tracing: adding function timings to function profiler
[linux-2.6.git] / kernel / trace / trace.h
1 #ifndef _LINUX_KERNEL_TRACE_H
2 #define _LINUX_KERNEL_TRACE_H
3
4 #include <linux/fs.h>
5 #include <asm/atomic.h>
6 #include <linux/sched.h>
7 #include <linux/clocksource.h>
8 #include <linux/ring_buffer.h>
9 #include <linux/mmiotrace.h>
10 #include <linux/ftrace.h>
11 #include <trace/boot.h>
12 #include <trace/kmemtrace.h>
13 #include <trace/power.h>
14
15 enum trace_type {
16         __TRACE_FIRST_TYPE = 0,
17
18         TRACE_FN,
19         TRACE_CTX,
20         TRACE_WAKE,
21         TRACE_STACK,
22         TRACE_PRINT,
23         TRACE_BPRINT,
24         TRACE_SPECIAL,
25         TRACE_MMIO_RW,
26         TRACE_MMIO_MAP,
27         TRACE_BRANCH,
28         TRACE_BOOT_CALL,
29         TRACE_BOOT_RET,
30         TRACE_GRAPH_RET,
31         TRACE_GRAPH_ENT,
32         TRACE_USER_STACK,
33         TRACE_HW_BRANCHES,
34         TRACE_SYSCALL_ENTER,
35         TRACE_SYSCALL_EXIT,
36         TRACE_KMEM_ALLOC,
37         TRACE_KMEM_FREE,
38         TRACE_POWER,
39         TRACE_BLK,
40
41         __TRACE_LAST_TYPE,
42 };
43
44 /*
45  * The trace entry - the most basic unit of tracing. This is what
46  * is printed in the end as a single line in the trace output, such as:
47  *
48  *     bash-15816 [01]   235.197585: idle_cpu <- irq_enter
49  */
50 struct trace_entry {
51         unsigned char           type;
52         unsigned char           flags;
53         unsigned char           preempt_count;
54         int                     pid;
55         int                     tgid;
56 };
57
58 /*
59  * Function trace entry - function address and parent function addres:
60  */
61 struct ftrace_entry {
62         struct trace_entry      ent;
63         unsigned long           ip;
64         unsigned long           parent_ip;
65 };
66
67 /* Function call entry */
68 struct ftrace_graph_ent_entry {
69         struct trace_entry              ent;
70         struct ftrace_graph_ent         graph_ent;
71 };
72
73 /* Function return entry */
74 struct ftrace_graph_ret_entry {
75         struct trace_entry              ent;
76         struct ftrace_graph_ret         ret;
77 };
78 extern struct tracer boot_tracer;
79
80 /*
81  * Context switch trace entry - which task (and prio) we switched from/to:
82  */
83 struct ctx_switch_entry {
84         struct trace_entry      ent;
85         unsigned int            prev_pid;
86         unsigned char           prev_prio;
87         unsigned char           prev_state;
88         unsigned int            next_pid;
89         unsigned char           next_prio;
90         unsigned char           next_state;
91         unsigned int            next_cpu;
92 };
93
94 /*
95  * Special (free-form) trace entry:
96  */
97 struct special_entry {
98         struct trace_entry      ent;
99         unsigned long           arg1;
100         unsigned long           arg2;
101         unsigned long           arg3;
102 };
103
104 /*
105  * Stack-trace entry:
106  */
107
108 #define FTRACE_STACK_ENTRIES    8
109
110 struct stack_entry {
111         struct trace_entry      ent;
112         unsigned long           caller[FTRACE_STACK_ENTRIES];
113 };
114
115 struct userstack_entry {
116         struct trace_entry      ent;
117         unsigned long           caller[FTRACE_STACK_ENTRIES];
118 };
119
120 /*
121  * trace_printk entry:
122  */
123 struct bprint_entry {
124         struct trace_entry      ent;
125         unsigned long           ip;
126         const char              *fmt;
127         u32                     buf[];
128 };
129
130 struct print_entry {
131         struct trace_entry      ent;
132         unsigned long           ip;
133         char                    buf[];
134 };
135
136 #define TRACE_OLD_SIZE          88
137
138 struct trace_field_cont {
139         unsigned char           type;
140         /* Temporary till we get rid of this completely */
141         char                    buf[TRACE_OLD_SIZE - 1];
