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Commit 7bed1b3c authored by Srinivas Pandruvada's avatar Srinivas Pandruvada Committed by Zhang Rui
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Thermal: x86_pkg_temp: change spin lock 



x86_pkg_temp receives thermal notifications via a callback from a
therm_throt driver, where thermal interrupts are processed.
This callback is pkg_temp_thermal_platform_thermal_notify. Here to
avoid multiple interrupts from cores in a package, we disable the
source and also set a variable to avoid scheduling delayed work function.
This variable is protected via spin_lock_irqsave. On one buggy platform,
we still receiving interrupts even if the source is disabled. This
can cause deadlock/lockdep warning, when interrupt is generated while under
spinlock in work function.
Change spin_lock to spin_lock_irqsave and spin_unlock to
spin_unlock_irqrestore as the data it is trying to protect can also
be modified in a notification call called from interrupt handler.

Signed-off-by: default avatarSrinivas Pandruvada <srinivas.pandruvada@linux.intel.com>
Signed-off-by: default avatarZhang Rui <rui.zhang@intel.com>
parent 22356f44

drivers/thermal/x86_pkg_temp_thermal.c

+8 −6
Original line number Diff line number Diff line
@@ -316,18 +316,19 @@ static void pkg_temp_thermal_threshold_work_fn(struct work_struct *work) 
	int phy_id = topology_physical_package_id(cpu);

	struct phy_dev_entry *phdev = pkg_temp_thermal_get_phy_entry(cpu);

	bool notify = false;

	unsigned long flags;



	if (!phdev)

		return;



	spin_lock(&pkg_work_lock);

	spin_lock_irqsave(&pkg_work_lock, flags);

	++pkg_work_cnt;

	if (unlikely(phy_id > max_phy_id)) {

		spin_unlock(&pkg_work_lock);

		spin_unlock_irqrestore(&pkg_work_lock, flags);

		return;

	}

	pkg_work_scheduled[phy_id] = 0;

	spin_unlock(&pkg_work_lock);

	spin_unlock_irqrestore(&pkg_work_lock, flags);



	enable_pkg_thres_interrupt();

	rdmsrl(MSR_IA32_PACKAGE_THERM_STATUS, msr_val);
@@ -397,6 +398,7 @@ static int pkg_temp_thermal_device_add(unsigned int cpu) 
	int thres_count;

	u32 eax, ebx, ecx, edx;

	u8 *temp;

	unsigned long flags;



	cpuid(6, &eax, &ebx, &ecx, &edx);

	thres_count = ebx & 0x07;
@@ -420,19 +422,19 @@ static int pkg_temp_thermal_device_add(unsigned int cpu) 
		goto err_ret_unlock;

	}



	spin_lock(&pkg_work_lock);

	spin_lock_irqsave(&pkg_work_lock, flags);

	if (topology_physical_package_id(cpu) > max_phy_id)

		max_phy_id = topology_physical_package_id(cpu);

	temp = krealloc(pkg_work_scheduled,

			(max_phy_id+1) * sizeof(u8), GFP_ATOMIC);

	if (!temp) {

		spin_unlock(&pkg_work_lock);

		spin_unlock_irqrestore(&pkg_work_lock, flags);

		err = -ENOMEM;

		goto err_ret_free;

	}

	pkg_work_scheduled = temp;

	pkg_work_scheduled[topology_physical_package_id(cpu)] = 0;

	spin_unlock(&pkg_work_lock);

	spin_unlock_irqrestore(&pkg_work_lock, flags);



	phy_dev_entry->phys_proc_id = topology_physical_package_id(cpu);

	phy_dev_entry->first_cpu = cpu;