s390/dasd: Display FC Endpoint Security information via sysfs

Add a new sysfs attribute (fc_security) per device and per operational
channel path. The information of the current FC Endpoint Security state
is received through the CIO layer.

The state of the FC Endpoint Security can be either "Unsupported",
"Authentication", or "Encryption".

For example:
$ cat /sys/bus/ccw/devices/0.0.c600/fc_security
Encryption

If any of the operational paths is in a state different from all
others, the device sysfs attribute will display the additional state
"Inconsistent".

The sysfs attributes per paths are organised in a new directory called
"paths_info" with subdirectories for each path.

/sys/bus/ccw/devices/0.0.c600/paths_info/
├── 0.38
│   └── fc_security
├── 0.39
│   └── fc_security
├── 0.3a
│   └── fc_security
└── 0.3b
    └── fc_security

Signed-off-by: Jan Höppner <hoeppner@linux.ibm.com>
Signed-off-by: Stefan Haberland <sth@linux.ibm.com>
Reviewed-by: Stefan Haberland <sth@linux.ibm.com>
Reviewed-by: Cornelia Huck <cohuck@redhat.com>
Signed-off-by: Jens Axboe <axboe@kernel.dk>

1 files changed, 109 insertions, 0 deletions

diff --git a/drivers/s390/block/dasd_devmap.c b/drivers/s390/block/dasd_devmap.c
index 32fc51341d99..16bb135c20aa 100644
--- a/drivers/s390/block/dasd_devmap.c
+++ b/drivers/s390/block/dasd_devmap.c
@@ -576,6 +576,11 @@ dasd_create_device(struct ccw_device *cdev)
 	dev_set_drvdata(&cdev->dev, device);
 	spin_unlock_irqrestore(get_ccwdev_lock(cdev), flags);
 
+	device->paths_info = kset_create_and_add("paths_info", NULL,
+						 &device->cdev->dev.kobj);
+	if (!device->paths_info)
+		dev_warn(&cdev->dev, "Could not create paths_info kset\n");
+
 	return device;
 }
 
@@ -622,6 +627,9 @@ dasd_delete_device(struct dasd_device *device)
 	wait_event(dasd_delete_wq, atomic_read(&device->ref_count) == 0);
 
 	dasd_generic_free_discipline(device);
+
+	kset_unregister(device->paths_info);
+
 	/* Disconnect dasd_device structure from ccw_device structure. */
 	cdev = device->cdev;
 	device->cdev = NULL;
@@ -1641,6 +1649,39 @@ dasd_path_interval_store(struct device *dev, struct device_attribute *attr,
 static DEVICE_ATTR(path_interval, 0644, dasd_path_interval_show,
 		   dasd_path_interval_store);
 
+static ssize_t
+dasd_device_fcs_show(struct device *dev, struct device_attribute *attr,
+		     char *buf)
+{
+	struct dasd_device *device;
+	int fc_sec;
+	int rc;
+
+	device = dasd_device_from_cdev(to_ccwdev(dev));
+	if (IS_ERR(device))
+		return -ENODEV;
+	fc_sec = dasd_path_get_fcs_device(device);
+	if (fc_sec == -EINVAL)
+		rc = snprintf(buf, PAGE_SIZE, "Inconsistent\n");
+	else
+		rc = snprintf(buf, PAGE_SIZE, "%s\n", dasd_path_get_fcs_str(fc_sec));
+	dasd_put_device(device);
+
+	return rc;
+}
+static DEVICE_ATTR(fc_security, 0444, dasd_device_fcs_show, NULL);
+
+static ssize_t
+dasd_path_fcs_show(struct kobject *kobj, struct kobj_attribute *attr, char *buf)
+{
+	struct dasd_path *path = to_dasd_path(kobj);
+	unsigned int fc_sec = path->fc_security;
+
+	return snprintf(buf, PAGE_SIZE, "%s\n", dasd_path_get_fcs_str(fc_sec));
+}
+
+static struct kobj_attribute path_fcs_attribute =
+	__ATTR(fc_security, 0444, dasd_path_fcs_show, NULL);
 
 #define DASD_DEFINE_ATTR(_name, _func)					\
 static ssize_t dasd_##_name##_show(struct device *dev,			\
@@ -1697,6 +1738,7 @@ static struct attribute * dasd_attrs[] = {
 	&dev_attr_path_reset.attr,
 	&dev_attr_hpf.attr,
 	&dev_attr_ese.attr,
+	&dev_attr_fc_security.attr,
 	NULL,
 };
 
@@ -1777,6 +1819,73 @@ dasd_set_feature(struct ccw_device *cdev, int feature, int flag)
 }
 EXPORT_SYMBOL(dasd_set_feature);
 
+static struct attribute *paths_info_attrs[] = {
+	&path_fcs_attribute.attr,
+	NULL,
+};
+
+static struct kobj_type path_attr_type = {
+	.release	= dasd_path_release,
+	.default_attrs	= paths_info_attrs,
+	.sysfs_ops	= &kobj_sysfs_ops,
+};
+
+static void dasd_path_init_kobj(struct dasd_device *device, int chp)
+{
+	device->path[chp].kobj.kset = device->paths_info;
+	kobject_init(&device->path[chp].kobj, &path_attr_type);
+}
+
+void dasd_path_create_kobj(struct dasd_device *device, int chp)
+{
+	int rc;
+
+	if (test_bit(DASD_FLAG_OFFLINE, &device->flags))
+		return;
+	if (!device->paths_info) {
+		dev_warn(&device->cdev->dev, "Unable to create paths objects\n");
+		return;
+	}
+	if (device->path[chp].in_sysfs)
+		return;
+	if (!device->path[chp].conf_data)
+		return;
+
+	dasd_path_init_kobj(device, chp);
+
+	rc = kobject_add(&device->path[chp].kobj, NULL, "%x.%02x",
+			 device->path[chp].cssid, device->path[chp].chpid);
+	if (rc)
+		kobject_put(&device->path[chp].kobj);
+	device->path[chp].in_sysfs = true;
+}
+EXPORT_SYMBOL(dasd_path_create_kobj);
+
+void dasd_path_create_kobjects(struct dasd_device *device)
+{
+	u8 lpm, opm;
+
+	opm = dasd_path_get_opm(device);
+	for (lpm = 0x80; lpm; lpm >>= 1) {
+		if (!(lpm & opm))
+			continue;
+		dasd_path_create_kobj(device, pathmask_to_pos(lpm));
+	}
+}
+EXPORT_SYMBOL(dasd_path_create_kobjects);
+
+/*
+ * As we keep kobjects for the lifetime of a device, this function must not be
+ * called anywhere but in the context of offlining a device.
+ */
+void dasd_path_remove_kobj(struct dasd_device *device, int chp)
+{
+	if (device->path[chp].in_sysfs) {
+		kobject_put(&device->path[chp].kobj);
+		device->path[chp].in_sysfs = false;
+	}
+}
+EXPORT_SYMBOL(dasd_path_remove_kobj);
 
 int dasd_add_sysfs_files(struct ccw_device *cdev)
 {