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Diffstat (limited to 'c_src/linux/atomic64.c')
| -rw-r--r-- | c_src/linux/atomic64.c | 188 |
1 files changed, 0 insertions, 188 deletions
diff --git a/c_src/linux/atomic64.c b/c_src/linux/atomic64.c deleted file mode 100644 index 4654d092..00000000 --- a/c_src/linux/atomic64.c +++ /dev/null @@ -1,188 +0,0 @@ -/* - * Generic implementation of 64-bit atomics using spinlocks, - * useful on processors that don't have 64-bit atomic instructions. - * - * Copyright © 2009 Paul Mackerras, IBM Corp. <paulus@au1.ibm.com> - * - * This program is free software; you can redistribute it and/or - * modify it under the terms of the GNU General Public License - * as published by the Free Software Foundation; either version - * 2 of the License, or (at your option) any later version. - */ -#include <linux/types.h> -#include <linux/cache.h> -#include <linux/spinlock.h> -#include <linux/atomic.h> - -#ifdef ATOMIC64_SPINLOCK - -/* - * We use a hashed array of spinlocks to provide exclusive access - * to each atomic64_t variable. Since this is expected to used on - * systems with small numbers of CPUs (<= 4 or so), we use a - * relatively small array of 16 spinlocks to avoid wasting too much - * memory on the spinlock array. - */ -#define NR_LOCKS 16 - -/* - * Ensure each lock is in a separate cacheline. - */ -static union { - raw_spinlock_t lock; - char pad[L1_CACHE_BYTES]; -} atomic64_lock[NR_LOCKS] ____cacheline_aligned_in_smp = { - [0 ... (NR_LOCKS - 1)] = { - .lock = __RAW_SPIN_LOCK_UNLOCKED(atomic64_lock.lock), - }, -}; - -static inline raw_spinlock_t *lock_addr(const atomic64_t *v) -{ - unsigned long addr = (unsigned long) v; - - addr >>= L1_CACHE_SHIFT; - addr ^= (addr >> 8) ^ (addr >> 16); - return &atomic64_lock[addr & (NR_LOCKS - 1)].lock; -} - -long long atomic64_read(const atomic64_t *v) -{ - unsigned long flags; - raw_spinlock_t *lock = lock_addr(v); - long long val; - - raw_spin_lock_irqsave(lock, flags); - val = v->counter; - raw_spin_unlock_irqrestore(lock, flags); - return val; -} - -void atomic64_set(atomic64_t *v, long long i) -{ - unsigned long flags; - raw_spinlock_t *lock = lock_addr(v); - - raw_spin_lock_irqsave(lock, flags); - v->counter = i; - raw_spin_unlock_irqrestore(lock, flags); -} - -#define ATOMIC64_OP(op, c_op) \ -void atomic64_##op(long long a, atomic64_t *v) \ -{ \ - unsigned long flags; \ - raw_spinlock_t *lock = lock_addr(v); \ - \ - raw_spin_lock_irqsave(lock, flags); \ - v->counter c_op a; \ - raw_spin_unlock_irqrestore(lock, flags); \ -} - -#define ATOMIC64_OP_RETURN(op, c_op) \ -long long atomic64_##op##_return(long long a, atomic64_t *v) \ -{ \ - unsigned long flags; \ - raw_spinlock_t *lock = lock_addr(v); \ - long long val; \ - \ - raw_spin_lock_irqsave(lock, flags); \ - val = (v->counter c_op a); \ - raw_spin_unlock_irqrestore(lock, flags); \ - return val; \ -} - -#define ATOMIC64_FETCH_OP(op, c_op) \ -long long atomic64_fetch_##op(long long a, atomic64_t *v) \ -{ \ - unsigned long flags; \ - raw_spinlock_t *lock = lock_addr(v); \ - long long val; \ - \ - raw_spin_lock_irqsave(lock, flags); \ - val = v->counter; \ - v->counter c_op a; \ - raw_spin_unlock_irqrestore(lock, flags); \ - return val; \ -} - -#define ATOMIC64_OPS(op, c_op) \ - ATOMIC64_OP(op, c_op) \ - ATOMIC64_OP_RETURN(op, c_op) \ - ATOMIC64_FETCH_OP(op, c_op) - -ATOMIC64_OPS(add, +=) -ATOMIC64_OPS(sub, -=) - -#undef ATOMIC64_OPS -#define ATOMIC64_OPS(op, c_op) \ - ATOMIC64_OP(op, c_op) \ - ATOMIC64_OP_RETURN(op, c_op) \ - ATOMIC64_FETCH_OP(op, c_op) - -ATOMIC64_OPS(and, &=) -ATOMIC64_OPS(or, |=) -ATOMIC64_OPS(xor, ^=) - -#undef ATOMIC64_OPS -#undef ATOMIC64_FETCH_OP -#undef ATOMIC64_OP_RETURN -#undef ATOMIC64_OP - -long long atomic64_dec_if_positive(atomic64_t *v) -{ - unsigned long flags; - raw_spinlock_t *lock = lock_addr(v); - long long val; - - raw_spin_lock_irqsave(lock, flags); - val = v->counter - 1; - if (val >= 0) - v->counter = val; - raw_spin_unlock_irqrestore(lock, flags); - return val; -} - -long long atomic64_cmpxchg(atomic64_t *v, long long o, long long n) -{ - unsigned long flags; - raw_spinlock_t *lock = lock_addr(v); - long long val; - - raw_spin_lock_irqsave(lock, flags); - val = v->counter; - if (val == o) - v->counter = n; - raw_spin_unlock_irqrestore(lock, flags); - return val; -} - -long long atomic64_xchg(atomic64_t *v, long long new) -{ - unsigned long flags; - raw_spinlock_t *lock = lock_addr(v); - long long val; - - raw_spin_lock_irqsave(lock, flags); - val = v->counter; - v->counter = new; - raw_spin_unlock_irqrestore(lock, flags); - return val; -} - -int atomic64_add_unless(atomic64_t *v, long long a, long long u) -{ - unsigned long flags; - raw_spinlock_t *lock = lock_addr(v); - int ret = 0; - - raw_spin_lock_irqsave(lock, flags); - if (v->counter != u) { - v->counter += a; - ret = 1; - } - raw_spin_unlock_irqrestore(lock, flags); - return ret; -} - -#endif |