u-boot.git/include/linux/bitfield.h, branch main

bitfield: Add non-constant field_{prep, get}() helpers

2026-07-08T19:29:18Z

The existing FIELD_{GET,PREP}() macros are limited to compile-time constants. However, it is very common to prepare or extract bitfield elements where the bitfield mask is not a compile-time constant. To avoid this limitation, the AT91 clock driver and several other drivers already have their own non-const field_{prep,get}() macros. Make them available for general use by adding them to , and improve them slightly: 1. Avoid evaluating macro parameters more than once, 2. Replace "ffs() - 1" by "__ffs()", 3. Support 64-bit use on 32-bit architectures, 4. Wire field_{get,prep}() to FIELD_{GET,PREP}() when mask is actually constant. This is deliberately not merged into the existing FIELD_{GET,PREP}() macros, as people expressed the desire to keep stricter variants for increased safety, or for performance critical paths. Yury: use __mask within new macros. Signed-off-by: Geert Uytterhoeven Acked-by: Alexandre Belloni Acked-by: Jonathan Cameron Acked-by: Crt Mori Acked-by: Nuno Sá Acked-by: Richard Genoud Reviewed-by: Andy Shevchenko Reviewed-by: Yury Norov (NVIDIA) Signed-off-by: Yury Norov (NVIDIA) [Linux commit: c1c6ab80b25c8db1e2ef5ae3ac8075d2c242ae13] Signed-off-by: Mikhail Kshevetskiy Reviewed-by: David Lechner Reviewed-by: Simon Glass

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

2026-07-08T19:29:18Z

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

linux/bitfield.h: sync from Linux 6.15

2025-06-14T15:11:10Z

Sync bitfield.h header with Linux 6.15 version. Mainly is to permit the introduction of FIELD_PREP_CONST. The bug.h header changed to build_bug.h doesn't cause any regression as we also ship split header similar to how it's done with in Linux. Signed-off-by: Christian Marangi

linux/bitfield.h: Add primitives for manipulating bitfields both in host- and fixed-endian

2020-07-10T09:47:12Z

Imports Al Viro's original Linux commit 00b0c9b82663a, which contains an in depth explanation and two fixes from Johannes Berg: e7d4a95da86e0 "bitfield: fix *_encode_bits()", 37a3862e12382 "bitfield: add u8 helpers". Signed-off-by: Nicolas Saenz Julienne [s.nawrocki: added empty lines between functions and macros] Signed-off-by: Sylwester Nawrocki [mb: squash fix including byteorder.h] Signed-off-by: Matthias Brugger

linux/bitfield.h: import from Linux 4.13

2017-10-04T16:00:21Z

Copied from Linux 4.13. Commit log of 3e9b3112ec74 of Linux explains well why this header is useful. Signed-off-by: Masahiro Yamada