Commit a575d0b4 authored by Nicholas Graumann's avatar Nicholas Graumann Committed by Vinod Koul
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dmaengine: xilinx_dma: Introduce xilinx_dma_get_residue 



Introduce a function that can calculate residues for IPs that support it:
AXI DMA and CDMA.

Signed-off-by: default avatarNicholas Graumann <nick.graumann@gmail.com>
Signed-off-by: default avatarRadhey Shyam Pandey <radhey.shyam.pandey@xilinx.com>
Link: https://lore.kernel.org/r/1571150904-3988-5-git-send-email-radhey.shyam.pandey@xilinx.com


Signed-off-by: default avatarVinod Koul <vkoul@kernel.org>
parent 95f68c62

drivers/dma/xilinx/xilinx_dma.c

+54 −17
Original line number Diff line number Diff line
@@ -784,6 +784,44 @@ static void xilinx_dma_free_chan_resources(struct dma_chan *dchan) 
	}

}



/**

 * xilinx_dma_get_residue - Compute residue for a given descriptor

 * @chan: Driver specific dma channel

 * @desc: dma transaction descriptor

 *

 * Return: The number of residue bytes for the descriptor.

 */

static u32 xilinx_dma_get_residue(struct xilinx_dma_chan *chan,

				  struct xilinx_dma_tx_descriptor *desc)

{

	struct xilinx_cdma_tx_segment *cdma_seg;

	struct xilinx_axidma_tx_segment *axidma_seg;

	struct xilinx_cdma_desc_hw *cdma_hw;

	struct xilinx_axidma_desc_hw *axidma_hw;

	struct list_head *entry;

	u32 residue = 0;



	list_for_each(entry, &desc->segments) {

		if (chan->xdev->dma_config->dmatype == XDMA_TYPE_CDMA) {

			cdma_seg = list_entry(entry,

					      struct xilinx_cdma_tx_segment,

					      node);

			cdma_hw = &cdma_seg->hw;

			residue += (cdma_hw->control - cdma_hw->status) &

				   chan->xdev->max_buffer_len;

		} else {

			axidma_seg = list_entry(entry,

						struct xilinx_axidma_tx_segment,

						node);

			axidma_hw = &axidma_seg->hw;

			residue += (axidma_hw->control - axidma_hw->status) &

				   chan->xdev->max_buffer_len;

		}

	}



	return residue;

}



/**

 * xilinx_dma_chan_handle_cyclic - Cyclic dma callback

 * @chan: Driver specific dma channel
@@ -993,8 +1031,6 @@ static enum dma_status xilinx_dma_tx_status(struct dma_chan *dchan, 
{

	struct xilinx_dma_chan *chan = to_xilinx_chan(dchan);

	struct xilinx_dma_tx_descriptor *desc;

	struct xilinx_axidma_tx_segment *segment;

	struct xilinx_axidma_desc_hw *hw;

	enum dma_status ret;

	unsigned long flags;

	u32 residue = 0;
@@ -1003,22 +1039,20 @@ static enum dma_status xilinx_dma_tx_status(struct dma_chan *dchan, 
	if (ret == DMA_COMPLETE || !txstate)

		return ret;



	if (chan->xdev->dma_config->dmatype == XDMA_TYPE_AXIDMA) {

	spin_lock_irqsave(&chan->lock, flags);



	desc = list_last_entry(&chan->active_list,

			       struct xilinx_dma_tx_descriptor, node);

		if (chan->has_sg) {

			list_for_each_entry(segment, &desc->segments, node) {

				hw = &segment->hw;

				residue += (hw->control - hw->status) &

					   chan->xdev->max_buffer_len;

			}

		}

	/*

	 * VDMA and simple mode do not support residue reporting, so the

	 * residue field will always be 0.

	 */

	if (chan->has_sg && chan->xdev->dma_config->dmatype != XDMA_TYPE_VDMA)

		residue = xilinx_dma_get_residue(chan, desc);



	spin_unlock_irqrestore(&chan->lock, flags);



	dma_set_residue(txstate, residue);

	}



	return ret;

}
@@ -2705,12 +2739,15 @@ static int xilinx_dma_probe(struct platform_device *pdev) 
					  xilinx_dma_prep_dma_cyclic;

		xdev->common.device_prep_interleaved_dma =

					xilinx_dma_prep_interleaved;

		/* Residue calculation is supported by only AXI DMA */

		/* Residue calculation is supported by only AXI DMA and CDMA */

		xdev->common.residue_granularity =

					  DMA_RESIDUE_GRANULARITY_SEGMENT;

	} else if (xdev->dma_config->dmatype == XDMA_TYPE_CDMA) {

		dma_cap_set(DMA_MEMCPY, xdev->common.cap_mask);

		xdev->common.device_prep_dma_memcpy = xilinx_cdma_prep_memcpy;

		/* Residue calculation is supported by only AXI DMA and CDMA */

		xdev->common.residue_granularity =

					DMA_RESIDUE_GRANULARITY_SEGMENT;

	} else {

		xdev->common.device_prep_interleaved_dma =

				xilinx_vdma_dma_prep_interleaved;