From patchwork Thu Feb 13 21:59:56 2020 Content-Type: text/plain; charset="utf-8" MIME-Version: 1.0 Content-Transfer-Encoding: 7bit X-Patchwork-Submitter: "Rafael J. Wysocki" X-Patchwork-Id: 11381359 Return-Path: Received: from mail.kernel.org (pdx-korg-mail-1.web.codeaurora.org [172.30.200.123]) by pdx-korg-patchwork-2.web.codeaurora.org (Postfix) with ESMTP id F056417F0 for ; Thu, 13 Feb 2020 22:05:25 +0000 (UTC) Received: from vger.kernel.org (vger.kernel.org [209.132.180.67]) by mail.kernel.org (Postfix) with ESMTP id D9704217F4 for ; Thu, 13 Feb 2020 22:05:25 +0000 (UTC) Received: (majordomo@vger.kernel.org) by vger.kernel.org via listexpand id S1728483AbgBMWFI (ORCPT ); Thu, 13 Feb 2020 17:05:08 -0500 Received: from cloudserver094114.home.pl ([79.96.170.134]:57327 "EHLO cloudserver094114.home.pl" rhost-flags-OK-OK-OK-OK) by vger.kernel.org with ESMTP id S1728398AbgBMWFH (ORCPT ); Thu, 13 Feb 2020 17:05:07 -0500 Received: from 79.184.254.199.ipv4.supernova.orange.pl (79.184.254.199) (HELO kreacher.localnet) by serwer1319399.home.pl (79.96.170.134) with SMTP (IdeaSmtpServer 0.83.341) id 73a572daf3199568; Thu, 13 Feb 2020 23:05:05 +0100 From: "Rafael J. Wysocki" To: Linux PM Cc: Len Brown , LKML , Zhang Rui , "Rafael J. Wysocki" , Chen Yu Subject: [PATCH 2/9] intel_idle: Clean up definitions of cpuidle callbacks Date: Thu, 13 Feb 2020 22:59:56 +0100 Message-ID: <1923258.fxMWiWM92A@kreacher> In-Reply-To: <2960689.qre192dJKD@kreacher> References: <2960689.qre192dJKD@kreacher> MIME-Version: 1.0 Sender: linux-pm-owner@vger.kernel.org Precedence: bulk List-ID: X-Mailing-List: linux-pm@vger.kernel.org From: "Rafael J. Wysocki" Add proper kerneldoc descriptions to intel_idle() and intel_idle_s2idle(), annotate the latter with __cpuidle and reorder the declarations of local variables in both of them to reflect the mwait_idle_with_hints() arguments order. No intentional functional impact. Signed-off-by: Rafael J. Wysocki --- drivers/idle/intel_idle.c | 39 +++++++++++++++++++++++++++------------ 1 file changed, 27 insertions(+), 12 deletions(-) diff --git a/drivers/idle/intel_idle.c b/drivers/idle/intel_idle.c index 8d66efc53b89..5adc058c705d 100644 --- a/drivers/idle/intel_idle.c +++ b/drivers/idle/intel_idle.c @@ -892,19 +892,28 @@ static struct cpuidle_state dnv_cstates[] = { }; /** - * intel_idle - * @dev: cpuidle_device - * @drv: cpuidle driver - * @index: index of cpuidle state + * intel_idle - Ask the processor to enter the given idle state. + * @dev: cpuidle device of the target CPU. + * @drv: cpuidle driver (assumed to point to intel_idle_driver). + * @index: Target idle state index. + * + * Use the MWAIT instruction to notify the processor that the CPU represented by + * @dev is idle and it can try to enter the idle state corresponding to @index. + * + * If the local APIC timer is not known to be reliable in the target idle state, + * enable one-shot tick broadcasting for the target CPU before executing MWAIT. + * + * Optionally call leave_mm() for the target CPU upfront to avoid wakeups due to + * flushing user TLBs. * * Must be called under local_irq_disable(). */ static __cpuidle int intel_idle(struct cpuidle_device *dev, struct cpuidle_driver *drv, int index) { - unsigned long ecx = 1; /* break on interrupt flag */ struct cpuidle_state *state = &drv->states[index]; unsigned long eax = flg2MWAIT(state->flags); + unsigned long ecx = 1; /* break on interrupt flag */ bool uninitialized_var(tick); int cpu = smp_processor_id(); @@ -937,16 +946,22 @@ static __cpuidle int intel_idle(struct cpuidle_device *dev, } /** - * intel_idle_s2idle - simplified "enter" callback routine for suspend-to-idle - * @dev: cpuidle_device - * @drv: cpuidle driver - * @index: state index + * intel_idle_s2idle - Ask the processor to enter the given idle state. + * @dev: cpuidle device of the target CPU. + * @drv: cpuidle driver (assumed to point to intel_idle_driver). + * @index: Target idle state index. + * + * Use the MWAIT instruction to notify the processor that the CPU represented by + * @dev is idle and it can try to enter the idle state corresponding to @index. + * + * Invoked as a suspend-to-idle callback routine with frozen user space, frozen + * scheduler tick and suspended scheduler clock on the target CPU. */ -static void intel_idle_s2idle(struct cpuidle_device *dev, - struct cpuidle_driver *drv, int index) +static __cpuidle void intel_idle_s2idle(struct cpuidle_device *dev, + struct cpuidle_driver *drv, int index) { - unsigned long ecx = 1; /* break on interrupt flag */ unsigned long eax = flg2MWAIT(drv->states[index].flags); + unsigned long ecx = 1; /* break on interrupt flag */ mwait_idle_with_hints(eax, ecx); }