1/*
2 * linux/include/kmsg_dump.h
3 *
4 * Copyright (C) 2009 Net Insight AB
5 *
6 * Author: Simon Kagstrom <simon.kagstrom@netinsight.net>
7 *
8 * This file is subject to the terms and conditions of the GNU General Public
9 * License.  See the file COPYING in the main directory of this archive
10 * for more details.
11 */
12#ifndef _LINUX_KMSG_DUMP_H
13#define _LINUX_KMSG_DUMP_H
14
15#include <linux/errno.h>
16#include <linux/list.h>
17
18/*
19 * Keep this list arranged in rough order of priority. Anything listed after
20 * KMSG_DUMP_OOPS will not be logged by default unless printk.always_kmsg_dump
21 * is passed to the kernel.
22 */
23enum kmsg_dump_reason {
24	KMSG_DUMP_UNDEF,
25	KMSG_DUMP_PANIC,
26	KMSG_DUMP_OOPS,
27	KMSG_DUMP_EMERG,
28	KMSG_DUMP_RESTART,
29	KMSG_DUMP_HALT,
30	KMSG_DUMP_POWEROFF,
31};
32
33/**
34 * struct kmsg_dumper - kernel crash message dumper structure
35 * @list:	Entry in the dumper list (private)
36 * @dump:	Call into dumping code which will retrieve the data with
37 * 		through the record iterator
38 * @max_reason:	filter for highest reason number that should be dumped
39 * @registered:	Flag that specifies if this is already registered
40 */
41struct kmsg_dumper {
42	struct list_head list;
43	void (*dump)(struct kmsg_dumper *dumper, enum kmsg_dump_reason reason);
44	enum kmsg_dump_reason max_reason;
45	bool active;
46	bool registered;
47
48	/* private state of the kmsg iterator */
49	u32 cur_idx;
50	u32 next_idx;
51	u64 cur_seq;
52	u64 next_seq;
53};
54
55#ifdef CONFIG_PRINTK
56void kmsg_dump(enum kmsg_dump_reason reason);
57
58bool kmsg_dump_get_line_nolock(struct kmsg_dumper *dumper, bool syslog,
59			       char *line, size_t size, size_t *len);
60
61bool kmsg_dump_get_line(struct kmsg_dumper *dumper, bool syslog,
62			char *line, size_t size, size_t *len);
63
64bool kmsg_dump_get_buffer(struct kmsg_dumper *dumper, bool syslog,
65			  char *buf, size_t size, size_t *len);
66
67void kmsg_dump_rewind_nolock(struct kmsg_dumper *dumper);
68
69void kmsg_dump_rewind(struct kmsg_dumper *dumper);
70
71int kmsg_dump_register(struct kmsg_dumper *dumper);
72
73int kmsg_dump_unregister(struct kmsg_dumper *dumper);
74#else
75static inline void kmsg_dump(enum kmsg_dump_reason reason)
76{
77}
78
79static inline bool kmsg_dump_get_line_nolock(struct kmsg_dumper *dumper,
80					     bool syslog, const char *line,
81					     size_t size, size_t *len)
82{
83	return false;
84}
85
86static inline bool kmsg_dump_get_line(struct kmsg_dumper *dumper, bool syslog,
87				const char *line, size_t size, size_t *len)
88{
89	return false;
90}
91
92static inline bool kmsg_dump_get_buffer(struct kmsg_dumper *dumper, bool syslog,
93					char *buf, size_t size, size_t *len)
94{
95	return false;
96}
97
98static inline void kmsg_dump_rewind_nolock(struct kmsg_dumper *dumper)
99{
100}
101
102static inline void kmsg_dump_rewind(struct kmsg_dumper *dumper)
103{
104}
105
106static inline int kmsg_dump_register(struct kmsg_dumper *dumper)
107{
108	return -EINVAL;
109}
110
111static inline int kmsg_dump_unregister(struct kmsg_dumper *dumper)
112{
113	return -EINVAL;
114}
115#endif
116
117#endif /* _LINUX_KMSG_DUMP_H */
118