This is a note to let you know that I've just added the patch titled
irq_remap: disable IRQ remapping if any IOAPIC lacks an IOMMU
to the 3.4-stable tree which can be found at:
http://www.kernel.org/git/?p=linux/kernel/git/stable/stable-queue.git;a=summary
The filename of the patch is:
irq_remap-disable-irq-remapping-if-any-ioapic-lacks-an-iommu.patch
and it can be found in the queue-3.4 subdirectory.
If you, or anyone else, feels it should not be added to the stable tree,
please let <[email protected]> know about it.
>From 32ab31e01e2def6f48294d872d9bb42573aae00f Mon Sep 17 00:00:00 2001
From: Seth Forshee <[email protected]>
Date: Wed, 8 Aug 2012 08:27:03 -0500
Subject: irq_remap: disable IRQ remapping if any IOAPIC lacks an IOMMU
From: Seth Forshee <[email protected]>
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 <[email protected]>
Signed-off-by: Seth Forshee <[email protected]>
Acked-by: Yinghai Lu <[email protected]>
Signed-off-by: Joerg Roedel <[email protected]>
Acked-by: Cho, Yu-Chen <[email protected]>
Signed-off-by: Greg Kroah-Hartman <[email protected]>
---
drivers/iommu/intr_remapping.c | 18 +++++++++++++-----
1 file changed, 13 insertions(+), 5 deletions(-)
--- a/drivers/iommu/intr_remapping.c
+++ b/drivers/iommu/intr_remapping.c
@@ -752,6 +752,7 @@ 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;
@@ -764,13 +765,20 @@ 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)
Patches currently in stable-queue which might be from
[email protected] are
queue-3.4/irq_remap-disable-irq-remapping-if-any-ioapic-lacks-an-iommu.patch
--
To unsubscribe from this list: send the line "unsubscribe stable" in
the body of a message to [email protected]
More majordomo info at http://vger.kernel.org/majordomo-info.html
