[PATCH 02/19] gpio: altera: make use of raw_spinlock variants

[PATCH 02/19] gpio: altera: make use of raw_spinlock variants

[Julia Cartwright]

The altera 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>
---
 drivers/gpio/gpio-altera.c | 24 ++++++++++++------------
 1 file changed, 12 insertions(+), 12 deletions(-)

diff --git a/drivers/gpio/gpio-altera.c b/drivers/gpio/gpio-altera.c
index 3fe6a21e05a5..17485dc20384 100644
--- a/drivers/gpio/gpio-altera.c
+++ b/drivers/gpio/gpio-altera.c
@@ -38,7 +38,7 @@
 */
 struct altera_gpio_chip {
 	struct of_mm_gpio_chip mmchip;
-	spinlock_t gpio_lock;
+	raw_spinlock_t gpio_lock;
 	int interrupt_trigger;
 	int mapped_irq;
 };
@@ -53,12 +53,12 @@ static void altera_gpio_irq_unmask(struct irq_data *d)
 	altera_gc = gpiochip_get_data(irq_data_get_irq_chip_data(d));
 	mm_gc = &altera_gc->mmchip;
 
-	spin_lock_irqsave(&altera_gc->gpio_lock, flags);
+	raw_spin_lock_irqsave(&altera_gc->gpio_lock, flags);
 	intmask = readl(mm_gc->regs + ALTERA_GPIO_IRQ_MASK);
 	/* Set ALTERA_GPIO_IRQ_MASK bit to unmask */
 	intmask |= BIT(irqd_to_hwirq(d));
 	writel(intmask, mm_gc->regs + ALTERA_GPIO_IRQ_MASK);
-	spin_unlock_irqrestore(&altera_gc->gpio_lock, flags);
+	raw_spin_unlock_irqrestore(&altera_gc->gpio_lock, flags);
 }
 
 static void altera_gpio_irq_mask(struct irq_data *d)
@@ -71,12 +71,12 @@ static void altera_gpio_irq_mask(struct irq_data *d)
 	altera_gc = gpiochip_get_data(irq_data_get_irq_chip_data(d));
 	mm_gc = &altera_gc->mmchip;
 
-	spin_lock_irqsave(&altera_gc->gpio_lock, flags);
+	raw_spin_lock_irqsave(&altera_gc->gpio_lock, flags);
 	intmask = readl(mm_gc->regs + ALTERA_GPIO_IRQ_MASK);
 	/* Clear ALTERA_GPIO_IRQ_MASK bit to mask */
 	intmask &= ~BIT(irqd_to_hwirq(d));
 	writel(intmask, mm_gc->regs + ALTERA_GPIO_IRQ_MASK);
-	spin_unlock_irqrestore(&altera_gc->gpio_lock, flags);
+	raw_spin_unlock_irqrestore(&altera_gc->gpio_lock, flags);
 }
 
 /**
@@ -140,14 +140,14 @@ static void altera_gpio_set(struct gpio_chip *gc, unsigned offset, int value)
 	mm_gc = to_of_mm_gpio_chip(gc);
 	chip = gpiochip_get_data(gc);
 
-	spin_lock_irqsave(&chip->gpio_lock, flags);
+	raw_spin_lock_irqsave(&chip->gpio_lock, flags);
 	data_reg = readl(mm_gc->regs + ALTERA_GPIO_DATA);
 	if (value)
 		data_reg |= BIT(offset);
 	else
 		data_reg &= ~BIT(offset);
 	writel(data_reg, mm_gc->regs + ALTERA_GPIO_DATA);
-	spin_unlock_irqrestore(&chip->gpio_lock, flags);
+	raw_spin_unlock_irqrestore(&chip->gpio_lock, flags);
 }
 
 static int altera_gpio_direction_input(struct gpio_chip *gc, unsigned offset)
@@ -160,12 +160,12 @@ static int altera_gpio_direction_input(struct gpio_chip *gc, unsigned offset)
 	mm_gc = to_of_mm_gpio_chip(gc);
 	chip = gpiochip_get_data(gc);
 
-	spin_lock_irqsave(&chip->gpio_lock, flags);
+	raw_spin_lock_irqsave(&chip->gpio_lock, flags);
 	/* Set pin as input, assumes software controlled IP */
 	gpio_ddr = readl(mm_gc->regs + ALTERA_GPIO_DIR);
 	gpio_ddr &= ~BIT(offset);
 	writel(gpio_ddr, mm_gc->regs + ALTERA_GPIO_DIR);
-	spin_unlock_irqrestore(&chip->gpio_lock, flags);
+	raw_spin_unlock_irqrestore(&chip->gpio_lock, flags);
 
 	return 0;
 }
@@ -181,7 +181,7 @@ static int altera_gpio_direction_output(struct gpio_chip *gc,
 	mm_gc = to_of_mm_gpio_chip(gc);
 	chip = gpiochip_get_data(gc);
 
-	spin_lock_irqsave(&chip->gpio_lock, flags);
+	raw_spin_lock_irqsave(&chip->gpio_lock, flags);
 	/* Sets the GPIO value */
 	data_reg = readl(mm_gc->regs + ALTERA_GPIO_DATA);
 	if (value)
@@ -194,7 +194,7 @@ static int altera_gpio_direction_output(struct gpio_chip *gc,
 	gpio_ddr = readl(mm_gc->regs + ALTERA_GPIO_DIR);
 	gpio_ddr |= BIT(offset);
 	writel(gpio_ddr, mm_gc->regs + ALTERA_GPIO_DIR);
-	spin_unlock_irqrestore(&chip->gpio_lock, flags);
+	raw_spin_unlock_irqrestore(&chip->gpio_lock, flags);
 
 	return 0;
 }
@@ -262,7 +262,7 @@ static int altera_gpio_probe(struct platform_device *pdev)
 	if (!altera_gc)
 		return -ENOMEM;
 
-	spin_lock_init(&altera_gc->gpio_lock);
+	raw_spin_lock_init(&altera_gc->gpio_lock);
 
 	if (of_property_read_u32(node, "altr,ngpio", &reg))
 		/* By default assume maximum ngpio */
-- 
2.11.1

Re: [PATCH 02/19] gpio: altera: make use of raw_spinlock variants

[Linus Walleij]

On Thu, Mar 9, 2017 at 5:21 PM, Julia Cartwright <julia@ni.com> wrote:

> The altera 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>

Patch applied.

Yours,
Linus Walleij

[PATCH 05/19] gpio: 104-dio-48e: make use of raw_spinlock variants

[Julia Cartwright]

The 104-dio-48e 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>
---
 drivers/gpio/gpio-104-dio-48e.c | 38 +++++++++++++++++++-------------------
 1 file changed, 19 insertions(+), 19 deletions(-)

diff --git a/drivers/gpio/gpio-104-dio-48e.c b/drivers/gpio/gpio-104-dio-48e.c
index 17bd2ab4ebe2..61b50c40b87b 100644
--- a/drivers/gpio/gpio-104-dio-48e.c
+++ b/drivers/gpio/gpio-104-dio-48e.c
@@ -55,7 +55,7 @@ struct dio48e_gpio {
 	unsigned char io_state[6];
 	unsigned char out_state[6];
 	unsigned char control[2];
-	spinlock_t lock;
+	raw_spinlock_t lock;
 	unsigned base;
 	unsigned char irq_mask;
 };
@@ -78,7 +78,7 @@ static int dio48e_gpio_direction_input(struct gpio_chip *chip, unsigned offset)
 	unsigned long flags;
 	unsigned control;
 
-	spin_lock_irqsave(&dio48egpio->lock, flags);
+	raw_spin_lock_irqsave(&dio48egpio->lock, flags);
 
 	/* Check if configuring Port C */
 	if (io_port == 2 || io_port == 5) {
@@ -103,7 +103,7 @@ static int dio48e_gpio_direction_input(struct gpio_chip *chip, unsigned offset)
 	control &= ~BIT(7);
 	outb(control, control_addr);
 
-	spin_unlock_irqrestore(&dio48egpio->lock, flags);
+	raw_spin_unlock_irqrestore(&dio48egpio->lock, flags);
 
 	return 0;
 }
@@ -120,7 +120,7 @@ static int dio48e_gpio_direction_output(struct gpio_chip *chip, unsigned offset,
 	unsigned long flags;
 	unsigned control;
 
-	spin_lock_irqsave(&dio48egpio->lock, flags);
+	raw_spin_lock_irqsave(&dio48egpio->lock, flags);
 
 	/* Check if configuring Port C */
 	if (io_port == 2 || io_port == 5) {
@@ -153,7 +153,7 @@ static int dio48e_gpio_direction_output(struct gpio_chip *chip, unsigned offset,
 	control &= ~BIT(7);
 	outb(control, control_addr);
 
-	spin_unlock_irqrestore(&dio48egpio->lock, flags);
+	raw_spin_unlock_irqrestore(&dio48egpio->lock, flags);
 
 	return 0;
 }
@@ -167,17 +167,17 @@ static int dio48e_gpio_get(struct gpio_chip *chip, unsigned offset)
 	unsigned long flags;
 	unsigned port_state;
 
-	spin_lock_irqsave(&dio48egpio->lock, flags);
+	raw_spin_lock_irqsave(&dio48egpio->lock, flags);
 
 	/* ensure that GPIO is set for input */
 	if (!(dio48egpio->io_state[port] & mask)) {
-		spin_unlock_irqrestore(&dio48egpio->lock, flags);
+		raw_spin_unlock_irqrestore(&dio48egpio->lock, flags);
 		return -EINVAL;
 	}
 
 	port_state = inb(dio48egpio->base + in_port);
 
-	spin_unlock_irqrestore(&dio48egpio->lock, flags);
+	raw_spin_unlock_irqrestore(&dio48egpio->lock, flags);
 
 	return !!(port_state & mask);
 }
@@ -190,7 +190,7 @@ static void dio48e_gpio_set(struct gpio_chip *chip, unsigned offset, int value)
 	const unsigned out_port = (port > 2) ? port + 1 : port;
 	unsigned long flags;
 
-	spin_lock_irqsave(&dio48egpio->lock, flags);
+	raw_spin_lock_irqsave(&dio48egpio->lock, flags);
 
 	if (value)
 		dio48egpio->out_state[port] |= mask;
@@ -199,7 +199,7 @@ static void dio48e_gpio_set(struct gpio_chip *chip, unsigned offset, int value)
 
 	outb(dio48egpio->out_state[port], dio48egpio->base + out_port);
 
-	spin_unlock_irqrestore(&dio48egpio->lock, flags);
+	raw_spin_unlock_irqrestore(&dio48egpio->lock, flags);
 }
 
 static void dio48e_gpio_set_multiple(struct gpio_chip *chip,
@@ -225,14 +225,14 @@ static void dio48e_gpio_set_multiple(struct gpio_chip *chip,
 		out_port = (port > 2) ? port + 1 : port;
 		bitmask = mask[BIT_WORD(i)] & bits[BIT_WORD(i)];
 
-		spin_lock_irqsave(&dio48egpio->lock, flags);
+		raw_spin_lock_irqsave(&dio48egpio->lock, flags);
 
 		/* update output state data and set device gpio register */
 		dio48egpio->out_state[port] &= ~mask[BIT_WORD(i)];
 		dio48egpio->out_state[port] |= bitmask;
 		outb(dio48egpio->out_state[port], dio48egpio->base + out_port);
 
-		spin_unlock_irqrestore(&dio48egpio->lock, flags);
+		raw_spin_unlock_irqrestore(&dio48egpio->lock, flags);
 
 		/* prepare for next gpio register set */
 		mask[BIT_WORD(i)] >>= gpio_reg_size;
@@ -255,7 +255,7 @@ static void dio48e_irq_mask(struct irq_data *data)
 	if (offset != 19 && offset != 43)
 		return;
 
-	spin_lock_irqsave(&dio48egpio->lock, flags);
+	raw_spin_lock_irqsave(&dio48egpio->lock, flags);
 
 	if (offset == 19)
 		dio48egpio->irq_mask &= ~BIT(0);
@@ -266,7 +266,7 @@ static void dio48e_irq_mask(struct irq_data *data)
 		/* disable interrupts */
 		inb(dio48egpio->base + 0xB);
 
