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![Christophe Leroy](/assets/img/avatar_default.png)
Now that atomic_add() and atomic_sub() handle immediate operands, atomic_inc() and atomic_dec() have no added value compared to the generic fallback which calls atomic_add(1) and atomic_sub(1). Also remove atomic_inc_not_zero() which fallsback to atomic_add_unless() which itself fallsback to atomic_fetch_add_unless() which now handles immediate operands. Signed-off-by: Christophe Leroy <christophe.leroy@csgroup.eu> Signed-off-by: Michael Ellerman <mpe@ellerman.id.au> Link: https://lore.kernel.org/r/0bc64a2f18726055093dbb2e479cefc60a409cfd.1632236981.git.christophe.leroy@csgroup.eu
488 lines
12 KiB
C
488 lines
12 KiB
C
/* SPDX-License-Identifier: GPL-2.0 */
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#ifndef _ASM_POWERPC_ATOMIC_H_
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#define _ASM_POWERPC_ATOMIC_H_
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/*
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* PowerPC atomic operations
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*/
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#ifdef __KERNEL__
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#include <linux/types.h>
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#include <asm/cmpxchg.h>
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#include <asm/barrier.h>
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#include <asm/asm-const.h>
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/*
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* Since *_return_relaxed and {cmp}xchg_relaxed are implemented with
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* a "bne-" instruction at the end, so an isync is enough as a acquire barrier
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* on the platform without lwsync.
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*/
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#define __atomic_acquire_fence() \
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__asm__ __volatile__(PPC_ACQUIRE_BARRIER "" : : : "memory")
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#define __atomic_release_fence() \
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__asm__ __volatile__(PPC_RELEASE_BARRIER "" : : : "memory")
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static __inline__ int arch_atomic_read(const atomic_t *v)
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{
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int t;
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__asm__ __volatile__("lwz%U1%X1 %0,%1" : "=r"(t) : "m<>"(v->counter));
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return t;
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}
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static __inline__ void arch_atomic_set(atomic_t *v, int i)
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{
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__asm__ __volatile__("stw%U0%X0 %1,%0" : "=m<>"(v->counter) : "r"(i));
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}
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#define ATOMIC_OP(op, asm_op, suffix, sign, ...) \
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static __inline__ void arch_atomic_##op(int a, atomic_t *v) \
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{ \
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int t; \
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\
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__asm__ __volatile__( \
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"1: lwarx %0,0,%3 # atomic_" #op "\n" \
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#asm_op "%I2" suffix " %0,%0,%2\n" \
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" stwcx. %0,0,%3 \n" \
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" bne- 1b\n" \
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: "=&r" (t), "+m" (v->counter) \
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: "r"#sign (a), "r" (&v->counter) \
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: "cc", ##__VA_ARGS__); \
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} \
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#define ATOMIC_OP_RETURN_RELAXED(op, asm_op, suffix, sign, ...) \
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static inline int arch_atomic_##op##_return_relaxed(int a, atomic_t *v) \
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{ \
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int t; \
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\
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__asm__ __volatile__( \
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"1: lwarx %0,0,%3 # atomic_" #op "_return_relaxed\n" \
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#asm_op "%I2" suffix " %0,%0,%2\n" \
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" stwcx. %0,0,%3\n" \
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" bne- 1b\n" \
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: "=&r" (t), "+m" (v->counter) \
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: "r"#sign (a), "r" (&v->counter) \
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: "cc", ##__VA_ARGS__); \
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\
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return t; \
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}
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#define ATOMIC_FETCH_OP_RELAXED(op, asm_op, suffix, sign, ...) \
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static inline int arch_atomic_fetch_##op##_relaxed(int a, atomic_t *v) \
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{ \
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int res, t; \
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\
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__asm__ __volatile__( \
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"1: lwarx %0,0,%4 # atomic_fetch_" #op "_relaxed\n" \
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#asm_op "%I3" suffix " %1,%0,%3\n" \
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" stwcx. %1,0,%4\n" \
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" bne- 1b\n" \
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: "=&r" (res), "=&r" (t), "+m" (v->counter) \
