233 строки
6.8 KiB
C
233 строки
6.8 KiB
C
/*
|
|
* Copyright (c) 2013 ARM/Linaro
|
|
*
|
|
* Authors: Daniel Lezcano <daniel.lezcano@linaro.org>
|
|
* Lorenzo Pieralisi <lorenzo.pieralisi@arm.com>
|
|
* Nicolas Pitre <nicolas.pitre@linaro.org>
|
|
*
|
|
* 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.
|
|
*
|
|
* Maintainer: Lorenzo Pieralisi <lorenzo.pieralisi@arm.com>
|
|
* Maintainer: Daniel Lezcano <daniel.lezcano@linaro.org>
|
|
*/
|
|
#include <linux/cpuidle.h>
|
|
#include <linux/cpu_pm.h>
|
|
#include <linux/slab.h>
|
|
#include <linux/of.h>
|
|
|
|
#include <asm/cpu.h>
|
|
#include <asm/cputype.h>
|
|
#include <asm/cpuidle.h>
|
|
#include <asm/mcpm.h>
|
|
#include <asm/smp_plat.h>
|
|
#include <asm/suspend.h>
|
|
|
|
#include "dt_idle_states.h"
|
|
|
|
static int bl_enter_powerdown(struct cpuidle_device *dev,
|
|
struct cpuidle_driver *drv, int idx);
|
|
|
|
/*
|
|
* NB: Owing to current menu governor behaviour big and LITTLE
|
|
* index 1 states have to define exit_latency and target_residency for
|
|
* cluster state since, when all CPUs in a cluster hit it, the cluster
|
|
* can be shutdown. This means that when a single CPU enters this state
|
|
* the exit_latency and target_residency values are somewhat overkill.
|
|
* There is no notion of cluster states in the menu governor, so CPUs
|
|
* have to define CPU states where possibly the cluster will be shutdown
|
|
* depending on the state of other CPUs. idle states entry and exit happen
|
|
* at random times; however the cluster state provides target_residency
|
|
* values as if all CPUs in a cluster enter the state at once; this is
|
|
* somewhat optimistic and behaviour should be fixed either in the governor
|
|
* or in the MCPM back-ends.
|
|
* To make this driver 100% generic the number of states and the exit_latency
|
|
* target_residency values must be obtained from device tree bindings.
|
|
*
|
|
* exit_latency: refers to the TC2 vexpress test chip and depends on the
|
|
* current cluster operating point. It is the time it takes to get the CPU
|
|
* up and running when the CPU is powered up on cluster wake-up from shutdown.
|
|
* Current values for big and LITTLE clusters are provided for clusters
|
|
* running at default operating points.
|
|
*
|
|
* target_residency: it is the minimum amount of time the cluster has
|
|
* to be down to break even in terms of power consumption. cluster
|
|
* shutdown has inherent dynamic power costs (L2 writebacks to DRAM
|
|
* being the main factor) that depend on the current operating points.
|
|
* The current values for both clusters are provided for a CPU whose half
|
|
* of L2 lines are dirty and require cleaning to DRAM, and takes into
|
|
* account leakage static power values related to the vexpress TC2 testchip.
|
|
*/
|
|
static struct cpuidle_driver bl_idle_little_driver = {
|
|
.name = "little_idle",
|
|
.owner = THIS_MODULE,
|
|
.states[0] = ARM_CPUIDLE_WFI_STATE,
|
|
.states[1] = {
|
|
.enter = bl_enter_powerdown,
|
|
.exit_latency = 700,
|
|
.target_residency = 2500,
|
|
.flags = CPUIDLE_FLAG_TIME_VALID |
|
|
CPUIDLE_FLAG_TIMER_STOP,
|
|
.name = "C1",
|
|
.desc = "ARM little-cluster power down",
|
|
},
|
|
.state_count = 2,
|
|
};
|
|
|
|
static const struct of_device_id bl_idle_state_match[] __initconst = {
|
|
{ .compatible = "arm,idle-state",
|
|
.data = bl_enter_powerdown },
|
|
{ },
|
|
};
|
|
|
|
static struct cpuidle_driver bl_idle_big_driver = {
|
|
.name = "big_idle",
|
|
.owner = THIS_MODULE,
|
|
.states[0] = ARM_CPUIDLE_WFI_STATE,
|
|
.states[1] = {
|
|
.enter = bl_enter_powerdown,
|
|
.exit_latency = 500,
|
|
.target_residency = 2000,
|
|
.flags = CPUIDLE_FLAG_TIME_VALID |
|
|
CPUIDLE_FLAG_TIMER_STOP,
|
|
.name = "C1",
|
|
.desc = "ARM big-cluster power down",
|
|
},
|
|
.state_count = 2,
|
|
};
|
|
|
|
/*
|
|
* notrace prevents trace shims from getting inserted where they
|
|
* should not. Global jumps and ldrex/strex must not be inserted
|
|
* in power down sequences where caches and MMU may be turned off.
