From mboxrd@z Thu Jan 1 00:00:00 1970 From: Andi Kleen Subject: [PATCH] Handle disabled local apic better Date: Tue, 23 Mar 2004 21:35:51 +0100 Sender: acpi-devel-admin-5NWGOfrQmneRv+LV9MX5uipxlwaOVQ5f@public.gmane.org Message-ID: <20040323213551.4789bbae.ak@suse.de> Mime-Version: 1.0 Content-Type: text/plain; charset=US-ASCII Content-Transfer-Encoding: 7bit Return-path: Errors-To: acpi-devel-admin-5NWGOfrQmneRv+LV9MX5uipxlwaOVQ5f@public.gmane.org List-Unsubscribe: , List-Post: List-Help: List-Subscribe: , List-Archive: To: len.brown-ral2JQCrhuEAvxtiuMwx3w@public.gmane.org Cc: acpi-devel-5NWGOfrQmneRv+LV9MX5uipxlwaOVQ5f@public.gmane.org List-Id: linux-acpi@vger.kernel.org When a kernel is compiled with local and io apic code, but the local APIC is disabled before ACPI starts ACPI gets confused. The situation can occur in a mainline kernel too, e.g. when a dmi_scan entry disables the local apic early. The problem is that the ACPI code will do all the setup assuming there is a IO-APIC because the IO-APIC is not disabled, but the machine really runs in PIC mode. This usually leads to lost network (devices get an unreachable interrupt) or IDE hangs or other problems. This patch adds checks for local apic enabled to all paths that need it (basically everybody who has a #ifdef CONFIG_X86_LOCAL_APIC needs this check instead) It just handles the case there the up apic is disabled before ACPI boot, it can actually be disabled later too (e.g. when the APIC initialisation fails). This is probably still broken. Also removes an bogus error message - this path can trigger just with software disabled APIC. -Andi diff -u linux/arch/i386/kernel/acpi/boot.c-o linux/arch/i386/kernel/acpi/boot.c --- linux/arch/i386/kernel/acpi/boot.c-o 2004-03-23 17:32:22.000000000 +0100 +++ linux/arch/i386/kernel/acpi/boot.c 2004-03-23 17:34:23.000000000 +0100 @@ -685,6 +685,13 @@ #ifdef CONFIG_X86_LOCAL_APIC int count, error; + /* it's still wrong when the apic is disabled later */ + extern int enable_local_apic; + if (enable_local_apic < 0) { + printk(KERN_INFO "ACPI: local apic disabled\n"); + return; + } + count = acpi_table_parse(ACPI_APIC, acpi_parse_madt); if (count == 1) { diff -u linux/arch/i386/kernel/apic.c-o linux/arch/i386/kernel/apic.c --- linux/arch/i386/kernel/apic.c-o 2004-03-23 17:32:22.000000000 +0100 +++ linux/arch/i386/kernel/apic.c 2004-03-23 18:01:21.000000000 +0100 @@ -41,6 +41,8 @@ #include "io_ports.h" +extern int enable_local_apic; + static void apic_pm_activate(void); void __init apic_intr_init(void) @@ -190,6 +192,9 @@ { unsigned long value; + if (enable_local_apic < 0) + return; + clear_local_APIC(); /* @@ -1172,8 +1193,6 @@ * Complain if the BIOS pretends there is one. */ if (!cpu_has_apic && APIC_INTEGRATED(apic_version[boot_cpu_physical_apicid])) { - printk(KERN_ERR "BIOS bug, local APIC #%d not detected!...\n", - boot_cpu_physical_apicid); return -1; } diff -u linux/arch/i386/kernel/setup.c-o linux/arch/i386/kernel/setup.c --- linux/arch/i386/kernel/setup.c-o 2004-03-23 17:32:00.000000000 +0100 +++ linux/arch/i386/kernel/setup.c 2004-03-23 18:01:14.000000000 +0100 @@ -50,6 +50,10 @@ #include "setup_arch_pre.h" #include "mach_resources.h" +#ifdef CONFIG_X86_LOCAL_APIC +extern int enable_local_apic; +#endif + /* This value is set up by the early boot code to point to the value immediately after the boot time page tables. It contains a *physical* address, and must not be in the .bss segment! */ @@ -917,6 +925,7 @@ acpi_reserve_bootmem(); #endif #ifdef CONFIG_X86_FIND_SMP_CONFIG + if (enable_local_apic >= 0) /* * Find and reserve possible boot-time SMP configuration: */ @@ -1232,7 +1241,7 @@ acpi_boot_init(); #ifdef CONFIG_X86_LOCAL_APIC - if (smp_found_config) + if (smp_found_config && enable_local_apic >= 0) get_smp_config(); #endif diff -u linux/arch/x86_64/kernel/apic.c-o linux/arch/x86_64/kernel/apic.c --- linux/arch/x86_64/kernel/apic.c-o 2004-03-23 17:32:01.000000000 +0100 +++ linux/arch/x86_64/kernel/apic.c 2004-03-23 18:41:58.000000000 +0100 @@ -970,6 +970,7 @@ } int disable_apic; +int enable_local_apic = 1; /* * This initializes the IO-APIC and APIC hardware if this is @@ -1009,12 +1010,14 @@ static __init int setup_disableapic(char *str) { + enable_local_apic = -1; disable_apic = 1; return 0; } static __init int setup_nolapic(char *str) { + enable_local_apic = -1; disable_apic = 1; return 0; } ------------------------------------------------------- This SF.Net email is sponsored by: IBM Linux Tutorials Free Linux tutorial presented by Daniel Robbins, President and CEO of GenToo technologies. Learn everything from fundamentals to system administration.http://ads.osdn.com/?ad_id=1470&alloc_id=3638&op=click