FIELD_MODIFY(9)

💖 FIELD_MODIFY 💖

okay so this is the Kernel API Manual page for FIELD_MODIFY, section 9 — yes bestie, the manual name is right there, folded in near the top. It’s giving “tiny but mighty bitfield helper” energy. 💅

🌸 NAME 🌸

FIELD_MODIFY — modify a bitfield element ✨

🦋 SYNOPSIS 🦋

FIELD_MODIFY (_mask , _reg_p , _val );

🎀 ARGUMENTS 🎀

• _mask — shifted mask defining the field's length and position. It’s the little map that says which bits are the field, periodt. 🗺️
• _reg_p — pointer to the memory that should be updated. This is the address bestie is about to get a glow-up. 💫
• _val — value to store in the bitfield. The new resident of those bits, no cap. 👑

🌈 DESCRIPTION 🌈

FIELD_MODIFY modifies the set of bits in _reg_p specified by _mask, by replacing them with the bitfield value passed in as _val. That’s the whole vibe: mask picks the field, value moves in, register gets updated. Slay. 💅✨

🧚 SEE ALSO 🧚

Kernel file ./include/linux/bitfield.h has the friends and neighbors: FIELD_MAX(9), FIELD_FIT(9), FIELD_PREP(9), FIELD_PREP_CONST(9), FIELD_GET(9), FIELD_GET_SIGNED(9), field_prep(9), field_get(9). Go read the whole squad, iykyk. 🫶

sourced from ./include/linux, dated October 2026. mwah 💋