[PATCH v4 0/4] dma: sf-pdma: various sf-pdma updates for the mpfs platform

[PATCH v4 0/4] dma: sf-pdma: various sf-pdma updates for the mpfs platform

[shravan chippa]

From: Shravan Chippa <shravan.chippa@microchip.com>

Changes from V3 -> V4:

Removed unnecessary parentheses and extra space
Added review tags

Changes from V2 -> V3:

Removed whitespace
Change naming convention of the macros (modified code as per new macros)
updated with new API device_get_match_data()
modified dt-bindings as per the commmets from v2
modified compatible name string for mpfs platform

Changes from V1 -> V2:

Removed internal review tags
Commit massages modified.
Added devicetree patch with new compatible name for mpfs platform
Added of_dma_controller_free() clenup call in sf_pdma_remove() function

V1:

This series does the following
1. Adds a PolarFire SoC specific compatible and code to support for
out-of-order dma transfers 

2. Adds generic device tree bindings support by using 
of_dma_controller_register()

Shravan Chippa (4):
  dmaengine: sf-pdma: Support of_dma_controller_register()
  dt-bindings: dma: sf-pdma: add new compatible name
  dmaengine: sf-pdma: add mpfs-pdma compatible name
  riscv: dts: microchip: add specific compatible for mpfs' pdma

 .../bindings/dma/sifive,fu540-c000-pdma.yaml  |  1 +
 arch/riscv/boot/dts/microchip/mpfs.dtsi       |  2 +-
 drivers/dma/sf-pdma/sf-pdma.c                 | 71 ++++++++++++++++++-
 drivers/dma/sf-pdma/sf-pdma.h                 |  8 ++-
 4 files changed, 77 insertions(+), 5 deletions(-)

-- 
2.34.1

[PATCH v4 1/4] dmaengine: sf-pdma: Support of_dma_controller_register()

[shravan chippa]

From: Shravan Chippa <shravan.chippa@microchip.com>

Update sf-pdma driver to adopt generic DMA device tree bindings.
It calls of_dma_controller_register() with sf-pdma specific
of_dma_xlate to get the generic DMA device tree helper support
and the DMA clients can look up the sf-pdma controller using
standard APIs.

Signed-off-by: Shravan Chippa <shravan.chippa@microchip.com>
---
 drivers/dma/sf-pdma/sf-pdma.c | 44 +++++++++++++++++++++++++++++++++++
 1 file changed, 44 insertions(+)

diff --git a/drivers/dma/sf-pdma/sf-pdma.c b/drivers/dma/sf-pdma/sf-pdma.c
index d1c6956af452..4c456bdef882 100644
--- a/drivers/dma/sf-pdma/sf-pdma.c
+++ b/drivers/dma/sf-pdma/sf-pdma.c
@@ -20,6 +20,7 @@
 #include <linux/mod_devicetable.h>
 #include <linux/dma-mapping.h>
 #include <linux/of.h>
+#include <linux/of_dma.h>
 #include <linux/slab.h>
 
 #include "sf-pdma.h"
@@ -490,6 +491,33 @@ static void sf_pdma_setup_chans(struct sf_pdma *pdma)
 	}
 }
 
+static struct dma_chan *sf_pdma_of_xlate(struct of_phandle_args *dma_spec,
+					 struct of_dma *ofdma)
+{
+	struct sf_pdma *pdma = ofdma->of_dma_data;
+	struct device *dev = pdma->dma_dev.dev;
+	struct sf_pdma_chan *chan;
+	struct dma_chan *c;
+	u32 channel_id;
+
+	if (dma_spec->args_count != 1) {
+		dev_err(dev, "Bad number of cells\n");
+		return NULL;
+	}
+
+	channel_id = dma_spec->args[0];
+
+	chan = &pdma->chans[channel_id];
+
+	c = dma_get_slave_channel(&chan->vchan.chan);
+	if (!c) {
+		dev_err(dev, "No more channels available\n");
+		return NULL;
+	}
+
+	return c;
+}
+
 static int sf_pdma_probe(struct platform_device *pdev)
 {
 	struct sf_pdma *pdma;
@@ -563,7 +591,20 @@ static int sf_pdma_probe(struct platform_device *pdev)
 		return ret;
 	}
 
+	ret = of_dma_controller_register(pdev->dev.of_node,
+					 sf_pdma_of_xlate, pdma);
+	if (ret < 0) {
+		dev_err(&pdev->dev,
+			"Can't register SiFive Platform OF_DMA. (%d)\n", ret);
+		goto err_unregister;
+	}
+
 	return 0;
+
+err_unregister:
+	dma_async_device_unregister(&pdma->dma_dev);
+
+	return ret;
 }
 
 static int sf_pdma_remove(struct platform_device *pdev)
@@ -583,6 +624,9 @@ static int sf_pdma_remove(struct platform_device *pdev)
 		tasklet_kill(&ch->err_tasklet);
 	}
 
