[RFC PATCH V3 4/5] powerpc/cpuidle: Enable powernv cpuidle support.

[Deepthi Dharwar <deepthi@xxxxxxxxxxxxxxxxxx>]

The following patch extends the current powerpc backend
idle driver to the powernv platform.

Signed-off-by: Deepthi Dharwar <deepthi@xxxxxxxxxxxxxxxxxx>
---
 drivers/cpuidle/cpuidle-powerpc.c |   36 +++++++++++++++++++++++++++++++++---
 1 file changed, 33 insertions(+), 3 deletions(-)

diff --git a/drivers/cpuidle/cpuidle-powerpc.c b/drivers/cpuidle/cpuidle-powerpc.c
index 5756085..e1cf599 100644
--- a/drivers/cpuidle/cpuidle-powerpc.c
+++ b/drivers/cpuidle/cpuidle-powerpc.c
@@ -53,7 +53,9 @@ static int snooze_loop(struct cpuidle_device *dev,
 {
 	unsigned long in_purr;
 
-	idle_loop_prolog(&in_purr);
+	if (firmware_has_feature(FW_FEATURE_SPLPAR))
+		idle_loop_prolog(&in_purr);
+
 	local_irq_enable();
 	set_thread_flag(TIF_POLLING_NRFLAG);
 
@@ -67,7 +69,8 @@ static int snooze_loop(struct cpuidle_device *dev,
 	clear_thread_flag(TIF_POLLING_NRFLAG);
 	smp_mb();
 
-	idle_loop_epilog(in_purr);
+	if (firmware_has_feature(FW_FEATURE_SPLPAR))
+		idle_loop_epilog(in_purr);
 
 	return index;
 }
@@ -130,6 +133,15 @@ static int shared_cede_loop(struct cpuidle_device *dev,
 	return index;
 }
 
+static int nap_loop(struct cpuidle_device *dev,
+			struct cpuidle_driver *drv,
+			int index)
+{
+	ppc64_runlatch_off();
+	power7_idle();
+	return index;
+}
+
 /*
  * States for dedicated partition case.
  */
@@ -163,6 +175,23 @@ static struct cpuidle_state shared_states[MAX_IDLE_STATE_COUNT] = {
 		.enter = &shared_cede_loop },
 };
 
+static struct cpuidle_state powernv_states[MAX_IDLE_STATE_COUNT] = {
+	{ /* Snooze */
+		.name = "snooze",
+		.desc = "snooze",
+		.flags = CPUIDLE_FLAG_TIME_VALID,
+		.exit_latency = 0,
+		.target_residency = 0,
+		.enter = &snooze_loop },
+	{ /* NAP */
+		.name = "NAP",
+		.desc = "NAP",
+		.flags = CPUIDLE_FLAG_TIME_VALID,
+		.exit_latency = 10,
+		.target_residency = 100,
+		.enter = &nap_loop },
+};
+
 void update_smt_snooze_delay(int cpu, int residency)
 {
 	struct cpuidle_driver *drv = cpuidle_get_driver();
@@ -282,7 +311,6 @@ static int powerpc_idle_devices_init(void)
 			return -EIO;
 		}
 	}
-
 	return 0;
 }
 
@@ -309,6 +337,8 @@ static int powerpc_idle_probe(void)
 			cpuidle_state_table = shared_states;
 		else if (get_lppaca_is_shared_proc() == 0)
 			cpuidle_state_table = dedicated_states;
+	} else if (firmware_has_feature(FW_FEATURE_OPALv3)) {
+			cpuidle_state_table = powernv_states;
 	} else
 		return -ENODEV;