From: Radhey Shyam Pandey <radhey.shyam.pan...@xilinx.com>
AXI-DMA IP supports configurable (c_sg_length_width) buffer length
register width, hence read buffer length (xlnx,sg-length-width) DT
property and ensure that driver doesn't program buffer length
exceeding the supported limit. For VDMA and CDMA there is no change.
Cc: Rob Herring <robh...@kernel.org>
Cc: Mark Rutland <mark.rutl...@arm.com>
Cc: devicet...@vger.kernel.org
Signed-off-by: Radhey Shyam Pandey <radhey.shyam.pan...@xilinx.com>
Signed-off-by: Michal Simek <michal.si...@xilinx.com>
Signed-off-by: Andrea Merello <andrea.mere...@gmail.com> [rebase, reword]
---
Changes in v2:
- drop original patch and replace with the one in Xilinx tree
Changes in v3:
- cc DT maintainers/ML
---
drivers/dma/xilinx/xilinx_dma.c | 35 ++++++++++++++++++++++++---------
1 file changed, 26 insertions(+), 9 deletions(-)
diff --git a/drivers/dma/xilinx/xilinx_dma.c b/drivers/dma/xilinx/xilinx_dma.c
index 113d9bf1b6a1..7f0ab904b749 100644
--- a/drivers/dma/xilinx/xilinx_dma.c
+++ b/drivers/dma/xilinx/xilinx_dma.c
@@ -158,7 +158,8 @@
#define XILINX_DMA_REG_BTT 0x28
/* AXI DMA Specific Masks/Bit fields */
-#define XILINX_DMA_MAX_TRANS_LEN GENMASK(22, 0)
+#define XILINX_DMA_MAX_TRANS_LEN_MIN 8
+#define XILINX_DMA_MAX_TRANS_LEN_MAX 23
#define XILINX_DMA_CR_COALESCE_MAX GENMASK(23, 16)
#define XILINX_DMA_CR_CYCLIC_BD_EN_MASK BIT(4)
#define XILINX_DMA_CR_COALESCE_SHIFT 16
@@ -418,6 +419,7 @@ 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;
@@ -437,6 +439,7 @@ struct xilinx_dma_device {
struct clk *rxs_clk;
u32 nr_channels;
u32 chan_id;
+ u32 max_buffer_len;
};
/* Macros */
@@ -985,7 +988,7 @@ 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);
@@ -1237,7 +1240,7 @@ 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);
@@ -1340,7 +1343,7 @@ 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);
@@ -1701,7 +1704,7 @@ 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);
@@ -1792,7 +1795,7 @@ static struct dma_async_tx_descriptor
*xilinx_dma_prep_slave_sg(
* 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);
+ chan->xdev->max_buffer_len);
if ((copy + sg_used < sg_dma_len(sg)) &&
chan->xdev->common.copy_align) {
@@ -1907,7 +1910,7 @@ static struct dma_async_tx_descriptor
*xilinx_dma_prep_dma_cyclic(
* making sure it is less than the hw limit
*/
copy = min_t(size_t, period_len - sg_used,
- XILINX_DMA_MAX_TRANS_LEN);
+ chan->xdev->max_buffer_len);
if ((copy + sg_used < period_len) &&
chan->xdev->common.copy_align) {
@@ -2590,7 +2593,7 @@ static int xilinx_dma_probe(struct platform_device *pdev)
struct xilinx_dma_device *xdev;
struct device_node *child, *np = pdev->dev.of_node;
struct resource *io;
- u32 num_frames, addr_width;
+ u32 num_frames, addr_width, len_width;
int i, err;
/* Allocate and initialize the DMA engine structure */
@@ -2622,8 +2625,22 @@ 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");
- if (xdev->dma_config->dmatype == XDMA_TYPE_AXIDMA)
+ xdev->max_buffer_len = GENMASK(XILINX_DMA_MAX_TRANS_LEN_MAX - 1, 0);
+
+ if (xdev->dma_config->dmatype == XDMA_TYPE_AXIDMA) {
xdev->mcdma = of_property_read_bool(node, "xlnx,mcdma");
+ if (!of_property_read_u32(node, "xlnx,sg-length-width",
+ &len_width)) {
+ if (len_width < XILINX_DMA_MAX_TRANS_LEN_MIN ||
+ len_width > XILINX_DMA_MAX_TRANS_LEN_MAX) {
+ dev_warn(xdev->dev,
+ "invalid xlnx,sg-length-width property
value using default width\n");
+ } else {
+ xdev->max_buffer_len = GENMASK(len_width - 1,
+ 0);
+ }
+ }
+ }
if (xdev->dma_config->dmatype == XDMA_TYPE_VDMA) {
err = of_property_read_u32(node, "xlnx,num-fstores",
--
2.17.1