142 };
143
144 struct trace_mmiotrace_rw {
145         struct trace_entry      ent;
146         struct mmiotrace_rw     rw;
147 };
148
149 struct trace_mmiotrace_map {
150         struct trace_entry      ent;
151         struct mmiotrace_map    map;
152 };
153
154 struct trace_boot_call {
155         struct trace_entry      ent;
156         struct boot_trace_call boot_call;
157 };
158
159 struct trace_boot_ret {
160         struct trace_entry      ent;
161         struct boot_trace_ret boot_ret;
162 };
163
164 #define TRACE_FUNC_SIZE 30
165 #define TRACE_FILE_SIZE 20
166 struct trace_branch {
167         struct trace_entry      ent;
168         unsigned                line;
169         char                    func[TRACE_FUNC_SIZE+1];
170         char                    file[TRACE_FILE_SIZE+1];
171         char                    correct;
172 };
173
174 struct hw_branch_entry {
175         struct trace_entry      ent;
176         u64                     from;
177         u64                     to;
178 };
179
180 struct trace_power {
181         struct trace_entry      ent;
182         struct power_trace      state_data;
183 };
184
185 struct kmemtrace_alloc_entry {
186         struct trace_entry      ent;
187         enum kmemtrace_type_id type_id;
188         unsigned long call_site;
189         const void *ptr;
190         size_t bytes_req;
191         size_t bytes_alloc;
192         gfp_t gfp_flags;
193         int node;
194 };
195
196 struct kmemtrace_free_entry {
197         struct trace_entry      ent;
198         enum kmemtrace_type_id type_id;
199         unsigned long call_site;
200         const void *ptr;
201 };
202
203 struct syscall_trace_enter {
204         struct trace_entry      ent;
205         int                     nr;
206         unsigned long           args[];
207 };
208
209 struct syscall_trace_exit {
210         struct trace_entry      ent;
211         int                     nr;
212         unsigned long           ret;
213 };
214
215
216 /*
217  * trace_flag_type is an enumeration that holds different
218  * states when a trace occurs. These are:
219  *  IRQS_OFF            - interrupts were disabled
220  *  IRQS_NOSUPPORT      - arch does not support irqs_disabled_flags
221  *  NEED_RESCED         - reschedule is requested
222  *  HARDIRQ             - inside an interrupt handler
223  *  SOFTIRQ             - inside a softirq handler
224  */
225 enum trace_flag_type {
226         TRACE_FLAG_IRQS_OFF             = 0x01,
227         TRACE_FLAG_IRQS_NOSUPPORT       = 0x02,
228         TRACE_FLAG_NEED_RESCHED         = 0x04,
229         TRACE_FLAG_HARDIRQ              = 0x08,
230         TRACE_FLAG_SOFTIRQ              = 0x10,
231 };
232
233 #define TRACE_BUF_SIZE          1024
234
235 /*
236  * The CPU trace array - it consists of thousands of trace entries
237  * plus some other descriptor data: (for example which task started
238  * the trace, etc.)
239  */
240 struct trace_array_cpu {
241         atomic_t                disabled;
242         void                    *buffer_page;   /* ring buffer spare */
243
244         /* these fields get copied into max-trace: */
245         unsigned long           trace_idx;
246         unsigned long           overrun;
247         unsigned long           saved_latency;
248         unsigned long           critical_start;
249         unsigned long           critical_end;
250         unsigned long           critical_sequence;
251         unsigned long           nice;
252         unsigned long           policy;
253         unsigned long           rt_priority;
254         cycle_t                 preempt_timestamp;
255         pid_t                   pid;
256         uid_t                   uid;
257         char                    comm[TASK_COMM_LEN];
258 };
259
260 struct trace_iterator;
261
262 /*
263  * The trace array - an array of per-CPU trace arrays. This is the
264  * highest level data structure that individual tracers deal with.