-	spin_unlock_irqrestore(&dio48egpio->lock, flags);
+	raw_spin_unlock_irqrestore(&dio48egpio->lock, flags);
 }
 
 static void dio48e_irq_unmask(struct irq_data *data)
@@ -280,7 +280,7 @@ static void dio48e_irq_unmask(struct irq_data *data)
 	if (offset != 19 && offset != 43)
 		return;
 
-	spin_lock_irqsave(&dio48egpio->lock, flags);
+	raw_spin_lock_irqsave(&dio48egpio->lock, flags);
 
 	if (!dio48egpio->irq_mask) {
 		/* enable interrupts */
@@ -293,7 +293,7 @@ static void dio48e_irq_unmask(struct irq_data *data)
 	else
 		dio48egpio->irq_mask |= BIT(1);
 
-	spin_unlock_irqrestore(&dio48egpio->lock, flags);
+	raw_spin_unlock_irqrestore(&dio48egpio->lock, flags);
 }
 
 static int dio48e_irq_set_type(struct irq_data *data, unsigned flow_type)
@@ -329,11 +329,11 @@ static irqreturn_t dio48e_irq_handler(int irq, void *dev_id)
 		generic_handle_irq(irq_find_mapping(chip->irqdomain,
 			19 + gpio*24));
 
-	spin_lock(&dio48egpio->lock);
+	raw_spin_lock(&dio48egpio->lock);
 
 	outb(0x00, dio48egpio->base + 0xF);
 
-	spin_unlock(&dio48egpio->lock);
+	raw_spin_unlock(&dio48egpio->lock);
 
 	return IRQ_HANDLED;
 }
@@ -388,7 +388,7 @@ static int dio48e_probe(struct device *dev, unsigned int id)
 	dio48egpio->chip.set_multiple = dio48e_gpio_set_multiple;
 	dio48egpio->base = base[id];
 
-	spin_lock_init(&dio48egpio->lock);
+	raw_spin_lock_init(&dio48egpio->lock);
 
 	err = devm_gpiochip_add_data(dev, &dio48egpio->chip, dio48egpio);
 	if (err) {
-- 
2.11.1

Re: [PATCH 05/19] gpio: 104-dio-48e: make use of raw_spinlock variants

[William Breathitt Gray]

On Thu, Mar 09, 2017 at 10:21:52AM -0600, Julia Cartwright wrote:
>The 104-dio-48e 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>

Acked-by: William Breathitt Gray <vilhelm.gray@gmail.com>

>---
> drivers/gpio/gpio-104-dio-48e.c | 38 +++++++++++++++++++-------------------
> 1 file changed, 19 insertions(+), 19 deletions(-)
>
>diff --git a/drivers/gpio/gpio-104-dio-48e.c b/drivers/gpio/gpio-104-dio-48e.c
>index 17bd2ab4ebe2..61b50c40b87b 100644
>--- a/drivers/gpio/gpio-104-dio-48e.c
>+++ b/drivers/gpio/gpio-104-dio-48e.c
>@@ -55,7 +55,7 @@ struct dio48e_gpio {
> 	unsigned char io_state[6];
> 	unsigned char out_state[6];
> 	unsigned char control[2];
>-	spinlock_t lock;
>+	raw_spinlock_t lock;
> 	unsigned base;
> 	unsigned char irq_mask;
> };
>@@ -78,7 +78,7 @@ static int dio48e_gpio_direction_input(struct gpio_chip *chip, unsigned offset)
> 	unsigned long flags;
> 	unsigned control;
> 
>-	spin_lock_irqsave(&dio48egpio->lock, flags);
>+	raw_spin_lock_irqsave(&dio48egpio->lock, flags);
> 
> 	/* Check if configuring Port C */
> 	if (io_port == 2 || io_port == 5) {
>@@ -103,7 +103,7 @@ static int dio48e_gpio_direction_input(struct gpio_chip *chip, unsigned offset)
> 	control &= ~BIT(7);
> 	outb(control, control_addr);
> 
>-	spin_unlock_irqrestore(&dio48egpio->lock, flags);
>+	raw_spin_unlock_irqrestore(&dio48egpio->lock, flags);
> 
> 	return 0;
> }
>@@ -120,7 +120,7 @@ static int dio48e_gpio_direction_output(struct gpio_chip *chip, unsigned offset,
> 	unsigned long flags;
> 	unsigned control;
> 
>-	spin_lock_irqsave(&dio48egpio->lock, flags);
>+	raw_spin_lock_irqsave(&dio48egpio->lock, flags);
> 
> 	/* Check if configuring Port C */
> 	if (io_port == 2 || io_port == 5) {
>@@ -153,7 +153,7 @@ static int dio48e_gpio_direction_output(struct gpio_chip *chip, unsigned offset,
> 	control &= ~BIT(7);
> 	outb(control, control_addr);
> 
>-	spin_unlock_irqrestore(&dio48egpio->lock, flags);
>+	raw_spin_unlock_irqrestore(&dio48egpio->lock, flags);
> 
> 	return 0;
> }
>@@ -167,17 +167,17 @@ static int dio48e_gpio_get(struct gpio_chip *chip, unsigned offset)
> 	unsigned long flags;
> 	unsigned port_state;
> 
>-	spin_lock_irqsave(&dio48egpio->lock, flags);
>+	raw_spin_lock_irqsave(&dio48egpio->lock, flags);
> 
> 	/* ensure that GPIO is set for input */
> 	if (!(dio48egpio->io_state[port] & mask)) {
>-		spin_unlock_irqrestore(&dio48egpio->lock, flags);
>+		raw_spin_unlock_irqrestore(&dio48egpio->lock, flags);
> 		return -EINVAL;
> 	}
> 
> 	port_state = inb(dio48egpio->base + in_port);
> 
>-	spin_unlock_irqrestore(&dio48egpio->lock, flags);
>+	raw_spin_unlock_irqrestore(&dio48egpio->lock, flags);
> 
> 	return !!(port_state & mask);
> }
>@@ -190,7 +190,7 @@ static void dio48e_gpio_set(struct gpio_chip *chip, unsigned offset, int value)
> 	const unsigned out_port = (port > 2) ? port + 1 : port;
> 	unsigned long flags;
> 
>-	spin_lock_irqsave(&dio48egpio->lock, flags);
>+	raw_spin_lock_irqsave(&dio48egpio->lock, flags);
> 
> 	if (value)
> 		dio48egpio->out_state[port] |= mask;
>@@ -199,7 +199,7 @@ static void dio48e_gpio_set(struct gpio_chip *chip, unsigned offset, int value)
> 
> 	outb(dio48egpio->out_state[port], dio48egpio->base + out_port);
> 
>-	spin_unlock_irqrestore(&dio48egpio->lock, flags);
>+	raw_spin_unlock_irqrestore(&dio48egpio->lock, flags);
> }
> 
> static void dio48e_gpio_set_multiple(struct gpio_chip *chip,
>@@ -225,14 +225,14 @@ static void dio48e_gpio_set_multiple(struct gpio_chip *chip,
> 		out_port = (port > 2) ? port + 1 : port;
> 		bitmask = mask[BIT_WORD(i)] & bits[BIT_WORD(i)];
> 
>-		spin_lock_irqsave(&dio48egpio->lock, flags);
>+		raw_spin_lock_irqsave(&dio48egpio->lock, flags);
> 
> 		/* update output state data and set device gpio register */
> 		dio48egpio->out_state[port] &= ~mask[BIT_WORD(i)];
> 		dio48egpio->out_state[port] |= bitmask;
> 		outb(dio48egpio->out_state[port], dio48egpio->base + out_port);
> 
>-		spin_unlock_irqrestore(&dio48egpio->lock, flags);
>+		raw_spin_unlock_irqrestore(&dio48egpio->lock, flags);
> 
> 		/* prepare for next gpio register set */
> 		mask[BIT_WORD(i)] >>= gpio_reg_size;
>@@ -255,7 +255,7 @@ static void dio48e_irq_mask(struct irq_data *data)
> 	if (offset != 19 && offset != 43)
> 		return;
> 
>-	spin_lock_irqsave(&dio48egpio->lock, flags);
>+	raw_spin_lock_irqsave(&dio48egpio->lock, flags);
> 
> 	if (offset == 19)
> 		dio48egpio->irq_mask &= ~BIT(0);
>@@ -266,7 +266,7 @@ static void dio48e_irq_mask(struct irq_data *data)
> 		/* disable interrupts */
> 		inb(dio48egpio->base + 0xB);
> 
>-	spin_unlock_irqrestore(&dio48egpio->lock, flags);
>+	raw_spin_unlock_irqrestore(&dio48egpio->lock, flags);
> }
> 
> static void dio48e_irq_unmask(struct irq_data *data)
>@@ -280,7 +280,7 @@ static void dio48e_irq_unmask(struct irq_data *data)
> 	if (offset != 19 && offset != 43)
> 		return;
> 
>-	spin_lock_irqsave(&dio48egpio->lock, flags);
>+	raw_spin_lock_irqsave(&dio48egpio->lock, flags);
> 
> 	if (!dio48egpio->irq_mask) {
> 		/* enable interrupts */
>@@ -293,7 +293,7 @@ static void dio48e_irq_unmask(struct irq_data *data)
> 	else
> 		dio48egpio->irq_mask |= BIT(1);
> 
>-	spin_unlock_irqrestore(&dio48egpio->lock, flags);
>+	raw_spin_unlock_irqrestore(&dio48egpio->lock, flags);
> }
> 
> static int dio48e_irq_set_type(struct irq_data *data, unsigned flow_type)
>@@ -329,11 +329,11 @@ static irqreturn_t dio48e_irq_handler(int irq, void *dev_id)
> 		generic_handle_irq(irq_find_mapping(chip->irqdomain,
> 			19 + gpio*24));
> 
>-	spin_lock(&dio48egpio->lock);
>+	raw_spin_lock(&dio48egpio->lock);
> 
> 	outb(0x00, dio48egpio->base + 0xF);
> 
>-	spin_unlock(&dio48egpio->lock);
>+	raw_spin_unlock(&dio48egpio->lock);
> 
> 	return IRQ_HANDLED;
> }
>@@ -388,7 +388,7 @@ static int dio48e_probe(struct device *dev, unsigned int id)
> 	dio48egpio->chip.set_multiple = dio48e_gpio_set_multiple;
> 	dio48egpio->base = base[id];
> 
>-	spin_lock_init(&dio48egpio->lock);
>+	raw_spin_lock_init(&dio48egpio->lock);
> 
> 	err = devm_gpiochip_add_data(dev, &dio48egpio->chip, dio48egpio);
> 	if (err) {
>-- 
>2.11.1
>

Re: [PATCH 05/19] gpio: 104-dio-48e: make use of raw_spinlock variants

[Linus Walleij]

On Thu, Mar 9, 2017 at 5:21 PM, Julia Cartwright <julia@ni.com> wrote:

> The 104-dio-48e 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>

Patch applied with Williams ACK.

