#include <linux/dmi.h>
#include <linux/moduleparam.h>
#include <linux/sched.h> /* need_resched() */
+#include <linux/latency.h>
#include <asm/io.h>
#include <asm/uaccess.h>
static void acpi_safe_halt(void)
{
current_thread_info()->status &= ~TS_POLLING;
- smp_mb__after_clear_bit();
+ /*
+ * TS_POLLING-cleared state must be visible before we
+ * test NEED_RESCHED:
+ */
+ smp_mb();
if (!need_resched())
safe_halt();
current_thread_info()->status |= TS_POLLING;
static atomic_t c3_cpu_count;
+/* Common C-state entry for C2, C3, .. */
+static void acpi_cstate_enter(struct acpi_processor_cx *cstate)
+{
+ if (cstate->space_id == ACPI_CSTATE_FFH) {
+ /* Call into architectural FFH based C-state */
+ acpi_processor_ffh_cstate_enter(cstate);
+ } else {
+ int unused;
+ /* IO port based C-state */
+ inb(cstate->address);
+ /* Dummy wait op - must do something useless after P_LVL2 read
+ because chipsets cannot guarantee that STPCLK# signal
+ gets asserted in time to freeze execution properly. */
+ unused = inl(acpi_fadt.xpm_tmr_blk.address);
+ }
+}
+
static void acpi_processor_idle(void)
{
struct acpi_processor *pr = NULL;
*/
if (cx->type == ACPI_STATE_C2 || cx->type == ACPI_STATE_C3) {
current_thread_info()->status &= ~TS_POLLING;
- smp_mb__after_clear_bit();
+ /*
+ * TS_POLLING-cleared state must be visible before we
+ * test NEED_RESCHED:
+ */
+ smp_mb();
if (need_resched()) {
current_thread_info()->status |= TS_POLLING;
local_irq_enable();
/* Get start time (ticks) */
t1 = inl(acpi_fadt.xpm_tmr_blk.address);
/* Invoke C2 */
- inb(cx->address);
- /* Dummy wait op - must do something useless after P_LVL2 read
- because chipsets cannot guarantee that STPCLK# signal
- gets asserted in time to freeze execution properly. */
- t2 = inl(acpi_fadt.xpm_tmr_blk.address);
+ acpi_cstate_enter(cx);
/* Get end time (ticks) */
t2 = inl(acpi_fadt.xpm_tmr_blk.address);
/* Get start time (ticks) */
t1 = inl(acpi_fadt.xpm_tmr_blk.address);
/* Invoke C3 */
- inb(cx->address);
- /* Dummy wait op (see above) */
- t2 = inl(acpi_fadt.xpm_tmr_blk.address);
+ acpi_cstate_enter(cx);
/* Get end time (ticks) */
t2 = inl(acpi_fadt.xpm_tmr_blk.address);
if (pr->flags.bm_check) {
*/
if (cx->promotion.state &&
((cx->promotion.state - pr->power.states) <= max_cstate)) {
- if (sleep_ticks > cx->promotion.threshold.ticks) {
+ 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 >=
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) {
+ 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;
}
return 0;
}
-static int acpi_processor_get_power_info_default_c1(struct acpi_processor *pr)
+static int acpi_processor_get_power_info_default(struct acpi_processor *pr)
{
-
- /* Zero initialize all the C-states info. */
- memset(pr->power.states, 0, sizeof(pr->power.states));
-
- /* set the first C-State to C1 */
- pr->power.states[ACPI_STATE_C1].type = ACPI_STATE_C1;
-
- /* the C0 state only exists as a filler in our array,
- * and all processors need to support C1 */
+ if (!pr->power.states[ACPI_STATE_C1].valid) {
+ /* set the first C-State to C1 */
+ /* all processors need to support C1 */
+ pr->power.states[ACPI_STATE_C1].type = ACPI_STATE_C1;
+ pr->power.states[ACPI_STATE_C1].valid = 1;
+ }
+ /* the C0 state only exists as a filler in our array */
pr->power.states[ACPI_STATE_C0].valid = 1;
- pr->power.states[ACPI_STATE_C1].valid = 1;
-
return 0;
}
if (nocst)
return -ENODEV;
- current_count = 1;
-
- /* Zero initialize C2 onwards and prepare for fresh CST lookup */
- for (i = 2; i < ACPI_PROCESSOR_MAX_POWER; i++)
- memset(&(pr->power.states[i]), 0,
- sizeof(struct acpi_processor_cx));
+ current_count = 0;
status = acpi_evaluate_object(pr->handle, "_CST", NULL, &buffer);
if (ACPI_FAILURE(status)) {
return -ENODEV;
}
- cst = (union acpi_object *)buffer.pointer;
+ cst = buffer.pointer;
/* There must be at least 2 elements */
if (!cst || (cst->type != ACPI_TYPE_PACKAGE) || cst->package.count < 2) {
memset(&cx, 0, sizeof(cx));
- element = (union acpi_object *)&(cst->package.elements[i]);
+ element = &(cst->package.elements[i]);
if (element->type != ACPI_TYPE_PACKAGE)
continue;
if (element->package.count != 4)
continue;
- obj = (union acpi_object *)&(element->package.elements[0]);
+ obj = &(element->package.elements[0]);
if (obj->type != ACPI_TYPE_BUFFER)
continue;
(reg->space_id != ACPI_ADR_SPACE_FIXED_HARDWARE))
continue;
- cx.address = (reg->space_id == ACPI_ADR_SPACE_FIXED_HARDWARE) ?
