STRUCT PCI_EPC_AUX_RESOURCE(9)

🌸 struct pci_epc_aux_resource(9) — like, the whole kernel-API-manual moment 💅

okay bestie, buckle up 🎀 this one's from the Kernel API Manual, and it's all about a struct that describes a physical auxiliary resource that somebody might wanna expose for a peer to use. yes, that's the whole vibe. let's get into it ✨

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✨ NAME ✨

struct pci_epc_aux_resource — a physical auxiliary resource that may be exposed for peer use 🫶

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🦋 SYNOPSIS 🦋

struct pci_epc_aux_resource {
    enum pci_epc_aux_resource_type type;
    phys_addr_t phys_addr;
    resource_size_t size;
    enum pci_barno bar;
    resource_size_t bar_offset;
    union {
      struct {
        int irq;
        u32 data;
      } db_mmio;
    } u;
 };

like, that's the literal shape of it, no cap 🔥

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💖 Members 💖

• type — the resource type, gorl. go check enum pci_epc_aux_resource_type if you wanna know the actual flavours 👀
• phys_addr — the physical base address of the resource. the where of it all 📍
• size — how big the resource is, in bytes. yes, bytes, the standard unit of "how much" 🍓
• bar — the BAR number where this resource is already exposed to the RC. and if it's not exposed? it's NO_BAR, bestie 💀
• bar_offset — the offset within bar where the resource actually starts. tiny little caveat tho: this is only valid iff bar != NO_BAR ⚠️ like, don't come for it if bar is NO_BAR, it literally doesn't apply 🙈
• u — type-specific metadata. it's a union, it's giving "depends on the type" main character energy:
  • db_mmio — the db_mmio struct inside the union, holding:
    • int irq — the irq field, an int
    • u32 data — the data field, a u32

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👑 SEE ALSO 👑

the kernel file ./include/linux/pci-epc.h, plus the whole little friend group of related pages:

• struct pci_epc_map(9)
• enum pci_epc_aux_resource_type(9)
• struct pci_epc_ops(9)
• struct pci_epc_mem_window(9)
• struct pci_epc_mem(9)
• struct pci_epc(9)
• enum pci_epc_bar_type(9)
• enum pci_epc_bar_rsvd_region_type(9)
• struct pci_epc_bar_rsvd_region(9)
• struct pci_epc_bar_desc(9)
• struct pci_epc_features(9)

like, that's the whole group chat, go read them all fr fr 📚

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ok that's the page!! mwah 💋 this one lives in ./include/linux and it's dated October 2026 — so yeah, mark your calendars, screenshot it, whatever, and go slay some EPC resources. periodt. 💜✨🌈