From mboxrd@z Thu Jan 1 00:00:00 1970 Return-Path: Received: (majordomo@vger.kernel.org) by vger.kernel.org via listexpand id S932129AbZKMTS0 (ORCPT ); Fri, 13 Nov 2009 14:18:26 -0500 Received: (majordomo@vger.kernel.org) by vger.kernel.org id S1757039AbZKMTSV (ORCPT ); Fri, 13 Nov 2009 14:18:21 -0500 Received: from hera.kernel.org ([140.211.167.34]:59240 "EHLO hera.kernel.org" rhost-flags-OK-OK-OK-OK) by vger.kernel.org with ESMTP id S1756927AbZKMTSU (ORCPT ); Fri, 13 Nov 2009 14:18:20 -0500 Message-ID: <4AFDB0AC.10302@kernel.org> Date: Fri, 13 Nov 2009 11:17:00 -0800 From: Yinghai Lu User-Agent: Thunderbird 2.0.0.23 (X11/20090817) MIME-Version: 1.0 To: Cyrill Gorcunov CC: Ingo Molnar , "Maciej W. Rozycki" , x86team , LKML Subject: Re: [RFC -tip] x86,io-apic: Do not map IO-APIC direct registers twice References: <20091112204852.GB5728@lenovo> <4AFC98CF.5030408@kernel.org> <20091113175057.GA5695@lenovo> <4AFDABE3.2050006@kernel.org> <20091113190955.GC5695@lenovo> In-Reply-To: <20091113190955.GC5695@lenovo> Content-Type: text/plain; charset=ISO-8859-1 Content-Transfer-Encoding: 7bit Sender: linux-kernel-owner@vger.kernel.org List-ID: X-Mailing-List: linux-kernel@vger.kernel.org Cyrill Gorcunov wrote: > On Fri, Nov 13, 2009 at 10:56:35AM -0800, Yinghai Lu wrote: >> 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. > > yeah, I just misread your patch, I thought you've changed second argument, > sorry. OK, I see what you mean, good catch, thanks! > >>>> + 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 ...? > > Print out what? Not sure I understand you right. Perhaps you mean > to check insert_resourse results? apic_printk(APIC_VERBOSE, "mapped IOAPIC to %08lx (%08lx)\n", - __fix_to_virt(idx), ioapic_phys); + __fix_to_virt(idx) + (ioapic_phys & ~PAGE_MASK), YH