gpio: use raw spinlock for gpio chip shadowed data

In case of PREEMPT_RT, there is a raw_spinlock -> spinlock dependency
as the lockdep report shows.

__irq_set_handler
  irq_get_desc_buslock
    __irq_get_desc_lock
      raw_spin_lock_irqsave(&desc->lock, *flags);  // raw spinlock get here
  __irq_do_set_handler
    mask_ack_irq
      dwapb_irq_ack
        spin_lock_irqsave(&gc->bgpio_lock, flags); // sleep able spinlock
  irq_put_desc_busunlock

Replace with a raw lock to avoid BUGs. This lock is only used to access
registers, and It's safe to replace with the raw lock without bad
influence.

[   15.090359][    T1] =============================
[   15.090365][    T1] [ BUG: Invalid wait context ]
[   15.090373][    T1] 5.10.59-rt52-00983-g186a6841c682-dirty #3 Not tainted
[   15.090386][    T1] -----------------------------
[   15.090392][    T1] swapper/0/1 is trying to lock:
[   15.090402][    T1] 70ff00018507c188 (&gc->bgpio_lock){....}-{3:3}, at: _raw_spin_lock_irqsave+0x1c/0x28
[   15.090470][    T1] other info that might help us debug this:
[   15.090477][    T1] context-{5:5}
[   15.090485][    T1] 3 locks held by swapper/0/1:
[   15.090497][    T1]  #0: c2ff0001816de1a0 (&dev->mutex){....}-{4:4}, at: __device_driver_lock+0x98/0x104
[   15.090553][    T1]  #1: ffff90001485b4b8 (irq_domain_mutex){+.+.}-{4:4}, at: irq_domain_associate+0xbc/0x6d4
[   15.090606][    T1]  #2: 4bff000185d7a8e0 (lock_class){....}-{2:2}, at: _raw_spin_lock_irqsave+0x1c/0x28
[   15.090654][    T1] stack backtrace:
[   15.090661][    T1] CPU: 4 PID: 1 Comm: swapper/0 Not tainted 5.10.59-rt52-00983-g186a6841c682-dirty #3
[   15.090682][    T1] Hardware name: Horizon Robotics Journey 5 DVB (DT)
[   15.090692][    T1] Call trace:
......
[   15.090811][    T1]  _raw_spin_lock_irqsave+0x1c/0x28
[   15.090828][    T1]  dwapb_irq_ack+0xb4/0x300
[   15.090846][    T1]  __irq_do_set_handler+0x494/0xb2c
[   15.090864][    T1]  __irq_set_handler+0x74/0x114
[   15.090881][    T1]  irq_set_chip_and_handler_name+0x44/0x58
[   15.090900][    T1]  gpiochip_irq_map+0x210/0x644

Signed-off-by: Schspa Shi <schspa@gmail.com>
Reviewed-by: Andy Shevchenko <andy.shevchenko@gmail.com>
Acked-by: Linus Walleij <linus.walleij@linaro.org>
Acked-by: Doug Berger <opendmb@gmail.com>
Acked-by: Serge Semin <fancer.lancer@gmail.com>
Signed-off-by: Bartosz Golaszewski <brgl@bgdev.pl>

1 files changed, 18 insertions, 18 deletions

diff --git a/drivers/gpio/gpio-dwapb.c b/drivers/gpio/gpio-dwapb.c
index b0f3aca61974..7130195da48d 100644
--- a/drivers/gpio/gpio-dwapb.c
+++ b/drivers/gpio/gpio-dwapb.c
@@ -243,9 +243,9 @@ static void dwapb_irq_ack(struct irq_data *d)
 	u32 val = BIT(irqd_to_hwirq(d));
 	unsigned long flags;
 
-	spin_lock_irqsave(&gc->bgpio_lock, flags);
+	raw_spin_lock_irqsave(&gc->bgpio_lock, flags);
 	dwapb_write(gpio, GPIO_PORTA_EOI, val);
-	spin_unlock_irqrestore(&gc->bgpio_lock, flags);
+	raw_spin_unlock_irqrestore(&gc->bgpio_lock, flags);
 }
 
 static void dwapb_irq_mask(struct irq_data *d)
@@ -255,10 +255,10 @@ static void dwapb_irq_mask(struct irq_data *d)
 	unsigned long flags;
 	u32 val;
 
-	spin_lock_irqsave(&gc->bgpio_lock, flags);
+	raw_spin_lock_irqsave(&gc->bgpio_lock, flags);
 	val = dwapb_read(gpio, GPIO_INTMASK) | BIT(irqd_to_hwirq(d));
 	dwapb_write(gpio, GPIO_INTMASK, val);
-	spin_unlock_irqrestore(&gc->bgpio_lock, flags);
+	raw_spin_unlock_irqrestore(&gc->bgpio_lock, flags);
 }
 
 static void dwapb_irq_unmask(struct irq_data *d)
@@ -268,10 +268,10 @@ static void dwapb_irq_unmask(struct irq_data *d)
 	unsigned long flags;
 	u32 val;
 
-	spin_lock_irqsave(&gc->bgpio_lock, flags);
+	raw_spin_lock_irqsave(&gc->bgpio_lock, flags);
 	val = dwapb_read(gpio, GPIO_INTMASK) & ~BIT(irqd_to_hwirq(d));
 	dwapb_write(gpio, GPIO_INTMASK, val);
-	spin_unlock_irqrestore(&gc->bgpio_lock, flags);
+	raw_spin_unlock_irqrestore(&gc->bgpio_lock, flags);
 }
 
 static void dwapb_irq_enable(struct irq_data *d)
@@ -281,11 +281,11 @@ static void dwapb_irq_enable(struct irq_data *d)
 	unsigned long flags;
 	u32 val;
 
