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8b699616f3
If an architecture does not define the atomic_{cmp,}xchg_*() variants,
the generic implementation defaults them to the fully-ordered version.
riscv's had its own variants since "the beginning", but it never told
(#define-d these for) the generic implementation: it is time to do so.
Signed-off-by: Andrea Parri <andrea.parri@amarulasolutions.com>
Acked-by: Peter Zijlstra (Intel) <peterz@infradead.org>
Signed-off-by: Palmer Dabbelt <palmer@sifive.com>
361 lines
10 KiB
C
361 lines
10 KiB
C
/*
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* Copyright (C) 2007 Red Hat, Inc. All Rights Reserved.
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* Copyright (C) 2012 Regents of the University of California
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* Copyright (C) 2017 SiFive
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*
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* This program is free software; you can redistribute it and/or
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* modify it under the terms of the GNU General Public Licence
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* as published by the Free Software Foundation; either version
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* 2 of the Licence, or (at your option) any later version.
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*/
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#ifndef _ASM_RISCV_ATOMIC_H
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#define _ASM_RISCV_ATOMIC_H
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#ifdef CONFIG_GENERIC_ATOMIC64
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# include <asm-generic/atomic64.h>
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#else
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# if (__riscv_xlen < 64)
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# error "64-bit atomics require XLEN to be at least 64"
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# endif
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#endif
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#include <asm/cmpxchg.h>
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#include <asm/barrier.h>
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#define ATOMIC_INIT(i) { (i) }
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#define __atomic_acquire_fence() \
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__asm__ __volatile__(RISCV_ACQUIRE_BARRIER "" ::: "memory")
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#define __atomic_release_fence() \
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__asm__ __volatile__(RISCV_RELEASE_BARRIER "" ::: "memory");
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static __always_inline int atomic_read(const atomic_t *v)
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{
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return READ_ONCE(v->counter);
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}
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static __always_inline void atomic_set(atomic_t *v, int i)
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{
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WRITE_ONCE(v->counter, i);
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}
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#ifndef CONFIG_GENERIC_ATOMIC64
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#define ATOMIC64_INIT(i) { (i) }
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static __always_inline long atomic64_read(const atomic64_t *v)
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{
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return READ_ONCE(v->counter);
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}
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static __always_inline void atomic64_set(atomic64_t *v, long i)
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{
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WRITE_ONCE(v->counter, i);
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}
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#endif
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/*
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* First, the atomic ops that have no ordering constraints and therefor don't
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* have the AQ or RL bits set. These don't return anything, so there's only
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* one version to worry about.
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*/
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#define ATOMIC_OP(op, asm_op, I, asm_type, c_type, prefix) \
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static __always_inline \
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void atomic##prefix##_##op(c_type i, atomic##prefix##_t *v) \
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{ \
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__asm__ __volatile__ ( \
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" amo" #asm_op "." #asm_type " zero, %1, %0" \
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: "+A" (v->counter) \
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: "r" (I) \
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: "memory"); \
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} \
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#ifdef CONFIG_GENERIC_ATOMIC64
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#define ATOMIC_OPS(op, asm_op, I) \
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ATOMIC_OP (op, asm_op, I, w, int, )
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#else
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#define ATOMIC_OPS(op, asm_op, I) \
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ATOMIC_OP (op, asm_op, I, w, int, ) \
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ATOMIC_OP (op, asm_op, I, d, long, 64)
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#endif
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ATOMIC_OPS(add, add, i)
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ATOMIC_OPS(sub, add, -i)
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ATOMIC_OPS(and, and, i)
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ATOMIC_OPS( or, or, i)
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ATOMIC_OPS(xor, xor, i)
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#undef ATOMIC_OP
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#undef ATOMIC_OPS
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/*
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* Atomic ops that have ordered, relaxed, acquire, and release variants.
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* There's two flavors of these: the arithmatic ops have both fetch and return
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* versions, while the logical ops only have fetch versions.
