| b.liu | e958203 | 2025-04-17 19:18:16 +0800 | [diff] [blame] | 1 | /* SPDX-License-Identifier: GPL-2.0-only */ |
| 2 | /* |
| 3 | * Copyright (C) 2012 Regents of the University of California |
| 4 | * |
| 5 | * Derived from arch/x86/include/asm/word-at-a-time.h |
| 6 | */ |
| 7 | |
| 8 | #ifndef _ASM_RISCV_WORD_AT_A_TIME_H |
| 9 | #define _ASM_RISCV_WORD_AT_A_TIME_H |
| 10 | |
| 11 | |
| 12 | #include <linux/kernel.h> |
| 13 | |
| 14 | struct word_at_a_time { |
| 15 | const unsigned long one_bits, high_bits; |
| 16 | }; |
| 17 | |
| 18 | #define WORD_AT_A_TIME_CONSTANTS { REPEAT_BYTE(0x01), REPEAT_BYTE(0x80) } |
| 19 | |
| 20 | static inline unsigned long has_zero(unsigned long val, |
| 21 | unsigned long *bits, const struct word_at_a_time *c) |
| 22 | { |
| 23 | unsigned long mask = ((val - c->one_bits) & ~val) & c->high_bits; |
| 24 | *bits = mask; |
| 25 | return mask; |
| 26 | } |
| 27 | |
| 28 | static inline unsigned long prep_zero_mask(unsigned long val, |
| 29 | unsigned long bits, const struct word_at_a_time *c) |
| 30 | { |
| 31 | return bits; |
| 32 | } |
| 33 | |
| 34 | static inline unsigned long create_zero_mask(unsigned long bits) |
| 35 | { |
| 36 | bits = (bits - 1) & ~bits; |
| 37 | return bits >> 7; |
| 38 | } |
| 39 | |
| 40 | static inline unsigned long find_zero(unsigned long mask) |
| 41 | { |
| 42 | return fls64(mask) >> 3; |
| 43 | } |
| 44 | |
| 45 | /* The mask we created is directly usable as a bytemask */ |
| 46 | #define zero_bytemask(mask) (mask) |
| 47 | |
| 48 | #endif /* _ASM_RISCV_WORD_AT_A_TIME_H */ |