diff options
Diffstat (limited to 'arch/arm/include/asm/word-at-a-time.h')
-rw-r--r-- | arch/arm/include/asm/word-at-a-time.h | 60 |
1 files changed, 60 insertions, 0 deletions
diff --git a/arch/arm/include/asm/word-at-a-time.h b/arch/arm/include/asm/word-at-a-time.h new file mode 100644 index 0000000000..a2b20be13d --- /dev/null +++ b/arch/arm/include/asm/word-at-a-time.h @@ -0,0 +1,60 @@ +/* SPDX-License-Identifier: GPL-2.0-only */ +/* + * Copyright (C) 2013 ARM Ltd. + */ +#ifndef __ASM_WORD_AT_A_TIME_H +#define __ASM_WORD_AT_A_TIME_H + +#if !defined(__AARCH64EB__) && !defined(__ARMEB__) + +#include <linux/kernel.h> +#include <linux/bitops.h> + +struct word_at_a_time { + const unsigned long one_bits, high_bits; +}; + +#define WORD_AT_A_TIME_CONSTANTS { REPEAT_BYTE(0x01), REPEAT_BYTE(0x80) } + +static inline unsigned long has_zero(unsigned long a, unsigned long *bits, + const struct word_at_a_time *c) +{ + unsigned long mask = ((a - c->one_bits) & ~a) & c->high_bits; + *bits = mask; + return mask; +} + +#define prep_zero_mask(a, bits, c) (bits) + +static inline unsigned long create_zero_mask(unsigned long bits) +{ + bits = (bits - 1) & ~bits; + return bits >> 7; +} + +static inline unsigned long find_zero(unsigned long mask) +{ + unsigned long ret; + +#if __LINUX_ARM_ARCH__ >= 8 + ret = fls64(mask) >> 3; +#elif __LINUX_ARM_ARCH__ >= 5 + /* We have clz available. */ + ret = fls(mask) >> 3; +#else + /* (000000 0000ff 00ffff ffffff) -> ( 1 1 2 3 ) */ + ret = (0x0ff0001 + mask) >> 23; + /* Fix the 1 for 00 case */ + ret &= mask; +#endif + + return ret; +} + +#define zero_bytemask(mask) (mask) + +#else /* __AARCH64EB__ || __ARMEB__ */ +#include <asm-generic/word-at-a-time.h> +#endif + +#endif /* __ASM_WORD_AT_A_TIME_H */ |