From mboxrd@z Thu Jan 1 00:00:00 1970 Return-Path: Received: (majordomo@vger.kernel.org) by vger.kernel.org via listexpand id S1752402AbZEYLDf (ORCPT ); Mon, 25 May 2009 07:03:35 -0400 Received: (majordomo@vger.kernel.org) by vger.kernel.org id S1751367AbZEYLD2 (ORCPT ); Mon, 25 May 2009 07:03:28 -0400 Received: from wa4ehsobe005.messaging.microsoft.com ([216.32.181.15]:46764 "EHLO WA4EHSOBE006.bigfish.com" rhost-flags-OK-OK-OK-FAIL) by vger.kernel.org with ESMTP id S1751599AbZEYLD1 convert rfc822-to-8bit (ORCPT ); Mon, 25 May 2009 07:03:27 -0400 X-BigFish: VPS4(zzzz1202hzzz32i6bh6di43j61h) X-Spam-TCS-SCL: 0:0 X-WSS-ID: 0KK75DF-01-2QZ-01 Date: Mon, 25 May 2009 13:03:18 +0200 From: Borislav Petkov To: "H. Peter Anvin" CC: akpm@linux-foundation.org, greg@kroah.com, mingo@elte.hu, norsk5@yahoo.com, tglx@linutronix.de, mchehab@redhat.com, aris@redhat.com, edt@aei.ca, linux-kernel@vger.kernel.org, Andreas Herrmann Subject: Re: [PATCH 01/22] x86: add methods for writing of an MSR on several CPUs Message-ID: <20090525110318.GB10303@aftab> References: <4A1392A9.9010609@zytor.com> <20090520144905.GA27991@aftab> <4A147891.5000906@zytor.com> <20090521140800.GA3462@aftab> <4A156361.2040507@zytor.com> <20090521162638.GA10824@aftab> <4A159179.6070607@zytor.com> <20090522143918.GA22850@aftab> <4A16D735.8090104@zytor.com> <20090525110147.GB8956@aftab> MIME-Version: 1.0 Content-Type: text/plain; charset="iso-8859-1" Content-Disposition: inline In-Reply-To: <20090525110147.GB8956@aftab> User-Agent: Mutt/1.5.18 (2008-05-17) X-OriginalArrivalTime: 25 May 2009 11:03:17.0206 (UTC) FILETIME=[681EF760:01C9DD28] Content-Transfer-Encoding: 8BIT Sender: linux-kernel-owner@vger.kernel.org List-ID: X-Mailing-List: linux-kernel@vger.kernel.org From: Borislav Petkov Date: Fri, 22 May 2009 13:52:19 +0200 Subject: [PATCH 02/26] x86: MSR: add methods for writing of an MSR on several CPUs Provide for concurrent MSR writes on all the CPUs in the cpumask. Also, add a temporary workaround for smp_call_function_many which skips the CPU we're executing on. CC: H. Peter Anvin Signed-off-by: Borislav Petkov --- arch/x86/include/asm/msr.h | 12 ++++++ arch/x86/lib/msr.c | 86 ++++++++++++++++++++++++++++++++++++++++--- 2 files changed, 92 insertions(+), 6 deletions(-) diff --git a/arch/x86/include/asm/msr.h b/arch/x86/include/asm/msr.h index 5e12132..2260376 100644 --- a/arch/x86/include/asm/msr.h +++ b/arch/x86/include/asm/msr.h @@ -227,6 +227,8 @@ do { \ #ifdef CONFIG_SMP int rdmsr_on_cpu(unsigned int cpu, u32 msr_no, u32 *l, u32 *h); int wrmsr_on_cpu(unsigned int cpu, u32 msr_no, u32 l, u32 h); +void rdmsr_on_cpus(const cpumask_t *mask, u32 msr_no, struct msr *msrs); +void wrmsr_on_cpus(const cpumask_t *mask, u32 msr_no, struct msr *msrs); int rdmsr_safe_on_cpu(unsigned int cpu, u32 msr_no, u32 *l, u32 *h); int wrmsr_safe_on_cpu(unsigned int cpu, u32 msr_no, u32 l, u32 h); #else /* CONFIG_SMP */ @@ -240,6 +242,16 @@ static inline int wrmsr_on_cpu(unsigned int cpu, u32 msr_no, u32 l, u32 h) wrmsr(msr_no, l, h); return 0; } +static inline void rdmsr_on_cpus(const cpumask_t *m, u32 msr_no, + struct msr *msrs) +{ + rdmsr_on_cpu(0, msr_no, &(msrs[0].l), &(msrs[0].h)); +} +static inline void wrmsr_on_cpus(const cpumask_t *m, u32 msr_no, + struct msr *msrs) +{ + wrmsr_on_cpu(0, msr_no, msrs[0].l, msrs[0].h); +} static