From 5c887b65bbd1a3fc28e2e20399acede0baa83edb Mon Sep 17 00:00:00 2001 From: Andy Shevchenko Date: Mon, 25 Mar 2024 19:16:25 +0200 Subject: gpiolib: Fix debug messaging in gpiod_find_and_request() When consolidating GPIO lookups in ACPI code, the debug messaging had been reworked that the user may see [ 13.401147] (NULL device *): using ACPI '\_SB.LEDS.led-0' for '(null)' GPIO lookup [ 13.401378] gpio gpiochip0: Persistence not supported for GPIO 40 [ 13.401402] gpio-40 (?): no flags found for (null) instead of [ 14.182962] gpio gpiochip0: Persistence not supported for GPIO 40 [ 14.182994] gpio-40 (?): no flags found for gpios The '(null)' parts are less informative and likely scare the users. Replace them by '(default)' which can point out to the default connection IDs, such as 'gpios'. While at it, amend other places where con_id is used in the messages. Reported-by: Ferry Toth Fixes: 8eb1f71e7acc ("gpiolib: consolidate GPIO lookups") Suggested-by: Dmitry Torokhov Tested-by: Ferry Toth Signed-off-by: Andy Shevchenko Signed-off-by: Bartosz Golaszewski --- drivers/gpio/gpiolib.c | 32 ++++++++++++++++++-------------- 1 file changed, 18 insertions(+), 14 deletions(-) (limited to 'drivers/gpio/gpiolib.c') diff --git a/drivers/gpio/gpiolib.c b/drivers/gpio/gpiolib.c index ce94e37bcbee..59ccf9a3e153 100644 --- a/drivers/gpio/gpiolib.c +++ b/drivers/gpio/gpiolib.c @@ -2397,6 +2397,11 @@ char *gpiochip_dup_line_label(struct gpio_chip *gc, unsigned int offset) } EXPORT_SYMBOL_GPL(gpiochip_dup_line_label); +static inline const char *function_name_or_default(const char *con_id) +{ + return con_id ?: "(default)"; +} + /** * gpiochip_request_own_desc - Allow GPIO chip to request its own descriptor * @gc: GPIO chip @@ -2425,10 +2430,11 @@ struct gpio_desc *gpiochip_request_own_desc(struct gpio_chip *gc, enum gpiod_flags dflags) { struct gpio_desc *desc = gpiochip_get_desc(gc, hwnum); + const char *name = function_name_or_default(label); int ret; if (IS_ERR(desc)) { - chip_err(gc, "failed to get GPIO descriptor\n"); + chip_err(gc, "failed to get GPIO %s descriptor\n", name); return desc; } @@ -2438,8 +2444,8 @@ struct gpio_desc *gpiochip_request_own_desc(struct gpio_chip *gc, ret = gpiod_configure_flags(desc, label, lflags, dflags); if (ret) { - chip_err(gc, "setup of own GPIO %s failed\n", label); gpiod_free_commit(desc); + chip_err(gc, "setup of own GPIO %s failed\n", name); return ERR_PTR(ret); } @@ -4153,19 +4159,17 @@ static struct gpio_desc *gpiod_find_by_fwnode(struct fwnode_handle *fwnode, enum gpiod_flags *flags, unsigned long *lookupflags) { + const char *name = function_name_or_default(con_id); struct gpio_desc *desc = ERR_PTR(-ENOENT); if (is_of_node(fwnode)) { - dev_dbg(consumer, "using DT '%pfw' for '%s' GPIO lookup\n", - fwnode, con_id); + dev_dbg(consumer, "using DT '%pfw' for '%s' GPIO lookup\n", fwnode, name); desc = of_find_gpio(to_of_node(fwnode), con_id, idx, lookupflags); } else if (is_acpi_node(fwnode)) { - dev_dbg(consumer, "using ACPI '%pfw' for '%s' GPIO lookup\n", - fwnode, con_id); + dev_dbg(consumer, "using ACPI '%pfw' for '%s' GPIO lookup\n", fwnode, name); desc = acpi_find_gpio(fwnode, con_id, idx, flags, lookupflags); } else if (is_software_node(fwnode)) { - dev_dbg(consumer, "using