PCI_FIND_NEXT_CAP(9)

💅 PCI_FIND_NEXT_CAP(9) — like, the kernel API manual bestie 💖

okay so this is a page from the Kernel API Manual, and we're talking about PCI_FIND_NEXT_CAP — the little macro that goes hunting for a PCI standard capability. no cap, it's lowkey iconic once you get it. let's go 🫶

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✨ NAME ✨

PCI_FIND_NEXT_CAP — bestie's official way to find a PCI standard capability 🎀

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🌸 SYNOPSIS 🌸

PCI_FIND_NEXT_CAP (read_cfg , start , cap , prev_ptr , args... );

literally just call it like that, exactly like that, don't get cute with it 💅

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🦋 ARGUMENTS 🦋

• read_cfg — a function pointer for reading PCI config space. yes, pointer to a function, it's giving callback energy 👑
• start — the starting position where the search begins. where we're picking up the hunt 🔥
• cap — the capability ID you're trying to find. the whole reason we're here 💖
• prev_ptr — a pointer used to store the position of the preceding capability. (optional, so no pressure 😌)
• args — the arguments you pass along to the read_cfg function. hand them over, she'll deal with it 🍓

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💜 DESCRIPTION 💜

so basically she searches the capability list in PCI config space looking for cap. super chill, super focused 🧚

if it's found, she updates *prev_ptr with the position of the preceding capability — but only if prev_ptr != NULL, okay? don't come for her if you passed a null, she checked 🙈

and the best part: it implements TTL (time-to-live) protection against infinite loops. so if the capability list is being a messy little gremlin and looping forever, TTL says "not today bestie" and stops it 💀🔥

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⭐ RETURN ⭐

you get the position of the capability if it's found — and 0 otherwise. that's it, that's the whole vibe check ✅

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🌈 SEE ALSO 🌈

kernel file ./drivers/pci/pci.h, plus the whole friend group:

• PCI_FIND_NEXT_EXT_CAP(9)
• pci_bar_index_is_valid(9)
• pci_id_from_device(9)
• pci_match_one_id(9)
• pci_resource_num(9)
• pci_dev_set_io_state(9)
• struct aer_err_info(9)

and the directory squad: ./drivers/pci 🫶

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that's the whole page, bestie — go find those capabilities, slay, and remember: TTL said no infinite loops in this house 💅✨

signing off from ./drivers/pci, dated October 2026, per the PCI_FIND_NEXT_CAP(9) era of the Kernel API Manual — ily, stay iconic 🎀💖