drm/xe: Do not grab forcewakes when issuing GGTT TLB invalidation via GuC

Forcewakes are not required for communication with the GuC via CTB
as it is a memory based interfaced. Acquring forcewakes takes
considerable time. With that, do not grab a forcewake when issuing a
GGTT TLB invalidation via the GuC.

Cc: Maarten Lankhorst <maarten.lankhorst@linux.intel.com>
Cc: Lucas De Marchi <lucas.demarchi@intel.com>
Cc: Matt Roper <matthew.d.roper@intel.com>
Signed-off-by: Matthew Brost <matthew.brost@intel.com>
Reviewed-by: Maarten Lankhorst <maarten.lankhorst@linux.intel.com>
Link: https://patchwork.freedesktop.org/patch/msgid/20240229194520.200642-1-matthew.brost@intel.com

drivers/gpu/drm/xe/xe_ggtt.c

@@ -257,16 +257,9 @@ static void ggtt_invalidate_gt_tlb(struct xe_gt *gt)
 	if (!gt)
 		return;
 
-	/*
-	 * Invalidation can happen when there's no in-flight work keeping the
-	 * GT awake.  We need to explicitly grab forcewake to ensure the GT
-	 * and GuC are accessible.
-	 */
-	xe_force_wake_get(gt_to_fw(gt), XE_FW_GT);
 	err = xe_gt_tlb_invalidation_ggtt(gt);
 	if (err)
 		drm_warn(&xe->drm, "xe_gt_tlb_invalidation_ggtt error=%d", err);
-	xe_force_wake_put(gt_to_fw(gt), XE_FW_GT);
 }
 
 void xe_ggtt_invalidate(struct xe_ggtt *ggtt)

drivers/gpu/drm/xe/xe_gt_tlb_invalidation.c

@@ -247,6 +247,7 @@ int xe_gt_tlb_invalidation_ggtt(struct xe_gt *gt)
 
 		xe_gt_tlb_invalidation_wait(gt, seqno);
 	} else if (xe_device_uc_enabled(xe)) {
+		xe_force_wake_get(gt_to_fw(gt), XE_FW_GT);
 		if (xe->info.platform == XE_PVC || GRAPHICS_VER(xe) >= 20) {
 			xe_mmio_write32(gt, PVC_GUC_TLB_INV_DESC1,
 					PVC_GUC_TLB_INV_DESC1_INVALIDATE);
@@ -256,6 +257,7 @@ int xe_gt_tlb_invalidation_ggtt(struct xe_gt *gt)
 			xe_mmio_write32(gt, GUC_TLB_INV_CR,
 					GUC_TLB_INV_CR_INVALIDATE);
 		}
+		xe_force_wake_put(gt_to_fw(gt), XE_FW_GT);
 	}
 
 	return 0;