static int acpi_processor_get_throttling(struct acpi_processor *pr);
int acpi_processor_set_throttling(struct acpi_processor *pr, int state);
+/*
+ * _TPC - Throttling Present Capabilities
+ */
static int acpi_processor_get_platform_limit(struct acpi_processor *pr)
{
acpi_status status = 0;
if (!pr)
return -EINVAL;
status = acpi_evaluate_integer(pr->handle, "_TPC", NULL, &tpc);
- if (ACPI_FAILURE(status) && status != AE_NOT_FOUND) {
- ACPI_EXCEPTION((AE_INFO, status, "Evaluating _TPC"));
+ if (ACPI_FAILURE(status)) {
+ if (status != AE_NOT_FOUND) {
+ ACPI_EXCEPTION((AE_INFO, status, "Evaluating _TPC"));
+ }
return -ENODEV;
}
pr->throttling_platform_limit = (int)tpc;
int acpi_processor_tstate_has_changed(struct acpi_processor *pr)
{
- return acpi_processor_get_platform_limit(pr);
+ int result = 0;
+ int throttling_limit;
+ int current_state;
+ struct acpi_processor_limit *limit;
+ int target_state;
+
+ result = acpi_processor_get_platform_limit(pr);
+ if (result) {
+ /* Throttling Limit is unsupported */
+ return result;
+ }
+
+ throttling_limit = pr->throttling_platform_limit;
+ if (throttling_limit >= pr->throttling.state_count) {
+ /* Uncorrect Throttling Limit */
+ return -EINVAL;
+ }
+
+ current_state = pr->throttling.state;
+ if (current_state > throttling_limit) {
+ /*
+ * The current state can meet the requirement of
+ * _TPC limit. But it is reasonable that OSPM changes
+ * t-states from high to low for better performance.
+ * Of course the limit condition of thermal
+ * and user should be considered.
+ */
+ limit = &pr->limit;
+ target_state = throttling_limit;
+ if (limit->thermal.tx > target_state)
+ target_state = limit->thermal.tx;
+ if (limit->user.tx > target_state)
+ target_state = limit->user.tx;
+ } else if (current_state == throttling_limit) {
+ /*
+ * Unnecessary to change the throttling state
+ */
+ return 0;
+ } else {
+ /*
+ * If the current state is lower than the limit of _TPC, it
+ * will be forced to switch to the throttling state defined
+ * by throttling_platfor_limit.
+ * Because the previous state meets with the limit condition
+ * of thermal and user, it is unnecessary to check it again.
+ */
+ target_state = throttling_limit;
+ }
+ return acpi_processor_set_throttling(pr, target_state);
}
-/* --------------------------------------------------------------------------
- _PTC, _TSS, _TSD support
- -------------------------------------------------------------------------- */
+/*
+ * _PTC - Processor Throttling Control (and status) register location
+ */
static int acpi_processor_get_throttling_control(struct acpi_processor *pr)
{
int result = 0;
status = acpi_evaluate_object(pr->handle, "_PTC", NULL, &buffer);
if (ACPI_FAILURE(status)) {
- ACPI_EXCEPTION((AE_INFO, status, "Evaluating _PTC"));
+ if (status != AE_NOT_FOUND) {
+ ACPI_EXCEPTION((AE_INFO, status, "Evaluating _PTC"));
+ }
return -ENODEV;
}
return result;
}
+
+/*
+ * _TSS - Throttling Supported States
+ */
static int acpi_processor_get_throttling_states(struct acpi_processor *pr)
{
int result = 0;
status = acpi_evaluate_object(pr->handle, "_TSS", NULL, &buffer);
if (ACPI_FAILURE(status)) {
- ACPI_EXCEPTION((AE_INFO, status, "Evaluating _TSS"));
+ if (status != AE_NOT_FOUND) {
+ ACPI_EXCEPTION((AE_INFO, status, "Evaluating _TSS"));
+ }
return -ENODEV;
}
return result;
}
+
+/*
+ * _TSD - T-State Dependencies
+ */
static int acpi_processor_get_tsd(struct acpi_processor *pr)
{
int result = 0;
status = acpi_evaluate_object(pr->handle, "_TSD", NULL, &buffer);
if (ACPI_FAILURE(status)) {
+ if (status != AE_NOT_FOUND) {
+ ACPI_EXCEPTION((AE_INFO, status, "Evaluating _TSD"));
+ }
return -ENODEV;
}
int result = 0;
int step = 0;
int i = 0;
- int no_ptc = 0;
- int no_tss = 0;
- int no_tsd = 0;
ACPI_DEBUG_PRINT((ACPI_DB_INFO,
"pblk_address[0x%08x] duty_offset[%d] duty_width[%d]\n",
if (!pr)
return -EINVAL;
- /* TBD: Support ACPI 2.0 objects */
- no_ptc = acpi_processor_get_throttling_control(pr);
- no_tss = acpi_processor_get_throttling_states(pr);
- no_tsd = acpi_processor_get_tsd(pr);
-
- if (no_ptc || no_tss) {
+ /*
+ * Evaluate _PTC, _TSS and _TPC
+ * They must all be present or none of them can be used.
+ */
+ if (acpi_processor_get_throttling_control(pr) ||
+ acpi_processor_get_throttling_states(pr) ||
+ acpi_processor_get_platform_limit(pr))
+ {
pr->throttling.acpi_processor_get_throttling =
&acpi_processor_get_throttling_fadt;
pr->throttling.acpi_processor_set_throttling =
&acpi_processor_set_throttling_ptc;
}
+ acpi_processor_get_tsd(pr);
+
if (!pr->throttling.address) {
ACPI_DEBUG_PRINT((ACPI_DB_INFO, "No throttling register\n"));
return 0;
pr->throttling.state_count - 1);
seq_puts(seq, "states:\n");
- if (acpi_processor_get_throttling == acpi_processor_get_throttling_fadt)
+ if (pr->throttling.acpi_processor_get_throttling ==
+ acpi_processor_get_throttling_fadt) {
for (i = 0; i < pr->throttling.state_count; i++)
seq_printf(seq, " %cT%d: %02d%%\n",
(i == pr->throttling.state ? '*' : ' '), i,
(pr->throttling.states[i].performance ? pr->
throttling.states[i].performance / 10 : 0));
- else
+ } else {
for (i = 0; i < pr->throttling.state_count; i++)
seq_printf(seq, " %cT%d: %02d%%\n",
(i == pr->throttling.state ? '*' : ' '), i,
(int)pr->throttling.states_tss[i].
freqpercentage);
+ }
end:
return 0;