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authorSeth Forshee <seth.forshee@canonical.com>2012-08-08 08:27:03 -0500
committerGreg Kroah-Hartman <gregkh@linuxfoundation.org>2012-10-02 10:40:01 -0700
commit398f3001cf89e55b06ada5072df5f9da0137c9c4 (patch)
tree31c770afb730839b62d26f07edfff48430d393f0
parent4320e705bd7b6e17f72bfec17dfb5d035af8af2f (diff)
irq_remap: disable IRQ remapping if any IOAPIC lacks an IOMMU
commit 32ab31e01e2def6f48294d872d9bb42573aae00f upstream. 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. v2: Move check to parse_ioapics_under_ir(), raise log level to KERN_ERR, and add FW_BUG to the log message v3: Skip check if IOMMU doesn't support interrupt remapping and remove existing check that the IOMMU count equals the IOAPIC count Acked-by: Suresh Siddha <suresh.b.siddha@intel.com> Signed-off-by: Seth Forshee <seth.forshee@canonical.com> Acked-by: Yinghai Lu <yinghai@kernel.org> Signed-off-by: Joerg Roedel <joerg.roedel@amd.com> Acked-by: Cho, Yu-Chen <acho@suse.com> Signed-off-by: Greg Kroah-Hartman <gregkh@linuxfoundation.org>
-rw-r--r--drivers/iommu/intel_irq_remapping.c18
1 files changed, 13 insertions, 5 deletions
diff --git a/drivers/iommu/intel_irq_remapping.c b/drivers/iommu/intel_irq_remapping.c
index 6d347064b8b0..55fe60dc3a07 100644
--- a/drivers/iommu/intel_irq_remapping.c
+++ b/drivers/iommu/intel_irq_remapping.c
@@ -736,6 +736,7 @@ int __init parse_ioapics_under_ir(void)
{
struct dmar_drhd_unit *drhd;
int ir_supported = 0;
+ int ioapic_idx;
for_each_drhd_unit(drhd) {
struct intel_iommu *iommu = drhd->iommu;
@@ -748,13 +749,20 @@ int __init parse_ioapics_under_ir(void)
}
}
- if (ir_supported && ir_ioapic_num != nr_ioapics) {
- printk(KERN_WARNING
- "Not all IO-APIC's listed under remapping hardware\n");
- return -1;
+ if (!ir_supported)
+ return 0;
+
+ 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_err(FW_BUG "ioapic %d has no mapping iommu, "
+ "interrupt remapping will be disabled\n",
+ ioapic_id);
+ return -1;
+ }
}
- return ir_supported;
+ return 1;
}
int __init ir_dev_scope_init(void)