STRUCT TB_SERVICE(9)

💖 NAME 💖

struct tb_service — the Thunderbolt service struct, bestie ✨

okay so real quick, this page is straight out of the Kernel API Manual and it's all about struct tb_service in <pink>struct tb_service(9)</pink> — like the little baby struct that represents one Thunderbolt service 🦋 iykyk

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✨ SYNOPSIS ✨

okay don't panic, here's the whole thing, typed out exactly, no cap:

struct tb_service {
    struct device dev;
    int id;
    const char *key;
    u32 prtcid;
    u32 prtcvers;
    u32 prtcrevs;
    u32 prtcstns;
    struct mutex lock;
    struct tb_property_dir *local_properties;
    struct tb_property_dir *remote_properties;
    struct dentry *debugfs_dir;
 };

like, that's the whole vibe check right there 👑

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🌸 Members 🌸

okay so now we go through every single field one by one because we do NOT skip ✨

• dev — the XDomain device 💅
• id — the ID of the service, and yes bestie it's shown in sysfs 🫶
• key — the protocol key, grabbed from the properties directory 🔑
• prtcid — the protocol ID, from the properties directory ✨
• prtcvers — the protocol version, from the properties directory 📖
• prtcrevs — the protocol software revision, from the properties directory 🔁
• prtcstns — the protocol settings mask, from the properties directory 🎀
• lock — protects this structure, like a little bodyguard for the struct 💀
• local_properties — properties owned by the service driver 🏠
• remote_properties — properties read from the remote service, and these are read-only, so don't even think about writing to them 🙈
• debugfs_dir — pointer to the service debugfs directory. it's always created when debugfs is enabled, and service drivers can use it to add their own entries under the service 🦋

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💜 Description 💜

so basically, each domain exposes a set of services it supports as a collection of properties 🌈 and for each service there's gonna be one corresponding struct tb_service. the service drivers get bound to these, that's just how it goes ✨

now, service drivers can add their own dynamic properties to local_properties — slay, go off — but whenever they do so, lock must be held. fr fr, held. every time 🫶 not optional, not negotiable 💅

bestie listen: the lock thing is not a suggestion, ok? if you're touching local_properties you're holding lock. periodt 💀

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🎀 SEE ALSO 🎀

• Kernel file ./include/linux/thunderbolt.h — go read it, it's giving main character energy 👑
• enum tb_security_level(9)
• struct tb(9)
• struct tb_property_dir(9)
• struct tb_property(9)
• enum tb_link_width(9)
• struct tb_xdomain(9)
• struct tb_protocol_handler(9)
• struct tb_service_driver(9)
• struct tb_nhi(9)
• struct tb_ring(9)
• enum ring_desc_flags(9)
• struct ring_frame(9)
• tb_ring_rx(9)
• tb_ring_tx(9)
• tb_ring_dma_device(9)

like, that's a whole friend group of references, and they all ate 💅✨

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and that's the page, bestie 🫶 it lives in ./include/linux, it's tagged October 2026, and if you ever forget what page you're on just remember: struct tb_service(9) 💖 mwah, go hold that lock 💜