[Skiboot] [PATCH v2] SLW: Remove stop1_lite and stop2_lite

[Akshay Adiga]

stop1_lite has been removed since it adds no additional benefit
over stop0_lite. stop2_lite has been removed since currently it adds
minimal benefit over stop2. However, the benefit is eclipsed by the time
required to ungate the clocks

Moreover, Lite states don't give up the SMT resources, can potentially
have a performance impact on sibling threads.

Signed-off-by: Akshay Adiga <akshay.adiga at linux.vnet.ibm.com>
---
 hw/slw.c | 36 ++++++++----------------------------
 1 file changed, 8 insertions(+), 28 deletions(-)

diff --git a/hw/slw.c b/hw/slw.c
index 2b305db..ff6e2a4 100644
--- a/hw/slw.c
+++ b/hw/slw.c
@@ -529,20 +529,9 @@ static struct cpu_idle_states power9_cpu_idle_states[] = {
 				 | OPAL_PM_PSSCR_ESL \
 				 | OPAL_PM_PSSCR_EC,
 		.pm_ctrl_reg_mask = OPAL_PM_PSSCR_MASK },
-	{
-		.name = "stop1_lite", /* Enter stop1 with no state loss */
-		.latency_ns = 4900,
-		.residency_ns = 49000,
-		.flags = 0*OPAL_PM_DEC_STOP \
-		       | 0*OPAL_PM_TIMEBASE_STOP  \
-		       | 0*OPAL_PM_LOSE_USER_CONTEXT \
-		       | 0*OPAL_PM_LOSE_HYP_CONTEXT \
-		       | 0*OPAL_PM_LOSE_FULL_CONTEXT \
-		       | 1*OPAL_PM_STOP_INST_FAST,
-		.pm_ctrl_reg_val = OPAL_PM_PSSCR_RL(1) \
-				 | OPAL_PM_PSSCR_MTL(3) \
-				 | OPAL_PM_PSSCR_TR(3),
-		.pm_ctrl_reg_mask = OPAL_PM_PSSCR_MASK },
+
+	/* stop1_lite has been removed since it adds no additional benefit over stop0_lite */
+
 	{
 		.name = "stop1",
 		.latency_ns = 5000,
@@ -559,20 +548,11 @@ static struct cpu_idle_states power9_cpu_idle_states[] = {
 				 | OPAL_PM_PSSCR_ESL \
 				 | OPAL_PM_PSSCR_EC,
 		.pm_ctrl_reg_mask = OPAL_PM_PSSCR_MASK },
-	{
-		.name = "stop2_lite", /* Enter stop2 with no state loss */
-		.latency_ns = 9900,
-		.residency_ns = 99000,
-		.flags = 0*OPAL_PM_DEC_STOP \
-		       | 0*OPAL_PM_TIMEBASE_STOP  \
-		       | 0*OPAL_PM_LOSE_USER_CONTEXT \
-		       | 0*OPAL_PM_LOSE_HYP_CONTEXT \
-		       | 0*OPAL_PM_LOSE_FULL_CONTEXT \
-		       | 1*OPAL_PM_STOP_INST_FAST,
-		.pm_ctrl_reg_val = OPAL_PM_PSSCR_RL(2) \
-				 | OPAL_PM_PSSCR_MTL(3) \
-				 | OPAL_PM_PSSCR_TR(3),
-		.pm_ctrl_reg_mask = OPAL_PM_PSSCR_MASK },
+	/*
+	 * stop2_lite has been removed since currently it adds minimal benefit over stop2.
+	 * However, the benefit is eclipsed by the time required to ungate the clocks
+	 */
+
 	{
 		.name = "stop2",
 		.latency_ns = 10000,
-- 
2.5.5