STRUCT UIO_MEM(9)

✨ struct uio_mem (9) ✨

okay so this page lives in the Kernel API Manual and it's literally all about struct uio_mem — the lil' description of a UIO memory region 🎀 bestie, if you're touching UIO drivers, this is your girl.

🌸 SYNOPSIS 🌸

here's the whole struct, every field, no skips, copy it exactly pls:

struct uio_mem {
    const char              *name;
    phys_addr_t addr;
    dma_addr_t dma_addr;
    unsigned long           offs;
    resource_size_t size;
    int memtype;
    void __iomem            *internal_addr;
    struct device           *dma_device;
    struct uio_map          *map;
 };

💅 Members 💅

• name — the name of the memory region, for identification. like a name tag but for memory 🏷️
• addr — the address of the device's memory, rounded to page size. and note the vibe check here: phys_addr is used since addr can be logical, virtual, or physical & phys_addr_t should always be large enough to handle any of the address types. highkey sensible 💜
• dma_addr — the DMA handle set by dma_alloc_coherent, used with UIO_MEM_DMA_COHERENT only (and addr should be the void * returned from the same dma_alloc_coherent call — same call, okay, not a different one, they're a package deal 🫶)
• offs — offset of device memory within the page. tiny but mighty ✨
• size — size of IO (multiple of page size). periodt.
• memtype — the type of memory that addr points to 🔥
• internal_addr — the ioremap-ped version of addr, for driver internal use. like, driver's-only, no guests 🙈
• dma_device — the device struct that was passed to dma_alloc_coherent, used with UIO_MEM_DMA_COHERENT only. again: only with that one, bestie 💀
• map — for use by the UIO core only. not you. not me. the core. 👑

ngl the map field is giving "do not touch" energy — leave it to the UIO core and nobody gets hurt 💖

🦋 SEE ALSO 🦋

go read these next, they're all connected iykyk:

• Kernel file ./include/linux/uio_driver.h
• struct uio_port(9)
• struct uio_info(9)
• uio_register_device(9)
• devm_uio_register_device(9)

okay that's the whole thing, no cap 🎀 this page comes from ./include/linux and it's dated October 2026 — so yeah, mark your calendars, the Kernel API Manual said what it said, slay 💅✨🦋