From: Peter Zijlstra peterz@infradead.org
commit a01353cf1896ea5b8a7bbc5e2b2d38feed8b7aaa upstream.
The whole disable-RCU, enable-IRQS dance is very intricate since changing IRQ state is traced, which depends on RCU.
Add two helpers for the cpuidle case that mirror the entry code:
ct_cpuidle_enter() ct_cpuidle_exit()
And fix all the cases where the enter/exit dance was buggy.
Signed-off-by: Peter Zijlstra (Intel) peterz@infradead.org Signed-off-by: Ingo Molnar mingo@kernel.org Tested-by: Tony Lindgren tony@atomide.com Tested-by: Ulf Hansson ulf.hansson@linaro.org Acked-by: Rafael J. Wysocki rafael.j.wysocki@intel.com Acked-by: Frederic Weisbecker frederic@kernel.org Link: https://lore.kernel.org/r/20230112195540.130014793@infradead.org Signed-off-by: Suren Baghdasaryan surenb@google.com Signed-off-by: Cheng-Jui Wang cheng-jui.wang@mediatek.com --- arch/arm/mach-imx/cpuidle-imx6q.c | 4 +-- arch/arm/mach-imx/cpuidle-imx6sx.c | 4 +-- arch/arm/mach-omap2/cpuidle34xx.c | 4 +-- arch/arm/mach-omap2/cpuidle44xx.c | 8 ++--- drivers/acpi/processor_idle.c | 8 +++-- drivers/cpuidle/cpuidle-big_little.c | 4 +-- drivers/cpuidle/cpuidle-mvebu-v7.c | 4 +-- drivers/cpuidle/cpuidle-psci.c | 4 +-- drivers/cpuidle/cpuidle-riscv-sbi.c | 4 +-- drivers/cpuidle/cpuidle-tegra.c | 8 ++--- drivers/cpuidle/cpuidle.c | 11 +++---- include/linux/clockchips.h | 4 +-- include/linux/cpuidle.h | 34 +++++++++++++++++++-- kernel/sched/idle.c | 45 ++++++++-------------------- kernel/time/tick-broadcast.c | 6 +++- 15 files changed, 86 insertions(+), 66 deletions(-)
diff --git a/arch/arm/mach-imx/cpuidle-imx6q.c b/arch/arm/mach-imx/cpuidle-imx6q.c index d086cbae09c3..c24c78a67cc1 100644 --- a/arch/arm/mach-imx/cpuidle-imx6q.c +++ b/arch/arm/mach-imx/cpuidle-imx6q.c @@ -25,9 +25,9 @@ static int imx6q_enter_wait(struct cpuidle_device *dev, imx6_set_lpm(WAIT_UNCLOCKED); raw_spin_unlock(&cpuidle_lock);
- ct_idle_enter(); + ct_cpuidle_enter(); cpu_do_idle(); - ct_idle_exit(); + ct_cpuidle_exit();
raw_spin_lock(&cpuidle_lock); if (num_idle_cpus-- == num_online_cpus()) diff --git a/arch/arm/mach-imx/cpuidle-imx6sx.c b/arch/arm/mach-imx/cpuidle-imx6sx.c index 1dc01f6b0f36..479f06286b50 100644 --- a/arch/arm/mach-imx/cpuidle-imx6sx.c +++ b/arch/arm/mach-imx/cpuidle-imx6sx.c @@ -47,9 +47,9 @@ static int imx6sx_enter_wait(struct cpuidle_device *dev, cpu_pm_enter(); cpu_cluster_pm_enter();
- ct_idle_enter(); + ct_cpuidle_enter(); cpu_suspend(0, imx6sx_idle_finish); - ct_idle_exit(); + ct_cpuidle_exit();
cpu_cluster_pm_exit(); cpu_pm_exit(); diff --git a/arch/arm/mach-omap2/cpuidle34xx.c b/arch/arm/mach-omap2/cpuidle34xx.c index cedf5cbe451f..6d63769cef0f 100644 --- a/arch/arm/mach-omap2/cpuidle34xx.c +++ b/arch/arm/mach-omap2/cpuidle34xx.c @@ -133,9 +133,9 @@ static int omap3_enter_idle(struct cpuidle_device *dev, }
/* Execute ARM wfi */ - ct_idle_enter(); + ct_cpuidle_enter(); omap_sram_idle(); - ct_idle_exit(); + ct_cpuidle_exit();
