Bug#604096: Bug#601341: Bug#602418: #601341, #602418 and #604096 seem to be duplicates

[Konrad Rzeszutek Wilk <konrad.wilk@oracle.com>]

> Thanks. S since the Debian kernel has has DRM/TTM from 2.6.33 I assume I
> want the NEEDS_IOREMAP (95518271) version.
> 
> I'm about to try my backport of devel/ttm.pci-api-v2 which contains:
>         drm/ttm: Add ttm_tt_free_page
>         ttm: Introduce a placeholder for DMA (bus) addresses.
>         ttm: Utilize the dma_addr_t array for pages that are to in DMA32 pool.
>         ttm: Expand (*populate) to support an array of DMA addresses.
>         radeon/ttm/PCIe: Use dma_addr if TTM has set it.
>         nouveau/ttm/PCIe: Use dma_addr if TTM has set it.
>         radeon/PCIe: Use the correct index field.
> plus:
>         9551827190db ttm: Set VM_IO only on pages with TTM_MEMTYPE_FLAG_NEEDS_IOREMAP set.
>         c54d5aa10b7a ttm: Change VMA flags if they != to the TTM flags.
>         c07fbfd17e61 fbmem: VM_IO set, but not propagated

Looks good.

>         d541daf6b956 pvops: make pte_flags() go via pvops

I've only hit that on a machine with a P4 Prescott with AGP. On nothing else - so
it might not be required... If you don't have it you just get a bunch of WARN.

> 
> In addition the Debian kernel already contains 
>         25021c9 x86: define arch_vm_get_page_prot to set _PAGE_IOMAP on VM_IO vmas
>         2eb6682 drm: recompute vma->vm_page_prot after changing vm_flags
>         
> "pvops: make pte_flags() go via pvops" was the only bit of the patches
> which were omitted from the Debian kernel (the revert of bcf16b6b4f34)
> which didn't already appear to have been replaced by the other patches
> (ignoring all the AGP stuff) so I figured I may as well give it a go.
> 
> My previous attempt (with all of the above except but "make pte_flags()
> go via pvops") failed because I botched the backport of "radeon/PCIe:
> Use the correct index field." and only fixed one of the wrong indexes.
> FWIW I think that patch should be folded down into the original patch
> for upstreaming.

Yeah, good idea. And also actually put my SOB on them.