+	if (pdev->dev.of_node)
+		of_dma_controller_free(pdev->dev.of_node);
+
 	dma_async_device_unregister(&pdma->dma_dev);
 
 	return 0;
-- 
2.34.1

[PATCH v4 2/4] dt-bindings: dma: sf-pdma: add new compatible name

[shravan chippa]

From: Shravan Chippa <shravan.chippa@microchip.com>

Add new compatible name microchip,mpfs-pdma to support
out of order dma transfers

Reviewed-by: Conor Dooley <conor.dooley@microchip.com>
Signed-off-by: Shravan Chippa <shravan.chippa@microchip.com>
---
 .../devicetree/bindings/dma/sifive,fu540-c000-pdma.yaml          | 1 +
 1 file changed, 1 insertion(+)

diff --git a/Documentation/devicetree/bindings/dma/sifive,fu540-c000-pdma.yaml b/Documentation/devicetree/bindings/dma/sifive,fu540-c000-pdma.yaml
index a1af0b906365..3b22183a1a37 100644
--- a/Documentation/devicetree/bindings/dma/sifive,fu540-c000-pdma.yaml
+++ b/Documentation/devicetree/bindings/dma/sifive,fu540-c000-pdma.yaml
@@ -29,6 +29,7 @@ properties:
   compatible:
     items:
       - enum:
+          - microchip,mpfs-pdma
           - sifive,fu540-c000-pdma
       - const: sifive,pdma0
     description:
-- 
2.34.1

[PATCH v4 3/4] dmaengine: sf-pdma: add mpfs-pdma compatible name

[shravan chippa]

From: Shravan Chippa <shravan.chippa@microchip.com>

Sifive platform dma does not allow out-of-order transfers,
Add a PolarFire SoC specific compatible and code to support
for out-of-order dma transfers

Reviewed-by: Emil Renner Berthing <emil.renner.berthing@canonical.com>
Signed-off-by: Shravan Chippa <shravan.chippa@microchip.com>
---
 drivers/dma/sf-pdma/sf-pdma.c | 27 ++++++++++++++++++++++++---
 drivers/dma/sf-pdma/sf-pdma.h |  8 +++++++-
 2 files changed, 31 insertions(+), 4 deletions(-)

diff --git a/drivers/dma/sf-pdma/sf-pdma.c b/drivers/dma/sf-pdma/sf-pdma.c
index 4c456bdef882..82ab12c40743 100644
--- a/drivers/dma/sf-pdma/sf-pdma.c
+++ b/drivers/dma/sf-pdma/sf-pdma.c
@@ -25,6 +25,8 @@
 
 #include "sf-pdma.h"
 
+#define PDMA_QUIRK_NO_STRICT_ORDERING   BIT(0)
+
 #ifndef readq
 static inline unsigned long long readq(void __iomem *addr)
 {
@@ -66,7 +68,7 @@ static struct sf_pdma_desc *sf_pdma_alloc_desc(struct sf_pdma_chan *chan)
 static void sf_pdma_fill_desc(struct sf_pdma_desc *desc,
 			      u64 dst, u64 src, u64 size)
 {
-	desc->xfer_type = PDMA_FULL_SPEED;
+	desc->xfer_type =  desc->chan->pdma->transfer_type;
 	desc->xfer_size = size;
 	desc->dst_addr = dst;
 	desc->src_addr = src;
@@ -520,6 +522,7 @@ static struct dma_chan *sf_pdma_of_xlate(struct of_phandle_args *dma_spec,
 
 static int sf_pdma_probe(struct platform_device *pdev)
 {
+	const struct sf_pdma_driver_platdata *ddata;
 	struct sf_pdma *pdma;
 	int ret, n_chans;
 	const enum dma_slave_buswidth widths =
@@ -545,6 +548,14 @@ static int sf_pdma_probe(struct platform_device *pdev)
 
 	pdma->n_chans = n_chans;
 
+	pdma->transfer_type = PDMA_FULL_SPEED | PDMA_STRICT_ORDERING;
+
+	ddata  = device_get_match_data(&pdev->dev);
+	if (ddata) {
+		if (ddata->quirks & PDMA_QUIRK_NO_STRICT_ORDERING)
+			pdma->transfer_type &= ~PDMA_STRICT_ORDERING;
+	}
+
 	pdma->membase = devm_platform_ioremap_resource(pdev, 0);
 	if (IS_ERR(pdma->membase))
 		return PTR_ERR(pdma->membase);
@@ -632,9 +643,19 @@ static int sf_pdma_remove(struct platform_device *pdev)
 	return 0;
 }
 
