mirror of
https://github.com/CTCaer/switch-l4t-atf.git
synced 2025-01-10 21:03:02 +00:00
82a0aca053
Current implementation of Bakery Lock does tight-loop waiting upon lock contention. This commit reworks the implementation to use WFE instruction for waiting, and SEV to signal lock availability. It also adds the rationale for choosing Bakery Locks instead of exclusion primitives, and more comments for the lock algorithm. Fixes ARM-software/tf-issue#67 Change-Id: Ie351d3dbb27ec8e64dbc9507c84af07bd385a7df Co-authored-by: Vikram Kanigiri <vikram.kanigiri@arm.com>
54 lines
2.1 KiB
C
54 lines
2.1 KiB
C
/*
|
|
* Copyright (c) 2013-2014, ARM Limited and Contributors. All rights reserved.
|
|
*
|
|
* Redistribution and use in source and binary forms, with or without
|
|
* modification, are permitted provided that the following conditions are met:
|
|
*
|
|
* Redistributions of source code must retain the above copyright notice, this
|
|
* list of conditions and the following disclaimer.
|
|
*
|
|
* Redistributions in binary form must reproduce the above copyright notice,
|
|
* this list of conditions and the following disclaimer in the documentation
|
|
* and/or other materials provided with the distribution.
|
|
*
|
|
* Neither the name of ARM nor the names of its contributors may be used
|
|
* to endorse or promote products derived from this software without specific
|
|
* prior written permission.
|
|
*
|
|
* 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 MERCHANTABILITY AND FITNESS FOR A PARTICULAR PURPOSE
|
|
* ARE DISCLAIMED. IN NO EVENT SHALL THE COPYRIGHT HOLDER OR CONTRIBUTORS BE
|
|
* LIABLE FOR ANY DIRECT, INDIRECT, INCIDENTAL, 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 DAMAGE.
|
|
*/
|
|
|
|
#ifndef __BAKERY_LOCK_H__
|
|
#define __BAKERY_LOCK_H__
|
|
|
|
#include <platform.h>
|
|
|
|
#define BAKERY_LOCK_MAX_CPUS PLATFORM_CORE_COUNT
|
|
|
|
#ifndef __ASSEMBLY__
|
|
typedef struct {
|
|
int owner;
|
|
volatile char entering[BAKERY_LOCK_MAX_CPUS];
|
|
volatile unsigned number[BAKERY_LOCK_MAX_CPUS];
|
|
} bakery_lock;
|
|
|
|
#define NO_OWNER (-1)
|
|
|
|
void bakery_lock_init(bakery_lock* bakery);
|
|
void bakery_lock_get(unsigned long mpidr, bakery_lock* bakery);
|
|
void bakery_lock_release(unsigned long mpidr, bakery_lock* bakery);
|
|
int bakery_lock_try(unsigned long mpidr, bakery_lock* bakery);
|
|
#endif /*__ASSEMBLY__*/
|
|
|
|
#endif /* __BAKERY_LOCK_H__ */
|