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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> |
26 | #include <linux/errno.h> | |
3d6d8d20 | 27 | #include <linux/kmsg_dump.h> |
67a101f5 | 28 | #include <linux/mutex.h> |
ea84b580 | 29 | #include <linux/semaphore.h> |
5bf6d1b9 MS |
30 | #include <linux/time.h> |
31 | #include <linux/types.h> | |
3d6d8d20 | 32 | |
9abdcccc KC |
33 | struct module; |
34 | ||
f0f23e54 JFG |
35 | /* |
36 | * pstore record types (see fs/pstore/platform.c for pstore_type_names[]) | |
37 | * These values may be written to storage (see EFI vars backend), so | |
38 | * they are kind of an ABI. Be careful changing the mappings. | |
39 | */ | |
ca01d6dd | 40 | enum pstore_type_id { |
f0f23e54 | 41 | /* Frontend storage types */ |
ca01d6dd TL |
42 | PSTORE_TYPE_DMESG = 0, |
43 | PSTORE_TYPE_MCE = 1, | |
f29e5956 | 44 | PSTORE_TYPE_CONSOLE = 2, |
060287b8 | 45 | PSTORE_TYPE_FTRACE = 3, |
f0f23e54 JFG |
46 | |
47 | /* PPC64-specific partition types */ | |
69020eea | 48 | PSTORE_TYPE_PPC_RTAS = 4, |
f33f748c | 49 | PSTORE_TYPE_PPC_OF = 5, |
a5e4797b | 50 | PSTORE_TYPE_PPC_COMMON = 6, |
9d5438f4 | 51 | PSTORE_TYPE_PMSG = 7, |
ae011d2e | 52 | PSTORE_TYPE_PPC_OPAL = 8, |
f0f23e54 JFG |
53 | |
54 | /* End of the list */ | |
55 | PSTORE_TYPE_MAX | |
ca01d6dd TL |
56 | }; |
57 | ||
f0f23e54 JFG |
58 | const char *pstore_type_to_name(enum pstore_type_id type); |
59 | enum pstore_type_id pstore_name_to_type(const char *name); | |
60 | ||
9abdcccc KC |
61 | struct pstore_info; |
62 | /** | |
63 | * struct pstore_record - details of a pstore record entry | |
64 | * @psi: pstore backend driver information | |
65 | * @type: pstore record type | |
66 | * @id: per-type unique identifier for record | |
67 | * @time: timestamp of the record | |
9abdcccc KC |
68 | * @buf: pointer to record contents |
69 | * @size: size of @buf | |
70 | * @ecc_notice_size: | |
71 | * ECC information for @buf | |
76cc9580 KC |
72 | * |
73 | * Valid for PSTORE_TYPE_DMESG @type: | |
74 | * | |
75 | * @count: Oops count since boot | |
76 | * @reason: kdump reason for notification | |
77 | * @part: position in a multipart record | |
78 | * @compressed: whether the buffer is compressed | |
79 | * | |
9abdcccc KC |
80 | */ |
81 | struct pstore_record { | |
82 | struct pstore_info *psi; | |
83 | enum pstore_type_id type; | |
84 | u64 id; | |
7aaa822e | 85 | struct timespec64 time; |
9abdcccc KC |
86 | char *buf; |
87 | ssize_t size; | |
88 | ssize_t ecc_notice_size; | |
76cc9580 KC |
89 | |
90 | int count; | |
91 | enum kmsg_dump_reason reason; | |
92 | unsigned int part; | |
93 | bool compressed; | |
9abdcccc | 94 | }; |
67a101f5 | 95 | |
0edae0b3 KC |
96 | /** |
97 | * struct pstore_info - backend pstore driver structure | |
98 | * | |
0eed84ff | 99 | * @owner: module which is responsible for this backend driver |
0edae0b3 KC |
100 | * @name: name of the backend driver |
101 | * | |
ea84b580 | 102 | * @buf_lock: semaphore to serialize access to @buf |
0edae0b3 | 103 | * @buf: preallocated crash dump buffer |
89d328f6 KC |
104 | * @bufsize: size of @buf available for crash dump bytes (must match |
105 | * smallest number of bytes available for writing to a | |
106 | * backend entry, since compressed bytes don't take kindly | |
107 | * to being truncated) | |
0edae0b3 KC |
108 | * |
109 | * @read_mutex: serializes @open, @read, @close, and @erase callbacks | |
