When the DU sources its frames from a VSP, it performs no memory access
and thus has no requirements on imported dma-buf memory types. In
particular the DU could import a physically non-contiguous buffer that
would later be mapped contiguously through the VSP IOMMU.
This use case isn't supported at the moment as the GEM CMA helpers will
reject any non-contiguous buffer, and the DU isn't connected to an IOMMU
that can make the buffer contiguous for DMA. Fix this by implementing a
custom .gem_prime_import_sg_table() operation that accepts all imported
dma-buf regardless of the number of scatterlist entries.
Signed-off-by: Laurent Pinchart <laurent.pinchart+renesas@xxxxxxxxxxxxxxxx>
---
Changes since v1:
- Duplicate the imported scatter gather table in
rcar_du_vsp_plane_prepare_fb()
This patch fixes a bug of the previous version and is posted in case anyone
would like to test the implementation. I still plan to give Noralf's GEM
library a try as an alternative approach to this series.
drivers/gpu/drm/rcar-du/rcar_du_drv.c | 2 +-
drivers/gpu/drm/rcar-du/rcar_du_kms.c | 39 +++++++++++++++++++++++++++++++++++
drivers/gpu/drm/rcar-du/rcar_du_kms.h | 7 +++++++
drivers/gpu/drm/rcar-du/rcar_du_vsp.c | 34 ++++++++++++++++++++++++++----
4 files changed, 77 insertions(+), 5 deletions(-)
diff --git a/drivers/gpu/drm/rcar-du/rcar_du_drv.c b/drivers/gpu/drm/rcar-du/rcar_du_drv.c
index 48c166f925a3..d999231f98c7 100644
--- a/drivers/gpu/drm/rcar-du/rcar_du_drv.c
+++ b/drivers/gpu/drm/rcar-du/rcar_du_drv.c
@@ -289,7 +289,7 @@ static struct drm_driver rcar_du_driver = {
.gem_prime_import = drm_gem_prime_import,
.gem_prime_export = drm_gem_prime_export,
.gem_prime_get_sg_table = drm_gem_cma_prime_get_sg_table,
- .gem_prime_import_sg_table = drm_gem_cma_prime_import_sg_table,
+ .gem_prime_import_sg_table = rcar_du_gem_prime_import_sg_table,
.gem_prime_vmap = drm_gem_cma_prime_vmap,
.gem_prime_vunmap = drm_gem_cma_prime_vunmap,
.gem_prime_mmap = drm_gem_cma_prime_mmap,
diff --git a/drivers/gpu/drm/rcar-du/rcar_du_kms.c b/drivers/gpu/drm/rcar-du/rcar_du_kms.c
index 566d1a948c8f..2dd0c2ba047d 100644
--- a/drivers/gpu/drm/rcar-du/rcar_du_kms.c
+++ b/drivers/gpu/drm/rcar-du/rcar_du_kms.c
@@ -20,6 +20,7 @@
#include <drm/drm_gem_cma_helper.h>
#include <drm/drm_gem_framebuffer_helper.h>
+#include <linux/dma-buf.h>
#include <linux/of_graph.h>
#include <linux/wait.h>
@@ -148,6 +149,44 @@ const struct rcar_du_format_info *rcar_du_format_info(u32 fourcc)
* Frame buffer
*/
+struct drm_gem_object *rcar_du_gem_prime_import_sg_table(struct drm_device *dev,
+ struct dma_buf_attachment *attach,
+ struct sg_table *sgt)
+{
+ struct rcar_du_device *rcdu = dev->dev_private;
+ struct drm_gem_cma_object *cma_obj;
+ struct drm_gem_object *gem_obj;
+ int ret;
+
+ if (!rcar_du_has(rcdu, RCAR_DU_FEATURE_VSP1_SOURCE))
+ return drm_gem_cma_prime_import_sg_table(dev, attach, sgt);
