STRUCT XE_MMIO(9)

💅 struct xe_mmio(9) — like, the register MMIO structure bestie

okay so this is a page from the Kernel API Manual (section 9, the kernel-API girlies know) and honestly? it's giving "here's how the CPU actually talks to the registers." let's get into it 💖

---

✨ NAME ✨

struct xe_mmio — the register mmio structure. that's it, that's the vibe 🎀

---

🌸 SYNOPSIS 🌸

struct xe_mmio {
    struct xe_tile *tile;
    void __iomem *regs;
    struct xe_gt *sriov_vf_gt;
    size_t regs_size;
    u32 adj_limit;
    u32 adj_offset;
 };

like, look at her. six fields. absolutely iconic 🫶

---

🦋 Members 🦋

• tile — backpointer to the tile, and it's literally only there for tracing. lowkey just a "remember where you came from" girly 💫
• regs — the map you use to access registers. that's the whole assignment.
• sriov_vf_gt — backpointer to the GT (the graphics tile, bestie).

ok important caveat: this pointer is only set for GT MMIO regions, and only when running as an SRIOV VF structure. so like, don't count on it being there 🙈

• regs_size — the length of the register region within the map. important distinction!!

so the size of the iomap set in *regs is generally larger than the register mmio space, because it includes unused regions and/or non-register regions such as the GGTT PTEs. she's roomy 💅

• adj_limit — adjust the MMIO address if the address is below this value.
• adj_offset — the offset you add to the MMIO address when you're adjusting. the little + that could ✨

---

🔥 Description 🔥

so what is this thing? it represents an MMIO region that the CPU may use to access registers. main character energy for real 👑

and here's the tea: a region may share its IO map with other regions. for example — all GTs within a tile share the same map with their parent tile, but they represent different subregions of the overall IO space. it's giving "same friend group, different subgenres" 🧚 no cap.

---

🌈 SEE ALSO 🌈

• Kernel file ./drivers/gpu/drm/xe/xe_mmio_types.h
• struct xe_mmio_range(9) — go read her too, iykyk 💜

---

and that's the page, bestie!! this one's from ./drivers/gpu/drm/xe, version date October 2026 — so like, technically from the future, which honestly tracks for this girlie. mwah, slay, periodt 💅✨