2022-05-04 17:22:54

by Indan Zupancic

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

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)
--

2022-05-09 06:11:29

by Indan Zupancic

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

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 <[email protected]>
---
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

2023-05-18 04:18:23

by Hongren Zheng

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

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 <[email protected]>
> ---
> 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
>
>