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Commit 2feec47d authored by Bob Moore's avatar Bob Moore Committed by Len Brown
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ACPICA: ACPI 5: Support for new FADT SleepStatus, SleepControl registers



Adds sleep and wake support for systems with these registers.
One new file, hwxfsleep.c

Signed-off-by: default avatarBob Moore <robert.moore@intel.com>
Signed-off-by: default avatarLen Brown <len.brown@intel.com>
parent 384fe875
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+2 −1
Original line number Diff line number Diff line
@@ -73,7 +73,8 @@ acpi-y += \
	hwregs.o	\
	hwsleep.o	\
	hwvalid.o	\
	hwxface.o
	hwxface.o	\
	hwxfsleep.o

acpi-$(ACPI_FUTURE_USAGE) += hwtimer.o

+17 −0
Original line number Diff line number Diff line
@@ -80,6 +80,23 @@ acpi_status acpi_hw_register_write(u32 register_id, u32 value);

acpi_status acpi_hw_clear_acpi_status(void);

/*
 * hwsleep - sleep/wake support
 */
void acpi_hw_execute_SST(u32 value);

acpi_status acpi_hw_extended_sleep(u8 sleep_state);

acpi_status acpi_hw_legacy_sleep(u8 sleep_state);

acpi_status acpi_hw_extended_wake_prep(u8 sleep_state);

acpi_status acpi_hw_extended_wake(u8 sleep_state);

acpi_status acpi_hw_legacy_wake_prep(u8 sleep_state);

acpi_status acpi_hw_legacy_wake(u8 sleep_state);

/*
 * hwvalid - Port I/O with validation
 */
+298 −268
Original line number Diff line number Diff line

/******************************************************************************
 *
 * Name: hwsleep.c - ACPI Hardware Sleep/Wake Interface
 * Name: hwsleep.c - ACPI Hardware Sleep/Wake Support Functions
 *
 *****************************************************************************/

@@ -44,212 +43,183 @@

#include <acpi/acpi.h>
#include "accommon.h"
#include "actables.h"
#include <linux/tboot.h>
#include <linux/module.h>

#define _COMPONENT          ACPI_HARDWARE
ACPI_MODULE_NAME("hwsleep")

/* Local prototypes */
static void acpi_hw_execute_GTS(u8 sleep_state);

static void acpi_hw_execute_BFS(u8 sleep_state);

static void acpi_hw_execute_WAK(u8 sleep_state);

static unsigned int gts, bfs;
module_param(gts, uint, 0644);
module_param(bfs, uint, 0644);
MODULE_PARM_DESC(gts, "Enable evaluation of _GTS on suspend.");
MODULE_PARM_DESC(bfs, "Enable evaluation of _BFS on resume".);

/*******************************************************************************
 *
 * FUNCTION:    acpi_set_firmware_waking_vector
 * FUNCTION:    acpi_hw_execute_GTS
 *
 * PARAMETERS:  physical_address    - 32-bit physical address of ACPI real mode
 *                                    entry point.
 * PARAMETERS:  sleep_state         - Sleep state that will be entered
 *
 * RETURN:      Status
 * RETURN:      None
 *
 * DESCRIPTION: Sets the 32-bit firmware_waking_vector field of the FACS
 * DESCRIPTION: Execute the optional _GTS method (Going To Sleep)
 *
 ******************************************************************************/
acpi_status
acpi_set_firmware_waking_vector(u32 physical_address)
{
	ACPI_FUNCTION_TRACE(acpi_set_firmware_waking_vector);


	/*
	 * According to the ACPI specification 2.0c and later, the 64-bit
	 * waking vector should be cleared and the 32-bit waking vector should
	 * be used, unless we want the wake-up code to be called by the BIOS in
	 * Protected Mode.  Some systems (for example HP dv5-1004nr) are known
	 * to fail to resume if the 64-bit vector is used.
	 */
static void acpi_hw_execute_GTS(u8 sleep_state)
{
	struct acpi_object_list arg_list;
	union acpi_object arg;
	acpi_status status;

	/* Set the 32-bit vector */
	if (!gts)
		return;

	acpi_gbl_FACS->firmware_waking_vector = physical_address;
	/* One argument, sleep_state */

