Struct gpio_device now provides a revocable provider to the underlying struct gpio_chip. Leverage revocable for accessing the struct gpio_chip.
Signed-off-by: Tzung-Bi Shih <[email protected]> --- v2: - Change usages accordingly after applying https://lore.kernel.org/all/[email protected]. - Preserve a local storage for `struct revocable`. - Combine multiple patches (see "v1:"). v1: - https://lore.kernel.org/all/[email protected] - https://lore.kernel.org/all/[email protected] - https://lore.kernel.org/all/[email protected] - https://lore.kernel.org/all/[email protected] - https://lore.kernel.org/all/[email protected] drivers/gpio/gpiolib-cdev.c | 70 ++++++++++++++++++------------------- 1 file changed, 34 insertions(+), 36 deletions(-) diff --git a/drivers/gpio/gpiolib-cdev.c b/drivers/gpio/gpiolib-cdev.c index aaa5de814468..ca9c04765df4 100644 --- a/drivers/gpio/gpiolib-cdev.c +++ b/drivers/gpio/gpiolib-cdev.c @@ -22,6 +22,7 @@ #include <linux/overflow.h> #include <linux/pinctrl/consumer.h> #include <linux/poll.h> +#include <linux/revocable.h> #include <linux/seq_file.h> #include <linux/spinlock.h> #include <linux/string.h> @@ -210,10 +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->gdev->chip_rp, gc); + if (!gc) return -ENODEV; switch (cmd) { @@ -1432,10 +1433,10 @@ static long linereq_ioctl(struct file *file, unsigned int cmd, { struct linereq *lr = file->private_data; void __user *ip = (void __user *)arg; + struct gpio_chip *gc; - guard(srcu)(&lr->gdev->srcu); - - if (!rcu_access_pointer(lr->gdev->chip)) + REVOCABLE_TRY_ACCESS_WITH(lr->gdev->chip_rp, gc); + if (!gc) return -ENODEV; switch (cmd) { @@ -1463,10 +1464,10 @@ static __poll_t linereq_poll(struct file *file, { struct linereq *lr = file->private_data; __poll_t events = 0; + struct gpio_chip *gc; - guard(srcu)(&lr->gdev->srcu); - - if (!rcu_access_pointer(lr->gdev->chip)) + REVOCABLE_TRY_ACCESS_WITH(lr->gdev->chip_rp, gc); + if (!gc) return EPOLLHUP | EPOLLERR; poll_wait(file, &lr->wait, wait); @@ -1485,10 +1486,10 @@ static ssize_t linereq_read(struct file *file, char __user *buf, struct gpio_v2_line_event le; ssize_t bytes_read = 0; int ret; + struct gpio_chip *gc; - guard(srcu)(&lr->gdev->srcu); - - if (!rcu_access_pointer(lr->gdev->chip)) + REVOCABLE_TRY_ACCESS_WITH(lr->gdev->chip_rp, gc); + if (!gc) return -ENODEV; if (count < sizeof(le)) @@ -1781,10 +1782,10 @@ static __poll_t lineevent_poll(struct file *file, { struct lineevent_state *le = file->private_data; __poll_t events = 0; + struct gpio_chip *gc; - guard(srcu)(&le->gdev->srcu); - - if (!rcu_access_pointer(le->gdev->chip)) + REVOCABLE_TRY_ACCESS_WITH(le->gdev->chip_rp, gc); + if (!gc) return EPOLLHUP | EPOLLERR; poll_wait(file, &le->wait, wait); @@ -1819,10 +1820,10 @@ static ssize_t lineevent_read(struct file *file, char __user *buf, ssize_t bytes_read = 0; ssize_t ge_size; int ret; + struct gpio_chip *gc; - guard(srcu)(&le->gdev->srcu); - - if (!rcu_access_pointer(le->gdev->chip)) + REVOCABLE_TRY_ACCESS_WITH(le->gdev->chip_rp, gc); + if (!gc) return -ENODEV; /* @@ -1901,10 +1902,10 @@ static long lineevent_ioctl(struct file *file, unsigned int cmd, struct lineevent_state *le = file->private_data; void __user *ip = (void __user *)arg; struct gpiohandle_data ghd; + struct gpio_chip *gc; - guard(srcu)(&le->gdev->srcu); - - if (!rcu_access_pointer(le->gdev->chip)) + REVOCABLE_TRY_ACCESS_WITH(le->gdev->chip_rp, gc); + if (!gc) return -ENODEV; /* @@ -2434,11 +2435,11 @@ static long gpio_ioctl(struct file *file, unsigned int cmd, unsigned long arg) struct gpio_chardev_data *cdev = file->private_data; struct gpio_device *gdev = cdev->gdev; void __user *ip = (void __user *)arg; - - guard(srcu)(&gdev->srcu); + struct gpio_chip *gc; /* We fail any subsequent ioctl():s when the chip is gone */ - if (!rcu_access_pointer(gdev->chip)) + REVOCABLE_TRY_ACCESS_WITH(gdev->chip_rp, gc); + if (!gc) return -ENODEV; /* Fill in the struct and pass to userspace */ @@ -2497,12 +2498,9 @@ static void lineinfo_changed_func(struct work_struct *work) * Pin functions are in general much more static and while it's * not 100% bullet-proof, it's good enough for most cases. */ - scoped_guard(srcu, &ctx->gdev->srcu) { - gc = srcu_dereference(ctx->gdev->chip, &ctx->gdev->srcu); - if (gc && - !pinctrl_gpio_can_use_line(gc, ctx->chg.info.offset)) - ctx->chg.info.flags |= GPIO_V2_LINE_FLAG_USED; - } + REVOCABLE_TRY_ACCESS_WITH(ctx->gdev->chip_rp, gc); + if (gc && !pinctrl_gpio_can_use_line(gc, ctx->chg.info.offset)) + ctx->chg.info.flags |= GPIO_V2_LINE_FLAG_USED; } ret = kfifo_in_spinlocked(&ctx->cdev->events, &ctx->chg, 1, @@ -2583,10 +2581,10 @@ static __poll_t lineinfo_watch_poll(struct file *file, { struct gpio_chardev_data *cdev = file->private_data; __poll_t events = 0; + struct gpio_chip *gc; - guard(srcu)(&cdev->gdev->srcu); - - if (!rcu_access_pointer(cdev->gdev->chip)) + REVOCABLE_TRY_ACCESS_WITH(cdev->gdev->chip_rp, gc); + if (!gc) return EPOLLHUP | EPOLLERR; poll_wait(file, &cdev->wait, pollt); @@ -2606,10 +2604,10 @@ static ssize_t lineinfo_watch_read(struct file *file, char __user *buf, ssize_t bytes_read = 0; int ret; size_t event_size; + struct gpio_chip *gc; - guard(srcu)(&cdev->gdev->srcu); - - if (!rcu_access_pointer(cdev->gdev->chip)) + REVOCABLE_TRY_ACCESS_WITH(cdev->gdev->chip_rp, gc); + if (!gc) return -ENODEV; #ifndef CONFIG_GPIO_CDEV_V1 -- 2.53.0.rc2.204.g2597b5adb4-goog
