diff options
Diffstat (limited to 'arch/x86/kernel/apic/vector.c')
| -rw-r--r-- | arch/x86/kernel/apic/vector.c | 17 |
1 files changed, 15 insertions, 2 deletions
diff --git a/arch/x86/kernel/apic/vector.c b/arch/x86/kernel/apic/vector.c index 3c9c7492252f..6dbdc7c22bb7 100644 --- a/arch/x86/kernel/apic/vector.c +++ b/arch/x86/kernel/apic/vector.c @@ -543,6 +543,14 @@ static int x86_vector_alloc_irqs(struct irq_domain *domain, unsigned int virq, if ((info->flags & X86_IRQ_ALLOC_CONTIGUOUS_VECTORS) && nr_irqs > 1) return -ENOSYS; + /* + * Catch any attempt to touch the cascade interrupt on a PIC + * equipped system. + */ + if (WARN_ON_ONCE(info->flags & X86_IRQ_ALLOC_LEGACY && + virq == PIC_CASCADE_IR)) + return -EINVAL; + for (i = 0; i < nr_irqs; i++) { irqd = irq_domain_get_irq_data(domain, virq + i); BUG_ON(!irqd); @@ -745,6 +753,11 @@ void __init lapic_assign_system_vectors(void) /* Mark the preallocated legacy interrupts */ for (i = 0; i < nr_legacy_irqs(); i++) { + /* + * Don't touch the cascade interrupt. It's unusable + * on PIC equipped machines. See the large comment + * in the IO/APIC code. + */ if (i != PIC_CASCADE_IR) irq_matrix_assign(vector_matrix, ISA_IRQ_VECTOR(i)); } @@ -1045,7 +1058,7 @@ void irq_force_complete_move(struct irq_desc *desc) * * But in case of cpu hotplug this should be a non issue * because if the affinity update happens right before all - * cpus rendevouz in stop machine, there is no way that the + * cpus rendezvous in stop machine, there is no way that the * interrupt can be blocked on the target cpu because all cpus * loops first with interrupts enabled in stop machine, so the * old vector is not yet cleaned up when the interrupt fires. @@ -1054,7 +1067,7 @@ void irq_force_complete_move(struct irq_desc *desc) * of the interrupt on the apic/system bus would be delayed * beyond the point where the target cpu disables interrupts * in stop machine. I doubt that it can happen, but at least - * there is a theroretical chance. Virtualization might be + * there is a theoretical chance. Virtualization might be * able to expose this, but AFAICT the IOAPIC emulation is not * as stupid as the real hardware. * |