[PATCH 1/2] drm/i915/xehp: GAM registers don't need to be re-applied on engine resets

Gustavo Sousa gustavo.sousa at intel.com
Wed Jan 25 19:43:29 UTC 2023


On Tue, Jan 24, 2023 at 05:14:06PM -0800, Matt Roper wrote:
> Register reset characteristics (i.e., whether the register maintains or
> loses its value on engine reset) is an important factor that determines
> which wa_list we want to add workarounds to.  We recently found out that
> the bspec documentation for the Xe_HP's "GAM" registers in the 0xC800 -
> 0xCFFF range was misleading; these registers do not actually lose their
> value on engine resets as the documentation implied.  This means there's
> no need to re-apply workarounds touching these registers after a reset,
> and the corresponding workarounds should be moved from the 'engine'
> lists back to the 'gt' list.
> 
> While moving these GAM-related workarounds to the various platforms' GT
> workaround functions, we should also take care to handle Wa_18018781329
> properly for MTL's two GTs --- the render/compute setting should be set
> on the primary GT where those engines reside, and the vd/ve/gsc setting
> should be set on the media GT.  Previously the VD/VE/GSC setting was not
> being properly applied.
> 
> Cc: Gustavo Sousa <gustavo.sousa at intel.com>
> Fixes: edf176f48d87 ("drm/i915/dg2: Move misplaced 'ctx' & 'gt' wa's to engine wa list")
> Fixes: b2006061ae28 ("drm/i915/xehpsdv: Move render/compute engine reset domains related workarounds")
> Fixes: 41bb543f5598 ("drm/i915/mtl: Add initial gt workarounds")
> Signed-off-by: Matt Roper <matthew.d.roper at intel.com>
> ---
>  drivers/gpu/drm/i915/gt/intel_gt_regs.h     |  1 +
>  drivers/gpu/drm/i915/gt/intel_workarounds.c | 88 +++++++++++++--------
>  drivers/gpu/drm/i915/i915_drv.h             |  4 +
>  3 files changed, 59 insertions(+), 34 deletions(-)
> 
> diff --git a/drivers/gpu/drm/i915/gt/intel_gt_regs.h b/drivers/gpu/drm/i915/gt/intel_gt_regs.h
> index 2727645864db..4a37d048b512 100644
> --- a/drivers/gpu/drm/i915/gt/intel_gt_regs.h
> +++ b/drivers/gpu/drm/i915/gt/intel_gt_regs.h
> @@ -1100,6 +1100,7 @@
>  #define XEHP_MERT_MOD_CTRL			MCR_REG(0xcf28)
>  #define RENDER_MOD_CTRL				MCR_REG(0xcf2c)
>  #define COMP_MOD_CTRL				MCR_REG(0xcf30)
> +#define GSC_MOD_CTRL				MCR_REG(0xcf30)	/* media GT only */
>  #define VDBX_MOD_CTRL				MCR_REG(0xcf34)
>  #define VEBX_MOD_CTRL				MCR_REG(0xcf38)
>  #define   FORCE_MISS_FTLB			REG_BIT(3)
> diff --git a/drivers/gpu/drm/i915/gt/intel_workarounds.c b/drivers/gpu/drm/i915/gt/intel_workarounds.c
> index 4efc1a532982..0e7f64bb2860 100644
> --- a/drivers/gpu/drm/i915/gt/intel_workarounds.c
> +++ b/drivers/gpu/drm/i915/gt/intel_workarounds.c
> @@ -1559,6 +1559,19 @@ xehpsdv_gt_workarounds_init(struct intel_gt *gt, struct i915_wa_list *wal)
>  
>  	/* Wa_14011060649:xehpsdv */
>  	wa_14011060649(gt, wal);
> +
> +	/* Wa_18018781329 */
> +	wa_mcr_write_or(wal, RENDER_MOD_CTRL, FORCE_MISS_FTLB);
> +	wa_mcr_write_or(wal, COMP_MOD_CTRL, FORCE_MISS_FTLB);
> +	wa_mcr_write_or(wal, VDBX_MOD_CTRL, FORCE_MISS_FTLB);
> +	wa_mcr_write_or(wal, VEBX_MOD_CTRL, FORCE_MISS_FTLB);

Maybe worth mentioning in the commit message that Wa_18018781329 is being
extended to XEHPSDV in this patch? This could also be on its own patch.

