From 959bc7b22bd25a3a907fbb9b26a1d0cbdf98ef40 Mon Sep 17 00:00:00 2001 From: Thierry Reding Date: Tue, 7 Nov 2017 19:15:59 +0100 Subject: [PATCH] gpio: Automatically add lockdep keys In order to avoid lockdep boilerplate in individual drivers, turn the gpiochip_add_data() function into a macro that creates a unique class key for each driver. Note that this has the slight disadvantage of adding a key for each driver registered with the system. However, these keys are 8 bytes in size, which is negligible and a small price to pay for generic infrastructure. Suggested-by: Grygorii Strashko Signed-off-by: Thierry Reding Acked-by: Grygorii Strashko [renane __gpiochip_add_data() to gpiochip_add_data_with_key] Signed-off-by: Linus Walleij --- drivers/gpio/gpiolib.c | 41 +++++++++++-------------------------- include/linux/gpio/driver.h | 36 +++++++++++++++++++++++++++++++- 2 files changed, 47 insertions(+), 30 deletions(-) diff --git a/drivers/gpio/gpiolib.c b/drivers/gpio/gpiolib.c index 6d5c366a1378..961b5da38bb9 100644 --- a/drivers/gpio/gpiolib.c +++ b/drivers/gpio/gpiolib.c @@ -72,7 +72,8 @@ static LIST_HEAD(gpio_lookup_list); LIST_HEAD(gpio_devices); static void gpiochip_free_hogs(struct gpio_chip *chip); -static int gpiochip_add_irqchip(struct gpio_chip *gpiochip); +static int gpiochip_add_irqchip(struct gpio_chip *gpiochip, + struct lock_class_key *key); static void gpiochip_irqchip_remove(struct gpio_chip *gpiochip); static int gpiochip_irqchip_init_valid_mask(struct gpio_chip *gpiochip); static void gpiochip_irqchip_free_valid_mask(struct gpio_chip *gpiochip); @@ -1098,30 +1099,8 @@ static void gpiochip_setup_devs(void) } } -/** - * gpiochip_add_data() - register a gpio_chip - * @chip: the chip to register, with chip->base initialized - * @data: driver-private data associated with this chip - * - * Context: potentially before irqs will work - * - * When gpiochip_add_data() is called very early during boot, so that GPIOs - * can be freely used, the chip->parent device must be registered before - * the gpio framework's arch_initcall(). Otherwise sysfs initialization - * for GPIOs will fail rudely. - * - * gpiochip_add_data() must only be called after gpiolib initialization, - * ie after core_initcall(). - * - * If chip->base is negative, this requests dynamic assignment of - * a range of valid GPIOs. - * - * Returns: - * A negative errno if the chip can't be registered, such as because the - * chip->base is invalid or already associated with a different chip. - * Otherwise it returns zero as a success code. - */ -int gpiochip_add_data(struct gpio_chip *chip, void *data) +int gpiochip_add_data_with_key(struct gpio_chip *chip, void *data, + struct lock_class_key *key) { unsigned long flags; int status = 0; @@ -1267,7 +1246,7 @@ int gpiochip_add_data(struct gpio_chip *chip, void *data) if (status) goto err_remove_from_list; - status = gpiochip_add_irqchip(chip); + status = gpiochip_add_irqchip(chip, key); if (status) goto err_remove_chip; @@ -1314,7 +1293,7 @@ int gpiochip_add_data(struct gpio_chip *chip, void *data) kfree(gdev); return status; } -EXPORT_SYMBOL_GPL(gpiochip_add_data); +EXPORT_SYMBOL_GPL(gpiochip_add_data_with_key); /** * gpiochip_get_data() - get per-subdriver data for the chip @@ -1733,8 +1712,10 @@ static int gpiochip_to_irq(struct gpio_chip *chip, unsigned offset) /** * gpiochip_add_irqchip() - adds an IRQ chip to a GPIO chip * @gpiochip: the GPIO chip to add the IRQ chip to + * @lock_key: lockdep class */ -static int gpiochip_add_irqchip(struct gpio_chip *gpiochip) +static int gpiochip_add_irqchip(struct gpio_chip *gpiochip, + struct lock_class_key *lock_key) { struct irq_chip *irqchip = gpiochip->irq.chip; const struct irq_domain_ops *ops; @@ -1771,6 +1752,7 @@ static int gpiochip_add_irqchip(struct gpio_chip *gpiochip) gpiochip->to_irq = gpiochip_to_irq; gpiochip->irq.default_type = type; + gpiochip->irq.lock_key = lock_key; if (gpiochip->irq.domain_ops) ops = gpiochip->irq.domain_ops; @@ -1957,7 +1939,8 @@ EXPORT_SYMBOL_GPL(gpiochip_irqchip_add_key); #else /* CONFIG_GPIOLIB_IRQCHIP */ -static inline int gpiochip_add_irqchip(struct gpio_chip *gpiochip) +static inline int gpiochip_add_irqchip(struct gpio_chip *gpiochip, + struct lock_dep_class *lock_key) { return 0; } diff --git a/include/linux/gpio/driver.h b/include/linux/gpio/driver.h index a77d4ada060c..8dd282c5167a 100644 --- a/include/linux/gpio/driver.h +++ b/include/linux/gpio/driver.h @@ -321,7 +321,41 @@ extern const char *gpiochip_is_requested(struct gpio_chip *chip, unsigned offset); /* add/remove chips */ -extern int gpiochip_add_data(struct gpio_chip *chip, void *data); +extern int gpiochip_add_data_with_key(struct gpio_chip *chip, void *data, + struct lock_class_key *lock_key); + +/** + * gpiochip_add_data() - register a gpio_chip + * @chip: the chip to register, with chip->base initialized + * @data: driver-private data associated with this chip + * + * Context: potentially before irqs will work + * + * When gpiochip_add_data() is called very early during boot, so that GPIOs + * can be freely used, the chip->parent device must be registered before + * the gpio framework's arch_initcall(). Otherwise sysfs initialization + * for GPIOs will fail rudely. + * + * gpiochip_add_data() must only be called after gpiolib initialization, + * ie after core_initcall(). + * + * If chip->base is negative, this requests dynamic assignment of + * a range of valid GPIOs. + * + * Returns: + * A negative errno if the chip can't be registered, such as because the + * chip->base is invalid or already associated with a different chip. + * Otherwise it returns zero as a success code. + */ +#ifdef CONFIG_LOCKDEP +#define gpiochip_add_data(chip, data) ({ \ + static struct lock_class_key key; \ + gpiochip_add_data_with_key(chip, data, &key); \ + }) +#else +#define gpiochip_add_data(chip, data) gpiochip_add_data_with_key(chip, data, NULL) +#endif + static inline int gpiochip_add(struct gpio_chip *chip) { return gpiochip_add_data(chip, NULL); -- 2.45.2