Re: [RFC][PATCH] Add primitives for manipulating bitfields both in host- and fixed-endian.
flat view
From: Jakub Kicinski <hidden>
Date: 2017-12-15 05:07:24
Also in:
lkml
Looks great to me! On Fri, 15 Dec 2017 02:33:43 +0000, Al Viro wrote:
The following primitives are defined in linux/bitfield.h:
* u32 le32_get_bits(__le32 val, u32 field) extracts the contents of the
bitfield specified by @field in little-endian 32bit value @val and
converts it to host-endian.
* void le32p_replace_bits(__le32 *p, u32 v, u32 field) replaces
the contents of the bitfield specified by @field in little-endian
32bit object pointet to by *p with the value of @v. New value is
given in host-endian and stored as little-endian.
* __le32 le32_replace_bits(__le32 old, u32 v, u32 field) is equivalent to
({__le32 tmp = old; le32p_replace_bits(&old, v, field); tmp;})
In other words, instead of modifying an object in memory, it takes
the initial value and returns the modified one.the current macros take filed/mask as first param, not sure if it's worth maintaining the order