Re: [PATCH] Enable GART-IOMMU only after setting up protection methods

[Yinghai Lu]

On Wed, Apr 8, 2009 at 2:08 PM, Mark Langsdorf <mark.langsdorf@xxxxxxx> wrote:
> The current code to set up the GART as an IOMMU enables GART
> translations before it removes the aperture from the kernel
> memory map, sets the GART PTEs to UC, sets up the guard and
> scratch pages, or does a wbinvd().  This leaves the possibility
> of cache aliasing open and can cause system crashes.
>
> Re-order the code and add tlbflush so as to enable the
> GART translations only after all safeguards are in place and
> the tlb has been flushed.
>
> AMD has tested this patch and seen no adverse effects.

how about system with AGP card and more than 4g system RAM?

also it seems flush_gart() in init_k8_gatt() and gart_iommu_init()
could be removed?

YH
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