Create xpt_sim_poll and refactor a bit using it.

xpt_sim_poll takes the sim to poll as an argument. It will do the
proper locking protocol, call the SIM polling routine, and then call
camisr_runqueue to process completions on any CCBs the SIM's poll
routine completed. It will be used during late shutdown when a SIM is
waiting for CCBs it sent during shutdown to finish and the scheduler
isn't running because we've panic'd.

This sequence was used twice in cam_xpt, so refactor those to use this
new function.

Sponsored by: Netflix
Differential Review: https://reviews.freebsd.org/D16663

1 files changed, 21 insertions, 19 deletions

diff --git a/sys/cam/cam_xpt.c b/sys/cam/cam_xpt.c
index a1b3016c7695..3ce61e7f6198 100644
--- a/sys/cam/cam_xpt.c
+++ b/sys/cam/cam_xpt.c
@@ -3198,6 +3198,25 @@ call_sim:
 		start_ccb->ccb_h.status));
 }
 
+/*
+ * Call the sim poll routine to allow the sim to complete
+ * any inflight requests, then call camisr_runqueue to
+ * complete any CCB that the polling completed.
+ */
+void
+xpt_sim_poll(struct cam_sim *sim)
+{
+	struct mtx *mtx;
+
+	mtx = sim->mtx;
+	if (mtx)
+		mtx_lock(mtx);
+	(*(sim->sim_poll))(sim);
+	if (mtx)
+		mtx_unlock(mtx);
+	camisr_runqueue();
+}
+
 uint32_t
 xpt_poll_setup(union ccb *start_ccb)
 {
@@ -3205,12 +3224,10 @@ xpt_poll_setup(union ccb *start_ccb)
 	struct	  cam_sim *sim;
 	struct	  cam_devq *devq;
 	struct	  cam_ed *dev;
-	struct mtx *mtx;
 
 	timeout = start_ccb->ccb_h.timeout * 10;
 	sim = start_ccb->ccb_h.path->bus->sim;
 	devq = sim->devq;
-	mtx = sim->mtx;
 	dev = start_ccb->ccb_h.path->device;
 
 	/*
@@ -3223,12 +3240,7 @@ xpt_poll_setup(union ccb *start_ccb)
 	    (--timeout > 0)) {
 		mtx_unlock(&devq->send_mtx);
 		DELAY(100);
-		if (mtx)
-			mtx_lock(mtx);
-		(*(sim->sim_poll))(sim);
-		if (mtx)
-			mtx_unlock(mtx);
-		camisr_runqueue();
+		xpt_sim_poll(sim);
 		mtx_lock(&devq->send_mtx);
 	}
 	dev->ccbq.dev_openings++;
@@ -3240,19 +3252,9 @@ xpt_poll_setup(union ccb *start_ccb)
 void
 xpt_pollwait(union ccb *start_ccb, uint32_t timeout)
 {
-	struct cam_sim	*sim;
-	struct mtx	*mtx;
-
-	sim = start_ccb->ccb_h.path->bus->sim;
-	mtx = sim->mtx;
 
 	while (--timeout > 0) {
-		if (mtx)
-			mtx_lock(mtx);
-		(*(sim->sim_poll))(sim);
-		if (mtx)
-			mtx_unlock(mtx);
-		camisr_runqueue();
+		xpt_sim_poll(start_ccb->ccb_h.path->bus->sim);
 		if ((start_ccb->ccb_h.status & CAM_STATUS_MASK)
 		    != CAM_REQ_INPROG)
 			break;