265  * They have on/off state as well:
266  */
267 struct trace_array {
268         struct ring_buffer      *buffer;
269         unsigned long           entries;
270         int                     cpu;
271         cycle_t                 time_start;
272         struct task_struct      *waiter;
273         struct trace_array_cpu  *data[NR_CPUS];
274 };
275
276 #define FTRACE_CMP_TYPE(var, type) \
277         __builtin_types_compatible_p(typeof(var), type *)
278
279 #undef IF_ASSIGN
280 #define IF_ASSIGN(var, entry, etype, id)                \
281         if (FTRACE_CMP_TYPE(var, etype)) {              \
282                 var = (typeof(var))(entry);             \
283                 WARN_ON(id && (entry)->type != id);     \
284                 break;                                  \
285         }
286
287 /* Will cause compile errors if type is not found. */
288 extern void __ftrace_bad_type(void);
289
290 /*
291  * The trace_assign_type is a verifier that the entry type is
292  * the same as the type being assigned. To add new types simply
293  * add a line with the following format:
294  *
295  * IF_ASSIGN(var, ent, type, id);
296  *
297  *  Where "type" is the trace type that includes the trace_entry
298  *  as the "ent" item. And "id" is the trace identifier that is
299  *  used in the trace_type enum.
300  *
301  *  If the type can have more than one id, then use zero.
302  */
303 #define trace_assign_type(var, ent)                                     \
304         do {                                                            \
305                 IF_ASSIGN(var, ent, struct ftrace_entry, TRACE_FN);     \
306                 IF_ASSIGN(var, ent, struct ctx_switch_entry, 0);        \
307                 IF_ASSIGN(var, ent, struct stack_entry, TRACE_STACK);   \
308                 IF_ASSIGN(var, ent, struct userstack_entry, TRACE_USER_STACK);\
309                 IF_ASSIGN(var, ent, struct print_entry, TRACE_PRINT);   \
310                 IF_ASSIGN(var, ent, struct bprint_entry, TRACE_BPRINT); \
311                 IF_ASSIGN(var, ent, struct special_entry, 0);           \
312                 IF_ASSIGN(var, ent, struct trace_mmiotrace_rw,          \
313                           TRACE_MMIO_RW);                               \
314                 IF_ASSIGN(var, ent, struct trace_mmiotrace_map,         \
315                           TRACE_MMIO_MAP);                              \
316                 IF_ASSIGN(var, ent, struct trace_boot_call, TRACE_BOOT_CALL);\
317                 IF_ASSIGN(var, ent, struct trace_boot_ret, TRACE_BOOT_RET);\
318                 IF_ASSIGN(var, ent, struct trace_branch, TRACE_BRANCH); \
319                 IF_ASSIGN(var, ent, struct ftrace_graph_ent_entry,      \
320                           TRACE_GRAPH_ENT);             \
321                 IF_ASSIGN(var, ent, struct ftrace_graph_ret_entry,      \
322                           TRACE_GRAPH_RET);             \
323                 IF_ASSIGN(var, ent, struct hw_branch_entry, TRACE_HW_BRANCHES);\
324                 IF_ASSIGN(var, ent, struct trace_power, TRACE_POWER); \
325                 IF_ASSIGN(var, ent, struct kmemtrace_alloc_entry,       \
326                           TRACE_KMEM_ALLOC);    \
327                 IF_ASSIGN(var, ent, struct kmemtrace_free_entry,        \
328                           TRACE_KMEM_FREE);     \
329                 IF_ASSIGN(var, ent, struct syscall_trace_enter,         \
330                           TRACE_SYSCALL_ENTER);                         \
331                 IF_ASSIGN(var, ent, struct syscall_trace_exit,          \
332                           TRACE_SYSCALL_EXIT);                          \
333                 __ftrace_bad_type();                                    \
334         } while (0)
335
336 /* Return values for print_line callback */
337 enum print_line_t {
338         TRACE_TYPE_PARTIAL_LINE = 0,    /* Retry after flushing the seq */
339         TRACE_TYPE_HANDLED      = 1,
340         TRACE_TYPE_UNHANDLED    = 2,    /* Relay to other output functions */
341         TRACE_TYPE_NO_CONSUME   = 3     /* Handled but ask to not consume */
342 };
343
344
345 /*
346  * An option specific to a tracer. This is a boolean value.