/* * Call idle CPU PM enter notifier chain to restore diff --git a/arch/arm/mach-omap2/cpuidle44xx.c b/arch/arm/mach-omap2/cpuidle44xx.c index 953ad888737c..3c97d5676e81 100644 --- a/arch/arm/mach-omap2/cpuidle44xx.c +++ b/arch/arm/mach-omap2/cpuidle44xx.c @@ -105,9 +105,9 @@ static int omap_enter_idle_smp(struct cpuidle_device *dev, } raw_spin_unlock_irqrestore(&mpu_lock, flag);
- ct_idle_enter(); + ct_cpuidle_enter(); omap4_enter_lowpower(dev->cpu, cx->cpu_state); - ct_idle_exit(); + ct_cpuidle_exit();
raw_spin_lock_irqsave(&mpu_lock, flag); if (cx->mpu_state_vote == num_online_cpus()) @@ -186,10 +186,10 @@ static int omap_enter_idle_coupled(struct cpuidle_device *dev, } }
- ct_idle_enter(); + ct_cpuidle_enter(); omap4_enter_lowpower(dev->cpu, cx->cpu_state); cpu_done[dev->cpu] = true; - ct_idle_exit(); + ct_cpuidle_exit();
/* Wakeup CPU1 only if it is not offlined */ if (dev->cpu == 0 && cpumask_test_cpu(1, cpu_online_mask)) { diff --git a/drivers/acpi/processor_idle.c b/drivers/acpi/processor_idle.c index ae42d530d080..ff40b001e0fa 100644 --- a/drivers/acpi/processor_idle.c +++ b/drivers/acpi/processor_idle.c @@ -644,6 +644,8 @@ static int __cpuidle acpi_idle_enter_bm(struct cpuidle_driver *drv, */ bool dis_bm = pr->flags.bm_control;
+ instrumentation_begin(); + /* If we can skip BM, demote to a safe state. */ if (!cx->bm_sts_skip && acpi_idle_bm_check()) { dis_bm = false; @@ -665,11 +667,11 @@ static int __cpuidle acpi_idle_enter_bm(struct cpuidle_driver *drv, raw_spin_unlock(&c3_lock); }
- ct_idle_enter(); + ct_cpuidle_enter();
acpi_idle_do_entry(cx);
- ct_idle_exit(); + ct_cpuidle_exit();
/* Re-enable bus master arbitration */ if (dis_bm) { @@ -679,6 +681,8 @@ static int __cpuidle acpi_idle_enter_bm(struct cpuidle_driver *drv, raw_spin_unlock(&c3_lock); }
+ instrumentation_end(); + return index; }
diff --git a/drivers/cpuidle/cpuidle-big_little.c b/drivers/cpuidle/cpuidle-big_little.c index fffd4ed0c4d1..5858db21e08c 100644 --- a/drivers/cpuidle/cpuidle-big_little.c +++ b/drivers/cpuidle/cpuidle-big_little.c @@ -126,13 +126,13 @@ static int bl_enter_powerdown(struct cpuidle_device *dev, struct cpuidle_driver *drv, int idx) { cpu_pm_enter(); - ct_idle_enter(); + ct_cpuidle_enter();
cpu_suspend(0, bl_powerdown_finisher);
/* signals the MCPM core that CPU is out of low power state */ mcpm_cpu_powered_up(); - ct_idle_exit(); + ct_cpuidle_exit();
cpu_pm_exit();
diff --git a/drivers/cpuidle/cpuidle-mvebu-v7.c b/drivers/cpuidle/cpuidle-mvebu-v7.c index c9568aa9410c..20bfb26d5a88 100644 --- a/drivers/cpuidle/cpuidle-mvebu-v7.c +++ b/drivers/cpuidle/cpuidle-mvebu-v7.c @@ -36,9 +36,9 @@ static int mvebu_v7_enter_idle(struct cpuidle_device *dev, if (drv->states[index].flags & MVEBU_V7_FLAG_DEEP_IDLE) deepidle = true;
- ct_idle_enter(); + ct_cpuidle_enter(); ret = mvebu_v7_cpu_suspend(deepidle); - ct_idle_exit(); + ct_cpuidle_exit();
cpu_pm_exit();
