Commit 984245b6 authored by Vladimir Oltean's avatar Vladimir Oltean Committed by Linus Walleij
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pinctrl: armada-37xx: make irq_lock a raw spinlock to avoid invalid wait context 



The irqchip->irq_set_type method is called by __irq_set_trigger() under
the desc->lock raw spinlock.

The armada-37xx implementation, armada_37xx_irq_set_type(), takes a
plain spinlock, the kind that becomes sleepable on RT.

Therefore, this is an invalid locking scheme for which we get a kernel
splat stating just that ("[ BUG: Invalid wait context ]"), because the
context in which the plain spinlock may sleep is atomic due to the raw
spinlock. We need to go raw spinlocks all the way.

Replace the driver's irq_lock with a raw spinlock, to disable preemption
even on RT.

Cc: <stable@vger.kernel.org> # 5.15+
Fixes: 2f227605 ("pinctrl: armada-37xx: Add irqchip support")
Signed-off-by: default avatarVladimir Oltean <vladimir.oltean@nxp.com>
Link: https://lore.kernel.org/r/20220716233745.1704677-2-vladimir.oltean@nxp.com


Signed-off-by: default avatarLinus Walleij <linus.walleij@linaro.org>
parent 41ef3c1a

drivers/pinctrl/mvebu/pinctrl-armada-37xx.c

+19 −19
Original line number Diff line number Diff line
@@ -102,7 +102,7 @@ struct armada_37xx_pinctrl { 
	struct device			*dev;

	struct gpio_chip		gpio_chip;

	struct irq_chip			irq_chip;

	spinlock_t			irq_lock;

	raw_spinlock_t			irq_lock;

	struct pinctrl_desc		pctl;

	struct pinctrl_dev		*pctl_dev;

	struct armada_37xx_pin_group	*groups;
@@ -523,9 +523,9 @@ static void armada_37xx_irq_ack(struct irq_data *d) 
	unsigned long flags;



	armada_37xx_irq_update_reg(&reg, d);

	spin_lock_irqsave(&info->irq_lock, flags);

	raw_spin_lock_irqsave(&info->irq_lock, flags);

	writel(d->mask, info->base + reg);

	spin_unlock_irqrestore(&info->irq_lock, flags);

	raw_spin_unlock_irqrestore(&info->irq_lock, flags);

}



static void armada_37xx_irq_mask(struct irq_data *d)
@@ -536,10 +536,10 @@ static void armada_37xx_irq_mask(struct irq_data *d) 
	unsigned long flags;



	armada_37xx_irq_update_reg(&reg, d);

	spin_lock_irqsave(&info->irq_lock, flags);

	raw_spin_lock_irqsave(&info->irq_lock, flags);

	val = readl(info->base + reg);

	writel(val & ~d->mask, info->base + reg);

	spin_unlock_irqrestore(&info->irq_lock, flags);

	raw_spin_unlock_irqrestore(&info->irq_lock, flags);

}



static void armada_37xx_irq_unmask(struct irq_data *d)
@@ -550,10 +550,10 @@ static void armada_37xx_irq_unmask(struct irq_data *d) 
	unsigned long flags;



	armada_37xx_irq_update_reg(&reg, d);

	spin_lock_irqsave(&info->irq_lock, flags);

	raw_spin_lock_irqsave(&info->irq_lock, flags);

	val = readl(info->base + reg);

	writel(val | d->mask, info->base + reg);

	spin_unlock_irqrestore(&info->irq_lock, flags);

	raw_spin_unlock_irqrestore(&info->irq_lock, flags);

}



static int armada_37xx_irq_set_wake(struct irq_data *d, unsigned int on)
@@ -564,14 +564,14 @@ static int armada_37xx_irq_set_wake(struct irq_data *d, unsigned int on) 
	unsigned long flags;



	armada_37xx_irq_update_reg(&reg, d);

	spin_lock_irqsave(&info->irq_lock, flags);

	raw_spin_lock_irqsave(&info->irq_lock, flags);

	val = readl(info->base + reg);

	if (on)

		val |= (BIT(d->hwirq % GPIO_PER_REG));

	else

		val &= ~(BIT(d->hwirq % GPIO_PER_REG));

	writel(val, info->base + reg);

	spin_unlock_irqrestore(&info->irq_lock, flags);

	raw_spin_unlock_irqrestore(&info->irq_lock, flags);



	return 0;

