STRUCT TM_SCSW(9)

📦 version 7.3.1, in nixpkgs unstable

okay so you've wandered into the Kernel API Manual, and the page you're on is struct tm_scsw(9) — transport-mode subchannel status word 💅 buckle up bestie, it's s390 and it's iconic.

✨ NAME ✨

struct tm_scsw — the transport-mode subchannel status word, aka the glow-up status report for a transport-mode subchannel 🦋

🌸 SYNOPSIS 🌸

like, the whole struct, exactly as it lives, no edits:

struct tm_scsw {
    u32 key:4;
    u32 :1;
    u32 eswf:1;
    u32 cc:2;
    u32 fmt:3;
    u32 x:1;
    u32 q:1;
    u32 :1;
    u32 ectl:1;
    u32 pno:1;
    u32 :1;
    u32 fctl:3;
    u32 actl:7;
    u32 stctl:5;
    dma32_t tcw;
    u32 dstat:8;
    u32 cstat:8;
    u32 fcxs:8;
    u32 ifob:1;
    u32 sesq:7;
 };
yeah there are unnamed u32 :1; gaps hanging out in there — they're part of the struct, so just let them vibe, okay? don't touch.

🎀 Members 🎀

the bitfields, one by one, main-character energy each:

  • key — the subchannel key 🔑
  • eswf — esw format
  • cc — deferred condition code
  • fmt — format
  • x — IRB-format control
  • q — interrogate-complete
  • ectl — extended control
  • pno — path not operational
  • fctl — function control
  • actl — activity control
  • stctl — status control
  • tcw — TCW address
  • dstat — device status
  • cstat — subchannel status
  • fcxs — FCX status
ngl, ifob and sesq are literally right there in the struct and this page doesn't describe them under Members. so we're not gonna make up lore for them. iykyk 🫶

👑 SEE ALSO 👑

the whole friend group, in order, fr fr:

Kernel file ./arch/s390/include/asm/scsw.h — then: struct cmd_scsw(9), struct eadm_scsw(9), union scsw(9), scsw_is_tm(9), scsw_key(9), scsw_eswf(9), scsw_cc(9), scsw_ectl(9), scsw_pno(9), scsw_fctl(9), scsw_actl(9), scsw_stctl(9), scsw_dstat(9), scsw_cstat(9), scsw_cmd_is_valid_key(9), scsw_cmd_is_valid_sctl(9), scsw_cmd_is_valid_eswf(9), scsw_cmd_is_valid_cc(9), scsw_cmd_is_valid_fmt(9), scsw_cmd_is_valid_pfch(9), scsw_cmd_is_valid_isic(9), scsw_cmd_is_valid_alcc(9), scsw_cmd_is_valid_ssi(9), scsw_cmd_is_valid_zcc(9), scsw_cmd_is_valid_ectl(9), scsw_cmd_is_valid_pno(9), scsw_cmd_is_valid_fctl(9), scsw_cmd_is_valid_actl(9), scsw_cmd_is_valid_stctl(9), scsw_cmd_is_valid_dstat(9), scsw_cmd_is_valid_cstat(9), scsw_tm_is_valid_key(9), scsw_tm_is_valid_eswf(9), scsw_tm_is_valid_cc(9), scsw_tm_is_valid_fmt(9), scsw_tm_is_valid_x(9), scsw_tm_is_valid_q(9), scsw_tm_is_valid_ectl(9), scsw_tm_is_valid_pno(9), scsw_tm_is_valid_fctl(9), scsw_tm_is_valid_actl(9), scsw_tm_is_valid_stctl(9), scsw_tm_is_valid_dstat(9), scsw_tm_is_valid_cstat(9), scsw_tm_is_valid_fcxs(9), scsw_tm_is_valid_schxs(9), scsw_is_valid_actl(9), scsw_is_valid_cc(9), scsw_is_valid_cstat(9), scsw_is_valid_dstat(9), scsw_is_valid_ectl(9), scsw_is_valid_eswf(9), scsw_is_valid_fctl(9), scsw_is_valid_key(9), scsw_is_valid_pno(9), scsw_is_valid_stctl(9), scsw_cmd_is_solicited(9), scsw_tm_is_solicited(9), scsw_is_solicited(9).

and that's the page, bestie ✨ it ships out of ./arch/s390/include/asm and it's dated October 2026 — so it's giving future classic, highkey. go read the friends, stay hydrated, slay 💖🦋🎀

📦 where this page comes from