From 616f0f81d857e248a72b5af45ab185196556ae2e Mon Sep 17 00:00:00 2001 From: Andrea Merello Date: Tue, 20 Nov 2018 16:31:45 +0100 Subject: [PATCH] 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: Vinod Koul Signed-off-by: Andrea Merello Reviewed-by: Radhey Shyam Pandey Signed-off-by: Vinod Koul --- drivers/dma/xilinx/xilinx_dma.c | 39 ++++++++++++++++++++++++++------- 1 file changed, 31 insertions(+), 8 deletions(-) diff --git a/drivers/dma/xilinx/xilinx_dma.c b/drivers/dma/xilinx/xilinx_dma.c index 02880963092f..fd9f37bafab0 100644 --- a/drivers/dma/xilinx/xilinx_dma.c +++ b/drivers/dma/xilinx/xilinx_dma.c @@ -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");