51 lines
1.1 KiB
C
51 lines
1.1 KiB
C
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/****************************************************************************
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*
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* Copyright (c) 2014 - 2016 Samsung Electronics Co., Ltd. All rights reserved
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*
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****************************************************************************/
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#ifndef __SCSC_PETERSON_H
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#define __SCSC_PETERSON_H
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#include <linux/delay.h>
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#include "mif_reg.h"
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#define R4_PROCESS 0
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#define AP_PROCESS 1
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#define DELAY_NS 100 /* delay in ns*/
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static inline void peterson_mutex_init(struct peterson_mutex *p_mutex)
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{
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if (!p_mutex) {
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pr_info("Mutex not declared\n");
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return;
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}
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p_mutex->flag[0] = false;
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p_mutex->flag[1] = false;
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p_mutex->turn = 0;
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}
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static inline void peterson_mutex_lock(struct peterson_mutex *p_mutex, unsigned int process)
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{
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unsigned int other = 1 - process;
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p_mutex->flag[process] = true;
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/* write barrier */
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smp_wmb();
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p_mutex->turn = other;
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/* write barrier */
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smp_wmb();
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while ((p_mutex->flag[other]) && (p_mutex->turn == other))
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ndelay(DELAY_NS);
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}
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static inline void peterson_mutex_unlock(struct peterson_mutex *p_mutex, unsigned int process)
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{
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p_mutex->flag[process] = false;
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/* write barrier */
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smp_wmb();
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}
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#endif
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