xref: /linux/tools/perf/util/mmap.h (revision 2dbc0838bcf24ca59cabc3130cf3b1d6809cdcd4)
1 #ifndef __PERF_MMAP_H
2 #define __PERF_MMAP_H 1
3 
4 #include <linux/compiler.h>
5 #include <linux/refcount.h>
6 #include <linux/types.h>
7 #include <linux/ring_buffer.h>
8 #include <stdbool.h>
9 #ifdef HAVE_AIO_SUPPORT
10 #include <aio.h>
11 #endif
12 #include "auxtrace.h"
13 #include "event.h"
14 
15 struct aiocb;
16 /**
17  * struct perf_mmap - perf's ring buffer mmap details
18  *
19  * @refcnt - e.g. code using PERF_EVENT_IOC_SET_OUTPUT to share this
20  */
21 struct perf_mmap {
22 	void		 *base;
23 	int		 mask;
24 	int		 fd;
25 	int		 cpu;
26 	refcount_t	 refcnt;
27 	u64		 prev;
28 	u64		 start;
29 	u64		 end;
30 	bool		 overwrite;
31 	struct auxtrace_mmap auxtrace_mmap;
32 	char		 event_copy[PERF_SAMPLE_MAX_SIZE] __aligned(8);
33 #ifdef HAVE_AIO_SUPPORT
34 	struct {
35 		void		 **data;
36 		struct aiocb	 *cblocks;
37 		struct aiocb	 **aiocb;
38 		int		 nr_cblocks;
39 	} aio;
40 #endif
41 	cpu_set_t	affinity_mask;
42 	u64		flush;
43 	void		*data;
44 	int		comp_level;
45 };
46 
47 /*
48  * State machine of bkw_mmap_state:
49  *
50  *                     .________________(forbid)_____________.
51  *                     |                                     V
52  * NOTREADY --(0)--> RUNNING --(1)--> DATA_PENDING --(2)--> EMPTY
53  *                     ^  ^              |   ^               |
54  *                     |  |__(forbid)____/   |___(forbid)___/|
55  *                     |                                     |
56  *                      \_________________(3)_______________/
57  *
58  * NOTREADY     : Backward ring buffers are not ready
59  * RUNNING      : Backward ring buffers are recording
60  * DATA_PENDING : We are required to collect data from backward ring buffers
61  * EMPTY        : We have collected data from backward ring buffers.
62  *
63  * (0): Setup backward ring buffer
64  * (1): Pause ring buffers for reading
65  * (2): Read from ring buffers
66  * (3): Resume ring buffers for recording
67  */
68 enum bkw_mmap_state {
69 	BKW_MMAP_NOTREADY,
70 	BKW_MMAP_RUNNING,
71 	BKW_MMAP_DATA_PENDING,
72 	BKW_MMAP_EMPTY,
73 };
74 
75 struct mmap_params {
76 	int prot, mask, nr_cblocks, affinity, flush, comp_level;
77 	struct auxtrace_mmap_params auxtrace_mp;
78 };
79 
80 int perf_mmap__mmap(struct perf_mmap *map, struct mmap_params *mp, int fd, int cpu);
81 void perf_mmap__munmap(struct perf_mmap *map);
82 
83 void perf_mmap__get(struct perf_mmap *map);
84 void perf_mmap__put(struct perf_mmap *map);
85 
86 void perf_mmap__consume(struct perf_mmap *map);
87 
88 static inline u64 perf_mmap__read_head(struct perf_mmap *mm)
89 {
90 	return ring_buffer_read_head(mm->base);
91 }
92 
93 static inline void perf_mmap__write_tail(struct perf_mmap *md, u64 tail)
94 {
95 	ring_buffer_write_tail(md->base, tail);
96 }
97 
98 union perf_event *perf_mmap__read_forward(struct perf_mmap *map);
99 
100 union perf_event *perf_mmap__read_event(struct perf_mmap *map);
101 
102 int perf_mmap__push(struct perf_mmap *md, void *to,
103 		    int push(struct perf_mmap *map, void *to, void *buf, size_t size));
104 
105 size_t perf_mmap__mmap_len(struct perf_mmap *map);
106 
107 int perf_mmap__read_init(struct perf_mmap *md);
108 void perf_mmap__read_done(struct perf_mmap *map);
109 #endif /*__PERF_MMAP_H */
110