diff mbox series

pinctrl: samsung: use raw_spinlock for locking

Message ID 20210121030009.25673-1-chanho61.park@samsung.com (mailing list archive)
State New, archived
Headers show
Series pinctrl: samsung: use raw_spinlock for locking | expand

Commit Message

Chanho Park Jan. 21, 2021, 3 a.m. UTC 
This patch converts spin_[lock|unlock] functions of pin bank to
raw_spinlock to support preempt-rt. This can avoid BUG() assertion when
irqchip callbacks are triggerred. Spinlocks can be converted rt_mutex
which is preemptible when we apply preempt-rt patches.

According to "Documentation/driver-api/gpio/driver.rst",

"Realtime considerations: a realtime compliant GPIO driver should not
use spinlock_t or any sleepable APIs (like PM runtime) as part of its
irqchip implementation.

- spinlock_t should be replaced with raw_spinlock_t.[1]
"

Cc: Tomasz Figa <tomasz.figa@gmail.com>
Cc: Krzysztof Kozlowski <krzk@kernel.org>
Cc: Sylwester Nawrocki <s.nawrocki@samsung.com>
Cc: Linus Walleij <linus.walleij@linaro.org>
Signed-off-by: Chanho Park <chanho61.park@samsung.com>
---
 drivers/pinctrl/samsung/pinctrl-exynos.c  | 16 ++++++++--------
 drivers/pinctrl/samsung/pinctrl-s3c24xx.c |  4 ++--
 drivers/pinctrl/samsung/pinctrl-samsung.c | 22 +++++++++++-----------
 drivers/pinctrl/samsung/pinctrl-samsung.h |  2 +-
 4 files changed, 22 insertions(+), 22 deletions(-)

Comments

Linus Walleij Jan. 22, 2021, 1:15 p.m. UTC | #1 
On Thu, Jan 21, 2021 at 4:00 AM Chanho Park <chanho61.park@samsung.com> wrote:

> This patch converts spin_[lock|unlock] functions of pin bank to
> raw_spinlock to support preempt-rt. This can avoid BUG() assertion when
> irqchip callbacks are triggerred. Spinlocks can be converted rt_mutex
> which is preemptible when we apply preempt-rt patches.
>
> According to "Documentation/driver-api/gpio/driver.rst",
>
> "Realtime considerations: a realtime compliant GPIO driver should not
> use spinlock_t or any sleepable APIs (like PM runtime) as part of its
> irqchip implementation.
>
> - spinlock_t should be replaced with raw_spinlock_t.[1]
> "
>
> Cc: Tomasz Figa <tomasz.figa@gmail.com>
> Cc: Krzysztof Kozlowski <krzk@kernel.org>
> Cc: Sylwester Nawrocki <s.nawrocki@samsung.com>
> Cc: Linus Walleij <linus.walleij@linaro.org>
> Signed-off-by: Chanho Park <chanho61.park@samsung.com>

Looks correct to me.
Reviewed-by: Linus Walleij <linus.walleij@linaro.org>

Krzysztof, will you collect Samsung patches for this merge window or
shall I apply it directly?

Yours,
Linus Walleij
Krzysztof Kozlowski Jan. 22, 2021, 1:21 p.m. UTC | #2 
On Fri, Jan 22, 2021 at 02:15:18PM +0100, Linus Walleij wrote:
> On Thu, Jan 21, 2021 at 4:00 AM Chanho Park <chanho61.park@samsung.com> wrote:
> 
> > This patch converts spin_[lock|unlock] functions of pin bank to
> > raw_spinlock to support preempt-rt. This can avoid BUG() assertion when
> > irqchip callbacks are triggerred. Spinlocks can be converted rt_mutex
> > which is preemptible when we apply preempt-rt patches.
> >
> > According to "Documentation/driver-api/gpio/driver.rst",
> >
> > "Realtime considerations: a realtime compliant GPIO driver should not
> > use spinlock_t or any sleepable APIs (like PM runtime) as part of its
> > irqchip implementation.
> >
> > - spinlock_t should be replaced with raw_spinlock_t.[1]
> > "
> >
> > Cc: Tomasz Figa <tomasz.figa@gmail.com>
> > Cc: Krzysztof Kozlowski <krzk@kernel.org>
> > Cc: Sylwester Nawrocki <s.nawrocki@samsung.com>
> > Cc: Linus Walleij <linus.walleij@linaro.org>
> > Signed-off-by: Chanho Park <chanho61.park@samsung.com>
> 
> Looks correct to me.
> Reviewed-by: Linus Walleij <linus.walleij@linaro.org>
> 
> Krzysztof, will you collect Samsung patches for this merge window or
> shall I apply it directly?

