Return-Path: Received: (majordomo@vger.kernel.org) by vger.kernel.org via listexpand id S1753610Ab0DMVCd (ORCPT ); Tue, 13 Apr 2010 17:02:33 -0400 Received: from g4t0014.houston.hp.com ([15.201.24.17]:7066 "EHLO g4t0014.houston.hp.com" rhost-flags-OK-OK-OK-OK) by vger.kernel.org with ESMTP id S1752674Ab0DMVCb (ORCPT ); Tue, 13 Apr 2010 17:02:31 -0400 Subject: Re: [PATCH -v2 1/2] x86: Reserve [0xa0000, 0x100000] in e820 map From: Bjorn Helgaas To: Yinghai 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 In-Reply-To: <4BC39F67.4090407@oracle.com> 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> Content-Type: text/plain Date: Tue, 13 Apr 2010 15:02:07 -0600 Message-Id: <1271192527.6035.44.camel@dc7800.home> Mime-Version: 1.0 X-Mailer: Evolution 2.22.3.1 Content-Transfer-Encoding: 7bit Sender: linux-kernel-owner@vger.kernel.org List-ID: X-Mailing-List: linux-kernel@vger.kernel.org Content-Length: 4231 Lines: 116 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? > 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? I don't feel like I know enough about x86 architecture to ack this patch, but I don't object to it. Bjorn > sanitize_e820_map(e820.map, ARRAY_SIZE(e820.map), &e820.nr_map); > } > > @@ -1052,20 +1052,3 @@ void __init setup_arch(char **cmdline_p) > > mcheck_init(); > } > - > -#ifdef CONFIG_X86_32 > - > -static struct resource video_ram_resource = { > - .name = "Video RAM area", > - .start = 0xa0000, > - .end = 0xbffff, > - .flags = IORESOURCE_BUSY | IORESOURCE_MEM > -}; > - > -void __init i386_reserve_resources(void) > -{ > - request_resource(&iomem_resource, &video_ram_resource); > - reserve_standard_io_resources(); > -} > - > -#endif /* CONFIG_X86_32 */ -- To unsubscribe from this list: send the line "unsubscribe linux-kernel" in the body of a message to majordomo@vger.kernel.org More majordomo info at http://vger.kernel.org/majordomo-info.html Please read the FAQ at http://www.tux.org/lkml/