- 0 : reg->address;
-
/* There should be an easy way to extract an integer... */
- obj = (union acpi_object *)&(element->package.elements[1]);
+ obj = &(element->package.elements[1]);
if (obj->type != ACPI_TYPE_INTEGER)
continue;
cx.type = obj->integer.value;
+ /*
+ * Some buggy BIOSes won't list C1 in _CST -
+ * Let acpi_processor_get_power_info_default() handle them later
+ */
+ if (i == 1 && cx.type != ACPI_STATE_C1)
+ current_count++;
+
+ cx.address = reg->address;
+ cx.index = current_count + 1;
+
+ cx.space_id = ACPI_CSTATE_SYSTEMIO;
+ if (reg->space_id == ACPI_ADR_SPACE_FIXED_HARDWARE) {
+ if (acpi_processor_ffh_cstate_probe
+ (pr->id, &cx, reg) == 0) {
+ cx.space_id = ACPI_CSTATE_FFH;
+ } else if (cx.type != ACPI_STATE_C1) {
+ /*
+ * C1 is a special case where FIXED_HARDWARE
+ * can be handled in non-MWAIT way as well.
+ * In that case, save this _CST entry info.
+ * That is, we retain space_id of SYSTEM_IO for
+ * halt based C1.
+ * Otherwise, ignore this info and continue.
+ */
+ continue;
+ }
+ }
- if ((cx.type != ACPI_STATE_C1) &&
- (reg->space_id != ACPI_ADR_SPACE_SYSTEM_IO))
- continue;
-
- if ((cx.type < ACPI_STATE_C2) || (cx.type > ACPI_STATE_C3))
- continue;
-
- obj = (union acpi_object *)&(element->package.elements[2]);
+ obj = &(element->package.elements[2]);
if (obj->type != ACPI_TYPE_INTEGER)
continue;
cx.latency = obj->integer.value;
- obj = (union acpi_object *)&(element->package.elements[3]);
+ obj = &(element->package.elements[3]);
if (obj->type != ACPI_TYPE_INTEGER)
continue;
/* NOTE: the idle thread may not be running while calling
* this function */
- /* Adding C1 state */
- acpi_processor_get_power_info_default_c1(pr);
+ /* Zero initialize all the C-states info. */
+ memset(pr->power.states, 0, sizeof(pr->power.states));
+
result = acpi_processor_get_power_info_cst(pr);
if (result == -ENODEV)
- acpi_processor_get_power_info_fadt(pr);
+ result = acpi_processor_get_power_info_fadt(pr);
+
+ if (result)
+ return result;
+
+ acpi_processor_get_power_info_default(pr);
pr->power.count = acpi_processor_power_verify(pr);
static int acpi_processor_power_seq_show(struct seq_file *seq, void *offset)
{
- struct acpi_processor *pr = (struct acpi_processor *)seq->private;
+ struct acpi_processor *pr = seq->private;
unsigned int i;
seq_printf(seq, "active state: C%zd\n"
"max_cstate: C%d\n"
- "bus master activity: %08x\n",
+ "bus master activity: %08x\n"
+ "maximum allowed latency: %d usec\n",
pr->power.state ? pr->power.state - pr->power.states : 0,
- max_cstate, (unsigned)pr->power.bm_activity);
+ max_cstate, (unsigned)pr->power.bm_activity,
+ system_latency_constraint());
seq_puts(seq, "states:\n");
.release = single_release,
};
-int acpi_processor_power_init(struct acpi_processor *pr,
+#ifdef CONFIG_SMP
+static void smp_callback(void *v)
+{
+ /* we already woke the CPU up, nothing more to do */
+}
+
+/*
+ * This function gets called when a part of the kernel has a new latency
+ * requirement. This means we need to get all processors out of their C-state,
+ * and then recalculate a new suitable C-state. Just do a cross-cpu IPI; that
+ * wakes them all right up.
+ */
+static int acpi_processor_latency_notify(struct notifier_block *b,
+ unsigned long l, void *v)
+{
+ smp_call_function(smp_callback, NULL, 0, 1);
+ return NOTIFY_OK;
+}
+
+static struct notifier_block acpi_processor_latency_notifier = {
+ .notifier_call = acpi_processor_latency_notify,
+};
+#endif
+
+int __cpuinit acpi_processor_power_init(struct acpi_processor *pr,
struct acpi_device *device)
{
acpi_status status = 0;
"ACPI: processor limited to max C-state %d\n",
max_cstate);
first_run++;
+#ifdef CONFIG_SMP
+ register_latency_notifier(&acpi_processor_latency_notifier);
+#endif
}
if (!pr)
* copies of pm_idle before proceeding.
*/
cpu_idle_wait();
+#ifdef CONFIG_SMP
+ unregister_latency_notifier(&acpi_processor_latency_notifier);
+#endif
}
return 0;
git://git.onelab.eu / linux-2.6.git / blobdiff