powerpc/pasemi: Use raw spinlock in SMP TB sync

spin_lock() can hang if called while the timebase is frozen,
so use a raw lock instead, also disable interrupts while
at it.

Signed-off-by: Benjamin Herrenschmidt <benh@kernel.crashing.org>

1 files changed, 10 insertions, 5 deletions

diff --git a/arch/powerpc/platforms/pasemi/setup.c b/arch/powerpc/platforms/pasemi/setup.c
index 153051eb6d93..a4619347aa7e 100644
--- a/arch/powerpc/platforms/pasemi/setup.c
+++ b/arch/powerpc/platforms/pasemi/setup.c
@@ -71,20 +71,25 @@ static void pas_restart(char *cmd)
 }
 
 #ifdef CONFIG_SMP
-static DEFINE_SPINLOCK(timebase_lock);
+static raw_spinlock_t timebase_lock;
 static unsigned long timebase;
 
 static void __devinit pas_give_timebase(void)
 {
-        spin_lock(&timebase_lock);
+        unsigned long flags;
+
+        local_irq_save(flags);
+        hard_irq_disable();
+        __raw_spin_lock(&timebase_lock);
         mtspr(SPRN_TBCTL, TBCTL_FREEZE);
         isync();
         timebase = get_tb();
-        spin_unlock(&timebase_lock);
+        __raw_spin_unlock(&timebase_lock);
 
         while (timebase)
                 barrier();
         mtspr(SPRN_TBCTL, TBCTL_RESTART);
+        local_irq_restore(flags);
 }
 
 static void __devinit pas_take_timebase(void)
@@ -92,10 +97,10 @@ static void __devinit pas_take_timebase(void)
         while (!timebase)
                 smp_rmb();
 
-        spin_lock(&timebase_lock);
+        __raw_spin_lock(&timebase_lock);
         set_tb(timebase >> 32, timebase & 0xffffffff);
         timebase = 0;
-        spin_unlock(&timebase_lock);
+        __raw_spin_unlock(&timebase_lock);
 }
 
 struct smp_ops_t pas_smp_ops = {