+static const struct sf_pdma_driver_platdata mpfs_pdma = {
+	.quirks = PDMA_QUIRK_NO_STRICT_ORDERING,
+};
+
 static const struct of_device_id sf_pdma_dt_ids[] = {
-	{ .compatible = "sifive,fu540-c000-pdma" },
-	{ .compatible = "sifive,pdma0" },
+	{
+		.compatible = "sifive,fu540-c000-pdma",
+	}, {
+		.compatible = "sifive,pdma0",
+	}, {
+		.compatible = "microchip,mpfs-pdma",
+		.data	    = &mpfs_pdma,
+	},
 	{},
 };
 MODULE_DEVICE_TABLE(of, sf_pdma_dt_ids);
diff --git a/drivers/dma/sf-pdma/sf-pdma.h b/drivers/dma/sf-pdma/sf-pdma.h
index 5c398a83b491..267e79a5e0a5 100644
--- a/drivers/dma/sf-pdma/sf-pdma.h
+++ b/drivers/dma/sf-pdma/sf-pdma.h
@@ -48,7 +48,8 @@
 #define PDMA_ERR_STATUS_MASK				GENMASK(31, 31)
 
 /* Transfer Type */
-#define PDMA_FULL_SPEED					0xFF000008
+#define PDMA_FULL_SPEED					0xFF000000
+#define PDMA_STRICT_ORDERING				BIT(3)
 
 /* Error Recovery */
 #define MAX_RETRY					1
@@ -112,8 +113,13 @@ struct sf_pdma {
 	struct dma_device       dma_dev;
 	void __iomem            *membase;
 	void __iomem            *mappedbase;
+	u32			transfer_type;
 	u32			n_chans;
 	struct sf_pdma_chan	chans[];
 };
 
+struct sf_pdma_driver_platdata {
+	u32 quirks;
+};
+
 #endif /* _SF_PDMA_H */
-- 
2.34.1

[PATCH v4 4/4] riscv: dts: microchip: add specific compatible for mpfs' pdma

[shravan chippa]

From: Shravan Chippa <shravan.chippa@microchip.com>

Add specific compatible for PolarFire SoC for The SiFive PDMA driver

Reviewed-by: Conor Dooley <conor.dooley@microchip.com>
Signed-off-by: Shravan Chippa <shravan.chippa@microchip.com>
---
 arch/riscv/boot/dts/microchip/mpfs.dtsi | 2 +-
 1 file changed, 1 insertion(+), 1 deletion(-)

diff --git a/arch/riscv/boot/dts/microchip/mpfs.dtsi b/arch/riscv/boot/dts/microchip/mpfs.dtsi
index 104504352e99..f43486e9a090 100644
--- a/arch/riscv/boot/dts/microchip/mpfs.dtsi
+++ b/arch/riscv/boot/dts/microchip/mpfs.dtsi
@@ -221,7 +221,7 @@ plic: interrupt-controller@c000000 {
 		};
 
 		pdma: dma-controller@3000000 {
-			compatible = "sifive,fu540-c000-pdma", "sifive,pdma0";
+			compatible = "microchip,mpfs-pdma", "sifive,pdma0";
 			reg = <0x0 0x3000000 0x0 0x8000>;
 			interrupt-parent = <&plic>;
 			interrupts = <5 6>, <7 8>, <9 10>, <11 12>;
-- 
2.34.1

RE: [PATCH v4 0/4] dma: sf-pdma: various sf-pdma updates for the mpfs platform

[Shravan.Chippa]

Hi,

Gentle ping!

