alloc_iova_fast(9)

✨ alloc_iova_fast(9) ✨

okay so this is a page from the Kernel API Manual — yes, the kernel really does have its own manual, and yes, this function lives in it 💅

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🎀 NAME 🎀

alloc_iova_fast — allocates an iova from rcache. that's the whole vibe, bestie ✨

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🌸 SYNOPSIS 🌸

unsigned long alloc_iova_fast (struct iova_domain *iovad , unsigned long
size , unsigned long limit_pfn , bool flush_rcache );

like look at it, four args, returns an unsigned long, very demure, very mindful 🫶

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💖 ARGUMENTS 💖

• iovad — the iova domain in question, aka the whole little world we're allocating inside 🌍
• size — size of page frames to allocate, so it's giving "how much room do i need" 📏
• limit_pfn — max limit address, the ceiling, the "do not go past this" line 🚧
• flush_rcache — set to flush rcache on regular allocation failure. and bestie, this part is the whole plot, so let me spill 👀: this function tries to satisfy an iova allocation from the rcache, and falls back to regular allocation on failure. if regular allocation fails too and the flush_rcache flag is set, then the rcache will be flushed. that's it, that's the tea 🔥

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🦋 SEE ALSO 🦋

it's the friend group, they all hang out in the kernel file ./drivers/iommu/iova.c 🧚:

• alloc_iova(9)
• find_iova(9)
• __free_iova(9)
• free_iova(9)
• free_iova_fast(9)
• put_iova_domain(9)
• reserve_iova(9)

ngl every function on this list is worth a read if you're actually messing with iova domains — they're literally neighbors in the same source file, so go say hi 💜

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and that's the page!! signing off from ./drivers/iommu, October 2026 — go allocate something iconic, bestie 👑✨