From 4a0c20bf8c0fe2116f8fd7d3da6122bf8a01f026 Mon Sep 17 00:00:00 2001 From: Dmitry Torokhov Date: Fri, 29 Apr 2005 01:23:47 -0500 Subject: [PATCH] sysfs: (driver/base) if show/store is missing return -EIO sysfs: fix drivers/base so if an attribute doesn't implement show or store method read/write will return -EIO instead of 0. Signed-off-by: Dmitry Torokhov Signed-off-by: Greg Kroah-Hartman --- drivers/base/bus.c | 4 ++-- 1 file changed, 2 insertions(+), 2 deletions(-) (limited to 'drivers/base/bus.c') diff --git a/drivers/base/bus.c b/drivers/base/bus.c index 3cb04bb04c2..80ce88de56f 100644 --- a/drivers/base/bus.c +++ b/drivers/base/bus.c @@ -36,7 +36,7 @@ drv_attr_show(struct kobject * kobj, struct attribute * attr, char * buf) { struct driver_attribute * drv_attr = to_drv_attr(attr); struct device_driver * drv = to_driver(kobj); - ssize_t ret = 0; + ssize_t ret = -EIO; if (drv_attr->show) ret = drv_attr->show(drv, buf); @@ -49,7 +49,7 @@ drv_attr_store(struct kobject * kobj, struct attribute * attr, { struct driver_attribute * drv_attr = to_drv_attr(attr); struct device_driver * drv = to_driver(kobj); - ssize_t ret = 0; + ssize_t ret = -EIO; if (drv_attr->store) ret = drv_attr->store(drv, buf, count); -- cgit From af70316af182f4716cc5eec7e0d27fc731d164bd Mon Sep 17 00:00:00 2001 From: "mochel@digitalimplant.org" Date: Mon, 21 Mar 2005 10:41:04 -0800 Subject: [PATCH] Add a semaphore to struct device to synchronize calls to its driver. This adds a per-device semaphore that is taken before every call from the core to a driver method. This prevents e.g. simultaneous calls to the ->suspend() or ->resume() and ->probe() or ->release(), potentially saving a whole lot of headaches. It also moves us a step closer to removing the bus rwsem, since it protects the fields in struct device that are modified by the core. Signed-off-by: Patrick Mochel Signed-off-by: Greg Kroah-Hartman --- drivers/base/bus.c | 14 +++++++++++--- 1 file changed, 11 insertions(+), 3 deletions(-) (limited to 'drivers/base/bus.c') diff --git a/drivers/base/bus.c b/drivers/base/bus.c index 80ce88de56f..aa27f76d28c 100644 --- a/drivers/base/bus.c +++ b/drivers/base/bus.c @@ -283,18 +283,22 @@ void device_bind_driver(struct device * dev) */ int driver_probe_device(struct device_driver * drv, struct device * dev) { + int error = 0; + if (drv->bus->match && !drv->bus->match(dev, drv)) return -ENODEV; + down(&dev->sem); dev->driver = drv; if (drv->probe) { - int error = drv->probe(dev); + error = drv->probe(dev); if (error) { dev->driver = NULL; + up(&dev->sem); return error; } } - + up(&dev->sem); device_bind_driver(dev); return 0; } @@ -385,7 +389,10 @@ void driver_attach(struct device_driver * drv) void device_release_driver(struct device * dev) { - struct device_driver * drv = dev->driver; + struct device_driver * drv; + + down(&dev->sem); + drv = dev->driver; if (drv) { sysfs_remove_link(&drv->kobj, kobject_name(&dev->kobj)); sysfs_remove_link(&dev->kobj, "driver"); @@ -394,6 +401,7 @@ void device_release_driver(struct device * dev) drv->remove(dev); dev->driver = NULL; } + up(&dev->sem); } -- cgit From 07e4a3e27fe414980ddc85a358e5a56abc48b363 Mon Sep 17 00:00:00 2001 From: "mochel@digitalimplant.org" Date: Mon, 21 Mar 2005 10:52:54 -0800 Subject: [PATCH] Move device/driver code to drivers/base/dd.c This relocates the driver binding/unbinding code to drivers/base/dd.c. This is done for two