/* SPDX-License-Identifier: GPL-2.0-or-later */ /* * Copyright (C) 2007 Red Hat, Inc. All Rights Reserved. * Copyright (C) 2012 Regents of the University of California * Copyright (C) 2017 SiFive */ #ifndef _ASM_RISCV_ATOMIC_H #define _ASM_RISCV_ATOMIC_H #ifdef CONFIG_GENERIC_ATOMIC64 # include #else # if (__riscv_xlen < 64) # error "64-bit atomics require XLEN to be at least 64" # endif #endif #include #include #define ATOMIC_INIT(i) { (i) } #define __atomic_acquire_fence() \ __asm__ __volatile__(RISCV_ACQUIRE_BARRIER "" ::: "memory") #define __atomic_release_fence() \ __asm__ __volatile__(RISCV_RELEASE_BARRIER "" ::: "memory"); static __always_inline int atomic_read(const atomic_t *v) { return READ_ONCE(v->counter); } static __always_inline void atomic_set(atomic_t *v, int i) { WRITE_ONCE(v->counter, i); } #ifndef CONFIG_GENERIC_ATOMIC64 #define ATOMIC64_INIT(i) { (i) } static __always_inline s64 atomic64_read(const atomic64_t *v) { return READ_ONCE(v->counter); } static __always_inline void atomic64_set(atomic64_t *v, s64 i) { WRITE_ONCE(v->counter, i); } #endif /* * First, the atomic ops that have no ordering constraints and therefor don't * have the AQ or RL bits set. These don't return anything, so there's only * one version to worry about. */ #define ATOMIC_OP(op, asm_op, I, asm_type, c_type, prefix) \ static __always_inline \ void atomic##prefix##_##op(c_type i, atomic##prefix##_t *v) \ { \ __asm__ __volatile__ ( \ " amo" #asm_op "." #asm_type " zero, %1, %0" \ : "+A" (v->counter) \ : "r" (I) \ : "memory"); \ } \ #ifdef CONFIG_GENERIC_ATOMIC64 #define ATOMIC_OPS(op, asm_op, I) \ ATOMIC_OP (op, asm_op, I, w, int, ) #else #define ATOMIC_OPS(op, asm_op, I) \ ATOMIC_OP (op, asm_op, I, w, int, ) \ ATOMIC_OP (op, asm_op, I, d, s64, 64) #endif ATOMIC_OPS(add, add, i) ATOMIC_OPS(sub, add, -i) ATOMIC_OPS(and, and, i) ATOMIC_OPS( or, or, i) ATOMIC_OPS(xor, xor, i) #undef ATOMIC_OP #undef ATOMIC_OPS /* * Atomic ops that have ordered, relaxed, acquire, and release variants. * There's two flavors of these: the arithmatic ops have both fetch and return * versions, while the logical ops only have fetch versions. */ #define ATOMIC_FETCH_OP(op, asm_op, I, asm_type, c_type, prefix) \ static __always_inline \ c_type atomic##prefix##_fetch_##op##_relaxed(c_type i, \ atomic##prefix##_t *v) \ { \ register c_type ret; \ __asm__ __volatile__ ( \ " amo" #asm_op "." #asm_type " %1, %2, %0" \ : "+A" (v->counter), "=r" (ret) \ : "r" (I) \ : "memory"); \ return ret; \ } \ static __always_inline \ c_type atomic##prefix##_fetch_##op(c_type i, atomic##prefix##_t *v) \ { \ register c_type ret; \ __asm__ __volatile__ ( \ " amo" #asm_op "." #asm_type ".aqrl %1, %2, %0" \ : "+A" (v->counter), "=r" (ret) \ : "r" (I) \ : "memory"); \ return ret; \ } #define ATOMIC_OP_RETURN(op, asm_op, c_op, I, asm_type, c_type, prefix) \ static __always_inline \ c_type atomic##prefix##_##op##_return_relaxed(c_type i, \ atomic##prefix##_t *v) \ { \ return atomic##prefix##_fetch_##op##_relaxed(i, v) c_op I; \ } \ static __always_inline \ c_type atomic##prefix##_##op##_return(c_type i, atomic##prefix##_t *v) \ { \ return atomic##prefix##_fetch_##op(i, v) c_op