[POWERPC] Fix irq enable/disable in smp_generic_take_timebase

Eran Ben-Avi <eranpublic@yahoo.com> pointed out that the arch/ppc version
of smp_generic_take_timebase disables interrupts on entry but exits without
restoring them.  However, both it and the arch/powerpc version have another
problem, which is that they use local_irq_disable/enable rather than
local_irq_save/restore, and they are called with interrupts disabled.

This fixes both problems; it changes a return to a break in the arch/ppc
version, and changes both versions to use local_irq_save/restore.

Signed-off-by: Paul Mackerras <paulus@samba.org>

1 files changed, 3 insertions, 2 deletions

diff --git a/arch/powerpc/kernel/smp-tbsync.c b/arch/powerpc/kernel/smp-tbsync.c
index f19e2e0e61e7..de59c6c31a5b 100644
--- a/arch/powerpc/kernel/smp-tbsync.c
+++ b/arch/powerpc/kernel/smp-tbsync.c
@@ -45,8 +45,9 @@ void __devinit smp_generic_take_timebase(void)
 {
         int cmd;
         u64 tb;
+        unsigned long flags;
 
-        local_irq_disable();
+        local_irq_save(flags);
         while (!running)
                 barrier();
         rmb();
@@ -70,7 +71,7 @@ void __devinit smp_generic_take_timebase(void)
                         set_tb(tb >> 32, tb & 0xfffffffful);
                 enter_contest(tbsync->mark, -1);
         }
-        local_irq_enable();
+        local_irq_restore(flags);
 }
 
 static int __devinit start_contest(int cmd, long offset, int num)