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authorMarek Vasut <marex@denx.de>2023-01-16 12:49:56 +0300
committerGreg Kroah-Hartman <gregkh@linuxfoundation.org>2023-02-01 10:34:18 +0300
commit4141fdfd78478cc907d7c42d9086957927dcc716 (patch)
treed0949b3ded32c99c4fb8bdc870d149767fa1c35a /drivers
parentd314d0c3de79138f42edbea4051ec3a084c5afaa (diff)
downloadlinux-4141fdfd78478cc907d7c42d9086957927dcc716.tar.xz
gpio: mxc: Protect GPIO irqchip RMW with bgpio spinlock
[ Upstream commit e5464277625c1aca5c002e0f470377cdd6816dcf ] 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: 07bd1a6cc7cbb ("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> Signed-off-by: Sasha Levin <sashal@kernel.org>
Diffstat (limited to 'drivers')
-rw-r--r--drivers/gpio/gpio-mxc.c11
1 files changed, 11 insertions, 0 deletions
diff --git a/drivers/gpio/gpio-mxc.c b/drivers/gpio/gpio-mxc.c
index c871602fc5ba..6cc98a5684ae 100644
--- a/drivers/gpio/gpio-mxc.c
+++ b/drivers/gpio/gpio-mxc.c
@@ -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>
@@ -147,6 +148,7 @@ 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;
@@ -185,6 +187,8 @@ 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)
@@ -204,15 +208,20 @@ static int gpio_set_irq_type(struct irq_data *d, u32 type)
writel(1 << gpio_idx, port->base + GPIO_ISR);
+ 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);
@@ -230,6 +239,8 @@ 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 */