Messages in this thread | | | Subject | Re: [git pull] drm patches for 2.6.27-rc1 | From | Keith Packard <> | Date | Sat, 18 Oct 2008 17:38:11 -0700 |
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On Sun, 2008-10-19 at 00:32 +0200, Ingo Molnar wrote:
> the _real_ remapping in a graphics aperture happens on the GPU level > anyway, you manage an in-RAM GPU pagetable that just works like an > IOMMU, correct?
Yes, a one-level linear MMU which uses BIOS-reserved memory.
So, at least for a prototype, on 64-bit we can just use ioremap_wc and hold the mapping while the driver is open? Is there any huge benefit to using the kernel mapping?
> so on 32-bit we have the INVLPG TLB overhead and preemption restrictions > - but we knew that. We'd have to allow atomic_kmap() on non-highmem as > well but that's fair.
Yes, the non-highmem case is currently in fairly bad shape.
> Mind sending patches for this? :-)
I've got Venki lined up to do this work for me; once we're happy enough with the API. In particular, the non-highmem 32-bit case seems a bit tricky.
Also, does anyone have a better set of names for this stuff? io_reserve_pci_mapping seems fairly ugly to me.
-- keith.packard@intel.com [unhandled content-type:application/pgp-signature] | |