| Message ID | 20190512012508.10608-2-elder@linaro.org |
|---|---|
| State | Accepted |
| Commit | e31a50162feb352147d3fc87b9e036703c8f2636 |
| Headers | show |
| Series | net: introduce Qualcomm IPA driver | expand |
Alex Elder <elder@linaro.org> writes: > Define FIELD_MAX(), which supplies the maximum value that can be > represented by a field value. Define field_max() as well, to go > along with the lower-case forms of the field mask functions. > > Signed-off-by: Alex Elder <elder@linaro.org> Via which tree is this going? I assume I do not have take it unless someone says otherwise. -- Kalle Valo
On 5/12/19 1:33 AM, Kalle Valo wrote: > Alex Elder <elder@linaro.org> writes: > >> Define FIELD_MAX(), which supplies the maximum value that can be >> represented by a field value. Define field_max() as well, to go >> along with the lower-case forms of the field mask functions. >> >> Signed-off-by: Alex Elder <elder@linaro.org> > > Via which tree is this going? I assume I do not have take it unless > someone says otherwise. Sorry about that, perhaps I should have posted it separately. I don't have an answer, but we could avoid having to coordinate if it went together with the rest. -Alex
On Sun, 2019-05-12 at 07:18 -0500, Alex Elder wrote: > On 5/12/19 1:33 AM, Kalle Valo wrote: > > Alex Elder <elder@linaro.org> writes: > > > > > Define FIELD_MAX(), which supplies the maximum value that can be > > > represented by a field value. Define field_max() as well, to go > > > along with the lower-case forms of the field mask functions. > > > > > > Signed-off-by: Alex Elder <elder@linaro.org> > > > > Via which tree is this going? I assume I do not have take it unless > > someone says otherwise. > > Sorry about that, perhaps I should have posted it separately. > > I don't have an answer, but we could avoid having to coordinate > if it went together with the rest. It's unlikely to conflict, and I don't think anyone really thinks that the file is "theirs" (being basically standalone), so I think you should just take it with whatever code that needs it. johannes
diff --git a/include/linux/bitfield.h b/include/linux/bitfield.h index 3f1ef4450a7c..cf4f06774520 100644 --- a/include/linux/bitfield.h +++ b/include/linux/bitfield.h @@ -63,6 +63,19 @@ (1ULL << __bf_shf(_mask))); \ }) +/** + * FIELD_MAX() - produce the maximum value representable by a field + * @_mask: shifted mask defining the field's length and position + * + * FIELD_MAX() returns the maximum value that can be held in the field + * specified by @_mask. + */ +#define FIELD_MAX(_mask) \ + ({ \ + __BF_FIELD_CHECK(_mask, 0ULL, 0ULL, "FIELD_MAX: "); \ + (typeof(_mask))((_mask) >> __bf_shf(_mask)); \ + }) + /** * FIELD_FIT() - check if value fits in the field * @_mask: shifted mask defining the field's length and position @@ -118,6 +131,7 @@ static __always_inline u64 field_mask(u64 field) { return field / field_multiplier(field); } +#define field_max(field) ((typeof(field))field_mask(field)) #define ____MAKE_OP(type,base,to,from) \ static __always_inline __##type type##_encode_bits(base v, base field) \ { \
Define FIELD_MAX(), which supplies the maximum value that can be represented by a field value. Define field_max() as well, to go along with the lower-case forms of the field mask functions. Signed-off-by: Alex Elder <elder@linaro.org> --- include/linux/bitfield.h | 14 ++++++++++++++ 1 file changed, 14 insertions(+) -- 2.20.1