From mboxrd@z Thu Jan 1 00:00:00 1970 Return-Path: Received: (majordomo@vger.kernel.org) by vger.kernel.org via listexpand id S1753237AbbAPLKX (ORCPT ); Fri, 16 Jan 2015 06:10:23 -0500 Received: from mail.skyhub.de ([78.46.96.112]:55114 "EHLO mail.skyhub.de" rhost-flags-OK-OK-OK-OK) by vger.kernel.org with ESMTP id S1751090AbbAPLKW (ORCPT ); Fri, 16 Jan 2015 06:10:22 -0500 Date: Fri, 16 Jan 2015 12:10:19 +0100 From: Borislav Petkov To: Thomas Gleixner Cc: LKML , Jiang Liu , Joerg Roedel , x86@kernel.org, Tony Luck Subject: Re: [patch 04/23] x86/ioapic: Check x2apic really Message-ID: <20150116111019.GD18880@pd.tnic> References: <20150115210458.625399149@linutronix.de> <20150115211702.541280622@linutronix.de> MIME-Version: 1.0 Content-Type: text/plain; charset=utf-8 Content-Disposition: inline In-Reply-To: <20150115211702.541280622@linutronix.de> User-Agent: Mutt/1.5.23 (2014-03-12) Sender: linux-kernel-owner@vger.kernel.org List-ID: X-Mailing-List: linux-kernel@vger.kernel.org On Thu, Jan 15, 2015 at 09:22:14PM -0000, Thomas Gleixner wrote: > The x2apic_preenabled flag is just a horrible hack and if X2APIC > support is disabled it does not reflect the actual hardware > state. Check the hardware instead. > > Signed-off-by: Thomas Gleixner > --- > arch/x86/include/asm/apic.h | 2 -- > arch/x86/kernel/apic/apic.c | 4 +++- > arch/x86/kernel/apic/io_apic.c | 2 +- > 3 files changed, 4 insertions(+), 4 deletions(-) > > Index: tip/arch/x86/include/asm/apic.h > =================================================================== > --- tip.orig/arch/x86/include/asm/apic.h > +++ tip/arch/x86/include/asm/apic.h > @@ -177,7 +177,6 @@ static inline u64 native_x2apic_icr_read > > extern int x2apic_mode; > extern int x2apic_phys; > -extern int x2apic_preenabled; > extern void check_x2apic(void); > extern void enable_x2apic(void); > static inline int x2apic_enabled(void) > @@ -209,7 +208,6 @@ static inline void x2apic_force_phys(voi > } > > #define x2apic_mode (0) > -#define x2apic_preenabled (0) > #define x2apic_supported() (0) > #endif > > Index: tip/arch/x86/kernel/apic/apic.c > =================================================================== > --- tip.orig/arch/x86/kernel/apic/apic.c > +++ tip/arch/x86/kernel/apic/apic.c > @@ -1480,7 +1480,7 @@ static bool nox2apic __initdata; > #ifdef CONFIG_X86_X2APIC > int x2apic_mode; > /* x2apic enabled before OS handover */ > -int x2apic_preenabled; > +static int x2apic_preenabled; Bah, let's get rid of this knob completely (ontop of your patch): --- Index: b/arch/x86/kernel/apic/apic.c =================================================================== --- a/arch/x86/kernel/apic/apic.c 2015-01-16 12:09:08.116801555 +0100 +++ b/arch/x86/kernel/apic/apic.c 2015-01-16 12:08:41.004802076 +0100 @@ -1480,7 +1480,6 @@ static bool nox2apic __initdata; #ifdef CONFIG_X86_X2APIC int x2apic_mode; /* x2apic enabled before OS handover */ -static int x2apic_preenabled; static int x2apic_disabled; static int __init setup_nox2apic(char *str) { @@ -1546,7 +1545,7 @@ void check_x2apic(void) { if (x2apic_enabled()) { pr_info("x2apic enabled by BIOS, switching to x2apic ops\n"); - x2apic_preenabled = x2apic_mode = 1; + x2apic_mode = 1; } } @@ -1570,7 +1569,6 @@ void enable_x2apic(void) } } #else -#define x2apic_preenabled (0) #endif /* CONFIG_X86_X2APIC */ static int __init try_to_enable_IR(void) @@ -1599,7 +1597,7 @@ static __init void try_to_enable_x2apic( (IS_ENABLED(CONFIG_HYPERVISOR_GUEST) && !hypervisor_x2apic_available())) { pr_info("IRQ remapping doesn't support X2APIC mode, disable x2apic.\n"); - if (x2apic_preenabled) + if (x2apic_enabled()) disable_x2apic(); return; } @@ -1643,7 +1641,7 @@ void __init enable_IR_x2apic(void) legacy_pic->mask_all(); mask_ioapic_entries(); - if (x2apic_preenabled && nox2apic) + if (x2apic_enabled() && nox2apic) disable_x2apic(); /* If irq_remapping_prepare() succeded, try to enable it */ if (ir_stat >= 0) -- -- Regards/Gruss, Boris. Sent from a fat crate under my desk. Formatting is fine. --