pstore_info for the backend
 *
 *	Returns 0 on success, and non-zero on error.
 *
 * @write_buf_user:
 *	Perform a frontend write to a backend record, using a specified
 *	buffer that is coming directly from userspace.
 *
 *	@type:	in: pstore record type to write
 *	@reason:
 *		in: pstore write reason
 *	@id:	out: unique identifier for the record
 *	@part:	in: position in a multipart write
 *	@buf:	in: pointer to userspace contents to write to backend record
 *	@compressed:
 *		in: if the record is compressed
 *	@size:	in: size of the write
 *	@psi:	in: pointer to the struct pstore_info for the backend
 *
 *	Returns 0 on success, and non-zero on error.
 *
 * @erase:
 *	Delete a record from backend storage.  Different backends
 *	identify records differently, so all possible methods of
 *	identification are included to help the backend locate the
 *	record to remove.
 *
 *	@type:	in: pstore record type to write
 *	@id:	in: per-type unique identifier for the record
 *	@count:	in: Oops count
 *	@time:	in: timestamp for the record
 *	@psi:	in: pointer to the struct pstore_info for the backend
 *
 *	Returns 0 on success, and non-zero on error.
 *
 */
struct pstore_info {
	struct module	*owner;
	char		*name;

	spinlock_t	buf_lock;
	char		*buf;
	size_t		bufsize;

	struct mutex	read_mutex;

	int		flags;
	void		*data;

	int		(*open)(struct pstore_info *psi);
	int		(*close)(struct pstore_info *psi);
	ssize_t		(*read)(u64 *id, enum pstore_type_id *type,
			int *count, struct timespec *time, char **buf,
			bool *compressed, ssize_t *ecc_notice_size,
			struct pstore_info *psi);
	int		(*write)(enum pstore_type_id type,
			enum kmsg_dump_reason reason, u64 *id,
			unsigned int part, int count, bool compressed,
			size_t size, struct pstore_info *psi);
	int		(*write_buf)(enum pstore_type_id type,
			enum kmsg_dump_reason reason, u64 *id,
			unsigned int part, const char *buf, bool compressed,
			size_t size, struct pstore_info *psi);
	int		(*write_buf_user)(enum pstore_type_id type,
			enum kmsg_dump_reason reason, u64 *id,
			unsigned int part, const char __user *buf,
			bool compressed, size_t size, struct pstore_info *psi);
	int		(*erase)(enum pstore_type_id type, u64 id,
			int count, struct timespec time,
			struct pstore_info *psi);
};

/* Supported frontends */
#define PSTORE_FLAGS_DMESG	(1 << 0)
#define PSTORE_FLAGS_CONSOLE	(1 << 1)
#define PSTORE_FLAGS_FTRACE	(1 << 2)
#define PSTORE_FLAGS_PMSG	(1 << 3)

extern int pstore_register(struct pstore_info *);
extern void pstore_unregister(struct pstore_info *);
extern bool pstore_cannot_block_path(enum kmsg_dump_reason reason);

struct pstore_ftrace_record {
	unsigned long ip;
	unsigned long parent_ip;
	u64 ts;
};

/*
 * ftrace related stuff: Both backends and frontends need these so expose
 * them here.
 */

#if NR_CPUS <= 2 && defined(CONFIG_ARM_THUMB)
#define PSTORE_CPU_IN_IP 0x1
#elif NR_CPUS <= 4 && defined(CONFIG_ARM)
#define PSTORE_CPU_IN_IP 0x3
#endif

#define TS_CPU_SHIFT 8
#define TS_CPU_MASK (BIT(TS_CPU_SHIFT) - 1)

/*
 * If CPU number can be stored in IP, store it there, otherwise store it in
 * the time stamp. This means more timestamp resolution is available when
 * the CPU can be stored in the IP.
 */
#ifdef PSTORE_CPU_IN_IP
static inline void
pstore_ftrace_encode_cpu(struct pstore_ftrace_record *rec, unsigned int cpu)
{
	rec->ip |= cpu;
}

static inline unsigned int
pstore_ftrace_decode_cpu(struct pstore_ftrace_record *rec)
{
	return rec->ip & PSTORE_CPU_IN_IP;
}

static inline u64
pstore_ftrace_read_timestamp(struct pstore_ftrace_record *rec)
{
	return rec->ts;
}

