1 #ifndef _LINUX_RING_BUFFER_BACKEND_TYPES_H
2 #define _LINUX_RING_BUFFER_BACKEND_TYPES_H
5 * linux/ringbuffer/backend_types.h
7 * Copyright (C) 2008-2010 - Mathieu Desnoyers <mathieu.desnoyers@efficios.com>
9 * Ring buffer backend (types).
11 * Dual LGPL v2.1/GPL v2 license.
14 struct lib_ring_buffer_backend_page
{
15 void *virt
; /* page virtual address (cached) */
16 struct page
*page
; /* pointer to page structure */
19 struct lib_ring_buffer_backend_pages
{
20 unsigned long mmap_offset
; /* offset of the subbuffer in mmap */
21 union v_atomic records_commit
; /* current records committed count */
22 union v_atomic records_unread
; /* records to read */
23 unsigned long data_size
; /* Amount of data to read from subbuf */
24 struct lib_ring_buffer_backend_page p
[];
27 struct lib_ring_buffer_backend_subbuffer
{
28 /* Identifier for subbuf backend pages. Exchanged atomically. */
29 unsigned long id
; /* backend subbuffer identifier */
33 * Forward declaration of frontend-specific channel and ring_buffer.
36 struct lib_ring_buffer
;
38 struct lib_ring_buffer_backend
{
39 /* Array of ring_buffer_backend_subbuffer for writer */
40 struct lib_ring_buffer_backend_subbuffer
*buf_wsb
;
41 /* ring_buffer_backend_subbuffer for reader */
42 struct lib_ring_buffer_backend_subbuffer buf_rsb
;
44 * Pointer array of backend pages, for whole buffer.
45 * Indexed by ring_buffer_backend_subbuffer identifier (id) index.
47 struct lib_ring_buffer_backend_pages
**array
;
48 unsigned int num_pages_per_subbuf
;
50 struct channel
*chan
; /* Associated channel */
51 int cpu
; /* This buffer's cpu. -1 if global. */
52 union v_atomic records_read
; /* Number of records read */
53 unsigned int allocated
:1; /* Bool: is buffer allocated ? */
56 struct channel_backend
{
57 unsigned long buf_size
; /* Size of the buffer */
58 unsigned long subbuf_size
; /* Sub-buffer size */
59 unsigned int subbuf_size_order
; /* Order of sub-buffer size */
60 unsigned int num_subbuf_order
; /*
61 * Order of number of sub-buffers/buffer
64 unsigned int buf_size_order
; /* Order of buffer size */
65 int extra_reader_sb
:1; /* Bool: has extra reader subbuffer */
66 struct lib_ring_buffer
*buf
; /* Channel per-cpu buffers */
68 unsigned long num_subbuf
; /* Number of sub-buffers for writer */
69 u64 start_tsc
; /* Channel creation TSC value */
70 void *priv
; /* Client-specific information */
71 const struct lib_ring_buffer_config
*config
; /* Ring buffer configuration */
72 char name
[NAME_MAX
]; /* Channel name */
75 #endif /* _LINUX_RING_BUFFER_BACKEND_TYPES_H */