[tip: locking/core] thermal/x86_pkg_temp: Make pkg_temp_lock a raw_spinlock_t

From: tip-bot2 for Clark Williams
Date: Sat Mar 28 2020 - 08:26:25 EST


The following commit has been merged into the locking/core branch of tip:

Commit-ID: fc32150e6f43d6cb93ea75937bb6a88a1764cc37
Gitweb: https://git.kernel.org/tip/fc32150e6f43d6cb93ea75937bb6a88a1764cc37
Author: Clark Williams <williams@xxxxxxxxxx>
AuthorDate: Tue, 08 Oct 2019 13:00:21 +02:00
Committer: Thomas Gleixner <tglx@xxxxxxxxxxxxx>
CommitterDate: Sat, 28 Mar 2020 13:21:08 +01:00

thermal/x86_pkg_temp: Make pkg_temp_lock a raw_spinlock_t

The pkg_temp_lock spinlock is acquired in the thermal vector handler which
is truly atomic context even on PREEMPT_RT kernels.

The critical sections are tiny, so change it to a raw spinlock.

Signed-off-by: Clark Williams <williams@xxxxxxxxxx>
Signed-off-by: Sebastian Andrzej Siewior <bigeasy@xxxxxxxxxxxxx>
Signed-off-by: Thomas Gleixner <tglx@xxxxxxxxxxxxx>
Link: https://lore.kernel.org/r/20191008110021.2j44ayunal7fkb7i@xxxxxxxxxxxxx
---
drivers/thermal/intel/x86_pkg_temp_thermal.c | 24 +++++++++----------
1 file changed, 12 insertions(+), 12 deletions(-)

diff --git a/drivers/thermal/intel/x86_pkg_temp_thermal.c b/drivers/thermal/intel/x86_pkg_temp_thermal.c
index ddb4a97..e18758a 100644
--- a/drivers/thermal/intel/x86_pkg_temp_thermal.c
+++ b/drivers/thermal/intel/x86_pkg_temp_thermal.c
@@ -63,7 +63,7 @@ static int max_id __read_mostly;
/* Array of zone pointers */
static struct zone_device **zones;
/* Serializes interrupt notification, work and hotplug */
-static DEFINE_SPINLOCK(pkg_temp_lock);
+static DEFINE_RAW_SPINLOCK(pkg_temp_lock);
/* Protects zone operation in the work function against hotplug removal */
static DEFINE_MUTEX(thermal_zone_mutex);

@@ -266,12 +266,12 @@ static void pkg_temp_thermal_threshold_work_fn(struct work_struct *work)
u64 msr_val, wr_val;

mutex_lock(&thermal_zone_mutex);
- spin_lock_irq(&pkg_temp_lock);
+ raw_spin_lock_irq(&pkg_temp_lock);
++pkg_work_cnt;

zonedev = pkg_temp_thermal_get_dev(cpu);
if (!zonedev) {
- spin_unlock_irq(&pkg_temp_lock);
+ raw_spin_unlock_irq(&pkg_temp_lock);
mutex_unlock(&thermal_zone_mutex);
return;
}
@@ -285,7 +285,7 @@ static void pkg_temp_thermal_threshold_work_fn(struct work_struct *work)
}

enable_pkg_thres_interrupt();
- spin_unlock_irq(&pkg_temp_lock);
+ raw_spin_unlock_irq(&pkg_temp_lock);

/*
* If tzone is not NULL, then thermal_zone_mutex will prevent the
@@ -310,7 +310,7 @@ static int pkg_thermal_notify(u64 msr_val)
struct zone_device *zonedev;
unsigned long flags;

- spin_lock_irqsave(&pkg_temp_lock, flags);
+ raw_spin_lock_irqsave(&pkg_temp_lock, flags);
++pkg_interrupt_cnt;

disable_pkg_thres_interrupt();
@@ -322,7 +322,7 @@ static int pkg_thermal_notify(u64 msr_val)
pkg_thermal_schedule_work(zonedev->cpu, &zonedev->work);
}

- spin_unlock_irqrestore(&pkg_temp_lock, flags);
+ raw_spin_unlock_irqrestore(&pkg_temp_lock, flags);
return 0;
}

@@ -368,9 +368,9 @@ static int pkg_temp_thermal_device_add(unsigned int cpu)
zonedev->msr_pkg_therm_high);

cpumask_set_cpu(cpu, &zonedev->cpumask);
- spin_lock_irq(&pkg_temp_lock);
+ raw_spin_lock_irq(&pkg_temp_lock);
zones[id] = zonedev;
- spin_unlock_irq(&pkg_temp_lock);
+ raw_spin_unlock_irq(&pkg_temp_lock);
return 0;
}

@@ -407,7 +407,7 @@ static int pkg_thermal_cpu_offline(unsigned int cpu)
}

/* Protect against work and interrupts */
- spin_lock_irq(&pkg_temp_lock);
+ raw_spin_lock_irq(&pkg_temp_lock);

/*
* Check whether this cpu was the current target and store the new
@@ -439,9 +439,9 @@ static int pkg_thermal_cpu_offline(unsigned int cpu)
* To cancel the work we need to drop the lock, otherwise
* we might deadlock if the work needs to be flushed.
*/
- spin_unlock_irq(&pkg_temp_lock);
+ raw_spin_unlock_irq(&pkg_temp_lock);
cancel_delayed_work_sync(&zonedev->work);
- spin_lock_irq(&pkg_temp_lock);
+ raw_spin_lock_irq(&pkg_temp_lock);
/*
* If this is not the last cpu in the package and the work
* did not run after we dropped the lock above, then we
@@ -452,7 +452,7 @@ static int pkg_thermal_cpu_offline(unsigned int cpu)
pkg_thermal_schedule_work(target, &zonedev->work);
}

- spin_unlock_irq(&pkg_temp_lock);
+ raw_spin_unlock_irq(&pkg_temp_lock);

/* Final cleanup if this is the last cpu */
if (lastcpu)