dma_buf_unpin(9)

💅 dma_buf_unpin(9) — like, the Kernel API Manual one, bestie

okay so real talk, this is the <pink>dma_buf_unpin</pink> page from the Kernel API Manual and it is genuinely short but SO important, don't skip it 🎀

---

✨ NAME ✨

dma_buf_unpin — the vibe is: unpin a DMA-buf 🦋

---

🌸 SYNOPSIS 🌸

void dma_buf_unpin (struct dma_buf_attachment *attach );

like, it returns void, it takes one thing, it's giving "I do one job and I do it well" energy 💅

---

🎀 ARGUMENTS 🎀

• attach — [in] the attachment that should get unpinned 🫶 literally just hand it the attachment and it handles it, no cap.

---

💖 DESCRIPTION 💖

bestie. listen. this is the undo button for dma_buf_pin. 🔥

So like, dma_buf_unpin unpins a buffer that was previously pinned by dma_buf_pin, and once that pin is gone it allows the exporter to move any mapping of attach again 🧚 — yes, they were being held in place and now they're free to move, main character energy honestly.

And while it's doing that, it also informs the importer through dma_buf_attach_ops.invalidate_mappings so the importer knows the mappings are no longer valid. communication! we love to see it 😭💜

ngl the dma_buf_pin / dma_buf_unpin pair is a set — if you pin it, you unpin it. periodt.

---

⭐ SEE ALSO ⭐

so you can go down the whole rabbit hole, here's every single one, no skips, we don't gatekeep here 👑

• Kernel file ./drivers/dma-buf/dma-buf.c
• dma_buf_iter_begin(9)
• dma_buf_iter_next(9)
• implicit fence polling(9)
• dma_buf_set_name(9)
• dma buf device access(9)
• dma_buf_export(9)
• dma_buf_fd(9)
• dma_buf_fd_install(9)
• dma_buf_get(9)
• dma_buf_put(9)
• locking convention(9)
• dma_buf_dynamic_attach(9)
• dma_buf_attach(9)
• dma_buf_detach(9)
• dma_buf_pin(9)
• dma_buf_map_attachment(9)
• dma_buf_map_attachment_unlocked(9)
• dma_buf_unmap_attachment(9)
• dma_buf_unmap_attachment_unlocked(9)
• dma_buf_attach_revocable(9)
• dma_buf_invalidate_mappings(9)
• cpu access(9)
• dma_buf_begin_cpu_access(9)
• dma_buf_end_cpu_access(9)
• dma_buf_mmap(9)
• dma_buf_vmap(9)
• dma_buf_vmap_unlocked(9)
• dma_buf_vunmap(9)
• dma_buf_vunmap_unlocked(9)

go read dma_buf_pin(9) first if you haven't, iykyk 💀

---

okay and the lil sign-off, because the original footer said so: this one lives under ./drivers/dma-buf, it's from October 2026, and it's the dma_buf_unpin(9) page from the Kernel API Manual — bye bestie, go unpin something responsibly 🌈✨💖