[PATCH v3 1/2] dmaengine: vdma: Add 64 bit addressing support for the axi dma

[PATCH v3 1/2] dmaengine: vdma: Add 64 bit addressing support for the axi dma

[Kedareswara rao Appana]

The AXI DMA is a soft ip, which can be programmed to support
32 bit addressing or greater than 32 bit addressing.

When the AXI DMA ip is configured for 32 bit address space
in simple dma mode the buffer address is specified by a single register
(18h for MM2S channel and 48h for S2MM channel). When configured in SG mode
The current descriptor and tail descriptor are specified by a single
Register(08h for curdesc 10h for tail desc for MM2S channel and 38h for
Curdesc and 40h for tail desc for S2MM).

When the  AXI DMA core is configured for an address space greater
than 32 then each buffer address or descriptor address is specified by
a combination of two registers.

The first register specifies the LSB 32 bits of address,
while the next register specifies the MSB 32 bits of address.

For example, 48h will specify the LSB 32 bits while 4Ch will
specify the MSB 32 bits of the first start address.
So we need to program two registers at a time.

This patch adds the 64 bit addressing support for the axidma
IP in the driver.

Signed-off-by: Kedareswara rao Appana <appanad@xilinx.com>
---
Changes for v3:
--> Removed repeated code and used wrappers as suggested by vinod.
Changes for v2:
--> New patch. 

 drivers/dma/xilinx/xilinx_vdma.c |   63 ++++++++++++++++++++++++++++---------
 1 files changed, 47 insertions(+), 16 deletions(-)

diff --git a/drivers/dma/xilinx/xilinx_vdma.c b/drivers/dma/xilinx/xilinx_vdma.c
index 0f5b38a..dd990fc 100644
--- a/drivers/dma/xilinx/xilinx_vdma.c
+++ b/drivers/dma/xilinx/xilinx_vdma.c
@@ -45,6 +45,7 @@
 #include <linux/of_irq.h>
 #include <linux/slab.h>
 #include <linux/clk.h>
+#include <linux/io-64-nonatomic-lo-hi.h>
 
 #include "../dmaengine.h"
 
@@ -195,22 +196,22 @@ struct xilinx_vdma_desc_hw {
 /**
  * struct xilinx_axidma_desc_hw - Hardware Descriptor for AXI DMA
  * @next_desc: Next Descriptor Pointer @0x00
- * @pad1: Reserved @0x04
+ * @next_desc_msb: MSB of Next Descriptor Pointer @0x04
  * @buf_addr: Buffer address @0x08
- * @pad2: Reserved @0x0C
- * @pad3: Reserved @0x10
- * @pad4: Reserved @0x14
+ * @buf_addr_msb: MSB of Buffer address @0x0C
+ * @pad1: Reserved @0x10
+ * @pad2: Reserved @0x14
  * @control: Control field @0x18
  * @status: Status field @0x1C
  * @app: APP Fields @0x20 - 0x30
  */
 struct xilinx_axidma_desc_hw {
 	u32 next_desc;
-	u32 pad1;
+	u32 next_desc_msb;
 	u32 buf_addr;
+	u32 buf_addr_msb;
+	u32 pad1;
 	u32 pad2;
-	u32 pad3;
-	u32 pad4;
 	u32 control;
 	u32 status;
 	u32 app[XILINX_DMA_NUM_APP_WORDS];
@@ -461,6 +462,34 @@ static inline void vdma_desc_write_64(struct xilinx_dma_chan *chan, u32 reg,
 	writel(value_msb, chan->xdev->regs + chan->desc_offset + reg + 4);
 }
 
+static inline void dma_writeq(struct xilinx_dma_chan *chan, u32 reg, u64 value)
+{
+	lo_hi_writeq(value, chan->xdev->regs + chan->ctrl_offset + reg);
+}
+
+static inline void xilinx_write(struct xilinx_dma_chan *chan, u32 reg,
+				dma_addr_t addr)
+{
+	if (chan->ext_addr)
+		dma_writeq(chan, reg, addr);
+	else
+		dma_ctrl_write(chan, reg, addr);
+}
+
+static inline void xilinx_axidma_buf(struct xilinx_dma_chan *chan,
+				     struct xilinx_axidma_desc_hw *hw,
+				     dma_addr_t buf_addr, size_t sg_used,
+				     size_t period_len)
+{
+	if (chan->ext_addr) {
+		hw->buf_addr = lower_32_bits(buf_addr + sg_used + period_len);
+		hw->buf_addr_msb = upper_32_bits(buf_addr + sg_used +
+						 period_len);
+	} else {
+		hw->buf_addr = buf_addr + sg_used + period_len;
+	}
+}
+
 /* -----------------------------------------------------------------------------
  * Descriptors and segments alloc and free
  */
@@ -1190,8 +1219,8 @@ static void xilinx_dma_start_transfer(struct xilinx_dma_chan *chan)
 	}
 
 	if (chan->has_sg)
-		dma_ctrl_write(chan, XILINX_DMA_REG_CURDESC,
-			       head_desc->async_tx.phys);
+		xilinx_write(chan, XILINX_DMA_REG_CURDESC,
+			     head_desc->async_tx.phys);
 
 	xilinx_dma_start(chan);
 
