This is a note to let you know that I've just added the patch titled
gpio: Don't fiddle with irqchips marked as immutable
to the 5.15-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-don-t-fiddle-with-irqchips-marked-as-immutable.patch
and it can be found in the queue-5.15 subdirectory.
If you, or anyone else, feels it should not be added to the stable tree,
please let <stable@xxxxxxxxxxxxxxx> know about it.
commit dd90d8333e44d313ef8adebadb597025d77c844e
Author: Marc Zyngier <maz@xxxxxxxxxx>
Date: Tue Apr 19 15:18:37 2022 +0100
gpio: Don't fiddle with irqchips marked as immutable
[ Upstream commit 6c846d026d490b2383d395bc8e7b06336219667b ]
In order to move away from gpiolib messing with the internals of
unsuspecting irqchips, add a flag by which irqchips advertise
that they are not to be messed with, and do solemnly swear that
they correctly call into the gpiolib helpers when required.
Also nudge the users into converting their drivers to the
new model.
Reviewed-by: Andy Shevchenko <andy.shevchenko@xxxxxxxxx>
Reviewed-by: Bartosz Golaszewski <brgl@xxxxxxxx>
Signed-off-by: Marc Zyngier <maz@xxxxxxxxxx>
Link: https://lore.kernel.org/r/20220419141846.598305-2-maz@xxxxxxxxxx
Stable-dep-of: 9860370c2172 ("gpio: xilinx: Convert gpio_lock to raw spinlock")
Signed-off-by: Sasha Levin <sashal@xxxxxxxxxx>
diff --git a/drivers/gpio/gpiolib.c b/drivers/gpio/gpiolib.c
index 5eb4edcf03bd4..631eaf2e418a7 100644
--- a/drivers/gpio/gpiolib.c
+++ b/drivers/gpio/gpiolib.c
@@ -1484,6 +1484,11 @@ static void gpiochip_set_irq_hooks(struct gpio_chip *gc)
{
struct irq_chip *irqchip = gc->irq.chip;
+ if (irqchip->flags & IRQCHIP_IMMUTABLE)
+ return;
+
+ chip_warn(gc, "not an immutable chip, please consider fixing it!\n");
+
if (!irqchip->irq_request_resources &&
!irqchip->irq_release_resources) {
irqchip->irq_request_resources = gpiochip_irq_reqres;
@@ -1651,7 +1656,7 @@ static void gpiochip_irqchip_remove(struct gpio_chip *gc)
irq_domain_remove(gc->irq.domain);
}
- if (irqchip) {
+ if (irqchip && !(irqchip->flags & IRQCHIP_IMMUTABLE)) {
if (irqchip->irq_request_resources == gpiochip_irq_reqres) {
irqchip->irq_request_resources = NULL;
irqchip->irq_release_resources = NULL;
diff --git a/include/linux/irq.h b/include/linux/irq.h
index 4fd8d900a1b86..38399d7f508fd 100644
--- a/include/linux/irq.h
+++ b/include/linux/irq.h
@@ -570,6 +570,7 @@ struct irq_chip {
* IRQCHIP_ENABLE_WAKEUP_ON_SUSPEND: Invokes __enable_irq()/__disable_irq() for wake irqs
* in the suspend path if they are in disabled state
* IRQCHIP_AFFINITY_PRE_STARTUP: Default affinity update before startup
+ * IRQCHIP_IMMUTABLE: Don't ever change anything in this chip
*/
enum {
IRQCHIP_SET_TYPE_MASKED = (1 << 0),
@@ -583,6 +584,7 @@ enum {
IRQCHIP_SUPPORTS_NMI = (1 << 8),
IRQCHIP_ENABLE_WAKEUP_ON_SUSPEND = (1 << 9),
IRQCHIP_AFFINITY_PRE_STARTUP = (1 << 10),
+ IRQCHIP_IMMUTABLE = (1 << 11),
};
#include <linux/irqdesc.h>
diff --git a/kernel/irq/debugfs.c b/kernel/irq/debugfs.c
index e4cff358b437e..7ff52d94b42c0 100644
--- a/kernel/irq/debugfs.c
+++ b/kernel/irq/debugfs.c
@@ -58,6 +58,7 @@ static const struct irq_bit_descr irqchip_flags[] = {
BIT_MASK_DESCR(IRQCHIP_SUPPORTS_LEVEL_MSI),
BIT_MASK_DESCR(IRQCHIP_SUPPORTS_NMI),
BIT_MASK_DESCR(IRQCHIP_ENABLE_WAKEUP_ON_SUSPEND),
+ BIT_MASK_DESCR(IRQCHIP_IMMUTABLE),
};
static void
