From mboxrd@z Thu Jan 1 00:00:00 1970 Return-Path: Received: (majordomo@vger.kernel.org) by vger.kernel.org via listexpand id S1754684Ab1FMAoU (ORCPT ); Sun, 12 Jun 2011 20:44:20 -0400 Received: from smtp-out.google.com ([216.239.44.51]:26227 "EHLO smtp-out.google.com" rhost-flags-OK-OK-OK-OK) by vger.kernel.org with ESMTP id S1753964Ab1FMAoR (ORCPT ); Sun, 12 Jun 2011 20:44:17 -0400 From: Colin Cross To: linux-arm-kernel@lists.infradead.org Cc: linux-kernel@vger.kernel.org, Russell King , Catalin Marinas , Santosh Shilimkar , Colin Cross Subject: [PATCH 3/3] ARM: vfp: Use cpu pm notifiers to save vfp state Date: Sun, 12 Jun 2011 17:43:45 -0700 Message-Id: <1307925825-28566-4-git-send-email-ccross@android.com> X-Mailer: git-send-email 1.7.4.1 In-Reply-To: <1307925825-28566-1-git-send-email-ccross@android.com> References: <1307925825-28566-1-git-send-email-ccross@android.com> X-System-Of-Record: true Sender: linux-kernel-owner@vger.kernel.org List-ID: X-Mailing-List: linux-kernel@vger.kernel.org When the cpu is powered down in a low power mode, the vfp registers may be reset. This patch uses CPU_PM_ENTER and CPU_PM_EXIT notifiers to save and restore the cpu's vfp registers. Signed-off-by: Colin Cross --- arch/arm/vfp/vfpmodule.c | 40 ++++++++++++++++++++++++++++++++++++++++ 1 files changed, 40 insertions(+), 0 deletions(-) diff --git a/arch/arm/vfp/vfpmodule.c b/arch/arm/vfp/vfpmodule.c index f25e7ec..6f08dbe 100644 --- a/arch/arm/vfp/vfpmodule.c +++ b/arch/arm/vfp/vfpmodule.c @@ -21,6 +21,7 @@ #include #include #include +#include #include "vfpinstr.h" #include "vfp.h" @@ -169,6 +170,44 @@ static struct notifier_block vfp_notifier_block = { .notifier_call = vfp_notifier, }; +#ifdef CONFIG_CPU_PM +static int vfp_cpu_pm_notifier(struct notifier_block *self, unsigned long cmd, + void *v) +{ + u32 fpexc = fmrx(FPEXC); + unsigned int cpu = smp_processor_id(); + + switch (cmd) { + case CPU_PM_ENTER: + if (last_VFP_context[cpu]) { + fmxr(FPEXC, fpexc | FPEXC_EN); + vfp_save_state(last_VFP_context[cpu], fpexc); + /* force a reload when coming back from idle */ + last_VFP_context[cpu] = NULL; + fmxr(FPEXC, fpexc & ~FPEXC_EN); + } + break; + case CPU_PM_ENTER_FAILED: + case CPU_PM_EXIT: + /* make sure VFP is disabled when leaving idle */ + fmxr(FPEXC, fpexc & ~FPEXC_EN); + break; + } + return NOTIFY_OK; +} + +static struct notifier_block vfp_cpu_pm_notifier_block = { + .notifier_call = vfp_cpu_pm_notifier, +}; + +static void vfp_cpu_pm_init(void) +{ + cpu_pm_register_notifier(&vfp_cpu_pm_notifier_block); +} +#else +static inline void vfp_cpu_pm_init(void) { } +#endif + /* * Raise a SIGFPE for the current process. * sicode describes the signal being raised. @@ -563,6 +602,7 @@ static int __init vfp_init(void) vfp_vector = vfp_support_entry; thread_register_notifier(&vfp_notifier_block); + vfp_cpu_pm_init(); vfp_pm_init(); /* -- 1.7.4.1