pci_epf_align_inbound_addr(9)

📦 version 7.3.1, in nixpkgs unstable

✨ pci_epf_align_inbound_addr ✨

okay so bestie, this is a page from the Kernel API Manual — it's pci_epf_align_inbound_addr(9) and it's genuinely one of those little helper functions that just does its job and slays. let's get into it 💅

🌸 NAME 🌸

pci_epf_align_inbound_addr — aligns the address you hand it so it actually matches the BAR alignment requirement, no cap 🎀

🦋 SYNOPSIS 🦋

int pci_epf_align_inbound_addr (struct pci_epf *epf , enum pci_barno bar
, u64 addr , dma_addr_t *base , size_t *off );

like, five args, one int back. she's compact. she's iconic. 🫶

💖 ARGUMENTS 💖

  • epf — the EPF device itself, the main character here 👑
  • bar — the BAR number that goes with the addr you're passing in
  • addr — the inbound address that's about to get aligned, glow-up incoming ✨
  • base — out-param: gets the base address that matches the bar alignment requirement
  • off — out-param: gets the offset you need to add to that base address

🌈 DESCRIPTION 🌈

so this is a helper function that aligns the input addr based on the BAR's alignment requirement. that's literally it, and that's the vibe 💜

the aligned base address and the offset both come back out through base and off — so you don't return them, you hand her the pointers and she fills them in. lowkey elegant.

⭐ NOTE ⭐

ngl, important one: pci_epf_alloc_space already accounts for alignment. so don't come for this function thinking it's for memory you got from there 🙈

this API is primarily intended for use with other memory regions not allocated by pci_epf_alloc_space — like peripheral register spaces, or the message address of a platform MSI controller. iykyk 🧚

🍓 RETURN 🍓

0 on success, errno otherwise. that's the whole story bestie 💀

🔥 SEE ALSO 🔥

kernel file ./drivers/pci/endpoint/pci-epf-core.c, plus the whole friend group:

and that's the page!! 🎀 this one lives over in ./drivers/pci/endpoint, dated October 2026, and it's filed under pci_epf_align_inbound_addr(9) — go off, alignment function, periodt 💅✨

📦 where this page comes from