xref: /openbmc/linux/kernel/trace/trace.h (revision 545e4006)
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/mmiotrace.h>
9 
10 enum trace_type {
11 	__TRACE_FIRST_TYPE = 0,
12 
13 	TRACE_FN,
14 	TRACE_CTX,
15 	TRACE_WAKE,
16 	TRACE_STACK,
17 	TRACE_SPECIAL,
18 	TRACE_MMIO_RW,
19 	TRACE_MMIO_MAP,
20 
21 	__TRACE_LAST_TYPE
22 };
23 
24 /*
25  * Function trace entry - function address and parent function addres:
26  */
27 struct ftrace_entry {
28 	unsigned long		ip;
29 	unsigned long		parent_ip;
30 };
31 
32 /*
33  * Context switch trace entry - which task (and prio) we switched from/to:
34  */
35 struct ctx_switch_entry {
36 	unsigned int		prev_pid;
37 	unsigned char		prev_prio;
38 	unsigned char		prev_state;
39 	unsigned int		next_pid;
40 	unsigned char		next_prio;
41 	unsigned char		next_state;
42 };
43 
44 /*
45  * Special (free-form) trace entry:
46  */
47 struct special_entry {
48 	unsigned long		arg1;
49 	unsigned long		arg2;
50 	unsigned long		arg3;
51 };
52 
53 /*
54  * Stack-trace entry:
55  */
56 
57 #define FTRACE_STACK_ENTRIES	8
58 
59 struct stack_entry {
60 	unsigned long		caller[FTRACE_STACK_ENTRIES];
61 };
62 
63 /*
64  * The trace entry - the most basic unit of tracing. This is what
65  * is printed in the end as a single line in the trace output, such as:
66  *
67  *     bash-15816 [01]   235.197585: idle_cpu <- irq_enter
68  */
69 struct trace_entry {
70 	char			type;
71 	char			cpu;
72 	char			flags;
73 	char			preempt_count;
74 	int			pid;
75 	cycle_t			t;
76 	union {
77 		struct ftrace_entry		fn;
78 		struct ctx_switch_entry		ctx;
79 		struct special_entry		special;
80 		struct stack_entry		stack;
81 		struct mmiotrace_rw		mmiorw;
82 		struct mmiotrace_map		mmiomap;
83 	};
84 };
85 
86 #define TRACE_ENTRY_SIZE	sizeof(struct trace_entry)
87 
88 /*
89  * The CPU trace array - it consists of thousands of trace entries
90  * plus some other descriptor data: (for example which task started
91  * the trace, etc.)
92  */
93 struct trace_array_cpu {
94 	struct list_head	trace_pages;
95 	atomic_t		disabled;
96 	raw_spinlock_t		lock;
97 	struct lock_class_key	lock_key;
98 
99 	/* these fields get copied into max-trace: */
100 	unsigned		trace_head_idx;
101 	unsigned		trace_tail_idx;
102 	void			*trace_head; /* producer */
103 	void			*trace_tail; /* consumer */
104 	unsigned long		trace_idx;
105 	unsigned long		overrun;
106 	unsigned long		saved_latency;
107 	unsigned long		critical_start;
108 	unsigned long		critical_end;
109 	unsigned long		critical_sequence;
110 	unsigned long		nice;
111 	unsigned long		policy;
112 	unsigned long		rt_priority;
113 	cycle_t			preempt_timestamp;
114 	pid_t			pid;
115 	uid_t			uid;
116 	char			comm[TASK_COMM_LEN];
117 };
118 
119 struct trace_iterator;
120 
121 /*
122  * The trace array - an array of per-CPU trace arrays. This is the
123  * highest level data structure that individual tracers deal with.
