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ARM: OMAP4: CPUidle: Use coupled cpuidle states to implement SMP cpuidle.

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OMAP4 CPUDILE driver is converted mainly based on notes from the
coupled cpuidle patch series.

The changes include :
- Register both CPUs and C-states to cpuidle driver.
- Set struct cpuidle_device.coupled_cpus
- Set struct cpuidle_device.safe_state to non coupled state.
- Set CPUIDLE_FLAG_COUPLED in struct cpuidle_state.flags for each
  state that affects multiple cpus.
- Separate ->enter hooks for coupled & simple idle.
- CPU0 wait loop for CPU1 power transition.
- CPU1 wakeup mechanism for the idle exit.
- Enabling ARCH_NEEDS_CPU_IDLE_COUPLED for OMAP4.

Thanks to Kevin Hilman and Colin Cross on the suggestions/fixes
on the intermediate version of this patch.

Signed-off-by: Santosh Shilimkar <santosh.shilimkar@ti.com>
Signed-off-by: Kevin Hilman <khilman@ti.com>
This commit is contained in:
Santosh Shilimkar 2011-12-25 21:00:40 +05:30 committed by Kevin Hilman
parent 11d6ec2e48
commit dd3ad97c56
2 changed files with 65 additions and 44 deletions
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1
arch/arm/mach-omap2/Kconfig
View File

@ -55,6 +55,7 @@ config ARCH_OMAP4
select PM_OPP if PM
select USB_ARCH_HAS_EHCI if USB_SUPPORT
select ARM_CPU_SUSPEND if PM
select ARCH_NEEDS_CPU_IDLE_COUPLED
comment "OMAP Core Type"
depends on ARCH_OMAP2

