| /* |
| * SPDX-License-Identifier: GPL-2.0-or-later |
| * Atomic extract 64 from 128-bit, generic version. |
| * |
| * Copyright (C) 2023 Linaro, Ltd. |
| */ |
| |
| #ifndef HOST_LOAD_EXTRACT_AL16_AL8_H |
| #define HOST_LOAD_EXTRACT_AL16_AL8_H |
| |
| /** |
| * load_atom_extract_al16_or_al8: |
| * @pv: host address |
| * @s: object size in bytes, @s <= 8. |
| * |
| * Load @s bytes from @pv, when pv % s != 0. If [p, p+s-1] does not |
| * cross an 16-byte boundary then the access must be 16-byte atomic, |
| * otherwise the access must be 8-byte atomic. |
| */ |
| static inline uint64_t ATTRIBUTE_ATOMIC128_OPT |
| load_atom_extract_al16_or_al8(void *pv, int s) |
| { |
| uintptr_t pi = (uintptr_t)pv; |
| int o = pi & 7; |
| int shr = (HOST_BIG_ENDIAN ? 16 - s - o : o) * 8; |
| Int128 r; |
| |
| pv = (void *)(pi & ~7); |
| if (pi & 8) { |
| uint64_t *p8 = __builtin_assume_aligned(pv, 16, 8); |
| uint64_t a = qatomic_read__nocheck(p8); |
| uint64_t b = qatomic_read__nocheck(p8 + 1); |
| |
| if (HOST_BIG_ENDIAN) { |
| r = int128_make128(b, a); |
| } else { |
| r = int128_make128(a, b); |
| } |
| } else { |
| r = atomic16_read_ro(pv); |
| } |
| return int128_getlo(int128_urshift(r, shr)); |
| } |
| |
| #endif /* HOST_LOAD_EXTRACT_AL16_AL8_H */ |
