[Intel-gfx] [PATCH v6] drm/i915: Add Wa_18022495364

[Matt Roper]

On Fri, Sep 15, 2023 at 01:10:32AM +0530, Dnyaneshwar Bhadane wrote:
> Invalidate instruction and State cache bit using INDIRECT_CTX on
> every gpu context switch for gen12.
> The goal of this workaround is to actually perform an explicit
> invalidation of that cache (by re-writing the register) during every GPU
> context switch, which is accomplished via a "workaround batchbuffer"
> that's attached to the context via INDIRECT_CTX. (Matt Ropper)
> BSpec: 11354
> 
> Please refer [1] for more reviews and comment on the same patch
> 
> [1] https://patchwork.freedesktop.org/patch/556154/
> 
> v2:
> - Remove extra parentheses from the condition (Lucas)
> - Align spacing and new line (Lucas)
> 
> v3:
> - Fix commit message.
> 
> v4:
> - Only GEN12 changes are kept  (Matt Ropper)
> - Fix the commit message for r-b (Matt Ropper)
> - Rename the register bit in define
> 
> v5:
> - Move out this workaround from golden context init (Matt Roper)
> - Use INDIRECT_CTX to set bit on each GPU context switch (Matt Roper)
> 
> v6:
> - Change IP Version base condition for Gen12 (Matt Ropper)
> - Made imperative form of commit version messages (Suraj)
> - s/Added/Add in patch header (Suraj)
> 
> Cc: Lucas De Marchi <lucas.demarchi at intel.com>
> Cc: Matt Roper <matthew.d.roper at intel.com>
> Cc: Suraj Kandpal <suraj.kandpal at intel.com>
> Signed-off-by: Dnyaneshwar Bhadane <dnyaneshwar.bhadane at intel.com>

Reviewed-by: Matt Roper <matthew.d.roper at intel.com>

> 
> ---
>  drivers/gpu/drm/i915/gt/intel_gt_regs.h |  2 ++
>  drivers/gpu/drm/i915/gt/intel_lrc.c     | 13 +++++++++++++
>  2 files changed, 15 insertions(+)
> 
> diff --git a/drivers/gpu/drm/i915/gt/intel_gt_regs.h b/drivers/gpu/drm/i915/gt/intel_gt_regs.h
> index a00ff51c681d..0d5260d126d8 100644
> --- a/drivers/gpu/drm/i915/gt/intel_gt_regs.h
> +++ b/drivers/gpu/drm/i915/gt/intel_gt_regs.h
> @@ -164,6 +164,8 @@
>  #define GEN9_CSFE_CHICKEN1_RCS			_MMIO(0x20d4)
>  #define   GEN9_PREEMPT_GPGPU_SYNC_SWITCH_DISABLE	(1 << 2)
>  #define   GEN11_ENABLE_32_PLANE_MODE		(1 << 7)
> +#define GEN12_CS_DEBUG_MODE2			_MMIO(0x20d8)
> +#define   INSTRUCTION_STATE_CACHE_INVALIDATE	REG_BIT(6)
>  
>  #define GEN7_FF_SLICE_CS_CHICKEN1		_MMIO(0x20e0)
>  #define   GEN9_FFSC_PERCTX_PREEMPT_CTRL		(1 << 14)
> diff --git a/drivers/gpu/drm/i915/gt/intel_lrc.c b/drivers/gpu/drm/i915/gt/intel_lrc.c
> index b99efa348ad1..56c916730e9b 100644
> --- a/drivers/gpu/drm/i915/gt/intel_lrc.c
> +++ b/drivers/gpu/drm/i915/gt/intel_lrc.c
> @@ -1333,6 +1333,15 @@ dg2_emit_draw_watermark_setting(u32 *cs)
>  	return cs;
>  }
>  
> +static u32 *
> +gen12_invalidate_state_cache(u32 *cs)
> +{
> +	*cs++ = MI_LOAD_REGISTER_IMM(1);
> +	*cs++ = i915_mmio_reg_offset(GEN12_CS_DEBUG_MODE2);
> +	*cs++ = _MASKED_BIT_ENABLE(INSTRUCTION_STATE_CACHE_INVALIDATE);
> +	return cs;
> +}
> +
>  static u32 *
>  gen12_emit_indirect_ctx_rcs(const struct intel_context *ce, u32 *cs)
>  {
> @@ -1346,6 +1355,10 @@ gen12_emit_indirect_ctx_rcs(const struct intel_context *ce, u32 *cs)
>  
>  	cs = gen12_emit_aux_table_inv(ce->engine, cs);
>  
> +	/* Wa_18022495364 */
> +	if (IS_GFX_GT_IP_RANGE(ce->engine->gt, IP_VER(12, 0), IP_VER(12, 10)))
> +		cs = gen12_invalidate_state_cache(cs);
> +
>  	/* Wa_16014892111 */
>  	if (IS_GFX_GT_IP_STEP(ce->engine->gt, IP_VER(12, 70), STEP_A0, STEP_B0) ||
>  	    IS_GFX_GT_IP_STEP(ce->engine->gt, IP_VER(12, 71), STEP_A0, STEP_B0) ||
> -- 
> 2.34.1
> 

-- 
Matt Roper
Graphics Software Engineer
Linux GPU Platform Enablement
Intel Corporation