swnode '%pfw' for '%s' GPIO lookup\n", - fwnode, con_id); + dev_dbg(consumer, "using swnode '%pfw' for '%s' GPIO lookup\n", fwnode, name); desc = swnode_find_gpio(fwnode, con_id, idx, lookupflags); } @@ -4181,6 +4185,7 @@ struct gpio_desc *gpiod_find_and_request(struct device *consumer, bool platform_lookup_allowed) { unsigned long lookupflags = GPIO_LOOKUP_FLAGS_DEFAULT; + const char *name = function_name_or_default(con_id); /* * scoped_guard() is implemented as a for loop, meaning static * analyzers will complain about these two not being initialized. @@ -4203,8 +4208,7 @@ struct gpio_desc *gpiod_find_and_request(struct device *consumer, } if (IS_ERR(desc)) { - dev_dbg(consumer, "No GPIO consumer %s found\n", - con_id); + dev_dbg(consumer, "No GPIO consumer %s found\n", name); return desc; } @@ -4226,15 +4230,14 @@ struct gpio_desc *gpiod_find_and_request(struct device *consumer, * * FIXME: Make this more sane and safe. */ - dev_info(consumer, - "nonexclusive access to GPIO for %s\n", con_id); + dev_info(consumer, "nonexclusive access to GPIO for %s\n", name); return desc; } ret = gpiod_configure_flags(desc, con_id, lookupflags, flags); if (ret < 0) { - dev_dbg(consumer, "setup of GPIO %s failed\n", con_id); gpiod_put(desc); + dev_dbg(consumer, "setup of GPIO %s failed\n", name); return ERR_PTR(ret); } @@ -4350,6 +4353,7 @@ EXPORT_SYMBOL_GPL(gpiod_get_optional); int gpiod_configure_flags(struct gpio_desc *desc, const char *con_id, unsigned long lflags, enum gpiod_flags dflags) { + const char *name = function_name_or_default(con_id); int ret; if (lflags & GPIO_ACTIVE_LOW) @@ -4393,7 +4397,7 @@ int gpiod_configure_flags(struct gpio_desc *desc, const char *con_id, /* No particular flag request, return here... */ if (!(dflags & GPIOD_FLAGS_BIT_DIR_SET)) { - gpiod_dbg(desc, "no flags found for %s\n", con_id); + gpiod_dbg(desc, "no flags found for GPIO %s\n", name); return 0; } -- cgit v1.2.3-59-g8ed1b From 39c9049770f8b5911beed49250d7c6b135685ebc Mon Sep 17 00:00:00 2001 From: Peng Fan Date: Mon, 25 Mar 2024 19:16:26 +0200 Subject: gpiolib: use dev_err() when gpiod_configure_flags failed When gpio-ranges property was missed to be added in the gpio node, using dev_err() to show an error message will helping to locate issues easier. Signed-off-by: Peng Fan Signed-off-by: Andy Shevchenko Signed-off-by: Bartosz Golaszewski --- drivers/gpio/gpiolib.c | 2 +- 1 file changed, 1 insertion(+), 1 deletion(-) (limited to 'drivers/gpio/gpiolib.c') diff --git a/drivers/gpio/gpiolib.c b/drivers/gpio/gpiolib.c index 59ccf9a3e153..6c963a4fbc72 100644 --- a/drivers/gpio/gpiolib.c +++ b/drivers/gpio/gpiolib.c @@ -4237,7 +4237,7 @@ struct gpio_desc *gpiod_find_and_request(struct device *consumer, ret = gpiod_configure_flags(desc, con_id, lookupflags, flags); if (ret < 0) { gpiod_put(desc); - dev_dbg(consumer, "setup of GPIO %s failed\n", name); + dev_err(consumer, "setup of GPIO %s failed: %d\n", name, ret); return ERR_PTR(ret); } -- cgit v1.2.3-59-g8ed1b From e8acd2d209a387f2358c2c83fe894b444db9ea46 Mon Sep 17 00:00:00 2001 From: Hans de Goede Date: Tue, 2 Apr 2024 18:43:45 +0200 Subject: gpiolib: Fix triggering "kobject: 'gpiochipX' is not initialized, yet" kobject_get() errors When a gpiochip