[PATCH] UIO: Let uio_pdrv_genirq support cached memory

[PATCH] UIO: Let uio_pdrv_genirq support cached memory

[Indan Zupancic]

If 'cacheable' DT property exists, the memory mapping will be
done with UIO_MEM_IOVA instead of the default UIO_MEM_PHYS.
---
  Documentation/driver-api/uio-howto.rst | 3 ++-
  drivers/uio/uio_pdrv_genirq.c          | 8 ++++++--
  2 files changed, 8 insertions(+), 3 deletions(-)

diff --git a/Documentation/driver-api/uio-howto.rst 
b/Documentation/driver-api/uio-howto.rst
index 907ffa3b38f5..3cb48fc757d9 100644
--- a/Documentation/driver-api/uio-howto.rst
+++ b/Documentation/driver-api/uio-howto.rst
@@ -413,7 +413,8 @@ probed with the ``"of_id"`` module parameter set to 
the ``"compatible"``
  string of the node the driver is supposed to handle. By default, the
  node's name (without the unit address) is exposed as name for the
  UIO device in userspace. To set a custom name, a property named
-``"linux,uio-name"`` may be specified in the DT node.
+``"linux,uio-name"`` may be specified in the DT node. If a property
+named ``cacheable`` exists, the memory will be mapped cacheable.

  Using uio_dmem_genirq for platform devices
  ------------------------------------------
diff --git a/drivers/uio/uio_pdrv_genirq.c 
b/drivers/uio/uio_pdrv_genirq.c
index 63258b6accc4..269784ce0ba3 100644
--- a/drivers/uio/uio_pdrv_genirq.c
+++ b/drivers/uio/uio_pdrv_genirq.c
@@ -115,6 +115,7 @@ static int uio_pdrv_genirq_probe(struct 
platform_device *pdev)
  	struct uio_mem *uiomem;
  	int ret = -EINVAL;
  	int i;
+	int memtype = UIO_MEM_PHYS;

  	if (node) {
  		const char *name;
@@ -132,7 +133,10 @@ static int uio_pdrv_genirq_probe(struct 
platform_device *pdev)
  		else
  			uioinfo->name = devm_kasprintf(&pdev->dev, GFP_KERNEL,
  						       "%pOFn", node);
-
+		if (of_get_property(node, "cacheable", NULL)) {
+			dev_info(&pdev->dev, "%s cacheable\n", uioinfo->name);
+			memtype = UIO_MEM_IOVA;
+		}
  		uioinfo->version = "devicetree";
  		/* Multiple IRQs are not supported */
  	}
@@ -204,7 +208,7 @@ static int uio_pdrv_genirq_probe(struct 
platform_device *pdev)
  			break;
  		}

-		uiomem->memtype = UIO_MEM_PHYS;
+		uiomem->memtype = memtype;
  		uiomem->addr = r->start & PAGE_MASK;
  		uiomem->offs = r->start & ~PAGE_MASK;
  		uiomem->size = (uiomem->offs + resource_size(r)
-- 

Re: [PATCH] UIO: Let uio_pdrv_genirq support cached memory

[Greg KH]

On Wed, May 04, 2022 at 04:52:53PM +0200, Indan Zupancic wrote:
> If 'cacheable' DT property exists, the memory mapping will be
> done with UIO_MEM_IOVA instead of the default UIO_MEM_PHYS.
> ---
>  Documentation/driver-api/uio-howto.rst | 3 ++-
>  drivers/uio/uio_pdrv_genirq.c          | 8 ++++++--
>  2 files changed, 8 insertions(+), 3 deletions(-)
> 
> diff --git a/Documentation/driver-api/uio-howto.rst
> b/Documentation/driver-api/uio-howto.rst
> index 907ffa3b38f5..3cb48fc757d9 100644
> --- a/Documentation/driver-api/uio-howto.rst
> +++ b/Documentation/driver-api/uio-howto.rst
> @@ -413,7 +413,8 @@ probed with the ``"of_id"`` module parameter set to the
> ``"compatible"``
>  string of the node the driver is supposed to handle. By default, the
>  node's name (without the unit address) is exposed as name for the
>  UIO device in userspace. To set a custom name, a property named
> -``"linux,uio-name"`` may be specified in the DT node.
> +``"linux,uio-name"`` may be specified in the DT node. If a property
> +named ``cacheable`` exists, the memory will be mapped cacheable.
> 
>  Using uio_dmem_genirq for platform devices
>  ------------------------------------------
> diff --git a/drivers/uio/uio_pdrv_genirq.c b/drivers/uio/uio_pdrv_genirq.c
> index 63258b6accc4..269784ce0ba3 100644
> --- a/drivers/uio/uio_pdrv_genirq.c
> +++ b/drivers/uio/uio_pdrv_genirq.c
> @@ -115,6 +115,7 @@ static int uio_pdrv_genirq_probe(struct platform_device
> *pdev)
>  	struct uio_mem *uiomem;
>  	int ret = -EINVAL;
>  	int i;
> +	int memtype = UIO_MEM_PHYS;
> 
>  	if (node) {
>  		const char *name;
> @@ -132,7 +133,10 @@ static int uio_pdrv_genirq_probe(struct platform_device
> *pdev)
>  		else
>  			uioinfo->name = devm_kasprintf(&pdev->dev, GFP_KERNEL,
>  						       "%pOFn", node);
> -
> +		if (of_get_property(node, "cacheable", NULL)) {
> +			dev_info(&pdev->dev, "%s cacheable\n", uioinfo->name);
> +			memtype = UIO_MEM_IOVA;
> +		}
>  		uioinfo->version = "devicetree";
>  		/* Multiple IRQs are not supported */
>  	}
> @@ -204,7 +208,7 @@ static int uio_pdrv_genirq_probe(struct platform_device
> *pdev)
>  			break;
>  		}
> 
> -		uiomem->memtype = UIO_MEM_PHYS;
> +		uiomem->memtype = memtype;
>  		uiomem->addr = r->start & PAGE_MASK;
>  		uiomem->offs = r->start & ~PAGE_MASK;
>  		uiomem->size = (uiomem->offs + resource_size(r)
> -- 

