[PATCH 0/5] Fix Intel IRQ remapping initialization order

From: Joerg Roedel
Date: Mon Dec 15 2014 - 10:14:41 EST


Hi,

here is a patch-set against tip/x86/apic to fix an initialization order
problem with the IRQ remapping code. The problem is in the ordering of
the irq_remapping_prepare and irq_remapping_supported functions.

Currently the call-order is irq_remapping_prepare ->
irq_remapping_supported, so that 'prepare' can succeed but 'supported'
fails, so that interrupt remapping gets initialized but not enabled.
This causes a broken interrupt setup on affected systems (machines with
an Intel IOMMU without, or broken, IRQ remapping support). The result
are lost interrupts and a non-bootable system.

Both functions do checks whether IRQ remapping can be enabled on the
machine. The reason for this is that some checks rely on
dmar_table_init() and thus have to be done in irq_remapping_prepare().

This patch-set moves all these checks into the irq_remapping_prepare()
path with the right ordering and removes the irq_remapping_supported()
function and its call-backs. This fixes the initializion order problem
and simplifies the exported API from the IOMMU code.

Please review.

Thanks,

Joerg

Joerg Roedel (5):
iommu/vt-d: Allocate IRQ remapping data structures only for all IOMMUs
iommu/vt-d: Don't check for ecap_ir_support in
intel_irq_remapping_supported
iommu/vt-d: Move supported-checks to intel_prepare_irq_remapping()
iommu/amd: Check for irq-remap support amd_iommu_prepare()
iommu, x86, apic: Remove irq_remapping_supported()

arch/x86/kernel/apic/apic.c | 5 ---
drivers/iommu/amd_iommu.c | 1 -
drivers/iommu/amd_iommu_init.c | 8 ++---
drivers/iommu/amd_iommu_proto.h | 1 -
drivers/iommu/intel_irq_remapping.c | 62 +++++++++++++++++--------------------
drivers/iommu/irq_remapping.c | 11 -------
drivers/iommu/irq_remapping.h | 3 --
7 files changed, 31 insertions(+), 60 deletions(-)

--
1.9.1

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