amdgpu_mm_rdoorbell(9)

✨ amdgpu_mm_rdoorbell — read a doorbell dword 💅

Okay bestie, so this one is a Kernel API Manual page, and it's literally about reading a doorbell dword — like, the tiniest little peek into the doorbell aperture. So cozy. So demure. Let's get into it 🎀

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🌸 SYNOPSIS 🌸

u32 amdgpu_mm_rdoorbell (struct amdgpu_device *adev , u32 index );

Yeah, that's the whole vibe — you hand it a device and an index, it hands you back a u32. Iconic behavior, no notes ✨

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💖 ARGUMENTS 💖

• adev — an amdgpu_device pointer. It's giving "the whole GPU, in pointer form." You need this one, fr fr 🫶
• index — the doorbell index. Which doorbell are we ringing? This is the number that tells you 👑

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🦋 DESCRIPTION 🦋

So what does it do? It returns the value in the doorbell aperture at the requested doorbell index (CIK). That's it, that's the whole function — pure main character energy, zero extra drama ✨

Lowkey beautiful how a function can just... do its one job. Read the u32. Slay 💅

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⭐ SEE ALSO ⭐

• Kernel file ./drivers/gpu/drm/amd/amdgpu/amdgpu_doorbell_mgr.c — go read the source, iykyk 📖
• amdgpu_mm_wdoorbell(9) — the writing counterpart 👀
• amdgpu_mm_rdoorbell64(9) — same vibe, but 64 🎀
• amdgpu_mm_wdoorbell64(9) — writes, but bigger 🌈
• amdgpu_doorbell_index_on_bar(9) — where the index lives on the BAR
• amdgpu_doorbell_create_kernel_doorbells(9) — making kernel doorbells happen
• amdgpu_doorbell_init(9) — the setup era
• amdgpu_doorbell_fini(9) — the cleanup era, we love a tidy exit 🧹

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🌈 THE CUTE SIGN-OFF 🌈

This little page lives in ./drivers/gpu/drm/amd/amdgpu, it's dated October 2026, and it's part of the Kernel API Manual. Go forth and read those doorbell dwords, bestie — you're gonna eat 💖🔥👑