powerpc/e500mc: Add support for the wait instruction in e500_idle
e500mc cannot doze or nap due to an erratum (as well as having a
different mechanism than previous e500), but it has a "wait" instruction
that is similar to doze.
On 64-bit, due to the soft-irq-disable mechanism, the existing
book3e_idle should be used instead.
Signed-off-by: Vakul Garg <vakul@freescale.com>
Signed-off-by: Scott Wood <scottwood@freescale.com>
Signed-off-by: Kumar Gala <galak@kernel.crashing.org>
diff --git a/arch/powerpc/kernel/idle_e500.S b/arch/powerpc/kernel/idle_e500.S
index 47a1a98..3e2b95c 100644
--- a/arch/powerpc/kernel/idle_e500.S
+++ b/arch/powerpc/kernel/idle_e500.S
@@ -26,6 +26,17 @@
ori r4,r4,_TLF_NAPPING /* so when we take an exception */
stw r4,TI_LOCAL_FLAGS(r3) /* it will return to our caller */
+#ifdef CONFIG_E500MC
+ wrteei 1
+1: wait
+
+ /*
+ * Guard against spurious wakeups (e.g. from a hypervisor) --
+ * any real interrupt will cause us to return to LR due to
+ * _TLF_NAPPING.
+ */
+ b 1b
+#else
/* Check if we can nap or doze, put HID0 mask in r3 */
lis r3,0
BEGIN_FTR_SECTION
@@ -72,6 +83,7 @@
mtmsr r7
isync
2: b 2b
+#endif /* !E500MC */
/*
* Return from NAP/DOZE mode, restore some CPU specific registers,