mirror of
https://git.kernel.org/pub/scm/linux/kernel/git/stable/linux.git
synced 2024-09-04 01:49:36 +00:00
![Tony Lindgren](/assets/img/avatar_default.png)
We get suspcious RCU usage splats with cpuidle in several places in omap_enter_idle_coupled() with the kernel debug options enabled: RCU used illegally from extended quiescent state! ... (_raw_spin_lock_irqsave) (omap_enter_idle_coupled+0x17c/0x2d8) (omap_enter_idle_coupled) (cpuidle_enter_state) (cpuidle_enter_state_coupled) (cpuidle_enter) Let's use RCU_NONIDLE to suppress these splats. Things got changed around with commit1098582a0f
("sched,idle,rcu: Push rcu_idle deeper into the idle path") that started triggering these warnings. For the tick_broadcast related calls, ideally we'd just switch over to using CPUIDLE_FLAG_TIMER_STOP for omap_enter_idle_coupled() to have the generic cpuidle code handle the tick_broadcast related calls for us and then just drop the tick_broadcast calls here. But we're currently missing the call in the common cpuidle code for tick_broadcast_enable() that CPU1 hotplug needs as described in earlier commit50d6b3cf94
("ARM: OMAP2+: fix lack of timer interrupts on CPU1 after hotplug"). Cc: Daniel Lezcano <daniel.lezcano@linaro.org> Cc: Paul E. McKenney <paulmck@kernel.org> Cc: Russell King <rmk+kernel@armlinux.org.uk> Acked-by: Paul E. McKenney <paulmck@kernel.org> Signed-off-by: Tony Lindgren <tony@atomide.com>
327 lines
7.8 KiB
C
327 lines
7.8 KiB
C
// SPDX-License-Identifier: GPL-2.0-only
|
|
/*
|
|
* OMAP4+ CPU idle Routines
|
|
*
|
|
* Copyright (C) 2011-2013 Texas Instruments, Inc.
|
|
* Santosh Shilimkar <santosh.shilimkar@ti.com>
|
|
* Rajendra Nayak <rnayak@ti.com>
|
|
*/
|
|
|
|
#include <linux/sched.h>
|
|
#include <linux/cpuidle.h>
|
|
#include <linux/cpu_pm.h>
|
|
#include <linux/export.h>
|
|
#include <linux/tick.h>
|
|
|
|
#include <asm/cpuidle.h>
|
|
|
|
#include "common.h"
|
|
#include "pm.h"
|
|
#include "prm.h"
|
|
#include "soc.h"
|
|
#include "clockdomain.h"
|
|
|
|
#define MAX_CPUS 2
|
|
|
|
/* Machine specific information */
|
|
struct idle_statedata {
|
|
u32 cpu_state;
|
|
u32 mpu_logic_state;
|
|
u32 mpu_state;
|
|
u32 mpu_state_vote;
|
|
};
|
|
|
|
static struct idle_statedata omap4_idle_data[] = {
|
|
{
|
|
.cpu_state = PWRDM_POWER_ON,
|
|
.mpu_state = PWRDM_POWER_ON,
|
|
.mpu_logic_state = PWRDM_POWER_RET,
|
|
},
|
|
{
|
|
.cpu_state = PWRDM_POWER_OFF,
|
|
.mpu_state = PWRDM_POWER_RET,
|
|
.mpu_logic_state = PWRDM_POWER_RET,
|
|
},
|
|
{
|
|
.cpu_state = PWRDM_POWER_OFF,
|
|
.mpu_state = PWRDM_POWER_RET,
|
|
.mpu_logic_state = PWRDM_POWER_OFF,
|
|
},
|
|
};
|
|
|
|
static struct idle_statedata omap5_idle_data[] = {
|
|
{
|
|
.cpu_state = PWRDM_POWER_ON,
|
|
.mpu_state = PWRDM_POWER_ON,
|
|
.mpu_logic_state = PWRDM_POWER_ON,
|
|
},
|
|
{
|
|
.cpu_state = PWRDM_POWER_RET,
|
|
.mpu_state = PWRDM_POWER_RET,
|
|
.mpu_logic_state = PWRDM_POWER_RET,
|
|
},
|
|
};
|
|
|
|
static struct powerdomain *mpu_pd, *cpu_pd[MAX_CPUS];
|
|
static struct clockdomain *cpu_clkdm[MAX_CPUS];
|
|
|
|
static atomic_t abort_barrier;
|
|
static bool cpu_done[MAX_CPUS];
|
|
static struct idle_statedata *state_ptr = &omap4_idle_data[0];
|
|
static DEFINE_RAW_SPINLOCK(mpu_lock);
|
|
|
|
/* Private functions */
|
|
|
|
/**
|
|
* omap_enter_idle_[simple/coupled] - OMAP4PLUS cpuidle entry functions
|
|
* @dev: cpuidle device
|
|
* @drv: cpuidle driver
|
|
* @index: the index of state to be entered
|
|
*
|
|
* Called from the CPUidle framework to program the device to the
|
|
* specified low power state selected by the governor.
|
|
* Returns the amount of time spent in the low power state.
