xilinx_dma_prep_slave_sg(9)

💖 xilinx_dma_prep_slave_sg(9) 💖

okay so bestie, this is xilinx_dma_prep_slave_sg from the Kernel API Manual, and it's literally the glow-up guide for prepping descriptors for a DMA_SLAVE transaction 💅✨

🌸 NAME 🌸

xilinx_dma_prep_slave_sg — prepare descriptors for a DMA_SLAVE transaction. that's the whole vibe: getting those descriptors ready before the transfer goes off 🫶

✨ SYNOPSIS ✨

here's the signature in all its main-character glory:

struct dma_async_tx_descriptor * xilinx_dma_prep_slave_sg (struct
dma_chan *dchan , struct scatterlist *sgl , unsigned int sg_len , enum
dma_transfer_direction direction , unsigned long flags , void *context
);

🎀 ARGUMENTS 🎀

okay so every single parameter, no skipping, because we don't do that here:

• dchan — the DMA channel you're working with. main character energy, fr.
• sgl — the scatterlist you're transferring to/from. it's giving data itinerary 🦋
• sg_len — number of entries in the scatterlist. count them, bestie 🔢
• direction — the DMA direction. which way is the data going? iconic question.
• flags — transfer ack flags. keep an eye on these 👀
• context — the APP words of the descriptor. yes, that's what it says.

🌈 RETURN 🌈

on success you get an async transaction descriptor; on failure you get NULL. that's the whole return vibe. descriptor = yay, NULL = crying in the club 😭

🦋 SEE ALSO 🦋

if you're going down the Xilinx DMA rabbit hole (and honestly, same), start with the kernel file ./drivers/dma/xilinx/xilinx_dma.c and then these absolutely iconic references:

• the kernel file ./drivers/dma/xilinx/xilinx_dma.c
• 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_dma_get_metadata_ptr(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_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)

okay that's the whole page, bestie 💖 source/version: ./drivers/dma/xilinx, date: October 2026. now go prep those descriptors and be iconic 👑✨