}
@@ -583,7 +583,7 @@ static int armada_37xx_irq_set_type(struct irq_data *d, unsigned int type) 
	u32 val, reg = IRQ_POL;

	unsigned long flags;



	spin_lock_irqsave(&info->irq_lock, flags);

	raw_spin_lock_irqsave(&info->irq_lock, flags);

	armada_37xx_irq_update_reg(&reg, d);

	val = readl(info->base + reg);

	switch (type) {
@@ -607,11 +607,11 @@ static int armada_37xx_irq_set_type(struct irq_data *d, unsigned int type) 
		break;

	}

	default:

		spin_unlock_irqrestore(&info->irq_lock, flags);

		raw_spin_unlock_irqrestore(&info->irq_lock, flags);

		return -EINVAL;

	}

	writel(val, info->base + reg);

	spin_unlock_irqrestore(&info->irq_lock, flags);

	raw_spin_unlock_irqrestore(&info->irq_lock, flags);



	return 0;

}
@@ -626,7 +626,7 @@ static int armada_37xx_edge_both_irq_swap_pol(struct armada_37xx_pinctrl *info, 


	regmap_read(info->regmap, INPUT_VAL + 4*reg_idx, &l);



	spin_lock_irqsave(&info->irq_lock, flags);

	raw_spin_lock_irqsave(&info->irq_lock, flags);

	p = readl(info->base + IRQ_POL + 4 * reg_idx);

	if ((p ^ l) & (1 << bit_num)) {

		/*
@@ -647,7 +647,7 @@ static int armada_37xx_edge_both_irq_swap_pol(struct armada_37xx_pinctrl *info, 
		ret = -1;

	}



	spin_unlock_irqrestore(&info->irq_lock, flags);

	raw_spin_unlock_irqrestore(&info->irq_lock, flags);

	return ret;

}
@@ -664,11 +664,11 @@ static void armada_37xx_irq_handler(struct irq_desc *desc) 
		u32 status;

		unsigned long flags;



		spin_lock_irqsave(&info->irq_lock, flags);

		raw_spin_lock_irqsave(&info->irq_lock, flags);

		status = readl_relaxed(info->base + IRQ_STATUS + 4 * i);

		/* Manage only the interrupt that was enabled */

		status &= readl_relaxed(info->base + IRQ_EN + 4 * i);

		spin_unlock_irqrestore(&info->irq_lock, flags);

		raw_spin_unlock_irqrestore(&info->irq_lock, flags);

		while (status) {

			u32 hwirq = ffs(status) - 1;

			u32 virq = irq_find_mapping(d, hwirq +
@@ -695,12 +695,12 @@ static void armada_37xx_irq_handler(struct irq_desc *desc) 


update_status:

			/* Update status in case a new IRQ appears */

			spin_lock_irqsave(&info->irq_lock, flags);

			raw_spin_lock_irqsave(&info->irq_lock, flags);

			status = readl_relaxed(info->base +

					       IRQ_STATUS + 4 * i);

			/* Manage only the interrupt that was enabled */

			status &= readl_relaxed(info->base + IRQ_EN + 4 * i);

			spin_unlock_irqrestore(&info->irq_lock, flags);

			raw_spin_unlock_irqrestore(&info->irq_lock, flags);

		}

	}

	chained_irq_exit(chip, desc);
@@ -731,7 +731,7 @@ static int armada_37xx_irqchip_register(struct platform_device *pdev, 
	struct device *dev = &pdev->dev;

	unsigned int i, nr_irq_parent;



	spin_lock_init(&info->irq_lock);

	raw_spin_lock_init(&info->irq_lock);



	nr_irq_parent = of_irq_count(np);

	if (!nr_irq_parent) {