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202 lines
4.3 KiB
202 lines
4.3 KiB
// SPDX-License-Identifier: GPL-2.0 |
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/* |
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* atomic32.c: 32-bit atomic_t implementation |
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* |
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* Copyright (C) 2004 Keith M Wesolowski |
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* Copyright (C) 2007 Kyle McMartin |
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* |
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* Based on asm-parisc/atomic.h Copyright (C) 2000 Philipp Rumpf |
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*/ |
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#include <linux/atomic.h> |
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#include <linux/spinlock.h> |
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#include <linux/module.h> |
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#ifdef CONFIG_SMP |
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#define ATOMIC_HASH_SIZE 4 |
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#define ATOMIC_HASH(a) (&__atomic_hash[(((unsigned long)a)>>8) & (ATOMIC_HASH_SIZE-1)]) |
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spinlock_t __atomic_hash[ATOMIC_HASH_SIZE] = { |
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[0 ... (ATOMIC_HASH_SIZE-1)] = __SPIN_LOCK_UNLOCKED(__atomic_hash) |
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}; |
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#else /* SMP */ |
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static DEFINE_SPINLOCK(dummy); |
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#define ATOMIC_HASH_SIZE 1 |
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#define ATOMIC_HASH(a) (&dummy) |
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#endif /* SMP */ |
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#define ATOMIC_FETCH_OP(op, c_op) \ |
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int arch_atomic_fetch_##op(int i, atomic_t *v) \ |
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{ \ |
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int ret; \ |
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unsigned long flags; \ |
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spin_lock_irqsave(ATOMIC_HASH(v), flags); \ |
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\ |
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ret = v->counter; \ |
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v->counter c_op i; \ |
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\ |
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spin_unlock_irqrestore(ATOMIC_HASH(v), flags); \ |
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return ret; \ |
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} \ |
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EXPORT_SYMBOL(arch_atomic_fetch_##op); |
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#define ATOMIC_OP_RETURN(op, c_op) \ |
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int arch_atomic_##op##_return(int i, atomic_t *v) \ |
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{ \ |
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int ret; \ |
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unsigned long flags; \ |
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spin_lock_irqsave(ATOMIC_HASH(v), flags); \ |
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\ |
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ret = (v->counter c_op i); \ |
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\ |
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spin_unlock_irqrestore(ATOMIC_HASH(v), flags); \ |
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return ret; \ |
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} \ |
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EXPORT_SYMBOL(arch_atomic_##op##_return); |
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ATOMIC_OP_RETURN(add, +=) |
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ATOMIC_FETCH_OP(add, +=) |
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ATOMIC_FETCH_OP(and, &=) |
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ATOMIC_FETCH_OP(or, |=) |
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ATOMIC_FETCH_OP(xor, ^=) |
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#undef ATOMIC_FETCH_OP |
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#undef ATOMIC_OP_RETURN |
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int arch_atomic_xchg(atomic_t *v, int new) |
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{ |
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int ret; |
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unsigned long flags; |
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spin_lock_irqsave(ATOMIC_HASH(v), flags); |
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ret = v->counter; |
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v->counter = new; |
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spin_unlock_irqrestore(ATOMIC_HASH(v), flags); |
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return ret; |
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} |
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EXPORT_SYMBOL(arch_atomic_xchg); |
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int arch_atomic_cmpxchg(atomic_t *v, int old, int new) |
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{ |
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int ret; |
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unsigned long flags; |
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spin_lock_irqsave(ATOMIC_HASH(v), flags); |
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ret = v->counter; |
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if (likely(ret == old)) |
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v->counter = new; |
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spin_unlock_irqrestore(ATOMIC_HASH(v), flags); |
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return ret; |
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} |
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EXPORT_SYMBOL(arch_atomic_cmpxchg); |
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int arch_atomic_fetch_add_unless(atomic_t *v, int a, int u) |
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{ |
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int ret; |
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unsigned long flags; |
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spin_lock_irqsave(ATOMIC_HASH(v), flags); |
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ret = v->counter; |
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if (ret != u) |
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v->counter += a; |
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spin_unlock_irqrestore(ATOMIC_HASH(v), flags); |
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return ret; |
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} |
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EXPORT_SYMBOL(arch_atomic_fetch_add_unless); |
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/* Atomic operations are already serializing */ |
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void arch_atomic_set(atomic_t *v, int i) |
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{ |
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unsigned long flags; |
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spin_lock_irqsave(ATOMIC_HASH(v), flags); |
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v->counter = i; |
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spin_unlock_irqrestore(ATOMIC_HASH(v), flags); |
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} |
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EXPORT_SYMBOL(arch_atomic_set); |
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unsigned long ___set_bit(unsigned long *addr, unsigned long mask) |
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{ |
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unsigned long old, flags; |
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spin_lock_irqsave(ATOMIC_HASH(addr), flags); |
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old = *addr; |
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*addr = old | mask; |
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spin_unlock_irqrestore(ATOMIC_HASH(addr), flags); |
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return old & mask; |
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} |
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EXPORT_SYMBOL(___set_bit); |
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unsigned long ___clear_bit(unsigned long *addr, unsigned long mask) |
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{ |
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unsigned long old, flags; |
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spin_lock_irqsave(ATOMIC_HASH(addr), flags); |
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old = *addr; |
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*addr = old & ~mask; |
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spin_unlock_irqrestore(ATOMIC_HASH(addr), flags); |
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return old & mask; |
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} |
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EXPORT_SYMBOL(___clear_bit); |
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unsigned long ___change_bit(unsigned long *addr, unsigned long mask) |
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{ |
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unsigned long old, flags; |
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spin_lock_irqsave(ATOMIC_HASH(addr), flags); |
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old = *addr; |
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*addr = old ^ mask; |
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spin_unlock_irqrestore(ATOMIC_HASH(addr), flags); |
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return old & mask; |
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} |
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EXPORT_SYMBOL(___change_bit); |
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unsigned long __cmpxchg_u32(volatile u32 *ptr, u32 old, u32 new) |
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{ |
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unsigned long flags; |
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u32 prev; |
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spin_lock_irqsave(ATOMIC_HASH(ptr), flags); |
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if ((prev = *ptr) == old) |
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*ptr = new; |
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spin_unlock_irqrestore(ATOMIC_HASH(ptr), flags); |
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return (unsigned long)prev; |
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} |
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EXPORT_SYMBOL(__cmpxchg_u32); |
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u64 __cmpxchg_u64(u64 *ptr, u64 old, u64 new) |
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{ |
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unsigned long flags; |
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u64 prev; |
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spin_lock_irqsave(ATOMIC_HASH(ptr), flags); |
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if ((prev = *ptr) == old) |
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*ptr = new; |
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spin_unlock_irqrestore(ATOMIC_HASH(ptr), flags); |
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return prev; |
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} |
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EXPORT_SYMBOL(__cmpxchg_u64); |
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unsigned long __xchg_u32(volatile u32 *ptr, u32 new) |
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{ |
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unsigned long flags; |
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u32 prev; |
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spin_lock_irqsave(ATOMIC_HASH(ptr), flags); |
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prev = *ptr; |
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*ptr = new; |
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spin_unlock_irqrestore(ATOMIC_HASH(ptr), flags); |
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return (unsigned long)prev; |
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} |
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EXPORT_SYMBOL(__xchg_u32);
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