gets added by loading a module, then another driver may be waiting for that gpiochip to load on the deferred-probe list. If the deferred-probe for the consumer of gpiochip then triggers between the gpiodev_add_to_list_unlocked() calls which makes gpio_device_find() see the chip and the gpiochip_setup_dev() later then gpio_device_find() does a kobject_get() on an uninitialized kobject since the kobject is initialized by gpiochip_setup_dev() calling device_initialize(): arizona spi-10WM5102:00: cannot find GPIO chip arizona, deferring arizona spi-10WM5102:00: cannot find GPIO chip arizona, deferring ------------[ cut here ]------------ kobject: 'gpiochip5' (00000000241466f2): is not initialized, yet kobject_get() is being called. WARNING: CPU: 3 PID: 42 at lib/kobject.c:640 kobject_get+0x43/0x70 Call Trace: kobject_get gpio_device_find gpiod_find_and_request gpiod_get snd_byt_wm5102_mc_probe Not only is the device not initialized yet, but when the gpio-device is added to the list things like the irqchip also have not been initialized yet. So gpio_device_find() should really ignore the gpio-device until gpiochip_add_data_with_key() is fully done. Add a device_is_registered() check to gpio_device_find() to ignore gpio-devices on the list which are not yet fully initialized. Fixes: aab5c6f20023 ("gpio: set device type for GPIO chips") Suggested-by: Bartosz Golaszewski Signed-off-by: Hans de Goede Reviewed-by: Andy Shevchenko [Bartosz: fix a typo in commit message] Signed-off-by: Bartosz Golaszewski --- drivers/gpio/gpiolib.c | 3 +++ 1 file changed, 3 insertions(+) (limited to 'drivers/gpio/gpiolib.c') diff --git a/drivers/gpio/gpiolib.c b/drivers/gpio/gpiolib.c index 59ccf9a3e153..94903fc1c145 100644 --- a/drivers/gpio/gpiolib.c +++ b/drivers/gpio/gpiolib.c @@ -1175,6 +1175,9 @@ struct gpio_device *gpio_device_find(const void *data, list_for_each_entry_srcu(gdev, &gpio_devices, list, srcu_read_lock_held(&gpio_devices_srcu)) { + if (!device_is_registered(&gdev->dev)) + continue; + guard(srcu)(&gdev->srcu); gc = srcu_dereference(gdev->chip, &gdev->srcu); -- cgit v1.2.3-59-g8ed1b From 1685f72a6dcc55b6a5e50c127b9a0165e8c682a3 Mon Sep 17 00:00:00 2001 From: Andy Shevchenko Date: Tue, 26 Mar 2024 20:11:20 +0200 Subject: gpiolib: Do not mention legacy GPIOF_* in the code We are going to remove legacy API from kernel, don't mention it in the code that does not use it already for a while. Signed-off-by: Andy Shevchenko Signed-off-by: Bartosz Golaszewski --- drivers/gpio/gpiolib.c | 5 ++++- 1 file changed, 4 insertions(+), 1 deletion(-) (limited to 'drivers/gpio/gpiolib.c') diff --git a/drivers/gpio/gpiolib.c b/drivers/gpio/gpiolib.c index 6c963a4fbc72..f20367b1ea8e 100644 --- a/drivers/gpio/gpiolib.c +++ b/drivers/gpio/gpiolib.c @@ -365,7 +365,10 @@ int gpiod_get_direction(struct gpio_desc *desc) if (ret < 0) return ret; - /* GPIOF_DIR_IN or other positive, otherwise GPIOF_DIR_OUT */ + /* + * GPIO_LINE_DIRECTION_IN or other positive, + * otherwise GPIO_LINE_DIRECTION_OUT. + */ if (ret > 0) ret = 1; -- cgit v1.2.3-59-g8ed1b From 8a7a6103258715857310253ec2193bcc4d1d7082 Mon Sep 17 00:00:00 2001 From: Andy Shevchenko Date: Wed, 21 Feb 2024 23:31:56 +0200 Subject: gpiolib: Get rid of never false