|
|
*/
|
|
static int omap_enter_idle_simple(struct cpuidle_device *dev,
|
|
struct cpuidle_driver *drv,
|
|
int index)
|
|
{
|
|
omap_do_wfi();
|
|
return index;
|
|
}
|
|
|
|
static int omap_enter_idle_smp(struct cpuidle_device *dev,
|
|
struct cpuidle_driver *drv,
|
|
int index)
|
|
{
|
|
struct idle_statedata *cx = state_ptr + index;
|
|
unsigned long flag;
|
|
|
|
raw_spin_lock_irqsave(&mpu_lock, flag);
|
|
cx->mpu_state_vote++;
|
|
if (cx->mpu_state_vote == num_online_cpus()) {
|
|
pwrdm_set_logic_retst(mpu_pd, cx->mpu_logic_state);
|
|
omap_set_pwrdm_state(mpu_pd, cx->mpu_state);
|
|
}
|
|
raw_spin_unlock_irqrestore(&mpu_lock, flag);
|
|
|
|
omap4_enter_lowpower(dev->cpu, cx->cpu_state);
|
|
|
|
raw_spin_lock_irqsave(&mpu_lock, flag);
|
|
if (cx->mpu_state_vote == num_online_cpus())
|
|
omap_set_pwrdm_state(mpu_pd, PWRDM_POWER_ON);
|
|
cx->mpu_state_vote--;
|
|
raw_spin_unlock_irqrestore(&mpu_lock, flag);
|
|
|
|
return index;
|
|
}
|
|
|
|
static int omap_enter_idle_coupled(struct cpuidle_device *dev,
|
|
struct cpuidle_driver *drv,
|
|
int index)
|
|
{
|
|
struct idle_statedata *cx = state_ptr + index;
|
|
u32 mpuss_can_lose_context = 0;
|
|
int error;
|
|
|
|
/*
|
|
* 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.
|
|
*/
|
|
if (dev->cpu == 0 && cpumask_test_cpu(1, cpu_online_mask)) {
|
|
while (pwrdm_read_pwrst(cpu_pd[1]) != PWRDM_POWER_OFF) {
|
|
cpu_relax();
|
|
|
|
/*
|
|
* CPU1 could have already entered & exited idle
|
|
* without hitting off because of a wakeup
|
|
* or a failed attempt to hit off mode. Check for
|
|
* that here, otherwise we could spin forever
|
|
* waiting for CPU1 off.
|
|
*/
|
|
if (cpu_done[1])
|
|
goto fail;
|
|
|
|
}
|
|
}
|
|
|
|
mpuss_can_lose_context = (cx->mpu_state == PWRDM_POWER_RET) &&
|
|
(cx->mpu_logic_state == PWRDM_POWER_OFF);
|
|
|
|
/* Enter broadcast mode for periodic timers */
|
|
RCU_NONIDLE(tick_broadcast_enable());
|
|
|
|
/* Enter broadcast mode for one-shot timers */
|
|
RCU_NONIDLE(tick_broadcast_enter());
|
|
|
|
/*
|
|
* Call idle CPU PM enter notifier chain so that
|
|
* VFP and per CPU interrupt context is saved.
|
|
*/
|
|
error = cpu_pm_enter();
|
|
if (error)
|
|
goto cpu_pm_out;
|
|
|
|
if (dev->cpu == 0) {
|
|
pwrdm_set_logic_retst(mpu_pd, cx->mpu_logic_state);
|
|
RCU_NONIDLE(omap_set_pwrdm_state(mpu_pd, cx->mpu_state));
|
|
|
|
/*
|
|
* Call idle CPU cluster PM enter notifier chain
|
|
* to save GIC and wakeupgen context.
|
|
*/
|
|
if (mpuss_can_lose_context) {
|
|
error = cpu_cluster_pm_enter();
|
|
if (error) {
|
|
index = 0;
|
|
cx = state_ptr + index;
|
|
pwrdm_set_logic_retst(mpu_pd, cx->mpu_logic_state);
|
|
RCU_NONIDLE(omap_set_pwrdm_state(mpu_pd, cx->mpu_state));
|
|
mpuss_can_lose_context = 0;
|
|
}
|
|
}
|
|
}
|
|
|
|
omap4_enter_lowpower(dev->cpu, cx->cpu_state);
|
|
cpu_done[dev->cpu] = true;
|
|
|
|
/* Wakeup CPU1 only if it is not offlined */
|
|
if (dev->cpu == 0 && cpumask_test_cpu(1, cpu_online_mask)) {
|
|
|
|
if (IS_PM44XX_ERRATUM(PM_OMAP4_ROM_SMP_BOOT_ERRATUM_GICD) &&
|
|
mpuss_can_lose_context)
|
|
gic_dist_disable();
|
|
|
|
RCU_NONIDLE(clkdm_deny_idle(cpu_clkdm[1]));
|
|
RCU_NONIDLE(omap_set_pwrdm_state(cpu_pd[1], PWRDM_POWER_ON));
|
|
RCU_NONIDLE(clkdm_allow_idle(cpu_clkdm[1]));
|
|
|
|
if (IS_PM44XX_ERRATUM(PM_OMAP4_ROM_SMP_BOOT_ERRATUM_GICD) &&
|
|
mpuss_can_lose_context) {
|
|
while (gic_dist_disabled()) {
|
|
udelay(1);
|
|
cpu_relax();
|
|
}
|
|
gic_timer_retrigger();
|
|
}
|
|
}
|
|
|
|
/*
|
|
* Call idle CPU cluster PM exit notifier chain
|
|
* to restore GIC and wakeupgen context.
