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@redhat.com>
Signed-off-by: Sebastian Andrzej Siewior <bigeasy@linutronix.de>
Signed-off-by: Thomas Gleixner <tglx@linutronix.de>
Link: https://lore.kernel.org/r/20191008110021.2j44ayunal7fkb7i@linutronix.de

diff --git a/drivers/thermal/intel/x86_pkg_temp_thermal.c b/drivers/thermal/intel/x86_pkg_temp_thermal.c
index ddb4a973c698606b735dd3ae3b9820488bb87257..e18758a8e911a75707acadf3be7f9d1a94dbddd3 100644 (file)
--- 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)