[PATCH 094/112] ACPI: enable MWAIT for C1 idle

Len Brown
2008-02-07T09:36:53Z

From: venkatesh.pallipadi@intel.com <venkatesh.pallipadi@intel.com>

Add MWAIT idle for C1 state instead of halt, on platforms that support
C1 state with MWAIT.

Renames cx->space_id to something more appropriate.

Signed-off-by: Venkatesh Pallipadi <venkatesh.pallipadi@intel.com>
Signed-off-by: Len Brown <len.brown@intel.com>
---
drivers/acpi/processor_idle.c | 20 ++++++++++++--------
include/acpi/processor.h | 3 ++-
2 files changed, 14 insertions(+), 9 deletions(-)

diff --git a/drivers/acpi/processor_idle.c b/drivers/acpi/processor_idle.c
index 106a229..4ba3a9a 100644
--- a/drivers/acpi/processor_idle.c
+++ b/drivers/acpi/processor_idle.c
@@ -265,7 +265,7 @@ 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) {
+ if (cstate->entry_method == ACPI_CSTATE_FFH) {
/* Call into architectural FFH based C-state */
acpi_processor_ffh_cstate_enter(cstate);
} else {
@@ -929,20 +929,20 @@ static int acpi_processor_get_power_info_cst(struct acpi_processor *pr)
cx.address = reg->address;
cx.index = current_count + 1;

- cx.space_id = ACPI_CSTATE_SYSTEMIO;
+ cx.entry_method = 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) {
+ cx.entry_method = 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.
*/
+ cx.entry_method = ACPI_CSTATE_HALT;
+ } else {
continue;
}
}
@@ -1376,12 +1376,16 @@ static inline void acpi_idle_update_bm_rld(struct acpi_processor *pr,
/**
* acpi_idle_do_entry - a helper function that does C2 and C3 type entry
* @cx: cstate data
+ *
+ * Caller disables interrupt before call and enables interrupt after return.
*/
static inline void acpi_idle_do_entry(struct acpi_processor_cx *cx)
{
- if (cx->space_id == ACPI_CSTATE_FFH) {
+ if (cx->entry_method == ACPI_CSTATE_FFH) {
/* Call into architectural FFH based C-state */
acpi_processor_ffh_cstate_enter(cx);
+ } else if (cx->entry_method == ACPI_CSTATE_HALT) {
+ acpi_safe_halt();
} else {
int unused;
/* IO port based C-state */
@@ -1414,7 +1418,7 @@ static int acpi_idle_enter_c1(struct cpuidle_device *dev,
if (pr->flags.bm_check)
acpi_idle_update_bm_rld(pr, cx);

- acpi_safe_halt();
+ acpi_idle_do_entry(cx);

local_irq_enable();
cx->usage++;
diff --git a/include/acpi/processor.h b/include/acpi/processor.h
index 6e253b5..f6d7c50 100644
--- a/include/acpi/processor.h
+++ b/include/acpi/processor.h
@@ -34,6 +34,7 @@

#define ACPI_CSTATE_SYSTEMIO (0)
#define ACPI_CSTATE_FFH (1)
+#define ACPI_CSTATE_HALT (2)

/* Power Management */

@@ -64,7 +65,7 @@ struct acpi_processor_cx {
u8 valid;
u8 type;
u32 address;
- u8 space_id;
+ u8 entry_method;
u8 index;
u32 latency;
u32 latency_ticks;
--
1.5.4.23.gef5b9