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>

arch/powerpc/kernel/idle_e500.S

@@ -26,6 +26,17 @@ _GLOBAL(e500_idle)
 	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 @@ END_FTR_SECTION_IFSET(CPU_FTR_L2CSR|CPU_FTR_CAN_NAP)
 	mtmsr	r7
 	isync
 2:	b	2b
+#endif /* !E500MC */
 
 /*
  * Return from NAP/DOZE mode, restore some CPU specific registers,

arch/powerpc/platforms/85xx/p3041_ds.c

@@ -69,6 +69,7 @@ define_machine(p3041_ds) {
 	.restart		= fsl_rstcr_restart,
 	.calibrate_decr		= generic_calibrate_decr,
 	.progress		= udbg_progress,
+	.power_save		= e500_idle,
 };
 
 machine_device_initcall(p3041_ds, corenet_ds_publish_devices);

arch/powerpc/platforms/85xx/p4080_ds.c

@@ -68,6 +68,7 @@ define_machine(p4080_ds) {
 	.restart		= fsl_rstcr_restart,
 	.calibrate_decr		= generic_calibrate_decr,
 	.progress		= udbg_progress,
+	.power_save		= e500_idle,
 };
 
 machine_device_initcall(p4080_ds, corenet_ds_publish_devices);

arch/powerpc/platforms/85xx/p5020_ds.c

@@ -74,6 +74,11 @@ define_machine(p5020_ds) {
 	.restart		= fsl_rstcr_restart,
 	.calibrate_decr		= generic_calibrate_decr,
 	.progress		= udbg_progress,
+#ifdef CONFIG_PPC64
+	.power_save		= book3e_idle,
+#else
+	.power_save		= e500_idle,
+#endif
 };
 
 machine_device_initcall(p5020_ds, corenet_ds_publish_devices);