Yours,
Linus Walleij

[PATCH 06/19] gpio: ath79: make use of raw_spinlock variants

[Julia Cartwright]

The ath79 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>
---
 drivers/gpio/gpio-ath79.c | 28 ++++++++++++++--------------
 1 file changed, 14 insertions(+), 14 deletions(-)

diff --git a/drivers/gpio/gpio-ath79.c b/drivers/gpio/gpio-ath79.c
index dc37dbe4b46d..f33d4a5fe671 100644
--- a/drivers/gpio/gpio-ath79.c
+++ b/drivers/gpio/gpio-ath79.c
@@ -32,7 +32,7 @@
 struct ath79_gpio_ctrl {
 	struct gpio_chip gc;
 	void __iomem *base;
-	spinlock_t lock;
+	raw_spinlock_t lock;
 	unsigned long both_edges;
 };
 
@@ -74,9 +74,9 @@ static void ath79_gpio_irq_unmask(struct irq_data *data)
 	u32 mask = BIT(irqd_to_hwirq(data));
 	unsigned long flags;
 
-	spin_lock_irqsave(&ctrl->lock, flags);
+	raw_spin_lock_irqsave(&ctrl->lock, flags);
 	ath79_gpio_update_bits(ctrl, AR71XX_GPIO_REG_INT_MASK, mask, mask);
-	spin_unlock_irqrestore(&ctrl->lock, flags);
+	raw_spin_unlock_irqrestore(&ctrl->lock, flags);
 }
 
 static void ath79_gpio_irq_mask(struct irq_data *data)
@@ -85,9 +85,9 @@ static void ath79_gpio_irq_mask(struct irq_data *data)
 	u32 mask = BIT(irqd_to_hwirq(data));
 	unsigned long flags;
 
-	spin_lock_irqsave(&ctrl->lock, flags);
+	raw_spin_lock_irqsave(&ctrl->lock, flags);
 	ath79_gpio_update_bits(ctrl, AR71XX_GPIO_REG_INT_MASK, mask, 0);
-	spin_unlock_irqrestore(&ctrl->lock, flags);
+	raw_spin_unlock_irqrestore(&ctrl->lock, flags);
 }
 
 static void ath79_gpio_irq_enable(struct irq_data *data)
@@ -96,10 +96,10 @@ static void ath79_gpio_irq_enable(struct irq_data *data)
 	u32 mask = BIT(irqd_to_hwirq(data));
 	unsigned long flags;
 
-	spin_lock_irqsave(&ctrl->lock, flags);
+	raw_spin_lock_irqsave(&ctrl->lock, flags);
 	ath79_gpio_update_bits(ctrl, AR71XX_GPIO_REG_INT_ENABLE, mask, mask);
 	ath79_gpio_update_bits(ctrl, AR71XX_GPIO_REG_INT_MASK, mask, mask);
-	spin_unlock_irqrestore(&ctrl->lock, flags);
+	raw_spin_unlock_irqrestore(&ctrl->lock, flags);
 }
 
 static void ath79_gpio_irq_disable(struct irq_data *data)
@@ -108,10 +108,10 @@ static void ath79_gpio_irq_disable(struct irq_data *data)
 	u32 mask = BIT(irqd_to_hwirq(data));
 	unsigned long flags;
 
-	spin_lock_irqsave(&ctrl->lock, flags);
+	raw_spin_lock_irqsave(&ctrl->lock, flags);
 	ath79_gpio_update_bits(ctrl, AR71XX_GPIO_REG_INT_MASK, mask, 0);
 	ath79_gpio_update_bits(ctrl, AR71XX_GPIO_REG_INT_ENABLE, mask, 0);
-	spin_unlock_irqrestore(&ctrl->lock, flags);
+	raw_spin_unlock_irqrestore(&ctrl->lock, flags);
 }
 
 static int ath79_gpio_irq_set_type(struct irq_data *data,
@@ -140,7 +140,7 @@ static int ath79_gpio_irq_set_type(struct irq_data *data,
 		return -EINVAL;
 	}
 
-	spin_lock_irqsave(&ctrl->lock, flags);
+	raw_spin_lock_irqsave(&ctrl->lock, flags);
 
 	if (flow_type == IRQ_TYPE_EDGE_BOTH) {
 		ctrl->both_edges |= mask;
@@ -165,7 +165,7 @@ static int ath79_gpio_irq_set_type(struct irq_data *data,
 		ath79_gpio_update_bits(
 			ctrl, AR71XX_GPIO_REG_INT_ENABLE, mask, mask);
 
-	spin_unlock_irqrestore(&ctrl->lock, flags);
+	raw_spin_unlock_irqrestore(&ctrl->lock, flags);
 
 	return 0;
 }
@@ -191,7 +191,7 @@ static void ath79_gpio_irq_handler(struct irq_desc *desc)
 
 	chained_irq_enter(irqchip, desc);
 
-	spin_lock_irqsave(&ctrl->lock, flags);
+	raw_spin_lock_irqsave(&ctrl->lock, flags);
 
 	pending = ath79_gpio_read(ctrl, AR71XX_GPIO_REG_INT_PENDING);
 
@@ -203,7 +203,7 @@ static void ath79_gpio_irq_handler(struct irq_desc *desc)
 				both_edges, ~state);
 	}
 
-	spin_unlock_irqrestore(&ctrl->lock, flags);
+	raw_spin_unlock_irqrestore(&ctrl->lock, flags);
 
 	if (pending) {
 		for_each_set_bit(irq, &pending, gc->ngpio)
@@ -262,7 +262,7 @@ static int ath79_gpio_probe(struct platform_device *pdev)
 	if (!ctrl->base)
 		return -ENOMEM;
 
-	spin_lock_init(&ctrl->lock);
+	raw_spin_lock_init(&ctrl->lock);
 	err = bgpio_init(&ctrl->gc, &pdev->dev, 4,
 			ctrl->base + AR71XX_GPIO_REG_IN,
 			ctrl->base + AR71XX_GPIO_REG_SET,
-- 
2.11.1

Re: [PATCH 06/19] gpio: ath79: make use of raw_spinlock variants

[Alban]

[-- Attachment #1: Type: text/plain, Size: 686 bytes --]

On Thu, 9 Mar 2017 10:21:53 -0600
Julia Cartwright <julia@ni.com> wrote:

> The ath79 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>

Acked-by: Aban Bedel <albeu@free.fr>

[-- Attachment #2: OpenPGP digital signature --]
[-- Type: application/pgp-signature, Size: 819 bytes --]

Re: [PATCH 06/19] gpio: ath79: make use of raw_spinlock variants

[Linus Walleij]

On Thu, Mar 9, 2017 at 5:21 PM, Julia Cartwright <julia@ni.com> wrote:

> The ath79 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>

Patch applied with Alban's ACK.

Yours,
Linus Walleij

[PATCH 07/19] gpio: bcm-kona: make use of raw_spinlock variants

[Julia Cartwright]

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>
---
 drivers/gpio/gpio-bcm-kona.c | 48 ++++++++++++++++++++++----------------------
 1 file changed, 24 insertions(+), 24 deletions(-)

diff --git a/drivers/gpio/gpio-bcm-kona.c b/drivers/gpio/gpio-bcm-kona.c
index 41d0ac142580..dfcf56ee3c61 100644
--- a/drivers/gpio/gpio-bcm-kona.c
+++ b/drivers/gpio/gpio-bcm-kona.c
@@ -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;
 
-- 
2.11.1

Re: [PATCH 07/19] gpio: bcm-kona: make use of raw_spinlock variants

[Ray Jui]

Hi Julia/Linus,

On 3/9/2017 8:21 AM, Julia Cartwright wrote:
> 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.

This is new to me. But it seems like, for the vast majority cases, user
can still continue to use spin_lock as it is without needing to worry
about the underlying difference between standard or RT kernels. But in
certain cases, e.g., irq_chips, extra care needs to be done, i.e.,
switching to use raw spin lock to make sure that it is not blocking in
the case of RT.

Is such API use change well accepted by the open source community already?

Thanks,

Ray

> 
> Signed-off-by: Julia Cartwright <julia@ni.com>
> ---
>  drivers/gpio/gpio-bcm-kona.c | 48 ++++++++++++++++++++++----------------------
>  1 file changed, 24 insertions(+), 24 deletions(-)
> 
> diff --git a/drivers/gpio/gpio-bcm-kona.c b/drivers/gpio/gpio-bcm-kona.c
> index 41d0ac142580..dfcf56ee3c61 100644
> --- a/drivers/gpio/gpio-bcm-kona.c
> +++ b/drivers/gpio/gpio-bcm-kona.c
> @@ -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;
>  
> 

Re: [PATCH 07/19] gpio: bcm-kona: make use of raw_spinlock variants

[Julia Cartwright]

[-- Attachment #1: Type: text/plain, Size: 1979 bytes --]

On Fri, Mar 10, 2017 at 09:28:08AM -0800, Ray Jui wrote:
> Hi Julia/Linus,
>
> On 3/9/2017 8:21 AM, Julia Cartwright wrote:
> > 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.
>
> This is new to me. But it seems like, for the vast majority cases, user
> can still continue to use spin_lock as it is without needing to worry
> about the underlying difference between standard or RT kernels.

If by "user" you mean, "driver developer", then yes.  For most driver
authors, the distinction between raw and non-raw spinlocks is
irrelevant, they can use spinlocks and everything will work out just
fine w/ mainline and on RT.

> But in certain cases, e.g., irq_chips, extra care needs to be done,
> i.e., swtching to use raw spin lock to make sure that it is not
> blocking in the case of RT.

Correct, on RT the goal is to push as much as possible into a
preemptible context, including driver interrupts, etc.  However, there
are still codepaths which necessarily need to be executed in hardirq
context, including anything necessary to support scheduling.  This
includes: interrupt-dispatching (irq_chips), timers, and the scheduler
itself, which is why this "core" code must use the raw spinlock
variants.

> Is such API use change well accepted by the open source community
> already?

In what way is this an API change?  The API isn't changing, what's
changing in this patch is to fix what is an irq_chip implementation
which is _currently broken_ on RT.

   Julia

[-- Attachment #2: signature.asc --]
[-- Type: application/pgp-signature, Size: 488 bytes --]

Re: [PATCH 07/19] gpio: bcm-kona: make use of raw_spinlock variants

[Linus Walleij]

On Fri, Mar 10, 2017 at 6:28 PM, Ray Jui <ray.jui@broadcom.com> wrote:

> Is such API use change well accepted by the open source community already?

The raw_*spinlock APIs are in the kernel header files and used at several
sites in the kernel, so yes.

Yours,
Linus Walleij

Re: [PATCH 07/19] gpio: bcm-kona: make use of raw_spinlock variants

[Linus Walleij]

On Thu, Mar 9, 2017 at 5:21 PM, Julia Cartwright <julia@ni.com> wrote:

> 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>

Patch applied.

Yours,
Linus Walleij

[PATCH 08/19] gpio: etraxfs: make use of raw_spinlock variants

[Julia Cartwright]

The etraxfs 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>
---
 drivers/gpio/gpio-etraxfs.c | 24 ++++++++++++------------
 1 file changed, 12 insertions(+), 12 deletions(-)

diff --git a/drivers/gpio/gpio-etraxfs.c b/drivers/gpio/gpio-etraxfs.c
index a254d5b07b94..14c6aac26780 100644
--- a/drivers/gpio/gpio-etraxfs.c
+++ b/drivers/gpio/gpio-etraxfs.c
@@ -54,7 +54,7 @@
 struct etraxfs_gpio_info;
 
 struct etraxfs_gpio_block {
-	spinlock_t lock;
+	raw_spinlock_t lock;
 	u32 mask;
 	u32 cfg;
 	u32 pins;
@@ -233,10 +233,10 @@ static void etraxfs_gpio_irq_mask(struct irq_data *d)
 	struct etraxfs_gpio_block *block = chip->block;
 	unsigned int grpirq = etraxfs_gpio_to_group_irq(d->hwirq);
 
-	spin_lock(&block->lock);
+	raw_spin_lock(&block->lock);
 	block->mask &= ~BIT(grpirq);
 	writel(block->mask, block->regs + block->info->rw_intr_mask);
-	spin_unlock(&block->lock);
+	raw_spin_unlock(&block->lock);
 }
 
 static void etraxfs_gpio_irq_unmask(struct irq_data *d)
@@ -246,10 +246,10 @@ static void etraxfs_gpio_irq_unmask(struct irq_data *d)
 	struct etraxfs_gpio_block *block = chip->block;
 	unsigned int grpirq = etraxfs_gpio_to_group_irq(d->hwirq);
 
-	spin_lock(&block->lock);
+	raw_spin_lock(&block->lock);
 	block->mask |= BIT(grpirq);
 	writel(block->mask, block->regs + block->info->rw_intr_mask);
-	spin_unlock(&block->lock);
+	raw_spin_unlock(&block->lock);
 }
 
 static int etraxfs_gpio_irq_set_type(struct irq_data *d, u32 type)
@@ -280,11 +280,11 @@ static int etraxfs_gpio_irq_set_type(struct irq_data *d, u32 type)
 		return -EINVAL;
 	}
 
