1 files changed, 287 insertions, 0 deletions
diff --git a/drivers/media/pci/ivtv/ivtv-queue.c b/drivers/media/pci/ivtv/ivtv-queue.c
new file mode 100644
index 0000000000..f9b192ab7e
--- /dev/null
+++ b/drivers/media/pci/ivtv/ivtv-queue.c
@@ -0,0 +1,287 @@
+// SPDX-License-Identifier: GPL-2.0-or-later
+/*
+    buffer queues.
+    Copyright (C) 2003-2004  Kevin Thayer <nufan_wfk at yahoo.com>
+    Copyright (C) 2004  Chris Kennedy <c@groovy.org>
+    Copyright (C) 2005-2007  Hans Verkuil <hverkuil@xs4all.nl>
+
+ */
+
+#include "ivtv-driver.h"
+#include "ivtv-queue.h"
+
+int ivtv_buf_copy_from_user(struct ivtv_stream *s, struct ivtv_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 ivtv_buf_swap(struct ivtv_buffer *buf)
+{
+	int i;
+
+	for (i = 0; i < buf->bytesused; i += 4)
+		swab32s((u32 *)(buf->buf + i));
+}
+
+void ivtv_queue_init(struct ivtv_queue *q)
+{
+	INIT_LIST_HEAD(&q->list);
+	q->buffers = 0;
+	q->length = 0;
+	q->bytesused = 0;
+}
+
+void ivtv_enqueue(struct ivtv_stream *s, struct ivtv_buffer *buf, struct ivtv_queue *q)
+{
+	unsigned long flags;
+
+	/* 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;
+		buf->dma_xfer_cnt = 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 ivtv_buffer *ivtv_dequeue(struct ivtv_stream *s, struct ivtv_queue *q)
+{
+	struct ivtv_buffer *buf = NULL;
+	unsigned long flags;
+
+	spin_lock_irqsave(&s->qlock, flags);
+	if (!list_empty(&q->list)) {
+		buf = list_entry(q->list.next, struct ivtv_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;
+}
+
+static void ivtv_queue_move_buf(struct ivtv_stream *s, struct ivtv_queue *from,
+		struct ivtv_queue *to, int clear)
+{
+	struct ivtv_buffer *buf = list_entry(from->list.next, struct ivtv_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 = buf->dma_xfer_cnt = 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, but only if 'from' is the free queue.
+
+   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 ivtv_queue_move(struct ivtv_stream *s, struct ivtv_queue *from, struct ivtv_queue *steal,
+		    struct ivtv_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, bytes_steal;
+
+	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_steal = (from_free && steal) ? steal->length : 0;
+
+	if (bytes_available + bytes_steal < needed_bytes) {
+		spin_unlock_irqrestore(&s->qlock, flags);
+		return -ENOMEM;
+	}
+	while (steal && bytes_available < needed_bytes) {
+		struct ivtv_buffer *buf = list_entry(steal->list.prev, struct ivtv_buffer, list);
+		u16 dma_xfer_cnt = buf->dma_xfer_cnt;
+
+		/* move buffers from the tail of the 'steal' queue to the tail of the
+		   'from' queue. Always copy all the buffers with the same dma_xfer_cnt
+		   value, this ensures that you do not end up with partial frame data
+		   if one frame is stored in multiple buffers. */
+		while (dma_xfer_cnt == buf->dma_xfer_cnt) {
+			list_move_tail(steal->list.prev, &from->list);
+			rc++;
+			steal->buffers--;
+			steal->length -= s->buf_size;
+			steal->bytesused -= buf->bytesused - buf->readpos;
+			buf->bytesused = buf->readpos = buf->b_flags = buf->dma_xfer_cnt = 0;
+			from->buffers++;
+			from->length += s->buf_size;
+			bytes_available += s->buf_size;
+			if (list_empty(&steal->list))
+				break;
+			buf = list_entry(steal->list.prev, struct ivtv_buffer, list);
+		}
+	}
+	if (from_free) {
+		u32 old_length = to->length;
+
+		while (to->length - old_length < needed_bytes) {
+			ivtv_queue_move_buf(s, from, to, 1);
+		}
+	}
