From mboxrd@z Thu Jan 1 00:00:00 1970 Return-Path: Received: (majordomo@vger.kernel.org) by vger.kernel.org via listexpand id S933006AbcJLMyb (ORCPT ); Wed, 12 Oct 2016 08:54:31 -0400 Received: from mx2.suse.de ([195.135.220.15]:36262 "EHLO mx2.suse.de" rhost-flags-OK-OK-OK-OK) by vger.kernel.org with ESMTP id S1755454AbcJLMvs (ORCPT ); Wed, 12 Oct 2016 08:51:48 -0400 Date: Wed, 12 Oct 2016 14:51:44 +0200 From: Borislav Petkov To: Grzegorz Andrejczuk Cc: tglx@linutronix.de, mingo@redhat.com, hpa@zytor.com, x86@kernel.org, dave.hansen@linux.intel.com, linux-kernel@vger.kernel.org, lukasz.daniluk@intel.com, james.h.cownie@intel.com Subject: Re: [PATCH v2 4/4] Add R3MWAIT to CPU features Message-ID: <20161012125144.GA4476@nazgul.tnic> References: <1476274585-21679-1-git-send-email-grzegorz.andrejczuk@intel.com> <1476274585-21679-5-git-send-email-grzegorz.andrejczuk@intel.com> MIME-Version: 1.0 Content-Type: text/plain; charset=utf-8 Content-Disposition: inline Content-Transfer-Encoding: 8bit In-Reply-To: <1476274585-21679-5-git-send-email-grzegorz.andrejczuk@intel.com> User-Agent: Mutt/1.6.0 (2016-04-01) Sender: linux-kernel-owner@vger.kernel.org List-ID: X-Mailing-List: linux-kernel@vger.kernel.org On Wed, Oct 12, 2016 at 02:16:25PM +0200, Grzegorz Andrejczuk wrote: > Add cpu feature for ring 3 monitor/mwait. > > Change-Id: Iba4d20639efd8d3637d37db9294cbc43a98f009a Please take your time when incorporating review comments - these internal commit IDs have no meaning when submitting upstream so please remove them. I already pointed that out previously... Also, please do not set v3 immediately but give other people a couple of days to take a look at those patches and give you review comments. > Signed-off-by: Grzegorz Andrejczuk > --- > arch/x86/include/asm/cpufeatures.h | 2 ++ > arch/x86/kernel/cpu/common.c | 3 +++ > arch/x86/kernel/cpu/scattered.c | 5 +++++ > 3 files changed, 10 insertions(+) > > diff --git a/arch/x86/include/asm/cpufeatures.h b/arch/x86/include/asm/cpufeatures.h > index 92a8308..9caf9c4 100644 > --- a/arch/x86/include/asm/cpufeatures.h > +++ b/arch/x86/include/asm/cpufeatures.h > @@ -71,6 +71,8 @@ > #define X86_FEATURE_RECOVERY ( 2*32+ 0) /* CPU in recovery mode */ > #define X86_FEATURE_LONGRUN ( 2*32+ 1) /* Longrun power control */ > #define X86_FEATURE_LRTI ( 2*32+ 3) /* LongRun table interface */ > +/* non architectural Intel-defined CPU features not present in CPUID */ No need for that comment - we have other synthetic CPUID bits already. > +#define X86_FEATURE_PHIR3MWAIT (2*32+ 4) > > /* Other features, Linux-defined mapping, word 3 */ > /* This range is used for feature bits which conflict or are synthesized */ > diff --git a/arch/x86/kernel/cpu/common.c b/arch/x86/kernel/cpu/common.c > index 93ffaa5..15fe27f 100644 > --- a/arch/x86/kernel/cpu/common.c > +++ b/arch/x86/kernel/cpu/common.c > @@ -1108,6 +1108,9 @@ static void identify_cpu(struct cpuinfo_x86 *c) > #endif > /* The boot/hotplug time assigment got cleared, restore it */ > c->logical_proc_id = topology_phys_to_logical_pkg(c->phys_proc_id); > + > + if (cpu_has(c, X86_FEATURE_PHIR3MWAIT)) > + elf_hwcap2 |= HWCAP2_PHIR3MWAIT; > } > > /* > diff --git a/arch/x86/kernel/cpu/scattered.c b/arch/x86/kernel/cpu/scattered.c > index 8cb57df..e4ff3d0 100644 > --- a/arch/x86/kernel/cpu/scattered.c > +++ b/arch/x86/kernel/cpu/scattered.c > @@ -29,6 +29,7 @@ void init_scattered_cpuid_features(struct cpuinfo_x86 *c) > u32 max_level; > u32 regs[4]; > const struct cpuid_bit *cb; > + u64 misc_thd_enable; > > static const struct cpuid_bit cpuid_bits[] = { > { X86_FEATURE_INTEL_PT, CR_EBX,25, 0x00000007, 0 }, > @@ -54,4 +55,8 @@ void init_scattered_cpuid_features(struct cpuinfo_x86 *c) > if (regs[cb->reg] & (1 << cb->bit)) > set_cpu_cap(c, cb->feature); > } > + > + rdmsrl(MSR_PHI_MISC_THD_FEATURE, misc_thd_enable); > + if ((misc_thd_enable & MSR_PHI_MISC_THD_FEATURE_R3MWAIT) != 0) > + set_cpu_cap(c, X86_FEATURE_PHIR3MWAIT); I didn't realize this bit is not a CPUID bit, sorry. In that case, you can move that code into init_intel() in arch/x86/kernel/cpu/intel.c, i.e., vendor-specific code. -- Regards/Gruss, Boris. SUSE Linux GmbH, GF: Felix Imendörffer, Jane Smithard, Graham Norton, HRB 21284 (AG Nürnberg) --