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>

diff --git a/arch/powerpc/platforms/pasemi/setup.c b/arch/powerpc/platforms/pasemi/setup.c
index 153051eb6d9330643e0c3924273a3e6d04a8921f..a4619347aa7e61a702e7a7f6c584080a31d5f4fb 100644 (file)
--- 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 = {