| Niranjan Yadla | 19336af | 2018-04-19 12:19:27 -0700 | [diff] [blame] | 1 | /******************************************************************************* |
| 2 | * Copyright (C) 2018 Cadence Design Systems, Inc. |
| 3 | * |
| 4 | * Permission is hereby granted, free of charge, to any person obtaining |
| 5 | * a copy of this software and associated documentation files (the |
| 6 | * "Software"), to use this Software with Cadence processor cores only and |
| 7 | * not with any other processors and platforms, subject to |
| 8 | * the following conditions: |
| 9 | * |
| 10 | * The above copyright notice and this permission notice shall be included |
| 11 | * in all copies or substantial portions of the Software. |
| 12 | * |
| 13 | * THE SOFTWARE IS PROVIDED "AS IS", WITHOUT WARRANTY OF ANY KIND, |
| 14 | * EXPRESS OR IMPLIED, INCLUDING BUT NOT LIMITED TO THE WARRANTIES OF |
| 15 | * MERCHANTABILITY, FITNESS FOR A PARTICULAR PURPOSE AND NONINFRINGEMENT. |
| 16 | * IN NO EVENT SHALL THE AUTHORS OR COPYRIGHT HOLDERS BE LIABLE FOR ANY |
| 17 | * CLAIM, DAMAGES OR OTHER LIABILITY, WHETHER IN AN ACTION OF CONTRACT, |
| 18 | * TORT OR OTHERWISE, ARISING FROM, OUT OF OR IN CONNECTION WITH THE |
| 19 | * SOFTWARE OR THE USE OR OTHER DEALINGS IN THE SOFTWARE. |
| 20 | |
| 21 | ******************************************************************************/ |
| 22 | |
| 23 | /******************************************************************************* |
| 24 | * mutex.h |
| 25 | * |
| 26 | * |
| 27 | * Implementation of "non-robust" Szymanski linear-waiting algorithm. Types of |
| 28 | * failures tolerated by Szymanski's "robust" algorithm are not specific for |
| 29 | * Xtensa DSP cluster and therefore more lightweight version of the algorithm |
| 30 | * is used. FIFO servicing property is of low importance, and faster/smaller |
| 31 | * version with linear-wait property is preferable. |
| 32 | * |
| 33 | * We assume there is just a single mutex in the system, and all communication |
| 34 | * variables are defined somewhere in board-specific headers and imported here |
| 35 | * by means of macros MUTEX_SHARED_READ/WRITE. |
| 36 | ******************************************************************************/ |
| 37 | |
| 38 | #ifndef __MUTEX_H |
| 39 | #define __MUTEX_H |
| 40 | |
| 41 | /******************************************************************************* |
| 42 | * Imported macros |
| 43 | ******************************************************************************/ |
| 44 | |
| 45 | #if !defined(MUTEX_SHARED_READ) || !defined(MUTEX_SHARED_WRITE) |
| 46 | #error "Macros MUTEX_SHARED_READ and/or MUTEX_SHARED_WRITE not defined" |
| 47 | #endif |
| 48 | |
| 49 | /******************************************************************************* |
| 50 | * Entry points |
| 51 | ******************************************************************************/ |
| 52 | |
| 53 | /* ...acquire global mutex from i-th core */ |
| 54 | extern void mutex_lock(u32 i); |
| 55 | |
| 56 | /* ...release global mutex from i-th core */ |
| 57 | extern void mutex_unlock(u32 i); |
| 58 | |
| 59 | #endif /* __MUTEX_H */ |