From mboxrd@z Thu Jan 1 00:00:00 1970 Return-Path: Received: (majordomo@vger.kernel.org) by vger.kernel.org via listexpand id S1755298AbZCLKol (ORCPT ); Thu, 12 Mar 2009 06:44:41 -0400 Received: (majordomo@vger.kernel.org) by vger.kernel.org id S1752056AbZCLKoc (ORCPT ); Thu, 12 Mar 2009 06:44:32 -0400 Received: from vpn.id2.novell.com ([195.33.99.129]:32621 "EHLO vpn.id2.novell.com" rhost-flags-OK-OK-OK-OK) by vger.kernel.org with ESMTP id S1751499AbZCLKob convert rfc822-to-8bit (ORCPT ); Thu, 12 Mar 2009 06:44:31 -0400 Message-Id: <49B8F5C4.76E4.0078.0@novell.com> X-Mailer: Novell GroupWise Internet Agent 8.0.0 Date: Thu, 12 Mar 2009 10:45:08 +0000 From: "Jan Beulich" To: , , Cc: , Subject: [PATCH] x86-64: improve e820_search_gap() Mime-Version: 1.0 Content-Type: text/plain; charset=US-ASCII Content-Transfer-Encoding: 8BIT Content-Disposition: inline Sender: linux-kernel-owner@vger.kernel.org List-ID: X-Mailing-List: linux-kernel@vger.kernel.org Blindly putting the gap close after max_pfn might be fine for native (though even there I'm uncertain regarding memory hotplug), but will certainly present a problem on Xen. And properly searching for a gap above 4Gb shouldn't hurt native. Also, make the function static to ensure there are no other users that could depend on the previous behavior regarding the way start_addr gets specified. Signed-off-by: Jan Beulich Cc: Jeremy Fitzhardinge --- arch/x86/include/asm/e820.h | 2 -- arch/x86/kernel/e820.c | 11 +++++++++-- 2 files changed, 9 insertions(+), 4 deletions(-) --- linux-2.6.29-rc7/arch/x86/include/asm/e820.h 2009-03-11 17:52:10.000000000 +0100 +++ 2.6.29-rc7-x86_64-e820-setup-gap-64bit/arch/x86/include/asm/e820.h 2009-03-06 11:25:35.000000000 +0100 @@ -79,8 +79,6 @@ extern u64 e820_remove_range(u64 start, int checktype); extern void update_e820(void); extern void e820_setup_gap(void); -extern int e820_search_gap(unsigned long *gapstart, unsigned long *gapsize, - unsigned long start_addr, unsigned long long end_addr); struct setup_data; extern void parse_e820_ext(struct setup_data *data, unsigned long pa_data); --- linux-2.6.29-rc7/arch/x86/kernel/e820.c 2009-03-11 17:52:10.000000000 +0100 +++ 2.6.29-rc7-x86_64-e820-setup-gap-64bit/arch/x86/kernel/e820.c 2009-03-06 11:24:34.000000000 +0100 @@ -533,13 +533,19 @@ static void __init update_e820_saved(voi /* * Search for a gap in the e820 memory space from start_addr to end_addr. */ -__init int e820_search_gap(unsigned long *gapstart, unsigned long *gapsize, +static int __init +e820_search_gap(unsigned long *gapstart, unsigned long *gapsize, unsigned long start_addr, unsigned long long end_addr) { unsigned long long last; int i = e820.nr_map; int found = 0; +#ifdef CONFIG_X86_64 + if (start_addr >= MAX_GAP_END) + last = end_addr ?: (1UL << boot_cpu_data.x86_phys_bits); + else +#endif last = (end_addr && end_addr < MAX_GAP_END) ? end_addr : MAX_GAP_END; while (--i >= 0) { @@ -585,11 +591,12 @@ __init void e820_setup_gap(void) #ifdef CONFIG_X86_64 if (!found) { - gapstart = (max_pfn << PAGE_SHIFT) + 1024*1024; printk(KERN_ERR "PCI: Warning: Cannot find a gap in the 32bit " "address range\n" KERN_ERR "PCI: Unassigned devices with 32bit resource " "registers may break!\n"); + found = e820_search_gap(&gapstart, &gapsize, MAX_GAP_END, 0); + BUG_ON(!found); } #endif