| 1 | /* |
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| 2 | * xbarrier.c - Busy-waiting, trans-clusters, kernel barrier implementation. |
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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 | #include <hal_kernel_types.h> |
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| 25 | #include <hal_remote.h> |
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| 26 | #include <hal_atomic.h> |
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| 27 | #include <xbarrier.h> |
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| 28 | |
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| 29 | |
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| 30 | ///////////////////////////////////////////////// |
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| 31 | inline void xbarrier_wait( xptr_t barrier_xp, |
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| 32 | uint32_t count ) |
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| 33 | { |
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| 34 | uint32_t expected; |
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| 35 | |
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| 36 | xbarrier_t * ptr = GET_PTR( barrier_xp ); |
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| 37 | cxy_t cxy = GET_CXY( barrier_xp ); |
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| 38 | |
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| 39 | // get barrier sense value |
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| 40 | uint32_t sense = hal_remote_l32( XPTR( cxy , &ptr->sense ) ); |
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| 41 | |
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| 42 | // compute expected value |
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| 43 | if ( sense == 0 ) expected = 1; |
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| 44 | else expected = 0; |
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| 45 | |
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| 46 | // atomically increment current |
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| 47 | uint32_t current = hal_remote_atomic_add( XPTR( cxy , &ptr->current ) , 1 ); |
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| 48 | |
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| 49 | // last task reset current and toggle sense |
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| 50 | if( current == (count-1) ) |
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| 51 | { |
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| 52 | hal_remote_s32( XPTR( cxy , &ptr->current) , 0 ); |
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| 53 | hal_remote_s32( XPTR( cxy , &ptr->sense ) , expected ); |
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| 54 | } |
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| 55 | else // other tasks poll the sense |
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| 56 | { |
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| 57 | while( hal_remote_l32( XPTR( cxy , &ptr->sense ) ) != expected ) asm volatile ("nop"); |
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| 58 | } |
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| 59 | } |
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| 60 | |
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