-	spin_lock(&block->lock);
+	raw_spin_lock(&block->lock);
 	block->cfg &= ~(0x7 << (grpirq * 3));
 	block->cfg |= (cfg << (grpirq * 3));
 	writel(block->cfg, block->regs + block->info->rw_intr_cfg);
-	spin_unlock(&block->lock);
+	raw_spin_unlock(&block->lock);
 
 	return 0;
 }
@@ -297,7 +297,7 @@ static int etraxfs_gpio_irq_request_resources(struct irq_data *d)
 	unsigned int grpirq = etraxfs_gpio_to_group_irq(d->hwirq);
 	int ret = -EBUSY;
 
-	spin_lock(&block->lock);
+	raw_spin_lock(&block->lock);
 	if (block->group[grpirq])
 		goto out;
 
@@ -316,7 +316,7 @@ static int etraxfs_gpio_irq_request_resources(struct irq_data *d)
 	}
 
 out:
-	spin_unlock(&block->lock);
+	raw_spin_unlock(&block->lock);
 	return ret;
 }
 
@@ -327,10 +327,10 @@ static void etraxfs_gpio_irq_release_resources(struct irq_data *d)
 	struct etraxfs_gpio_block *block = chip->block;
 	unsigned int grpirq = etraxfs_gpio_to_group_irq(d->hwirq);
 
-	spin_lock(&block->lock);
+	raw_spin_lock(&block->lock);
 	block->group[grpirq] = 0;
 	gpiochip_unlock_as_irq(&chip->gc, d->hwirq);
-	spin_unlock(&block->lock);
+	raw_spin_unlock(&block->lock);
 }
 
 static struct irq_chip etraxfs_gpio_irq_chip = {
@@ -391,7 +391,7 @@ static int etraxfs_gpio_probe(struct platform_device *pdev)
 	if (!block)
 		return -ENOMEM;
 
-	spin_lock_init(&block->lock);
+	raw_spin_lock_init(&block->lock);
 
 	block->regs = regs;
 	block->info = info;
-- 
2.11.1

Re: [PATCH 08/19] gpio: etraxfs: make use of raw_spinlock variants

[Linus Walleij]

On Thu, Mar 9, 2017 at 5:21 PM, Julia Cartwright <julia@ni.com> wrote:

> The etraxfs 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>

Patch applied.

Yours,
Linus Walleij

[PATCH 09/19] gpio: pl061: make use of raw_spinlock variants

[Julia Cartwright]

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 <julia@ni.com>
---
 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;
-- 
2.11.1

Re: [PATCH 09/19] gpio: pl061: make use of raw_spinlock variants

[Linus Walleij]

On Thu, Mar 9, 2017 at 5:21 PM, Julia Cartwright <julia@ni.com> wrote:

> 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 <julia@ni.com>

Patch applied.

Yours,
Linus Walleij

[PATCH 10/19] gpio: ws16c48: make use of raw_spinlock variants

[Julia Cartwright]

The ws16c48 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>
---
 drivers/gpio/gpio-ws16c48.c | 46 ++++++++++++++++++++++-----------------------
 1 file changed, 23 insertions(+), 23 deletions(-)

diff --git a/drivers/gpio/gpio-ws16c48.c b/drivers/gpio/gpio-ws16c48.c
index 901b5ccb032d..87d63695dfcf 100644
--- a/drivers/gpio/gpio-ws16c48.c
+++ b/drivers/gpio/gpio-ws16c48.c
@@ -51,7 +51,7 @@ struct ws16c48_gpio {
 	struct gpio_chip chip;
 	unsigned char io_state[6];
 	unsigned char out_state[6];
-	spinlock_t lock;
+	raw_spinlock_t lock;
 	unsigned long irq_mask;
 	unsigned long flow_mask;
 	unsigned base;
@@ -73,13 +73,13 @@ static int ws16c48_gpio_direction_input(struct gpio_chip *chip, unsigned offset)
 	const unsigned mask = BIT(offset % 8);
 	unsigned long flags;
 
-	spin_lock_irqsave(&ws16c48gpio->lock, flags);
+	raw_spin_lock_irqsave(&ws16c48gpio->lock, flags);
 
 	ws16c48gpio->io_state[port] |= mask;
 	ws16c48gpio->out_state[port] &= ~mask;
 	outb(ws16c48gpio->out_state[port], ws16c48gpio->base + port);
 
-	spin_unlock_irqrestore(&ws16c48gpio->lock, flags);
+	raw_spin_unlock_irqrestore(&ws16c48gpio->lock, flags);
 
 	return 0;
 }
@@ -92,7 +92,7 @@ static int ws16c48_gpio_direction_output(struct gpio_chip *chip,
 	const unsigned mask = BIT(offset % 8);
 	unsigned long flags;
 
-	spin_lock_irqsave(&ws16c48gpio->lock, flags);
+	raw_spin_lock_irqsave(&ws16c48gpio->lock, flags);
 
 	ws16c48gpio->io_state[port] &= ~mask;
 	if (value)
@@ -101,7 +101,7 @@ static int ws16c48_gpio_direction_output(struct gpio_chip *chip,
 		ws16c48gpio->out_state[port] &= ~mask;
 	outb(ws16c48gpio->out_state[port], ws16c48gpio->base + port);
 
-	spin_unlock_irqrestore(&ws16c48gpio->lock, flags);
+	raw_spin_unlock_irqrestore(&ws16c48gpio->lock, flags);
 
 	return 0;
 }
@@ -114,17 +114,17 @@ static int ws16c48_gpio_get(struct gpio_chip *chip, unsigned offset)
 	unsigned long flags;
 	unsigned port_state;
 
-	spin_lock_irqsave(&ws16c48gpio->lock, flags);
+	raw_spin_lock_irqsave(&ws16c48gpio->lock, flags);
 
 	/* ensure that GPIO is set for input */
 	if (!(ws16c48gpio->io_state[port] & mask)) {
-		spin_unlock_irqrestore(&ws16c48gpio->lock, flags);
+		raw_spin_unlock_irqrestore(&ws16c48gpio->lock, flags);
 		return -EINVAL;
 	}
 
 	port_state = inb(ws16c48gpio->base + port);
 
-	spin_unlock_irqrestore(&ws16c48gpio->lock, flags);
+	raw_spin_unlock_irqrestore(&ws16c48gpio->lock, flags);
 
 	return !!(port_state & mask);
 }
@@ -136,11 +136,11 @@ static void ws16c48_gpio_set(struct gpio_chip *chip, unsigned offset, int value)
 	const unsigned mask = BIT(offset % 8);
 	unsigned long flags;
 
-	spin_lock_irqsave(&ws16c48gpio->lock, flags);
+	raw_spin_lock_irqsave(&ws16c48gpio->lock, flags);
 
 	/* ensure that GPIO is set for output */
 	if (ws16c48gpio->io_state[port] & mask) {
-		spin_unlock_irqrestore(&ws16c48gpio->lock, flags);
+		raw_spin_unlock_irqrestore(&ws16c48gpio->lock, flags);
 		return;
 	}
 
@@ -150,7 +150,7 @@ static void ws16c48_gpio_set(struct gpio_chip *chip, unsigned offset, int value)
 		ws16c48gpio->out_state[port] &= ~mask;
 	outb(ws16c48gpio->out_state[port], ws16c48gpio->base + port);
 
-	spin_unlock_irqrestore(&ws16c48gpio->lock, flags);
+	raw_spin_unlock_irqrestore(&ws16c48gpio->lock, flags);
 }
 
 static void ws16c48_gpio_set_multiple(struct gpio_chip *chip,
@@ -178,14 +178,14 @@ static void ws16c48_gpio_set_multiple(struct gpio_chip *chip,
 		iomask = mask[BIT_WORD(i)] & ~ws16c48gpio->io_state[port];
 		bitmask = iomask & bits[BIT_WORD(i)];
 
-		spin_lock_irqsave(&ws16c48gpio->lock, flags);
+		raw_spin_lock_irqsave(&ws16c48gpio->lock, flags);
 
 		/* update output state data and set device gpio register */
 		ws16c48gpio->out_state[port] &= ~iomask;
 		ws16c48gpio->out_state[port] |= bitmask;
 		outb(ws16c48gpio->out_state[port], ws16c48gpio->base + port);
 
-		spin_unlock_irqrestore(&ws16c48gpio->lock, flags);
+		raw_spin_unlock_irqrestore(&ws16c48gpio->lock, flags);
 
 		/* prepare for next gpio register set */
 		mask[BIT_WORD(i)] >>= gpio_reg_size;
@@ -207,7 +207,7 @@ static void ws16c48_irq_ack(struct irq_data *data)
 	if (port > 2)
 		return;
 
-	spin_lock_irqsave(&ws16c48gpio->lock, flags);
+	raw_spin_lock_irqsave(&ws16c48gpio->lock, flags);
 
 	port_state = ws16c48gpio->irq_mask >> (8*port);
 
@@ -216,7 +216,7 @@ static void ws16c48_irq_ack(struct irq_data *data)
 	outb(port_state | mask, ws16c48gpio->base + 8 + port);
 	outb(0xC0, ws16c48gpio->base + 7);
 
-	spin_unlock_irqrestore(&ws16c48gpio->lock, flags);
+	raw_spin_unlock_irqrestore(&ws16c48gpio->lock, flags);
 }
 
 static void ws16c48_irq_mask(struct irq_data *data)
@@ -232,7 +232,7 @@ static void ws16c48_irq_mask(struct irq_data *data)
 	if (port > 2)
 		return;
 
-	spin_lock_irqsave(&ws16c48gpio->lock, flags);
+	raw_spin_lock_irqsave(&ws16c48gpio->lock, flags);
 
 	ws16c48gpio->irq_mask &= ~mask;
 
@@ -240,7 +240,7 @@ static void ws16c48_irq_mask(struct irq_data *data)
 	outb(ws16c48gpio->irq_mask >> (8*port), ws16c48gpio->base + 8 + port);
 	outb(0xC0, ws16c48gpio->base + 7);
 
-	spin_unlock_irqrestore(&ws16c48gpio->lock, flags);
+	raw_spin_unlock_irqrestore(&ws16c48gpio->lock, flags);
 }
 
 static void ws16c48_irq_unmask(struct irq_data *data)
@@ -256,7 +256,7 @@ static void ws16c48_irq_unmask(struct irq_data *data)
 	if (port > 2)
 		return;
 
-	spin_lock_irqsave(&ws16c48gpio->lock, flags);
+	raw_spin_lock_irqsave(&ws16c48gpio->lock, flags);
 
 	ws16c48gpio->irq_mask |= mask;
 
@@ -264,7 +264,7 @@ static void ws16c48_irq_unmask(struct irq_data *data)
 	outb(ws16c48gpio->irq_mask >> (8*port), ws16c48gpio->base + 8 + port);
 	outb(0xC0, ws16c48gpio->base + 7);
 
-	spin_unlock_irqrestore(&ws16c48gpio->lock, flags);
+	raw_spin_unlock_irqrestore(&ws16c48gpio->lock, flags);
 }
 
 static int ws16c48_irq_set_type(struct irq_data *data, unsigned flow_type)
@@ -280,7 +280,7 @@ static int ws16c48_irq_set_type(struct irq_data *data, unsigned flow_type)
 	if (port > 2)
 		return -EINVAL;
 
-	spin_lock_irqsave(&ws16c48gpio->lock, flags);
+	raw_spin_lock_irqsave(&ws16c48gpio->lock, flags);
 
 	switch (flow_type) {
 	case IRQ_TYPE_NONE:
@@ -292,7 +292,7 @@ static int ws16c48_irq_set_type(struct irq_data *data, unsigned flow_type)
 		ws16c48gpio->flow_mask &= ~mask;
 		break;
 	default:
-		spin_unlock_irqrestore(&ws16c48gpio->lock, flags);
+		raw_spin_unlock_irqrestore(&ws16c48gpio->lock, flags);
 		return -EINVAL;
 	}
 
