[v10,2/2] Documentation: fpga: dfl: Add description for DFL UIO support

Commit Message

Xu Yilun Feb. 1, 2021, 5:38 a.m. UTC

This patch adds description for UIO support for dfl devices on DFL
bus.

Signed-off-by: Xu Yilun <[e-mail]>
Reviewed-by: Tom Rix <[e-mail]>
---
v2: no doc in v1, add it for v2.
v3: some documentation fixes.
v4: documentation change since the driver matching is changed.
v5: no change.
v6: improve the title of the userspace driver support section.
    some word improvement.
v7: rebased to next-20210119
v8: some doc fixes.
v9: some doc change since we switch to the driver in drivers/uio.
v10: no change.
---
 Documentation/fpga/dfl.rst | 23 +++++++++++++++++++++++
 1 file changed, 23 insertions(+)

Comments

Wu, Hao Feb. 1, 2021, 12:59 p.m. UTC | #1

> Subject: [PATCH v10 2/2] Documentation: fpga: dfl: Add description for DFL UIO
> support
> 
> This patch adds description for UIO support for dfl devices on DFL
> bus.
> 
> Signed-off-by: Xu Yilun <[e-mail]>
> Reviewed-by: Tom Rix <[e-mail]>
> ---
> v2: no doc in v1, add it for v2.
> v3: some documentation fixes.
> v4: documentation change since the driver matching is changed.
> v5: no change.
> v6: improve the title of the userspace driver support section.
>     some word improvement.
> v7: rebased to next-20210119
> v8: some doc fixes.
> v9: some doc change since we switch to the driver in drivers/uio.
> v10: no change.
> ---
>  Documentation/fpga/dfl.rst | 23 +++++++++++++++++++++++
>  1 file changed, 23 insertions(+)
> 
> diff --git a/Documentation/fpga/dfl.rst b/Documentation/fpga/dfl.rst
> index c41ac76..e35cf87 100644
> --- a/Documentation/fpga/dfl.rst
> +++ b/Documentation/fpga/dfl.rst
> @@ -7,6 +7,7 @@ Authors:
>  - Enno Luebbers <[e-mail]>
>  - Xiao Guangrong <[e-mail]>
>  - Wu Hao <[e-mail]>
> +- Xu Yilun <[e-mail]>
> 
>  The Device Feature List (DFL) FPGA framework (and drivers according to
>  this framework) hides the very details of low layer hardwares and provides
> @@ -530,6 +531,28 @@ Being able to specify more than one DFL per BAR has
> been considered, but it
>  was determined the use case did not provide value.  Specifying a single DFL
>  per BAR simplifies the implementation and allows for extra error checking.
> 
> +
> +Userspace driver support for DFL devices
> +========================================
> +The purpose of an FPGA is to be reprogrammed with newly developed
> hardware
> +components. New hardware can instantiate a new private feature in the DFL,
> and
> +then present a DFL device in the system. In some cases users may need a
> +userspace driver for the DFL device:
> +
> +* Users may need to run some diagnostic test for their hardware.
> +* Users may prototype the kernel driver in user space.
> +* Some hardware is designed for specific purposes and does not fit into one of
> +  the standard kernel subsystems.
> +
> +This requires direct access to MMIO space and interrupt handling from
> +userspace. The uio_dfl module exposes the UIO device interfaces for this
> +purpose.

Current uio_dfl doesn't have interrupt handling support, right? I guess we need
to make sure no confusion on the description here. other place looks good to me.

Hao

> +
> +UIO_DFL should be selected to enable the uio_dfl module driver. To support a
> +new DFL feature via UIO direct access, its feature id should be added to the
> +driver's id_table.
> +
> +
>  Open discussion
>  ===============
>  FME driver exports one ioctl (DFL_FPGA_FME_PORT_PR) for partial
> reconfiguration
> --
> 2.7.4

