STRUCT PCI_EPF_HEADER(9)

💖 struct pci_epf_header(9) — the Kernel API Manual, but make it make sense

okay so bestie, this is the manpage for struct pci_epf_header(9) — it literally represents the standard configuration header. That's the whole vibe. It's the glow-up config block that tells everyone who your PCI endpoint function is and what it does 💅

✨ SYNOPSIS ✨

here's the whole struct, copy it exactly, no autocomplete crimes:

struct pci_epf_header {
    u16 vendorid;
    u16 deviceid;
    u8 revid;
    u8 progif_code;
    u8 subclass_code;
    u8 baseclass_code;
    u8 cache_line_size;
    u16 subsys_vendor_id;
    u16 subsys_id;
    enum pci_interrupt_pin interrupt_pin;
 };

🎀 Members 🎀

bestie, go member by member with me, this is the whole syllabus:

• vendorid — identifies the device manufacturer 🏭 like whose house is this
• deviceid — identifies a particular device 👑 the specific main character
• revid — specifies a device-specific revision identifier 🔄 the "v2 actually fixed it" energy
• progif_code — identifies a specific register-level programming interface 🧚 very specific, very demure
• subclass_code — identifies more specifically the function of the device 🔍 zooming in on the job description
• baseclass_code — broadly classifies the type of function the device performs 🌈 the big-picture category
• cache_line_size — specifies the system cacheline size in units of DWORDs 📏 yes, in units of DWORDs, that's the unit, don't @ me
• subsys_side — wait no 😭 it's subsys_vendor_id — vendor of the add-in card or subsystem 💳 the card's own plug
• subsys_id — ID specific to vendor 🍓 pairs with the one above, they're giving duo
• interrupt_pin — interrupt pin the device (or device function) uses ⚡ which pin is doing the knocking

ngl the field names are load-bearing — copy them exactly, character for character, or the vibe check fails 🫶

🔥 SEE ALSO 🔥

all my fave linked structs, in one place, iykyk:

• Kernel file ./include/linux/pci-epf.h
• struct pci_epf_ops(9)
• struct pci_epc_event_ops(9)
• struct pci_epf_driver(9)
• struct pci_epf_bar_submap(9)
• struct pci_epf_bar(9)
• struct pci_epf_doorbell_msg(9)
• struct pci_epf(9)
• struct pci_epf_msix_tbl(9)

okay that's the whole page, no cap, every member accounted for 💀💅 and this iconic little drop comes from ./include/linux, dated October 2026, shipping under the Kernel API Manual banner — slay, periodt, go read the source 💖✨🦋