From mboxrd@z Thu Jan 1 00:00:00 1970 Return-Path: Received: (majordomo@vger.kernel.org) by vger.kernel.org via listexpand id S1161368AbWJKVTj (ORCPT ); Wed, 11 Oct 2006 17:19:39 -0400 Received: (majordomo@vger.kernel.org) by vger.kernel.org id S1161434AbWJKVTE (ORCPT ); Wed, 11 Oct 2006 17:19:04 -0400 Received: from smtp.osdl.org ([65.172.181.4]:36809 "EHLO smtp.osdl.org") by vger.kernel.org with ESMTP id S1161492AbWJKVSe (ORCPT ); Wed, 11 Oct 2006 17:18:34 -0400 Date: Wed, 11 Oct 2006 14:18:13 -0700 From: Andrew Morton To: Peter Zijlstra Cc: linux-kernel , sfr@canb.auug.org.au, Ingo Molnar Subject: Re: [PATCH] lockdep: annotate i386 apm Message-Id: <20061011141813.79fb278f.akpm@osdl.org> In-Reply-To: <1160574022.2006.82.camel@taijtu> References: <1160574022.2006.82.camel@taijtu> X-Mailer: Sylpheed version 2.2.7 (GTK+ 2.8.6; i686-pc-linux-gnu) Mime-Version: 1.0 Content-Type: text/plain; charset=US-ASCII Content-Transfer-Encoding: 7bit Sender: linux-kernel-owner@vger.kernel.org X-Mailing-List: linux-kernel@vger.kernel.org On Wed, 11 Oct 2006 15:40:22 +0200 Peter Zijlstra wrote: > > Lockdep doesn't like to enable interrupts when they are enabled already. > > ... > > --- linux-2.6.18.noarch.orig/arch/i386/kernel/apm.c > +++ linux-2.6.18.noarch/arch/i386/kernel/apm.c > @@ -539,11 +539,22 @@ static inline void apm_restore_cpus(cpum > * Also, we KNOW that for the non error case of apm_bios_call, there > * is no useful data returned in the low order 8 bits of eax. > */ > -#define APM_DO_CLI \ > - if (apm_info.allow_ints) \ > - local_irq_enable(); \ > - else \ > - local_irq_disable(); > +#define APM_DO_CLI \ > + do { \ > + if (apm_info.allow_ints) { \ > + if (irqs_disabled_flags(flags)) \ > + local_irq_enable(); \ > + } else \ > + local_irq_disable(); \ > + } while (0) > + > +#define APM_DO_STI \ > + do { \ > + if (irqs_disabled_flags(flags)) \ > + local_irq_disable(); \ > + else if (irqs_disabled()) \ > + local_irq_enable(); \ > + } while (0) > > #ifdef APM_ZERO_SEGS > # define APM_DECL_SEGS \ > @@ -600,7 +611,7 @@ static u8 apm_bios_call(u32 func, u32 eb > APM_DO_SAVE_SEGS; > apm_bios_call_asm(func, ebx_in, ecx_in, eax, ebx, ecx, edx, esi); > APM_DO_RESTORE_SEGS; > - local_irq_restore(flags); > + APM_DO_STI; > gdt[0x40 / 8] = save_desc_40; > put_cpu(); > apm_restore_cpus(cpus); > @@ -644,7 +655,7 @@ static u8 apm_bios_call_simple(u32 func, > APM_DO_SAVE_SEGS; > error = apm_bios_call_simple_asm(func, ebx_in, ecx_in, eax); > APM_DO_RESTORE_SEGS; > - local_irq_restore(flags); > + APM_DO_STI; > gdt[0x40 / 8] = save_desc_40; > put_cpu(); > apm_restore_cpus(cpus); ick. Does this work? --- a/arch/i386/kernel/apm.c~lockdep-annotate-i386-apm +++ a/arch/i386/kernel/apm.c @@ -540,12 +540,6 @@ static inline void apm_restore_cpus(cpum * Also, we KNOW that for the non error case of apm_bios_call, there * is no useful data returned in the low order 8 bits of eax. */ -#define APM_DO_CLI \ - if (apm_info.allow_ints) \ - local_irq_enable(); \ - else \ - local_irq_disable(); - #ifdef APM_ZERO_SEGS # define APM_DECL_SEGS \ unsigned int saved_fs; unsigned int saved_gs; @@ -596,8 +590,9 @@ static u8 apm_bios_call(u32 func, u32 eb save_desc_40 = gdt[0x40 / 8]; gdt[0x40 / 8] = bad_bios_desc; - local_save_flags(flags); - APM_DO_CLI; + local_irq_save(flags); + if (apm_info.allow_ints) + local_irq_enable(); APM_DO_SAVE_SEGS; apm_bios_call_asm(func, ebx_in, ecx_in, eax, ebx, ecx, edx, esi); APM_DO_RESTORE_SEGS; @@ -640,8 +635,9 @@ static u8 apm_bios_call_simple(u32 func, save_desc_40 = gdt[0x40 / 8]; gdt[0x40 / 8] = bad_bios_desc; - local_save_flags(flags); - APM_DO_CLI; + local_irq_save(flags); + if (apm_info.allow_ints) + local_irq_enable(); APM_DO_SAVE_SEGS; error = apm_bios_call_simple_asm(func, ebx_in, ecx_in, eax); APM_DO_RESTORE_SEGS; _