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path: root/drivers/media/video/cx18/cx18-queue.c
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Diffstat (limited to 'drivers/media/video/cx18/cx18-queue.c')
-rw-r--r--drivers/media/video/cx18/cx18-queue.c282
1 files changed, 282 insertions, 0 deletions
diff --git a/drivers/media/video/cx18/cx18-queue.c b/drivers/media/video/cx18/cx18-queue.c
new file mode 100644
index 00000000000..65af1bb507c
--- /dev/null
+++ b/drivers/media/video/cx18/cx18-queue.c
@@ -0,0 +1,282 @@
+/*
+ * cx18 buffer queues
+ *
+ * Derived from ivtv-queue.c
+ *
+ * Copyright (C) 2007 Hans Verkuil <hverkuil@xs4all.nl>
+ *
+ * This program is free software; you can redistribute it and/or modify
+ * it under the terms of the GNU General Public License as published by
+ * the Free Software Foundation; either version 2 of the License, or
+ * (at your option) any later version.
+ *
+ * This program is distributed in the hope that it will be useful,
+ * but WITHOUT ANY WARRANTY; without even the implied warranty of
+ * MERCHANTABILITY or FITNESS FOR A PARTICULAR PURPOSE. See the
+ * GNU General Public License for more details.
+ *
+ * You should have received a copy of the GNU General Public License
+ * along with this program; if not, write to the Free Software
+ * Foundation, Inc., 59 Temple Place, Suite 330, Boston, MA
+ * 02111-1307 USA
+ */
+
+#include "cx18-driver.h"
+#include "cx18-streams.h"
+#include "cx18-queue.h"
+#include "cx18-scb.h"
+
+int cx18_buf_copy_from_user(struct cx18_stream *s, struct cx18_buffer *buf,
+ const char __user *src, int copybytes)
+{
+ if (s->buf_size - buf->bytesused < copybytes)
+ copybytes = s->buf_size - buf->bytesused;
+ if (copy_from_user(buf->buf + buf->bytesused, src, copybytes))
+ return -EFAULT;
+ buf->bytesused += copybytes;
+ return copybytes;
+}
+
+void cx18_buf_swap(struct cx18_buffer *buf)
+{
+ int i;
+
+ for (i = 0; i < buf->bytesused; i += 4)
+ swab32s((u32 *)(buf->buf + i));
+}
+
+void cx18_queue_init(struct cx18_queue *q)
+{
+ INIT_LIST_HEAD(&q->list);
+ q->buffers = 0;
+ q->length = 0;
+ q->bytesused = 0;
+}
+
+void cx18_enqueue(struct cx18_stream *s, struct cx18_buffer *buf,
+ struct cx18_queue *q)
+{
+ unsigned long flags = 0;
+
+ /* clear the buffer if it is going to be enqueued to the free queue */
+ if (q == &s->q_free) {
+ buf->bytesused = 0;
+ buf->readpos = 0;
+ buf->b_flags = 0;
+ }
+ spin_lock_irqsave(&s->qlock, flags);
+ list_add_tail(&buf->list, &q->list);
+ q->buffers++;
+ q->length += s->buf_size;
+ q->bytesused += buf->bytesused - buf->readpos;
+ spin_unlock_irqrestore(&s->qlock, flags);
+}
+
+struct cx18_buffer *cx18_dequeue(struct cx18_stream *s, struct cx18_queue *q)
+{
+ struct cx18_buffer *buf = NULL;
+ unsigned long flags = 0;
+
+ spin_lock_irqsave(&s->qlock, flags);
+ if (!list_empty(&q->list)) {
+ buf = list_entry(q->list.next, struct cx18_buffer, list);
+ list_del_init(q->list.next);
+ q->buffers--;
+ q->length -= s->buf_size;
+ q->bytesused -= buf->bytesused - buf->readpos;
+ }
+ spin_unlock_irqrestore(&s->qlock, flags);
+ return buf;
+}
+
+struct cx18_buffer *cx18_queue_find_buf(struct cx18_stream *s, u32 id,
+ u32 bytesused)
+{
+ struct cx18 *cx = s->cx;
+ struct list_head *p;
+
+ list_for_each(p, &s->q_free.list) {
+ struct cx18_buffer *buf =
+ list_entry(p, struct cx18_buffer, list);
+
+ if (buf->id != id)
+ continue;
+ buf->bytesused = bytesused;
+ /* the transport buffers are handled differently,
+ so there is no need to move them to the full queue */
+ if (s->type == CX18_ENC_STREAM_TYPE_TS)
+ return buf;
+ s->q_free.buffers--;
+ s->q_free.length -= s->buf_size;
+ s->q_full.buffers++;
+ s->q_full.length += s->buf_size;
+ s->q_full.bytesused += buf->bytesused;
+ list_move_tail(&buf->list, &s->q_full.list);
+ return buf;
+ }
+ CX18_ERR("Cannot find buffer %d for stream %s\n", id, s->name);
+ return NULL;
+}
+
+static void cx18_queue_move_buf(struct cx18_stream *s, struct cx18_queue *from,
+ struct cx18_queue *to, int clear, int full)
+{
+ struct cx18_buffer *buf =
+ list_entry(from->list.next, struct cx18_buffer, list);
+
+ list_move_tail(from->list.next, &to->list);
+ from->buffers--;
+ from->length -= s->buf_size;
+ from->bytesused -= buf->bytesused - buf->readpos;
+ /* special handling for q_free */
+ if (clear)
+ buf->bytesused = buf->readpos = buf->b_flags = 0;
+ else if (full) {
+ /* special handling for stolen buffers, assume
+ all bytes are used. */
+ buf->bytesused = s->buf_size;
+ buf->readpos = buf->b_flags = 0;
+ }
+ to->buffers++;
+ to->length += s->buf_size;
+ to->bytesused += buf->bytesused - buf->readpos;
+}
+
+/* Move 'needed_bytes' worth of buffers from queue 'from' into queue 'to'.