Thanks,
Shravan

> -----Original Message-----
> From: shravan chippa <shravan.chippa@microchip.com>
> Sent: Tuesday, October 31, 2023 10:58 AM
> To: green.wan@sifive.com; vkoul@kernel.org; robh+dt@kernel.org;
> krzysztof.kozlowski+dt@linaro.org; palmer@dabbelt.com;
> paul.walmsley@sifive.com; conor+dt@kernel.org
> Cc: dmaengine@vger.kernel.org; devicetree@vger.kernel.org; linux-
> riscv@lists.infradead.org; linux-kernel@vger.kernel.org; Nagasuresh Relli -
> I67208 <Nagasuresh.Relli@microchip.com>; Praveen Kumar - I30718
> <Praveen.Kumar@microchip.com>; shravan Chippa - I35088
> <Shravan.Chippa@microchip.com>
> Subject: [PATCH v4 0/4] dma: sf-pdma: various sf-pdma updates for the mpfs
> platform
> 
> From: Shravan Chippa <shravan.chippa@microchip.com>
> 
> Changes from V3 -> V4:
> 
> Removed unnecessary parentheses and extra space Added review tags
> 
> Changes from V2 -> V3:
> 
> Removed whitespace
> Change naming convention of the macros (modified code as per new macros)
> updated with new API device_get_match_data() modified dt-bindings as per
> the commmets from v2 modified compatible name string for mpfs platform
> 
> Changes from V1 -> V2:
> 
> Removed internal review tags
> Commit massages modified.
> Added devicetree patch with new compatible name for mpfs platform Added
> of_dma_controller_free() clenup call in sf_pdma_remove() function
> 
> V1:
> 
> This series does the following
> 1. Adds a PolarFire SoC specific compatible and code to support for out-of-
> order dma transfers
> 
> 2. Adds generic device tree bindings support by using
> of_dma_controller_register()
> 
> Shravan Chippa (4):
>   dmaengine: sf-pdma: Support of_dma_controller_register()
>   dt-bindings: dma: sf-pdma: add new compatible name
>   dmaengine: sf-pdma: add mpfs-pdma compatible name
>   riscv: dts: microchip: add specific compatible for mpfs' pdma
> 
>  .../bindings/dma/sifive,fu540-c000-pdma.yaml  |  1 +
>  arch/riscv/boot/dts/microchip/mpfs.dtsi       |  2 +-
>  drivers/dma/sf-pdma/sf-pdma.c                 | 71 ++++++++++++++++++-
>  drivers/dma/sf-pdma/sf-pdma.h                 |  8 ++-
>  4 files changed, 77 insertions(+), 5 deletions(-)
> 
> --
> 2.34.1

Re: [PATCH v4 1/4] dmaengine: sf-pdma: Support of_dma_controller_register()

[Vinod Koul]

On 31-10-23, 10:57, shravan chippa wrote:
> From: Shravan Chippa <shravan.chippa@microchip.com>
> 
> Update sf-pdma driver to adopt generic DMA device tree bindings.
> It calls of_dma_controller_register() with sf-pdma specific
> of_dma_xlate to get the generic DMA device tree helper support
> and the DMA clients can look up the sf-pdma controller using
> standard APIs.
> 
> Signed-off-by: Shravan Chippa <shravan.chippa@microchip.com>
> ---
>  drivers/dma/sf-pdma/sf-pdma.c | 44 +++++++++++++++++++++++++++++++++++
>  1 file changed, 44 insertions(+)
> 
> diff --git a/drivers/dma/sf-pdma/sf-pdma.c b/drivers/dma/sf-pdma/sf-pdma.c
> index d1c6956af452..4c456bdef882 100644
> --- a/drivers/dma/sf-pdma/sf-pdma.c
> +++ b/drivers/dma/sf-pdma/sf-pdma.c
> @@ -20,6 +20,7 @@
>  #include <linux/mod_devicetable.h>
>  #include <linux/dma-mapping.h>
>  #include <linux/of.h>
> +#include <linux/of_dma.h>
>  #include <linux/slab.h>
>  
>  #include "sf-pdma.h"
> @@ -490,6 +491,33 @@ static void sf_pdma_setup_chans(struct sf_pdma *pdma)
>  	}
>  }
>  
> +static struct dma_chan *sf_pdma_of_xlate(struct of_phandle_args *dma_spec,
> +					 struct of_dma *ofdma)
> +{
> +	struct sf_pdma *pdma = ofdma->of_dma_data;
> +	struct device *dev = pdma->dma_dev.dev;
> +	struct sf_pdma_chan *chan;
> +	struct dma_chan *c;
> +	u32 channel_id;
> +
> +	if (dma_spec->args_count != 1) {
> +		dev_err(dev, "Bad number of cells\n");
> +		return NULL;
> +	}
> +
> +	channel_id = dma_spec->args[0];
> +
> +	chan = &pdma->chans[channel_id];
> +
> +	c = dma_get_slave_channel(&chan->vchan.chan);
> +	if (!c) {
> +		dev_err(dev, "No more channels available\n");
> +		return NULL;
> +	}
> +
> +	return c;
> +}

This seems could be replaced by of_dma_xlate_by_chan_id() can you tell
me why that cant be used?

> +
>  static int sf_pdma_probe(struct platform_device *pdev)
>  {
>  	struct sf_pdma *pdma;
> @@ -563,7 +591,20 @@ static int sf_pdma_probe(struct platform_device *pdev)
>  		return ret;
>  	}
>  
> +	ret = of_dma_controller_register(pdev->dev.of_node,
> +					 sf_pdma_of_xlate, pdma);
> +	if (ret < 0) {
> +		dev_err(&pdev->dev,
> +			"Can't register SiFive Platform OF_DMA. (%d)\n", ret);
> +		goto err_unregister;
> +	}
> +
>  	return 0;
> +
> +err_unregister:
> +	dma_async_device_unregister(&pdma->dma_dev);
> +
> +	return ret;
>  }
>  
>  static int sf_pdma_remove(struct platform_device *pdev)
> @@ -583,6 +624,9 @@ static int sf_pdma_remove(struct platform_device *pdev)
>  		tasklet_kill(&ch->err_tasklet);
>  	}
>  
> +	if (pdev->dev.of_node)
> +		of_dma_controller_free(pdev->dev.of_node);
> +
>  	dma_async_device_unregister(&pdma->dma_dev);
>  
>  	return 0;
> -- 
> 2.34.1

