1 files changed, 428 insertions, 0 deletions

diff --git a/drivers/media/pci/cx18/cx18-queue.c b/drivers/media/pci/cx18/cx18-queue.c
new file mode 100644
index 0000000000..013694bfcb
--- /dev/null
+++ b/drivers/media/pci/cx18/cx18-queue.c
@@ -0,0 +1,428 @@
+// SPDX-License-Identifier: GPL-2.0-or-later
+/*
+ *  cx18 buffer queues
+ *
+ *  Derived from ivtv-queue.c
+ *
+ *  Copyright (C) 2007  Hans Verkuil <hverkuil@xs4all.nl>
+ *  Copyright (C) 2008  Andy Walls <awalls@md.metrocast.net>
+ */
+
+#include "cx18-driver.h"
+#include "cx18-queue.h"
+#include "cx18-streams.h"
+#include "cx18-scb.h"
+#include "cx18-io.h"
+
+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_mdl_swap(struct cx18_mdl *mdl)
+{
+	struct cx18_buffer *buf;
+
+	list_for_each_entry(buf, &mdl->buf_list, list) {
+		if (buf->bytesused == 0)
+			break;
+		cx18_buf_swap(buf);
+	}
+}
+
+void cx18_queue_init(struct cx18_queue *q)
+{
+	INIT_LIST_HEAD(&q->list);
+	atomic_set(&q->depth, 0);
+	q->bytesused = 0;
+}
+
+struct cx18_queue *_cx18_enqueue(struct cx18_stream *s, struct cx18_mdl *mdl,
+				 struct cx18_queue *q, int to_front)
+{
+	/* clear the mdl if it is not to be enqueued to the full queue */
+	if (q != &s->q_full) {
+		mdl->bytesused = 0;
+		mdl->readpos = 0;
+		mdl->m_flags = 0;
+		mdl->skipped = 0;
+		mdl->curr_buf = NULL;
+	}
+
+	/* q_busy is restricted to a max buffer count imposed by firmware */
+	if (q == &s->q_busy &&
+	    atomic_read(&q->depth) >= CX18_MAX_FW_MDLS_PER_STREAM)
+		q = &s->q_free;
+
+	spin_lock(&q->lock);
+
+	if (to_front)
+		list_add(&mdl->list, &q->list); /* LIFO */
+	else
+		list_add_tail(&mdl->list, &q->list); /* FIFO */
+	q->bytesused += mdl->bytesused - mdl->readpos;
+	atomic_inc(&q->depth);
+
+	spin_unlock(&q->lock);
+	return q;
+}
+
+struct cx18_mdl *cx18_dequeue(struct cx18_stream *s, struct cx18_queue *q)
+{
+	struct cx18_mdl *mdl = NULL;
+
+	spin_lock(&q->lock);
+	if (!list_empty(&q->list)) {
+		mdl = list_first_entry(&q->list, struct cx18_mdl, list);
+		list_del_init(&mdl->list);
+		q->bytesused -= mdl->bytesused - mdl->readpos;
+		mdl->skipped = 0;
+		atomic_dec(&q->depth);
+	}
+	spin_unlock(&q->lock);
+	return mdl;
+}
+
+static void _cx18_mdl_update_bufs_for_cpu(struct cx18_stream *s,
+					  struct cx18_mdl *mdl)
+{
+	struct cx18_buffer *buf;
+	u32 buf_size = s->buf_size;
+	u32 bytesused = mdl->bytesused;
+
+	list_for_each_entry(buf, &mdl->buf_list, list) {
+		buf->readpos = 0;
+		if (bytesused >= buf_size) {
+			buf->bytesused = buf_size;
+			bytesused -= buf_size;
+		} else {
+			buf->bytesused = bytesused;
+			bytesused = 0;
+		}
+		cx18_buf_sync_for_cpu(s, buf);
+	}
+}
+
+static inline void cx18_mdl_update_bufs_for_cpu(struct cx18_stream *s,
+						struct cx18_mdl *mdl)
+{
+	struct cx18_buffer *buf;
+
+	if (list_is_singular(&mdl->buf_list)) {
+		buf = list_first_entry(&mdl->buf_list, struct cx18_buffer,
+				       list);
+		buf->bytesused = mdl->bytesused;
+		buf->readpos = 0;
+		cx18_buf_sync_for_cpu(s, buf);
+	} else {
+		_cx18_mdl_update_bufs_for_cpu(s, mdl);
+	}
+}
+
+struct cx18_mdl *cx18_queue_get_mdl(struct cx18_stream *s, u32 id,
+	u32 bytesused)
+{
+	struct cx18 *cx = s->cx;
+	struct cx18_mdl *mdl;
+	struct cx18_mdl *tmp;
+	struct cx18_mdl *ret = NULL;
+	LIST_HEAD(sweep_up);
+
+	/*
+	 * We don't have to acquire multiple q locks here, because we are
+	 * serialized by the single threaded work handler.
