projects / mirror_ubuntu-artful-kernel.git / blame
| Commit | Line | Data |
|---|---|---|
| 36126f8f LT |
1 | #ifndef _ASM_WORD_AT_A_TIME_H |
| 2 | #define _ASM_WORD_AT_A_TIME_H | |
| 3 | ||
| 4 | /* | |
| 5 | * This says "generic", but it's actually big-endian only. | |
| 6 | * Little-endian can use more efficient versions of these | |
| 7 | * interfaces, see for example | |
| 8 | * arch/x86/include/asm/word-at-a-time.h | |
| 9 | * for those. | |
| 10 | */ | |
| 11 | ||
| 12 | #include <linux/kernel.h> | |
| 13 | ||
| 14 | struct word_at_a_time { | |
| 15 | const unsigned long high_bits, low_bits; | |
| 16 | }; | |
| 17 | ||
| 18 | #define WORD_AT_A_TIME_CONSTANTS { REPEAT_BYTE(0xfe) + 1, REPEAT_BYTE(0x7f) } | |
| 19 | ||
| 20 | /* Bit set in the bytes that have a zero */ | |
| 21 | static inline long prep_zero_mask(unsigned long val, unsigned long rhs, const struct word_at_a_time *c) | |
| 22 | { | |
| 23 | unsigned long mask = (val & c->low_bits) + c->low_bits; | |
| 24 | return ~(mask | rhs); | |
| 25 | } | |
| 26 | ||
| 27 | #define create_zero_mask(mask) (mask) | |
| 28 | ||
| 29 | static inline long find_zero(unsigned long mask) | |
| 30 | { | |
| 31 | long byte = 0; | |
| 32 | #ifdef CONFIG_64BIT | |
| 33 | if (mask >> 32) | |
| 34 | mask >>= 32; | |
| 35 | else | |
| 36 | byte = 4; | |
| 37 | #endif | |
| 38 | if (mask >> 16) | |
| 39 | mask >>= 16; | |
| 40 | else | |
| 41 | byte += 2; | |
| 42 | return (mask >> 8) ? byte : byte + 1; | |
| 43 | } | |
| 44 | ||
| 45 | static inline bool has_zero(unsigned long val, unsigned long *data, const struct word_at_a_time *c) | |
| 46 | { | |
| 47 | unsigned long rhs = val | c->low_bits; | |
| 48 | *data = rhs; | |
| 49 | return (val + c->high_bits) & ~rhs; | |
| 50 | } | |
| 51 | ||
| 52 | #endif /* _ASM_WORD_AT_A_TIME_H */ |