Messages in this thread | ![/](/images/icornerl.gif) | | Subject | Re: [PATCH] x86/PCI: never allocate PCI MMIO resources below BIOS_END | From | "H. Peter Anvin" <> | Date | Mon, 26 Apr 2010 19:02:49 -0700 |
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The 1 MB range is only one case of a prereserved space. It's special only in the sense that it is *always* reserved, even if the map doesn't mark it as such. Fixed (or SMM-used) resources in reserved space above 1 MB are exactly the same issue.
"Jesse Barnes" <jbarnes@virtuousgeek.org> wrote:
>On Mon, 26 Apr 2010 18:27:27 -0700 (PDT) >Linus Torvalds <torvalds@linux-foundation.org> wrote: > >> >> >> On Mon, 26 Apr 2010, Jesse Barnes wrote: >> > >> > Glad we agree. As I said (and echoing Bjorn), I think it would be best >> > to reserve this space in a way that doesn't just use IORESOURCE_BUSY. >> > We want and need to do allocations from the special region, so we >> > should mark it as such. >> >> I think Bjorn's patch to pcibios_align_resource() is really good and >> clever, and I think it should take care of the need for IORESOURCE_BUSY, >> no? We do want to let devices that are _already_ allocated there insert >> their resources, it's just that we never want to allocate new ones in the >> low 1M region. >> >> Do we actually have a regression left with Bjorn's patch? > >No, I think we're covered. But it sounded like Peter was also >concerned about making new allocations from the 1M space, which would >mean we'd need something other than the IORESOURCE_BUSY bit. But maybe >Bjorn's patch plus simply removing the IORESOURCE_BUSY line is >sufficient for that. The downside there is that it doesn't clearly >communicate the special nature of the 1M region. > >-- >Jesse Barnes, Intel Open Source Technology Center
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