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  *  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 a max buffer count imposed by firmware */
  59         if (q == &s->q_busy &&
  60             atomic_read(&q->buffers) >= CX18_MAX_FW_MDLS_PER_STREAM)
  61                 q = &s->q_free;
  62
  63         if (to_front)
  64                 list_add(&buf->list, &q->list); /* LIFO */
  65         else
  66                 list_add_tail(&buf->list, &q->list); /* FIFO */
  67         q->bytesused += buf->bytesused - buf->readpos;
  68         atomic_inc(&q->buffers);
  69
  70         mutex_unlock(&s->qlock);
  71         return q;
  72 }
  73
  74 struct cx18_buffer *cx18_dequeue(struct cx18_stream *s, struct cx18_queue *q)
  75 {
  76         struct cx18_buffer *buf = NULL;
  77
  78         mutex_lock(&s->qlock);
  79         if (!list_empty(&q->list)) {
  80                 buf = list_first_entry(&q->list, struct cx18_buffer, list);
  81                 list_del_init(&buf->list);
  82                 q->bytesused -= buf->bytesused - buf->readpos;
  83                 buf->skipped = 0;
  84                 atomic_dec(&q->buffers);
  85         }
  86         mutex_unlock(&s->qlock);
  87         return buf;
  88 }
  89
  90 struct cx18_buffer *cx18_queue_get_buf(struct cx18_stream *s, u32 id,
  91         u32 bytesused)
  92 {
  93         struct cx18 *cx = s->cx;
  94         struct cx18_buffer *buf;
  95         struct cx18_buffer *tmp;
  96         struct cx18_buffer *ret = NULL;
  97
  98         mutex_lock(&s->qlock);
  99         list_for_each_entry_safe(buf, tmp, &s->q_busy.list, list) {
 100                 if (buf->id != id) {
 101                         buf->skipped++;
 102                         if (buf->skipped >= atomic_read(&s->q_busy.buffers)-1) {
 103                                 /* buffer must have fallen out of rotation */
 104                                 CX18_WARN("Skipped %s, buffer %d, %d "
 105                                           "times - it must have dropped out of "
 106                                           "rotation\n", s->name, buf->id,
 107                                           buf->skipped);
 108                                 /* move it to q_free */
 109                                 list_move_tail(&buf->list, &s->q_free.list);
 110                                 buf->bytesused = buf->readpos = buf->b_flags =
 111                                         buf->skipped = 0;
 112                                 atomic_dec(&s->q_busy.buffers);
 113                                 atomic_inc(&s->q_free.buffers);
 114                         }
 115                         continue;
 116                 }
 117
 118                 buf->bytesused = bytesused;
 119                 /* Sync the buffer before we release the qlock */
 120                 cx18_buf_sync_for_cpu(s, buf);
 121                 if (s->type == CX18_ENC_STREAM_TYPE_TS) {
 122                         /*
 123                          * TS doesn't use q_full.  As we pull the buffer off of
 124                          * the queue here, the caller will have to put it back.
 125                          */
 126                         list_del_init(&buf->list);
 127                 } else {
 128                         /* Move buffer from q_busy to q_full */
 129                         list_move_tail(&buf->list, &s->q_full.list);
 130                         set_bit(CX18_F_B_NEED_BUF_SWAP, &buf->b_flags);
 131                         s->q_full.bytesused += buf->bytesused;
 132                         atomic_inc(&s->q_full.buffers);
 133                 }
 134                 atomic_dec(&s->q_busy.buffers);
 135
 136                 ret = buf;
 137                 break;
 138         }
 139         mutex_unlock(&s->qlock);
 140         return ret;
 141 }
 142
 143 /* Move all buffers of a queue to q_free, while flushing the buffers */
 144 static void cx18_queue_flush(struct cx18_stream *s, struct cx18_queue *q)
 145 {
 146         struct cx18_buffer *buf;
 147
 148         if (q == &s->q_free)
 149                 return;
 150
 151         mutex_lock(&s->qlock);
 152         while (!list_empty(&q->list)) {
 153                 buf = list_first_entry(&q->list, struct cx18_buffer, list);
 154                 list_move_tail(&buf->list, &s->q_free.list);
 155                 buf->bytesused = buf->readpos = buf->b_flags = buf->skipped = 0;
 156                 atomic_inc(&s->q_free.buffers);
 157         }
 158         cx18_queue_init(q);
 159         mutex_unlock(&s->qlock);
 160 }
 161
 162 void cx18_flush_queues(struct cx18_stream *s)
 163 {
 164         cx18_queue_flush(s, &s->q_busy);
 165         cx18_queue_flush(s, &s->q_full);
 166 }
 167
 168 int cx18_stream_alloc(struct cx18_stream *s)
 169 {
 170         struct cx18 *cx = s->cx;
 171         int i;
 172
 173         if (s->buffers == 0)
 174                 return 0;
 175
 176         CX18_DEBUG_INFO("Allocate %s stream: %d x %d buffers (%dkB total)\n",
 177                 s->name, s->buffers, s->buf_size,
 178                 s->buffers * s->buf_size / 1024);
 179
 180         if (((char __iomem *)&cx->scb->cpu_mdl[cx->mdl_offset + s->buffers] -
 181                                 (char __iomem *)cx->scb) > SCB_RESERVED_SIZE) {
 182                 unsigned bufsz = (((char __iomem *)cx->scb) + SCB_RESERVED_SIZE -
 183                                         ((char __iomem *)cx->scb->cpu_mdl));
 184
 185                 CX18_ERR("Too many buffers, cannot fit in SCB area\n");
 186                 CX18_ERR("Max buffers = %zd\n",
 187                         bufsz / sizeof(struct cx18_mdl));
 188                 return -ENOMEM;
 189         }
 190
 191         s->mdl_offset = cx->mdl_offset;
 192
 193         /* allocate stream buffers. Initially all buffers are in q_free. */
 194         for (i = 0; i < s->buffers; i++) {
 195                 struct cx18_buffer *buf = kzalloc(sizeof(struct cx18_buffer),
 196                                                 GFP_KERNEL|__GFP_NOWARN);
 197
 198                 if (buf == NULL)
 199                         break;
 200                 buf->buf = kmalloc(s->buf_size, GFP_KERNEL|__GFP_NOWARN);
 201                 if (buf->buf == NULL) {
 202                         kfree(buf);
 203                         break;
 204                 }
 205                 buf->id = cx->buffer_id++;
 206                 INIT_LIST_HEAD(&buf->list);
 207                 buf->dma_handle = pci_map_single(s->cx->pci_dev,
 208                                 buf->buf, s->buf_size, s->dma);
 209                 cx18_buf_sync_for_cpu(s, buf);
 210                 cx18_enqueue(s, buf, &s->q_free);
 211         }
 212         if (i == s->buffers) {
 213                 cx->mdl_offset += s->buffers;
 214                 return 0;
 215         }
 216         CX18_ERR("Couldn't allocate buffers for %s stream\n", s->name);
 217         cx18_stream_free(s);
 218         return -ENOMEM;
 219 }
 220
 221 void cx18_stream_free(struct cx18_stream *s)
 222 {
 223         struct cx18_buffer *buf;
 224
 225         /* move all buffers to q_free */
 226         cx18_flush_queues(s);
 227
 228         /* empty q_free */
 229         while ((buf = cx18_dequeue(s, &s->q_free))) {
 230                 pci_unmap_single(s->cx->pci_dev, buf->dma_handle,
 231                                 s->buf_size, s->dma);
 232                 kfree(buf->buf);
 233                 kfree(buf);
 234         }
 235 }