p2sb_bar(9)

okay bestie, welcome to p2sb_bar(9), straight from the Kernel API Manual 💖 this little icon gets the Primary to Sideband (P2SB) bridge device BAR, and yes it’s giving very niche-kernel-cute. let’s get into it 🫶

✨ NAME ✨

p2sb_bar — Get Primary to Sideband (P2SB) bridge device BAR 💅

🎀 SYNOPSIS 🎀

int p2sb_bar (struct pci_bus *bus , unsigned int devfn , struct resource
*mem );

💖 ARGUMENTS 💖

• bus — PCI bus to communicate with. this is the bus you’re talking to, bestie.
• devfn — PCI slot and function to communicate with. slot plus function combo, iconic.
• mem — memory resource to be filled in. it gets the fill-in, no cap.

🌈 DESCRIPTION 🌈

If bus is NULL, the bus 0 in domain 0 will be used. no cap, that’s the fallback 💅

If devfn is 0, it will be replaced by devfn of the P2SB device — the device’s own devfn steps in, periodt.

Caller must provide a valid pointer to mem. like, fr fr: valid pointer or don’t come at it 😭 because it’s filling that memory resource in.

🔥 RETURN 🔥

0 on success or appropriate errno value on error. that’s it: 0 = slay, errno = the kernel’s way of saying something went sideways 💀

🦋 SEE ALSO 🦋

• Kernel file ./drivers/platform/x86/p2sb.c — go read the source, iykyk 📖✨

xoxo, from ./drivers/platform/x86, October 2026 — p2sb_bar(9) 💅🎀✨