124  * They have on/off state as well:
125  */
126 struct trace_array {
127 	unsigned long		entries;
128 	long			ctrl;
129 	int			cpu;
130 	cycle_t			time_start;
131 	struct task_struct	*waiter;
132 	struct trace_array_cpu	*data[NR_CPUS];
133 };
134 
135 /*
136  * A specific tracer, represented by methods that operate on a trace array:
137  */
138 struct tracer {
139 	const char		*name;
140 	void			(*init)(struct trace_array *tr);
141 	void			(*reset)(struct trace_array *tr);
142 	void			(*open)(struct trace_iterator *iter);
143 	void			(*pipe_open)(struct trace_iterator *iter);
144 	void			(*close)(struct trace_iterator *iter);
145 	void			(*start)(struct trace_iterator *iter);
146 	void			(*stop)(struct trace_iterator *iter);
147 	ssize_t			(*read)(struct trace_iterator *iter,
148 					struct file *filp, char __user *ubuf,
149 					size_t cnt, loff_t *ppos);
150 	void			(*ctrl_update)(struct trace_array *tr);
151 #ifdef CONFIG_FTRACE_STARTUP_TEST
152 	int			(*selftest)(struct tracer *trace,
153 					    struct trace_array *tr);
154 #endif
155 	int			(*print_line)(struct trace_iterator *iter);
156 	struct tracer		*next;
157 	int			print_max;
158 };
159 
160 struct trace_seq {
161 	unsigned char		buffer[PAGE_SIZE];
162 	unsigned int		len;
163 	unsigned int		readpos;
164 };
165 
166 /*
167  * Trace iterator - used by printout routines who present trace
168  * results to users and which routines might sleep, etc:
169  */
170 struct trace_iterator {
171 	struct trace_array	*tr;
172 	struct tracer		*trace;
173 	void			*private;
174 	long			last_overrun[NR_CPUS];
175 	long			overrun[NR_CPUS];
176 
177 	/* The below is zeroed out in pipe_read */
178 	struct trace_seq	seq;
179 	struct trace_entry	*ent;
180 	int			cpu;
181 
182 	struct trace_entry	*prev_ent;
183 	int			prev_cpu;
184 
185 	unsigned long		iter_flags;
186 	loff_t			pos;
187 	unsigned long		next_idx[NR_CPUS];
188 	struct list_head	*next_page[NR_CPUS];
189 	unsigned		next_page_idx[NR_CPUS];
190 	long			idx;
191 };
192 
193 void tracing_reset(struct trace_array_cpu *data);
194 int tracing_open_generic(struct inode *inode, struct file *filp);
195 struct dentry *tracing_init_dentry(void);
196 void init_tracer_sysprof_debugfs(struct dentry *d_tracer);
197 
198 void ftrace(struct trace_array *tr,
199 			    struct trace_array_cpu *data,
200 			    unsigned long ip,
201 			    unsigned long parent_ip,
202 			    unsigned long flags);
203 void tracing_sched_switch_trace(struct trace_array *tr,
204 				struct trace_array_cpu *data,
205 				struct task_struct *prev,
206 				struct task_struct *next,
207 				unsigned long flags);
208 void tracing_record_cmdline(struct task_struct *tsk);
209 
210 void tracing_sched_wakeup_trace(struct trace_array *tr,
211 				struct trace_array_cpu *data,
212 				struct task_struct *wakee,
213 				struct task_struct *cur,
214 				unsigned long flags);
215 void trace_special(struct trace_array *tr,
216 		   struct trace_array_cpu *data,
217 		   unsigned long arg1,
218 		   unsigned long arg2,
219 		   unsigned long arg3);
220 void trace_function(struct trace_array *tr,
221 		    struct trace_array_cpu *data,
222 		    unsigned long ip,
223 		    unsigned long parent_ip,
224 		    unsigned long flags);
225 
226 void tracing_start_cmdline_record(void);
227 void tracing_stop_cmdline_record(void);
228 int register_tracer(struct tracer *type);
229 void unregister_tracer(struct tracer *type);
230 
231 extern unsigned long nsecs_to_usecs(unsigned long nsecs);
232 
233 extern unsigned long tracing_max_latency;
234 extern unsigned long tracing_thresh;
