LXR linux/tools/perf/util/mmap.h

   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
  15struct 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 */
  21struct 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 */
  68enum bkw_mmap_state {
  69        BKW_MMAP_NOTREADY,
  70        BKW_MMAP_RUNNING,
  71        BKW_MMAP_DATA_PENDING,
  72        BKW_MMAP_EMPTY,
  73};
  74
  75struct mmap_params {
  76        int prot, mask, nr_cblocks, affinity, flush, comp_level;
  77        struct auxtrace_mmap_params auxtrace_mp;
  78};
  79
  80int perf_mmap__mmap(struct perf_mmap *map, struct mmap_params *mp, int fd, int cpu);
  81void perf_mmap__munmap(struct perf_mmap *map);
  82
  83void perf_mmap__get(struct perf_mmap *map);
  84void perf_mmap__put(struct perf_mmap *map);
  85
  86void perf_mmap__consume(struct perf_mmap *map);
  87
  88static inline u64 perf_mmap__read_head(struct perf_mmap *mm)
  89{
  90        return ring_buffer_read_head(mm->base);
  91}
  92
  93static inline void perf_mmap__write_tail(struct perf_mmap *md, u64 tail)
  94{
  95        ring_buffer_write_tail(md->base, tail);
  96}
  97
  98union perf_event *perf_mmap__read_forward(struct perf_mmap *map);
  99
 100union perf_event *perf_mmap__read_event(struct perf_mmap *map);
 101
 102int perf_mmap__push(struct perf_mmap *md, void *to,
 103                    int push(struct perf_mmap *map, void *to, void *buf, size_t size));
 104
 105size_t perf_mmap__mmap_len(struct perf_mmap *map);
 106
 107int perf_mmap__read_init(struct perf_mmap *md);
 108void perf_mmap__read_done(struct perf_mmap *map);
 109#endif /*__PERF_MMAP_H */
 110