diff options
| author | Namhyung Kim <namhyung@kernel.org> | 2025-02-05 14:57:18 -0800 |
|---|---|---|
| committer | Namhyung Kim <namhyung@kernel.org> | 2025-02-05 14:57:18 -0800 |
| commit | 9e676a024fa1fa2bd8150c2d2ba85478280353bc (patch) | |
| tree | 5cf0e1d4ab27002fcafdc7dc5bdfdd9ff3f3c9f1 /include/linux/bitops.h | |
| parent | 357b965deba9fb71467413e473764ec4e1694d8d (diff) | |
| parent | 2014c95afecee3e76ca4a56956a936e23283f05b (diff) | |
Merge tag 'v6.14-rc1' into perf-tools-next
To get the various fixes in the current master.
Signed-off-by: Namhyung Kim <namhyung@kernel.org>
Diffstat (limited to 'include/linux/bitops.h')
| -rw-r--r-- | include/linux/bitops.h | 31 |
1 files changed, 31 insertions, 0 deletions
diff --git a/include/linux/bitops.h b/include/linux/bitops.h index ba35bbf07798..c1cb53cf2f0f 100644 --- a/include/linux/bitops.h +++ b/include/linux/bitops.h @@ -230,6 +230,37 @@ static inline int get_count_order_long(unsigned long l) } /** + * parity8 - get the parity of an u8 value + * @value: the value to be examined + * + * Determine the parity of the u8 argument. + * + * Returns: + * 0 for even parity, 1 for odd parity + * + * Note: This function informs you about the current parity. Example to bail + * out when parity is odd: + * + * if (parity8(val) == 1) + * return -EBADMSG; + * + * If you need to calculate a parity bit, you need to draw the conclusion from + * this result yourself. Example to enforce odd parity, parity bit is bit 7: + * + * if (parity8(val) == 0) + * val ^= BIT(7); + */ +static inline int parity8(u8 val) +{ + /* + * One explanation of this algorithm: + * https://funloop.org/codex/problem/parity/README.html + */ + val ^= val >> 4; + return (0x6996 >> (val & 0xf)) & 1; +} + +/** * __ffs64 - find first set bit in a 64 bit word * @word: The 64 bit word * |
