[PATCH 17/19] pinctrl: amd: make use of raw_spinlock variants

From: Julia Cartwright
Date: Thu Mar 09 2017 - 12:45:20 EST


The amd pinctrl drivers currently implement 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@xxxxxx>
---
drivers/pinctrl/pinctrl-amd.c | 66 +++++++++++++++++++++----------------------
drivers/pinctrl/pinctrl-amd.h | 2 +-
2 files changed, 34 insertions(+), 34 deletions(-)

diff --git a/drivers/pinctrl/pinctrl-amd.c b/drivers/pinctrl/pinctrl-amd.c
index d69e357a7a98..043ac9bcbccb 100644
--- a/drivers/pinctrl/pinctrl-amd.c
+++ b/drivers/pinctrl/pinctrl-amd.c
@@ -41,11 +41,11 @@ static int amd_gpio_direction_input(struct gpio_chip *gc, unsigned offset)
u32 pin_reg;
struct amd_gpio *gpio_dev = gpiochip_get_data(gc);

- spin_lock_irqsave(&gpio_dev->lock, flags);
+ raw_spin_lock_irqsave(&gpio_dev->lock, flags);
pin_reg = readl(gpio_dev->base + offset * 4);
pin_reg &= ~BIT(OUTPUT_ENABLE_OFF);
writel(pin_reg, gpio_dev->base + offset * 4);
- spin_unlock_irqrestore(&gpio_dev->lock, flags);
+ raw_spin_unlock_irqrestore(&gpio_dev->lock, flags);

return 0;
}
@@ -57,7 +57,7 @@ static int amd_gpio_direction_output(struct gpio_chip *gc, unsigned offset,
unsigned long flags;
struct amd_gpio *gpio_dev = gpiochip_get_data(gc);

- spin_lock_irqsave(&gpio_dev->lock, flags);
+ raw_spin_lock_irqsave(&gpio_dev->lock, flags);
pin_reg = readl(gpio_dev->base + offset * 4);
pin_reg |= BIT(OUTPUT_ENABLE_OFF);
if (value)
@@ -65,7 +65,7 @@ static int amd_gpio_direction_output(struct gpio_chip *gc, unsigned offset,
else
pin_reg &= ~BIT(OUTPUT_VALUE_OFF);
writel(pin_reg, gpio_dev->base + offset * 4);
- spin_unlock_irqrestore(&gpio_dev->lock, flags);
+ raw_spin_unlock_irqrestore(&gpio_dev->lock, flags);

return 0;
}
@@ -76,9 +76,9 @@ static int amd_gpio_get_value(struct gpio_chip *gc, unsigned offset)
unsigned long flags;
struct amd_gpio *gpio_dev = gpiochip_get_data(gc);

- spin_lock_irqsave(&gpio_dev->lock, flags);
+ raw_spin_lock_irqsave(&gpio_dev->lock, flags);
pin_reg = readl(gpio_dev->base + offset * 4);
- spin_unlock_irqrestore(&gpio_dev->lock, flags);
+ raw_spin_unlock_irqrestore(&gpio_dev->lock, flags);

return !!(pin_reg & BIT(PIN_STS_OFF));
}
@@ -89,14 +89,14 @@ static void amd_gpio_set_value(struct gpio_chip *gc, unsigned offset, int value)
unsigned long flags;
struct amd_gpio *gpio_dev = gpiochip_get_data(gc);

- spin_lock_irqsave(&gpio_dev->lock, flags);
+ raw_spin_lock_irqsave(&gpio_dev->lock, flags);
pin_reg = readl(gpio_dev->base + offset * 4);
if (value)
pin_reg |= BIT(OUTPUT_VALUE_OFF);
else
pin_reg &= ~BIT(OUTPUT_VALUE_OFF);
writel(pin_reg, gpio_dev->base + offset * 4);
- spin_unlock_irqrestore(&gpio_dev->lock, flags);
+ raw_spin_unlock_irqrestore(&gpio_dev->lock, flags);
}

static int amd_gpio_set_debounce(struct gpio_chip *gc, unsigned offset,
@@ -108,7 +108,7 @@ static int amd_gpio_set_debounce(struct gpio_chip *gc, unsigned offset,
unsigned long flags;
struct amd_gpio *gpio_dev = gpiochip_get_data(gc);

- spin_lock_irqsave(&gpio_dev->lock, flags);
+ raw_spin_lock_irqsave(&gpio_dev->lock, flags);
pin_reg = readl(gpio_dev->base + offset * 4);

if (debounce) {
@@ -159,7 +159,7 @@ static int amd_gpio_set_debounce(struct gpio_chip *gc, unsigned offset,
pin_reg &= ~DB_CNTRl_MASK;
}
writel(pin_reg, gpio_dev->base + offset * 4);
- spin_unlock_irqrestore(&gpio_dev->lock, flags);
+ raw_spin_unlock_irqrestore(&gpio_dev->lock, flags);

