pt_upper_range(9)

📦 version 7.3.1, in nixpkgs unstable

💅 pt_upper_range — wait, bestie, this is the manual for it

okay so real talk, we're in the Kernel API Manual today and the star of the show is pt_upper_range(9). yes, a whole manpage, for one lil function. she's iconic like that 🎀

✨ NAME ✨

pt_upper_range — returns a range that spans part of the top level. yep, part of it, not the whole thing, depending on how the vibes (okay, the feature flags) are set 🦋

🌸 SYNOPSIS 🌸

struct pt_range pt_upper_range (struct pt_common *common );

that's it. that's the whole call. one argument, returns a struct pt_range, we love a low-maintenance queen 👑

🫶 ARGUMENTS 🫶

  • common — the table. that's the whole description in the original and honestly? respect the brevity. it's the table, bestie, hand it over 💖

💅 DESCRIPTION 💅

okay so here's the tea ☕

for PT_FEAT_SIGN_EXTEND this returns the upper range, and it covers half the total page table. literally half. 50%. a whole 0.5 of the page table, no cap.

otherwise — like, if that feature isn't in the picture — it just returns the entire page table. the whole thing. all of it. main character range energy 👑

so like, tl;dr: sometimes you get half, sometimes you get everything. depends on PT_FEAT_SIGN_EXTEND. check before you assume, iykyk 🤞

🌈 SEE ALSO 🌈

okay this list is long, buckle up bestie, we're going on a tour of the whole pt family 🧚✨

kernel file ./drivers/iommu/generic_pt/pt_iter.h — that's where the magic lives, go read it, she's gorgeous 💜

and then all of these icons:

go click through them like it's a playlist, fr fr 🎧🔥

ngl the entire vibe of this page is "small function, big range energy". go read the neighbours, they explain the ecosystem 💖

okay that's the whole page, we ate and left no crumbs 🍓

she ships out of ./drivers/iommu/generic_pt, dated October 2026 — like, the version stamp is literally part of the lore, periodt 🎀 pt_upper_range(9) forever, mwah 💋

📦 where this page comes from