linux/drivers/acpi/acpica/evglock.c
Lv Zheng 10622bf8ce ACPICA: Linuxize: Change indentation of C labels.
It is reported by kernel build test systems that all ACPICA source
files in the kernel tree have incorrect label indentation.  This
patch changes default indent option used in the release process to
fix this bug.  Lv Zheng.

Signed-off-by: Lv Zheng <lv.zheng@intel.com>
Signed-off-by: Bob Moore <robert.moore@intel.com>
Signed-off-by: Rafael J. Wysocki <rafael.j.wysocki@intel.com>
2013-10-31 14:35:36 +01:00

345 lines
10 KiB
C

/******************************************************************************
*
* Module Name: evglock - Global Lock support
*
*****************************************************************************/
/*
* Copyright (C) 2000 - 2013, Intel Corp.
* All rights reserved.
*
* Redistribution and use in source and binary forms, with or without
* modification, are permitted provided that the following conditions
* are met:
* 1. Redistributions of source code must retain the above copyright
* notice, this list of conditions, and the following disclaimer,
* without modification.
* 2. Redistributions in binary form must reproduce at minimum a disclaimer
* substantially similar to the "NO WARRANTY" disclaimer below
* ("Disclaimer") and any redistribution must be conditioned upon
* including a substantially similar Disclaimer requirement for further
* binary redistribution.
* 3. Neither the names of the above-listed copyright holders nor the names
* of any contributors may be used to endorse or promote products derived
* from this software without specific prior written permission.
*
* Alternatively, this software may be distributed under the terms of the
* GNU General Public License ("GPL") version 2 as published by the Free
* Software Foundation.
*
* NO WARRANTY
* THIS SOFTWARE IS PROVIDED BY THE COPYRIGHT HOLDERS AND CONTRIBUTORS
* "AS IS" AND ANY EXPRESS OR IMPLIED WARRANTIES, INCLUDING, BUT NOT
* LIMITED TO, THE IMPLIED WARRANTIES OF MERCHANTIBILITY AND FITNESS FOR
* A PARTICULAR PURPOSE ARE DISCLAIMED. IN NO EVENT SHALL THE COPYRIGHT
* HOLDERS OR CONTRIBUTORS BE LIABLE FOR SPECIAL, EXEMPLARY, OR CONSEQUENTIAL
* DAMAGES (INCLUDING, BUT NOT LIMITED TO, PROCUREMENT OF SUBSTITUTE GOODS
* OR SERVICES; LOSS OF USE, DATA, OR PROFITS; OR BUSINESS INTERRUPTION)
* HOWEVER CAUSED AND ON ANY THEORY OF LIABILITY, WHETHER IN CONTRACT,
* STRICT LIABILITY, OR TORT (INCLUDING NEGLIGENCE OR OTHERWISE) ARISING
* IN ANY WAY OUT OF THE USE OF THIS SOFTWARE, EVEN IF ADVISED OF THE
* POSSIBILITY OF SUCH DAMAGES.
*/
#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 */