reasons: One, it's not code related to the bus_type itself; it uses some from that, some from devices, and some from drivers. And Two, it will make it easier to do some of the upcoming lock removal on that code.. Signed-off-by: Patrick Mochel Signed-off-by: Greg Kroah-Hartman --- drivers/base/bus.c | 182 ----------------------------------------------------- 1 file changed, 182 deletions(-) (limited to 'drivers/base/bus.c') diff --git a/drivers/base/bus.c b/drivers/base/bus.c index aa27f76d28c..1b05c1399e3 100644 --- a/drivers/base/bus.c +++ b/drivers/base/bus.c @@ -18,7 +18,6 @@ #include "power/power.h" #define to_dev(node) container_of(node, struct device, bus_list) -#define to_drv(node) container_of(node, struct device_driver, kobj.entry) #define to_bus_attr(_attr) container_of(_attr, struct bus_attribute, attr) #define to_bus(obj) container_of(obj, struct bus_type, subsys.kset.kobj) @@ -243,181 +242,6 @@ int bus_for_each_drv(struct bus_type * bus, struct device_driver * start, return ret; } -/** - * device_bind_driver - bind a driver to one device. - * @dev: device. - * - * Allow manual attachment of a driver to a device. - * Caller must have already set @dev->driver. - * - * Note that this does not modify the bus reference count - * nor take the bus's rwsem. Please verify those are accounted - * for before calling this. (It is ok to call with no other effort - * from a driver's probe() method.) - */ - -void device_bind_driver(struct device * dev) -{ - pr_debug("bound device '%s' to driver '%s'\n", - dev->bus_id, dev->driver->name); - list_add_tail(&dev->driver_list, &dev->driver->devices); - sysfs_create_link(&dev->driver->kobj, &dev->kobj, - kobject_name(&dev->kobj)); - sysfs_create_link(&dev->kobj, &dev->driver->kobj, "driver"); -} - - -/** - * driver_probe_device - attempt to bind device & driver. - * @drv: driver. - * @dev: device. - * - * First, we call the bus's match function, if one present, which - * should compare the device IDs the driver supports with the - * device IDs of the device. Note we don't do this ourselves - * because we don't know the format of the ID structures, nor what - * is to be considered a match and what is not. - * - * If we find a match, we call @drv->probe(@dev) if it exists, and - * call device_bind_driver() above. - */ -int driver_probe_device(struct device_driver * drv, struct device * dev) -{ - int error = 0; - - if (drv->bus->match && !drv->bus->match(dev, drv)) - return -ENODEV; - - down(&dev->sem); - dev->driver = drv; - if (drv->probe) { - error = drv->probe(dev); - if (error) { - dev->driver = NULL; - up(&dev->sem); - return error; - } - } - up(&dev->sem); - device_bind_driver(dev); - return 0; -} - - -/** - * device_attach - try to attach device to a driver. - * @dev: device. - * - * Walk the list of drivers that the bus has and call - * driver_probe_device() for each pair. If a compatible - * pair is found, break out and return. - */ -int device_attach(struct device * dev) -{ - struct bus_type * bus = dev->bus; - struct list_head * entry; - int error; - - if (dev->driver) { - device_bind_driver(dev); - return 1; - } - - if (bus->match) { - list_for_each(entry, &bus->drivers.list) { - struct device_driver * drv = to_drv(entry); - error = driver_probe_device(drv, dev); - if (!error) - /* success, driver matched */ - return 1; - if (error != -ENODEV && error != -ENXIO) - /* driver matched but the probe failed */ - printk(KERN_WARNING - "%s: probe of %s failed with error %d\n", - drv->name, dev->bus_id, error); - } - } - - return 0; -} - - -/** - * driver_attach - try to bind driver to devices. - * @drv: driver. - * - * Walk the list of devices that the bus has on it and try to - * match the driver with each one. If driver_probe_device() - * returns 0 and the @dev->driver is set, we've found a - * compatible pair. - * - * Note that we ignore the -ENODEV error from driver_probe_device(), - * since it's perfectly valid for a driver not to bind to any devices. - */ -void driver_attach(struct device_driver * drv) -{ - struct bus_type * bus = drv->bus; - struct list_head * entry; - int error; - - if (!bus->match) - return; - - list_for_each(entry, &bus->devices.list) { - struct device * dev = container_of(entry, struct device, bus_list); - if (!dev->driver) { - error = driver_probe_device(drv, dev); - if (error && (error != -ENODEV)) - /* driver matched but the probe failed */ - printk(KERN_WARNING - "%s: probe of %s failed with error %d\n", - drv->name, dev->bus_id, error); - } - } -} - - -/** - * device_release_driver - manually detach device from driver. - * @dev: device. - * - * Manually detach device from driver. - * Note that this is called without incrementing the bus - * reference count nor taking the bus's rwsem. Be sure that - * those are accounted for before calling this function. - */ - -void device_release_driver(struct device * dev) -{ - struct device_driver * drv; - - down(&dev->sem); - drv = dev->driver; - if (drv) { - sysfs_remove_link(&drv->kobj, kobject_name(&dev->kobj)); - sysfs_remove_link(&dev->kobj, "driver"); - list_del_init(&dev->driver_list); - if (drv->remove) - drv->remove(dev); - dev->driver = NULL; - } - up(&dev->sem); -} - - -/** - * driver_detach - detach driver from all devices it controls. - * @drv: driver. - */ - -static void driver_detach(struct device_driver * drv) -{ - while (!list_empty(&drv->devices)) { - struct device * dev = container_of(drv->devices.next, struct device, driver_list); - device_release_driver(dev); - } -} - static int device_add_attrs(struct bus_type * bus, struct device * dev) { int error = 0; @@ -757,12 +581,6 @@ int __init buses_init(void) EXPORT_SYMBOL_GPL(bus_for_each_dev); EXPORT_SYMBOL_GPL(bus_for_each_drv); -EXPORT_SYMBOL_GPL(driver_probe_device); -EXPORT_SYMBOL_GPL(device_bind_driver); -EXPORT_SYMBOL_GPL(device_release_driver); -EXPORT_SYMBOL_GPL(device_attach); -EXPORT_SYMBOL_GPL(driver_attach); - EXPORT_SYMBOL_GPL(bus_add_device); EXPORT_SYMBOL_GPL(bus_remove_device); EXPORT_SYMBOL_GPL(bus_register); -- cgit From 465c7a3a3a5aabcedd2e43612cac5a12f23da19a Mon Sep 17 00:00:00 2001 From: "mochel@digitalimplant.org" Date: Mon, 21 Mar 2005 11:49:14 -0800 Subject: [PATCH] Add a klist to struct bus_type for its devices. - Use it for bus_for_each_dev(). - Use the klist spinlock instead of the bus rwsem. Signed-off-by: Patrick Mochel Signed-off-by: Greg Kroah-Hartman --- drivers/base/bus.c | 54 ++++++++++++++++++++++++------------------------------ 1 file changed, 24 insertions(+), 30 deletions(-) (limited to 'drivers/base/bus.c') diff --git a/drivers/base/bus.c b/drivers/base/bus.c index 1b05c1399e3..c8da37230b3 100644 --- a/drivers/base/bus.c +++ b/drivers/base/bus.c @@ -134,28 +134,6 @@ static struct kobj_type ktype_bus = { decl_subsys(bus, &ktype_bus, NULL); -static int __bus_for_each_dev(struct bus_type *bus, struct device *start, - void *data, int (*fn)(struct device *, void *)) -{ - struct list_head *head; - struct device *dev; - int error = 0; - - if (!