static inline void
pstore_ftrace_write_timestamp(struct pstore_ftrace_record *rec, u64 val)
{
	rec->ts = val;
}
#else
static inline void
pstore_ftrace_encode_cpu(struct pstore_ftrace_record *rec, unsigned int cpu)
{
	rec->ts &= ~(TS_CPU_MASK);
	rec->ts |= cpu;
}

static inline unsigned int
pstore_ftrace_decode_cpu(struct pstore_ftrace_record *rec)
{
	return rec->ts & TS_CPU_MASK;
}

static inline u64
pstore_ftrace_read_timestamp(struct pstore_ftrace_record *rec)
{
	return rec->ts >> TS_CPU_SHIFT;
}

static inline void
pstore_ftrace_write_timestamp(struct pstore_ftrace_record *rec, u64 val)
{
	rec->ts = (rec->ts & TS_CPU_MASK) | (val << TS_CPU_SHIFT);
}
#endif

#endif /*_LINUX_PSTORE_H*/
Commit	Line	Data
ca01d6dd TL	1	/*
	2	* Persistent Storage - pstore.h
	3	*
	4	* Copyright (C) 2010 Intel Corporation <tony.luck@intel.com>
	5	*
	6	* This code is the generic layer to export data records from platform
	7	* level persistent storage via a file system.
	8	*
	9	* This program is free software; you can redistribute it and/or modify
	10	* it under the terms of the GNU General Public License version 2 as
	11	* published by the Free Software Foundation.
	12	*
	13	* This program is distributed in the hope that it will be useful,
	14	* but WITHOUT ANY WARRANTY; without even the implied warranty of
	15	* MERCHANTABILITY or FITNESS FOR A PARTICULAR PURPOSE. See the
	16	* GNU General Public License for more details.
	17	*
	18	* You should have received a copy of the GNU General Public License
	19	* along with this program; if not, write to the Free Software
	20	* Foundation, Inc., 59 Temple Place, Suite 330, Boston, MA 02111-1307 USA
	21	*/
	22	#ifndef _LINUX_PSTORE_H
	23	#define _LINUX_PSTORE_H
	24
5bf6d1b9 MS	25	#include <linux/compiler.h>
5bf6d1b9 MS	26	#include <linux/errno.h>
3d6d8d20	27	#include <linux/kmsg_dump.h>
67a101f5	28	#include <linux/mutex.h>
67a101f5	29	#include <linux/spinlock.h>
5bf6d1b9 MS	30	#include <linux/time.h>
5bf6d1b9 MS	31	#include <linux/types.h>
3d6d8d20	32
0edae0b3	33	/* pstore record types (see fs/pstore/inode.c for filename templates) */
ca01d6dd TL	34	enum pstore_type_id {
	35	PSTORE_TYPE_DMESG = 0,
	36	PSTORE_TYPE_MCE = 1,
f29e5956	37	PSTORE_TYPE_CONSOLE = 2,
060287b8	38	PSTORE_TYPE_FTRACE = 3,
69020eea AB	39	/* PPC64 partition types */
69020eea AB	40	PSTORE_TYPE_PPC_RTAS = 4,
f33f748c	41	PSTORE_TYPE_PPC_OF = 5,
a5e4797b	42	PSTORE_TYPE_PPC_COMMON = 6,
9d5438f4	43	PSTORE_TYPE_PMSG = 7,
ae011d2e	44	PSTORE_TYPE_PPC_OPAL = 8,
ca01d6dd TL	45	PSTORE_TYPE_UNKNOWN = 255
	46	};
	47
67a101f5 AV	48	struct module;
67a101f5 AV	49
0edae0b3 KC	50	/**
	51	* struct pstore_info - backend pstore driver structure
	52	*
	53	* @owner: module which is repsonsible for this backend driver
	54	* @name: name of the backend driver
	55	*
	56	* @buf_lock: spinlock to serialize access to @buf
	57	* @buf: preallocated crash dump buffer
	58	* @bufsize: size of @buf available for crash dump writes
	59	*
	60	* @read_mutex: serializes @open, @read, @close, and @erase callbacks
	61	* @flags: bitfield of frontends the backend can accept writes for
	62	* @data: backend-private pointer passed back during callbacks
	63	*
	64	* Callbacks:
	65	*
	66	* @open:
	67	* Notify backend that pstore is starting a full read of backend
	68	* records. Followed by one or more @read calls, and a final @close.
	69	*
	70	* @psi: in: pointer to the struct pstore_info for the backend
	71	*
	72	* Returns 0 on success, and non-zero on error.
	73	*
	74	* @close:
	75	* Notify backend that pstore has finished a full read of backend
	76	* records. Always preceded by an @open call and one or more @read
	77	* calls.
	78	*