@@ -1201,11 +1230,11 @@ static void xilinx_dma_start_transfer(struct xilinx_dma_chan *chan)
 	/* Start the transfer */
 	if (chan->has_sg) {
 		if (chan->cyclic)
-			dma_ctrl_write(chan, XILINX_DMA_REG_TAILDESC,
-				       chan->cyclic_seg_v->phys);
+			xilinx_write(chan, XILINX_DMA_REG_TAILDESC,
+				     chan->cyclic_seg_v->phys);
 		else
-			dma_ctrl_write(chan, XILINX_DMA_REG_TAILDESC,
-				       tail_segment->phys);
+			xilinx_write(chan, XILINX_DMA_REG_TAILDESC,
+				     tail_segment->phys);
 	} else {
 		struct xilinx_axidma_tx_segment *segment;
 		struct xilinx_axidma_desc_hw *hw;
@@ -1215,7 +1244,7 @@ static void xilinx_dma_start_transfer(struct xilinx_dma_chan *chan)
 					   node);
 		hw = &segment->hw;
 
-		dma_ctrl_write(chan, XILINX_DMA_REG_SRCDSTADDR, hw->buf_addr);
+		xilinx_write(chan, XILINX_DMA_REG_SRCDSTADDR, hw->buf_addr);
 
 		/* Start the transfer */
 		dma_ctrl_write(chan, XILINX_DMA_REG_BTT,
@@ -1679,7 +1708,8 @@ static struct dma_async_tx_descriptor *xilinx_dma_prep_slave_sg(
 			hw = &segment->hw;
 
 			/* Fill in the descriptor */
-			hw->buf_addr = sg_dma_address(sg) + sg_used;
+			xilinx_axidma_buf(chan, hw, sg_dma_address(sg),
+					  sg_used, 0);
 
 			hw->control = copy;
 
@@ -1777,7 +1807,8 @@ static struct dma_async_tx_descriptor *xilinx_dma_prep_dma_cyclic(
 			copy = min_t(size_t, period_len - sg_used,
 				     XILINX_DMA_MAX_TRANS_LEN);
 			hw = &segment->hw;
-			hw->buf_addr = buf_addr + sg_used + (period_len * i);
+			xilinx_axidma_buf(chan, hw, buf_addr, sg_used,
+					  period_len * i);
 			hw->control = copy;
 
 			if (prev)
-- 
1.7.1

[PATCH v3 2/2] dmaengine: vdma: Add 64 bit addressing support for the axi cdma

[Kedareswara rao Appana]

The AXI CDMA is a soft ip, which can be programmed to support
32 bit addressing or greater than 32 bit addressing.

When the AXI CDMA ip is configured for 32 bit address space
in simple dma mode the source/destination buffer address is
specified by a single register(18h for Source buffer address and
20h for Destination buffer address). When configured in SG mode
the current descriptor and tail descriptor are specified by a
Single register(08h for curdesc 10h for tail desc).

When the  AXI CDMA core is configured for an address space greater
than 32 then each buffer address or descriptor address is specified by
a combination of two registers.

The first register specifies the LSB 32 bits of address,
while the next register specifies the MSB 32 bits of address.

For example, 08h will specify the LSB 32 bits while 0Ch will
specify the MSB 32 bits of the first start address.
So we need to program two registers at a time.

This patch adds the 64 bit addressing support to the axicdma
IP in the driver.

