STRUCT IO_TLB_SLOT(9)

💅 struct io_tlb_slot(9) — Kernel API Manual core 🎀

okay so bestie, welcome to the glow-up of struct io_tlb_slot(9), straight out of the Kernel API Manual ✨ this is the little descriptor that lives in the IO TLB and honestly? it's giving backstage-pass energy. let's get into it 💖

✨ NAME ✨

struct io_tlb_slot — the IO TLB slot descriptor, no cap 🫶

🌸 SYNOPSIS 🌸

struct io_tlb_slot {
    phys_addr_t orig_addr;
    size_t alloc_size;
    unsigned short list;
    unsigned short pad_slots;
 };

look at her. four fields. absolute main character energy 👑

🦋 MEMBERS 🦋

• orig_addr — the original address that corresponds to a mapped entry. like, where it actually came from before things got mapped 💫
• alloc_size — the size of the allocated buffer. that's it, that's the whole vibe 🍓
• list — the free list, and she's describing the number of free entries available from each index. lowkey the most bookkeeping-coded field here 📋
• pad_slots — the number of preceding padding slots. heads up though 🚨 this one is valid only in the first allocated non-padding slot — anywhere else and it's just sitting there being invalid, iykyk 🙈

🧚 SEE ALSO 🧚

kernel file ./kernel/dma/swiotlb.c, plus this whole friend group 💜:

• struct io_tlb_area(9)
• swiotlb_adjust_nareas(9)
• limit_nareas(9)
• add_mem_pool(9)
• alloc_dma_pages(9)
• swiotlb_alloc_tlb(9)
• swiotlb_free_tlb(9)
• swiotlb_alloc_pool(9)
• swiotlb_dyn_alloc(9)
• __swiotlb_find_pool(9)
• swiotlb_del_pool(9)
• swiotlb_dev_init(9)
• swiotlb_align_offset(9)
• swiotlb_search_pool_area(9)
• swiotlb_search_area(9)
• swiotlb_find_slots(9)
• mem_pool_used(9)
• mem_used(9)
• swiotlb_tbl_map_single(9)
• swiotlb_del_transient(9)
• is_swiotlb_allocated(9)
• default_swiotlb_base(9)
• default_swiotlb_limit(9)

and that's the whole page, bestie, we ate and left zero crumbs 💅✨ sign-off time: this one lives under ./kernel/dma, dated October 2026, and it's filed as struct io_tlb_slot(9) — periodt 🌈👑