Re: [RFCv5 PATCH 05/15] vb2-dma-sg: add get_dmabuf
Hi Hans,
Thank you for the patch.
On Fri, Nov 7, 2014 at 5:50 PM, Hans Verkuil hverk...@xs4all.nl wrote:
From: Hans Verkuil hansv...@cisco.com
Add DMABUF export support to vb2-dma-sg.
I think we should mention in the subject that this adds dmabuf export to dma-sg.
Signed-off-by: Hans Verkuil hansv...@cisco.com
---
drivers/media/v4l2-core/videobuf2-dma-sg.c | 170
+
1 file changed, 170 insertions(+)
diff --git a/drivers/media/v4l2-core/videobuf2-dma-sg.c
b/drivers/media/v4l2-core/videobuf2-dma-sg.c
index 2795c27..ca28a50 100644
--- a/drivers/media/v4l2-core/videobuf2-dma-sg.c
+++ b/drivers/media/v4l2-core/videobuf2-dma-sg.c
@@ -407,6 +407,175 @@ static int vb2_dma_sg_mmap(void *buf_priv, struct
vm_area_struct *vma)
}
/*/
+/* DMABUF ops for exporters */
+/*/
+
+struct vb2_dma_sg_attachment {
+ struct sg_table sgt;
+ enum dma_data_direction dir;
+};
+
+static int vb2_dma_sg_dmabuf_ops_attach(struct dma_buf *dbuf, struct device
*dev,
+ struct dma_buf_attachment *dbuf_attach)
+{
+ struct vb2_dma_sg_attachment *attach;
+ unsigned int i;
+ struct scatterlist *rd, *wr;
+ struct sg_table *sgt;
+ struct vb2_dma_sg_buf *buf = dbuf-priv;
+ int ret;
+
+ attach = kzalloc(sizeof(*attach), GFP_KERNEL);
+ if (!attach)
+ return -ENOMEM;
+
+ sgt = attach-sgt;
+ /* Copy the buf-base_sgt scatter list to the attachment, as we can't
+* map the same scatter list to multiple attachments at the same time.
+*/
+ ret = sg_alloc_table(sgt, buf-dma_sgt-orig_nents, GFP_KERNEL);
+ if (ret) {
+ kfree(attach);
+ return -ENOMEM;
+ }
+
+ rd = buf-dma_sgt-sgl;
+ wr = sgt-sgl;
+ for (i = 0; i sgt-orig_nents; ++i) {
+ sg_set_page(wr, sg_page(rd), rd-length, rd-offset);
+ rd = sg_next(rd);
+ wr = sg_next(wr);
+ }
+
+ attach-dir = DMA_NONE;
+ dbuf_attach-priv = attach;
+
+ return 0;
+}
+
+static void vb2_dma_sg_dmabuf_ops_detach(struct dma_buf *dbuf,
+ struct dma_buf_attachment *db_attach)
+{
+ struct vb2_dma_sg_attachment *attach = db_attach-priv;
+ struct sg_table *sgt;
+
+ if (!attach)
+ return;
+
+ sgt = attach-sgt;
+
+ /* release the scatterlist cache */
+ if (attach-dir != DMA_NONE)
+ dma_unmap_sg(db_attach-dev, sgt-sgl, sgt-orig_nents,
+ attach-dir);
+ sg_free_table(sgt);
+ kfree(attach);
+ db_attach-priv = NULL;
+}
+
+static struct sg_table *vb2_dma_sg_dmabuf_ops_map(
+ struct dma_buf_attachment *db_attach, enum dma_data_direction dir)
+{
+ struct vb2_dma_sg_attachment *attach = db_attach-priv;
+ /* stealing dmabuf mutex to serialize map/unmap operations */
+ struct mutex *lock = db_attach-dmabuf-lock;
