[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, 49 insertions, 2 deletions

diff --git a/drivers/s390/block/dasd_eckd.c b/drivers/s390/block/dasd_eckd.c
index ee09ef33d08d..7d5a6cee4bd8 100644
--- a/drivers/s390/block/dasd_eckd.c
+++ b/drivers/s390/block/dasd_eckd.c
@@ -446,6 +446,39 @@ dasd_eckd_cdl_reclen(int recid)
         return LABEL_SIZE;
 }
 
+/*
+ * Generate device unique id that specifies the physical device.
+ */
+static int
+dasd_eckd_generate_uid(struct dasd_device *device, struct dasd_uid *uid)
+{
+        struct dasd_eckd_private *private;
+        struct dasd_eckd_confdata *confdata;
+
+        private = (struct dasd_eckd_private *) device->private;
+        if (!private)
+                return -ENODEV;
+        confdata = &private->conf_data;
+        if (!confdata)
+                return -ENODEV;
+
+        memset(uid, 0, sizeof(struct dasd_uid));
+        strncpy(uid->vendor, confdata->ned1.HDA_manufacturer,
+                sizeof(uid->vendor) - 1);
+        EBCASC(uid->vendor, sizeof(uid->vendor) - 1);
+        strncpy(uid->serial, confdata->ned1.HDA_location,
+                sizeof(uid->serial) - 1);
+        EBCASC(uid->serial, sizeof(uid->serial) - 1);
+        uid->ssid = confdata->neq.subsystemID;
+        if (confdata->ned2.sneq.flags == 0x40) {
+                uid->alias = 1;
+                uid->unit_addr = confdata->ned2.sneq.base_unit_addr;
+        } else
+                uid->unit_addr = confdata->ned1.unit_addr;
+
+        return 0;
+}
+
 static int
 dasd_eckd_read_conf(struct dasd_device *device)
 {
@@ -507,11 +540,15 @@ dasd_eckd_read_conf(struct dasd_device *device)
         return 0;
 }
 
-
+/*
+ * Check device characteristics.
+ * If the device is accessible using ECKD discipline, the device is enabled.
+ */
 static int
 dasd_eckd_check_characteristics(struct dasd_device *device)
 {
         struct dasd_eckd_private *private;
+        struct dasd_uid uid;
         void *rdc_data;
         int rc;
 
@@ -536,6 +573,7 @@ dasd_eckd_check_characteristics(struct dasd_device *device)
 
         /* Read Device Characteristics */
         rdc_data = (void *) &(private->rdc_data);
+        memset(rdc_data, 0, sizeof(rdc_data));
         rc = read_dev_chars(device->cdev, &rdc_data, 64);
         if (rc) {
                 DEV_MESSAGE(KERN_WARNING, device,
@@ -556,8 +594,17 @@ dasd_eckd_check_characteristics(struct dasd_device *device)
 
         /* Read Configuration Data */
         rc = dasd_eckd_read_conf (device);
-        return rc;
+        if (rc)
+                return rc;
+
+        /* Generate device unique id and register in devmap */
+        rc = dasd_eckd_generate_uid(device, &uid);
+        if (rc)
+                return rc;
 
+        rc = dasd_set_uid(device->cdev, &uid);
+
+        return rc;
 }
 
 static struct dasd_ccw_req *