PERFORCE change 97407 for review

[Scott Long]

http://perforce.freebsd.org/chv.cgi?CH=97407

Change 97407 by scottl at scottl-x64 on 2006/05/18 14:48:08

	Introduce the xpt_lock and protect the fields in the xpt_softc with
	it.

Affected files ...

.. //depot/projects/scottl-camlock/src/sys/cam/cam_xpt.c#32 edit

Differences ...

==== //depot/projects/scottl-camlock/src/sys/cam/cam_xpt.c#32 (text+ko) ====

@@ -249,6 +249,8 @@
 	u_int			bus_generation;
 
 	struct intr_config_hook	*xpt_config_hook;
+
+	struct mtx		xpt_lock;
 };
 
 static const char quantum[] = "QUANTUM";
@@ -1375,6 +1377,7 @@
 	xsoftc.num_highpower = CAM_MAX_HIGHPOWER;
 
 	mtx_init(&cam_bioq_lock, "CAM BIOQ lock", NULL, MTX_DEF);
+	mtx_init(&xsoftc.xpt_lock, "XPT lock", NULL, MTX_DEF);
 
 	/*
 	 * The xpt layer is, itself, the equivelent of a SIM.
@@ -1488,7 +1491,7 @@
 		splx(s);
 	}
 
-	xsoftc.xpt_generation++;
+	atomic_add_int(&xsoftc.xpt_generation, 1);
 
 	return (status);
 }
@@ -1519,7 +1522,7 @@
 		splx(s);
 	}
 
-	xsoftc.xpt_generation++;
+	atomic_add_int(&xsoftc.xpt_generation, 1);
 
 }
 
@@ -2637,15 +2640,19 @@
 
 	retval = 1;
 
+	mtx_lock(&xsoftc.xpt_lock);
 	for (bus = (start_bus ? start_bus : TAILQ_FIRST(&xsoftc.xpt_busses));
 	     bus != NULL;
 	     bus = next_bus) {
 		next_bus = TAILQ_NEXT(bus, links);
 
+		mtx_unlock(&xsoftc.xpt_lock);
 		retval = tr_func(bus, arg);
 		if (retval == 0)
 			return(retval);
+		mtx_lock(&xsoftc.xpt_lock);
 	}
+	mtx_unlock(&xsoftc.xpt_lock);
 
 	return(retval);
 }
@@ -3895,6 +3902,7 @@
 
 		if ((work_ccb->ccb_h.flags & CAM_HIGH_POWER) != 0) {
 
+			mtx_lock(&xsoftc.xpt_lock);
 		 	if (xsoftc.num_highpower <= 0) {
 				/*
 				 * We got a high power command, but we
@@ -3916,6 +3924,7 @@
 				 */
 				xsoftc.num_highpower--;
 			}
+			mtx_unlock(&xsoftc.xpt_lock);
 		}
 		devq->active_dev = device;
 		cam_ccbq_remove_ccb(&device->ccbq, work_ccb);
@@ -4394,6 +4403,7 @@
 	new_bus->refcount = 1;	/* Held until a bus_deregister event */
 	new_bus->generation = 0;
 	s = splcam();
+	mtx_lock(&xsoftc.xpt_lock);
 	old_bus = TAILQ_FIRST(&xsoftc.xpt_busses);
 	while (old_bus != NULL
 	    && old_bus->path_id < new_bus->path_id)
@@ -4403,6 +4413,7 @@
 	else
 		TAILQ_INSERT_TAIL(&xsoftc.xpt_busses, new_bus, links);
 	xsoftc.bus_generation++;
+	mtx_unlock(&xsoftc.xpt_lock);
 	splx(s);
 
 	/* Notify interested parties */
@@ -4497,6 +4508,7 @@
 	const char *strval;
 
 	pathid = 0;
+	mtx_lock(&xsoftc.xpt_lock);
 	bus = TAILQ_FIRST(&xsoftc.xpt_busses);
 retry:
 	/* Find an unoccupied pathid */
@@ -4506,6 +4518,7 @@
 			pathid++;
 		bus = TAILQ_NEXT(bus, links);
 	}
+	mtx_unlock(&xsoftc.xpt_lock);
 
 	/*
 	 * Ensure that this pathid is not reserved for
@@ -4514,6 +4527,7 @@
 	if (resource_string_value("scbus", pathid, "at", &strval) == 0) {
 		++pathid;
 		/* Start the search over */
+		mtx_lock(&xsoftc.xpt_lock);
 		goto retry;
 	}
 	return (pathid);
@@ -4999,8 +5013,10 @@
 	s = splcam();
 	if ((--bus->refcount == 0)
 	 && (TAILQ_FIRST(&bus->et_entries) == NULL)) {
+		mtx_lock(&xsoftc.xpt_lock);
 		TAILQ_REMOVE(&xsoftc.xpt_busses, bus, links);
 		xsoftc.bus_generation++;
+		mtx_unlock(&xsoftc.xpt_lock);
 		splx(s);
 		free(bus, M_CAMXPT);
 	} else
@@ -5230,6 +5246,7 @@
 {
 	struct cam_eb *bus;
 
+	mtx_lock(&xsoftc.xpt_lock);
 	for (bus = TAILQ_FIRST(&xsoftc.xpt_busses);
 	     bus != NULL;
 	     bus = TAILQ_NEXT(bus, links)) {
@@ -5238,6 +5255,7 @@
 			break;
 		}
 	}
+	mtx_unlock(&xsoftc.xpt_lock);
 	return (bus);
 }
 
@@ -7125,6 +7143,7 @@
 			struct highpowerlist	*hphead;
 			union ccb		*send_ccb;
 
+			mtx_lock(&xsoftc.xpt_lock);
 			hphead = &xsoftc.highpowerq;
 
 			send_ccb = (union ccb *)STAILQ_FIRST(hphead);
@@ -7133,6 +7152,7 @@
 			 * Increment the count since this command is done.
 			 */
 			xsoftc.num_highpower++;
+			mtx_unlock(&xsoftc.xpt_lock);
 
 			/* 
 			 * Any high powered commands queued up?