ab420ef094c17a38bcfeb4d1be5f216563830d5b
2 * Persistent Storage - pstore.h
4 * Copyright (C) 2010 Intel Corporation <tony.luck@intel.com>
6 * This code is the generic layer to export data records from platform
7 * level persistent storage via a file system.
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.
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.
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
22 #ifndef _LINUX_PSTORE_H
23 #define _LINUX_PSTORE_H
25 #include <linux/compiler.h>
26 #include <linux/errno.h>
27 #include <linux/kmsg_dump.h>
28 #include <linux/mutex.h>
29 #include <linux/spinlock.h>
30 #include <linux/time.h>
31 #include <linux/types.h>
35 /* pstore record types (see fs/pstore/inode.c for filename templates) */
37 PSTORE_TYPE_DMESG
= 0,
39 PSTORE_TYPE_CONSOLE
= 2,
40 PSTORE_TYPE_FTRACE
= 3,
41 /* PPC64 partition types */
42 PSTORE_TYPE_PPC_RTAS
= 4,
43 PSTORE_TYPE_PPC_OF
= 5,
44 PSTORE_TYPE_PPC_COMMON
= 6,
46 PSTORE_TYPE_PPC_OPAL
= 8,
47 PSTORE_TYPE_ANNOTATE
= 9,
48 PSTORE_TYPE_UNKNOWN
= 255
53 * struct pstore_record - details of a pstore record entry
54 * @psi: pstore backend driver information
55 * @type: pstore record type
56 * @id: per-type unique identifier for record
57 * @time: timestamp of the record
58 * @buf: pointer to record contents
61 * ECC information for @buf
63 * Valid for PSTORE_TYPE_DMESG @type:
65 * @count: Oops count since boot
66 * @reason: kdump reason for notification
67 * @part: position in a multipart record
68 * @compressed: whether the buffer is compressed
71 struct pstore_record
{
72 struct pstore_info
*psi
;
73 enum pstore_type_id type
;
78 ssize_t ecc_notice_size
;
81 enum kmsg_dump_reason reason
;
87 * struct pstore_info - backend pstore driver structure
89 * @owner: module which is repsonsible for this backend driver
90 * @name: name of the backend driver
92 * @buf_lock: spinlock to serialize access to @buf
93 * @buf: preallocated crash dump buffer
94 * @bufsize: size of @buf available for crash dump bytes (must match
95 * smallest number of bytes available for writing to a
96 * backend entry, since compressed bytes don't take kindly
99 * @read_mutex: serializes @open, @read, @close, and @erase callbacks
100 * @flags: bitfield of frontends the backend can accept writes for
101 * @data: backend-private pointer passed back during callbacks
106 * Notify backend that pstore is starting a full read of backend
107 * records. Followed by one or more @read calls, and a final @close.
109 * @psi: in: pointer to the struct pstore_info for the backend
111 * Returns 0 on success, and non-zero on error.
114 * Notify backend that pstore has finished a full read of backend
115 * records. Always preceded by an @open call and one or more @read
118 * @psi: in: pointer to the struct pstore_info for the backend
120 * Returns 0 on success, and non-zero on error. (Though pstore will
124 * Read next available backend record. Called after a successful
128 * pointer to record to populate. @buf should be allocated
129 * by the backend and filled. At least @type and @id should
130 * be populated, since these are used when creating pstorefs
133 * Returns record size on success, zero when no more records are
134 * available, or negative on error.
137 * A newly generated record needs to be written to backend storage.
140 * pointer to record metadata. When @type is PSTORE_TYPE_DMESG,
141 * @buf will be pointing to the preallocated @psi.buf, since
142 * memory allocation may be broken during an Oops. Regardless,
143 * @buf must be proccesed or copied before returning. The
144 * backend is also expected to write @id with something that
145 * can help identify this record to a future @erase callback.
