STRUCT DMA_FILTER(9)

✨ struct dma_filter(9) ✨

okay so this is a page from the Kernel API Manual, bestie — it's all about struct dma_filter, which is literally just the info you need to map a slave device/channel onto its filter_fn/param situation. 💅

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🌸 NAME 🌸

struct dma_filter — the whole info bundle for slave device/channel → filter_fn/param mapping. it's giving "matchmaker but for DMA channels" fr fr 🎀

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✨ SYNOPSIS ✨

struct dma_filter {
    dma_filter_fn fn;
    int mapcnt;
    const struct dma_slave_map *map;
 };

like, that's the whole struct. no cap, three members, that's it. 🦋

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💖 Members 💖

• fn — the filter function callback. yes bestie, this is the actual function that does the filtering ✨
• mapcnt — how many slave device/channels live in the map. it's the count, it counts. 🔢
• map — the array of channel-to-filter mapping data. the vibes live here 💅

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👑 SEE ALSO 👑

Kernel file ./include/linux/dmaengine.h — plus a whole friend group of related pages, and yes we're listing every single one because they're all iconic:

• dma_cookie_t(9)
• enum dma_status(9)
• enum dma_transaction_type(9)
• enum dma_transfer_direction(9)
• struct data_chunk(9)
• struct dma_interleaved_template(9)
• struct dma_vec(9)
• enum dma_ctrl_flags(9)
• enum sum_check_bits(9)
• enum sum_check_flags(9)
• enum dma_desc_metadata_mode(9)
• struct dma_chan_percpu(9)
• struct dma_router(9)
• struct dma_chan(9)
• struct dma_chan_dev(9)
• enum dma_slave_buswidth(9)
• struct dma_slave_config(9)
• enum dma_residue_granularity(9)
• struct dma_slave_caps(9)
• dma_filter_fn(9)
• struct dma_async_tx_descriptor(9)
• struct dma_tx_state(9)
• enum dmaengine_alignment(9)
• struct dma_slave_map(9)
• struct dma_device(9)
• dmaengine_prep_peripheral_dma_vec(9)
• dmaengine_prep_config_sg_safe(9)
• dmaengine_prep_config_single_safe(9)
• dmaengine_prep_dma_memset(9)
• dmaengine_terminate_all(9)
• dmaengine_terminate_async(9)
• dmaengine_synchronize(9)
• dmaengine_terminate_sync(9)
• dma_async_issue_pending(9)
• dma_async_is_tx_complete(9)
• dma_async_is_complete(9)

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🫶 that's the whole page, bestie. go read dmaengine.h if you want the deep lore. iykyk 💜

okayyy signing off 🧚 this one came from ./include/linux, dated October 2026 — mwah, slay, periodt. 🌈💖