1 /* 2 * SPDX-License-Identifier: GPL-2.0-or-later 3 * Compare-and-swap for 128-bit atomic operations, generic version. 4 * 5 * Copyright (C) 2018, 2023 Linaro, Ltd. 6 * 7 * See docs/devel/atomics.rst for discussion about the guarantees each 8 * atomic primitive is meant to provide. 9 */ 10 11 #ifndef HOST_ATOMIC128_CAS_H 12 #define HOST_ATOMIC128_CAS_H 13 14 #if defined(CONFIG_ATOMIC128) 15 static inline Int128 ATTRIBUTE_ATOMIC128_OPT 16 atomic16_cmpxchg(Int128 *ptr, Int128 cmp, Int128 new) 17 { 18 __int128_t *ptr_align = __builtin_assume_aligned(ptr, 16); 19 Int128Alias r, c, n; 20 21 c.s = cmp; 22 n.s = new; 23 r.i = qatomic_cmpxchg__nocheck(ptr_align, c.i, n.i); 24 return r.s; 25 } 26 # define HAVE_CMPXCHG128 1 27 #elif defined(CONFIG_CMPXCHG128) 28 static inline Int128 ATTRIBUTE_ATOMIC128_OPT 29 atomic16_cmpxchg(Int128 *ptr, Int128 cmp, Int128 new) 30 { 31 __int128_t *ptr_align = __builtin_assume_aligned(ptr, 16); 32 Int128Alias r, c, n; 33 34 c.s = cmp; 35 n.s = new; 36 r.i = __sync_val_compare_and_swap_16(ptr_align, c.i, n.i); 37 return r.s; 38 } 39 # define HAVE_CMPXCHG128 1 40 #else 41 /* Fallback definition that must be optimized away, or error. */ 42 Int128 QEMU_ERROR("unsupported atomic") 43 atomic16_cmpxchg(Int128 *ptr, Int128 cmp, Int128 new); 44 # define HAVE_CMPXCHG128 0 45 #endif 46 47 #endif /* HOST_ATOMIC128_CAS_H */ 48