347  * The bit is the bit index that sets its value on the
348  * flags value in struct tracer_flags.
349  */
350 struct tracer_opt {
351         const char      *name; /* Will appear on the trace_options file */
352         u32             bit; /* Mask assigned in val field in tracer_flags */
353 };
354
355 /*
356  * The set of specific options for a tracer. Your tracer
357  * have to set the initial value of the flags val.
358  */
359 struct tracer_flags {
360         u32                     val;
361         struct tracer_opt       *opts;
362 };
363
364 /* Makes more easy to define a tracer opt */
365 #define TRACER_OPT(s, b)        .name = #s, .bit = b
366
367
368 /**
369  * struct tracer - a specific tracer and its callbacks to interact with debugfs
370  * @name: the name chosen to select it on the available_tracers file
371  * @init: called when one switches to this tracer (echo name > current_tracer)
372  * @reset: called when one switches to another tracer
373  * @start: called when tracing is unpaused (echo 1 > tracing_enabled)
374  * @stop: called when tracing is paused (echo 0 > tracing_enabled)
375  * @open: called when the trace file is opened
376  * @pipe_open: called when the trace_pipe file is opened
377  * @wait_pipe: override how the user waits for traces on trace_pipe
378  * @close: called when the trace file is released
379  * @read: override the default read callback on trace_pipe
380  * @splice_read: override the default splice_read callback on trace_pipe
381  * @selftest: selftest to run on boot (see trace_selftest.c)
382  * @print_headers: override the first lines that describe your columns
383  * @print_line: callback that prints a trace
384  * @set_flag: signals one of your private flags changed (trace_options file)
385  * @flags: your private flags
386  */
387 struct tracer {
388         const char              *name;
389         int                     (*init)(struct trace_array *tr);
390         void                    (*reset)(struct trace_array *tr);
391         void                    (*start)(struct trace_array *tr);
392         void                    (*stop)(struct trace_array *tr);
393         void                    (*open)(struct trace_iterator *iter);
394         void                    (*pipe_open)(struct trace_iterator *iter);
395         void                    (*wait_pipe)(struct trace_iterator *iter);
396         void                    (*close)(struct trace_iterator *iter);
397         ssize_t                 (*read)(struct trace_iterator *iter,
398                                         struct file *filp, char __user *ubuf,
399                                         size_t cnt, loff_t *ppos);
400         ssize_t                 (*splice_read)(struct trace_iterator *iter,
401                                                struct file *filp,
402                                                loff_t *ppos,
403                                                struct pipe_inode_info *pipe,
404                                                size_t len,
405                                                unsigned int flags);
406 #ifdef CONFIG_FTRACE_STARTUP_TEST
407         int                     (*selftest)(struct tracer *trace,
408                                             struct trace_array *tr);
409 #endif
410         void                    (*print_header)(struct seq_file *m);
411         enum print_line_t       (*print_line)(struct trace_iterator *iter);
412         /* If you handled the flag setting, return 0 */
413         int                     (*set_flag)(u32 old_flags, u32 bit, int set);
414         struct tracer           *next;
415         int                     print_max;
416         struct tracer_flags     *flags;
417         struct tracer_stat      *stats;
418 };
419
420 struct trace_seq {
421         unsigned char           buffer[PAGE_SIZE];
422         unsigned int            len;
423         unsigned int            readpos;
424 };
425
426 static inline void
427 trace_seq_init(struct trace_seq *s)
428 {
429         s->len = 0;
430         s->readpos = 0;
431 }
432
433
434 #define TRACE_PIPE_ALL_CPU      -1
435
436 /*
437  * Trace iterator - used by printout routines who present trace
438  * results to users and which routines might sleep, etc:
439  */
440 struct trace_iterator {
441         struct trace_array      *tr;
442         struct tracer           *trace;
443         void                    *private;
444         int                     cpu_file;
445         struct mutex            mutex;
