From e5464277625c1aca5c002e0f470377cdd6816dcf Mon Sep 17 00:00:00 2001 From: Marek Vasut Date: Mon, 16 Jan 2023 10:49:56 +0100 Subject: [PATCH] gpio: mxc: Protect GPIO irqchip RMW with bgpio spinlock The driver currently performs register read-modify-write without locking in its irqchip part, this could lead to a race condition when configuring interrupt mode setting. Add the missing bgpio spinlock lock/unlock around the register read-modify-write. Reviewed-by: Linus Walleij Reviewed-by: Marc Zyngier Fixes: 07bd1a6cc7cbb ("MXC arch: Add gpio support for the whole platform") Signed-off-by: Marek Vasut Signed-off-by: Bartosz Golaszewski --- drivers/gpio/gpio-mxc.c | 11 +++++++++++ 1 file changed, 11 insertions(+) diff --git a/drivers/gpio/gpio-mxc.c b/drivers/gpio/gpio-mxc.c index d5626c5..2d9d498 100644 --- a/drivers/gpio/gpio-mxc.c +++ b/drivers/gpio/gpio-mxc.c @@ -18,6 +18,7 @@ #include #include #include +#include #include #include #include @@ -159,6 +160,7 @@ static int gpio_set_irq_type(struct irq_data *d, u32 type) { struct irq_chip_generic *gc = irq_data_get_irq_chip_data(d); struct mxc_gpio_port *port = gc->private; + unsigned long flags; u32 bit, val; u32 gpio_idx = d->hwirq; int edge; @@ -197,6 +199,8 @@ static int gpio_set_irq_type(struct irq_data *d, u32 type) return -EINVAL; } + raw_spin_lock_irqsave(&port->gc.bgpio_lock, flags); + if (GPIO_EDGE_SEL >= 0) { val = readl(port->base + GPIO_EDGE_SEL); if (edge == GPIO_INT_BOTH_EDGES) @@ -217,15 +221,20 @@ static int gpio_set_irq_type(struct irq_data *d, u32 type) writel(1 << gpio_idx, port->base + GPIO_ISR); port->pad_type[gpio_idx] = type; + raw_spin_unlock_irqrestore(&port->gc.bgpio_lock, flags); + return 0; } static void mxc_flip_edge(struct mxc_gpio_port *port, u32 gpio) { void __iomem *reg = port->base; + unsigned long flags; u32 bit, val; int edge; + raw_spin_lock_irqsave(&port->gc.bgpio_lock, flags); + reg += GPIO_ICR1 + ((gpio & 0x10) >> 2); /* lower or upper register */ bit = gpio & 0xf; val = readl(reg); @@ -243,6 +252,8 @@ static void mxc_flip_edge(struct mxc_gpio_port *port, u32 gpio) return; } writel(val | (edge << (bit << 1)), reg); + + raw_spin_unlock_irqrestore(&port->gc.bgpio_lock, flags); } /* handle 32 interrupts in one status register */ -- 2.7.4