I don't have anything in the queue so far and I don't see any patches
incomming, so maybe take it directly?

Reviewed-by: Krzysztof Kozlowski <krzk@kernel.org>

Best regards,
Krzysztof
Linus Walleij Jan. 23, 2021, 10:34 p.m. UTC | #3 
On Thu, Jan 21, 2021 at 4:00 AM Chanho Park <chanho61.park@samsung.com> wrote:

> This patch converts spin_[lock|unlock] functions of pin bank to
> raw_spinlock to support preempt-rt. This can avoid BUG() assertion when
> irqchip callbacks are triggerred. Spinlocks can be converted rt_mutex
> which is preemptible when we apply preempt-rt patches.
>
> According to "Documentation/driver-api/gpio/driver.rst",
>
> "Realtime considerations: a realtime compliant GPIO driver should not
> use spinlock_t or any sleepable APIs (like PM runtime) as part of its
> irqchip implementation.
>
> - spinlock_t should be replaced with raw_spinlock_t.[1]
> "
>
> Cc: Tomasz Figa <tomasz.figa@gmail.com>
> Cc: Krzysztof Kozlowski <krzk@kernel.org>
> Cc: Sylwester Nawrocki <s.nawrocki@samsung.com>
> Cc: Linus Walleij <linus.walleij@linaro.org>
> Signed-off-by: Chanho Park <chanho61.park@samsung.com>

Patch applied!

Yours,
Linus Walleij
diff mbox series

Patch

diff --git a/drivers/pinctrl/samsung/pinctrl-exynos.c b/drivers/pinctrl/samsung/pinctrl-exynos.c
index b9ea09fabf84..0cd7f33cdf25 100644
--- a/drivers/pinctrl/samsung/pinctrl-exynos.c
+++ b/drivers/pinctrl/samsung/pinctrl-exynos.c
@@ -58,13 +58,13 @@  static void exynos_irq_mask(struct irq_data *irqd)
 	unsigned long mask;
 	unsigned long flags;
 
-	spin_lock_irqsave(&bank->slock, flags);
+	raw_spin_lock_irqsave(&bank->slock, flags);
 
 	mask = readl(bank->eint_base + reg_mask);
 	mask |= 1 << irqd->hwirq;
 	writel(mask, bank->eint_base + reg_mask);
 
-	spin_unlock_irqrestore(&bank->slock, flags);
+	raw_spin_unlock_irqrestore(&bank->slock, flags);
 }
 
 static void exynos_irq_ack(struct irq_data *irqd)
@@ -97,13 +97,13 @@  static void exynos_irq_unmask(struct irq_data *irqd)
 	if (irqd_get_trigger_type(irqd) & IRQ_TYPE_LEVEL_MASK)
 		exynos_irq_ack(irqd);
 
-	spin_lock_irqsave(&bank->slock, flags);
+	raw_spin_lock_irqsave(&bank->slock, flags);
 
 	mask = readl(bank->eint_base + reg_mask);
 	mask &= ~(1 << irqd->hwirq);
 	writel(mask, bank->eint_base + reg_mask);
 
