mirrors
/
linux-stable
mirror of https://git.kernel.org/pub/scm/linux/kernel/git/stable/linux.git
1
0
Fork 0
Code Issues Releases Wiki Activity

gpio fixes for v6.8-rc1 

- 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
 -----BEGIN PGP SIGNATURE-----
 
 iQIzBAABCgAdFiEEFp3rbAvDxGAT0sefEacuoBRx13IFAmWpGfgACgkQEacuoBRx
 13K92A//TonLW0SmSJ5OM0jn9pqUhYLsSxbknu9M9RVmX+GTIq9YK+S5SiCbRS50
 rXn4q3WSqbocM+9R0MUlJJJK8UkGT+JU330vPlJl4gZAy0bK8aoeOqg7vb7nY12e
 0/PvroMpTHoBEIp5XloK4Wjxp3dnc1mGfozSJ7af9FXuY9i1cv8KhnrI8krKbszr
 quuWlZRrtMxKeR3FnsZVn8WNvEWqB5gAN1QJrX0h4sOe0/ZFVfdpZaCW4j1YZtux
 aF6d/9XyEnoR/yJpAE/Rt5Wy727RkilRvSiihnijnJd5JqdMU89CdXdgUF2oFOZ6
 rTAh6XrXiJaaAst4H+5rRe37PR0FOBEAwY1pWUlk9caikfPujNhzPmjvXbdAW7N9
 xe8J+2hTxYfOPYPNtSD/yjcWOudgOb8iiaRREWcRzR96vX/K6R94nF/8hOOEnm+F
 q/xbon1Rt8zhtjZ5lylGsmKoBlKDHlch+c3BXSBf4AxahMNgkebgx8pbkl3jUfg8
 30k+Z5wl08t7oRgeydBKfw7Y42LElBMqAFikjEK8ACyhEGC/e5XD8H0xlWGaKqU5
 sGhd5VS5Y2BQjsrpWkpdQGyOGquz86z5AjwDAAQp3nLgCNrs1UJ8imMPn5c2MPXl
 JAQhMg+zM1NlUhLrXwChYpQ08vypgFUsbGVQ+SDnEbFUo9DbHpg=
 =g2QY
 -----END PGP SIGNATURE-----

Merge tag 'gpio-fixes-for-v6.8-rc1' of git://git.kernel.org/pub/scm/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
This commit is contained in:
Linus Torvalds 2024-01-18 17:03:51 -08:00
parent 5c93506983 efb8235bfd
commit 3455135839
9 changed files with 114 additions and 101 deletions
Show Stats Download Patch File Download Diff File Expand all files Collapse all files

2
Documentation/devicetree/bindings/gpio/xlnx,gpio-xilinx.yaml
View File

@ -126,7 +126,7 @@ examples:
- |
#include <dt-bindings/interrupt-controller/arm-gic.h>
gpio@e000a000 {
gpio@a0020000 {
compatible = "xlnx,xps-gpio-1.00.a";
reg = <0xa0020000 0x10000>;
#gpio-cells = <2>;

6
drivers/gpio/gpio-en7523.c
View File

@ -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 {

2
drivers/gpio/gpio-mlxbf3.c
View File

@ -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;

15
drivers/gpio/gpio-rtd.c
View File

@ -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)

45
drivers/gpio/gpiolib-sysfs.c
View File

@ -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);

6
drivers/gpio/gpiolib-sysfs.h
View File

@ -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)
{
}

135
drivers/gpio/gpiolib.c
View File

@ -2,7 +2,6 @@
#include <linux/acpi.h>
#include <linux/bitmap.h>
#include <linux/cleanup.h>
#include <linux/compat.h>
#include <linux/debugfs.h>
#include <linux/device.h>
@ -16,7 +15,6 @@
#include <linux/kernel.h>
#include <linux/list.h>
#include <linux/module.h>
#include <linux/mutex.h>
#include <linux/of.h>
#include <linux/pinctrl/consumer.h>
#include <linux/seq_file.h>
@ -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;
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];
spin_lock_irqsave(&gpio_lock, flags);
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;
@ -871,45 +878,48 @@ 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;
}
for (i = 0; i < gc->ngpio; i++)
gdev->descs[i].gdev = gdev;
/*
* 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) {
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);
@ -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;

2
drivers/gpio/gpiolib.h
View File

@ -15,7 +15,6 @@
#include <linux/gpio/consumer.h> /* for enum gpiod_flags */
#include <linux/gpio/driver.h>
#include <linux/module.h>
#include <linux/mutex.h>
#include <linux/notifier.h>
#include <linux/rwsem.h>
@ -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);

2
include/linux/gpio/driver.h
View File

@ -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);