-	spin_lock_irqsave(&gc->bgpio_lock, flags);
+	raw_spin_lock_irqsave(&gc->bgpio_lock, flags);
 	val = dwapb_read(gpio, GPIO_INTEN);
 	val |= BIT(irqd_to_hwirq(d));
 	dwapb_write(gpio, GPIO_INTEN, val);
-	spin_unlock_irqrestore(&gc->bgpio_lock, flags);
+	raw_spin_unlock_irqrestore(&gc->bgpio_lock, flags);
 }
 
 static void dwapb_irq_disable(struct irq_data *d)
@@ -295,11 +295,11 @@ static void dwapb_irq_disable(struct irq_data *d)
 	unsigned long flags;
 	u32 val;
 
-	spin_lock_irqsave(&gc->bgpio_lock, flags);
+	raw_spin_lock_irqsave(&gc->bgpio_lock, flags);
 	val = dwapb_read(gpio, GPIO_INTEN);
 	val &= ~BIT(irqd_to_hwirq(d));
 	dwapb_write(gpio, GPIO_INTEN, val);
-	spin_unlock_irqrestore(&gc->bgpio_lock, flags);
+	raw_spin_unlock_irqrestore(&gc->bgpio_lock, flags);
 }
 
 static int dwapb_irq_set_type(struct irq_data *d, u32 type)
@@ -309,7 +309,7 @@ static int dwapb_irq_set_type(struct irq_data *d, u32 type)
 	irq_hw_number_t bit = irqd_to_hwirq(d);
 	unsigned long level, polarity, flags;
 
-	spin_lock_irqsave(&gc->bgpio_lock, flags);
+	raw_spin_lock_irqsave(&gc->bgpio_lock, flags);
 	level = dwapb_read(gpio, GPIO_INTTYPE_LEVEL);
 	polarity = dwapb_read(gpio, GPIO_INT_POLARITY);
 
@@ -344,7 +344,7 @@ static int dwapb_irq_set_type(struct irq_data *d, u32 type)
 	dwapb_write(gpio, GPIO_INTTYPE_LEVEL, level);
 	if (type != IRQ_TYPE_EDGE_BOTH)
 		dwapb_write(gpio, GPIO_INT_POLARITY, polarity);
-	spin_unlock_irqrestore(&gc->bgpio_lock, flags);
+	raw_spin_unlock_irqrestore(&gc->bgpio_lock, flags);
 
 	return 0;
 }
@@ -374,7 +374,7 @@ static int dwapb_gpio_set_debounce(struct gpio_chip *gc,
 	unsigned long flags, val_deb;
 	unsigned long mask = BIT(offset);
 
-	spin_lock_irqsave(&gc->bgpio_lock, flags);
+	raw_spin_lock_irqsave(&gc->bgpio_lock, flags);
 
 	val_deb = dwapb_read(gpio, GPIO_PORTA_DEBOUNCE);
 	if (debounce)
@@ -383,7 +383,7 @@ static int dwapb_gpio_set_debounce(struct gpio_chip *gc,
 		val_deb &= ~mask;
 	dwapb_write(gpio, GPIO_PORTA_DEBOUNCE, val_deb);
 
-	spin_unlock_irqrestore(&gc->bgpio_lock, flags);
+	raw_spin_unlock_irqrestore(&gc->bgpio_lock, flags);
 
 	return 0;
 }
@@ -738,7 +738,7 @@ static int dwapb_gpio_suspend(struct device *dev)
 	unsigned long flags;
 	int i;
 
-	spin_lock_irqsave(&gc->bgpio_lock, flags);
+	raw_spin_lock_irqsave(&gc->bgpio_lock, flags);
 	for (i = 0; i < gpio->nr_ports; i++) {
 		unsigned int offset;
 		unsigned int idx = gpio->ports[i].idx;
@@ -765,7 +765,7 @@ static int dwapb_gpio_suspend(struct device *dev)
 			dwapb_write(gpio, GPIO_INTMASK, ~ctx->wake_en);
 		}
 	}
-	spin_unlock_irqrestore(&gc->bgpio_lock, flags);
+	raw_spin_unlock_irqrestore(&gc->bgpio_lock, flags);
 
 	clk_bulk_disable_unprepare(DWAPB_NR_CLOCKS, gpio->clks);
 
@@ -785,7 +785,7 @@ static int dwapb_gpio_resume(struct device *dev)
 		return err;
 	}
 
-	spin_lock_irqsave(&gc->bgpio_lock, flags);
+	raw_spin_lock_irqsave(&gc->bgpio_lock, flags);
 	for (i = 0; i < gpio->nr_ports; i++) {
 		unsigned int offset;
 		unsigned int idx = gpio->ports[i].idx;
@@ -812,7 +812,7 @@ static int dwapb_gpio_resume(struct device *dev)
 			dwapb_write(gpio, GPIO_PORTA_EOI, 0xffffffff);
 		}
 	}
-	spin_unlock_irqrestore(&gc->bgpio_lock, flags);
+	raw_spin_unlock_irqrestore(&gc->bgpio_lock, flags);
 
 	return 0;
 }