i915_gem_mmap_offset_ioctl(9)

💖 NAME 💖

okay so bestie, welcome to i915_gem_mmap_offset_ioctl(9) from the Kernel API Manual — this function’s whole name and vibe is prepare an object for GTT mmap'ing. 🎀 that’s it, that’s the plot, and honestly it’s giving “small but crucial little helper.” 💅

✨ SYNOPSIS ✨

the signature, exactly as it appears, no edits:

int i915_gem_mmap_offset_ioctl (struct drm_device *dev , void *data ,
       struct drm_file *file );

🫶 ARGUMENTS 🫶

• dev — DRM device. the DRM device, bestie. 💖
• data — GTT mapping ioctl data. yes, the data for the GTT mapping ioctl. ✨
• file — GEM object info. the GEM object info, periodt. 🎀

🌸 DESCRIPTION 🌸

so what does it do? it simply returns the fake offset to userspace so it can mmap it. lowkey iconic, highkey straightforward. 💖

the mmap call will end up in drm_gem_mmap, which will set things up so we can get faults in the handler above. 🌀

the fault handler will take care of:

• binding the object into the GTT (since it may have been evicted to make room for something),
• allocating a fence register,
• and mapping the appropriate aperture address into userspace.

it’s giving “bind, allocate, map” main character energy, and we love that for it. 👑✨

🦋 SEE ALSO 🦋

• Kernel file ./drivers/gpu/drm/i915/gem/i915_gem_mman.c — that’s the kernel file the page points at, bestie. 🫶
• i915_gem_mmap_ioctl(9) — see also, iykyk. 💜
• i915_gem_mmap_gtt_version(9) — also see-also, no cap. 🦋

and that’s the page, bestie! 💖 this one’s source/version footer points at ./drivers/gpu/drm/i915/gem, it’s dated October 2026, and it’s living its best life in the Kernel API Manual. go forth and mmap something cute, mwah 💋✨