git.oblomov.eu Git - linux-2.6/blob - 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 }