@@ -300,7 +300,7 @@ static int ws16c48_irq_set_type(struct irq_data *data, unsigned flow_type)
 	outb(ws16c48gpio->flow_mask >> (8*port), ws16c48gpio->base + 8 + port);
 	outb(0xC0, ws16c48gpio->base + 7);
 
-	spin_unlock_irqrestore(&ws16c48gpio->lock, flags);
+	raw_spin_unlock_irqrestore(&ws16c48gpio->lock, flags);
 
 	return 0;
 }
@@ -387,7 +387,7 @@ static int ws16c48_probe(struct device *dev, unsigned int id)
 	ws16c48gpio->chip.set_multiple = ws16c48_gpio_set_multiple;
 	ws16c48gpio->base = base[id];
 
-	spin_lock_init(&ws16c48gpio->lock);
+	raw_spin_lock_init(&ws16c48gpio->lock);
 
 	err = devm_gpiochip_add_data(dev, &ws16c48gpio->chip, ws16c48gpio);
 	if (err) {
-- 
2.11.1

Re: [PATCH 10/19] gpio: ws16c48: make use of raw_spinlock variants

[William Breathitt Gray]

On Thu, Mar 09, 2017 at 10:21:57AM -0600, Julia Cartwright wrote:
>The ws16c48 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>

Acked-by: William Breathitt Gray <vilhelm.gray@gmail.com>

>---
> drivers/gpio/gpio-ws16c48.c | 46 ++++++++++++++++++++++-----------------------
> 1 file changed, 23 insertions(+), 23 deletions(-)
>
>diff --git a/drivers/gpio/gpio-ws16c48.c b/drivers/gpio/gpio-ws16c48.c
>index 901b5ccb032d..87d63695dfcf 100644
>--- a/drivers/gpio/gpio-ws16c48.c
>+++ b/drivers/gpio/gpio-ws16c48.c
>@@ -51,7 +51,7 @@ struct ws16c48_gpio {
> 	struct gpio_chip chip;
> 	unsigned char io_state[6];
> 	unsigned char out_state[6];
>-	spinlock_t lock;
>+	raw_spinlock_t lock;
> 	unsigned long irq_mask;
> 	unsigned long flow_mask;
> 	unsigned base;
>@@ -73,13 +73,13 @@ static int ws16c48_gpio_direction_input(struct gpio_chip *chip, unsigned offset)
> 	const unsigned mask = BIT(offset % 8);
> 	unsigned long flags;
> 
>-	spin_lock_irqsave(&ws16c48gpio->lock, flags);
>+	raw_spin_lock_irqsave(&ws16c48gpio->lock, flags);
> 
> 	ws16c48gpio->io_state[port] |= mask;
> 	ws16c48gpio->out_state[port] &= ~mask;
> 	outb(ws16c48gpio->out_state[port], ws16c48gpio->base + port);
> 
>-	spin_unlock_irqrestore(&ws16c48gpio->lock, flags);
>+	raw_spin_unlock_irqrestore(&ws16c48gpio->lock, flags);
> 
> 	return 0;
> }
>@@ -92,7 +92,7 @@ static int ws16c48_gpio_direction_output(struct gpio_chip *chip,
> 	const unsigned mask = BIT(offset % 8);
> 	unsigned long flags;
> 
>-	spin_lock_irqsave(&ws16c48gpio->lock, flags);
>+	raw_spin_lock_irqsave(&ws16c48gpio->lock, flags);
> 
> 	ws16c48gpio->io_state[port] &= ~mask;
> 	if (value)
>@@ -101,7 +101,7 @@ static int ws16c48_gpio_direction_output(struct gpio_chip *chip,
> 		ws16c48gpio->out_state[port] &= ~mask;
> 	outb(ws16c48gpio->out_state[port], ws16c48gpio->base + port);
> 
>-	spin_unlock_irqrestore(&ws16c48gpio->lock, flags);
>+	raw_spin_unlock_irqrestore(&ws16c48gpio->lock, flags);
> 
> 	return 0;
> }
>@@ -114,17 +114,17 @@ static int ws16c48_gpio_get(struct gpio_chip *chip, unsigned offset)
> 	unsigned long flags;
> 	unsigned port_state;
> 
>-	spin_lock_irqsave(&ws16c48gpio->lock, flags);
>+	raw_spin_lock_irqsave(&ws16c48gpio->lock, flags);
> 
> 	/* ensure that GPIO is set for input */
> 	if (!(ws16c48gpio->io_state[port] & mask)) {
>-		spin_unlock_irqrestore(&ws16c48gpio->lock, flags);
>+		raw_spin_unlock_irqrestore(&ws16c48gpio->lock, flags);
> 		return -EINVAL;
> 	}
> 
> 	port_state = inb(ws16c48gpio->base + port);
> 
>-	spin_unlock_irqrestore(&ws16c48gpio->lock, flags);
>+	raw_spin_unlock_irqrestore(&ws16c48gpio->lock, flags);
> 
> 	return !!(port_state & mask);
> }
>@@ -136,11 +136,11 @@ static void ws16c48_gpio_set(struct gpio_chip *chip, unsigned offset, int value)
> 	const unsigned mask = BIT(offset % 8);
> 	unsigned long flags;
> 
>-	spin_lock_irqsave(&ws16c48gpio->lock, flags);
>+	raw_spin_lock_irqsave(&ws16c48gpio->lock, flags);
> 
> 	/* ensure that GPIO is set for output */
> 	if (ws16c48gpio->io_state[port] & mask) {
>-		spin_unlock_irqrestore(&ws16c48gpio->lock, flags);
>+		raw_spin_unlock_irqrestore(&ws16c48gpio->lock, flags);
> 		return;
> 	}
> 
>@@ -150,7 +150,7 @@ static void ws16c48_gpio_set(struct gpio_chip *chip, unsigned offset, int value)
> 		ws16c48gpio->out_state[port] &= ~mask;
> 	outb(ws16c48gpio->out_state[port], ws16c48gpio->base + port);
> 
>-	spin_unlock_irqrestore(&ws16c48gpio->lock, flags);
>+	raw_spin_unlock_irqrestore(&ws16c48gpio->lock, flags);
> }
> 
> static void ws16c48_gpio_set_multiple(struct gpio_chip *chip,
>@@ -178,14 +178,14 @@ static void ws16c48_gpio_set_multiple(struct gpio_chip *chip,
> 		iomask = mask[BIT_WORD(i)] & ~ws16c48gpio->io_state[port];
> 		bitmask = iomask & bits[BIT_WORD(i)];
> 
>-		spin_lock_irqsave(&ws16c48gpio->lock, flags);
>+		raw_spin_lock_irqsave(&ws16c48gpio->lock, flags);
> 
> 		/* update output state data and set device gpio register */
> 		ws16c48gpio->out_state[port] &= ~iomask;
> 		ws16c48gpio->out_state[port] |= bitmask;
> 		outb(ws16c48gpio->out_state[port], ws16c48gpio->base + port);
> 
>-		spin_unlock_irqrestore(&ws16c48gpio->lock, flags);
>+		raw_spin_unlock_irqrestore(&ws16c48gpio->lock, flags);
> 
> 		/* prepare for next gpio register set */
> 		mask[BIT_WORD(i)] >>= gpio_reg_size;
>@@ -207,7 +207,7 @@ static void ws16c48_irq_ack(struct irq_data *data)
> 	if (port > 2)
> 		return;
> 
>-	spin_lock_irqsave(&ws16c48gpio->lock, flags);
>+	raw_spin_lock_irqsave(&ws16c48gpio->lock, flags);
> 
> 	port_state = ws16c48gpio->irq_mask >> (8*port);
> 
>@@ -216,7 +216,7 @@ static void ws16c48_irq_ack(struct irq_data *data)
> 	outb(port_state | mask, ws16c48gpio->base + 8 + port);
> 	outb(0xC0, ws16c48gpio->base + 7);
> 
>-	spin_unlock_irqrestore(&ws16c48gpio->lock, flags);
>+	raw_spin_unlock_irqrestore(&ws16c48gpio->lock, flags);
> }
> 
> static void ws16c48_irq_mask(struct irq_data *data)
>@@ -232,7 +232,7 @@ static void ws16c48_irq_mask(struct irq_data *data)
> 	if (port > 2)
> 		return;
> 
>-	spin_lock_irqsave(&ws16c48gpio->lock, flags);
>+	raw_spin_lock_irqsave(&ws16c48gpio->lock, flags);
> 
> 	ws16c48gpio->irq_mask &= ~mask;
> 
>@@ -240,7 +240,7 @@ static void ws16c48_irq_mask(struct irq_data *data)
> 	outb(ws16c48gpio->irq_mask >> (8*port), ws16c48gpio->base + 8 + port);
> 	outb(0xC0, ws16c48gpio->base + 7);
> 
>-	spin_unlock_irqrestore(&ws16c48gpio->lock, flags);
>+	raw_spin_unlock_irqrestore(&ws16c48gpio->lock, flags);
> }
> 
> static void ws16c48_irq_unmask(struct irq_data *data)
>@@ -256,7 +256,7 @@ static void ws16c48_irq_unmask(struct irq_data *data)
> 	if (port > 2)
> 		return;
> 
>-	spin_lock_irqsave(&ws16c48gpio->lock, flags);
>+	raw_spin_lock_irqsave(&ws16c48gpio->lock, flags);
> 
> 	ws16c48gpio->irq_mask |= mask;
> 
>@@ -264,7 +264,7 @@ static void ws16c48_irq_unmask(struct irq_data *data)
> 	outb(ws16c48gpio->irq_mask >> (8*port), ws16c48gpio->base + 8 + port);
> 	outb(0xC0, ws16c48gpio->base + 7);
> 
>-	spin_unlock_irqrestore(&ws16c48gpio->lock, flags);
>+	raw_spin_unlock_irqrestore(&ws16c48gpio->lock, flags);
> }
> 
> static int ws16c48_irq_set_type(struct irq_data *data, unsigned flow_type)
>@@ -280,7 +280,7 @@ static int ws16c48_irq_set_type(struct irq_data *data, unsigned flow_type)
> 	if (port > 2)
> 		return -EINVAL;
> 
>-	spin_lock_irqsave(&ws16c48gpio->lock, flags);
>+	raw_spin_lock_irqsave(&ws16c48gpio->lock, flags);
> 
> 	switch (flow_type) {
> 	case IRQ_TYPE_NONE:
>@@ -292,7 +292,7 @@ static int ws16c48_irq_set_type(struct irq_data *data, unsigned flow_type)
> 		ws16c48gpio->flow_mask &= ~mask;
> 		break;
> 	default:
>-		spin_unlock_irqrestore(&ws16c48gpio->lock, flags);
>+		raw_spin_unlock_irqrestore(&ws16c48gpio->lock, flags);
> 		return -EINVAL;
> 	}
> 
>@@ -300,7 +300,7 @@ static int ws16c48_irq_set_type(struct irq_data *data, unsigned flow_type)
> 	outb(ws16c48gpio->flow_mask >> (8*port), ws16c48gpio->base + 8 + port);
> 	outb(0xC0, ws16c48gpio->base + 7);
> 
>-	spin_unlock_irqrestore(&ws16c48gpio->lock, flags);
>+	raw_spin_unlock_irqrestore(&ws16c48gpio->lock, flags);
> 
> 	return 0;
> }
>@@ -387,7 +387,7 @@ static int ws16c48_probe(struct device *dev, unsigned int id)
> 	ws16c48gpio->chip.set_multiple = ws16c48_gpio_set_multiple;
> 	ws16c48gpio->base = base[id];
> 
>-	spin_lock_init(&ws16c48gpio->lock);
>+	raw_spin_lock_init(&ws16c48gpio->lock);
> 
> 	err = devm_gpiochip_add_data(dev, &ws16c48gpio->chip, ws16c48gpio);
> 	if (err) {
>-- 
>2.11.1
>

Re: [PATCH 10/19] gpio: ws16c48: make use of raw_spinlock variants

[Linus Walleij]

On Thu, Mar 9, 2017 at 5:21 PM, Julia Cartwright <julia@ni.com> wrote:

> The ws16c48 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>

Patch applied with William's ACK.

