diff options
Diffstat (limited to 'include/linux/bitfield.h')
| -rw-r--r-- | include/linux/bitfield.h | 18 |
1 files changed, 17 insertions, 1 deletions
diff --git a/include/linux/bitfield.h b/include/linux/bitfield.h index 54aeeef1f0ec..14f86e455a67 100644 --- a/include/linux/bitfield.h +++ b/include/linux/bitfield.h @@ -44,7 +44,7 @@ * FIELD_MODIFY(REG_FIELD_C, ®, c); */ -#define __bf_shf(x) (__builtin_ffsll(x) - 1) +#define __bf_shf __builtin_ctzll #define __scalar_type_to_unsigned_cases(type) \ unsigned type: (unsigned type)0, \ @@ -179,6 +179,22 @@ }) /** + * FIELD_GET_SIGNED() - extract a signed bitfield element + * @mask: shifted mask defining the field's length and position + * @reg: value of entire bitfield + * + * Returns the sign-extended field specified by @_mask from the + * bitfield passed in as @reg by masking and shifting it down. + */ +#define FIELD_GET_SIGNED(mask, reg) \ + ({ \ + __BF_FIELD_CHECK(mask, reg, 0U, "FIELD_GET_SIGNED: "); \ + ((__signed_scalar_typeof(mask)) \ + (((long long)(reg) << __builtin_clzll(mask)) >> \ + (__builtin_clzll(mask) + __builtin_ctzll(mask)))); \ + }) + +/** * FIELD_MODIFY() - modify a bitfield element * @_mask: shifted mask defining the field's length and position * @_reg_p: pointer to the memory that should be updated |