[S390] Convert extmem spin_lock into a mutex.

There's no need to have a spin_lock here, but need sleepable context
for vmem_map. Therefore convert the spin_lock into a mutex.
Signed-off-by: Heiko Carstens <heiko.carstens@de.ibm.com>
Signed-off-by: Martin Schwidefsky <schwidefsky@de.ibm.com>

arch/s390/mm/extmem.c

@@ -78,7 +78,7 @@ struct dcss_segment {
 	int segcnt;
 };
 
-static DEFINE_SPINLOCK(dcss_lock);
+static DEFINE_MUTEX(dcss_lock);
 static struct list_head dcss_list = LIST_HEAD_INIT(dcss_list);
 static char *segtype_string[] = { "SW", "EW", "SR", "ER", "SN", "EN", "SC",
 					"EW/EN-MIXED" };
@@ -114,7 +114,7 @@ segment_by_name (char *name)
 	struct list_head *l;
 	struct dcss_segment *tmp, *retval = NULL;
 
-	assert_spin_locked(&dcss_lock);
+	BUG_ON(!mutex_is_locked(&dcss_lock));
 	dcss_mkname (name, dcss_name);
 	list_for_each (l, &dcss_list) {
 		tmp = list_entry (l, struct dcss_segment, list);
@@ -269,7 +269,7 @@ segment_overlaps_others (struct dcss_segment *seg)
 	struct list_head *l;
 	struct dcss_segment *tmp;
 
-	assert_spin_locked(&dcss_lock);
+	BUG_ON(!mutex_is_locked(&dcss_lock));
 	list_for_each(l, &dcss_list) {
 		tmp = list_entry(l, struct dcss_segment, list);
 		if ((tmp->start_addr >> 20) > (seg->end >> 20))
@@ -426,7 +426,7 @@ segment_load (char *name, int do_nonshared, unsigned long *addr,
 	if (!MACHINE_IS_VM)
 		return -ENOSYS;
 
-	spin_lock (&dcss_lock);
+	mutex_lock(&dcss_lock);
 	seg = segment_by_name (name);
 	if (seg == NULL)
 		rc = __segment_load (name, do_nonshared, addr, end);
@@ -441,7 +441,7 @@ segment_load (char *name, int do_nonshared, unsigned long *addr,
 			rc    = -EPERM;
 		}
 	}
-	spin_unlock (&dcss_lock);
+	mutex_unlock(&dcss_lock);
 	return rc;
 }
 
@@ -464,7 +464,7 @@ segment_modify_shared (char *name, int do_nonshared)
 	unsigned long dummy;
 	int dcss_command, rc, diag_cc;
 
-	spin_lock (&dcss_lock);
+	mutex_lock(&dcss_lock);
 	seg = segment_by_name (name);
 	if (seg == NULL) {
 		rc = -EINVAL;
@@ -505,7 +505,7 @@ segment_modify_shared (char *name, int do_nonshared)
 		  &dummy, &dummy);
 	kfree(seg);
  out_unlock:
-	spin_unlock(&dcss_lock);
+	mutex_unlock(&dcss_lock);
 	return rc;
 }
 
@@ -523,7 +523,7 @@ segment_unload(char *name)
 	if (!MACHINE_IS_VM)
 		return;
 
-	spin_lock(&dcss_lock);
+	mutex_lock(&dcss_lock);
 	seg = segment_by_name (name);
 	if (seg == NULL) {
 		PRINT_ERR ("could not find segment %s in segment_unload, "
@@ -537,7 +537,7 @@ segment_unload(char *name)
 		kfree(seg);
 	}
 out_unlock:
-	spin_unlock(&dcss_lock);
+	mutex_unlock(&dcss_lock);
 }
 
 /*
@@ -556,7 +556,7 @@ segment_save(char *name)
 	if (!MACHINE_IS_VM)
 		return;
 
-	spin_lock(&dcss_lock);
+	mutex_lock(&dcss_lock);
 	seg = segment_by_name (name);
 
 	if (seg == NULL) {
@@ -589,7 +589,7 @@ segment_save(char *name)
 		goto out;
 	}
 out:
-	spin_unlock(&dcss_lock);
+	mutex_unlock(&dcss_lock);
 }
 
 EXPORT_SYMBOL(segment_load);