Introduce a new taskqueue that runs completely free of Giant, and in

turns runs its tasks free of Giant too.  It is intended that as drivers
become locked down, they will move out of the old, Giant-bound taskqueue
and into this new one.  The old taskqueue has been renamed to
taskqueue_swi_giant, and the new one keeps the name taskqueue_swi.

sys/dev/aac/aac.c

@@ -660,7 +660,7 @@ aac_intr(void *arg)
 	/* It's not ok to return here because of races with the previous step */
 	if (reason & AAC_DB_RESPONSE_READY)
 		/* handle completion processing */
-		taskqueue_enqueue(taskqueue_swi, &sc->aac_task_complete);
+		taskqueue_enqueue(taskqueue_swi_giant, &sc->aac_task_complete);
 
 	/* controller wants to talk to the log */
 	if (reason & AAC_DB_PRINTF) {

sys/dev/amr/amr.c

@@ -1370,7 +1370,7 @@ amr_done(struct amr_softc *sc)
     /* handle completion and timeouts */
 #if __FreeBSD_version >= 500005
     if (sc->amr_state & AMR_STATE_INTEN) 
-	taskqueue_enqueue(taskqueue_swi, &sc->amr_task_complete);
+	taskqueue_enqueue(taskqueue_swi_giant, &sc->amr_task_complete);
     else
 #endif
 	amr_complete(sc, 0);

sys/dev/mly/mly.c

@@ -1610,7 +1610,7 @@ mly_done(struct mly_softc *sc)
     if (worked) {
 #if __FreeBSD_version >= 500005
 	if (sc->mly_state & MLY_STATE_INTERRUPTS_ON)
-	    taskqueue_enqueue(taskqueue_swi, &sc->mly_task_complete);
+	    taskqueue_enqueue(taskqueue_swi_giant, &sc->mly_task_complete);
 	else
 #endif
 	    mly_complete(sc, 0);

sys/kern/subr_taskqueue.c

@@ -41,6 +41,7 @@ static MALLOC_DEFINE(M_TASKQUEUE, "taskqueue", "Task Queues");
 static STAILQ_HEAD(taskqueue_list, taskqueue) taskqueue_queues;
 
 static void	*taskqueue_ih;
+static void	*taskqueue_giant_ih;
 static struct mtx taskqueue_queues_mutex;
 
 struct taskqueue {
@@ -219,6 +220,22 @@ taskqueue_swi_run(void *dummy)
 	taskqueue_run(taskqueue_swi);
 }
 
+static void
+taskqueue_swi_giant_enqueue(void *context)
+{
+	swi_sched(taskqueue_giant_ih, 0);
+}
+
+static void
+taskqueue_swi_giant_run(void *dummy)
+{
+	taskqueue_run(taskqueue_swi_giant);
+}
+
 TASKQUEUE_DEFINE(swi, taskqueue_swi_enqueue, 0,
-		 swi_add(NULL, "task queue", taskqueue_swi_run, NULL, SWI_TQ, 0,
-		     &taskqueue_ih)); 
+		 swi_add(NULL, "task queue", taskqueue_swi_run, NULL, SWI_TQ,
+		     INTR_MPSAFE, &taskqueue_ih)); 
+
+TASKQUEUE_DEFINE(swi_giant, taskqueue_swi_giant_enqueue, 0,
+		 swi_add(NULL, "Giant task queue", taskqueue_swi_giant_run,
+		     NULL, SWI_TQ_GIANT, 0, &taskqueue_giant_ih)); 

sys/modules/aac/Makefile

@@ -12,5 +12,6 @@ SRCS+=	device_if.h bus_if.h pci_if.h
 # To enable debug output from the driver, uncomment these two lines.
 #CFLAGS+= -DAAC_DEBUG=2
 #SRCS+=	aac_debug.c
+CFLAGS+= -g
 
