media: vb2: add bidirectional flag in vb2_queue

This change is intended to give to the v4l2 drivers a choice to
change the default behavior of the v4l2-core DMA mapping direction
from DMA_TO/FROM_DEVICE (depending on the buffer type CAPTURE or
OUTPUT) to DMA_BIDIRECTIONAL during queue_init time.

Initially the issue with DMA mapping direction has been found in
Venus encoder driver where the hardware (firmware side) adds few
lines padding on bottom of the image buffer, and the consequence
is triggering of IOMMU protection faults.

This will help supporting venus encoder (and probably other drivers
in the future) which wants to map output type of buffers as
read/write.

Signed-off-by: Stanimir Varbanov <stanimir.varbanov@linaro.org>
Acked-by: Marek Szyprowski <m.szyprowski@samsung.com>
Signed-off-by: Hans Verkuil <hansverk@cisco.com>
Signed-off-by: Mauro Carvalho Chehab <mchehab@s-opensource.com>

4 files changed, 18 insertions, 14 deletions

diff --git a/drivers/media/v4l2-core/videobuf2-core.c b/drivers/media/v4l2-core/videobuf2-core.c
index 0924594989b4..cb115ba6a1d2 100644
--- a/drivers/media/v4l2-core/videobuf2-core.c
+++ b/drivers/media/v4l2-core/videobuf2-core.c
@@ -194,8 +194,6 @@ static void __enqueue_in_driver(struct vb2_buffer *vb);
 static int __vb2_buf_mem_alloc(struct vb2_buffer *vb)
 {
 	struct vb2_queue *q = vb->vb2_queue;
-	enum dma_data_direction dma_dir =
-		q->is_output ? DMA_TO_DEVICE : DMA_FROM_DEVICE;
 	void *mem_priv;
 	int plane;
 	int ret = -ENOMEM;
@@ -209,7 +207,7 @@ static int __vb2_buf_mem_alloc(struct vb2_buffer *vb)
 
 		mem_priv = call_ptr_memop(vb, alloc,
 				q->alloc_devs[plane] ? : q->dev,
-				q->dma_attrs, size, dma_dir, q->gfp_flags);
+				q->dma_attrs, size, q->dma_dir, q->gfp_flags);
 		if (IS_ERR_OR_NULL(mem_priv)) {
 			if (mem_priv)
 				ret = PTR_ERR(mem_priv);
@@ -978,8 +976,6 @@ static int __prepare_userptr(struct vb2_buffer *vb, const void *pb)
 	void *mem_priv;
 	unsigned int plane;
 	int ret = 0;
-	enum dma_data_direction dma_dir =
-		q->is_output ? DMA_TO_DEVICE : DMA_FROM_DEVICE;
 	bool reacquired = vb->planes[0].mem_priv == NULL;
 
 	memset(planes, 0, sizeof(planes[0]) * vb->num_planes);
@@ -1030,7 +1026,7 @@ static int __prepare_userptr(struct vb2_buffer *vb, const void *pb)
 		mem_priv = call_ptr_memop(vb, get_userptr,
 				q->alloc_devs[plane] ? : q->dev,
 				planes[plane].m.userptr,
-				planes[plane].length, dma_dir);
+				planes[plane].length, q->dma_dir);
 		if (IS_ERR(mem_priv)) {
 			dprintk(1, "failed acquiring userspace memory for plane %d\n",
 				plane);
@@ -1096,8 +1092,6 @@ static int __prepare_dmabuf(struct vb2_buffer *vb, const void *pb)
 	void *mem_priv;
 	unsigned int plane;
 	int ret = 0;
-	enum dma_data_direction dma_dir =
-		q->is_output ? DMA_TO_DEVICE : DMA_FROM_DEVICE;
 	bool reacquired = vb->planes[0].mem_priv == NULL;
 
 	memset(planes, 0, sizeof(planes[0]) * vb->num_planes);
@@ -1156,7 +1150,7 @@ static int __prepare_dmabuf(struct vb2_buffer *vb, const void *pb)
 		/* Acquire each plane's memory */
 		mem_priv = call_ptr_memop(vb, attach_dmabuf,
 				q->alloc_devs[plane] ? : q->dev,
-				dbuf, planes[plane].length, dma_dir);
+				dbuf, planes[plane].length, q->dma_dir);
 		if (IS_ERR(mem_priv)) {
 			dprintk(1, "failed to attach dmabuf\n");
 			ret = PTR_ERR(mem_priv);
@@ -2003,6 +1997,11 @@ int vb2_core_queue_init(struct vb2_queue *q)
 	if (q->buf_struct_size == 0)
 		q->buf_struct_size = sizeof(struct vb2_buffer);
 
