17810853b4f80a6cac8bebca17dac0288bf6fcd2
[safe/jmp/linux-2.6] / include / linux / ftrace_event.h
1 #ifndef _LINUX_FTRACE_EVENT_H
2 #define _LINUX_FTRACE_EVENT_H
3
4 #include <linux/trace_seq.h>
5 #include <linux/ring_buffer.h>
6
7
8 struct trace_array;
9 struct tracer;
10
11 /*
12  * The trace entry - the most basic unit of tracing. This is what
13  * is printed in the end as a single line in the trace output, such as:
14  *
15  *     bash-15816 [01]   235.197585: idle_cpu <- irq_enter
16  */
17 struct trace_entry {
18         unsigned char           type;
19         unsigned char           flags;
20         unsigned char           preempt_count;
21         int                     pid;
22         int                     tgid;
23 };
24
25 /*
26  * Trace iterator - used by printout routines who present trace
27  * results to users and which routines might sleep, etc:
28  */
29 struct trace_iterator {
30         struct trace_array      *tr;
31         struct tracer           *trace;
32         void                    *private;
33         int                     cpu_file;
34         struct mutex            mutex;
35         struct ring_buffer_iter *buffer_iter[NR_CPUS];
36
37         /* The below is zeroed out in pipe_read */
38         struct trace_seq        seq;
39         struct trace_entry      *ent;
40         int                     cpu;
41         u64                     ts;
42
43         unsigned long           iter_flags;
44         loff_t                  pos;
45         long                    idx;
46
47         cpumask_var_t           started;
48 };
49
50
51 typedef enum print_line_t (*trace_print_func)(struct trace_iterator *iter,
52                                               int flags);
53 struct trace_event {
54         struct hlist_node       node;
55         int                     type;
56         trace_print_func        trace;
57         trace_print_func        raw;
58         trace_print_func        hex;
59         trace_print_func        binary;
60 };
61
62 extern int register_ftrace_event(struct trace_event *event);
63 extern int unregister_ftrace_event(struct trace_event *event);
64
65 /* Return values for print_line callback */
66 enum print_line_t {
67         TRACE_TYPE_PARTIAL_LINE = 0,    /* Retry after flushing the seq */
68         TRACE_TYPE_HANDLED      = 1,
69         TRACE_TYPE_UNHANDLED    = 2,    /* Relay to other output functions */
70         TRACE_TYPE_NO_CONSUME   = 3     /* Handled but ask to not consume */
71 };
72
73
74 struct ring_buffer_event *
75 trace_current_buffer_lock_reserve(unsigned char type, unsigned long len,
76                                   unsigned long flags, int pc);
77 void trace_current_buffer_unlock_commit(struct ring_buffer_event *event,
78                                         unsigned long flags, int pc);
79 void trace_nowake_buffer_unlock_commit(struct ring_buffer_event *event,
80                                         unsigned long flags, int pc);
81 void trace_current_buffer_discard_commit(struct ring_buffer_event *event);
82
83 void tracing_record_cmdline(struct task_struct *tsk);
84
85 struct ftrace_event_call {
86         struct list_head        list;
87         char                    *name;
88         char                    *system;
89         struct dentry           *dir;
90         int                     enabled;
91         int                     (*regfunc)(void);
92         void                    (*unregfunc)(void);
93         int                     id;
94         int                     (*raw_init)(void);
95         int                     (*show_format)(struct trace_seq *s);
96         int                     (*define_fields)(void);
97         struct list_head        fields;
98         int                     n_preds;
99         struct filter_pred      **preds;
100
101 #ifdef CONFIG_EVENT_PROFILE
102         atomic_t        profile_count;
103         int             (*profile_enable)(struct ftrace_event_call *);
104         void            (*profile_disable)(struct ftrace_event_call *);
105 #endif
106 };
107
108 #define MAX_FILTER_PRED         8
109 #define MAX_FILTER_STR_VAL      128
110
111 extern int init_preds(struct ftrace_event_call *call);
112 extern int filter_match_preds(struct ftrace_event_call *call, void *rec);
113 extern int filter_current_check_discard(struct ftrace_event_call *call,
114                                         void *rec,
115                                         struct ring_buffer_event *event);
116
117 extern int trace_define_field(struct ftrace_event_call *call, char *type,
118                               char *name, int offset, int size);
119
120
121 /*
122  * The double __builtin_constant_p is because gcc will give us an error
123  * if we try to allocate the static variable to fmt if it is not a
124  * constant. Even with the outer if statement optimizing out.
125  */
126 #define event_trace_printk(ip, fmt, args...)                            \
127 do {                                                                    \
128         __trace_printk_check_format(fmt, ##args);                       \
129         tracing_record_cmdline(current);                                \
130         if (__builtin_constant_p(fmt)) {                                \
131                 static const char *trace_printk_fmt                     \
132                   __attribute__((section("__trace_printk_fmt"))) =      \
133                         __builtin_constant_p(fmt) ? fmt : NULL;         \
134                                                                         \
135                 __trace_bprintk(ip, trace_printk_fmt, ##args);          \
136         } else                                                          \
137                 __trace_printk(ip, fmt, ##args);                        \
138 } while (0)
139
140 #define __common_field(type, item)                                      \
141         ret = trace_define_field(event_call, #type, "common_" #item,    \
142                                  offsetof(typeof(field.ent), item),     \
143                                  sizeof(field.ent.item));               \
144         if (ret)                                                        \
145                 return ret;
146
147 #endif /* _LINUX_FTRACE_EVENT_H */