235 
236 void update_max_tr(struct trace_array *tr, struct task_struct *tsk, int cpu);
237 void update_max_tr_single(struct trace_array *tr,
238 			  struct task_struct *tsk, int cpu);
239 
240 extern cycle_t ftrace_now(int cpu);
241 
242 #ifdef CONFIG_FTRACE
243 void tracing_start_function_trace(void);
244 void tracing_stop_function_trace(void);
245 #else
246 # define tracing_start_function_trace()		do { } while (0)
247 # define tracing_stop_function_trace()		do { } while (0)
248 #endif
249 
250 #ifdef CONFIG_CONTEXT_SWITCH_TRACER
251 typedef void
252 (*tracer_switch_func_t)(void *private,
253 			void *__rq,
254 			struct task_struct *prev,
255 			struct task_struct *next);
256 
257 struct tracer_switch_ops {
258 	tracer_switch_func_t		func;
259 	void				*private;
260 	struct tracer_switch_ops	*next;
261 };
262 
263 #endif /* CONFIG_CONTEXT_SWITCH_TRACER */
264 
265 #ifdef CONFIG_DYNAMIC_FTRACE
266 extern unsigned long ftrace_update_tot_cnt;
267 #define DYN_FTRACE_TEST_NAME trace_selftest_dynamic_test_func
268 extern int DYN_FTRACE_TEST_NAME(void);
269 #endif
270 
271 #ifdef CONFIG_MMIOTRACE
272 extern void __trace_mmiotrace_rw(struct trace_array *tr,
273 				struct trace_array_cpu *data,
274 				struct mmiotrace_rw *rw);
275 extern void __trace_mmiotrace_map(struct trace_array *tr,
276 				struct trace_array_cpu *data,
277 				struct mmiotrace_map *map);
278 #endif
279 
280 #ifdef CONFIG_FTRACE_STARTUP_TEST
281 #ifdef CONFIG_FTRACE
282 extern int trace_selftest_startup_function(struct tracer *trace,
283 					   struct trace_array *tr);
284 #endif
285 #ifdef CONFIG_IRQSOFF_TRACER
286 extern int trace_selftest_startup_irqsoff(struct tracer *trace,
287 					  struct trace_array *tr);
288 #endif
289 #ifdef CONFIG_PREEMPT_TRACER
290 extern int trace_selftest_startup_preemptoff(struct tracer *trace,
291 					     struct trace_array *tr);
292 #endif
293 #if defined(CONFIG_IRQSOFF_TRACER) && defined(CONFIG_PREEMPT_TRACER)
294 extern int trace_selftest_startup_preemptirqsoff(struct tracer *trace,
295 						 struct trace_array *tr);
296 #endif
297 #ifdef CONFIG_SCHED_TRACER
298 extern int trace_selftest_startup_wakeup(struct tracer *trace,
299 					 struct trace_array *tr);
300 #endif
301 #ifdef CONFIG_CONTEXT_SWITCH_TRACER
302 extern int trace_selftest_startup_sched_switch(struct tracer *trace,
303 					       struct trace_array *tr);
304 #endif
305 #ifdef CONFIG_SYSPROF_TRACER
306 extern int trace_selftest_startup_sysprof(struct tracer *trace,
307 					       struct trace_array *tr);
308 #endif
309 #endif /* CONFIG_FTRACE_STARTUP_TEST */
310 
311 extern void *head_page(struct trace_array_cpu *data);
312 extern int trace_seq_printf(struct trace_seq *s, const char *fmt, ...);
313 extern ssize_t trace_seq_to_user(struct trace_seq *s, char __user *ubuf,
314 				 size_t cnt);
315 extern long ns2usecs(cycle_t nsec);
316 
317 extern unsigned long trace_flags;
318 
319 /*
320  * trace_iterator_flags is an enumeration that defines bit
321  * positions into trace_flags that controls the output.
322  *
323  * NOTE: These bits must match the trace_options array in
324  *       trace.c.
325  */
326 enum trace_iterator_flags {
327 	TRACE_ITER_PRINT_PARENT		= 0x01,
328 	TRACE_ITER_SYM_OFFSET		= 0x02,
329 	TRACE_ITER_SYM_ADDR		= 0x04,
330 	TRACE_ITER_VERBOSE		= 0x08,
331 	TRACE_ITER_RAW			= 0x10,
332 	TRACE_ITER_HEX			= 0x20,
333 	TRACE_ITER_BIN			= 0x40,
334 	TRACE_ITER_BLOCK		= 0x80,
335 	TRACE_ITER_STACKTRACE		= 0x100,
336 	TRACE_ITER_SCHED_TREE		= 0x200,
337 };
338 
339 #endif /* _LINUX_KERNEL_TRACE_H */
340