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Groups > linux.kernel > #1606061 > unrolled thread
| Started by | Julia Cartwright <julia@ni.com> |
|---|---|
| First post | 2017-03-22 00:00 +0100 |
| Last post | 2017-03-28 11:30 +0200 |
| Articles | 3 — 3 participants |
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[PATCH v2 9/9] gpio: pci-idio-16: make use of raw_spinlock variants Julia Cartwright <julia@ni.com> - 2017-03-22 00:00 +0100
Re: [PATCH v2 9/9] gpio: pci-idio-16: make use of raw_spinlock variants William Breathitt Gray <vilhelm.gray@gmail.com> - 2017-03-22 14:00 +0100
Re: [PATCH v2 9/9] gpio: pci-idio-16: make use of raw_spinlock variants Linus Walleij <linus.walleij@linaro.org> - 2017-03-28 11:30 +0200
| From | Julia Cartwright <julia@ni.com> |
|---|---|
| Date | 2017-03-22 00:00 +0100 |
| Subject | [PATCH v2 9/9] gpio: pci-idio-16: make use of raw_spinlock variants |
| Message-ID | <tnAUV-1rR-9@gated-at.bofh.it> |
The pci-idio-16 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>
---
New patch as of v2 of series.
drivers/gpio/gpio-pci-idio-16.c | 28 ++++++++++++++--------------
1 file changed, 14 insertions(+), 14 deletions(-)
diff --git a/drivers/gpio/gpio-pci-idio-16.c b/drivers/gpio/gpio-pci-idio-16.c
index 269ab628634b..7de4f6a2cb49 100644
--- a/drivers/gpio/gpio-pci-idio-16.c
+++ b/drivers/gpio/gpio-pci-idio-16.c
@@ -59,7 +59,7 @@ struct idio_16_gpio_reg {
*/
struct idio_16_gpio {
struct gpio_chip chip;
- spinlock_t lock;
+ raw_spinlock_t lock;
struct idio_16_gpio_reg __iomem *reg;
unsigned long irq_mask;
};
@@ -121,7 +121,7 @@ static void idio_16_gpio_set(struct gpio_chip *chip, unsigned int offset,
} else
base = &idio16gpio->reg->out0_7;
- spin_lock_irqsave(&idio16gpio->lock, flags);
+ raw_spin_lock_irqsave(&idio16gpio->lock, flags);
if (value)
out_state = ioread8(base) | mask;
@@ -130,7 +130,7 @@ static void idio_16_gpio_set(struct gpio_chip *chip, unsigned int offset,
iowrite8(out_state, base);
- spin_unlock_irqrestore(&idio16gpio->lock, flags);
+ raw_spin_unlock_irqrestore(&idio16gpio->lock, flags);
}
static void idio_16_gpio_set_multiple(struct gpio_chip *chip,
@@ -140,7 +140,7 @@ static void idio_16_gpio_set_multiple(struct gpio_chip *chip,
unsigned long flags;
unsigned int out_state;
- spin_lock_irqsave(&idio16gpio->lock, flags);
+ raw_spin_lock_irqsave(&idio16gpio->lock, flags);
/* process output lines 0-7 */
if (*mask & 0xFF) {
@@ -160,7 +160,7 @@ static void idio_16_gpio_set_multiple(struct gpio_chip *chip,
iowrite8(out_state, &idio16gpio->reg->out8_15);
}
- spin_unlock_irqrestore(&idio16gpio->lock, flags);
+ raw_spin_unlock_irqrestore(&idio16gpio->lock, flags);
}
static void idio_16_irq_ack(struct irq_data *data)
@@ -177,11 +177,11 @@ static void idio_16_irq_mask(struct irq_data *data)
idio16gpio->irq_mask &= ~mask;
if (!idio16gpio->irq_mask) {
- spin_lock_irqsave(&idio16gpio->lock, flags);
+ raw_spin_lock_irqsave(&idio16gpio->lock, flags);
iowrite8(0, &idio16gpio->reg->irq_ctl);
- spin_unlock_irqrestore(&idio16gpio->lock, flags);
+ raw_spin_unlock_irqrestore(&idio16gpio->lock, flags);
}
}
@@ -196,11 +196,11 @@ static void idio_16_irq_unmask(struct irq_data *data)