	79	* @psi: in: pointer to the struct pstore_info for the backend
	80	*
	81	* Returns 0 on success, and non-zero on error. (Though pstore will
	82	* ignore the error.)
	83	*
	84	* @read:
	85	* Read next available backend record. Called after a successful
	86	* @open.
	87	*
	88	* @id: out: unique identifier for the record
	89	* @type: out: pstore record type
	90	* @count: out: for PSTORE_TYPE_DMESG, the Oops count.
	91	* @time: out: timestamp for the record
	92	* @buf: out: kmalloc copy of record contents, to be freed by pstore
	93	* @compressed:
	94	* out: if the record contents are compressed
	95	* @ecc_notice_size:
	96	* out: ECC information
	97	* @psi: in: pointer to the struct pstore_info for the backend
	98	*
	99	* Returns record size on success, zero when no more records are
	100	* available, or negative on error.
	101	*
	102	* @write:
	103	* Perform a frontend notification of a write to a backend record. The
	104	* data to be stored has already been written to the registered @buf
	105	* of the @psi structure.
	106	*
	107	* @type: in: pstore record type to write
	108	* @reason:
	109	* in: pstore write reason
	110	* @id: out: unique identifier for the record
	111	* @part: in: position in a multipart write
	112	* @count: in: increasing from 0 since boot, the number of this Oops
	113	* @compressed:
114	* in: if the record is compressed
115	* @size: in: size of the write
116	* @psi: in: pointer to the struct pstore_info for the backend
117	*
118	* Returns 0 on success, and non-zero on error.
119	*
120	* @write_buf:
121	* Perform a frontend write to a backend record, using a specified
122	* buffer. Unlike @write, this does not use the @psi @buf.
123	*
124	* @type: in: pstore record type to write
125	* @reason:
126	* in: pstore write reason
127	* @id: out: unique identifier for the record
128	* @part: in: position in a multipart write
129	* @buf: in: pointer to contents to write to backend record
130	* @compressed:
131	* in: if the record is compressed
132	* @size: in: size of the write
133	* @psi: in: pointer to the struct pstore_info for the backend
134	*
135	* Returns 0 on success, and non-zero on error.
136	*
137	* @write_buf_user:
138	* Perform a frontend write to a backend record, using a specified
139	* buffer that is coming directly from userspace.
140	*
141	* @type: in: pstore record type to write
142	* @reason:
143	* in: pstore write reason
144	* @id: out: unique identifier for the record
145	* @part: in: position in a multipart write
146	* @buf: in: pointer to userspace contents to write to backend record
147	* @compressed:
148	* in: if the record is compressed
149	* @size: in: size of the write
150	* @psi: in: pointer to the struct pstore_info for the backend
151	*
152	* Returns 0 on success, and non-zero on error.
153	*
154	* @erase:
155	* Delete a record from backend storage. Different backends
156	* identify records differently, so all possible methods of
157	* identification are included to help the backend locate the
158	* record to remove.
159	*
160	* @type: in: pstore record type to write
161	* @id: in: per-type unique identifier for the record
162	* @count: in: Oops count
163	* @time: in: timestamp for the record
164	* @psi: in: pointer to the struct pstore_info for the backend
165	*
166	* Returns 0 on success, and non-zero on error.
167	*
168	*/
ca01d6dd TL	169	struct pstore_info {
	170	struct module *owner;
	171	char *name;
0edae0b3 KC	172
0edae0b3 KC	173	spinlock_t buf_lock;
ca01d6dd TL	174	char *buf;
ca01d6dd TL	175	size_t bufsize;
0edae0b3 KC	176
	177	struct mutex read_mutex;
	178
df36ac1b	179	int flags;
0edae0b3 KC	180	void *data;
0edae0b3 KC	181
