drm_memcpy_from_wc(9)

📦 version 7.3.1, in nixpkgs unstable

💅 drm_memcpy_from_wc — the Kernel API Manual, bestie edition ✨

okay so you're in the Kernel API Manual (yes, the drm_memcpy_from_wc(9) one, that's literally the page you're on 🫶) and you wanna know about the fastest available memcpy from a source that might be WC. Say less, I got you.

🌸 NAME 🌸

drm_memcpy_from_wc — bestie, it performs the fastest available memcpy from a source that may be WC. That's the whole vibe. No cap. 💖

✨ SYNOPSIS ✨

void drm_memcpy_from_wc (struct iosys_map *dst , const struct iosys_map
       *src , unsigned long len );

like… look at her. iconic signature. 👑

🎀 ARGUMENTS 🎀

  • dst — the destination pointer. where the bytes are going, periodt. 📍
  • src — the source pointer. where the bytes are coming from, the main character of this operation fr fr. 🌟
  • len — the size of the area of transfer, in bytes. literally just how much we're moving. count it. 🔢

🦋 DESCRIPTION 🦋

So here's the tea ☕: this function tries an arch optimized memcpy for prefetching reading out of a WC region — like, the fancy arch-specific one that's built for peeking out of WC land 🔥 — and if no such beast is available, it falls back to a normal memcpy.

that's it. that's the whole function. tries the cool one, defaults to the regular one. no drama, no cap. 💅✨

ngl "no such beast is available" is the most iconic phrasing in kernel documentation and I will not be taking questions 🙈

🌈 SEE ALSO 🌈

go read these next, bestie, they're all in the kernel file ./drivers/gpu/drm/drm_cache.c 🗂️:

all three. read them. slay. 💜

aaaand that's the page!! mwah 💋 — sourced from ./drivers/gpu/drm, dated October 2026, and yeah the footer still says drm_memcpy_from_wc(9) because she's consistent like that. bye bestie, go memcpy something 🧚‍♀️🍓🌸

📦 where this page comes from