STRUCT CDX_DEV_PARAMS(9)

📦 version 7.3.1, in nixpkgs unstable

💜 struct cdx_dev_params — CDX device parameters

okay so bestie, welcome to the Kernel API Manual (that's the manpage section 9 vibe, struct cdx_dev_params(9), iykyk) — this is where the kernel keeps the whole little profile of a CDX device. Think of it as the device's main character sheet ✨

🌸 NAME 🌸

struct cdx_dev_params — literally the CDX device parameters, no cap

✨ SYNOPSIS ✨

struct cdx_dev_params {
    struct cdx_controller *cdx;
    struct device *parent;
    u16 vendor;
    u16 device;
    u16 subsys_vendor;
    u16 subsys_device;
    u8 bus_num;
    u8 dev_num;
    struct resource res[MAX_CDX_DEV_RESOURCES];
    u8 res_count;
    u32 req_id;
    u32 class;
    u8 revision;
    u32 msi_dev_id;
    u32 num_msi;
 };

🫶 like, that's the whole struct. copy it exactly, don't be out here freelancing with the fields bestie.

🎀 Members 🎀

  • cdx — the CDX controller this device is associated with 👑 (its ride-or-die)
  • parent — the associated CDX Bus device, the parent it belongs to
  • vendor — the Vendor ID for the CDX device 🏷️
  • device — the Device ID for the CDX device
  • subsys_vendor — the Sub vendor ID for the CDX device (yes, a sub vendor, still iconic)
  • subsys_device — the Sub device ID for the CDX device
  • bus_num — the Bus number for this CDX device 🚌
  • dev_num — the Device number for this device
  • res — an array of MMIO region entries 📚 (it's giving "a whole list of them")
  • res_count — the number of valid MMIO regions 🔢 — so like, how many of those res entries actually count
  • req_id — the Requestor ID associated with the CDX device
  • class — the Class of the CDX Device 🎓 (it's giving very "what kind of device is this")
  • revision — the Revision of the CDX device
  • msi_dev_id — the MSI device ID associated with the CDX device
  • num_msi — the Number of MSI's supported by the device ⚡
heads up bestie: res_count is the one telling you how many of the res entries are actually valid MMIO regions — don't go reading past that, fr fr 🙈

🦋 SEE ALSO 🦋

go read those, they're all in their own lane and they're lowkey obsessed with each other 💅

✨ that's the whole page, periodt ✨ this lives in ./drivers/cdx and the version vibes are dated October 2026 — slay, go write some device code bestie 🎀🦋💖

📦 where this page comes from