blob: 80fff0643a693900ae1d8237f4351956f166dabe [file] [log] [blame]
/*
* SPDX-License-Identifier: GPL-2.0-or-later
* Load/store for 128-bit atomic operations, generic version.
*
* Copyright (C) 2018, 2023 Linaro, Ltd.
*
* See docs/devel/atomics.rst for discussion about the guarantees each
* atomic primitive is meant to provide.
*/
#ifndef HOST_ATOMIC128_LDST_H
#define HOST_ATOMIC128_LDST_H
#if defined(CONFIG_ATOMIC128)
# define HAVE_ATOMIC128_RO 1
# define HAVE_ATOMIC128_RW 1
static inline Int128 ATTRIBUTE_ATOMIC128_OPT
atomic16_read_ro(const Int128 *ptr)
{
const __int128_t *ptr_align = __builtin_assume_aligned(ptr, 16);
Int128Alias r;
r.i = qatomic_read__nocheck(ptr_align);
return r.s;
}
static inline Int128 ATTRIBUTE_ATOMIC128_OPT
atomic16_read_rw(Int128 *ptr)
{
return atomic16_read_ro(ptr);
}
static inline void ATTRIBUTE_ATOMIC128_OPT
atomic16_set(Int128 *ptr, Int128 val)
{
__int128_t *ptr_align = __builtin_assume_aligned(ptr, 16);
Int128Alias v;
v.s = val;
qatomic_set__nocheck(ptr_align, v.i);
}
#elif defined(CONFIG_CMPXCHG128)
# define HAVE_ATOMIC128_RO 0
# define HAVE_ATOMIC128_RW 1
Int128 QEMU_ERROR("unsupported atomic") atomic16_read_ro(const Int128 *ptr);
static inline Int128 ATTRIBUTE_ATOMIC128_OPT
atomic16_read_rw(Int128 *ptr)
{
/* Maybe replace 0 with 0, returning the old value. */
Int128 z = int128_make64(0);
return atomic16_cmpxchg(ptr, z, z);
}
static inline void ATTRIBUTE_ATOMIC128_OPT
atomic16_set(Int128 *ptr, Int128 val)
{
__int128_t *ptr_align = __builtin_assume_aligned(ptr, 16);
__int128_t old;
Int128Alias new;
new.s = val;
do {
old = *ptr_align;
} while (!__sync_bool_compare_and_swap_16(ptr_align, old, new.i));
}
#else
# define HAVE_ATOMIC128_RO 0
# define HAVE_ATOMIC128_RW 0
/* Fallback definitions that must be optimized away, or error. */
Int128 QEMU_ERROR("unsupported atomic") atomic16_read_ro(const Int128 *ptr);
Int128 QEMU_ERROR("unsupported atomic") atomic16_read_rw(Int128 *ptr);
void QEMU_ERROR("unsupported atomic") atomic16_set(Int128 *ptr, Int128 val);
#endif
#endif /* HOST_ATOMIC128_LDST_H */