[Mesa-dev] [PATCH 6/8] st/mesa: setup hw atomic limits. (v1.1)

[Dave Airlie]

From: Dave Airlie <airlied at redhat.com>

HW atomics need to use caps to set some limits, and some
other limits may also need limiting.

This fixes things up to work for evergreen hw, it may need
more changes in the future if other hw wants to use this path.

v1.1: fix indent.

Reviewed-by: Nicolai Hähnle <nicolai.haehnle at amd.com>
Signed-off-by: Dave Airlie <airlied at redhat.com>
---
 src/mesa/state_tracker/st_extensions.c | 45 ++++++++++++++++++++++++++--------
 1 file changed, 35 insertions(+), 10 deletions(-)

diff --git a/src/mesa/state_tracker/st_extensions.c b/src/mesa/state_tracker/st_extensions.c
index fa2d002..d4b8dc9 100644
--- a/src/mesa/state_tracker/st_extensions.c
+++ b/src/mesa/state_tracker/st_extensions.c
@@ -79,6 +79,7 @@ void st_init_limits(struct pipe_screen *screen,
    unsigned sh;
    boolean can_ubo = TRUE;
    int temp;
+   bool ssbo_atomic = true;
 
    c->MaxTextureLevels
       = _min(screen->get_param(screen, PIPE_CAP_MAX_TEXTURE_2D_LEVELS),
@@ -243,11 +244,21 @@ void st_init_limits(struct pipe_screen *screen,
                                           c->MaxUniformBlockSize / 4 *
                                           pc->MaxUniformBlocks);
 
-      pc->MaxAtomicCounters = MAX_ATOMIC_COUNTERS;
-      pc->MaxAtomicBuffers = screen->get_shader_param(
-            screen, sh, PIPE_SHADER_CAP_MAX_SHADER_BUFFERS) / 2;
-      pc->MaxShaderStorageBlocks = pc->MaxAtomicBuffers;
-
+      temp = screen->get_shader_param(screen, sh, PIPE_SHADER_CAP_MAX_HW_ATOMIC_COUNTERS);
+      if (temp) {
+         /*
+          * for separate atomic counters get the actual hw limits
+          * per stage on atomic counters and buffers
+          */
+         ssbo_atomic = false;
+         pc->MaxAtomicCounters = temp;
+         pc->MaxAtomicBuffers = screen->get_shader_param(screen, sh, PIPE_SHADER_CAP_MAX_HW_ATOMIC_COUNTER_BUFFERS);
+         pc->MaxShaderStorageBlocks = screen->get_shader_param(screen, sh, PIPE_SHADER_CAP_MAX_SHADER_BUFFERS);
+      } else {
+         pc->MaxAtomicCounters = MAX_ATOMIC_COUNTERS;
+         pc->MaxAtomicBuffers = screen->get_shader_param(screen, sh, PIPE_SHADER_CAP_MAX_SHADER_BUFFERS) / 2;
+         pc->MaxShaderStorageBlocks = pc->MaxAtomicBuffers;
+      }
       pc->MaxImageUniforms = screen->get_shader_param(
             screen, sh, PIPE_SHADER_CAP_MAX_SHADER_IMAGES);
 
@@ -407,14 +418,26 @@ void st_init_limits(struct pipe_screen *screen,
       screen->get_param(screen, PIPE_CAP_TGSI_FS_FACE_IS_INTEGER_SYSVAL);
 
    c->MaxAtomicBufferBindings =
-         c->Program[MESA_SHADER_FRAGMENT].MaxAtomicBuffers;
-   c->MaxCombinedAtomicBuffers =
+          c->Program[MESA_SHADER_FRAGMENT].MaxAtomicBuffers;
+
+   if (!ssbo_atomic) {
+      /* for separate atomic buffers - there atomic buffer size will be
+         limited */
+      c->MaxAtomicBufferSize = c->Program[MESA_SHADER_FRAGMENT].MaxAtomicCounters * ATOMIC_COUNTER_SIZE;
+      /* on all HW with separate atomic (evergreen) the following
+         lines are true. not sure it's worth adding CAPs for this at this
+         stage. */
+      c->MaxCombinedAtomicCounters = c->Program[MESA_SHADER_FRAGMENT].MaxAtomicCounters;
+      c->MaxCombinedAtomicBuffers = c->Program[MESA_SHADER_FRAGMENT].MaxAtomicBuffers;
+   } else {
+      c->MaxCombinedAtomicBuffers =
          c->Program[MESA_SHADER_VERTEX].MaxAtomicBuffers +
          c->Program[MESA_SHADER_TESS_CTRL].MaxAtomicBuffers +
          c->Program[MESA_SHADER_TESS_EVAL].MaxAtomicBuffers +
          c->Program[MESA_SHADER_GEOMETRY].MaxAtomicBuffers +
          c->Program[MESA_SHADER_FRAGMENT].MaxAtomicBuffers;
-   assert(c->MaxCombinedAtomicBuffers <= MAX_COMBINED_ATOMIC_BUFFERS);
+      assert(c->MaxCombinedAtomicBuffers <= MAX_COMBINED_ATOMIC_BUFFERS);
+   }
 
    if (c->MaxCombinedAtomicBuffers > 0) {
       extensions->ARB_shader_atomic_counters = GL_TRUE;
@@ -425,8 +448,10 @@ void st_init_limits(struct pipe_screen *screen,
    c->ShaderStorageBufferOffsetAlignment =
       screen->get_param(screen, PIPE_CAP_SHADER_BUFFER_OFFSET_ALIGNMENT);
    if (c->ShaderStorageBufferOffsetAlignment) {
-      c->MaxCombinedShaderStorageBlocks = c->MaxShaderStorageBufferBindings =
-         c->MaxCombinedAtomicBuffers;
+      /* for hw atomic counters leaves these at default for now */
+      if (ssbo_atomic)
+         c->MaxCombinedShaderStorageBlocks = c->MaxShaderStorageBufferBindings =
+            c->MaxCombinedAtomicBuffers;
       c->MaxCombinedShaderOutputResources +=
          c->MaxCombinedShaderStorageBlocks;
       c->MaxShaderStorageBlockSize = 1 << 27;
-- 
2.9.5