swiotlb_search_pool_area(9)

📦 version 7.3.1, in nixpkgs unstable

✨ swiotlb_search_pool_area 💅

okay bestie, welcome to the swiotlb_search_pool_area(9) page from the Kernel API Manual — yes that's the whole title, we're folding it in here at the top like a little name tag 🎀

Like, the whole entire vibe of this function? Searching, like, one memory area in one pool. That's it. That's the function. And honestly? iconic.

🌸 SYNOPSIS 🌸

int swiotlb_search_pool_area (struct device *dev , struct io_tlb_pool
*pool , int area_index , phys_addr_t orig_addr , dma_addr_t tbl_dma_addr
, size_t alloc_size , unsigned int alloc_align_mask );

no cap, that's the whole signature, character for character, don't come for me 🫶

🦋 ARGUMENTS 🦋

  • dev — the device that's mapping the buffer. main character energy tbh.
  • pool — the memory pool we're gonna search through. like digging through your bag for your lip gloss 💄
  • area_index — the index of the IO TLB memory area we're searching. yes, an index. a number. specific.
  • orig_addr — the original (non-bounced) IO buffer address. the real one. the pre-bounce one. periodt.
  • tbl_dma_addr — the DMA address of the bounce buffer.
  • alloc_size — total requested size of the bounce buffer, including the initial alignment padding. don't forget the padding bestie, it's part of the size fr fr.
  • alloc_align_mask — the required alignment of the allocated buffer. the mask. the alignment. you know how it is ✨

🧚 DESCRIPTION 🧚

So what does it do? It finds a suitable sequence of IO TLB entries for the request and allocates a buffer from the given IO TLB memory area. Literally that. Match made in heaven between your request and some entries 💖

And the best part? This function takes care of locking. like, it handles the locking for you. no need to stress, she's got it 👑

⭐ RETURN ⭐

  • The index of the first allocated slot — slay 💅
  • Or -1 on error — 😭 it happens, we move on

🌈 SEE ALSO 🌈

okay this is the whole squad, everybody's here, no one got left out 🫶

Kernel file ./kernel/dma/swiotlb.c — plus, in no particular order but actually yes this exact order:

ok that's the page!! go touch some DMA buffers, stay aligned, and remember: she handles the locking for you 💜

mwah 💋 — this little number lives in ./kernel/dma, dated October 2026, and it's called swiotlb_search_pool_area(9) if you forgot already (you didn't, you're doing amazing) 🎀

📦 where this page comes from