Re: [PATCH] x86: amd_iommu: fix nasty bug that caused ILLEGAL_DEVICE_TABLE_ENTRY errors

Joerg Roedel
2008-10-16T15:00:11Z

Argh. Very stupid bug. This explains why it worked on my system with 1G
RAM and failed on some others with more. Thanks for the fix. I also CC
stable@kernel.org.

On Thu, Oct 16, 2008 at 04:27:36PM +0200, Andreas Herrmann wrote:
> We are on 64-bit so better use u64 instead of u32 to deal with
> addresses:
>
> static void __init iommu_set_device_table(struct amd_iommu *iommu)
> {
> u64 entry;
> ...
> entry = virt_to_phys(amd_iommu_dev_table);
> ...
>
> (I am wondering why gcc 4.2.x did not warn about the assignment
> between u32 and unsigned long.)
>
> Cc: iommu@lists.linux-foundation.org
> Cc: Joerg Roedel <joerg.roedel@amd.com>
> Signed-off-by: Andreas Herrmann <andreas.herrmann3@amd.com>

Signed-off-by: Joerg Roedel <joerg.roedel@amd.com>

>
> ---
> arch/x86/kernel/amd_iommu_init.c | 2 +-
> 1 files changed, 1 insertions(+), 1 deletions(-)
>
> Patch is against today's tip/x86/amd-iommu
> Joerg is on vacation. That is why I post this patch
> directly to you.
>
> Regards,
>
> Andreas
>
> diff --git a/arch/x86/kernel/amd_iommu_init.c b/arch/x86/kernel/amd_iommu_init.c
> index a69cc0f..bccd0ef 100644
> --- a/arch/x86/kernel/amd_iommu_init.c
> +++ b/arch/x86/kernel/amd_iommu_init.c
> @@ -210,7 +210,7 @@ static void __init iommu_set_exclusion_range(struct amd_iommu *iommu)
> /* Programs the physical address of the device table into the IOMMU hardware */
> static void __init iommu_set_device_table(struct amd_iommu *iommu)
> {
> - u32 entry;
> + u64 entry;
>
> BUG_ON(iommu->mmio_base == NULL);
>
> --
> 1.6.0.2
>
>
>
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