I; \ } #ifdef CONFIG_GENERIC_ATOMIC64 #define ATOMIC_OPS(op, asm_op, c_op, I) \ ATOMIC_FETCH_OP( op, asm_op, I, w, int, ) \ ATOMIC_OP_RETURN(op, asm_op, c_op, I, w, int, ) #else #define ATOMIC_OPS(op, asm_op, c_op, I) \ ATOMIC_FETCH_OP( op, asm_op, I, w, int, ) \ ATOMIC_OP_RETURN(op, asm_op, c_op, I, w, int, ) \ ATOMIC_FETCH_OP( op, asm_op, I, d, s64, 64) \ ATOMIC_OP_RETURN(op, asm_op, c_op, I, d, s64, 64) #endif ATOMIC_OPS(add, add, +, i) ATOMIC_OPS(sub, add, +, -i) #define atomic_add_return_relaxed atomic_add_return_relaxed #define atomic_sub_return_relaxed atomic_sub_return_relaxed #define atomic_add_return atomic_add_return #define atomic_sub_return atomic_sub_return #define atomic_fetch_add_relaxed atomic_fetch_add_relaxed #define atomic_fetch_sub_relaxed atomic_fetch_sub_relaxed #define atomic_fetch_add atomic_fetch_add #define atomic_fetch_sub atomic_fetch_sub #ifndef CONFIG_GENERIC_ATOMIC64 #define atomic64_add_return_relaxed atomic64_add_return_relaxed #define atomic64_sub_return_relaxed atomic64_sub_return_relaxed #define atomic64_add_return atomic64_add_return #define atomic64_sub_return atomic64_sub_return #define atomic64_fetch_add_relaxed atomic64_fetch_add_relaxed #define atomic64_fetch_sub_relaxed atomic64_fetch_sub_relaxed #define atomic64_fetch_add atomic64_fetch_add #define atomic64_fetch_sub atomic64_fetch_sub #endif #undef ATOMIC_OPS #ifdef CONFIG_GENERIC_ATOMIC64 #define ATOMIC_OPS(op, asm_op, I) \ ATOMIC_FETCH_OP(op, asm_op, I, w, int, ) #else #define ATOMIC_OPS(op, asm_op, I) \ ATOMIC_FETCH_OP(op, asm_op, I, w, int, ) \ ATOMIC_FETCH_OP(op, asm_op, I, d, s64, 64) #endif ATOMIC_OPS(and, and, i) ATOMIC_OPS( or, or, i) ATOMIC_OPS(xor, xor, i) #define atomic_fetch_and_relaxed atomic_fetch_and_relaxed #define atomic_fetch_or_relaxed atomic_fetch_or_relaxed #define atomic_fetch_xor_relaxed atomic_fetch_xor_relaxed #define atomic_fetch_and atomic_fetch_and #define atomic_fetch_or atomic_fetch_or #define atomic_fetch_xor atomic_fetch_xor #ifndef CONFIG_GENERIC_ATOMIC64 #define atomic64_fetch_and_relaxed atomic64_fetch_and_relaxed #define atomic64_fetch_or_relaxed atomic64_fetch_or_relaxed #define atomic64_fetch_xor_relaxed atomic64_fetch_xor_relaxed #define atomic64_fetch_and atomic64_fetch_and #define atomic64_fetch_or atomic64_fetch_or #define atomic64_fetch_xor atomic64_fetch_xor #endif #undef ATOMIC_OPS #undef ATOMIC_FETCH_OP #undef ATOMIC_OP_RETURN /* This is required to provide a full barrier on success. */ static __always_inline int atomic_fetch_add_unless(atomic_t *v, int a, int u) { int prev, rc; __asm__ __volatile__ ( "0: lr.w %[p], %[c]\n" " beq %[p], %[u], 1f\n" " add %[rc], %[p], %[a]\n" " sc.w.rl %[rc], %[rc], %[c]\n" " bnez %[rc], 0b\n" " fence rw, rw\n" "1:\n" : [p]"=&r" (prev), [rc]"=&r" (rc), [c]"+A" (v->counter) : [a]"r" (a), [u]"r" (u) : "memory"); return prev; } #define atomic_fetch_add_unless atomic_fetch_add_unless #ifndef CONFIG_GENERIC_ATOMIC64 static __always_inline s64 atomic64_fetch_add_unless(atomic64_t *v, s64 a, s64 u) { s64 prev; long rc; __asm__ __volatile__ ( "0: lr.d %[p], %[c]\n" " beq %[p], %[u], 1f\n" " add %[rc], %[p], %[a]\n" " sc.d.rl %[rc], %[rc], %[c]\n" " bnez %[rc], 0b\n" " fence rw, rw\n" "1:\n" : [p]"=&r" (prev), [rc]"=&r" (rc), [c]"+A" (v->counter) : [a]"r" (a), [u]"r" (u) : "memory"); return prev; } #define atomic64_fetch_add_unless atomic64_fetch_add_unless #endif /* * atomic_{cmp,}xchg is required to have exactly the same ordering semantics as * {cmp,}xchg and the operations that return, so they need a full barrier. */ #define ATOMIC_OP(c_t, prefix, size) \ static __always_inline \ c_t atomic##prefix##_xchg_relaxed(atomic##prefix##_t *v, c_t n) \ { \ return __xchg_relaxed(&(v->counter), n, size); \ } \ static __always_inline \ c_t atomic##prefix##_xchg_acquire(atomic##prefix##_t *v, c_t n) \ { \ return __xchg_acquire(&(v->counter), n, size); \ } \ static __always_inline \ c_t atomic##prefix##_xchg_release(atomic##prefix##_t *v, c_t n) \ { \ return __xchg_release(&(v->counter), n, size); \ } \ static __always_inline \ c_t atomic##prefix##_xchg(atomic##prefix##_t *v, c_t n) \ { \ return __xchg(&(v->counter), n, size); \ } \ static __always_inline \ c_t atomic##prefix##_cmpxchg_relaxed(atomic##prefix##_t *v, \ c_t o, c_t n) \ { \ return __cmpxchg_relaxed(&(v->counter), o, n, size); \ } \ static __always_inline \ c_t atomic##prefix##_cmpxchg_acquire(atomic##prefix##_t *v, \ c_t o, c_t n) \ { \ return __cmpxchg_acquire(&(v->counter), o, n, size); \ } \ static __always_inline \ c_t atomic##prefix##_cmpxchg_release(atomic##prefix##_t *v, \ c_t o, c_t n) \ { \ return __cmpxchg_release(&(v->counter), o, n, size); \ } \ static __always_inline \ c_t atomic##prefix##_cmpxchg(atomic##prefix##_t *v, c_t o, c_t n) \ { \ return __cmpxchg(&(v->counter), o, n, size); \ } #ifdef CONFIG_GENERIC_ATOMIC64 #define ATOMIC_OPS() \ ATOMIC_OP(int, , 4) #else #define ATOMIC_OPS() \ ATOMIC_OP(int, , 4) \ ATOMIC_OP(s64, 64, 8) #endif ATOMIC_OPS() #define atomic_xchg_relaxed atomic_xchg_relaxed #define atomic_xchg_acquire atomic_xchg_acquire #define atomic_xchg_release atomic_xchg_release #define atomic_xchg atomic_xchg #define atomic_cmpxchg_relaxed atomic_cmpxchg_relaxed #define atomic_cmpxchg_acquire atomic_cmpxchg_acquire #define atomic_cmpxchg_release atomic_cmpxchg_release #define atomic_cmpxchg atomic_cmpxchg #undef ATOMIC_OPS #undef ATOMIC_OP static __always_inline int atomic_sub_if_positive(atomic_t *v, int offset) { int prev, rc; __asm__ __volatile__ ( "0: lr.w %[p], %[c]\n" " sub %[rc], %[p], %[o]\n" " bltz %[rc], 1f\n" " sc.w.rl %[rc], %[rc], %[c]\n" " bnez %[rc], 0b\n" " fence rw, rw\n" "1:\n" : [p]"=&r" (prev), [rc]"=&r" (rc), [c]"+A" (v->counter) : [o]"r" (offset) : "memory"); return prev - offset; } #define atomic_dec_if_positive(v) atomic_sub_if_positive(v, 1) #ifndef CONFIG_GENERIC_ATOMIC64 static __always_inline s64 atomic64_sub_if_positive(atomic64_t *v, s64 offset) { s64 prev; long rc; __asm__ __volatile__ ( "0: lr.d %[p], %[c]\n" " sub %[rc], %[p], %[o]\n" " bltz %[rc], 1f\n" " sc.d.rl %[rc], %[rc], %[c]\n" " bnez %[rc], 0b\n" " fence rw, rw\n" "1:\n" : [p]"=&r" (prev), [rc]"=&r" (rc), [c]"+A" (v->counter) : [o]"r" (offset) : "memory"); return prev - offset; } #define atomic64_dec_if_positive(v) atomic64_sub_if_positive(v, 1) #endif #endif /* _ASM_RISCV_ATOMIC_H */