diff --git a/drivers/cpuidle/cpuidle-psci.c b/drivers/cpuidle/cpuidle-psci.c index 6a259c94b8b2..32ad942d3e5a 100644 --- a/drivers/cpuidle/cpuidle-psci.c +++ b/drivers/cpuidle/cpuidle-psci.c @@ -74,7 +74,7 @@ static int __psci_enter_domain_idle_state(struct cpuidle_device *dev, else pm_runtime_put_sync_suspend(pd_dev);
- ct_idle_enter(); + ct_cpuidle_enter();
state = psci_get_domain_state(); if (!state) @@ -82,7 +82,7 @@ static int __psci_enter_domain_idle_state(struct cpuidle_device *dev,
ret = psci_cpu_suspend_enter(state) ? -1 : idx;
- ct_idle_exit(); + ct_cpuidle_exit();
if (s2idle) dev_pm_genpd_resume(pd_dev); diff --git a/drivers/cpuidle/cpuidle-riscv-sbi.c b/drivers/cpuidle/cpuidle-riscv-sbi.c index cbdbb11b972b..0a480f5799a7 100644 --- a/drivers/cpuidle/cpuidle-riscv-sbi.c +++ b/drivers/cpuidle/cpuidle-riscv-sbi.c @@ -126,7 +126,7 @@ static int __sbi_enter_domain_idle_state(struct cpuidle_device *dev, else pm_runtime_put_sync_suspend(pd_dev);
- ct_idle_enter(); + ct_cpuidle_enter();
if (sbi_is_domain_state_available()) state = sbi_get_domain_state(); @@ -135,7 +135,7 @@ static int __sbi_enter_domain_idle_state(struct cpuidle_device *dev,
ret = sbi_suspend(state) ? -1 : idx;
- ct_idle_exit(); + ct_cpuidle_exit();
if (s2idle) dev_pm_genpd_resume(pd_dev); diff --git a/drivers/cpuidle/cpuidle-tegra.c b/drivers/cpuidle/cpuidle-tegra.c index 3ca5cfb9d322..9c2903c1b1c0 100644 --- a/drivers/cpuidle/cpuidle-tegra.c +++ b/drivers/cpuidle/cpuidle-tegra.c @@ -183,7 +183,7 @@ static int tegra_cpuidle_state_enter(struct cpuidle_device *dev, tegra_pm_set_cpu_in_lp2(); cpu_pm_enter();
- ct_idle_enter(); + ct_cpuidle_enter();
switch (index) { case TEGRA_C7: @@ -199,7 +199,7 @@ static int tegra_cpuidle_state_enter(struct cpuidle_device *dev, break; }
- ct_idle_exit(); + ct_cpuidle_exit();
cpu_pm_exit(); tegra_pm_clear_cpu_in_lp2(); @@ -240,10 +240,10 @@ static int tegra_cpuidle_enter(struct cpuidle_device *dev,
if (index == TEGRA_C1) { if (do_rcu) - ct_idle_enter(); + ct_cpuidle_enter(); ret = arm_cpuidle_simple_enter(dev, drv, index); if (do_rcu) - ct_idle_exit(); + ct_cpuidle_exit(); } else ret = tegra_cpuidle_state_enter(dev, index, cpu);
diff --git a/drivers/cpuidle/cpuidle.c b/drivers/cpuidle/cpuidle.c index 6eceb1988243..caeb543c7ea0 100644 --- a/drivers/cpuidle/cpuidle.c +++ b/drivers/cpuidle/cpuidle.c @@ -14,6 +14,7 @@ #include <linux/mutex.h> #include <linux/sched.h> #include <linux/sched/clock.h> +#include <linux/sched/idle.h> #include <linux/notifier.h> #include <linux/pm_qos.h> #include <linux/cpu.h> @@ -152,12 +153,12 @@ static void enter_s2idle_proper(struct cpuidle_driver *drv, */ stop_critical_timings(); if (!(target_state->flags & CPUIDLE_FLAG_RCU_IDLE)) - ct_idle_enter(); + ct_cpuidle_enter(); target_state->enter_s2idle(dev, drv, index); if (WARN_ON_ONCE(!irqs_disabled())) - local_irq_disable(); + raw_local_irq_disable(); if (!(target_state->flags & CPUIDLE_FLAG_RCU_IDLE)) - ct_idle_exit(); + ct_cpuidle_exit(); tick_unfreeze(); start_critical_timings();
