free_dma_buffer(9)

📦 version 7.3.1, in nixpkgs unstable

💅 free_dma_buffer(9) — a Kernel API Manual moment

okay bestie, welcome to the free_dma_buffer(9) glow-up page ✨ this one's from the Kernel API Manual, and it's literally the cleanup arc of the DMA buffer saga 🧹🎀

✨ NAME ✨

free_dma_buffer — Free DMA Buffer. that's it, that's the whole vibe. it frees. the buffer. periodt 💅

🦋 SYNOPSIS 🦋

void free_dma_buffer (struct vio_dev *vdev , size_t size , void *vaddr ,
dma_addr_t dma_handle );

no cap, that's the whole signature — void return, four args, she's not giving you anything back except freed memory 🌸

🎀 ARGUMENTS 🎀

  • vdev — a vio_dev struct. yes that's literally all the original says, she's mysterious like that 🙈
  • size — the "Size field". iconic label, no notes.
  • vaddr — the "Address field". also iconic, also no notes.
  • dma_handle — the "DMA address field". the third field bestie, we love a consistent naming scheme 💀

🔥 DESCRIPTION 🔥

so what does she actually do? two things, and they're both important:

  • releases memory for a command queue 🫶
  • unmaps mapped remote memory 🌈

that's it. that's the tea. she's the undo button for alloc_dma_buffer(9) and she ate 👑

⭐ SEE ALSO ⭐

okay this list is LONG and we are NOT skipping a single one of them, iykyk. also hi 👋 the kernel file is ./drivers/misc/ibmvmc.c:

like, go read them. all of them. main character energy only 💜

ngl bestie, that's the whole page — short, sweet, and fully free'd 🍓

and that's a wrap! 🧚 this lil page lives in ./drivers/misc, dated October 2026, and it's the free_dma_buffer(9) page — so long, farewell, your buffer has been released 💖✨

📦 where this page comes from