|
|
*/
|
|
if (dev->cpu == 0 && mpuss_can_lose_context)
|
|
cpu_cluster_pm_exit();
|
|
|
|
/*
|
|
* Call idle CPU PM exit notifier chain to restore
|
|
* VFP and per CPU IRQ context.
|
|
*/
|
|
cpu_pm_exit();
|
|
|
|
cpu_pm_out:
|
|
RCU_NONIDLE(tick_broadcast_exit());
|
|
|
|
fail:
|
|
cpuidle_coupled_parallel_barrier(dev, &abort_barrier);
|
|
cpu_done[dev->cpu] = false;
|
|
|
|
return index;
|
|
}
|
|
|
|
static struct cpuidle_driver omap4_idle_driver = {
|
|
.name = "omap4_idle",
|
|
.owner = THIS_MODULE,
|
|
.states = {
|
|
{
|
|
/* C1 - CPU0 ON + CPU1 ON + MPU ON */
|
|
.exit_latency = 2 + 2,
|
|
.target_residency = 5,
|
|
.enter = omap_enter_idle_simple,
|
|
.name = "C1",
|
|
.desc = "CPUx ON, MPUSS ON"
|
|
},
|
|
{
|
|
/* C2 - CPU0 OFF + CPU1 OFF + MPU CSWR */
|
|
.exit_latency = 328 + 440,
|
|
.target_residency = 960,
|
|
.flags = CPUIDLE_FLAG_COUPLED,
|
|
.enter = omap_enter_idle_coupled,
|
|
.name = "C2",
|
|
.desc = "CPUx OFF, MPUSS CSWR",
|
|
},
|
|
{
|
|
/* C3 - CPU0 OFF + CPU1 OFF + MPU OSWR */
|
|
.exit_latency = 460 + 518,
|
|
.target_residency = 1100,
|
|
.flags = CPUIDLE_FLAG_COUPLED,
|
|
.enter = omap_enter_idle_coupled,
|
|
.name = "C3",
|
|
.desc = "CPUx OFF, MPUSS OSWR",
|
|
},
|
|
},
|
|
.state_count = ARRAY_SIZE(omap4_idle_data),
|
|
.safe_state_index = 0,
|
|
};
|
|
|
|
static struct cpuidle_driver omap5_idle_driver = {
|
|
.name = "omap5_idle",
|
|
.owner = THIS_MODULE,
|
|
.states = {
|
|
{
|
|
/* C1 - CPU0 ON + CPU1 ON + MPU ON */
|
|
.exit_latency = 2 + 2,
|
|
.target_residency = 5,
|
|
.enter = omap_enter_idle_simple,
|
|
.name = "C1",
|
|
.desc = "CPUx WFI, MPUSS ON"
|
|
},
|
|
{
|
|
/* C2 - CPU0 RET + CPU1 RET + MPU CSWR */
|
|
.exit_latency = 48 + 60,
|
|
.target_residency = 100,
|
|
.flags = CPUIDLE_FLAG_TIMER_STOP,
|
|
.enter = omap_enter_idle_smp,
|
|
.name = "C2",
|
|
.desc = "CPUx CSWR, MPUSS CSWR",
|
|
},
|
|
},
|
|
.state_count = ARRAY_SIZE(omap5_idle_data),
|
|
.safe_state_index = 0,
|
|
};
|
|
|
|
/* Public functions */
|
|
|
|
/**
|
|
* omap4_idle_init - Init routine for OMAP4+ idle
|
|
*
|
|
* Registers the OMAP4+ specific cpuidle driver to the cpuidle
|
|
* framework with the valid set of states.
|
|
*/
|
|
int __init omap4_idle_init(void)
|
|
{
|
|
struct cpuidle_driver *idle_driver;
|
|
|
|
if (soc_is_omap54xx()) {
|
|
state_ptr = &omap5_idle_data[0];
|
|
idle_driver = &omap5_idle_driver;
|
|
} else {
|
|
state_ptr = &omap4_idle_data[0];
|
|
idle_driver = &omap4_idle_driver;
|
|
}
|
|
|
|
mpu_pd = pwrdm_lookup("mpu_pwrdm");
|
|
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;
|
|
|
|
cpu_clkdm[0] = clkdm_lookup("mpu0_clkdm");
|
|
cpu_clkdm[1] = clkdm_lookup("mpu1_clkdm");
|
|
if (!cpu_clkdm[0] || !cpu_clkdm[1])
|
|
return -ENODEV;
|
|
|
|
return cpuidle_register(idle_driver, cpu_online_mask);
|
|
}
|