Commit 5b643660 authored Jan 20, 2023 by Matthew Brost Committed by Rodrigo Vivi Dec 19, 2023

drm/xe: Don't process TLB invalidation done in CT fast-path

We can't currently do this due to TLB invalidation done handler
expecting the seqno being received in-order, with the fast-path a TLB
invalidation done could pass one being processed in the slow-path in an
extreme corner case. Remove TLB invalidation done from the fast-path for
now and in a follow up reenable this once the TLB invalidation done
handler can deal with out of order seqno.

Signed-off-by: Matthew Brost <matthew.brost@intel.com>
Reviewed-by: Niranjana Vishwanathapura <niranjana.vishwanathapura@intel.com>
Signed-off-by: Rodrigo Vivi <rodrigo.vivi@intel.com>

parent e89b384c

drivers/gpu/drm/xe/xe_guc_ct.c

+8 −1

Original line number	Diff line number	Diff line
		@@ -966,7 +966,14 @@ static int g2h_read(struct xe_guc_ct ct, u32 msg, bool fast_path)
		return 0;

		switch (FIELD_GET(GUC_HXG_EVENT_MSG_0_ACTION, msg[1])) {
		case XE_GUC_ACTION_TLB_INVALIDATION_DONE:
		/*
		* FIXME: We really should process
		* XE_GUC_ACTION_TLB_INVALIDATION_DONE here in the fast-path as
		* these critical for page fault performance. We currently can't
		* due to TLB invalidation done algorithm expecting the seqno
		* returned in-order. With some small changes to the algorithm
		* and locking we should be able to support out-of-order seqno.
		*/
		case XE_GUC_ACTION_REPORT_PAGE_FAULT_REQ_DESC:
		break; /* Process these in fast-path */
		default: