Re: [PATCH v15 5/6] fpga: image-load: create status sysfs node

[Russ Weight]

On 9/10/21 1:52 AM, Xu Yilun wrote:
> On Wed, Sep 08, 2021 at 07:18:45PM -0700, Russ Weight wrote:
>> Extend the FPGA Image Load class driver to include a status sysfs node that
>> can be viewed to determine from the command line if an image load is in
>> progress. Status will be one of: idle, starting, preparing, writing, or
>> programming.
> The FPGA_IMAGE_LOAD_STATUS ioctl already provides the progress info.
> Why we need 2 user interfaces for the same information?

Updates on Vista Creek can take up to 40 minutes. I thought it might
be helpful to have a simple way, from the command line, to verify
whether or not there is an image upload in progress. Do you agree? Or
do you think this is unnecessary? Should I remove it? Or save it for
a later patch (after the main patches have been accepted)?

- Russ

>
> Thanks,
> Yilun
>
>> Signed-off-by: Russ Weight <russell.h.weight@xxxxxxxxx>
>> ---
>> v15:
>>  - Compare to previous patch:
>>      [PATCH v14 3/6] fpga: sec-mgr: expose sec-mgr update status
>>  - Changed file, symbol, and config names to reflect the new driver name
>>  - Removed signed-off/reviewed-by tags
>> v14:
>>  - Updated ABI documentation date and kernel version
>> v13:
>>   - No change
>> v12:
>>   - Updated Date and KernelVersion fields in ABI documentation
>>   - Changed syntax of sec_mgr_prog_str[] array definition from:
>> 	"idle",			/* FPGA_SEC_PROG_IDLE */
>>     to:
>> 	[FPGA_SEC_PROG_IDLE]	    = "idle",
>> v11:
>>   - No change
>> v10:
>>   - Rebased to 5.12-rc2 next
>>   - Updated Date and KernelVersion in ABI documentation
>> v9:
>>   - Updated Date and KernelVersion in ABI documentation
>> v8:
>>   - No change
>> v7:
>>   - Changed Date in documentation file to December 2020
>> v6:
>>   - No change
>> v5:
>>   - Use new function sysfs_emit() in the status_show() function
>> v4:
>>   - Changed from "Intel FPGA Security Manager" to FPGA Security Manager"
>>     and removed unnecessary references to "Intel".
>>   - Changed: iops -> sops, imgr -> smgr, IFPGA_ -> FPGA_, ifpga_ to fpga_
>> v3:
>>   - Use a local variable to read progress once in status_show()
>>   - Use dev_err to report invalid progress status
>> v2:
>>   - Bumped documentation date and version
>>   - Changed progress state "read_file" to "reading"
>> ---
>>  .../ABI/testing/sysfs-class-fpga-image-load   |  7 ++++
>>  MAINTAINERS                                   |  1 +
>>  drivers/fpga/fpga-image-load.c                | 33 +++++++++++++++++++
>>  3 files changed, 41 insertions(+)
>>  create mode 100644 Documentation/ABI/testing/sysfs-class-fpga-image-load
>>
>> diff --git a/Documentation/ABI/testing/sysfs-class-fpga-image-load b/Documentation/ABI/testing/sysfs-class-fpga-image-load
>> new file mode 100644
>> index 000000000000..6c04a49f01cc
>> --- /dev/null
>> +++ b/Documentation/ABI/testing/sysfs-class-fpga-image-load
>> @@ -0,0 +1,7 @@
>> +What: 		/sys/class/fpga_image_load/fpga_imageX/status
>> +Date:		Aug 2021
>> +KernelVersion:	5.15
>> +Contact:	Russ Weight <russell.h.weight@xxxxxxxxx>
>> +Description:	Read-only. Returns a string describing the current status
>> +		of an FPGA image upload. The string will be one of the
>> +		following: idle, starting, preparing, writing, programming.
>> diff --git a/MAINTAINERS b/MAINTAINERS
>> index 637bc003ca81..e3fbc1bde9bc 100644
>> --- a/MAINTAINERS
>> +++ b/MAINTAINERS
>> @@ -7362,6 +7362,7 @@ FPGA SECURITY MANAGER DRIVERS
>>  M:	Russ Weight <russell.h.weight@xxxxxxxxx>
>>  L:	linux-fpga@xxxxxxxxxxxxxxx
>>  S:	Maintained
>> +F:	Documentation/ABI/testing/sysfs-class-fpga-image-load
>>  F:	Documentation/fpga/fpga-image-load.rst
>>  F:	drivers/fpga/fpga-image-load.c
>>  F:	include/linux/fpga/fpga-image-load.h
>> diff --git a/drivers/fpga/fpga-image-load.c b/drivers/fpga/fpga-image-load.c
>> index 99a47b21c995..6ec0a39f07b3 100644
>> --- a/drivers/fpga/fpga-image-load.c
>> +++ b/drivers/fpga/fpga-image-load.c
>> @@ -236,6 +236,38 @@ static const struct file_operations fpga_image_load_fops = {
>>  	.unlocked_ioctl = fpga_image_load_ioctl,
>>  };
>>  
>> +static const char * const image_load_prog_str[] = {
>> +	[FPGA_IMAGE_PROG_IDLE]	      = "idle",
>> +	[FPGA_IMAGE_PROG_STARTING]    = "starting",
>> +	[FPGA_IMAGE_PROG_PREPARING]   = "preparing",
>> +	[FPGA_IMAGE_PROG_WRITING]     = "writing",
>> +	[FPGA_IMAGE_PROG_PROGRAMMING] = "programming"
>> +};
>> +
>> +static ssize_t
>> +status_show(struct device *dev, struct device_attribute *attr, char *buf)
>> +{
>> +	struct fpga_image_load *imgld = to_image_load(dev);
>> +	const char *status = "unknown-status";
>> +	enum fpga_image_prog progress;
>> +
>> +	progress = imgld->progress;
>> +	if (progress < FPGA_IMAGE_PROG_MAX)
>> +		status = image_load_prog_str[progress];
>> +	else
>> +		dev_err(dev, "Invalid status during secure update: %d\n",
>> +			progress);
>> +
>> +	return sysfs_emit(buf, "%s\n", status);
>> +}
>> +static DEVICE_ATTR_RO(status);
>> +
>> +static struct attribute *fpga_image_load_attrs[] = {
>> +	&dev_attr_status.attr,
>> +	NULL,
>> +};
>> +ATTRIBUTE_GROUPS(fpga_image_load);
>> +
>>  /**
>>   * fpga_image_load_register - create and register an FPGA Image Load Device
>>   *
>> @@ -373,6 +405,7 @@ static int __init fpga_image_load_class_init(void)
>>  	if (ret)
>>  		goto exit_destroy_class;
>>  
>> +	fpga_image_load_class->dev_groups = fpga_image_load_groups;
>>  	fpga_image_load_class->dev_release = fpga_image_load_dev_release;
>>  
>>  	return 0;
>> -- 
>> 2.25.1