	/* Clear the 64-bit vector if it exists */
	arg_list.count = 1;
	arg_list.pointer = &arg;
	arg.type = ACPI_TYPE_INTEGER;
	arg.integer.value = sleep_state;

	if ((acpi_gbl_FACS->length > 32) && (acpi_gbl_FACS->version >= 1)) {
		acpi_gbl_FACS->xfirmware_waking_vector = 0;
	status = acpi_evaluate_object(NULL, METHOD_NAME__GTS, &arg_list, NULL);
	if (ACPI_FAILURE(status) && status != AE_NOT_FOUND) {
		ACPI_EXCEPTION((AE_INFO, status,
				"While executing method _GTS"));
	}

	return_ACPI_STATUS(AE_OK);
}

ACPI_EXPORT_SYMBOL(acpi_set_firmware_waking_vector)

#if ACPI_MACHINE_WIDTH == 64
/*******************************************************************************
 *
 * FUNCTION:    acpi_set_firmware_waking_vector64
 * FUNCTION:    acpi_hw_execute_BFS
 *
 * PARAMETERS:  physical_address    - 64-bit physical address of ACPI protected
 *                                    mode entry point.
 * PARAMETERS:  sleep_state         - Which sleep state we just exited
 *
 * RETURN:      Status
 * RETURN:      None
 *
 * DESCRIPTION: Sets the 64-bit X_firmware_waking_vector field of the FACS, if
 *              it exists in the table. This function is intended for use with
 *              64-bit host operating systems.
 * DESCRIPTION: Execute the optional _BFS method (Back From Sleep)
 *
 ******************************************************************************/
acpi_status
acpi_set_firmware_waking_vector64(u64 physical_address)
{
	ACPI_FUNCTION_TRACE(acpi_set_firmware_waking_vector64);


	/* Determine if the 64-bit vector actually exists */
static void acpi_hw_execute_BFS(u8 sleep_state)
{
	struct acpi_object_list arg_list;
	union acpi_object arg;
	acpi_status status;

	if ((acpi_gbl_FACS->length <= 32) || (acpi_gbl_FACS->version < 1)) {
		return_ACPI_STATUS(AE_NOT_EXIST);
	}
	if (!bfs)
		return;

	/* Clear 32-bit vector, set the 64-bit X_ vector */
	/* One argument, sleep_state */

	acpi_gbl_FACS->firmware_waking_vector = 0;
	acpi_gbl_FACS->xfirmware_waking_vector = physical_address;
	arg_list.count = 1;
	arg_list.pointer = &arg;
	arg.type = ACPI_TYPE_INTEGER;
	arg.integer.value = sleep_state;

	return_ACPI_STATUS(AE_OK);
	status = acpi_evaluate_object(NULL, METHOD_NAME__BFS, &arg_list, NULL);
	if (ACPI_FAILURE(status) && status != AE_NOT_FOUND) {
		ACPI_EXCEPTION((AE_INFO, status,
				"While executing method _BFS"));
	}
}

ACPI_EXPORT_SYMBOL(acpi_set_firmware_waking_vector64)
#endif

/*******************************************************************************
 *
 * FUNCTION:    acpi_enter_sleep_state_prep
 * FUNCTION:    acpi_hw_execute_WAK
 *
 * PARAMETERS:  sleep_state         - Which sleep state to enter
 * PARAMETERS:  sleep_state         - Which sleep state we just exited
 *
 * RETURN:      Status
 * RETURN:      None
 *
 * DESCRIPTION: Prepare to enter a system sleep state (see ACPI 2.0 spec p 231)
 *              This function must execute with interrupts enabled.
 *              We break sleeping into 2 stages so that OSPM can handle
 *              various OS-specific tasks between the two steps.
 * DESCRIPTION: Execute the _WAK method (System Wake)
 *
 ******************************************************************************/
acpi_status acpi_enter_sleep_state_prep(u8 sleep_state)

static void acpi_hw_execute_WAK(u8 sleep_state)
{
	acpi_status status;
	struct acpi_object_list arg_list;
	union acpi_object arg;
	acpi_status status;

	ACPI_FUNCTION_TRACE(acpi_enter_sleep_state_prep);