Hi,

This is the friendly patch-bot of Greg Kroah-Hartman.  You have sent him
a patch that has triggered this response.  He used to manually respond
to these common problems, but in order to save his sanity (he kept
writing the same thing over and over, yet to different people), I was
created.  Hopefully you will not take offence and will fix the problem
in your patch and resubmit it so that it can be accepted into the Linux
kernel tree.

You are receiving this message because of the following common error(s)
as indicated below:

- Your patch is malformed (tabs converted to spaces, linewrapped, etc.)
  and can not be applied.  Please read the file,
  Documentation/email-clients.txt in order to fix this.

- Your patch does not have a Signed-off-by: line.  Please read the
  kernel file, Documentation/SubmittingPatches and resend it after
  adding that line.  Note, the line needs to be in the body of the
  email, before the patch, not at the bottom of the patch or in the
  email signature.

- You did not specify a description of why the patch is needed, or
  possibly, any description at all, in the email body.  Please read the
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  Documentation/SubmittingPatches for what is needed in order to
  properly describe the change.

- You did not write a descriptive Subject: for the patch, allowing Greg,
  and everyone else, to know what this patch is all about.  Please read
  the section entitled "The canonical patch format" in the kernel file,
  Documentation/SubmittingPatches for what a proper Subject: line should
  look like.

If you wish to discuss this problem further, or you have questions about
how to resolve this issue, please feel free to respond to this email and
Greg will reply once he has dug out from the pending patches received
from other developers.

thanks,

greg k-h's patch email bot

[PATCH v2] UIO: Let uio_pdrv_genirq support cached memory

[Indan Zupancic]

If 'cacheable' DT property exists, the memory mapping will be
done with UIO_MEM_IOVA instead of the default UIO_MEM_PHYS.

Signed-off-by: Indan Zupancic <Indan.Zupancic@mep-info.com>
---
 Documentation/driver-api/uio-howto.rst | 3 ++-
 drivers/uio/uio_pdrv_genirq.c          | 8 ++++++--
 2 files changed, 8 insertions(+), 3 deletions(-)

diff --git a/Documentation/driver-api/uio-howto.rst b/Documentation/driver-api/uio-howto.rst
index 907ffa3b38f5..3cb48fc757d9 100644
--- a/Documentation/driver-api/uio-howto.rst
+++ b/Documentation/driver-api/uio-howto.rst
@@ -413,7 +413,8 @@ probed with the ``"of_id"`` module parameter set to the ``"compatible"``
 string of the node the driver is supposed to handle. By default, the
 node's name (without the unit address) is exposed as name for the
 UIO device in userspace. To set a custom name, a property named
-``"linux,uio-name"`` may be specified in the DT node.
+``"linux,uio-name"`` may be specified in the DT node. If a property
+named ``cacheable`` exists, the memory will be mapped cacheable.
 
