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McKenney" , Andy Shevchenko , Wolfram Sang Cc: linux-gpio@vger.kernel.org, linux-kernel@vger.kernel.org, Bartosz Golaszewski Subject: [PATCH 06/22] gpio: add SRCU infrastructure to struct gpio_desc Date: Tue, 30 Jan 2024 13:48:12 +0100 Message-Id: <20240130124828.14678-7-brgl@bgdev.pl> X-Mailer: git-send-email 2.40.1 In-Reply-To: <20240130124828.14678-1-brgl@bgdev.pl> References: <20240130124828.14678-1-brgl@bgdev.pl> Precedence: bulk X-Mailing-List: linux-gpio@vger.kernel.org List-Id: List-Subscribe: List-Unsubscribe: MIME-Version: 1.0 From: Bartosz Golaszewski Extend the GPIO descriptor with an SRCU structure in order to serialize the access to the label. Initialize and clean it up where applicable. Signed-off-by: Bartosz Golaszewski Reviewed-by: Linus Walleij --- drivers/gpio/gpiolib.c | 18 ++++++++++++++++-- drivers/gpio/gpiolib.h | 3 +++ 2 files changed, 19 insertions(+), 2 deletions(-) diff --git a/drivers/gpio/gpiolib.c b/drivers/gpio/gpiolib.c index 4e6b26b3febb..94e1a603cf8b 100644 --- a/drivers/gpio/gpiolib.c +++ b/drivers/gpio/gpiolib.c @@ -672,6 +672,10 @@ EXPORT_SYMBOL_GPL(gpiochip_line_is_valid); static void gpiodev_release(struct device *dev) { struct gpio_device *gdev = to_gpio_device(dev); + unsigned int i; + + for (i = 0; i < gdev->ngpio; i++) + cleanup_srcu_struct(&gdev->descs[i].srcu); ida_free(&gpio_ida, gdev->id); kfree_const(gdev->label); @@ -829,7 +833,7 @@ int gpiochip_add_data_with_key(struct gpio_chip *gc, void *data, struct lock_class_key *request_key) { struct gpio_device *gdev; - unsigned int i; + unsigned int i, j; int base = 0; int ret = 0; @@ -962,6 +966,13 @@ int gpiochip_add_data_with_key(struct gpio_chip *gc, void *data, for (i = 0; i < gc->ngpio; i++) { struct gpio_desc *desc = &gdev->descs[i]; + ret = init_srcu_struct(&desc->srcu); + if (ret) { + for (j = 0; j < i; j++) + cleanup_srcu_struct(&desc->srcu); + goto err_remove_of_chip; + } + if (gc->get_direction && gpiochip_line_is_valid(gc, i)) { assign_bit(FLAG_IS_OUT, &desc->flags, !gc->get_direction(gc, i)); @@ -973,7 +984,7 @@ int gpiochip_add_data_with_key(struct gpio_chip *gc, void *data, ret = gpiochip_add_pin_ranges(gc); if (ret) - goto err_remove_of_chip; + goto err_cleanup_desc_srcu; acpi_gpiochip_add(gc); @@ -1012,6 +1023,9 @@ int gpiochip_add_data_with_key(struct gpio_chip *gc, void *data, gpiochip_irqchip_free_valid_mask(gc); err_remove_acpi_chip: acpi_gpiochip_remove(gc); +err_cleanup_desc_srcu: + for (i = 0; i < gdev->ngpio; i++) + cleanup_srcu_struct(&gdev->descs[i].srcu); err_remove_of_chip: gpiochip_free_hogs(gc); of_gpiochip_remove(gc); diff --git a/drivers/gpio/gpiolib.h b/drivers/gpio/gpiolib.h index 1058f326fe2b..6e14b629c48b 100644 --- a/drivers/gpio/gpiolib.h +++ b/drivers/gpio/gpiolib.h @@ -17,6 +17,7 @@ #include #include #include +#include #define GPIOCHIP_NAME "gpiochip" @@ -147,6 +148,7 @@ void gpiod_line_state_notify(struct gpio_desc *desc, unsigned long action); * @label: Name of the consumer * @name: Line name * @hog: Pointer to the device node that hogs this line (if any) + * @srcu: SRCU struct protecting the label pointer. * * These are obtained using gpiod_get() and are preferable to the old * integer-based handles. @@ -184,6 +186,7 @@ struct gpio_desc { #ifdef CONFIG_OF_DYNAMIC struct device_node *hog; #endif + struct srcu_struct srcu; }; #define gpiod_not_found(desc) (IS_ERR(desc) && PTR_ERR(desc) == -ENOENT)