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e69eb9c460
In preparation for altering the non-atomic bitops with a macro, wrap
them in a transparent definition. This requires prepending one more
'_' to their names in order to be able to do that seamlessly. It is
a simple change, given that all the non-prefixed definitions are now
in asm-generic.
sparc32 already has several triple-underscored functions, so I had
to rename them ('___' -> 'sp32_').
Signed-off-by: Alexander Lobakin <alexandr.lobakin@intel.com>
Reviewed-by: Marco Elver <elver@google.com>
Reviewed-by: Andy Shevchenko <andriy.shevchenko@linux.intel.com>
Signed-off-by: Yury Norov <yury.norov@gmail.com>
203 lines
4.4 KiB
C
203 lines
4.4 KiB
C
// 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 sp32___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(sp32___set_bit);
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unsigned long sp32___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(sp32___clear_bit);
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unsigned long sp32___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(sp32___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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