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: "r"#sign (a), "r" (&v->counter) \
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: "cc", ##__VA_ARGS__); \
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\
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return res; \
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}
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#define ATOMIC_OPS(op, asm_op, suffix, sign, ...) \
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ATOMIC_OP(op, asm_op, suffix, sign, ##__VA_ARGS__) \
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ATOMIC_OP_RETURN_RELAXED(op, asm_op, suffix, sign, ##__VA_ARGS__)\
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ATOMIC_FETCH_OP_RELAXED(op, asm_op, suffix, sign, ##__VA_ARGS__)
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ATOMIC_OPS(add, add, "c", I, "xer")
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ATOMIC_OPS(sub, sub, "c", I, "xer")
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#define arch_atomic_add_return_relaxed arch_atomic_add_return_relaxed
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#define arch_atomic_sub_return_relaxed arch_atomic_sub_return_relaxed
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#define arch_atomic_fetch_add_relaxed arch_atomic_fetch_add_relaxed
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#define arch_atomic_fetch_sub_relaxed arch_atomic_fetch_sub_relaxed
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#undef ATOMIC_OPS
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#define ATOMIC_OPS(op, asm_op, suffix, sign) \
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ATOMIC_OP(op, asm_op, suffix, sign) \
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ATOMIC_FETCH_OP_RELAXED(op, asm_op, suffix, sign)
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ATOMIC_OPS(and, and, ".", K)
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ATOMIC_OPS(or, or, "", K)
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ATOMIC_OPS(xor, xor, "", K)
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#define arch_atomic_fetch_and_relaxed arch_atomic_fetch_and_relaxed
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#define arch_atomic_fetch_or_relaxed arch_atomic_fetch_or_relaxed
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#define arch_atomic_fetch_xor_relaxed arch_atomic_fetch_xor_relaxed
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#undef ATOMIC_OPS
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#undef ATOMIC_FETCH_OP_RELAXED
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#undef ATOMIC_OP_RETURN_RELAXED
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#undef ATOMIC_OP
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#define arch_atomic_cmpxchg(v, o, n) \
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(arch_cmpxchg(&((v)->counter), (o), (n)))
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#define arch_atomic_cmpxchg_relaxed(v, o, n) \
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arch_cmpxchg_relaxed(&((v)->counter), (o), (n))
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#define arch_atomic_cmpxchg_acquire(v, o, n) \
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arch_cmpxchg_acquire(&((v)->counter), (o), (n))
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#define arch_atomic_xchg(v, new) \
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(arch_xchg(&((v)->counter), new))
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#define arch_atomic_xchg_relaxed(v, new) \
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arch_xchg_relaxed(&((v)->counter), (new))
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/*
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* Don't want to override the generic atomic_try_cmpxchg_acquire, because
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* we add a lock hint to the lwarx, which may not be wanted for the
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* _acquire case (and is not used by the other _acquire variants so it
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* would be a surprise).
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*/
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static __always_inline bool
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arch_atomic_try_cmpxchg_lock(atomic_t *v, int *old, int new)
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{
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int r, o = *old;
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__asm__ __volatile__ (
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"1: lwarx %0,0,%2,%5 # atomic_try_cmpxchg_acquire \n"
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" cmpw 0,%0,%3 \n"
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" bne- 2f \n"
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" stwcx. %4,0,%2 \n"
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" bne- 1b \n"
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"\t" PPC_ACQUIRE_BARRIER " \n"
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"2: \n"
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: "=&r" (r), "+m" (v->counter)
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: "r" (&v->counter), "r" (o), "r" (new), "i" (IS_ENABLED(CONFIG_PPC64) ? 1 : 0)
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: "cr0", "memory");
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if (unlikely(r != o))
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*old = r;
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return likely(r == o);
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}
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/**
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* atomic_fetch_add_unless - add unless the number is a given value
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* @v: pointer of type atomic_t
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* @a: the amount to add to v...
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* @u: ...unless v is equal to u.
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*
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* Atomically adds @a to @v, so long as it was not @u.
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* Returns the old value of @v.
