From mboxrd@z Thu Jan 1 00:00:00 1970 Return-Path: Received: (majordomo@vger.kernel.org) by vger.kernel.org via listexpand id S1755572AbcAXWi0 (ORCPT ); Sun, 24 Jan 2016 17:38:26 -0500 Received: from mail.kernel.org ([198.145.29.136]:41805 "EHLO mail.kernel.org" rhost-flags-OK-OK-OK-OK) by vger.kernel.org with ESMTP id S1753531AbcAXWiT (ORCPT ); Sun, 24 Jan 2016 17:38:19 -0500 From: Andy Lutomirski To: x86@kernel.org, linux-kernel@vger.kernel.org Cc: Borislav Petkov , Fenghua Yu , Oleg Nesterov , Peter Zijlstra , Sai Praneeth Prakhya , yu-cheng yu , Dave Hansen , Rik van Riel , Linus Torvalds , Andy Lutomirski Subject: [PATCH v2 3/5] x86/fpu: Fold fpu_copy into fpu__copy Date: Sun, 24 Jan 2016 14:38:08 -0800 Message-Id: <3eb5a63a9c5c84077b2677a7dfe684eef96fe59e.1453675014.git.luto@kernel.org> X-Mailer: git-send-email 2.5.0 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 Splitting it into two functions needlessly obfuscated the code. While we're at it, improve the comment slightly. Signed-off-by: Andy Lutomirski --- arch/x86/kernel/fpu/core.c | 32 +++++++++++--------------------- 1 file changed, 11 insertions(+), 21 deletions(-) diff --git a/arch/x86/kernel/fpu/core.c b/arch/x86/kernel/fpu/core.c index 7a9244df33e2..299b58bb975b 100644 --- a/arch/x86/kernel/fpu/core.c +++ b/arch/x86/kernel/fpu/core.c @@ -231,14 +231,15 @@ void fpstate_init(union fpregs_state *state) } EXPORT_SYMBOL_GPL(fpstate_init); -/* - * Copy the current task's FPU state to a new task's FPU context. - * - * In both the 'eager' and the 'lazy' case we save hardware registers - * directly to the destination buffer. - */ -static void fpu_copy(struct fpu *dst_fpu, struct fpu *src_fpu) +int fpu__copy(struct fpu *dst_fpu, struct fpu *src_fpu) { + dst_fpu->counter = 0; + dst_fpu->fpregs_active = 0; + dst_fpu->last_cpu = -1; + + if (!src_fpu->fpstate_active || !cpu_has_fpu) + return 0; + WARN_ON_FPU(src_fpu != ¤t->thread.fpu); /* @@ -251,10 +252,9 @@ static void fpu_copy(struct fpu *dst_fpu, struct fpu *src_fpu) /* * Save current FPU registers directly into the child * FPU context, without any memory-to-memory copying. - * - * If the FPU context got destroyed in the process (FNSAVE - * done on old CPUs) then copy it back into the source - * context and mark the current task for lazy restore. + * In lazy mode, if the FPU context isn't loaded into + * fpregs, CR0.TS will be set and do_device_not_available + * will load the FPU context. * * We have to do all this with preemption disabled, * mostly because of the FNSAVE case, because in that @@ -274,16 +274,6 @@ static void fpu_copy(struct fpu *dst_fpu, struct fpu *src_fpu) fpregs_deactivate(src_fpu); } preempt_enable(); -} - -int fpu__copy(struct fpu *dst_fpu, struct fpu *src_fpu) -{ - dst_fpu->counter = 0; - dst_fpu->fpregs_active = 0; - dst_fpu->last_cpu = -1; - - if (src_fpu->fpstate_active && cpu_has_fpu) - fpu_copy(dst_fpu, src_fpu); return 0; } -- 2.5.0