Yours,
Linus Walleij

[PATCH 11/19] gpio: zx: make use of raw_spinlock variants

[Julia Cartwright]

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 <julia@ni.com>
---
 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;
-- 
2.11.1

Re: [PATCH 11/19] gpio: zx: make use of raw_spinlock variants

[Linus Walleij]

On Thu, Mar 9, 2017 at 5:21 PM, Julia Cartwright <julia@ni.com> wrote:

> 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 <julia@ni.com>

Patch applied.

Yours,
Linus Walleij

[PATCH 16/19] pinctrl: bcm: make use of raw_spinlock variants

[Julia Cartwright]

The bcm 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@ni.com>
---
 drivers/pinctrl/bcm/pinctrl-iproc-gpio.c | 44 +++++++++++++++---------------
 drivers/pinctrl/bcm/pinctrl-nsp-gpio.c   | 46 ++++++++++++++++----------------
 2 files changed, 45 insertions(+), 45 deletions(-)

diff --git a/drivers/pinctrl/bcm/pinctrl-iproc-gpio.c b/drivers/pinctrl/bcm/pinctrl-iproc-gpio.c
index 3ca925dfefd1..af5e904d4a1e 100644
--- a/drivers/pinctrl/bcm/pinctrl-iproc-gpio.c
+++ b/drivers/pinctrl/bcm/pinctrl-iproc-gpio.c
@@ -99,7 +99,7 @@ struct iproc_gpio {
 	void __iomem *base;
 	void __iomem *io_ctrl;
 
-	spinlock_t lock;
+	raw_spinlock_t lock;
 
 	struct gpio_chip gc;
 	unsigned num_banks;
@@ -221,9 +221,9 @@ static void iproc_gpio_irq_mask(struct irq_data *d)
 	struct iproc_gpio *chip = gpiochip_get_data(gc);
 	unsigned long flags;
 
-	spin_lock_irqsave(&chip->lock, flags);
+	raw_spin_lock_irqsave(&chip->lock, flags);
 	iproc_gpio_irq_set_mask(d, false);
-	spin_unlock_irqrestore(&chip->lock, flags);
+	raw_spin_unlock_irqrestore(&chip->lock, flags);
 }
 
 static void iproc_gpio_irq_unmask(struct irq_data *d)
@@ -232,9 +232,9 @@ static void iproc_gpio_irq_unmask(struct irq_data *d)
 	struct iproc_gpio *chip = gpiochip_get_data(gc);
 	unsigned long flags;
 
-	spin_lock_irqsave(&chip->lock, flags);
+	raw_spin_lock_irqsave(&chip->lock, flags);
 	iproc_gpio_irq_set_mask(d, true);
-	spin_unlock_irqrestore(&chip->lock, flags);
+	raw_spin_unlock_irqrestore(&chip->lock, flags);
 }
 
 static int iproc_gpio_irq_set_type(struct irq_data *d, unsigned int type)
@@ -274,13 +274,13 @@ static int iproc_gpio_irq_set_type(struct irq_data *d, unsigned int type)
 		return -EINVAL;
 	}
 
-	spin_lock_irqsave(&chip->lock, flags);
+	raw_spin_lock_irqsave(&chip->lock, flags);
 	iproc_set_bit(chip, IPROC_GPIO_INT_TYPE_OFFSET, gpio,
 		       level_triggered);
 	iproc_set_bit(chip, IPROC_GPIO_INT_DE_OFFSET, gpio, dual_edge);
 	iproc_set_bit(chip, IPROC_GPIO_INT_EDGE_OFFSET, gpio,
 		       rising_or_high);
-	spin_unlock_irqrestore(&chip->lock, flags);
+	raw_spin_unlock_irqrestore(&chip->lock, flags);
 
 	dev_dbg(chip->dev,
 		"gpio:%u level_triggered:%d dual_edge:%d rising_or_high:%d\n",
@@ -328,9 +328,9 @@ static int iproc_gpio_direction_input(struct gpio_chip *gc, unsigned gpio)
 	struct iproc_gpio *chip = gpiochip_get_data(gc);
 	unsigned long flags;
 
-	spin_lock_irqsave(&chip->lock, flags);
+	raw_spin_lock_irqsave(&chip->lock, flags);
 	iproc_set_bit(chip, IPROC_GPIO_OUT_EN_OFFSET, gpio, false);
-	spin_unlock_irqrestore(&chip->lock, flags);
+	raw_spin_unlock_irqrestore(&chip->lock, flags);
 
 	dev_dbg(chip->dev, "gpio:%u set input\n", gpio);
 
@@ -343,10 +343,10 @@ static int iproc_gpio_direction_output(struct gpio_chip *gc, unsigned gpio,
 	struct iproc_gpio *chip = gpiochip_get_data(gc);
 	unsigned long flags;
 
-	spin_lock_irqsave(&chip->lock, flags);
+	raw_spin_lock_irqsave(&chip->lock, flags);
 	iproc_set_bit(chip, IPROC_GPIO_OUT_EN_OFFSET, gpio, true);
 	iproc_set_bit(chip, IPROC_GPIO_DATA_OUT_OFFSET, gpio, !!(val));
-	spin_unlock_irqrestore(&chip->lock, flags);
+	raw_spin_unlock_irqrestore(&chip->lock, flags);
 
 	dev_dbg(chip->dev, "gpio:%u set output, value:%d\n", gpio, val);
 
@@ -358,9 +358,9 @@ static void iproc_gpio_set(struct gpio_chip *gc, unsigned gpio, int val)
 	struct iproc_gpio *chip = gpiochip_get_data(gc);
 	unsigned long flags;
 
-	spin_lock_irqsave(&chip->lock, flags);
+	raw_spin_lock_irqsave(&chip->lock, flags);
 	iproc_set_bit(chip, IPROC_GPIO_DATA_OUT_OFFSET, gpio, !!(val));
-	spin_unlock_irqrestore(&chip->lock, flags);
+	raw_spin_unlock_irqrestore(&chip->lock, flags);
 
 	dev_dbg(chip->dev, "gpio:%u set, value:%d\n", gpio, val);
 }
@@ -461,7 +461,7 @@ static int iproc_gpio_set_pull(struct iproc_gpio *chip, unsigned gpio,
 {
 	unsigned long flags;
 
-	spin_lock_irqsave(&chip->lock, flags);
+	raw_spin_lock_irqsave(&chip->lock, flags);
 
 	if (disable) {
 		iproc_set_bit(chip, IPROC_GPIO_RES_EN_OFFSET, gpio, false);
@@ -471,7 +471,7 @@ static int iproc_gpio_set_pull(struct iproc_gpio *chip, unsigned gpio,
 		iproc_set_bit(chip, IPROC_GPIO_RES_EN_OFFSET, gpio, true);
 	}
 
-	spin_unlock_irqrestore(&chip->lock, flags);
+	raw_spin_unlock_irqrestore(&chip->lock, flags);
 
 	dev_dbg(chip->dev, "gpio:%u set pullup:%d\n", gpio, pull_up);
 
@@ -483,10 +483,10 @@ static void iproc_gpio_get_pull(struct iproc_gpio *chip, unsigned gpio,
 {
 	unsigned long flags;
 
-	spin_lock_irqsave(&chip->lock, flags);
+	raw_spin_lock_irqsave(&chip->lock, flags);
 	*disable = !iproc_get_bit(chip, IPROC_GPIO_RES_EN_OFFSET, gpio);
 	*pull_up = iproc_get_bit(chip, IPROC_GPIO_PAD_RES_OFFSET, gpio);
-	spin_unlock_irqrestore(&chip->lock, flags);
+	raw_spin_unlock_irqrestore(&chip->lock, flags);
 }
 
 static int iproc_gpio_set_strength(struct iproc_gpio *chip, unsigned gpio,
@@ -515,7 +515,7 @@ static int iproc_gpio_set_strength(struct iproc_gpio *chip, unsigned gpio,
 	dev_dbg(chip->dev, "gpio:%u set drive strength:%d mA\n", gpio,
 		strength);
 
-	spin_lock_irqsave(&chip->lock, flags);
+	raw_spin_lock_irqsave(&chip->lock, flags);
 	strength = (strength / 2) - 1;
 	for (i = 0; i < GPIO_DRV_STRENGTH_BITS; i++) {
 		val = readl(base + offset);
@@ -524,7 +524,7 @@ static int iproc_gpio_set_strength(struct iproc_gpio *chip, unsigned gpio,
 		writel(val, base + offset);
 		offset += 4;
 	}
-	spin_unlock_irqrestore(&chip->lock, flags);
+	raw_spin_unlock_irqrestore(&chip->lock, flags);
 
 	return 0;
 }
@@ -548,7 +548,7 @@ static int iproc_gpio_get_strength(struct iproc_gpio *chip, unsigned gpio,
 
 	shift = IPROC_GPIO_SHIFT(gpio);
 
-	spin_lock_irqsave(&chip->lock, flags);
+	raw_spin_lock_irqsave(&chip->lock, flags);
 	*strength = 0;
 	for (i = 0; i < GPIO_DRV_STRENGTH_BITS; i++) {
 		val = readl(base + offset) & BIT(shift);
@@ -559,7 +559,7 @@ static int iproc_gpio_get_strength(struct iproc_gpio *chip, unsigned gpio,
 
 	/* convert to mA */
 	*strength = (*strength + 1) * 2;
-	spin_unlock_irqrestore(&chip->lock, flags);
+	raw_spin_unlock_irqrestore(&chip->lock, flags);
 
 	return 0;
 }
@@ -769,7 +769,7 @@ static int iproc_gpio_probe(struct platform_device *pdev)
 		return -ENODEV;
 	}
 
-	spin_lock_init(&chip->lock);
+	raw_spin_lock_init(&chip->lock);
 
 	gc = &chip->gc;
 	gc->base = -1;
diff --git a/drivers/pinctrl/bcm/pinctrl-nsp-gpio.c b/drivers/pinctrl/bcm/pinctrl-nsp-gpio.c
index 91ea32dc1e7f..22442438275a 100644
--- a/drivers/pinctrl/bcm/pinctrl-nsp-gpio.c
+++ b/drivers/pinctrl/bcm/pinctrl-nsp-gpio.c
@@ -73,7 +73,7 @@ struct nsp_gpio {
 	struct pinctrl_dev *pctl;
 	struct pinctrl_desc pctldesc;
 	struct irq_domain *irq_domain;
-	spinlock_t lock;
+	raw_spinlock_t lock;
 };
 
 enum base_type {
@@ -203,9 +203,9 @@ static void nsp_gpio_irq_mask(struct irq_data *d)
 	struct nsp_gpio *chip = irq_data_get_irq_chip_data(d);
 	unsigned long flags;
 
-	spin_lock_irqsave(&chip->lock, flags);
+	raw_spin_lock_irqsave(&chip->lock, flags);
 	nsp_gpio_irq_set_mask(d, false);
-	spin_unlock_irqrestore(&chip->lock, flags);
+	raw_spin_unlock_irqrestore(&chip->lock, flags);
 }
 
 static void nsp_gpio_irq_unmask(struct irq_data *d)
@@ -213,9 +213,9 @@ static void nsp_gpio_irq_unmask(struct irq_data *d)
 	struct nsp_gpio *chip = irq_data_get_irq_chip_data(d);
 	unsigned long flags;
 
-	spin_lock_irqsave(&chip->lock, flags);
+	raw_spin_lock_irqsave(&chip->lock, flags);
 	nsp_gpio_irq_set_mask(d, true);
-	spin_unlock_irqrestore(&chip->lock, flags);
+	raw_spin_unlock_irqrestore(&chip->lock, flags);
 }
 
 static int nsp_gpio_irq_set_type(struct irq_data *d, unsigned int type)
@@ -226,7 +226,7 @@ static int nsp_gpio_irq_set_type(struct irq_data *d, unsigned int type)
 	bool falling;
 	unsigned long flags;
 
