Re: [PATCH v3 1/7] drivers: Introduce device lookup variants by name

[Heikki Krogerus <heikki.krogerus@linux.intel.com>]

On Tue, Jul 23, 2019 at 11:18:32PM +0100, Suzuki K Poulose wrote:
> Add a helper to match the device name for device lookup. Also
> reuse this generic exported helper for the existing bus_find_device_by_name().
> and add similar variants for driver/class.
> 
> Cc: Alessandro Zummo <a.zummo@towertech.it>
> Cc: Alexander Aring <alex.aring@gmail.com>
> Cc: Alexander Shishkin <alexander.shishkin@linux.intel.com>
> Cc: Alexandre Belloni <alexandre.belloni@bootlin.com>
> Cc: Arnd Bergmann <arnd@arndb.de>
> Cc: Dan Murphy <dmurphy@ti.com>
> Cc: Greg Kroah-Hartman <gregkh@linuxfoundation.org>
> Cc: Harald Freudenberger <freude@linux.ibm.com>
> Cc: Heikki Krogerus <heikki.krogerus@linux.intel.com>
> Cc: Heiko Carstens <heiko.carstens@de.ibm.com>
> Cc: Jacek Anaszewski <jacek.anaszewski@gmail.com>
> Cc: Lee Jones <lee.jones@linaro.org>
> Cc: linux-leds@vger.kernel.org
> Cc: linux-rtc@vger.kernel.org
> Cc: linux-usb@vger.kernel.org
> Cc: linux-wpan@vger.kernel.org
> Cc: Maxime Coquelin <mcoquelin.stm32@gmail.com>
> Cc: Pavel Machek <pavel@ucw.cz>
> Cc: Peter Oberparleiter <oberpar@linux.ibm.com>
> Cc: "Rafael J. Wysocki" <rafael@kernel.org>
> Cc: Stefan Schmidt <stefan@datenfreihafen.org>
> Cc: Greg Kroah-Hartman <gregkh@linuxfoundation.org>
> Cc: "Rafael J. Wysocki" <rafael.j.wysocki@intel.com>
> Signed-off-by: Suzuki K Poulose <suzuki.poulose@arm.com>

Reviewed-by: Heikki Krogerus <heikki.krogerus@linux.intel.coM>

> ---
>  drivers/base/bus.c               | 24 ------------------
>  drivers/base/core.c              |  6 +++++
>  drivers/hwtracing/stm/core.c     |  9 +------
>  drivers/leds/led-class.c         |  9 +------
>  drivers/rtc/interface.c          | 11 +--------
>  drivers/s390/cio/ccwgroup.c      | 10 +-------
>  drivers/s390/cio/device.c        | 15 +-----------
>  drivers/s390/crypto/zcrypt_api.c | 11 +--------
>  drivers/usb/roles/class.c        |  8 +-----
>  drivers/usb/typec/class.c        |  8 +-----
>  include/linux/device.h           | 42 +++++++++++++++++++++++++++++---
>  net/ieee802154/core.c            |  7 +-----
>  12 files changed, 54 insertions(+), 106 deletions(-)
> 
> diff --git a/drivers/base/bus.c b/drivers/base/bus.c
> index df3cac739813..a1d1e8256324 100644
> --- a/drivers/base/bus.c
> +++ b/drivers/base/bus.c
> @@ -342,30 +342,6 @@ struct device *bus_find_device(struct bus_type *bus,
>  }
>  EXPORT_SYMBOL_GPL(bus_find_device);
>  
> -static int match_name(struct device *dev, const void *data)
> -{
> -	const char *name = data;
> -
> -	return sysfs_streq(name, dev_name(dev));
> -}
> -
> -/**
> - * bus_find_device_by_name - device iterator for locating a particular device of a specific name
> - * @bus: bus type
> - * @start: Device to begin with
> - * @name: name of the device to match
> - *
> - * This is similar to the bus_find_device() function above, but it handles
> - * searching by a name automatically, no need to write another strcmp matching
> - * function.
