From mboxrd@z Thu Jan 1 00:00:00 1970 Return-Path: Received: (majordomo@vger.kernel.org) by vger.kernel.org via listexpand id S1756121AbZETHpt (ORCPT ); Wed, 20 May 2009 03:45:49 -0400 Received: (majordomo@vger.kernel.org) by vger.kernel.org id S1752220AbZETHpm (ORCPT ); Wed, 20 May 2009 03:45:42 -0400 Received: from sca-es-mail-2.Sun.COM ([192.18.43.133]:57943 "EHLO sca-es-mail-2.sun.com" rhost-flags-OK-OK-OK-OK) by vger.kernel.org with ESMTP id S1751105AbZETHpl (ORCPT ); Wed, 20 May 2009 03:45:41 -0400 MIME-version: 1.0 Content-transfer-encoding: 7BIT Content-type: text/plain; CHARSET=US-ASCII Date: Wed, 20 May 2009 00:45:16 -0700 From: Yinghai Lu Subject: [PATCH] x86: don't allocate dummy page for wrong madt/mptable In-reply-to: <4A1393CD.7080604@kernel.org> To: Ingo Molnar , Thomas Gleixner , "H. Peter Anvin" , Andrew Morton Cc: "linux-kernel@vger.kernel.org" Message-id: <4A13B50C.5080201@sun.com> References: <4A1393CD.7080604@kernel.org> User-Agent: Thunderbird 2.0.0.19 (X11/20081227) Sender: linux-kernel-owner@vger.kernel.org List-ID: X-Mailing-List: linux-kernel@vger.kernel.org in io_apic_init_mapping, if nr_ioapics > 0, we don't need to check smp_found_config further. also don't need to allocate dummy pages if we got wrong mptable/madt. like bad ioapic address. because skip_ioapic_setup already guard that later. [ Impact: save 4k when bad mptable/madt or skip_ioapic_setup ] Sign-off-by: Yinghai Lu --- arch/x86/kernel/apic/io_apic.c | 48 +++++++++++++++++++++-------------------- 1 file changed, 25 insertions(+), 23 deletions(-) Index: linux-2.6/arch/x86/kernel/apic/io_apic.c =================================================================== --- linux-2.6.orig/arch/x86/kernel/apic/io_apic.c +++ linux-2.6/arch/x86/kernel/apic/io_apic.c @@ -1887,7 +1887,9 @@ __apicdebuginit(int) print_all_ICs(void) return 0; print_all_local_APICs(); - print_IO_APIC(); + + if (!skip_ioapic_setup && nr_ioapics) + print_IO_APIC(); return 0; } @@ -3828,6 +3830,9 @@ void __init probe_nr_irqs_gsi(void) { int nr = 0; + if (skip_ioapic_setup) + return; + nr = acpi_probe_gsi(); if (nr > nr_irqs_gsi) { nr_irqs_gsi = nr; @@ -4139,29 +4144,26 @@ void __init ioapic_init_mappings(void) struct resource *ioapic_res; int i; - ioapic_res = ioapic_setup_resources(); + if (nr_ioapics < 1 || skip_ioapic_setup) + return; + for (i = 0; i < nr_ioapics; i++) { - if (smp_found_config) { - ioapic_phys = mp_ioapics[i].apicaddr; -#ifdef CONFIG_X86_32 - if (!ioapic_phys) { - printk(KERN_ERR - "WARNING: bogus zero IO-APIC " - "address found in MPTABLE, " - "disabling IO/APIC support!\n"); - smp_found_config = 0; - skip_ioapic_setup = 1; - goto fake_ioapic_page; - } -#endif - } else { -#ifdef CONFIG_X86_32 -fake_ioapic_page: -#endif - ioapic_phys = (unsigned long) - alloc_bootmem_pages(PAGE_SIZE); - ioapic_phys = __pa(ioapic_phys); + ioapic_phys = mp_ioapics[i].apicaddr; + if (!ioapic_phys) { + printk(KERN_ERR + "WARNING: bogus zero IO-APIC " + "address found in MPTABLE or MADT, " + "disabling IO/APIC support!\n"); + smp_found_config = 0; + skip_ioapic_setup = 1; + return; } + } + + ioapic_res = ioapic_setup_resources(); + for (i = 0; i < nr_ioapics; i++) { + ioapic_phys = mp_ioapics[i].apicaddr; + /* * when acpi ioapic is used, mp_register_ioapic() map * ioapic_phys already @@ -4187,7 +4189,7 @@ static int __init ioapic_insert_resource struct resource *r = ioapic_resources; if (!r) { - if (nr_ioapics > 0) { + if (nr_ioapics > 0 && !skip_ioapic_setup) { printk(KERN_ERR "IO APIC resources couldn't be allocated.\n"); return -1;