1/* 2 * SPDX-License-Identifier: GPL-2.0-or-later 3 * Atomic extract 64 from 128-bit, generic version. 4 * 5 * Copyright (C) 2023 Linaro, Ltd. 6 */ 7 8#ifndef HOST_LOAD_EXTRACT_AL16_AL8_H 9#define HOST_LOAD_EXTRACT_AL16_AL8_H 10 11/** 12 * load_atom_extract_al16_or_al8: 13 * @pv: host address 14 * @s: object size in bytes, @s <= 8. 15 * 16 * Load @s bytes from @pv, when pv % s != 0. If [p, p+s-1] does not 17 * cross an 16-byte boundary then the access must be 16-byte atomic, 18 * otherwise the access must be 8-byte atomic. 19 */ 20static inline uint64_t ATTRIBUTE_ATOMIC128_OPT 21load_atom_extract_al16_or_al8(void *pv, int s) 22{ 23 uintptr_t pi = (uintptr_t)pv; 24 int o = pi & 7; 25 int shr = (HOST_BIG_ENDIAN ? 16 - s - o : o) * 8; 26 Int128 r; 27 28 pv = (void *)(pi & ~7); 29 if (pi & 8) { 30 uint64_t *p8 = __builtin_assume_aligned(pv, 16, 8); 31 uint64_t a = qatomic_read__nocheck(p8); 32 uint64_t b = qatomic_read__nocheck(p8 + 1); 33 34 if (HOST_BIG_ENDIAN) { 35 r = int128_make128(b, a); 36 } else { 37 r = int128_make128(a, b); 38 } 39 } else { 40 r = atomic16_read_ro(pv); 41 } 42 return int128_getlo(int128_urshift(r, shr)); 43} 44 45#endif /* HOST_LOAD_EXTRACT_AL16_AL8_H */ 46