[S390] set modalias for ccw bus uevents.

Add the MODALIAS environment variable for ccw bus uevents.

Signed-off-by: Peter Oberparleiter <peter.oberparleiter@de.ibm.com>
Signed-off-by: Martin Schwidefsky <schwidefsky@de.ibm.com>

1 files changed, 66 insertions, 43 deletions

diff --git a/drivers/s390/cio/device.c b/drivers/s390/cio/device.c
index 646da5640401..688945662c15 100644
--- a/drivers/s390/cio/device.c
+++ b/drivers/s390/cio/device.c
@@ -52,53 +52,81 @@ ccw_bus_match (struct device * dev, struct device_driver * drv)
         return 1;
 }
 
-/*
- * Hotplugging interface for ccw devices.
- * Heavily modeled on pci and usb hotplug.
- */
-static int
-ccw_uevent (struct device *dev, char **envp, int num_envp,
-             char *buffer, int buffer_size)
+/* Store modalias string delimited by prefix/suffix string into buffer with
+ * specified size. Return length of resulting string (excluding trailing '\0')
+ * even if string doesn't fit buffer (snprintf semantics). */
+static int snprint_alias(char *buf, size_t size, const char *prefix,
+                         struct ccw_device_id *id, const char *suffix)
 {
-        struct ccw_device *cdev = to_ccwdev(dev);
-        int i = 0;
-        int length = 0;
+        int len;
 
-        if (!cdev)
-                return -ENODEV;
+        len = snprintf(buf, size, "%sccw:t%04Xm%02X", prefix, id->cu_type,
+                       id->cu_model);
+        if (len > size)
+                return len;
+        buf += len;
+        size -= len;
 
-        /* what we want to pass to /sbin/hotplug */
+        if (id->dev_type != 0)
+                len += snprintf(buf, size, "dt%04Xdm%02X%s", id->dev_type,
+                                id->dev_model, suffix);
+        else
+                len += snprintf(buf, size, "dtdm%s", suffix);
 
-        envp[i++] = buffer;
-        length += scnprintf(buffer, buffer_size - length, "CU_TYPE=%04X",
-                           cdev->id.cu_type);
-        if ((buffer_size - length <= 0) || (i >= num_envp))
-                return -ENOMEM;
-        ++length;
-        buffer += length;
+        return len;
+}
 
+/* Set up environment variables for ccw device uevent. Return 0 on success,
+ * non-zero otherwise. */
+static int ccw_uevent(struct device *dev, char **envp, int num_envp,
+                      char *buffer, int buffer_size)
+{
+        struct ccw_device *cdev = to_ccwdev(dev);
+        struct ccw_device_id *id = &(cdev->id);
+        int i = 0;
+        int len;
+
+        /* CU_TYPE= */
+        len = snprintf(buffer, buffer_size, "CU_TYPE=%04X", id->cu_type) + 1;
+        if (len > buffer_size || i >= num_envp)
+                return -ENOMEM;
         envp[i++] = buffer;
-        length += scnprintf(buffer, buffer_size - length, "CU_MODEL=%02X",
-                           cdev->id.cu_model);
-        if ((buffer_size - length <= 0) || (i >= num_envp))
+        buffer += len;
+        buffer_size -= len;
+
+        /* CU_MODEL= */
+        len = snprintf(buffer, buffer_size, "CU_MODEL=%02X", id->cu_model) + 1;
+        if (len > buffer_size || i >= num_envp)
                 return -ENOMEM;
-        ++length;
-        buffer += length;
+        envp[i++] = buffer;
+        buffer += len;
+        buffer_size -= len;
 
         /* The next two can be zero, that's ok for us */
-        envp[i++] = buffer;
-        length += scnprintf(buffer, buffer_size - length, "DEV_TYPE=%04X",
-                           cdev->id.dev_type);
-        if ((buffer_size - length <= 0) || (i >= num_envp))
+        /* DEV_TYPE= */
+        len = snprintf(buffer, buffer_size, "DEV_TYPE=%04X", id->dev_type) + 1;
+        if (len > buffer_size || i >= num_envp)
                 return -ENOMEM;
-        ++length;
-        buffer += length;
+        envp[i++] = buffer;
+        buffer += len;
+        buffer_size -= len;
 
+        /* DEV_MODEL= */
+        len = snprintf(buffer, buffer_size, "DEV_MODEL=%02X",
+                        (unsigned char) id->dev_model) + 1;
+        if (len > buffer_size || i >= num_envp)
+                return -ENOMEM;
         envp[i++] = buffer;
-        length += scnprintf(buffer, buffer_size - length, "DEV_MODEL=%02X",
-                           cdev->id.dev_model);
-        if ((buffer_size - length <= 0) || (i >= num_envp))
+        buffer += len;
+        buffer_size -= len;
+
+        /* MODALIAS=  */
+        len = snprint_alias(buffer, buffer_size, "MODALIAS=", id, "") + 1;
+        if (len > buffer_size || i >= num_envp)
                 return -ENOMEM;
+        envp[i++] = buffer;
+        buffer += len;
+        buffer_size -= len;
 
         envp[i] = NULL;
 
@@ -251,16 +279,11 @@ modalias_show (struct device *dev, struct device_attribute *attr, char *buf)
 {
         struct ccw_device *cdev = to_ccwdev(dev);
         struct ccw_device_id *id = &(cdev->id);
-        int ret;
+        int len;
 
-        ret = sprintf(buf, "ccw:t%04Xm%02X",
-                        id->cu_type, id->cu_model);
-        if (id->dev_type != 0)
-                ret += sprintf(buf + ret, "dt%04Xdm%02X\n",
-                                id->dev_type, id->dev_model);
-        else
-                ret += sprintf(buf + ret, "dtdm\n");
-        return ret;
+        len = snprint_alias(buf, PAGE_SIZE, "", id, "\n") + 1;
+
+        return len > PAGE_SIZE ? PAGE_SIZE : len;
 }
 
 static ssize_t