STRUCT DMA_BUF_ATTACHMENT(9)

💅 struct dma_buf_attachment(9)

okay so bestie, welcome to the Kernel API Manual — yes, the real one, the one that lives in the kernel docs. we're talking about struct dma_buf_attachment today and honestly? she's kind of the main character of buffer sharing. let's get into it 🫶

---

✨ NAME ✨

struct dma_buf_attachment — holds device-buffer attachment data. that's it, that's the whole vibe: it's the little struct that keeps track of who's attached to the buffer 💖

---

🌸 SYNOPSIS 🌸

struct dma_buf_attachment {
    struct dma_buf *dmabuf;
    struct device *dev;
    struct list_head node;
    bool peer2peer;
    const struct dma_buf_attach_ops *importer_ops;
    void *importer_priv;
    void *priv;
 };

copy that exactly, no cap, character for character 👑

---

🎀 Members 🎀

okay the field-by-field breakdown, because every single one of these matters:

• dmabuf — the buffer for this attachment. the actual star of the show 🦋
• dev — the device that's attached to the buffer. hi bestie, welcome to the party 🌈
• node — the list of dma_buf_attachment, and it's protected by the dma_resv lock of the dmabuf. do not touch it without that lock, i'm literally begging 🙈
• peer2peer — true if the importer can handle peer resources without pages. fancy. iconic. love that for her ⭐
• importer_ops — importer operations for this attachment. and lowkey important: if provided, dma_buf_map/unmap_attachment must be called with the dma_resv lock held. don't skip that part, i'm serious 😭
• importer_priv — importer specific attachment data. hers, not yours 💅
• priv — exporter specific attachment data. the other side's stash 🍓

---

🔥 Description 🔥

so like, what does she actually do? this structure holds the attachment information between the dma_buf buffer and its user device(s). the list contains one attachment struct per device attached to the buffer. one per device, periodt.

an attachment is created by calling dma_buf_attach, and released again by calling dma_buf_detach. that's the whole lifecycle, very demure of her ✨

and the DMA mapping itself — the thing you actually need to initiate a transfer — is created by dma_buf_map_attachment and freed again by calling dma_buf_unmap_attachment. map it, transfer, unmap it. the trinity. iykyk 🧚

---

💜 SEE ALSO 💜

go read these next, bestie, they're all in the kernel file ./include/linux/dma-buf.h:

• struct dma_buf_ops(9)
• struct dma_buf(9)
• struct dma_buf_attach_ops(9)
• struct dma_buf_export_info(9)
• DEFINE_DMA_BUF_EXPORT_INFO(9)
• get_dma_buf(9)
• dma_buf_is_dynamic(9)

---

🫶 and that's the whole page! sourced straight from ./include/linux, dated October 2026, for struct dma_buf_attachment(9). slay, go attach some buffers responsibly 💖