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8256e47c MD |
1 | #ifndef _LINUX_MARKER_H |
2 | #define _LINUX_MARKER_H | |
3 | ||
4 | /* | |
5 | * Code markup for dynamic and static tracing. | |
6 | * | |
7 | * See Documentation/marker.txt. | |
8 | * | |
9 | * (C) Copyright 2006 Mathieu Desnoyers <mathieu.desnoyers@polymtl.ca> | |
10 | * | |
11 | * This file is released under the GPLv2. | |
12 | * See the file COPYING for more details. | |
13 | */ | |
14 | ||
15 | #include <linux/types.h> | |
16 | ||
17 | struct module; | |
18 | struct marker; | |
19 | ||
20 | /** | |
21 | * marker_probe_func - Type of a marker probe function | |
fb40bd78 MD |
22 | * @probe_private: probe private data |
23 | * @call_private: call site private data | |
8256e47c | 24 | * @fmt: format string |
fb40bd78 MD |
25 | * @args: variable argument list pointer. Use a pointer to overcome C's |
26 | * inability to pass this around as a pointer in a portable manner in | |
27 | * the callee otherwise. | |
8256e47c MD |
28 | * |
29 | * Type of marker probe functions. They receive the mdata and need to parse the | |
30 | * format string to recover the variable argument list. | |
31 | */ | |
fb40bd78 MD |
32 | typedef void marker_probe_func(void *probe_private, void *call_private, |
33 | const char *fmt, va_list *args); | |
34 | ||
35 | struct marker_probe_closure { | |
36 | marker_probe_func *func; /* Callback */ | |
37 | void *probe_private; /* Private probe data */ | |
38 | }; | |
8256e47c MD |
39 | |
40 | struct marker { | |
41 | const char *name; /* Marker name */ | |
42 | const char *format; /* Marker format string, describing the | |
43 | * variable argument list. | |
44 | */ | |
45 | char state; /* Marker state. */ | |
fb40bd78 | 46 | char ptype; /* probe type : 0 : single, 1 : multi */ |
dc102a8f MD |
47 | /* Probe wrapper */ |
48 | void (*call)(const struct marker *mdata, void *call_private, ...); | |
fb40bd78 MD |
49 | struct marker_probe_closure single; |
50 | struct marker_probe_closure *multi; | |
8256e47c MD |
51 | } __attribute__((aligned(8))); |
52 | ||
53 | #ifdef CONFIG_MARKERS | |
54 | ||
55 | /* | |
56 | * Note : the empty asm volatile with read constraint is used here instead of a | |
57 | * "used" attribute to fix a gcc 4.1.x bug. | |
58 | * Make sure the alignment of the structure in the __markers section will | |
59 | * not add unwanted padding between the beginning of the section and the | |
60 | * structure. Force alignment to the same alignment as the section start. | |
0aa977f5 MD |
61 | * |
62 | * The "generic" argument controls which marker enabling mechanism must be used. | |
63 | * If generic is true, a variable read is used. | |
64 | * If generic is false, immediate values are used. | |
8256e47c | 65 | */ |
0aa977f5 | 66 | #define __trace_mark(generic, name, call_private, format, args...) \ |
8256e47c | 67 | do { \ |
b2e3e658 | 68 | static const char __mstrtab_##name[] \ |
8256e47c | 69 | __attribute__((section("__markers_strings"))) \ |
b2e3e658 | 70 | = #name "\0" format; \ |
8256e47c MD |
71 | static struct marker __mark_##name \ |
72 | __attribute__((section("__markers"), aligned(8))) = \ | |
b2e3e658 | 73 | { __mstrtab_##name, &__mstrtab_##name[sizeof(#name)], \ |
fb40bd78 MD |
74 | 0, 0, marker_probe_cb, \ |
75 | { __mark_empty_function, NULL}, NULL }; \ | |
8256e47c MD |
76 | __mark_check_format(format, ## args); \ |
77 | if (unlikely(__mark_##name.state)) { \ | |
8256e47c | 78 | (*__mark_##name.call) \ |
dc102a8f | 79 | (&__mark_##name, call_private, ## args);\ |
8256e47c MD |
