accel/habanalabs: capture interrupt timestamp in handler

In order for interrupt timestamp to be more accurate we should
capture it during the interrupt handling rather than in threaded
irq context.
Signed-off-by: Ofir Bitton <obitton@habana.ai>
Reviewed-by: Oded Gabbay <ogabbay@kernel.org>
Signed-off-by: Oded Gabbay <ogabbay@kernel.org>
Reviewed-by: Stanislaw Gruszka <stanislaw.gruszka@linux.intel.com>

drivers/accel/habanalabs/common/habanalabs.h

@@ -1107,6 +1107,7 @@ enum hl_user_interrupt_type {
  * @type: user interrupt type
  * @wait_list_head: head to the list of user threads pending on this interrupt
  * @wait_list_lock: protects wait_list_head
+ * @timestamp: last timestamp taken upon interrupt
  * @interrupt_id: msix interrupt id
  */
 struct hl_user_interrupt {
@@ -1114,6 +1115,7 @@ struct hl_user_interrupt {
 	enum hl_user_interrupt_type	type;
 	struct list_head		wait_list_head;
 	spinlock_t			wait_list_lock;
+	ktime_t				timestamp;
 	u32				interrupt_id;
 };
 

drivers/accel/habanalabs/common/irq.c

@@ -280,7 +280,6 @@ static void handle_user_interrupt(struct hl_device *hdev, struct hl_user_interru
 	struct list_head *ts_reg_free_list_head = NULL;
 	struct timestamp_reg_work_obj *job;
 	bool reg_node_handle_fail = false;
-	ktime_t now = ktime_get();
 	int rc;
 
 	/* For registration nodes:
@@ -303,13 +302,13 @@ static void handle_user_interrupt(struct hl_device *hdev, struct hl_user_interru
 			if (pend->ts_reg_info.buf) {
 				if (!reg_node_handle_fail) {
 					rc = handle_registration_node(hdev, pend,
-								&ts_reg_free_list_head, now);
+							&ts_reg_free_list_head, intr->timestamp);
 					if (rc)
 						reg_node_handle_fail = true;
 				}
 			} else {
 				/* Handle wait target value node */
-				pend->fence.timestamp = now;
+				pend->fence.timestamp = intr->timestamp;
 				complete_all(&pend->fence.completion);
 			}
 		}
@@ -335,6 +334,10 @@ static void handle_user_interrupt(struct hl_device *hdev, struct hl_user_interru
  */
 irqreturn_t hl_irq_handler_user_interrupt(int irq, void *arg)
 {
+	struct hl_user_interrupt *user_int = arg;
+
+	user_int->timestamp = ktime_get();
+
 	return IRQ_WAKE_THREAD;
 }