t4vf_bar2_sge_qregs(9)

📦 version 7.3.1, in nixpkgs unstable

👑 t4vf_bar2_sge_qregs — return BAR2 SGE Queue register information 💅

okay so bestie, welcome to the Kernel API Manual ✨ — yes we're in kernel-land today, and no, it's not scary, i promise 🫶. this one's a little function with a big name: t4vf_bar2_sge_qregs. say it with me. iconic.

🌸 SYNOPSIS 🌸

int t4vf_bar2_sge_qregs (struct adapter *adapter , unsigned int qid ,
enum t4_bar2_qtype qtype , u64 *pbar2_qoffset , unsigned int *pbar2_qid
);

she takes a bunch of stuff and returns an int, that's the whole vibe 🎀

💖 ARGUMENTS 💖

  • adapter — the adapter. yes. that's it. that's the whole description. the adapter. 🦋
  • qid — the Queue ID. lowkey the main character of this whole function ngl.
  • qtype — the Ingress or Egress type for qid. pick your fighter 🌈
  • pbar2_qoffset — the BAR2 Offset of the qid Registers. she gets written into, she's a pointer bestie 💫
  • pbar2_qid — the BAR2 SGE Queue ID, or 0 of qid. two moods fr fr 😭

🔥 DESCRIPTION 🔥

so what does she actually do. buckle up 🎢

Returns the BAR2 SGE Queue Registers information associated with the indicated Absolute Queue ID. all that good stuff gets passed back through the return value pointers — that's literally why pbar2_qoffset and pbar2_qid are pointers, they're the delivery mechanism 🚚✨

qtype should be T4_BAR2_QTYPE_EGRESS for Egress Queue and T4_BAR2_QTYPE_INGRESS for Ingress Queues. no cap, those are the two values, don't get creative 💅

⚠️ heads up bestie: this may return an error which indicates that BAR2 SGE Queue registers aren't available. so like. sometimes she just says no. it's not you, it's the hardware 😭

If an error is not returned, then the following values are returned:

  • If the returned BAR2 Queue ID is 0, then BAR2 SGE registers which require the "Inferred Queue ID" ability may be used. E.g. the Write Combining Doorbell Buffer. 🔔 slay.
  • If the BAR2 Queue ID is not 0, then these "Inferred Queue ID" register may not be used. that's the whole rule. no inferred queue id for you 🙈

so basically: 0 = you get the fancy inferred-queue-id registers, not-0 = you don't. vibe check passed ✅

🦋 SEE ALSO 🦋

Kernel file ./drivers/net/ethernet/chelsio/cxgb4vf/t4vf_hw.c — that's where the source lives btw, go read her 💜

and now the whole friend group, in order, no one gets left out 🫶:

and that's the page bestie 💖✨ go forth and query your BAR2 SGE Queue registers responsibly 🎀

source/version: ./drivers/net/ethernet/chelsio... · dated October 2026 · mwah, bye 🍓

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