| /******************************************************************************* |
| * Copyright (C) 2018 Cadence Design Systems, Inc. |
| * |
| * Permission is hereby granted, free of charge, to any person obtaining |
| * a copy of this software and associated documentation files (the |
| * "Software"), to use this Software with Cadence processor cores only and |
| * not with any other processors and platforms, subject to |
| * the following conditions: |
| * |
| * The above copyright notice and this permission notice shall be included |
| * in all copies or substantial portions of the Software. |
| * |
| * THE SOFTWARE IS PROVIDED "AS IS", WITHOUT WARRANTY OF ANY KIND, |
| * EXPRESS OR IMPLIED, INCLUDING BUT NOT LIMITED TO THE WARRANTIES OF |
| * MERCHANTABILITY, FITNESS FOR A PARTICULAR PURPOSE AND NONINFRINGEMENT. |
| * IN NO EVENT SHALL THE AUTHORS OR COPYRIGHT HOLDERS BE LIABLE FOR ANY |
| * CLAIM, DAMAGES OR OTHER LIABILITY, WHETHER IN AN ACTION OF CONTRACT, |
| * TORT OR OTHERWISE, ARISING FROM, OUT OF OR IN CONNECTION WITH THE |
| * SOFTWARE OR THE USE OR OTHER DEALINGS IN THE SOFTWARE. |
| |
| ******************************************************************************/ |
| |
| /******************************************************************************* |
| * mutex.h |
| * |
| * |
| * Implementation of "non-robust" Szymanski linear-waiting algorithm. Types of |
| * failures tolerated by Szymanski's "robust" algorithm are not specific for |
| * Xtensa DSP cluster and therefore more lightweight version of the algorithm |
| * is used. FIFO servicing property is of low importance, and faster/smaller |
| * version with linear-wait property is preferable. |
| * |
| * We assume there is just a single mutex in the system, and all communication |
| * variables are defined somewhere in board-specific headers and imported here |
| * by means of macros MUTEX_SHARED_READ/WRITE. |
| ******************************************************************************/ |
| |
| #ifndef __MUTEX_H |
| #define __MUTEX_H |
| |
| /******************************************************************************* |
| * Imported macros |
| ******************************************************************************/ |
| |
| #if !defined(MUTEX_SHARED_READ) || !defined(MUTEX_SHARED_WRITE) |
| #error "Macros MUTEX_SHARED_READ and/or MUTEX_SHARED_WRITE not defined" |
| #endif |
| |
| /******************************************************************************* |
| * Entry points |
| ******************************************************************************/ |
| |
| /* ...acquire global mutex from i-th core */ |
| extern void mutex_lock(u32 i); |
| |
| /* ...release global mutex from i-th core */ |
| extern void mutex_unlock(u32 i); |
| |
| #endif /* __MUTEX_H */ |