From f1e8bf56320a7fb32095b6c51b707459361b403b Mon Sep 17 00:00:00 2001 From: Zijun Hu Date: Tue, 24 Dec 2024 21:05:03 +0800 Subject: driver core: Constify API device_find_child() and adapt for various usages MIME-Version: 1.0 Content-Type: text/plain; charset=UTF-8 Content-Transfer-Encoding: 8bit Constify the following API: struct device *device_find_child(struct device *dev, void *data, int (*match)(struct device *dev, void *data)); To : struct device *device_find_child(struct device *dev, const void *data, device_match_t match); typedef int (*device_match_t)(struct device *dev, const void *data); with the following reasons: - Protect caller's match data @*data which is for comparison and lookup and the API does not actually need to modify @*data. - Make the API's parameters (@match)() and @data have the same type as all of other device finding APIs (bus|class|driver)_find_device(). - All kinds of existing device match functions can be directly taken as the API's argument, they were exported by driver core. Constify the API and adapt for various existing usages. BTW, various subsystem changes are squashed into this commit to meet 'git bisect' requirement, and this commit has the minimal and simplest changes to complement squashing shortcoming, and that may bring extra code improvement. Reviewed-by: Alison Schofield Reviewed-by: Takashi Sakamoto Acked-by: Uwe Kleine-König # for drivers/pwm Signed-off-by: Zijun Hu Reviewed-by: Jonathan Cameron Reviewed-by: Mathieu Poirier Link: https://lore.kernel.org/r/20241224-const_dfc_done-v5-4-6623037414d4@quicinc.com Signed-off-by: Greg Kroah-Hartman --- include/linux/device.h | 4 ++-- 1 file changed, 2 insertions(+), 2 deletions(-) (limited to 'include/linux/device.h') diff --git a/include/linux/device.h b/include/linux/device.h index 667cb6db9019..0e0bc9bfe0d1 100644 --- a/include/linux/device.h +++ b/include/linux/device.h @@ -1081,8 +1081,8 @@ int device_for_each_child_reverse(struct device *dev, void *data, int device_for_each_child_reverse_from(struct device *parent, struct device *from, const void *data, int (*fn)(struct device *, const void *)); -struct device *device_find_child(struct device *dev, void *data, - int (*match)(struct device *dev, void *data)); +struct device *device_find_child(struct device *dev, const void *data, + device_match_t match); struct device *device_find_child_by_name(struct device *parent, const char *name); struct device *device_find_any_child(struct device *parent); -- cgit v1.2.3 From ab017a15fdb2222002cdc6bdf86699fb21a0721a Mon Sep 17 00:00:00 2001 From: Zijun Hu Date: Sun, 5 Jan 2025 16:34:05 +0800 Subject: driver core: Rename declaration parameter name for API device_find_child() cluster For APIs: device_find_child() device_for_each_child() device_for_each_child_reverse() Their declaration has parameter name 'dev', but their defination changes the name to 'parent'. Rename declaration name to defination 'parent' to make both have the same name. Reviewed-by: Fan Ni Reviewed-by: Jonathan Cameron Signed-off-by: Zijun Hu Link: https://lore.kernel.org/r/20250105-class_fix-v6-4-3a2f1768d4d4@quicinc.com Signed-off-by: Greg Kroah-Hartman --- include/linux/device.h | 6 +++--- 1 file changed, 3 insertions(+), 3 deletions(-) (limited to 'include/linux/device.h') diff --git a/include/linux/device.h b/include/linux/device.h index 0e0bc9bfe0d1..a9d928398895 100644 --- a/include/linux/device.h +++ b/include/linux/device.h @@ -1074,14 +1074,14 @@ void device_del(struct device *dev); DEFINE_FREE(device_del, struct device *, if (_T) device_del(_T)) -int device_for_each_child(struct device *dev, void *data, +int device_for_each_child(struct device *parent, void *data, int (*fn)(struct device *dev, void *data)); -int device_for_each_child_reverse(struct device *dev, void *data, +int device_for_each_child_reverse(struct device *parent, void *data, int (*fn)(struct device *dev, void *data)); int device_for_each_child_reverse_from(struct device *parent, struct device *from, const void *data, int (*fn)(struct device *, const void *)); -struct device *device_find_child(struct device *dev, const void *data, +struct device *device_find_child(struct device *parent, const void *data, device_match_t match); struct device *device_find_child_by_name(struct device *parent, const char *name); -- cgit v1.2.3 From 523c6b3ed7702a638e0f8fd02708a7ed4f938269 Mon Sep 17 00:00:00 2001 From: Zijun Hu Date: Sun, 5 Jan 2025 16:34:07 +0800 Subject: driver core: Correct API device_for_each_child_reverse_from() prototype For API device_for_each_child_reverse_from(..., const void *data, int (*fn)(struct device *dev, const void *data)) - Type of @data is const pointer, and means caller's data @*data is not allowed to be modified, but that usually is not proper for such non finding device iterating API. - Types for both @data and @fn are not consistent with all other for_each device iterating APIs device_for_each_child(_reverse)(), bus_for_each_dev() and (driver|class)_for_each_device(). Correct its prototype by removing const from parameter types, then adapt for various existing usages. An dedicated typedef device_iter_t will be introduced as @fn() type for various for_each device interating APIs later. Reviewed-by: Jonathan Cameron Signed-off-by: Zijun Hu Link: https://lore.kernel.org/r/20250105-class_fix-v6-6-3a2f1768d4d4@quicinc.com Signed-off-by: Greg Kroah-Hartman --- drivers/base/core.c | 4 ++-- drivers/cxl/core/hdm.c | 2 +- drivers/cxl/core/region.c | 2 +- include/linux/device.h | 4 ++-- 4 files changed, 6 insertions(+), 6 deletions(-) (limited to 'include/linux/device.h') diff --git a/drivers/base/core.c b/drivers/base/core.c index d3800f0dc5bb..5ee53b3bca6a 100644 --- a/drivers/base/core.c +++ b/drivers/base/core.c @@ -4043,8 +4043,8 @@ EXPORT_SYMBOL_GPL(device_for_each_child_reverse); * device_for_each_child_reverse_from(); */ int device_for_each_child_reverse_from(struct device *parent, - struct device *from, const void *data, - int (*fn)(struct device *, const void *)) + struct device *from, void *data, + int (*fn)(struct device *, void *)) { struct klist_iter i; struct device *child; diff --git a/drivers/cxl/core/hdm.c b/drivers/cxl/core/hdm.c index 28edd5822486..50e6a45b30ba 100644 --- a/drivers/cxl/core/hdm.c +++ b/drivers/cxl/core/hdm.c @@ -703,7 +703,7 @@ static int cxl_decoder_commit(struct cxl_decoder *cxld) return 0; } -static int commit_reap(struct device *dev, const void *data) +static int commit_reap(struct device *dev, void *data) { struct cxl_port *port = to_cxl_port(dev->parent); struct cxl_decoder *cxld; diff --git a/drivers/cxl/core/region.c b/drivers/cxl/core/region.c index bfecd71040c2..a4cff4c266e7 100644 --- a/drivers/cxl/core/region.c +++ b/drivers/cxl/core/region.c @@ -778,7 +778,7 @@ out: return rc; } -static int check_commit_order(struct device *dev, const void *data) +static int check_commit_order(struct device *dev, void *data) { struct cxl_decoder *cxld = to_cxl_decoder(dev); diff --git a/include/linux/device.h b/include/linux/device.h index a9d928398895..025bac08fca7 100644 --- a/include/linux/device.h +++ b/include/linux/device.h @@ -1079,8 +1079,8 @@ int device_for_each_child(struct device *parent, void *data, int device_for_each_child_reverse(struct device *parent, void *data, int (*fn)(struct device *dev, void *data)); int device_for_each_child_reverse_from(struct device *parent, - struct device *from, const void *data, - int (*fn)(struct device *, const void *)); + struct device *from, void *data, + int (*fn)(struct device *, void *)); struct device *device_find_child(struct device *parent, const void *data, device_match_t match); struct device *device_find_child_by_name(struct device *parent, -- cgit v1.2.3 From 767b74e0d1fc7890a94d1770acf05a442474bd87 Mon Sep 17 00:00:00 2001 From: Zijun Hu Date: Sun, 5 Jan 2025 16:34:08 +0800 Subject: driver core: Introduce device_iter_t for device iterating APIs There are several for_each APIs which has parameter with type below: int (*fn)(struct device *dev, void *data) They iterate over various device lists and call @fn() for each device with caller provided data @*data, and they usually need to modify @*data. Give the type an dedicated typedef with advantages shown below: typedef int (*device_iter_t)(struct device *dev, void *data) - Shorter API declarations and definitions - Prevent further for_each APIs from using bad parameter type So introduce device_iter_t and apply it to various existing APIs below: bus_for_each_dev() (class|driver)_for_each_device() device_for_each_child(_reverse|_reverse_from)(). Reviewed-by: Jonathan Cameron Signed-off-by: Zijun Hu Link: https://lore.kernel.org/r/20250105-class_fix-v6-7-3a2f1768d4d4@quicinc.com Signed-off-by: Greg Kroah-Hartman --- drivers/base/bus.c | 2 +- drivers/base/class.c | 2 +- drivers/base/core.c | 6 +++--- drivers/base/driver.c | 2 +- include/linux/device.h | 6 +++--- include/linux/device/bus.h | 7 +++++-- include/linux/device/class.h | 4 ++-- include/linux/device/driver.h | 2 +- 8 files changed, 17 insertions(+), 14 deletions(-) (limited to 'include/linux/device.h') diff --git a/drivers/base/bus.c b/drivers/base/bus.c index 73a56f376d3a..6b9e65a42cd2 100644 --- a/drivers/base/bus.c +++ b/drivers/base/bus.c @@ -354,7 +354,7 @@ static struct device *next_device(struct klist_iter *i) * count in the supplied callback. */ int bus_for_each_dev(const struct bus_type *bus, struct device *start, - void *data, int (*fn)(struct device *, void *)) + void *data, device_iter_t fn) { struct subsys_private *sp = bus_to_subsys(bus); struct klist_iter i; diff --git a/drivers/base/class.c b/drivers/base/class.c index d57f277978dc..70ee6a7ba5a3 100644 --- a/drivers/base/class.c +++ b/drivers/base/class.c @@ -402,7 +402,7 @@ EXPORT_SYMBOL_GPL(class_dev_iter_exit); * code. There's no locking restriction. */ int class_for_each_device(const struct class *class, const struct device *start, - void *data, int (*fn)(struct device *, void *)) + void *data, device_iter_t fn) { struct subsys_private *sp = class_to_subsys(class); struct class_dev_iter iter; diff --git a/drivers/base/core.c b/drivers/base/core.c index 5ee53b3bca6a..7d79a0549ac7 100644 --- a/drivers/base/core.c +++ b/drivers/base/core.c @@ -3980,7 +3980,7 @@ const char *device_get_devnode(const struct device *dev, * other than 0, we break out and return that value. */ int device_for_each_child(struct device *parent, void *data, - int (*fn)(struct device *dev, void *data)) + device_iter_t fn) { struct klist_iter i; struct device *child; @@ -4010,7 +4010,7 @@ EXPORT_SYMBOL_GPL(device_for_each_child); * other than 0, we break out and return that value. */ int device_for_each_child_reverse(struct device *parent, void *data, - int (*fn)(struct device *dev, void *data)) + device_iter_t fn) { struct klist_iter i; struct device *child; @@ -4044,7 +4044,7 @@ EXPORT_SYMBOL_GPL(device_for_each_child_reverse); */ int device_for_each_child_reverse_from(struct device *parent, struct device *from, void *data, - int (*fn)(struct device *, void *)) + device_iter_t fn) { struct klist_iter i; struct device *child; diff --git a/drivers/base/driver.c b/drivers/base/driver.c index 6f033a741aa7..8ab010ddf709 100644 --- a/drivers/base/driver.c +++ b/drivers/base/driver.c @@ -115,7 +115,7 @@ EXPORT_SYMBOL_GPL(driver_set_override); * Iterate over the @drv's list of devices calling @fn for each one. */ int