path: root/kernel/irq/internals.h
diff options
authorThomas Gleixner <tglx@linutronix.de>2019-06-28 13:11:49 +0200
committerThomas Gleixner <tglx@linutronix.de>2019-07-03 10:12:28 +0200
commit4001d8e8762f57d418b66e4e668601791900a1dd (patch)
tree8424f1b08fd15896521cbc842571042fe9f242fe /kernel/irq/internals.h
parentc8c4076723daca08bf35ccd68f22ea1c6219e207 (diff)
genirq: Delay deactivation in free_irq()
When interrupts are shutdown, they are immediately deactivated in the irqdomain hierarchy. While this looks obviously correct there is a subtle issue: There might be an interrupt in flight when free_irq() is invoking the shutdown. This is properly handled at the irq descriptor / primary handler level, but the deactivation might completely disable resources which are required to acknowledge the interrupt. Split the shutdown code and deactivate the interrupt after synchronization in free_irq(). Fixup all other usage sites where this is not an issue to invoke the combined shutdown_and_deactivate() function instead. This still might be an issue if the interrupt in flight servicing is delayed on a remote CPU beyond the invocation of synchronize_irq(), but that cannot be handled at that level and needs to be handled in the synchronize_irq() context. Fixes: f8264e34965a ("irqdomain: Introduce new interfaces to support hierarchy irqdomains") Reported-by: Robert Hodaszi <Robert.Hodaszi@digi.com> Signed-off-by: Thomas Gleixner <tglx@linutronix.de> Reviewed-by: Marc Zyngier <marc.zyngier@arm.com> Link: https://lkml.kernel.org/r/20190628111440.098196390@linutronix.de
Diffstat (limited to 'kernel/irq/internals.h')
1 files changed, 1 insertions, 0 deletions
diff --git a/kernel/irq/internals.h b/kernel/irq/internals.h
index 70c3053bc1f6..9c957f8b1198 100644
--- a/kernel/irq/internals.h
+++ b/kernel/irq/internals.h
@@ -82,6 +82,7 @@ extern int irq_activate_and_startup(struct irq_desc *desc, bool resend);
extern int irq_startup(struct irq_desc *desc, bool resend, bool force);
extern void irq_shutdown(struct irq_desc *desc);
+extern void irq_shutdown_and_deactivate(struct irq_desc *desc);
extern void irq_enable(struct irq_desc *desc);
extern void irq_disable(struct irq_desc *desc);
extern void irq_percpu_enable(struct irq_desc *desc, unsigned int cpu);