	/* _PSW methods could be run here to enable wake-on keyboard, LAN, etc. */

	status = acpi_get_sleep_type_data(sleep_state,
					  &acpi_gbl_sleep_type_a,
					  &acpi_gbl_sleep_type_b);
	if (ACPI_FAILURE(status)) {
		return_ACPI_STATUS(status);
	}

	/* Setup parameter object */
	/* One argument, sleep_state */

	arg_list.count = 1;
	arg_list.pointer = &arg;

	arg.type = ACPI_TYPE_INTEGER;
	arg.integer.value = sleep_state;

	/* Run the _PTS method */

	status = acpi_evaluate_object(NULL, METHOD_NAME__PTS, &arg_list, NULL);
	status = acpi_evaluate_object(NULL, METHOD_NAME__WAK, &arg_list, NULL);
	if (ACPI_FAILURE(status) && status != AE_NOT_FOUND) {
		return_ACPI_STATUS(status);
		ACPI_EXCEPTION((AE_INFO, status,
				"While executing method _WAK"));
	}
	/* TBD: _WAK "sometimes" returns stuff - do we want to look at it? */
}

	/* Setup the argument to _SST */

	switch (sleep_state) {
	case ACPI_STATE_S0:
		arg.integer.value = ACPI_SST_WORKING;
		break;
/*******************************************************************************
 *
 * FUNCTION:    acpi_hw_execute_SST
 *
 * PARAMETERS:  indicator_id        - Value to be passed to the _SST method
 *
 * RETURN:      None
 *
 * DESCRIPTION: Execute the optional _SST method (System Status)
 *
 ******************************************************************************/

	case ACPI_STATE_S1:
	case ACPI_STATE_S2:
	case ACPI_STATE_S3:
		arg.integer.value = ACPI_SST_SLEEPING;
		break;
void acpi_hw_execute_SST(u32 indicator_id)
{
	struct acpi_object_list arg_list;
	union acpi_object arg;
	acpi_status status;

	case ACPI_STATE_S4:
		arg.integer.value = ACPI_SST_SLEEP_CONTEXT;
		break;
	/* One argument, status indicator ID */

	default:
		arg.integer.value = ACPI_SST_INDICATOR_OFF;	/* Default is off */
		break;
	}
	arg_list.count = 1;
	arg_list.pointer = &arg;
	arg.type = ACPI_TYPE_INTEGER;

	/*
	 * Set the system indicators to show the desired sleep state.
	 * _SST is an optional method (return no error if not found)
	 */
	arg.integer.value = indicator_id;
	status = acpi_evaluate_object(NULL, METHOD_NAME__SST, &arg_list, NULL);
	if (ACPI_FAILURE(status) && status != AE_NOT_FOUND) {
		ACPI_EXCEPTION((AE_INFO, status,
				"While executing method _SST"));
	}

	return_ACPI_STATUS(AE_OK);
}

ACPI_EXPORT_SYMBOL(acpi_enter_sleep_state_prep)

static unsigned int gts, bfs;
module_param(gts, uint, 0644);
module_param(bfs, uint, 0644);
MODULE_PARM_DESC(gts, "Enable evaluation of _GTS on suspend.");
MODULE_PARM_DESC(bfs, "Enable evaluation of _BFS on resume".);

/*******************************************************************************
 *
 * FUNCTION:    acpi_enter_sleep_state
 * FUNCTION:    acpi_hw_legacy_sleep
 *
 * PARAMETERS:  sleep_state         - Which sleep state to enter
 *
 * RETURN:      Status
 *
 * DESCRIPTION: Enter a system sleep state (see ACPI 2.0 spec p 231)
 * DESCRIPTION: Enter a system sleep state via the legacy FADT PM registers
 *              THIS FUNCTION MUST BE CALLED WITH INTERRUPTS DISABLED
 *
 ******************************************************************************/
acpi_status asmlinkage acpi_enter_sleep_state(u8 sleep_state)

acpi_status acpi_hw_legacy_sleep(u8 sleep_state)
{
	u32 pm1a_control;
	u32 pm1b_control;
	struct acpi_bit_register_info *sleep_type_reg_info;
	struct acpi_bit_register_info *sleep_enable_reg_info;
	u32 pm1a_control;
	u32 pm1b_control;
	u32 in_value;
	struct acpi_object_list arg_list;
	union acpi_object arg;
	acpi_status status;

