sdma_v4_4_2_..._copy_buffer(9)

📦 version 7.3.1, in nixpkgs unstable

💅 sdma_v4_4_2_emit_copy_buffer 💅

okay so this is a page from the Kernel API Manual bestie, and it's all about sdma_v4_4_2_emit_copy_buffer — say that five times fast, i literally can't 😭

✨ NAME ✨

sdma_v4_4_2_emit_copy_buffer — copy buffer using the sDMA engine 🫶

🌸 SYNOPSIS 🌸

void sdma_v4_4_2_emit_copy_buffer (struct amdgpu_ib *ib , uint64_t
src_offset , uint64_t dst_offset , uint32_t byte_count , uint32_t
copy_flags );

like, yes, that's the whole signature, no cap 💀

🎀 ARGUMENTS 🎀

  • ib — indirect buffer to copy to. this is the destination of the command, not the data, before u get confused bestie 💖
  • src_offset — src GPU address 👑
  • dst_offset — dst GPU address 👑
  • byte_count — number of bytes to xfer. yes "xfer", that's what it says, i don't make the rules 🦋
  • copy_flags — copy flags for the buffers ✨

🧚 DESCRIPTION 🧚

so what does it do? it copies GPU buffers using the DMA engine, literally that's it, main character energy 🔥

and like, the important lore: it's used by the amdgpu ttm implementation to move pages if it's registered as the asic copy callback. that "if" is doing so much work, pay attention to it 🙈

🌈 SEE ALSO 🌈

the kernel file lives at ./drivers/gpu/drm/amd/amdgpu/sdma_v4_4_2.c — go read it iykwim 💅

and here's the whole friend group, all of them, every single one, i'm not skipping anybody 🫶:

💀 ok real talk: hierarchy is sdma_v4_4_2 → emit_copy_buffer, everything else is a sibling. keep them straight and ur fine ✨

and that's the page bestie, mwah 🎀 this came out of ./drivers/gpu/drm/amd/amdgpu, dated October 2026, and yes it's giving "kernel docs meet group chat" — slay, periodt, go move some pages 💜🦋

📦 where this page comes from