acpi_pptt_walk_cache(9)

📦 version 7.3.1, in nixpkgs unstable

💅 acpi_pptt_walk_cache — Kernel API Manual, section 9 🎀

okay so bestie, this page is acpi_pptt_walk_cache(9) and it's literally about digging through the PPTT table until you find the exact cache level you're looking for. it's giving "detective but make it firmware" 🔍✨ no cap.

✨ NAME ✨

acpi_pptt_walk_cache — attempt to find the requested acpi_pptt_cache, that's it, that's the whole vibe 🫶

🦋 SYNOPSIS 🦋

unsigned int acpi_pptt_walk_cache (struct acpi_table_header *table_hdr ,
unsigned int local_level , unsigned int *split_levels , struct
acpi_subtable_header *res , struct acpi_pptt_cache **found , unsigned
int level , int type );

look at all those parameters, main character energy fr fr 👑

🌸 ARGUMENTS 🌸

  • table_hdr — pointer to the head of the PPTT table. like, the very top, the entrance, the VIP door 🚪
  • local_level — the res you passed in reflects this cache level. so it's telling you where you already are, bestie 📍
  • split_levels — number of split cache levels (data/instruction). so like, when the caches get divided by vibe 🍓
  • res — the cache resource in the PPTT we want to walk. our little starting point 🧚
  • found — returns a pointer to the requested level if it's found. emphasis on if, hun 💅
  • level — the requested cache level. the one we're hunting for 🔥
  • type — the requested cache type. gotta match, no substitutes 👑
  • level and type together are the whole personality test, honestly 😭

💜 DESCRIPTION 💜

attempt to find a given cache level, while counting the max number of cache levels for the cache node. two jobs, one function, she's multitasking, we love to see it ✨

given a ppdt resource — okay so given a pptt resource — verify that it is a cache node first (vibe check ✅), then walk down each level of caches, counting how many levels are found as well as checking the cache type (icache, dcache, unified). if a level & type match, then we set found, and continue the search. yes, we keep going, we don't stop at the first hit, that's the plot twist 😤

once the entire cache branch has been walked, return its max depth. that's the whole journey, start to finish, no shortcuts 🌈

⭐ RETURN ⭐

the cache structure and the level we terminated with. two things, one return, iconic behavior honestly 🫶

💀 SEE ALSO 💀

kernel file ./drivers/acpi/pptt.c, plus a whole friend group of functions:

ngl bestie, go read ./drivers/acpi/pptt.c if you want the real lore, this page is just the trailer 🎬

and that's the whole page!! 🎀 this came from ./drivers/acpi, dated October 2026, and it's acpi_pptt_walk_cache(9) from the Kernel API Manual — slay, go read your caches, ily, bye 💖🦋✨

📦 where this page comes from