=============
- Using stack instead kzalloc/kcalloc
Changes in v5
=============
- Use generic cpuidle constant CPUIDLE_NAME_LEN
- Fix return code handling for of_property_read_string_array
- Use DT flags to determine if are using stop instruction, instead of
cpu_has_feature
- Removed uncessary cast with names
- &stop_loop -> stop_loop
- Added POWERNV_THRESHOLD_LATENCY_NS to filter out idle states with high latency
drivers/cpuidle/cpuidle-powernv.c | 61 +++++++++++++++++++++++++++++++++++++++
1 file changed, 61 insertions(+)
@@ -20,6 +20,8 @@
#include <asm/opal.h>
#include <asm/runlatch.h>
+#define POWERNV_THRESHOLD_LATENCY_NS 200000
+
struct cpuidle_driver powernv_idle_driver = {
.name = "powernv_idle",
.owner = THIS_MODULE,
@@ -27,6 +29,9 @@ struct cpuidle_driver powernv_idle_driver = {
static int max_idle_state;
static struct cpuidle_state *cpuidle_state_table;
+
+static u64 stop_psscr_table[CPUIDLE_STATE_MAX];
+
static u64 snooze_timeout;
static bool snooze_timeout_en;
@@ -91,6 +96,17 @@ static int fastsleep_loop(struct cpuidle_device *dev,
return index;
}
#endif
+
+static int stop_loop(struct cpuidle_device *dev,
+ struct cpuidle_driver *drv,
+ int index)
+{
+ ppc64_runlatch_off();
+ power9_idle_stop(stop_psscr_table[index]);
+ ppc64_runlatch_on();
+ return index;
+}
+
/*
* States for dedicated partition case.
*/
@@ -169,6 +185,8 @@ static int powernv_add_idle_states(void)
u32 latency_ns[CPUIDLE_STATE_MAX];
u32 residency_ns[CPUIDLE_STATE_MAX];
u32 flags[CPUIDLE_STATE_MAX];
+ u64 psscr_val[CPUIDLE_STATE_MAX];
+ const char *names[CPUIDLE_STATE_MAX];
int i, rc;
/* Currently we have snooze statically defined */
@@ -207,11 +225,34 @@ static int powernv_add_idle_states(void)
pr_warn("cpuidle-powernv: missing ibm,cpu-idle-state-latencies-ns in DT\n");
goto out;
}
+ if (of_property_read_string_array(power_mgt,
+ "ibm,cpu-idle-state-names", names, dt_idle_states)) {
+ pr_warn("cpuidle-powernv: missing ibm,cpu-idle-state-names in DT\n");
+ goto out;
+ }
+
+ /*
+ * If the idle states use stop instruction, probe for psscr values
+ * which are necessary to specify required stop level.
+ */
+ if (flags[0] & (OPAL_PM_STOP_INST_FAST | OPAL_PM_STOP_INST_DEEP))
+ if (of_property_read_u64_array(power_mgt,
+ "ibm,cpu-idle-state-psscr", psscr_val, dt_idle_states)) {
+ pr_warn("cpuidle-powernv: missing ibm,cpu-idle-states-psscr in DT\n");
+ goto out;
+ }
rc = of_property_read_u32_array(power_mgt,
"ibm,cpu-idle-state-residency-ns", residency_ns, dt_idle_states);
for (i = 0; i < dt_idle_states; i++) {
+ /*
+ * If an idle state has exit latency beyond
+ * POWERNV_THRESHOLD_LATENCY_NS then don't use it
+ * in cpu-idle.
+ */
+ if (latency_ns[i] > POWERNV_THRESHOLD_LATENCY_NS)
+ continue;
/*
* Cpuidle accepts exit_latency and target_residency in us.
@@ -224,6 +265,16 @@ static int powernv_add_idle_states(void)
powernv_states[nr_idle_states].flags = 0;
powernv_states[nr_idle_states].target_residency = 100;
powernv_states[nr_idle_states].enter = nap_loop;
+ } else if ((flags[i] & OPAL_PM_STOP_INST_FAST) &&
+ !(flags[i] & OPAL_PM_TIMEBASE_STOP)) {
+ strncpy(powernv_states[nr_idle_states].name,
+ names[i], CPUIDLE_NAME_LEN);
+ strncpy(powernv_states[nr_idle_states].desc,
+ names[i], CPUIDLE_NAME_LEN);
+ powernv_states[nr_idle_states].flags = 0;
+
+ powernv_states[nr_idle_states].enter = stop_loop;
+ stop_psscr_table[nr_idle_states] = psscr_val[i];
}
/*
@@ -239,6 +290,16 @@ static int powernv_add_idle_states(void)
powernv_states[nr_idle_states].flags = CPUIDLE_FLAG_TIMER_STOP;
powernv_states[nr_idle_states].target_residency = 300000;
powernv_states[nr_idle_states].enter = fastsleep_loop;
+ } else if ((flags[i] & OPAL_PM_STOP_INST_DEEP) &&
+ (flags[i] & OPAL_PM_TIMEBASE_STOP)) {
+ strncpy(powernv_states[nr_idle_states].name,
+ names[i], CPUIDLE_NAME_LEN);
+ strncpy(powernv_states[nr_idle_states].desc,
+ names[i], CPUIDLE_NAME_LEN);
+
+ powernv_states[nr_idle_states].flags = CPUIDLE_FLAG_TIMER_STOP;
+ powernv_states[nr_idle_states].enter = stop_loop;
+ stop_psscr_table[nr_idle_states] = psscr_val[i];
}
#endif
powernv_states[nr_idle_states].exit_latency =