(bus = get_bus(bus))) - return -EINVAL; - - head = &bus->devices.list; - dev = list_prepare_entry(start, head, bus_list); - list_for_each_entry_continue(dev, head, bus_list) { - get_device(dev); - error = fn(dev, data); - put_device(dev); - if (error) - break; - } - put_bus(bus); - return error; -} static int __bus_for_each_drv(struct bus_type *bus, struct device_driver *start, void * data, int (*fn)(struct device_driver *, void *)) @@ -180,6 +158,13 @@ static int __bus_for_each_drv(struct bus_type *bus, struct device_driver *start, return error; } + +static struct device * next_device(struct klist_iter * i) +{ + struct klist_node * n = klist_next(i); + return n ? container_of(n, struct device, knode_bus) : NULL; +} + /** * bus_for_each_dev - device iterator. * @bus: bus type. @@ -203,12 +188,19 @@ static int __bus_for_each_drv(struct bus_type *bus, struct device_driver *start, int bus_for_each_dev(struct bus_type * bus, struct device * start, void * data, int (*fn)(struct device *, void *)) { - int ret; + struct klist_iter i; + struct device * dev; + int error = 0; - down_read(&bus->subsys.rwsem); - ret = __bus_for_each_dev(bus, start, data, fn); - up_read(&bus->subsys.rwsem); - return ret; + if (!bus) + return -EINVAL; + + klist_iter_init_node(&bus->klist_devices, &i, + (start ? &start->knode_bus : NULL)); + while ((dev = next_device(&i)) && !error) + error = fn(dev, data); + klist_iter_exit(&i); + return error; } /** @@ -293,6 +285,7 @@ int bus_add_device(struct device * dev) list_add_tail(&dev->bus_list, &dev->bus->devices.list); device_attach(dev); up_write(&dev->bus->subsys.rwsem); + klist_add_tail(&bus->klist_devices, &dev->knode_bus); device_add_attrs(bus, dev); sysfs_create_link(&bus->devices.kobj, &dev->kobj, dev->bus_id); sysfs_create_link(&dev->kobj, &dev->bus->subsys.kset.kobj, "bus"); @@ -315,6 +308,7 @@ void bus_remove_device(struct device * dev) sysfs_remove_link(&dev->kobj, "bus"); sysfs_remove_link(&dev->bus->devices.kobj, dev->bus_id); device_remove_attrs(dev->bus, dev); + klist_remove(&dev->knode_bus); down_write(&dev->bus->subsys.rwsem); pr_debug("bus %s: remove device %s\n", dev->bus->name, dev->bus_id); device_release_driver(dev); @@ -439,9 +433,7 @@ int bus_rescan_devices(struct bus_type * bus) { int count = 0; - down_write(&bus->subsys.rwsem); - __bus_for_each_dev(bus, NULL, &count, bus_rescan_devices_helper); - up_write(&bus->subsys.rwsem); + bus_for_each_dev(bus, NULL, &count, bus_rescan_devices_helper); return count; } @@ -542,6 +534,8 @@ int bus_register(struct bus_type * bus) retval = kset_register(&bus->drivers); if (retval) goto bus_drivers_fail; + + klist_init(&bus->klist_devices); bus_add_attrs(bus); pr_debug("bus type '%s' registered\n", bus->name); -- cgit From 38fdac3cdce276554b4484a41f8ec2daf81cb2ff Mon Sep 17 00:00:00 2001 From: "mochel@digitalimplant.org" Date: Mon, 21 Mar 2005 12:00:18 -0800 Subject: [PATCH] Add a klist to struct bus_type for its drivers. - Use it in bus_for_each_drv(). - Use the klist spinlock instead of the bus rwsem. Signed-off-by: Patrick Mochel Signed-off-by: Greg Kroah-Hartman --- drivers/base/bus.c | 52 +++++++++++++++++++++++----------------------------- 1 file changed, 23 insertions(+), 29 deletions(-) (limited to 'drivers/base/bus.c') diff --git a/drivers/base/bus.c b/drivers/base/bus.c index c8da37230b3..736dc1f5a31 100644 --- a/drivers/base/bus.c +++ b/drivers/base/bus.c @@ -135,30 +135,6 @@ static struct kobj_type ktype_bus = { decl_subsys(bus, &ktype_bus, NULL); -static int __bus_for_each_drv(struct bus_type *bus, struct device_driver *start, - void * data, int (*fn)(struct device_driver *, void *)) -{ - struct list_head *head; - struct device_driver *drv; - int error = 0; - - if (!