311 lines
8.7 KiB
C
311 lines
8.7 KiB
C
|
// SPDX-License-Identifier: BSD-3-Clause OR GPL-2.0
|
||
|
|
/******************************************************************************
|
||
|
|
*
|
||
|
|
* Module Name: evglock - Global Lock support
|
||
|
|
*
|
||
|
|
* Copyright (C) 2000 - 2022, Intel Corp.
|
||
|
|
*
|
||
|
|
*****************************************************************************/
|
||
|
|
|
||
|
|
#include <acpi/acpi.h>
|
||
|
|
#include "accommon.h"
|
||
|
|
#include "acevents.h"
|
||
|
|
#include "acinterp.h"
|
||
|
|
|
||
|
|
#define _COMPONENT ACPI_EVENTS
|
||
|
|
ACPI_MODULE_NAME("evglock")
|
||
|
|
#if (!ACPI_REDUCED_HARDWARE) /* Entire module */
|
||
|
|
/* Local prototypes */
|
||
|
|
static u32 acpi_ev_global_lock_handler(void *context);
|
||
|
|
|
||
|
|
/*******************************************************************************
|
||
|
|
*
|
||
|
|
* FUNCTION: acpi_ev_init_global_lock_handler
|
||
|
|
*
|
||
|
|
* PARAMETERS: None
|
||
|
|
*
|
||
|
|
* RETURN: Status
|
||
|
|
*
|
||
|
|
* DESCRIPTION: Install a handler for the global lock release event
|
||
|
|
*
|
||
|
|
******************************************************************************/
|
||
|
|
|
||
|
|
acpi_status acpi_ev_init_global_lock_handler(void)
|
||
|
|
{
|
||
|
|
acpi_status status;
|
||
|
|
|
||
|
|
ACPI_FUNCTION_TRACE(ev_init_global_lock_handler);
|
||
|
|
|
||
|
|
/* If Hardware Reduced flag is set, there is no global lock */
|
||
|
|
|
||
|
|
if (acpi_gbl_reduced_hardware) {
|
||
|
|
return_ACPI_STATUS(AE_OK);
|
||
|
|
}
|
||
|
|
|
||
|
|
/* Attempt installation of the global lock handler */
|
||
|
|
|
||
|
|
status = acpi_install_fixed_event_handler(ACPI_EVENT_GLOBAL,
|
||
|
|
acpi_ev_global_lock_handler,
|
||
|
|
NULL);
|
||
|
|
|
||
|
|
/*
|
||
|
|
* If the global lock does not exist on this platform, the attempt to
|
||
|
|
* enable GBL_STATUS will fail (the GBL_ENABLE bit will not stick).
|
||
|
|
* Map to AE_OK, but mark global lock as not present. Any attempt to
|
||
|
|
* actually use the global lock will be flagged with an error.
