From eae7c26938af25357e25933bd70aefd0d48dcdaf Mon Sep 17 00:00:00 2001 From: Bartosz Golaszewski Date: Wed, 31 Oct 2018 14:55:47 +0100 Subject: [PATCH] gpio: mockup: add locking MIME-Version: 1.0 Content-Type: text/plain; charset=utf8 Content-Transfer-Encoding: 8bit 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 Signed-off-by: Bartosz Golaszewski --- drivers/gpio/gpio-mockup.c | 50 ++++++++++++++++++++++++++++++++------ 1 file changed, 43 insertions(+), 7 deletions(-) diff --git a/drivers/gpio/gpio-mockup.c b/drivers/gpio/gpio-mockup.c index 6a50f9f59c901..b4c1de6acf742 100644 --- a/drivers/gpio/gpio-mockup.c +++ b/drivers/gpio/gpio-mockup.c @@ -54,6 +54,7 @@ struct gpio_mockup_chip { struct gpio_mockup_line_status *lines; struct irq_sim irqsim; struct dentry *dbg_dir; + struct mutex lock; }; 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]; } -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); return chip->lines[offset].value; } -static void gpio_mockup_set(struct gpio_chip *gc, - unsigned int offset, int value) +static int gpio_mockup_get(struct gpio_chip *gc, unsigned int offset) +{ + 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); 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, unsigned long *mask, unsigned long *bits) { + struct gpio_mockup_chip *chip = gpiochip_get_data(gc); unsigned int bit; + mutex_lock(&chip->lock); 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, @@ -112,8 +137,10 @@ static int gpio_mockup_dirout(struct gpio_chip *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; + __gpio_mockup_set(gc, offset, value); + mutex_unlock(&chip->lock); 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); + mutex_lock(&chip->lock); chip->lines[offset].dir = GPIO_MOCKUP_DIR_IN; + mutex_unlock(&chip->lock); 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) { 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) @@ -283,6 +317,8 @@ static int gpio_mockup_probe(struct platform_device *pdev) return -ENOMEM; } + mutex_init(&chip->lock); + gc = &chip->gc; gc->base = base; gc->ngpio = ngpio; -- 2.39.5