From: Peter Zijlstra <peterz@xxxxxxxxxxxxx>
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@xxxxxxxxxxxxx>
[ rjw: Moved the intel_idle() kerneldoc comment next to the function ]
Cc: 5.16+ <stable@xxxxxxxxxxxxxxx> # 5.16+
Signed-off-by: Rafael J. Wysocki <rafael.j.wysocki@xxxxxxxxx>
Signed-off-by: Greg Kroah-Hartman <gregkh@xxxxxxxxxxxxxxxxxxx>
---
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
@@ -115,6 +115,18 @@ 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.
@@ -132,16 +144,19 @@ 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;
}
/**
@@ -1668,6 +1683,9 @@ 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) &&
