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 000000000000..65af1bb507ca
--- /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);
+        }
+}