> +
> +	/* Wa_14012362059:xehpsdv */
> +	wa_mcr_write_or(wal, XEHP_MERT_MOD_CTRL, FORCE_MISS_FTLB);
> +
> +	/* Wa_14014368820:xehpsdv */
> +	wa_write_or(wal, GEN12_GAMCNTRL_CTRL,
> +		    INVALIDATION_BROADCAST_MODE_DIS | GLOBAL_INVALIDATION_MODE);
>  }
>  
>  static void
> @@ -1599,6 +1612,12 @@ dg2_gt_workarounds_init(struct intel_gt *gt, struct i915_wa_list *wal)
>  				DSS_ROUTER_CLKGATE_DIS);
>  	}
>  
> +	if (IS_DG2_GRAPHICS_STEP(gt->i915, G10, STEP_A0, STEP_B0) ||
> +	    IS_DG2_GRAPHICS_STEP(gt->i915, G11, STEP_A0, STEP_B0)) {
> +		/* Wa_14012362059:dg2 */
> +		wa_mcr_write_or(wal, XEHP_MERT_MOD_CTRL, FORCE_MISS_FTLB);
> +	}
> +
>  	if (IS_DG2_GRAPHICS_STEP(gt->i915, G10, STEP_A0, STEP_B0)) {
>  		/* Wa_14010948348:dg2_g10 */
>  		wa_write_or(wal, UNSLCGCTL9430, MSQDUNIT_CLKGATE_DIS);
> @@ -1644,6 +1663,12 @@ dg2_gt_workarounds_init(struct intel_gt *gt, struct i915_wa_list *wal)
>  
>  		/* Wa_14011028019:dg2_g10 */
>  		wa_mcr_write_or(wal, SSMCGCTL9530, RTFUNIT_CLKGATE_DIS);
> +
> +		/* Wa_14010680813:dg2_g10 */
> +		wa_write_or(wal, GEN12_GAMSTLB_CTRL,
> +			    CONTROL_BLOCK_CLKGATE_DIS |
> +			    EGRESS_BLOCK_CLKGATE_DIS |
> +			    TAG_BLOCK_CLKGATE_DIS);
>  	}
>  
>  	/* Wa_14014830051:dg2 */
> @@ -1658,6 +1683,16 @@ dg2_gt_workarounds_init(struct intel_gt *gt, struct i915_wa_list *wal)
>  
>  	/* Wa_14015795083 */
>  	wa_mcr_write_clr(wal, GEN8_MISCCPCTL, GEN12_DOP_CLOCK_GATE_RENDER_ENABLE);
> +
> +	/* Wa_18018781329 */
> +	wa_mcr_write_or(wal, RENDER_MOD_CTRL, FORCE_MISS_FTLB);
> +	wa_mcr_write_or(wal, COMP_MOD_CTRL, FORCE_MISS_FTLB);
> +	wa_mcr_write_or(wal, VDBX_MOD_CTRL, FORCE_MISS_FTLB);
> +	wa_mcr_write_or(wal, VEBX_MOD_CTRL, FORCE_MISS_FTLB);
> +
> +	/* Wa_1509235366:dg2 */
> +	wa_write_or(wal, GEN12_GAMCNTRL_CTRL,
