bitfield: Add less-checking __FIELD_{GET,PREP}()

The BUILD_BUG_ON_MSG() check against "~0ull" works only with "unsigned
(long) long" _mask types.  For constant masks, that condition is usually
met, as GENMASK() yields an UL value.  The few places where the
constant mask is stored in an intermediate variable were fixed by
changing the variable type to u64.

However, for non-constant masks, smaller unsigned types should be valid,
too, but currently lead to "result of comparison of constant
18446744073709551615 with expression of type ... is always
false"-warnings with clang and W=1.

Hence refactor the __BF_FIELD_CHECK() helper, and factor out
__FIELD_{GET,PREP}().  The later lack the single problematic check, but
are otherwise identical to FIELD_{GET,PREP}(), and are intended to be
used in the fully non-const variants later.

Signed-off-by: Geert Uytterhoeven <[email protected]>
Signed-off-by: Yury Norov (NVIDIA) <[email protected]>
[Linux commit: 2a6c045640c38a407a39cd40c3c4d8dd2fd89aa8]
Signed-off-by: Mikhail Kshevetskiy <[email protected]>
Reviewed-by: David Lechner <[email protected]>
Reviewed-by: Simon Glass <[email protected]>
Signed-off-by: Scott Wood <[email protected]>
Acked-by: Gerald Van Baren <[email protected]>
Reviewed-by: Andre Przywara <[email protected]>
Signed-off-by: Masahiro Yamada <[email protected]>

0 files changed, 0 insertions, 0 deletions