+	if (q->bidirectional)
+		q->dma_dir = DMA_BIDIRECTIONAL;
+	else
+		q->dma_dir = q->is_output ? DMA_TO_DEVICE : DMA_FROM_DEVICE;
+
 	return 0;
 }
 EXPORT_SYMBOL_GPL(vb2_core_queue_init);
diff --git a/drivers/media/v4l2-core/videobuf2-dma-contig.c b/drivers/media/v4l2-core/videobuf2-dma-contig.c
index 5b90a66b9e78..9f389f36566d 100644
--- a/drivers/media/v4l2-core/videobuf2-dma-contig.c
+++ b/drivers/media/v4l2-core/videobuf2-dma-contig.c
@@ -508,7 +508,8 @@ static void *vb2_dc_get_userptr(struct device *dev, unsigned long vaddr,
 	buf->dma_dir = dma_dir;
 
 	offset = vaddr & ~PAGE_MASK;
-	vec = vb2_create_framevec(vaddr, size, dma_dir == DMA_FROM_DEVICE);
+	vec = vb2_create_framevec(vaddr, size, dma_dir == DMA_FROM_DEVICE ||
+					       dma_dir == DMA_BIDIRECTIONAL);
 	if (IS_ERR(vec)) {
 		ret = PTR_ERR(vec);
 		goto fail_buf;
diff --git a/drivers/media/v4l2-core/videobuf2-dma-sg.c b/drivers/media/v4l2-core/videobuf2-dma-sg.c
index 54f33938d45b..6808231a6bdc 100644
--- a/drivers/media/v4l2-core/videobuf2-dma-sg.c
+++ b/drivers/media/v4l2-core/videobuf2-dma-sg.c
@@ -239,7 +239,8 @@ static void *vb2_dma_sg_get_userptr(struct device *dev, unsigned long vaddr,
 	buf->offset = vaddr & ~PAGE_MASK;
 	buf->size = size;
 	buf->dma_sgt = &buf->sg_table;
-	vec = vb2_create_framevec(vaddr, size, buf->dma_dir == DMA_FROM_DEVICE);
+	vec = vb2_create_framevec(vaddr, size, dma_dir == DMA_FROM_DEVICE ||
+					       dma_dir == DMA_BIDIRECTIONAL);
 	if (IS_ERR(vec))
 		goto userptr_fail_pfnvec;
 	buf->vec = vec;
@@ -292,7 +293,8 @@ static void vb2_dma_sg_put_userptr(void *buf_priv)
 		vm_unmap_ram(buf->vaddr, buf->num_pages);
 	sg_free_table(buf->dma_sgt);
 	while (--i >= 0) {
-		if (buf->dma_dir == DMA_FROM_DEVICE)
+		if (buf->dma_dir == DMA_FROM_DEVICE ||
+		    buf->dma_dir == DMA_BIDIRECTIONAL)
 			set_page_dirty_lock(buf->pages[i]);
 	}
 	vb2_destroy_framevec(buf->vec);
diff --git a/drivers/media/v4l2-core/videobuf2-vmalloc.c b/drivers/media/v4l2-core/videobuf2-vmalloc.c
index 6bc130fe84f6..3a7c80cd1a17 100644
--- a/drivers/media/v4l2-core/videobuf2-vmalloc.c
+++ b/drivers/media/v4l2-core/videobuf2-vmalloc.c
@@ -87,7 +87,8 @@ static void *vb2_vmalloc_get_userptr(struct device *dev, unsigned long vaddr,
 	buf->dma_dir = dma_dir;
 	offset = vaddr & ~PAGE_MASK;
 	buf->size = size;
-	vec = vb2_create_framevec(vaddr, size, dma_dir == DMA_FROM_DEVICE);
+	vec = vb2_create_framevec(vaddr, size, dma_dir == DMA_FROM_DEVICE ||
+					       dma_dir == DMA_BIDIRECTIONAL);
 	if (IS_ERR(vec)) {
 		ret = PTR_ERR(vec);
 		goto fail_pfnvec_create;
@@ -137,7 +138,8 @@ static void vb2_vmalloc_put_userptr(void *buf_priv)
 		pages = frame_vector_pages(buf->vec);
 		if (vaddr)
 			vm_unmap_ram((void *)vaddr, n_pages);
-		if (buf->dma_dir == DMA_FROM_DEVICE)
+		if (buf->dma_dir == DMA_FROM_DEVICE ||
+		    buf->dma_dir == DMA_BIDIRECTIONAL)
 			for (i = 0; i < n_pages; i++)
 				set_page_dirty_lock(pages[i]);
 	} else {