Merge branch 'for-linus' of git://oss.sgi.com/xfs/xfs
[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         atomic_set(&q->buffers, 0);
41         q->bytesused = 0;
42 }
43
44 void cx18_enqueue(struct cx18_stream *s, struct cx18_buffer *buf,
45                 struct cx18_queue *q)
46 {
47         unsigned long flags = 0;
48
49         /* clear the buffer if it is going to be enqueued to the free queue */
50         if (q == &s->q_free) {
51                 buf->bytesused = 0;
52                 buf->readpos = 0;
53                 buf->b_flags = 0;
54         }
55         spin_lock_irqsave(&s->qlock, flags);
56         list_add_tail(&buf->list, &q->list);
57         atomic_inc(&q->buffers);
58         q->bytesused += buf->bytesused - buf->readpos;
59         spin_unlock_irqrestore(&s->qlock, flags);
60 }
61
62 struct cx18_buffer *cx18_dequeue(struct cx18_stream *s, struct cx18_queue *q)
63 {
64         struct cx18_buffer *buf = NULL;
65         unsigned long flags = 0;
66
67         spin_lock_irqsave(&s->qlock, flags);
68         if (!list_empty(&q->list)) {
69                 buf = list_entry(q->list.next, struct cx18_buffer, list);
70                 list_del_init(q->list.next);
71                 atomic_dec(&q->buffers);
72                 q->bytesused -= buf->bytesused - buf->readpos;
73         }
74         spin_unlock_irqrestore(&s->qlock, flags);
75         return buf;
76 }
77
78 struct cx18_buffer *cx18_queue_get_buf_irq(struct cx18_stream *s, u32 id,
79         u32 bytesused)
80 {
81         struct cx18 *cx = s->cx;
82         struct list_head *p;
83
84         spin_lock(&s->qlock);
85         list_for_each(p, &s->q_free.list) {
86                 struct cx18_buffer *buf =
87                         list_entry(p, struct cx18_buffer, list);
88
89                 if (buf->id != id)
90                         continue;
91
92                 buf->bytesused = bytesused;
93                 atomic_dec(&s->q_free.buffers);
94                 atomic_inc(&s->q_full.buffers);
95                 s->q_full.bytesused += buf->bytesused;
96                 list_move_tail(&buf->list, &s->q_full.list);
97
98                 spin_unlock(&s->qlock);
99                 return buf;
100         }
101         spin_unlock(&s->qlock);
102         CX18_ERR("Cannot find buffer %d for stream %s\n", id, s->name);
103         return NULL;
104 }
105
106 /* Move all buffers of a queue to q_free, while flushing the buffers */
107 static void cx18_queue_flush(struct cx18_stream *s, struct cx18_queue *q)
108 {
109         unsigned long flags;
110         struct cx18_buffer *buf;
111
112         if (q == &s->q_free)
113                 return;
114
115         spin_lock_irqsave(&s->qlock, flags);
116         while (!list_empty(&q->list)) {
117                 buf = list_entry(q->list.next, struct cx18_buffer, list);
118                 list_move_tail(q->list.next, &s->q_free.list);
119                 buf->bytesused = buf->readpos = buf->b_flags = 0;
120                 atomic_inc(&s->q_free.buffers);
121         }
122         cx18_queue_init(q);
123         spin_unlock_irqrestore(&s->qlock, flags);
124 }
125
126 void cx18_flush_queues(struct cx18_stream *s)
127 {
128         cx18_queue_flush(s, &s->q_io);
129         cx18_queue_flush(s, &s->q_full);
130 }
131
132 int cx18_stream_alloc(struct cx18_stream *s)
133 {
134         struct cx18 *cx = s->cx;
135         int i;
136
137         if (s->buffers == 0)
138                 return 0;
139
140         CX18_DEBUG_INFO("Allocate %s stream: %d x %d buffers (%dkB total)\n",
141                 s->name, s->buffers, s->buf_size,
142                 s->buffers * s->buf_size / 1024);
143
144         if (((char __iomem *)&cx->scb->cpu_mdl[cx->mdl_offset + s->buffers] -
145                                 (char __iomem *)cx->scb) > SCB_RESERVED_SIZE) {
146                 unsigned bufsz = (((char __iomem *)cx->scb) + SCB_RESERVED_SIZE -
147                                         ((char __iomem *)cx->scb->cpu_mdl));
148
149                 CX18_ERR("Too many buffers, cannot fit in SCB area\n");
150                 CX18_ERR("Max buffers = %zd\n",
151                         bufsz / sizeof(struct cx18_mdl));
152                 return -ENOMEM;
153         }
154
155         s->mdl_offset = cx->mdl_offset;
156
157         /* allocate stream buffers. Initially all buffers are in q_free. */
158         for (i = 0; i < s->buffers; i++) {
159                 struct cx18_buffer *buf = kzalloc(sizeof(struct cx18_buffer),
160                                                 GFP_KERNEL|__GFP_NOWARN);
161
162                 if (buf == NULL)
163                         break;
164                 buf->buf = kmalloc(s->buf_size, GFP_KERNEL|__GFP_NOWARN);
165                 if (buf->buf == NULL) {
166                         kfree(buf);
167                         break;
168                 }
169                 buf->id = cx->buffer_id++;
170                 INIT_LIST_HEAD(&buf->list);
171                 buf->dma_handle = pci_map_single(s->cx->dev,
172                                 buf->buf, s->buf_size, s->dma);
173                 cx18_buf_sync_for_cpu(s, buf);
174                 cx18_enqueue(s, buf, &s->q_free);
175         }
176         if (i == s->buffers) {
177                 cx->mdl_offset += s->buffers;
178                 return 0;
179         }
180         CX18_ERR("Couldn't allocate buffers for %s stream\n", s->name);
181         cx18_stream_free(s);
182         return -ENOMEM;
183 }
184
185 void cx18_stream_free(struct cx18_stream *s)
186 {
187         struct cx18_buffer *buf;
188
189         /* move all buffers to q_free */
190         cx18_flush_queues(s);
191
192         /* empty q_free */
193         while ((buf = cx18_dequeue(s, &s->q_free))) {
194                 pci_unmap_single(s->cx->dev, buf->dma_handle,
195                                 s->buf_size, s->dma);
196                 kfree(buf->buf);
197                 kfree(buf);
198         }
199 }