146 * The @time field will be prepopulated with the current time,
147 * when available. The @size field will have the size of data
150 * Returns 0 on success, and non-zero on error.
153 * Perform a frontend write to a backend record, using a specified
154 * buffer that is coming directly from userspace, instead of the
157 * @record: pointer to record metadata.
158 * @buf: pointer to userspace contents to write to backend
160 * Returns 0 on success, and non-zero on error.
163 * Delete a record from backend storage. Different backends
164 * identify records differently, so entire original record is
165 * passed back to assist in identification of what the backend
166 * should remove from storage.
168 * @record: pointer to record metadata.
170 * Returns 0 on success, and non-zero on error.
174 struct module
*owner
;
181 struct mutex read_mutex
;
186 int (*open
)(struct pstore_info
*psi
);
187 int (*close
)(struct pstore_info
*psi
);
188 ssize_t (*read
)(struct pstore_record
*record
);
189 int (*write
)(struct pstore_record
*record
);
190 int (*write_user
)(struct pstore_record
*record
,
191 const char __user
*buf
);
192 int (*erase
)(struct pstore_record
*record
);
195 /* Supported frontends */
196 #define PSTORE_FLAGS_DMESG (1 << 0)
197 #define PSTORE_FLAGS_CONSOLE (1 << 1)
198 #define PSTORE_FLAGS_FTRACE (1 << 2)
199 #define PSTORE_FLAGS_PMSG (1 << 3)
200 #define PSTORE_FLAGS_ANNOTATE (1 << 4)
202 extern int pstore_register(struct pstore_info
*);
203 extern void pstore_unregister(struct pstore_info
*);
204 extern bool pstore_cannot_block_path(enum kmsg_dump_reason reason
);
205 extern int pstore_annotate(const char *buf
);
207 struct pstore_ftrace_record
{
209 unsigned long parent_ip
;
214 * ftrace related stuff: Both backends and frontends need these so expose
218 #if NR_CPUS <= 2 && defined(CONFIG_ARM_THUMB)
219 #define PSTORE_CPU_IN_IP 0x1
220 #elif NR_CPUS <= 4 && defined(CONFIG_ARM)
221 #define PSTORE_CPU_IN_IP 0x3
224 #define TS_CPU_SHIFT 8
225 #define TS_CPU_MASK (BIT(TS_CPU_SHIFT) - 1)
228 * If CPU number can be stored in IP, store it there, otherwise store it in
229 * the time stamp. This means more timestamp resolution is available when
230 * the CPU can be stored in the IP.
232 #ifdef PSTORE_CPU_IN_IP
234 pstore_ftrace_encode_cpu(struct pstore_ftrace_record
*rec
, unsigned int cpu
)
239 static inline unsigned int
240 pstore_ftrace_decode_cpu(struct pstore_ftrace_record
*rec
)
242 return rec
->ip
& PSTORE_CPU_IN_IP
;
246 pstore_ftrace_read_timestamp(struct pstore_ftrace_record
*rec
)
252 pstore_ftrace_write_timestamp(struct pstore_ftrace_record
*rec
, u64 val
)
258 pstore_ftrace_encode_cpu(struct pstore_ftrace_record
*rec
, unsigned int cpu
)
260 rec
->ts
&= ~(TS_CPU_MASK
);
264 static inline unsigned int
265 pstore_ftrace_decode_cpu(struct pstore_ftrace_record
*rec
)
267 return rec
->ts
& TS_CPU_MASK
;
271 pstore_ftrace_read_timestamp(struct pstore_ftrace_record
*rec
)
273 return rec
->ts
>> TS_CPU_SHIFT
;
277 pstore_ftrace_write_timestamp(struct pstore_ftrace_record
*rec
, u64 val
)
279 rec
->ts
= (rec
->ts
& TS_CPU_MASK
) | (val
<< TS_CPU_SHIFT
);
283 #endif /*_LINUX_PSTORE_H*/