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

[Russ Weight <russell.h.weight@intel.com>]

On 9/10/21 1:50 AM, Xu Yilun wrote:
> 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@intel.com>
>> ---
>> 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.
Thanks - I'll fix it.
>
>> + *
>> + * 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?
We could, but I did see a lot of uapi header file examples that use
enum for IOCTL structures. Is there a reason to prefer __u32? If I change
these to __u32, then I suppose I need to change from enum declarations to
#define macros?

- Russ

>
> Thanks,
> Yilun
>
>> +};
>> +
>>  #endif /* _UAPI_LINUX_FPGA_IMAGE_LOAD_H */
>> -- 
>> 2.25.1