gallium: add hw atomic buffer binding API.

This API binds atomic buffers for all bound shaders (as per the
GL semantics).

This is needed to support cross shader hw atomic counters.

Reviewed-by: Nicolai Hähnle <nicolai.haehnle@amd.com>
Reviewed-by: Marek Olšák <marek.olsak@amd.com>
Tested-By: Gert Wollny <gw.fossdev@gmail.com>
Signed-off-by: Dave Airlie <airlied@redhat.com>

2 files changed, 24 insertions, 0 deletions

diff --git a/src/gallium/docs/source/context.rst b/src/gallium/docs/source/context.rst
index 8aee21b2ed4..9d069b37d7e 100644
--- a/src/gallium/docs/source/context.rst
+++ b/src/gallium/docs/source/context.rst
@@ -145,6 +145,14 @@ to the array index which is used for sampling.
 * ``sampler_view_destroy`` destroys a sampler view and releases its reference
   to associated texture.
 
+Hardware Atomic buffers
+^^^^^^^^^^^^^^^^^^^^^^^
+
+Buffers containing hw atomics are required to support the feature
+on some drivers.
+
+Drivers that require this need to fill the ``set_hw_atomic_buffers`` method.
+
 Shader Resources
 ^^^^^^^^^^^^^^^^
 
diff --git a/src/gallium/include/pipe/p_context.h b/src/gallium/include/pipe/p_context.h
index 0dd4ad12424..b74e6492196 100644
--- a/src/gallium/include/pipe/p_context.h
+++ b/src/gallium/include/pipe/p_context.h
@@ -332,6 +332,22 @@ struct pipe_context {
                               const struct pipe_shader_buffer *buffers);
 
    /**
+    * Bind an array of hw atomic buffers for use by all shaders.
+    * And buffers that were previously bound to the specified range
+    * will be unbound.
+    *
+    * \param start_slot first buffer slot to bind.
+    * \param count      number of consecutive buffers to bind.
+    * \param buffers    array of pointers to the buffers to bind, it
+    *                   should contain at least \a count elements
+    *                   unless it's NULL, in which case no buffers will
+    *                   be bound.
+    */
+   void (*set_hw_atomic_buffers)(struct pipe_context *,
+                                 unsigned start_slot, unsigned count,
+                                 const struct pipe_shader_buffer *buffers);
+
+   /**
     * Bind an array of images that will be used by a shader.
     * Any images that were previously bound to the specified range
     * will be unbound.