[Mesa-dev] [PATCH] i965/gen8/cs: fix constant push buffer

[Jordan Justen]

Ah! I had just also discovered this issue yesterday in some related
work but I didn't get the chance to try the CTS yet! :)

For the subject I had: "Gen 8 requires 64 byte alignment for push
constant data"

On 2015-12-15 03:55:15, Iago Toral Quiroga wrote:
> Page 502 of the Command Reference Broadwell PRM says that CURBE Total
> Data Length must be 64-bit aligned.

I think both the base and the size alignments are bumped from 32 to
64. Could you add the base address? How about giving the
volume/chapter/section in the spec reference rather than the page
number?

Also, could you update the call to brw_state_batch to also use 64 byte
alignment for the base on gen8+?

-Jordan

> 
> Fixes the following CTS tests:
> ES31-CTS.shader_storage_buffer_object.basic-atomic-case1-cs
> ES31-CTS.shader_storage_buffer_object.basic-operations-case1-cs
> ES31-CTS.shader_storage_buffer_object.basic-operations-case2-cs
> ES31-CTS.shader_storage_buffer_object.basic-stdLayout_UBO_SSBO-case2-cs
> ES31-CTS.shader_storage_buffer_object.advanced-write-fragment-cs
> ES31-CTS.shader_storage_buffer_object.advanced-indirectAddressing-case2-cs
> ES31-CTS.shader_storage_buffer_object.advanced-matrix-cs
> ---
>  src/mesa/drivers/dri/i965/gen7_cs_state.c | 6 ++++--
>  1 file changed, 4 insertions(+), 2 deletions(-)
> 
> diff --git a/src/mesa/drivers/dri/i965/gen7_cs_state.c b/src/mesa/drivers/dri/i965/gen7_cs_state.c
> index 1fde69c..dbd1967 100644
> --- a/src/mesa/drivers/dri/i965/gen7_cs_state.c
> +++ b/src/mesa/drivers/dri/i965/gen7_cs_state.c
> @@ -77,7 +77,8 @@ brw_upload_cs_state(struct brw_context *brw)
>  
>     unsigned push_constant_data_size =
>        (prog_data->nr_params + local_id_dwords) * sizeof(gl_constant_value);
> -   unsigned reg_aligned_constant_size = ALIGN(push_constant_data_size, 32);
> +   unsigned reg_aligned_constant_size =
> +      ALIGN(push_constant_data_size, brw->gen < 8 ? 32 : 64);
>     unsigned push_constant_regs = reg_aligned_constant_size / 32;
>     unsigned threads = get_cs_thread_count(cs_prog_data);
>  
> @@ -241,7 +242,8 @@ brw_upload_cs_push_constants(struct brw_context *brw,
>  
>        const unsigned push_constant_data_size =
>           (local_id_dwords + prog_data->nr_params) * sizeof(gl_constant_value);
> -      const unsigned reg_aligned_constant_size = ALIGN(push_constant_data_size, 32);
> +      const unsigned reg_aligned_constant_size =
> +         ALIGN(push_constant_data_size, brw->gen < 8 ? 32 : 64);
>        const unsigned param_aligned_count =
>           reg_aligned_constant_size / sizeof(*param);
>  
> -- 
> 1.9.1
>