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 #include <linux/cpumask.h>
15 #include <linux/types.h>
17 struct lib_ring_buffer_backend_page
{
18 void *virt
; /* page virtual address (cached) */
19 struct page
*page
; /* pointer to page structure */
22 struct lib_ring_buffer_backend_pages
{
23 unsigned long mmap_offset
; /* offset of the subbuffer in mmap */
24 union v_atomic records_commit
; /* current records committed count */
25 union v_atomic records_unread
; /* records to read */
26 unsigned long data_size
; /* Amount of data to read from subbuf */
27 struct lib_ring_buffer_backend_page p
[];
30 struct lib_ring_buffer_backend_subbuffer
{
31 /* Identifier for subbuf backend pages. Exchanged atomically. */
32 unsigned long id
; /* backend subbuffer identifier */
36 * Forward declaration of frontend-specific channel and ring_buffer.
39 struct lib_ring_buffer
;
41 struct lib_ring_buffer_backend
{
42 /* Array of ring_buffer_backend_subbuffer for writer */
43 struct lib_ring_buffer_backend_subbuffer
*buf_wsb
;
44 /* ring_buffer_backend_subbuffer for reader */
45 struct lib_ring_buffer_backend_subbuffer buf_rsb
;
47 * Pointer array of backend pages, for whole buffer.
48 * Indexed by ring_buffer_backend_subbuffer identifier (id) index.
50 struct lib_ring_buffer_backend_pages
**array
;
51 unsigned int num_pages_per_subbuf
;
53 struct channel
*chan
; /* Associated channel */
54 int cpu
; /* This buffer's cpu. -1 if global. */
55 union v_atomic records_read
; /* Number of records read */
56 unsigned int allocated
:1; /* is buffer allocated ? */
59 struct channel_backend
{
60 unsigned long buf_size
; /* Size of the buffer */
61 unsigned long subbuf_size
; /* Sub-buffer size */
62 unsigned int subbuf_size_order
; /* Order of sub-buffer size */
63 unsigned int num_subbuf_order
; /*
64 * Order of number of sub-buffers/buffer
67 unsigned int buf_size_order
; /* Order of buffer size */
68 unsigned int extra_reader_sb
:1; /* has extra reader subbuffer ? */
69 struct lib_ring_buffer
*buf
; /* Channel per-cpu buffers */
71 unsigned long num_subbuf
; /* Number of sub-buffers for writer */
72 u64 start_tsc
; /* Channel creation TSC value */
73 void *priv
; /* Client-specific information */
74 struct notifier_block cpu_hp_notifier
; /* CPU hotplug notifier */
76 * We need to copy config because the module containing the
77 * source config can vanish before the last reference to this
78 * channel's streams is released.
80 struct lib_ring_buffer_config config
; /* Ring buffer configuration */
81 cpumask_var_t cpumask
; /* Allocated per-cpu buffers cpumask */
82 char name
[NAME_MAX
]; /* Channel name */
85 #endif /* _LINUX_RING_BUFFER_BACKEND_TYPES_H */