From mboxrd@z Thu Jan 1 00:00:00 1970 Return-Path: Received: (majordomo@vger.kernel.org) by vger.kernel.org via listexpand id S1759941AbZAaDMz (ORCPT ); Fri, 30 Jan 2009 22:12:55 -0500 Received: (majordomo@vger.kernel.org) by vger.kernel.org id S1757494AbZAaCrx (ORCPT ); Fri, 30 Jan 2009 21:47:53 -0500 Received: from kroah.org ([198.145.64.141]:55650 "EHLO coco.kroah.org" rhost-flags-OK-OK-OK-FAIL) by vger.kernel.org with ESMTP id S1756491AbZAaCrq (ORCPT ); Fri, 30 Jan 2009 21:47:46 -0500 Date: Fri, 30 Jan 2009 18:44:53 -0800 From: Greg KH To: linux-kernel@vger.kernel.org, stable@kernel.org, greg@kroah.com Cc: Justin Forbes , Zwane Mwaikambo , "Theodore Ts'o" , Randy Dunlap , Dave Jones , Chuck Wolber , Chris Wedgwood , Michael Krufky , Chuck Ebbert , Domenico Andreoli , Willy Tarreau , Rodrigo Rubira Branco , Jake Edge , Eugene Teo , torvalds@linux-foundation.org, akpm@linux-foundation.org, alan@lxorguk.ukuu.org.uk, Suresh Siddha , Venkatesh Pallipadi , Ingo Molnar , tvignaud@mandriva.com Subject: [patch 38/43] x86, pat: fix reserve_memtype() for legacy 1MB range Message-ID: <20090131024453.GM12368@kroah.com> References: <20090131022548.656772939@mini.kroah.org> MIME-Version: 1.0 Content-Type: text/plain; charset=us-ascii Content-Disposition: inline; filename="fix_reserve_memtype_1MB.patch" In-Reply-To: <20090131024158.GA12368@kroah.com> User-Agent: Mutt/1.5.16 (2007-06-09) Sender: linux-kernel-owner@vger.kernel.org List-ID: X-Mailing-List: linux-kernel@vger.kernel.org 2.6.28-stable review patch. If anyone has any objections, please let us know. ------------------ From: Suresh Siddha commit 5cca0cf15a94417f49625ce52e23589eed0a1675 upstream Thierry Vignaud reported: > http://bugzilla.kernel.org/show_bug.cgi?id=12372 > > On P4 with an SiS motherboard (video card is a SiS 651) > X server fails to start with error: > xf86MapVidMem: Could not mmap framebuffer (0x00000000,0x2000) (Invalid > argument) Here X is trying to map first 8KB of memory using /dev/mem. Existing code treats first 0-4KB of memory as non-RAM and 4KB-8KB as RAM. Recent code changes don't allow to map memory with different attributes at the same time. Fix this by treating the first 1MB legacy region as special and always track the attribute requests with in this region using linear linked list (and don't bother if the range is RAM or non-RAM or mixed) Reported-and-tested-by: Thierry Vignaud Signed-off-by: Suresh Siddha Signed-off-by: Venkatesh Pallipadi Signed-off-by: Ingo Molnar Signed-off-by: Greg Kroah-Hartman --- arch/x86/mm/pat.c | 37 +++++++++++++++++++++++++++---------- 1 file changed, 27 insertions(+), 10 deletions(-) --- a/arch/x86/mm/pat.c +++ b/arch/x86/mm/pat.c @@ -333,11 +333,20 @@ int reserve_memtype(u64 start, u64 end, req_type & _PAGE_CACHE_MASK); } - is_range_ram = pagerange_is_ram(start, end); - if (is_range_ram == 1) - return reserve_ram_pages_type(start, end, req_type, new_type); - else if (is_range_ram < 0) - return -EINVAL; + /* + * For legacy reasons, some parts of the physical address range in the + * legacy 1MB region is treated as non-RAM (even when listed as RAM in + * the e820 tables). So we will track the memory attributes of this + * legacy 1MB region using the linear memtype_list always. + */ + if (end >= ISA_END_ADDRESS) { + is_range_ram = pagerange_is_ram(start, end); + if (is_range_ram == 1) + return reserve_ram_pages_type(start, end, req_type, + new_type); + else if (is_range_ram < 0) + return -EINVAL; + } new = kmalloc(sizeof(struct memtype), GFP_KERNEL); if (!new) @@ -437,11 +446,19 @@ int free_memtype(u64 start, u64 end) if (is_ISA_range(start, end - 1)) return 0; - is_range_ram = pagerange_is_ram(start, end); - if (is_range_ram == 1) - return free_ram_pages_type(start, end); - else if (is_range_ram < 0) - return -EINVAL; + /* + * For legacy reasons, some parts of the physical address range in the + * legacy 1MB region is treated as non-RAM (even when listed as RAM in + * the e820 tables). So we will track the memory attributes of this + * legacy 1MB region using the linear memtype_list always. + */ + if (end >= ISA_END_ADDRESS) { + is_range_ram = pagerange_is_ram(start, end); + if (is_range_ram == 1) + return free_ram_pages_type(start, end); + else if (is_range_ram < 0) + return -EINVAL; + } spin_lock(&memtype_lock); list_for_each_entry(entry, &memtype_list, nd) {