STRUCT __GUC_MMIO_REG_DESCR(9)

✨ struct __guc_mmio_reg_descr ✨

okay bestie so we're in the Kernel API Manual rn and this page is literally all about struct __guc_mmio_reg_descr — the GuC mmio register descriptor 💅 lowkey iconic, highkey niche, and yes we're gonna get through it together 🫶

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🌸 NAME 🌸

struct __guc_mmio_reg_descr — GuC mmio register descriptor. that's it, that's the name, no notes 💖

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🎀 SYNOPSIS 🎀

struct __guc_mmio_reg_descr {
    struct xe_reg reg;
    enum capture_register_data_type data_type;
    u32 flags;
    u32 mask;
    u32 dss_id;
    const char *regname;
 };

like look at that little guy. six members. baby struct. we love to see it 💜

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🦋 Members 🦋

okay so let's do a vibe check on every single field, no skipping, periodt:

• reg — the register. that's the whole job. it's the register 🎀
• data_type — data type of the register. could be 32 bit, low or hi dword of a 64 bit, see enum capture_register_data_type. so many possibilities, so little time 😭
• flags — Flags for the register. capital F Flags. respect 🫶
• mask — The mask to apply. apply it. slay 💅
• dss_id — Cached index for steered registers ✨ (it's cached, it's steered, it's doing its thing)
• regname — Name of the register. it has a name!! main character energy fr fr 👑

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🌈 Description 🌈

so here's the tea: the xe_guc_capture module uses these structures to define a register (offsets, names, flags,...) — and not just for decoration, bestie. these definitions get used at the ADS registration time as well as during runtime processing and reporting of error-capture states generated by GuC just prior to engine reset events 🔥

so like… GuC generates error-capture states right before engine resets, and these structs are how the module knows what the heck it's looking at. offsets, names, flags, the whole fit. genuinely obsessed with how much work a tiny struct does ngl 💀

notice the ... in "(offsets, names, flags,...)" — that's from the original, it's not me being lazy, i promise 😭

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🧚 SEE ALSO 🧚

• Kernel file ./drivers/gpu/drm/xe/xe_guc_capture_types.h
• struct __guc_mmio_reg_descr_group(9)

go read those next, bestie, iykyk 💖

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and that's the whole page!! source/version is ./drivers/gpu/drm/xe, dated October 2026, and it's all about struct __guc_mmio_reg_descr(9) — love that for us, bye bestie 🌸🦋💜