From patchwork Thu Nov 21 11:24:12 2013 Content-Type: text/plain; charset="utf-8" MIME-Version: 1.0 Content-Transfer-Encoding: 7bit X-Patchwork-Submitter: Lorenzo Pieralisi X-Patchwork-Id: 3217551 Return-Path: X-Original-To: patchwork-linux-pm@patchwork.kernel.org Delivered-To: patchwork-parsemail@patchwork2.web.kernel.org Received: from mail.kernel.org (mail.kernel.org [198.145.19.201]) by patchwork2.web.kernel.org (Postfix) with ESMTP id E0051C045B for ; Thu, 21 Nov 2013 11:25:15 +0000 (UTC) Received: from mail.kernel.org (localhost [127.0.0.1]) by mail.kernel.org (Postfix) with ESMTP id C88EB2078B for ; Thu, 21 Nov 2013 11:25:13 +0000 (UTC) Received: from vger.kernel.org (vger.kernel.org [209.132.180.67]) by mail.kernel.org (Postfix) with ESMTP id AE75C2074A for ; Thu, 21 Nov 2013 11:25:12 +0000 (UTC) Received: (majordomo@vger.kernel.org) by vger.kernel.org via listexpand id S1753935Ab3KULY4 (ORCPT ); Thu, 21 Nov 2013 06:24:56 -0500 Received: from service87.mimecast.com ([91.220.42.44]:32929 "EHLO service87.mimecast.com" rhost-flags-OK-OK-OK-OK) by vger.kernel.org with ESMTP id S1753861Ab3KULYz (ORCPT ); Thu, 21 Nov 2013 06:24:55 -0500 Received: from cam-owa1.Emea.Arm.com (fw-tnat.cambridge.arm.com [217.140.96.21]) by service87.mimecast.com; Thu, 21 Nov 2013 11:24:52 +0000 Received: from red-moon.cambridge.arm.com ([10.1.255.212]) by cam-owa1.Emea.Arm.com with Microsoft SMTPSVC(6.0.3790.3959); Thu, 21 Nov 2013 11:24:51 +0000 From: Lorenzo Pieralisi To: linux-arm-kernel@lists.infradead.org, linux-pm@vger.kernel.org Cc: Lorenzo Pieralisi , Dave Martin , Will Deacon , Catalin Marinas , Marc Zyngier , Mark Rutland , Sudeep KarkadaNagesha , Russell King , Colin Cross , Yu Tang , Zhou Zhu , Kumar Sankaran , Loc Ho , Feng Kan , Nicolas Pitre , Santosh Shilimkar , Stephen Boyd , Graeme Gregory , Hanjun Guo , Daniel Lezcano , Christoffer Dall Subject: [PATCH RFC v3 05/12] arm64: kernel: implement fpsimd CPU PM notifier Date: Thu, 21 Nov 2013 11:24:12 +0000 Message-Id: <1385033059-25896-6-git-send-email-lorenzo.pieralisi@arm.com> X-Mailer: git-send-email 1.8.4 In-Reply-To: <1385033059-25896-1-git-send-email-lorenzo.pieralisi@arm.com> References: <1385033059-25896-1-git-send-email-lorenzo.pieralisi@arm.com> X-OriginalArrivalTime: 21 Nov 2013 11:24:51.0816 (UTC) FILETIME=[4BA48680:01CEE6AC] X-MC-Unique: 113112111245300301 Sender: linux-pm-owner@vger.kernel.org Precedence: bulk List-ID: X-Mailing-List: linux-pm@vger.kernel.org X-Spam-Status: No, score=-7.4 required=5.0 tests=BAYES_00, RCVD_IN_DNSWL_HI, RP_MATCHES_RCVD, UNPARSEABLE_RELAY autolearn=ham version=3.3.1 X-Spam-Checker-Version: SpamAssassin 3.3.1 (2010-03-16) on mail.kernel.org X-Virus-Scanned: ClamAV using ClamSMTP When a CPU enters a low power state, its FP register content is lost. This patch adds a notifier to save the FP context on CPU shutdown and restore it on CPU resume. The context is saved and restored only if the suspending thread is not a kernel thread, mirroring the current context switch behaviour. Signed-off-by: Lorenzo Pieralisi --- arch/arm64/kernel/fpsimd.c | 36 ++++++++++++++++++++++++++++++++++++ 1 file changed, 36 insertions(+) diff --git a/arch/arm64/kernel/fpsimd.c b/arch/arm64/kernel/fpsimd.c index bb785d2..4aef42a 100644 --- a/arch/arm64/kernel/fpsimd.c +++ b/arch/arm64/kernel/fpsimd.c @@ -17,6 +17,7 @@ * along with this program. If not, see . */ +#include #include #include #include @@ -113,6 +114,39 @@ EXPORT_SYMBOL(kernel_neon_end); #endif /* CONFIG_KERNEL_MODE_NEON */ +#ifdef CONFIG_CPU_PM +static int fpsimd_cpu_pm_notifier(struct notifier_block *self, + unsigned long cmd, void *v) +{ + switch (cmd) { + case CPU_PM_ENTER: + if (current->mm) + fpsimd_save_state(¤t->thread.fpsimd_state); + break; + case CPU_PM_EXIT: + if (current->mm) + fpsimd_load_state(¤t->thread.fpsimd_state); + break; + case CPU_PM_ENTER_FAILED: + default: + return NOTIFY_DONE; + } + return NOTIFY_OK; +} + +static struct notifier_block fpsimd_cpu_pm_notifier_block = { + .notifier_call = fpsimd_cpu_pm_notifier, +}; + +static void fpsimd_pm_init(void) +{ + cpu_pm_register_notifier(&fpsimd_cpu_pm_notifier_block); +} + +#else +static inline void fpsimd_pm_init(void) { } +#endif /* CONFIG_CPU_PM */ + /* * FP/SIMD support code initialisation. */ @@ -131,6 +165,8 @@ static int __init fpsimd_init(void) else elf_hwcap |= HWCAP_ASIMD; + fpsimd_pm_init(); + return 0; } late_initcall(fpsimd_init);