From c72bed23b9e45accdeab626cf2cb2bd08d846f3e Mon Sep 17 00:00:00 2001 From: Hans de Goede Date: Mon, 16 Dec 2019 21:51:18 +0100 Subject: [PATCH] pinctrl: Allow modules to use pinctrl_[un]register_mappings Currently only the drivers/pinctrl/devicetree.c code allows registering pinctrl-mappings which may later be unregistered, all other mappings are assumed to be permanent. Non-dt platforms may also want to register pinctrl mappings from code which is build as a module, which requires being able to unregister the mapping when the module is unloaded to avoid dangling pointers. To allow unregistering the mappings the devicetree code uses 2 internal functions: pinctrl_register_map and pinctrl_unregister_map. pinctrl_register_map allows the devicetree code to tell the core to not memdup the mappings as it retains ownership of them and pinctrl_unregister_map does the unregistering, note this only works when the mappings where not memdupped. The only code relying on the memdup/shallow-copy done by pinctrl_register_mappings is arch/arm/mach-u300/core.c this commit replaces the __initdata with const, so that the shallow-copy is no longer necessary. After that we can get rid of the internal pinctrl_unregister_map function and just use pinctrl_register_mappings directly everywhere. This commit also renames pinctrl_unregister_map to pinctrl_unregister_mappings so that its naming matches its pinctrl_register_mappings counter-part and exports it. Together these 2 changes will allow non-dt platform code to register pinctrl-mappings from modules without breaking things on module unload (as they can now unregister the mapping on unload). Signed-off-by: Hans de Goede Link: https://lore.kernel.org/r/20191216205122.1850923-2-hdegoede@redhat.com Signed-off-by: Linus Walleij --- arch/arm/mach-u300/core.c | 2 +- drivers/pinctrl/core.c | 43 +++++++++++++-------------------- drivers/pinctrl/core.h | 4 --- drivers/pinctrl/devicetree.c | 4 +-- include/linux/pinctrl/machine.h | 5 ++++ 5 files changed, 25 insertions(+), 33 deletions(-) diff --git a/arch/arm/mach-u300/core.c b/arch/arm/mach-u300/core.c index a79fa3b0c8ed..a1694d977ec9 100644 --- a/arch/arm/mach-u300/core.c +++ b/arch/arm/mach-u300/core.c @@ -201,7 +201,7 @@ static unsigned long pin_highz_conf[] = { }; /* Pin control settings */ -static struct pinctrl_map __initdata u300_pinmux_map[] = { +static const struct pinctrl_map u300_pinmux_map[] = { /* anonymous maps for chip power and EMIFs */ PIN_MAP_MUX_GROUP_HOG_DEFAULT("pinctrl-u300", NULL, "power"), PIN_MAP_MUX_GROUP_HOG_DEFAULT("pinctrl-u300", NULL, "emif0"), diff --git a/drivers/pinctrl/core.c b/drivers/pinctrl/core.c index 2bbd8ee93507..b0eea728455d 100644 --- a/drivers/pinctrl/core.c +++ b/drivers/pinctrl/core.c @@ -1376,8 +1376,15 @@ void devm_pinctrl_put(struct pinctrl *p) } EXPORT_SYMBOL_GPL(devm_pinctrl_put); -int pinctrl_register_map(const struct pinctrl_map *maps, unsigned num_maps, - bool dup) +/** + * pinctrl_register_mappings() - register a set of pin controller mappings + * @maps: the pincontrol mappings table to register. Note the pinctrl-core + * keeps a reference to the passed in maps, so they should _not_ be + * marked with __initdata. + * @num_maps: the number of maps in the mapping table + */ +int pinctrl_register_mappings(const struct pinctrl_map *maps, + unsigned num_maps) { int i, ret; struct pinctrl_maps *maps_node; @@ -1430,17 +1437,8 @@ int pinctrl_register_map(const struct pinctrl_map *maps, unsigned num_maps, if (!maps_node) return -ENOMEM; + maps_node->maps = maps; maps_node->num_maps = num_maps; - if (dup) { - maps_node->maps = kmemdup(maps, sizeof(*maps) * num_maps, - GFP_KERNEL); - if (!maps_node->maps) { - kfree(maps_node); - return -ENOMEM; - } - } else { - maps_node->maps = maps; - } mutex_lock(&pinctrl_maps_mutex); list_add_tail(&maps_node->node, &pinctrl_maps); @@ -1448,22 +1446,14 @@ int pinctrl_register_map(const struct pinctrl_map *maps, unsigned num_maps, return 0; } - -/** - * pinctrl_register_mappings() - register a set of pin controller mappings - * @maps: the pincontrol mappings table to register. This should probably be - * marked with __initdata so it can be discarded after boot. This - * function will perform a shallow copy for the mapping entries. - * @num_maps: the number of maps in the mapping table - */ -int pinctrl_register_mappings(const struct pinctrl_map *maps, - unsigned num_maps) -{ - return pinctrl_register_map(maps, num_maps, true); -} EXPORT_SYMBOL_GPL(pinctrl_register_mappings); -void pinctrl_unregister_map(const struct pinctrl_map *map) +/** + * pinctrl_unregister_mappings() - unregister a set of pin controller mappings + * @maps: the pincontrol mappings table passed to pinctrl_register_mappings() + * when registering the mappings. + */ +void pinctrl_unregister_mappings(const struct pinctrl_map *map) { struct pinctrl_maps *maps_node; @@ -1478,6 +1468,7 @@ void pinctrl_unregister_map(const struct pinctrl_map *map) } mutex_unlock(&pinctrl_maps_mutex); } +EXPORT_SYMBOL_GPL(pinctrl_unregister_mappings); /** * pinctrl_force_sleep() - turn a given controller device into sleep state diff --git a/drivers/pinctrl/core.h b/drivers/pinctrl/core.h index 7f34167a0405..840103c40c14 100644 --- a/drivers/pinctrl/core.h +++ b/drivers/pinctrl/core.h @@ -236,10 +236,6 @@ extern struct pinctrl_gpio_range * pinctrl_find_gpio_range_from_pin_nolock(struct pinctrl_dev *pctldev, unsigned int pin); -int pinctrl_register_map(const struct pinctrl_map *maps, unsigned num_maps, - bool dup); -void pinctrl_unregister_map(const struct pinctrl_map *map); - extern int pinctrl_force_sleep(struct pinctrl_dev *pctldev); extern int pinctrl_force_default(struct pinctrl_dev *pctldev); diff --git a/drivers/pinctrl/devicetree.c b/drivers/pinctrl/devicetree.c index 674920daac26..9357f7c46cf3 100644 --- a/drivers/pinctrl/devicetree.c +++ b/drivers/pinctrl/devicetree.c @@ -51,7 +51,7 @@ void pinctrl_dt_free_maps(struct pinctrl *p) struct pinctrl_dt_map *dt_map, *n1; list_for_each_entry_safe(dt_map, n1, &p->dt_maps, node) { - pinctrl_unregister_map(dt_map->map); + pinctrl_unregister_mappings(dt_map->map); list_del(&dt_map->node); dt_free_map(dt_map->pctldev, dt_map->map, dt_map->num_maps); @@ -92,7 +92,7 @@ static int dt_remember_or_free_map(struct pinctrl *p, const char *statename, dt_map->num_maps = num_maps; list_add_tail(&dt_map->node, &p->dt_maps); - return pinctrl_register_map(map, num_maps, false); + return pinctrl_register_mappings(map, num_maps); err_free_map: dt_free_map(pctldev, map, num_maps); diff --git a/include/linux/pinctrl/machine.h b/include/linux/pinctrl/machine.h index ddd1b2773431..e987dc9fd2af 100644 --- a/include/linux/pinctrl/machine.h +++ b/include/linux/pinctrl/machine.h @@ -153,6 +153,7 @@ struct pinctrl_map { extern int pinctrl_register_mappings(const struct pinctrl_map *map, unsigned num_maps); +extern void pinctrl_unregister_mappings(const struct pinctrl_map *map); extern void pinctrl_provide_dummies(void); #else @@ -162,6 +163,10 @@ static inline int pinctrl_register_mappings(const struct pinctrl_map *map, return 0; } +static inline void pinctrl_unregister_mappings(const struct pinctrl_map *map) +{ +} + static inline void pinctrl_provide_dummies(void) { }