2 * Copyright (c) 2010-2012 Broadcom. All rights reserved.
4 * Redistribution and use in source and binary forms, with or without
5 * modification, are permitted provided that the following conditions
7 * 1. Redistributions of source code must retain the above copyright
8 * notice, this list of conditions, and the following disclaimer,
9 * without modification.
10 * 2. Redistributions in binary form must reproduce the above copyright
11 * notice, this list of conditions and the following disclaimer in the
12 * documentation and/or other materials provided with the distribution.
13 * 3. The names of the above-listed copyright holders may not be used
14 * to endorse or promote products derived from this software without
15 * specific prior written permission.
17 * ALTERNATIVELY, this software may be distributed under the terms of the
18 * GNU General Public License ("GPL") version 2, as published by the Free
19 * Software Foundation.
21 * THIS SOFTWARE IS PROVIDED BY THE COPYRIGHT HOLDERS AND CONTRIBUTORS "AS
22 * IS" AND ANY EXPRESS OR IMPLIED WARRANTIES, INCLUDING, BUT NOT LIMITED TO,
23 * THE IMPLIED WARRANTIES OF MERCHANTABILITY AND FITNESS FOR A PARTICULAR
24 * PURPOSE ARE DISCLAIMED. IN NO EVENT SHALL THE COPYRIGHT OWNER OR
25 * CONTRIBUTORS BE LIABLE FOR ANY DIRECT, INDIRECT, INCIDENTAL, SPECIAL,
26 * EXEMPLARY, OR CONSEQUENTIAL DAMAGES (INCLUDING, BUT NOT LIMITED TO,
27 * PROCUREMENT OF SUBSTITUTE GOODS OR SERVICES; LOSS OF USE, DATA, OR
28 * PROFITS; OR BUSINESS INTERRUPTION) HOWEVER CAUSED AND ON ANY THEORY OF
29 * LIABILITY, WHETHER IN CONTRACT, STRICT LIABILITY, OR TORT (INCLUDING
30 * NEGLIGENCE OR OTHERWISE) ARISING IN ANY WAY OUT OF THE USE OF THIS
31 * SOFTWARE, EVEN IF ADVISED OF THE POSSIBILITY OF SUCH DAMAGE.
34 #include "vchiq_util.h"
35 #include "vchiq_killable.h"
37 static inline int is_pow2(int i)
39 return i && !(i & (i - 1));
42 int vchiu_queue_init(VCHIU_QUEUE_T *queue, int size)
44 WARN_ON(!is_pow2(size));
49 queue->initialized = 1;
51 sema_init(&queue->pop, 0);
52 sema_init(&queue->push, 0);
54 queue->storage = kzalloc(size * sizeof(VCHIQ_HEADER_T *), GFP_KERNEL);
55 if (queue->storage == NULL) {
56 vchiu_queue_delete(queue);
62 void vchiu_queue_delete(VCHIU_QUEUE_T *queue)
64 if (queue->storage != NULL)
65 kfree(queue->storage);
68 int vchiu_queue_is_empty(VCHIU_QUEUE_T *queue)
70 return queue->read == queue->write;
73 int vchiu_queue_is_full(VCHIU_QUEUE_T *queue)
75 return queue->write == queue->read + queue->size;
78 void vchiu_queue_push(VCHIU_QUEUE_T *queue, VCHIQ_HEADER_T *header)
80 if (!queue->initialized)
83 while (queue->write == queue->read + queue->size) {
84 if (down_interruptible(&queue->pop) != 0) {
85 flush_signals(current);
90 * Write to queue->storage must be visible after read from
95 queue->storage[queue->write & (queue->size - 1)] = header;
98 * Write to queue->storage must be visible before write to
108 VCHIQ_HEADER_T *vchiu_queue_peek(VCHIU_QUEUE_T *queue)
110 while (queue->write == queue->read) {
111 if (down_interruptible(&queue->push) != 0) {
112 flush_signals(current);
116 up(&queue->push); // We haven't removed anything from the queue.
119 * Read from queue->storage must be visible after read from
124 return queue->storage[queue->read & (queue->size - 1)];
127 VCHIQ_HEADER_T *vchiu_queue_pop(VCHIU_QUEUE_T *queue)
129 VCHIQ_HEADER_T *header;
131 while (queue->write == queue->read) {
132 if (down_interruptible(&queue->push) != 0) {
133 flush_signals(current);
138 * Read from queue->storage must be visible after read from
143 header = queue->storage[queue->read & (queue->size - 1)];
146 * Read from queue->storage must be visible before write to