linux-stable/drivers/acpi/acpica/hwesleep.c
Kirill A. Shutemov 1d4e0b3abb ACPICA: Hardware: Do not flush CPU cache when entering S4 and S5
ACPICA commit 3dd7e1f3996456ef81bfe14cba29860e8d42949e

According to ACPI 6.4, Section 16.2, the CPU cache flushing is
required on entering to S1, S2, and S3, but the ACPICA code
flushes the CPU cache regardless of the sleep state.

Blind cache flush on entering S5 causes problems for TDX.

Flushing happens with WBINVD that is not supported in the TDX
environment.

TDX only supports S5 and adjusting ACPICA code to conform to the
spec more strictly fixes the issue.

Link: https://github.com/acpica/acpica/commit/3dd7e1f3
Signed-off-by: Kirill A. Shutemov <kirill.shutemov@linux.intel.com>
[ rjw: Subject and changelog edits ]
Signed-off-by: Rafael J. Wysocki <rafael.j.wysocki@intel.com>
Signed-off-by: Bob Moore <robert.moore@intel.com>
Signed-off-by: Rafael J. Wysocki <rafael.j.wysocki@intel.com>
2021-12-27 17:01:28 +01:00

204 lines
5.7 KiB
C

// SPDX-License-Identifier: BSD-3-Clause OR GPL-2.0
/******************************************************************************
*
* Name: hwesleep.c - ACPI Hardware Sleep/Wake Support functions for the
* extended FADT-V5 sleep registers.
*
* Copyright (C) 2000 - 2021, Intel Corp.
*
*****************************************************************************/
#include <acpi/acpi.h>
#include "accommon.h"
#define _COMPONENT ACPI_HARDWARE
ACPI_MODULE_NAME("hwesleep")
/*******************************************************************************
*
* FUNCTION: acpi_hw_execute_sleep_method
*
* PARAMETERS: method_pathname - Pathname of method to execute
* integer_argument - Argument to pass to the method
*
* RETURN: None
*
* DESCRIPTION: Execute a sleep/wake related method with one integer argument
* and no return value.
*
******************************************************************************/
void acpi_hw_execute_sleep_method(char *method_pathname, u32 integer_argument)
{
struct acpi_object_list arg_list;
union acpi_object arg;
acpi_status status;
ACPI_FUNCTION_TRACE(hw_execute_sleep_method);
/* One argument, integer_argument; No return value expected */
arg_list.count = 1;
arg_list.pointer = &arg;
arg.type = ACPI_TYPE_INTEGER;
arg.integer.value = (u64)integer_argument;
status = acpi_evaluate_object(NULL, method_pathname, &arg_list, NULL);
if (ACPI_FAILURE(status) && status != AE_NOT_FOUND) {
ACPI_EXCEPTION((AE_INFO, status, "While executing method %s",
method_pathname));
}
return_VOID;
}
/*******************************************************************************
*
* 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_control;
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((u64)ACPI_X_WAKE_STATUS,
&acpi_gbl_FADT.sleep_status);
if (ACPI_FAILURE(status)) {
return_ACPI_STATUS(status);
}
acpi_gbl_system_awake_and_running = FALSE;
/*
* 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_control = ((acpi_gbl_sleep_type_a << ACPI_X_SLEEP_TYPE_POSITION) &
ACPI_X_SLEEP_TYPE_MASK) | ACPI_X_SLEEP_ENABLE;
/* Flush caches, as per ACPI specification */
if (sleep_state < ACPI_STATE_S4) {
ACPI_FLUSH_CPU_CACHE();
}
status = acpi_os_enter_sleep(sleep_state, sleep_control, 0);
if (status == AE_CTRL_TERMINATE) {
return_ACPI_STATUS(AE_OK);
}
if (ACPI_FAILURE(status)) {
return_ACPI_STATUS(status);
}
status = acpi_write((u64)sleep_control, &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)
{
u8 sleep_type_value;
ACPI_FUNCTION_TRACE(hw_extended_wake_prep);
if (acpi_gbl_sleep_type_a_s0 != ACPI_SLEEP_TYPE_INVALID) {
sleep_type_value =
((acpi_gbl_sleep_type_a_s0 << ACPI_X_SLEEP_TYPE_POSITION) &
ACPI_X_SLEEP_TYPE_MASK);
(void)acpi_write((u64)(sleep_type_value | ACPI_X_SLEEP_ENABLE),
&acpi_gbl_FADT.sleep_control);
}
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_sleep_method(METHOD_PATHNAME__SST, ACPI_SST_WAKING);
acpi_hw_execute_sleep_method(METHOD_PATHNAME__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((u64)ACPI_X_WAKE_STATUS, &acpi_gbl_FADT.sleep_status);
acpi_gbl_system_awake_and_running = TRUE;
acpi_hw_execute_sleep_method(METHOD_PATHNAME__SST, ACPI_SST_WORKING);
return_ACPI_STATUS(AE_OK);
}