|
||
|
|
*/
|
||
|
|
acpi_gbl_global_lock_present = FALSE;
|
||
|
|
if (status == AE_NO_HARDWARE_RESPONSE) {
|
||
|
|
ACPI_ERROR((AE_INFO,
|
||
|
|
"No response from Global Lock hardware, disabling lock"));
|
||
|
|
|
||
|
|
return_ACPI_STATUS(AE_OK);
|
||
|
|
}
|
||
|
|
|
||
|
|
status = acpi_os_create_lock(&acpi_gbl_global_lock_pending_lock);
|
||
|
|
if (ACPI_FAILURE(status)) {
|
||
|
|
return_ACPI_STATUS(status);
|
||
|
|
}
|
||
|
|
|
||
|
|
acpi_gbl_global_lock_pending = FALSE;
|
||
|
|
acpi_gbl_global_lock_present = TRUE;
|
||
|
|
return_ACPI_STATUS(status);
|
||
|
|
}
|
||
|
|
|
||
|
|
/*******************************************************************************
|
||
|
|
*
|
||
|
|
* FUNCTION: acpi_ev_remove_global_lock_handler
|
||
|
|
*
|
||
|
|
* PARAMETERS: None
|
||
|
|
*
|
||
|
|
* RETURN: Status
|
||
|
|
*
|
||
|
|
* DESCRIPTION: Remove the handler for the Global Lock
|
||
|
|
*
|
||
|
|
******************************************************************************/
|
||
|
|
|
||
|
|
acpi_status acpi_ev_remove_global_lock_handler(void)
|
||
|
|
{
|
||
|
|
acpi_status status;
|
||
|
|
|
||
|
|
ACPI_FUNCTION_TRACE(ev_remove_global_lock_handler);
|
||
|
|
|
||
|
|
acpi_gbl_global_lock_present = FALSE;
|
||
|
|
status = acpi_remove_fixed_event_handler(ACPI_EVENT_GLOBAL,
|
||
|
|
acpi_ev_global_lock_handler);
|
||
|
|
|
||
|
|
acpi_os_delete_lock(acpi_gbl_global_lock_pending_lock);
|
||
|
|
return_ACPI_STATUS(status);
|
||
|
|
}
|
||
|
|
|
||
|
|
/*******************************************************************************
|
||
|
|
*
|
||
|
|
* FUNCTION: acpi_ev_global_lock_handler
|
||
|
|
*
|
||
|
|
* PARAMETERS: context - From thread interface, not used
|
||
|
|
*
|
||
|
|
* RETURN: ACPI_INTERRUPT_HANDLED
|
||
|
|
*
|
||
|
|
* DESCRIPTION: Invoked directly from the SCI handler when a global lock
|
||
|
|
* release interrupt occurs. If there is actually a pending
|
||
|
|
* request for the lock, signal the waiting thread.
|
||
|
|
*
|
||
|
|
******************************************************************************/
|
||
|
|
|
||
|
|
static u32 acpi_ev_global_lock_handler(void *context)
|
||
|
|
{
|
||
|
|
acpi_status status;
|
||
|
|
acpi_cpu_flags flags;
|
||
|
|
|
||
|
|
flags = acpi_os_acquire_lock(acpi_gbl_global_lock_pending_lock);
|
||
|
|
|
||
|
|
/*
|
||
|
|
* If a request for the global lock is not actually pending,
|
||
|
|
* we are done. This handles "spurious" global lock interrupts
|
||
|
|
* which are possible (and have been seen) with bad BIOSs.
|
||
|
|
*/
|
||
|
|
if (!acpi_gbl_global_lock_pending) {
|
||
|
|
goto cleanup_and_exit;
|
||
|
|
}
|
||
|
|
|
||
|
|
/*
|
||
|
|
* Send a unit to the global lock semaphore. The actual acquisition
|
||
|
|
* of the global lock will be performed by the waiting thread.
|
||
|
|
*/
|
||
|
|
status = acpi_os_signal_semaphore(acpi_gbl_global_lock_semaphore, 1);
|
||
|
|
if (ACPI_FAILURE(status)) {
|
||
|
|
ACPI_ERROR((AE_INFO, "Could not signal Global Lock semaphore"));
|
||
|
|
}
|
||
|
|
|
||
|
|
acpi_gbl_global_lock_pending = FALSE;
|
||
|
|
|
||
|
|
cleanup_and_exit:
|
||
|
|
|
||
|
|
acpi_os_release_lock(acpi_gbl_global_lock_pending_lock, flags);
|
||
|
|
return (ACPI_INTERRUPT_HANDLED);
|
||
|
|
}
|
||
|
|
|
||
|
|
/******************************************************************************
|
||
|
|
*
|
||
|
|
* FUNCTION: acpi_ev_acquire_global_lock
|
||
|
|
*
|
||
|
|
* PARAMETERS: timeout - Max time to wait for the lock, in millisec.
|
||
|
|
*
|
||
|
|
* RETURN: Status
|
||
|
|
*
|
||
|
|
* DESCRIPTION: Attempt to gain ownership of the Global Lock.
