[PATCH v3 20/24] gpio: add the can_sleep flag to struct gpio_device

Bartosz Golaszewski
2024-02-08T09:59:47Z

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>
---
drivers/gpio/gpiolib.c | 11 ++++++-----
drivers/gpio/gpiolib.h | 3 +++
2 files changed, 9 insertions(+), 5 deletions(-)

diff --git a/drivers/gpio/gpiolib.c b/drivers/gpio/gpiolib.c
index 140a44dec0be..6b696087c7f5 100644
--- 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 9b7afe87f1bd..43ff4931e2c3 100644
--- 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;
--
2.40.1