diff options
Diffstat (limited to 'kernel/irq/resend.c')
| -rw-r--r-- | kernel/irq/resend.c | 53 |
1 files changed, 51 insertions, 2 deletions
diff --git a/kernel/irq/resend.c b/kernel/irq/resend.c index bef72dcfb79b..27634f4022d0 100644 --- a/kernel/irq/resend.c +++ b/kernel/irq/resend.c @@ -91,7 +91,7 @@ static int irq_sw_resend(struct irq_desc *desc) * * Is called with interrupts disabled and desc->lock held. */ -int check_irq_resend(struct irq_desc *desc) +int check_irq_resend(struct irq_desc *desc, bool inject) { int err = 0; @@ -108,7 +108,7 @@ int check_irq_resend(struct irq_desc *desc) if (desc->istate & IRQS_REPLAY) return -EBUSY; - if (!(desc->istate & IRQS_PENDING)) + if (!(desc->istate & IRQS_PENDING) && !inject) return 0; desc->istate &= ~IRQS_PENDING; @@ -122,3 +122,52 @@ int check_irq_resend(struct irq_desc *desc) desc->istate |= IRQS_REPLAY; return err; } + +#ifdef CONFIG_GENERIC_IRQ_INJECTION +/** + * irq_inject_interrupt - Inject an interrupt for testing/error injection + * @irq: The interrupt number + * + * This function must only be used for debug and testing purposes! + * + * Especially on x86 this can cause a premature completion of an interrupt + * affinity change causing the interrupt line to become stale. Very + * unlikely, but possible. + * + * The injection can fail for various reasons: + * - Interrupt is not activated + * - Interrupt is NMI type or currently replaying + * - Interrupt is level type + * - Interrupt does not support hardware retrigger and software resend is + * either not enabled or not possible for the interrupt. + */ +int irq_inject_interrupt(unsigned int irq) +{ + struct irq_desc *desc; + unsigned long flags; + int err; + + /* Try the state injection hardware interface first */ + if (!irq_set_irqchip_state(irq, IRQCHIP_STATE_PENDING, true)) + return 0; + + /* That failed, try via the resend mechanism */ + desc = irq_get_desc_buslock(irq, &flags, 0); + if (!desc) + return -EINVAL; + + /* + * Only try to inject when the interrupt is: + * - not NMI type + * - activated + */ + if ((desc->istate & IRQS_NMI) || !irqd_is_activated(&desc->irq_data)) + err = -EINVAL; + else + err = check_irq_resend(desc, true); + + irq_put_desc_busunlock(desc, flags); + return err; +} +EXPORT_SYMBOL_GPL(irq_inject_interrupt); +#endif |