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gpio: mockup: add locking 

While no user reported any race condition problems with gpio-mockup,
let's be on the safe side and use a mutex when performing any changes
on the dummy chip structures.

Suggested-by: Uwe Kleine-König <u.kleine-koenig@pengutronix.de>
Signed-off-by: Bartosz Golaszewski <bgolaszewski@baylibre.com>
This commit is contained in:
Bartosz Golaszewski 2018-10-31 14:55:47 +01:00
parent 8d91ecc84d
commit 9212492f6e
1 changed files with 43 additions and 7 deletions
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50
drivers/gpio/gpio-mockup.c
View File

@ -54,6 +54,7 @@ struct gpio_mockup_chip {
struct gpio_mockup_line_status *lines; struct gpio_mockup_line_status *lines;
struct irq_sim irqsim; struct irq_sim irqsim;
struct dentry *dbg_dir; struct dentry *dbg_dir;
struct mutex lock;
}; };
struct gpio_mockup_dbgfs_private { struct gpio_mockup_dbgfs_private {
@ -82,29 +83,53 @@ static int gpio_mockup_range_ngpio(unsigned int index)
return gpio_mockup_ranges[index * 2 + 1]; return gpio_mockup_ranges[index * 2 + 1];
} }
static int gpio_mockup_get(struct gpio_chip *gc, unsigned int offset) static int __gpio_mockup_get(struct gpio_chip *gc, unsigned int offset)
{ {
struct gpio_mockup_chip *chip = gpiochip_get_data(gc); struct gpio_mockup_chip *chip = gpiochip_get_data(gc);
return chip->lines[offset].value; return chip->lines[offset].value;
} }
static void gpio_mockup_set(struct gpio_chip *gc, static int gpio_mockup_get(struct gpio_chip *gc, unsigned int offset)
unsigned int offset, int value) {
struct gpio_mockup_chip *chip = gpiochip_get_data(gc);
int val;
mutex_lock(&chip->lock);
val = __gpio_mockup_get(gc, offset);
mutex_unlock(&chip->lock);
return val;
}
static void __gpio_mockup_set(struct gpio_chip *gc,
unsigned int offset, int value)
{ {
struct gpio_mockup_chip *chip = gpiochip_get_data(gc); struct gpio_mockup_chip *chip = gpiochip_get_data(gc);
chip->lines[offset].value = !!value; chip->lines[offset].value = !!value;
} }
static void gpio_mockup_set(struct gpio_chip *gc,
unsigned int offset, int value)
{
struct gpio_mockup_chip *chip = gpiochip_get_data(gc);
mutex_lock(&chip->lock);
__gpio_mockup_set(gc, offset, value);
mutex_unlock(&chip->lock);
}
static void gpio_mockup_set_multiple(struct gpio_chip *gc, static void gpio_mockup_set_multiple(struct gpio_chip *gc,
unsigned long *mask, unsigned long *bits) unsigned long *mask, unsigned long *bits)
{ {
struct gpio_mockup_chip *chip = gpiochip_get_data(gc);
unsigned int bit; unsigned int bit;
mutex_lock(&chip->lock);
for_each_set_bit(bit, mask, gc->ngpio) for_each_set_bit(bit, mask, gc->ngpio)
gpio_mockup_set(gc, bit, test_bit(bit, bits)); __gpio_mockup_set(gc, bit, test_bit(bit, bits));
mutex_unlock(&chip->lock);
} }
static int gpio_mockup_dirout(struct gpio_chip *gc, static int gpio_mockup_dirout(struct gpio_chip *gc,
@ -112,8 +137,10 @@ static int gpio_mockup_dirout(struct gpio_chip *gc,
{ {
struct gpio_mockup_chip *chip = gpiochip_get_data(gc); struct gpio_mockup_chip *chip = gpiochip_get_data(gc);
gpio_mockup_set(gc, offset, value); mutex_lock(&chip->lock);
chip->lines[offset].dir = GPIO_MOCKUP_DIR_OUT; chip->lines[offset].dir = GPIO_MOCKUP_DIR_OUT;
__gpio_mockup_set(gc, offset, value);
mutex_unlock(&chip->lock);
return 0; return 0;
} }
@ -122,7 +149,9 @@ static int gpio_mockup_dirin(struct gpio_chip *gc, unsigned int offset)
{ {
struct gpio_mockup_chip *chip = gpiochip_get_data(gc); struct gpio_mockup_chip *chip = gpiochip_get_data(gc);
mutex_lock(&chip->lock);
chip->lines[offset].dir = GPIO_MOCKUP_DIR_IN; chip->lines[offset].dir = GPIO_MOCKUP_DIR_IN;
mutex_unlock(&chip->lock);
return 0; return 0;
} }
@ -130,8 +159,13 @@ static int gpio_mockup_dirin(struct gpio_chip *gc, unsigned int offset)
static int gpio_mockup_get_direction(struct gpio_chip *gc, unsigned int offset) static int gpio_mockup_get_direction(struct gpio_chip *gc, unsigned int offset)
{ {
struct gpio_mockup_chip *chip = gpiochip_get_data(gc); struct gpio_mockup_chip *chip = gpiochip_get_data(gc);
int direction;
return !chip->lines[offset].dir; mutex_lock(&chip->lock);
direction = !chip->lines[offset].dir;
mutex_unlock(&chip->lock);
return direction;
} }
static int gpio_mockup_to_irq(struct gpio_chip *gc, unsigned int offset) static int gpio_mockup_to_irq(struct gpio_chip *gc, unsigned int offset)
@ -283,6 +317,8 @@ static int gpio_mockup_probe(struct platform_device *pdev)
return -ENOMEM; return -ENOMEM;
} }
mutex_init(&chip->lock);
gc = &chip->gc; gc = &chip->gc;
gc->base = base; gc->base = base;
gc->ngpio = ngpio; gc->ngpio = ngpio;