STRUCT IIO_DMA_BUFFER_BLOCK(9)

💅 struct iio_dma_buffer_block(9) — the Kernel API Manual, but make it make sense

okay bestie, so we're in the kernel API manual for struct iio_dma_buffer_block(9) — yes that's the whole title, no this isn't a drill 🎀 this is literally the struct that describes one IIO buffer block, and we're about to know her intimately.

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✨ NAME ✨

struct iio_dma_buffer_block — IIO buffer block. that's it, that's the name, short and iconic 👑

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🦋 SYNOPSIS 🦋

here's the whole struct, verbatim, don't touch a single character:

struct iio_dma_buffer_block {
    struct list_head head;
    size_t bytes_used;
    void *vaddr;
    dma_addr_t phys_addr;
    size_t size;
    struct iio_dma_buffer_queue *queue;
    struct kref kref;
    enum iio_block_state state;
    bool cyclic;
    bool fileio;
    struct sg_table *sg_table;
    struct dma_fence *fence;
 };

like, look at her. twelve members. main character energy fr fr 💜

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🌸 Members 🌸

every single field, no skipping, we don't do that here 🫶

• head — the list head. she's a struct list_head, she links 💅
• bytes_used — number of bytes that actually contain valid data. not the whole thing, just the real ones ✨
• vaddr — the virutal address of the block's memory (yes "virutal", that's genuinely what the doc says, not me being sloppy 😭🙈). a void *.
• phys_addr — the physical address of the block's memory. a dma_addr_t. the real-real address 🔥
• size — total size of the block, in bytes. the whole vibe, not just the used part 🎀
• queue — the parent DMA buffer queue, as a struct iio_dma_buffer_queue *. who's her mom? that's her mom.
• kref — a struct kref used to manage the lifetime of the block. keeping her alive, responsibly 🧚
• state — current state of the block, of type enum iio_block_state. vibe check as a field 💀
• cyclic — a bool, true if this is a cyclic buffer. she loops 👑
• fileio — a bool, true if this buffer is used for fileio mode. lowkey a whole different mode 🌈
• sg_table — DMA table for the transfer when transferring a DMABUF. a struct sg_table * that does the heavy lifting ⭐
• fence — DMA fence to be signaled when a DMABUF transfer is complete. a struct dma_fence *. she's literally the "we're done here" signal, no cap 🦋

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💖 SEE ALSO 💖

go read these next, i'm obsessed:

• Kernel file ./include/linux/iio/buffer-dma.h
• enum iio_block_state(9)
• struct iio_dma_buffer_queue_fileio(9)
• struct iio_dma_buffer_queue(9)
• struct iio_dma_buffer_ops(9)

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ngl this whole page is documented under ./include/linux/iio, dated October 2026, and the footer is out here calling itself struct iio_dma_buffer_block(9) again like we forgot 💀

and that's the tea, bestie — periodt. go forth and buffer responsibly 🍓💜