From: Linus Torvalds Date: Fri, 19 Jan 2024 01:03:51 +0000 (-0800) Subject: Merge tag 'gpio-fixes-for-v6.8-rc1' of git://git.kernel.org/pub/scm/linux/kernel... X-Git-Tag: v6.8-rc1~39 X-Git-Url: http://git.samba.org/samba.git/?a=commitdiff_plain;h=345513583974110107300824375a91ff602d72ba;hp=5c93506983626419fb8719a7301b53faea1e0bb3;p=sfrench%2Fcifs-2.6.git Merge tag 'gpio-fixes-for-v6.8-rc1' of git://git./linux/kernel/git/brgl/linux Pull gpio fixes from Bartosz Golaszewski: "Apart from some regular driver fixes there's a relatively big revert of the locking changes that were introduced to GPIOLIB in this merge window. This is because it turned out that some legacy GPIO interfaces - that need to translate a number from the global GPIO numberspace to the address of the relevant descriptor, thus running a GPIO device lookup and taking the GPIO device list lock - are still used in old code from atomic context resulting in "scheduling while atomic" errors. I'll try to make the read-only part of the list access entirely lockless using SRCU but this will take some time so let's go back to the old global spinlock for now. Summary: - revert the changes aiming to use a read-write semaphore to protect the list of GPIO devices due to calls to legacy API taking that lock from atomic context in old code - fix inverted logic in DEFINE_FREE() for GPIO device references - check the return value of bgpio_init() in gpio-mlxbf3 - fix node address in the DT bindings example for gpio-xilinx - fix signedness bug in gpio-rtd - fix kernel-doc warnings in gpio-en7523" * tag 'gpio-fixes-for-v6.8-rc1' of git://git.kernel.org/pub/scm/linux/kernel/git/brgl/linux: gpiolib: revert the attempt to protect the GPIO device list with an rwsem gpio: EN7523: fix kernel-doc warnings gpiolib: Fix scope-based gpio_device refcounting gpio: mlxbf3: add an error code check in mlxbf3_gpio_probe dt-bindings: gpio: xilinx: Fix node address in gpio gpio: rtd: Fix signedness bug in probe --- diff --git a/Documentation/devicetree/bindings/gpio/xlnx,gpio-xilinx.yaml b/Documentation/devicetree/bindings/gpio/xlnx,gpio-xilinx.yaml index c1060e5fcef3..d3d8a2e143ed 100644 --- a/Documentation/devicetree/bindings/gpio/xlnx,gpio-xilinx.yaml +++ b/Documentation/devicetree/bindings/gpio/xlnx,gpio-xilinx.yaml @@ -126,7 +126,7 @@ examples: - | #include - gpio@e000a000 { + gpio@a0020000 { compatible = "xlnx,xps-gpio-1.00.a"; reg = <0xa0020000 0x10000>; #gpio-cells = <2>; diff --git a/drivers/gpio/gpio-en7523.c b/drivers/gpio/gpio-en7523.c index f836a8db4c1d..69834db2c1cf 100644 --- a/drivers/gpio/gpio-en7523.c +++ b/drivers/gpio/gpio-en7523.c @@ -12,11 +12,11 @@ #define AIROHA_GPIO_MAX 32 /** - * airoha_gpio_ctrl - Airoha GPIO driver data + * struct airoha_gpio_ctrl - Airoha GPIO driver data * @gc: Associated gpio_chip instance. * @data: The data register. - * @dir0: The direction register for the lower 16 pins. - * @dir1: The direction register for the higher 16 pins. + * @dir: [0] The direction register for the lower 16 pins. + * [1]: The direction register for the higher 16 pins. * @output: The output enable register. */ struct airoha_gpio_ctrl { diff --git a/drivers/gpio/gpio-mlxbf3.c b/drivers/gpio/gpio-mlxbf3.c index 7a3e1760fc5b..d5906d419b0a 100644 --- a/drivers/gpio/gpio-mlxbf3.c +++ b/drivers/gpio/gpio-mlxbf3.c @@ -215,6 +215,8 @@ static int mlxbf3_gpio_probe(struct platform_device *pdev) gs->gpio_clr_io + MLXBF_GPIO_FW_DATA_OUT_CLEAR, gs->gpio_set_io + MLXBF_GPIO_FW_OUTPUT_ENABLE_SET, gs->gpio_clr_io + MLXBF_GPIO_FW_OUTPUT_ENABLE_CLEAR, 0); + if (ret) + return dev_err_probe(dev, ret, "%s: bgpio_init() failed", __func__); gc->request = gpiochip_generic_request; gc->free = gpiochip_generic_free; diff --git a/drivers/gpio/gpio-rtd.c b/drivers/gpio/gpio-rtd.c index a7939bd0aa56..bf7f008f58d7 100644 --- a/drivers/gpio/gpio-rtd.c +++ b/drivers/gpio/gpio-rtd.c @@ -525,18 +525,21 @@ static int rtd_gpio_probe(struct platform_device *pdev) struct device *dev = &pdev->dev; struct gpio_irq_chip *irq_chip; struct rtd_gpio *data; + int ret; data = devm_kzalloc(dev, sizeof(*data), GFP_KERNEL); if (!data) return -ENOMEM; - data->irqs[0] = platform_get_irq(pdev, 0); - if (data->irqs[0] < 0) - return data->irqs[0]; + ret = platform_get_irq(pdev, 0); + if (ret < 0) + return ret; + data->irqs[0] = ret; - data->irqs[1] = platform_get_irq(pdev, 1); - if (data->irqs[1] < 0) - return data->irqs[1]; + ret = platform_get_irq(pdev, 1); + if (ret < 0) + return ret; + data->irqs[1] = ret; data->info = device_get_match_data(dev); if (!data->info) diff --git a/drivers/gpio/gpiolib-sysfs.c b/drivers/gpio/gpiolib-sysfs.c index 4dbf298bb5dd..6bf5332136e5 100644 --- a/drivers/gpio/gpiolib-sysfs.c +++ b/drivers/gpio/gpiolib-sysfs.c @@ -768,25 +768,6 @@ int gpiochip_sysfs_register(struct gpio_device *gdev) return 0; } -int gpiochip_sysfs_register_all(void) -{ - struct gpio_device *gdev; - int ret; - - guard(rwsem_read)(&gpio_devices_sem); - - list_for_each_entry(gdev, &gpio_devices, list) { - if (gdev->mockdev) - continue; - - ret = gpiochip_sysfs_register(gdev); - if (ret) - return ret; - } - - return 0; -} - void gpiochip_sysfs_unregister(struct gpio_device *gdev) { struct gpio_desc *desc; @@ -811,7 +792,9 @@ void gpiochip_sysfs_unregister(struct gpio_device *gdev) static int __init gpiolib_sysfs_init(void) { - int status; + int status; + unsigned long flags; + struct gpio_device *gdev; status = class_register(&gpio_class); if (status < 0) @@ -823,6 +806,26 @@ static int __init gpiolib_sysfs_init(void) * We run before arch_initcall() so chip->dev nodes can have * registered, and so arch_initcall() can always gpiod_export(). */ - return gpiochip_sysfs_register_all(); + spin_lock_irqsave(&gpio_lock, flags); + list_for_each_entry(gdev, &gpio_devices, list) { + if (gdev->mockdev) + continue; + + /* + * TODO we yield gpio_lock here because + * gpiochip_sysfs_register() acquires a mutex. This is unsafe + * and needs to be fixed. + * + * Also it would be nice to use gpio_device_find() here so we + * can keep gpio_chips local to gpiolib.c, but the yield of + * gpio_lock prevents us from doing this. + */ + spin_unlock_irqrestore(&gpio_lock, flags); + status = gpiochip_sysfs_register(gdev); + spin_lock_irqsave(&gpio_lock, flags); + } + spin_unlock_irqrestore(&gpio_lock, flags); + + return status; } postcore_initcall(gpiolib_sysfs_init); diff --git a/drivers/gpio/gpiolib-sysfs.h b/drivers/gpio/gpiolib-sysfs.h index ab157cec0b4b..b794b396d6a5 100644 --- a/drivers/gpio/gpiolib-sysfs.h +++ b/drivers/gpio/gpiolib-sysfs.h @@ -8,7 +8,6 @@ struct gpio_device; #ifdef CONFIG_GPIO_SYSFS int gpiochip_sysfs_register(struct gpio_device *gdev); -int gpiochip_sysfs_register_all(void); void gpiochip_sysfs_unregister(struct gpio_device *gdev); #else @@ -18,11 +17,6 @@ static inline int gpiochip_sysfs_register(struct gpio_device *gdev) return 0; } -static inline int gpiochip_sysfs_register_all(void) -{ - return 0; -} - static inline void gpiochip_sysfs_unregister(struct gpio_device *gdev) { } diff --git a/drivers/gpio/gpiolib.c b/drivers/gpio/gpiolib.c index 4c93cf73a826..44c8f5743a24 100644 --- a/drivers/gpio/gpiolib.c +++ b/drivers/gpio/gpiolib.c @@ -2,7 +2,6 @@ #include #include -#include #include #include #include @@ -16,7 +15,6 @@ #include #include #include -#include #include #include #include @@ -83,9 +81,7 @@ DEFINE_SPINLOCK(gpio_lock); static DEFINE_MUTEX(gpio_lookup_lock); static