STRUCT TSB(9)

✨ NAME ✨

okay so welcome to the Kernel API Manual, bestie 💖 — this page is all about struct tsb, aka the Transport-Status Block (TSB). it's giving lowkey iconic kernel struct energy, fr fr 🎀

🌸 SYNOPSIS 🌸

here's the whole shape of it, exactly as it appears — no cap, don't let the formatting jump-scare you:

       struct tsb {
           u32 length:8;
           u32 flags:8;
           u32 dcw_offset:16;
           u32 count;
           u32 :32;
           union {
             struct tsa_iostat iostat;
             struct tsa_ddpc ddpc;
             struct tsa_intrg intrg;
           } tsa;
        };

🎀 Members 🎀

• length — Length. that's the whole vibe for this one 💅
• flags — Flags, bestie. Can be an arithmetic OR of the following constants: TSB_FLAGS_DCW_OFFSET_VALID, TSB_FLAGS_COUNT_VALID, TSB_FLAGS_CACHE_MISS, TSB_FLAGS_TIME_VALID. yes, all four — collect them like little kernel stickers 🌈
• dcw_offset — DCW Offset. slay ✨
• count — Count. iconic, honestly 👑
• tsa — Transport-Status-Area. main character union energy 🦋

🦋 SEE ALSO 🦋

Kernel file ./arch/s390/include/asm/fcx.h — go peek, iykyk 👀

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

mwah 💋 this lil page lives under ./arch/s390/include/asm and is dated October 2026 — periodt, that's the sign-off bestie 🫶