Struct gpio_device now provides a revocable provider to the underlying struct gpio_chip. Leverage revocable for linehandle_fileops so that it doesn't need to handle the synchronization by accessing the SRCU explicitly.
Also, it's unneeded to hold a reference count to the struct gpio_device while the file is opening. The struct gpio_device (i.e., (struct gpio_chip *)->gpiodev)) is valid as long as struct gpio_chip is valid. Signed-off-by: Tzung-Bi Shih <[email protected]> --- drivers/gpio/gpiolib-cdev.c | 18 +++++++++++------- 1 file changed, 11 insertions(+), 7 deletions(-) diff --git a/drivers/gpio/gpiolib-cdev.c b/drivers/gpio/gpiolib-cdev.c index 832a542c4f7a..f7c6f1367235 100644 --- a/drivers/gpio/gpiolib-cdev.c +++ b/drivers/gpio/gpiolib-cdev.c @@ -67,13 +67,13 @@ static_assert(IS_ALIGNED(sizeof(struct gpio_v2_line_values), 8)); #ifdef CONFIG_GPIO_CDEV_V1 /** * struct linehandle_state - contains the state of a userspace handle - * @gdev: the GPIO device the handle pertains to + * @chip_rev: revocable consumer handle for the corresponding struct gpio_chip * @label: consumer label used to tag descriptors * @descs: the GPIO descriptors held by this handle * @num_descs: the number of descriptors held in the descs array */ struct linehandle_state { - struct gpio_device *gdev; + struct revocable *chip_rev; const char *label; struct gpio_desc *descs[GPIOHANDLES_MAX]; u32 num_descs; @@ -211,10 +211,10 @@ static long linehandle_ioctl(struct file *file, unsigned int cmd, DECLARE_BITMAP(vals, GPIOHANDLES_MAX); unsigned int i; int ret; + struct gpio_chip *gc; - guard(srcu)(&lh->gdev->srcu); - - if (!rcu_access_pointer(lh->gdev->chip)) + REVOCABLE_TRY_ACCESS_WITH(lh->chip_rev, gc); + if (!gc) return -ENODEV; switch (cmd) { @@ -279,7 +279,8 @@ static void linehandle_free(struct linehandle_state *lh) if (lh->descs[i]) gpiod_free(lh->descs[i]); kfree(lh->label); - gpio_device_put(lh->gdev); + if (lh->chip_rev) + revocable_free(lh->chip_rev); kfree(lh); } @@ -322,7 +323,10 @@ static int linehandle_create(struct gpio_device *gdev, void __user *ip) lh = kzalloc(sizeof(*lh), GFP_KERNEL); if (!lh) return -ENOMEM; - lh->gdev = gpio_device_get(gdev); + + lh->chip_rev = revocable_alloc(gdev->chip_rp); + if (!lh->chip_rev) + return -ENOMEM; if (handlereq.consumer_label[0] != '\0') { /* label is only initialized if consumer_label is set */ -- 2.52.0.457.g6b5491de43-goog
