[Mesa-dev] [PATCH 6/9] st/mesa: setup hw atomic limits.

[Nicolai Hähnle]

On 03.11.2017 08:24, Dave Airlie wrote:
> 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.
> 
> 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..ea5002b 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;

Inconsistent indentation.


> +         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;

It's not true for GCN GDS-based atomics, because we can just use normal 
GDS instruction there (rather than the limited ordered append counters). 
But we can deal with that when we get there.

With the indentation fixed, this patch:

Reviewed-by: Nicolai Hähnle <nicolai.haehnle at amd.com>


> +   } 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;
> 


-- 
Lerne, wie die Welt wirklich ist,
Aber vergiss niemals, wie sie sein sollte.