STRUCT CIW(9)

📦 version 7.3.1, in nixpkgs unstable

okay bestie, welcome to the struct ciw(9) page from the Kernel API Manual ✨ this one is short and sweet: it’s the layout of a command information word, aka CIW. no cap, that’s the whole vibe 💅

🎀 NAME 🎀

struct ciw — command information word (CIW) layout 💖

✨ SYNOPSIS ✨

struct ciw {
    __u32 et       :  2;
    __u32 reserved :  2;
    __u32 ct       :  4;
    __u32 cmd      :  8;
    __u32 count    : 16;
 };

🌸 Members 🌸

  • et — entry type 🍓
  • reserved — reserved bits 🙈
  • ct — command type 🎀
  • cmd — command code ⭐
  • count — command count 🔥

💜 SEE ALSO 💜

peep these related pages and that kernel file 👀: Kernel file ./arch/s390/include/asm/cio.h, plus struct ccw1(9), struct ccw0(9), struct erw(9), struct erw_eadm(9), struct sublog(9), struct esw0(9), struct esw1(9), struct esw2(9), struct esw3(9), struct esw_eadm(9), struct irb(9), struct ccw_dev_id(9), ccw_dev_id_is_equal(9), and pathmask_to_pos(9) 🦋

and that’s the whole page, bestie 🫶 source/version: ./arch/s390/include/asm — dated October 2026 — and it’s the struct ciw(9) page. mwah 💋

📦 where this page comes from