Return-Path: Received: (majordomo@vger.kernel.org) by vger.kernel.org via listexpand id S934076Ab0D3TZ4 (ORCPT ); Fri, 30 Apr 2010 15:25:56 -0400 Received: from mail.windriver.com ([147.11.1.11]:56959 "EHLO mail.windriver.com" rhost-flags-OK-OK-OK-OK) by vger.kernel.org with ESMTP id S1759536Ab0D3TZm (ORCPT ); Fri, 30 Apr 2010 15:25:42 -0400 Date: Fri, 30 Apr 2010 23:34:42 +0800 From: Liang Li To: Ingo Molnar Cc: linux-kernel@vger.kernel.org, akpm@linux-foundation.org, wangchen@cn.fujitsu.com, tglx@linutronix.de, hpa@zytor.com, yinghai@kernel.org, jeremy.fitzhardinge@citrix.com, konrad.wilk@oracle.com Subject: Re: [v3 PATCH] x86: let 'reservetop' functioning right Message-ID: <20100430153442.GA18064@localhost> Reply-To: Liang Li References: <1272621711-8683-1-git-send-email-liang.li@windriver.com> <20100430102205.GE14202@elte.hu> MIME-Version: 1.0 Content-Type: text/plain; charset=us-ascii Content-Disposition: inline In-Reply-To: <20100430102205.GE14202@elte.hu> User-Agent: Mutt/1.5.20 (2009-08-17) X-OriginalArrivalTime: 30 Apr 2010 15:36:38.0039 (UTC) FILETIME=[EC3A7A70:01CAE87A] Sender: linux-kernel-owner@vger.kernel.org List-ID: X-Mailing-List: linux-kernel@vger.kernel.org Content-Length: 6159 Lines: 164 On Fri, Apr 30, 2010 at 12:22:05PM +0200, Ingo Molnar wrote: > > * Liang Li wrote: > > > When specify 'reservetop=0xbadc0de' kernel parameter, the kernel will > > stop booting due to a early_ioremap bug that relate to commit 8827247ff. > > > > The root cause of boot failure problem is the value of 'slot_virt[i]' > > was initialized in setup_arch->early_ioremap_init. But later in > > setup_arch, the function 'parse_early_param' will modify 'FIXADDR_TOP' > > when 'reservetop=0xbadc0de' being specified. > > > > The simplest fix might be use __fix_to_virt(idx0) to get updated value > > of 'FIXADDR_TOP' in '__early_ioremap' instead of reference old value > > from slot_virt[slot] directly. > > > > Changelog since v0: > > > > -v1: When reservetop being handled then FIXADDR_TOP get adjusted, Hence > > check prev_map then re-initialize slot_virt and PMD based on new > > FIXADDR_TOP. > > > > -v2: place fixup_early_ioremap hence call early_ioremap_init in > > reserve_top_address to re-initialize slot_virt and corresponding PMD > > when parse_reservertop > > > > -v3: move fixup_early_ioremap out of reserve_top_address to make sure > > other clients of reserve_top_address like xen/lguest won't broken > > > > Signed-off-by: Liang Li > > Cc: Wang Chen > > Cc: Ingo Molnar > > Cc: Thomas Gleixner > > Cc: "H. Peter Anvin" > > Cc: Andrew Morton > > Acked-by: Yinghai Lu > > Acked-by: Jeremy Fitzhardinge > > Tested-by: Konrad Rzeszutek Wilk > > --- > > Hi all, > > > > Just resend the patch according to Ingo's demand. > > Thanks. > > > > arch/x86/include/asm/io.h | 1 + > > arch/x86/mm/ioremap.c | 15 +++++++++++++++ > > arch/x86/mm/pgtable_32.c | 1 + > > 3 files changed, 17 insertions(+), 0 deletions(-) > > Applied, thanks. Note, i cleaned up the fixup_early_ioremap() code (and > changed the BUG_ON to WARN_ON - we dont want to crash the box), mind double > checking the end result? See the commit below. Checked. It is fine. Thanks. :) Regards, -Liang Li > > Ingo > > -----------------> > >From e67a807f3d9a82fa91817871f1c0e2e04da993b8 Mon Sep 17 00:00:00 2001 > From: Liang Li > Date: Fri, 30 Apr 2010 18:01:51 +0800 > Subject: [PATCH] x86: Fix 'reservetop=' functionality > > When specifying the 'reservetop=0xbadc0de' kernel parameter, > the kernel will stop booting due to a early_ioremap bug that > relates to commit 8827247ff. > > The root cause of boot failure problem is the value of > 'slot_virt[i]' was initialized in setup_arch->early_ioremap_init(). > But later in setup_arch, the function 'parse_early_param' will > modify 'FIXADDR_TOP' when 'reservetop=0xbadc0de' being specified. > > The simplest fix might be use __fix_to_virt(idx0) to get updated > value of 'FIXADDR_TOP' in '__early_ioremap' instead of reference > old value from slot_virt[slot] directly. > > Changelog since v0: > > -v1: When reservetop being handled then FIXADDR_TOP get > adjusted, Hence check prev_map then re-initialize slot_virt and > PMD based on new FIXADDR_TOP. > > -v2: place fixup_early_ioremap hence call early_ioremap_init in > reserve_top_address to re-initialize slot_virt and > corresponding PMD when parse_reservertop > > -v3: move fixup_early_ioremap out of reserve_top_address to make > sure other clients of reserve_top_address like xen/lguest won't > broken > > Signed-off-by: Liang Li > Tested-by: Konrad Rzeszutek Wilk > Acked-by: Yinghai Lu > Acked-by: Jeremy Fitzhardinge > Cc: Wang Chen > Cc: "H. Peter Anvin" > Cc: Andrew Morton > LKML-Reference: <1272621711-8683-1-git-send-email-liang.li@windriver.com> > [ fixed three small cleanliness details in fixup_early_ioremap() ] > Signed-off-by: Ingo Molnar > --- > arch/x86/include/asm/io.h | 1 + > arch/x86/mm/ioremap.c | 14 ++++++++++++++ > arch/x86/mm/pgtable_32.c | 1 + > 3 files changed, 16 insertions(+), 0 deletions(-) > > diff --git a/arch/x86/include/asm/io.h b/arch/x86/include/asm/io.h > index a1dcfa3..30a3e97 100644 > --- a/arch/x86/include/asm/io.h > +++ b/arch/x86/include/asm/io.h > @@ -347,6 +347,7 @@ extern void __iomem *early_ioremap(resource_size_t phys_addr, > extern void __iomem *early_memremap(resource_size_t phys_addr, > unsigned long size); > extern void early_iounmap(void __iomem *addr, unsigned long size); > +extern void fixup_early_ioremap(void); > > #define IO_SPACE_LIMIT 0xffff > > diff --git a/arch/x86/mm/ioremap.c b/arch/x86/mm/ioremap.c > index 5eb1ba7..12e4d2d 100644 > --- a/arch/x86/mm/ioremap.c > +++ b/arch/x86/mm/ioremap.c > @@ -448,6 +448,20 @@ static inline void __init early_clear_fixmap(enum fixed_addresses idx) > static void __iomem *prev_map[FIX_BTMAPS_SLOTS] __initdata; > static unsigned long prev_size[FIX_BTMAPS_SLOTS] __initdata; > > +void __init fixup_early_ioremap(void) > +{ > + int i; > + > + for (i = 0; i < FIX_BTMAPS_SLOTS; i++) { > + if (prev_map[i]) { > + WARN_ON(1); > + break; > + } > + } > + > + early_ioremap_init(); > +} > + > static int __init check_early_ioremap_leak(void) > { > int count = 0; > diff --git a/arch/x86/mm/pgtable_32.c b/arch/x86/mm/pgtable_32.c > index 1a8faf0..26eadaa 100644 > --- a/arch/x86/mm/pgtable_32.c > +++ b/arch/x86/mm/pgtable_32.c > @@ -128,6 +128,7 @@ static int __init parse_reservetop(char *arg) > > address = memparse(arg, &arg); > reserve_top_address(address); > + fixup_early_ioremap(); > return 0; > } > early_param("reservetop", parse_reservetop); -- 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/