+ If 'needed_bytes' == 0, then move all buffers from 'from' into 'to'.
+ If 'steal' != NULL, then buffers may also taken from that queue if
+ needed.
+
+ The buffer is automatically cleared if it goes to the free queue. It is
+ also cleared if buffers need to be taken from the 'steal' queue and
+ the 'from' queue is the free queue.
+
+ When 'from' is q_free, then needed_bytes is compared to the total
+ available buffer length, otherwise needed_bytes is compared to the
+ bytesused value. For the 'steal' queue the total available buffer
+ length is always used.
+
+ -ENOMEM is returned if the buffers could not be obtained, 0 if all
+ buffers where obtained from the 'from' list and if non-zero then
+ the number of stolen buffers is returned. */
+int cx18_queue_move(struct cx18_stream *s, struct cx18_queue *from,
+ struct cx18_queue *steal, struct cx18_queue *to, int needed_bytes)
+{
+ unsigned long flags;
+ int rc = 0;
+ int from_free = from == &s->q_free;
+ int to_free = to == &s->q_free;
+ int bytes_available;
+
+ spin_lock_irqsave(&s->qlock, flags);
+ if (needed_bytes == 0) {
+ from_free = 1;
+ needed_bytes = from->length;
+ }
+
+ bytes_available = from_free ? from->length : from->bytesused;
+ bytes_available += steal ? steal->length : 0;
+
+ if (bytes_available < needed_bytes) {
+ spin_unlock_irqrestore(&s->qlock, flags);
+ return -ENOMEM;
+ }
+ if (from_free) {
+ u32 old_length = to->length;
+
+ while (to->length - old_length < needed_bytes) {
+ if (list_empty(&from->list))
+ from = steal;
+ if (from == steal)
+ rc++; /* keep track of 'stolen' buffers */
+ cx18_queue_move_buf(s, from, to, 1, 0);
+ }
+ } else {
+ u32 old_bytesused = to->bytesused;
+
+ while (to->bytesused - old_bytesused < needed_bytes) {
+ if (list_empty(&from->list))
+ from = steal;
+ if (from == steal)
+ rc++; /* keep track of 'stolen' buffers */
+ cx18_queue_move_buf(s, from, to, to_free, rc);
+ }
+ }
+ spin_unlock_irqrestore(&s->qlock, flags);
+ return rc;
+}
+
+void cx18_flush_queues(struct cx18_stream *s)
+{
+ cx18_queue_move(s, &s->q_io, NULL, &s->q_free, 0);
+ cx18_queue_move(s, &s->q_full, NULL, &s->q_free, 0);
+}
+
+int cx18_stream_alloc(struct cx18_stream *s)
+{
+ struct cx18 *cx = s->cx;
+ int i;
+
+ if (s->buffers == 0)
+ return 0;
+
+ CX18_DEBUG_INFO("Allocate %s stream: %d x %d buffers (%dkB total)\n",
+ s->name, s->buffers, s->buf_size,
+ s->buffers * s->buf_size / 1024);
+
+ if (((char *)&cx->scb->cpu_mdl[cx->mdl_offset + s->buffers] -
+ (char *)cx->scb) > SCB_RESERVED_SIZE) {
+ unsigned bufsz = (((char *)cx->scb) + SCB_RESERVED_SIZE -
+ ((char *)cx->scb->cpu_mdl));
+
+ CX18_ERR("Too many buffers, cannot fit in SCB area\n");
+ CX18_ERR("Max buffers = %zd\n",
+ bufsz / sizeof(struct cx18_mdl));
+ return -ENOMEM;
+ }
+
+ s->mdl_offset = cx->mdl_offset;
+
+ /* allocate stream buffers. Initially all buffers are in q_free. */
+ for (i = 0; i < s->buffers; i++) {
+ struct cx18_buffer *buf =
+ kzalloc(sizeof(struct cx18_buffer), GFP_KERNEL);
+
+ if (buf == NULL)
+ break;
+ buf->buf = kmalloc(s->buf_size, GFP_KERNEL);
+ if (buf->buf == NULL) {
+ kfree(buf);
+ break;
+ }
+ buf->id = cx->buffer_id++;
+ INIT_LIST_HEAD(&buf->list);
+ buf->dma_handle = pci_map_single(s->cx->dev,
+ buf->buf, s->buf_size, s->dma);
+ cx18_buf_sync_for_cpu(s, buf);
+ cx18_enqueue(s, buf, &s->q_free);
+ }
+ if (i == s->buffers) {
+ cx->mdl_offset += s->buffers;
+ return 0;
+ }
+ CX18_ERR("Couldn't allocate buffers for %s stream\n", s->name);
+ cx18_stream_free(s);
+ return -ENOMEM;
+}
+
+void cx18_stream_free(struct cx18_stream *s)
+{
+ struct cx18_buffer *buf;
+
+ /* move all buffers to q_free */
+ cx18_flush_queues(s);
+
+ /* empty q_free */
+ while ((buf = cx18_dequeue(s, &s->q_free))) {
+ pci_unmap_single(s->cx->dev, buf->dma_handle,
+ s->buf_size, s->dma);
+ kfree(buf->buf);
+ kfree(buf);
+ }
+}