Commit 616f0f81 authored by Andrea Merello's avatar Andrea Merello Committed by Vinod Koul
Browse files

dmaengine: xilinx_dma: commonize DMA copy size calculation 



This patch removes a bit of duplicated code by introducing a new
function that implements calculations for DMA copy size, and
prepares for changes to the copy size calculation that will
happen in following patches.

Suggested-by: default avatarVinod Koul <vkoul@kernel.org>
Signed-off-by: default avatarAndrea Merello <andrea.merello@gmail.com>
Reviewed-by: default avatarRadhey Shyam Pandey <radhey.shyam.pandey@xilinx.com>
Signed-off-by: default avatarVinod Koul <vkoul@kernel.org>
parent bfeffd15

drivers/dma/xilinx/xilinx_dma.c

+31 −8
Original line number Diff line number Diff line
@@ -425,6 +425,7 @@ struct xilinx_dma_config { 
 * @rxs_clk: DMA s2mm stream clock

 * @nr_channels: Number of channels DMA device supports

 * @chan_id: DMA channel identifier

 * @max_buffer_len: Max buffer length

 */

struct xilinx_dma_device {

	void __iomem *regs;
@@ -444,6 +445,7 @@ struct xilinx_dma_device { 
	struct clk *rxs_clk;

	u32 nr_channels;

	u32 chan_id;

	u32 max_buffer_len;

};



/* Macros */
@@ -959,6 +961,25 @@ static int xilinx_dma_alloc_chan_resources(struct dma_chan *dchan) 
	return 0;

}



/**

 * xilinx_dma_calc_copysize - Calculate the amount of data to copy

 * @chan: Driver specific DMA channel

 * @size: Total data that needs to be copied

 * @done: Amount of data that has been already copied

 *

 * Return: Amount of data that has to be copied

 */

static int xilinx_dma_calc_copysize(struct xilinx_dma_chan *chan,

				    int size, int done)

{

	size_t copy;



	copy = min_t(size_t, size - done,

		     chan->xdev->max_buffer_len);



	return copy;

}



/**

 * xilinx_dma_tx_status - Get DMA transaction status

 * @dchan: DMA channel
@@ -992,7 +1013,7 @@ static enum dma_status xilinx_dma_tx_status(struct dma_chan *dchan, 
			list_for_each_entry(segment, &desc->segments, node) {

				hw = &segment->hw;

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

					   XILINX_DMA_MAX_TRANS_LEN;

					   chan->xdev->max_buffer_len;

			}

		}

		spin_unlock_irqrestore(&chan->lock, flags);
@@ -1254,7 +1275,7 @@ static void xilinx_cdma_start_transfer(struct xilinx_dma_chan *chan) 


		/* Start the transfer */

		dma_ctrl_write(chan, XILINX_DMA_REG_BTT,

				hw->control & XILINX_DMA_MAX_TRANS_LEN);

				hw->control & chan->xdev->max_buffer_len);

	}



	list_splice_tail_init(&chan->pending_list, &chan->active_list);
@@ -1357,7 +1378,7 @@ static void xilinx_dma_start_transfer(struct xilinx_dma_chan *chan) 


		/* Start the transfer */

		dma_ctrl_write(chan, XILINX_DMA_REG_BTT,

			       hw->control & XILINX_DMA_MAX_TRANS_LEN);

			       hw->control & chan->xdev->max_buffer_len);

	}



	list_splice_tail_init(&chan->pending_list, &chan->active_list);
@@ -1718,7 +1739,7 @@ xilinx_cdma_prep_memcpy(struct dma_chan *dchan, dma_addr_t dma_dst, 
	struct xilinx_cdma_tx_segment *segment;

	struct xilinx_cdma_desc_hw *hw;



	if (!len || len > XILINX_DMA_MAX_TRANS_LEN)

	if (!len || len > chan->xdev->max_buffer_len)

		return NULL;



	desc = xilinx_dma_alloc_tx_descriptor(chan);
@@ -1808,8 +1829,8 @@ static struct dma_async_tx_descriptor *xilinx_dma_prep_slave_sg( 
			 * Calculate the maximum number of bytes to transfer,

			 * making sure it is less than the hw limit

			 */

			copy = min_t(size_t, sg_dma_len(sg) - sg_used,

				     XILINX_DMA_MAX_TRANS_LEN);

			copy = xilinx_dma_calc_copysize(chan, sg_dma_len(sg),

							sg_used);

			hw = &segment->hw;



			/* Fill in the descriptor */
@@ -1913,8 +1934,8 @@ static struct dma_async_tx_descriptor *xilinx_dma_prep_dma_cyclic( 
			 * Calculate the maximum number of bytes to transfer,

			 * making sure it is less than the hw limit

			 */

			copy = min_t(size_t, period_len - sg_used,

				     XILINX_DMA_MAX_TRANS_LEN);

			copy = xilinx_dma_calc_copysize(chan, period_len,

							sg_used);

			hw = &segment->hw;

			xilinx_axidma_buf(chan, hw, buf_addr, sg_used,

					  period_len * i);
@@ -2628,6 +2649,8 @@ static int xilinx_dma_probe(struct platform_device *pdev) 


	/* Retrieve the DMA engine properties from the device tree */

	xdev->has_sg = of_property_read_bool(node, "xlnx,include-sg");

	xdev->max_buffer_len = XILINX_DMA_MAX_TRANS_LEN;



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

		xdev->mcdma = of_property_read_bool(node, "xlnx,mcdma");

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