remap_io_sg(9)

💅 remap_io_sg(9) 💅

okay bestie, this is the Kernel API Manual page for remap_io_sg(9), and it is lowkey iconic. It's giving remap an IO mapping to userspace energy, with six arguments and one very real safety note. Let's go, no cap. 🫶✨

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🌸 NAME 🌸

remap_io_sg — remap an IO mapping to userspace. That's the whole main character moment: IO mapping gets remapped to userspace. Slay. 💅

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🦋 SYNOPSIS 🦋

int remap_io_sg (struct vm_area_struct *vma , unsigned long addr ,
       unsigned long size , struct scatterlist *sgl , unsigned long offset ,
       resource_size_t iobase );

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💖 ARGUMENTS 💖

Six args, bestie. Every single one is important, so no skipping the vibe check:

• vma — user vma to map to. That's the user vma you're mapping to, periodt. 💜
• addr — target user address to start at. The target user address where the map starts. 🎯
• size — size of map area. Literally the size of the map area. 📏
• sgl — Start sg entry: the sg entry where the journey starts. 🧺
• offset — offset from the start of the page. Just the offset from the start of the page, bestie. 📐
• iobase — Use stored dma address offset by this address or pfn if -1. That's the rule, fr fr. 🧚

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🚨 NOTE 🚨

this is only safe if the mm semaphore is held when called. Like, only safe, bestie. Hold the mm semaphore when you call this — the note is literally the safety rule. 😭 No cap.

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👀 SEE ALSO 👀

• Kernel file ./drivers/gpu/drm/i915/i915_mm.c
• remap_io_mapping(9)

iykyk, go peek at those if you need the sister pages. 🦋

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made with 💖 from ./drivers/gpu/drm/i915, dated October 2026 — cute sign-off, bye bestie! 🎀🌷