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*/
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#define ATOMIC_FETCH_OP(op, asm_op, I, asm_type, c_type, prefix) \
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static __always_inline \
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c_type atomic##prefix##_fetch_##op##_relaxed(c_type i, \
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atomic##prefix##_t *v) \
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{ \
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register c_type ret; \
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__asm__ __volatile__ ( \
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" amo" #asm_op "." #asm_type " %1, %2, %0" \
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: "+A" (v->counter), "=r" (ret) \
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: "r" (I) \
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: "memory"); \
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return ret; \
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} \
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static __always_inline \
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c_type atomic##prefix##_fetch_##op(c_type i, atomic##prefix##_t *v) \
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{ \
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register c_type ret; \
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__asm__ __volatile__ ( \
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" amo" #asm_op "." #asm_type ".aqrl %1, %2, %0" \
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: "+A" (v->counter), "=r" (ret) \
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: "r" (I) \
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: "memory"); \
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return ret; \
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}
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#define ATOMIC_OP_RETURN(op, asm_op, c_op, I, asm_type, c_type, prefix) \
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static __always_inline \
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c_type atomic##prefix##_##op##_return_relaxed(c_type i, \
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atomic##prefix##_t *v) \
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{ \
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return atomic##prefix##_fetch_##op##_relaxed(i, v) c_op I; \
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} \
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static __always_inline \
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c_type atomic##prefix##_##op##_return(c_type i, atomic##prefix##_t *v) \
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{ \
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return atomic##prefix##_fetch_##op(i, v) c_op I; \
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}
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#ifdef CONFIG_GENERIC_ATOMIC64
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#define ATOMIC_OPS(op, asm_op, c_op, I) \
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ATOMIC_FETCH_OP( op, asm_op, I, w, int, ) \
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ATOMIC_OP_RETURN(op, asm_op, c_op, I, w, int, )
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#else
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#define ATOMIC_OPS(op, asm_op, c_op, I) \
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ATOMIC_FETCH_OP( op, asm_op, I, w, int, ) \
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ATOMIC_OP_RETURN(op, asm_op, c_op, I, w, int, ) \
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ATOMIC_FETCH_OP( op, asm_op, I, d, long, 64) \
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ATOMIC_OP_RETURN(op, asm_op, c_op, I, d, long, 64)
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#endif
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ATOMIC_OPS(add, add, +, i)
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ATOMIC_OPS(sub, add, +, -i)
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#define atomic_add_return_relaxed atomic_add_return_relaxed
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#define atomic_sub_return_relaxed atomic_sub_return_relaxed
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#define atomic_add_return atomic_add_return
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#define atomic_sub_return atomic_sub_return
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#define atomic_fetch_add_relaxed atomic_fetch_add_relaxed
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#define atomic_fetch_sub_relaxed atomic_fetch_sub_relaxed
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#define atomic_fetch_add atomic_fetch_add
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#define atomic_fetch_sub atomic_fetch_sub
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#ifndef CONFIG_GENERIC_ATOMIC64
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#define atomic64_add_return_relaxed atomic64_add_return_relaxed
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#define atomic64_sub_return_relaxed atomic64_sub_return_relaxed
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#define atomic64_add_return atomic64_add_return
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#define atomic64_sub_return atomic64_sub_return
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#define atomic64_fetch_add_relaxed atomic64_fetch_add_relaxed
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#define atomic64_fetch_sub_relaxed atomic64_fetch_sub_relaxed
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#define atomic64_fetch_add atomic64_fetch_add
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#define atomic64_fetch_sub atomic64_fetch_sub
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#endif
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#undef ATOMIC_OPS
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#ifdef CONFIG_GENERIC_ATOMIC64
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#define ATOMIC_OPS(op, asm_op, I) \
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ATOMIC_FETCH_OP(op, asm_op, I, w, int, )
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#else
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#define ATOMIC_OPS(op, asm_op, I) \
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ATOMIC_FETCH_OP(op, asm_op, I, w, int, ) \
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ATOMIC_FETCH_OP(op, asm_op, I, d, long, 64)
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#endif
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ATOMIC_OPS(and, and, i)
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ATOMIC_OPS( or, or, i)
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ATOMIC_OPS(xor, xor, i)
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#define atomic_fetch_and_relaxed atomic_fetch_and_relaxed
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#define atomic_fetch_or_relaxed atomic_fetch_or_relaxed
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#define atomic_fetch_xor_relaxed atomic_fetch_xor_relaxed
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#define atomic_fetch_and atomic_fetch_and
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#define atomic_fetch_or atomic_fetch_or
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#define atomic_fetch_xor atomic_fetch_xor
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#ifndef CONFIG_GENERIC_ATOMIC64
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#define atomic64_fetch_and_relaxed atomic64_fetch_and_relaxed
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#define atomic64_fetch_or_relaxed atomic64_fetch_or_relaxed
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#define atomic64_fetch_xor_relaxed atomic64_fetch_xor_relaxed
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#define atomic64_fetch_and atomic64_fetch_and
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#define atomic64_fetch_or atomic64_fetch_or
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#define atomic64_fetch_xor atomic64_fetch_xor
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#endif
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#undef ATOMIC_OPS
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#undef ATOMIC_FETCH_OP
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#undef ATOMIC_OP_RETURN
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/* This is required to provide a full barrier on success. */
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static __always_inline int atomic_fetch_add_unless(atomic_t *v, int a, int u)
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{
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int prev, rc;
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__asm__ __volatile__ (
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"0: lr.w %[p], %[c]\n"
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" beq %[p], %[u], 1f\n"
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" add %[rc], %[p], %[a]\n"
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" sc.w.rl %[rc], %[rc], %[c]\n"
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" bnez %[rc], 0b\n"
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" fence rw, rw\n"
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"1:\n"
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: [p]"=&r" (prev), [rc]"=&r" (rc), [c]"+A" (v->counter)
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: [a]"r" (a), [u]"r" (u)
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: "memory");
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return prev;
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}
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#define atomic_fetch_add_unless atomic_fetch_add_unless
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#ifndef CONFIG_GENERIC_ATOMIC64
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static __always_inline long atomic64_fetch_add_unless(atomic64_t *v, long a, long u)
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{
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long prev, rc;
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__asm__ __volatile__ (
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"0: lr.d %[p], %[c]\n"
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" beq %[p], %[u], 1f\n"
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" add %[rc], %[p], %[a]\n"
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" sc.d.rl %[rc], %[rc], %[c]\n"
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" bnez %[rc], 0b\n"
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" fence rw, rw\n"
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"1:\n"
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: [p]"=&r" (prev), [rc]"=&r" (rc), [c]"+A" (v->counter)
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: [a]"r" (a), [u]"r" (u)
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: "memory");
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return prev;
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}
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#define atomic64_fetch_add_unless atomic64_fetch_add_unless
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#endif
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/*
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* atomic_{cmp,}xchg is required to have exactly the same ordering semantics as
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* {cmp,}xchg and the operations that return, so they need a full barrier.