idio16gpio->irq_mask |= mask;
if (!prev_irq_mask) {
- spin_lock_irqsave(&idio16gpio->lock, flags);
+ raw_spin_lock_irqsave(&idio16gpio->lock, flags);
ioread8(&idio16gpio->reg->irq_ctl);
- spin_unlock_irqrestore(&idio16gpio->lock, flags);
+ raw_spin_unlock_irqrestore(&idio16gpio->lock, flags);
}
}
@@ -229,11 +229,11 @@ static irqreturn_t idio_16_irq_handler(int irq, void *dev_id)
struct gpio_chip *const chip = &idio16gpio->chip;
int gpio;
- spin_lock(&idio16gpio->lock);
+ raw_spin_lock(&idio16gpio->lock);
irq_status = ioread8(&idio16gpio->reg->irq_status);
- spin_unlock(&idio16gpio->lock);
+ raw_spin_unlock(&idio16gpio->lock);
/* Make sure our device generated IRQ */
if (!(irq_status & 0x3) || !(irq_status & 0x4))
@@ -242,12 +242,12 @@ static irqreturn_t idio_16_irq_handler(int irq, void *dev_id)
for_each_set_bit(gpio, &idio16gpio->irq_mask, chip->ngpio)
generic_handle_irq(irq_find_mapping(chip->irqdomain, gpio));
- spin_lock(&idio16gpio->lock);
+ raw_spin_lock(&idio16gpio->lock);
/* Clear interrupt */
iowrite8(0, &idio16gpio->reg->in0_7);
- spin_unlock(&idio16gpio->lock);
+ raw_spin_unlock(&idio16gpio->lock);
return IRQ_HANDLED;
}
@@ -302,7 +302,7 @@ static int idio_16_probe(struct pci_dev *pdev, const struct pci_device_id *id)
idio16gpio->chip.set = idio_16_gpio_set;
idio16gpio->chip.set_multiple = idio_16_gpio_set_multiple;
- spin_lock_init(&idio16gpio->lock);
+ raw_spin_lock_init(&idio16gpio->lock);
err = devm_gpiochip_add_data(dev, &idio16gpio->chip, idio16gpio);
if (err) {
--
2.12.0
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| From | William Breathitt Gray <vilhelm.gray@gmail.com> |
|---|---|
| Date | 2017-03-22 14:00 +0100 |
| Subject | Re: [PATCH v2 9/9] gpio: pci-idio-16: make use of raw_spinlock variants |
| Message-ID | <tnO1R-2wP-45@gated-at.bofh.it> |
| In reply to | #1606061 |
On Tue, Mar 21, 2017 at 05:43:09PM -0500, Julia Cartwright wrote:
>The pci-idio-16 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>
>---
>New patch as of v2 of series.
>
> drivers/gpio/gpio-pci-idio-16.c | 28 ++++++++++++++--------------
> 1 file changed, 14 insertions(+), 14 deletions(-)
>
>diff --git a/drivers/gpio/gpio-pci-idio-16.c b/drivers/gpio/gpio-pci-idio-16.c
>index 269ab628634b..7de4f6a2cb49 100644
>--- a/drivers/gpio/gpio-pci-idio-16.c
>+++ b/drivers/gpio/gpio-pci-idio-16.c
>@@ -59,7 +59,7 @@ struct idio_16_gpio_reg {
> */
> struct idio_16_gpio {
> struct gpio_chip chip;
>- spinlock_t lock;
>+ raw_spinlock_t lock;
> struct idio_16_gpio_reg __iomem *reg;
> unsigned long irq_mask;
> };
>@@ -121,7 +121,7 @@ static void idio_16_gpio_set(struct gpio_chip *chip, unsigned int offset,
> } else
> base = &idio16gpio->reg->out0_7;
>
>- spin_lock_irqsave(&idio16gpio->lock, flags);
>+ raw_spin_lock_irqsave(&idio16gpio->lock, flags);
>
> if (value)
> out_state = ioread8(base) | mask;
>@@ -130,7 +130,7 @@ static void idio_16_gpio_set(struct gpio_chip *chip, unsigned int offset,
>
> iowrite8(out_state, base);
>
>- spin_unlock_irqrestore(&idio16gpio->lock, flags);
>+ raw_spin_unlock_irqrestore(&idio16gpio->lock, flags);
> }
>
> static void idio_16_gpio_set_multiple(struct gpio_chip *chip,
