Release 4.14 drivers/cpuidle/cpuidle-arm.c

/*
 * ARM/ARM64 generic CPU idle driver.
 *
 * Copyright (C) 2014 ARM Ltd.
 * Author: Lorenzo Pieralisi <lorenzo.pieralisi@arm.com>
 *
 * This program is free software; you can redistribute it and/or modify
 * it under the terms of the GNU General Public License version 2 as
 * published by the Free Software Foundation.
 */


#define pr_fmt(fmt) "CPUidle arm: " fmt

#include <linux/cpuidle.h>
#include <linux/cpumask.h>
#include <linux/cpu_pm.h>
#include <linux/kernel.h>
#include <linux/module.h>
#include <linux/of.h>
#include <linux/slab.h>
#include <linux/topology.h>

#include <asm/cpuidle.h>

#include "dt_idle_states.h"

/*
 * arm_enter_idle_state - Programs CPU to enter the specified state
 *
 * dev: cpuidle device
 * drv: cpuidle driver
 * idx: state index
 *
 * Called from the CPUidle framework to program the device to the
 * specified target state selected by the governor.
 */


static int arm_enter_idle_state(struct cpuidle_device *dev,
				struct cpuidle_driver *drv, int idx)
{
	/*
         * Pass idle state index to arm_cpuidle_suspend which in turn
         * will call the CPU ops suspend protocol with idle index as a
         * parameter.
         */
	return CPU_PM_CPU_IDLE_ENTER(arm_cpuidle_suspend, idx);
}

Contributors
Person
Tokens
Prop
Commits
CommitProp
Lorenzo Pieralisi
23
82.14%
1
33.33%
Sudeep Holla
4
14.29%
1
33.33%
Daniel Lezcano
1
3.57%
1
33.33%
Total
28
100.00%
3
100.00%


static struct cpuidle_driver arm_idle_driver __initdata = {
	.name = "arm_idle",
	.owner = THIS_MODULE,
	/*
         * State at index 0 is standby wfi and considered standard
         * on all ARM platforms. If in some platforms simple wfi
         * can't be used as "state 0", DT bindings must be implemented
         * to work around this issue and allow installing a special
         * handler for idle state index 0.
         */
	.states[0] = {
		.enter                  = arm_enter_idle_state,
		.exit_latency           = 1,
		.target_residency       = 1,
		.power_usage		= UINT_MAX,
		.name                   = "WFI",
		.desc                   = "ARM WFI",
        }
};


static const struct of_device_id arm_idle_state_match[] __initconst = {
	{ .compatible = "arm,idle-state",
	  .data = arm_enter_idle_state },
	{ },
};

/*
 * arm_idle_init
 *
 * Registers the arm specific cpuidle driver with the cpuidle
 * framework. It relies on core code to parse the idle states
 * and initialize them using driver data structures accordingly.
 */


static int __init arm_idle_init(void)
{
	int cpu, ret;
	struct cpuidle_driver *drv;
	struct cpuidle_device *dev;

	for_each_possible_cpu(cpu) {

		drv = kmemdup(&arm_idle_driver, sizeof(*drv), GFP_KERNEL);
		if (!drv) {
			ret = -ENOMEM;
			goto out_fail;
		}

		drv->cpumask = (struct cpumask *)cpumask_of(cpu);

		/*
                 * Initialize idle states data, starting at index 1.  This
                 * driver is DT only, if no DT idle states are detected (ret
                 * == 0) let the driver initialization fail accordingly since
                 * there is no reason to initialize the idle driver if only
                 * wfi is supported.
                 */
		ret = dt_init_idle_driver(drv, arm_idle_state_match, 1);
		if (ret <= 0) {
			ret = ret ? : -ENODEV;
			goto init_fail;
		}

		ret = cpuidle_register_driver(drv);
		if (ret) {
			pr_err("Failed to register cpuidle driver\n");
			goto init_fail;
		}

		/*
                 * Call arch CPU operations in order to initialize
                 * idle states suspend back-end specific data
                 */
		ret = arm_cpuidle_init(cpu);

		/*
                 * Skip the cpuidle device initialization if the reported
                 * failure is a HW misconfiguration/breakage (-ENXIO).
                 */
		if (ret == -ENXIO)
			continue;

		if (ret) {
			pr_err("CPU %d failed to init idle CPU ops\n", cpu);
			goto out_fail;
		}

		dev = kzalloc(sizeof(*dev), GFP_KERNEL);
		if (!dev) {
			pr_err("Failed to allocate cpuidle device\n");
			ret = -ENOMEM;
			goto out_fail;
		}
		dev->cpu = cpu;

		ret = cpuidle_register_device(dev);
		if (ret) {
			pr_err("Failed to register cpuidle device for CPU %d\n",
			       cpu);
			kfree(dev);
			goto out_fail;
		}
	}

	return 0;
init_fail:
	kfree(drv);
out_fail:
	while (--cpu >= 0) {
		dev = per_cpu(cpuidle_devices, cpu);
		cpuidle_unregister_device(dev);
		kfree(dev);
		drv = cpuidle_get_driver();
		cpuidle_unregister_driver(drv);
		kfree(drv);
	}

	return ret;
}
Contributors
Person
Tokens
Prop
Commits
CommitProp
Daniel Lezcano
206
72.28%
4
50.00%
Lorenzo Pieralisi
65
22.81%
2
25.00%
Stefan Wahren
9
3.16%
1
12.50%
Christophe Jaillet
5
1.75%
1
12.50%
Total
285
100.00%
8
100.00%


device_initcall(arm_idle_init);
Overall Contributors
Person
Tokens
Prop
Commits
CommitProp
Daniel Lezcano
225
51.25%
4
44.44%
Lorenzo Pieralisi
196
44.65%
2
22.22%
Stefan Wahren
9
2.05%
1
11.11%
Christophe Jaillet
5
1.14%
1
11.11%
Sudeep Holla
4
0.91%
1
11.11%
Total
439
100.00%
9
100.00%
Directory: drivers/cpuidle

Information contained on this website is for historical information purposes only and does not indicate or represent copyright ownership.