[PATCH] s390: dasd device identifiers

Generate new sysfs-attribute 'uid' that contains an device specific unique
identifier.  This can be used to identity multiple ALIASES of the same
physical device (PAV).  In addition the sysfs-attributes 'vendor' (containing
the manufacturer of the device) and 'alias' (identify alias or base device) is
added.  This is first part of PAV support in LPAR (also valid on zVM).

Signed-off-by: Horst Hummel <horst.hummel@de.ibm.com>
Signed-off-by: Martin Schwidefsky <schwidefsky@de.ibm.com>
Signed-off-by: Andrew Morton <akpm@osdl.org>
Signed-off-by: Linus Torvalds <torvalds@osdl.org>

1 files changed, 102 insertions, 0 deletions

diff --git a/drivers/s390/block/dasd_devmap.c b/drivers/s390/block/dasd_devmap.c
index c1c6f1381150..216bc4fba199 100644
--- a/drivers/s390/block/dasd_devmap.c
+++ b/drivers/s390/block/dasd_devmap.c
@@ -45,6 +45,7 @@ struct dasd_devmap {
         unsigned int devindex;
         unsigned short features;
 	struct dasd_device *device;
+	struct dasd_uid uid;
 };
 
 /*
@@ -716,6 +717,68 @@ dasd_discipline_show(struct device *dev, struct device_attribute *attr, char *bu
 
 static DEVICE_ATTR(discipline, 0444, dasd_discipline_show, NULL);
 
+static ssize_t
+dasd_alias_show(struct device *dev, struct device_attribute *attr, char *buf)
+{
+	struct dasd_devmap *devmap;
+	int alias;
+
+	devmap = dasd_find_busid(dev->bus_id);
+	spin_lock(&dasd_devmap_lock);
+	if (!IS_ERR(devmap))
+		alias = devmap->uid.alias;
+	else
+		alias = 0;
+	spin_unlock(&dasd_devmap_lock);
+
+	return sprintf(buf, alias ? "1\n" : "0\n");
+}
+
+static DEVICE_ATTR(alias, 0444, dasd_alias_show, NULL);
+
+static ssize_t
+dasd_vendor_show(struct device *dev, struct device_attribute *attr, char *buf)
+{
+	struct dasd_devmap *devmap;
+	char *vendor;
+
+	devmap = dasd_find_busid(dev->bus_id);
+	spin_lock(&dasd_devmap_lock);
+	if (!IS_ERR(devmap) && strlen(devmap->uid.vendor) > 0)
+		vendor = devmap->uid.vendor;
+	else
+		vendor = "";
+	spin_unlock(&dasd_devmap_lock);
+
+	return snprintf(buf, PAGE_SIZE, "%s\n", vendor);
+}
+
+static DEVICE_ATTR(vendor, 0444, dasd_vendor_show, NULL);
+
+#define UID_STRLEN ( /* vendor */ 3 + 1 + /* serial    */ 14 + 1 +\
+		     /* SSID   */ 4 + 1 + /* unit addr */ 2 + 1)
+
+static ssize_t
+dasd_uid_show(struct device *dev, struct device_attribute *attr, char *buf)
+{
+	struct dasd_devmap *devmap;
+	char uid[UID_STRLEN];
+
+	devmap = dasd_find_busid(dev->bus_id);
+	spin_lock(&dasd_devmap_lock);
+	if (!IS_ERR(devmap) && strlen(devmap->uid.vendor) > 0)
+		snprintf(uid, sizeof(uid), "%s.%s.%04x.%02x",
+			 devmap->uid.vendor, devmap->uid.serial,
+			 devmap->uid.ssid, devmap->uid.unit_addr);
+	else
+		uid[0] = 0;
+	spin_unlock(&dasd_devmap_lock);
+
+	return snprintf(buf, PAGE_SIZE, "%s\n", uid);
+}
+
+static DEVICE_ATTR(uid, 0444, dasd_uid_show, NULL);
+
 /*
  * extended error-reporting
  */
@@ -759,6 +822,9 @@ static DEVICE_ATTR(eer_enabled, 0644, dasd_eer_show, dasd_eer_store);
 static struct attribute * dasd_attrs[] = {
 	&dev_attr_readonly.attr,
 	&dev_attr_discipline.attr,
+	&dev_attr_alias.attr,
+	&dev_attr_vendor.attr,
+	&dev_attr_uid.attr,
 	&dev_attr_use_diag.attr,
 	&dev_attr_eer_enabled.attr,
 	NULL,
@@ -768,6 +834,42 @@ static struct attribute_group dasd_attr_group = {
 	.attrs = dasd_attrs,
 };
 
+
+/*
+ * Return copy of the device unique identifier.
+ */
+int
+dasd_get_uid(struct ccw_device *cdev, struct dasd_uid *uid)
+{
+	struct dasd_devmap *devmap;
+
+	devmap = dasd_find_busid(cdev->dev.bus_id);
+	if (IS_ERR(devmap))
+		return PTR_ERR(devmap);
+	spin_lock(&dasd_devmap_lock);
+	*uid = devmap->uid;
+	spin_unlock(&dasd_devmap_lock);
+	return 0;
+}
+
+/*
+ * Register the given device unique identifier into devmap struct.
+ */
+int
+dasd_set_uid(struct ccw_device *cdev, struct dasd_uid *uid)
+{
+	struct dasd_devmap *devmap;
+
+	devmap = dasd_find_busid(cdev->dev.bus_id);
+	if (IS_ERR(devmap))
+		return PTR_ERR(devmap);
+	spin_lock(&dasd_devmap_lock);
+	devmap->uid = *uid;
+	spin_unlock(&dasd_devmap_lock);
+	return 0;
+}
+EXPORT_SYMBOL(dasd_set_uid);
+
 /*
  * Return value of the specified feature.
  */