	ACPI_FUNCTION_TRACE(acpi_enter_sleep_state);

	if ((acpi_gbl_sleep_type_a > ACPI_SLEEP_TYPE_MAX) ||
	    (acpi_gbl_sleep_type_b > ACPI_SLEEP_TYPE_MAX)) {
		ACPI_ERROR((AE_INFO, "Sleep values out of range: A=0x%X B=0x%X",
			    acpi_gbl_sleep_type_a, acpi_gbl_sleep_type_b));
		return_ACPI_STATUS(AE_AML_OPERAND_VALUE);
	}
	ACPI_FUNCTION_TRACE(hw_legacy_sleep);

	sleep_type_reg_info =
	    acpi_hw_get_bit_register_info(ACPI_BITREG_SLEEP_TYPE);
@@ -271,6 +241,18 @@ acpi_status asmlinkage acpi_enter_sleep_state(u8 sleep_state)
		return_ACPI_STATUS(status);
	}

	if (sleep_state != ACPI_STATE_S5) {
		/*
		 * Disable BM arbitration. This feature is contained within an
		 * optional register (PM2 Control), so ignore a BAD_ADDRESS
		 * exception.
		 */
		status = acpi_write_bit_register(ACPI_BITREG_ARB_DISABLE, 1);
		if (ACPI_FAILURE(status) && (status != AE_BAD_ADDRESS)) {
			return_ACPI_STATUS(status);
		}
	}

	/*
	 * 1) Disable/Clear all GPEs
	 * 2) Enable all wakeup GPEs
@@ -286,19 +268,9 @@ acpi_status asmlinkage acpi_enter_sleep_state(u8 sleep_state)
		return_ACPI_STATUS(status);
	}

	if (gts) {
		/* Execute the _GTS method */

		arg_list.count = 1;
		arg_list.pointer = &arg;
		arg.type = ACPI_TYPE_INTEGER;
		arg.integer.value = sleep_state;
	/* Execute the _GTS method (Going To Sleep) */

		status = acpi_evaluate_object(NULL, METHOD_NAME__GTS, &arg_list, NULL);
		if (ACPI_FAILURE(status) && status != AE_NOT_FOUND) {
			return_ACPI_STATUS(status);
		}
	}
	acpi_hw_execute_GTS(sleep_state);

	/* Get current value of PM1A control */

@@ -375,114 +347,43 @@ acpi_status asmlinkage acpi_enter_sleep_state(u8 sleep_state)
		}
	}

	/* Wait until we enter sleep state */

	do {
		status = acpi_read_bit_register(ACPI_BITREG_WAKE_STATUS,
						    &in_value);
		if (ACPI_FAILURE(status)) {
			return_ACPI_STATUS(status);
		}

		/* Spin until we wake */

	} while (!in_value);

	return_ACPI_STATUS(AE_OK);
}

ACPI_EXPORT_SYMBOL(acpi_enter_sleep_state)

/*******************************************************************************
 *
 * FUNCTION:    acpi_enter_sleep_state_s4bios
 *
 * PARAMETERS:  None
 *
 * RETURN:      Status
 *
 * DESCRIPTION: Perform a S4 bios request.
 *              THIS FUNCTION MUST BE CALLED WITH INTERRUPTS DISABLED
 *
 ******************************************************************************/
acpi_status asmlinkage acpi_enter_sleep_state_s4bios(void)
{
	u32 in_value;
	acpi_status status;

	ACPI_FUNCTION_TRACE(acpi_enter_sleep_state_s4bios);

	/* Clear the wake status bit (PM1) */

	status =
	    acpi_write_bit_register(ACPI_BITREG_WAKE_STATUS, ACPI_CLEAR_STATUS);
	if (ACPI_FAILURE(status)) {
		return_ACPI_STATUS(status);
	}

	status = acpi_hw_clear_acpi_status();
	if (ACPI_FAILURE(status)) {
		return_ACPI_STATUS(status);
	}

