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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
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>
32
33/* types */
34enum pstore_type_id {
35 PSTORE_TYPE_DMESG = 0,
36 PSTORE_TYPE_MCE = 1,
37 PSTORE_TYPE_CONSOLE = 2,
38 PSTORE_TYPE_FTRACE = 3,
39 /* PPC64 partition types */
40 PSTORE_TYPE_PPC_RTAS = 4,
41 PSTORE_TYPE_PPC_OF = 5,
42 PSTORE_TYPE_PPC_COMMON = 6,
43 PSTORE_TYPE_PMSG = 7,
44 PSTORE_TYPE_PPC_OPAL = 8,
45 PSTORE_TYPE_UNKNOWN = 255
46};
47
48struct module;
49
50struct pstore_info {
51 struct module *owner;
52 char *name;
53 spinlock_t buf_lock; /* serialize access to 'buf' */
54 char *buf;
55 size_t bufsize;
56 struct mutex read_mutex; /* serialize open/read/close */
57 int flags;
58 int (*open)(struct pstore_info *psi);
59 int (*close)(struct pstore_info *psi);
60 ssize_t (*read)(u64 *id, enum pstore_type_id *type,
61 int *count, struct timespec *time, char **buf,
62 bool *compressed, ssize_t *ecc_notice_size,
63 struct pstore_info *psi);
64 int (*write)(enum pstore_type_id type,
65 enum kmsg_dump_reason reason, u64 *id,
66 unsigned int part, int count, bool compressed,
67 size_t size, struct pstore_info *psi);
68 int (*write_buf)(enum pstore_type_id type,
69 enum kmsg_dump_reason reason, u64 *id,
70 unsigned int part, const char *buf, bool compressed,
71 size_t size, struct pstore_info *psi);
72 int (*write_buf_user)(enum pstore_type_id type,
73 enum kmsg_dump_reason reason, u64 *id,
74 unsigned int part, const char __user *buf,
75 bool compressed, size_t size, struct pstore_info *psi);
76 int (*erase)(enum pstore_type_id type, u64 id,
77 int count, struct timespec time,
78 struct pstore_info *psi);
79 void *data;
80};
81
82#define PSTORE_FLAGS_DMESG (1 << 0)
83#define PSTORE_FLAGS_FRAGILE PSTORE_FLAGS_DMESG
84#define PSTORE_FLAGS_CONSOLE (1 << 1)
85#define PSTORE_FLAGS_FTRACE (1 << 2)
86#define PSTORE_FLAGS_PMSG (1 << 3)
87
88extern int pstore_register(struct pstore_info *);
89extern void pstore_unregister(struct pstore_info *);
90extern bool pstore_cannot_block_path(enum kmsg_dump_reason reason);
91
92struct pstore_ftrace_record {
93 unsigned long ip;
94 unsigned long parent_ip;
95 u64 ts;
96};
97
98/*
99 * ftrace related stuff: Both backends and frontends need these so expose
100 * them here.
101 */
102
103#if NR_CPUS <= 2 && defined(CONFIG_ARM_THUMB)
104#define PSTORE_CPU_IN_IP 0x1
105#elif NR_CPUS <= 4 && defined(CONFIG_ARM)
106#define PSTORE_CPU_IN_IP 0x3
107#endif
108
109#define TS_CPU_SHIFT 8
110#define TS_CPU_MASK (BIT(TS_CPU_SHIFT) - 1)
111
112/*
113 * If CPU number can be stored in IP, store it there, otherwise store it in
114 * the time stamp. This means more timestamp resolution is available when
115 * the CPU can be stored in the IP.
116 */
117#ifdef PSTORE_CPU_IN_IP
118static inline void
119pstore_ftrace_encode_cpu(struct pstore_ftrace_record *rec, unsigned int cpu)
120{
121 rec->ip |= cpu;
122}
123
124static inline unsigned int
125pstore_ftrace_decode_cpu(struct pstore_ftrace_record *rec)
126{
127 return rec->ip & PSTORE_CPU_IN_IP;
128}
129
130static inline u64
131pstore_ftrace_read_timestamp(struct pstore_ftrace_record *rec)
132{
133 return rec->ts;
134}
135
136static inline void
137pstore_ftrace_write_timestamp(struct pstore_ftrace_record *rec, u64 val)
138{
139 rec->ts = val;
140}
141#else
142static inline void
143pstore_ftrace_encode_cpu(struct pstore_ftrace_record *rec, unsigned int cpu)
144{
145 rec->ts &= ~(TS_CPU_MASK);
146 rec->ts |= cpu;
147}
148
149static inline unsigned int
150pstore_ftrace_decode_cpu(struct pstore_ftrace_record *rec)
151{
152 return rec->ts & TS_CPU_MASK;
153}
154
155static inline u64
156pstore_ftrace_read_timestamp(struct pstore_ftrace_record *rec)
157{
158 return rec->ts >> TS_CPU_SHIFT;
159}
160
161static inline void
162pstore_ftrace_write_timestamp(struct pstore_ftrace_record *rec, u64 val)
163{
164 rec->ts = (rec->ts & TS_CPU_MASK) | (val << TS_CPU_SHIFT);
165}
166#endif
167
168#endif /*_LINUX_PSTORE_H*/