/**
* menu_select - selects the next idle state to enter
* @dev: the CPU
*/
static int menu_select(struct cpuidle_device *dev)
{
struct menu_device *data = &__get_cpu_var(menu_devices);
int latency_req = pm_qos_requirement(PM_QOS_CPU_DMA_LATENCY);
int i;
/* Special case when user has set very strict latency requirement */
if (unlikely(latency_req == 0)) {
data->last_state_idx = 0;
return 0;
}
/* determine the expected residency time */
data->expected_us =
(u32) ktime_to_ns(tick_nohz_get_sleep_length()) / 1000;
/* find the deepest idle state that satisfies our constraints */
for (i = CPUIDLE_DRIVER_STATE_START + 1; i < dev->state_count; i++) {
struct cpuidle_state *s = &dev->states[i];
if (s->target_residency > data->expected_us)
break;
if (s->target_residency > data->predicted_us)
break;
if (s->exit_latency > latency_req)
break;
}
data->last_state_idx = i - 1;
return i - 1;
}
/**
* ladder_select_state - selects the next state to enter
* @dev: the CPU
*/
static int ladder_select_state(struct cpuidle_device *dev)
{
struct ladder_device *ldev = &__get_cpu_var(ladder_devices);
struct ladder_device_state *last_state;
int last_residency, last_idx = ldev->last_state_idx;
int latency_req = pm_qos_requirement(PM_QOS_CPU_DMA_LATENCY);
/* Special case when user has set very strict latency requirement */
if (unlikely(latency_req == 0)) {
ladder_do_selection(ldev, last_idx, 0);
return 0;
}
last_state = &ldev->states[last_idx];
if (dev->states[last_idx].flags & CPUIDLE_FLAG_TIME_VALID)
last_residency = cpuidle_get_last_residency(dev) - dev->states[last_idx].exit_latency;
else
last_residency = last_state->threshold.promotion_time + 1;
/* consider promotion */
if (last_idx < dev->state_count - 1 &&
last_residency > last_state->threshold.promotion_time &&
dev->states[last_idx + 1].exit_latency <= latency_req) {
last_state->stats.promotion_count++;
last_state->stats.demotion_count = 0;
if (last_state->stats.promotion_count >= last_state->threshold.promotion_count) {
ladder_do_selection(ldev, last_idx, last_idx + 1);
return last_idx + 1;
}
}
/* consider demotion */
if (last_idx > CPUIDLE_DRIVER_STATE_START &&
dev->states[last_idx].exit_latency > latency_req) {
int i;
for (i = last_idx - 1; i > CPUIDLE_DRIVER_STATE_START; i--) {
if (dev->states[i].exit_latency <= latency_req)
break;
}
ladder_do_selection(ldev, last_idx, i);
return i;
}
if (last_idx > CPUIDLE_DRIVER_STATE_START &&
last_residency < last_state->threshold.demotion_time) {
last_state->stats.demotion_count++;
last_state->stats.promotion_count = 0;
if (last_state->stats.demotion_count >= last_state->threshold.demotion_count) {
ladder_do_selection(ldev, last_idx, last_idx - 1);
return last_idx - 1;
}
}
/* otherwise remain at the current state */
return last_idx;
}
static int acpi_processor_power_seq_show(struct seq_file *seq, void *offset)
{
struct acpi_processor *pr = seq->private;
unsigned int i;
if (!pr)
goto end;
seq_printf(seq, "active state: C%zd\n"
"max_cstate: C%d\n"
"maximum allowed latency: %d usec\n",
pr->power.state ? pr->power.state - pr->power.states : 0,
max_cstate, pm_qos_requirement(PM_QOS_CPU_DMA_LATENCY));
seq_puts(seq, "states:\n");
for (i = 1; i <= pr->power.count; i++) {
seq_printf(seq, " %cC%d: ",
(&pr->power.states[i] ==
pr->power.state ? '*' : ' '), i);
if (!pr->power.states[i].valid) {
seq_puts(seq, "<not supported>\n");
continue;
}
switch (pr->power.states[i].type) {
case ACPI_STATE_C1:
seq_printf(seq, "type[C1] ");
break;
case ACPI_STATE_C2:
seq_printf(seq, "type[C2] ");
break;
case ACPI_STATE_C3:
seq_printf(seq, "type[C3] ");
break;
default:
seq_printf(seq, "type[--] ");
break;
}
seq_puts(seq, "promotion[--] ");
seq_puts(seq, "demotion[--] ");
seq_printf(seq, "latency[%03d] usage[%08d] duration[%020Lu]\n",
pr->power.states[i].latency,
pr->power.states[i].usage,
us_to_pm_timer_ticks(pr->power.states[i].time));
}
end:
return 0;
}
/**
* menu_select - selects the next idle state to enter
* @dev: the CPU
*/
static int menu_select(struct cpuidle_device *dev)
{
struct menu_device *data = &__get_cpu_var(menu_devices);
int i;
/* determine the expected residency time */
data->expected_us =
(u32) ktime_to_ns(tick_nohz_get_sleep_length()) / 1000;
/* find the deepest idle state that satisfies our constraints */
for (i = 1; i < dev->state_count; i++) {
struct cpuidle_state *s = &dev->states[i];
if (s->target_residency > data->expected_us)
break;
if (s->target_residency > data->predicted_us)
break;
if (s->exit_latency > pm_qos_requirement(PM_QOS_CPU_DMA_LATENCY))
break;
}
data->last_state_idx = i - 1;
return i - 1;
}
