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/*
* Copyright (c) 2013, The Regents of the University of California (Regents).
* All Rights Reserved.
*
* Redistribution and use in source and binary forms, with or without
* modification, are permitted provided that the following conditions are met:
* 1. Redistributions of source code must retain the above copyright
* notice, this list of conditions and the following disclaimer.
* 2. Redistributions in binary form must reproduce the above copyright
* notice, this list of conditions and the following disclaimer in the
* documentation and/or other materials provided with the distribution.
* 3. Neither the name of the Regents nor the
* names of its contributors may be used to endorse or promote products
* derived from this software without specific prior written permission.
*
* IN NO EVENT SHALL REGENTS BE LIABLE TO ANY PARTY FOR DIRECT, INDIRECT,
* SPECIAL, INCIDENTAL, OR CONSEQUENTIAL DAMAGES, INCLUDING LOST PROFITS, ARISING
* OUT OF THE USE OF THIS SOFTWARE AND ITS DOCUMENTATION, EVEN IF REGENTS HAS
* BEEN ADVISED OF THE POSSIBILITY OF SUCH DAMAGE.
*
* REGENTS SPECIFICALLY DISCLAIMS ANY WARRANTIES, INCLUDING, BUT NOT LIMITED TO,
* THE IMPLIED WARRANTIES OF MERCHANTABILITY AND FITNESS FOR A PARTICULAR
* PURPOSE. THE SOFTWARE AND ACCOMPANYING DOCUMENTATION, IF ANY, PROVIDED
* HEREUNDER IS PROVIDED "AS IS". REGENTS HAS NO OBLIGATION TO PROVIDE
* MAINTENANCE, SUPPORT, UPDATES, ENHANCEMENTS, OR MODIFICATIONS.
*/
#ifndef _RISCV_ATOMIC_H
#define _RISCV_ATOMIC_H
#include <arch/encoding.h>
#define disable_irqsave() clear_csr(sstatus, SSTATUS_IE)
#define enable_irqrestore(flags) set_csr(sstatus, (flags) & SSTATUS_IE)
typedef struct { int lock; } spinlock_t;
#define SPINLOCK_INIT {0}
#define mb() __sync_synchronize()
#define atomic_set(ptr, val) (*(volatile typeof(*(ptr)) *)(ptr) = val)
#define atomic_read(ptr) (*(volatile typeof(*(ptr)) *)(ptr))
#ifdef PK_ENABLE_ATOMICS
# define atomic_add(ptr, inc) __sync_fetch_and_add(ptr, inc)
# define atomic_swap(ptr, swp) __sync_lock_test_and_set(ptr, swp)
# define atomic_cas(ptr, cmp, swp) __sync_val_compare_and_swap(ptr, cmp, swp)
#else
# define atomic_add(ptr, inc) ({ \
long flags = disable_irqsave(); \
typeof(ptr) res = *(volatile typeof(ptr))(ptr); \
*(volatile typeof(ptr))(ptr) = res + (inc); \
enable_irqrestore(flags); \
res; })
# define atomic_swap(ptr, swp) ({ \
long flags = disable_irqsave(); \
typeof(*ptr) res = *(volatile typeof(ptr))(ptr); \
*(volatile typeof(ptr))(ptr) = (swp); \
enable_irqrestore(flags); \
res; })
# define atomic_cas(ptr, cmp, swp) ({ \
long flags = disable_irqsave(); \
typeof(ptr) res = *(volatile typeof(ptr))(ptr); \
if (res == (cmp)) *(volatile typeof(ptr))(ptr) = (swp); \
enable_irqrestore(flags); \
res; })
#endif
static inline void spinlock_lock(spinlock_t* lock)
{
do
{
while (atomic_read(&lock->lock))
;
} while (atomic_swap(&lock->lock, -1));
mb();
}
static inline void spinlock_unlock(spinlock_t* lock)
{
mb();
atomic_set(&lock->lock,0);
}
static inline long spinlock_lock_irqsave(spinlock_t* lock)
{
long flags = disable_irqsave();
spinlock_lock(lock);
return flags;
}
static inline void spinlock_unlock_irqrestore(spinlock_t* lock, long flags)
{
spinlock_unlock(lock);
enable_irqrestore(flags);
}
#endif
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