> - */
> -struct device *bus_find_device_by_name(struct bus_type *bus,
> -				       struct device *start, const char *name)
> -{
> -	return bus_find_device(bus, start, (void *)name, match_name);
> -}
> -EXPORT_SYMBOL_GPL(bus_find_device_by_name);
> -
>  /**
>   * subsys_find_device_by_id - find a device with a specific enumeration number
>   * @subsys: subsystem
> diff --git a/drivers/base/core.c b/drivers/base/core.c
> index da84a73f2ba6..fb83647d685a 100644
> --- a/drivers/base/core.c
> +++ b/drivers/base/core.c
> @@ -3357,6 +3357,12 @@ void device_set_of_node_from_dev(struct device *dev, const struct device *dev2)
>  }
>  EXPORT_SYMBOL_GPL(device_set_of_node_from_dev);
>  
> +int device_match_name(struct device *dev, const void *name)
> +{
> +	return sysfs_streq(dev_name(dev), name);
> +}
> +EXPORT_SYMBOL_GPL(device_match_name);
> +
>  int device_match_of_node(struct device *dev, const void *np)
>  {
>  	return dev->of_node == np;
> diff --git a/drivers/hwtracing/stm/core.c b/drivers/hwtracing/stm/core.c
> index e55b902560de..2b6bd42632e8 100644
> --- a/drivers/hwtracing/stm/core.c
> +++ b/drivers/hwtracing/stm/core.c
> @@ -89,13 +89,6 @@ static struct class stm_class = {
>  	.dev_groups	= stm_groups,
>  };
>  
> -static int stm_dev_match(struct device *dev, const void *data)
> -{
> -	const char *name = data;
> -
> -	return sysfs_streq(name, dev_name(dev));
> -}
> -
>  /**
>   * stm_find_device() - find stm device by name
>   * @buf:	character buffer containing the name
> @@ -116,7 +109,7 @@ struct stm_device *stm_find_device(const char *buf)
>  	if (!stm_core_up)
>  		return NULL;
>  
> -	dev = class_find_device(&stm_class, NULL, buf, stm_dev_match);
> +	dev = class_find_device_by_name(&stm_class, buf);
>  	if (!dev)
>  		return NULL;
>  
> diff --git a/drivers/leds/led-class.c b/drivers/leds/led-class.c
> index 4793e77808e2..d54c8e4d8954 100644
> --- a/drivers/leds/led-class.c
> +++ b/drivers/leds/led-class.c
> @@ -213,13 +213,6 @@ static int led_resume(struct device *dev)
>  
>  static SIMPLE_DEV_PM_OPS(leds_class_dev_pm_ops, led_suspend, led_resume);
>  
> -static int match_name(struct device *dev, const void *data)
> -{
> -	if (!dev_name(dev))
> -		return 0;
> -	return !strcmp(dev_name(dev), (char *)data);
> -}
> -
>  static int led_classdev_next_name(const char *init_name, char *name,
>  				  size_t len)
>  {
> @@ -230,7 +223,7 @@ static int led_classdev_next_name(const char *init_name, char *name,
>  	strlcpy(name, init_name, len);
>  
>  	while ((ret < len) &&
> -	       (dev = class_find_device(leds_class, NULL, name, match_name))) {
> +	       (dev = class_find_device_by_name(leds_class, name))) {
>  		put_device(dev);
>  		ret = snprintf(name, len, "%s_%u", init_name, ++i);
>  	}
> diff --git a/drivers/rtc/interface.c b/drivers/rtc/interface.c
> index 72b7ddc43116..c93ef33b01d3 100644
> --- a/drivers/rtc/interface.c
> +++ b/drivers/rtc/interface.c
> @@ -663,21 +663,12 @@ void rtc_update_irq(struct rtc_device *rtc,
>  }
>  EXPORT_SYMBOL_GPL(rtc_update_irq);
>  
> -static int __rtc_match(struct device *dev, const void *data)
> -{
> -	const char *name = data;
> -
> -	if (strcmp(dev_name(dev), name) == 0)
> -		return 1;
> -	return 0;
> -}
> -