	/*
	 * 1) Disable/Clear all GPEs
	 * 2) Enable all wakeup GPEs
	 */
	status = acpi_hw_disable_all_gpes();
	if (ACPI_FAILURE(status)) {
		return_ACPI_STATUS(status);
	}
	acpi_gbl_system_awake_and_running = FALSE;

	status = acpi_hw_enable_all_wakeup_gpes();
	if (ACPI_FAILURE(status)) {
		return_ACPI_STATUS(status);
	}

	ACPI_FLUSH_CPU_CACHE();

	status = acpi_hw_write_port(acpi_gbl_FADT.smi_command,
				    (u32) acpi_gbl_FADT.S4bios_request, 8);
	/* Wait for transition back to Working State */

	do {
		acpi_os_stall(1000);
		status =
		    acpi_read_bit_register(ACPI_BITREG_WAKE_STATUS, &in_value);
		if (ACPI_FAILURE(status)) {
			return_ACPI_STATUS(status);
		}

	} while (!in_value);

	return_ACPI_STATUS(AE_OK);
}

ACPI_EXPORT_SYMBOL(acpi_enter_sleep_state_s4bios)

/*******************************************************************************
 *
 * FUNCTION:    acpi_leave_sleep_state_prep
 * FUNCTION:    acpi_hw_legacy_wake_prep
 *
 * PARAMETERS:  sleep_state         - Which sleep state we are exiting
 * PARAMETERS:  sleep_state         - Which sleep state we just exited
 *
 * RETURN:      Status
 *
 * DESCRIPTION: Perform the first state of OS-independent ACPI cleanup after a
 *              sleep.
 *              Called with interrupts DISABLED.
 *              Called with interrupts ENABLED.
 *
 ******************************************************************************/
acpi_status acpi_leave_sleep_state_prep(u8 sleep_state)

acpi_status acpi_hw_legacy_wake_prep(u8 sleep_state)
{
	struct acpi_object_list arg_list;
	union acpi_object arg;
	acpi_status status;
	struct acpi_bit_register_info *sleep_type_reg_info;
	struct acpi_bit_register_info *sleep_enable_reg_info;
	u32 pm1a_control;
	u32 pm1b_control;

	ACPI_FUNCTION_TRACE(acpi_leave_sleep_state_prep);
	ACPI_FUNCTION_TRACE(hw_legacy_wake_prep);

	/*
	 * Set SLP_TYPE and SLP_EN to state S0.
@@ -525,25 +426,13 @@ acpi_status acpi_leave_sleep_state_prep(u8 sleep_state)
		}
	}

	if (bfs) {
		/* Execute the _BFS method */

		arg_list.count = 1;
		arg_list.pointer = &arg;
		arg.type = ACPI_TYPE_INTEGER;
		arg.integer.value = sleep_state;

		status = acpi_evaluate_object(NULL, METHOD_NAME__BFS, &arg_list, NULL);
		if (ACPI_FAILURE(status) && status != AE_NOT_FOUND) {
			ACPI_EXCEPTION((AE_INFO, status, "During Method _BFS"));
		}
	}
	acpi_hw_execute_BFS(sleep_state);
	return_ACPI_STATUS(status);
}

/*******************************************************************************
 *
 * FUNCTION:    acpi_leave_sleep_state
 * FUNCTION:    acpi_hw_legacy_wake
 *
 * PARAMETERS:  sleep_state         - Which sleep state we just exited
 *
@@ -553,31 +442,17 @@ acpi_status acpi_leave_sleep_state_prep(u8 sleep_state)
 *              Called with interrupts ENABLED.
 *
 ******************************************************************************/
acpi_status acpi_leave_sleep_state(u8 sleep_state)

acpi_status acpi_hw_legacy_wake(u8 sleep_state)
{
	struct acpi_object_list arg_list;
	union acpi_object arg;
	acpi_status status;

	ACPI_FUNCTION_TRACE(acpi_leave_sleep_state);
	ACPI_FUNCTION_TRACE(hw_legacy_wake);

	/* Ensure enter_sleep_state_prep -> enter_sleep_state ordering */

	acpi_gbl_sleep_type_a = ACPI_SLEEP_TYPE_INVALID;

	/* Setup parameter object */

	arg_list.count = 1;
	arg_list.pointer = &arg;
	arg.type = ACPI_TYPE_INTEGER;