446         struct ring_buffer_iter *buffer_iter[NR_CPUS];
447
448         /* The below is zeroed out in pipe_read */
449         struct trace_seq        seq;
450         struct trace_entry      *ent;
451         int                     cpu;
452         u64                     ts;
453
454         unsigned long           iter_flags;
455         loff_t                  pos;
456         long                    idx;
457
458         cpumask_var_t           started;
459 };
460
461 int tracer_init(struct tracer *t, struct trace_array *tr);
462 int tracing_is_enabled(void);
463 void trace_wake_up(void);
464 void tracing_reset(struct trace_array *tr, int cpu);
465 void tracing_reset_online_cpus(struct trace_array *tr);
466 int tracing_open_generic(struct inode *inode, struct file *filp);
467 struct dentry *tracing_init_dentry(void);
468 void init_tracer_sysprof_debugfs(struct dentry *d_tracer);
469
470 struct ring_buffer_event;
471
472 struct ring_buffer_event *trace_buffer_lock_reserve(struct trace_array *tr,
473                                                     unsigned char type,
474                                                     unsigned long len,
475                                                     unsigned long flags,
476                                                     int pc);
477 void trace_buffer_unlock_commit(struct trace_array *tr,
478                                 struct ring_buffer_event *event,
479                                 unsigned long flags, int pc);
480
481 struct ring_buffer_event *
482 trace_current_buffer_lock_reserve(unsigned char type, unsigned long len,
483                                   unsigned long flags, int pc);
484 void trace_current_buffer_unlock_commit(struct ring_buffer_event *event,
485                                         unsigned long flags, int pc);
486
487 struct trace_entry *tracing_get_trace_entry(struct trace_array *tr,
488                                                 struct trace_array_cpu *data);
489
490 struct trace_entry *trace_find_next_entry(struct trace_iterator *iter,
491                                           int *ent_cpu, u64 *ent_ts);
492
493 void tracing_generic_entry_update(struct trace_entry *entry,
494                                   unsigned long flags,
495                                   int pc);
496
497 void default_wait_pipe(struct trace_iterator *iter);
498 void poll_wait_pipe(struct trace_iterator *iter);
499
500 void ftrace(struct trace_array *tr,
501                             struct trace_array_cpu *data,
502                             unsigned long ip,
503                             unsigned long parent_ip,
504                             unsigned long flags, int pc);
505 void tracing_sched_switch_trace(struct trace_array *tr,
506                                 struct task_struct *prev,
507                                 struct task_struct *next,
508                                 unsigned long flags, int pc);
509 void tracing_record_cmdline(struct task_struct *tsk);
510
511 void tracing_sched_wakeup_trace(struct trace_array *tr,
512                                 struct task_struct *wakee,
513                                 struct task_struct *cur,
514                                 unsigned long flags, int pc);
515 void trace_special(struct trace_array *tr,
516                    struct trace_array_cpu *data,
517                    unsigned long arg1,
518                    unsigned long arg2,
519                    unsigned long arg3, int pc);
520 void trace_function(struct trace_array *tr,
521                     unsigned long ip,
522                     unsigned long parent_ip,
523                     unsigned long flags, int pc);
524
525 void trace_graph_return(struct ftrace_graph_ret *trace);
526 int trace_graph_entry(struct ftrace_graph_ent *trace);
527
528 void tracing_start_cmdline_record(void);
529 void tracing_stop_cmdline_record(void);
530 void tracing_sched_switch_assign_trace(struct trace_array *tr);
531 void tracing_stop_sched_switch_record(void);
532 void tracing_start_sched_switch_record(void);
533 int register_tracer(struct tracer *type);
534 void unregister_tracer(struct tracer *type);
535
536 extern unsigned long nsecs_to_usecs(unsigned long nsecs);
537
538 extern unsigned long tracing_max_latency;
539 extern unsigned long tracing_thresh;
540
541 void update_max_tr(struct trace_array *tr, struct task_struct *tsk, int cpu);
542 void update_max_tr_single(struct trace_array *tr,
543                           struct task_struct *tsk, int cpu);
544
