[v0][PATCH 1/1] powerpc/book3e: disable interrupt after preempt_schedule_irq

From: Tiejun Chen
Date: Sun Jan 06 2013 - 05:49:37 EST


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@xxxxxxxxxxxxx>
---
arch/powerpc/kernel/entry_64.S | 13 +++++++++++++
1 file changed, 13 insertions(+)

diff --git a/arch/powerpc/kernel/entry_64.S b/arch/powerpc/kernel/entry_64.S
index e9a906c..4e1de34 100644
--- a/arch/powerpc/kernel/entry_64.S
+++ b/arch/powerpc/kernel/entry_64.S
@@ -662,6 +662,19 @@ 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
--
1.7.9.5

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