110 | * @flags: bitfield of frontends the backend can accept writes for | |
111 | * @data: backend-private pointer passed back during callbacks | |
112 | * | |
113 | * Callbacks: | |
114 | * | |
115 | * @open: | |
116 | * Notify backend that pstore is starting a full read of backend | |
117 | * records. Followed by one or more @read calls, and a final @close. | |
118 | * | |
119 | * @psi: in: pointer to the struct pstore_info for the backend | |
120 | * | |
121 | * Returns 0 on success, and non-zero on error. | |
122 | * | |
123 | * @close: | |
124 | * Notify backend that pstore has finished a full read of backend | |
125 | * records. Always preceded by an @open call and one or more @read | |
126 | * calls. | |
127 | * | |
128 | * @psi: in: pointer to the struct pstore_info for the backend | |
129 | * | |
130 | * Returns 0 on success, and non-zero on error. (Though pstore will | |
131 | * ignore the error.) | |
132 | * | |
133 | * @read: | |
134 | * Read next available backend record. Called after a successful | |
135 | * @open. | |
136 | * | |
125cc42b KC |
137 | * @record: |
138 | * pointer to record to populate. @buf should be allocated | |
139 | * by the backend and filled. At least @type and @id should | |
140 | * be populated, since these are used when creating pstorefs | |
141 | * file names. | |
0edae0b3 KC |
142 | * |
143 | * Returns record size on success, zero when no more records are | |
144 | * available, or negative on error. | |
145 | * | |
146 | * @write: | |
4c9ec219 | 147 | * A newly generated record needs to be written to backend storage. |
0edae0b3 | 148 | * |
76cc9580 | 149 | * @record: |
4c9ec219 KC |
150 | * pointer to record metadata. When @type is PSTORE_TYPE_DMESG, |
151 | * @buf will be pointing to the preallocated @psi.buf, since | |
152 | * memory allocation may be broken during an Oops. Regardless, | |
153 | * @buf must be proccesed or copied before returning. The | |
154 | * backend is also expected to write @id with something that | |
c7f3c595 KC |
155 | * can help identify this record to a future @erase callback. |
156 | * The @time field will be prepopulated with the current time, | |
157 | * when available. The @size field will have the size of data | |
158 | * in @buf. | |
0edae0b3 KC |
159 | * |
160 | * Returns 0 on success, and non-zero on error. | |
161 | * | |
4c9ec219 | 162 | * @write_user: |
0edae0b3 | 163 | * Perform a frontend write to a backend record, using a specified |
fdd03118 KC |
164 | * buffer that is coming directly from userspace, instead of the |
165 | * @record @buf. | |
166 | * | |
167 | * @record: pointer to record metadata. | |
168 | * @buf: pointer to userspace contents to write to backend | |
0edae0b3 KC |
169 | * |
170 | * Returns 0 on success, and non-zero on error. | |
171 | * | |
172 | * @erase: | |
173 | * Delete a record from backend storage. Different backends | |
a61072aa KC |
174 | * identify records differently, so entire original record is |
175 | * passed back to assist in identification of what the backend | |
176 | * should remove from storage. | |
0edae0b3 | 177 | * |
a61072aa | 178 | * @record: pointer to record metadata. |
0edae0b3 KC |
179 | * |
180 | * Returns 0 on success, and non-zero on error. | |
181 | * | |
182 | */ | |
ca01d6dd TL |
183 | struct pstore_info { |
184 | struct module *owner; | |
185 | char *name; | |
0edae0b3 | 186 | |
ea84b580 | 187 | struct semaphore buf_lock; |
ca01d6dd TL |
188 | char *buf; |
