pbus_select_window_for_type(9)

💅 pbus_select_window_for_type(9) 💅

okay so this is a page from the Kernel API Manual, and the star of the show is pbus_select_window_for_type — one function, one job, and honestly? she serves. 🎀

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✨ NAME ✨

pbus_select_window_for_type — pick a bridge window for a resource type, that's it, that's the whole vibe 🦋

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🌈 SYNOPSIS 🌈

struct resource * pbus_select_window_for_type (struct pci_bus *bus ,
unsigned long type );

like, exactly that, no cap, copy it character for character bestie 💖

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🫶 ARGUMENTS 🫶

• bus — the PCI bus in question, she's the main character here 👑
• type — the resource type. and here's the cute part: resource flags can be passed as is, no translation era needed ✨

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🔥 DESCRIPTION 🔥

so the whole point of her is: select the bridge window based on a resource type. simple. iconic. periodt. 💅

For memory resources, the selection goes down like this — and yes I'm giving you the full rundown because every clause matters:

• Any non-prefetchable resource gets put into the non-prefetchable window. no drama, no debate.
• If there's, like, no prefetchable MMIO window at all? then all memory resources go into the non-prefetchable window. everybody squeezes in together 🫂
• If there is a 64-bit prefetchable MMIO window, then all 64-bit prefetchable resources go into it, and the 32-bit prefetchable memory gets placed into the non-prefetchable window. yes, that's the rule, don't @ me 😭
• Otherwise — like in every other case — all prefetchable resources go into the prefetchable window 🌸

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⭐ RETURN ⭐

she returns the bridge window resource ✨ or NULL if no bridge window is found 😔 (sad girl hours but make it a return value)

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🌈 SEE ALSO 🌈

Kernel file ./drivers/pci/setup-bus.c — and her besties:

• pci_dev_res_add_to_list(9)
• pbus_select_window(9)
• reassign_resources_sorted(9)
• assign_requested_resources_sorted(9)
• pbus_size_io(9)
• pbus_size_mem(9)

iykyk, go read them, they're all linked in the group chat 🔥

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okay that's the whole page bestie!! 💜 this came out of ./drivers/pci and it's dated October 2026 — so like, mark your calendar and stan responsibly 🧚‍♀️🦋💖