Merge branch 'linus' into x86/spinlocks
[linux-2.6] / drivers / media / video / cx18 / cx18-queue.c
1 /*
2  *  cx18 buffer queues
3  *
4  *  Derived from ivtv-queue.c
5  *
6  *  Copyright (C) 2007  Hans Verkuil <hverkuil@xs4all.nl>
7  *
8  *  This program is free software; you can redistribute it and/or modify
9  *  it under the terms of the GNU General Public License as published by
10  *  the Free Software Foundation; either version 2 of the License, or
11  *  (at your option) any later version.
12  *
13  *  This program is distributed in the hope that it will be useful,
14  *  but WITHOUT ANY WARRANTY; without even the implied warranty of
15  *  MERCHANTABILITY or FITNESS FOR A PARTICULAR PURPOSE.  See the
16  *  GNU General Public License for more details.
17  *
18  *  You should have received a copy of the GNU General Public License
19  *  along with this program; if not, write to the Free Software
20  *  Foundation, Inc., 59 Temple Place, Suite 330, Boston, MA
21  *  02111-1307  USA
22  */
23
24 #include "cx18-driver.h"
25 #include "cx18-streams.h"
26 #include "cx18-queue.h"
27 #include "cx18-scb.h"
28
29 void cx18_buf_swap(struct cx18_buffer *buf)
30 {
31         int i;
32
33         for (i = 0; i < buf->bytesused; i += 4)
34                 swab32s((u32 *)(buf->buf + i));
35 }
36
37 void cx18_queue_init(struct cx18_queue *q)
38 {
39         INIT_LIST_HEAD(&q->list);
40         q->buffers = 0;
41         q->length = 0;
42         q->bytesused = 0;
43 }
44
45 void cx18_enqueue(struct cx18_stream *s, struct cx18_buffer *buf,
46                 struct cx18_queue *q)
47 {
48         unsigned long flags = 0;
49
50         /* clear the buffer if it is going to be enqueued to the free queue */
51         if (q == &s->q_free) {
52                 buf->bytesused = 0;
53                 buf->readpos = 0;
54                 buf->b_flags = 0;
55         }
56         spin_lock_irqsave(&s->qlock, flags);
57         list_add_tail(&buf->list, &q->list);
58         q->buffers++;
59         q->length += s->buf_size;
60         q->bytesused += buf->bytesused - buf->readpos;
61         spin_unlock_irqrestore(&s->qlock, flags);
62 }
63
64 struct cx18_buffer *cx18_dequeue(struct cx18_stream *s, struct cx18_queue *q)
65 {
66         struct cx18_buffer *buf = NULL;
67         unsigned long flags = 0;
68
69         spin_lock_irqsave(&s->qlock, flags);
70         if (!list_empty(&q->list)) {
71                 buf = list_entry(q->list.next, struct cx18_buffer, list);
72                 list_del_init(q->list.next);
73                 q->buffers--;
74                 q->length -= s->buf_size;
75                 q->bytesused -= buf->bytesused - buf->readpos;
76         }
77         spin_unlock_irqrestore(&s->qlock, flags);
78         return buf;
79 }
80
81 struct cx18_buffer *cx18_queue_get_buf_irq(struct cx18_stream *s, u32 id,
82         u32 bytesused)
83 {
84         struct cx18 *cx = s->cx;
85         struct list_head *p;
86
87         spin_lock(&s->qlock);
88         list_for_each(p, &s->q_free.list) {
89                 struct cx18_buffer *buf =
90                         list_entry(p, struct cx18_buffer, list);
91
92                 if (buf->id != id)
93                         continue;
94                 buf->bytesused = bytesused;
95                 /* the transport buffers are handled differently,
96                    they are not moved to the full queue */
97                 if (s->type != CX18_ENC_STREAM_TYPE_TS) {
98                         s->q_free.buffers--;
99                         s->q_free.length -= s->buf_size;
100                         s->q_full.buffers++;
101                         s->q_full.length += s->buf_size;
102                         s->q_full.bytesused += buf->bytesused;
103                         list_move_tail(&buf->list, &s->q_full.list);
104                 }