189 | size_t bufsize; | |
0edae0b3 KC |
190 | |
191 | struct mutex read_mutex; | |
192 | ||
df36ac1b | 193 | int flags; |
0edae0b3 KC |
194 | void *data; |
195 | ||
06cf91b4 CG |
196 | int (*open)(struct pstore_info *psi); |
197 | int (*close)(struct pstore_info *psi); | |
125cc42b | 198 | ssize_t (*read)(struct pstore_record *record); |
76cc9580 | 199 | int (*write)(struct pstore_record *record); |
4c9ec219 KC |
200 | int (*write_user)(struct pstore_record *record, |
201 | const char __user *buf); | |
a61072aa | 202 | int (*erase)(struct pstore_record *record); |
ca01d6dd TL |
203 | }; |
204 | ||
0edae0b3 | 205 | /* Supported frontends */ |
4af62a64 KC |
206 | #define PSTORE_FLAGS_DMESG BIT(0) |
207 | #define PSTORE_FLAGS_CONSOLE BIT(1) | |
208 | #define PSTORE_FLAGS_FTRACE BIT(2) | |
209 | #define PSTORE_FLAGS_PMSG BIT(3) | |
c950fd6f | 210 | |
ca01d6dd | 211 | extern int pstore_register(struct pstore_info *); |
ee1d2674 | 212 | extern void pstore_unregister(struct pstore_info *); |
ca01d6dd | 213 | |
fbccdeb8 JF |
214 | struct pstore_ftrace_record { |
215 | unsigned long ip; | |
216 | unsigned long parent_ip; | |
217 | u64 ts; | |
218 | }; | |
219 | ||
220 | /* | |
221 | * ftrace related stuff: Both backends and frontends need these so expose | |
222 | * them here. | |
223 | */ | |
224 | ||
225 | #if NR_CPUS <= 2 && defined(CONFIG_ARM_THUMB) | |
226 | #define PSTORE_CPU_IN_IP 0x1 | |
227 | #elif NR_CPUS <= 4 && defined(CONFIG_ARM) | |
228 | #define PSTORE_CPU_IN_IP 0x3 | |
229 | #endif | |
230 | ||
231 | #define TS_CPU_SHIFT 8 | |
232 | #define TS_CPU_MASK (BIT(TS_CPU_SHIFT) - 1) | |
233 | ||
234 | /* | |
235 | * If CPU number can be stored in IP, store it there, otherwise store it in | |
236 | * the time stamp. This means more timestamp resolution is available when | |
237 | * the CPU can be stored in the IP. | |
238 | */ | |
239 | #ifdef PSTORE_CPU_IN_IP | |
240 | static inline void | |
241 | pstore_ftrace_encode_cpu(struct pstore_ftrace_record *rec, unsigned int cpu) | |
242 | { | |
243 | rec->ip |= cpu; | |
244 | } | |
245 | ||
246 | static inline unsigned int | |
247 | pstore_ftrace_decode_cpu(struct pstore_ftrace_record *rec) | |
248 | { | |
249 | return rec->ip & PSTORE_CPU_IN_IP; | |
250 | } | |
251 | ||
252 | static inline u64 | |
253 | pstore_ftrace_read_timestamp(struct pstore_ftrace_record *rec) | |
254 | { | |
255 | return rec->ts; | |
256 | } | |
257 | ||
258 | static inline void | |
259 | pstore_ftrace_write_timestamp(struct pstore_ftrace_record *rec, u64 val) | |
260 | { | |
261 | rec->ts = val; | |
262 | } | |
263 | #else | |
264 | static inline void | |
265 | pstore_ftrace_encode_cpu(struct pstore_ftrace_record *rec, unsigned int cpu) | |
266 | { | |
267 | rec->ts &= ~(TS_CPU_MASK); | |
268 | rec->ts |= cpu; | |
269 | } | |
270 | ||
271 | static inline unsigned int | |
272 | pstore_ftrace_decode_cpu(struct pstore_ftrace_record *rec) | |
273 | { | |
274 | return rec->ts & TS_CPU_MASK; | |
275 | } | |
276 | ||
277 | static inline u64 | |
278 | pstore_ftrace_read_timestamp(struct pstore_ftrace_record *rec) | |
279 | { | |
280 | return rec->ts >> TS_CPU_SHIFT; | |
281 | } | |
282 | ||
283 | static inline void | |
284 | pstore_ftrace_write_timestamp(struct pstore_ftrace_record *rec, u64 val) | |
285 | { | |
286 | rec->ts = (rec->ts & TS_CPU_MASK) | (val << TS_CPU_SHIFT); | |
287 | } | |
288 | #endif | |
289 | ||
ca01d6dd | 290 | #endif /*_LINUX_PSTORE_H*/ |