SAFE public projects git trees. - safe/jmp/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  *  Copyright (C) 2008  Andy Walls <awalls@radix.net>
   8  *
   9  *  This program is free software; you can redistribute it and/or modify
  10  *  it under the terms of the GNU General Public License as published by
  11  *  the Free Software Foundation; either version 2 of the License, or
  12  *  (at your option) any later version.
  13  *
  14  *  This program is distributed in the hope that it will be useful,
  15  *  but WITHOUT ANY WARRANTY; without even the implied warranty of
  16  *  MERCHANTABILITY or FITNESS FOR A PARTICULAR PURPOSE.  See the
  17  *  GNU General Public License for more details.
  18  *
  19  *  You should have received a copy of the GNU General Public License
  20  *  along with this program; if not, write to the Free Software
  21  *  Foundation, Inc., 59 Temple Place, Suite 330, Boston, MA
  22  *  02111-1307  USA
  23  */
  24
  25 #include "cx18-driver.h"
  26 #include "cx18-streams.h"
  27 #include "cx18-queue.h"
  28 #include "cx18-scb.h"
  29
  30 void cx18_buf_swap(struct cx18_buffer *buf)
  31 {
  32         int i;
  33
  34         for (i = 0; i < buf->bytesused; i += 4)
  35                 swab32s((u32 *)(buf->buf + i));
  36 }
  37
  38 void cx18_queue_init(struct cx18_queue *q)
  39 {
  40         INIT_LIST_HEAD(&q->list);
  41         atomic_set(&q->buffers, 0);
  42         q->bytesused = 0;
  43 }
  44
  45 struct cx18_queue *_cx18_enqueue(struct cx18_stream *s, struct cx18_buffer *buf,
  46                                  struct cx18_queue *q, int to_front)
  47 {
  48         /* clear the buffer if it is not to be enqueued to the full queue */
  49         if (q != &s->q_full) {
  50                 buf->bytesused = 0;
  51                 buf->readpos = 0;
  52                 buf->b_flags = 0;
  53                 buf->skipped = 0;
  54         }
  55
  56         mutex_lock(&s->qlock);
  57
  58         /* q_busy is restricted to 63 buffers to stay within firmware limits */
  59         if (q == &s->q_busy && atomic_read(&q->buffers) >= 63)
  60                 q = &s->q_free;
  61
  62         if (to_front)
  63                 list_add(&buf->list, &q->list); /* LIFO */
  64         else
  65                 list_add_tail(&buf->list, &q->list); /* FIFO */
  66         q->bytesused += buf->bytesused - buf->readpos;
  67         atomic_inc(&q->buffers);
  68
  69         mutex_unlock(&s->qlock);
  70         return q;
  71 }
  72
  73 struct cx18_buffer *cx18_dequeue(struct cx18_stream *s, struct cx18_queue *q)
  74 {
  75         struct cx18_buffer *buf = NULL;
  76
  77         mutex_lock(&s->qlock);
  78         if (!list_empty(&q->list)) {
  79                 buf = list_entry(q->list.next, struct cx18_buffer, list);
  80                 list_del_init(q->list.next);
  81                 q->bytesused -= buf->bytesused - buf->readpos;
  82                 buf->skipped = 0;
  83                 atomic_dec(&q->buffers);
  84         }
  85         mutex_unlock(&s->qlock);
  86         return buf;
  87 }
  88
  89 struct cx18_buffer *cx18_queue_get_buf(struct cx18_stream *s, u32 id,
  90         u32 bytesused)
  91 {
  92         struct cx18 *cx = s->cx;
  93         struct cx18_buffer *buf;
  94         struct cx18_buffer *ret = NULL;
  95         struct list_head *p, *t;
  96
  97         mutex_lock(&s->qlock);
  98         list_for_each_safe(p, t, &s->q_busy.list) {
  99                 buf = list_entry(p, struct cx18_buffer, list);
 100
 101                 if (buf->id != id) {
 102                         buf->skipped++;
 103                         if (buf->skipped >= atomic_read(&s->q_busy.buffers)-1) {
 104                                 /* buffer must have fallen out of rotation */
 105                                 CX18_WARN("Skipped %s, buffer %d, %d "
 106                                           "times - it must have dropped out of "
 107                                           "rotation\n", s->name, buf->id,
 108                                           buf->skipped);
 109                                 /* move it to q_free */
 110                                 list_move_tail(&buf->list, &s->q_free.list);
 111                                 buf->bytesused = buf->readpos = buf->b_flags =
 112                                         buf->skipped = 0;
 113                                 atomic_dec(&s->q_busy.buffers);
 114                                 atomic_inc(&s->q_free.buffers);
 115                         }
 116                         continue;
 117                 }
 118
 119                 buf->bytesused = bytesused;
 120                 if (s->type == CX18_ENC_STREAM_TYPE_TS) {
 121                         /*
 122                          * TS doesn't use q_full, but for sweeping up lost
 123                          * buffers, we want the TS to requeue the buffer just
 124                          * before sending the MDL back to the firmware, so we
 125                          * pull it off the list here.