> +		    INVALIDATION_BROADCAST_MODE_DIS | GLOBAL_INVALIDATION_MODE);
>  }
>  
>  static void
> @@ -1667,16 +1702,27 @@ pvc_gt_workarounds_init(struct intel_gt *gt, struct i915_wa_list *wal)
>  
>  	/* Wa_14015795083 */
>  	wa_mcr_write_clr(wal, GEN8_MISCCPCTL, GEN12_DOP_CLOCK_GATE_RENDER_ENABLE);
> +
> +	/* Wa_18018781329 */
> +	wa_mcr_write_or(wal, RENDER_MOD_CTRL, FORCE_MISS_FTLB);
> +	wa_mcr_write_or(wal, COMP_MOD_CTRL, FORCE_MISS_FTLB);
> +	wa_mcr_write_or(wal, VDBX_MOD_CTRL, FORCE_MISS_FTLB);
> +	wa_mcr_write_or(wal, VEBX_MOD_CTRL, FORCE_MISS_FTLB);
>  }
>  
>  static void
>  xelpg_gt_workarounds_init(struct intel_gt *gt, struct i915_wa_list *wal)
>  {
> -	/* Wa_14014830051 */
>  	if (IS_MTL_GRAPHICS_STEP(gt->i915, M, STEP_A0, STEP_B0) ||
> -	    IS_MTL_GRAPHICS_STEP(gt->i915, P, STEP_A0, STEP_B0))
> +	    IS_MTL_GRAPHICS_STEP(gt->i915, P, STEP_A0, STEP_B0)) {
> +		/* Wa_14014830051 */
>  		wa_mcr_write_clr(wal, SARB_CHICKEN1, COMP_CKN_IN);
>  
> +		/* Wa_18018781329 */
> +		wa_mcr_write_or(wal, RENDER_MOD_CTRL, FORCE_MISS_FTLB);
> +		wa_mcr_write_or(wal, COMP_MOD_CTRL, FORCE_MISS_FTLB);
> +	}
> +
>  	/*
>  	 * Unlike older platforms, we no longer setup implicit steering here;
>  	 * all MCR accesses are explicitly steered.
> @@ -1687,7 +1733,12 @@ xelpg_gt_workarounds_init(struct intel_gt *gt, struct i915_wa_list *wal)
>  static void
>  xelpmp_gt_workarounds_init(struct intel_gt *gt, struct i915_wa_list *wal)
>  {
> -	/* FIXME: Actual workarounds will be added in future patch(es) */
> +	if (IS_MTL_MEDIA_STEP(gt->i915, STEP_A0, STEP_B0)) {
> +		/* Wa_18018781329 */
> +		wa_mcr_write_or(wal, GSC_MOD_CTRL, FORCE_MISS_FTLB);
> +		wa_mcr_write_or(wal, VDBX_MOD_CTRL, FORCE_MISS_FTLB);
> +		wa_mcr_write_or(wal, VEBX_MOD_CTRL, FORCE_MISS_FTLB);

