STRUCT TCCB_TCAH(9)

💅 struct tccb_tcah(9) — like, the whole kernel API manual vibe, bestie

okay so real talk, this page lives in the Kernel API Manual and it's about one very specific little struct. no cap, it's niche, but it's iconic niche. 🎀

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✨ NAME ✨

struct tccb_tcah — the Transport-Command-Area Header, aka TCAH for the girlies who don't have time to spell it out 💅

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🌸 SYNOPSIS 🌸

here's the whole look, character for character, do not touch:

struct tccb_tcah {
    u32 format:8;
    u32 :24;
    u32 :24;
    u32 tcal:8;
    u32 sac:16;
    u32 :8;
    u32 prio:8;
    u32 :32;
 };

like yes bestie those unnamed :24, :24, :8 and :32 bitfields are just there breathing, they're padding, they're vibing, they have no name and honestly? main character energy of not needing one. 🦋

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👑 Members 👑

k so member by member, here's the tea:

• format — the Format field. it should be TCCB_FORMAT_DEFAULT. that's the default, that's the vibe, don't be weird about it. ✨
• tcal — Transport-Command-Area Length. literally how long the Transport-Command-Area is. that's it, that's the field. 📏
• sac — Service-Action Code. it can be one of TCCB_SAC_DEFAULT or TCCB_SAC_INTRG. two options, pick your fighter. 🫶
• prio — Priority. the priority. the importance level. the "notice me" factor. 🔥

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🔍 SEE ALSO 🔍

go look at the kernel file ./arch/s390/include/asm/fcx.h (iykyk 💜), plus these absolute legends:

• struct tcw(9)
• struct tidaw(9)
• struct tsa_iostat(9)
• struct tsa_intrg(9)
• struct tsb(9)
• struct dcw_intrg_data(9)
• struct dcw(9)
• struct tccb_tcat(9)
• struct tccb(9)

like a whole friend group of structs fr fr 🌈

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ngl this page is short but she ate. every field accounted for, no crumbs left. 🍓

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and that's a wrap, bestie!! shoutout to ./arch/s390/include/asm for housing all this, dated October 2026, and it's still struct tccb_tcah(9) at the end of the day — periodt. 💖🧚⭐