drm/xe: Add xe_gt_tlb_invalidation_done_handler

Decouple GT TLB seqno handling from G2H handler.

v2:
 - Add kernel doc

Reviewed-by: Stuart Summers <stuart.summers@intel.com>
Signed-off-by: Matthew Brost <matthew.brost@intel.com>
Link: https://lore.kernel.org/r/20250826182911.392550-6-stuart.summers@intel.com

Author: mbrost05

drivers/gpu/drm/xe/xe_gt_tlb_inval.c

@@ -506,27 +506,18 @@ void xe_gt_tlb_inval_vm(struct xe_gt *gt, struct xe_vm *vm)
 }
 
 /**
- * xe_guc_tlb_inval_done_handler - TLB invalidation done handler
- * @guc: guc
- * @msg: message indicating TLB invalidation done
- * @len: length of message
- *
- * Parse seqno of TLB invalidation, wake any waiters for seqno, and signal any
- * invalidation fences for seqno. Algorithm for this depends on seqno being
- * received in-order and asserts this assumption.
+ * xe_gt_tlb_inval_done_handler - GT TLB invalidation done handler
+ * @gt: gt
+ * @seqno: seqno of invalidation that is done
  *
- * Return: 0 on success, -EPROTO for malformed messages.
+ * Update recv seqno, signal any GT TLB invalidation fences, and restart TDR
  */
-int xe_guc_tlb_inval_done_handler(struct xe_guc *guc, u32 *msg, u32 len)
+static void xe_gt_tlb_inval_done_handler(struct xe_gt *gt, int seqno)
 {
-	struct xe_gt *gt = guc_to_gt(guc);
 	struct xe_device *xe = gt_to_xe(gt);
 	struct xe_gt_tlb_inval_fence *fence, *next;
 	unsigned long flags;
 
-	if (unlikely(len != 1))
-		return -EPROTO;
-
 	/*
 	 * This can also be run both directly from the IRQ handler and also in
 	 * process_g2h_msg(). Only one may process any individual CT message,
@@ -543,12 +534,12 @@ int xe_guc_tlb_inval_done_handler(struct xe_guc *guc, u32 *msg, u32 len)
 	 * process_g2h_msg().
 	 */
 	spin_lock_irqsave(&gt->tlb_inval.pending_lock, flags);
-	if (tlb_inval_seqno_past(gt, msg[0])) {
+	if (tlb_inval_seqno_past(gt, seqno)) {
 		spin_unlock_irqrestore(&gt->tlb_inval.pending_lock, flags);
-		return 0;
+		return;
 	}
 
-	WRITE_ONCE(gt->tlb_inval.seqno_recv, msg[0]);
+	WRITE_ONCE(gt->tlb_inval.seqno_recv, seqno);
 
 	list_for_each_entry_safe(fence, next,
 				 &gt->tlb_inval.pending_fences, link) {
@@ -568,6 +559,28 @@ int xe_guc_tlb_inval_done_handler(struct xe_guc *guc, u32 *msg, u32 len)
 		cancel_delayed_work(&gt->tlb_inval.fence_tdr);
 
 	spin_unlock_irqrestore(&gt->tlb_inval.pending_lock, flags);
+}
+
+/**
+ * xe_guc_tlb_inval_done_handler - TLB invalidation done handler
+ * @guc: guc
+ * @msg: message indicating TLB invalidation done
+ * @len: length of message
+ *
+ * Parse seqno of TLB invalidation, wake any waiters for seqno, and signal any
+ * invalidation fences for seqno. Algorithm for this depends on seqno being
+ * received in-order and asserts this assumption.
+ *
+ * Return: 0 on success, -EPROTO for malformed messages.
+ */
+int xe_guc_tlb_inval_done_handler(struct xe_guc *guc, u32 *msg, u32 len)
+{
+	struct xe_gt *gt = guc_to_gt(guc);
+
+	if (unlikely(len != 1))
+		return -EPROTO;
+
+	xe_gt_tlb_inval_done_handler(gt, msg[0]);
 
 	return 0;
 }