The ACPI tables in the Macbook Air 5,1 define a single IOAPIC with id 2, but the only remapping unit described in the DMAR table matches id 0. Interrupt remapping fails as a result, and the kernel panics with the message "timer doesn't work through Interrupt-remapped IO-APIC."
To fix this, check each IOAPIC for a corresponding IOMMU. If an IOMMU is not found, do not allow IRQ remapping to be enabled. Signed-off-by: Seth Forshee <[email protected]> --- drivers/iommu/intel_irq_remapping.c | 11 +++++++++++ 1 file changed, 11 insertions(+) diff --git a/drivers/iommu/intel_irq_remapping.c b/drivers/iommu/intel_irq_remapping.c index e0b18f3..ce2c0c6 100644 --- a/drivers/iommu/intel_irq_remapping.c +++ b/drivers/iommu/intel_irq_remapping.c @@ -526,6 +526,7 @@ static int __init intel_irq_remapping_supported(void) static int __init intel_enable_irq_remapping(void) { struct dmar_drhd_unit *drhd; + int ioapic_idx; int setup = 0; int eim = 0; @@ -534,6 +535,16 @@ static int __init intel_enable_irq_remapping(void) return -1; } + for (ioapic_idx = 0; ioapic_idx < nr_ioapics; ioapic_idx++) { + int ioapic_id = mpc_ioapic_id(ioapic_idx); + if (!map_ioapic_to_ir(ioapic_id)) { + pr_info("ioapic %d has no mapping iommu, " + "interrupt remapping will be disabled\n", + ioapic_id); + return -1; + } + } + if (x2apic_supported()) { eim = !dmar_x2apic_optout(); WARN(!eim, KERN_WARNING -- 1.7.9.5 -- To unsubscribe from this list: send the line "unsubscribe linux-kernel" in the body of a message to [email protected] More majordomo info at http://vger.kernel.org/majordomo-info.html Please read the FAQ at http://www.tux.org/lkml/
