Patch "cpufreq: intel_pstate: Make hwp_notify_lock a raw spinlock" has been added to the 6.6-stable tree

[Sasha Levin <sashal@xxxxxxxxxx>]

This is a note to let you know that I've just added the patch titled

    cpufreq: intel_pstate: Make hwp_notify_lock a raw spinlock

to the 6.6-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:
     cpufreq-intel_pstate-make-hwp_notify_lock-a-raw-spin.patch
and it can be found in the queue-6.6 subdirectory.

If you, or anyone else, feels it should not be added to the stable tree,
please let <stable@xxxxxxxxxxxxxxx> know about it.



commit 12ece7b7eda838489b08fbe44e0445d67af49266
Author: Uwe Kleine-König <ukleinek@xxxxxxxxxx>
Date:   Sun Oct 6 22:51:07 2024 +0200

    cpufreq: intel_pstate: Make hwp_notify_lock a raw spinlock
    
    commit 8b4865cd904650cbed7f2407e653934c621b8127 upstream.
    
    notify_hwp_interrupt() is called via sysvec_thermal() ->
    smp_thermal_vector() -> intel_thermal_interrupt() in hard irq context.
    For this reason it must not use a simple spin_lock that sleeps with
    PREEMPT_RT enabled. So convert it to a raw spinlock.
    
    Reported-by: xiao sheng wen <atzlinux@xxxxxxxx>
    Link: https://bugs.debian.org/1076483
    Signed-off-by: Uwe Kleine-König <ukleinek@xxxxxxxxxx>
    Acked-by: Srinivas Pandruvada <srinivas.pandruvada@xxxxxxxxxxxxxxx>
    Acked-by: Sebastian Andrzej Siewior <bigeasy@xxxxxxxxxxxxx>
    Tested-by: xiao sheng wen <atzlinux@xxxxxxxx>
    Link: https://patch.msgid.link/20240919081121.10784-2-ukleinek@xxxxxxxxxx
    Cc: All applicable <stable@xxxxxxxxxxxxxxx>
    Signed-off-by: Rafael J. Wysocki <rafael.j.wysocki@xxxxxxxxx>
    [ukleinek: Backport to v6.6.y]
    Signed-off-by: Uwe Kleine-König <ukleinek@xxxxxxxxxx>
    Signed-off-by: Sasha Levin <sashal@xxxxxxxxxx>

diff --git a/drivers/cpufreq/intel_pstate.c b/drivers/cpufreq/intel_pstate.c
index 0ee3a04bb1022..8a4fdf212ce0d 100644
--- a/drivers/cpufreq/intel_pstate.c
+++ b/drivers/cpufreq/intel_pstate.c
@@ -1632,7 +1632,7 @@ static void intel_pstate_notify_work(struct work_struct *work)
 	wrmsrl_on_cpu(cpudata->cpu, MSR_HWP_STATUS, 0);
 }
 
-static DEFINE_SPINLOCK(hwp_notify_lock);
+static DEFINE_RAW_SPINLOCK(hwp_notify_lock);
 static cpumask_t hwp_intr_enable_mask;
 
 void notify_hwp_interrupt(void)
@@ -1649,7 +1649,7 @@ void notify_hwp_interrupt(void)
 	if (!(value & 0x01))
 		return;
 
-	spin_lock_irqsave(&hwp_notify_lock, flags);
+	raw_spin_lock_irqsave(&hwp_notify_lock, flags);
 
 	if (!cpumask_test_cpu(this_cpu, &hwp_intr_enable_mask))
 		goto ack_intr;
@@ -1673,13 +1673,13 @@ void notify_hwp_interrupt(void)
 
 	schedule_delayed_work(&cpudata->hwp_notify_work, msecs_to_jiffies(10));
 
-	spin_unlock_irqrestore(&hwp_notify_lock, flags);
+	raw_spin_unlock_irqrestore(&hwp_notify_lock, flags);
 
 	return;
 
 ack_intr:
 	wrmsrl_safe(MSR_HWP_STATUS, 0);
-	spin_unlock_irqrestore(&hwp_notify_lock, flags);
+	raw_spin_unlock_irqrestore(&hwp_notify_lock, flags);
 }
 
 static void intel_pstate_disable_hwp_interrupt(struct cpudata *cpudata)
@@ -1692,10 +1692,10 @@ static void intel_pstate_disable_hwp_interrupt(struct cpudata *cpudata)
 	/* wrmsrl_on_cpu has to be outside spinlock as this can result in IPC */
 	wrmsrl_on_cpu(cpudata->cpu, MSR_HWP_INTERRUPT, 0x00);
 
-	spin_lock_irqsave(&hwp_notify_lock, flags);
+	raw_spin_lock_irqsave(&hwp_notify_lock, flags);
 	if (cpumask_test_and_clear_cpu(cpudata->cpu, &hwp_intr_enable_mask))
 		cancel_delayed_work(&cpudata->hwp_notify_work);
-	spin_unlock_irqrestore(&hwp_notify_lock, flags);
+	raw_spin_unlock_irqrestore(&hwp_notify_lock, flags);
 }
 
 static void intel_pstate_enable_hwp_interrupt(struct cpudata *cpudata)
@@ -1704,10 +1704,10 @@ static void intel_pstate_enable_hwp_interrupt(struct cpudata *cpudata)
 	if (boot_cpu_has(X86_FEATURE_HWP_NOTIFY)) {
 		unsigned long flags;
 
-		spin_lock_irqsave(&hwp_notify_lock, flags);
+		raw_spin_lock_irqsave(&hwp_notify_lock, flags);
 		INIT_DELAYED_WORK(&cpudata->hwp_notify_work, intel_pstate_notify_work);
 		cpumask_set_cpu(cpudata->cpu, &hwp_intr_enable_mask);
-		spin_unlock_irqrestore(&hwp_notify_lock, flags);
+		raw_spin_unlock_irqrestore(&hwp_notify_lock, flags);
 
 		/* wrmsrl_on_cpu has to be outside spinlock as this can result in IPC */
 		wrmsrl_on_cpu(cpudata->cpu, MSR_HWP_INTERRUPT, 0x01);
@@ -3136,10 +3136,10 @@ static void intel_pstate_driver_cleanup(void)
 			if (intel_pstate_driver == &intel_pstate)
 				intel_pstate_clear_update_util_hook(cpu);
 
-			spin_lock(&hwp_notify_lock);
+			raw_spin_lock(&hwp_notify_lock);
 			kfree(all_cpu_data[cpu]);
 			WRITE_ONCE(all_cpu_data[cpu], NULL);
-			spin_unlock(&hwp_notify_lock);
+			raw_spin_unlock(&hwp_notify_lock);
 		}
 	}
 	cpus_read_unlock();