>  struct rtc_device *rtc_class_open(const char *name)
>  {
>  	struct device *dev;
>  	struct rtc_device *rtc = NULL;
>  
> -	dev = class_find_device(rtc_class, NULL, name, __rtc_match);
> +	dev = class_find_device_by_name(rtc_class, name);
>  	if (dev)
>  		rtc = to_rtc_device(dev);
>  
> diff --git a/drivers/s390/cio/ccwgroup.c b/drivers/s390/cio/ccwgroup.c
> index c522e9313c50..d843e362c167 100644
> --- a/drivers/s390/cio/ccwgroup.c
> +++ b/drivers/s390/cio/ccwgroup.c
> @@ -608,13 +608,6 @@ void ccwgroup_driver_unregister(struct ccwgroup_driver *cdriver)
>  }
>  EXPORT_SYMBOL(ccwgroup_driver_unregister);
>  
> -static int __ccwgroupdev_check_busid(struct device *dev, const void *id)
> -{
> -	const char *bus_id = id;
> -
> -	return (strcmp(bus_id, dev_name(dev)) == 0);
> -}
> -
>  /**
>   * get_ccwgroupdev_by_busid() - obtain device from a bus id
>   * @gdrv: driver the device is owned by
> @@ -631,8 +624,7 @@ struct ccwgroup_device *get_ccwgroupdev_by_busid(struct ccwgroup_driver *gdrv,
>  {
>  	struct device *dev;
>  
> -	dev = driver_find_device(&gdrv->driver, NULL, bus_id,
> -				 __ccwgroupdev_check_busid);
> +	dev = driver_find_device_by_name(&gdrv->driver, bus_id);
>  
>  	return dev ? to_ccwgroupdev(dev) : NULL;
>  }
> diff --git a/drivers/s390/cio/device.c b/drivers/s390/cio/device.c
> index c421899be20f..131430bd48d9 100644
> --- a/drivers/s390/cio/device.c
> +++ b/drivers/s390/cio/device.c
> @@ -1695,18 +1695,6 @@ int ccw_device_force_console(struct ccw_device *cdev)
>  EXPORT_SYMBOL_GPL(ccw_device_force_console);
>  #endif
>  
> -/*
> - * get ccw_device matching the busid, but only if owned by cdrv
> - */
> -static int
> -__ccwdev_check_busid(struct device *dev, const void *id)
> -{
> -	const char *bus_id = id;
> -
> -	return (strcmp(bus_id, dev_name(dev)) == 0);
> -}
> -
> -
>  /**
>   * get_ccwdev_by_busid() - obtain device from a bus id
>   * @cdrv: driver the device is owned by
> @@ -1723,8 +1711,7 @@ struct ccw_device *get_ccwdev_by_busid(struct ccw_driver *cdrv,
>  {
>  	struct device *dev;
>  
> -	dev = driver_find_device(&cdrv->driver, NULL, (void *)bus_id,
> -				 __ccwdev_check_busid);
> +	dev = driver_find_device_by_name(&cdrv->driver, bus_id);
>  
>  	return dev ? to_ccwdev(dev) : NULL;
>  }
> diff --git a/drivers/s390/crypto/zcrypt_api.c b/drivers/s390/crypto/zcrypt_api.c
> index 1058b4b5cc1e..38a5a47b8c9c 100644
> --- a/drivers/s390/crypto/zcrypt_api.c
> +++ b/drivers/s390/crypto/zcrypt_api.c
> @@ -133,12 +133,6 @@ struct zcdn_device {
>  static int zcdn_create(const char *name);
>  static int zcdn_destroy(const char *name);
>  
> -/* helper function, matches the name for find_zcdndev_by_name() */
> -static int __match_zcdn_name(struct device *dev, const void *data)
> -{
> -	return strcmp(dev_name(dev), (const char *)data) == 0;
> -}
> -
>  /* helper function, matches the devt value for find_zcdndev_by_devt() */
>  static int __match_zcdn_devt(struct device *dev, const void *data)
>  {
> @@ -152,10 +146,7 @@ static int __match_zcdn_devt(struct device *dev, const void *data)
>   */
>  static inline struct zcdn_device *find_zcdndev_by_name(const char *name)
>  {
> -	struct device *dev =
> -		class_find_device(zcrypt_class, NULL,
> -				  (void *) name,
> -				  __match_zcdn_name);