 .include <bsd.kmod.mk>

sys/netgraph/bluetooth/socket/ng_btsocket_hci_raw.c

@@ -251,7 +251,7 @@ ng_btsocket_hci_raw_node_rcvmsg(node_p node, item_p item, hook_p lasthook)
 			error = ENOBUFS;
 		} else {
 			NG_BT_ITEMQ_ENQUEUE(&ng_btsocket_hci_raw_queue, item);
-			error = taskqueue_enqueue(taskqueue_swi,
+			error = taskqueue_enqueue(taskqueue_swi_giant,
 						&ng_btsocket_hci_raw_task);
 		}
 		mtx_unlock(&ng_btsocket_hci_raw_queue_mtx);
@@ -300,7 +300,7 @@ ng_btsocket_hci_raw_node_rcvdata(hook_p hook, item_p item)
 			error = ENOBUFS;
 		} else {
 			NG_BT_ITEMQ_ENQUEUE(&ng_btsocket_hci_raw_queue, item);
-			error = taskqueue_enqueue(taskqueue_swi,
+			error = taskqueue_enqueue(taskqueue_swi_giant,
 						&ng_btsocket_hci_raw_task);
 		}
 		mtx_unlock(&ng_btsocket_hci_raw_queue_mtx);

sys/netgraph/bluetooth/socket/ng_btsocket_l2cap.c

@@ -309,7 +309,7 @@ ng_btsocket_l2cap_node_disconnect(hook_p hook)
 	 */
 
 	if (NG_HOOK_PRIVATE(hook) != NULL)
-		return (taskqueue_enqueue(taskqueue_swi, 
+		return (taskqueue_enqueue(taskqueue_swi_giant, 
 				&ng_btsocket_l2cap_rt_task));
 
 	NG_HOOK_UNREF(hook); /* Remove extra reference */
@@ -343,7 +343,7 @@ ng_btsocket_l2cap_node_rcvmsg(node_p node, item_p item, hook_p hook)
 			}
 
 			NG_BT_ITEMQ_ENQUEUE(&ng_btsocket_l2cap_queue, item);
-			error = taskqueue_enqueue(taskqueue_swi,
+			error = taskqueue_enqueue(taskqueue_swi_giant,
 						&ng_btsocket_l2cap_queue_task);
 		}
 		mtx_unlock(&ng_btsocket_l2cap_queue_mtx);
@@ -377,7 +377,7 @@ ng_btsocket_l2cap_node_rcvdata(hook_p hook, item_p item)
 		NGI_SET_HOOK(item, hook);
 
 		NG_BT_ITEMQ_ENQUEUE(&ng_btsocket_l2cap_queue, item);
-		error = taskqueue_enqueue(taskqueue_swi,
+		error = taskqueue_enqueue(taskqueue_swi_giant,
 						&ng_btsocket_l2cap_queue_task);
 	}
 	mtx_unlock(&ng_btsocket_l2cap_queue_mtx);

sys/netgraph/bluetooth/socket/ng_btsocket_l2cap_raw.c

@@ -242,7 +242,7 @@ ng_btsocket_l2cap_raw_node_disconnect(hook_p hook)
 	 */
 
 	if (NG_HOOK_PRIVATE(hook) != NULL)
-		return (taskqueue_enqueue(taskqueue_swi, 
+		return (taskqueue_enqueue(taskqueue_swi_giant, 
 				&ng_btsocket_l2cap_raw_rt_task));
 
 	NG_HOOK_UNREF(hook); /* Remove extra reference */
@@ -276,7 +276,7 @@ ng_btsocket_l2cap_raw_node_rcvmsg(node_p node, item_p item, hook_p hook)
 			}
 
 			NG_BT_ITEMQ_ENQUEUE(&ng_btsocket_l2cap_raw_queue, item);
-			error = taskqueue_enqueue(taskqueue_swi,
+			error = taskqueue_enqueue(taskqueue_swi_giant,
 					&ng_btsocket_l2cap_raw_queue_task);
 		}
 		mtx_unlock(&ng_btsocket_l2cap_raw_queue_mtx);

sys/sys/interrupt.h

@@ -94,8 +94,9 @@ struct ithd {
 #define	SWI_CAMNET	2
 #define	SWI_CAMBIO	3
 #define	SWI_VM		4
-#define	SWI_TQ		5
-#define	SWI_CLOCK	6
+#define	SWI_TQ_GIANT	5
+#define	SWI_TQ		6
+#define	SWI_CLOCK	7
 
 extern struct	ithd *tty_ithd;
 extern struct	ithd *clk_ithd;

sys/sys/taskqueue.h

@@ -110,6 +110,7 @@ struct __hack
  * This queue is serviced by a software interrupt handler.  To enqueue
  * a task, call taskqueue_enqueue(taskqueue_swi, &task).
  */
+TASKQUEUE_DECLARE(swi_giant);
 TASKQUEUE_DECLARE(swi);
 
 #endif /* !_SYS_TASKQUEUE_H_ */