From mboxrd@z Thu Jan 1 00:00:00 1970 Return-Path: Received: (majordomo@vger.kernel.org) by vger.kernel.org via listexpand id S967517Ab0GTBwm (ORCPT ); Mon, 19 Jul 2010 21:52:42 -0400 Received: from hera.kernel.org ([140.211.167.34]:44408 "EHLO hera.kernel.org" rhost-flags-OK-OK-OK-OK) by vger.kernel.org with ESMTP id S967455Ab0GTBwj (ORCPT ); Mon, 19 Jul 2010 21:52:39 -0400 Date: Tue, 20 Jul 2010 01:52:22 GMT From: tip-bot for Suresh Siddha Cc: linux-kernel@vger.kernel.org, hpa@zytor.com, mingo@redhat.com, suresh.b.siddha@intel.com, tglx@linutronix.de, hpa@linux.intel.com Reply-To: mingo@redhat.com, hpa@zytor.com, linux-kernel@vger.kernel.org, suresh.b.siddha@intel.com, tglx@linutronix.de, hpa@linux.intel.com In-Reply-To: <20100719230205.604014179@sbs-t61.sc.intel.com> References: <20100719230205.604014179@sbs-t61.sc.intel.com> To: linux-tip-commits@vger.kernel.org Subject: [tip:x86/xsave] x86, xsave: Use xsaveopt in context-switch path when supported Message-ID: Git-Commit-ID: 6bad06b768920e278c7cedfdda56a0b4c6a35ee9 X-Mailer: tip-git-log-daemon MIME-Version: 1.0 Content-Type: text/plain; charset=UTF-8 Content-Disposition: inline X-Greylist: Sender IP whitelisted, not delayed by milter-greylist-4.2.3 (hera.kernel.org [127.0.0.1]); Tue, 20 Jul 2010 01:52:22 +0000 (UTC) Sender: linux-kernel-owner@vger.kernel.org List-ID: X-Mailing-List: linux-kernel@vger.kernel.org Commit-ID: 6bad06b768920e278c7cedfdda56a0b4c6a35ee9 Gitweb: http://git.kernel.org/tip/6bad06b768920e278c7cedfdda56a0b4c6a35ee9 Author: Suresh Siddha AuthorDate: Mon, 19 Jul 2010 16:05:52 -0700 Committer: H. Peter Anvin CommitDate: Mon, 19 Jul 2010 17:52:24 -0700 x86, xsave: Use xsaveopt in context-switch path when supported xsaveopt is a more optimized form of xsave specifically designed for the context switch usage. xsaveopt doesn't save the state that's not modified from the prior xrstor. And if a specific feature state gets modified to the init state, then xsaveopt just updates the header bit in the xsave memory layout without updating the corresponding memory layout. Signed-off-by: Suresh Siddha LKML-Reference: <20100719230205.604014179@sbs-t61.sc.intel.com> Signed-off-by: H. Peter Anvin --- arch/x86/include/asm/i387.h | 2 +- arch/x86/include/asm/xsave.h | 9 ++++++--- arch/x86/kernel/cpu/common.c | 8 ++++++++ 3 files changed, 15 insertions(+), 4 deletions(-) diff --git a/arch/x86/include/asm/i387.h b/arch/x86/include/asm/i387.h index bb370fd..59bd93a 100644 --- a/arch/x86/include/asm/i387.h +++ b/arch/x86/include/asm/i387.h @@ -60,7 +60,7 @@ extern int restore_i387_xstate_ia32(void __user *buf); static __always_inline __pure bool use_xsaveopt(void) { - return 0; + return static_cpu_has(X86_FEATURE_XSAVEOPT); } static __always_inline __pure bool use_xsave(void) diff --git a/arch/x86/include/asm/xsave.h b/arch/x86/include/asm/xsave.h index 0c72adc..ec86c5f 100644 --- a/arch/x86/include/asm/xsave.h +++ b/arch/x86/include/asm/xsave.h @@ -125,8 +125,11 @@ static inline void fpu_xsave(struct fpu *fpu) { /* This, however, we can work around by forcing the compiler to select an addressing mode that doesn't require extended registers. */ - __asm__ __volatile__(".byte " REX_PREFIX "0x0f,0xae,0x27" - : : "D" (&(fpu->state->xsave)), - "a" (-1), "d"(-1) : "memory"); + alternative_input( + ".byte " REX_PREFIX "0x0f,0xae,0x27", + ".byte " REX_PREFIX "0x0f,0xae,0x37", + X86_FEATURE_XSAVEOPT, + [fx] "D" (&fpu->state->xsave), "a" (-1), "d" (-1) : + "memory"); } #endif diff --git a/arch/x86/kernel/cpu/common.c b/arch/x86/kernel/cpu/common.c index c735830..3f715ef 100644 --- a/arch/x86/kernel/cpu/common.c +++ b/arch/x86/kernel/cpu/common.c @@ -140,10 +140,18 @@ EXPORT_PER_CPU_SYMBOL_GPL(gdt_page); static int __init x86_xsave_setup(char *s) { setup_clear_cpu_cap(X86_FEATURE_XSAVE); + setup_clear_cpu_cap(X86_FEATURE_XSAVEOPT); return 1; } __setup("noxsave", x86_xsave_setup); +static int __init x86_xsaveopt_setup(char *s) +{ + setup_clear_cpu_cap(X86_FEATURE_XSAVEOPT); + return 1; +} +__setup("noxsaveopt", x86_xsaveopt_setup); + #ifdef CONFIG_X86_32 static int cachesize_override __cpuinitdata = -1; static int disable_x86_serial_nr __cpuinitdata = 1;