 126                          */
 127                         list_del_init(&buf->list);
 128                 } else {
 129                         list_move_tail(&buf->list, &s->q_full.list);
 130                         s->q_full.bytesused += buf->bytesused;
 131                         atomic_inc(&s->q_full.buffers);
 132                 }
 133                 atomic_dec(&s->q_busy.buffers);
 134
 135                 ret = buf;
 136                 break;
 137         }
 138
 139         /* Put more buffers into the transfer rotation from q_free, if we can */
 140         cx18_stream_load_fw_queue_nolock(s);
 141         mutex_unlock(&s->qlock);
 142         return ret;
 143 }
 144
 145 /* Move all buffers of a queue to q_free, while flushing the buffers */
 146 static void cx18_queue_flush(struct cx18_stream *s, struct cx18_queue *q)
 147 {
 148         struct cx18_buffer *buf;
 149
 150         if (q == &s->q_free)
 151                 return;
 152
 153         mutex_lock(&s->qlock);
 154         while (!list_empty(&q->list)) {
 155                 buf = list_entry(q->list.next, struct cx18_buffer, list);
 156                 list_move_tail(q->list.next, &s->q_free.list);
 157                 buf->bytesused = buf->readpos = buf->b_flags = buf->skipped = 0;
 158                 atomic_inc(&s->q_free.buffers);
 159         }
 160         cx18_queue_init(q);
 161         mutex_unlock(&s->qlock);
 162 }
 163
 164 void cx18_flush_queues(struct cx18_stream *s)
 165 {
 166         cx18_queue_flush(s, &s->q_busy);
 167         cx18_queue_flush(s, &s->q_full);
 168 }
 169
 170 int cx18_stream_alloc(struct cx18_stream *s)
 171 {
 172         struct cx18 *cx = s->cx;
 173         int i;
 174
 175         if (s->buffers == 0)
 176                 return 0;
 177
 178         CX18_DEBUG_INFO("Allocate %s stream: %d x %d buffers (%dkB total)\n",
 179                 s->name, s->buffers, s->buf_size,
 180                 s->buffers * s->buf_size / 1024);
 181
 182         if (((char __iomem *)&cx->scb->cpu_mdl[cx->mdl_offset + s->buffers] -
 183                                 (char __iomem *)cx->scb) > SCB_RESERVED_SIZE) {
 184                 unsigned bufsz = (((char __iomem *)cx->scb) + SCB_RESERVED_SIZE -
 185                                         ((char __iomem *)cx->scb->cpu_mdl));
 186
 187                 CX18_ERR("Too many buffers, cannot fit in SCB area\n");
 188                 CX18_ERR("Max buffers = %zd\n",
 189                         bufsz / sizeof(struct cx18_mdl));
 190                 return -ENOMEM;
 191         }
 192
 193         s->mdl_offset = cx->mdl_offset;
 194
 195         /* allocate stream buffers. Initially all buffers are in q_free. */
 196         for (i = 0; i < s->buffers; i++) {
 197                 struct cx18_buffer *buf = kzalloc(sizeof(struct cx18_buffer),
 198                                                 GFP_KERNEL|__GFP_NOWARN);
 199
 200                 if (buf == NULL)
 201                         break;
 202                 buf->buf = kmalloc(s->buf_size, GFP_KERNEL|__GFP_NOWARN);
 203                 if (buf->buf == NULL) {
 204                         kfree(buf);
 205                         break;
 206                 }
 207                 buf->id = cx->buffer_id++;
 208                 INIT_LIST_HEAD(&buf->list);
 209                 buf->dma_handle = pci_map_single(s->cx->dev,
 210                                 buf->buf, s->buf_size, s->dma);
 211                 cx18_buf_sync_for_cpu(s, buf);
 212                 cx18_enqueue(s, buf, &s->q_free);
 213         }
 214         if (i == s->buffers) {
 215                 cx->mdl_offset += s->buffers;
 216                 return 0;
 217         }
 218         CX18_ERR("Couldn't allocate buffers for %s stream\n", s->name);
 219         cx18_stream_free(s);
 220         return -ENOMEM;
 221 }
 222
 223 void cx18_stream_free(struct cx18_stream *s)
 224 {
 225         struct cx18_buffer *buf;
 226
 227         /* move all buffers to q_free */
 228         cx18_flush_queues(s);
 229
 230         /* empty q_free */
 231         while ((buf = cx18_dequeue(s, &s->q_free))) {
 232                 pci_unmap_single(s->cx->dev, buf->dma_handle,
 233                                 s->buf_size, s->dma);
 234                 kfree(buf->buf);
 235                 kfree(buf);
 236         }
 237 }