diff options
| -rw-r--r-- | include/bitfield.h | 32 |
1 files changed, 32 insertions, 0 deletions
diff --git a/include/bitfield.h b/include/bitfield.h index b884c74600..a59f3c279a 100644 --- a/include/bitfield.h +++ b/include/bitfield.h @@ -27,6 +27,12 @@ * old = bitfield_extract(old_reg_val, 10, 5); * new_reg_val = bitfield_replace(old_reg_val, 10, 5, new); * + * or + * + * mask = bitfield_mask(10, 5); + * old = bitfield_extract_by_mask(old_reg_val, mask); + * new_reg_val = bitfield_replace_by_mask(old_reg_val, mask, new); + * * The numbers 10 and 5 could for example come from data * tables which describe all bitfields in all registers. */ @@ -56,3 +62,29 @@ static inline uint bitfield_replace(uint reg_val, uint shift, uint width, return (reg_val & ~mask) | ((bitfield_val << shift) & mask); } + +/* Produces a shift of the bitfield given a mask */ +static inline uint bitfield_shift(uint mask) +{ + return mask ? ffs(mask) - 1 : 0; +} + +/* Extract the value of a bitfield found within a given register value */ +static inline uint bitfield_extract_by_mask(uint reg_val, uint mask) +{ + uint shift = bitfield_shift(mask); + + return (reg_val & mask) >> shift; +} + +/* + * Replace the value of a bitfield found within a given register value + * Returns the newly modified uint value with the replaced field. + */ +static inline uint bitfield_replace_by_mask(uint reg_val, uint mask, + uint bitfield_val) +{ + uint shift = bitfield_shift(mask); + + return (reg_val & ~mask) | ((bitfield_val << shift) & mask); +} |
