From 99b9b45de8808994ea9a176241e52bb6fab71cdd Mon Sep 17 00:00:00 2001 From: Julia Cartwright Date: Thu, 9 Mar 2017 10:21:56 -0600 Subject: [PATCH] gpio: pl061: make use of raw_spinlock variants The pl061 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-pl061.c | 28 ++++++++++++++-------------- 1 file changed, 14 insertions(+), 14 deletions(-) diff --git a/drivers/gpio/gpio-pl061.c b/drivers/gpio/gpio-pl061.c index 0a6bfd2b06e5..3d3d6b6645a7 100644 --- a/drivers/gpio/gpio-pl061.c +++ b/drivers/gpio/gpio-pl061.c @@ -50,7 +50,7 @@ struct pl061_context_save_regs { #endif struct pl061 { - spinlock_t lock; + raw_spinlock_t lock; void __iomem *base; struct gpio_chip gc; @@ -74,11 +74,11 @@ static int pl061_direction_input(struct gpio_chip *gc, unsigned offset) unsigned long flags; unsigned char gpiodir; - spin_lock_irqsave(&pl061->lock, flags); + raw_spin_lock_irqsave(&pl061->lock, flags); gpiodir = readb(pl061->base + GPIODIR); gpiodir &= ~(BIT(offset)); writeb(gpiodir, pl061->base + GPIODIR); - spin_unlock_irqrestore(&pl061->lock, flags); + raw_spin_unlock_irqrestore(&pl061->lock, flags); return 0; } @@ -90,7 +90,7 @@ static int pl061_direction_output(struct gpio_chip *gc, unsigned offset, unsigned long flags; unsigned char gpiodir; - spin_lock_irqsave(&pl061->lock, flags); + raw_spin_lock_irqsave(&pl061->lock, flags); writeb(!!value << offset, pl061->base + (BIT(offset + 2))); gpiodir = readb(pl061->base + GPIODIR); gpiodir |= BIT(offset); @@ -101,7 +101,7 @@ static int pl061_direction_output(struct gpio_chip *gc, unsigned offset, * a gpio pin before configuring it in OUT mode. */ writeb(!!value << offset, pl061->base + (BIT(offset + 2))); - spin_unlock_irqrestore(&pl061->lock, flags); + raw_spin_unlock_irqrestore(&pl061->lock, flags); return 0; } @@ -143,7 +143,7 @@ static int pl061_irq_type(struct irq_data *d, unsigned trigger) } - spin_lock_irqsave(&pl061->lock, flags); + raw_spin_lock_irqsave(&pl061->lock, flags); gpioiev = readb(pl061->base + GPIOIEV); gpiois = readb(pl061->base + GPIOIS); @@ -203,7 +203,7 @@ static int pl061_irq_type(struct irq_data *d, unsigned trigger) writeb(gpioibe, pl061->base + GPIOIBE); writeb(gpioiev, pl061->base + GPIOIEV); - spin_unlock_irqrestore(&pl061->lock, flags); + raw_spin_unlock_irqrestore(&pl061->lock, flags); return 0; } @@ -235,10 +235,10 @@ static void pl061_irq_mask(struct irq_data *d) u8 mask = BIT(irqd_to_hwirq(d) % PL061_GPIO_NR); u8 gpioie; - spin_lock(&pl061->lock); + raw_spin_lock(&pl061->lock); gpioie = readb(pl061->base + GPIOIE) & ~mask; writeb(gpioie, pl061->base + GPIOIE); - spin_unlock(&pl061->lock); + raw_spin_unlock(&pl061->lock); } static void pl061_irq_unmask(struct irq_data *d) @@ -248,10 +248,10 @@ static void pl061_irq_unmask(struct irq_data *d) u8 mask = BIT(irqd_to_hwirq(d) % PL061_GPIO_NR); u8 gpioie; - spin_lock(&pl061->lock); + raw_spin_lock(&pl061->lock); gpioie = readb(pl061->base + GPIOIE) | mask; writeb(gpioie, pl061->base + GPIOIE); - spin_unlock(&pl061->lock); + raw_spin_unlock(&pl061->lock); } /** @@ -268,9 +268,9 @@ static void pl061_irq_ack(struct irq_data *d) struct pl061 *pl061 = gpiochip_get_data(gc); u8 mask = BIT(irqd_to_hwirq(d) % PL061_GPIO_NR); - spin_lock(&pl061->lock); + raw_spin_lock(&pl061->lock); writeb(mask, pl061->base + GPIOIC); - spin_unlock(&pl061->lock); + raw_spin_unlock(&pl061->lock); } static int pl061_irq_set_wake(struct irq_data *d, unsigned int state) @@ -304,7 +304,7 @@ static int pl061_probe(struct amba_device *adev, const struct amba_id *id) if (IS_ERR(pl061->base)) return PTR_ERR(pl061->base); - spin_lock_init(&pl061->lock); + raw_spin_lock_init(&pl061->lock); if (of_property_read_bool(dev->of_node, "gpio-ranges")) { pl061->gc.request = gpiochip_generic_request; pl061->gc.free = gpiochip_generic_free; -- 2.20.1