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gpio: mxc: Protect GPIO irqchip RMW with bgpio spinlock

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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 <linus.walleij@linaro.org>
Reviewed-by: Marc Zyngier <maz@kernel.org>
Fixes: 07bd1a6cc7 ("MXC arch: Add gpio support for the whole platform")
Signed-off-by: Marek Vasut <marex@denx.de>
Signed-off-by: Bartosz Golaszewski <bartosz.golaszewski@linaro.org>
This commit is contained in:
Marek Vasut 2023-01-16 10:49:56 +01:00 committed by Bartosz Golaszewski
parent 5dc4c995db
commit e546427762
1 changed files with 11 additions and 0 deletions
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11
drivers/gpio/gpio-mxc.c
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@ -18,6 +18,7 @@
#include <linux/module.h>
#include <linux/platform_device.h>
#include <linux/slab.h>
#include <linux/spinlock.h>
#include <linux/syscore_ops.h>
#include <linux/gpio/driver.h>
#include <linux/of.h>
@ -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 */