+ struct sg_table *sgt;
+ int ret;
+
+ mutex_lock(lock);
+
+ sgt = attach-sgt;
+ /* return previously mapped sg table */
+ if (attach-dir == dir) {
+ mutex_unlock(lock);
+ return sgt;
+ }
+
+ /* release any previous cache */
+ if (attach-dir != DMA_NONE) {
+ dma_unmap_sg(db_attach-dev, sgt-sgl, sgt-orig_nents,
+ attach-dir);
+ attach-dir = DMA_NONE;
+ }
+
+ /* mapping to the client with new direction */
+ ret = dma_map_sg(db_attach-dev, sgt-sgl, sgt-orig_nents, dir);
+ if (ret = 0) {
+ pr_err(failed to map scatterlist\n);
+ mutex_unlock(lock);
+ return ERR_PTR(-EIO);
+ }
+
+ attach-dir = dir;
+
+ mutex_unlock(lock);
+
+ return sgt;
+}
+
+static void vb2_dma_sg_dmabuf_ops_unmap(struct dma_buf_attachment *db_attach,
+ struct sg_table *sgt, enum dma_data_direction dir)
+{
+ /* nothing to be done here */
+}
+
+static void vb2_dma_sg_dmabuf_ops_release(struct dma_buf *dbuf)
+{
+ /* drop reference obtained in vb2_dma_sg_get_dmabuf */
+ vb2_dma_sg_put(dbuf-priv);
+}
+
+static void *vb2_dma_sg_dmabuf_ops_kmap(struct dma_buf *dbuf, unsigned long
pgnum)
+{
+ struct vb2_dma_sg_buf *buf = dbuf-priv;
+
+ return buf-vaddr + pgnum * PAGE_SIZE;
As opposed to contig, which assigns vaddr on alloc(), vaddr can very
well be NULL here for sg.
--
Best regards,
Pawel Osciak
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[RFCv5 PATCH 05/15] vb2-dma-sg: add get_dmabuf
From: Hans Verkuil hansv...@cisco.com
Add DMABUF export support to vb2-dma-sg.
Signed-off-by: Hans Verkuil hansv...@cisco.com
---
drivers/media/v4l2-core/videobuf2-dma-sg.c | 170 +
1 file changed, 170 insertions(+)
diff --git a/drivers/media/v4l2-core/videobuf2-dma-sg.c
b/drivers/media/v4l2-core/videobuf2-dma-sg.c
index 2795c27..ca28a50 100644
--- a/drivers/media/v4l2-core/videobuf2-dma-sg.c
+++ b/drivers/media/v4l2-core/videobuf2-dma-sg.c
@@ -407,6 +407,175 @@ static int vb2_dma_sg_mmap(void *buf_priv, struct
vm_area_struct *vma)
}
/*/
+/* DMABUF ops for exporters */
+/*/
+
+struct vb2_dma_sg_attachment {
+ struct sg_table sgt;
+ enum dma_data_direction dir;
+};
+
+static int vb2_dma_sg_dmabuf_ops_attach(struct dma_buf *dbuf, struct device
*dev,
+ struct dma_buf_attachment *dbuf_attach)
+{
+ struct vb2_dma_sg_attachment *attach;
+ unsigned int i;
+ struct scatterlist *rd, *wr;
+ struct sg_table *sgt;
+ struct vb2_dma_sg_buf *buf = dbuf-priv;
+ int ret;
+
+ attach = kzalloc(sizeof(*attach), GFP_KERNEL);
+ if (!attach)
+ return -ENOMEM;
+
+ sgt = attach-sgt;
+ /* Copy the buf-base_sgt scatter list to the attachment, as we can't
+* map the same scatter list to multiple attachments at the same time.
