Re: [PATCH v3 18/21] fpga: dfl: afu: add header sub feature support

[Wu Hao <hao.wu-ral2JQCrhuEAvxtiuMwx3w@public.gmane.org>]

On Mon, Feb 12, 2018 at 11:43:28AM -0600, Alan Tull wrote:
> On Mon, Nov 27, 2017 at 12:42 AM, Wu Hao <hao.wu-ral2JQCrhuEAvxtiuMwx3w@public.gmane.org> wrote:
> 
> Hi Hao,
> 
> Thanks for documenting the reset.  Please add this documentation to
> the function header that is in fpga-dfl.h.

Sure, thanks for the review. 

I will add the description to the function header.

> 
> One question for clarification below.
> 
> This patch looks good.
> 
> > The port header register set is always present for port, it is mainly
> > for capability, control and status of the ports that AFU connected to.
> >
> > This patch implements header sub feature support. Below user interfaces
> > are created by this patch.
> >
> > Sysfs interface:
> > * /sys/class/fpga_region/<regionX>/<fpga-dfl-port.x>/id
> >   Read-only. Port ID.
> >
> > Ioctl interface:
> > * FPGA_PORT_RESET
> >   Reset the FPGA Port and its AFU.
> >
> > Signed-off-by: Tim Whisonant <tim.whisonant-ral2JQCrhuEAvxtiuMwx3w@public.gmane.org>
> > Signed-off-by: Enno Luebbers <enno.luebbers-ral2JQCrhuEAvxtiuMwx3w@public.gmane.org>
> > Signed-off-by: Shiva Rao <shiva.rao-ral2JQCrhuEAvxtiuMwx3w@public.gmane.org>
> > Signed-off-by: Christopher Rauer <christopher.rauer-ral2JQCrhuEAvxtiuMwx3w@public.gmane.org>
> > Signed-off-by: Xiao Guangrong <guangrong.xiao-VuQAYsv1563Yd54FQh9/CA@public.gmane.org>
> > Signed-off-by: Wu Hao <hao.wu-ral2JQCrhuEAvxtiuMwx3w@public.gmane.org>
> 
> Acked-by: Alan Tull <atull-DgEjT+Ai2ygdnm+yROfE0A@public.gmane.org>
> 
> > ----
> > v3: rename driver name to fpga-dfl-afu
> >     add more description for reset ioctl.
> >     fix some checkpatch issues.
> > ---
> >  .../ABI/testing/sysfs-platform-fpga-dfl-afu        |  7 ++++
> >  drivers/fpga/dfl-afu-main.c                        | 44 +++++++++++++++++++++-
> >  include/uapi/linux/fpga-dfl.h                      | 17 +++++++++
> >  3 files changed, 67 insertions(+), 1 deletion(-)
> >  create mode 100644 Documentation/ABI/testing/sysfs-platform-fpga-dfl-afu
> >
> > diff --git a/Documentation/ABI/testing/sysfs-platform-fpga-dfl-afu b/Documentation/ABI/testing/sysfs-platform-fpga-dfl-afu
> > new file mode 100644
> > index 0000000..f4bcd94
> > --- /dev/null
> > +++ b/Documentation/ABI/testing/sysfs-platform-fpga-dfl-afu
> > @@ -0,0 +1,7 @@
> > +What:          /sys/bus/platform/devices/fpga-dfl-port.0/id
> > +Date:          November 2017
> > +KernelVersion:  4.15
> > +Contact:       Wu Hao <hao.wu-ral2JQCrhuEAvxtiuMwx3w@public.gmane.org>
> > +Description:   Read-only. It returns id of this port. One DFL FPGA device
> > +               may have more than one port. Userspace could use this id to
> > +               distinguish different ports under same FPGA device.
> 
> Potentially >1 port per FPGA, but only one port per fpga-region, right?

Yes.