+	else {
+		u32 old_bytesused = to->bytesused;
+
+		while (to->bytesused - old_bytesused < needed_bytes) {
+			ivtv_queue_move_buf(s, from, to, to_free);
+		}
+	}
+	spin_unlock_irqrestore(&s->qlock, flags);
+	return rc;
+}
+
+void ivtv_flush_queues(struct ivtv_stream *s)
+{
+	ivtv_queue_move(s, &s->q_io, NULL, &s->q_free, 0);
+	ivtv_queue_move(s, &s->q_full, NULL, &s->q_free, 0);
+	ivtv_queue_move(s, &s->q_dma, NULL, &s->q_free, 0);
+	ivtv_queue_move(s, &s->q_predma, NULL, &s->q_free, 0);
+}
+
+int ivtv_stream_alloc(struct ivtv_stream *s)
+{
+	struct ivtv *itv = s->itv;
+	int SGsize = sizeof(struct ivtv_sg_host_element) * s->buffers;
+	int i;
+
+	if (s->buffers == 0)
+		return 0;
+
+	IVTV_DEBUG_INFO("Allocate %s%s stream: %d x %d buffers (%dkB total)\n",
+		s->dma != DMA_NONE ? "DMA " : "",
+		s->name, s->buffers, s->buf_size, s->buffers * s->buf_size / 1024);
+
+	s->sg_pending = kzalloc(SGsize, GFP_KERNEL|__GFP_NOWARN);
+	if (s->sg_pending == NULL) {
+		IVTV_ERR("Could not allocate sg_pending for %s stream\n", s->name);
+		return -ENOMEM;
+	}
+	s->sg_pending_size = 0;
+
+	s->sg_processing = kzalloc(SGsize, GFP_KERNEL|__GFP_NOWARN);
+	if (s->sg_processing == NULL) {
+		IVTV_ERR("Could not allocate sg_processing for %s stream\n", s->name);
+		kfree(s->sg_pending);
+		s->sg_pending = NULL;
+		return -ENOMEM;
+	}
+	s->sg_processing_size = 0;
+
+	s->sg_dma = kzalloc(sizeof(struct ivtv_sg_element),
+					GFP_KERNEL|__GFP_NOWARN);
+	if (s->sg_dma == NULL) {
+		IVTV_ERR("Could not allocate sg_dma for %s stream\n", s->name);
+		kfree(s->sg_pending);
+		s->sg_pending = NULL;
+		kfree(s->sg_processing);
+		s->sg_processing = NULL;
+		return -ENOMEM;
+	}
+	if (ivtv_might_use_dma(s)) {
+		s->sg_handle = dma_map_single(&itv->pdev->dev, s->sg_dma,
+					      sizeof(struct ivtv_sg_element),
+					      DMA_TO_DEVICE);
+		ivtv_stream_sync_for_cpu(s);
+	}
+
+	/* allocate stream buffers. Initially all buffers are in q_free. */
+	for (i = 0; i < s->buffers; i++) {
+		struct ivtv_buffer *buf = kzalloc(sizeof(struct ivtv_buffer),
+						GFP_KERNEL|__GFP_NOWARN);
+
+		if (buf == NULL)
+			break;
+		buf->buf = kmalloc(s->buf_size + 256, GFP_KERNEL|__GFP_NOWARN);
+		if (buf->buf == NULL) {
+			kfree(buf);
+			break;
+		}
+		INIT_LIST_HEAD(&buf->list);
+		if (ivtv_might_use_dma(s)) {
+			buf->dma_handle = dma_map_single(&s->itv->pdev->dev,
+				buf->buf, s->buf_size + 256, s->dma);
+			ivtv_buf_sync_for_cpu(s, buf);
+		}
+		ivtv_enqueue(s, buf, &s->q_free);
+	}
+	if (i == s->buffers)
+		return 0;
+	IVTV_ERR("Couldn't allocate buffers for %s stream\n", s->name);
+	ivtv_stream_free(s);
+	return -ENOMEM;
+}
+
+void ivtv_stream_free(struct ivtv_stream *s)
+{
+	struct ivtv_buffer *buf;
+
+	/* move all buffers to q_free */
+	ivtv_flush_queues(s);
+
+	/* empty q_free */
+	while ((buf = ivtv_dequeue(s, &s->q_free))) {
+		if (ivtv_might_use_dma(s))
+			dma_unmap_single(&s->itv->pdev->dev, buf->dma_handle,
+					 s->buf_size + 256, s->dma);
+		kfree(buf->buf);
+		kfree(buf);
+	}
+
+	/* Free SG Array/Lists */
+	if (s->sg_dma != NULL) {
+		if (s->sg_handle != IVTV_DMA_UNMAPPED) {
+			dma_unmap_single(&s->itv->pdev->dev, s->sg_handle,
+					 sizeof(struct ivtv_sg_element),
+					 DMA_TO_DEVICE);
+			s->sg_handle = IVTV_DMA_UNMAPPED;
+		}
+		kfree(s->sg_pending);
+		kfree(s->sg_processing);
+		kfree(s->sg_dma);
+		s->sg_pending = NULL;
+		s->sg_processing = NULL;
+		s->sg_dma = NULL;
+		s->sg_pending_size = 0;
+		s->sg_processing_size = 0;
+	}
+}