| Message ID | 154345154182.18040.12736221516488918534.stgit@ahduyck-desk1.amr.corp.intel.com (mailing list archive) |
|---|---|
| State | Superseded |
| Headers | show |
| Series | Add NUMA aware async_schedule calls | expand |
On Wed, Nov 28, 2018 at 04:32:21PM -0800, Alexander Duyck wrote: > Try to consolidate all of the locking and unlocking of both the parent and > device when attaching or removing a driver from a given device. > > To do that I first consolidated the lock pattern into two functions > __device_driver_lock and __device_driver_unlock. After doing that I then > created functions specific to attaching and detaching the driver while > acquiring these locks. By doing this I was able to reduce the number of > spots where we touch need_parent_lock from 12 down to 4. While this later is true, it gives the impression there are functional changes but I see none. It can help reviewers / future reviewers of this commit if its clearly stated that this patch introduces no functional changes. > Reviewed-by: Bart Van Assche <bvanassche@acm.org> > Reviewed-by: Dan Williams <dan.j.williams@intel.com> > Reviewed-by: Rafael J. Wysocki <rafael.j.wysocki@intel.com> > Signed-off-by: Alexander Duyck <alexander.h.duyck@linux.intel.com> Reviewed-by: Luis Chamberlain <mcgrof@kernel.org> Luis > --- > drivers/base/base.h | 2 + > drivers/base/bus.c | 23 ++----------- > drivers/base/dd.c | 91 ++++++++++++++++++++++++++++++++++++++++----------- > 3 files changed, 77 insertions(+), 39 deletions(-) > > diff --git a/drivers/base/base.h b/drivers/base/base.h > index 7a419a7a6235..3f22ebd6117a 100644 > --- a/drivers/base/base.h > +++ b/drivers/base/base.h > @@ -124,6 +124,8 @@ extern int driver_add_groups(struct device_driver *drv, > const struct attribute_group **groups); > extern void driver_remove_groups(struct device_driver *drv, > const struct attribute_group **groups); > +int device_driver_attach(struct device_driver *drv, struct device *dev); > +void device_driver_detach(struct device *dev); > > extern char *make_class_name(const char *name, struct kobject *kobj); > > diff --git a/drivers/base/bus.c b/drivers/base/bus.c > index 8bfd27ec73d6..8a630f9bd880 100644 > --- a/drivers/base/bus.c > +++ b/drivers/base/bus.c > @@ -184,11 +184,7 @@ static ssize_t unbind_store(struct device_driver *drv, const char *buf, > > dev = bus_find_device_by_name(bus, NULL, buf); > if (dev && dev->driver == drv) { > - if (dev->parent && dev->bus->need_parent_lock) > - device_lock(dev->parent); > - device_release_driver(dev); > - if (dev->parent && dev->bus->need_parent_lock) > - device_unlock(dev->parent); > + device_driver_detach(dev); > err = count; > } > put_device(dev); > @@ -211,13 +207,7 @@ static ssize_t bind_store(struct device_driver *drv, const char *buf, > > dev = bus_find_device_by_name(bus, NULL, buf); > if (dev && dev->driver == NULL && driver_match_device(drv, dev)) { > - if (dev->parent && bus->need_parent_lock) > - device_lock(dev->parent); > - device_lock(dev); > - err = driver_probe_device(drv, dev); > - device_unlock(dev); > - if (dev->parent && bus->need_parent_lock) > - device_unlock(dev->parent); > + err = device_driver_attach(drv, dev); > > if (err > 0) { > /* success */ > @@ -769,13 +759,8 @@ EXPORT_SYMBOL_GPL(bus_rescan_devices); > */ > int device_reprobe(struct device *dev) > { > - if (dev->driver) { > - if (dev->parent && dev->bus->need_parent_lock) > - device_lock(dev->parent); > - device_release_driver(dev); > - if (dev->parent && dev->bus->need_parent_lock) > - device_unlock(dev->parent); > - } > + if (dev->driver) > + device_driver_detach(dev); > return bus_rescan_devices_helper(dev, NULL); > } > EXPORT_SYMBOL_GPL(device_reprobe); > diff --git a/drivers/base/dd.c b/drivers/base/dd.c > index ef3f70a7cb5a..d2515520569e 100644 > --- a/drivers/base/dd.c > +++ b/drivers/base/dd.c > @@ -875,6 +875,60 @@ void device_initial_probe(struct device *dev) > __device_attach(dev, true); > } > > +/* > + * __device_driver_lock - acquire locks needed to manipulate dev->drv > + * @dev: Device we will update driver info for > + * @parent: Parent device. Needed if the bus requires parent lock > + * > + * This function will take the required locks for manipulating dev->drv. > + * Normally this will just be the @dev lock, but when called for a USB > + * interface, @parent lock will be held as well. > + */ > +static void __device_driver_lock(struct device *dev, struct device *parent) > +{ > + if (parent && dev->bus->need_parent_lock) > + device_lock(parent); > + device_lock(dev); > +} > + > +/* > + * __device_driver_unlock - release locks needed to manipulate