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Diffstat (limited to 'arch/riscv/include/asm/atomic.h')
| -rw-r--r-- | arch/riscv/include/asm/atomic.h | 356 |
1 files changed, 356 insertions, 0 deletions
diff --git a/arch/riscv/include/asm/atomic.h b/arch/riscv/include/asm/atomic.h new file mode 100644 index 000000000..400a8c8b6 --- /dev/null +++ b/arch/riscv/include/asm/atomic.h @@ -0,0 +1,356 @@ +/* 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 <asm-generic/atomic64.h> +#else +# if (__riscv_xlen < 64) +# error "64-bit atomics require XLEN to be at least 64" +# endif +#endif + +#include <asm/cmpxchg.h> +#include <asm/barrier.h> + +#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 */ |