-#endif
-
- /*
- * Promotion?
- * ----------
- * Track the number of longs (time asleep is greater than threshold)
- * and promote when the count threshold is reached. Note that bus
- * mastering activity may prevent promotions.
- * Do not promote above max_cstate.
- */
- if (cx->promotion.state &&
- ((cx->promotion.state - pr->power.states) <= max_cstate)) {
- if (sleep_ticks > cx->promotion.threshold.ticks &&
- cx->promotion.state->latency <= system_latency_constraint()) {
- cx->promotion.count++;
- cx->demotion.count = 0;
- if (cx->promotion.count >=
- cx->promotion.threshold.count) {
- if (pr->flags.bm_check) {
- if (!
- (pr->power.bm_activity & cx->
- promotion.threshold.bm)) {
- next_state =
- cx->promotion.state;
- goto end;
- }
- } else {
- next_state = cx->promotion.state;
- goto end;
- }
- }
- }
- }
-
- /*
- * Demotion?
- * ---------
- * Track the number of shorts (time asleep is less than time threshold)
- * and demote when the usage threshold is reached.
- */
- if (cx->demotion.state) {
- if (sleep_ticks < cx->demotion.threshold.ticks) {
- cx->demotion.count++;
- cx->promotion.count = 0;
- if (cx->demotion.count >= cx->demotion.threshold.count) {
- next_state = cx->demotion.state;
- goto end;
- }
- }
- }
-
- end:
- /*
- * Demote if current state exceeds max_cstate
- * or if the latency of the current state is unacceptable
- */
- if ((pr->power.state - pr->power.states) > max_cstate ||
- pr->power.state->latency > system_latency_constraint()) {
- if (cx->demotion.state)
- next_state = cx->demotion.state;
- }
-
- /*
- * New Cx State?
- * -------------
- * If we're going to start using a new Cx state we must clean up
- * from the previous and prepare to use the new.
- */
- if (next_state != pr->power.state)
- acpi_processor_power_activate(pr, next_state);
-}
-
-static int acpi_processor_set_power_policy(struct acpi_processor *pr)
-{
- unsigned int i;
- unsigned int state_is_set = 0;
- struct acpi_processor_cx *lower = NULL;
- struct acpi_processor_cx *higher = NULL;
- struct acpi_processor_cx *cx;
-
-
- if (!pr)
- return -EINVAL;
-
- /*
- * This function sets the default Cx state policy (OS idle handler).
- * Our scheme is to promote quickly to C2 but more conservatively
- * to C3. We're favoring C2 for its characteristics of low latency
- * (quick response), good power savings, and ability to allow bus
- * mastering activity. Note that the Cx state policy is completely
- * customizable and can be altered dynamically.
- */
-
- /* startup state */
- for (i = 1; i < ACPI_PROCESSOR_MAX_POWER; i++) {
- cx = &pr->power.states[i];
- if (!cx->valid)
- continue;
-
- if (!state_is_set)
- pr->power.state = cx;
- state_is_set++;
- break;
- }
-
- if (!state_is_set)
- return -ENODEV;
-
- /* demotion */
- for (i = 1; i < ACPI_PROCESSOR_MAX_POWER; i++) {
- cx = &pr->power.states[i];
- if (!cx->valid)
- continue;
-
- if (lower) {
- cx->demotion.state = lower;
- cx->demotion.threshold.ticks = cx->latency_ticks;
- cx->demotion.threshold.count = 1;
- if (cx->type == ACPI_STATE_C3)
- cx->demotion.threshold.bm = bm_history;
- }
-
- lower = cx;
- }
-
- /* promotion */
- for (i = (ACPI_PROCESSOR_MAX_POWER - 1); i > 0; i--) {
- cx = &pr->power.states[i];
- if (!cx->valid)
- continue;
-
- if (higher) {
- cx->promotion.state = higher;
- cx->promotion.threshold.ticks = cx->latency_ticks;
- if (cx->type >= ACPI_STATE_C2)
- cx->promotion.threshold.count = 4;
- else
- cx->promotion.threshold.count = 10;
- if (higher->type == ACPI_STATE_C3)
- cx->promotion.threshold.bm = bm_history;
- }
-
- higher = cx;
- }
-
- return 0;