powerpc/book3e: Disable interrupt after preempt_schedule_irq

In preempt case current arch_local_irq_restore() from
preempt_schedule_irq() may enable hard interrupt but we really
should disable interrupts when we return from the interrupt,
and so that we don't get interrupted after loading SRR0/1.

Signed-off-by: Tiejun Chen <tiejun.chen@windriver.com>
CC: <stable@vger.kernel.org>
Signed-off-by: Benjamin Herrenschmidt <benh@kernel.crashing.org>

diff --git a/arch/powerpc/kernel/entry_64.S b/arch/powerpc/kernel/entry_64.S
index b310a05..3d990d3 100644 (file)
--- a/arch/powerpc/kernel/entry_64.S
+++ b/arch/powerpc/kernel/entry_64.S
@@ -664,6 +664,19 @@ resume_kernel:
        ld      r4,TI_FLAGS(r9)
        andi.   r0,r4,_TIF_NEED_RESCHED
        bne     1b
+
+       /*
+        * arch_local_irq_restore() from preempt_schedule_irq above may
+        * enable hard interrupt but we really should disable interrupts
+        * when we return from the interrupt, and so that we don't get
+        * interrupted after loading SRR0/1.
+        */
+#ifdef CONFIG_PPC_BOOK3E
+       wrteei  0
+#else
+       ld      r10,PACAKMSR(r13) /* Get kernel MSR without EE */
+       mtmsrd  r10,1             /* Update machine state */
+#endif /* CONFIG_PPC_BOOK3E */
 #endif /* CONFIG_PREEMPT */
 
        .globl  fast_exc_return_irq