545 void __trace_stack(struct trace_array *tr,
546                    unsigned long flags,
547                    int skip, int pc);
548
549 extern cycle_t ftrace_now(int cpu);
550
551 #ifdef CONFIG_CONTEXT_SWITCH_TRACER
552 typedef void
553 (*tracer_switch_func_t)(void *private,
554                         void *__rq,
555                         struct task_struct *prev,
556                         struct task_struct *next);
557
558 struct tracer_switch_ops {
559         tracer_switch_func_t            func;
560         void                            *private;
561         struct tracer_switch_ops        *next;
562 };
563 #endif /* CONFIG_CONTEXT_SWITCH_TRACER */
564
565 extern void trace_find_cmdline(int pid, char comm[]);
566
567 #ifdef CONFIG_DYNAMIC_FTRACE
568 extern unsigned long ftrace_update_tot_cnt;
569 #define DYN_FTRACE_TEST_NAME trace_selftest_dynamic_test_func
570 extern int DYN_FTRACE_TEST_NAME(void);
571 #endif
572
573 #ifdef CONFIG_FTRACE_STARTUP_TEST
574 extern int trace_selftest_startup_function(struct tracer *trace,
575                                            struct trace_array *tr);
576 extern int trace_selftest_startup_function_graph(struct tracer *trace,
577                                                  struct trace_array *tr);
578 extern int trace_selftest_startup_irqsoff(struct tracer *trace,
579                                           struct trace_array *tr);
580 extern int trace_selftest_startup_preemptoff(struct tracer *trace,
581                                              struct trace_array *tr);
582 extern int trace_selftest_startup_preemptirqsoff(struct tracer *trace,
583                                                  struct trace_array *tr);
584 extern int trace_selftest_startup_wakeup(struct tracer *trace,
585                                          struct trace_array *tr);
586 extern int trace_selftest_startup_nop(struct tracer *trace,
587                                          struct trace_array *tr);
588 extern int trace_selftest_startup_sched_switch(struct tracer *trace,
589                                                struct trace_array *tr);
590 extern int trace_selftest_startup_sysprof(struct tracer *trace,
591                                                struct trace_array *tr);
592 extern int trace_selftest_startup_branch(struct tracer *trace,
593                                          struct trace_array *tr);
594 #endif /* CONFIG_FTRACE_STARTUP_TEST */
595
596 extern void *head_page(struct trace_array_cpu *data);
597 extern long ns2usecs(cycle_t nsec);
598 extern int
599 trace_vbprintk(unsigned long ip, const char *fmt, va_list args);
600 extern int
601 trace_vprintk(unsigned long ip, const char *fmt, va_list args);
602
603 extern unsigned long trace_flags;
604
605 /* Standard output formatting function used for function return traces */
606 #ifdef CONFIG_FUNCTION_GRAPH_TRACER
607 extern enum print_line_t print_graph_function(struct trace_iterator *iter);
608 extern enum print_line_t
609 trace_print_graph_duration(unsigned long long duration, struct trace_seq *s);
610
611 #ifdef CONFIG_DYNAMIC_FTRACE
612 /* TODO: make this variable */
613 #define FTRACE_GRAPH_MAX_FUNCS          32
614 extern int ftrace_graph_count;
615 extern unsigned long ftrace_graph_funcs[FTRACE_GRAPH_MAX_FUNCS];
616
617 static inline int ftrace_graph_addr(unsigned long addr)
618 {
619         int i;
620
621         if (!ftrace_graph_count || test_tsk_trace_graph(current))
622                 return 1;
623
624         for (i = 0; i < ftrace_graph_count; i++) {
625                 if (addr == ftrace_graph_funcs[i])
626                         return 1;
627         }
628
629         return 0;
630 }
631 #else
632 static inline int ftrace_trace_addr(unsigned long addr)
633 {
634         return 1;
635 }
636 static inline int ftrace_graph_addr(unsigned long addr)
637 {
638         return 1;
639 }
640 #endif /* CONFIG_DYNAMIC_FTRACE */
641 #else /* CONFIG_FUNCTION_GRAPH_TRACER */
642 static inline enum print_line_t
643 print_graph_function(struct trace_iterator *iter)
644 {
645         return TRACE_TYPE_UNHANDLED;
646 }
647 #endif /* CONFIG_FUNCTION_GRAPH_TRACER */
648
649 extern struct pid *ftrace_pid_trace;
650
651 static inline int ftrace_trace_task(struct task_struct *task)
652 {
653         if (!ftrace_pid_trace)
654                 return 1;
655
656         return test_tsk_trace_trace(task);
657 }
658
659 /*
660  * trace_iterator_flags is an enumeration that defines bit
661  * positions into trace_flags that controls the output.
