[mirror_ubuntu-jammy-kernel.git] / tools / perf / util / mmap.h

#ifndef __PERF_MMAP_H
#define __PERF_MMAP_H 1

#include <linux/compiler.h>
#include <linux/refcount.h>
#include <linux/types.h>
#include <asm/barrier.h>
#include <stdbool.h>
#include "auxtrace.h"
#include "event.h"

/**
 * struct perf_mmap - perf's ring buffer mmap details
 *
 * @refcnt - e.g. code using PERF_EVENT_IOC_SET_OUTPUT to share this
 */
struct perf_mmap {
	void		 *base;
	int		 mask;
	int		 fd;
	refcount_t	 refcnt;
	u64		 prev;
	struct auxtrace_mmap auxtrace_mmap;
	char		 event_copy[PERF_SAMPLE_MAX_SIZE] __aligned(8);
};

/*
 * State machine of bkw_mmap_state:
 *
 *                     .________________(forbid)_____________.
 *                     |                                     V
 * NOTREADY --(0)--> RUNNING --(1)--> DATA_PENDING --(2)--> EMPTY
 *                     ^  ^              |   ^               |
 *                     |  |__(forbid)____/   |___(forbid)___/|
 *                     |                                     |
 *                      \_________________(3)_______________/
 *
 * NOTREADY     : Backward ring buffers are not ready
 * RUNNING      : Backward ring buffers are recording
 * DATA_PENDING : We are required to collect data from backward ring buffers
 * EMPTY        : We have collected data from backward ring buffers.
 *
 * (0): Setup backward ring buffer
 * (1): Pause ring buffers for reading
 * (2): Read from ring buffers
 * (3): Resume ring buffers for recording
 */
enum bkw_mmap_state {
	BKW_MMAP_NOTREADY,
	BKW_MMAP_RUNNING,
	BKW_MMAP_DATA_PENDING,
	BKW_MMAP_EMPTY,
};

struct mmap_params {
	int			    prot, mask;
	struct auxtrace_mmap_params auxtrace_mp;
};

int perf_mmap__mmap(struct perf_mmap *map, struct mmap_params *mp, int fd);
void perf_mmap__munmap(struct perf_mmap *map);

void perf_mmap__get(struct perf_mmap *map);
void perf_mmap__put(struct perf_mmap *map);

void perf_mmap__consume(struct perf_mmap *map, bool overwrite);

void perf_mmap__read_catchup(struct perf_mmap *md);

static inline u64 perf_mmap__read_head(struct perf_mmap *mm)
{
	struct perf_event_mmap_page *pc = mm->base;
	u64 head = READ_ONCE(pc->data_head);
	rmb();
	return head;
}

static inline void perf_mmap__write_tail(struct perf_mmap *md, u64 tail)
{
	struct perf_event_mmap_page *pc = md->base;

	/*
	 * ensure all reads are done before we write the tail out.
	 */
	mb();
	pc->data_tail = tail;
}

union perf_event *perf_mmap__read_forward(struct perf_mmap *map);
union perf_event *perf_mmap__read_backward(struct perf_mmap *map);

int perf_mmap__push(struct perf_mmap *md, bool backward,
		    void *to, int push(void *to, void *buf, size_t size));

size_t perf_mmap__mmap_len(struct perf_mmap *map);

#endif /*__PERF_MMAP_H */
Commit	Line	Data
16958497 ACM	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	*/
	17	struct 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	*/
	48	enum bkw_mmap_state {
	49	BKW_MMAP_NOTREADY,
	50	BKW_MMAP_RUNNING,
	51	BKW_MMAP_DATA_PENDING,
	52	BKW_MMAP_EMPTY,
	53	};
	54
	55	struct mmap_params {
	56	int prot, mask;
	57	struct auxtrace_mmap_params auxtrace_mp;
	58	};
	59
	60	int perf_mmap__mmap(struct perf_mmap map, struct mmap_params mp, int fd);
	61	void perf_mmap__munmap(struct perf_mmap *map);
	62
	63	void perf_mmap__get(struct perf_mmap *map);
	64	void perf_mmap__put(struct perf_mmap *map);
65
66	void perf_mmap__consume(struct perf_mmap *map, bool overwrite);
67
68	void perf_mmap__read_catchup(struct perf_mmap *md);
69
70	static inline u64 perf_mmap__read_head(struct perf_mmap *mm)
71	{
72	struct perf_event_mmap_page *pc = mm->base;
f971e511	73	u64 head = READ_ONCE(pc->data_head);
16958497 ACM	74	rmb();
	75	return head;
	76	}
	77
	78	static 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
8eb7a1fe	89	union perf_event perf_mmap__read_forward(struct perf_mmap map);
16958497 ACM	90	union perf_event perf_mmap__read_backward(struct perf_mmap map);
16958497 ACM	91
ca6a9a05	92	int perf_mmap__push(struct perf_mmap *md, bool backward,
73c17d81 ACM	93	void to, int push(void to, void *buf, size_t size));
73c17d81 ACM	94
16958497 ACM	95	size_t perf_mmap__mmap_len(struct perf_mmap *map);
	96
	97	#endif /__PERF_MMAP_H /