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         /* clear the buffer if it is going to be enqueued to the free queue */
  48         if (q == &s->q_free) {
  49                 buf->bytesused = 0;
  50                 buf->readpos = 0;
  51                 buf->b_flags = 0;
  52                 buf->skipped = 0;
  53         }
  54         mutex_lock(&s->qlock);
  55         list_add_tail(&buf->list, &q->list);
  56         atomic_inc(&q->buffers);
  57         q->bytesused += buf->bytesused - buf->readpos;
  58         mutex_unlock(&s->qlock);
  59 }
  60
  61 struct cx18_buffer *cx18_dequeue(struct cx18_stream *s, struct cx18_queue *q)
  62 {
  63         struct cx18_buffer *buf = NULL;
  64
  65         mutex_lock(&s->qlock);
  66         if (!list_empty(&q->list)) {
  67                 buf = list_entry(q->list.next, struct cx18_buffer, list);
  68                 list_del_init(q->list.next);
  69                 atomic_dec(&q->buffers);
  70                 q->bytesused -= buf->bytesused - buf->readpos;
  71                 buf->skipped = 0;
  72         }
  73         mutex_unlock(&s->qlock);
  74         return buf;
  75 }
  76
  77 struct cx18_buffer *cx18_queue_get_buf(struct cx18_stream *s, u32 id,
  78         u32 bytesused)
  79 {
  80         struct cx18 *cx = s->cx;
  81         struct cx18_buffer *buf;
  82         struct cx18_buffer *ret = NULL;
  83         struct list_head *p, *t;
  84         LIST_HEAD(r);
  85
  86         mutex_lock(&s->qlock);
  87         list_for_each_safe(p, t, &s->q_free.list) {
  88                 buf = list_entry(p, struct cx18_buffer, list);
  89
  90                 if (buf->id != id) {
  91                         buf->skipped++;
  92                         if (buf->skipped >= atomic_read(&s->q_free.buffers)-1) {
  93                                 /* buffer must have fallen out of rotation */
  94                                 atomic_dec(&s->q_free.buffers);
  95                                 list_move_tail(&buf->list, &r);
  96                                 CX18_WARN("Skipped %s, buffer %d, %d "
  97                                           "times - it must have dropped out of "
  98                                           "rotation\n", s->name, buf->id,
  99                                           buf->skipped);
 100                         }
 101                         continue;
 102                 }
 103
 104                 buf->bytesused = bytesused;
 105                 atomic_dec(&s->q_free.buffers);
 106                 if (s->type == CX18_ENC_STREAM_TYPE_TS) {
 107                         /*
 108                          * TS doesn't use q_full, but for sweeping up lost
 109                          * buffers, we want the TS to requeue the buffer just
 110                          * before sending the MDL back to the firmware, so we
 111                          * pull it off the list here.