-- 
~Vinod

Re: [PATCH v4 3/4] dmaengine: sf-pdma: add mpfs-pdma compatible name

[Vinod Koul]

On 31-10-23, 10:57, shravan chippa wrote:
> From: Shravan Chippa <shravan.chippa@microchip.com>
> 
> Sifive platform dma does not allow out-of-order transfers,
> Add a PolarFire SoC specific compatible and code to support
> for out-of-order dma transfers

By default dma xtions are not supposed to be out of order, so why does
it make sense specifying that here?

> 
> Reviewed-by: Emil Renner Berthing <emil.renner.berthing@canonical.com>
> Signed-off-by: Shravan Chippa <shravan.chippa@microchip.com>
> ---
>  drivers/dma/sf-pdma/sf-pdma.c | 27 ++++++++++++++++++++++++---
>  drivers/dma/sf-pdma/sf-pdma.h |  8 +++++++-
>  2 files changed, 31 insertions(+), 4 deletions(-)
> 
> diff --git a/drivers/dma/sf-pdma/sf-pdma.c b/drivers/dma/sf-pdma/sf-pdma.c
> index 4c456bdef882..82ab12c40743 100644
> --- a/drivers/dma/sf-pdma/sf-pdma.c
> +++ b/drivers/dma/sf-pdma/sf-pdma.c
> @@ -25,6 +25,8 @@
>  
>  #include "sf-pdma.h"
>  
> +#define PDMA_QUIRK_NO_STRICT_ORDERING   BIT(0)
> +
>  #ifndef readq
>  static inline unsigned long long readq(void __iomem *addr)
>  {
> @@ -66,7 +68,7 @@ static struct sf_pdma_desc *sf_pdma_alloc_desc(struct sf_pdma_chan *chan)
>  static void sf_pdma_fill_desc(struct sf_pdma_desc *desc,
>  			      u64 dst, u64 src, u64 size)
>  {
> -	desc->xfer_type = PDMA_FULL_SPEED;
> +	desc->xfer_type =  desc->chan->pdma->transfer_type;
>  	desc->xfer_size = size;
>  	desc->dst_addr = dst;
>  	desc->src_addr = src;
> @@ -520,6 +522,7 @@ static struct dma_chan *sf_pdma_of_xlate(struct of_phandle_args *dma_spec,
>  
>  static int sf_pdma_probe(struct platform_device *pdev)
>  {
> +	const struct sf_pdma_driver_platdata *ddata;
>  	struct sf_pdma *pdma;
>  	int ret, n_chans;
>  	const enum dma_slave_buswidth widths =
> @@ -545,6 +548,14 @@ static int sf_pdma_probe(struct platform_device *pdev)
>  
>  	pdma->n_chans = n_chans;
>  
> +	pdma->transfer_type = PDMA_FULL_SPEED | PDMA_STRICT_ORDERING;
> +
> +	ddata  = device_get_match_data(&pdev->dev);
> +	if (ddata) {
> +		if (ddata->quirks & PDMA_QUIRK_NO_STRICT_ORDERING)
> +			pdma->transfer_type &= ~PDMA_STRICT_ORDERING;
> +	}
> +
>  	pdma->membase = devm_platform_ioremap_resource(pdev, 0);
>  	if (IS_ERR(pdma->membase))
>  		return PTR_ERR(pdma->membase);
> @@ -632,9 +643,19 @@ static int sf_pdma_remove(struct platform_device *pdev)
>  	return 0;
>  }
>  
> +static const struct sf_pdma_driver_platdata mpfs_pdma = {
> +	.quirks = PDMA_QUIRK_NO_STRICT_ORDERING,
> +};
> +
>  static const struct of_device_id sf_pdma_dt_ids[] = {
> -	{ .compatible = "sifive,fu540-c000-pdma" },
> -	{ .compatible = "sifive,pdma0" },
> +	{
> +		.compatible = "sifive,fu540-c000-pdma",
> +	}, {
> +		.compatible = "sifive,pdma0",
> +	}, {
> +		.compatible = "microchip,mpfs-pdma",
> +		.data	    = &mpfs_pdma,
> +	},
>  	{},
>  };
>  MODULE_DEVICE_TABLE(of, sf_pdma_dt_ids);
> diff --git a/drivers/dma/sf-pdma/sf-pdma.h b/drivers/dma/sf-pdma/sf-pdma.h
> index 5c398a83b491..267e79a5e0a5 100644
> --- a/drivers/dma/sf-pdma/sf-pdma.h
> +++ b/drivers/dma/sf-pdma/sf-pdma.h
> @@ -48,7 +48,8 @@
>  #define PDMA_ERR_STATUS_MASK				GENMASK(31, 31)
>  
>  /* Transfer Type */
> -#define PDMA_FULL_SPEED					0xFF000008
> +#define PDMA_FULL_SPEED					0xFF000000
> +#define PDMA_STRICT_ORDERING				BIT(3)
>  
>  /* Error Recovery */
>  #define MAX_RETRY					1
> @@ -112,8 +113,13 @@ struct sf_pdma {
>  	struct dma_device       dma_dev;
>  	void __iomem            *membase;
>  	void __iomem            *mappedbase;
> +	u32			transfer_type;
>  	u32			n_chans;
>  	struct sf_pdma_chan	chans[];
>  };
>  
> +struct sf_pdma_driver_platdata {
> +	u32 quirks;
> +};
> +
>  #endif /* _SF_PDMA_H */
> -- 
> 2.34.1

