gpio: add the can_sleep flag to struct gpio_device

Duplicating the can_sleep value in GPIO device will allow us to not
needlessly dereference the chip pointer in several places and reduce the
number of SRCU read-only critical sections.

Signed-off-by: Bartosz Golaszewski <bartosz.golaszewski@linaro.org>
Reviewed-by: Linus Walleij <linus.walleij@linaro.org>
Acked-by: Andy Shevchenko <andriy.shevchenko@linux.intel.com>

diff --git a/drivers/gpio/gpiolib.c b/drivers/gpio/gpiolib.c
index 76c27ba9ee6410644d679414d0f82bb4849b624b..40052de2361c7d18274c3fdf52b7c14188063ef1 100644 (file)
--- a/drivers/gpio/gpiolib.c
+++ b/drivers/gpio/gpiolib.c
@@ -901,6 +901,7 @@ int gpiochip_add_data_with_key(struct gpio_chip *gc, void *data,
        }
 
        gdev->ngpio = gc->ngpio;
+       gdev->can_sleep = gc->can_sleep;
 
        scoped_guard(mutex, &gpio_devices_lock) {
                /*
@@ -3072,7 +3073,7 @@ int gpiod_get_raw_value(const struct gpio_desc *desc)
 {
        VALIDATE_DESC(desc);
        /* Should be using gpiod_get_raw_value_cansleep() */
-       WARN_ON(desc->gdev->chip->can_sleep);
+       WARN_ON(desc->gdev->can_sleep);
        return gpiod_get_raw_value_commit(desc);
 }
 EXPORT_SYMBOL_GPL(gpiod_get_raw_value);
@@ -3093,7 +3094,7 @@ int gpiod_get_value(const struct gpio_desc *desc)
 
        VALIDATE_DESC(desc);
        /* Should be using gpiod_get_value_cansleep() */
-       WARN_ON(desc->gdev->chip->can_sleep);
+       WARN_ON(desc->gdev->can_sleep);
 
        value = gpiod_get_raw_value_commit(desc);
        if (value < 0)
@@ -3366,7 +3367,7 @@ void gpiod_set_raw_value(struct gpio_desc *desc, int value)
 {
        VALIDATE_DESC_VOID(desc);
        /* Should be using gpiod_set_raw_value_cansleep() */
-       WARN_ON(desc->gdev->chip->can_sleep);
+       WARN_ON(desc->gdev->can_sleep);
        gpiod_set_raw_value_commit(desc, value);
 }
 EXPORT_SYMBOL_GPL(gpiod_set_raw_value);
@@ -3407,7 +3408,7 @@ void gpiod_set_value(struct gpio_desc *desc, int value)
 {
        VALIDATE_DESC_VOID(desc);
        /* Should be using gpiod_set_value_cansleep() */
-       WARN_ON(desc->gdev->chip->can_sleep);
+       WARN_ON(desc->gdev->can_sleep);
        gpiod_set_value_nocheck(desc, value);
 }
 EXPORT_SYMBOL_GPL(gpiod_set_value);
@@ -3471,7 +3472,7 @@ EXPORT_SYMBOL_GPL(gpiod_set_array_value);
 int gpiod_cansleep(const struct gpio_desc *desc)
 {
        VALIDATE_DESC(desc);
-       return desc->gdev->chip->can_sleep;
+       return desc->gdev->can_sleep;
 }
 EXPORT_SYMBOL_GPL(gpiod_cansleep);
 

diff --git a/drivers/gpio/gpiolib.h b/drivers/gpio/gpiolib.h
index 9b7afe87f1bd057915aa80f32a0f1d05f60b7981..43ff4931e2c369f9cc2a927fda6006d1f19d7ad2 100644 (file)
--- a/drivers/gpio/gpiolib.h
+++ b/drivers/gpio/gpiolib.h
@@ -34,6 +34,8 @@
  * @descs: array of ngpio descriptors.
  * @ngpio: the number of GPIO lines on this GPIO device, equal to the size
  * of the @descs array.
+ * @can_sleep: indicate whether the GPIO chip driver's callbacks can sleep
+ * implying that they cannot be used from atomic context
  * @base: GPIO base in the DEPRECATED global Linux GPIO numberspace, assigned
  * at device creation time.
  * @label: a descriptive name for the GPIO device, such as the part number
@@ -64,6 +66,7 @@ struct gpio_device {
        struct gpio_desc        *descs;
        int                     base;
        u16                     ngpio;
+       bool                    can_sleep;
        const char              *label;
        void                    *data;
        struct list_head        list;