cik_sdma_emit_copy_buffer(9)

📦 version 7.3.1, in nixpkgs unstable

👑 cik_sdma_emit_copy_buffer(9) — the Kernel API Manual, bestie edition ✨

okay so this is a page out of the Kernel API Manual and honestly? it's giving "small function, big responsibilities" energy. sit down, grab a 🍓, we're learning how the sDMA engine copies buffers 💅

🌸 NAME 🌸

cik_sdma_emit_copy_buffer — copy buffer using the sDMA engine ✨

🦋 SYNOPSIS 🦋

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

like, that's the whole vibe. void return, five args, no drama 🎀

💖 ARGUMENTS 💖

  • ib — the indirect buffer we're copying to. this is the destination of the emit, not the copy, don't get it twisted 🫶
  • src_offset — the src GPU address (where the bytes are coming from) ⭐
  • dst_offset — the dst GPU address (where they're going to) 🌈
  • byte_count — number of bytes to xfer, a uint32_t, so yes the count has a ceiling, no cap 🧢
  • copy_flags — unused. literally unused. it's there, it's invited, it does nothing 🙈

🔥 DESCRIPTION 🔥

so what it does: it copies GPU buffers using the DMA engine (CIK). that's it, that's the whole thing 💀

and who's out here calling it? the amdgpu ttm implementation, to move pages — but only if this thing is registered as the asic copy callback. main character energy, but conditional 👑

ngl if you're reading this expecting extra lore, there isn't any — the original page is short and sweet and we respect that 🎀

🌟 SEE ALSO 🌟

first up, the kernel file it lives in — go read the source, bestie, it's right there:

  • Kernel file ./drivers/gpu/drm/amd/amdgpu/cik_sdma.c

and then the whole friend group 😭💜:

✨ and that's the page!! ✨ this came to you from the source dir ./drivers/gpu/drm/amd/amdgpu, dated October 2026, and it's the cik_sdma_emit_copy_buffer(9) page — go copy some buffers, bestie, you're gonna slay 💅🫶💖

📦 where this page comes from