pci_resize_resource(9)

💅 pci_resize_resource(9) — the kernel API manual, but make it cute ✨

okay so bestie, welcome to the glow-up era of pci_resize_resource(9) — this is the page from the Kernel API Manual and it's literally about reconfiguring a Resizable BAR and its resources. no cap, it's giving main character energy for your PCI device 🎀

---

✨ SYNOPSIS ✨

int pci_resize_resource (struct pci_dev *dev , int resno , int size ,
       int exclude_bars );

like, that's the whole vibe. one function, four args, let's go 🫶

---

🌸 ARGUMENTS 🌸

• dev — the PCI device 💖 the actual star of the show.
• resno — index of the BAR to be resized ✨ pick your fighter.
• size — new size as defined in the spec (0=1MB, 31=128TB) 📏 iconic range honestly, from smol to absolutely massive.
• exclude_bars — a mask of BARs that should not be released 🙈 hands off these ones.

---

🦋 DESCRIPTION 🦋

So here's the tea: this reconfigures resno to size and re-runs the resource assignment algorithm with the new size. it's giving "makeover montage" 🔥

Prior to resize, release dev resources that share a bridge window with resno. this unpins the bridge window resource to allow changing it — lowkey necessary, you gotta let it breathe 💅

The caller may prevent releasing a particular BAR by providing exclude_bars mask, but this may result in the resize operation failing due to insufficient space. 😭 so yeah, protect a BAR and you might run out of room. choices were made.

---

⭐ RETURN ⭐

0 on success, or negative on error 🎀 and ngl, in case of an error, the resources are restored to their original places — so it puts everything back where it found it, we love a clean exit ✨

---

👑 SEE ALSO 👑

Kernel file ./drivers/pci/rebar.c plus the whole rebar bestie squad:

• pci_rebar_bytes_to_size(9)
• pci_rebar_size_to_bytes(9)
• pci_rebar_find_pos(9)
• pci_rebar_get_possible_sizes(9)
• pci_rebar_size_supported(9)
• pci_rebar_get_max_size(9)
• pci_rebar_get_current_size(9)
• pci_rebar_set_size(9)

---

and that's the whole page, bestie 🌈✨ this iconic little manual lives in ./drivers/pci, dated October 2026 — mwah, 10/10, no notes 💋🎀🧚💜