> +	struct device *dev = class_find_device_by_name(zcrypt_class, name);
>  
>  	return dev ? to_zcdn_dev(dev) : NULL;
>  }
> diff --git a/drivers/usb/roles/class.c b/drivers/usb/roles/class.c
> index 86defca6623e..c8efe60e2465 100644
> --- a/drivers/usb/roles/class.c
> +++ b/drivers/usb/roles/class.c
> @@ -90,11 +90,6 @@ static int switch_fwnode_match(struct device *dev, const void *fwnode)
>  	return dev_fwnode(dev) == fwnode;
>  }
>  
> -static int switch_name_match(struct device *dev, const void *name)
> -{
> -	return !strcmp((const char *)name, dev_name(dev));
> -}
> -
>  static void *usb_role_switch_match(struct device_connection *con, int ep,
>  				   void *data)
>  {
> @@ -107,8 +102,7 @@ static void *usb_role_switch_match(struct device_connection *con, int ep,
>  		dev = class_find_device(role_class, NULL, con->fwnode,
>  					switch_fwnode_match);
>  	} else {
> -		dev = class_find_device(role_class, NULL, con->endpoint[ep],
> -					switch_name_match);
> +		dev = class_find_device_by_name(role_class, con->endpoint[ep]);
>  	}
>  
>  	return dev ? to_role_switch(dev) : ERR_PTR(-EPROBE_DEFER);
> diff --git a/drivers/usb/typec/class.c b/drivers/usb/typec/class.c
> index a18285a990a8..9b0d15b487e5 100644
> --- a/drivers/usb/typec/class.c
> +++ b/drivers/usb/typec/class.c
> @@ -210,11 +210,6 @@ static int typec_port_fwnode_match(struct device *dev, const void *fwnode)
>  	return dev_fwnode(dev) == fwnode;
>  }
>  
> -static int typec_port_name_match(struct device *dev, const void *name)
> -{
> -	return !strcmp((const char *)name, dev_name(dev));
> -}
> -
>  static void *typec_port_match(struct device_connection *con, int ep, void *data)
>  {
>  	struct device *dev;
> @@ -227,8 +222,7 @@ static void *typec_port_match(struct device_connection *con, int ep, void *data)
>  		return class_find_device(typec_class, NULL, con->fwnode,
>  					 typec_port_fwnode_match);
>  
> -	dev = class_find_device(typec_class, NULL, con->endpoint[ep],
> -				typec_port_name_match);
> +	dev = class_find_device_by_name(typec_class, con->endpoint[ep]);
>  
>  	return dev ? dev : ERR_PTR(-EPROBE_DEFER);
>  }
> diff --git a/include/linux/device.h b/include/linux/device.h
> index c330b75c6c57..3ba376b8b456 100644
> --- a/include/linux/device.h
> +++ b/include/linux/device.h
> @@ -164,6 +164,7 @@ void subsys_dev_iter_init(struct subsys_dev_iter *iter,
>  struct device *subsys_dev_iter_next(struct subsys_dev_iter *iter);
>  void subsys_dev_iter_exit(struct subsys_dev_iter *iter);
>  
> +int device_match_name(struct device *dev, const void *name);
>  int device_match_of_node(struct device *dev, const void *np);
>  
>  int bus_for_each_dev(struct bus_type *bus, struct device *start, void *data,
> @@ -171,9 +172,20 @@ int bus_for_each_dev(struct bus_type *bus, struct device *start, void *data,
>  struct device *bus_find_device(struct bus_type *bus, struct device *start,
>  			       const void *data,
>  			       int (*match)(struct device *dev, const void *data));
> -struct device *bus_find_device_by_name(struct bus_type *bus,
> -				       struct device *start,
> -				       const char *name);
> +/**
> + * bus_find_device_by_name - device iterator for locating a particular device
> + * of a specific name.
