ccio_unmap_sg(9)

📦 version 7.3.1, in nixpkgs unstable

💅 ccio_unmap_sg — like, the un-mapping one, bestie

okay so real talk, this is page ccio_unmap_sg(9) from the Kernel API Manual, and if you're here it's because something got mapped into the IOMMU and now it's gotta come back out. we love a cleanup era. ✨

🎀 NAME 🎀

ccio_unmap_sg — unmap the scatter/gather list from the IOMMU. that's the whole vibe. in goes a list, out goes the mapping. periodt.

🦋 SYNOPSIS 🦋

void  ccio_unmap_sg (struct device *dev , struct scatterlist *sglist ,
int nents , enum dma_data_direction direction , unsigned long attrs );

literally just those five things and you're done. no cap. 💅

🌸 ARGUMENTS 🌸

okay let's meet the cast 🫶

  • dev — the PCI device. the main character, honestly. it's the one whose stuff is getting unmapped.
  • sglist — the scatter/gather list that's getting unmapped from the IOMMU. this is the list. the actual list. hold it gently.
  • nents — the number of entries in the scatter/gather list. a count. a whole number. don't lie to it. 😭
  • direction — the direction of the DMA transaction (to/from device). iykyk.
  • attrs — attributes. yes that's it. that's the description. attributes. 🙈

🧚 DESCRIPTION 🧚

so what does it do? this function implements the pci_unmap_sg function. that's it. that's the tea. ☕

like, it's the pci_unmap_sg implementation for this bad boy right here, and honestly? iconic. it shows up, it unmaps, it leaves. no notes. ✨

👑 SEE ALSO 👑

bestie you are NOT ready for this reading list, it's giving syllabus day 📚💀

kernel file ./drivers/parisc/ccio-dma.c, plus the whole friend group:

🍓 friendly reminder that ccio_map_sg(9) is right there in the list — the mapping one — so if you're reading the *un*mapping page you probably already know each other. slay.

and that's the page!! this gem lives in ./drivers/parisc, dated October 2026, and it's brought to you by the Kernel API Manual (section 9). go unmap something, bestie. mwah 💖🧚‍♀️

📦 where this page comes from