Commit bc71bec9 authored by venkatesh.pallipadi@intel.com's avatar venkatesh.pallipadi@intel.com Committed by Len Brown
Browse files

ACPI: enable MWAIT for C1 idle 



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: default avatarVenkatesh Pallipadi <venkatesh.pallipadi@intel.com>
Signed-off-by: default avatarLen Brown <len.brown@intel.com>
parent 2e906655

drivers/acpi/processor_idle.c

+12 −8
Original line number Diff line number Diff line
@@ -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++;

include/acpi/processor.h

+2 −1
Original line number Diff line number Diff line
@@ -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;