[Mesa-dev] [PATCH 1/2] st/va: ensure linear memory for dmabuf

[Julien Isorce]

In order to do zero-copy between two different devices
the memory should not be tiled.

This is currently no way to set pipe_resource template's flag
from pipe_video_buffer template. So disabled_tiling is added.

Choosed "disable" prefix so that CALLOC keeps tiling enabled
by default.

Tested with GStreamer on a laptop that has 2 GPUs:
1- gstvaapidecode:
   HW decoding and dmabuf export with nouveau driver on Nvidia GPU.
2- glimagesink:
   EGLImage imports dmabuf on Intel GPU.

Note that tiling is working if 1 and 2 are done on the same GPU.
So it is up to the application to set or not the flag:
VA_SURFACE_EXTBUF_DESC_ENABLE_TILING

Signed-off-by: Julien Isorce <j.isorce at samsung.com>
---
 src/gallium/auxiliary/vl/vl_video_buffer.c | 3 +++
 src/gallium/include/pipe/p_video_codec.h   | 1 +
 src/gallium/state_trackers/va/surface.c    | 5 +++++
 3 files changed, 9 insertions(+)

diff --git a/src/gallium/auxiliary/vl/vl_video_buffer.c b/src/gallium/auxiliary/vl/vl_video_buffer.c
index 6cd2557..62f4aa9 100644
--- a/src/gallium/auxiliary/vl/vl_video_buffer.c
+++ b/src/gallium/auxiliary/vl/vl_video_buffer.c
@@ -253,6 +253,9 @@ vl_video_buffer_template(struct pipe_resource *templ,
    templ->bind = PIPE_BIND_SAMPLER_VIEW | PIPE_BIND_RENDER_TARGET;
    templ->usage = usage;
 
+   if (tmpl->disable_tiling)
+      templ->bind |= PIPE_BIND_LINEAR;
+
    if (plane > 0) {
       if (tmpl->chroma_format == PIPE_VIDEO_CHROMA_FORMAT_420) {
          templ->width0 /= 2;
diff --git a/src/gallium/include/pipe/p_video_codec.h b/src/gallium/include/pipe/p_video_codec.h
index 196d00b..dbfffd9 100644
--- a/src/gallium/include/pipe/p_video_codec.h
+++ b/src/gallium/include/pipe/p_video_codec.h
@@ -125,6 +125,7 @@ struct pipe_video_buffer
    enum pipe_video_chroma_format chroma_format;
    unsigned width;
    unsigned height;
+   bool disable_tiling;
    bool interlaced;
 
    /**
diff --git a/src/gallium/state_trackers/va/surface.c b/src/gallium/state_trackers/va/surface.c
index c052c8f..f7043ad 100644
--- a/src/gallium/state_trackers/va/surface.c
+++ b/src/gallium/state_trackers/va/surface.c
@@ -616,6 +616,11 @@ vlVaCreateSurfaces2(VADriverContextP ctx, unsigned int format,
 
       switch (memory_type) {
       case VA_SURFACE_ATTRIB_MEM_TYPE_VA:
+         /* The application will clear the TILING flag when the surface is
+          * intended to be exported as dmabuf. */
+         templat.disable_tiling = memory_attibute &&
+            !(memory_attibute->flags & VA_SURFACE_EXTBUF_DESC_ENABLE_TILING);
+
          surf->buffer = drv->pipe->create_video_buffer(drv->pipe, &templat);
          if (!surf->buffer) {
             FREE(surf);
-- 
1.9.1