[PATCH v4 16/16] crypto/nx: Add sysfs interface to export NX capabilities

[Haren Myneni]

On Thu, 2021-06-03 at 14:57 +1000, Nicholas Piggin wrote:
> Excerpts from Haren Myneni's message of May 21, 2021 7:42 pm:
> > Changes to export the following NXGZIP capabilities through sysfs:
> > 
> > /sys/devices/vio/ibm,compression-v1/NxGzCaps:
> 
> Where's the horrible camel case name coming from? PowerVM?

Yes, pHyp provides the capabalities string.

Capability Description Descriptor Value Descriptor ascii Value
Overall NX Capabilities 0x4E78204361707320 “Nx Caps ”
NX GZIP Capabilities 0x4E78477A43617073 “NxGzCaps”


> 
> Thanks,
> Nick
> 
> > min_compress_len  /*Recommended minimum compress length in bytes*/
> > min_decompress_len /*Recommended minimum decompress length in
> > bytes*/
> > req_max_processed_len /* Maximum number of bytes processed in one
> > 			request */
> > 
> > NX will return RMA_Reject if the request buffer size is greater
> > than req_max_processed_len.
> > 
> > Signed-off-by: Haren Myneni <haren at linux.ibm.com>
> > Acked-by: Herbert Xu <herbert at gondor.apana.org.au>
> > ---
> >  drivers/crypto/nx/nx-common-pseries.c | 43
> > +++++++++++++++++++++++++++
> >  1 file changed, 43 insertions(+)
> > 
> > diff --git a/drivers/crypto/nx/nx-common-pseries.c
> > b/drivers/crypto/nx/nx-common-pseries.c
> > index 4a7278464156..121718a337fd 100644
> > --- a/drivers/crypto/nx/nx-common-pseries.c
> > +++ b/drivers/crypto/nx/nx-common-pseries.c
> > @@ -968,6 +968,36 @@ static struct attribute_group
> > nx842_attribute_group = {
> >  	.attrs = nx842_sysfs_entries,
> >  };
> >  
> > +#define	nxct_caps_read(_name)					
> > 	\
> > +static ssize_t nxct_##_name##_show(struct device *dev,		
> > 	\
> > +			struct device_attribute *attr, char *buf)	\
> > +{									
> > \
> > +	return sprintf(buf, "%lld\n", nx_ct_caps._name);		\
> > +}
> > +
> > +#define NXCT_ATTR_RO(_name)					
> > 	\
> > +	nxct_caps_read(_name);						
> > \
> > +	static struct device_attribute dev_attr_##_name = __ATTR(_name,
> > 	\
> > +						0444,			
> > \
> > +						nxct_##_name##_show,	
> > \
> > +						NULL);
> > +
> > +NXCT_ATTR_RO(req_max_processed_len);
> > +NXCT_ATTR_RO(min_compress_len);
> > +NXCT_ATTR_RO(min_decompress_len);
> > +
> > +static struct attribute *nxct_caps_sysfs_entries[] = {
> > +	&dev_attr_req_max_processed_len.attr,
> > +	&dev_attr_min_compress_len.attr,
> > +	&dev_attr_min_decompress_len.attr,
> > +	NULL,
> > +};
> > +
> > +static struct attribute_group nxct_caps_attr_group = {
> > +	.name	=	nx_ct_caps.name,
> > +	.attrs	=	nxct_caps_sysfs_entries,
> > +};
> > +
> >  static struct nx842_driver nx842_pseries_driver = {
> >  	.name =		KBUILD_MODNAME,
> >  	.owner =	THIS_MODULE,
> > @@ -1057,6 +1087,16 @@ static int nx842_probe(struct vio_dev
> > *viodev,
> >  		goto error;
> >  	}
> >  
> > +	if (caps_feat) {
> > +		if (sysfs_create_group(&viodev->dev.kobj,
> > +					&nxct_caps_attr_group)) {
> > +			dev_err(&viodev->dev,
> > +				"Could not create sysfs NX capability
> > entries\n");
> > +			ret = -1;
> > +			goto error;
> > +		}
> > +	}
> > +
> >  	return 0;
> >  
> >  error_unlock:
> > @@ -1076,6 +1116,9 @@ static void nx842_remove(struct vio_dev
> > *viodev)
> >  	pr_info("Removing IBM Power 842 compression device\n");
> >  	sysfs_remove_group(&viodev->dev.kobj, &nx842_attribute_group);
> >  
> > +	if (caps_feat)
> > +		sysfs_remove_group(&viodev->dev.kobj,
> > &nxct_caps_attr_group);
> > +
> >  	crypto_unregister_alg(&nx842_pseries_alg);
> >  
> >  	spin_lock_irqsave(&devdata_mutex, flags);
> > -- 
> > 2.18.2
> > 
> > 
> >