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*/
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static __inline__ int arch_atomic_fetch_add_unless(atomic_t *v, int a, int u)
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{
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int t;
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__asm__ __volatile__ (
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PPC_ATOMIC_ENTRY_BARRIER
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"1: lwarx %0,0,%1 # atomic_fetch_add_unless\n\
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cmpw 0,%0,%3 \n\
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beq 2f \n\
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add%I2c %0,%0,%2 \n"
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" stwcx. %0,0,%1 \n\
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bne- 1b \n"
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PPC_ATOMIC_EXIT_BARRIER
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" sub%I2c %0,%0,%2 \n\
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2:"
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: "=&r" (t)
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: "r" (&v->counter), "rI" (a), "r" (u)
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: "cc", "memory", "xer");
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return t;
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}
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#define arch_atomic_fetch_add_unless arch_atomic_fetch_add_unless
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/*
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* Atomically test *v and decrement if it is greater than 0.
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* The function returns the old value of *v minus 1, even if
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* the atomic variable, v, was not decremented.
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*/
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static __inline__ int arch_atomic_dec_if_positive(atomic_t *v)
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{
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int t;
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__asm__ __volatile__(
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PPC_ATOMIC_ENTRY_BARRIER
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"1: lwarx %0,0,%1 # atomic_dec_if_positive\n\
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cmpwi %0,1\n\
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addi %0,%0,-1\n\
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blt- 2f\n"
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" stwcx. %0,0,%1\n\
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bne- 1b"
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PPC_ATOMIC_EXIT_BARRIER
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"\n\
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2:" : "=&b" (t)
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: "r" (&v->counter)
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: "cc", "memory");
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return t;
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}
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#define arch_atomic_dec_if_positive arch_atomic_dec_if_positive
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#ifdef __powerpc64__
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#define ATOMIC64_INIT(i) { (i) }
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static __inline__ s64 arch_atomic64_read(const atomic64_t *v)
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{
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s64 t;
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__asm__ __volatile__("ld%U1%X1 %0,%1" : "=r"(t) : "m<>"(v->counter));
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return t;
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}
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static __inline__ void arch_atomic64_set(atomic64_t *v, s64 i)
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{
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__asm__ __volatile__("std%U0%X0 %1,%0" : "=m<>"(v->counter) : "r"(i));
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}
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#define ATOMIC64_OP(op, asm_op) \
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static __inline__ void arch_atomic64_##op(s64 a, atomic64_t *v) \
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{ \
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s64 t; \
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\
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__asm__ __volatile__( \
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"1: ldarx %0,0,%3 # atomic64_" #op "\n" \
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#asm_op " %0,%2,%0\n" \
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" stdcx. %0,0,%3 \n" \
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" bne- 1b\n" \
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: "=&r" (t), "+m" (v->counter) \
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: "r" (a), "r" (&v->counter) \
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: "cc"); \
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}
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#define ATOMIC64_OP_RETURN_RELAXED(op, asm_op) \
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static inline s64 \
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arch_atomic64_##op##_return_relaxed(s64 a, atomic64_t *v) \
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{ \
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s64 t; \
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\
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__asm__ __volatile__( \
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"1: ldarx %0,0,%3 # atomic64_" #op "_return_relaxed\n" \
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#asm_op " %0,%2,%0\n" \
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" stdcx. %0,0,%3\n" \
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" bne- 1b\n" \
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: "=&r" (t), "+m" (v->counter) \
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: "r" (a), "r" (&v->counter) \
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: "cc"); \
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\
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return t; \
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}
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#define ATOMIC64_FETCH_OP_RELAXED(op, asm_op) \
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static inline s64 \
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arch_atomic64_fetch_##op##_relaxed(s64 a, atomic64_t *v) \
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{ \
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s64 res, t; \
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\
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__asm__ __volatile__( \
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"1: ldarx %0,0,%4 # atomic64_fetch_" #op "_relaxed\n" \
