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Subject[PATCH 3.11 12/25] Thermal: x86_pkg_temp: change spin lock
Date
3.11-stable review patch.  If anyone has any objections, please let me know.

------------------

From: Srinivas Pandruvada <srinivas.pandruvada@linux.intel.com>

commit 7bed1b3caaedd5918f0820b29f3b7a2ddc812922 upstream.

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: Srinivas Pandruvada <srinivas.pandruvada@linux.intel.com>
Signed-off-by: Zhang Rui <rui.zhang@intel.com>
Cc: Jonghwan Choi <jhbird.choi@gmail.com>
Signed-off-by: Greg Kroah-Hartman <gregkh@linuxfoundation.org>

---
drivers/thermal/x86_pkg_temp_thermal.c | 14 ++++++++------
1 file changed, 8 insertions(+), 6 deletions(-)

--- a/drivers/thermal/x86_pkg_temp_thermal.c
+++ b/drivers/thermal/x86_pkg_temp_thermal.c
@@ -316,18 +316,19 @@ static void pkg_temp_thermal_threshold_w
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(u
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(u
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;



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