From patchwork Wed Aug 28 11:35:59 2013 Content-Type: text/plain; charset="utf-8" MIME-Version: 1.0 Content-Transfer-Encoding: 7bit X-Patchwork-Submitter: Lorenzo Pieralisi X-Patchwork-Id: 2850746 Return-Path: X-Original-To: patchwork-linux-arm@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 5AF56BF546 for ; Wed, 28 Aug 2013 12:59:51 +0000 (UTC) Received: from mail.kernel.org (localhost [127.0.0.1]) by mail.kernel.org (Postfix) with ESMTP id 7D24C204AD for ; Wed, 28 Aug 2013 12:59:46 +0000 (UTC) Received: from casper.infradead.org (casper.infradead.org [85.118.1.10]) (using TLSv1 with cipher DHE-RSA-AES256-SHA (256/256 bits)) (No client certificate requested) by mail.kernel.org (Postfix) with ESMTPS id 0C22F204AC for ; Wed, 28 Aug 2013 12:59:45 +0000 (UTC) Received: from merlin.infradead.org ([2001:4978:20e::2]) by casper.infradead.org with esmtps (Exim 4.80.1 #2 (Red Hat Linux)) id 1VEe4N-0003to-GG; Wed, 28 Aug 2013 11:37:52 +0000 Received: from localhost ([::1] helo=merlin.infradead.org) by merlin.infradead.org with esmtp (Exim 4.80.1 #2 (Red Hat Linux)) id 1VEe3X-0000xl-9A; Wed, 28 Aug 2013 11:36:59 +0000 Received: from service87.mimecast.com ([91.220.42.44]) by merlin.infradead.org with esmtp (Exim 4.80.1 #2 (Red Hat Linux)) id 1VEe2y-0000rd-Ih for linux-arm-kernel@lists.infradead.org; Wed, 28 Aug 2013 11:36:29 +0000 Received: from cam-owa2.Emea.Arm.com (fw-tnat.cambridge.arm.com [217.140.96.21]) by service87.mimecast.com; Wed, 28 Aug 2013 12:36:06 +0100 Received: from red-moon.cambridge.arm.com ([10.1.255.212]) by cam-owa2.Emea.Arm.com with Microsoft SMTPSVC(6.0.3790.3959); Wed, 28 Aug 2013 12:36:04 +0100 From: Lorenzo Pieralisi To: linux-pm@vger.kernel.org, linux-arm-kernel@lists.infradead.org Subject: [RFC PATCH 07/14] arm64: kernel: implement fpsimd CPU PM notifier Date: Wed, 28 Aug 2013 12:35:59 +0100 Message-Id: <1377689766-17642-8-git-send-email-lorenzo.pieralisi@arm.com> X-Mailer: git-send-email 1.8.3.4 In-Reply-To: <1377689766-17642-1-git-send-email-lorenzo.pieralisi@arm.com> References: <1377689766-17642-1-git-send-email-lorenzo.pieralisi@arm.com> X-OriginalArrivalTime: 28 Aug 2013 11:36:04.0719 (UTC) FILETIME=[C79C9FF0:01CEA3E2] X-MC-Unique: 113082812360601501 X-CRM114-Version: 20100106-BlameMichelson ( TRE 0.8.0 (BSD) ) MR-646709E3 X-CRM114-CacheID: sfid-20130828_073625_026250_D1BDAB5F X-CRM114-Status: GOOD ( 13.35 ) X-Spam-Score: -2.6 (--) Cc: Mark Rutland , Feng Kan , Stephen Boyd , Lorenzo Pieralisi , Russell King , Graeme Gregory , Nicolas Pitre , Marc Zyngier , Catalin Marinas , Yu Tang , Will Deacon , Sudeep KarkadaNagesha , Santosh Shilimkar , Loc Ho , Colin Cross , Kumar Sankaran , Dave Martin , Hanjun Guo , Zhou Zhu X-BeenThere: linux-arm-kernel@lists.infradead.org X-Mailman-Version: 2.1.15 Precedence: list List-Id: List-Unsubscribe: , List-Archive: List-Post: List-Help: List-Subscribe: , MIME-Version: 1.0 Sender: "linux-arm-kernel" Errors-To: linux-arm-kernel-bounces+patchwork-linux-arm=patchwork.kernel.org@lists.infradead.org X-Spam-Status: No, score=-6.7 required=5.0 tests=BAYES_00, RCVD_IN_DNSWL_MED, RP_MATCHES_RCVD, UNPARSEABLE_RELAY autolearn=unavailable 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 e8b8357..b5b94f6 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 @@ -83,6 +84,39 @@ void fpsimd_flush_thread(void) fpsimd_load_state(¤t->thread.fpsimd_state); } +#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. */ @@ -101,6 +135,8 @@ static int __init fpsimd_init(void) else elf_hwcap |= HWCAP_ASIMD; + fpsimd_pm_init(); + return 0; } late_initcall(fpsimd_init);