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         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 }