return ret;
}
@@ -224,9 +224,9 @@ static void amd_gpio_dbg_show(struct seq_file *s, struct gpio_chip *gc)
}
for (; i < pin_num; i++) {
seq_printf(s, "pin%d\t", i);
- spin_lock_irqsave(&gpio_dev->lock, flags);
+ raw_spin_lock_irqsave(&gpio_dev->lock, flags);
pin_reg = readl(gpio_dev->base + i * 4);
- spin_unlock_irqrestore(&gpio_dev->lock, flags);
+ raw_spin_unlock_irqrestore(&gpio_dev->lock, flags);

if (pin_reg & BIT(INTERRUPT_ENABLE_OFF)) {
interrupt_enable = "interrupt is enabled|";
@@ -331,12 +331,12 @@ static void amd_gpio_irq_enable(struct irq_data *d)
struct gpio_chip *gc = irq_data_get_irq_chip_data(d);
struct amd_gpio *gpio_dev = gpiochip_get_data(gc);

- spin_lock_irqsave(&gpio_dev->lock, flags);
+ raw_spin_lock_irqsave(&gpio_dev->lock, flags);
pin_reg = readl(gpio_dev->base + (d->hwirq)*4);
pin_reg |= BIT(INTERRUPT_ENABLE_OFF);
pin_reg |= BIT(INTERRUPT_MASK_OFF);
writel(pin_reg, gpio_dev->base + (d->hwirq)*4);
- spin_unlock_irqrestore(&gpio_dev->lock, flags);
+ raw_spin_unlock_irqrestore(&gpio_dev->lock, flags);
}

static void amd_gpio_irq_disable(struct irq_data *d)
@@ -346,12 +346,12 @@ static void amd_gpio_irq_disable(struct irq_data *d)
struct gpio_chip *gc = irq_data_get_irq_chip_data(d);
struct amd_gpio *gpio_dev = gpiochip_get_data(gc);

- spin_lock_irqsave(&gpio_dev->lock, flags);
+ raw_spin_lock_irqsave(&gpio_dev->lock, flags);
pin_reg = readl(gpio_dev->base + (d->hwirq)*4);
pin_reg &= ~BIT(INTERRUPT_ENABLE_OFF);
pin_reg &= ~BIT(INTERRUPT_MASK_OFF);
writel(pin_reg, gpio_dev->base + (d->hwirq)*4);
- spin_unlock_irqrestore(&gpio_dev->lock, flags);
+ raw_spin_unlock_irqrestore(&gpio_dev->lock, flags);
}

static void amd_gpio_irq_mask(struct irq_data *d)
@@ -361,11 +361,11 @@ static void amd_gpio_irq_mask(struct irq_data *d)
struct gpio_chip *gc = irq_data_get_irq_chip_data(d);
struct amd_gpio *gpio_dev = gpiochip_get_data(gc);

- spin_lock_irqsave(&gpio_dev->lock, flags);
+ raw_spin_lock_irqsave(&gpio_dev->lock, flags);
pin_reg = readl(gpio_dev->base + (d->hwirq)*4);
pin_reg &= ~BIT(INTERRUPT_MASK_OFF);
writel(pin_reg, gpio_dev->base + (d->hwirq)*4);
- spin_unlock_irqrestore(&gpio_dev->lock, flags);
+ raw_spin_unlock_irqrestore(&gpio_dev->lock, flags);
}

static void amd_gpio_irq_unmask(struct irq_data *d)
@@ -375,11 +375,11 @@ static void amd_gpio_irq_unmask(struct irq_data *d)
struct gpio_chip *gc = irq_data_get_irq_chip_data(d);
struct amd_gpio *gpio_dev = gpiochip_get_data(gc);

- spin_lock_irqsave(&gpio_dev->lock, flags);
+ raw_spin_lock_irqsave(&gpio_dev->lock, flags);
pin_reg = readl(gpio_dev->base + (d->hwirq)*4);
pin_reg |= BIT(INTERRUPT_MASK_OFF);
writel(pin_reg, gpio_dev->base + (d->hwirq)*4);
- spin_unlock_irqrestore(&gpio_dev->lock, flags);
+ raw_spin_unlock_irqrestore(&gpio_dev->lock, flags);
}

static void amd_gpio_irq_eoi(struct irq_data *d)
@@ -389,11 +389,11 @@ static void amd_gpio_irq_eoi(struct irq_data *d)
struct gpio_chip *gc = irq_data_get_irq_chip_data(d);
struct amd_gpio *gpio_dev = gpiochip_get_data(gc);

- spin_lock_irqsave(&gpio_dev->lock, flags);
+ raw_spin_lock_irqsave(&gpio_dev->lock, flags);
reg = readl(gpio_dev->base + WAKE_INT_MASTER_REG);
reg |= EOI_MASK;
writel(reg, gpio_dev->base + WAKE_INT_MASTER_REG);
- spin_unlock_irqrestore(&gpio_dev->lock, flags);
+ raw_spin_unlock_irqrestore(&gpio_dev->lock, flags);
}

static int amd_gpio_irq_set_type(struct irq_data *d, unsigned int type)
@@ -404,7 +404,7 @@ static int amd_gpio_irq_set_type(struct irq_data *d, unsigned int type)
struct gpio_chip *gc = irq_data_get_irq_chip_data(d);
struct amd_gpio *gpio_dev = gpiochip_get_data(gc);