Signed-off-by: Kedareswara rao Appana <appanad@xilinx.com>
---
Changes for v3:
--> Removed repeated code and used wrappers as suggested by vinod.
Changes for v2:
--> New patch.

 drivers/dma/xilinx/xilinx_vdma.c |   28 ++++++++++++++++------------
 1 files changed, 16 insertions(+), 12 deletions(-)

diff --git a/drivers/dma/xilinx/xilinx_vdma.c b/drivers/dma/xilinx/xilinx_vdma.c
index dd990fc..cbcf595 100644
--- a/drivers/dma/xilinx/xilinx_vdma.c
+++ b/drivers/dma/xilinx/xilinx_vdma.c
@@ -220,21 +220,21 @@ struct xilinx_axidma_desc_hw {
 /**
  * struct xilinx_cdma_desc_hw - Hardware Descriptor
  * @next_desc: Next Descriptor Pointer @0x00
- * @pad1: Reserved @0x04
+ * @next_descmsb: Next Descriptor Pointer MSB @0x04
  * @src_addr: Source address @0x08
- * @pad2: Reserved @0x0C
+ * @src_addrmsb: Source address MSB @0x0C
  * @dest_addr: Destination address @0x10
- * @pad3: Reserved @0x14
+ * @dest_addrmsb: Destination address MSB @0x14
  * @control: Control field @0x18
  * @status: Status field @0x1C
  */
 struct xilinx_cdma_desc_hw {
 	u32 next_desc;
-	u32 pad1;
+	u32 next_desc_msb;
 	u32 src_addr;
-	u32 pad2;
+	u32 src_addr_msb;
 	u32 dest_addr;
-	u32 pad3;
+	u32 dest_addr_msb;
 	u32 control;
 	u32 status;
 } __aligned(64);
@@ -1137,12 +1137,12 @@ static void xilinx_cdma_start_transfer(struct xilinx_dma_chan *chan)
 	}
 
 	if (chan->has_sg) {
-		dma_ctrl_write(chan, XILINX_DMA_REG_CURDESC,
-			   head_desc->async_tx.phys);
+		xilinx_write(chan, XILINX_DMA_REG_CURDESC,
+			     head_desc->async_tx.phys);
 
 		/* Update tail ptr register which will start the transfer */
-		dma_ctrl_write(chan, XILINX_DMA_REG_TAILDESC,
-			       tail_segment->phys);
+		xilinx_write(chan, XILINX_DMA_REG_TAILDESC,
+			     tail_segment->phys);
 	} else {
 		/* In simple mode */
 		struct xilinx_cdma_tx_segment *segment;
@@ -1154,8 +1154,8 @@ static void xilinx_cdma_start_transfer(struct xilinx_dma_chan *chan)
 
 		hw = &segment->hw;
 
-		dma_ctrl_write(chan, XILINX_CDMA_REG_SRCADDR, hw->src_addr);
-		dma_ctrl_write(chan, XILINX_CDMA_REG_DSTADDR, hw->dest_addr);
+		xilinx_write(chan, XILINX_CDMA_REG_SRCADDR, hw->src_addr);
+		xilinx_write(chan, XILINX_CDMA_REG_DSTADDR, hw->dest_addr);
 
 		/* Start the transfer */
 		dma_ctrl_write(chan, XILINX_DMA_REG_BTT,
@@ -1626,6 +1626,10 @@ xilinx_cdma_prep_memcpy(struct dma_chan *dchan, dma_addr_t dma_dst,
 	hw->control = len;
 	hw->src_addr = dma_src;
 	hw->dest_addr = dma_dst;
+	if (chan->ext_addr) {
+		hw->src_addr_msb = upper_32_bits(dma_src);
+		hw->dest_addr_msb = upper_32_bits(dma_dst);
+	}
 
 	/* Fill the previous next descriptor with current */
 	prev = list_last_entry(&desc->segments,
-- 
1.7.1

[PATCH v3 1/2] dmaengine: vdma: Add 64 bit addressing support for the axi dma

[Vinod Koul]

On Tue, Jun 07, 2016 at 07:21:15PM +0530, Kedareswara rao Appana wrote:
> The AXI DMA is a soft ip, which can be programmed to support
> 32 bit addressing or greater than 32 bit addressing.
> 
> When the AXI DMA ip is configured for 32 bit address space
> in simple dma mode the buffer address is specified by a single register
> (18h for MM2S channel and 48h for S2MM channel). When configured in SG mode
> The current descriptor and tail descriptor are specified by a single
> Register(08h for curdesc 10h for tail desc for MM2S channel and 38h for
> Curdesc and 40h for tail desc for S2MM).
> 
> When the  AXI DMA core is configured for an address space greater
> than 32 then each buffer address or descriptor address is specified by
> a combination of two registers.
> 
> The first register specifies the LSB 32 bits of address,
> while the next register specifies the MSB 32 bits of address.
> 
> For example, 48h will specify the LSB 32 bits while 4Ch will
> specify the MSB 32 bits of the first start address.
> So we need to program two registers at a time.
> 
> This patch adds the 64 bit addressing support for the axidma
> IP in the driver.

Applied both, thanks

-- 
~Vinod