[Intel-gfx] [PATCH] drm/i915: disable sampler indirect state in bindless heap

[Lionel Landwerlin]

On 07/04/2023 12:32, Lionel Landwerlin wrote:
> By default the indirect state sampler data (border colors) are stored
> in the same heap as the SAMPLER_STATE structure. For userspace drivers
> that can be 2 different heaps (dynamic state heap & bindless sampler
> state heap). This means that border colors have to copied in 2
> different places so that the same SAMPLER_STATE structure find the
> right data.
>
> This change is forcing the indirect state sampler data to only be in
> the dynamic state pool (more convinient for userspace drivers, they
> only have to have one copy of the border colors). This is reproducing
> the behavior of the Windows drivers.
>
> BSpec: 46052
>
> Signed-off-by: Lionel Landwerlin <lionel.g.landwerlin at intel.com>
> Cc: stable at vger.kernel.org
> Reviewed-by: Haridhar Kalvala <haridhar.kalvala at intel.com>


Screwed up the subject-prefix, but this is v4.

Rebased due to another change touching the same register.


-Lionel


> ---
>   drivers/gpu/drm/i915/gt/intel_gt_regs.h     |  1 +
>   drivers/gpu/drm/i915/gt/intel_workarounds.c | 19 +++++++++++++++++++
>   2 files changed, 20 insertions(+)
>
> diff --git a/drivers/gpu/drm/i915/gt/intel_gt_regs.h b/drivers/gpu/drm/i915/gt/intel_gt_regs.h
> index 492b3de6678d7..fd1f9cd35e9d7 100644
> --- a/drivers/gpu/drm/i915/gt/intel_gt_regs.h
> +++ b/drivers/gpu/drm/i915/gt/intel_gt_regs.h
> @@ -1145,6 +1145,7 @@
>   #define   SC_DISABLE_POWER_OPTIMIZATION_EBB	REG_BIT(9)
>   #define   GEN11_SAMPLER_ENABLE_HEADLESS_MSG	REG_BIT(5)
>   #define   MTL_DISABLE_SAMPLER_SC_OOO		REG_BIT(3)
> +#define   GEN11_INDIRECT_STATE_BASE_ADDR_OVERRIDE	REG_BIT(0)
>   
>   #define GEN9_HALF_SLICE_CHICKEN7		MCR_REG(0xe194)
>   #define   DG2_DISABLE_ROUND_ENABLE_ALLOW_FOR_SSLA	REG_BIT(15)
> diff --git a/drivers/gpu/drm/i915/gt/intel_workarounds.c b/drivers/gpu/drm/i915/gt/intel_workarounds.c
> index 6ea453ddd0116..b925ef47304b6 100644
> --- a/drivers/gpu/drm/i915/gt/intel_workarounds.c
> +++ b/drivers/gpu/drm/i915/gt/intel_workarounds.c
> @@ -2971,6 +2971,25 @@ general_render_compute_wa_init(struct intel_engine_cs *engine, struct i915_wa_li
>   
>   	add_render_compute_tuning_settings(i915, wal);
>   
> +	if (GRAPHICS_VER(i915) >= 11) {
> +		/* This is not a Wa (although referred to as
> +		 * WaSetInidrectStateOverride in places), this allows
> +		 * applications that reference sampler states through
> +		 * the BindlessSamplerStateBaseAddress to have their
> +		 * border color relative to DynamicStateBaseAddress
> +		 * rather than BindlessSamplerStateBaseAddress.
> +		 *
> +		 * Otherwise SAMPLER_STATE border colors have to be
> +		 * copied in multiple heaps (DynamicStateBaseAddress &
> +		 * BindlessSamplerStateBaseAddress)
> +		 *
> +		 * BSpec: 46052
> +		 */
> +		wa_mcr_masked_en(wal,
> +				 GEN10_SAMPLER_MODE,
> +				 GEN11_INDIRECT_STATE_BASE_ADDR_OVERRIDE);
> +	}
> +
>   	if (IS_MTL_GRAPHICS_STEP(i915, M, STEP_B0, STEP_FOREVER) ||
>   	    IS_MTL_GRAPHICS_STEP(i915, P, STEP_B0, STEP_FOREVER))
>   		/* Wa_14017856879 */