gpio_is_valid() calls In the cases when gpio_is_valid() is called with unsigned parameter the result is always true in the GPIO library code, hence the check for false won't ever be true. Get rid of such calls. While at it, move GPIO device base to be unsigned to clearly show it won't ever be negative. This requires a new definition for the maximum GPIO number in the system. Signed-off-by: Andy Shevchenko Reviewed-by: Linus Walleij Signed-off-by: Bartosz Golaszewski --- drivers/gpio/gpiolib-legacy.c | 10 +++++----- drivers/gpio/gpiolib-sysfs.c | 2 +- drivers/gpio/gpiolib.c | 19 +++++++++---------- drivers/gpio/gpiolib.h | 2 +- include/linux/gpio.h | 6 ++++++ 5 files changed, 22 insertions(+), 17 deletions(-) (limited to 'drivers/gpio/gpiolib.c') diff --git a/drivers/gpio/gpiolib-legacy.c b/drivers/gpio/gpiolib-legacy.c index 616d60187f85..5a9911ae9125 100644 --- a/drivers/gpio/gpiolib-legacy.c +++ b/drivers/gpio/gpiolib-legacy.c @@ -28,10 +28,9 @@ int gpio_request_one(unsigned gpio, unsigned long flags, const char *label) struct gpio_desc *desc; int err; - desc = gpio_to_desc(gpio); - /* Compatibility: assume unavailable "valid" GPIOs will appear later */ - if (!desc && gpio_is_valid(gpio)) + desc = gpio_to_desc(gpio); + if (!desc) return -EPROBE_DEFER; err = gpiod_request(desc, label); @@ -63,10 +62,11 @@ EXPORT_SYMBOL_GPL(gpio_request_one); */ int gpio_request(unsigned gpio, const char *label) { - struct gpio_desc *desc = gpio_to_desc(gpio); + struct gpio_desc *desc; /* Compatibility: assume unavailable "valid" GPIOs will appear later */ - if (!desc && gpio_is_valid(gpio)) + desc = gpio_to_desc(gpio); + if (!desc) return -EPROBE_DEFER; return gpiod_request(desc, label); diff --git a/drivers/gpio/gpiolib-sysfs.c b/drivers/gpio/gpiolib-sysfs.c index 6853ecd98bcb..26202586fd39 100644 --- a/drivers/gpio/gpiolib-sysfs.c +++ b/drivers/gpio/gpiolib-sysfs.c @@ -412,7 +412,7 @@ static ssize_t base_show(struct device *dev, { const struct gpio_device *gdev = dev_get_drvdata(dev); - return sysfs_emit(buf, "%d\n", gdev->base); + return sysfs_emit(buf, "%u\n", gdev->base); } static DEVICE_ATTR_RO(base); diff --git a/drivers/gpio/gpiolib.c b/drivers/gpio/gpiolib.c index f20367b1ea8e..f749ece2d3cd 100644 --- a/drivers/gpio/gpiolib.c +++ b/drivers/gpio/gpiolib.c @@ -150,9 +150,6 @@ struct gpio_desc *gpio_to_desc(unsigned gpio) } } - if (!gpio_is_valid(gpio)) - pr_warn("invalid GPIO %d\n", gpio); - return NULL; } EXPORT_SYMBOL_GPL(gpio_to_desc); @@ -297,10 +294,10 @@ struct gpio_chip *gpio_device_get_chip(struct gpio_device *gdev) EXPORT_SYMBOL_GPL(gpio_device_get_chip); /* dynamic allocation of GPIOs, e.g. on a hotplugged device */ -static int gpiochip_find_base_unlocked(int ngpio) +static int gpiochip_find_base_unlocked(u16 ngpio) { + unsigned int base = GPIO_DYNAMIC_BASE; struct gpio_device *gdev; - int base = GPIO_DYNAMIC_BASE; list_for_each_entry_srcu(gdev, &gpio_devices, list, lockdep_is_held(&gpio_devices_lock)) { @@ -311,9 +308,11 @@ static int gpiochip_find_base_unlocked(int ngpio) base = gdev->base + gdev->ngpio; if (base < GPIO_DYNAMIC_BASE) base = GPIO_DYNAMIC_BASE; + if (base > GPIO_DYNAMIC_MAX - ngpio) + break; } - if (gpio_is_valid(base)) { + if (base <= GPIO_DYNAMIC_MAX - ngpio) { pr_debug("%s: found new base at %d\n", __func__, base); return base; } else { @@ -749,7 +748,7 @@ static int gpiochip_setup_dev(struct gpio_device *gdev) if (ret) goto err_remove_device; - dev_dbg(&gdev->dev, "registered GPIOs %d to %d on %s\n", gdev->base, + dev_dbg(&gdev->dev, "registered GPIOs %u to %u on %s\n", gdev->base, gdev->base + gdev->ngpio - 1, gdev->label); return 0; @@ -4788,14 +4787,14 @@ static void gpiolib_dbg_show(struct seq_file *s, struct gpio_device *gdev) value = gpio_chip_get_value(gc, desc); is_irq = test_bit(FLAG_USED_AS_IRQ, &desc->flags); active_low = test_bit(FLAG_ACTIVE_LOW, &desc->flags); - seq_printf(s, " gpio-%-3d (%-20.20s|%-20.20s) %s %s %s%s\n", + seq_printf(s, " gpio-%-3u (%-20.20s|%-20.20s) %s %s %s%s\n", gpio, desc->name ?: "", gpiod_get_label(desc), is_out ? "out" : "in ", value >= 0 ? (value ? "hi" : "lo") : "? ", is_irq ? "IRQ " : "", active_low ? "ACTIVE LOW" : ""); } else if (desc->name) { - seq_printf(s, " gpio-%-3d (%-20.20s)\n", gpio, desc->name); + seq_printf(s, " gpio-%-3u (%-20.20s)\n", gpio, desc->name); } gpio++; @@ -4867,7 +4866,7 @@ static int gpiolib_seq_show(struct seq_file *s, void *v) return 0; } - seq_printf(s, "%s%s: GPIOs %d-%d", priv->newline ? "\n" : "", + seq_printf(s, "%s%s: GPIOs %u-%u", priv->newline ? "\n" : "", dev_name(&gdev->dev), gdev->base, gdev->base + gdev->ngpio - 1); parent = gc->parent; diff --git a/drivers/gpio/gpiolib.h b/drivers/gpio/gpiolib.h index f67d5991ab1c..7f94580efdbc 100644 --- a/drivers/gpio/gpiolib.h +++ b/drivers/gpio/gpiolib.h @@ -61,7 +61,7 @@ struct gpio_device { struct module *owner; struct gpio_chip __rcu *chip; struct gpio_desc *descs; - int base; + unsigned int base; u16 ngpio; bool can_sleep; const char *label; diff --git a/include/linux/gpio.h b/include/linux/gpio.h index 4aaedcf424ce..56ac7e7a2889 100644 --- a/include/linux/gpio.h +++ b/include/linux/gpio.h @@ -74,6 +74,12 @@ static inline bool gpio_is_valid(int number) * Until they are all fixed, leave 0-512 space for them. */ #define GPIO_DYNAMIC_BASE 512 +/* + * Define the maximum of the possible GPIO in the global numberspace. + * While the GPIO base and numbers are positive, we limit it with signed + * maximum as a lot of code is using negative values for special cases. + */ +#define GPIO_DYNAMIC_MAX INT_MAX /* Always use the library code for GPIO management calls, * or when sleeping may be involved. -- cgit v1.2.3-59-g8ed1b From a86d27693066a34a29be86f394bbad847b2d1749 Mon Sep 17 00:00:00 2001 From: Bartosz Golaszewski Date: Tue, 7 May 2024 14:13:46 +0200 Subject: gpiolib: fix the speed of descriptor label setting with SRCU Commit 1f2bcb8c8ccd ("gpio: protect the descriptor label with SRCU") caused a massive drop in performance of requesting GPIO lines due to the call to synchronize_srcu() on each label change. Rework the code to not wait until all read-only users are done with reading the label but instead atomically replace the label pointer and schedule its release after all read-only critical sections are done. To that end wrap the descriptor label in a struct that also contains the rcu_head struct required for deferring tasks using call_srcu() and stop using kstrdup_const() as we're required to allocate memory anyway. Just allocate