+	 * MDLs from the firmware will thus remain in order as
+	 * they are moved from q_busy to q_full or to the dvb ring buffer.
+	 */
+	spin_lock(&s->q_busy.lock);
+	list_for_each_entry_safe(mdl, tmp, &s->q_busy.list, list) {
+		/*
+		 * We should find what the firmware told us is done,
+		 * right at the front of the queue.  If we don't, we likely have
+		 * missed an mdl done message from the firmware.
+		 * Once we skip an mdl repeatedly, relative to the size of
+		 * q_busy, we have high confidence we've missed it.
+		 */
+		if (mdl->id != id) {
+			mdl->skipped++;
+			if (mdl->skipped >= atomic_read(&s->q_busy.depth)-1) {
+				/* mdl must have fallen out of rotation */
+				CX18_WARN("Skipped %s, MDL %d, %d times - it must have dropped out of rotation\n",
+					  s->name, mdl->id,
+					  mdl->skipped);
+				/* Sweep it up to put it back into rotation */
+				list_move_tail(&mdl->list, &sweep_up);
+				atomic_dec(&s->q_busy.depth);
+			}
+			continue;
+		}
+		/*
+		 * We pull the desired mdl off of the queue here.  Something
+		 * will have to put it back on a queue later.
+		 */
+		list_del_init(&mdl->list);
+		atomic_dec(&s->q_busy.depth);
+		ret = mdl;
+		break;
+	}
+	spin_unlock(&s->q_busy.lock);
+
+	/*
+	 * We found the mdl for which we were looking.  Get it ready for
+	 * the caller to put on q_full or in the dvb ring buffer.
+	 */
+	if (ret != NULL) {
+		ret->bytesused = bytesused;
+		ret->skipped = 0;
+		/* 0'ed readpos, m_flags & curr_buf when mdl went on q_busy */
+		cx18_mdl_update_bufs_for_cpu(s, ret);
+		if (s->type != CX18_ENC_STREAM_TYPE_TS)
+			set_bit(CX18_F_M_NEED_SWAP, &ret->m_flags);
+	}
+
+	/* Put any mdls the firmware is ignoring back into normal rotation */
+	list_for_each_entry_safe(mdl, tmp, &sweep_up, list) {
+		list_del_init(&mdl->list);
+		cx18_enqueue(s, mdl, &s->q_free);
+	}
+	return ret;
+}
+
+/* Move all mdls of a queue, while flushing the mdl */
+static void cx18_queue_flush(struct cx18_stream *s,
+			     struct cx18_queue *q_src, struct cx18_queue *q_dst)
+{
+	struct cx18_mdl *mdl;
+
+	/* It only makes sense to flush to q_free or q_idle */
+	if (q_src == q_dst || q_dst == &s->q_full || q_dst == &s->q_busy)
+		return;
+
+	spin_lock(&q_src->lock);
+	spin_lock(&q_dst->lock);
+	while (!list_empty(&q_src->list)) {
+		mdl = list_first_entry(&q_src->list, struct cx18_mdl, list);
+		list_move_tail(&mdl->list, &q_dst->list);
+		mdl->bytesused = 0;
+		mdl->readpos = 0;
+		mdl->m_flags = 0;
+		mdl->skipped = 0;
+		mdl->curr_buf = NULL;
+		atomic_inc(&q_dst->depth);
+	}
+	cx18_queue_init(q_src);
+	spin_unlock(&q_src->lock);