Thanks
Hao

> 
> > diff --git a/drivers/fpga/dfl-afu-main.c b/drivers/fpga/dfl-afu-main.c
> > index d9f4b81..b01376c 100644
> > --- a/drivers/fpga/dfl-afu-main.c
> > +++ b/drivers/fpga/dfl-afu-main.c
> > @@ -18,25 +18,66 @@
> >
> >  #include <linux/kernel.h>
> >  #include <linux/module.h>
> > +#include <linux/fpga-dfl.h>
> >
> >  #include "fpga-dfl.h"
> >
> > +static ssize_t
> > +id_show(struct device *dev, struct device_attribute *attr, char *buf)
> > +{
> > +       int id = fpga_port_id(to_platform_device(dev));
> > +
> > +       return scnprintf(buf, PAGE_SIZE, "%d\n", id);
> > +}
> > +static DEVICE_ATTR_RO(id);
> > +
> > +static const struct attribute *port_hdr_attrs[] = {
> > +       &dev_attr_id.attr,
> > +       NULL,
> > +};
> > +
> >  static int port_hdr_init(struct platform_device *pdev, struct feature *feature)
> >  {
> >         dev_dbg(&pdev->dev, "PORT HDR Init.\n");
> >
> > -       return 0;
> > +       fpga_port_reset(pdev);
> > +
> > +       return sysfs_create_files(&pdev->dev.kobj, port_hdr_attrs);
> >  }
> >
> >  static void port_hdr_uinit(struct platform_device *pdev,
> >                            struct feature *feature)
> >  {
> >         dev_dbg(&pdev->dev, "PORT HDR UInit.\n");
> > +
> > +       sysfs_remove_files(&pdev->dev.kobj, port_hdr_attrs);
> > +}
> > +
> > +static long
> > +port_hdr_ioctl(struct platform_device *pdev, struct feature *feature,
> > +              unsigned int cmd, unsigned long arg)
> > +{
> > +       long ret;
> > +
> > +       switch (cmd) {
> > +       case FPGA_PORT_RESET:
> > +               if (!arg)
> > +                       ret = fpga_port_reset(pdev);
> > +               else
> > +                       ret = -EINVAL;
> > +               break;
> > +       default:
> > +               dev_dbg(&pdev->dev, "%x cmd not handled", cmd);
> > +               ret = -ENODEV;
> > +       }
> > +
> > +       return ret;
> >  }
> >
> >  static const struct feature_ops port_hdr_ops = {
> >         .init = port_hdr_init,
> >         .uinit = port_hdr_uinit,
> > +       .ioctl = port_hdr_ioctl,
> >  };
> >
> >  static struct feature_driver port_feature_drvs[] = {
> > @@ -76,6 +117,7 @@ static int afu_release(struct inode *inode, struct file *filp)
> >
> >         dev_dbg(&pdev->dev, "Device File Release\n");
> >
> > +       fpga_port_reset(pdev);
> >         feature_dev_use_end(pdata);
> >
> >         return 0;
> > diff --git a/include/uapi/linux/fpga-dfl.h b/include/uapi/linux/fpga-dfl.h
> > index 75bdf88..9bf273d 100644
> > --- a/include/uapi/linux/fpga-dfl.h
> > +++ b/include/uapi/linux/fpga-dfl.h
> > @@ -30,8 +30,11 @@
> >  #define FPGA_MAGIC 0xB6
> >
> >  #define FPGA_BASE 0
> > +#define PORT_BASE 0x40
> >  #define FME_BASE 0x80
> >
> > +/* Common IOCTLs for both FME and AFU file descriptor */
> > +
> >  /**
> >   * FPGA_GET_API_VERSION - _IO(FPGA_MAGIC, FPGA_BASE + 0)
> >   *
> > @@ -50,6 +53,20 @@
> >
> >  #define FPGA_CHECK_EXTENSION   _IO(FPGA_MAGIC, FPGA_BASE + 1)
> >
> > +/* IOCTLs for AFU file descriptor */
> > +
> > +/**
> > + * FPGA_PORT_RESET - _IO(FPGA_MAGIC, PORT_BASE + 0)
> > + *
> > + * Reset the FPGA Port and its AFU. No parameters are supported.
> > + * Userspace can do Port reset at any time, e.g during DMA or PR. But
> > + * it should never cause any system level issue, only functional failure
> > + * (e.g DMA or PR operation failure) and be recoverable from the failure.
> > + * Return: 0 on success, -errno of failure
> > + */
> > +
> > +#define FPGA_PORT_RESET                _IO(FPGA_MAGIC, PORT_BASE + 0)
> > +
> >  /* IOCTLs for FME file descriptor */
> >
> >  /**
> > --
> > 1.8.3.1
> >