Commit 959bc7b2 authored by Thierry Reding's avatar Thierry Reding Committed by Linus Walleij
Browse files

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: default avatarGrygorii Strashko <grygorii.strashko@ti.com>
Signed-off-by: default avatarThierry Reding <treding@nvidia.com>
Acked-by: default avatarGrygorii Strashko <grygorii.strashko@ti.com>
[renane __gpiochip_add_data() to gpiochip_add_data_with_key]
Signed-off-by: default avatarLinus Walleij <linus.walleij@linaro.org>
parent 8302cf58

drivers/gpio/gpiolib.c

+12 −29
Original line number Diff line number Diff line
@@ -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 @@ err_free_gdev: 
	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;

}

include/linux/gpio/driver.h

+35 −1
Original line number Diff line number Diff line
@@ -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);

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