(bus = get_bus(bus))) - return -EINVAL; - - head = &bus->drivers.list; - drv = list_prepare_entry(start, head, kobj.entry); - list_for_each_entry_continue(drv, head, kobj.entry) { - get_driver(drv); - error = fn(drv, data); - put_driver(drv); - if (error) - break; - } - put_bus(bus); - return error; -} - - static struct device * next_device(struct klist_iter * i) { struct klist_node * n = klist_next(i); @@ -203,6 +179,14 @@ int bus_for_each_dev(struct bus_type * bus, struct device * start, return error; } + + +static struct device_driver * next_driver(struct klist_iter * i) +{ + struct klist_node * n = klist_next(i); + return n ? container_of(n, struct device_driver, knode_bus) : NULL; +} + /** * bus_for_each_drv - driver iterator * @bus: bus we're dealing with. @@ -226,12 +210,19 @@ int bus_for_each_dev(struct bus_type * bus, struct device * start, int bus_for_each_drv(struct bus_type * bus, struct device_driver * start, void * data, int (*fn)(struct device_driver *, void *)) { - int ret; + struct klist_iter i; + struct device_driver * drv; + int error = 0; - down_read(&bus->subsys.rwsem); - ret = __bus_for_each_drv(bus, start, data, fn); - up_read(&bus->subsys.rwsem); - return ret; + if (!bus) + return -EINVAL; + + klist_iter_init_node(&bus->klist_drivers, &i, + start ? &start->knode_bus : NULL); + while ((drv = next_driver(&i)) && !error) + error = fn(drv, data); + klist_iter_exit(&i); + return error; } static int device_add_attrs(struct bus_type * bus, struct device * dev) @@ -376,6 +367,7 @@ int bus_add_driver(struct device_driver * drv) down_write(&bus->subsys.rwsem); driver_attach(drv); up_write(&bus->subsys.rwsem); + klist_add_tail(&bus->klist_drivers, &drv->knode_bus); module_add_driver(drv->owner, drv); driver_add_attrs(bus, drv); @@ -397,6 +389,7 @@ void bus_remove_driver(struct device_driver * drv) { if (drv->bus) { driver_remove_attrs(drv->bus, drv); + klist_remove(&drv->knode_bus); down_write(&drv->bus->subsys.rwsem); pr_debug("bus %s: remove driver %s\n", drv->bus->name, drv->name); driver_detach(drv); @@ -536,6 +529,7 @@ int bus_register(struct bus_type * bus) goto bus_drivers_fail; klist_init(&bus->klist_devices); + klist_init(&bus->klist_drivers); bus_add_attrs(bus); pr_debug("bus type '%s' registered\n", bus->name); -- cgit From 6eded061b1263847aedac7469339e99579aec5e5 Mon Sep 17 00:00:00 2001 From: "mochel@digitalimplant.org" Date: Thu, 24 Mar 2005 13:02:28 -0800 Subject: [PATCH] Fix up bus code and remove use of rwsem. - Don't add devices to bus's embedded kset, since it's not used by anyone anymore. - Don't need to take the bus rwsem when calling {device,driver}_attach(), since those functions use the klists and the klists' spinlocks. Signed-off-by: Patrick Mochel Signed-off-by: Greg Kroah-Hartman --- drivers/base/bus.c | 12 ------------ 1 file changed, 12 deletions(-) (limited to 'drivers/base/bus.c') diff --git a/drivers/base/bus.c b/drivers/base/bus.c index 736dc1f5a31..4eb19525e06 100644 --- a/drivers/base/bus.c +++ b/drivers/base/bus.c @@ -17,8 +17,6 @@ #include "base.h" #include "power/power.h" -#define to_dev(node) container_of(node, struct device, bus_list) - #define to_bus_attr(_attr) container_of(_attr, struct bus_attribute, attr) #define to_bus(obj) container_of(obj, struct bus_type, subsys.kset.kobj) @@ -271,11 +269,8 @@ int bus_add_device(struct device * dev) int error = 0; if (bus) { - down_write(&dev->bus->subsys.rwsem); pr_debug("bus %s: add device %s\n", bus->name, dev->bus_id); - list_add_tail(&dev->bus_list, &dev->bus->devices.list); device_attach(dev); - up_write(&dev->bus->subsys.rwsem); klist_add_tail(&bus->klist_devices, &dev->knode_bus); device_add_attrs(bus, dev); sysfs_create_link(&bus->devices.kobj, &dev->kobj, dev->bus_id); @@ -300,11 +295,8 @@ void bus_remove_device(struct device * dev) sysfs_remove_link(&dev->bus->devices.kobj, dev->bus_id); device_remove_attrs(dev->bus, dev); klist_remove(&dev->knode_bus); - down_write(&dev->bus->subsys.rwsem); pr_debug("bus %s: remove device %s\n", dev->bus->name, dev->bus_id); device_release_driver(dev); - list_del_init(&dev->bus_list); - up_write(&dev->bus->subsys.rwsem); put_bus(dev->bus); } } @@ -364,9 +356,7 @@ int bus_add_driver(struct device_driver * drv) return error; } - down_write(&bus->subsys.rwsem); driver_attach(drv); - up_write(&bus->subsys.rwsem); klist_add_tail(&bus->klist_drivers, &drv->knode_bus); module_add_driver(drv->owner, drv); @@ -390,10 +380,8 @@ void bus_remove_driver(struct device_driver * drv) if (drv->bus) { driver_remove_attrs(drv->bus, drv); klist_remove(&drv->knode_bus); - down_write(&drv->bus->subsys.rwsem); pr_debug("bus %s: remove driver %s\n", drv->bus->name, drv->name); driver_detach(drv); - up_write(&drv->bus->subsys.rwsem); module_remove_driver(drv); kobject_unregister(&drv->kobj); put_bus(drv->bus); -- cgit From ca2b94ba12f3c36fd3d6ed9d38b3798d4dad0d8b Mon Sep 17 00:00:00 2001 From: Hannes Reinecke Date: Wed, 18 May 2005 10:42:23 +0200 Subject: [PATCH] driver core: fix error handling in bus_add_device The error handling in bus_add_device() and device_attach() is simply non-existing. This patch propagates any error from device_attach to the upper layers to allow for a proper recovery. From: Hannes Reinecke Signed-off-by: Greg Kroah-Hartman --- drivers/base/bus.c | 13 ++++++++----- 1 file changed, 8 insertions(+), 5 deletions(-) (limited to 'drivers/base/bus.c') diff --git a/drivers/base/bus.c b/drivers/base/bus.c index 4eb19525e06..43722af90bd 100644 --- a/drivers/base/bus.c +++ b/drivers/base/bus.c @@ -270,11 +270,14 @@ int bus_add_device(struct device * dev) if (bus) { pr_debug("bus %s: add device %s\n", bus->name, dev->bus_id); - device_attach(dev); + error = device_attach(dev); klist_add_tail(&bus->klist_devices, &dev->knode_bus); - device_add_attrs(bus, dev); - sysfs_create_link(&bus->devices.kobj, &dev->kobj, dev->bus_id); - sysfs_create_link(&dev->kobj, &dev->bus->subsys.kset.kobj, "bus"); + if (error >= 0) + error = device_add_attrs(bus, dev); + if (!error) { + sysfs_create_link(&bus->devices.kobj, &dev->kobj, dev->bus_id); + sysfs_create_link(&dev->kobj, &dev->bus->subsys.kset.kobj, "bus"); + } } return error; } @@ -394,7 +397,7 @@ static int bus_rescan_devices_helper(struct device *dev, void *data) { int *count = data; - if (!dev->driver && device_attach(dev)) + if (!dev->driver && (device_attach(dev) > 0)) (*count)++; return 0; -- cgit