+	spin_unlock(&q_dst->lock);
+}
+
+void cx18_flush_queues(struct cx18_stream *s)
+{
+	cx18_queue_flush(s, &s->q_busy, &s->q_free);
+	cx18_queue_flush(s, &s->q_full, &s->q_free);
+}
+
+/*
+ * Note, s->buf_pool is not protected by a lock,
+ * the stream better not have *anything* going on when calling this
+ */
+void cx18_unload_queues(struct cx18_stream *s)
+{
+	struct cx18_queue *q_idle = &s->q_idle;
+	struct cx18_mdl *mdl;
+	struct cx18_buffer *buf;
+
+	/* Move all MDLS to q_idle */
+	cx18_queue_flush(s, &s->q_busy, q_idle);
+	cx18_queue_flush(s, &s->q_full, q_idle);
+	cx18_queue_flush(s, &s->q_free, q_idle);
+
+	/* Reset MDL id's and move all buffers back to the stream's buf_pool */
+	spin_lock(&q_idle->lock);
+	list_for_each_entry(mdl, &q_idle->list, list) {
+		while (!list_empty(&mdl->buf_list)) {
+			buf = list_first_entry(&mdl->buf_list,
+					       struct cx18_buffer, list);
+			list_move_tail(&buf->list, &s->buf_pool);
+			buf->bytesused = 0;
+			buf->readpos = 0;
+		}
+		mdl->id = s->mdl_base_idx; /* reset id to a "safe" value */
+		/* all other mdl fields were cleared by cx18_queue_flush() */
+	}
+	spin_unlock(&q_idle->lock);
+}
+
+/*
+ * Note, s->buf_pool is not protected by a lock,
+ * the stream better not have *anything* going on when calling this
+ */
+void cx18_load_queues(struct cx18_stream *s)
+{
+	struct cx18 *cx = s->cx;
+	struct cx18_mdl *mdl;
+	struct cx18_buffer *buf;
+	int mdl_id;
+	int i;
+	u32 partial_buf_size;
+
+	/*
+	 * Attach buffers to MDLs, give the MDLs ids, and add MDLs to q_free
+	 * Excess MDLs are left on q_idle
+	 * Excess buffers are left in buf_pool and/or on an MDL in q_idle
+	 */
+	mdl_id = s->mdl_base_idx;
+	for (mdl = cx18_dequeue(s, &s->q_idle), i = s->bufs_per_mdl;
+	     mdl != NULL && i == s->bufs_per_mdl;
+	     mdl = cx18_dequeue(s, &s->q_idle)) {
+
+		mdl->id = mdl_id;
+
+		for (i = 0; i < s->bufs_per_mdl; i++) {
+			if (list_empty(&s->buf_pool))
+				break;
+
+			buf = list_first_entry(&s->buf_pool, struct cx18_buffer,
+					       list);
+			list_move_tail(&buf->list, &mdl->buf_list);
+
+			/* update the firmware's MDL array with this buffer */
+			cx18_writel(cx, buf->dma_handle,
+				    &cx->scb->cpu_mdl[mdl_id + i].paddr);
+			cx18_writel(cx, s->buf_size,
+				    &cx->scb->cpu_mdl[mdl_id + i].length);
+		}
+
+		if (i == s->bufs_per_mdl) {
+			/*
+			 * The encoder doesn't honor s->mdl_size.  So in the
+			 * case of a non-integral number of buffers to meet
+			 * mdl_size, we lie about the size of the last buffer
+			 * in the MDL to get the encoder to really only send
+			 * us mdl_size bytes per MDL transfer.