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*/
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#define ATOMIC_OP(c_t, prefix, size) \
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static __always_inline \
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c_t atomic##prefix##_xchg_relaxed(atomic##prefix##_t *v, c_t n) \
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{ \
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return __xchg_relaxed(&(v->counter), n, size); \
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} \
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static __always_inline \
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c_t atomic##prefix##_xchg_acquire(atomic##prefix##_t *v, c_t n) \
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{ \
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return __xchg_acquire(&(v->counter), n, size); \
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} \
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static __always_inline \
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c_t atomic##prefix##_xchg_release(atomic##prefix##_t *v, c_t n) \
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{ \
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return __xchg_release(&(v->counter), n, size); \
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} \
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static __always_inline \
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c_t atomic##prefix##_xchg(atomic##prefix##_t *v, c_t n) \
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{ \
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return __xchg(&(v->counter), n, size); \
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} \
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static __always_inline \
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c_t atomic##prefix##_cmpxchg_relaxed(atomic##prefix##_t *v, \
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c_t o, c_t n) \
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{ \
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return __cmpxchg_relaxed(&(v->counter), o, n, size); \
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} \
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static __always_inline \
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c_t atomic##prefix##_cmpxchg_acquire(atomic##prefix##_t *v, \
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c_t o, c_t n) \
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{ \
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return __cmpxchg_acquire(&(v->counter), o, n, size); \
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} \
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static __always_inline \
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c_t atomic##prefix##_cmpxchg_release(atomic##prefix##_t *v, \
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c_t o, c_t n) \
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{ \
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return __cmpxchg_release(&(v->counter), o, n, size); \
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} \
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static __always_inline \
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c_t atomic##prefix##_cmpxchg(atomic##prefix##_t *v, c_t o, c_t n) \
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{ \
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return __cmpxchg(&(v->counter), o, n, size); \
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}
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#ifdef CONFIG_GENERIC_ATOMIC64
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#define ATOMIC_OPS() \
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ATOMIC_OP( int, , 4)
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#else
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#define ATOMIC_OPS() \
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ATOMIC_OP( int, , 4) \
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ATOMIC_OP(long, 64, 8)
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#endif
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ATOMIC_OPS()
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#define atomic_xchg_relaxed atomic_xchg_relaxed
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#define atomic_xchg_acquire atomic_xchg_acquire
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#define atomic_xchg_release atomic_xchg_release
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#define atomic_xchg atomic_xchg
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#define atomic_cmpxchg_relaxed atomic_cmpxchg_relaxed
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#define atomic_cmpxchg_acquire atomic_cmpxchg_acquire
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#define atomic_cmpxchg_release atomic_cmpxchg_release
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#define atomic_cmpxchg atomic_cmpxchg
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#undef ATOMIC_OPS
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#undef ATOMIC_OP
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static __always_inline int atomic_sub_if_positive(atomic_t *v, int offset)
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{
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int prev, rc;
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__asm__ __volatile__ (
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"0: lr.w %[p], %[c]\n"
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" sub %[rc], %[p], %[o]\n"
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" bltz %[rc], 1f\n"
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" sc.w.rl %[rc], %[rc], %[c]\n"
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" bnez %[rc], 0b\n"
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" fence rw, rw\n"
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"1:\n"
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: [p]"=&r" (prev), [rc]"=&r" (rc), [c]"+A" (v->counter)
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: [o]"r" (offset)
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: "memory");
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return prev - offset;
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}
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#define atomic_dec_if_positive(v) atomic_sub_if_positive(v, 1)
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#ifndef CONFIG_GENERIC_ATOMIC64
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static __always_inline long atomic64_sub_if_positive(atomic64_t *v, int offset)
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{
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long prev, rc;
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__asm__ __volatile__ (
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"0: lr.d %[p], %[c]\n"
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" sub %[rc], %[p], %[o]\n"
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" bltz %[rc], 1f\n"
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" sc.d.rl %[rc], %[rc], %[c]\n"
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" bnez %[rc], 0b\n"
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" fence rw, rw\n"
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"1:\n"
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: [p]"=&r" (prev), [rc]"=&r" (rc), [c]"+A" (v->counter)
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: [o]"r" (offset)
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: "memory");
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return prev - offset;
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}
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#define atomic64_dec_if_positive(v) atomic64_sub_if_positive(v, 1)
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#endif
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#endif /* _ASM_RISCV_ATOMIC_H */
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