[PATCH] drm/i915: Reduce MCR lock surface

[Nirmoy Das]

Take the mcr lock only when driver needs to write
into mcr based tlb based registers.

Signed-off-by: Nirmoy Das <nirmoy.das at intel.com>
---
 drivers/gpu/drm/i915/gt/intel_tlb.c | 9 ++++++---
 1 file changed, 6 insertions(+), 3 deletions(-)

diff --git a/drivers/gpu/drm/i915/gt/intel_tlb.c b/drivers/gpu/drm/i915/gt/intel_tlb.c
index 139608c30d97..69b0044039d6 100644
--- a/drivers/gpu/drm/i915/gt/intel_tlb.c
+++ b/drivers/gpu/drm/i915/gt/intel_tlb.c
@@ -59,7 +59,6 @@ static void mmio_invalidate_full(struct intel_gt *gt)
 
 	intel_uncore_forcewake_get(uncore, FORCEWAKE_ALL);
 
-	intel_gt_mcr_lock(gt, &flags);
 	spin_lock(&uncore->lock); /* serialise invalidate with GT reset */
 
 	awake = 0;
@@ -67,10 +66,15 @@ static void mmio_invalidate_full(struct intel_gt *gt)
 		if (!intel_engine_pm_is_awake(engine))
 			continue;
 
-		if (engine->tlb_inv.mcr)
+		if (engine->tlb_inv.mcr) {
+			spin_unlock(&uncore->lock);
+			intel_gt_mcr_lock(gt, &flags);
 			intel_gt_mcr_multicast_write_fw(gt,
 							engine->tlb_inv.reg.mcr_reg,
 							engine->tlb_inv.request);
+			intel_gt_mcr_unlock(gt, flags);
+			spin_lock(&uncore->lock); /* serialise invalidate with GT reset */
+		}
 		else
 			intel_uncore_write_fw(uncore,
 					      engine->tlb_inv.reg.reg,
@@ -91,7 +95,6 @@ static void mmio_invalidate_full(struct intel_gt *gt)
 		intel_uncore_write_fw(uncore, GEN12_OA_TLB_INV_CR, 1);
 
 	spin_unlock(&uncore->lock);
-	intel_gt_mcr_unlock(gt, flags);
 
 	for_each_engine_masked(engine, gt, awake, tmp) {
 		if (wait_for_invalidate(engine))
-- 
2.41.0