 Using uio_dmem_genirq for platform devices
 ------------------------------------------
diff --git a/drivers/uio/uio_pdrv_genirq.c b/drivers/uio/uio_pdrv_genirq.c
index 63258b6accc4..269784ce0ba3 100644
--- a/drivers/uio/uio_pdrv_genirq.c
+++ b/drivers/uio/uio_pdrv_genirq.c
@@ -115,6 +115,7 @@ static int uio_pdrv_genirq_probe(struct platform_device *pdev)
 	struct uio_mem *uiomem;
 	int ret = -EINVAL;
 	int i;
+	int memtype = UIO_MEM_PHYS;
 
 	if (node) {
 		const char *name;
@@ -132,7 +133,10 @@ static int uio_pdrv_genirq_probe(struct platform_device *pdev)
 		else
 			uioinfo->name = devm_kasprintf(&pdev->dev, GFP_KERNEL,
 						       "%pOFn", node);
-
+		if (of_get_property(node, "cacheable", NULL)) {
+			dev_info(&pdev->dev, "%s cacheable\n", uioinfo->name);
+			memtype = UIO_MEM_IOVA;
+		}
 		uioinfo->version = "devicetree";
 		/* Multiple IRQs are not supported */
 	}
@@ -204,7 +208,7 @@ static int uio_pdrv_genirq_probe(struct platform_device *pdev)
 			break;
 		}
 
-		uiomem->memtype = UIO_MEM_PHYS;
+		uiomem->memtype = memtype;
 		uiomem->addr = r->start & PAGE_MASK;
 		uiomem->offs = r->start & ~PAGE_MASK;
 		uiomem->size = (uiomem->offs + resource_size(r)
-- 
2.30.2

Re: [PATCH v2] UIO: Let uio_pdrv_genirq support cached memory

[Hongren Zheng]

On Thu, May 05, 2022 at 02:15:19PM +0200, Indan Zupancic wrote:
> If 'cacheable' DT property exists, the memory mapping will be
> done with UIO_MEM_IOVA instead of the default UIO_MEM_PHYS.
> 
> Signed-off-by: Indan Zupancic <Indan.Zupancic@mep-info.com>
> ---
>  Documentation/driver-api/uio-howto.rst | 3 ++-
>  drivers/uio/uio_pdrv_genirq.c          | 8 ++++++--
>  2 files changed, 8 insertions(+), 3 deletions(-)

I assume this is fundamentally OK? What else should be done to get this merged?

I plan to add similar functionality for uio_pci_generic,
especially for the RedHat IVSHMEM pcie device where
bar2 is just normal memory and should be marked
as UIO_MEM_IOVA as this has performance implication,
is that acceptable?

Cc'ed uio_pci_generic maintainer here.

> 
> diff --git a/Documentation/driver-api/uio-howto.rst b/Documentation/driver-api/uio-howto.rst
> index 907ffa3b38f5..3cb48fc757d9 100644
> --- a/Documentation/driver-api/uio-howto.rst
> +++ b/Documentation/driver-api/uio-howto.rst
> @@ -413,7 +413,8 @@ probed with the ``"of_id"`` module parameter set to the ``"compatible"``
>  string of the node the driver is supposed to handle. By default, the
>  node's name (without the unit address) is exposed as name for the
>  UIO device in userspace. To set a custom name, a property named
> -``"linux,uio-name"`` may be specified in the DT node.
> +``"linux,uio-name"`` may be specified in the DT node. If a property
> +named ``cacheable`` exists, the memory will be mapped cacheable.
>  
>  Using uio_dmem_genirq for platform devices
>  ------------------------------------------
> diff --git a/drivers/uio/uio_pdrv_genirq.c b/drivers/uio/uio_pdrv_genirq.c
> index 63258b6accc4..269784ce0ba3 100644
> --- a/drivers/uio/uio_pdrv_genirq.c
> +++ b/drivers/uio/uio_pdrv_genirq.c
> @@ -115,6 +115,7 @@ static int uio_pdrv_genirq_probe(struct platform_device *pdev)
>  	struct uio_mem *uiomem;
>  	int ret = -EINVAL;
>  	int i;
> +	int memtype = UIO_MEM_PHYS;
>  
>  	if (node) {
>  		const char *name;
> @@ -132,7 +133,10 @@ static int uio_pdrv_genirq_probe(struct platform_device *pdev)
>  		else
>  			uioinfo->name = devm_kasprintf(&pdev->dev, GFP_KERNEL,
>  						       "%pOFn", node);
> -
> +		if (of_get_property(node, "cacheable", NULL)) {
> +			dev_info(&pdev->dev, "%s cacheable\n", uioinfo->name);
> +			memtype = UIO_MEM_IOVA;
> +		}
>  		uioinfo->version = "devicetree";
>  		/* Multiple IRQs are not supported */
>  	}
> @@ -204,7 +208,7 @@ static int uio_pdrv_genirq_probe(struct platform_device *pdev)
>  			break;
>  		}
>  
> -		uiomem->memtype = UIO_MEM_PHYS;
> +		uiomem->memtype = memtype;
>  		uiomem->addr = r->start & PAGE_MASK;
>  		uiomem->offs = r->start & ~PAGE_MASK;
>  		uiomem->size = (uiomem->offs + resource_size(r)
> -- 
> 2.30.2
> 
>