105                 spin_unlock(&s->qlock);
106                 return buf;
107         }
108         spin_unlock(&s->qlock);
109         CX18_ERR("Cannot find buffer %d for stream %s\n", id, s->name);
110         return NULL;
111 }
112
113 /* Move all buffers of a queue to q_free, while flushing the buffers */
114 static void cx18_queue_flush(struct cx18_stream *s, struct cx18_queue *q)
115 {
116         unsigned long flags;
117         struct cx18_buffer *buf;
118
119         if (q == &s->q_free)
120                 return;
121
122         spin_lock_irqsave(&s->qlock, flags);
123         while (!list_empty(&q->list)) {
124                 buf = list_entry(q->list.next, struct cx18_buffer, list);
125                 list_move_tail(q->list.next, &s->q_free.list);
126                 buf->bytesused = buf->readpos = buf->b_flags = 0;
127                 s->q_free.buffers++;
128                 s->q_free.length += s->buf_size;
129         }
130         cx18_queue_init(q);
131         spin_unlock_irqrestore(&s->qlock, flags);
132 }
133
134 void cx18_flush_queues(struct cx18_stream *s)
135 {
136         cx18_queue_flush(s, &s->q_io);
137         cx18_queue_flush(s, &s->q_full);
138 }
139
140 int cx18_stream_alloc(struct cx18_stream *s)
141 {
142         struct cx18 *cx = s->cx;
143         int i;
144
145         if (s->buffers == 0)
146                 return 0;
147
148         CX18_DEBUG_INFO("Allocate %s stream: %d x %d buffers (%dkB total)\n",
149                 s->name, s->buffers, s->buf_size,
150                 s->buffers * s->buf_size / 1024);
151
152         if (((char __iomem *)&cx->scb->cpu_mdl[cx->mdl_offset + s->buffers] -
153                                 (char __iomem *)cx->scb) > SCB_RESERVED_SIZE) {
154                 unsigned bufsz = (((char __iomem *)cx->scb) + SCB_RESERVED_SIZE -
155                                         ((char __iomem *)cx->scb->cpu_mdl));
156
157                 CX18_ERR("Too many buffers, cannot fit in SCB area\n");
158                 CX18_ERR("Max buffers = %zd\n",
159                         bufsz / sizeof(struct cx18_mdl));
160                 return -ENOMEM;
161         }
162
163         s->mdl_offset = cx->mdl_offset;
164
165         /* allocate stream buffers. Initially all buffers are in q_free. */
166         for (i = 0; i < s->buffers; i++) {
167                 struct cx18_buffer *buf = kzalloc(sizeof(struct cx18_buffer),
168                                                 GFP_KERNEL|__GFP_NOWARN);
169
170                 if (buf == NULL)
171                         break;
172                 buf->buf = kmalloc(s->buf_size, GFP_KERNEL|__GFP_NOWARN);
173                 if (buf->buf == NULL) {
174                         kfree(buf);
175                         break;
176                 }
177                 buf->id = cx->buffer_id++;
178                 INIT_LIST_HEAD(&buf->list);
179                 buf->dma_handle = pci_map_single(s->cx->dev,
180                                 buf->buf, s->buf_size, s->dma);
181                 cx18_buf_sync_for_cpu(s, buf);
182                 cx18_enqueue(s, buf, &s->q_free);
183         }
184         if (i == s->buffers) {
185                 cx->mdl_offset += s->buffers;
186                 return 0;
187         }
188         CX18_ERR("Couldn't allocate buffers for %s stream\n", s->name);
189         cx18_stream_free(s);
190         return -ENOMEM;
191 }
192
193 void cx18_stream_free(struct cx18_stream *s)
194 {
195         struct cx18_buffer *buf;
196
197         /* move all buffers to q_free */
198         cx18_flush_queues(s);
199
200         /* empty q_free */
201         while ((buf = cx18_dequeue(s, &s->q_free))) {
202                 pci_unmap_single(s->cx->dev, buf->dma_handle,
203                                 s->buf_size, s->dma);
204                 kfree(buf->buf);
205                 kfree(buf);
206         }
207 }