-- 
~Vinod

RE: [PATCH v4 3/4] dmaengine: sf-pdma: add mpfs-pdma compatible name

[Shravan.Chippa]

Hi Vinod,

> -----Original Message-----
> From: Vinod Koul <vkoul@kernel.org>
> Sent: Friday, November 24, 2023 5:42 PM
> To: shravan Chippa - I35088 <Shravan.Chippa@microchip.com>
> Cc: green.wan@sifive.com; robh+dt@kernel.org;
> krzysztof.kozlowski+dt@linaro.org; palmer@dabbelt.com;
> paul.walmsley@sifive.com; conor+dt@kernel.org;
> dmaengine@vger.kernel.org; devicetree@vger.kernel.org; linux-
> riscv@lists.infradead.org; linux-kernel@vger.kernel.org; Nagasuresh Relli -
> I67208 <Nagasuresh.Relli@microchip.com>; Praveen Kumar - I30718
> <Praveen.Kumar@microchip.com>; Emil Renner Berthing
> <emil.renner.berthing@canonical.com>
> Subject: Re: [PATCH v4 3/4] dmaengine: sf-pdma: add mpfs-pdma compatible
> name
> 
> [Some people who received this message don't often get email from
> vkoul@kernel.org. Learn why this is important at
> https://aka.ms/LearnAboutSenderIdentification ]
> 
> EXTERNAL EMAIL: Do not click links or open attachments unless you know the
> content is safe
> 
> On 31-10-23, 10:57, shravan chippa wrote:
> > From: Shravan Chippa <shravan.chippa@microchip.com>
> >
> > Sifive platform dma does not allow out-of-order transfers, Add a
> > PolarFire SoC specific compatible and code to support for out-of-order
> > dma transfers
> 
> By default dma xtions are not supposed to be out of order, so why does it
> make sense specifying that here?

All the DMA transfers are mostly in-order; however, sf-pdma IP has programable configuration:
we can select the transfer type either in-order or out-of-order.
 
Sf-pdam IP will only support mem-to-mem transfers. 
 
We got better throughput in the PolarFire SoC platform if we use out-of-order DMA transfers type, instead of in-order configuration in the sf-pdma IP.
 
test results for in-order:
- moved 16 MB from 0x89000000 using pdmacpy to 0x88000000 (chan: 0) in 0.068962 secs (232.012 MB per sec)
 
test results for out-of-order:
- moved 16 MB from 0x89000000 using pdmacpy to 0x88000000 (chan: 0) in 0.037020 secs (432.199 MB per sec)