108
arch/arm/mach-omap2/cpuidle44xx.c
View File

@ -21,6 +21,7 @@
#include "common.h"
#include "pm.h"
#include "prm.h"
#include "clockdomain.h"
#ifdef CONFIG_CPU_IDLE
@ -49,10 +50,11 @@ static struct omap4_idle_statedata omap4_idle_data[] = {
},
};
static struct powerdomain *mpu_pd, *cpu0_pd, *cpu1_pd;
static struct powerdomain *mpu_pd, *cpu_pd[NR_CPUS];
static struct clockdomain *cpu_clkdm[NR_CPUS];
/**
* omap4_enter_idle - Programs OMAP4 to enter the specified state
* omap4_enter_idle_coupled_[simple/coupled] - OMAP4 cpuidle entry functions
* @dev: cpuidle device
* @drv: cpuidle driver
* @index: the index of state to be entered
@ -61,60 +63,71 @@ static struct powerdomain *mpu_pd, *cpu0_pd, *cpu1_pd;
* specified low power state selected by the governor.
* Returns the amount of time spent in the low power state.
*/
static int omap4_enter_idle(struct cpuidle_device *dev,
static int omap4_enter_idle_simple(struct cpuidle_device *dev,
struct cpuidle_driver *drv,
int index)
{
local_fiq_disable();
omap_do_wfi();
local_fiq_enable();
return index;
}
static int omap4_enter_idle_coupled(struct cpuidle_device *dev,
struct cpuidle_driver *drv,
int index)
{
struct omap4_idle_statedata *cx = &omap4_idle_data[index];
u32 cpu1_state;
int cpu_id = smp_processor_id();
local_fiq_disable();
/*
* CPU0 has to stay ON (i.e in C1) until CPU1 is OFF state.
* CPU0 has to wait and stay ON until CPU1 is OFF state.
* This is necessary to honour hardware recommondation
* of triggeing all the possible low power modes once CPU1 is
* out of coherency and in OFF mode.
* Update dev->last_state so that governor stats reflects right
* data.
*/
cpu1_state = pwrdm_read_pwrst(cpu1_pd);
if (cpu1_state != PWRDM_POWER_OFF) {
index = drv->safe_state_index;
cx = &omap4_idle_data[index];
if (dev->cpu == 0 && cpumask_test_cpu(1, cpu_online_mask)) {
while (pwrdm_read_pwrst(cpu_pd[1]) != PWRDM_POWER_OFF)
cpu_relax();
}
if (index > 0)
clockevents_notify(CLOCK_EVT_NOTIFY_BROADCAST_ENTER, &cpu_id);
clockevents_notify(CLOCK_EVT_NOTIFY_BROADCAST_ENTER, &cpu_id);
/*
* Call idle CPU PM enter notifier chain so that
* VFP and per CPU interrupt context is saved.
*/
if (cx->cpu_state == PWRDM_POWER_OFF)
cpu_pm_enter();
cpu_pm_enter();
pwrdm_set_logic_retst(mpu_pd, cx->mpu_logic_state);
omap_set_pwrdm_state(mpu_pd, cx->mpu_state);
if (dev->cpu == 0) {
pwrdm_set_logic_retst(mpu_pd, cx->mpu_logic_state);
omap_set_pwrdm_state(mpu_pd, cx->mpu_state);
/*
* Call idle CPU cluster PM enter notifier chain
* to save GIC and wakeupgen context.
*/
if ((cx->mpu_state == PWRDM_POWER_RET) &&
(cx->mpu_logic_state == PWRDM_POWER_OFF))
cpu_cluster_pm_enter();
/*
* Call idle CPU cluster PM enter notifier chain
* to save GIC and wakeupgen context.
*/
if ((cx->mpu_state == PWRDM_POWER_RET) &&
(cx->mpu_logic_state == PWRDM_POWER_OFF))
cpu_cluster_pm_enter();
}
omap4_enter_lowpower(dev->cpu, cx->cpu_state);
/* Wakeup CPU1 only if it is not offlined */
if (dev->cpu == 0 && cpumask_test_cpu(1, cpu_online_mask)) {
clkdm_wakeup(cpu_clkdm[1]);
clkdm_allow_idle(cpu_clkdm[1]);
}
/*
* Call idle CPU PM exit notifier chain to restore
* VFP and per CPU IRQ context. Only CPU0 state is
* considered since CPU1 is managed by CPU hotplug.
* VFP and per CPU IRQ context.
*/
if (pwrdm_read_prev_pwrst(cpu0_pd) == PWRDM_POWER_OFF)
cpu_pm_exit();
cpu_pm_exit();
/*
* Call idle CPU cluster PM exit notifier chain
@ -123,8 +136,7 @@ static int omap4_enter_idle(struct cpuidle_device *dev,
if (omap4_mpuss_read_prev_context_state())
cpu_cluster_pm_exit();
if (index > 0)
clockevents_notify(CLOCK_EVT_NOTIFY_BROADCAST_EXIT, &cpu_id);
clockevents_notify(CLOCK_EVT_NOTIFY_BROADCAST_EXIT, &cpu_id);
local_fiq_enable();
@ -143,7 +155,7 @@ struct cpuidle_driver omap4_idle_driver = {
.exit_latency = 2 + 2,
.target_residency = 5,
.flags = CPUIDLE_FLAG_TIME_VALID,
.enter = omap4_enter_idle,
.enter = omap4_enter_idle_simple,
.name = "C1",
.desc = "MPUSS ON"
},
@ -151,8 +163,8 @@ struct cpuidle_driver omap4_idle_driver = {
/* C2 - CPU0 OFF + CPU1 OFF + MPU CSWR */
.exit_latency = 328 + 440,
.target_residency = 960,
.flags = CPUIDLE_FLAG_TIME_VALID,
.enter = omap4_enter_idle,
.flags = CPUIDLE_FLAG_TIME_VALID | CPUIDLE_FLAG_COUPLED,
.enter = omap4_enter_idle_coupled,
.name = "C2",
.desc = "MPUSS CSWR",
},
@ -160,8 +172,8 @@ struct cpuidle_driver omap4_idle_driver = {
/* C3 - CPU0 OFF + CPU1 OFF + MPU OSWR */
.exit_latency = 460 + 518,
.target_residency = 1100,
.flags = CPUIDLE_FLAG_TIME_VALID,
.enter = omap4_enter_idle,
.flags = CPUIDLE_FLAG_TIME_VALID | CPUIDLE_FLAG_COUPLED,
.enter = omap4_enter_idle_coupled,
.name = "C3",
.desc = "MPUSS OSWR",
},
@ -182,19 +194,27 @@ int __init omap4_idle_init(void)
unsigned int cpu_id = 0;
mpu_pd = pwrdm_lookup("mpu_pwrdm");
cpu0_pd = pwrdm_lookup("cpu0_pwrdm");
cpu1_pd = pwrdm_lookup("cpu1_pwrdm");
if ((!mpu_pd) || (!cpu0_pd) || (!cpu1_pd))
cpu_pd[0] = pwrdm_lookup("cpu0_pwrdm");
cpu_pd[1] = pwrdm_lookup("cpu1_pwrdm");
if ((!mpu_pd) || (!cpu_pd[0]) || (!cpu_pd[1]))
return -ENODEV;
dev = &per_cpu(omap4_idle_dev, cpu_id);
dev->cpu = cpu_id;
cpu_clkdm[0] = clkdm_lookup("mpu0_clkdm");
cpu_clkdm[1] = clkdm_lookup("mpu1_clkdm");
if (!cpu_clkdm[0] || !cpu_clkdm[1])
return -ENODEV;
cpuidle_register_driver(&omap4_idle_driver);
for_each_cpu(cpu_id, cpu_online_mask) {
dev = &per_cpu(omap4_idle_dev, cpu_id);
dev->cpu = cpu_id;
dev->coupled_cpus = *cpu_online_mask;
if (cpuidle_register_device(dev)) {
pr_err("%s: CPUidle register device failed\n", __func__);
return -EIO;
cpuidle_register_driver(&omap4_idle_driver);
if (cpuidle_register_device(dev)) {
pr_err("%s: CPUidle register failed\n", __func__);
return -EIO;
}
}
return 0;