Commit 5a2876f0 authored by Benjamin Block's avatar Benjamin Block Committed by Martin K. Petersen
Browse files

scsi: zfcp: introduce sysfs interface to read the local B2B-Credit 

In addition to the diagnostic data from the local SFP transceiver this
patch adds an interface to read the advertised buffer-to-buffer credit from
the local FC_Port.

With this patch the userspace-interface will only read data stored in the
corresponding "diagnostic buffer" (that was stored during completion of a
previous Exchange Config Data command). Implicit updating will follow later
in this series.

Link: https://lore.kernel.org/r/8a53aef87b53c50cfb1a3425b799bacb6f82b832.1572018132.git.bblock@linux.ibm.com


Reviewed-by: default avatarSteffen Maier <maier@linux.ibm.com>
Signed-off-by: default avatarBenjamin Block <bblock@linux.ibm.com>
Signed-off-by: default avatarMartin K. Petersen <martin.petersen@oracle.com>
parent 8155eb07

drivers/s390/scsi/zfcp_sysfs.c

+40 −0
Original line number Diff line number Diff line
@@ -666,6 +666,45 @@ struct device_attribute *zfcp_sysfs_shost_attrs[] = { 
	NULL

};



static ssize_t zfcp_sysfs_adapter_diag_b2b_credit_show(

	struct device *dev, struct device_attribute *attr, char *buf)

{

	struct zfcp_adapter *adapter = zfcp_ccw_adapter_by_cdev(to_ccwdev(dev));

	struct zfcp_diag_header *diag_hdr;

	struct fc_els_flogi *nsp;

	ssize_t rc = -ENOLINK;

	unsigned long flags;

	unsigned int status;



	if (!adapter)

		return -ENODEV;



	status = atomic_read(&adapter->status);

	if (0 == (status & ZFCP_STATUS_COMMON_OPEN) ||

	    0 == (status & ZFCP_STATUS_COMMON_UNBLOCKED) ||

	    0 != (status & ZFCP_STATUS_COMMON_ERP_FAILED))

		goto out;



	diag_hdr = &adapter->diagnostics->config_data.header;



	spin_lock_irqsave(&diag_hdr->access_lock, flags);

	/* nport_serv_param doesn't contain the ELS_Command code */

	nsp = (struct fc_els_flogi *)((unsigned long)

					      adapter->diagnostics->config_data

						      .data.nport_serv_param -

				      sizeof(u32));



	rc = scnprintf(buf, 5 + 2, "%hu\n",

		       be16_to_cpu(nsp->fl_csp.sp_bb_cred));

	spin_unlock_irqrestore(&diag_hdr->access_lock, flags);



out:

	zfcp_ccw_adapter_put(adapter);

	return rc;

}

static ZFCP_DEV_ATTR(adapter_diag, b2b_credit, 0400,

		     zfcp_sysfs_adapter_diag_b2b_credit_show, NULL);



#define ZFCP_DEFINE_DIAG_SFP_ATTR(_name, _qtcb_member, _prtsize, _prtfmt)      \

	static ssize_t zfcp_sysfs_adapter_diag_sfp_##_name##_show(	       \

		struct device *dev, struct device_attribute *attr, char *buf)  \
@@ -733,6 +772,7 @@ static struct attribute *zfcp_sysfs_diag_attrs[] = { 
	&dev_attr_adapter_diag_sfp_sfp_invalid.attr,

	&dev_attr_adapter_diag_sfp_connector_type.attr,

	&dev_attr_adapter_diag_sfp_fec_active.attr,

	&dev_attr_adapter_diag_b2b_credit.attr,

	NULL,

};