LIST_HEAD(gpio_lookup_list); - LIST_HEAD(gpio_devices); -DECLARE_RWSEM(gpio_devices_sem); static DEFINE_MUTEX(gpio_machine_hogs_mutex); static LIST_HEAD(gpio_machine_hogs); @@ -117,15 +113,20 @@ static inline void desc_set_label(struct gpio_desc *d, const char *label) struct gpio_desc *gpio_to_desc(unsigned gpio) { struct gpio_device *gdev; + unsigned long flags; + + spin_lock_irqsave(&gpio_lock, flags); - scoped_guard(rwsem_read, &gpio_devices_sem) { - list_for_each_entry(gdev, &gpio_devices, list) { - if (gdev->base <= gpio && - gdev->base + gdev->ngpio > gpio) - return &gdev->descs[gpio - gdev->base]; + list_for_each_entry(gdev, &gpio_devices, list) { + if (gdev->base <= gpio && + gdev->base + gdev->ngpio > gpio) { + spin_unlock_irqrestore(&gpio_lock, flags); + return &gdev->descs[gpio - gdev->base]; } } + spin_unlock_irqrestore(&gpio_lock, flags); + if (!gpio_is_valid(gpio)) pr_warn("invalid GPIO %d\n", gpio); @@ -398,21 +399,26 @@ static int gpiodev_add_to_list_unlocked(struct gpio_device *gdev) static struct gpio_desc *gpio_name_to_desc(const char * const name) { struct gpio_device *gdev; + unsigned long flags; if (!name) return NULL; - guard(rwsem_read)(&gpio_devices_sem); + spin_lock_irqsave(&gpio_lock, flags); list_for_each_entry(gdev, &gpio_devices, list) { struct gpio_desc *desc; for_each_gpio_desc(gdev->chip, desc) { - if (desc->name && !strcmp(desc->name, name)) + if (desc->name && !strcmp(desc->name, name)) { + spin_unlock_irqrestore(&gpio_lock, flags); return desc; + } } } + spin_unlock_irqrestore(&gpio_lock, flags); + return NULL; } @@ -807,6 +813,7 @@ int gpiochip_add_data_with_key(struct gpio_chip *gc, void *data, struct lock_class_key *request_key) { struct gpio_device *gdev; + unsigned long flags; unsigned int i; int base = 0; int ret = 0; @@ -871,46 +878,49 @@ int gpiochip_add_data_with_key(struct gpio_chip *gc, void *data, gdev->ngpio = gc->ngpio; - scoped_guard(rwsem_write, &gpio_devices_sem) { - /* - * TODO: this allocates a Linux GPIO number base in the global - * GPIO numberspace for this chip. In the long run we want to - * get *rid* of this numberspace and use only descriptors, but - * it may be a pipe dream. It will not happen before we get rid - * of the sysfs interface anyways. - */ - base = gc->base; + spin_lock_irqsave(&gpio_lock, flags); + /* + * TODO: this allocates a Linux GPIO number base in the global + * GPIO numberspace for this chip. In the long run we want to + * get *rid* of this numberspace and use only descriptors, but + * it may be a pipe dream. It will not happen before we get rid + * of the sysfs interface anyways. + */ + base = gc->base; + if (base < 0) { + base = gpiochip_find_base_unlocked(gc->ngpio); if (base < 0) { - base = gpiochip_find_base_unlocked(gc->ngpio); - if (base < 0) { - ret = base; - base = 0; - goto err_free_label; - } - /* - * TODO: it should not be necessary to reflect the assigned - * base outside of the GPIO subsystem. Go over drivers and - * see if anyone makes use of this, else drop this and assign - * a poison instead. - */ - gc->base = base; - } else { - dev_warn(&gdev->dev, - "Static allocation of GPIO base is deprecated, use dynamic allocation.\n"); - } - gdev->base = base; - - ret = gpiodev_add_to_list_unlocked(gdev); - if (ret) { - chip_err(gc, "GPIO integer space overlap, cannot add chip\n"); + spin_unlock_irqrestore(&gpio_lock, flags); + ret = base; + base = 0; goto err_free_label; } + /* + * TODO: it should not be necessary to reflect the assigned + * base outside of the GPIO subsystem. Go over drivers and + * see if anyone makes use of this, else drop this and assign + * a poison instead. + */ + gc->base = base; + } else { + dev_warn(&gdev->dev, + "Static allocation of GPIO base is deprecated, use dynamic allocation.