[PATCH 04/36] cpuidle,intel_idle: Fix CPUIDLE_FLAG_IRQ_ENABLE
From: Peter Zijlstra <peterz@infradead.org>
Date: 2022-06-08 14:47:53
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Commit c227233ad64c ("intel_idle: enable interrupts before C1 on
Xeons") wrecked intel_idle in two ways:
- must not have tracing in idle functions
- must return with IRQs disabled
Additionally, it added a branch for no good reason.
Fixes: c227233ad64c ("intel_idle: enable interrupts before C1 on Xeons")
Signed-off-by: Peter Zijlstra (Intel) <peterz@infradead.org>
---
drivers/idle/intel_idle.c | 48 +++++++++++++++++++++++++++++++++++-----------
1 file changed, 37 insertions(+), 11 deletions(-)
--- a/drivers/idle/intel_idle.c
+++ b/drivers/idle/intel_idle.c@@ -129,21 +137,37 @@ static unsigned int mwait_substates __in * * Must be called under local_irq_disable(). */ + -static __cpuidle int intel_idle(struct cpuidle_device *dev, - struct cpuidle_driver *drv, int index) +static __always_inline int __intel_idle(struct cpuidle_device *dev, + struct cpuidle_driver *drv, int index) { struct cpuidle_state *state = &drv->states[index]; unsigned long eax = flg2MWAIT(state->flags); unsigned long ecx = 1; /* break on interrupt flag */ - if (state->flags & CPUIDLE_FLAG_IRQ_ENABLE) - local_irq_enable(); - mwait_idle_with_hints(eax, ecx); return index; } +static __cpuidle int intel_idle(struct cpuidle_device *dev, + struct cpuidle_driver *drv, int index) +{ + return __intel_idle(dev, drv, index); +} + +static __cpuidle int intel_idle_irq(struct cpuidle_device *dev, + struct cpuidle_driver *drv, int index) +{ + int ret; + + raw_local_irq_enable(); + ret = __intel_idle(dev, drv, index); + raw_local_irq_disable(); + + return ret; +} + /** * intel_idle_s2idle - Ask the processor to enter the given idle state. * @dev: cpuidle device of the target CPU.
@@ -1801,6 +1824,9 @@ static void __init intel_idle_init_cstat /* Structure copy. */ drv->states[drv->state_count] = cpuidle_state_table[cstate]; + if (cpuidle_state_table[cstate].flags & CPUIDLE_FLAG_IRQ_ENABLE) + drv->states[drv->state_count].enter = intel_idle_irq; + if ((disabled_states_mask & BIT(drv->state_count)) || ((icpu->use_acpi || force_use_acpi) && intel_idle_off_by_default(mwait_hint) &&