STRUCT MV_XOR_CHAN(9)

💅 struct mv_xor_chan(9)

okay so bestie, welcome to the Kernel API Manual ✨ — section 9, we're in the deep kernel lore now. This page is all about struct mv_xor_chan, and it's literally the internal representation of a XOR channel 🔥. iykyk.

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✨ NAME ✨

struct mv_xor_chan — the internal representation of a XOR channel. that's it, that's the vibe 🫶

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🎀 SYNOPSIS 🎀

here's the whole struct, laid out exactly as it lives in the source, no cap:

struct mv_xor_chan {
    int pending;
    spinlock_t lock;
    void __iomem            *mmr_base;
    void __iomem            *mmr_high_base;
    unsigned int            idx;
    int irq;
    struct list_head        chain;
    struct list_head        free_slots;
    struct list_head        allocated_slots;
    struct list_head        completed_slots;
    dma_addr_t dma_desc_pool;
    void *dma_desc_pool_virt;
    size_t pool_size;
    struct dma_device       dmadev;
    struct dma_chan         dmachan;
    int slots_allocated;
    struct tasklet_struct   irq_tasklet;
    int op_in_desc;
    char dummy_src[MV_XOR_MIN_BYTE_COUNT];
    char dummy_dst[MV_XOR_MIN_BYTE_COUNT];
    dma_addr_t dummy_src_addr, dummy_dst_addr;
    u32 saved_config_reg, saved_int_mask_reg;
    struct mv_xor_device    *xordev;
 };

like, look at her. main character struct energy 💜

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🦋 Members 🦋

okay so these are the fields the page actually spills the tea on:

• pending — allows batching of hardware operations. lowkey the queue-collector of the group chat 🎀
• lock — serializes enqueue/dequeue operations to the descriptors pool. one at a time, bestie, we're not doing chaos today 💅
• mmr_base — memory mapped register base. the literal address home base ✨
• idx — the index of the xor channel. which one of the siblings she is 🌸
• chain — device chain view of the descriptors. the big-picture friendship bracelet view 🔗
• free_slots — free slots usable by the channel. available, unbothered, moisturised 🧚
• allocated_slots — slots allocated by the driver. taken, claimed, spoken for 👑
• completed_slots — slots completed by HW but still need to be acked. girl did the work, now she needs her receipt signed 😭
• slots_allocated — records the actual size of the descriptor slot pool. the real, factual headcount fr fr
• irq_tasklet — bottom half where mv_xor_slot_cleanup runs. the cleanup crew, off the main thread 🌈
• op_in_desc — new mode of driver, each op is written to descriptor. it's giving new-era behaviour, periodt 🔥

ngl, a bunch of the other fields — mmr_high_base, irq, dma_desc_pool, dma_desc_pool_virt, pool_size, dmadev, dmachan, dummy_src, dummy_dst, dummy_src_addr, dummy_dst_addr, saved_config_reg, saved_int_mask_reg, xordev — show up in the struct above but this page doesn't spell out a description for them, so i'm not gonna invent one 🙈 you saw the exact source, that's what we've got.

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🌟 SEE ALSO 🌟

• Kernel file ./drivers/dma/mv_xor.h
• struct mv_xor_desc_slot(9) — go read her sister page too, bestie 💖

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and that's the whole page! this one came from ./drivers/dma, dated October 2026, and it's struct mv_xor_chan(9) all the way down. slay, go forth and XOR responsibly 💅✨🦋