[PATCH v9 09/18] drm/amdgpu: add SVM notifier invalidate callback and checkpoint

From: Honglei Huang <[email protected]>

Add invalidate_ranges callback and checkpoint timestamp:
- amdgpu_svm_capture_checkpoint_ts: capture interrupt handler write
  pointer timestamp for stale retry fault filtering
- amdgpu_svm_range_invalidate: invalidate_ranges callback dispatching
  per range notifier begin/end with TLB flush batching, checkpoint
  timestamp capture on MMU_NOTIFY_UNMAP events

Signed-off-by: Honglei Huang <[email protected]>
---
 drivers/gpu/drm/amd/amdgpu/amdgpu_svm_range.c | 71 +++++++++++++++++++
 drivers/gpu/drm/amd/amdgpu/amdgpu_svm_range.h |  6 ++
 2 files changed, 77 insertions(+)

diff --git a/drivers/gpu/drm/amd/amdgpu/amdgpu_svm_range.c b/drivers/gpu/drm/amd/amdgpu/amdgpu_svm_range.c
index 9e348390795a6..ed057545d0964 100644
--- a/drivers/gpu/drm/amd/amdgpu/amdgpu_svm_range.c
+++ b/drivers/gpu/drm/amd/amdgpu/amdgpu_svm_range.c
@@ -728,3 +728,74 @@ void amdgpu_svm_range_unqueue(struct amdgpu_svm *svm,
 	if (put)
 		drm_gpusvm_range_put(&range->base);
 }
+
+/**
+ * amdgpu_svm_capture_checkpoint_ts() - Record the IH ring write pointer time
+ * @svm: The SVM context.
+ *
+ * Capture the timestamp of the most recent interrupt handler write pointer
+ * into @svm->checkpoint_ts. Retry faults whose timestamp predates this
+ * checkpoint are stale and are dropped by the fault handler.
+ */
+void amdgpu_svm_capture_checkpoint_ts(struct amdgpu_svm *svm)
+{
+	struct amdgpu_device *adev = svm->adev;
+	struct amdgpu_ih_ring *ih;
+	uint32_t checkpoint_wptr;
+
+	if (!adev->irq.retry_cam_enabled && adev->irq.ih1.ring_size) {
+		ih = &adev->irq.ih1;
+		checkpoint_wptr = amdgpu_ih_get_wptr(adev, ih);
+		if (ih->rptr != checkpoint_wptr) {
+			WRITE_ONCE(svm->checkpoint_ts,
+				   amdgpu_ih_decode_iv_ts(adev, ih,
+							  checkpoint_wptr, -1));
+			return;
+		}
+	}
+
+	ih = &adev->irq.ih_soft;
+	checkpoint_wptr = amdgpu_ih_get_wptr(adev, ih);
+	if (ih->rptr != checkpoint_wptr)
+		WRITE_ONCE(svm->checkpoint_ts,
+			   amdgpu_ih_decode_iv_ts(adev, ih,
+						  checkpoint_wptr, -1));
+}
+
+/**
+ * amdgpu_svm_range_invalidate() - MMU notifier invalidate_ranges callback
+ * @svm: The SVM context.
+ * @notifier: The GPU SVM notifier covering the invalidated ranges.
+ * @mmu_range: The MMU notifier range describing the event.
+ * @first: First GPU SVM range in the affected interval.
+ * @adj_start: Adjusted start address of the affected interval.
+ * @adj_end: Adjusted end address of the affected interval.
+ *
+ * Dispatch the two phase notifier handling across every range in
+ * [@adj_start, @adj_end): run the begin phase for all ranges, then
+ * the end phase. On an unmap event, also capture a checkpoint timestamp
+ * so stale retry faults can be filtered.
+ */
+void amdgpu_svm_range_invalidate(struct amdgpu_svm *svm,
+				 struct drm_gpusvm_notifier *notifier,
+				 const struct mmu_notifier_range *mmu_range,
+				 struct drm_gpusvm_range *first,
+				 uint64_t adj_start, uint64_t adj_end)
+{
+	struct drm_gpusvm_range *r;
+	bool needs_flush = false;
+
+	if (mmu_range->event == MMU_NOTIFY_UNMAP)
+		amdgpu_svm_capture_checkpoint_ts(svm);
+
+	r = first;
+	drm_gpusvm_for_each_range(r, notifier, adj_start, adj_end)
+		needs_flush |= amdgpu_svm_range_notifier_event_begin(svm, r,
+								     mmu_range);
+	if (needs_flush)
+		amdgpu_svm_flush_tlb(svm);
+
+	r = first;
+	drm_gpusvm_for_each_range(r, notifier, adj_start, adj_end)
+		amdgpu_svm_range_notifier_event_end(svm, r, mmu_range);
+}
diff --git a/drivers/gpu/drm/amd/amdgpu/amdgpu_svm_range.h b/drivers/gpu/drm/amd/amdgpu/amdgpu_svm_range.h
index f423be277a85a..5e49d774711ce 100644
--- a/drivers/gpu/drm/amd/amdgpu/amdgpu_svm_range.h
+++ b/drivers/gpu/drm/amd/amdgpu/amdgpu_svm_range.h
@@ -175,6 +175,12 @@ amdgpu_svm_range_find_or_insert(struct amdgpu_svm *svm, unsigned long addr,
 int amdgpu_svm_range_get_pages(struct amdgpu_svm *svm,
 			       struct drm_gpusvm_range *range,
 			       struct drm_gpusvm_ctx *ctx);
+void amdgpu_svm_capture_checkpoint_ts(struct amdgpu_svm *svm);
+void amdgpu_svm_range_invalidate(struct amdgpu_svm *svm,
+				 struct drm_gpusvm_notifier *notifier,
+				 const struct mmu_notifier_range *mmu_range,
+				 struct drm_gpusvm_range *first,
+				 uint64_t adj_start, uint64_t adj_end);
 bool amdgpu_svm_range_notifier_event_begin(struct amdgpu_svm *svm,
 					   struct drm_gpusvm_range *range,
 					   const struct mmu_notifier_range *mmu_range);
-- 
2.53.0