ttm_bo_kmap_try_from_panic(9)

📦 version 7.3.1, in nixpkgs unstable

✨ ttm_bo_kmap_try_from_panic ✨

okay bestie, welcome to the Kernel API Manual entry for ttm_bo_kmap_try_from_panic(9) — yes the name is a mouthful, no I will not be shortening it, we respect her full government name 💅

🎀 NAME 🎀

ttm_bo_kmap_try_from_panic — and that's it, that's the whole name section. The original page gives us literally nothing else here, no cap. Iconic minimalism, honestly. 🦋

⭐ SYNOPSIS ⭐

void * ttm_bo_kmap_try_from_panic (struct ttm_buffer_object *bo ,
unsigned long page );

🌸 ARGUMENTS 🌸

  • bo — the buffer object, aka the whole point of this function, the main character 🫶
  • page — the page that's getting mapped, the lil guy we're here for

🔥 DESCRIPTION 🔥

So what does she actually do? She sets up a kernel virtual mapping using kmap_local_page_try_from_panic. That's the vibe. ✨

⚠️ ok so listen, this one comes with a big rule: this should only be called from the panic handler, and only if you make sure the bo is the one being displayed — so it's properly allocated and protected. Like, that's not a suggestion, that's the whole condition for using this thing. Don't be out here calling it from random places, bestie, I'm begging 😭

She returns the vaddr, which you can use to write to the bo, and which you should pass to kunmap_local when you're done with this page. Or she returns NULL if the bo is in iomem. That's the whole deal 💖

👑 SEE ALSO 👑

Kernel file ./drivers/gpu/drm/ttm/ttm_bo_util.c — go read it, it's giving lore 🧚

And the whole friend group:

and that's the page!! 🎀✨ mwah, love u, go read ur kernel source. this lil masterpiece lives at ./drivers/gpu/drm/ttm and it's stamped October 2026 — yes, girl, mark the calendar 💜🙈

📦 where this page comes from