72 lines
2.0 KiB
C
72 lines
2.0 KiB
C
/*
|
|
* Copyright (C) 2018 Intel Corporation.
|
|
*
|
|
* SPDX-License-Identifier: BSD-3-Clause
|
|
*/
|
|
|
|
#ifndef SHARED_BUF_H
|
|
#define SHARED_BUF_H
|
|
|
|
#include <linux/types.h>
|
|
|
|
#define SBUF_MAGIC 0x5aa57aa71aa13aa3
|
|
#define SBUF_MAX_SIZE (1ULL << 22)
|
|
#define SBUF_HEAD_SIZE 64
|
|
|
|
/* sbuf flags */
|
|
#define OVERRUN_CNT_EN (1ULL << 0) /* whether overrun counting is enabled */
|
|
#define OVERWRITE_EN (1ULL << 1) /* whether overwrite is enabled */
|
|
|
|
typedef unsigned char uint8_t;
|
|
typedef unsigned int uint32_t;
|
|
typedef unsigned long uint64_t;
|
|
|
|
/**
|
|
* (sbuf) head + buf (store (ele_num - 1) elements at most)
|
|
* buffer empty: tail == head
|
|
* buffer full: (tail + ele_size) % size == head
|
|
*
|
|
* Base of memory for elements
|
|
* |
|
|
* |
|
|
* ---------------------------------------------------------------------------------------
|
|
* | shared_buf_t | raw data (ele_size)| raw date (ele_size) | ... | raw data (ele_size) |
|
|
* ---------------------------------------------------------------------------------------
|
|
* |
|
|
* |
|
|
* shared_buf_t *buf
|
|
*/
|
|
|
|
/* Make sure sizeof(shared_buf_t) == SBUF_HEAD_SIZE */
|
|
typedef struct shared_buf {
|
|
uint64_t magic;
|
|
uint32_t ele_num; /* number of elements */
|
|
uint32_t ele_size; /* sizeof of elements */
|
|
uint32_t head; /* offset from base, to read */
|
|
uint32_t tail; /* offset from base, to write */
|
|
uint64_t flags;
|
|
uint32_t overrun_cnt; /* count of overrun */
|
|
uint32_t size; /* ele_num * ele_size */
|
|
uint32_t padding[6];
|
|
} shared_buf_t;
|
|
|
|
static inline void sbuf_clear_flags(shared_buf_t *sbuf, uint64_t flags)
|
|
{
|
|
sbuf->flags &= ~flags;
|
|
}
|
|
|
|
static inline void sbuf_set_flags(shared_buf_t *sbuf, uint64_t flags)
|
|
{
|
|
sbuf->flags = flags;
|
|
}
|
|
|
|
static inline void sbuf_add_flags(shared_buf_t *sbuf, uint64_t flags)
|
|
{
|
|
sbuf->flags |= flags;
|
|
}
|
|
|
|
int sbuf_get(shared_buf_t *sbuf, uint8_t *data);
|
|
int sbuf_write(int fd, shared_buf_t *sbuf);
|
|
int sbuf_clear_buffered(shared_buf_t *sbuf);
|
|
#endif /* SHARED_BUF_H */
|