\n"); + } + gdev->base = base; - for (i = 0; i < gc->ngpio; i++) - gdev->descs[i].gdev = gdev; + ret = gpiodev_add_to_list_unlocked(gdev); + if (ret) { + spin_unlock_irqrestore(&gpio_lock, flags); + chip_err(gc, "GPIO integer space overlap, cannot add chip\n"); + goto err_free_label; } + for (i = 0; i < gc->ngpio; i++) + gdev->descs[i].gdev = gdev; + + spin_unlock_irqrestore(&gpio_lock, flags); + BLOCKING_INIT_NOTIFIER_HEAD(&gdev->line_state_notifier); BLOCKING_INIT_NOTIFIER_HEAD(&gdev->device_notifier); init_rwsem(&gdev->sem); @@ -1001,8 +1011,9 @@ err_free_gpiochip_mask: goto err_print_message; } err_remove_from_list: - scoped_guard(rwsem_write, &gpio_devices_sem) - list_del(&gdev->list); + spin_lock_irqsave(&gpio_lock, flags); + list_del(&gdev->list); + spin_unlock_irqrestore(&gpio_lock, flags); err_free_label: kfree_const(gdev->label); err_free_descs: @@ -1065,7 +1076,7 @@ void gpiochip_remove(struct gpio_chip *gc) dev_crit(&gdev->dev, "REMOVING GPIOCHIP WITH GPIOS STILL REQUESTED\n"); - scoped_guard(rwsem_write, &gpio_devices_sem) + scoped_guard(spinlock_irqsave, &gpio_lock) list_del(&gdev->list); /* @@ -1114,7 +1125,7 @@ struct gpio_device *gpio_device_find(void *data, */ might_sleep(); - guard(rwsem_read)(&gpio_devices_sem); + guard(spinlock_irqsave)(&gpio_lock); list_for_each_entry(gdev, &gpio_devices, list) { if (gdev->chip && match(gdev->chip, data)) @@ -4725,33 +4736,35 @@ static void gpiolib_dbg_show(struct seq_file *s, struct gpio_device *gdev) static void *gpiolib_seq_start(struct seq_file *s, loff_t *pos) { + unsigned long flags; struct gpio_device *gdev = NULL; loff_t index = *pos; s->private = ""; - guard(rwsem_read)(&gpio_devices_sem); - - list_for_each_entry(gdev, &gpio_devices, list) { - if (index-- == 0) + spin_lock_irqsave(&gpio_lock, flags); + list_for_each_entry(gdev, &gpio_devices, list) + if (index-- == 0) { + spin_unlock_irqrestore(&gpio_lock, flags); return gdev; - } + } + spin_unlock_irqrestore(&gpio_lock, flags); return NULL; } static void *gpiolib_seq_next(struct seq_file *s, void *v, loff_t *pos) { + unsigned long flags; struct gpio_device *gdev = v; void *ret = NULL; - scoped_guard(rwsem_read, &gpio_devices_sem) { - if (list_is_last(&gdev->list, &gpio_devices)) - ret = NULL; - else - ret = list_first_entry(&gdev->list, struct gpio_device, - list); - } + spin_lock_irqsave(&gpio_lock, flags); + if (list_is_last(&gdev->list, &gpio_devices)) + ret = NULL; + else + ret = list_first_entry(&gdev->list, struct gpio_device, list); + spin_unlock_irqrestore(&gpio_lock, flags); s->private = "\n"; ++*pos; diff --git a/drivers/gpio/gpiolib.h b/drivers/gpio/gpiolib.h index 97df54abf57a..a4a2520b5f31 100644 --- a/drivers/gpio/gpiolib.h +++ b/drivers/gpio/gpiolib.h @@ -15,7 +15,6 @@ #include /* for enum gpiod_flags */ #include #include -#include #include #include @@ -137,7 +136,6 @@ int gpiod_set_transitory(struct gpio_desc *desc, bool transitory); extern spinlock_t gpio_lock; extern struct list_head gpio_devices; -extern struct rw_semaphore gpio_devices_sem; void gpiod_line_state_notify(struct gpio_desc *desc, unsigned long action); diff --git a/include/linux/gpio/driver.h b/include/linux/gpio/driver.h index e846bd4e7559..9a5c6c76e653 100644 --- a/include/linux/gpio/driver.h +++ b/include/linux/gpio/driver.h @@ -635,7 +635,7 @@ struct gpio_device *gpio_device_get(struct gpio_device *gdev); void gpio_device_put(struct gpio_device *gdev); DEFINE_FREE(gpio_device_put, struct gpio_device *, - if (IS_ERR_OR_NULL(_T)) gpio_device_put(_T)); + if (!IS_ERR_OR_NULL(_T)) gpio_device_put(_T)) struct device *gpio_device_to_device(struct gpio_device *gdev);