+			 */
+			partial_buf_size = s->mdl_size % s->buf_size;
+			if (partial_buf_size) {
+				cx18_writel(cx, partial_buf_size,
+				      &cx->scb->cpu_mdl[mdl_id + i - 1].length);
+			}
+			cx18_enqueue(s, mdl, &s->q_free);
+		} else {
+			/* Not enough buffers for this MDL; we won't use it */
+			cx18_push(s, mdl, &s->q_idle);
+		}
+		mdl_id += i;
+	}
+}
+
+void _cx18_mdl_sync_for_device(struct cx18_stream *s, struct cx18_mdl *mdl)
+{
+	int dma = s->dma;
+	u32 buf_size = s->buf_size;
+	struct pci_dev *pci_dev = s->cx->pci_dev;
+	struct cx18_buffer *buf;
+
+	list_for_each_entry(buf, &mdl->buf_list, list)
+		dma_sync_single_for_device(&pci_dev->dev, buf->dma_handle,
+					   buf_size, dma);
+}
+
+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 (%d.%02d kB total)\n",
+		s->name, s->buffers, s->buf_size,
+		s->buffers * s->buf_size / 1024,
+		(s->buffers * s->buf_size * 100 / 1024) % 100);
+
+	if (((char __iomem *)&cx->scb->cpu_mdl[cx->free_mdl_idx + s->buffers] -
+				(char __iomem *)cx->scb) > SCB_RESERVED_SIZE) {
+		unsigned bufsz = (((char __iomem *)cx->scb) + SCB_RESERVED_SIZE -
+					((char __iomem *)cx->scb->cpu_mdl));
+
+		CX18_ERR("Too many buffers, cannot fit in SCB area\n");
+		CX18_ERR("Max buffers = %zu\n",
+			bufsz / sizeof(struct cx18_mdl_ent));
+		return -ENOMEM;
+	}
+
+	s->mdl_base_idx = cx->free_mdl_idx;
+
+	/* allocate stream buffers and MDLs */
+	for (i = 0; i < s->buffers; i++) {
+		struct cx18_mdl *mdl;
+		struct cx18_buffer *buf;
+
+		/* 1 MDL per buffer to handle the worst & also default case */
+		mdl = kzalloc(sizeof(struct cx18_mdl), GFP_KERNEL|__GFP_NOWARN);
+		if (mdl == NULL)
+			break;
+
+		buf = kzalloc(sizeof(struct cx18_buffer),
+				GFP_KERNEL|__GFP_NOWARN);
+		if (buf == NULL) {
+			kfree(mdl);
+			break;
+		}
+
+		buf->buf = kmalloc(s->buf_size, GFP_KERNEL|__GFP_NOWARN);
+		if (buf->buf == NULL) {
+			kfree(mdl);
+			kfree(buf);
+			break;
+		}
+
+		INIT_LIST_HEAD(&mdl->list);
+		INIT_LIST_HEAD(&mdl->buf_list);
+		mdl->id = s->mdl_base_idx; /* a somewhat safe value */
+		cx18_enqueue(s, mdl, &s->q_idle);
+
+		INIT_LIST_HEAD(&buf->list);
+		buf->dma_handle = dma_map_single(&s->cx->pci_dev->dev,
+						 buf->buf, s->buf_size,
+						 s->dma);
+		cx18_buf_sync_for_cpu(s, buf);
+		list_add_tail(&buf->list, &s->buf_pool);
+	}
+	if (i == s->buffers) {
+		cx->free_mdl_idx += 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_mdl *mdl;
+	struct cx18_buffer *buf;
+	struct cx18 *cx = s->cx;
+
+	CX18_DEBUG_INFO("Deallocating buffers for %s stream\n", s->name);
+
+	/* move all buffers to buf_pool and all MDLs to q_idle */
+	cx18_unload_queues(s);
+
+	/* empty q_idle */
+	while ((mdl = cx18_dequeue(s, &s->q_idle)))
+		kfree(mdl);
+
+	/* empty buf_pool */
+	while (!list_empty(&s->buf_pool)) {
+		buf = list_first_entry(&s->buf_pool, struct cx18_buffer, list);
+		list_del_init(&buf->list);
+
+		dma_unmap_single(&s->cx->pci_dev->dev, buf->dma_handle,
+				 s->buf_size, s->dma);
+		kfree(buf->buf);
+		kfree(buf);
+	}
+}