80 | } \ |
81 | } while (0) | |
82 | ||
83 | extern void marker_update_probe_range(struct marker *begin, | |
fb40bd78 | 84 | struct marker *end); |
8256e47c | 85 | #else /* !CONFIG_MARKERS */ |
0aa977f5 | 86 | #define __trace_mark(generic, name, call_private, format, args...) \ |
8256e47c MD |
87 | __mark_check_format(format, ## args) |
88 | static inline void marker_update_probe_range(struct marker *begin, | |
fb40bd78 | 89 | struct marker *end) |
8256e47c MD |
90 | { } |
91 | #endif /* CONFIG_MARKERS */ | |
92 | ||
93 | /** | |
0aa977f5 | 94 | * trace_mark - Marker using code patching |
8256e47c MD |
95 | * @name: marker name, not quoted. |
96 | * @format: format string | |
97 | * @args...: variable argument list | |
98 | * | |
0aa977f5 MD |
99 | * Places a marker using optimized code patching technique (imv_read()) |
100 | * to be enabled when immediate values are present. | |
8256e47c MD |
101 | */ |
102 | #define trace_mark(name, format, args...) \ | |
0aa977f5 MD |
103 | __trace_mark(0, name, NULL, format, ## args) |
104 | ||
105 | /** | |
106 | * _trace_mark - Marker using variable read | |
107 | * @name: marker name, not quoted. | |
108 | * @format: format string | |
109 | * @args...: variable argument list | |
110 | * | |
111 | * Places a marker using a standard memory read (_imv_read()) to be | |
112 | * enabled. Should be used for markers in code paths where instruction | |
113 | * modification based enabling is not welcome. (__init and __exit functions, | |
114 | * lockdep, some traps, printk). | |
115 | */ | |
116 | #define _trace_mark(name, format, args...) \ | |
117 | __trace_mark(1, name, NULL, format, ## args) | |
8256e47c | 118 | |
8256e47c MD |
119 | /** |
120 | * MARK_NOARGS - Format string for a marker with no argument. | |
121 | */ | |
122 | #define MARK_NOARGS " " | |
123 | ||
124 | /* To be used for string format validity checking with gcc */ | |
acc4988b | 125 | static inline void __printf(1, 2) ___mark_check_format(const char *fmt, ...) |
8256e47c MD |
126 | { |
127 | } | |
128 | ||
acc4988b MD |
129 | #define __mark_check_format(format, args...) \ |
130 | do { \ | |
131 | if (0) \ | |
132 | ___mark_check_format(format, ## args); \ | |
133 | } while (0) | |
134 | ||
8256e47c MD |
135 | extern marker_probe_func __mark_empty_function; |
136 | ||
fb40bd78 | 137 | extern void marker_probe_cb(const struct marker *mdata, |
dc102a8f | 138 | void *call_private, ...); |
fb40bd78 | 139 | extern void marker_probe_cb_noarg(const struct marker *mdata, |
dc102a8f | 140 | void *call_private, ...); |
fb40bd78 | 141 | |
8256e47c MD |
142 | /* |
143 | * Connect a probe to a marker. | |
144 | * private data pointer must be a valid allocated memory address, or NULL. | |
145 | */ | |
146 | extern int marker_probe_register(const char *name, const char *format, | |
fb40bd78 | 147 | marker_probe_func *probe, void *probe_private); |
8256e47c MD |
148 | |
149 | /* | |
150 | * Returns the private data given to marker_probe_register. | |
151 | */ | |
fb40bd78 MD |
152 | extern int marker_probe_unregister(const char *name, |
153 | marker_probe_func *probe, void *probe_private); | |
8256e47c MD |
154 | /* |
155 | * Unregister a marker by providing the registered private data. | |
156 | */ | |
fb40bd78 MD |
157 | extern int marker_probe_unregister_private_data(marker_probe_func *probe, |
158 | void *probe_private); | |
8256e47c | 159 | |
fb40bd78 MD |
160 | extern void *marker_get_private_data(const char *name, marker_probe_func *probe, |
161 | int num); | |
8256e47c MD |
162 | |
163 | #endif |