From 5a2876f0d1ef26b76755749f978d46e4666013dd Mon Sep 17 00:00:00 2001 From: Benjamin Block Date: Fri, 25 Oct 2019 18:12:49 +0200 Subject: [PATCH] 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: Steffen Maier Signed-off-by: Benjamin Block Signed-off-by: Martin K. Petersen --- drivers/s390/scsi/zfcp_sysfs.c | 40 ++++++++++++++++++++++++++++++++++ 1 file changed, 40 insertions(+) diff --git a/drivers/s390/scsi/zfcp_sysfs.c b/drivers/s390/scsi/zfcp_sysfs.c index a2fa3db5695d..376d76b9f337 100644 --- a/drivers/s390/scsi/zfcp_sysfs.c +++ b/drivers/s390/scsi/zfcp_sysfs.c @@ -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, };