@@ -304,10 +304,13 @@ static void __vb2_plane_dmabuf_put(struct vb2_buffer *vb, struct vb2_plane *p)
if (!p->mem_priv)
return;
- if (p->dbuf_mapped)
- call_void_memop(vb, unmap_dmabuf, p->mem_priv);
+ if (!p->dbuf_duplicated) {
+ if (p->dbuf_mapped)
+ call_void_memop(vb, unmap_dmabuf, p->mem_priv);
+
+ call_void_memop(vb, detach_dmabuf, p->mem_priv);
+ }
- call_void_memop(vb, detach_dmabuf, p->mem_priv);
dma_buf_put(p->dbuf);
p->mem_priv = NULL;
p->dbuf = NULL;
@@ -316,6 +319,7 @@ static void __vb2_plane_dmabuf_put(struct vb2_buffer *vb, struct vb2_plane *p)
p->length = 0;
p->m.fd = 0;
p->data_offset = 0;
+ p->dbuf_duplicated = false;
}
/*
@@ -1374,7 +1378,7 @@ static int __prepare_dmabuf(struct vb2_buffer *vb)
struct vb2_plane planes[VB2_MAX_PLANES];
struct vb2_queue *q = vb->vb2_queue;
void *mem_priv;
- unsigned int plane;
+ unsigned int plane, i;
int ret = 0;
bool reacquired = vb->planes[0].mem_priv == NULL;
@@ -1427,6 +1431,24 @@ static int __prepare_dmabuf(struct vb2_buffer *vb)
}
for (plane = 0; plane < vb->num_planes; ++plane) {
+ /*
+ * This is an optimization to reduce dma_buf attachment/mapping.
+ * When the same dma_buf is used for multiple planes, there is no need
+ * to create duplicated attachments.
+ */
+ for (i = 0; i < plane; ++i) {
+ if (planes[plane].dbuf == vb->planes[i].dbuf &&
+ q->alloc_devs[plane] == q->alloc_devs[i]) {
+ vb->planes[plane].dbuf_duplicated = true;
+ vb->planes[plane].dbuf = vb->planes[i].dbuf;
+ vb->planes[plane].mem_priv = vb->planes[i].mem_priv;
+ break;
+ }
+ }
+
+ if (vb->planes[plane].dbuf_duplicated)
+ continue;
+
/* Acquire each plane's memory */
mem_priv = call_ptr_memop(attach_dmabuf,
vb,
@@ -154,6 +154,8 @@ struct vb2_mem_ops {
* @mem_priv: private data with this plane.
* @dbuf: dma_buf - shared buffer object.
* @dbuf_mapped: flag to show whether dbuf is mapped or not
+ * @duplicated_dbuf: boolean to show whether dbuf is duplicated with a
+ * previous plane of the buffer.
* @bytesused: number of bytes occupied by data in the plane (payload).
* @length: size of this plane (NOT the payload) in bytes. The maximum
* valid size is MAX_UINT - PAGE_SIZE.
@@ -179,6 +181,7 @@ struct vb2_plane {
void *mem_priv;
struct dma_buf *dbuf;
unsigned int dbuf_mapped;
+ bool dbuf_duplicated;
unsigned int bytesused;
unsigned int length;
unsigned int min_length;
When multiple planes use the same dma buf, each plane will have its own dma buf attachment and mapping. It is a waste of IOVA space. This patch adds a dbuf_duplicated boolean in vb2_plane. If a plane's dbuf is the same as an existing plane, do not create another attachment and mapping. Signed-off-by: Yunke Cao <yunkec@chromium.org> --- v4 - Only set dbuf_duplicated when alloc_devs are equal. v3 - Adjust the patch according to the previous patches to resolve conflicts. - Add comment to explain the purpose of the change. v2 - Separate out the refactor changes out to previous patches. - Fix mem_priv check. --- .../media/common/videobuf2/videobuf2-core.c | 30 ++++++++++++++++--- include/media/videobuf2-core.h | 3 ++ 2 files changed, 29 insertions(+), 4 deletions(-)