+
+ /* Create a CMA GEM buffer. */
+ cma_obj = kzalloc(sizeof(*cma_obj), GFP_KERNEL);
+ if (!cma_obj)
+ return ERR_PTR(-ENOMEM);
+ gem_obj = &cma_obj->base;
+
+ ret = drm_gem_object_init(dev, gem_obj, attach->dmabuf->size);
+ if (ret)
+ goto error;
+
+ ret = drm_gem_create_mmap_offset(gem_obj);
+ if (ret) {
+ drm_gem_object_release(gem_obj);
+ goto error;
+ }
+
+ cma_obj->paddr = 0;
+ cma_obj->sgt = sgt;
+
+ return gem_obj;
+
+error:
+ kfree(cma_obj);
+ return ERR_PTR(ret);
+}
+
int rcar_du_dumb_create(struct drm_file *file, struct drm_device *dev,
struct drm_mode_create_dumb *args)
{
diff --git a/drivers/gpu/drm/rcar-du/rcar_du_kms.h b/drivers/gpu/drm/rcar-du/rcar_du_kms.h
index 07951d5fe38b..10b2bb0f0df9 100644
--- a/drivers/gpu/drm/rcar-du/rcar_du_kms.h
+++ b/drivers/gpu/drm/rcar-du/rcar_du_kms.h
@@ -16,10 +16,13 @@
#include <linux/types.h>
+struct dma_buf_attachment;
struct drm_file;
struct drm_device;
+struct drm_gem_object;
struct drm_mode_create_dumb;
struct rcar_du_device;
+struct sg_table;
struct rcar_du_format_info {
u32 fourcc;
@@ -36,4 +39,8 @@ int rcar_du_modeset_init(struct rcar_du_device *rcdu);
int rcar_du_dumb_create(struct drm_file *file, struct drm_device *dev,
struct drm_mode_create_dumb *args);
+struct drm_gem_object *rcar_du_gem_prime_import_sg_table(struct drm_device *dev,
+ struct dma_buf_attachment *attach,
+ struct sg_table *sgt);
+
#endif /* __RCAR_DU_KMS_H__ */
diff --git a/drivers/gpu/drm/rcar-du/rcar_du_vsp.c b/drivers/gpu/drm/rcar-du/rcar_du_vsp.c
index 2c260c33840b..73fdc814aa39 100644
--- a/drivers/gpu/drm/rcar-du/rcar_du_vsp.c
+++ b/drivers/gpu/drm/rcar-du/rcar_du_vsp.c
@@ -224,10 +224,36 @@ static int rcar_du_vsp_plane_prepare_fb(struct drm_plane *plane,
drm_fb_cma_get_gem_obj(state->fb, i);
struct sg_table *sgt = &rstate->sg_tables[i];
- ret = dma_get_sgtable(rcdu->dev, sgt, gem->vaddr, gem->paddr,
- gem->base.size);
- if (ret)
- goto fail;
+ if (gem->sgt) {
+ struct scatterlist *src;
+ struct scatterlist *dst;
+
+ /*
+ * If the GEM buffer has a scatter gather table, it has
+ * been imported from a dma-buf and has no physical
+ * address as it might not be physically contiguous.
+ * Copy the original scatter gather table to map it to
+ * the VSP.
+ */
+ ret = sg_alloc_table(sgt, gem->sgt->orig_nents,
+ GFP_KERNEL);
+ if (ret)
+ goto fail;
+
+ src = gem->sgt->sgl;
+ dst = sgt->sgl;
+ for (i = 0; i < gem->sgt->orig_nents; ++i) {
+ sg_set_page(dst, sg_page(src), src->length,
+ src->offset);
+ src = sg_next(src);
+ dst = sg_next(dst);
+ }
+ } else {
+ ret = dma_get_sgtable(rcdu->dev, sgt, gem->vaddr,
+ gem->paddr, gem->base.size);
+ if (ret)
+ goto fail;
+ }
ret = vsp1_du_map_sg(vsp->vsp, sgt);
if (!ret) {
--
Regards,
Laurent Pinchart
_______________________________________________
dri-devel mailing list
dri-devel@xxxxxxxxxxxxxxxxxxxxx
https://lists.freedesktop.org/mailman/listinfo/dri-devel