@@ -235,10 +236,10 @@ int cpuidle_enter_state(struct cpuidle_device *dev, struct cpuidle_driver *drv,
stop_critical_timings(); if (!(target_state->flags & CPUIDLE_FLAG_RCU_IDLE)) - ct_idle_enter(); + ct_cpuidle_enter(); entered_state = target_state->enter(dev, drv, index); if (!(target_state->flags & CPUIDLE_FLAG_RCU_IDLE)) - ct_idle_exit(); + ct_cpuidle_exit(); start_critical_timings();
sched_clock_idle_wakeup_event(); diff --git a/include/linux/clockchips.h b/include/linux/clockchips.h index 8ae9a95ebf5b..9aac31d856f3 100644 --- a/include/linux/clockchips.h +++ b/include/linux/clockchips.h @@ -211,7 +211,7 @@ extern int tick_receive_broadcast(void); extern void tick_setup_hrtimer_broadcast(void); extern int tick_check_broadcast_expired(void); # else -static inline int tick_check_broadcast_expired(void) { return 0; } +static __always_inline int tick_check_broadcast_expired(void) { return 0; } static inline void tick_setup_hrtimer_broadcast(void) { } # endif
@@ -219,7 +219,7 @@ static inline void tick_setup_hrtimer_broadcast(void) { }
static inline void clockevents_suspend(void) { } static inline void clockevents_resume(void) { } -static inline int tick_check_broadcast_expired(void) { return 0; } +static __always_inline int tick_check_broadcast_expired(void) { return 0; } static inline void tick_setup_hrtimer_broadcast(void) { }
#endif /* !CONFIG_GENERIC_CLOCKEVENTS */ diff --git a/include/linux/cpuidle.h b/include/linux/cpuidle.h index 0ddc11e44302..630c879143c7 100644 --- a/include/linux/cpuidle.h +++ b/include/linux/cpuidle.h @@ -14,6 +14,7 @@ #include <linux/percpu.h> #include <linux/list.h> #include <linux/hrtimer.h> +#include <linux/context_tracking.h>
#define CPUIDLE_STATE_MAX 10 #define CPUIDLE_NAME_LEN 16 @@ -115,6 +116,35 @@ struct cpuidle_device { DECLARE_PER_CPU(struct cpuidle_device *, cpuidle_devices); DECLARE_PER_CPU(struct cpuidle_device, cpuidle_dev);
+static __always_inline void ct_cpuidle_enter(void) +{ + lockdep_assert_irqs_disabled(); + /* + * Idle is allowed to (temporary) enable IRQs. It + * will return with IRQs disabled. + * + * Trace IRQs enable here, then switch off RCU, and have + * arch_cpu_idle() use raw_local_irq_enable(). Note that + * ct_idle_enter() relies on lockdep IRQ state, so switch that + * last -- this is very similar to the entry code. + */ + trace_hardirqs_on_prepare(); + lockdep_hardirqs_on_prepare(); + instrumentation_end(); + ct_idle_enter(); + lockdep_hardirqs_on(_RET_IP_); +} + +static __always_inline void ct_cpuidle_exit(void) +{ + /* + * Carefully undo the above. + */ + lockdep_hardirqs_off(_RET_IP_); + ct_idle_exit(); + instrumentation_begin(); +} + /**************************** * CPUIDLE DRIVER INTERFACE * ****************************/ @@ -289,9 +319,9 @@ extern s64 cpuidle_governor_latency_req(unsigned int cpu); if (!is_retention) \ __ret = cpu_pm_enter(); \ if (!__ret) { \ - ct_idle_enter(); \ + ct_cpuidle_enter(); \ __ret = low_level_idle_enter(state); \ - ct_idle_exit(); \ + ct_cpuidle_exit(); \ if (!is_retention) \ cpu_pm_exit(); \ } \ diff --git a/kernel/sched/idle.c b/kernel/sched/idle.c index f26ab2675f7d..e924602ec43b 100644 --- a/kernel/sched/idle.c +++ b/kernel/sched/idle.c @@ -51,18 +51,22 @@ __setup("hlt", cpu_idle_nopoll_setup);
