From: Vladimir Oltean <vladimir.oltean@nxp.com> To: linux-arm-kernel@lists.infradead.org Cc: "Andrew Lunn" <andrew@lunn.ch>, "Gregory Clement" <gregory.clement@bootlin.com>, "Sebastian Hesselbarth" <sebastian.hesselbarth@gmail.com>, "Linus Walleij" <linus.walleij@linaro.org>, linux-gpio@vger.kernel.org, linux-kernel@vger.kernel.org, "Marek Behún" <kabel@kernel.org>, "Pali Rohár" <pali@kernel.org> Subject: [PATCH 1/2] pinctrl: armada-37xx: make irq_lock a raw spinlock to avoid invalid wait context Date: Sun, 17 Jul 2022 02:37:44 +0300 [thread overview] Message-ID: <20220716233745.1704677-2-vladimir.oltean@nxp.com> (raw) In-Reply-To: <20220716233745.1704677-1-vladimir.oltean@nxp.com> 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. Fixes: 2f227605394b ("pinctrl: armada-37xx: Add irqchip support") Signed-off-by: Vladimir Oltean <vladimir.oltean@nxp.com> --- drivers/pinctrl/mvebu/pinctrl-armada-37xx.c | 38 ++++++++++----------- 1 file changed, 19 insertions(+), 19 deletions(-) diff --git a/drivers/pinctrl/mvebu/pinctrl-armada-37xx.c b/drivers/pinctrl/mvebu/pinctrl-armada-37xx.c index a140b6bfbfaa..8fddc67271b4 100644 --- a/drivers/pinctrl/mvebu/pinctrl-armada-37xx.c +++ b/drivers/pinctrl/mvebu/pinctrl-armada-37xx.c @@ -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(®, 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(®, 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(®, 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(®, 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(®, 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) { -- 2.34.1
WARNING: multiple messages have this Message-ID (diff)
From: Vladimir Oltean <vladimir.oltean@nxp.com> To: linux-arm-kernel@lists.infradead.org Cc: "Andrew Lunn" <andrew@lunn.ch>, "Gregory Clement" <gregory.clement@bootlin.com>, "Sebastian Hesselbarth" <sebastian.hesselbarth@gmail.com>, "Linus Walleij" <linus.walleij@linaro.org>, linux-gpio@vger.kernel.org, linux-kernel@vger.kernel.org, "Marek Behún" <kabel@kernel.org>, "Pali Rohár" <pali@kernel.org> Subject: [PATCH 1/2] pinctrl: armada-37xx: make irq_lock a raw spinlock to avoid invalid wait context Date: Sun, 17 Jul 2022 02:37:44 +0300 [thread overview] Message-ID: <20220716233745.1704677-2-vladimir.oltean@nxp.com> (raw) In-Reply-To: <20220716233745.1704677-1-vladimir.oltean@nxp.com> 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. Fixes: 2f227605394b ("pinctrl: armada-37xx: Add irqchip support") Signed-off-by: Vladimir Oltean <vladimir.oltean@nxp.com> --- drivers/pinctrl/mvebu/pinctrl-armada-37xx.c | 38 ++++++++++----------- 1 file changed, 19 insertions(+), 19 deletions(-) diff --git a/drivers/pinctrl/mvebu/pinctrl-armada-37xx.c b/drivers/pinctrl/mvebu/pinctrl-armada-37xx.c index a140b6bfbfaa..8fddc67271b4 100644 --- a/drivers/pinctrl/mvebu/pinctrl-armada-37xx.c +++ b/drivers/pinctrl/mvebu/pinctrl-armada-37xx.c @@ -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(®, 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(®, 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(®, 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(®, 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(®, 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) { -- 2.34.1 _______________________________________________ linux-arm-kernel mailing list linux-arm-kernel@lists.infradead.org http://lists.infradead.org/mailman/listinfo/linux-arm-kernel
next prev parent reply other threads:[~2022-07-16 23:38 UTC|newest] Thread overview: 10+ messages / expand[flat|nested] mbox.gz Atom feed top 2022-07-16 23:37 [PATCH 0/2] Fix kernel splats on boot with armada-37xx irqchip driver Vladimir Oltean 2022-07-16 23:37 ` Vladimir Oltean 2022-07-16 23:37 ` Vladimir Oltean [this message] 2022-07-16 23:37 ` [PATCH 1/2] pinctrl: armada-37xx: make irq_lock a raw spinlock to avoid invalid wait context Vladimir Oltean 2022-07-16 23:37 ` [PATCH 2/2] pinctrl: armada-37xx: use raw spinlocks for regmap " Vladimir Oltean 2022-07-16 23:37 ` Vladimir Oltean 2022-07-18 13:43 ` [PATCH 0/2] Fix kernel splats on boot with armada-37xx irqchip driver Linus Walleij 2022-07-18 13:43 ` Linus Walleij 2022-07-18 14:06 ` Vladimir Oltean 2022-07-18 14:06 ` Vladimir Oltean
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