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cpuidle,intel_idle: Fix CPUIDLE_FLAG_IRQ_ENABLE 

commit 32d4fd5751 upstream.

Commit c227233ad6 ("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: c227233ad6 ("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>
This commit is contained in:
Peter Zijlstra 2022-06-08 16:27:27 +02:00 committed by Greg Kroah-Hartman
parent 30fd1b5662
commit 2e9d662a04
1 changed files with 25 additions and 7 deletions
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32
drivers/idle/intel_idle.c
View File

@ -109,6 +109,18 @@ static unsigned int mwait_substates __initdata;
#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 __initdata;
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_cstates_icpu(struct cpuidle_driver *drv)
/* 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) &&