diff options
Diffstat (limited to 'sys/kern/subr_bus.c')
| -rw-r--r-- | sys/kern/subr_bus.c | 89 |
1 files changed, 82 insertions, 7 deletions
diff --git a/sys/kern/subr_bus.c b/sys/kern/subr_bus.c index 2964b8c..67f0918 100644 --- a/sys/kern/subr_bus.c +++ b/sys/kern/subr_bus.c @@ -46,6 +46,7 @@ __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> @@ -192,6 +193,54 @@ 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 */ @@ -364,7 +413,6 @@ 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, @@ -1061,6 +1109,7 @@ 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) @@ -1759,6 +1808,7 @@ 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 */ @@ -1857,7 +1907,7 @@ device_probe_child(device_t dev, device_t child) int result, pri = 0; int hasclass = (child->devclass != NULL); - GIANT_REQUIRED; + NBL_ASSERT(SA_XLOCKED); dc = dev->devclass; if (!dc) @@ -2508,7 +2558,7 @@ device_probe(device_t dev) { int error; - GIANT_REQUIRED; + NBL_ASSERT(SA_XLOCKED); if (dev->state >= DS_ALIVE && (dev->flags & DF_REBID) == 0) return (-1); @@ -2542,7 +2592,7 @@ device_probe_and_attach(device_t dev) { int error; - GIANT_REQUIRED; + NBL_ASSERT(SA_XLOCKED); error = device_probe(dev); if (error == -1) @@ -2576,6 +2626,8 @@ 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); @@ -2617,7 +2669,7 @@ device_detach(device_t dev) { int error; - GIANT_REQUIRED; + NBL_ASSERT(SA_XLOCKED); PDEBUG(("%s", DEVICENAME(dev))); if (dev->state == DS_BUSY) @@ -2661,6 +2713,8 @@ int device_quiesce(device_t dev) { + NBL_ASSERT(SA_XLOCKED); + PDEBUG(("%s", DEVICENAME(dev))); if (dev->state == DS_BUSY) return (EBUSY); @@ -2681,6 +2735,7 @@ device_quiesce(device_t dev) int device_shutdown(device_t dev) { + if (dev->state < DS_ATTACHED) return (0); return (DEVICE_SHUTDOWN(dev)); @@ -3096,6 +3151,8 @@ bus_generic_attach(device_t dev) { device_t child; + NBL_ASSERT(SA_XLOCKED); + TAILQ_FOREACH(child, &dev->children, link) { device_probe_and_attach(child); } @@ -3116,6 +3173,8 @@ bus_generic_detach(device_t dev) device_t child; int error; + NBL_ASSERT(SA_XLOCKED); + if (dev->state != DS_ATTACHED) return (EBUSY); @@ -3996,6 +4055,7 @@ 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"; @@ -4055,14 +4115,28 @@ 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); - error = 0; + if (bus_devclass == NULL) { + NBL_XUNLOCK(); + return (ENOMEM); + } - switch (what) { + 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; @@ -4115,6 +4189,7 @@ driver_module_handler(module_t mod, int what, void *arg) error = EOPNOTSUPP; break; } + NBL_XUNLOCK(); return (error); } |
