page_ext_from_phys(9)

🦋 page_ext_from_phys(9) — a Kernel API Manual moment ✨

okay bestie, buckle up, this is a page from the Kernel API Manual and it's lowkey iconic 💅

---

✨ NAME ✨

page_ext_from_phys — get the page_ext structure for a physical address, no cap 🎀

---

🌸 SYNOPSIS 🌸

struct page_ext * page_ext_from_phys (phys_addr_t phys );

---

🫶 ARGUMENTS 🫶

• phys — the physical address you wanna query, bestie. that's the whole assignment 💖

---

🔥 DESCRIPTION 🔥

so this function safely gets the struct page_ext that's associated with a given physical address. the way it does it is honestly so responsible of it — it performs validation to make sure the address actually corresponds to a valid, online struct page before it even thinks about accessing it 🙈 like, it does a whole vibe check first, which is main character energy fr fr.

and if the vibe check fails? it returns NULL for MMIO, ZONE_DEVICE, holes and offline memory. periodt. 💯

---

⭐ RETURN ⭐

NULL if no page_ext exists for this physical address. that's it, that's the tea 🍓

---

💜 CONTEXT 💜

any context works here, bestie — it's giving flexible ✨

⚠️ but listen: the caller may not sleep until they have called page_ext_put. do not nap on the job, i'm so serious 😭

---

🌈 SEE ALSO 🌈

kernel file ./mm/page_ext.c and its besties page_ext_lookup(9), page_ext_get(9), page_ext_put(9) — go read them, iykyk 👑

---

mwah 💋 that's a wrap! this lil page lives in the ./mm source and it's dated October 2026 — go off, kernel docs, you ate 🎀💖🧚