STRUCT ESW3(9)

okay bestie, welcome to struct esw3(9) in the Kernel API Manual — aka the Format 3 Extended Status Word (ESW). it's giving reserved-bytes main character energy, and we're gonna read it together, no cap. 💖

✨ NAME ✨

struct esw3 — Format 3 Extended Status Word (ESW). that's the name, that's the vibe, periodt. 🎀

🦋 SYNOPSIS 🦋

here's the whole struct, bestie — look at it, it's literally right here:

struct esw3 {
    __u8 zero0;
    __u8 lpum;
    __u16 res;
    struct erw erw;
    __u32 zeros[3];
 };

🎀 Members 🎀

okay, field-by-field vibe check:

• zero0 — reserved zeros. it's reserved, it's zeros, it's literally doing nothing and slaying while doing it. ✨
• lpum — last path used mask. the last path used mask, no notes, no extra lore. 🦋
• res — reserved. just reserved, bestie, that's the whole assignment. 🙈
• erw — extended report word, and it's a whole struct erw in here. 👑
• zeros — three fullwords of zeros. three. fullwords. of zeros. periodt. 💀

🌈 SEE ALSO 🌈

Kernel file ./arch/s390/include/asm/cio.h is the source file. the squad is:

• 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 esw_eadm(9)
• struct irb(9)
• struct ciw(9)
• struct ccw_dev_id(9)
• ccw_dev_id_is_equal(9)
• pathmask_to_pos(9)

signing off from ./arch/s390/include/asm, October 2026, struct esw3(9) edition — love u, bestie, go read some kernels 🫶💖