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path: root/drivers/acpi/processor_idle.c
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Diffstat (limited to 'drivers/acpi/processor_idle.c')
-rw-r--r--drivers/acpi/processor_idle.c85
1 files changed, 68 insertions, 17 deletions
diff --git a/drivers/acpi/processor_idle.c b/drivers/acpi/processor_idle.c
index 80ffc782991..f18261368e7 100644
--- a/drivers/acpi/processor_idle.c
+++ b/drivers/acpi/processor_idle.c
@@ -63,6 +63,7 @@
ACPI_MODULE_NAME("processor_idle");
#define ACPI_PROCESSOR_FILE_POWER "power"
#define US_TO_PM_TIMER_TICKS(t) ((t * (PM_TIMER_FREQUENCY/1000)) / 1000)
+#define PM_TIMER_TICK_NS (1000000000ULL/PM_TIMER_FREQUENCY)
#define C2_OVERHEAD 4 /* 1us (3.579 ticks per us) */
#define C3_OVERHEAD 4 /* 1us (3.579 ticks per us) */
static void (*pm_idle_save) (void) __read_mostly;
@@ -324,6 +325,23 @@ static void acpi_state_timer_broadcast(struct acpi_processor *pr,
#endif
+/*
+ * Suspend / resume control
+ */
+static int acpi_idle_suspend;
+
+int acpi_processor_suspend(struct acpi_device * device, pm_message_t state)
+{
+ acpi_idle_suspend = 1;
+ return 0;
+}
+
+int acpi_processor_resume(struct acpi_device * device)
+{
+ acpi_idle_suspend = 0;
+ return 0;
+}
+
static void acpi_processor_idle(void)
{
struct acpi_processor *pr = NULL;
@@ -354,7 +372,7 @@ static void acpi_processor_idle(void)
}
cx = pr->power.state;
- if (!cx) {
+ if (!cx || acpi_idle_suspend) {
if (pm_idle_save)
pm_idle_save();
else
@@ -462,6 +480,9 @@ static void acpi_processor_idle(void)
* TBD: Can't get time duration while in C1, as resumes
* go to an ISR rather than here. Need to instrument
* base interrupt handler.
+ *
+ * Note: the TSC better not stop in C1, sched_clock() will
+ * skew otherwise.
*/
sleep_ticks = 0xFFFFFFFF;
break;
@@ -469,28 +490,45 @@ static void acpi_processor_idle(void)
case ACPI_STATE_C2:
/* Get start time (ticks) */
t1 = inl(acpi_gbl_FADT.xpm_timer_block.address);
+ /* Tell the scheduler that we are going deep-idle: */
+ sched_clock_idle_sleep_event();
/* Invoke C2 */
acpi_state_timer_broadcast(pr, cx, 1);
acpi_cstate_enter(cx);
/* Get end time (ticks) */
t2 = inl(acpi_gbl_FADT.xpm_timer_block.address);
-#ifdef CONFIG_GENERIC_TIME
+#if defined (CONFIG_GENERIC_TIME) && defined (CONFIG_X86_TSC)
/* TSC halts in C2, so notify users */
mark_tsc_unstable("possible TSC halt in C2");
#endif
+ /* Compute time (ticks) that we were actually asleep */
+ sleep_ticks = ticks_elapsed(t1, t2);
+
+ /* Tell the scheduler how much we idled: */
+ sched_clock_idle_wakeup_event(sleep_ticks*PM_TIMER_TICK_NS);
+
/* Re-enable interrupts */
local_irq_enable();
+ /* Do not account our idle-switching overhead: */
+ sleep_ticks -= cx->latency_ticks + C2_OVERHEAD;
+
current_thread_info()->status |= TS_POLLING;
- /* Compute time (ticks) that we were actually asleep */
- sleep_ticks =
- ticks_elapsed(t1, t2) - cx->latency_ticks - C2_OVERHEAD;
acpi_state_timer_broadcast(pr, cx, 0);
break;
case ACPI_STATE_C3:
-
- if (pr->flags.bm_check) {
+ /*
+ * disable bus master
+ * bm_check implies we need ARB_DIS
+ * !bm_check implies we need cache flush
+ * bm_control implies whether we can do ARB_DIS
+ *
+ * That leaves a case where bm_check is set and bm_control is
+ * not set. In that case we cannot do much, we enter C3
+ * without doing anything.
+ */
+ if (pr->flags.bm_check && pr->flags.bm_control) {
if (atomic_inc_return(&c3_cpu_count) ==
num_online_cpus()) {
/*
@@ -499,7 +537,7 @@ static void acpi_processor_idle(void)
*/
acpi_set_register(ACPI_BITREG_ARB_DISABLE, 1);
}
- } else {
+ } else if (!pr->flags.bm_check) {
/* SMP with no shared cache... Invalidate cache */
ACPI_FLUSH_CPU_CACHE();
}
@@ -508,25 +546,32 @@ static void acpi_processor_idle(void)
t1 = inl(acpi_gbl_FADT.xpm_timer_block.address);
/* Invoke C3 */
acpi_state_timer_broadcast(pr, cx, 1);
+ /* Tell the scheduler that we are going deep-idle: */
+ sched_clock_idle_sleep_event();
acpi_cstate_enter(cx);
/* Get end time (ticks) */
t2 = inl(acpi_gbl_FADT.xpm_timer_block.address);
- if (pr->flags.bm_check) {
+ if (pr->flags.bm_check && pr->flags.bm_control) {
/* Enable bus master arbitration */
atomic_dec(&c3_cpu_count);
acpi_set_register(ACPI_BITREG_ARB_DISABLE, 0);
}
-#ifdef CONFIG_GENERIC_TIME
+#if defined (CONFIG_GENERIC_TIME) && defined (CONFIG_X86_TSC)
/* TSC halts in C3, so notify users */
mark_tsc_unstable("TSC halts in C3");
#endif
+ /* Compute time (ticks) that we were actually asleep */
+ sleep_ticks = ticks_elapsed(t1, t2);
+ /* Tell the scheduler how much we idled: */
+ sched_clock_idle_wakeup_event(sleep_ticks*PM_TIMER_TICK_NS);
+
/* Re-enable interrupts */
local_irq_enable();
+ /* Do not account our idle-switching overhead: */
+ sleep_ticks -= cx->latency_ticks + C3_OVERHEAD;
+
current_thread_info()->status |= TS_POLLING;
- /* Compute time (ticks) that we were actually asleep */
- sleep_ticks =
- ticks_elapsed(t1, t2) - cx->latency_ticks - C3_OVERHEAD;
acpi_state_timer_broadcast(pr, cx, 0);
break;
@@ -959,11 +1004,17 @@ static void acpi_processor_power_verify_c3(struct acpi_processor *pr,
}
if (pr->flags.bm_check) {
- /* bus mastering control is necessary */
if (!pr->flags.bm_control) {
- ACPI_DEBUG_PRINT((ACPI_DB_INFO,
- "C3 support requires bus mastering control\n"));
- return;
+ if (pr->flags.has_cst != 1) {
+ /* bus mastering control is necessary */
+ ACPI_DEBUG_PRINT((ACPI_DB_INFO,
+ "C3 support requires BM control\n"));
+ return;
+ } else {
+ /* Here we enter C3 without bus mastering */
+ ACPI_DEBUG_PRINT((ACPI_DB_INFO,
+ "C3 support without BM control\n"));
+ }
}
} else {
/*
generated by cgit v1.2.3 (git 2.25.1) at 2024-10-31 04:03:00 +0000