ap_apqn_in_m...d_by_def_drv(9)

📦 version 7.3.1, in nixpkgs unstable

💅 NAME 💅

ok so ap_apqn_in_matrix_owned_by_def_drv — bestie, it's a whole mouthful, i know — is literally just a yes/no check: it tells you whether every single APQN in a set is reserved for the host drivers or not. like, all of them. not most. all. ✨

🦋 SYNOPSIS 🦋

int ap_apqn_in_matrix_owned_by_def_drv (unsigned long *apm , unsigned long *aqm );

that's it. two pointers in, one int out. iconic signature, no notes. 💅

🎀 ARGUMENTS 🎀

  • apm — a bitmap that spells out a set of APIDs, and those APIDs are the APQNs you wanna check. like, this is the first half of every APQN in the set, okay? 🫶
  • aqm — a bitmap that spells out a set of APQIs, and those APQIs are the other half of the very same APQNs you're checking. so apm + aqm = the full APQN set, fr fr.

⚠️ NOTE ⚠️

bestie please read this one 😭 — the ap_attr_mutex must be locked by the caller of this function. like, you gotta hold it before you call this. the function is not gonna do it for you. no cap.

👑 RETURN 👑

it hands back an int that tells you whether each APQN is reserved for the host or not:

  • 1 — yep, reserved for the host 💖
  • 0 — nope, not reserved 🙈

🌈 SEE ALSO 🌈

kernel file ./drivers/s390/crypto/ap_bus.c — that's the home base for all of this 🏠

and the whole squad of related functions, in the order the OG page lists them, because i would never do them dirty:

and that's the whole page, bestie, you ate that 🍓 this lil beauty lives in the Kernel API Manual, ships from ./drivers/s390/crypto, and it's dated October 2026 — see you in the next group chat 👑💜

📦 where this page comes from