Thanks,
Shravan

> 
> >
> > Reviewed-by: Emil Renner Berthing <emil.renner.berthing@canonical.com>
> > Signed-off-by: Shravan Chippa <shravan.chippa@microchip.com>
> > ---
> >  drivers/dma/sf-pdma/sf-pdma.c | 27 ++++++++++++++++++++++++---
> > drivers/dma/sf-pdma/sf-pdma.h |  8 +++++++-
> >  2 files changed, 31 insertions(+), 4 deletions(-)
> >
> > diff --git a/drivers/dma/sf-pdma/sf-pdma.c
> > b/drivers/dma/sf-pdma/sf-pdma.c index 4c456bdef882..82ab12c40743
> > 100644
> > --- a/drivers/dma/sf-pdma/sf-pdma.c
> > +++ b/drivers/dma/sf-pdma/sf-pdma.c
> > @@ -25,6 +25,8 @@
> >
> >  #include "sf-pdma.h"
> >
> > +#define PDMA_QUIRK_NO_STRICT_ORDERING   BIT(0)
> > +
> >  #ifndef readq
> >  static inline unsigned long long readq(void __iomem *addr)  { @@
> > -66,7 +68,7 @@ static struct sf_pdma_desc *sf_pdma_alloc_desc(struct
> > sf_pdma_chan *chan)  static void sf_pdma_fill_desc(struct sf_pdma_desc
> *desc,
> >                             u64 dst, u64 src, u64 size)  {
> > -     desc->xfer_type = PDMA_FULL_SPEED;
> > +     desc->xfer_type =  desc->chan->pdma->transfer_type;
> >       desc->xfer_size = size;
> >       desc->dst_addr = dst;
> >       desc->src_addr = src;
> > @@ -520,6 +522,7 @@ static struct dma_chan *sf_pdma_of_xlate(struct
> > of_phandle_args *dma_spec,
> >
> >  static int sf_pdma_probe(struct platform_device *pdev)  {
> > +     const struct sf_pdma_driver_platdata *ddata;
> >       struct sf_pdma *pdma;
> >       int ret, n_chans;
> >       const enum dma_slave_buswidth widths = @@ -545,6 +548,14 @@
> > static int sf_pdma_probe(struct platform_device *pdev)
> >
> >       pdma->n_chans = n_chans;
> >
> > +     pdma->transfer_type = PDMA_FULL_SPEED | PDMA_STRICT_ORDERING;
> > +
> > +     ddata  = device_get_match_data(&pdev->dev);
> > +     if (ddata) {
> > +             if (ddata->quirks & PDMA_QUIRK_NO_STRICT_ORDERING)
> > +                     pdma->transfer_type &= ~PDMA_STRICT_ORDERING;
> > +     }
> > +
> >       pdma->membase = devm_platform_ioremap_resource(pdev, 0);
> >       if (IS_ERR(pdma->membase))
> >               return PTR_ERR(pdma->membase); @@ -632,9 +643,19 @@
> > static int sf_pdma_remove(struct platform_device *pdev)
> >       return 0;
> >  }
> >
> > +static const struct sf_pdma_driver_platdata mpfs_pdma = {
> > +     .quirks = PDMA_QUIRK_NO_STRICT_ORDERING, };
> > +
> >  static const struct of_device_id sf_pdma_dt_ids[] = {
> > -     { .compatible = "sifive,fu540-c000-pdma" },
> > -     { .compatible = "sifive,pdma0" },
> > +     {
> > +             .compatible = "sifive,fu540-c000-pdma",
> > +     }, {
> > +             .compatible = "sifive,pdma0",
> > +     }, {
> > +             .compatible = "microchip,mpfs-pdma",
> > +             .data       = &mpfs_pdma,
> > +     },
> >       {},
> >  };
> >  MODULE_DEVICE_TABLE(of, sf_pdma_dt_ids); diff --git
> > a/drivers/dma/sf-pdma/sf-pdma.h b/drivers/dma/sf-pdma/sf-pdma.h
> index
> > 5c398a83b491..267e79a5e0a5 100644
> > --- a/drivers/dma/sf-pdma/sf-pdma.h
> > +++ b/drivers/dma/sf-pdma/sf-pdma.h
> > @@ -48,7 +48,8 @@
> >  #define PDMA_ERR_STATUS_MASK                         GENMASK(31, 31)
> >
> >  /* Transfer Type */
> > -#define PDMA_FULL_SPEED                                      0xFF000008
> > +#define PDMA_FULL_SPEED                                      0xFF000000
> > +#define PDMA_STRICT_ORDERING                         BIT(3)
> >
> >  /* Error Recovery */
> >  #define MAX_RETRY                                    1
> > @@ -112,8 +113,13 @@ struct sf_pdma {
> >       struct dma_device       dma_dev;
> >       void __iomem            *membase;
> >       void __iomem            *mappedbase;
> > +     u32                     transfer_type;
> >       u32                     n_chans;
> >       struct sf_pdma_chan     chans[];
> >  };
> >
> > +struct sf_pdma_driver_platdata {
> > +     u32 quirks;
> > +};
> > +
> >  #endif /* _SF_PDMA_H */
> > --
> > 2.34.1
> 
> --
> ~Vinod

RE: [PATCH v4 1/4] dmaengine: sf-pdma: Support of_dma_controller_register()

[Shravan.Chippa]