- spin_lock_irqsave(&gpio_dev->lock, flags);
+ raw_spin_lock_irqsave(&gpio_dev->lock, flags);
pin_reg = readl(gpio_dev->base + (d->hwirq)*4);

/* Ignore the settings coming from the client and
@@ -469,7 +469,7 @@ static int amd_gpio_irq_set_type(struct irq_data *d, unsigned int type)

pin_reg |= CLR_INTR_STAT << INTERRUPT_STS_OFF;
writel(pin_reg, gpio_dev->base + (d->hwirq)*4);
- spin_unlock_irqrestore(&gpio_dev->lock, flags);
+ raw_spin_unlock_irqrestore(&gpio_dev->lock, flags);

return ret;
}
@@ -511,14 +511,14 @@ static void amd_gpio_irq_handler(struct irq_desc *desc)

chained_irq_enter(chip, desc);
/*enable GPIO interrupt again*/
- spin_lock_irqsave(&gpio_dev->lock, flags);
+ raw_spin_lock_irqsave(&gpio_dev->lock, flags);
reg = readl(gpio_dev->base + WAKE_INT_STATUS_REG1);
reg64 = reg;
reg64 = reg64 << 32;

reg = readl(gpio_dev->base + WAKE_INT_STATUS_REG0);
reg64 |= reg;
- spin_unlock_irqrestore(&gpio_dev->lock, flags);
+ raw_spin_unlock_irqrestore(&gpio_dev->lock, flags);

/*
* first 46 bits indicates interrupt status.
@@ -546,11 +546,11 @@ static void amd_gpio_irq_handler(struct irq_desc *desc)
if (handled == 0)
handle_bad_irq(desc);

- spin_lock_irqsave(&gpio_dev->lock, flags);
+ raw_spin_lock_irqsave(&gpio_dev->lock, flags);
reg = readl(gpio_dev->base + WAKE_INT_MASTER_REG);
reg |= EOI_MASK;
writel(reg, gpio_dev->base + WAKE_INT_MASTER_REG);
- spin_unlock_irqrestore(&gpio_dev->lock, flags);
+ raw_spin_unlock_irqrestore(&gpio_dev->lock, flags);

chained_irq_exit(chip, desc);
}
@@ -602,9 +602,9 @@ static int amd_pinconf_get(struct pinctrl_dev *pctldev,
struct amd_gpio *gpio_dev = pinctrl_dev_get_drvdata(pctldev);
enum pin_config_param param = pinconf_to_config_param(*config);

- spin_lock_irqsave(&gpio_dev->lock, flags);
+ raw_spin_lock_irqsave(&gpio_dev->lock, flags);
pin_reg = readl(gpio_dev->base + pin*4);
- spin_unlock_irqrestore(&gpio_dev->lock, flags);
+ raw_spin_unlock_irqrestore(&gpio_dev->lock, flags);
switch (param) {
case PIN_CONFIG_INPUT_DEBOUNCE:
arg = pin_reg & DB_TMR_OUT_MASK;
@@ -644,7 +644,7 @@ static int amd_pinconf_set(struct pinctrl_dev *pctldev, unsigned int pin,
enum pin_config_param param;
struct amd_gpio *gpio_dev = pinctrl_dev_get_drvdata(pctldev);

- spin_lock_irqsave(&gpio_dev->lock, flags);
+ raw_spin_lock_irqsave(&gpio_dev->lock, flags);
for (i = 0; i < num_configs; i++) {
param = pinconf_to_config_param(configs[i]);
arg = pinconf_to_config_argument(configs[i]);
@@ -683,7 +683,7 @@ static int amd_pinconf_set(struct pinctrl_dev *pctldev, unsigned int pin,

writel(pin_reg, gpio_dev->base + pin*4);
}
- spin_unlock_irqrestore(&gpio_dev->lock, flags);
+ raw_spin_unlock_irqrestore(&gpio_dev->lock, flags);

return ret;
}
@@ -751,7 +751,7 @@ static int amd_gpio_probe(struct platform_device *pdev)
if (!gpio_dev)
return -ENOMEM;

- spin_lock_init(&gpio_dev->lock);
+ raw_spin_lock_init(&gpio_dev->lock);

res = platform_get_resource(pdev, IORESOURCE_MEM, 0);
if (!res) {
diff --git a/drivers/pinctrl/pinctrl-amd.h b/drivers/pinctrl/pinctrl-amd.h
index c03f77822069..5b1cb965c767 100644
--- a/drivers/pinctrl/pinctrl-amd.h
+++ b/drivers/pinctrl/pinctrl-amd.h
@@ -87,7 +87,7 @@ struct amd_function {
};

struct amd_gpio {
- spinlock_t lock;
+ raw_spinlock_t lock;
void __iomem *base;

const struct amd_pingroup *groups;
--
2.11.1