static noinline int __cpuidle cpu_idle_poll(void) { + instrumentation_begin(); trace_cpu_idle(0, smp_processor_id()); stop_critical_timings(); - ct_idle_enter(); - local_irq_enable(); + ct_cpuidle_enter();
+ raw_local_irq_enable(); while (!tif_need_resched() && (cpu_idle_force_poll || tick_check_broadcast_expired())) cpu_relax(); + raw_local_irq_disable();
- ct_idle_exit(); + ct_cpuidle_exit(); start_critical_timings(); trace_cpu_idle(PWR_EVENT_EXIT, smp_processor_id()); + local_irq_enable(); + instrumentation_end();
return 1; } @@ -85,44 +89,21 @@ void __weak arch_cpu_idle(void) */ void __cpuidle default_idle_call(void) { - if (current_clr_polling_and_test()) { - local_irq_enable(); - } else { - + instrumentation_begin(); + if (!current_clr_polling_and_test()) { trace_cpu_idle(1, smp_processor_id()); stop_critical_timings();
- /* - * arch_cpu_idle() is supposed to enable IRQs, however - * we can't do that because of RCU and tracing. - * - * Trace IRQs enable here, then switch off RCU, and have - * arch_cpu_idle() use raw_local_irq_enable(). Note that - * ct_idle_enter() relies on lockdep IRQ state, so switch that - * last -- this is very similar to the entry code. - */ - trace_hardirqs_on_prepare(); - lockdep_hardirqs_on_prepare(); - ct_idle_enter(); - lockdep_hardirqs_on(_THIS_IP_); - + ct_cpuidle_enter(); arch_cpu_idle(); - - /* - * OK, so IRQs are enabled here, but RCU needs them disabled to - * turn itself back on.. funny thing is that disabling IRQs - * will cause tracing, which needs RCU. Jump through hoops to - * make it 'work'. - */ raw_local_irq_disable(); - lockdep_hardirqs_off(_THIS_IP_); - ct_idle_exit(); - lockdep_hardirqs_on(_THIS_IP_); - raw_local_irq_enable(); + ct_cpuidle_exit();
start_critical_timings(); trace_cpu_idle(PWR_EVENT_EXIT, smp_processor_id()); } + local_irq_enable(); + instrumentation_end(); }
static int call_cpuidle_s2idle(struct cpuidle_driver *drv, diff --git a/kernel/time/tick-broadcast.c b/kernel/time/tick-broadcast.c index f7fe6fe36173..93bf2b4e47e5 100644 --- a/kernel/time/tick-broadcast.c +++ b/kernel/time/tick-broadcast.c @@ -622,9 +622,13 @@ struct cpumask *tick_get_broadcast_oneshot_mask(void) * to avoid a deep idle transition as we are about to get the * broadcast IPI right away. */ -int tick_check_broadcast_expired(void) +noinstr int tick_check_broadcast_expired(void) { +#ifdef _ASM_GENERIC_BITOPS_INSTRUMENTED_NON_ATOMIC_H + return arch_test_bit(smp_processor_id(), cpumask_bits(tick_broadcast_force_mask)); +#else return cpumask_test_cpu(smp_processor_id(), tick_broadcast_force_mask); +#endif }
/*