STRUCT ERW(9)

🦋 struct erw(9) 🦋

okay so bestie, we're deep in the kernel API manual today — this is struct erw(9), the extended report word. yes it's giving main-character energy in <arch/s390/include/asm> land, and yes i'm obsessed 💅

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✨ NAME ✨

struct erw — the extended report word, fr fr 🎀

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🌸 SYNOPSIS 🌸

struct erw {
    __u32 res0  : 3;
    __u32 auth  : 1;
    __u32 pvrf  : 1;
    __u32 cpt   : 1;
    __u32 fsavf : 1;
    __u32 cons  : 1;
    __u32 scavf : 1;
    __u32 fsaf  : 1;
    __u32 scnt  : 6;
    __u32 res16 : 16;
 };

like… look at her. all bitfields, all iconic, no notes 💖 (yes, the closing brace has a lil extra space before it in the original — we keep it exactly, periodt)

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💅 Members 💅

ok so here's the bit-by-bit breakdown, and ngl every single one matters:

• res0 — reserved 🫶 (not yours, don't touch)
• auth — authorization check
• pvrf — path-verification-required flag
• cpt — channel-path timeout
• fsavf — failing storage address validity flag
• cons — concurrent sense
• scavf — secondary ccw address validity flag
• fsaf — failing storage address format
• scnt — sense count, but only if cons == 1 👀 (read the room, bestie — it's conditional)
• res16 — reserved, again 💀 (also not yours)

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🔥 SEE ALSO 🔥

go read the whole friend group, they're all linked from Kernel file ./arch/s390/include/asm/cio.h:

• struct ccw1(9)
• struct ccw0(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 ciw(9)
• struct ccw_dev_id(9)
• ccw_dev_id_is_equal(9)
• pathmask_to_pos(9)

like genuinely a whole squad — say hi to all of them for me 🌈

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⭐ and that's the whole vibe check! every field, every flag, every see-also, nothing skipped. iykyk 😌

okay bye bestie, mwah 💜 this little page came to you from ./arch/s390/include/asm, dated October 2026, and it's still out here living its best struct erw(9) life 🦋✨🌸