From: Tzung-Bi Shih Date: Mon, 23 Feb 2026 06:17:24 +0000 (+0800) Subject: gpio: Ensure struct gpio_chip for gpiochip_setup_dev() X-Git-Url: http://git.ipfire.org/cgi-bin/gitweb.cgi?a=commitdiff_plain;h=cf674f1a0c9893ee1acef832679562007a94250a;p=thirdparty%2Fkernel%2Flinux.git gpio: Ensure struct gpio_chip for gpiochip_setup_dev() Ensure struct gpio_chip for gpiochip_setup_dev(). This eliminates a few checks for struct gpio_chip. Signed-off-by: Tzung-Bi Shih Link: https://patch.msgid.link/20260223061726.82161-5-tzungbi@kernel.org Signed-off-by: Bartosz Golaszewski --- diff --git a/drivers/gpio/gpiolib-cdev.c b/drivers/gpio/gpiolib-cdev.c index c919ec0d0a660..58a6e9a6ec62d 100644 --- a/drivers/gpio/gpiolib-cdev.c +++ b/drivers/gpio/gpiolib-cdev.c @@ -2733,11 +2733,13 @@ static const struct file_operations gpio_fileops = { #endif }; -int gpiolib_cdev_register(struct gpio_device *gdev, dev_t devt) +int gpiolib_cdev_register(struct gpio_chip *gc, dev_t devt) { - struct gpio_chip *gc; + struct gpio_device *gdev = gc->gpiodev; int ret; + lockdep_assert_held(&gdev->srcu); + cdev_init(&gdev->chrdev, &gpio_fileops); gdev->chrdev.owner = THIS_MODULE; gdev->dev.devt = MKDEV(MAJOR(devt), gdev->id); @@ -2753,14 +2755,6 @@ int gpiolib_cdev_register(struct gpio_device *gdev, dev_t devt) return ret; } - guard(srcu)(&gdev->srcu); - gc = srcu_dereference(gdev->chip, &gdev->srcu); - if (!gc) { - cdev_device_del(&gdev->chrdev, &gdev->dev); - destroy_workqueue(gdev->line_state_wq); - return -ENODEV; - } - gpiochip_dbg(gc, "added GPIO chardev (%d:%d)\n", MAJOR(devt), gdev->id); return 0; diff --git a/drivers/gpio/gpiolib-cdev.h b/drivers/gpio/gpiolib-cdev.h index b42644cbffb80..4a9cb3335d990 100644 --- a/drivers/gpio/gpiolib-cdev.h +++ b/drivers/gpio/gpiolib-cdev.h @@ -7,7 +7,7 @@ struct gpio_device; -int gpiolib_cdev_register(struct gpio_device *gdev, dev_t devt); +int gpiolib_cdev_register(struct gpio_chip *gc, dev_t devt); void gpiolib_cdev_unregister(struct gpio_device *gdev); #endif /* GPIOLIB_CDEV_H */ diff --git a/drivers/gpio/gpiolib-sysfs.c b/drivers/gpio/gpiolib-sysfs.c index 1c25a7dd3db42..748a3eb1bf352 100644 --- a/drivers/gpio/gpiolib-sysfs.c +++ b/drivers/gpio/gpiolib-sysfs.c @@ -983,13 +983,15 @@ void gpiod_unexport(struct gpio_desc *desc) } EXPORT_SYMBOL_GPL(gpiod_unexport); -int gpiochip_sysfs_register(struct gpio_device *gdev) +int gpiochip_sysfs_register(struct gpio_chip *gc) { + struct gpio_device *gdev = gc->gpiodev; struct gpiodev_data *data; - struct gpio_chip *chip; struct device *parent; int err; + lockdep_assert_held(&gdev->srcu); + /* * Many systems add gpio chips for SOC support very early, * before driver model support is available. In those cases we @@ -999,18 +1001,12 @@ int gpiochip_sysfs_register(struct gpio_device *gdev) if (!class_is_registered(&gpio_class)) return 0; - guard(srcu)(&gdev->srcu); - - chip = srcu_dereference(gdev->chip, &gdev->srcu); - if (!chip) - return -ENODEV; - /* * For sysfs backward compatibility we need to preserve this * preferred parenting to the gpio_chip parent field, if set. */ - if (chip->parent) - parent = chip->parent; + if (gc->parent) + parent = gc->parent; else parent = &gdev->dev; @@ -1029,7 +1025,7 @@ int gpiochip_sysfs_register(struct gpio_device *gdev) MKDEV(0, 0), data, gpiochip_groups, GPIOCHIP_NAME "%d", - chip->base); + gc->base); if (IS_ERR(data->cdev_base)) { err = PTR_ERR(data->cdev_base); kfree(data); @@ -1085,10 +1081,9 @@ void gpiochip_sysfs_unregister(struct gpio_chip *gc) */ static int gpiofind_sysfs_register(struct gpio_chip *gc, const void *data) { - struct gpio_device *gdev = gc->gpiodev; int ret; - ret = gpiochip_sysfs_register(gdev); + ret = gpiochip_sysfs_register(gc); if (ret) gpiochip_err(gc, "failed to register the sysfs entry: %d\n", ret); diff --git a/drivers/gpio/gpiolib-sysfs.h b/drivers/gpio/gpiolib-sysfs.h index fd5db5384681a..d0998de043a22 100644 --- a/drivers/gpio/gpiolib-sysfs.h +++ b/drivers/gpio/gpiolib-sysfs.h @@ -7,12 +7,12 @@ struct gpio_device; #ifdef CONFIG_GPIO_SYSFS -int gpiochip_sysfs_register(struct gpio_device *gdev); +int gpiochip_sysfs_register(struct gpio_chip *gc); void gpiochip_sysfs_unregister(struct gpio_chip *gc); #else -static inline int gpiochip_sysfs_register(struct gpio_device *gdev) +static inline int gpiochip_sysfs_register(struct gpio_chip *gc) { return 0; } diff --git a/drivers/gpio/gpiolib.c b/drivers/gpio/gpiolib.c index 8001ec1f9799b..bbb96e52197cf 100644 --- a/drivers/gpio/gpiolib.c +++ b/drivers/gpio/gpiolib.c @@ -882,14 +882,14 @@ static const struct device_type gpio_dev_type = { }; #ifdef CONFIG_GPIO_CDEV -#define gcdev_register(gdev, devt) gpiolib_cdev_register((gdev), (devt)) +#define gcdev_register(gc, devt) gpiolib_cdev_register((gc), (devt)) #define gcdev_unregister(gdev) gpiolib_cdev_unregister((gdev)) #else /* * gpiolib_cdev_register() indirectly calls device_add(), which is still * required even when cdev is not selected. */ -#define gcdev_register(gdev, devt) device_add(&(gdev)->dev) +#define gcdev_register(gc, devt) device_add(&(gc)->gpiodev->dev) #define gcdev_unregister(gdev) device_del(&(gdev)->dev) #endif @@ -897,8 +897,9 @@ static const struct device_type gpio_dev_type = { * An initial reference count has been held in gpiochip_add_data_with_key(). * The caller should drop the reference via gpio_device_put() on errors. */ -static int gpiochip_setup_dev(struct gpio_device *gdev) +static int gpiochip_setup_dev(struct gpio_chip *gc) { + struct gpio_device *gdev = gc->gpiodev; struct fwnode_handle *fwnode = dev_fwnode(&gdev->dev); int ret; @@ -911,11 +912,11 @@ static int gpiochip_setup_dev(struct gpio_device *gdev) if (fwnode && !fwnode->dev) fwnode_dev_initialized(fwnode, false); - ret = gcdev_register(gdev, gpio_devt); + ret = gcdev_register(gc, gpio_devt); if (ret) return ret; - ret = gpiochip_sysfs_register(gdev); + ret = gpiochip_sysfs_register(gc); if (ret) goto err_remove_device; @@ -962,13 +963,22 @@ static void machine_gpiochip_add(struct gpio_chip *gc) static void gpiochip_setup_devs(void) { struct gpio_device *gdev; + struct gpio_chip *gc; int ret; guard(srcu)(&gpio_devices_srcu); list_for_each_entry_srcu(gdev, &gpio_devices, list, srcu_read_lock_held(&gpio_devices_srcu)) { - ret = gpiochip_setup_dev(gdev); + guard(srcu)(&gdev->srcu); + + gc = srcu_dereference(gdev->chip, &gdev->srcu); + if (!gc) { + dev_err(&gdev->dev, "Underlying GPIO chip is gone\n"); + continue; + } + + ret = gpiochip_setup_dev(gc); if (ret) { gpio_device_put(gdev); dev_err(&gdev->dev, @@ -1226,7 +1236,7 @@ int gpiochip_add_data_with_key(struct gpio_chip *gc, void *data, * (i.e., `gpio_bus_type` is ready). Otherwise, defer until later. */ if (gpiolib_initialized) { - ret = gpiochip_setup_dev(gdev); + ret = gpiochip_setup_dev(gc); if (ret) goto err_teardown_shared; }