inline int rdmsr_safe_on_cpu(unsigned int cpu, u32 msr_no, u32 *l, u32 *h) { diff --git a/arch/x86/lib/msr.c b/arch/x86/lib/msr.c index cade714..52edaf0 100644 --- a/arch/x86/lib/msr.c +++ b/arch/x86/lib/msr.c @@ -6,21 +6,37 @@ struct msr_info { u32 msr_no; struct msr reg; + struct msr *msrs; + int off; int err; }; static void __rdmsr_on_cpu(void *info) { struct msr_info *rv = info; + struct msr *reg; + int this_cpu = raw_smp_processor_id(); - rdmsr(rv->msr_no, rv->reg.l, rv->reg.h); + if (rv->msrs) + reg = &rv->msrs[this_cpu - rv->off]; + else + reg = &rv->reg; + + rdmsr(rv->msr_no, reg->l, reg->h); } static void __wrmsr_on_cpu(void *info) { struct msr_info *rv = info; + struct msr *reg; + int this_cpu = raw_smp_processor_id(); + + if (rv->msrs) + reg = &rv->msrs[this_cpu - rv->off]; + else + reg = &rv->reg; - wrmsr(rv->msr_no, rv->reg.l, rv->reg.h); + wrmsr(rv->msr_no, reg->l, reg->h); } int rdmsr_on_cpu(unsigned int cpu, u32 msr_no, u32 *l, u32 *h) @@ -35,6 +51,7 @@ int rdmsr_on_cpu(unsigned int cpu, u32 msr_no, u32 *l, u32 *h) return err; } +EXPORT_SYMBOL(rdmsr_on_cpu); int wrmsr_on_cpu(unsigned int cpu, u32 msr_no, u32 l, u32 h) { @@ -48,6 +65,66 @@ int wrmsr_on_cpu(unsigned int cpu, u32 msr_no, u32 l, u32 h) return err; } +EXPORT_SYMBOL(wrmsr_on_cpu); + +/* rdmsr on a bunch of CPUs + * + * @mask: which CPUs + * @msr_no: which MSR + * @msrs: array of MSR values + * + */ +void rdmsr_on_cpus(const cpumask_t *mask, u32 msr_no, struct msr *msrs) +{ + struct msr_info rv; + int this_cpu; + + rv.off = cpumask_first(mask); + rv.msrs = msrs; + rv.msr_no = msr_no; + + preempt_disable(); + /* + * FIXME: handle the CPU we're executing on separately for now until + * smp_call_function_many has been fixed to not skip it. + */ + this_cpu = raw_smp_processor_id(); + smp_call_function_single(this_cpu, __rdmsr_on_cpu, &rv, 1); + + smp_call_function_many(mask, __rdmsr_on_cpu, &rv, 1); + preempt_enable(); +} +EXPORT_SYMBOL(rdmsr_on_cpus); + +/* + * wrmsr on a bunch of CPUs + * + * @mask: which CPUs + * @msr_no: which MSR + * @msrs: array of MSR values + * + */ +void wrmsr_on_cpus(const cpumask_t *mask, u32 msr_no, struct msr *msrs) +{ + struct msr_info rv; + int this_cpu; + + rv.off = cpumask_first(mask); + rv.msrs = msrs; + rv.msr_no = msr_no; + + preempt_disable(); + /* + * FIXME: handle the CPU we're executing on separately for now until + * smp_call_function_many has been fixed to not skip it. + */ + this_cpu = raw_smp_processor_id(); + smp_call_function_single(this_cpu, __wrmsr_on_cpu, &rv, 1); + + smp_call_function_many(mask, __wrmsr_on_cpu, &rv, 1); + preempt_enable(); +} +EXPORT_SYMBOL(wrmsr_on_cpus); /* These "safe" variants are slower and should be used when the target MSR may not actually exist. */ @@ -77,6 +154,7 @@ int rdmsr_safe_on_cpu(unsigned int cpu, u32 msr_no, u32 *l, u32 *h) return err ? err : rv.err; } +EXPORT_SYMBOL(rdmsr_safe_on_cpu); int wrmsr_safe_on_cpu(unsigned int cpu, u32 msr_no, u32 l, u32 h) { @@ -90,8 +168,4 @@ int wrmsr_safe_on_cpu(unsigned int cpu, u32 msr_no, u32 l, u32 h) return err ? err : rv.err; } - -EXPORT_SYMBOL(rdmsr_on_cpu); -EXPORT_SYMBOL(wrmsr_on_cpu); -EXPORT_SYMBOL(rdmsr_safe_on_cpu); EXPORT_SYMBOL(wrmsr_safe_on_cpu); -- 1.6.2.4 -- Regards/Gruss, Boris. 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