driver_for_each_device(struct device_driver *drv, struct device *start, - void *data, int (*fn)(struct device *, void *)) + void *data, device_iter_t fn) { struct klist_iter i; struct device *dev; diff --git a/include/linux/device.h b/include/linux/device.h index 025bac08fca7..36d1a1607712 100644 --- a/include/linux/device.h +++ b/include/linux/device.h @@ -1075,12 +1075,12 @@ void device_del(struct device *dev); DEFINE_FREE(device_del, struct device *, if (_T) device_del(_T)) int device_for_each_child(struct device *parent, void *data, - int (*fn)(struct device *dev, void *data)); + device_iter_t fn); int device_for_each_child_reverse(struct device *parent, void *data, - int (*fn)(struct device *dev, void *data)); + device_iter_t fn); int device_for_each_child_reverse_from(struct device *parent, struct device *from, void *data, - int (*fn)(struct device *, void *)); + device_iter_t fn); struct device *device_find_child(struct device *parent, const void *data, device_match_t match); struct device *device_find_child_by_name(struct device *parent, diff --git a/include/linux/device/bus.h b/include/linux/device/bus.h index bc3fd74bb763..3d3517da41a1 100644 --- a/include/linux/device/bus.h +++ b/include/linux/device/bus.h @@ -139,9 +139,12 @@ int device_match_acpi_dev(struct device *dev, const void *adev); int device_match_acpi_handle(struct device *dev, const void *handle); int device_match_any(struct device *dev, const void *unused); +/* Device iterating function type for various driver core for_each APIs */ +typedef int (*device_iter_t)(struct device *dev, void *data); + /* iterator helpers for buses */ -int bus_for_each_dev(const struct bus_type *bus, struct device *start, void *data, - int (*fn)(struct device *dev, void *data)); +int bus_for_each_dev(const struct bus_type *bus, struct device *start, + void *data, device_iter_t fn); struct device *bus_find_device(const struct bus_type *bus, struct device *start, const void *data, device_match_t match); /** diff --git a/include/linux/device/class.h b/include/linux/device/class.h index 518c9c83d64b..aa67d4736816 100644 --- a/include/linux/device/class.h +++ b/include/linux/device/class.h @@ -92,8 +92,8 @@ void class_dev_iter_init(struct class_dev_iter *iter, const struct class *class, struct device *class_dev_iter_next(struct class_dev_iter *iter); void class_dev_iter_exit(struct class_dev_iter *iter); -int class_for_each_device(const struct class *class, const struct device *start, void *data, - int (*fn)(struct device *dev, void *data)); +int class_for_each_device(const struct class *class, const struct device *start, + void *data, device_iter_t fn); struct device *class_find_device(const struct class *class, const struct device *start, const void *data, device_match_t match); diff --git a/include/linux/device/driver.h b/include/linux/device/driver.h index 5c04b8e3833b..cd8e0f0a634b 100644 --- a/include/linux/device/driver.h +++ b/include/linux/device/driver.h @@ -154,7 +154,7 @@ void driver_remove_file(const struct device_driver *driver, int driver_set_override(struct device *dev, const char **override, const char *s, size_t len); int __must_check driver_for_each_device(struct device_driver *drv, struct device *start, - void *data, int (*fn)(struct device *dev, void *)); + void *data, device_iter_t fn); struct device *driver_find_device(const struct device_driver *drv, struct device *start, const void *data, device_match_t match); -- cgit v1.2.3 From 51796f5e2960130fe53e9a71d07152622d5e024c Mon Sep 17 00:00:00 2001 From: Zijun Hu Date: Sun, 5 Jan 2025 16:34:09 +0800 Subject: driver core: Move two simple APIs for finding child device to header The following two APIs are for finding child device, and both only have one line code in function body. device_find_child_by_name() device_find_any_child() Move