662  *
663  * NOTE: These bits must match the trace_options array in
664  *       trace.c.
665  */
666 enum trace_iterator_flags {
667         TRACE_ITER_PRINT_PARENT         = 0x01,
668         TRACE_ITER_SYM_OFFSET           = 0x02,
669         TRACE_ITER_SYM_ADDR             = 0x04,
670         TRACE_ITER_VERBOSE              = 0x08,
671         TRACE_ITER_RAW                  = 0x10,
672         TRACE_ITER_HEX                  = 0x20,
673         TRACE_ITER_BIN                  = 0x40,
674         TRACE_ITER_BLOCK                = 0x80,
675         TRACE_ITER_STACKTRACE           = 0x100,
676         TRACE_ITER_SCHED_TREE           = 0x200,
677         TRACE_ITER_PRINTK               = 0x400,
678         TRACE_ITER_PREEMPTONLY          = 0x800,
679         TRACE_ITER_BRANCH               = 0x1000,
680         TRACE_ITER_ANNOTATE             = 0x2000,
681         TRACE_ITER_USERSTACKTRACE       = 0x4000,
682         TRACE_ITER_SYM_USEROBJ          = 0x8000,
683         TRACE_ITER_PRINTK_MSGONLY       = 0x10000,
684         TRACE_ITER_CONTEXT_INFO         = 0x20000, /* Print pid/cpu/time */
685         TRACE_ITER_LATENCY_FMT          = 0x40000,
686         TRACE_ITER_GLOBAL_CLK           = 0x80000,
687         TRACE_ITER_SLEEP_TIME           = 0x100000,
688 };
689
690 /*
691  * TRACE_ITER_SYM_MASK masks the options in trace_flags that
692  * control the output of kernel symbols.
693  */
694 #define TRACE_ITER_SYM_MASK \
695         (TRACE_ITER_PRINT_PARENT|TRACE_ITER_SYM_OFFSET|TRACE_ITER_SYM_ADDR)
696
697 extern struct tracer nop_trace;
698
699 /**
700  * ftrace_preempt_disable - disable preemption scheduler safe
701  *
702  * When tracing can happen inside the scheduler, there exists
703  * cases that the tracing might happen before the need_resched
704  * flag is checked. If this happens and the tracer calls
705  * preempt_enable (after a disable), a schedule might take place
706  * causing an infinite recursion.
707  *
708  * To prevent this, we read the need_resched flag before
709  * disabling preemption. When we want to enable preemption we
710  * check the flag, if it is set, then we call preempt_enable_no_resched.
711  * Otherwise, we call preempt_enable.
712  *
713  * The rational for doing the above is that if need_resched is set
714  * and we have yet to reschedule, we are either in an atomic location
715  * (where we do not need to check for scheduling) or we are inside
716  * the scheduler and do not want to resched.
