Re: [PATCH v15 4/6] fpga: image-load: add status ioctl

[Xu Yilun]

On Wed, Sep 08, 2021 at 07:18:44PM -0700, Russ Weight wrote:
> Extend the FPGA Image Load class driver to include an
> FPGA_IMAGE_LOAD_STATUS IOCTL that can be used to monitor the progress
> of an ongoing image load.  The status returned includes how much data
> remains to be transferred, the progress of the image load, and error
> information in the case of a failure.
> 
> Signed-off-by: Russ Weight <russell.h.weight@xxxxxxxxx>
> ---
> V15:
>  - This patch is new to the patchset and provides an FPGA_IMAGE_LOAD_STATUS
>    IOCTL to return the current values for: remaining_size, progress,
>    err_progress, and err_code.
>  - This patch has elements of the following three patches from the previous
>    patch-set:
>      [PATCH v14 3/6] fpga: sec-mgr: expose sec-mgr update status
>      [PATCH v14 4/6] fpga: sec-mgr: expose sec-mgr update errors
>      [PATCH v14 5/6] fpga: sec-mgr: expose sec-mgr update size
>  - Changed file, symbol, and config names to reflect the new driver name
>  - There are some minor changes to locking to enable this ioctl to return
>    coherent data.
> ---
>  Documentation/fpga/fpga-image-load.rst |  6 +++
>  drivers/fpga/fpga-image-load.c         | 53 ++++++++++++++++++++++----
>  include/uapi/linux/fpga-image-load.h   | 18 +++++++++
>  3 files changed, 70 insertions(+), 7 deletions(-)
> 
> diff --git a/Documentation/fpga/fpga-image-load.rst b/Documentation/fpga/fpga-image-load.rst
> index 739d735592a5..3d5eb51223e3 100644
> --- a/Documentation/fpga/fpga-image-load.rst
> +++ b/Documentation/fpga/fpga-image-load.rst
> @@ -31,3 +31,9 @@ updated. This is an exclusive operation; an attempt to start concurrent image
>  load for the same device will fail with EBUSY. An eventfd file descriptor
>  parameter is provided to this IOCTL, and it will be signalled at the
>  completion of the image load.
> +
> +FPGA_IMAGE_LOAD_STATUS:
> +
> +Collect status for an on-going image upload. The status returned includes
> +how much data remains to be transferred, the progress of the image load,
> +and error information in the case of a failure.
> diff --git a/drivers/fpga/fpga-image-load.c b/drivers/fpga/fpga-image-load.c
> index b784456765b0..99a47b21c995 100644
> --- a/drivers/fpga/fpga-image-load.c
> +++ b/drivers/fpga/fpga-image-load.c
> @@ -22,10 +22,27 @@ static dev_t fpga_image_devt;
>  
>  #define to_image_load(d) container_of(d, struct fpga_image_load, dev)
>  
> -static void fpga_image_dev_error(struct fpga_image_load *imgld,
> +static void fpga_image_update_progress(struct fpga_image_load *imgld,
> +				       enum fpga_image_prog new_progress)
> +{
> +	mutex_lock(&imgld->lock);
> +	imgld->progress = new_progress;
> +	mutex_unlock(&imgld->lock);
> +}
> +
> +static void fpga_image_set_error(struct fpga_image_load *imgld,
>  				 enum fpga_image_err err_code)
>  {
> +	mutex_lock(&imgld->lock);
> +	imgld->err_progress = imgld->progress;
>  	imgld->err_code = err_code;
> +	mutex_unlock(&imgld->lock);
> +}
> +
> +static void fpga_image_dev_error(struct fpga_image_load *imgld,
> +				 enum fpga_image_err err_code)
> +{
> +	fpga_image_set_error(imgld, err_code);
>  	imgld->lops->cancel(imgld);
>  }
>  
> @@ -49,18 +66,18 @@ static void fpga_image_do_load(struct work_struct *work)
>  
>  	get_device(&imgld->dev);
>  	if (!try_module_get(imgld->dev.parent->driver->owner)) {
> -		imgld->err_code = FPGA_IMAGE_ERR_BUSY;
> +		fpga_image_set_error(imgld, FPGA_IMAGE_ERR_BUSY);
