Return-Path: Received: (majordomo@vger.kernel.org) by vger.kernel.org via listexpand id S1751067Ab0DIAqv (ORCPT ); Thu, 8 Apr 2010 20:46:51 -0400 Received: from mail.windriver.com ([147.11.1.11]:59209 "EHLO mail.windriver.com" rhost-flags-OK-OK-OK-OK) by vger.kernel.org with ESMTP id S1750743Ab0DIAqu (ORCPT ); Thu, 8 Apr 2010 20:46:50 -0400 From: Liang Li To: linux-kernel@vger.kernel.org Cc: wangchen@cn.fujitsu.com, mingo@elte.hu, tglx@linutronix.de, hpa@zytor.com, yinghai@kernel.org, akpm@linux-foundation.org, jeremy.fitzhardinge@citrix.com, konrad.wilk@oracle.com Subject: [PATCH v3] x86: let 'reservetop' functioning right Date: Fri, 9 Apr 2010 08:43:55 +0800 Message-Id: <1270773835-2689-1-git-send-email-liang.li@windriver.com> X-Mailer: git-send-email 1.6.6 X-OriginalArrivalTime: 09 Apr 2010 00:45:24.0863 (UTC) FILETIME=[F10E98F0:01CAD77D] Sender: linux-kernel-owner@vger.kernel.org List-ID: X-Mailing-List: linux-kernel@vger.kernel.org Content-Length: 3371 Lines: 98 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_reservetop -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: Yinghai Lu Cc: Andrew Morton Acked-by: Jeremy Fitzhardinge Tested-by: Konrad Rzeszutek Wilk --- 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(-) 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..e4ab706 100644 --- a/arch/x86/mm/ioremap.c +++ b/arch/x86/mm/ioremap.c @@ -448,6 +448,21 @@ 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]) + break; + } + + if (i < FIX_BTMAPS_SLOTS) + BUG_ON(1); + + early_ioremap_init(); + return; +} + 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); -- 1.6.6 -- 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/