amdgpu_mm_wdoorbell64(9)

💅 amdgpu_mm_wdoorbell64 — write a doorbell Qword ✨

Okay bestie, so this one lives in the Kernel API Manual (section 9, kernel space only, no cap), and it's literally the tiny little function that goes ding dong on a doorbell. Let's get into it 🎀

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✨ SYNOPSIS ✨

void amdgpu_mm_wdoorbell64 (struct amdgpu_device *adev , u32 index , u64 v );

That's it. That's the whole vibe. Three args, no return value, she just does the thing 💅

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🎀 ARGUMENTS 🎀

• adev — amdgpu_device pointer 🫶 this is your GPU's whole identity card, like the main character of the story
• index — doorbell index 🔔 which doorbell we're ringing, fr fr
• v — value to write ✍️ the actual 64-bit goodie getting yeeted into the aperture

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🌸 DESCRIPTION 🌸

So basically: this writes v to the doorbell aperture at the requested doorbell index. That's it, that's the plot 🦋

Heads up bestie — this one is VEGA10+ only. Like, if you're on older silicon, this is not your era, periodt 💀

It's giving "small function, big responsibilities" energy, honestly 👑

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🌈 SEE ALSO 🌈

Kernel file: ./drivers/gpu/drm/amd/amdgpu/amdgpu_doorbell_mgr.c — go read her, she's iconic 💖

The whole doorbell friend group, lowkey obsessed with them all:

• amdgpu_mm_rdoorbell(9)
• amdgpu_mm_wdoorbell(9)
• amdgpu_mm_rdoorbell64(9)
• amdgpu_doorbell_index_on_bar(9)
• amdgpu_doorbell_create_kernel_doorbells(9)
• amdgpu_doorbell_init(9)
• amdgpu_doorbell_fini(9)

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Okay that's the whole page, bestie — go ring some doorbells responsibly 🧚

Shoutout to the source, ./drivers/gpu/drm/amd/amdgpu, dated October 2026 — slay, see you in the next manpage 🎀✨💜