|
|
*/
|
|
static int notrace bl_powerdown_finisher(unsigned long arg)
|
|
{
|
|
/* MCPM works with HW CPU identifiers */
|
|
unsigned int mpidr = read_cpuid_mpidr();
|
|
unsigned int cluster = MPIDR_AFFINITY_LEVEL(mpidr, 1);
|
|
unsigned int cpu = MPIDR_AFFINITY_LEVEL(mpidr, 0);
|
|
|
|
mcpm_set_entry_vector(cpu, cluster, cpu_resume);
|
|
|
|
/*
|
|
* Residency value passed to mcpm_cpu_suspend back-end
|
|
* has to be given clear semantics. Set to 0 as a
|
|
* temporary value.
|
|
*/
|
|
mcpm_cpu_suspend(0);
|
|
|
|
/* return value != 0 means failure */
|
|
return 1;
|
|
}
|
|
|
|
/**
|
|
* bl_enter_powerdown - Programs CPU to enter the specified state
|
|
* @dev: cpuidle device
|
|
* @drv: The target state to be programmed
|
|
* @idx: state index
|
|
*
|
|
* Called from the CPUidle framework to program the device to the
|
|
* specified target state selected by the governor.
|
|
*/
|
|
static int bl_enter_powerdown(struct cpuidle_device *dev,
|
|
struct cpuidle_driver *drv, int idx)
|
|
{
|
|
cpu_pm_enter();
|
|
|
|
cpu_suspend(0, bl_powerdown_finisher);
|
|
|
|
/* signals the MCPM core that CPU is out of low power state */
|
|
mcpm_cpu_powered_up();
|
|
|
|
cpu_pm_exit();
|
|
|
|
return idx;
|
|
}
|
|
|
|
static int __init bl_idle_driver_init(struct cpuidle_driver *drv, int part_id)
|
|
{
|
|
struct cpumask *cpumask;
|
|
int cpu;
|
|
|
|
cpumask = kzalloc(cpumask_size(), GFP_KERNEL);
|
|
if (!cpumask)
|
|
return -ENOMEM;
|
|
|
|
for_each_possible_cpu(cpu)
|
|
if (smp_cpuid_part(cpu) == part_id)
|
|
cpumask_set_cpu(cpu, cpumask);
|
|
|
|
drv->cpumask = cpumask;
|
|
|
|
return 0;
|
|
}
|
|
|
|
static const struct of_device_id compatible_machine_match[] = {
|
|
{ .compatible = "arm,vexpress,v2p-ca15_a7" },
|
|
{ .compatible = "samsung,exynos5420" },
|
|
{ .compatible = "samsung,exynos5800" },
|
|
{},
|
|
};
|
|
|
|
static int __init bl_idle_init(void)
|
|
{
|
|
int ret;
|
|
struct device_node *root = of_find_node_by_path("/");
|
|
|
|
if (!root)
|
|
return -ENODEV;
|
|
|
|
/*
|
|
* Initialize the driver just for a compliant set of machines
|
|
*/
|
|
if (!of_match_node(compatible_machine_match, root))
|
|
return -ENODEV;
|
|
/*
|
|
* For now the differentiation between little and big cores
|
|
* is based on the part number. A7 cores are considered little
|
|
* cores, A15 are considered big cores. This distinction may
|
|
* evolve in the future with a more generic matching approach.
|
|
*/
|
|
ret = bl_idle_driver_init(&bl_idle_little_driver,
|
|
ARM_CPU_PART_CORTEX_A7);
|
|
if (ret)
|
|
return ret;
|
|
|
|
ret = bl_idle_driver_init(&bl_idle_big_driver, ARM_CPU_PART_CORTEX_A15);
|
|
if (ret)
|
|
goto out_uninit_little;
|
|
|
|
/* Start at index 1, index 0 standard WFI */
|
|
ret = dt_init_idle_driver(&bl_idle_big_driver, bl_idle_state_match, 1);
|
|
if (ret < 0)
|
|
goto out_uninit_big;
|
|
|
|
/* Start at index 1, index 0 standard WFI */
|
|
ret = dt_init_idle_driver(&bl_idle_little_driver,
|
|
bl_idle_state_match, 1);
|
|
if (ret < 0)
|
|
goto out_uninit_big;
|
|
|
|
ret = cpuidle_register(&bl_idle_little_driver, NULL);
|
|
if (ret)
|
|
goto out_uninit_big;
|
|
|
|
ret = cpuidle_register(&bl_idle_big_driver, NULL);
|
|
if (ret)
|
|
goto out_unregister_little;
|
|
|
|
return 0;
|
|
|
|
out_unregister_little:
|
|
cpuidle_unregister(&bl_idle_little_driver);
|
|
out_uninit_big:
|
|
kfree(bl_idle_big_driver.cpumask);
|
|
out_uninit_little:
|
|
kfree(bl_idle_little_driver.cpumask);
|
|
|
|
return ret;
|
|
}
|
|
device_initcall(bl_idle_init);
|