-	spin_unlock_irqrestore(&bank->slock, flags);
+	raw_spin_unlock_irqrestore(&bank->slock, flags);
 }
 
 static int exynos_irq_set_type(struct irq_data *irqd, unsigned int type)
@@ -169,14 +169,14 @@  static int exynos_irq_request_resources(struct irq_data *irqd)
 	shift = irqd->hwirq * bank_type->fld_width[PINCFG_TYPE_FUNC];
 	mask = (1 << bank_type->fld_width[PINCFG_TYPE_FUNC]) - 1;
 
-	spin_lock_irqsave(&bank->slock, flags);
+	raw_spin_lock_irqsave(&bank->slock, flags);
 
 	con = readl(bank->pctl_base + reg_con);
 	con &= ~(mask << shift);
 	con |= EXYNOS_PIN_FUNC_EINT << shift;
 	writel(con, bank->pctl_base + reg_con);
 
-	spin_unlock_irqrestore(&bank->slock, flags);
+	raw_spin_unlock_irqrestore(&bank->slock, flags);
 
 	return 0;
 }
@@ -192,14 +192,14 @@  static void exynos_irq_release_resources(struct irq_data *irqd)
 	shift = irqd->hwirq * bank_type->fld_width[PINCFG_TYPE_FUNC];
 	mask = (1 << bank_type->fld_width[PINCFG_TYPE_FUNC]) - 1;
 
-	spin_lock_irqsave(&bank->slock, flags);
+	raw_spin_lock_irqsave(&bank->slock, flags);
 
 	con = readl(bank->pctl_base + reg_con);
 	con &= ~(mask << shift);
 	con |= EXYNOS_PIN_FUNC_INPUT << shift;
 	writel(con, bank->pctl_base + reg_con);
 
-	spin_unlock_irqrestore(&bank->slock, flags);
+	raw_spin_unlock_irqrestore(&bank->slock, flags);
 
 	gpiochip_unlock_as_irq(&bank->gpio_chip, irqd->hwirq);
 }
diff --git a/drivers/pinctrl/samsung/pinctrl-s3c24xx.c b/drivers/pinctrl/samsung/pinctrl-s3c24xx.c
index 2223ead5bd72..00d77d6946b5 100644
--- a/drivers/pinctrl/samsung/pinctrl-s3c24xx.c
+++ b/drivers/pinctrl/samsung/pinctrl-s3c24xx.c
@@ -145,14 +145,14 @@  static void s3c24xx_eint_set_function(struct samsung_pinctrl_drv_data *d,
 	shift = pin * bank_type->fld_width[PINCFG_TYPE_FUNC];
 	mask = (1 << bank_type->fld_width[PINCFG_TYPE_FUNC]) - 1;
 
-	spin_lock_irqsave(&bank->slock, flags);
+	raw_spin_lock_irqsave(&bank->slock, flags);
 
 	val = readl(reg);
 	val &= ~(mask << shift);
 	val |= bank->eint_func << shift;
 	writel(val, reg);
 
-	spin_unlock_irqrestore(&bank->slock, flags);
+	raw_spin_unlock_irqrestore(&bank->slock, flags);
 }
 
 static int s3c24xx_eint_type(struct irq_data *data, unsigned int type)
diff --git a/drivers/pinctrl/samsung/pinctrl-samsung.c b/drivers/pinctrl/samsung/pinctrl-samsung.c
index 608eb5a07248..376876bd6605 100644
--- a/drivers/pinctrl/samsung/pinctrl-samsung.c
+++ b/drivers/pinctrl/samsung/pinctrl-samsung.c
@@ -400,14 +400,14 @@  static void samsung_pinmux_setup(struct pinctrl_dev *pctldev, unsigned selector,
 		reg += 4;
 	}
 
-	spin_lock_irqsave(&bank->slock, flags);
+	raw_spin_lock_irqsave(&bank->slock, flags);
 
 	data = readl(reg + type->reg_offset[PINCFG_TYPE_FUNC]);
 	data &= ~(mask << shift);
 	data |= func->val << shift;
 	writel(data, reg + type->reg_offset[PINCFG_TYPE_FUNC]);
 