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#asm_op " %1,%3,%0\n" \
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" stdcx. %1,0,%4\n" \
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" bne- 1b\n" \
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: "=&r" (res), "=&r" (t), "+m" (v->counter) \
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: "r" (a), "r" (&v->counter) \
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: "cc"); \
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\
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return res; \
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}
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#define ATOMIC64_OPS(op, asm_op) \
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ATOMIC64_OP(op, asm_op) \
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ATOMIC64_OP_RETURN_RELAXED(op, asm_op) \
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ATOMIC64_FETCH_OP_RELAXED(op, asm_op)
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ATOMIC64_OPS(add, add)
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ATOMIC64_OPS(sub, subf)
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#define arch_atomic64_add_return_relaxed arch_atomic64_add_return_relaxed
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#define arch_atomic64_sub_return_relaxed arch_atomic64_sub_return_relaxed
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#define arch_atomic64_fetch_add_relaxed arch_atomic64_fetch_add_relaxed
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#define arch_atomic64_fetch_sub_relaxed arch_atomic64_fetch_sub_relaxed
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#undef ATOMIC64_OPS
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#define ATOMIC64_OPS(op, asm_op) \
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ATOMIC64_OP(op, asm_op) \
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ATOMIC64_FETCH_OP_RELAXED(op, asm_op)
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ATOMIC64_OPS(and, and)
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ATOMIC64_OPS(or, or)
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ATOMIC64_OPS(xor, xor)
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#define arch_atomic64_fetch_and_relaxed arch_atomic64_fetch_and_relaxed
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#define arch_atomic64_fetch_or_relaxed arch_atomic64_fetch_or_relaxed
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#define arch_atomic64_fetch_xor_relaxed arch_atomic64_fetch_xor_relaxed
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#undef ATOPIC64_OPS
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#undef ATOMIC64_FETCH_OP_RELAXED
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#undef ATOMIC64_OP_RETURN_RELAXED
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#undef ATOMIC64_OP
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static __inline__ void arch_atomic64_inc(atomic64_t *v)
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{
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s64 t;
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__asm__ __volatile__(
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"1: ldarx %0,0,%2 # atomic64_inc\n\
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addic %0,%0,1\n\
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stdcx. %0,0,%2 \n\
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bne- 1b"
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: "=&r" (t), "+m" (v->counter)
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: "r" (&v->counter)
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: "cc", "xer");
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}
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#define arch_atomic64_inc arch_atomic64_inc
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static __inline__ s64 arch_atomic64_inc_return_relaxed(atomic64_t *v)
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{
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s64 t;
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__asm__ __volatile__(
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"1: ldarx %0,0,%2 # atomic64_inc_return_relaxed\n"
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" addic %0,%0,1\n"
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" stdcx. %0,0,%2\n"
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" bne- 1b"
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: "=&r" (t), "+m" (v->counter)
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: "r" (&v->counter)
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: "cc", "xer");
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return t;
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}
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static __inline__ void arch_atomic64_dec(atomic64_t *v)
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{
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s64 t;
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__asm__ __volatile__(
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"1: ldarx %0,0,%2 # atomic64_dec\n\
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addic %0,%0,-1\n\
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stdcx. %0,0,%2\n\
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bne- 1b"
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: "=&r" (t), "+m" (v->counter)
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: "r" (&v->counter)
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: "cc", "xer");
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}
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#define arch_atomic64_dec arch_atomic64_dec
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static __inline__ s64 arch_atomic64_dec_return_relaxed(atomic64_t *v)
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{
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s64 t;
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__asm__ __volatile__(
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"1: ldarx %0,0,%2 # atomic64_dec_return_relaxed\n"
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" addic %0,%0,-1\n"
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" stdcx. %0,0,%2\n"
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" bne- 1b"
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: "=&r" (t), "+m" (v->counter)
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: "r" (&v->counter)
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: "cc", "xer");
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return t;
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}
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#define arch_atomic64_inc_return_relaxed arch_atomic64_inc_return_relaxed
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#define arch_atomic64_dec_return_relaxed arch_atomic64_dec_return_relaxed
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/*
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* Atomically test *v and decrement if it is greater than 0.
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* The function returns the old value of *v minus 1.