enough for the label string and rcu_head in one go. Reported-by: Neil Armstrong Closes: https://lore.kernel.org/linux-gpio/CAMRc=Mfig2oooDQYTqo23W3PXSdzhVO4p=G4+P8y1ppBOrkrJQ@mail.gmail.com/ Fixes: 1f2bcb8c8ccd ("gpio: protect the descriptor label with SRCU") Suggested-by: "Paul E. McKenney" Tested-by: Neil Armstrong # on SM8650-QRD Acked-by: "Paul E. McKenney" Link: https://lore.kernel.org/r/20240507121346.16969-1-brgl@bgdev.pl Signed-off-by: Bartosz Golaszewski --- drivers/gpio/gpiolib.c | 31 ++++++++++++++++++++++++------- drivers/gpio/gpiolib.h | 7 ++++++- 2 files changed, 30 insertions(+), 8 deletions(-) (limited to 'drivers/gpio/gpiolib.c') diff --git a/drivers/gpio/gpiolib.c b/drivers/gpio/gpiolib.c index 94903fc1c145..2fa3756c9073 100644 --- a/drivers/gpio/gpiolib.c +++ b/drivers/gpio/gpiolib.c @@ -101,6 +101,7 @@ static bool gpiolib_initialized; const char *gpiod_get_label(struct gpio_desc *desc) { + struct gpio_desc_label *label; unsigned long flags; flags = READ_ONCE(desc->flags); @@ -108,23 +109,36 @@ const char *gpiod_get_label(struct gpio_desc *desc) !test_bit(FLAG_REQUESTED, &flags)) return "interrupt"; - return test_bit(FLAG_REQUESTED, &flags) ? - srcu_dereference(desc->label, &desc->srcu) : NULL; + if (!test_bit(FLAG_REQUESTED, &flags)) + return NULL; + + label = srcu_dereference_check(desc->label, &desc->srcu, + srcu_read_lock_held(&desc->srcu)); + + return label->str; +} + +static void desc_free_label(struct rcu_head *rh) +{ + kfree(container_of(rh, struct gpio_desc_label, rh)); } static int desc_set_label(struct gpio_desc *desc, const char *label) { - const char *new = NULL, *old; + struct gpio_desc_label *new = NULL, *old; if (label) { - new = kstrdup_const(label, GFP_KERNEL); + new = kzalloc(struct_size(new, str, strlen(label) + 1), + GFP_KERNEL); if (!new) return -ENOMEM; + + strcpy(new->str, label); } old = rcu_replace_pointer(desc->label, new, 1); - synchronize_srcu(&desc->srcu); - kfree_const(old); + if (old) + call_srcu(&desc->srcu, &old->rh, desc_free_label); return 0; } @@ -697,8 +711,11 @@ 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++) + for (i = 0; i < gdev->ngpio; i++) { + /* Free pending label. */ + synchronize_srcu(&gdev->descs[i].srcu); cleanup_srcu_struct(&gdev->descs[i].srcu); + } ida_free(&gpio_ida, gdev->id); kfree_const(gdev->label); diff --git a/drivers/gpio/gpiolib.h b/drivers/gpio/gpiolib.h index f67d5991ab1c..69a353c789f0 100644 --- a/drivers/gpio/gpiolib.h +++ b/drivers/gpio/gpiolib.h @@ -137,6 +137,11 @@ int gpiod_set_transitory(struct gpio_desc *desc, bool transitory); void gpiod_line_state_notify(struct gpio_desc *desc, unsigned long action); +struct gpio_desc_label { + struct rcu_head rh; + char str[]; +}; + /** * struct gpio_desc - Opaque descriptor for a GPIO * @@ -177,7 +182,7 @@ struct gpio_desc { #define FLAG_EVENT_CLOCK_HTE 19 /* GPIO CDEV reports hardware timestamps in events */ /* Connection label */ - const char __rcu *label; + struct gpio_desc_label __rcu *label; /* Name of the GPIO */ const char *name; #ifdef CONFIG_OF_DYNAMIC -- cgit v1.2.3-59-g8ed1b From 7765ffed533d4a9f0291a0edc660496d104396ec Mon Sep 17 00:00:00 2001 From: Bartosz Golaszewski Date: Tue, 7 May 2024 19:24:14 +0200 Subject: gpiolib: use a single SRCU