dma_contiguous_reserve(9)

💖 dma_contiguous_reserve(9) 💖

okay so bestie, welcome to the Kernel API Manual — this one's a dma_contiguous_reserve(9) moment and it's lowkey iconic. it's a function, it reserves stuff, and it has main character energy in the boot path. let's get into it ✨

---

🌸 NAME 🌸

dma_contiguous_reserve — reserve area(s) for contiguous memory handling 🫶

like, plural on the "area(s)" bestie, we're not playing around.

---

🎀 SYNOPSIS 🎀

void dma_contiguous_reserve (phys_addr_t limit );

no return value, no drama. it's void. it just does the thing 💅

---

🦋 ARGUMENTS 🦋

• limit — the end address of the reserved memory. it's optional, and if you pass 0 it literally means "any" — she's flexible like that 💖

---

🌈 DESCRIPTION 🌈

so what does she actually do? this function reserves memory from the early allocator. periodt.

it should be called by arch specific code — so like, your architecture's own setup — and the timing is everything ngl. it has to happen:

• once the early allocator (memblock or bootmem) has been activated, and
• after all other subsystems have already allocated/reserved memory

⭐ vibe check: it's an early thing. if you show up late to this party, it's not giving what it's supposed to give. read the two bullet points again before you call her, bestie 😭

---

👑 SEE ALSO 👑

the kernel file itself is over at ./kernel/dma/contiguous.c — that's the home base 🏠 and here's the whole friend group:

• dma_contiguous_get_area_by_idx(9)
• dma_contiguous_reserve_area(9)
• dma_alloc_from_contiguous(9)
• dma_release_from_contiguous(9)
• dma_alloc_contiguous(9)
• dma_free_contiguous(9)

---

and that's the page!! 🎀 source is ./kernel/dma, dated October 2026 — so she's fresh, she's cunty, she's documented. go reserve some contiguous memory bestie, you got this 💜✨🔥