From 91b9969d9c6bb7c02253bbfc536bfd892f636fdc Mon Sep 17 00:00:00 2001 From: Jason Gunthorpe Date: Tue, 6 Apr 2021 16:40:27 -0300 Subject: vfio/mdev: Simplify driver registration This is only done once, we don't need to generate code to initialize a structure stored in the ELF .data segment. Fill in the three required .driver members directly instead of copying data into them during mdev_register_driver(). Further the to_mdev_driver() function doesn't belong in a public header, just inline it into the two places that need it. Finally, we can now clearly see that 'drv' derived from dev->driver cannot be NULL, firstly because the driver core forbids it, and secondly because NULL won't pass through the container_of(). Remove the dead code. Reviewed-by: Christoph Hellwig Reviewed-by: Kevin Tian Reviewed-by: Cornelia Huck Signed-off-by: Jason Gunthorpe Message-Id: <4-v2-d36939638fc6+d54-vfio2_jgg@nvidia.com> Signed-off-by: Alex Williamson --- Documentation/driver-api/vfio-mediated-device.rst | 5 +---- drivers/vfio/mdev/mdev_driver.c | 15 +++++++-------- drivers/vfio/mdev/vfio_mdev.c | 8 ++++++-- include/linux/mdev.h | 6 +----- 4 files changed, 15 insertions(+), 19 deletions(-) diff --git a/Documentation/driver-api/vfio-mediated-device.rst b/Documentation/driver-api/vfio-mediated-device.rst index c43c1dc33333..1779b85f014e 100644 --- a/Documentation/driver-api/vfio-mediated-device.rst +++ b/Documentation/driver-api/vfio-mediated-device.rst @@ -98,13 +98,11 @@ structure to represent a mediated device's driver:: /* * struct mdev_driver [2] - Mediated device's driver - * @name: driver name * @probe: called when new device created * @remove: called when device removed * @driver: device driver structure */ struct mdev_driver { - const char *name; int (*probe) (struct mdev_device *dev); void (*remove) (struct mdev_device *dev); struct device_driver driver; @@ -115,8 +113,7 @@ to register and unregister itself with the core driver: * Register:: - extern int mdev_register_driver(struct mdev_driver *drv, - struct module *owner); + extern int mdev_register_driver(struct mdev_driver *drv); * Unregister:: diff --git a/drivers/vfio/mdev/mdev_driver.c b/drivers/vfio/mdev/mdev_driver.c index 44c3ba7e56d9..041699571b7e 100644 --- a/drivers/vfio/mdev/mdev_driver.c +++ b/drivers/vfio/mdev/mdev_driver.c @@ -39,7 +39,8 @@ static void mdev_detach_iommu(struct mdev_device *mdev) static int mdev_probe(struct device *dev) { - struct mdev_driver *drv = to_mdev_driver(dev->driver); + struct mdev_driver *drv = + container_of(dev->driver, struct mdev_driver, driver); struct mdev_device *mdev = to_mdev_device(dev); int ret; @@ -47,7 +48,7 @@ static int mdev_probe(struct device *dev) if (ret) return ret; - if (drv && drv->probe) { + if (drv->probe) { ret = drv->probe(mdev); if (ret) mdev_detach_iommu(mdev); @@ -58,10 +59,11 @@ static int mdev_probe(struct device *dev) static int mdev_remove(struct device *dev) { - struct mdev_driver *drv = to_mdev_driver(dev->driver); + struct mdev_driver *drv = + container_of(dev->driver, struct mdev_driver, driver); struct mdev_device *mdev = to_mdev_device(dev); - if (drv && drv->remove) + if (drv->remove) drv->remove(mdev); mdev_detach_iommu(mdev); @@ -79,16 +81,13 @@ EXPORT_SYMBOL_GPL(mdev_bus_type); /** * mdev_register_driver - register a new MDEV driver * @drv: the driver to register - * @owner: module owner of driver to be registered * * Returns a negative value on error, otherwise 0. **/ -int mdev_register_driver(struct mdev_driver *drv, struct module *owner) +int mdev_register_driver(struct mdev_driver *drv) { /* initialize common driver fields */ - drv->driver.name = drv->name; drv->driver.bus = &mdev_bus_type; - drv->driver.owner = owner; /* register with core */ return driver_register(&drv->driver); diff --git a/drivers/vfio/mdev/vfio_mdev.c b/drivers/vfio/mdev/vfio_mdev.c index 91b7b8b9eb9c..cc9507ed85a1 100644 --- a/drivers/vfio/mdev/vfio_mdev.c +++ b/drivers/vfio/mdev/vfio_mdev.c @@ -152,14 +152,18 @@ static void vfio_mdev_remove(struct mdev_device *mdev) } static struct mdev_driver vfio_mdev_driver = { - .name = "vfio_mdev", + .driver = { + .name = "vfio_mdev", + .owner = THIS_MODULE, + .mod_name = KBUILD_MODNAME, + }, .probe = vfio_mdev_probe, .remove = vfio_mdev_remove, }; static int __init vfio_mdev_init(void) { - return mdev_register_driver(&vfio_mdev_driver, THIS_MODULE); + return mdev_register_driver(&vfio_mdev_driver); } static void __exit vfio_mdev_exit(void) diff --git a/include/linux/mdev.h b/include/linux/mdev.h index 52f7ea19dd0f..cb771c712da0 100644 --- a/include/linux/mdev.h +++ b/include/linux/mdev.h @@ -137,21 +137,17 @@ struct mdev_type_attribute mdev_type_attr_##_name = \ /** * struct mdev_driver - Mediated device driver - * @name: driver name * @probe: called when new device created * @remove: called when device removed * @driver: device driver structure * **/ struct mdev_driver { - const char *name; int (*probe)(struct mdev_device *dev); void (*remove)(struct mdev_device *dev); struct device_driver driver; }; -#define to_mdev_driver(drv) container_of(drv, struct mdev_driver, driver) - static inline void *mdev_get_drvdata(struct mdev_device *mdev) { return mdev->driver_data; @@ -170,7 +166,7 @@ extern struct bus_type mdev_bus_type; int mdev_register_device(struct device *dev, const struct mdev_parent_ops *ops); void mdev_unregister_device(struct device *dev); -int mdev_register_driver(struct mdev_driver *drv, struct module *owner); +int mdev_register_driver(struct mdev_driver *drv); void mdev_unregister_driver(struct mdev_driver *drv); struct device *mdev_parent_dev(struct mdev_device *mdev); -- cgit v1.2.3-59-g8ed1b