From mboxrd@z Thu Jan 1 00:00:00 1970 Return-Path: Received: (majordomo@vger.kernel.org) by vger.kernel.org via listexpand id S274882AbTHKXdb (ORCPT ); Mon, 11 Aug 2003 19:33:31 -0400 Received: (majordomo@vger.kernel.org) by vger.kernel.org id S274888AbTHKXdb (ORCPT ); Mon, 11 Aug 2003 19:33:31 -0400 Received: from meryl.it.uu.se ([130.238.12.42]:33758 "EHLO meryl.it.uu.se") by vger.kernel.org with ESMTP id S274882AbTHKXdZ convert rfc822-to-8bit (ORCPT ); Mon, 11 Aug 2003 19:33:25 -0400 MIME-Version: 1.0 Content-Type: text/plain; charset=iso-8859-1 Content-Transfer-Encoding: 8BIT Message-ID: <16184.10173.412201.802953@gargle.gargle.HOWL> Date: Tue, 12 Aug 2003 01:33:17 +0200 From: Mikael Pettersson To: Dave Jones Cc: marcelo@conectiva.com.br, fxkuehl@gmx.de, linux-kernel@vger.kernel.org, willy@w.ods.org Subject: [PATCH][2.4.22-rc2] Disable APIC on reboot. In-Reply-To: <16183.51974.508883.472043@gargle.gargle.HOWL> References: <16183.50273.723650.136532@gargle.gargle.HOWL> <20030811163834.GA21568@redhat.com> <16183.51974.508883.472043@gargle.gargle.HOWL> X-Mailer: VM 6.90 under Emacs 20.7.1 Sender: linux-kernel-owner@vger.kernel.org X-Mailing-List: linux-kernel@vger.kernel.org Here is a patch for 2.4.22-rc2 to disable the local APIC before reboot. This fixes BIOS reboot problems reported by a few people. disable_local_APIC() now checks if detect_init_APIC() enabled the local APIC via the APIC_BASE MSR, and if so it now disables APIC_BASE. Previously we would leave APIC_BASE enabled, and that made some BIOSen unhappy. The SMP reboot code calls disable_local_APIC(). On SMP HW there is no change since detect_init_APIC() isn't called and APIC_BASE isn't enabled by us. An SMP kernel on UP HW behaves just like an UP_APIC kernel, so it disables APIC_BASE if we enabled it at boot. The UP_APIC disable-before-suspend code is simplified since the existing code to disable APIC_BASE is moved into disable_local_APIC(). (Felix Kühling originally reported the BIOS reboot problem. This is a fixed-up version of his preliminary patch.) /Mikael --- linux-2.4.22-rc2/arch/i386/kernel/apic.c.~1~ 2003-06-14 13:30:19.000000000 +0200 +++ linux-2.4.22-rc2/arch/i386/kernel/apic.c 2003-08-11 23:42:39.000000000 +0200 @@ -38,6 +38,8 @@ int prof_old_multiplier[NR_CPUS] = { 1, }; int prof_counter[NR_CPUS] = { 1, }; +static int enabled_via_apicbase; + int get_maxlvt(void) { unsigned int v, ver, maxlvt; @@ -142,6 +144,13 @@ value = apic_read(APIC_SPIV); value &= ~APIC_SPIV_APIC_ENABLED; apic_write_around(APIC_SPIV, value); + + if (enabled_via_apicbase) { + unsigned int l, h; + rdmsr(MSR_IA32_APICBASE, l, h); + l &= ~MSR_IA32_APICBASE_ENABLE; + wrmsr(MSR_IA32_APICBASE, l, h); + } } /* @@ -464,7 +473,6 @@ static void apic_pm_suspend(void *data) { - unsigned int l, h; unsigned long flags; if (apic_pm_state.perfctr_pmdev) @@ -484,9 +492,6 @@ __save_flags(flags); __cli(); disable_local_APIC(); - rdmsr(MSR_IA32_APICBASE, l, h); - l &= ~MSR_IA32_APICBASE_ENABLE; - wrmsr(MSR_IA32_APICBASE, l, h); __restore_flags(flags); } @@ -636,6 +641,7 @@ l &= ~MSR_IA32_APICBASE_BASE; l |= MSR_IA32_APICBASE_ENABLE | APIC_DEFAULT_PHYS_BASE; wrmsr(MSR_IA32_APICBASE, l, h); + enabled_via_apicbase = 1; } } /* --- linux-2.4.22-rc2/arch/i386/kernel/process.c.~1~ 2003-08-11 21:27:40.000000000 +0200 +++ linux-2.4.22-rc2/arch/i386/kernel/process.c 2003-08-11 23:11:44.000000000 +0200 @@ -47,6 +47,7 @@ #ifdef CONFIG_MATH_EMULATION #include #endif +#include #include @@ -399,6 +400,14 @@ * other OSs see a clean IRQ state. */ smp_send_stop(); +#elif CONFIG_X86_LOCAL_APIC + if (cpu_has_apic) { + __cli(); + disable_local_APIC(); + __sti(); + } +#endif +#ifdef CONFIG_X86_IO_APIC disable_IO_APIC(); #endif