> + * @bus: bus type
> + * @start: Device to begin with
> + * @name: name of the device to match
> + */
> +static inline struct device *bus_find_device_by_name(struct bus_type *bus,
> +						     struct device *start,
> +						     const char *name)
> +{
> +	return bus_find_device(bus, start, name, device_match_name);
> +}
> +
>  struct device *subsys_find_device_by_id(struct bus_type *bus, unsigned int id,
>  					struct device *hint);
>  int bus_for_each_drv(struct bus_type *bus, struct device_driver *start,
> @@ -342,6 +354,18 @@ struct device *driver_find_device(struct device_driver *drv,
>  				  struct device *start, const void *data,
>  				  int (*match)(struct device *dev, const void *data));
>  
> +/**
> + * driver_find_device_by_name - device iterator for locating a particular device
> + * of a specific name.
> + * @driver: the driver we're iterating
> + * @name: name of the device to match
> + */
> +static inline struct device *driver_find_device_by_name(struct device_driver *drv,
> +							const char *name)
> +{
> +	return driver_find_device(drv, NULL, name, device_match_name);
> +}
> +
>  void driver_deferred_probe_add(struct device *dev);
>  int driver_deferred_probe_check_state(struct device *dev);
>  int driver_deferred_probe_check_state_continue(struct device *dev);
> @@ -471,6 +495,18 @@ extern struct device *class_find_device(struct class *class,
>  					struct device *start, const void *data,
>  					int (*match)(struct device *, const void *));
>  
> +/**
> + * class_find_device_by_name - device iterator for locating a particular device
> + * of a specific name.
> + * @class: class type
> + * @name: name of the device to match
> + */
> +static inline struct device *class_find_device_by_name(struct class *class,
> +						       const char *name)
> +{
> +	return class_find_device(class, NULL, name, device_match_name);
> +}
> +
>  struct class_attribute {
>  	struct attribute attr;
>  	ssize_t (*show)(struct class *class, struct class_attribute *attr,
> diff --git a/net/ieee802154/core.c b/net/ieee802154/core.c
> index 60b7ac56a1f5..de259b5170ab 100644
> --- a/net/ieee802154/core.c
> +++ b/net/ieee802154/core.c
> @@ -23,11 +23,6 @@
>  LIST_HEAD(cfg802154_rdev_list);
>  int cfg802154_rdev_list_generation;
>  
> -static int wpan_phy_match(struct device *dev, const void *data)
> -{
> -	return !strcmp(dev_name(dev), (const char *)data);
> -}
> -
>  struct wpan_phy *wpan_phy_find(const char *str)
>  {
>  	struct device *dev;
> @@ -35,7 +30,7 @@ struct wpan_phy *wpan_phy_find(const char *str)
>  	if (WARN_ON(!str))
>  		return NULL;
>  
> -	dev = class_find_device(&wpan_phy_class, NULL, str, wpan_phy_match);
> +	dev = class_find_device_by_name(&wpan_phy_class, str);
>  	if (!dev)
>  		return NULL;
>  
> -- 
> 2.21.0

thanks,

-- 
heikki