-	spin_lock_irqsave(&chip->lock, flags);
+	raw_spin_lock_irqsave(&chip->lock, flags);
 	falling = nsp_get_bit(chip, REG, NSP_GPIO_EVENT_INT_POLARITY, gpio);
 	level_low = nsp_get_bit(chip, REG, NSP_GPIO_INT_POLARITY, gpio);
 
@@ -250,13 +250,13 @@ static int nsp_gpio_irq_set_type(struct irq_data *d, unsigned int type)
 	default:
 		dev_err(chip->dev, "invalid GPIO IRQ type 0x%x\n",
 			type);
-		spin_unlock_irqrestore(&chip->lock, flags);
+		raw_spin_unlock_irqrestore(&chip->lock, flags);
 		return -EINVAL;
 	}
 
 	nsp_set_bit(chip, REG, NSP_GPIO_EVENT_INT_POLARITY, gpio, falling);
 	nsp_set_bit(chip, REG, NSP_GPIO_INT_POLARITY, gpio, level_low);
-	spin_unlock_irqrestore(&chip->lock, flags);
+	raw_spin_unlock_irqrestore(&chip->lock, flags);
 
 	dev_dbg(chip->dev, "gpio:%u level_low:%s falling:%s\n", gpio,
 		level_low ? "true" : "false", falling ? "true" : "false");
@@ -295,9 +295,9 @@ static int nsp_gpio_direction_input(struct gpio_chip *gc, unsigned gpio)
 	struct nsp_gpio *chip = gpiochip_get_data(gc);
 	unsigned long flags;
 
-	spin_lock_irqsave(&chip->lock, flags);
+	raw_spin_lock_irqsave(&chip->lock, flags);
 	nsp_set_bit(chip, REG, NSP_GPIO_OUT_EN, gpio, false);
-	spin_unlock_irqrestore(&chip->lock, flags);
+	raw_spin_unlock_irqrestore(&chip->lock, flags);
 
 	dev_dbg(chip->dev, "gpio:%u set input\n", gpio);
 	return 0;
@@ -309,10 +309,10 @@ static int nsp_gpio_direction_output(struct gpio_chip *gc, unsigned gpio,
 	struct nsp_gpio *chip = gpiochip_get_data(gc);
 	unsigned long flags;
 
-	spin_lock_irqsave(&chip->lock, flags);
+	raw_spin_lock_irqsave(&chip->lock, flags);
 	nsp_set_bit(chip, REG, NSP_GPIO_OUT_EN, gpio, true);
 	nsp_set_bit(chip, REG, NSP_GPIO_DATA_OUT, gpio, !!(val));
-	spin_unlock_irqrestore(&chip->lock, flags);
+	raw_spin_unlock_irqrestore(&chip->lock, flags);
 
 	dev_dbg(chip->dev, "gpio:%u set output, value:%d\n", gpio, val);
 	return 0;
@@ -323,9 +323,9 @@ static void nsp_gpio_set(struct gpio_chip *gc, unsigned gpio, int val)
 	struct nsp_gpio *chip = gpiochip_get_data(gc);
 	unsigned long flags;
 
-	spin_lock_irqsave(&chip->lock, flags);
+	raw_spin_lock_irqsave(&chip->lock, flags);
 	nsp_set_bit(chip, REG, NSP_GPIO_DATA_OUT, gpio, !!(val));
-	spin_unlock_irqrestore(&chip->lock, flags);
+	raw_spin_unlock_irqrestore(&chip->lock, flags);
 
 	dev_dbg(chip->dev, "gpio:%u set, value:%d\n", gpio, val);
 }
@@ -381,10 +381,10 @@ static int nsp_gpio_set_pull(struct nsp_gpio *chip, unsigned gpio,
 {
 	unsigned long flags;
 
-	spin_lock_irqsave(&chip->lock, flags);
+	raw_spin_lock_irqsave(&chip->lock, flags);
 	nsp_set_bit(chip, IO_CTRL, NSP_PULL_DOWN_EN, gpio, pull_down);
 	nsp_set_bit(chip, IO_CTRL, NSP_PULL_UP_EN, gpio, pull_up);
-	spin_unlock_irqrestore(&chip->lock, flags);
+	raw_spin_unlock_irqrestore(&chip->lock, flags);
 
 	dev_dbg(chip->dev, "gpio:%u set pullup:%d pulldown: %d\n",
 		gpio, pull_up, pull_down);
@@ -396,10 +396,10 @@ static void nsp_gpio_get_pull(struct nsp_gpio *chip, unsigned gpio,
 {
 	unsigned long flags;
 
-	spin_lock_irqsave(&chip->lock, flags);
+	raw_spin_lock_irqsave(&chip->lock, flags);
 	*pull_up = nsp_get_bit(chip, IO_CTRL, NSP_PULL_UP_EN, gpio);
 	*pull_down = nsp_get_bit(chip, IO_CTRL, NSP_PULL_DOWN_EN, gpio);
-	spin_unlock_irqrestore(&chip->lock, flags);
+	raw_spin_unlock_irqrestore(&chip->lock, flags);
 }
 
 static int nsp_gpio_set_strength(struct nsp_gpio *chip, unsigned gpio,
@@ -417,7 +417,7 @@ static int nsp_gpio_set_strength(struct nsp_gpio *chip, unsigned gpio,
 	offset = NSP_GPIO_DRV_CTRL;
 	dev_dbg(chip->dev, "gpio:%u set drive strength:%d mA\n", gpio,
 		strength);
-	spin_lock_irqsave(&chip->lock, flags);
+	raw_spin_lock_irqsave(&chip->lock, flags);
 	strength = (strength / 2) - 1;
 	for (i = GPIO_DRV_STRENGTH_BITS; i > 0; i--) {
 		val = readl(chip->io_ctrl + offset);
@@ -426,7 +426,7 @@ static int nsp_gpio_set_strength(struct nsp_gpio *chip, unsigned gpio,
 		writel(val, chip->io_ctrl + offset);
 		offset += 4;
 	}
-	spin_unlock_irqrestore(&chip->lock, flags);
+	raw_spin_unlock_irqrestore(&chip->lock, flags);
 
 	return 0;
 }
@@ -442,7 +442,7 @@ static int nsp_gpio_get_strength(struct nsp_gpio *chip, unsigned gpio,
 	offset = NSP_GPIO_DRV_CTRL;
 	shift = gpio;
 
-	spin_lock_irqsave(&chip->lock, flags);
+	raw_spin_lock_irqsave(&chip->lock, flags);
 	*strength = 0;
 	for (i = (GPIO_DRV_STRENGTH_BITS - 1); i >= 0; i--) {
 		val = readl(chip->io_ctrl + offset) & BIT(shift);
@@ -453,7 +453,7 @@ static int nsp_gpio_get_strength(struct nsp_gpio *chip, unsigned gpio,
 
 	/* convert to mA */
 	*strength = (*strength + 1) * 2;
-	spin_unlock_irqrestore(&chip->lock, flags);
+	raw_spin_unlock_irqrestore(&chip->lock, flags);
 
 	return 0;
 }
@@ -660,7 +660,7 @@ static int nsp_gpio_probe(struct platform_device *pdev)
 		return PTR_ERR(chip->io_ctrl);
 	}
 
-	spin_lock_init(&chip->lock);
+	raw_spin_lock_init(&chip->lock);
 	gc = &chip->gc;
 	gc->base = -1;
 	gc->can_sleep = false;
-- 
2.11.1

Re: [PATCH 16/19] pinctrl: bcm: make use of raw_spinlock variants

[Linus Walleij]

On Thu, Mar 9, 2017 at 5:22 PM, Julia Cartwright <julia@ni.com> wrote:

> The bcm 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@ni.com>

Patch applied.

Yours,
Linus Walleij

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

[Julia Cartwright]

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@ni.com>
---
 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

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

[Linus Walleij]

On Thu, Mar 9, 2017 at 5:22 PM, Julia Cartwright <julia@ni.com> wrote:

> 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@ni.com>

Patch applied.

Yours,
Linus Walleij

[PATCH 18/19] pinctrl: sirf: atlas7: make use of raw_spinlock variants

[Julia Cartwright]

The sirf atlas7 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@ni.com>
---
 drivers/pinctrl/sirf/pinctrl-atlas7.c | 44 +++++++++++++++++------------------
 1 file changed, 22 insertions(+), 22 deletions(-)

diff --git a/drivers/pinctrl/sirf/pinctrl-atlas7.c b/drivers/pinctrl/sirf/pinctrl-atlas7.c
index 600d6427a978..1efa315a7dbe 100644
--- a/drivers/pinctrl/sirf/pinctrl-atlas7.c
+++ b/drivers/pinctrl/sirf/pinctrl-atlas7.c
@@ -352,7 +352,7 @@ struct atlas7_gpio_chip {
 	void __iomem *reg;
 	struct clk *clk;
 	int nbank;
-	spinlock_t lock;
+	raw_spinlock_t lock;
 	struct gpio_chip chip;
 	struct atlas7_gpio_bank banks[0];
 };
@@ -5650,13 +5650,13 @@ static void atlas7_gpio_irq_ack(struct irq_data *d)
 	pin_in_bank = d->hwirq - bank->gpio_offset;
 	ctrl_reg = ATLAS7_GPIO_CTRL(bank, pin_in_bank);
 
-	spin_lock_irqsave(&a7gc->lock, flags);
+	raw_spin_lock_irqsave(&a7gc->lock, flags);
 
 	val = readl(ctrl_reg);
 	/* clear interrupt status */
 	writel(val, ctrl_reg);
 
-	spin_unlock_irqrestore(&a7gc->lock, flags);
+	raw_spin_unlock_irqrestore(&a7gc->lock, flags);
 }
 
 static void __atlas7_gpio_irq_mask(struct atlas7_gpio_chip *a7gc, int idx)
@@ -5681,11 +5681,11 @@ static void atlas7_gpio_irq_mask(struct irq_data *d)
 	struct atlas7_gpio_chip *a7gc = gpiochip_get_data(gc);
 	unsigned long flags;
 
-	spin_lock_irqsave(&a7gc->lock, flags);
+	raw_spin_lock_irqsave(&a7gc->lock, flags);
 
 	__atlas7_gpio_irq_mask(a7gc, d->hwirq);
 
-	spin_unlock_irqrestore(&a7gc->lock, flags);
+	raw_spin_unlock_irqrestore(&a7gc->lock, flags);
 }
 
 static void atlas7_gpio_irq_unmask(struct irq_data *d)
@@ -5701,14 +5701,14 @@ static void atlas7_gpio_irq_unmask(struct irq_data *d)
 	pin_in_bank = d->hwirq - bank->gpio_offset;
 	ctrl_reg = ATLAS7_GPIO_CTRL(bank, pin_in_bank);
 
-	spin_lock_irqsave(&a7gc->lock, flags);
+	raw_spin_lock_irqsave(&a7gc->lock, flags);
 
 	val = readl(ctrl_reg);
 	val &= ~ATLAS7_GPIO_CTL_INTR_STATUS_MASK;
 	val |= ATLAS7_GPIO_CTL_INTR_EN_MASK;
 	writel(val, ctrl_reg);
 
-	spin_unlock_irqrestore(&a7gc->lock, flags);
+	raw_spin_unlock_irqrestore(&a7gc->lock, flags);
 }
 
 static int atlas7_gpio_irq_type(struct irq_data *d,
@@ -5725,7 +5725,7 @@ static int atlas7_gpio_irq_type(struct irq_data *d,
 	pin_in_bank = d->hwirq - bank->gpio_offset;
 	ctrl_reg = ATLAS7_GPIO_CTRL(bank, pin_in_bank);
 
-	spin_lock_irqsave(&a7gc->lock, flags);
+	raw_spin_lock_irqsave(&a7gc->lock, flags);
 
 	val = readl(ctrl_reg);
 	val &= ~(ATLAS7_GPIO_CTL_INTR_STATUS_MASK |
@@ -5768,7 +5768,7 @@ static int atlas7_gpio_irq_type(struct irq_data *d,
 
 	writel(val, ctrl_reg);
 
