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: bcm-kona: make use of raw_spinlock variants 

The bcm-kona 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 <julia@ni.com>
Signed-off-by: Linus Walleij <linus.walleij@linaro.org>
This commit is contained in:
Julia Cartwright 2017-03-09 10:21:54 -06:00 committed by Linus Walleij
parent 45897809d5
commit c69fcea57e
1 changed files with 24 additions and 24 deletions
Show Stats Download Patch File Download Diff File Expand all files Collapse all files

48
drivers/gpio/gpio-bcm-kona.c
View File

@ -67,7 +67,7 @@
struct bcm_kona_gpio {
void __iomem *reg_base;
int num_bank;
spinlock_t lock;
raw_spinlock_t lock;
struct gpio_chip gpio_chip;
struct irq_domain *irq_domain;
struct bcm_kona_gpio_bank *banks;
@ -95,13 +95,13 @@ static void bcm_kona_gpio_lock_gpio(struct bcm_kona_gpio *kona_gpio,
unsigned long flags;
int bank_id = GPIO_BANK(gpio);
spin_lock_irqsave(&kona_gpio->lock, flags);
raw_spin_lock_irqsave(&kona_gpio->lock, flags);
val = readl(kona_gpio->reg_base + GPIO_PWD_STATUS(bank_id));
val |= BIT(gpio);
bcm_kona_gpio_write_lock_regs(kona_gpio->reg_base, bank_id, val);
spin_unlock_irqrestore(&kona_gpio->lock, flags);
raw_spin_unlock_irqrestore(&kona_gpio->lock, flags);
}
static void bcm_kona_gpio_unlock_gpio(struct bcm_kona_gpio *kona_gpio,
@ -111,13 +111,13 @@ static void bcm_kona_gpio_unlock_gpio(struct bcm_kona_gpio *kona_gpio,
unsigned long flags;
int bank_id = GPIO_BANK(gpio);
spin_lock_irqsave(&kona_gpio->lock, flags);
raw_spin_lock_irqsave(&kona_gpio->lock, flags);
val = readl(kona_gpio->reg_base + GPIO_PWD_STATUS(bank_id));
val &= ~BIT(gpio);
bcm_kona_gpio_write_lock_regs(kona_gpio->reg_base, bank_id, val);
spin_unlock_irqrestore(&kona_gpio->lock, flags);
raw_spin_unlock_irqrestore(&kona_gpio->lock, flags);
}
static int bcm_kona_gpio_get_dir(struct gpio_chip *chip, unsigned gpio)
@ -141,7 +141,7 @@ static void bcm_kona_gpio_set(struct gpio_chip *chip, unsigned gpio, int value)
kona_gpio = gpiochip_get_data(chip);
reg_base = kona_gpio->reg_base;
spin_lock_irqsave(&kona_gpio->lock, flags);
raw_spin_lock_irqsave(&kona_gpio->lock, flags);
/* this function only applies to output pin */
if (bcm_kona_gpio_get_dir(chip, gpio) == GPIOF_DIR_IN)
@ -154,7 +154,7 @@ static void bcm_kona_gpio_set(struct gpio_chip *chip, unsigned gpio, int value)
writel(val, reg_base + reg_offset);
out:
spin_unlock_irqrestore(&kona_gpio->lock, flags);
raw_spin_unlock_irqrestore(&kona_gpio->lock, flags);
}
static int bcm_kona_gpio_get(struct gpio_chip *chip, unsigned gpio)
@ -168,7 +168,7 @@ static int bcm_kona_gpio_get(struct gpio_chip *chip, unsigned gpio)
kona_gpio = gpiochip_get_data(chip);
reg_base = kona_gpio->reg_base;
spin_lock_irqsave(&kona_gpio->lock, flags);
raw_spin_lock_irqsave(&kona_gpio->lock, flags);
if (bcm_kona_gpio_get_dir(chip, gpio) == GPIOF_DIR_IN)
reg_offset = GPIO_IN_STATUS(bank_id);
@ -178,7 +178,7 @@ static int bcm_kona_gpio_get(struct gpio_chip *chip, unsigned gpio)
/* read the GPIO bank status */
val = readl(reg_base + reg_offset);
spin_unlock_irqrestore(&kona_gpio->lock, flags);
raw_spin_unlock_irqrestore(&kona_gpio->lock, flags);
/* return the specified bit status */
return !!(val & BIT(bit));
@ -208,14 +208,14 @@ static int bcm_kona_gpio_direction_input(struct gpio_chip *chip, unsigned gpio)
kona_gpio = gpiochip_get_data(chip);
reg_base = kona_gpio->reg_base;
spin_lock_irqsave(&kona_gpio->lock, flags);
raw_spin_lock_irqsave(&kona_gpio->lock, flags);
val = readl(reg_base + GPIO_CONTROL(gpio));
val &= ~GPIO_GPCTR0_IOTR_MASK;
