From mboxrd@z Thu Jan 1 00:00:00 1970 Return-Path: Received: (majordomo@vger.kernel.org) by vger.kernel.org via listexpand id S1753943Ab0DMVML (ORCPT ); Tue, 13 Apr 2010 17:12:11 -0400 Received: from rcsinet11.oracle.com ([148.87.113.123]:23587 "EHLO rcsinet11.oracle.com" rhost-flags-OK-OK-OK-OK) by vger.kernel.org with ESMTP id S1753492Ab0DMVMJ (ORCPT ); Tue, 13 Apr 2010 17:12:09 -0400 Message-ID: <4BC4DD45.8090804@oracle.com> Date: Tue, 13 Apr 2010 14:08:21 -0700 From: Yinghai User-Agent: Mozilla/5.0 (X11; U; Linux x86_64; en-US; rv:1.9.1.9) Gecko/20100317 SUSE/3.0.4-1.1.1 Thunderbird/3.0.4 MIME-Version: 1.0 To: Bjorn Helgaas CC: "H. Peter Anvin" , Thomas Gleixner , Ingo Molnar , Andy Isaacson , guenter.roeck@ericsson.com, Linus Torvalds , "linux-pci@vger.kernel.org" , "x86@kernel.org" , "linux-kernel@vger.kernel.org" , Thomas Renninger Subject: Re: [PATCH -v2 1/2] x86: Reserve [0xa0000, 0x100000] in e820 map References: <20100409223532.GC11130@hexapodia.org> <4BBFB1D8.6090802@oracle.com> <20100410000030.GE11130@hexapodia.org> <4BBFD019.9040405@oracle.com> <20100410014308.GG11130@hexapodia.org> <4BBFD8EF.6020108@oracle.com> <20100410015711.GH11130@hexapodia.org> <4BBFE66C.2040603@oracle.com> <20100412185416.GA19959@hexapodia.org> <4BC375D9.4040503@oracle.com> <20100412200224.GO11130@hexapodia.org> <4BC39F67.4090407@oracle.com> <1271192527.6035.44.camel@dc7800.home> In-Reply-To: <1271192527.6035.44.camel@dc7800.home> Content-Type: text/plain; charset=ISO-8859-1 Content-Transfer-Encoding: 7bit X-Source-IP: acsmt355.oracle.com [141.146.40.155] X-Auth-Type: Internal IP X-CT-RefId: str=0001.0A090206.4BC4DE01.00C5:SCFMA4539814,ss=1,fgs=0 Sender: linux-kernel-owner@vger.kernel.org List-ID: X-Mailing-List: linux-kernel@vger.kernel.org On 04/13/2010 02:02 PM, Bjorn Helgaas wrote: > On Mon, 2010-04-12 at 15:32 -0700, Yinghai wrote: >> Update e820 at first, and later put them resource tree. >> >> -V2: reserved that early, no PCI BAR can use it, force them to get new one >> >> Signed-off-by: Yinghai Lu >> Cc: Guenter Roeck >> Cc: Andy Isaacson >> Tested-by: Andy Isaacson >> Cc: Bjorn Helgaas >> Acked-by: H. Peter Anvin >> >> --- >> arch/x86/include/asm/setup.h | 1 - >> arch/x86/kernel/head32.c | 1 - >> arch/x86/kernel/setup.c | 19 +------------------ >> 3 files changed, 1 insertion(+), 20 deletions(-) >> >> Index: linux-2.6/arch/x86/include/asm/setup.h >> =================================================================== >> --- linux-2.6.orig/arch/x86/include/asm/setup.h >> +++ linux-2.6/arch/x86/include/asm/setup.h >> @@ -44,7 +44,6 @@ static inline void visws_early_detect(vo >> extern unsigned long saved_video_mode; >> >> extern void reserve_standard_io_resources(void); >> -extern void i386_reserve_resources(void); >> extern void setup_default_timer_irq(void); >> >> #ifdef CONFIG_X86_MRST >> Index: linux-2.6/arch/x86/kernel/head32.c >> =================================================================== >> --- linux-2.6.orig/arch/x86/kernel/head32.c >> +++ linux-2.6/arch/x86/kernel/head32.c >> @@ -22,7 +22,6 @@ static void __init i386_default_early_se >> { >> /* Initilize 32bit specific setup functions */ >> x86_init.resources.probe_roms = probe_roms; >> - x86_init.resources.reserve_resources = i386_reserve_resources; >> x86_init.mpparse.setup_ioapic_ids = setup_ioapic_ids_from_mpc; >> >> reserve_ebda_region(); > > I like the fact that this makes x86_64 and x86_32 handle the legacy VGA > framebuffer the same way. > > What about arch/x86/kernel/probe_roms_32.c? That deals with expansion > ROMs in the 0xc0000-0xfffff range, including the VGA ROM. We only build > it for x86_32; is that correct, or should it be unified, too? looks that file could be dropped. We already put 0xa0000 - 0x100000 to reserved region. > >> Index: linux-2.6/arch/x86/kernel/setup.c >> =================================================================== >> --- linux-2.6.orig/arch/x86/kernel/setup.c >> +++ linux-2.6/arch/x86/kernel/setup.c >> @@ -693,7 +693,7 @@ static void __init trim_bios_range(void) >> * area (640->1Mb) as ram even though it is not. >> * take them out. >> */ >> - e820_remove_range(BIOS_BEGIN, BIOS_END - BIOS_BEGIN, E820_RAM, 1); >> + e820_add_region(BIOS_BEGIN, BIOS_END - BIOS_BEGIN, E820_RESERVED); > > Let me see if I understand this. On Andy's machine, the e820 map > doesn't mention the 0xa0000-0xf0000 range at all: > > BIOS-e820: 0000000000000000 - 000000000009ec00 (usable) > BIOS-e820: 00000000000f0000 - 0000000000100000 (reserved) > > e820_reserve_resources() inserts resources for some e820 entries (those > that start before 0x100000 or are not E820_RESERVED). Andy's machine > didn't supply any e820 entries that cover 0xa0000-0xf0000, so we didn't > insert any resources there, and PCI assumed that range was available. > > This patch adds the [0xa0000-0x100000] range as E820_RESERVED. Since > that starts below 0x100000, e820_reserve_resources() will insert a > corresponding resource marked as BUSY. > > Then the second patch prevents PCI from using that BUSY region to > allocate resources to devices. > > Is my understanding correct? yes. > > I don't feel like I know enough about x86 architecture to ack this > patch, but I don't object to it. Thanks Yinghai