On Tue, Apr 09, 2024 at 07:39:42PM -0400, Peter Colberg wrote:
> From: Xu Yilun <yilun.xu@xxxxxxxxx>
>
> DFL ports are registered as platform devices in PF mode. The port device
> should be removed from the host when the user wants to configure the
> port as a VF and pass through to a virtual machine. The FME device
> ioctls DFL_FPGA_FME_PORT_RELEASE/ASSIGN are designed for this purpose.
>
> In the previous implementation, the port platform device is not completely
> destroyed on port release: it is removed from the system by
> platform_device_del(), but the platform device instance is retained.
> When the port assign ioctl is called, the platform device is added back by
> platform_device_add(), which conflicts with this comment of device_add():
> "Do not call this routine more than once for any device structure", and
> will cause a kernel warning at runtime.
>
> This patch tries to completely unregister the port platform device on
> release and registers a new one on assign. But the main work is to remove
> the dependency on struct dfl_feature_platform_data for many internal DFL
> APIs. This structure holds many DFL enumeration infos for feature devices.
> Many DFL APIs are expected to work with these info even when the port
> platform device is unregistered. But with the change the platform_data will
> be freed in this case. So this patch introduces a new structure
> dfl_feature_dev_data for these APIs, which acts similarly to the previous
> dfl_feature_platform_data. The dfl_feature_platform_data then only needs a
> pointer to dfl_feature_dev_data to make the feature device driver work.
>
> Signed-off-by: Xu Yilun <yilun.xu@xxxxxxxxx>
> Signed-off-by: Russ Weight <russell.h.weight@xxxxxxxxx>
> Signed-off-by: Peter Colberg <peter.colberg@xxxxxxxxx>
> ---
> v2:
> - Split monolithic patch into series at request of maintainer
> - Substitute binfo->type for removed function feature_dev_id_type() in
> parse_feature_irqs().
> - Return ERR_PTR(-ENOMEM) on !feature->params in
> binfo_create_feature_dev_data().
> - Reorder cdev as first member of struct dfl_feature_platform_data
> such that container_of() to obtain pdata evaluates to a no-op.
> - Align kernel-doc function name for __dfl_fpga_cdev_find_port_data().
> ---
> drivers/fpga/dfl-afu-main.c | 9 +-
> drivers/fpga/dfl-fme-br.c | 24 +-
> drivers/fpga/dfl-fme-main.c | 6 +-
> drivers/fpga/dfl.c | 430 +++++++++++++++++-------------------
> drivers/fpga/dfl.h | 86 +++++---
> 5 files changed, 281 insertions(+), 274 deletions(-)
>
> diff --git a/drivers/fpga/dfl-afu-main.c b/drivers/fpga/dfl-afu-main.c
> index 42928cc7e42b..ead03b7aea70 100644
> --- a/drivers/fpga/dfl-afu-main.c
> +++ b/drivers/fpga/dfl-afu-main.c
> @@ -143,9 +143,8 @@ static int port_reset(struct platform_device *pdev)
> return ret;
> }
>
> -static int port_get_id(struct platform_device *pdev)
> +static int port_get_id(struct dfl_feature_dev_data *fdata)
> {
> - struct dfl_feature_dev_data *fdata = to_dfl_feature_dev_data(&pdev->dev);
> void __iomem *base;
>
> base = dfl_get_feature_ioaddr_by_id(fdata, PORT_FEATURE_ID_HEADER);
> @@ -156,7 +155,8 @@ static int port_get_id(struct platform_device *pdev)
> static ssize_t
> id_show(struct device *dev, struct device_attribute *attr, char *buf)
> {
> - int id = port_get_id(to_platform_device(dev));
> + struct dfl_feature_dev_data *fdata = to_dfl_feature_dev_data(dev);
> + int id = port_get_id(fdata);
My quick idea is we go with these steps:
1. refactor struct dfl_feature_platform_data then replace all dev/pdev
arguments with pdata when necessary.
2. factor out fdata from pdata, add fdata helpers.
3. massive pdata->fdata replacement.
4. delete all unused pdata helpers.
Please check if it is possible.
Thanks,
Yilun