them to header as static inline function. Reviewed-by: Jonathan Cameron Signed-off-by: Zijun Hu Link: https://lore.kernel.org/r/20250105-class_fix-v6-8-3a2f1768d4d4@quicinc.com Signed-off-by: Greg Kroah-Hartman --- drivers/base/core.c | 32 -------------------------------- include/linux/device.h | 32 +++++++++++++++++++++++++++++--- 2 files changed, 29 insertions(+), 35 deletions(-) (limited to 'include/linux/device.h') diff --git a/drivers/base/core.c b/drivers/base/core.c index 7d79a0549ac7..5a1f05198114 100644 --- a/drivers/base/core.c +++ b/drivers/base/core.c @@ -4100,38 +4100,6 @@ struct device *device_find_child(struct device *parent, const void *data, } EXPORT_SYMBOL_GPL(device_find_child); -/** - * device_find_child_by_name - device iterator for locating a child device. - * @parent: parent struct device - * @name: name of the child device - * - * This is similar to the device_find_child() function above, but it - * returns a reference to a device that has the name @name. - * - * NOTE: you will need to drop the reference with put_device() after use. - */ -struct device *device_find_child_by_name(struct device *parent, - const char *name) -{ - return device_find_child(parent, name, device_match_name); -} -EXPORT_SYMBOL_GPL(device_find_child_by_name); - -/** - * device_find_any_child - device iterator for locating a child device, if any. - * @parent: parent struct device - * - * This is similar to the device_find_child() function above, but it - * returns a reference to a child device, if any. - * - * NOTE: you will need to drop the reference with put_device() after use. - */ -struct device *device_find_any_child(struct device *parent) -{ - return device_find_child(parent, NULL, device_match_any); -} -EXPORT_SYMBOL_GPL(device_find_any_child); - int __init devices_init(void) { devices_kset = kset_create_and_add("devices", &device_uevent_ops, NULL); diff --git a/include/linux/device.h b/include/linux/device.h index 36d1a1607712..1e9aded9a086 100644 --- a/include/linux/device.h +++ b/include/linux/device.h @@ -1083,9 +1083,35 @@ int device_for_each_child_reverse_from(struct device *parent, device_iter_t fn); struct device *device_find_child(struct device *parent, const void *data, device_match_t match); -struct device *device_find_child_by_name(struct device *parent, - const char *name); -struct device *device_find_any_child(struct device *parent); +/** + * device_find_child_by_name - device iterator for locating a child device. + * @parent: parent struct device + * @name: name of the child device + * + * This is similar to the device_find_child() function above, but it + * returns a reference to a device that has the name @name. + * + * NOTE: you will need to drop the reference with put_device() after use. + */ +static inline struct device *device_find_child_by_name(struct device *parent, + const char *name) +{ + return device_find_child(parent, name, device_match_name); +} + +/** + * device_find_any_child - device iterator for locating a child device, if any. + * @parent: parent struct device + * + * This is similar to the device_find_child() function above, but it + * returns a reference to a child device, if any. + * + * NOTE: you will need to drop the reference with put_device() after use. + */ +static inline struct device *device_find_any_child(struct device *parent) +{ + return device_find_child(parent, NULL, device_match_any); +} int device_rename(struct device *dev, const char *new_name); int device_move(struct device *dev, struct device *new_parent, -- cgit v1.2.3 From f1725160fd28a2e65e47166637aa44856a1a7f89 Mon Sep 17 00:00:00 2001 From: Danilo Krummrich Date: Tue, 7 Jan 2025 13:25:10 +0100 Subject: devres: add devm_remove_action_nowarn() devm_remove_action() warns if the action to remove