06cf91b4 CG	182	int (open)(struct pstore_info psi);
06cf91b4 CG	183	int (close)(struct pstore_info psi);
8d38d74b	184	ssize_t (read)(u64 id, enum pstore_type_id *type,
755d4fe4	185	int count, struct timespec time, char **buf,
8cfc8ddc GT	186	bool compressed, ssize_t ecc_notice_size,
8cfc8ddc GT	187	struct pstore_info *psi);
3d6d8d20 KC	188	int (*write)(enum pstore_type_id type,
3d6d8d20 KC	189	enum kmsg_dump_reason reason, u64 *id,
b3b515bb	190	unsigned int part, int count, bool compressed,
6bbbca73	191	size_t size, struct pstore_info *psi);
897dba02 AV	192	int (*write_buf)(enum pstore_type_id type,
897dba02 AV	193	enum kmsg_dump_reason reason, u64 *id,
b3b515bb	194	unsigned int part, const char *buf, bool compressed,
6bbbca73	195	size_t size, struct pstore_info *psi);
5bf6d1b9 MS	196	int (*write_buf_user)(enum pstore_type_id type,
	197	enum kmsg_dump_reason reason, u64 *id,
	198	unsigned int part, const char __user *buf,
	199	bool compressed, size_t size, struct pstore_info *psi);
56280682	200	int (*erase)(enum pstore_type_id type, u64 id,
755d4fe4 SA	201	int count, struct timespec time,
755d4fe4 SA	202	struct pstore_info *psi);
ca01d6dd TL	203	};
ca01d6dd TL	204
0edae0b3	205	/* Supported frontends */
c950fd6f	206	#define PSTORE_FLAGS_DMESG (1 << 0)
c950fd6f NK	207	#define PSTORE_FLAGS_CONSOLE (1 << 1)
	208	#define PSTORE_FLAGS_FTRACE (1 << 2)
	209	#define PSTORE_FLAGS_PMSG (1 << 3)
	210
ca01d6dd	211	extern int pstore_register(struct pstore_info *);
ee1d2674	212	extern void pstore_unregister(struct pstore_info *);
9f244e9c	213	extern bool pstore_cannot_block_path(enum kmsg_dump_reason reason);
ca01d6dd	214
fbccdeb8 JF	215	struct pstore_ftrace_record {
	216	unsigned long ip;
	217	unsigned long parent_ip;
	218	u64 ts;
	219	};
	220
	221	/*
	222	* ftrace related stuff: Both backends and frontends need these so expose
	223	* them here.
	224	*/
	225
	226	#if NR_CPUS <= 2 && defined(CONFIG_ARM_THUMB)
	227	#define PSTORE_CPU_IN_IP 0x1
	228	#elif NR_CPUS <= 4 && defined(CONFIG_ARM)
	229	#define PSTORE_CPU_IN_IP 0x3
	230	#endif
	231
	232	#define TS_CPU_SHIFT 8
	233	#define TS_CPU_MASK (BIT(TS_CPU_SHIFT) - 1)
	234
	235	/*
	236	* If CPU number can be stored in IP, store it there, otherwise store it in
	237	* the time stamp. This means more timestamp resolution is available when
	238	* the CPU can be stored in the IP.
	239	*/
	240	#ifdef PSTORE_CPU_IN_IP
	241	static inline void
	242	pstore_ftrace_encode_cpu(struct pstore_ftrace_record *rec, unsigned int cpu)
	243	{
	244	rec->ip \|= cpu;
	245	}
	246
	247	static inline unsigned int
	248	pstore_ftrace_decode_cpu(struct pstore_ftrace_record *rec)
	249	{
	250	return rec->ip & PSTORE_CPU_IN_IP;
	251	}
	252
	253	static inline u64
	254	pstore_ftrace_read_timestamp(struct pstore_ftrace_record *rec)
	255	{
	256	return rec->ts;
	257	}
	258
	259	static inline void
	260	pstore_ftrace_write_timestamp(struct pstore_ftrace_record *rec, u64 val)
	261	{
	262	rec->ts = val;
	263	}
	264	#else
	265	static inline void
	266	pstore_ftrace_encode_cpu(struct pstore_ftrace_record *rec, unsigned int cpu)
	267	{
	268	rec->ts &= ~(TS_CPU_MASK);
	269	rec->ts \|= cpu;
	270	}
	271
	272	static inline unsigned int
	273	pstore_ftrace_decode_cpu(struct pstore_ftrace_record *rec)
	274	{
	275	return rec->ts & TS_CPU_MASK;
	276	}
	277
	278	static inline u64
279	pstore_ftrace_read_timestamp(struct pstore_ftrace_record *rec)
280	{
281	return rec->ts >> TS_CPU_SHIFT;
282	}
283
284	static inline void
285	pstore_ftrace_write_timestamp(struct pstore_ftrace_record *rec, u64 val)
286	{
287	rec->ts = (rec->ts & TS_CPU_MASK) \| (val << TS_CPU_SHIFT);
288	}
289	#endif
290
ca01d6dd	291	#endif /_LINUX_PSTORE_H/