Hi Vinod,


> -----Original Message-----
> From: Vinod Koul <vkoul@kernel.org>
> Sent: Friday, November 24, 2023 5:39 PM
> To: shravan Chippa - I35088 <Shravan.Chippa@microchip.com>
> Cc: green.wan@sifive.com; robh+dt@kernel.org;
> krzysztof.kozlowski+dt@linaro.org; palmer@dabbelt.com;
> paul.walmsley@sifive.com; conor+dt@kernel.org;
> dmaengine@vger.kernel.org; devicetree@vger.kernel.org; linux-
> riscv@lists.infradead.org; linux-kernel@vger.kernel.org; Nagasuresh Relli -
> I67208 <Nagasuresh.Relli@microchip.com>; Praveen Kumar - I30718
> <Praveen.Kumar@microchip.com>
> Subject: Re: [PATCH v4 1/4] dmaengine: sf-pdma: Support
> of_dma_controller_register()
> 
> EXTERNAL EMAIL: Do not click links or open attachments unless you know the
> content is safe
> 
> On 31-10-23, 10:57, shravan chippa wrote:
> > From: Shravan Chippa <shravan.chippa@microchip.com>
> >
> > Update sf-pdma driver to adopt generic DMA device tree bindings.
> > It calls of_dma_controller_register() with sf-pdma specific
> > of_dma_xlate to get the generic DMA device tree helper support and the
> > DMA clients can look up the sf-pdma controller using standard APIs.
> >
> > Signed-off-by: Shravan Chippa <shravan.chippa@microchip.com>
> > ---
> >  drivers/dma/sf-pdma/sf-pdma.c | 44
> > +++++++++++++++++++++++++++++++++++
> >  1 file changed, 44 insertions(+)
> >
> > diff --git a/drivers/dma/sf-pdma/sf-pdma.c
> > b/drivers/dma/sf-pdma/sf-pdma.c index d1c6956af452..4c456bdef882
> > 100644
> > --- a/drivers/dma/sf-pdma/sf-pdma.c
> > +++ b/drivers/dma/sf-pdma/sf-pdma.c
> > @@ -20,6 +20,7 @@
> >  #include <linux/mod_devicetable.h>
> >  #include <linux/dma-mapping.h>
> >  #include <linux/of.h>
> > +#include <linux/of_dma.h>
> >  #include <linux/slab.h>
> >
> >  #include "sf-pdma.h"
> > @@ -490,6 +491,33 @@ static void sf_pdma_setup_chans(struct sf_pdma
> *pdma)
> >       }
> >  }
> >
> > +static struct dma_chan *sf_pdma_of_xlate(struct of_phandle_args
> *dma_spec,
> > +                                      struct of_dma *ofdma) {
> > +     struct sf_pdma *pdma = ofdma->of_dma_data;
> > +     struct device *dev = pdma->dma_dev.dev;
> > +     struct sf_pdma_chan *chan;
> > +     struct dma_chan *c;
> > +     u32 channel_id;
> > +
> > +     if (dma_spec->args_count != 1) {
> > +             dev_err(dev, "Bad number of cells\n");
> > +             return NULL;
> > +     }
> > +
> > +     channel_id = dma_spec->args[0];
> > +
> > +     chan = &pdma->chans[channel_id];
> > +
> > +     c = dma_get_slave_channel(&chan->vchan.chan);
> > +     if (!c) {
> > +             dev_err(dev, "No more channels available\n");
> > +             return NULL;
> > +     }
> > +
> > +     return c;
> > +}
> 
> This seems could be replaced by of_dma_xlate_by_chan_id() can you tell me
> why that cant be used?

I will try to use the of_dma_xlate_by_chan_id() function instead of a custom function, I will try to send the next revision.

Thanks,
Shravan


> 
> > +
> >  static int sf_pdma_probe(struct platform_device *pdev)  {
> >       struct sf_pdma *pdma;
> > @@ -563,7 +591,20 @@ static int sf_pdma_probe(struct platform_device
> *pdev)
> >               return ret;
> >       }
> >
> > +     ret = of_dma_controller_register(pdev->dev.of_node,
> > +                                      sf_pdma_of_xlate, pdma);
> > +     if (ret < 0) {
> > +             dev_err(&pdev->dev,
> > +                     "Can't register SiFive Platform OF_DMA. (%d)\n", ret);
> > +             goto err_unregister;
> > +     }
> > +
> >       return 0;
> > +
> > +err_unregister:
> > +     dma_async_device_unregister(&pdma->dma_dev);
> > +
> > +     return ret;
> >  }
> >
> >  static int sf_pdma_remove(struct platform_device *pdev) @@ -583,6
> > +624,9 @@ static int sf_pdma_remove(struct platform_device *pdev)
> >               tasklet_kill(&ch->err_tasklet);
> >       }
> >
> > +     if (pdev->dev.of_node)
> > +             of_dma_controller_free(pdev->dev.of_node);
> > +
> >       dma_async_device_unregister(&pdma->dma_dev);
> >
> >       return 0;
> > --
> > 2.34.1
> 
> --
> ~Vinod