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*/
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static __inline__ s64 arch_atomic64_dec_if_positive(atomic64_t *v)
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{
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s64 t;
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__asm__ __volatile__(
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PPC_ATOMIC_ENTRY_BARRIER
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"1: ldarx %0,0,%1 # atomic64_dec_if_positive\n\
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addic. %0,%0,-1\n\
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blt- 2f\n\
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stdcx. %0,0,%1\n\
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bne- 1b"
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PPC_ATOMIC_EXIT_BARRIER
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"\n\
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2:" : "=&r" (t)
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: "r" (&v->counter)
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: "cc", "xer", "memory");
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return t;
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}
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#define arch_atomic64_dec_if_positive arch_atomic64_dec_if_positive
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#define arch_atomic64_cmpxchg(v, o, n) \
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(arch_cmpxchg(&((v)->counter), (o), (n)))
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#define arch_atomic64_cmpxchg_relaxed(v, o, n) \
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arch_cmpxchg_relaxed(&((v)->counter), (o), (n))
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#define arch_atomic64_cmpxchg_acquire(v, o, n) \
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arch_cmpxchg_acquire(&((v)->counter), (o), (n))
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#define arch_atomic64_xchg(v, new) \
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(arch_xchg(&((v)->counter), new))
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#define arch_atomic64_xchg_relaxed(v, new) \
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arch_xchg_relaxed(&((v)->counter), (new))
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/**
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* atomic64_fetch_add_unless - add unless the number is a given value
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* @v: pointer of type atomic64_t
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* @a: the amount to add to v...
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* @u: ...unless v is equal to u.
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*
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* Atomically adds @a to @v, so long as it was not @u.
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* Returns the old value of @v.
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*/
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static __inline__ s64 arch_atomic64_fetch_add_unless(atomic64_t *v, s64 a, s64 u)
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{
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s64 t;
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__asm__ __volatile__ (
|
|
PPC_ATOMIC_ENTRY_BARRIER
|
|
"1: ldarx %0,0,%1 # atomic64_fetch_add_unless\n\
|
|
cmpd 0,%0,%3 \n\
|
|
beq 2f \n\
|
|
add %0,%2,%0 \n"
|
|
" stdcx. %0,0,%1 \n\
|
|
bne- 1b \n"
|
|
PPC_ATOMIC_EXIT_BARRIER
|
|
" subf %0,%2,%0 \n\
|
|
2:"
|
|
: "=&r" (t)
|
|
: "r" (&v->counter), "r" (a), "r" (u)
|
|
: "cc", "memory");
|
|
|
|
return t;
|
|
}
|
|
#define arch_atomic64_fetch_add_unless arch_atomic64_fetch_add_unless
|
|
|
|
/**
|
|
* atomic_inc64_not_zero - increment unless the number is zero
|
|
* @v: pointer of type atomic64_t
|
|
*
|
|
* Atomically increments @v by 1, so long as @v is non-zero.
|
|
* Returns non-zero if @v was non-zero, and zero otherwise.
|
|
*/
|
|
static __inline__ int arch_atomic64_inc_not_zero(atomic64_t *v)
|
|
{
|
|
s64 t1, t2;
|
|
|
|
__asm__ __volatile__ (
|
|
PPC_ATOMIC_ENTRY_BARRIER
|
|
"1: ldarx %0,0,%2 # atomic64_inc_not_zero\n\
|
|
cmpdi 0,%0,0\n\
|
|
beq- 2f\n\
|
|
addic %1,%0,1\n\
|
|
stdcx. %1,0,%2\n\
|
|
bne- 1b\n"
|
|
PPC_ATOMIC_EXIT_BARRIER
|
|
"\n\
|
|
2:"
|
|
: "=&r" (t1), "=&r" (t2)
|
|
: "r" (&v->counter)
|
|
: "cc", "xer", "memory");
|
|
|
|
return t1 != 0;
|
|
}
|
|
#define arch_atomic64_inc_not_zero(v) arch_atomic64_inc_not_zero((v))
|
|
|
|
#endif /* __powerpc64__ */
|
|
|
|
#endif /* __KERNEL__ */
|
|
#endif /* _ASM_POWERPC_ATOMIC_H_ */
|