sg_phys(9)

📦 version 7.3.1, in nixpkgs unstable

💫 sg_phys(9) — the kernel API manual, but make it make sense

okay bestie, so the manual page name is sg_phys and it lives in section 9 of the Kernel API Manual — that's the Linux kernel docs, and yes we're absolutely going to get into it 🎀

✨ NAME ✨

sg_phys — returns the physical address of an sg entry. that's it, that's the whole vibe 🦋

🌸 SYNOPSIS 🌸

dma_addr_t sg_phys (struct scatterlist *sg );

like, you hand it a struct scatterlist * and it hands you back a dma_addr_t. no cap, that's the whole transaction 💅

🎀 ARGUMENTS 🎀

  • sg — the SG entry. literally just the scatterlist entry you're curious about ✨

💖 DESCRIPTION 💖

so what this does is: it calls page_to_phys on the page inside this sg entry, and then it adds the sg offset on top. that's the whole recipe, periodt 🔥

⚠️ okay but listen — the caller must know that it's legal to call page_to_phys on the sg page. like, that's on you, not on this function. pls don't come for sg_phys if you rolled up with an illegal page 😭

🫶 SEE ALSO 🫶

kernel file ./include/linux/scatterlist.h — and also, the entire friend group:

and that's the page, bestie 🧚 this one's from the ./include/linux directory, dated October 2026, and it's filed under sg_phys(9) — go forth and compute physical addresses responsibly 💜🌈⭐

📦 where this page comes from