From patchwork Wed Nov 7 19:48:46 2018 Content-Type: text/plain; charset="utf-8" MIME-Version: 1.0 Content-Transfer-Encoding: 7bit X-Patchwork-Submitter: Sebastian Andrzej Siewior X-Patchwork-Id: 10672975 Return-Path: Received: from mail.wl.linuxfoundation.org (pdx-wl-mail.web.codeaurora.org [172.30.200.125]) by pdx-korg-patchwork-2.web.codeaurora.org (Postfix) with ESMTP id 20EBA15A6 for ; Wed, 7 Nov 2018 19:51:12 +0000 (UTC) Received: from mail.wl.linuxfoundation.org (localhost [127.0.0.1]) by mail.wl.linuxfoundation.org (Postfix) with ESMTP id 11BCF2CFD1 for ; Wed, 7 Nov 2018 19:51:12 +0000 (UTC) Received: by mail.wl.linuxfoundation.org (Postfix, from userid 486) id 100982CFF9; Wed, 7 Nov 2018 19:51:12 +0000 (UTC) X-Spam-Checker-Version: SpamAssassin 3.3.1 (2010-03-16) on pdx-wl-mail.web.codeaurora.org X-Spam-Level: X-Spam-Status: No, score=-7.9 required=2.0 tests=BAYES_00,MAILING_LIST_MULTI, RCVD_IN_DNSWL_HI autolearn=ham version=3.3.1 Received: from vger.kernel.org (vger.kernel.org [209.132.180.67]) by mail.wl.linuxfoundation.org (Postfix) with ESMTP id 8A8422CFF4 for ; Wed, 7 Nov 2018 19:51:11 +0000 (UTC) Received: (majordomo@vger.kernel.org) by vger.kernel.org via listexpand id S1727529AbeKHFVM (ORCPT ); Thu, 8 Nov 2018 00:21:12 -0500 Received: from Galois.linutronix.de ([146.0.238.70]:41899 "EHLO Galois.linutronix.de" rhost-flags-OK-OK-OK-OK) by vger.kernel.org with ESMTP id S1727337AbeKHFVM (ORCPT ); Thu, 8 Nov 2018 00:21:12 -0500 Received: from localhost ([127.0.0.1] helo=bazinga.breakpoint.cc) by Galois.linutronix.de with esmtp (Exim 4.80) (envelope-from ) id 1gKTpD-00070Q-C9; Wed, 07 Nov 2018 20:49:16 +0100 From: Sebastian Andrzej Siewior To: linux-kernel@vger.kernel.org Cc: x86@kernel.org, Andy Lutomirski , Paolo Bonzini , =?utf-8?b?UmFkaW0gS3LEjW3DocWZ?= , kvm@vger.kernel.org, "Jason A. Donenfeld" , Rik van Riel , Dave Hansen , Sebastian Andrzej Siewior Subject: [PATCH 11/23] x86/fpu: Add (__)make_fpregs_active helpers Date: Wed, 7 Nov 2018 20:48:46 +0100 Message-Id: <20181107194858.9380-12-bigeasy@linutronix.de> X-Mailer: git-send-email 2.19.1 In-Reply-To: <20181107194858.9380-1-bigeasy@linutronix.de> References: <20181107194858.9380-1-bigeasy@linutronix.de> MIME-Version: 1.0 Sender: kvm-owner@vger.kernel.org Precedence: bulk List-ID: X-Mailing-List: kvm@vger.kernel.org X-Virus-Scanned: ClamAV using ClamSMTP From: Rik van Riel Add helper function that ensures the floating point registers for the current task are active. Use with preemption disabled. Signed-off-by: Rik van Riel Signed-off-by: Sebastian Andrzej Siewior --- arch/x86/include/asm/fpu/api.h | 11 +++++++++++ arch/x86/include/asm/fpu/internal.h | 26 ++++++++++++++++---------- 2 files changed, 27 insertions(+), 10 deletions(-) diff --git a/arch/x86/include/asm/fpu/api.h b/arch/x86/include/asm/fpu/api.h index a9caac9d4a729..8c03b42416656 100644 --- a/arch/x86/include/asm/fpu/api.h +++ b/arch/x86/include/asm/fpu/api.h @@ -10,6 +10,7 @@ #ifndef _ASM_X86_FPU_API_H #define _ASM_X86_FPU_API_H +#include /* * Careful: __kernel_fpu_begin/end() must be called with preempt disabled @@ -27,6 +28,16 @@ extern void kernel_fpu_begin(void); extern void kernel_fpu_end(void); extern bool irq_fpu_usable(void); +static inline void __fpregs_changes_begin(void) +{ + preempt_disable(); +} + +static inline void __fpregs_changes_end(void) +{ + preempt_enable(); +} + /* * Query the presence of one or more xfeatures. Works on any legacy CPU as well. * diff --git a/arch/x86/include/asm/fpu/internal.h b/arch/x86/include/asm/fpu/internal.h index d7f9e14c73c19..260cd4f4ba2bb 100644 --- a/arch/x86/include/asm/fpu/internal.h +++ b/arch/x86/include/asm/fpu/internal.h @@ -512,6 +512,20 @@ static inline void fpregs_activate(struct fpu *fpu) trace_x86_fpu_regs_activated(fpu); } +/* + * Load the FPU state for the current task. Call with preemption disabled. + */ +static inline void __fpregs_load_activate(struct fpu *fpu, int cpu) +{ + if (!fpregs_state_valid(fpu, cpu)) { + if (current->mm) + copy_kernel_to_fpregs(&fpu->state); + else + copy_kernel_to_fpregs(&init_fpstate); + } + fpregs_activate(fpu); +} + /* * FPU state switching for scheduling. * @@ -547,16 +561,8 @@ switch_fpu_prepare(struct fpu *old_fpu, int cpu) */ static inline void switch_fpu_finish(struct fpu *new_fpu, int cpu) { - if (static_cpu_has(X86_FEATURE_FPU)) { - if (!fpregs_state_valid(new_fpu, cpu)) { - if (current->mm) - copy_kernel_to_fpregs(&new_fpu->state); - else - copy_kernel_to_fpregs(&init_fpstate); - } - - fpregs_activate(new_fpu); - } + if (static_cpu_has(X86_FEATURE_FPU)) + __fpregs_load_activate(new_fpu, cpu); } /*