xilinx_dma_get_metadata_ptr(9)

💅 xilinx_dma_get_metadata_ptr(9) — from the Kernel API Manual, bestie 🎀

okay so listen. this is a page straight out of the Kernel API Manual, and it's about one tiny little function in the Xilinx DMA corner of the kernel. it's not scary, i promise. it literally just hands you a pointer and tells you how much metadata fits. that's it. that's the whole vibe. 🦋

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✨ NAME ✨

xilinx_dma_get_metadata_ptr — populate the metadata pointer and the payload length, bestie. both. at once. iconic behavior honestly 👑

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🌸 SYNOPSIS 🌸

void * xilinx_dma_get_metadata_ptr (struct dma_async_tx_descriptor *tx ,
       size_t *payload_len , size_t *max_len );

like, it returns a void *, it takes a tx, and it wants two size_t *s to shove numbers into. she's lowkey simple and i'm obsessed 💖

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💅 ARGUMENTS 💅

• tx — the async transaction descriptor. this is the thing you're asking about. main character energy, fr fr.
• payload_len — the metadata payload length. the actual amount of metadata you've got going on. ✨
• max_len — the metadata max length. the ceiling. the limit. the "how much room is there even" number. 📏

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🔥 RETURN 🔥

the app field pointer. that's the answer. that's what you get back. go wild 🫶

ngl this is the entire payoff of the function — one pointer, no drama, no cap 💀

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🧚 SEE ALSO 🧚

okay bestie this list is LONG but i'm not skipping a single one, we're doing the whole thing. grab a snack 🍓

first up, the kernel file itself:

• ./drivers/dma/xilinx/xilinx_dma.c

and now the whole friend group (iykyk):

• struct xilinx_vdma_desc_hw(9)
• struct xilinx_axidma_desc_hw(9)
• struct xilinx_aximcdma_desc_hw(9)
• struct xilinx_cdma_desc_hw(9)
• struct xilinx_vdma_tx_segment(9)
• struct xilinx_axidma_tx_segment(9)
• struct xilinx_aximcdma_tx_segment(9)
• struct xilinx_cdma_tx_segment(9)
• struct xilinx_dma_tx_descriptor(9)
• struct xilinx_dma_chan(9)
• enum xdma_ip_type(9)
• struct xilinx_dma_device(9)
• vdma_desc_write_64(9)
• xilinx_vdma_alloc_tx_segment(9)
• xilinx_cdma_alloc_tx_segment(9)
• xilinx_axidma_alloc_tx_segment(9)
• xilinx_aximcdma_alloc_tx_segment(9)
• xilinx_dma_free_tx_segment(9)
• xilinx_mcdma_free_tx_segment(9)
• xilinx_cdma_free_tx_segment(9)
• xilinx_vdma_free_tx_segment(9)
• xilinx_dma_alloc_tx_descriptor(9)
• xilinx_dma_free_tx_descriptor(9)
• xilinx_dma_free_desc_list(9)
• xilinx_dma_free_descriptors(9)
• xilinx_dma_free_chan_resources(9)
• xilinx_dma_get_residue(9)
• xilinx_dma_chan_handle_cyclic(9)
• xilinx_dma_chan_desc_cleanup(9)
• xilinx_dma_do_tasklet(9)
• xilinx_dma_alloc_chan_resources(9)
• xilinx_dma_calc_copysize(9)
• xilinx_dma_tx_status(9)
• xilinx_dma_stop_transfer(9)
• xilinx_cdma_stop_transfer(9)
• xilinx_dma_start(9)
• xilinx_vdma_start_transfer(9)
• xilinx_cdma_start_transfer(9)
• xilinx_dma_start_transfer(9)
• xilinx_mcdma_start_transfer(9)
• xilinx_dma_issue_pending(9)
• xilinx_dma_device_config(9)
• xilinx_dma_complete_descriptor(9)
• xilinx_dma_reset(9)
• xilinx_dma_chan_reset(9)
• xilinx_mcdma_irq_handler(9)
• xilinx_dma_irq_handler(9)
• append_desc_queue(9)
• xilinx_dma_tx_submit(9)
• xilinx_vdma_dma_prep_interleaved(9)
• xilinx_cdma_prep_memcpy(9)
• xilinx_dma_prep_peripheral_dma_vec(9)
• xilinx_dma_prep_slave_sg(9)
• xilinx_dma_prep_dma_cyclic(9)
• xilinx_mcdma_prep_slave_sg(9)
• xilinx_dma_terminate_all(9)
• xilinx_vdma_channel_set_config(9)
• xilinx_dma_chan_remove(9)
• xilinx_dma_chan_probe(9)
• xilinx_dma_child_probe(9)
• of_dma_xilinx_xlate(9)
• xilinx_dma_probe(9)
• xilinx_dma_remove(9)

see? all of them. every single one. we ate that list and left no crumbs 💀✨

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and that's the whole page, bestie!! 🫶 this little cutie lives under ./drivers/dma/xilinx, and this particular edition of the page is dated October 2026 — so like, future vibes only. go forth and get that metadata pointer, you absolute icon 👑💖