Temporarily revert the new-bus locking for 8.0 release. It will be

reintroduced after HEAD is reopened for commits by re@.

Approved by:	re (kib), attilio

1 files changed, 6 insertions, 81 deletions

diff --git a/sys/kern/subr_bus.c b/sys/kern/subr_bus.c
index 52cd766..2964b8c 100644
--- a/sys/kern/subr_bus.c
+++ b/sys/kern/subr_bus.c
@@ -46,7 +46,6 @@ __FBSDID("$FreeBSD$");
 #include <sys/rman.h>
 #include <sys/selinfo.h>
 #include <sys/signalvar.h>
-#include <sys/sx.h>
 #include <sys/sysctl.h>
 #include <sys/systm.h>
 #include <sys/uio.h>
@@ -193,54 +192,6 @@ void print_devclass_list(void);
 #endif
 
 /*
- * Newbus locking facilities.
- */
-static struct sx newbus_lock;
-
-#define	NBL_LOCK_INIT()		sx_init(&newbus_lock, "newbus")
-#define	NBL_LOCK_DESTROY()	sx_destroy(&newbus_lock)
-#define	NBL_XLOCK()		sx_xlock(&newbus_lock)
-#define	NBL_SLOCK()		sx_slock(&newbus_lock)
-#define	NBL_XUNLOCK()		sx_xunlock(&newbus_lock)
-#define	NBL_SUNLOCK()		sx_sunlock(&newbus_lock)
-#ifdef INVARIANTS
-#define	NBL_ASSERT(what) do {						\
-	if (cold == 0)							\
-		sx_assert(&newbus_lock, (what));			\
-} while (0)
-#else
-#define	NBL_ASSERT(what)
-#endif
-
-void
-newbus_xlock()
-{
-
-	NBL_XLOCK();
-}
-
-void
-newbus_slock()
-{
-
-	NBL_SLOCK();
-}
-
-void
-newbus_xunlock()
-{
-
-	NBL_XUNLOCK();
-}
-
-void
-newbus_sunlock()
-{
-
-	NBL_SUNLOCK();
-}
-
-/*
  * dev sysctl tree
  */
 
@@ -413,6 +364,7 @@ static d_poll_t		devpoll;
 
 static struct cdevsw dev_cdevsw = {
 	.d_version =	D_VERSION,
+	.d_flags =	D_NEEDGIANT,
 	.d_open =	devopen,
 	.d_close =	devclose,
 	.d_read =	devread,
@@ -1109,7 +1061,6 @@ devclass_delete_driver(devclass_t busclass, driver_t *driver)
 	int i;
 	int error;
 
-	NBL_ASSERT(SA_XLOCKED);
 	PDEBUG(("%s from devclass %s", driver->name, DEVCLANAME(busclass)));
 
 	if (!dc)
@@ -1808,7 +1759,6 @@ device_delete_child(device_t dev, device_t child)
 	int error;
 	device_t grandchild;
 
-	NBL_ASSERT(SA_XLOCKED);
 	PDEBUG(("%s from %s", DEVICENAME(child), DEVICENAME(dev)));
 
 	/* remove children first */
@@ -1907,7 +1857,7 @@ device_probe_child(device_t dev, device_t child)
 	int result, pri = 0;
 	int hasclass = (child->devclass != NULL);
 
-	NBL_ASSERT(SA_XLOCKED);
+	GIANT_REQUIRED;
 
 	dc = dev->devclass;
 	if (!dc)
@@ -2558,7 +2508,7 @@ device_probe(device_t dev)
 {
 	int error;
 
-	NBL_ASSERT(SA_XLOCKED);
+	GIANT_REQUIRED;
 
 	if (dev->state >= DS_ALIVE && (dev->flags & DF_REBID) == 0)
 		return (-1);
@@ -2592,7 +2542,7 @@ device_probe_and_attach(device_t dev)
 {
 	int error;
 
-	NBL_ASSERT(SA_XLOCKED);
+	GIANT_REQUIRED;
 
 	error = device_probe(dev);
 	if (error == -1)
@@ -2626,8 +2576,6 @@ device_attach(device_t dev)
 {
 	int error;
 
-	NBL_ASSERT(SA_XLOCKED);
-
 	device_sysctl_init(dev);
 	if (!device_is_quiet(dev))
 		device_print_child(dev->parent, dev);
@@ -2669,7 +2617,7 @@ device_detach(device_t dev)
 {
 	int error;
 
-	NBL_ASSERT(SA_XLOCKED);
+	GIANT_REQUIRED;
 
 	PDEBUG(("%s", DEVICENAME(dev)));
 	if (dev->state == DS_BUSY)
@@ -2713,8 +2661,6 @@ int
 device_quiesce(device_t dev)
 {
 
-	NBL_ASSERT(SA_XLOCKED);
-
 	PDEBUG(("%s", DEVICENAME(dev)));
 	if (dev->state == DS_BUSY)
 		return (EBUSY);
@@ -2735,7 +2681,6 @@ device_quiesce(device_t dev)
 int
 device_shutdown(device_t dev)
 {
-
 	if (dev->state < DS_ATTACHED)
 		return (0);
 	return (DEVICE_SHUTDOWN(dev));
@@ -3151,8 +3096,6 @@ bus_generic_attach(device_t dev)
 {
 	device_t child;
 
-	NBL_ASSERT(SA_XLOCKED);
-
 	TAILQ_FOREACH(child, &dev->children, link) {
 		device_probe_and_attach(child);
 	}
@@ -3173,8 +3116,6 @@ bus_generic_detach(device_t dev)
 	device_t child;
 	int error;
 
-	NBL_ASSERT(SA_XLOCKED);
-
 	if (dev->state != DS_ATTACHED)
 		return (EBUSY);
 
@@ -4055,7 +3996,6 @@ root_bus_module_handler(module_t mod, int what, void* arg)
 	switch (what) {
 	case MOD_LOAD:
 		TAILQ_INIT(&bus_data_devices);
-		NBL_LOCK_INIT();
 		kobj_class_compile((kobj_class_t) &root_driver);
 		root_bus = make_device(NULL, "root", 0);
 		root_bus->desc = "System root bus";
@@ -4115,28 +4055,14 @@ driver_module_handler(module_t mod, int what, void *arg)
 	kobj_class_t driver;
 	int error, pass;
 
-	error = 0;
 	dmd = (struct driver_module_data *)arg;
-
-	/*
-	 * If MOD_SHUTDOWN is passed, return immediately in order to
-	 * avoid unnecessary locking and a LOR with the modules sx lock.
-	 */
-	if (what == MOD_SHUTDOWN)
-		return (EOPNOTSUPP);
-	NBL_XLOCK();
 	bus_devclass = devclass_find_internal(dmd->dmd_busname, NULL, TRUE);
-	if (bus_devclass == NULL) {
-		NBL_XUNLOCK();
-		return (ENOMEM);
-	}
+	error = 0;
 
 	switch (what) {
 	case MOD_LOAD:
 		if (dmd->dmd_chainevh)
 			error = dmd->dmd_chainevh(mod,what,dmd->dmd_chainarg);
-		if (error != 0)
-			break;
 
 		pass = dmd->dmd_pass;
 		driver = dmd->dmd_driver;
@@ -4189,7 +4115,6 @@ driver_module_handler(module_t mod, int what, void *arg)
 		error = EOPNOTSUPP;
 		break;
 	}
-	NBL_XUNLOCK();
 
 	return (error);
 }