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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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