From mboxrd@z Thu Jan 1 00:00:00 1970 Return-Path: Received: (majordomo@vger.kernel.org) by vger.kernel.org via listexpand id S1161162AbcFQUNf (ORCPT ); Fri, 17 Jun 2016 16:13:35 -0400 Received: from mga04.intel.com ([192.55.52.120]:28876 "EHLO mga04.intel.com" rhost-flags-OK-OK-OK-OK) by vger.kernel.org with ESMTP id S1752886AbcFQUNc (ORCPT ); Fri, 17 Jun 2016 16:13:32 -0400 X-ExtLoop1: 1 X-IronPort-AV: E=Sophos;i="5.26,485,1459839600"; d="scan'208";a="1000213627" From: Yu-cheng Yu To: linux-kernel@vger.kernel.org, x86@kernel.org, "H. Peter Anvin" , Thomas Gleixner , Ingo Molnar Cc: Dave Hansen , Sai Praneeth Prakhya , "Ravi V. Shankar" , Fenghua Yu , Yu-cheng Yu Subject: [PATCH 1/5] x86/fpu/xstate: Align xstate components according to CPUID Date: Fri, 17 Jun 2016 13:07:15 -0700 Message-Id: <331e2bef1a0a7a584f06adde095b6bbfbe166472.1466179491.git.yu-cheng.yu@intel.com> X-Mailer: git-send-email 1.9.1 In-Reply-To: References: In-Reply-To: References: Sender: linux-kernel-owner@vger.kernel.org List-ID: X-Mailing-List: linux-kernel@vger.kernel.org CPUID function 0x0d, sub function (i, i > 1) returns in ecx[1] the alignment requirement of component i when the compacted format is used. If ecx[1] is 0, component i is located immediately following the preceding component. If ecx[1] is 1, component i is located on the next 64-byte boundary following the preceding component. Signed-off-by: Yu-cheng Yu Reviewed-by: Dave Hansen --- arch/x86/kernel/fpu/xstate.c | 60 +++++++++++++++++++++++--------------------- 1 file changed, 32 insertions(+), 28 deletions(-) diff --git a/arch/x86/kernel/fpu/xstate.c b/arch/x86/kernel/fpu/xstate.c index 0b01f00..e6fcfcc6 100644 --- a/arch/x86/kernel/fpu/xstate.c +++ b/arch/x86/kernel/fpu/xstate.c @@ -270,6 +270,33 @@ static void __init print_xstate_features(void) } /* + * This check is important because it is easy to get XSTATE_* + * confused with XSTATE_BIT_*. + */ +#define CHECK_XFEATURE(nr) do { \ + WARN_ON(nr < FIRST_EXTENDED_XFEATURE); \ + WARN_ON(nr >= XFEATURE_MAX); \ +} while (0) + +/* + * We could cache this like xstate_size[], but we only use + * it here, so it would be a waste of space. + */ +static int xfeature_is_aligned(int xfeature_nr) +{ + u32 eax, ebx, ecx, edx; + + CHECK_XFEATURE(xfeature_nr); + cpuid_count(XSTATE_CPUID, xfeature_nr, &eax, &ebx, &ecx, &edx); + /* + * The value returned by ECX[1] indicates the alignment + * of state component i when the compacted format + * of the extended region of an XSAVE area is used + */ + return !!(ecx & 2); +} + +/* * This function sets up offsets and sizes of all extended states in * xsave area. This supports both standard format and compacted format * of the xsave aread. @@ -306,10 +333,14 @@ static void __init setup_xstate_comp(void) else xstate_comp_sizes[i] = 0; - if (i > FIRST_EXTENDED_XFEATURE) + if (i > FIRST_EXTENDED_XFEATURE) { xstate_comp_offsets[i] = xstate_comp_offsets[i-1] + xstate_comp_sizes[i-1]; + if (xfeature_is_aligned(i)) + xstate_comp_offsets[i] = + ALIGN(xstate_comp_offsets[i], 64); + } } } @@ -366,33 +397,6 @@ static int xfeature_is_user(int xfeature_nr) } */ -/* - * This check is important because it is easy to get XSTATE_* - * confused with XSTATE_BIT_*. - */ -#define CHECK_XFEATURE(nr) do { \ - WARN_ON(nr < FIRST_EXTENDED_XFEATURE); \ - WARN_ON(nr >= XFEATURE_MAX); \ -} while (0) - -/* - * We could cache this like xstate_size[], but we only use - * it here, so it would be a waste of space. - */ -static int xfeature_is_aligned(int xfeature_nr) -{ - u32 eax, ebx, ecx, edx; - - CHECK_XFEATURE(xfeature_nr); - cpuid_count(XSTATE_CPUID, xfeature_nr, &eax, &ebx, &ecx, &edx); - /* - * The value returned by ECX[1] indicates the alignment - * of state component i when the compacted format - * of the extended region of an XSAVE area is used - */ - return !!(ecx & 2); -} - static int xfeature_uncompacted_offset(int xfeature_nr) { u32 eax, ebx, ecx, edx; -- 1.9.1