|
||
|
|
*
|
||
|
|
* MUTEX: Interpreter must be locked
|
||
|
|
*
|
||
|
|
* Note: The original implementation allowed multiple threads to "acquire" the
|
||
|
|
* Global Lock, and the OS would hold the lock until the last thread had
|
||
|
|
* released it. However, this could potentially starve the BIOS out of the
|
||
|
|
* lock, especially in the case where there is a tight handshake between the
|
||
|
|
* Embedded Controller driver and the BIOS. Therefore, this implementation
|
||
|
|
* allows only one thread to acquire the HW Global Lock at a time, and makes
|
||
|
|
* the global lock appear as a standard mutex on the OS side.
|
||
|
|
*
|
||
|
|
*****************************************************************************/
|
||
|
|
|
||
|
|
acpi_status acpi_ev_acquire_global_lock(u16 timeout)
|
||
|
|
{
|
||
|
|
acpi_cpu_flags flags;
|
||
|
|
acpi_status status;
|
||
|
|
u8 acquired = FALSE;
|
||
|
|
|
||
|
|
ACPI_FUNCTION_TRACE(ev_acquire_global_lock);
|
||
|
|
|
||
|
|
/*
|
||
|
|
* Only one thread can acquire the GL at a time, the global_lock_mutex
|
||
|
|
* enforces this. This interface releases the interpreter if we must wait.
|
||
|
|
*/
|
||
|
|
status =
|
||
|
|
acpi_ex_system_wait_mutex(acpi_gbl_global_lock_mutex->mutex.
|
||
|
|
os_mutex, timeout);
|
||
|
|
if (ACPI_FAILURE(status)) {
|
||
|
|
return_ACPI_STATUS(status);
|
||
|
|
}
|
||
|
|
|
||
|
|
/*
|
||
|
|
* Update the global lock handle and check for wraparound. The handle is
|
||
|
|
* only used for the external global lock interfaces, but it is updated
|
||
|
|
* here to properly handle the case where a single thread may acquire the
|
||
|
|
* lock via both the AML and the acpi_acquire_global_lock interfaces. The
|
||
|
|
* handle is therefore updated on the first acquire from a given thread
|
||
|
|
* regardless of where the acquisition request originated.
|
||
|
|
*/
|
||
|
|
acpi_gbl_global_lock_handle++;
|
||
|
|
if (acpi_gbl_global_lock_handle == 0) {
|
||
|
|
acpi_gbl_global_lock_handle = 1;
|
||
|
|
}
|
||
|
|
|
||
|
|
/*
|
||
|
|
* Make sure that a global lock actually exists. If not, just
|
||
|
|
* treat the lock as a standard mutex.
|
||
|
|
*/
|
||
|
|
if (!acpi_gbl_global_lock_present) {
|
||
|
|
acpi_gbl_global_lock_acquired = TRUE;
|
||
|
|
return_ACPI_STATUS(AE_OK);
|
||
|
|
}
|
||
|
|
|
||
|
|
flags = acpi_os_acquire_lock(acpi_gbl_global_lock_pending_lock);
|
||
|
|
|
||
|
|
do {
|
||
|
|
|
||
|
|
/* Attempt to acquire the actual hardware lock */
|
||
|
|
|
||
|
|
ACPI_ACQUIRE_GLOBAL_LOCK(acpi_gbl_FACS, acquired);
|
||
|
|
if (acquired) {
|
||
|
|
acpi_gbl_global_lock_acquired = TRUE;
|
||
|
|
ACPI_DEBUG_PRINT((ACPI_DB_EXEC,
|
||
|
|
"Acquired hardware Global Lock\n"));
|
||
|
|
break;
|
||
|
|
}
|
||
|
|
|
||
|
|
/*
|
||
|
|
* Did not get the lock. The pending bit was set above, and
|
||
|
|
* we must now wait until we receive the global lock
|
||
|
|
* released interrupt.
