This is a note to let you know that I've just added the patch titled
gpio: mxc: Protect GPIO irqchip RMW with bgpio spinlock
to the 6.1-stable tree which can be found at:
http://www.kernel.org/git/?p=linux/kernel/git/stable/stable-queue.git;a=summary
The filename of the patch is:
gpio-mxc-protect-gpio-irqchip-rmw-with-bgpio-spinloc.patch
and it can be found in the queue-6.1 subdirectory.
If you, or anyone else, feels it should not be added to the stable tree,
please let <stable@xxxxxxxxxxxxxxx> know about it.
commit 36b6ec7fe3497ec8c2f2bc86cf0c94a552bb0e57
Author: Marek Vasut <marex@xxxxxxx>
Date: Mon Jan 16 10:49:56 2023 +0100
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@xxxxxxxxxx>
Reviewed-by: Marc Zyngier <maz@xxxxxxxxxx>
Fixes: 07bd1a6cc7cbb ("MXC arch: Add gpio support for the whole platform")
Signed-off-by: Marek Vasut <marex@xxxxxxx>
Signed-off-by: Bartosz Golaszewski <bartosz.golaszewski@xxxxxxxxxx>
Signed-off-by: Sasha Levin <sashal@xxxxxxxxxx>
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 */
