Prev: [PATCH 3/3] x86/amd-iommu: Fall back to GART if initialization fails
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From: Joerg Roedel on 1 Jun 2010 05:10
When request_mem_region fails the error path tries to
disable the IOMMUs. This accesses the mmio-region which was
not allocated leading to a kernel crash. This patch fixes
the issue.

Cc: stable(a)kernel.org
Signed-off-by: Joerg Roedel <joerg.roedel(a)amd.com>
---
arch/x86/kernel/amd_iommu_init.c | 11 ++++++++---
1 files changed, 8 insertions(+), 3 deletions(-)

diff --git a/arch/x86/kernel/amd_iommu_init.c b/arch/x86/kernel/amd_iommu_init.c
index 3bacb4d..1405346 100644
--- a/arch/x86/kernel/amd_iommu_init.c
+++ b/arch/x86/kernel/amd_iommu_init.c
@@ -287,8 +287,12 @@ static u8 * __init iommu_map_mmio_space(u64 address)
{
u8 *ret;

- if (!request_mem_region(address, MMIO_REGION_LENGTH, "amd_iommu"))
+ if (!request_mem_region(address, MMIO_REGION_LENGTH, "amd_iommu")) {
+ pr_err("AMD-Vi: Can not reserve memory region %llx for mmio\n",
+ address);
+ pr_err("AMD-Vi: This is a BIOS bug. Please contact your hardware vendor\n");
return NULL;
+ }

ret = ioremap_nocache(address, MMIO_REGION_LENGTH);
if (ret != NULL)
@@ -1314,7 +1318,7 @@ static int __init amd_iommu_init(void)
ret = amd_iommu_init_dma_ops();

if (ret)
- goto free;
+ goto free_disable;

amd_iommu_init_api();

@@ -1332,9 +1336,10 @@ static int __init amd_iommu_init(void)
out:
return ret;

-free:
+free_disable:
disable_iommus();

+free:
amd_iommu_uninit_devices();

free_pages((unsigned long)amd_iommu_pd_alloc_bitmap,
--
1.7.1


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Prev: [PATCH 3/3] x86/amd-iommu: Fall back to GART if initialization fails
Next: [tip:sched/urgent] sched, trace: Fix sched_switch() prev_state argument