Xu Yilun Feb. 2, 2021, 1:59 a.m. UTC | #2

On Mon, Feb 01, 2021 at 08:59:06PM +0800, Wu, Hao wrote:
> > Subject: [PATCH v10 2/2] Documentation: fpga: dfl: Add description for DFL UIO
> > support
> >
> > This patch adds description for UIO support for dfl devices on DFL
> > bus.
> >
> > Signed-off-by: Xu Yilun <[e-mail]>
> > Reviewed-by: Tom Rix <[e-mail]>
> > ---
> > v2: no doc in v1, add it for v2.
> > v3: some documentation fixes.
> > v4: documentation change since the driver matching is changed.
> > v5: no change.
> > v6: improve the title of the userspace driver support section.
> >     some word improvement.
> > v7: rebased to next-20210119
> > v8: some doc fixes.
> > v9: some doc change since we switch to the driver in drivers/uio.
> > v10: no change.
> > ---
> >  Documentation/fpga/dfl.rst | 23 +++++++++++++++++++++++
> >  1 file changed, 23 insertions(+)
> >
> > diff --git a/Documentation/fpga/dfl.rst b/Documentation/fpga/dfl.rst
> > index c41ac76..e35cf87 100644
> > --- a/Documentation/fpga/dfl.rst
> > +++ b/Documentation/fpga/dfl.rst
> > @@ -7,6 +7,7 @@ Authors:
> >  - Enno Luebbers <[e-mail]>
> >  - Xiao Guangrong <[e-mail]>
> >  - Wu Hao <[e-mail]>
> > +- Xu Yilun <[e-mail]>
> >
> >  The Device Feature List (DFL) FPGA framework (and drivers according to
> >  this framework) hides the very details of low layer hardwares and provides
> > @@ -530,6 +531,28 @@ Being able to specify more than one DFL per BAR has
> > been considered, but it
> >  was determined the use case did not provide value.  Specifying a single DFL
> >  per BAR simplifies the implementation and allows for extra error checking.
> >
> > +
> > +Userspace driver support for DFL devices
> > +========================================
> > +The purpose of an FPGA is to be reprogrammed with newly developed
> > hardware
> > +components. New hardware can instantiate a new private feature in the DFL,
> > and
> > +then present a DFL device in the system. In some cases users may need a
> > +userspace driver for the DFL device:
> > +
> > +* Users may need to run some diagnostic test for their hardware.
> > +* Users may prototype the kernel driver in user space.
> > +* Some hardware is designed for specific purposes and does not fit into one of
> > +  the standard kernel subsystems.
> > +
> > +This requires direct access to MMIO space and interrupt handling from
> > +userspace. The uio_dfl module exposes the UIO device interfaces for this
> > +purpose.
> 
> Current uio_dfl doesn't have interrupt handling support, right? I guess we need
> to make sure no confusion on the description here. other place looks good to me.

Will fix it.

Thanks,
Yilun

Patch

diff --git a/Documentation/fpga/dfl.rst b/Documentation/fpga/dfl.rst
index c41ac76..e35cf87 100644
--- a/Documentation/fpga/dfl.rst
+++ b/Documentation/fpga/dfl.rst
@@ -7,6 +7,7 @@  Authors:
 - Enno Luebbers <[e-mail]>
 - Xiao Guangrong <[e-mail]>
 - Wu Hao <[e-mail]>
+- Xu Yilun <[e-mail]>
 
 The Device Feature List (DFL) FPGA framework (and drivers according to
 this framework) hides the very details of low layer hardwares and provides
@@ -530,6 +531,28 @@  Being able to specify more than one DFL per BAR has been considered, but it
 was determined the use case did not provide value.  Specifying a single DFL
 per BAR simplifies the implementation and allows for extra error checking.
 
+
+Userspace driver support for DFL devices
+========================================
+The purpose of an FPGA is to be reprogrammed with newly developed hardware
+components. New hardware can instantiate a new private feature in the DFL, and
+then present a DFL device in the system. In some cases users may need a
+userspace driver for the DFL device:
+
+* Users may need to run some diagnostic test for their hardware.
+* Users may prototype the kernel driver in user space.
+* Some hardware is designed for specific purposes and does not fit into one of
+  the standard kernel subsystems.
+
+This requires direct access to MMIO space and interrupt handling from
+userspace. The uio_dfl module exposes the UIO device interfaces for this
+purpose.
+
+UIO_DFL should be selected to enable the uio_dfl module driver. To support a
+new DFL feature via UIO direct access, its feature id should be added to the
+driver's id_table.
+
+
 Open discussion
 ===============
 FME driver exports one ioctl (DFL_FPGA_FME_PORT_PR) for partial reconfiguration