Re: [PATCH v5 6/7] fpga: dfl: afu: add AFU interrupt support

[Marcelo Tosatti <mtosatti@redhat.com>]

On Mon, Apr 20, 2020 at 04:11:42PM +0800, Xu Yilun wrote:
> AFU (Accelerated Function Unit) is dynamic region of the DFL based FPGA,
> and always defined by users. Some DFL based FPGA cards allow users to
> implement their own interrupts in AFU. In order to support this,
> hardware implements a new UINT (AFU Interrupt) private feature with
> related capability register which describes the number of supported
> AFU interrupts as well as the local index of the interrupts for
> software enumeration, and from software side, driver follows the common
> DFL interrupt notification and handling mechanism, and it implements
> two ioctls below for user to query number of irqs supported and set/unset
> interrupt triggers.
> 
>  Ioctls:
>  * DFL_FPGA_PORT_UINT_GET_IRQ_NUM
>    get the number of irqs, which is used to determine how many interrupts
>    UINT feature supports.
> 
>  * DFL_FPGA_PORT_UINT_SET_IRQ
>    set/unset eventfds as AFU interrupt triggers.
> 
> Signed-off-by: Luwei Kang <luwei.kang@intel.com>
> Signed-off-by: Wu Hao <hao.wu@intel.com>
> Signed-off-by: Xu Yilun <yilun.xu@intel.com>
> Acked-by: Wu Hao <hao.wu@intel.com>
> ----
> v2: use DFL_FPGA_PORT_UINT_GET_IRQ_NUM instead of
>     DFL_FPGA_PORT_UINT_GET_INFO
>     Delete flags field for DFL_FPGA_PORT_UINT_SET_IRQ
> v3: put_user() instead of copy_to_user()
>     improves comments
> v4: use common functions to handle irq ioctls
> v5: Minor fixes for Hao's comments
> ---
>  drivers/fpga/dfl-afu-main.c   | 28 ++++++++++++++++++++++++++++
>  include/uapi/linux/fpga-dfl.h | 23 +++++++++++++++++++++++
>  2 files changed, 51 insertions(+)
> 
> diff --git a/drivers/fpga/dfl-afu-main.c b/drivers/fpga/dfl-afu-main.c
> index b1ed7b4..753cda4 100644
> --- a/drivers/fpga/dfl-afu-main.c
> +++ b/drivers/fpga/dfl-afu-main.c
> @@ -530,6 +530,30 @@ static const struct dfl_feature_ops port_stp_ops = {
>  	.init = port_stp_init,
>  };
>  
> +static long
> +port_uint_ioctl(struct platform_device *pdev, struct dfl_feature *feature,
> +		unsigned int cmd, unsigned long arg)
> +{
> +	switch (cmd) {
> +	case DFL_FPGA_PORT_UINT_GET_IRQ_NUM:
> +		return dfl_feature_ioctl_get_num_irqs(pdev, feature, arg);
> +	case DFL_FPGA_PORT_UINT_SET_IRQ:
> +		return dfl_feature_ioctl_set_irq(pdev, feature, arg);
> +	default:
> +		dev_dbg(&pdev->dev, "%x cmd not handled", cmd);
> +		return -ENODEV;
> +	}
> +}
> +
> +static const struct dfl_feature_id port_uint_id_table[] = {
> +	{.id = PORT_FEATURE_ID_UINT,},
> +	{0,}
> +};
> +
> +static const struct dfl_feature_ops port_uint_ops = {
> +	.ioctl = port_uint_ioctl,
> +};
> +
>  static struct dfl_feature_driver port_feature_drvs[] = {
>  	{
>  		.id_table = port_hdr_id_table,
> @@ -548,6 +572,10 @@ static struct dfl_feature_driver port_feature_drvs[] = {
>  		.ops = &port_stp_ops,
>  	},
>  	{
> +		.id_table = port_uint_id_table,
> +		.ops = &port_uint_ops,
> +	},
> +	{
>  		.ops = NULL,
>  	}
>  };
> diff --git a/include/uapi/linux/fpga-dfl.h b/include/uapi/linux/fpga-dfl.h
> index b6495ea..1621b07 100644
> --- a/include/uapi/linux/fpga-dfl.h
> +++ b/include/uapi/linux/fpga-dfl.h
> @@ -187,6 +187,29 @@ struct dfl_fpga_irq_set {
>  					     DFL_PORT_BASE + 6,	\
>  					     struct dfl_fpga_irq_set)
>  
> +/**
> + * DFL_FPGA_PORT_UINT_GET_IRQ_NUM - _IOR(DFL_FPGA_MAGIC, DFL_PORT_BASE + 7,
> + *								__u32 num_irqs)
> + *
> + * Get the number of irqs supported by the fpga AFU interrupt private
> + * feature.
> + * Return: 0 on success, -errno on failure.
> + */
> +#define DFL_FPGA_PORT_UINT_GET_IRQ_NUM	_IOR(DFL_FPGA_MAGIC,	\
> +					     DFL_PORT_BASE + 7, __u32)
> +
> +/**
> + * DFL_FPGA_PORT_UINT_SET_IRQ - _IOW(DFL_FPGA_MAGIC, DFL_PORT_BASE + 8,
> + *						struct dfl_fpga_irq_set)
> + *
> + * Set fpga AFU interrupt trigger if evtfds[n] is valid.
> + * Unset related interrupt trigger if evtfds[n] is a negative value.
> + * Return: 0 on success, -errno on failure.
> + */
> +#define DFL_FPGA_PORT_UINT_SET_IRQ	_IOW(DFL_FPGA_MAGIC,	\
> +					     DFL_PORT_BASE + 8,	\
> +					     struct dfl_fpga_irq_set)
> +
>  /* IOCTLs for FME file descriptor */
>  
>  /**
> -- 
> 2.7.4


Reviewed-by: Marcelo Tosatti <mtosatti@redhat.com>