>  		goto idle_exit;
>  	}
>  
> -	imgld->progress = FPGA_IMAGE_PROG_PREPARING;
> +	fpga_image_update_progress(imgld, FPGA_IMAGE_PROG_PREPARING);
>  	ret = imgld->lops->prepare(imgld);
>  	if (ret != FPGA_IMAGE_ERR_NONE) {
>  		fpga_image_dev_error(imgld, ret);
>  		goto modput_exit;
>  	}
>  
> -	imgld->progress = FPGA_IMAGE_PROG_WRITING;
> +	fpga_image_update_progress(imgld, FPGA_IMAGE_PROG_WRITING);
>  	while (imgld->remaining_size) {
>  		ret = imgld->lops->write_blk(imgld, offset);
>  		if (ret != FPGA_IMAGE_ERR_NONE) {
> @@ -71,7 +88,7 @@ static void fpga_image_do_load(struct work_struct *work)
>  		offset = size - imgld->remaining_size;
>  	}
>  
> -	imgld->progress = FPGA_IMAGE_PROG_PROGRAMMING;
> +	fpga_image_update_progress(imgld, FPGA_IMAGE_PROG_PROGRAMMING);
>  	ret = imgld->lops->poll_complete(imgld);
>  	if (ret != FPGA_IMAGE_ERR_NONE)
>  		fpga_image_dev_error(imgld, ret);
> @@ -151,20 +168,42 @@ static int fpga_image_load_ioctl_write(struct fpga_image_load *imgld,
>  	return ret;
>  }
>  
> +static int fpga_image_load_ioctl_status(struct fpga_image_load *imgld,
> +					unsigned long arg)
> +{
> +	struct fpga_image_status status;
> +
> +	memset(&status, 0, sizeof(status));
> +	status.progress = imgld->progress;
> +	status.remaining_size = imgld->remaining_size;
> +	status.err_progress = imgld->err_progress;
> +	status.err_code = imgld->err_code;
> +
> +	if (copy_to_user((void __user *)arg, &status, sizeof(status)))
> +		return -EFAULT;
> +
> +	return 0;
> +}
> +
>  static long fpga_image_load_ioctl(struct file *filp, unsigned int cmd,
>  				  unsigned long arg)
>  {
>  	struct fpga_image_load *imgld = filp->private_data;
>  	int ret = -ENOTTY;
>  
> +	mutex_lock(&imgld->lock);
> +
>  	switch (cmd) {
>  	case FPGA_IMAGE_LOAD_WRITE:
> -		mutex_lock(&imgld->lock);
>  		ret = fpga_image_load_ioctl_write(imgld, arg);
> -		mutex_unlock(&imgld->lock);
> +		break;
> +	case FPGA_IMAGE_LOAD_STATUS:
> +		ret = fpga_image_load_ioctl_status(imgld, arg);
>  		break;
>  	}
>  
> +	mutex_unlock(&imgld->lock);
> +
>  	return ret;
>  }
>  
> diff --git a/include/uapi/linux/fpga-image-load.h b/include/uapi/linux/fpga-image-load.h
> index a60da115adf5..6a995bcc0fb7 100644
> --- a/include/uapi/linux/fpga-image-load.h
> +++ b/include/uapi/linux/fpga-image-load.h
> @@ -38,6 +38,7 @@ enum fpga_image_err {
>  };
>  
>  #define FPGA_IMAGE_LOAD_WRITE	_IOW(FPGA_IMAGE_LOAD_MAGIC, 0, struct fpga_image_write)
> +#define FPGA_IMAGE_LOAD_STATUS	_IOR(FPGA_IMAGE_LOAD_MAGIC, 1, struct fpga_image_status)
>  
>  /**
>   * FPGA_IMAGE_LOAD_WRITE - _IOW(FPGA_IMAGE_LOAD_MAGIC, 0,
> @@ -56,4 +57,21 @@ struct fpga_image_write {
>  	__u64 buf;		/* User space address of source data */
>  };
>  
> +/**
> + * FPGA_IMAGE_LOAD_STATUS - _IOR(FPGA_IMAGE_LOAD_MAGIC, 1,
> + *				 struct fpga_image_status)
> + *
> + * Request status information for an ongoing update.
> + * data buffer, size, and an eventfd file descriptor.

This line is a typo.

> + *
> + * Return: 0 on success, -errno on failure.
> + */
> +struct fpga_image_status {
> +	/* Output */
> +	__u32 remaining_size;			/* size remaining to transfer */
> +	enum fpga_image_prog progress;		/* current progress of image load */
> +	enum fpga_image_prog err_progress;	/* progress at time of error */
> +	enum fpga_image_err err_code;		/* error code */

Should we use __u32 for these enumeration types?

Thanks,
Yilun

> +};
> +
>  #endif /* _UAPI_LINUX_FPGA_IMAGE_LOAD_H */
> -- 
> 2.25.1