Re: [Intel-gfx] [PATCH v3 3/5] drm/i915/gt: Enable the CCS_FLUSH bit in the pipe control

[Nirmoy Das <nirmoy.das@linux.intel.com>]

On 7/17/2023 2:51 PM, Andi Shyti wrote:
> Enable the CCS_FLUSH bit 13 in the control pipe for render and
> compute engines in platforms starting from Meteor Lake (BSPEC
> 43904 and 47112).
>
> Fixes: 972282c4cf24 ("drm/i915/gen12: Add aux table invalidate for all engines")
> Signed-off-by: Andi Shyti <andi.shyti@linux.intel.com>
> Cc: Jonathan Cavitt <jonathan.cavitt@intel.com>
> Cc: Nirmoy Das <nirmoy.das@intel.com>
> Cc: <stable@vger.kernel.org> # v5.8+
> ---
>   drivers/gpu/drm/i915/gt/gen8_engine_cs.c     | 12 +++++++++++-
>   drivers/gpu/drm/i915/gt/intel_engine_types.h |  1 +
>   drivers/gpu/drm/i915/gt/intel_gpu_commands.h |  1 +
>   3 files changed, 13 insertions(+), 1 deletion(-)
>
> diff --git a/drivers/gpu/drm/i915/gt/gen8_engine_cs.c b/drivers/gpu/drm/i915/gt/gen8_engine_cs.c
> index bee3b7dc595cf..04484385189ad 100644
> --- a/drivers/gpu/drm/i915/gt/gen8_engine_cs.c
> +++ b/drivers/gpu/drm/i915/gt/gen8_engine_cs.c
> @@ -207,7 +207,7 @@ int gen12_emit_flush_rcs(struct i915_request *rq, u32 mode)
>   	 * memory traffic is quiesced prior.
>   	 */
>   	if ((mode & EMIT_INVALIDATE) && !HAS_FLAT_CCS(engine->i915))
> -		mode |= EMIT_FLUSH;
> +		mode |= EMIT_FLUSH | EMIT_CCS_FLUSH;
>   
>   	if (mode & EMIT_FLUSH) {
>   		u32 flags = 0;
> @@ -232,6 +232,16 @@ int gen12_emit_flush_rcs(struct i915_request *rq, u32 mode)
>   
>   		flags |= PIPE_CONTROL_CS_STALL;
>   
> +		/*
> +		 * When required, in MTL+ platforms, in the render and compute
> +		 * engines we need to set the CCS_FLUSH bit in the pipe control
> +		 */
> +		if (mode & EMIT_CCS_FLUSH &&
> +		    GRAPHICS_VER_FULL(rq->i915) >= IP_VER(12, 70) &&
> +		    (engine->class == RENDER_CLASS ||
> +		     engine->class == COMPUTE_CLASS))
PIPE_CONTROL is only available for render and compute so we can skip 
this engine check.
> +			flags |= PIPE_CONTROL_CCS_FLUSH;

This "flags" is applied to DWORD 1 of PIPE_CONTROL but we need this for 
DWORD 0


Regards,

Nirmoy

> +
>   		if (!HAS_3D_PIPELINE(engine->i915))
>   			flags &= ~PIPE_CONTROL_3D_ARCH_FLAGS;
>   		else if (engine->class == COMPUTE_CLASS)
> diff --git a/drivers/gpu/drm/i915/gt/intel_engine_types.h b/drivers/gpu/drm/i915/gt/intel_engine_types.h
> index e99a6fa03d453..e2cae9d02bd62 100644
> --- a/drivers/gpu/drm/i915/gt/intel_engine_types.h
> +++ b/drivers/gpu/drm/i915/gt/intel_engine_types.h
> @@ -514,6 +514,7 @@ struct intel_engine_cs {
>   	int		(*emit_flush)(struct i915_request *request, u32 mode);
>   #define EMIT_INVALIDATE	BIT(0)
>   #define EMIT_FLUSH	BIT(1)
> +#define EMIT_CCS_FLUSH	BIT(2) /* MTL+ */
>   #define EMIT_BARRIER	(EMIT_INVALIDATE | EMIT_FLUSH)
>   	int		(*emit_bb_start)(struct i915_request *rq,
>   					 u64 offset, u32 length,
> diff --git a/drivers/gpu/drm/i915/gt/intel_gpu_commands.h b/drivers/gpu/drm/i915/gt/intel_gpu_commands.h
> index 5d143e2a8db03..5df7cce23197c 100644
> --- a/drivers/gpu/drm/i915/gt/intel_gpu_commands.h
> +++ b/drivers/gpu/drm/i915/gt/intel_gpu_commands.h
> @@ -299,6 +299,7 @@
>   #define   PIPE_CONTROL_QW_WRITE				(1<<14)
>   #define   PIPE_CONTROL_POST_SYNC_OP_MASK                (3<<14)
>   #define   PIPE_CONTROL_DEPTH_STALL			(1<<13)
> +#define   PIPE_CONTROL_CCS_FLUSH			(1<<13) /* MTL+ */
>   #define   PIPE_CONTROL_WRITE_FLUSH			(1<<12)
>   #define   PIPE_CONTROL_RENDER_TARGET_CACHE_FLUSH	(1<<12) /* gen6+ */
>   #define   PIPE_CONTROL_INSTRUCTION_CACHE_INVALIDATE	(1<<11) /* MBZ on ILK */