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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 <grygorii.strashko@ti.com>
Signed-off-by: Thierry Reding <treding@nvidia.com>
Acked-by: Grygorii Strashko <grygorii.strashko@ti.com>
[renane __gpiochip_add_data() to gpiochip_add_data_with_key]
Signed-off-by: Linus Walleij <linus.walleij@linaro.org>
This commit is contained in:
Thierry Reding 2017-11-07 19:15:59 +01:00 committed by Linus Walleij
parent 8302cf5852
commit 959bc7b22b
2 changed files with 47 additions and 30 deletions
Show Stats Download Patch File Download Diff File Expand all files Collapse all files

41
drivers/gpio/gpiolib.c
View File

@ -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;
}

36
include/linux/gpio/driver.h
View File

@ -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);