Messages in this thread | | | Date | Fri, 13 Nov 2009 10:56:35 -0800 | From | Yinghai Lu <> | Subject | Re: [RFC -tip] x86,io-apic: Do not map IO-APIC direct registers twice |
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Cyrill Gorcunov wrote: > On Thu, Nov 12, 2009 at 03:22:55PM -0800, Yinghai Lu wrote: >> Cyrill Gorcunov wrote: >>> Please review, I didn't manage to test (emulate actually since I don't >>> > ... > > First of all -- thanks a lot for review Yinghai! > >>> Also insert_resourse will not fail anymore on 1K aligned io-apics. >> looks that we don't need that ... >> not io_apic_base already have that + &. left problems are >> 1. display. >> 2. insert resource problem. >> >> YH >> >> diff --git a/arch/x86/kernel/apic/io_apic.c b/arch/x86/kernel/apic/io_apic.c >> index 90e8bc5..6a9379b 100644 >> --- a/arch/x86/kernel/apic/io_apic.c >> +++ b/arch/x86/kernel/apic/io_apic.c >> @@ -4140,11 +4140,13 @@ fake_ioapic_page: >> set_fixmap_nocache(idx, ioapic_phys); >> apic_printk(APIC_VERBOSE, >> "mapped IOAPIC to %08lx (%08lx)\n", >> - __fix_to_virt(idx), ioapic_phys); >> + __fix_to_virt(idx) + (ioapic_phys & ~PAGE_MASK), > > Don't understand, why? What is wrong with physical address, > could you elaborate please?
ioapic_phys could be 1k aligned, but __fix_to_virt(idx) will always return 4k aligned.
> >> + ioapic_phys); >> idx++; >> >> + /* spec says size is 1024 */ > > Hmm, MP says nothing about size of IO-APIC direct registers > cound and as a result -- the size of MMIO. It will (and > is) differ between IO-APIC versions. An example -- IO-APIC EOI register > which 82489DX just dont have at all. At moment (ICH-10) the lenght is 68 > bytes so you may note the comment in the former patch that we "hope" such > a size will be enough for quite a long time to cover all direct register > space an IO-APIC provides (though to be precise from this 68 bytes only > index,data,eoi registers specified). > >> ioapic_res->start = ioapic_phys; >> - ioapic_res->end = ioapic_phys + PAGE_SIZE-1; >> + ioapic_res->end = ioapic_phys + (1<<10) - 1; >> ioapic_res++; >> } >> } >> > > I think I've compicated the patch/idea too much indeed :) > Since we have fixmap for all io_apics build time reserved > even if some io-apic is 1K aligned we still may use new > fixmap index. So only issue remains -- resource allocation. > Here is an updated patch. Please review.
2. print out ...?
YH
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