-	spin_unlock_irqrestore(&bank->slock, flags);
+	raw_spin_unlock_irqrestore(&bank->slock, flags);
 }
 
 /* enable a specified pinmux by writing to registers */
@@ -451,7 +451,7 @@  static int samsung_pinconf_rw(struct pinctrl_dev *pctldev, unsigned int pin,
 	width = type->fld_width[cfg_type];
 	cfg_reg = type->reg_offset[cfg_type];
 
-	spin_lock_irqsave(&bank->slock, flags);
+	raw_spin_lock_irqsave(&bank->slock, flags);
 
 	mask = (1 << width) - 1;
 	shift = pin_offset * width;
@@ -468,7 +468,7 @@  static int samsung_pinconf_rw(struct pinctrl_dev *pctldev, unsigned int pin,
 		*config = PINCFG_PACK(cfg_type, data);
 	}
 
-	spin_unlock_irqrestore(&bank->slock, flags);
+	raw_spin_unlock_irqrestore(&bank->slock, flags);
 
 	return 0;
 }
@@ -561,9 +561,9 @@  static void samsung_gpio_set(struct gpio_chip *gc, unsigned offset, int value)
 	struct samsung_pin_bank *bank = gpiochip_get_data(gc);
 	unsigned long flags;
 
-	spin_lock_irqsave(&bank->slock, flags);
+	raw_spin_lock_irqsave(&bank->slock, flags);
 	samsung_gpio_set_value(gc, offset, value);
-	spin_unlock_irqrestore(&bank->slock, flags);
+	raw_spin_unlock_irqrestore(&bank->slock, flags);
 }
 
 /* gpiolib gpio_get callback function */
@@ -626,9 +626,9 @@  static int samsung_gpio_direction_input(struct gpio_chip *gc, unsigned offset)
 	unsigned long flags;
 	int ret;
 
-	spin_lock_irqsave(&bank->slock, flags);
+	raw_spin_lock_irqsave(&bank->slock, flags);
 	ret = samsung_gpio_set_direction(gc, offset, true);
-	spin_unlock_irqrestore(&bank->slock, flags);
+	raw_spin_unlock_irqrestore(&bank->slock, flags);
 	return ret;
 }
 
@@ -640,10 +640,10 @@  static int samsung_gpio_direction_output(struct gpio_chip *gc, unsigned offset,
 	unsigned long flags;
 	int ret;
 
-	spin_lock_irqsave(&bank->slock, flags);
+	raw_spin_lock_irqsave(&bank->slock, flags);
 	samsung_gpio_set_value(gc, offset, value);
 	ret = samsung_gpio_set_direction(gc, offset, false);
-	spin_unlock_irqrestore(&bank->slock, flags);
+	raw_spin_unlock_irqrestore(&bank->slock, flags);
 
 	return ret;
 }
@@ -1057,7 +1057,7 @@  samsung_pinctrl_get_soc_data(struct samsung_pinctrl_drv_data *d,
 		bank->eint_offset = bdata->eint_offset;
 		bank->name = bdata->name;
 
-		spin_lock_init(&bank->slock);
+		raw_spin_lock_init(&bank->slock);
 		bank->drvdata = d;
 		bank->pin_base = d->nr_pins;
 		d->nr_pins += bank->nr_pins;
diff --git a/drivers/pinctrl/samsung/pinctrl-samsung.h b/drivers/pinctrl/samsung/pinctrl-samsung.h
index 379f34a9a482..de44f8ec330b 100644
--- a/drivers/pinctrl/samsung/pinctrl-samsung.h
+++ b/drivers/pinctrl/samsung/pinctrl-samsung.h
@@ -171,7 +171,7 @@  struct samsung_pin_bank {
 	struct gpio_chip gpio_chip;
 	struct pinctrl_gpio_range grange;
 	struct exynos_irq_chip *irq_chip;
-	spinlock_t slock;
+	raw_spinlock_t slock;
 
 	u32 pm_save[PINCFG_TYPE_NUM + 1]; /* +1 to handle double CON registers*/
 };