-	spin_unlock_irqrestore(&a7gc->lock, flags);
+	raw_spin_unlock_irqrestore(&a7gc->lock, flags);
 
 	return 0;
 }
@@ -5863,7 +5863,7 @@ static int atlas7_gpio_request(struct gpio_chip *chip,
 	if (pinctrl_request_gpio(chip->base + gpio))
 		return -ENODEV;
 
-	spin_lock_irqsave(&a7gc->lock, flags);
+	raw_spin_lock_irqsave(&a7gc->lock, flags);
 
 	/*
 	 * default status:
@@ -5872,7 +5872,7 @@ static int atlas7_gpio_request(struct gpio_chip *chip,
 	__atlas7_gpio_set_input(a7gc, gpio);
 	__atlas7_gpio_irq_mask(a7gc, gpio);
 
-	spin_unlock_irqrestore(&a7gc->lock, flags);
+	raw_spin_unlock_irqrestore(&a7gc->lock, flags);
 
 	return 0;
 }
@@ -5883,12 +5883,12 @@ static void atlas7_gpio_free(struct gpio_chip *chip,
 	struct atlas7_gpio_chip *a7gc = gpiochip_get_data(chip);
 	unsigned long flags;
 
-	spin_lock_irqsave(&a7gc->lock, flags);
+	raw_spin_lock_irqsave(&a7gc->lock, flags);
 
 	__atlas7_gpio_irq_mask(a7gc, gpio);
 	__atlas7_gpio_set_input(a7gc, gpio);
 
-	spin_unlock_irqrestore(&a7gc->lock, flags);
+	raw_spin_unlock_irqrestore(&a7gc->lock, flags);
 
 	pinctrl_free_gpio(chip->base + gpio);
 }
@@ -5899,11 +5899,11 @@ static int atlas7_gpio_direction_input(struct gpio_chip *chip,
 	struct atlas7_gpio_chip *a7gc = gpiochip_get_data(chip);
 	unsigned long flags;
 
-	spin_lock_irqsave(&a7gc->lock, flags);
+	raw_spin_lock_irqsave(&a7gc->lock, flags);
 
 	__atlas7_gpio_set_input(a7gc, gpio);
 
-	spin_unlock_irqrestore(&a7gc->lock, flags);
+	raw_spin_unlock_irqrestore(&a7gc->lock, flags);
 
 	return 0;
 }
@@ -5936,11 +5936,11 @@ static int atlas7_gpio_direction_output(struct gpio_chip *chip,
 	struct atlas7_gpio_chip *a7gc = gpiochip_get_data(chip);
 	unsigned long flags;
 
-	spin_lock_irqsave(&a7gc->lock, flags);
+	raw_spin_lock_irqsave(&a7gc->lock, flags);
 
 	__atlas7_gpio_set_output(a7gc, gpio, value);
 
-	spin_unlock_irqrestore(&a7gc->lock, flags);
+	raw_spin_unlock_irqrestore(&a7gc->lock, flags);
 
 	return 0;
 }
@@ -5956,11 +5956,11 @@ static int atlas7_gpio_get_value(struct gpio_chip *chip,
 	bank = atlas7_gpio_to_bank(a7gc, gpio);
 	pin_in_bank = gpio - bank->gpio_offset;
 
-	spin_lock_irqsave(&a7gc->lock, flags);
+	raw_spin_lock_irqsave(&a7gc->lock, flags);
 
 	val = readl(ATLAS7_GPIO_CTRL(bank, pin_in_bank));
 
-	spin_unlock_irqrestore(&a7gc->lock, flags);
+	raw_spin_unlock_irqrestore(&a7gc->lock, flags);
 
 	return !!(val & ATLAS7_GPIO_CTL_DATAIN_MASK);
 }
@@ -5978,7 +5978,7 @@ static void atlas7_gpio_set_value(struct gpio_chip *chip,
 	pin_in_bank = gpio - bank->gpio_offset;
 	ctrl_reg = ATLAS7_GPIO_CTRL(bank, pin_in_bank);
 
-	spin_lock_irqsave(&a7gc->lock, flags);
+	raw_spin_lock_irqsave(&a7gc->lock, flags);
 
 	ctrl = readl(ctrl_reg);
 	if (value)
@@ -5987,7 +5987,7 @@ static void atlas7_gpio_set_value(struct gpio_chip *chip,
 		ctrl &= ~ATLAS7_GPIO_CTL_DATAOUT_MASK;
 	writel(ctrl, ctrl_reg);
 
-	spin_unlock_irqrestore(&a7gc->lock, flags);
+	raw_spin_unlock_irqrestore(&a7gc->lock, flags);
 }
 
 static const struct of_device_id atlas7_gpio_ids[] = {
@@ -6036,7 +6036,7 @@ static int atlas7_gpio_probe(struct platform_device *pdev)
 	}
 
 	a7gc->nbank = nbank;
-	spin_lock_init(&a7gc->lock);
+	raw_spin_lock_init(&a7gc->lock);
 
 	/* Setup GPIO Chip */
 	chip = &a7gc->chip;
-- 
2.11.1

Re: [PATCH 18/19] pinctrl: sirf: atlas7: make use of raw_spinlock variants

[Linus Walleij]

On Thu, Mar 9, 2017 at 5:22 PM, Julia Cartwright <julia@ni.com> wrote:

> The sirf atlas7 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@ni.com>

Patch applied.

Yours,
Linus Walleij

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

[Julia Cartwright]

The sunxi pinctrl driver 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@ni.com>
---
 drivers/pinctrl/sunxi/pinctrl-sunxi.c | 26 +++++++++++++-------------
 drivers/pinctrl/sunxi/pinctrl-sunxi.h |  2 +-
 2 files changed, 14 insertions(+), 14 deletions(-)

diff --git a/drivers/pinctrl/sunxi/pinctrl-sunxi.c b/drivers/pinctrl/sunxi/pinctrl-sunxi.c
index 60e6e36c4a7e..58774acfc814 100644
--- a/drivers/pinctrl/sunxi/pinctrl-sunxi.c
+++ b/drivers/pinctrl/sunxi/pinctrl-sunxi.c
@@ -581,11 +581,11 @@ static int sunxi_pconf_group_set(struct pinctrl_dev *pctldev,
 			return -ENOTSUPP;
 		}
 
-		spin_lock_irqsave(&pctl->lock, flags);
+		raw_spin_lock_irqsave(&pctl->lock, flags);
 		reg = readl(pctl->membase + offset);
 		reg &= ~(mask << shift);
 		writel(reg | val << shift, pctl->membase + offset);
-		spin_unlock_irqrestore(&pctl->lock, flags);
+		raw_spin_unlock_irqrestore(&pctl->lock, flags);
 	} /* for each config */
 
 	return 0;
@@ -634,7 +634,7 @@ static void sunxi_pmx_set(struct pinctrl_dev *pctldev,
 	unsigned long flags;
 	u32 val, mask;
 
-	spin_lock_irqsave(&pctl->lock, flags);
+	raw_spin_lock_irqsave(&pctl->lock, flags);
 
 	pin -= pctl->desc->pin_base;
 	val = readl(pctl->membase + sunxi_mux_reg(pin));
@@ -642,7 +642,7 @@ static void sunxi_pmx_set(struct pinctrl_dev *pctldev,
 	writel((val & ~mask) | config << sunxi_mux_offset(pin),
 		pctl->membase + sunxi_mux_reg(pin));
 
-	spin_unlock_irqrestore(&pctl->lock, flags);
+	raw_spin_unlock_irqrestore(&pctl->lock, flags);
 }
 
 static int sunxi_pmx_set_mux(struct pinctrl_dev *pctldev,
@@ -733,7 +733,7 @@ static void sunxi_pinctrl_gpio_set(struct gpio_chip *chip,
 	unsigned long flags;
 	u32 regval;
 
-	spin_lock_irqsave(&pctl->lock, flags);
+	raw_spin_lock_irqsave(&pctl->lock, flags);
 
 	regval = readl(pctl->membase + reg);
 
@@ -744,7 +744,7 @@ static void sunxi_pinctrl_gpio_set(struct gpio_chip *chip,
 
 	writel(regval, pctl->membase + reg);
 
-	spin_unlock_irqrestore(&pctl->lock, flags);
+	raw_spin_unlock_irqrestore(&pctl->lock, flags);
 }
 
 static int sunxi_pinctrl_gpio_direction_output(struct gpio_chip *chip,
@@ -856,7 +856,7 @@ static int sunxi_pinctrl_irq_set_type(struct irq_data *d, unsigned int type)
 		return -EINVAL;
 	}
 
-	spin_lock_irqsave(&pctl->lock, flags);
+	raw_spin_lock_irqsave(&pctl->lock, flags);
 
 	if (type & IRQ_TYPE_LEVEL_MASK)
 		irq_set_chip_handler_name_locked(d, &sunxi_pinctrl_level_irq_chip,
@@ -869,7 +869,7 @@ static int sunxi_pinctrl_irq_set_type(struct irq_data *d, unsigned int type)
 	regval &= ~(IRQ_CFG_IRQ_MASK << index);
 	writel(regval | (mode << index), pctl->membase + reg);
 
-	spin_unlock_irqrestore(&pctl->lock, flags);
+	raw_spin_unlock_irqrestore(&pctl->lock, flags);
 
 	return 0;
 }
@@ -893,13 +893,13 @@ static void sunxi_pinctrl_irq_mask(struct irq_data *d)
 	unsigned long flags;
 	u32 val;
 
-	spin_lock_irqsave(&pctl->lock, flags);
+	raw_spin_lock_irqsave(&pctl->lock, flags);
 
 	/* Mask the IRQ */
 	val = readl(pctl->membase + reg);
 	writel(val & ~(1 << idx), pctl->membase + reg);
 
-	spin_unlock_irqrestore(&pctl->lock, flags);
+	raw_spin_unlock_irqrestore(&pctl->lock, flags);
 }
 
 static void sunxi_pinctrl_irq_unmask(struct irq_data *d)
@@ -910,13 +910,13 @@ static void sunxi_pinctrl_irq_unmask(struct irq_data *d)
 	unsigned long flags;
 	u32 val;
 
-	spin_lock_irqsave(&pctl->lock, flags);
+	raw_spin_lock_irqsave(&pctl->lock, flags);
 
 	/* Unmask the IRQ */
 	val = readl(pctl->membase + reg);
 	writel(val | (1 << idx), pctl->membase + reg);
 
-	spin_unlock_irqrestore(&pctl->lock, flags);
+	raw_spin_unlock_irqrestore(&pctl->lock, flags);
 }
 
 static void sunxi_pinctrl_irq_ack_unmask(struct irq_data *d)
@@ -1253,7 +1253,7 @@ int sunxi_pinctrl_init_with_variant(struct platform_device *pdev,
 		return -ENOMEM;
 	platform_set_drvdata(pdev, pctl);
 
-	spin_lock_init(&pctl->lock);
+	raw_spin_lock_init(&pctl->lock);
 
 	res = platform_get_resource(pdev, IORESOURCE_MEM, 0);
 	pctl->membase = devm_ioremap_resource(&pdev->dev, res);
diff --git a/drivers/pinctrl/sunxi/pinctrl-sunxi.h b/drivers/pinctrl/sunxi/pinctrl-sunxi.h
index e1aedd260b2e..a9d315a1256c 100644
--- a/drivers/pinctrl/sunxi/pinctrl-sunxi.h
+++ b/drivers/pinctrl/sunxi/pinctrl-sunxi.h
@@ -134,7 +134,7 @@ struct sunxi_pinctrl {
 	unsigned			ngroups;
 	int				*irq;
 	unsigned			*irq_array;
-	spinlock_t			lock;
+	raw_spinlock_t			lock;
 	struct pinctrl_dev		*pctl_dev;
 	unsigned long			variant;
 };
-- 
2.11.1

Re: [PATCH 19/19] pinctrl: sunxi: make use of raw_spinlock variants

[Linus Walleij]

On Thu, Mar 9, 2017 at 5:22 PM, Julia Cartwright <julia@ni.com> wrote:

> The sunxi pinctrl driver 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@ni.com>

Patch applied.

Yours,
Linus Walleij