[Mesa-dev] [PATCH 07/10] st/mesa: assume that user constant buffers are always supported

[Marek Olšák]

From: Marek Olšák <marek.olsak at amd.com>

---
 src/mesa/state_tracker/st_atom_constbuf.c | 19 +++----------------
 src/mesa/state_tracker/st_context.c       |  2 --
 src/mesa/state_tracker/st_context.h       |  1 -
 src/mesa/state_tracker/st_pbo.c           | 18 +++---------------
 4 files changed, 6 insertions(+), 34 deletions(-)

diff --git a/src/mesa/state_tracker/st_atom_constbuf.c b/src/mesa/state_tracker/st_atom_constbuf.c
index 497d33f..0a6b23a 100644
--- a/src/mesa/state_tracker/st_atom_constbuf.c
+++ b/src/mesa/state_tracker/st_atom_constbuf.c
@@ -94,36 +94,23 @@ void st_upload_constants(struct st_context *st, struct gl_program *prog)
       /* Update the constants which come from fixed-function state, such as
        * transformation matrices, fog factors, etc.  The rest of the values in
        * the parameters list are explicitly set by the user with glUniform,
        * glProgramParameter(), etc.
        */
       if (params->StateFlags)
          _mesa_load_state_parameters(st->ctx, params);
 
       _mesa_shader_write_subroutine_indices(st->ctx, stage);
 
-      /* We always need to get a new buffer, to keep the drivers simple and
-       * avoid gratuitous rendering synchronization.
-       * Let's use a user buffer to avoid an unnecessary copy.
-       */
-      if (!st->has_user_constbuf) {
-         cb.buffer = NULL;
-         cb.user_buffer = NULL;
-         u_upload_data(st->pipe->const_uploader, 0, paramBytes,
-                       st->ctx->Const.UniformBufferOffsetAlignment,
-                       params->ParameterValues, &cb.buffer_offset, &cb.buffer);
-         u_upload_unmap(st->pipe->const_uploader);
-      } else {
-         cb.buffer = NULL;
-         cb.user_buffer = params->ParameterValues;
-         cb.buffer_offset = 0;
-      }
+      cb.buffer = NULL;
+      cb.user_buffer = params->ParameterValues;
+      cb.buffer_offset = 0;
       cb.buffer_size = paramBytes;
 
       if (ST_DEBUG & DEBUG_CONSTANTS) {
          debug_printf("%s(shader=%d, numParams=%d, stateFlags=0x%x)\n",
                       __func__, shader_type, params->NumParameters,
                       params->StateFlags);
          _mesa_print_parameter_list(params);
       }
 
       cso_set_constant_buffer(st->cso_context, shader_type, 0, &cb);
diff --git a/src/mesa/state_tracker/st_context.c b/src/mesa/state_tracker/st_context.c
index 7564a53..0a3de33 100644
--- a/src/mesa/state_tracker/st_context.c
+++ b/src/mesa/state_tracker/st_context.c
@@ -364,22 +364,20 @@ st_create_context_priv(struct gl_context *ctx, struct pipe_context *pipe,
    ctx->st = st;
 
    st->ctx = ctx;
    st->pipe = pipe;
 
    /* state tracker needs the VBO module */
    _vbo_CreateContext(ctx);
 
    st->dirty = ST_ALL_STATES_MASK;
 
-   st->has_user_constbuf =
-      screen->get_param(screen, PIPE_CAP_USER_CONSTANT_BUFFERS);
    st->can_bind_const_buffer_as_vertex =
       screen->get_param(screen, PIPE_CAP_CAN_BIND_CONST_BUFFER_AS_VERTEX);
 
    /* st/mesa always uploads zero-stride vertex attribs, and other user
     * vertex buffers are only possible with a compatibility profile.
     * So tell the u_vbuf module that user VBOs are not possible with the Core
     * profile, so that u_vbuf is bypassed completely if there is nothing else
     * to do.
     */
    unsigned vbuf_flags =
diff --git a/src/mesa/state_tracker/st_context.h b/src/mesa/state_tracker/st_context.h
index 9f33eed..0258bed 100644
--- a/src/mesa/state_tracker/st_context.h
+++ b/src/mesa/state_tracker/st_context.h
@@ -103,21 +103,20 @@ struct st_context
    boolean has_stencil_export; /**< can do shader stencil export? */
    boolean has_time_elapsed;
    boolean has_shader_model3;
    boolean has_etc1;
    boolean has_etc2;
    boolean prefer_blit_based_texture_transfer;
    boolean force_persample_in_shader;
    boolean has_shareable_shaders;
    boolean has_half_float_packing;
    boolean has_multi_draw_indirect;
-   boolean has_user_constbuf;
    boolean can_bind_const_buffer_as_vertex;
 
    /**
     * If a shader can be created when we get its source.
     * This means it has only 1 variant, not counting glBitmap and
     * glDrawPixels.
     */
    boolean shader_has_one_variant[MESA_SHADER_STAGES];
 
    boolean needs_texcoord_semantic;
diff --git a/src/mesa/state_tracker/st_pbo.c b/src/mesa/state_tracker/st_pbo.c
index 303c853..628e3ca 100644
--- a/src/mesa/state_tracker/st_pbo.c
+++ b/src/mesa/state_tracker/st_pbo.c
@@ -252,35 +252,23 @@ st_pbo_draw(struct st_context *st, const struct st_pbo_addresses *addr,
 
       cso_set_vertex_buffers(cso, velem.vertex_buffer_index, 1, &vbo);
 
       pipe_resource_reference(&vbo.buffer.resource, NULL);
    }
 
    /* Upload constants */
    {
       struct pipe_constant_buffer cb;
 
-      if (!st->has_user_constbuf) {
-         cb.buffer = NULL;
-         cb.user_buffer = NULL;
-         u_upload_data(st->pipe->const_uploader, 0, sizeof(addr->constants),
-                       st->ctx->Const.UniformBufferOffsetAlignment,
-                       &addr->constants, &cb.buffer_offset, &cb.buffer);
-         if (!cb.buffer)
-            return false;
-
-         u_upload_unmap(st->pipe->const_uploader);
-      } else {
-         cb.buffer = NULL;
-         cb.user_buffer = &addr->constants;
-         cb.buffer_offset = 0;
-      }
+      cb.buffer = NULL;
+      cb.user_buffer = &addr->constants;
+      cb.buffer_offset = 0;
       cb.buffer_size = sizeof(addr->constants);
 
       cso_set_constant_buffer(cso, PIPE_SHADER_FRAGMENT, 0, &cb);
 
       pipe_resource_reference(&cb.buffer, NULL);
    }
 
    /* Rasterizer state */
    cso_set_rasterizer(cso, &st->pbo.raster);
 
-- 
2.7.4