struct for all GPIO descriptors We used a per-descriptor SRCU struct in order to not impose a wait with synchronize_srcu() for descriptor X on read-only operations of descriptor Y. Now that we no longer call synchronize_srcu() on descriptor label change but only when releasing descriptor resources, we can use a single SRCU structure for all GPIO descriptors in a given chip. Suggested-by: "Paul E. McKenney" Acked-by: "Paul E. McKenney" Link: https://lore.kernel.org/r/20240507172414.28513-1-brgl@bgdev.pl Signed-off-by: Bartosz Golaszewski --- drivers/gpio/gpiolib-cdev.c | 2 +- drivers/gpio/gpiolib.c | 41 +++++++++++++++++++---------------------- drivers/gpio/gpiolib.h | 10 +++++----- 3 files changed, 25 insertions(+), 28 deletions(-) (limited to 'drivers/gpio/gpiolib.c') diff --git a/drivers/gpio/gpiolib-cdev.c b/drivers/gpio/gpiolib-cdev.c index d09c7d728365..fea149ae7774 100644 --- a/drivers/gpio/gpiolib-cdev.c +++ b/drivers/gpio/gpiolib-cdev.c @@ -2351,7 +2351,7 @@ static void gpio_desc_to_lineinfo(struct gpio_desc *desc, dflags = READ_ONCE(desc->flags); - scoped_guard(srcu, &desc->srcu) { + scoped_guard(srcu, &desc->gdev->desc_srcu) { label = gpiod_get_label(desc); if (label && test_bit(FLAG_REQUESTED, &dflags)) strscpy(info->consumer, label, diff --git a/drivers/gpio/gpiolib.c b/drivers/gpio/gpiolib.c index 2fa3756c9073..fa50db0c3605 100644 --- a/drivers/gpio/gpiolib.c +++ b/drivers/gpio/gpiolib.c @@ -112,8 +112,8 @@ const char *gpiod_get_label(struct gpio_desc *desc) if (!test_bit(FLAG_REQUESTED, &flags)) return NULL; - label = srcu_dereference_check(desc->label, &desc->srcu, - srcu_read_lock_held(&desc->srcu)); + label = srcu_dereference_check(desc->label, &desc->gdev->desc_srcu, + srcu_read_lock_held(&desc->gdev->desc_srcu)); return label->str; } @@ -138,7 +138,7 @@ static int desc_set_label(struct gpio_desc *desc, const char *label) old = rcu_replace_pointer(desc->label, new, 1); if (old) - call_srcu(&desc->srcu, &old->rh, desc_free_label); + call_srcu(&desc->gdev->desc_srcu, &old->rh, desc_free_label); return 0; } @@ -709,13 +709,10 @@ 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++) { - /* Free pending label. */ - synchronize_srcu(&gdev->descs[i].srcu); - cleanup_srcu_struct(&gdev->descs[i].srcu); - } + /* Call pending kfree()s for descriptor labels. */ + synchronize_srcu(&gdev->desc_srcu); + cleanup_srcu_struct(&gdev->desc_srcu); ida_free(&gpio_ida, gdev->id); kfree_const(gdev->label); @@ -992,6 +989,10 @@ int gpiochip_add_data_with_key(struct gpio_chip *gc, void *data, if (ret) goto err_remove_from_list; + ret = init_srcu_struct(&gdev->desc_srcu); + if (ret) + goto err_cleanup_gdev_srcu; + #ifdef CONFIG_PINCTRL INIT_LIST_HEAD(&gdev->pin_ranges); #endif @@ -999,23 +1000,19 @@ int gpiochip_add_data_with_key(struct gpio_chip *gc, void *data, if (gc->names) { ret = gpiochip_set_desc_names(gc); if (ret) - goto err_cleanup_gdev_srcu; + goto err_cleanup_desc_srcu; } ret = gpiochip_set_names(gc); if (ret) - goto err_cleanup_gdev_srcu; + goto err_cleanup_desc_srcu; ret = gpiochip_init_valid_mask(gc); if (ret) - goto err_cleanup_gdev_srcu; + goto err_cleanup_desc_srcu; for (desc_index = 0; desc_index < gc->ngpio; desc_index++) { struct gpio_desc *desc = &gdev->descs[desc_index]; - ret = init_srcu_struct(&desc->srcu); - if (ret) - goto err_cleanup_desc_srcu; - if (gc->get_direction && gpiochip_line_is_valid(gc, desc_index)) { assign_bit(FLAG_IS_OUT, &desc->flags, !gc->get_direction(gc, desc_index)); @@ -1027,7 +1024,7 @@ int gpiochip_add_data_with_key(struct gpio_chip *gc, void *data, ret = of_gpiochip_add(gc); if (ret) - goto err_cleanup_desc_srcu; + goto err_free_valid_mask; ret = gpiochip_add_pin_ranges(gc); if (ret) @@ -1074,10 +1071,10 @@ err_free_hogs: gpiochip_remove_pin_ranges(gc); err_remove_of_chip: of_gpiochip_remove(gc); -err_cleanup_desc_srcu: - while (desc_index--) - cleanup_srcu_struct(&gdev->descs[desc_index].srcu); +err_free_valid_mask: gpiochip_free_valid_mask(gc); +err_cleanup_desc_srcu: + cleanup_srcu_struct(&gdev->desc_srcu); err_cleanup_gdev_srcu: cleanup_srcu_struct(&gdev->srcu); err_remove_from_list: @@ -2407,7 +2404,7 @@ char *gpiochip_dup_line_label(struct gpio_chip *gc, unsigned int offset) if (!test_bit(FLAG_REQUESTED, &desc->flags)) return NULL; - guard(srcu)(&desc->srcu); + guard(srcu)(&desc->gdev->desc_srcu); label = kstrdup(gpiod_get_label(desc), GFP_KERNEL); if (!label) @@ -4798,7 +4795,7 @@ static void gpiolib_dbg_show(struct seq_file *s, struct gpio_device *gdev) } for_each_gpio_desc(gc, desc) { - guard(srcu)(&desc->srcu); + guard(srcu)(&desc->gdev->desc_srcu); if (test_bit(FLAG_REQUESTED, &desc->flags)) { gpiod_get_direction(desc); is_out = test_bit(FLAG_IS_OUT, &desc->flags); diff --git a/drivers/gpio/gpiolib.h b/drivers/gpio/gpiolib.h index 69a353c789f0..8e0e211ebf08 100644 --- a/drivers/gpio/gpiolib.h +++ b/drivers/gpio/gpiolib.h @@ -31,6 +31,7 @@ * @chip: pointer to the corresponding gpiochip, holding static * data for this device * @descs: array of ngpio descriptors. + * @desc_srcu: ensures consistent state of GPIO descriptors exposed to users * @ngpio: the number of GPIO lines on this GPIO device, equal to the size * of the @descs array. * @can_sleep: indicate whether the GPIO chip driver's callbacks can sleep @@ -61,6 +62,7 @@ struct gpio_device { struct module *owner; struct gpio_chip __rcu *chip; struct gpio_desc *descs; + struct srcu_struct desc_srcu; int base; u16 ngpio; bool can_sleep; @@ -150,7 +152,6 @@ struct gpio_desc_label { * @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. @@ -188,7 +189,6 @@ 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) @@ -256,7 +256,7 @@ static inline int gpio_chip_hwgpio(const struct gpio_desc *desc) #define gpiod_err(desc, fmt, ...) \ do { \ - scoped_guard(srcu, &desc->srcu) { \ + scoped_guard(srcu, &desc->gdev->desc_srcu) { \ pr_err("gpio-%d (%s): " fmt, desc_to_gpio(desc), \ gpiod_get_label(desc) ? : "?", ##__VA_ARGS__); \ } \ @@ -264,7 +264,7 @@ do { \ #define gpiod_warn(desc, fmt, ...) \ do { \ - scoped_guard(srcu, &desc->srcu) { \ + scoped_guard(srcu, &desc->gdev->desc_srcu) { \ pr_warn("gpio-%d (%s): " fmt, desc_to_gpio(desc), \ gpiod_get_label(desc) ? : "?", ##__VA_ARGS__); \ } \ @@ -272,7 +272,7 @@ do { \ #define gpiod_dbg(desc, fmt, ...) \ do { \ - scoped_guard(srcu, &desc->srcu) { \ + scoped_guard(srcu, &desc->gdev->desc_srcu) { \ pr_debug("gpio-%d (%s): " fmt, desc_to_gpio(desc), \ gpiod_get_label(desc) ? : "?", ##__VA_ARGS__); \ } \ -- cgit v1.2.3-59-g8ed1b