does not exist (anymore). The Rust devres abstraction, however, has a use-case to call devm_remove_action() at a point where it can't be guaranteed that the corresponding action hasn't been released yet. In particular, an instance of `Devres` may be dropped after the action has been released. So far, `Devres` worked around this by keeping the inner type alive. Hence, add devm_remove_action_nowarn(), which returns an error code if the action has been removed already. A subsequent patch uses devm_remove_action_nowarn() to remove the action when `Devres` is dropped. Signed-off-by: Danilo Krummrich Link: https://lore.kernel.org/r/20250107122609.8135-1-dakr@kernel.org Signed-off-by: Greg Kroah-Hartman --- drivers/base/devres.c | 23 ++++++++++++++++++----- include/linux/device.h | 18 +++++++++++++++++- 2 files changed, 35 insertions(+), 6 deletions(-) (limited to 'include/linux/device.h') diff --git a/drivers/base/devres.c b/drivers/base/devres.c index 2152eec0c135..93e7779ef21e 100644 --- a/drivers/base/devres.c +++ b/drivers/base/devres.c @@ -750,25 +750,38 @@ int __devm_add_action(struct device *dev, void (*action)(void *), void *data, co EXPORT_SYMBOL_GPL(__devm_add_action); /** - * devm_remove_action() - removes previously added custom action + * devm_remove_action_nowarn() - removes previously added custom action * @dev: Device that owns the action * @action: Function implementing the action * @data: Pointer to data passed to @action implementation * * Removes instance of @action previously added by devm_add_action(). * Both action and data should match one of the existing entries. + * + * In contrast to devm_remove_action(), this function does not WARN() if no + * entry could have been found. + * + * This should only be used if the action is contained in an object with + * independent lifetime management, e.g. the Devres rust abstraction. + * + * Causing the warning from regular driver code most likely indicates an abuse + * of the devres API. + * + * Returns: 0 on success, -ENOENT if no entry could have been found. */ -void devm_remove_action(struct device *dev, void (*action)(void *), void *data) +int devm_remove_action_nowarn(struct device *dev, + void (*action)(void *), + void *data) { struct action_devres devres = { .data = data, .action = action, }; - WARN_ON(devres_destroy(dev, devm_action_release, devm_action_match, - &devres)); + return devres_destroy(dev, devm_action_release, devm_action_match, + &devres); } -EXPORT_SYMBOL_GPL(devm_remove_action); +EXPORT_SYMBOL_GPL(devm_remove_action_nowarn); /** * devm_release_action() - release previously added custom action diff --git a/include/linux/device.h b/include/linux/device.h index 1e9aded9a086..80a5b3268986 100644 --- a/include/linux/device.h +++ b/include/linux/device.h @@ -399,7 +399,23 @@ void __iomem *devm_of_iomap(struct device *dev, #endif /* allows to add/remove a custom action to devres stack */ -void devm_remove_action(struct device *dev, void (*action)(void *), void *data); +int devm_remove_action_nowarn(struct device *dev, void (*action)(void *), void *data); + +/** + * devm_remove_action() - removes previously added custom action + * @dev: Device that owns the action + * @action: Function implementing the action + * @data: Pointer to data passed to @action implementation + * + * Removes instance of @action previously added by devm_add_action(). + * Both action and data should match one of the existing entries. + */ +static inline +void devm_remove_action(struct device *dev, void (*action)(void *), void *data) +{ + WARN_ON(devm_remove_action_nowarn(dev, action, data)); +} + void devm_release_action(struct device *dev, void (*action)(void *), void *data); int __devm_add_action(struct device *dev, void (*action)(void *), void *data, const char *name); -- cgit v1.2.3