On Sat, Dec 14, 2024 at 09:58:31AM +0100, Wolfram Sang wrote: > There are multiple open coded implementations for getting the parity of > a byte in the kernel, even using different approaches. Take the pretty > efficient version from SPD5118 driver and make it generally available by > putting it into the bitops header. As long as there is just one parity > calculation helper, the creation of a distinct 'parity.h' header was > discarded. Also, the usage of hweight8() for architectures having a > popcnt instruction is postponed until a use case within hot paths is > desired. The motivation for this patch is the frequent use of odd parity > in the I3C specification and to simplify drivers there. > > Changes compared to the original SPD5118 version are the addition of > kernel documentation, switching the return type from bool to int, and > renaming the argument of the function. > > Signed-off-by: Wolfram Sang <wsa+renesas@xxxxxxxxxxxxxxxxxxxx> Compare the results with hweight8(x) & 1 for correctness when x is in the range [0, 255]. Reviewed-by: Kuan-Wei Chiu <visitorckw@xxxxxxxxx> Tested-by: Kuan-Wei Chiu <visitorckw@xxxxxxxxx> Regards, Kuan-Wei
