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                 buf->bytesused = bytesused;
  92                 /* the transport buffers are handled differently,
  93                    they are not moved to the full queue */
  94                 if (s->type != CX18_ENC_STREAM_TYPE_TS) {
  95                         atomic_dec(&s->q_free.buffers);
  96                         atomic_inc(&s->q_full.buffers);
  97                         s->q_full.bytesused += buf->bytesused;
  98                         list_move_tail(&buf->list, &s->q_full.list);
  99                 }
 100                 spin_unlock(&s->qlock);
 101                 return buf;
 102         }
 103         spin_unlock(&s->qlock);
 104         CX18_ERR("Cannot find buffer %d for stream %s\n", id, s->name);
 105         return NULL;
 106 }
 107
 108 /* Move all buffers of a queue to q_free, while flushing the buffers */
 109 static void cx18_queue_flush(struct cx18_stream *s, struct cx18_queue *q)
 110 {
 111         unsigned long flags;
 112         struct cx18_buffer *buf;
 113
 114         if (q == &s->q_free)
 115                 return;
 116
 117         spin_lock_irqsave(&s->qlock, flags);
 118         while (!list_empty(&q->list)) {
 119                 buf = list_entry(q->list.next, struct cx18_buffer, list);
 120                 list_move_tail(q->list.next, &s->q_free.list);
 121                 buf->bytesused = buf->readpos = buf->b_flags = 0;
 122                 atomic_inc(&s->q_free.buffers);
 123         }
 124         cx18_queue_init(q);
 125         spin_unlock_irqrestore(&s->qlock, flags);
 126 }
 127
 128 void cx18_flush_queues(struct cx18_stream *s)
 129 {
 130         cx18_queue_flush(s, &s->q_io);
 131         cx18_queue_flush(s, &s->q_full);
 132 }
 133
 134 int cx18_stream_alloc(struct cx18_stream *s)
 135 {
 136         struct cx18 *cx = s->cx;
 137         int i;
 138
 139         if (s->buffers == 0)
 140                 return 0;
 141
 142         CX18_DEBUG_INFO("Allocate %s stream: %d x %d buffers (%dkB total)\n",
 143                 s->name, s->buffers, s->buf_size,
 144                 s->buffers * s->buf_size / 1024);
 145
 146         if (((char __iomem *)&cx->scb->cpu_mdl[cx->mdl_offset + s->buffers] -
 147                                 (char __iomem *)cx->scb) > SCB_RESERVED_SIZE) {
 148                 unsigned bufsz = (((char __iomem *)cx->scb) + SCB_RESERVED_SIZE -
 149                                         ((char __iomem *)cx->scb->cpu_mdl));
 150
 151                 CX18_ERR("Too many buffers, cannot fit in SCB area\n");
 152                 CX18_ERR("Max buffers = %zd\n",
 153                         bufsz / sizeof(struct cx18_mdl));
 154                 return -ENOMEM;
 155         }
 156
 157         s->mdl_offset = cx->mdl_offset;
 158
 159         /* allocate stream buffers. Initially all buffers are in q_free. */
 160         for (i = 0; i < s->buffers; i++) {
 161                 struct cx18_buffer *buf = kzalloc(sizeof(struct cx18_buffer),
 162                                                 GFP_KERNEL|__GFP_NOWARN);
 163
 164                 if (buf == NULL)
 165                         break;
 166                 buf->buf = kmalloc(s->buf_size, GFP_KERNEL|__GFP_NOWARN);
 167                 if (buf->buf == NULL) {
 168                         kfree(buf);
 169                         break;
 170                 }
 171                 buf->id = cx->buffer_id++;
 172                 INIT_LIST_HEAD(&buf->list);
 173                 buf->dma_handle = pci_map_single(s->cx->dev,
 174                                 buf->buf, s->buf_size, s->dma);
 175                 cx18_buf_sync_for_cpu(s, buf);
 176                 cx18_enqueue(s, buf, &s->q_free);
 177         }
 178         if (i == s->buffers) {
 179                 cx->mdl_offset += s->buffers;
 180                 return 0;
 181         }
 182         CX18_ERR("Couldn't allocate buffers for %s stream\n", s->name);
 183         cx18_stream_free(s);
 184         return -ENOMEM;
 185 }
 186
 187 void cx18_stream_free(struct cx18_stream *s)
 188 {
 189         struct cx18_buffer *buf;
 190
 191         /* move all buffers to q_free */
 192         cx18_flush_queues(s);
 193
 194         /* empty q_free */
 195         while ((buf = cx18_dequeue(s, &s->q_free))) {
 196                 pci_unmap_single(s->cx->dev, buf->dma_handle,
 197                                 s->buf_size, s->dma);
 198                 kfree(buf->buf);
 199                 kfree(buf);
 200         }
 201 }