	/* Ignore any errors from these methods */

	arg.integer.value = ACPI_SST_WAKING;
	status = acpi_evaluate_object(NULL, METHOD_NAME__SST, &arg_list, NULL);
	if (ACPI_FAILURE(status) && status != AE_NOT_FOUND) {
		ACPI_EXCEPTION((AE_INFO, status, "During Method _SST"));
	}
	acpi_hw_execute_SST(ACPI_SST_WAKING);

	/*
	 * GPEs must be enabled before _WAK is called as GPEs
@@ -591,25 +466,24 @@ acpi_status acpi_leave_sleep_state(u8 sleep_state)
	if (ACPI_FAILURE(status)) {
		return_ACPI_STATUS(status);
	}

	status = acpi_hw_enable_all_runtime_gpes();
	if (ACPI_FAILURE(status)) {
		return_ACPI_STATUS(status);
	}

	arg.integer.value = sleep_state;
	status = acpi_evaluate_object(NULL, METHOD_NAME__WAK, &arg_list, NULL);
	if (ACPI_FAILURE(status) && status != AE_NOT_FOUND) {
		ACPI_EXCEPTION((AE_INFO, status, "During Method _WAK"));
	}
	/* TBD: _WAK "sometimes" returns stuff - do we want to look at it? */
	/*
	 * Now we can execute _WAK, etc. Some machines require that the GPEs
	 * are enabled before the wake methods are executed.
	 */
	acpi_hw_execute_WAK(sleep_state);

	/*
	 * Some BIOSes assume that WAK_STS will be cleared on resume and use
	 * it to determine whether the system is rebooting or resuming. Clear
	 * it for compatibility.
	 * Some BIOS code assumes that WAK_STS will be cleared on resume
	 * and use it to determine whether the system is rebooting or
	 * resuming. Clear WAK_STS for compatibility.
	 */
	acpi_write_bit_register(ACPI_BITREG_WAKE_STATUS, 1);

	acpi_gbl_system_awake_and_running = TRUE;

	/* Enable power button */
@@ -624,13 +498,169 @@ acpi_status acpi_leave_sleep_state(u8 sleep_state)
				    [ACPI_EVENT_POWER_BUTTON].
				    status_register_id, ACPI_CLEAR_STATUS);

	arg.integer.value = ACPI_SST_WORKING;
	status = acpi_evaluate_object(NULL, METHOD_NAME__SST, &arg_list, NULL);
	if (ACPI_FAILURE(status) && status != AE_NOT_FOUND) {
		ACPI_EXCEPTION((AE_INFO, status, "During Method _SST"));
	/*
	 * Enable BM arbitration. This feature is contained within an
	 * optional register (PM2 Control), so ignore a BAD_ADDRESS
	 * exception.
	 */
	status = acpi_write_bit_register(ACPI_BITREG_ARB_DISABLE, 0);
	if (ACPI_FAILURE(status) && (status != AE_BAD_ADDRESS)) {
		return_ACPI_STATUS(status);
	}

	acpi_hw_execute_SST(ACPI_SST_WORKING);
	return_ACPI_STATUS(status);
}

ACPI_EXPORT_SYMBOL(acpi_leave_sleep_state)

/*******************************************************************************
 *
 * FUNCTION:    acpi_hw_extended_sleep
 *
 * PARAMETERS:  sleep_state         - Which sleep state to enter
 *
 * RETURN:      Status
 *
 * DESCRIPTION: Enter a system sleep state via the extended FADT sleep
 *              registers (V5 FADT).
 *              THIS FUNCTION MUST BE CALLED WITH INTERRUPTS DISABLED
 *
 ******************************************************************************/

acpi_status acpi_hw_extended_sleep(u8 sleep_state)
{
	acpi_status status;
	u8 sleep_type_value;
	u64 sleep_status;

	ACPI_FUNCTION_TRACE(hw_extended_sleep);

	/* Extended sleep registers must be valid */

	if (!acpi_gbl_FADT.sleep_control.address ||
	    !acpi_gbl_FADT.sleep_status.address) {
		return_ACPI_STATUS(AE_NOT_EXIST);
	}

	/* Clear wake status (WAK_STS) */

	status = acpi_write(ACPI_X_WAKE_STATUS, &acpi_gbl_FADT.sleep_status);
	if (ACPI_FAILURE(status)) {
		return_ACPI_STATUS(status);
	}

	acpi_gbl_system_awake_and_running = FALSE;

