[RFC 3/3] cpuidle/powernv : Add flags to identify stop state type

Abhishek Goel
2019-08-23T07:09:40Z

Removed threshold latency which was being used to decide if a state
is cpuidle type or not. This decision can be taken using flags, as this
information has been encapsulated in the state->flags and being read
from idle device-tree.

Signed-off-by: Abhishek Goel <huntbag@linux.vnet.ibm.com>
---
arch/powerpc/include/asm/opal-api.h | 7 +++++++
drivers/cpuidle/cpuidle-powernv.c | 16 +++++++++-------
2 files changed, 16 insertions(+), 7 deletions(-)

diff --git a/arch/powerpc/include/asm/opal-api.h b/arch/powerpc/include/asm/opal-api.h
index 383242eb0dea..b9068fee21d8 100644
--- a/arch/powerpc/include/asm/opal-api.h
+++ b/arch/powerpc/include/asm/opal-api.h
@@ -233,6 +233,13 @@
#define OPAL_PM_STOP_INST_FAST 0x00100000
#define OPAL_PM_STOP_INST_DEEP 0x00200000

+/*
+ * Flags for stop states to distinguish between cpuidle and
+ * cpuoffline type of states.
+ */
+#define OPAL_PM_STOP_CPUIDLE 0x01000000
+#define OPAL_PM_STOP_CPUHOTPLUG 0x02000000
+
/*
* OPAL_CONFIG_CPU_IDLE_STATE parameters
*/
diff --git a/drivers/cpuidle/cpuidle-powernv.c b/drivers/cpuidle/cpuidle-powernv.c
index 1b6c84d4ac77..1a33a548b769 100644
--- a/drivers/cpuidle/cpuidle-powernv.c
+++ b/drivers/cpuidle/cpuidle-powernv.c
@@ -270,8 +270,13 @@ static int powernv_add_idle_states(void)
goto out;
}

- /* TODO: Count only states which are eligible for cpuidle */
- dt_idle_states = nr_pnv_idle_states;
+ /* Count only cpuidle states*/
+ for (i = 0; i < nr_pnv_idle_states; i++) {
+ if (pnv_idle_states[i].flags & OPAL_PM_STOP_CPUIDLE)
+ dt_idle_states++;
+ }
+ pr_info("idle states in dt = %d , states with idle flag = %d",
+ nr_pnv_idle_states, dt_idle_states);

/*
* Since snooze is used as first idle state, max idle states allowed is
@@ -300,11 +305,8 @@ static int powernv_add_idle_states(void)
continue;
}

- /*
- * If an idle state has exit latency beyond
- * POWERNV_THRESHOLD_LATENCY_NS then don't use it in cpu-idle.
- */
- if (state->latency_ns > POWERNV_THRESHOLD_LATENCY_NS) {
+ /* Check whether a state is of cpuidle type */
+ if ((state->flags & OPAL_PM_STOP_CPUIDLE) != state->flags) {
pr_info("State %d is not idletype\n", i);
continue;
}
--
2.17.1