val |= GPIO_GPCTR0_IOTR_CMD_INPUT;
writel(val, reg_base + GPIO_CONTROL(gpio));
spin_unlock_irqrestore(&kona_gpio->lock, flags);
raw_spin_unlock_irqrestore(&kona_gpio->lock, flags);
return 0;
}
@ -232,7 +232,7 @@ static int bcm_kona_gpio_direction_output(struct gpio_chip *chip,
kona_gpio = gpiochip_get_data(chip);
reg_base = kona_gpio->reg_base;
spin_lock_irqsave(&kona_gpio->lock, flags);
raw_spin_lock_irqsave(&kona_gpio->lock, flags);
val = readl(reg_base + GPIO_CONTROL(gpio));
val &= ~GPIO_GPCTR0_IOTR_MASK;
@ -244,7 +244,7 @@ static int bcm_kona_gpio_direction_output(struct gpio_chip *chip,
val |= BIT(bit);
writel(val, reg_base + reg_offset);
spin_unlock_irqrestore(&kona_gpio->lock, flags);
raw_spin_unlock_irqrestore(&kona_gpio->lock, flags);
return 0;
}
@ -288,7 +288,7 @@ static int bcm_kona_gpio_set_debounce(struct gpio_chip *chip, unsigned gpio,
}
/* spin lock for read-modify-write of the GPIO register */
spin_lock_irqsave(&kona_gpio->lock, flags);
raw_spin_lock_irqsave(&kona_gpio->lock, flags);
val = readl(reg_base + GPIO_CONTROL(gpio));
val &= ~GPIO_GPCTR0_DBR_MASK;
@ -303,7 +303,7 @@ static int bcm_kona_gpio_set_debounce(struct gpio_chip *chip, unsigned gpio,
writel(val, reg_base + GPIO_CONTROL(gpio));
spin_unlock_irqrestore(&kona_gpio->lock, flags);
raw_spin_unlock_irqrestore(&kona_gpio->lock, flags);
return 0;
}
@ -347,13 +347,13 @@ static void bcm_kona_gpio_irq_ack(struct irq_data *d)
kona_gpio = irq_data_get_irq_chip_data(d);
reg_base = kona_gpio->reg_base;
spin_lock_irqsave(&kona_gpio->lock, flags);
raw_spin_lock_irqsave(&kona_gpio->lock, flags);
val = readl(reg_base + GPIO_INT_STATUS(bank_id));
val |= BIT(bit);
writel(val, reg_base + GPIO_INT_STATUS(bank_id));
spin_unlock_irqrestore(&kona_gpio->lock, flags);
raw_spin_unlock_irqrestore(&kona_gpio->lock, flags);
}
static void bcm_kona_gpio_irq_mask(struct irq_data *d)
@ -368,13 +368,13 @@ static void bcm_kona_gpio_irq_mask(struct irq_data *d)
kona_gpio = irq_data_get_irq_chip_data(d);
reg_base = kona_gpio->reg_base;
spin_lock_irqsave(&kona_gpio->lock, flags);
raw_spin_lock_irqsave(&kona_gpio->lock, flags);
val = readl(reg_base + GPIO_INT_MASK(bank_id));
val |= BIT(bit);
writel(val, reg_base + GPIO_INT_MASK(bank_id));
spin_unlock_irqrestore(&kona_gpio->lock, flags);
raw_spin_unlock_irqrestore(&kona_gpio->lock, flags);
}
static void bcm_kona_gpio_irq_unmask(struct irq_data *d)
@ -389,13 +389,13 @@ static void bcm_kona_gpio_irq_unmask(struct irq_data *d)
kona_gpio = irq_data_get_irq_chip_data(d);
reg_base = kona_gpio->reg_base;
spin_lock_irqsave(&kona_gpio->lock, flags);
raw_spin_lock_irqsave(&kona_gpio->lock, flags);
val = readl(reg_base + GPIO_INT_MSKCLR(bank_id));
val |= BIT(bit);
writel(val, reg_base + GPIO_INT_MSKCLR(bank_id));
spin_unlock_irqrestore(&kona_gpio->lock, flags);
raw_spin_unlock_irqrestore(&kona_gpio->lock, flags);
}
static int bcm_kona_gpio_irq_set_type(struct irq_data *d, unsigned int type)
@ -431,14 +431,14 @@ static int bcm_kona_gpio_irq_set_type(struct irq_data *d, unsigned int type)
return -EINVAL;
}
spin_lock_irqsave(&kona_gpio->lock, flags);
raw_spin_lock_irqsave(&kona_gpio->lock, flags);
val = readl(reg_base + GPIO_CONTROL(gpio));
val &= ~GPIO_GPCTR0_ITR_MASK;
val |= lvl_type << GPIO_GPCTR0_ITR_SHIFT;
writel(val, reg_base + GPIO_CONTROL(gpio));
spin_unlock_irqrestore(&kona_gpio->lock, flags);
raw_spin_unlock_irqrestore(&kona_gpio->lock, flags);
return 0;
}
@ -655,7 +655,7 @@ static int bcm_kona_gpio_probe(struct platform_device *pdev)
bank);
}
spin_lock_init(&kona_gpio->lock);
raw_spin_lock_init(&kona_gpio->lock);
return 0;