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Linux kernel mirror (for testing)
git.kernel.org/pub/scm/linux/kernel/git/torvalds/linux.git
kernel
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linux
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 <asm/barrier.h>
8#include <stdbool.h>
9#include "auxtrace.h"
10#include "event.h"
11
12/**
13 * struct perf_mmap - perf's ring buffer mmap details
14 *
15 * @refcnt - e.g. code using PERF_EVENT_IOC_SET_OUTPUT to share this
16 */
17struct perf_mmap {
18 void *base;
19 int mask;
20 int fd;
21 refcount_t refcnt;
22 u64 prev;
23 struct auxtrace_mmap auxtrace_mmap;
24 char event_copy[PERF_SAMPLE_MAX_SIZE] __aligned(8);
25};
26
27/*
28 * State machine of bkw_mmap_state:
29 *
30 * .________________(forbid)_____________.
31 * | V
32 * NOTREADY --(0)--> RUNNING --(1)--> DATA_PENDING --(2)--> EMPTY
33 * ^ ^ | ^ |
34 * | |__(forbid)____/ |___(forbid)___/|
35 * | |
36 * \_________________(3)_______________/
37 *
38 * NOTREADY : Backward ring buffers are not ready
39 * RUNNING : Backward ring buffers are recording
40 * DATA_PENDING : We are required to collect data from backward ring buffers
41 * EMPTY : We have collected data from backward ring buffers.
42 *
43 * (0): Setup backward ring buffer
44 * (1): Pause ring buffers for reading
45 * (2): Read from ring buffers
46 * (3): Resume ring buffers for recording
47 */
48enum bkw_mmap_state {
49 BKW_MMAP_NOTREADY,
50 BKW_MMAP_RUNNING,
51 BKW_MMAP_DATA_PENDING,
52 BKW_MMAP_EMPTY,
53};
54
55struct mmap_params {
56 int prot, mask;
57 struct auxtrace_mmap_params auxtrace_mp;
58};
59
60int perf_mmap__mmap(struct perf_mmap *map, struct mmap_params *mp, int fd);
61void perf_mmap__munmap(struct perf_mmap *map);
62
63void perf_mmap__get(struct perf_mmap *map);
64void perf_mmap__put(struct perf_mmap *map);
65
66void perf_mmap__consume(struct perf_mmap *map, bool overwrite);
67
68void perf_mmap__read_catchup(struct perf_mmap *md);
69
70static inline u64 perf_mmap__read_head(struct perf_mmap *mm)
71{
72 struct perf_event_mmap_page *pc = mm->base;
73 u64 head = ACCESS_ONCE(pc->data_head);
74 rmb();
75 return head;
76}
77
78static inline void perf_mmap__write_tail(struct perf_mmap *md, u64 tail)
79{
80 struct perf_event_mmap_page *pc = md->base;
81
82 /*
83 * ensure all reads are done before we write the tail out.
84 */
85 mb();
86 pc->data_tail = tail;
87}
88
89union perf_event *perf_mmap__read_forward(struct perf_mmap *map, bool check_messup);
90union perf_event *perf_mmap__read_backward(struct perf_mmap *map);
91
92int perf_mmap__push(struct perf_mmap *md, bool overwrite, bool backward,
93 void *to, int push(void *to, void *buf, size_t size));
94
95size_t perf_mmap__mmap_len(struct perf_mmap *map);
96
97#endif /*__PERF_MMAP_H */