	/* Execute the _GTS method (Going To Sleep) */

	acpi_hw_execute_GTS(sleep_state);

	/* Flush caches, as per ACPI specification */

	ACPI_FLUSH_CPU_CACHE();

	/*
	 * Set the SLP_TYP and SLP_EN bits.
	 *
	 * Note: We only use the first value returned by the \_Sx method
	 * (acpi_gbl_sleep_type_a) - As per ACPI specification.
	 */
	ACPI_DEBUG_PRINT((ACPI_DB_INIT,
			  "Entering sleep state [S%u]\n", sleep_state));

	sleep_type_value =
	    ((acpi_gbl_sleep_type_a << ACPI_X_SLEEP_TYPE_POSITION) &
	     ACPI_X_SLEEP_TYPE_MASK);

	status = acpi_write((sleep_type_value | ACPI_X_SLEEP_ENABLE),
			    &acpi_gbl_FADT.sleep_control);
	if (ACPI_FAILURE(status)) {
		return_ACPI_STATUS(status);
	}

	/* Wait for transition back to Working State */

	do {
		status = acpi_read(&sleep_status, &acpi_gbl_FADT.sleep_status);
		if (ACPI_FAILURE(status)) {
			return_ACPI_STATUS(status);
		}

	} while (!(((u8)sleep_status) & ACPI_X_WAKE_STATUS));

	return_ACPI_STATUS(AE_OK);
}

/*******************************************************************************
 *
 * FUNCTION:    acpi_hw_extended_wake_prep
 *
 * PARAMETERS:  sleep_state         - Which sleep state we just exited
 *
 * RETURN:      Status
 *
 * DESCRIPTION: Perform first part of OS-independent ACPI cleanup after
 *              a sleep. Called with interrupts ENABLED.
 *
 ******************************************************************************/

acpi_status acpi_hw_extended_wake_prep(u8 sleep_state)
{
	acpi_status status;
	u8 sleep_type_value;

	ACPI_FUNCTION_TRACE(hw_extended_wake_prep);

	status = acpi_get_sleep_type_data(ACPI_STATE_S0,
					  &acpi_gbl_sleep_type_a,
					  &acpi_gbl_sleep_type_b);
	if (ACPI_SUCCESS(status)) {
		sleep_type_value =
		    ((acpi_gbl_sleep_type_a << ACPI_X_SLEEP_TYPE_POSITION) &
		     ACPI_X_SLEEP_TYPE_MASK);

		(void)acpi_write((sleep_type_value | ACPI_X_SLEEP_ENABLE),
				 &acpi_gbl_FADT.sleep_control);
	}

	acpi_hw_execute_BFS(sleep_state);
	return_ACPI_STATUS(AE_OK);
}

/*******************************************************************************
 *
 * FUNCTION:    acpi_hw_extended_wake
 *
 * PARAMETERS:  sleep_state         - Which sleep state we just exited
 *
 * RETURN:      Status
 *
 * DESCRIPTION: Perform OS-independent ACPI cleanup after a sleep
 *              Called with interrupts ENABLED.
 *
 ******************************************************************************/

acpi_status acpi_hw_extended_wake(u8 sleep_state)
{
	ACPI_FUNCTION_TRACE(hw_extended_wake);

	/* Ensure enter_sleep_state_prep -> enter_sleep_state ordering */

	acpi_gbl_sleep_type_a = ACPI_SLEEP_TYPE_INVALID;

	/* Execute the wake methods */

	acpi_hw_execute_SST(ACPI_SST_WAKING);
	acpi_hw_execute_WAK(sleep_state);

	/*
	 * Some BIOS code assumes that WAK_STS will be cleared on resume
	 * and use it to determine whether the system is rebooting or
	 * resuming. Clear WAK_STS for compatibility.
	 */
	(void)acpi_write(ACPI_X_WAKE_STATUS, &acpi_gbl_FADT.sleep_status);
	acpi_gbl_system_awake_and_running = TRUE;

	acpi_hw_execute_SST(ACPI_SST_WORKING);
	return_ACPI_STATUS(AE_OK);
}