>@@ -140,7 +140,7 @@ static void idio_16_gpio_set_multiple(struct gpio_chip *chip,
> unsigned long flags;
> unsigned int out_state;
>
>- spin_lock_irqsave(&idio16gpio->lock, flags);
>+ raw_spin_lock_irqsave(&idio16gpio->lock, flags);
>
> /* process output lines 0-7 */
> if (*mask & 0xFF) {
>@@ -160,7 +160,7 @@ static void idio_16_gpio_set_multiple(struct gpio_chip *chip,
> iowrite8(out_state, &idio16gpio->reg->out8_15);
> }
>
>- spin_unlock_irqrestore(&idio16gpio->lock, flags);
>+ raw_spin_unlock_irqrestore(&idio16gpio->lock, flags);
> }
>
> static void idio_16_irq_ack(struct irq_data *data)
>@@ -177,11 +177,11 @@ static void idio_16_irq_mask(struct irq_data *data)
> idio16gpio->irq_mask &= ~mask;
>
> if (!idio16gpio->irq_mask) {
>- spin_lock_irqsave(&idio16gpio->lock, flags);
>+ raw_spin_lock_irqsave(&idio16gpio->lock, flags);
>
> iowrite8(0, &idio16gpio->reg->irq_ctl);
>
>- spin_unlock_irqrestore(&idio16gpio->lock, flags);
>+ raw_spin_unlock_irqrestore(&idio16gpio->lock, flags);
> }
> }
>
>@@ -196,11 +196,11 @@ static void idio_16_irq_unmask(struct irq_data *data)
> idio16gpio->irq_mask |= mask;
>
> if (!prev_irq_mask) {
>- spin_lock_irqsave(&idio16gpio->lock, flags);
>+ raw_spin_lock_irqsave(&idio16gpio->lock, flags);
>
> ioread8(&idio16gpio->reg->irq_ctl);
>
>- spin_unlock_irqrestore(&idio16gpio->lock, flags);
>+ raw_spin_unlock_irqrestore(&idio16gpio->lock, flags);
> }
> }
>
>@@ -229,11 +229,11 @@ static irqreturn_t idio_16_irq_handler(int irq, void *dev_id)
> struct gpio_chip *const chip = &idio16gpio->chip;
> int gpio;
>
>- spin_lock(&idio16gpio->lock);
>+ raw_spin_lock(&idio16gpio->lock);
>
> irq_status = ioread8(&idio16gpio->reg->irq_status);
>
>- spin_unlock(&idio16gpio->lock);
>+ raw_spin_unlock(&idio16gpio->lock);
>
> /* Make sure our device generated IRQ */
> if (!(irq_status & 0x3) || !(irq_status & 0x4))
>@@ -242,12 +242,12 @@ static irqreturn_t idio_16_irq_handler(int irq, void *dev_id)
> for_each_set_bit(gpio, &idio16gpio->irq_mask, chip->ngpio)
> generic_handle_irq(irq_find_mapping(chip->irqdomain, gpio));
>
>- spin_lock(&idio16gpio->lock);
>+ raw_spin_lock(&idio16gpio->lock);
>
> /* Clear interrupt */
> iowrite8(0, &idio16gpio->reg->in0_7);
>
>- spin_unlock(&idio16gpio->lock);
>+ raw_spin_unlock(&idio16gpio->lock);
>
> return IRQ_HANDLED;
> }
>@@ -302,7 +302,7 @@ static int idio_16_probe(struct pci_dev *pdev, const struct pci_device_id *id)
> idio16gpio->chip.set = idio_16_gpio_set;
> idio16gpio->chip.set_multiple = idio_16_gpio_set_multiple;
>
>- spin_lock_init(&idio16gpio->lock);
>+ raw_spin_lock_init(&idio16gpio->lock);
>
> err = devm_gpiochip_add_data(dev, &idio16gpio->chip, idio16gpio);
> if (err) {
>--
>2.12.0
>
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| From | Linus Walleij <linus.walleij@linaro.org> |
|---|---|
| Date | 2017-03-28 11:30 +0200 |
| Message-ID | <tpVBU-5sY-21@gated-at.bofh.it> |
| In reply to | #1606061 |
On Tue, Mar 21, 2017 at 11:43 PM, Julia Cartwright <julia@ni.com> wrote: > The pci-idio-16 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> > --- > New patch as of v2 of series. Patch applied with William's ACK. Yours, Linus Walleij
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