[Intel-xe] [PATCH v4 6/7] drm/xe/tlb: also update seqno_recv during reset

[Matthew Auld]

We might have various kworkers waiting for TLB flushes to complete which
are not tracked with an explicit TLB fence, however at this stage that
will never happen since the CT is already disabled, so make sure we
signal them here under the assumption that we have completed a full GT
reset.

Signed-off-by: Matthew Auld <matthew.auld at intel.com>
Cc: Matthew Brost <matthew.brost at intel.com>
Cc: José Roberto de Souza <jose.souza at intel.com>
---
 drivers/gpu/drm/xe/xe_gt_tlb_invalidation.c | 18 +++++++++++++++++-
 1 file changed, 17 insertions(+), 1 deletion(-)

diff --git a/drivers/gpu/drm/xe/xe_gt_tlb_invalidation.c b/drivers/gpu/drm/xe/xe_gt_tlb_invalidation.c
index b38da572d268..51789ec9ad57 100644
--- a/drivers/gpu/drm/xe/xe_gt_tlb_invalidation.c
+++ b/drivers/gpu/drm/xe/xe_gt_tlb_invalidation.c
@@ -89,10 +89,26 @@ invalidation_fence_signal(struct xe_gt_tlb_invalidation_fence *fence)
  void xe_gt_tlb_invalidation_reset(struct xe_gt *gt)
 {
 	struct xe_gt_tlb_invalidation_fence *fence, *next;
+	struct xe_guc *guc = &gt->uc.guc;
 
+	/*
+	 * CT channel is already disabled at this point. No new TLB requests can
+	 * appear.
+	 */
+
+	mutex_lock(&gt->uc.guc.ct.lock);
 	cancel_delayed_work(&gt->tlb_invalidation.fence_tdr);
+	/*
+	 * We might have various kworkers waiting for TLB flushes to complete
+	 * which are not tracked with an explicit TLB fence, however at this
+	 * stage that will never happen since the CT is already disabled, so
+	 * make sure we signal them here under the assumption that we have
+	 * completed a full GT reset.
+	 */
+	gt->tlb_invalidation.seqno_recv = gt->tlb_invalidation.seqno;
+	smp_wmb();
+	wake_up_all(&guc->ct.wq);
 
-	mutex_lock(&gt->uc.guc.ct.lock);
 	list_for_each_entry_safe(fence, next,
 				 &gt->tlb_invalidation.pending_fences, link)
 		invalidation_fence_signal(fence);
-- 
2.41.0