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

[Tom Rix <trix@redhat.com>]

On 9/10/21 4:23 PM, Russ Weight wrote:
>
> 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?

The __u32 makes sure the struct is a constant size.

yes, change the enums to #defines.

The layout of a new api should be consistent with similar older api.

review uapi/linux/fpga-dfl.h , the dfl_fpga_port_region_info struct.

Tom


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