dev->drv > + * @dev: Device we will update driver info for > + * @parent: Parent device. Needed if the bus requires parent lock > + * > + * This function will release the required locks for manipulating dev->drv. > + * Normally this will just be the the @dev lock, but when called for a > + * USB interface, @parent lock will be released as well. > + */ > +static void __device_driver_unlock(struct device *dev, struct device *parent) > +{ > + device_unlock(dev); > + if (parent && dev->bus->need_parent_lock) > + device_unlock(parent); > +} > + > +/** > + * device_driver_attach - attach a specific driver to a specific device > + * @drv: Driver to attach > + * @dev: Device to attach it to > + * > + * Manually attach driver to a device. Will acquire both @dev lock and > + * @dev->parent lock if needed. > + */ > +int device_driver_attach(struct device_driver *drv, struct device *dev) > +{ > + int ret = 0; > + > + __device_driver_lock(dev, dev->parent); > + > + if (!dev->driver) > + ret = driver_probe_device(drv, dev); > + > + __device_driver_unlock(dev, dev->parent); > + > + return ret; > +} > + > static int __driver_attach(struct device *dev, void *data) > { > struct device_driver *drv = data; > @@ -902,14 +956,7 @@ static int __driver_attach(struct device *dev, void *data) > return ret; > } /* ret > 0 means positive match */ > > - if (dev->parent && dev->bus->need_parent_lock) > - device_lock(dev->parent); > - device_lock(dev); > - if (!dev->driver) > - driver_probe_device(drv, dev); > - device_unlock(dev); > - if (dev->parent && dev->bus->need_parent_lock) > - device_unlock(dev->parent); > + device_driver_attach(drv, dev); > > return 0; > } > @@ -948,15 +995,11 @@ static void __device_release_driver(struct device *dev, struct device *parent) > drv = dev->driver; > if (drv) { > while (device_links_busy(dev)) { > - device_unlock(dev); > - if (parent) > - device_unlock(parent); > + __device_driver_unlock(dev, parent); > > device_links_unbind_consumers(dev); > - if (parent) > - device_lock(parent); > > - device_lock(dev); > + __device_driver_lock(dev, parent); > /* > * A concurrent invocation of the same function might > * have released the driver successfully while this one > @@ -1009,16 +1052,12 @@ void device_release_driver_internal(struct device *dev, > struct device_driver *drv, > struct device *parent) > { > - if (parent && dev->bus->need_parent_lock) > - device_lock(parent); > + __device_driver_lock(dev, parent); > > - device_lock(dev); > if (!drv || drv == dev->driver) > __device_release_driver(dev, parent); > > - device_unlock(dev); > - if (parent && dev->bus->need_parent_lock) > - device_unlock(parent); > + __device_driver_unlock(dev, parent); > } > > /** > @@ -1043,6 +1082,18 @@ void device_release_driver(struct device *dev) > } > EXPORT_SYMBOL_GPL(device_release_driver); > > +/** > + * device_driver_detach - detach driver from a specific device > + * @dev: device to detach driver from > + * > + * Detach driver from device. Will acquire both @dev lock and @dev->parent > + * lock if needed. > + */ > +void device_driver_detach(struct device *dev) > +{ > + device_release_driver_internal(dev, NULL, dev->parent); > +} > + > /** > * driver_detach - detach driver from all devices it controls. > * @drv: driver. >
diff --git a/drivers/base/base.h b/drivers/base/base.h index 7a419a7a6235..3f22ebd6117a 100644 --- a/drivers/base/base.h +++ b/drivers/base/base.h @@ -124,6 +124,8 @@ extern int driver_add_groups(struct device_driver *drv, const struct attribute_group **groups); extern void driver_remove_groups(struct device_driver *drv, const struct attribute_group **groups); +int device_driver_attach(struct device_driver *drv, struct device *dev); +void device_driver_detach(struct device *dev); extern char *make_class_name(const char *name, struct kobject *kobj); diff --git a/drivers/base/bus.c b/drivers/base/bus.c index 8bfd27ec73d6..8a630f9bd880 100644 --- a/drivers/base/bus.c +++ b/drivers/base/bus.c @@ -184,11 +184,7 @@ static ssize_t unbind_store(struct device_driver *drv, const char *buf, dev = bus_find_device_by_name(bus, NULL, buf); if (dev && dev->driver == drv) { - if (dev->parent && dev->bus->need_parent_lock) - device_lock(dev->parent); - device_release_driver(dev); - if (dev->parent && dev->bus->need_parent_lock) - device_unlock(dev->parent); + device_driver_detach(dev); err = count; } put_device(dev); @@ -211,13 +207,7 @@ static ssize_t bind_store(struct device_driver *drv, const char *buf, dev = bus_find_device_by_name(bus, NULL, buf); if (dev && dev->driver == NULL && driver_match_device(drv, dev)) { - if (dev->parent && bus->need_parent_lock) - device_lock(dev->parent); - device_lock(dev); - err = driver_probe_device(drv, dev); - device_unlock(dev); - if (dev->parent && bus->need_parent_lock) - device_unlock(dev->parent); + err = device_driver_attach(drv, dev); if (err > 0) { /* success */ @@ -769,13 +759,8 @@ EXPORT_SYMBOL_GPL(bus_rescan_devices); */ int device_reprobe(struct device *dev) { - if (dev->driver) { - if (dev->parent && dev->bus->need_parent_lock) - device_lock(dev->parent); - device_release_driver(dev); - if (dev->parent && dev->bus->need_parent_lock) - device_unlock(dev->parent); - } + if (dev->driver) + device_driver_detach(dev); return bus_rescan_devices_helper(dev, NULL); } EXPORT_SYMBOL_GPL(device_reprobe); diff --git a/drivers/base/dd.c b/drivers/base/dd.c index ef3f70a7cb5a..d2515520569e 100644 --- a/drivers/base/dd.c +++ b/drivers/base/dd.c @@ -875,6 +875,60 @@ void device_initial_probe(struct device *dev) __device_attach(dev, true); } +/* + * __device_driver_lock - acquire locks needed to manipulate dev->drv + * @dev: Device we will update driver info for + * @parent: Parent device. Needed if the bus requires parent lock + * + * This function will take the required locks for manipulating dev->drv. + * Normally this will just be the @dev lock, but when called for a USB + * interface, @parent lock will be held as well. + */ +static void __device_driver_lock(struct device *dev, struct device *parent) +{ + if (parent && dev->bus->need_parent_lock) + device_lock(parent); + device_lock(dev); +} + +/* + * __device_driver_unlock - release locks needed to manipulate dev->drv + * @dev: Device we will update driver info for + * @parent: Parent device. Needed if the bus requires parent lock + * + * This function will release the required locks for manipulating dev->drv. + * Normally this will just be the the @dev lock, but when called for a + * USB interface, @parent lock will be released as well. + */ +static void __device_driver_unlock(struct device *dev, struct device *parent) +{ + device_unlock(dev); + if (parent && dev->bus->need_parent_lock) + device_unlock(parent); +} + +/** + * device_driver_attach - attach a specific driver to a specific device + * @drv: Driver to attach + * @dev: Device to attach it to + * + * Manually attach driver to a device. Will acquire both @dev lock and + * @dev->parent lock if needed. + */ +int device_driver_attach(struct device_driver *drv, struct device *dev) +{ + int ret = 0; + + __device_driver_lock(dev, dev->parent); + + if (!dev->driver) + ret = driver_probe_device(drv, dev); + + __device_driver_unlock(dev, dev->parent); + + return ret; +} + static int __driver_attach(struct device *dev, void *data) { struct device_driver *drv = data; @@ -902,14 +956,7 @@ static int __driver_attach(struct device *dev, void *data) return ret; } /* ret > 0 means positive match */ - if (dev->parent && dev->bus->need_parent_lock) - device_lock(dev->parent); - device_lock(dev); - if (!dev->driver) - driver_probe_device(drv, dev); - device_unlock(dev); - if (dev->parent && dev->bus->need_parent_lock) - device_unlock(dev->parent); + device_driver_attach(drv, dev); return 0; } @@ -948,15 +995,11 @@ static void __device_release_driver(struct device *dev, struct device *parent) drv = dev->driver; if (drv) { while (device_links_busy(dev)) { - device_unlock(dev); - if (parent) - device_unlock(parent); + __device_driver_unlock(dev, parent); device_links_unbind_consumers(dev); - if (parent) - device_lock(parent); - device_lock(dev); + __device_driver_lock(dev, parent); /* * A concurrent invocation of the same function might * have released the driver successfully while this one @@ -1009,16 +1052,12 @@ void device_release_driver_internal(struct device *dev, struct device_driver *drv, struct device *parent) { - if (parent && dev->bus->need_parent_lock) - device_lock(parent); + __device_driver_lock(dev, parent); - device_lock(dev); if (!drv || drv == dev->driver) __device_release_driver(dev, parent); - device_unlock(dev); - if (parent && dev->bus->need_parent_lock) - device_unlock(parent); + __device_driver_unlock(dev, parent); } /** @@ -1043,6 +1082,18 @@ void device_release_driver(struct device *dev) } EXPORT_SYMBOL_GPL(device_release_driver); +/** + * device_driver_detach - detach driver from a specific device + * @dev: device to detach driver from + * + * Detach driver from device. Will acquire both @dev lock and @dev->parent + * lock if needed. + */ +void device_driver_detach(struct device *dev) +{ + device_release_driver_internal(dev, NULL, dev->parent); +} + /** * driver_detach - detach driver from all devices it controls. * @drv: driver.