unmap_rx_buf(9)

📦 version 7.3.1, in nixpkgs unstable

💖 unmap_rx_buf 💖

okay so bestie, welcome to the Kernel API Manual ✨ — today's main character is unmap_rx_buf(9), and honestly? she's a lil function with a big job. let's get into it 🫶

🌸 NAME 🌸

unmap_rx_buf — unmap the current RX buffer on an SGE Free List 💅

✨ SYNOPSIS ✨

void unmap_rx_buf (struct adapter *adapter , struct sge_fl *fl );

like, that's the whole signature. no cap. 🎀

🦋 ARGUMENTS 🦋

  • adapter — the adapter 👑 (yes that's literally it, she's the whole adapter)
  • fl — the SGE Free List 🌈

💜 DESCRIPTION 💜

okay so here's the tea 🍓: unmap_rx_buf unmaps the current buffer on an SGE Free List RX queue.

⚠️ important warning bestie, do not skip this one: the buffer must be made inaccessible to HW before calling this function. like, that's non-negotiable. hardware is not invited to this party anymore. 💀

ngl this one is similar to free_rx_bufs (mentioned above) — but plot twist: it does not free the buffer. do note, though, that the FL still loses any further access to the buffer. so the FL is officially ghosted 👻, no more access, periodt.

so what's it actually for? it's used predominantly to "transfer ownership" of an FL buffer to another entity — typically an skb's fragment list. it's giving handing over the aux cord 🎧. the buffer moves on to its next era, main character energy, and this function is just the one who set it free. iconic. 🔥

🌟 SEE ALSO 🌟

Kernel file ./drivers/net/ethernet/chelsio/cxgb4vf/sge.c — yes, that's the source file, go look at her 🧚

and now the whole friend group, in order, no one left behind 💖:

✨ and that's the whole page, bestie ✨ this lil doc came from source ./drivers/net/ethernet/chelsio... and it's dated October 2026 — so mark your calendar 🎀 and remember, she's still unmap_rx_buf(9) at the end of the day. mwah 💋 🌸

📦 where this page comes from