 112                          */
 113                         list_del_init(&buf->list);
 114                 } else {
 115                         atomic_inc(&s->q_full.buffers);
 116                         s->q_full.bytesused += buf->bytesused;
 117                         list_move_tail(&buf->list, &s->q_full.list);
 118                 }
 119
 120                 ret = buf;
 121                 break;
 122         }
 123         mutex_unlock(&s->qlock);
 124
 125         /* Put lost buffers back into firmware transfer rotation */
 126         while (!list_empty(&r)) {
 127                 buf = list_entry(r.next, struct cx18_buffer, list);
 128                 list_del_init(r.next);
 129                 cx18_enqueue(s, buf, &s->q_free);
 130                 cx18_vapi(cx, CX18_CPU_DE_SET_MDL, 5, s->handle,
 131                        (void __iomem *)&cx->scb->cpu_mdl[buf->id] - cx->enc_mem,
 132                        1, buf->id, s->buf_size);
 133                 CX18_INFO("Returning %s, buffer %d back to transfer rotation\n",
 134                           s->name, buf->id);
 135                 /* and there was much rejoicing... */
 136         }
 137         return ret;
 138 }
 139
 140 /* Move all buffers of a queue to q_free, while flushing the buffers */
 141 static void cx18_queue_flush(struct cx18_stream *s, struct cx18_queue *q)
 142 {
 143         struct cx18_buffer *buf;
 144
 145         if (q == &s->q_free)
 146                 return;
 147
 148         mutex_lock(&s->qlock);
 149         while (!list_empty(&q->list)) {
 150                 buf = list_entry(q->list.next, struct cx18_buffer, list);
 151                 list_move_tail(q->list.next, &s->q_free.list);
 152                 buf->bytesused = buf->readpos = buf->b_flags = buf->skipped = 0;
 153                 atomic_inc(&s->q_free.buffers);
 154         }
 155         cx18_queue_init(q);
 156         mutex_unlock(&s->qlock);
 157 }
 158
 159 void cx18_flush_queues(struct cx18_stream *s)
 160 {
 161         cx18_queue_flush(s, &s->q_io);
 162         cx18_queue_flush(s, &s->q_full);
 163 }
 164
 165 int cx18_stream_alloc(struct cx18_stream *s)
 166 {
 167         struct cx18 *cx = s->cx;
 168         int i;
 169
 170         if (s->buffers == 0)
 171                 return 0;
 172
 173         CX18_DEBUG_INFO("Allocate %s stream: %d x %d buffers (%dkB total)\n",
 174                 s->name, s->buffers, s->buf_size,
 175                 s->buffers * s->buf_size / 1024);
 176
 177         if (((char __iomem *)&cx->scb->cpu_mdl[cx->mdl_offset + s->buffers] -
 178                                 (char __iomem *)cx->scb) > SCB_RESERVED_SIZE) {
 179                 unsigned bufsz = (((char __iomem *)cx->scb) + SCB_RESERVED_SIZE -
 180                                         ((char __iomem *)cx->scb->cpu_mdl));
 181
 182                 CX18_ERR("Too many buffers, cannot fit in SCB area\n");
 183                 CX18_ERR("Max buffers = %zd\n",
 184                         bufsz / sizeof(struct cx18_mdl));
 185                 return -ENOMEM;
 186         }
 187
 188         s->mdl_offset = cx->mdl_offset;
 189
 190         /* allocate stream buffers. Initially all buffers are in q_free. */
 191         for (i = 0; i < s->buffers; i++) {
 192                 struct cx18_buffer *buf = kzalloc(sizeof(struct cx18_buffer),
 193                                                 GFP_KERNEL|__GFP_NOWARN);
 194
 195                 if (buf == NULL)
 196                         break;
 197                 buf->buf = kmalloc(s->buf_size, GFP_KERNEL|__GFP_NOWARN);
 198                 if (buf->buf == NULL) {
 199                         kfree(buf);
 200                         break;
 201                 }
 202                 buf->id = cx->buffer_id++;
 203                 INIT_LIST_HEAD(&buf->list);
 204                 buf->dma_handle = pci_map_single(s->cx->dev,
 205                                 buf->buf, s->buf_size, s->dma);
 206                 cx18_buf_sync_for_cpu(s, buf);
 207                 cx18_enqueue(s, buf, &s->q_free);
 208         }
 209         if (i == s->buffers) {
 210                 cx->mdl_offset += s->buffers;
 211                 return 0;
 212         }
 213         CX18_ERR("Couldn't allocate buffers for %s stream\n", s->name);
 214         cx18_stream_free(s);
 215         return -ENOMEM;
 216 }
 217
 218 void cx18_stream_free(struct cx18_stream *s)
 219 {
 220         struct cx18_buffer *buf;
 221
 222         /* move all buffers to q_free */
 223         cx18_flush_queues(s);
 224
 225         /* empty q_free */
 226         while ((buf = cx18_dequeue(s, &s->q_free))) {
 227                 pci_unmap_single(s->cx->dev, buf->dma_handle,
 228                                 s->buf_size, s->dma);
 229                 kfree(buf->buf);
 230                 kfree(buf);
 231         }
 232 }