Return-Path: Received: (majordomo@vger.kernel.org) by vger.kernel.org via listexpand id S1753694AbaA3OKL (ORCPT ); Thu, 30 Jan 2014 09:10:11 -0500 Received: from mail-ea0-f175.google.com ([209.85.215.175]:53823 "EHLO mail-ea0-f175.google.com" rhost-flags-OK-OK-OK-OK) by vger.kernel.org with ESMTP id S1753305AbaA3OJZ (ORCPT ); Thu, 30 Jan 2014 09:09:25 -0500 From: Daniel Lezcano To: nicolas.pitre@linaro.org, peterz@infradead.org, mingo@redhat.com, tglx@linutronix.de, rjw@rjwysocki.net Cc: linux-kernel@vger.kernel.org, linux-pm@vger.kernel.org, linaro-kernel@lists.linaro.org Subject: [RFC PATCH 1/3] cpuidle: split cpuidle_idle_call main function into functions Date: Thu, 30 Jan 2014 15:09:20 +0100 Message-Id: <1391090962-15032-2-git-send-email-daniel.lezcano@linaro.org> X-Mailer: git-send-email 1.7.9.5 In-Reply-To: <1391090962-15032-1-git-send-email-daniel.lezcano@linaro.org> References: <1391090962-15032-1-git-send-email-daniel.lezcano@linaro.org> Sender: linux-kernel-owner@vger.kernel.org List-ID: X-Mailing-List: linux-kernel@vger.kernel.org In order to allow better integration between the cpuidle framework and the scheduler, reducing the distance between the sub-component helps. This patch splits the cpuidle_idle_call main entry function into 3 big chunks of API: 1. select the idle state 2. enter the idle state 3. reflect the idle state The cpuidle_idle_call now calls these three functions to implement the main idle entry function. Signed-off-by: Daniel Lezcano --- drivers/cpuidle/cpuidle.c | 105 ++++++++++++++++++++++++++++++++------------- include/linux/cpuidle.h | 7 +++ 2 files changed, 83 insertions(+), 29 deletions(-) diff --git a/drivers/cpuidle/cpuidle.c b/drivers/cpuidle/cpuidle.c index a55e68f..a8fbb28 100644 --- a/drivers/cpuidle/cpuidle.c +++ b/drivers/cpuidle/cpuidle.c @@ -108,6 +108,74 @@ int cpuidle_enter_state(struct cpuidle_device *dev, struct cpuidle_driver *drv, } /** + * cpuidle_select - ask the cpuidle framework to choose an idle state + * + * @drv: the cpuidle driver + * @dev: the cpuidle device + * + * Returns the index of the idle state. On error it returns: + * -NODEV : the cpuidle framework is available + * -EBUSY : the cpuidle framework is not initialized + */ +int cpuidle_select(struct cpuidle_driver *drv, struct cpuidle_device *dev) +{ + if (off || !initialized) + return -ENODEV; + + if (!drv || !dev || !dev->enabled) + return -EBUSY; + + return cpuidle_curr_governor->select(drv, dev); +} +EXPORT_SYMBOL(cpuidle_select); + +/** + * cpuidle_enter - enter into the specified idle state + * + * @drv: the cpuidle driver tied with the cpu + * @dev: the cpuidle device + * @index: the index in the idle state table + * + * Returns the index in the idle state, < 0 in case of error. + * The error code depends on the backend driver + */ +int cpuidle_enter(struct cpuidle_driver *drv, struct cpuidle_device *dev, + int index) +{ + int entered_state; + bool broadcast = !!