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>

4 files changed, 19 insertions, 0 deletions

diff --git a/arch/powerpc/kernel/idle_e500.S b/arch/powerpc/kernel/idle_e500.S
index 47a1a983ff88..3e2b95c6ae67 100644
--- a/arch/powerpc/kernel/idle_e500.S
+++ b/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,
diff --git a/arch/powerpc/platforms/85xx/p3041_ds.c b/arch/powerpc/platforms/85xx/p3041_ds.c
index e2cfb6b6fb25..1fcd233a9167 100644
--- a/arch/powerpc/platforms/85xx/p3041_ds.c
+++ b/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);
diff --git a/arch/powerpc/platforms/85xx/p4080_ds.c b/arch/powerpc/platforms/85xx/p4080_ds.c
index eed4b01deff7..430c8f969177 100644
--- a/arch/powerpc/platforms/85xx/p4080_ds.c
+++ b/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);
diff --git a/arch/powerpc/platforms/85xx/p5020_ds.c b/arch/powerpc/platforms/85xx/p5020_ds.c
index 94348c9b5dc6..f7220d47ddcb 100644
--- a/arch/powerpc/platforms/85xx/p5020_ds.c
+++ b/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);