Peter Zijlstra
2022-Jun-08 14:27 UTC
[PATCH 04/36] cpuidle,intel_idle: Fix CPUIDLE_FLAG_IRQ_ENABLE
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 at 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) &&
Rafael J. Wysocki
2022-Jun-08 15:01 UTC
[PATCH 04/36] cpuidle,intel_idle: Fix CPUIDLE_FLAG_IRQ_ENABLE
On Wed, Jun 8, 2022 at 4:47 PM Peter Zijlstra <peterz at infradead.org> wrote:> > 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 at infradead.org>Acked-by: Rafael J. Wysocki <rafael.j.wysocki at intel.com> And do I think correctly that this can be applied without the rest of the series?> --- > 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) && > >