By looking at the spec, I under the assumption that GAM registers in MTL Media
are not multicast. Am I wrong?

> +	}
>  
>  	debug_dump_steering(gt);
>  }
> @@ -2351,12 +2402,6 @@ rcs_engine_wa_init(struct intel_engine_cs *engine, struct i915_wa_list *wal)
>  				 GEN12_DISABLE_READ_SUPPRESSION);
>  	}
>  
> -	if (IS_DG2(i915)) {
> -		/* Wa_1509235366:dg2 */
> -		wa_write_or(wal, GEN12_GAMCNTRL_CTRL, INVALIDATION_BROADCAST_MODE_DIS |
> -			    GLOBAL_INVALIDATION_MODE);
> -	}
> -
>  	if (IS_DG2_GRAPHICS_STEP(i915, G11, STEP_A0, STEP_B0)) {
>  		/* Wa_14013392000:dg2_g11 */
>  		wa_mcr_masked_en(wal, GEN8_ROW_CHICKEN2, GEN12_ENABLE_LARGE_GRF_MODE);
> @@ -2416,18 +2461,6 @@ rcs_engine_wa_init(struct intel_engine_cs *engine, struct i915_wa_list *wal)
>  		wa_mcr_masked_en(wal, GEN9_HALF_SLICE_CHICKEN7,
>  				 DG2_DISABLE_ROUND_ENABLE_ALLOW_FOR_SSLA);
>  
> -	if (IS_DG2_GRAPHICS_STEP(engine->i915, G10, STEP_A0, STEP_B0)) {
> -		/* Wa_14010680813:dg2_g10 */
> -		wa_write_or(wal, GEN12_GAMSTLB_CTRL, CONTROL_BLOCK_CLKGATE_DIS |
> -			    EGRESS_BLOCK_CLKGATE_DIS | TAG_BLOCK_CLKGATE_DIS);
> -	}
> -
> -	if (IS_DG2_GRAPHICS_STEP(engine->i915, G10, STEP_A0, STEP_B0) ||
> -	    IS_DG2_GRAPHICS_STEP(engine->i915, G11, STEP_A0, STEP_B0)) {
> -		/* Wa_14012362059:dg2 */
> -		wa_mcr_write_or(wal, XEHP_MERT_MOD_CTRL, FORCE_MISS_FTLB);
> -	}
> -
>  	if (IS_DG2_GRAPHICS_STEP(i915, G11, STEP_B0, STEP_FOREVER) ||
>  	    IS_DG2_G10(i915)) {
>  		/* Wa_22014600077:dg2 */
> @@ -2990,12 +3023,6 @@ general_render_compute_wa_init(struct intel_engine_cs *engine, struct i915_wa_li
>  	    IS_MTL_GRAPHICS_STEP(i915, P, STEP_A0, STEP_B0) ||
>  	    IS_PONTEVECCHIO(i915) ||
>  	    IS_DG2(i915)) {
> -		/* Wa_18018781329 */
> -		wa_mcr_write_or(wal, RENDER_MOD_CTRL, FORCE_MISS_FTLB);
> -		wa_mcr_write_or(wal, COMP_MOD_CTRL, FORCE_MISS_FTLB);
> -		wa_mcr_write_or(wal, VDBX_MOD_CTRL, FORCE_MISS_FTLB);
> -		wa_mcr_write_or(wal, VEBX_MOD_CTRL, FORCE_MISS_FTLB);
> -
>  		/* Wa_22014226127 */
>  		wa_mcr_write_or(wal, LSC_CHICKEN_BIT_0, DISABLE_D8_D16_COASLESCE);
>  	}
> @@ -3062,13 +3089,6 @@ general_render_compute_wa_init(struct intel_engine_cs *engine, struct i915_wa_li
>  			wa_mcr_masked_dis(wal, MLTICTXCTL, TDONRENDER);
>  			wa_mcr_write_or(wal, L3SQCREG1_CCS0, FLUSHALLNONCOH);
>  		}
> -
> -		/* Wa_14012362059:xehpsdv */
> -		wa_mcr_write_or(wal, XEHP_MERT_MOD_CTRL, FORCE_MISS_FTLB);
> -
> -		/* Wa_14014368820:xehpsdv */
> -		wa_write_or(wal, GEN12_GAMCNTRL_CTRL, INVALIDATION_BROADCAST_MODE_DIS |
> -				GLOBAL_INVALIDATION_MODE);
>  	}
>  
>  	if (IS_DG2(i915) || IS_PONTEVECCHIO(i915)) {
> diff --git a/drivers/gpu/drm/i915/i915_drv.h b/drivers/gpu/drm/i915/i915_drv.h
> index 2a6e212f8824..e90baa28a308 100644
> --- a/drivers/gpu/drm/i915/i915_drv.h
> +++ b/drivers/gpu/drm/i915/i915_drv.h
> @@ -696,6 +696,10 @@ IS_SUBPLATFORM(const struct drm_i915_private *i915,
>  	(IS_METEORLAKE(__i915) && \
>  	 IS_DISPLAY_STEP(__i915, since, until))
>  
> +#define IS_MTL_MEDIA_STEP(__i915, since, until) \
> +	(IS_METEORLAKE(__i915) && \
> +	 IS_MEDIA_STEP(__i915, since, until))
> +
>  /*
>   * DG2 hardware steppings are a bit unusual.  The hardware design was forked to
>   * create three variants (G10, G11, and G12) which each have distinct
> -- 
> 2.39.0
> 


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