Return-Path: Received: (majordomo@vger.kernel.org) by vger.kernel.org via listexpand id S1757873AbZFJBc6 (ORCPT ); Tue, 9 Jun 2009 21:32:58 -0400 Received: (majordomo@vger.kernel.org) by vger.kernel.org id S1753383AbZFJBcw (ORCPT ); Tue, 9 Jun 2009 21:32:52 -0400 Received: from mga10.intel.com ([192.55.52.92]:60035 "EHLO fmsmga102.fm.intel.com" rhost-flags-OK-OK-OK-FAIL) by vger.kernel.org with ESMTP id S1754058AbZFJBcv (ORCPT ); Tue, 9 Jun 2009 21:32:51 -0400 X-ExtLoop1: 1 X-IronPort-AV: E=Sophos;i="4.41,336,1241420400"; d="scan'208,223";a="464981767" Message-ID: <4A2F0D45.2040602@linux.intel.com> Date: Tue, 09 Jun 2009 18:32:53 -0700 From: "H. Peter Anvin" Organization: Intel Open Source Technology Center User-Agent: Thunderbird 2.0.0.21 (X11/20090320) MIME-Version: 1.0 To: Matthew Wilcox , Jesse Barnes , Martin Mares , LKML , linux-pci@vger.kernel.org, the arch/x86 maintainers , David Woodhouse , linux-arch@vger.kernel.org Subject: RFC: x86: cap iomem_resource to addressable physical memory Content-Type: multipart/mixed; boundary="------------080009000602050700000706" Sender: linux-kernel-owner@vger.kernel.org List-ID: X-Mailing-List: linux-kernel@vger.kernel.org Content-Length: 2446 Lines: 69 This is a multi-part message in MIME format. --------------080009000602050700000706 Content-Type: text/plain; charset=UTF-8 Content-Transfer-Encoding: 7bit x86 cannot generate full 64-bit addresses; this patch clamps iomem addresses to the accessible range. I wanted to post it for review before committing it, however; comments would be appreciated, especially of the kind "this is done too early/too late/in the wrong place/incorrectly". -hpa --------------080009000602050700000706 Content-Type: text/x-patch; name="0001-x86-cap-iomem_resource-to-addressable-physical-memo.patch" Content-Transfer-Encoding: 7bit Content-Disposition: inline; filename*0="0001-x86-cap-iomem_resource-to-addressable-physical-memo.pat"; filename*1="ch" >From 8dd8d59d1d1586b350401d6a5f8c7a9e30f142d4 Mon Sep 17 00:00:00 2001 From: H. Peter Anvin Date: Tue, 9 Jun 2009 18:20:39 -0700 Subject: [PATCH] x86: cap iomem_resource to addressable physical memory iomem_resource is by default initialized to -1, which means 64 bits of physical address space if 64-bit resources are enabled. However, x86 CPUs cannot address 64 bits of physical address space. Thus, we want to cap the physical address space to what the union of all CPU can actually address. Without this patch, we may end up assigning inaccessible values to uninitialized 64-bit PCI memory resources. Signed-off-by: H. Peter Anvin Cc: Matthew Wilcox Cc: Jesse Barnes Cc: Martin Mares Cc: stable@kernel.org --- arch/x86/kernel/cpu/common.c | 3 +++ 1 files changed, 3 insertions(+), 0 deletions(-) diff --git a/arch/x86/kernel/cpu/common.c b/arch/x86/kernel/cpu/common.c index 77848d9..de8a49c 100644 --- a/arch/x86/kernel/cpu/common.c +++ b/arch/x86/kernel/cpu/common.c @@ -839,6 +839,9 @@ static void __cpuinit identify_cpu(struct cpuinfo_x86 *c) #if defined(CONFIG_NUMA) && defined(CONFIG_X86_64) numa_add_cpu(smp_processor_id()); #endif + + /* Cap the iomem address space to what is addressable on all CPUs */ + iomem_resource.end &= (1ULL << c->x86_phys_bits) - 1; } #ifdef CONFIG_X86_64 -- 1.6.0.6 --------------080009000602050700000706-- -- 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/