Return-Path: Received: (majordomo@vger.kernel.org) by vger.kernel.org via listexpand id S1751469AbZG1KaK (ORCPT ); Tue, 28 Jul 2009 06:30:10 -0400 Received: (majordomo@vger.kernel.org) by vger.kernel.org id S1751016AbZG1KaJ (ORCPT ); Tue, 28 Jul 2009 06:30:09 -0400 Received: from sg2ehsobe003.messaging.microsoft.com ([207.46.51.77]:34617 "EHLO SG2EHSOBE003.bigfish.com" rhost-flags-OK-OK-OK-FAIL) by vger.kernel.org with ESMTP id S1750824AbZG1KaH convert rfc822-to-8bit (ORCPT ); Tue, 28 Jul 2009 06:30:07 -0400 X-SpamScore: -12 X-BigFish: VPS-12(zz1432R98dNzz1202hzzz32i6bh203h6di43j61h) X-Spam-TCS-SCL: 0:0 X-WSS-ID: 0KNHMHJ-03-11G-01 Date: Tue, 28 Jul 2009 12:29:40 +0200 From: Borislav Petkov To: "H. Peter Anvin" CC: x86@kernel.org, linux-kernel@vger.kernel.org Subject: Re: [PATCH] [x86, msr]: execute on the correct CPU subset Message-ID: <20090728102940.GA6550@aftab> References: <1246890592-12256-1-git-send-email-borislav.petkov@amd.com> <4A526D38.7000803@zytor.com> <20090707103723.GD5668@aftab> <4A537010.3050905@zytor.com> <20090708111911.GC19315@aftab> <4A6E1222.5010709@zytor.com> MIME-Version: 1.0 Content-Type: text/plain; charset="iso-8859-1" Content-Disposition: inline In-Reply-To: <4A6E1222.5010709@zytor.com> User-Agent: Mutt/1.5.20 (2009-06-14) X-OriginalArrivalTime: 28 Jul 2009 10:29:41.0199 (UTC) FILETIME=[50ECB5F0:01CA0F6E] Content-Transfer-Encoding: 8BIT Sender: linux-kernel-owner@vger.kernel.org List-ID: X-Mailing-List: linux-kernel@vger.kernel.org Content-Length: 4250 Lines: 144 On Mon, Jul 27, 2009 at 01:46:26PM -0700, H. Peter Anvin wrote: > Borislav Petkov wrote: > > > > 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); > > + if (cpumask_test_cpu(this_cpu, mask)) > > + msr_func(&rv); > > + > > + smp_call_function_many(mask, msr_func, &rv, 1); > > preempt_enable(); > > } > > Any reason not to use get_cpu() ... put_cpu() instead? None, patch updated. -- From: Borislav Petkov Date: Mon, 6 Jul 2009 16:08:34 +0200 Subject: [PATCH] [x86, msr]: execute on the correct CPU subset rdmsr_on_cpus/wrmsr_on_cpus were erroneously executing on the current CPU even in the case where it wasn't in the supplied bitmask. Add a check for that and handle accordingly. While at it, since rdmsr_on_cpus and wrmsr_on_cpus are almost identical, fold them call into a common __rwmsr_on_cpus helper passing a function pointer arg to the actual MSR operation. Signed-off-by: Borislav Petkov --- arch/x86/lib/msr.c | 58 +++++++++++++++++++-------------------------------- 1 files changed, 22 insertions(+), 36 deletions(-) diff --git a/arch/x86/lib/msr.c b/arch/x86/lib/msr.c index 1440b9c..cf879f0 100644 --- a/arch/x86/lib/msr.c +++ b/arch/x86/lib/msr.c @@ -71,14 +71,9 @@ int wrmsr_on_cpu(unsigned int cpu, u32 msr_no, u32 l, u32 h) } 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) +static inline void __rwmsr_on_cpus(const cpumask_t *mask, u32 msr_no, + struct msr *msrs, + void (*msr_func) (void *info)) { struct msr_info rv; int this_cpu; @@ -89,16 +84,25 @@ void rdmsr_on_cpus(const cpumask_t *mask, u32 msr_no, struct msr *msrs) 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); + this_cpu = get_cpu(); - smp_call_function_many(mask, __rdmsr_on_cpu, &rv, 1); - preempt_enable(); + if (cpumask_test_cpu(this_cpu, mask)) + msr_func(&rv); + + smp_call_function_many(mask, msr_func, &rv, 1); + put_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) +{ + __rwmsr_on_cpus(mask, msr_no, msrs, __rdmsr_on_cpu); } EXPORT_SYMBOL(rdmsr_on_cpus); @@ -112,25 +116,7 @@ EXPORT_SYMBOL(rdmsr_on_cpus); */ void wrmsr_on_cpus(const cpumask_t *mask, u32 msr_no, struct msr *msrs) { - struct msr_info rv; - int this_cpu; - - memset(&rv, 0, sizeof(rv)); - - 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(); + __rwmsr_on_cpus(mask, msr_no, msrs, __wrmsr_on_cpu); } EXPORT_SYMBOL(wrmsr_on_cpus); -- 1.6.3.3 -- Regards/Gruss, Boris. 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