This is a note to let you know that I've just added the patch titled
cpuidle,intel_idle: Fix CPUIDLE_FLAG_IRQ_ENABLE
to the 5.17-stable tree which can be found at:
http://www.kernel.org/git/?p=linux/kernel/git/stable/stable-queue.git;a=summary
The filename of the patch is:
cpuidle-intel_idle-fix-cpuidle_flag_irq_enable.patch
and it can be found in the queue-5.17 subdirectory.
If you, or anyone else, feels it should not be added to the stable tree,
please let <stable@xxxxxxxxxxxxxxx> know about it.
>From 32d4fd5751eadbe1823a37eb38df85ec5c8e6207 Mon Sep 17 00:00:00 2001
From: Peter Zijlstra <peterz@xxxxxxxxxxxxx>
Date: Wed, 8 Jun 2022 16:27:27 +0200
Subject: cpuidle,intel_idle: Fix CPUIDLE_FLAG_IRQ_ENABLE
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
@@ -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) &&
Patches currently in stable-queue which might be from peterz@xxxxxxxxxxxxx are
queue-5.17/x86-cpu-elide-kcsan-for-cpu_has-and-friends.patch
queue-5.17/cpuidle-intel_idle-fix-cpuidle_flag_irq_enable.patch
queue-5.17/perf-parse-events-move-slots-event-for-the-hybrid-pl.patch
queue-5.17/jump_label-noinstr-avoid-instrumentation-for-jump_la.patch
queue-5.17/perf-c2c-fix-sorting-in-percent_rmt_hitm_cmp.patch
queue-5.17/perf-record-support-sample-read-topdown-metric-group.patch
queue-5.17/perf-evsel-fixes-topdown-events-in-a-weak-group-for-.patch
