Commit 12ebba42 authored by Rafael J. Wysocki's avatar Rafael J. Wysocki
Browse files

cpufreq: intel_pstate: Simplify spinlock locking 



Because intel_pstate_enable/disable_hwp_interrupt() are only called from
thread context, they need not save the IRQ flags when using a spinlock
as interrupts are guaranteed to be enabled when they run, so make them
use spin_lock/unlock_irq().

Signed-off-by: default avatarRafael J. Wysocki <rafael.j.wysocki@intel.com>
parent f186b2da

drivers/cpufreq/intel_pstate.c

+4 −8
Original line number Diff line number Diff line
@@ -1682,30 +1682,26 @@ void notify_hwp_interrupt(void) 


static void intel_pstate_disable_hwp_interrupt(struct cpudata *cpudata)

{

	unsigned long flags;



	if (!boot_cpu_has(X86_FEATURE_HWP_NOTIFY))

		return;



	/* 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);

	spin_lock_irq(&hwp_notify_lock);

	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);

	spin_unlock_irq(&hwp_notify_lock);

}



static void intel_pstate_enable_hwp_interrupt(struct cpudata *cpudata)

{

	/* Enable HWP notification interrupt for guaranteed performance change */

	if (boot_cpu_has(X86_FEATURE_HWP_NOTIFY)) {

		unsigned long flags;



		spin_lock_irqsave(&hwp_notify_lock, flags);

		spin_lock_irq(&hwp_notify_lock);

		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);

		spin_unlock_irq(&hwp_notify_lock);



		/* wrmsrl_on_cpu has to be outside spinlock as this can result in IPC */

		wrmsrl_on_cpu(cpudata->cpu, MSR_HWP_INTERRUPT, 0x01);