|
||
|
|
*/
|
||
|
|
acpi_gbl_global_lock_pending = TRUE;
|
||
|
|
acpi_os_release_lock(acpi_gbl_global_lock_pending_lock, flags);
|
||
|
|
|
||
|
|
ACPI_DEBUG_PRINT((ACPI_DB_EXEC,
|
||
|
|
"Waiting for hardware Global Lock\n"));
|
||
|
|
|
||
|
|
/*
|
||
|
|
* Wait for handshake with the global lock interrupt handler.
|
||
|
|
* This interface releases the interpreter if we must wait.
|
||
|
|
*/
|
||
|
|
status =
|
||
|
|
acpi_ex_system_wait_semaphore
|
||
|
|
(acpi_gbl_global_lock_semaphore, ACPI_WAIT_FOREVER);
|
||
|
|
|
||
|
|
flags = acpi_os_acquire_lock(acpi_gbl_global_lock_pending_lock);
|
||
|
|
|
||
|
|
} while (ACPI_SUCCESS(status));
|
||
|
|
|
||
|
|
acpi_gbl_global_lock_pending = FALSE;
|
||
|
|
acpi_os_release_lock(acpi_gbl_global_lock_pending_lock, flags);
|
||
|
|
|
||
|
|
return_ACPI_STATUS(status);
|
||
|
|
}
|
||
|
|
|
||
|
|
/*******************************************************************************
|
||
|
|
*
|
||
|
|
* FUNCTION: acpi_ev_release_global_lock
|
||
|
|
*
|
||
|
|
* PARAMETERS: None
|
||
|
|
*
|
||
|
|
* RETURN: Status
|
||
|
|
*
|
||
|
|
* DESCRIPTION: Releases ownership of the Global Lock.
|
||
|
|
*
|
||
|
|
******************************************************************************/
|
||
|
|
|
||
|
|
acpi_status acpi_ev_release_global_lock(void)
|
||
|
|
{
|
||
|
|
u8 pending = FALSE;
|
||
|
|
acpi_status status = AE_OK;
|
||
|
|
|
||
|
|
ACPI_FUNCTION_TRACE(ev_release_global_lock);
|
||
|
|
|
||
|
|
/* Lock must be already acquired */
|
||
|
|
|
||
|
|
if (!acpi_gbl_global_lock_acquired) {
|
||
|
|
ACPI_WARNING((AE_INFO,
|
||
|
|
"Cannot release the ACPI Global Lock, it has not been acquired"));
|
||
|
|
return_ACPI_STATUS(AE_NOT_ACQUIRED);
|
||
|
|
}
|
||
|
|
|
||
|
|
if (acpi_gbl_global_lock_present) {
|
||
|
|
|
||
|
|
/* Allow any thread to release the lock */
|
||
|
|
|
||
|
|
ACPI_RELEASE_GLOBAL_LOCK(acpi_gbl_FACS, pending);
|
||
|
|
|
||
|
|
/*
|
||
|
|
* If the pending bit was set, we must write GBL_RLS to the control
|
||
|
|
* register
|
||
|
|
*/
|
||
|
|
if (pending) {
|
||
|
|
status =
|
||
|
|
acpi_write_bit_register
|
||
|
|
(ACPI_BITREG_GLOBAL_LOCK_RELEASE,
|
||
|
|
ACPI_ENABLE_EVENT);
|
||
|
|
}
|
||
|
|
|
||
|
|
ACPI_DEBUG_PRINT((ACPI_DB_EXEC,
|
||
|
|
"Released hardware Global Lock\n"));
|
||
|
|
}
|
||
|
|
|
||
|
|
acpi_gbl_global_lock_acquired = FALSE;
|
||
|
|
|
||
|
|
/* Release the local GL mutex */
|
||
|
|
|
||
|
|
acpi_os_release_mutex(acpi_gbl_global_lock_mutex->mutex.os_mutex);
|
||
|
|
return_ACPI_STATUS(status);
|
||
|
|
}
|
||
|
|
|
||
|
|
#endif /* !ACPI_REDUCED_HARDWARE */
|