(drv->states[index].flags & CPUIDLE_FLAG_TIMER_STOP); + + if (broadcast) + clockevents_notify(CLOCK_EVT_NOTIFY_BROADCAST_ENTER, &dev->cpu); + + if (cpuidle_state_is_coupled(dev, drv, index)) + entered_state = cpuidle_enter_state_coupled(dev, drv, index); + else + entered_state = cpuidle_enter_state(dev, drv, index); + + if (broadcast) + clockevents_notify(CLOCK_EVT_NOTIFY_BROADCAST_EXIT, &dev->cpu); + + return entered_state; +} +EXPORT_SYMBOL(cpuidle_enter); + +/** + * cpuidle_reflect - tell the underlying governor what was the state + * we were in + * + * @dev : the cpuidle device + * @index: the index in the idle state table + * + */ +void cpuidle_reflect(struct cpuidle_device *dev, int index) +{ + if (cpuidle_curr_governor->reflect) + cpuidle_curr_governor->reflect(dev, index); +} +EXPORT_SYMBOL(cpuidle_reflect); + +/** * cpuidle_idle_call - the main idle loop * * NOTE: no locks or semaphores should be used here @@ -116,51 +184,30 @@ int cpuidle_enter_state(struct cpuidle_device *dev, struct cpuidle_driver *drv, int cpuidle_idle_call(void) { struct cpuidle_device *dev = __this_cpu_read(cpuidle_devices); - struct cpuidle_driver *drv; + struct cpuidle_driver *drv = cpuidle_get_cpu_driver(dev); int next_state, entered_state; - bool broadcast; - - if (off || !initialized) - return -ENODEV; - - /* check if the device is ready */ - if (!dev || !dev->enabled) - return -EBUSY; - - drv = cpuidle_get_cpu_driver(dev); /* ask the governor for the next state */ - next_state = cpuidle_curr_governor->select(drv, dev); + next_state = cpuidle_select(drv, dev); + if (next_state < 0) + return next_state; + if (need_resched()) { dev->last_residency = 0; /* give the governor an opportunity to reflect on the outcome */ - if (cpuidle_curr_governor->reflect) - cpuidle_curr_governor->reflect(dev, next_state); + cpuidle_reflect(dev, next_state); local_irq_enable(); return 0; } trace_cpu_idle_rcuidle(next_state, dev->cpu); - broadcast = !!(drv->states[next_state].flags & CPUIDLE_FLAG_TIMER_STOP); - - if (broadcast) - clockevents_notify(CLOCK_EVT_NOTIFY_BROADCAST_ENTER, &dev->cpu); - - if (cpuidle_state_is_coupled(dev, drv, next_state)) - entered_state = cpuidle_enter_state_coupled(dev, drv, - next_state); - else - entered_state = cpuidle_enter_state(dev, drv, next_state); - - if (broadcast) - clockevents_notify(CLOCK_EVT_NOTIFY_BROADCAST_EXIT, &dev->cpu); + entered_state = cpuidle_enter(drv, dev, next_state); trace_cpu_idle_rcuidle(PWR_EVENT_EXIT, dev->cpu); /* give the governor an opportunity to reflect on the outcome */ - if (cpuidle_curr_governor->reflect) - cpuidle_curr_governor->reflect(dev, entered_state); + cpuidle_reflect(dev, entered_state); return 0; } diff --git a/include/linux/cpuidle.h b/include/linux/cpuidle.h index 50fcbb0..1ebe9ff 100644 --- a/include/linux/cpuidle.h +++ b/include/linux/cpuidle.h @@ -119,6 +119,13 @@ struct cpuidle_driver { #ifdef CONFIG_CPU_IDLE extern void disable_cpuidle(void); + +extern int cpuidle_select(struct cpuidle_driver *drv, + struct cpuidle_device *dev); +extern int cpuidle_enter(struct cpuidle_driver *drv, + struct cpuidle_device *dev, int index); +extern void cpuidle_reflect(struct cpuidle_device *dev, int index); + extern int cpuidle_idle_call(void); extern int cpuidle_register_driver(struct cpuidle_driver *drv); extern struct cpuidle_driver *cpuidle_get_driver(void); -- 1.7.9.5 -- To unsubscribe from this list: send the line "unsubscribe linux-kernel" in the body of a message to majordomo@vger.kernel.org More majordomo info at http://vger.kernel.org/majordomo-info.html Please read the FAQ at http://www.tux.org/lkml/