| 1 | /* | 
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| 2 | * remote_spinlock.h - kernel remote spinlock definition. | 
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| 3 | * | 
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| 4 | * Author  Alain Greiner (2016,2017,2018) | 
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| 5 | * | 
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| 6 | * Copyright (c) UPMC Sorbonne Universites | 
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| 7 | * | 
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| 8 | * This file is part of ALMOS-MKH. | 
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| 9 | * | 
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| 10 | * ALMOS-MKH is free software; you can redistribute it and/or modify it | 
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| 11 | * under the terms of the GNU General Public License as published by | 
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| 12 | * the Free Software Foundation; version 2.0 of the License. | 
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| 13 | * | 
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| 14 | * ALMOS-MKH is distributed in the hope that it will be useful, but | 
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| 15 | * WITHOUT ANY WARRANTY; without even the implied warranty of | 
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| 16 | * MERCHANTABILITY or FITNESS FOR A PARTICULAR PURPOSE.  See the GNU | 
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| 17 | * General Public License for more details. | 
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| 18 | * | 
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| 19 | * You should have received a copy of the GNU General Public License | 
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| 20 | * along with ALMOS-MKH; if not, write to the Free Software Foundation, | 
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| 21 | * Inc., 51 Franklin St, Fifth Floor, Boston, MA 02110-1301 USA | 
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| 22 | */ | 
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| 23 |  | 
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| 24 | #ifndef _REMOTE_SPINLOCK_H_ | 
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| 25 | #define _REMOTE_SPINLOCK_H_ | 
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| 26 |  | 
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| 27 | #include <kernel_config.h> | 
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| 28 | #include <hal_kernel_types.h> | 
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| 29 | #include <xlist.h> | 
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| 30 |  | 
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| 31 | /*************************************************************************************** | 
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| 32 | * This structure defines a remote spinlock, that can be used to protect | 
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| 33 | * exclusive access to a trans-cluster shared resource. It can be taken by any | 
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| 34 | * thread running in any cluster. All access functions use remote pointers. | 
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| 35 | * The "owner" and "list" are optionnal fields used for debug. | 
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| 36 | * It register the list of all remote spinlocks taken by a given thread. | 
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| 37 | **************************************************************************************/ | 
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| 38 |  | 
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| 39 | typedef struct remote_spinlock_s | 
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| 40 | { | 
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| 41 | volatile uint32_t     taken;       /*! free if 0 / taken if non zero             */ | 
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| 42 |  | 
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| 43 | #if DEBUG_REMOTE_SPINLOCKS | 
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| 44 | xptr_t                owner;       /*! extended pointer on the owner thread      */ | 
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| 45 | xlist_entry_t         list;        /*! list of all remote_lock taken by owner    */ | 
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| 46 | #endif | 
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| 47 |  | 
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| 48 | } | 
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| 49 | remote_spinlock_t; | 
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| 50 |  | 
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| 51 | /*************************************************************************************** | 
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| 52 | * This function initializes a remote spinlock. | 
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| 53 | *************************************************************************************** | 
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| 54 | * @ lock_xp : extended pointer on the remote spinlock | 
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| 55 | **************************************************************************************/ | 
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| 56 | void remote_spinlock_init( xptr_t   lock_xp ); | 
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| 57 |  | 
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| 58 | /******************************************************************************************* | 
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| 59 | * This blocking function uses a busy waiting strategy to lock a remote spinlock. | 
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| 60 | * It polls the lock and returns only when the lock has been taken. | 
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| 61 | * All IRQs are disabled and will keep disabled until the lock is released. | 
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| 62 | * It increments the calling thread local_locks count when the lock has been taken. | 
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| 63 | ******************************************************************************************* | 
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| 64 | * @ lock_xp    : extended pointer on the remote spinlock. | 
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| 65 | * @ irq_state  : buffer to save the SR state (in the calling thread stack) | 
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| 66 | ******************************************************************************************/ | 
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| 67 | void remote_spinlock_lock_busy( xptr_t     lock_xp, | 
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| 68 | uint32_t * irq_state ); | 
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| 69 |  | 
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| 70 | /******************************************************************************************* | 
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| 71 | * This function releases a remote busy_waiting spinlock. | 
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| 72 | * It restores the CPU SR state. | 
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| 73 | * It decrements the calling thread locks count. | 
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| 74 | ******************************************************************************************* | 
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| 75 | * @ lock_xp    : extended pointer on remote spinlock. | 
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| 76 | * @ irq_state  : value to be resrored in CPU SR | 
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| 77 | ******************************************************************************************/ | 
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| 78 | void remote_spinlock_unlock_busy( xptr_t     lock_xp, | 
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| 79 | uint32_t   irq_state ); | 
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| 80 |  | 
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| 81 | /*************************************************************************************** | 
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| 82 | * This blocking function locks a remote spinlock. | 
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| 83 | * If the lock is already taken, the calling thread deschedule, and retry | 
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| 84 | * when it is rescheduled. | 
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| 85 | * It increments the calling thread locks count when the lock has been taken. | 
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| 86 | *************************************************************************************** | 
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| 87 | * @ lock_xp   : extended pointer on the remote spinlock | 
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| 88 | **************************************************************************************/ | 
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| 89 | void remote_spinlock_lock( xptr_t lock_xp ); | 
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| 90 |  | 
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| 91 | /*************************************************************************************** | 
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| 92 | * This non blocking function try once to lock a remote spinlock. | 
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| 93 | * It increments the calling thread locks count in case of success. | 
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| 94 | *************************************************************************************** | 
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| 95 | * @ lock_xp    : extended pointer on the remote spinlock | 
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| 96 | * @ returns O if success / returns non zero if lock already taken. | 
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| 97 | **************************************************************************************/ | 
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| 98 | error_t remote_spinlock_trylock( xptr_t  lock_xp ); | 
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| 99 |  | 
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| 100 | /*************************************************************************************** | 
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| 101 | * This function releases a remote spinlock. | 
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| 102 | * It decrements the calling thread locks count. | 
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| 103 | *************************************************************************************** | 
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| 104 | * @ lock_xp    : extended pointer on the remote spinlock | 
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| 105 | **************************************************************************************/ | 
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| 106 | void remote_spinlock_unlock( xptr_t  lock_xp ); | 
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| 107 |  | 
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| 108 | #endif | 
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