717  */
718 static inline int ftrace_preempt_disable(void)
719 {
720         int resched;
721
722         resched = need_resched();
723         preempt_disable_notrace();
724
725         return resched;
726 }
727
728 /**
729  * ftrace_preempt_enable - enable preemption scheduler safe
730  * @resched: the return value from ftrace_preempt_disable
731  *
732  * This is a scheduler safe way to enable preemption and not miss
733  * any preemption checks. The disabled saved the state of preemption.
734  * If resched is set, then we are either inside an atomic or
735  * are inside the scheduler (we would have already scheduled
736  * otherwise). In this case, we do not want to call normal
737  * preempt_enable, but preempt_enable_no_resched instead.
738  */
739 static inline void ftrace_preempt_enable(int resched)
740 {
741         if (resched)
742                 preempt_enable_no_resched_notrace();
743         else
744                 preempt_enable_notrace();
745 }
746
747 #ifdef CONFIG_BRANCH_TRACER
748 extern int enable_branch_tracing(struct trace_array *tr);
749 extern void disable_branch_tracing(void);
750 static inline int trace_branch_enable(struct trace_array *tr)
751 {
752         if (trace_flags & TRACE_ITER_BRANCH)
753                 return enable_branch_tracing(tr);
754         return 0;
755 }
756 static inline void trace_branch_disable(void)
757 {
758         /* due to races, always disable */
759         disable_branch_tracing();
760 }
761 #else
762 static inline int trace_branch_enable(struct trace_array *tr)
763 {
764         return 0;
765 }
766 static inline void trace_branch_disable(void)
767 {
768 }
769 #endif /* CONFIG_BRANCH_TRACER */
770
771 /* set ring buffers to default size if not already done so */
772 int tracing_update_buffers(void);
773
774 /* trace event type bit fields, not numeric */
775 enum {
776         TRACE_EVENT_TYPE_PRINTF         = 1,
777         TRACE_EVENT_TYPE_RAW            = 2,
778 };
779
780 struct ftrace_event_call {
781         char            *name;
782         char            *system;
783         struct dentry   *dir;
784         int             enabled;
785         int             (*regfunc)(void);
786         void            (*unregfunc)(void);
787         int             id;
788         int             (*raw_init)(void);
789         int             (*show_format)(struct trace_seq *s);
790
791 #ifdef CONFIG_EVENT_PROFILE
792         atomic_t        profile_count;
793         int             (*profile_enable)(struct ftrace_event_call *);
794         void            (*profile_disable)(struct ftrace_event_call *);
795 #endif
796 };
797
798 void event_trace_printk(unsigned long ip, const char *fmt, ...);
799 extern struct ftrace_event_call __start_ftrace_events[];
800 extern struct ftrace_event_call __stop_ftrace_events[];
801
802 #define for_each_event(event)                                           \
803         for (event = __start_ftrace_events;                             \
804              (unsigned long)event < (unsigned long)__stop_ftrace_events; \
805              event++)
806
807 extern const char *__start___trace_bprintk_fmt[];
808 extern const char *__stop___trace_bprintk_fmt[];
809
810 /*
811  * The double __builtin_constant_p is because gcc will give us an error
812  * if we try to allocate the static variable to fmt if it is not a
813  * constant. Even with the outer if statement optimizing out.
814  */
815 #define event_trace_printk(ip, fmt, args...)                            \
816 do {                                                                    \
817         __trace_printk_check_format(fmt, ##args);                       \
818         tracing_record_cmdline(current);                                \
819         if (__builtin_constant_p(fmt)) {                                \
820                 static const char *trace_printk_fmt                     \
821                   __attribute__((section("__trace_printk_fmt"))) =      \
822                         __builtin_constant_p(fmt) ? fmt : NULL;         \
823                                                                         \
824                 __trace_bprintk(ip, trace_printk_fmt, ##args);          \
825         } else                                                          \
826                 __trace_printk(ip, fmt, ##args);                        \
827 } while (0)
828
829 #endif /* _LINUX_KERNEL_TRACE_H */