[Intel-gfx] [PATCH] drm/i915/xehp: Drop aux table invalidation on FlatCCS platforms

[Lucas De Marchi]

On Mon, Feb 28, 2022 at 09:29:52PM -0800, Matt Roper wrote:
>Platforms with FlatCCS do not use auxiliary planes for compression
>control data and thus do not need traditional aux table invalidation
>(and the registers no longer even exist).
>
>Original-author: CQ Tang
>Signed-off-by: Matt Roper <matthew.d.roper at intel.com>
>---
> drivers/gpu/drm/i915/gt/gen8_engine_cs.c | 28 ++++++++++++++++--------
> 1 file changed, 19 insertions(+), 9 deletions(-)
>
>diff --git a/drivers/gpu/drm/i915/gt/gen8_engine_cs.c b/drivers/gpu/drm/i915/gt/gen8_engine_cs.c
>index 1f8cf4f790b2..13bbbf5d9737 100644
>--- a/drivers/gpu/drm/i915/gt/gen8_engine_cs.c
>+++ b/drivers/gpu/drm/i915/gt/gen8_engine_cs.c
>@@ -231,7 +231,7 @@ int gen12_emit_flush_rcs(struct i915_request *rq, u32 mode)
>
> 	if (mode & EMIT_INVALIDATE) {
> 		u32 flags = 0;
>-		u32 *cs;
>+		u32 *cs, count;
>
> 		flags |= PIPE_CONTROL_COMMAND_CACHE_INVALIDATE;
> 		flags |= PIPE_CONTROL_TLB_INVALIDATE;
>@@ -246,7 +246,12 @@ int gen12_emit_flush_rcs(struct i915_request *rq, u32 mode)
>
> 		flags |= PIPE_CONTROL_CS_STALL;
>
>-		cs = intel_ring_begin(rq, 8 + 4);
>+		if (!HAS_FLAT_CCS(rq->engine->i915))
>+			count = 8 + 4;
>+		else
>+			count = 8;

u32 count = 8;

...

if (!HAS_FLAT_CCS(rq->engine->i915))
	count += 4;

would probably be shorter, or even

cs = intel_ring_begin(rq, HAS_FLAT_CCS(...) ? 12 : 8)


but doesn't really matter

Reviewed-by: Lucas De Marchi <lucas.demarchi at intel.com>

Lucas De Marchi