+*/
+ ret = sg_alloc_table(sgt, buf-dma_sgt-orig_nents, GFP_KERNEL);
+ if (ret) {
+ kfree(attach);
+ return -ENOMEM;
+ }
+
+ rd = buf-dma_sgt-sgl;
+ wr = sgt-sgl;
+ for (i = 0; i sgt-orig_nents; ++i) {
+ sg_set_page(wr, sg_page(rd), rd-length, rd-offset);
+ rd = sg_next(rd);
+ wr = sg_next(wr);
+ }
+
+ attach-dir = DMA_NONE;
+ dbuf_attach-priv = attach;
+
+ return 0;
+}
+
+static void vb2_dma_sg_dmabuf_ops_detach(struct dma_buf *dbuf,
+ struct dma_buf_attachment *db_attach)
+{
+ struct vb2_dma_sg_attachment *attach = db_attach-priv;
+ struct sg_table *sgt;
+
+ if (!attach)
+ return;
+
+ sgt = attach-sgt;
+
+ /* release the scatterlist cache */
+ if (attach-dir != DMA_NONE)
+ dma_unmap_sg(db_attach-dev, sgt-sgl, sgt-orig_nents,
+ attach-dir);
+ sg_free_table(sgt);
+ kfree(attach);
+ db_attach-priv = NULL;
+}
+
+static struct sg_table *vb2_dma_sg_dmabuf_ops_map(
+ struct dma_buf_attachment *db_attach, enum dma_data_direction dir)
+{
+ struct vb2_dma_sg_attachment *attach = db_attach-priv;
+ /* stealing dmabuf mutex to serialize map/unmap operations */
+ struct mutex *lock = db_attach-dmabuf-lock;
+ struct sg_table *sgt;
+ int ret;
+
+ mutex_lock(lock);
+
+ sgt = attach-sgt;
+ /* return previously mapped sg table */
+ if (attach-dir == dir) {
+ mutex_unlock(lock);
+ return sgt;
+ }
+
+ /* release any previous cache */
+ if (attach-dir != DMA_NONE) {
+ dma_unmap_sg(db_attach-dev, sgt-sgl, sgt-orig_nents,
+ attach-dir);
+ attach-dir = DMA_NONE;
+ }
+
+ /* mapping to the client with new direction */
+ ret = dma_map_sg(db_attach-dev, sgt-sgl, sgt-orig_nents, dir);
+ if (ret = 0) {
+ pr_err(failed to map scatterlist\n);
+ mutex_unlock(lock);
+ return ERR_PTR(-EIO);
+ }
+
+ attach-dir = dir;
+
+ mutex_unlock(lock);
+
+ return sgt;
+}
+
+static void vb2_dma_sg_dmabuf_ops_unmap(struct dma_buf_attachment *db_attach,
+ struct sg_table *sgt, enum dma_data_direction dir)
+{
+ /* nothing to be done here */
+}
+
+static void vb2_dma_sg_dmabuf_ops_release(struct dma_buf *dbuf)
+{
+ /* drop reference obtained in vb2_dma_sg_get_dmabuf */
+ vb2_dma_sg_put(dbuf-priv);
+}
+
+static void *vb2_dma_sg_dmabuf_ops_kmap(struct dma_buf *dbuf, unsigned long
pgnum)
+{
+ struct vb2_dma_sg_buf *buf = dbuf-priv;
+
+ return buf-vaddr + pgnum * PAGE_SIZE;
+}
+
+static void *vb2_dma_sg_dmabuf_ops_vmap(struct dma_buf *dbuf)
+{
+ struct vb2_dma_sg_buf *buf = dbuf-priv;
+
+ return vb2_dma_sg_vaddr(buf);
+}
+
+static int vb2_dma_sg_dmabuf_ops_mmap(struct dma_buf *dbuf,
+ struct vm_area_struct *vma)
+{
+ return vb2_dma_sg_mmap(dbuf-priv, vma);
+}
+
+static struct dma_buf_ops vb2_dma_sg_dmabuf_ops = {
+ .attach = vb2_dma_sg_dmabuf_ops_attach,
+ .detach = vb2_dma_sg_dmabuf_ops_detach,
+ .map_dma_buf = vb2_dma_sg_dmabuf_ops_map,
+ .unmap_dma_buf = vb2_dma_sg_dmabuf_ops_unmap,
+ .kmap = vb2_dma_sg_dmabuf_ops_kmap,
+ .kmap_atomic = vb2_dma_sg_dmabuf_ops_kmap,
+ .vmap = vb2_dma_sg_dmabuf_ops_vmap,
+ .mmap =
