amdgpu_dma_...n_cpu_access(9)

💅 amdgpu_dma_...n_cpu_access(9) — like, the Kernel API Manual era 🎀

okay so bestie, welcome to the Kernel API Manual, and today's main character is amdgpu_dma_...n_cpu_access(9). yes the title is abbreviated with ellipsis, no that's not a typo, that's just how the man page do. let's get into it ✨

---

🌸 NAME 🌸

amdgpu_dma_buf_begin_cpu_access — literally the implementation of &dma_buf_ops.begin_cpu_access. that's it, that's the vibe. it's giving "I'm the callback behind the callback" energy 💅

---

🦋 SYNOPSIS 🦋

int amdgpu_dma_buf_begin_cpu_access (struct dma_buf *dma_buf , enum
       dma_data_direction direction );

like, that's the whole signature. int in, int out, two args, slay. 🔥

---

💖 ARGUMENTS 💖

• dma_buf — a shared DMA buffer. the buffer in question. the shared one. you know the one 🫶
• direction — the direction of the DMA transfer. which way is the data going, bestie? this tells you 🧭

---

✨ DESCRIPTION ✨

so this one gets called before CPU access to the shared DMA buffer's memory — like a little heads-up text before you show up 💌

and here's the cute part: if it's a read access, the buffer gets moved to the GTT domain if possible, because that's for optimal CPU read performance 👑 lowkey a glow-up for your read speeds, ngl.

note: it's if possible — the man page says so, so we say so. no cap.

---

🌈 RETURN 🌈

• 0 on success 🎉
• a negative error code on failure 😭

---

🎀 SEE ALSO 🎀

kernel file: ./drivers/gpu/drm/amd/amdgpu/amdgpu_dma_buf.c

and the whole friend group, in order, because we don't skip anyone in this house:

• PRIME Buffer Sharing(9)
• dma_buf_attach_adev(9)
• amdgpu_dma_buf_attach(9)
• amdgpu_dma_buf_detach(9)
• amdgpu_dma_buf_pin(9)
• amdgpu_dma_buf_unpin(9)
• amdgpu_dma_buf_map(9)
• amdgpu_dma_buf_unmap(9)
• amdgpu_gem_prime_export(9)
• amdgpu_dma_buf_create_obj(9)
• amdgpu_dma_buf_move_notify(9)
• amdgpu_gem_prime_import(9)
• amdgpu_dmabuf_is_xgmi_accessible(9)

like, the entire squad. obsessed. 💜

---

mwah 💋 that's the page! brought to you by the fine folks at ./drivers/gpu/drm/amd/amdgpu, stamped October 2026, and yeah we're still on amdgpu_dma_...n_cpu_access(9) — the ellipsis is forever iconic, periodt. 🍓