From: Peter Zijlstra peterz@infradead.org
commit 32d4fd5751eadbe1823a37eb38df85ec5c8e6207 upstream.
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 [ rjw: Moved the intel_idle() kerneldoc comment next to the function ] Cc: 5.16+ stable@vger.kernel.org # 5.16+ Signed-off-by: Rafael J. Wysocki rafael.j.wysocki@intel.com Signed-off-by: Greg Kroah-Hartman gregkh@linuxfoundation.org --- drivers/idle/intel_idle.c | 32 +++++++++++++++++++++++++------- 1 file changed, 25 insertions(+), 7 deletions(-)
--- a/drivers/idle/intel_idle.c +++ b/drivers/idle/intel_idle.c @@ -109,6 +109,18 @@ static unsigned int mwait_substates __in #define flg2MWAIT(flags) (((flags) >> 24) & 0xFF) #define MWAIT2flg(eax) ((eax & 0xFF) << 24)
+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 */ + + mwait_idle_with_hints(eax, ecx); + + return index; +} + /** * intel_idle - Ask the processor to enter the given idle state. * @dev: cpuidle device of the target CPU. @@ -129,16 +141,19 @@ static unsigned int mwait_substates __in static __cpuidle 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 */ + return __intel_idle(dev, drv, index); +}
- if (state->flags & CPUIDLE_FLAG_IRQ_ENABLE) - local_irq_enable(); +static __cpuidle int intel_idle_irq(struct cpuidle_device *dev, + struct cpuidle_driver *drv, int index) +{ + int ret;
- mwait_idle_with_hints(eax, ecx); + raw_local_irq_enable(); + ret = __intel_idle(dev, drv, index); + raw_local_irq_disable();
- return index; + return ret; }
/** @@ -1583,6 +1598,9 @@ 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) &&