From 8c41ab4f0521918452851392ed40ed03923623e2 Mon Sep 17 00:00:00 2001 From: Julia Cartwright Date: Thu, 9 Mar 2017 10:21:58 -0600 Subject: [PATCH] gpio: zx: make use of raw_spinlock variants The zx gpio driver currently implements an irq_chip for handling interrupts; due to how irq_chip handling is done, it's necessary for the irq_chip methods to be invoked from hardirq context, even on a a real-time kernel. Because the spinlock_t type becomes a "sleeping" spinlock w/ RT kernels, it is not suitable to be used with irq_chips. A quick audit of the operations under the lock reveal that they do only minimal, bounded work, and are therefore safe to do under a raw spinlock. Signed-off-by: Julia Cartwright Signed-off-by: Linus Walleij --- drivers/gpio/gpio-zx.c | 24 ++++++++++++------------ 1 file changed, 12 insertions(+), 12 deletions(-) diff --git a/drivers/gpio/gpio-zx.c b/drivers/gpio/gpio-zx.c index 93de8be0d885..be3a87da8438 100644 --- a/drivers/gpio/gpio-zx.c +++ b/drivers/gpio/gpio-zx.c @@ -41,7 +41,7 @@ #define ZX_GPIO_NR 16 struct zx_gpio { - spinlock_t lock; + raw_spinlock_t lock; void __iomem *base; struct gpio_chip gc; @@ -56,11 +56,11 @@ static int zx_direction_input(struct gpio_chip *gc, unsigned offset) if (offset >= gc->ngpio) return -EINVAL; - spin_lock_irqsave(&chip->lock, flags); + raw_spin_lock_irqsave(&chip->lock, flags); gpiodir = readw_relaxed(chip->base + ZX_GPIO_DIR); gpiodir &= ~BIT(offset); writew_relaxed(gpiodir, chip->base + ZX_GPIO_DIR); - spin_unlock_irqrestore(&chip->lock, flags); + raw_spin_unlock_irqrestore(&chip->lock, flags); return 0; } @@ -75,7 +75,7 @@ static int zx_direction_output(struct gpio_chip *gc, unsigned offset, if (offset >= gc->ngpio) return -EINVAL; - spin_lock_irqsave(&chip->lock, flags); + raw_spin_lock_irqsave(&chip->lock, flags); gpiodir = readw_relaxed(chip->base + ZX_GPIO_DIR); gpiodir |= BIT(offset); writew_relaxed(gpiodir, chip->base + ZX_GPIO_DIR); @@ -84,7 +84,7 @@ static int zx_direction_output(struct gpio_chip *gc, unsigned offset, writew_relaxed(BIT(offset), chip->base + ZX_GPIO_DO1); else writew_relaxed(BIT(offset), chip->base + ZX_GPIO_DO0); - spin_unlock_irqrestore(&chip->lock, flags); + raw_spin_unlock_irqrestore(&chip->lock, flags); return 0; } @@ -118,7 +118,7 @@ static int zx_irq_type(struct irq_data *d, unsigned trigger) if (offset < 0 || offset >= ZX_GPIO_NR) return -EINVAL; - spin_lock_irqsave(&chip->lock, flags); + raw_spin_lock_irqsave(&chip->lock, flags); gpioiev = readw_relaxed(chip->base + ZX_GPIO_IV); gpiois = readw_relaxed(chip->base + ZX_GPIO_IVE); @@ -151,7 +151,7 @@ static int zx_irq_type(struct irq_data *d, unsigned trigger) writew_relaxed(gpioi_epos, chip->base + ZX_GPIO_IEP); writew_relaxed(gpioi_eneg, chip->base + ZX_GPIO_IEN); writew_relaxed(gpioiev, chip->base + ZX_GPIO_IV); - spin_unlock_irqrestore(&chip->lock, flags); + raw_spin_unlock_irqrestore(&chip->lock, flags); return 0; } @@ -184,12 +184,12 @@ static void zx_irq_mask(struct irq_data *d) u16 mask = BIT(irqd_to_hwirq(d) % ZX_GPIO_NR); u16 gpioie; - spin_lock(&chip->lock); + raw_spin_lock(&chip->lock); gpioie = readw_relaxed(chip->base + ZX_GPIO_IM) | mask; writew_relaxed(gpioie, chip->base + ZX_GPIO_IM); gpioie = readw_relaxed(chip->base + ZX_GPIO_IE) & ~mask; writew_relaxed(gpioie, chip->base + ZX_GPIO_IE); - spin_unlock(&chip->lock); + raw_spin_unlock(&chip->lock); } static void zx_irq_unmask(struct irq_data *d) @@ -199,12 +199,12 @@ static void zx_irq_unmask(struct irq_data *d) u16 mask = BIT(irqd_to_hwirq(d) % ZX_GPIO_NR); u16 gpioie; - spin_lock(&chip->lock); + raw_spin_lock(&chip->lock); gpioie = readw_relaxed(chip->base + ZX_GPIO_IM) & ~mask; writew_relaxed(gpioie, chip->base + ZX_GPIO_IM); gpioie = readw_relaxed(chip->base + ZX_GPIO_IE) | mask; writew_relaxed(gpioie, chip->base + ZX_GPIO_IE); - spin_unlock(&chip->lock); + raw_spin_unlock(&chip->lock); } static struct irq_chip zx_irqchip = { @@ -230,7 +230,7 @@ static int zx_gpio_probe(struct platform_device *pdev) if (IS_ERR(chip->base)) return PTR_ERR(chip->base); - spin_lock_init(&chip->lock); + raw_spin_lock_init(&chip->lock); if (of_property_read_bool(dev->of_node, "gpio-ranges")) { chip->gc.request = gpiochip_generic_request; chip->gc.free = gpiochip_generic_free;