[SCTP] Use __get_free_pages() to allocate ssnmap.

This is needed to avoid kmalloc()'s 128K limit when an association is
initialized with a large no. of streams(more than 65000 inbound +
outbound streams).

net/sctp/ssnmap.c

@@ -56,8 +56,10 @@ static inline size_t sctp_ssnmap_size(__u16 in, __u16 out)
 struct sctp_ssnmap *sctp_ssnmap_new(__u16 in, __u16 out, int gfp)
 {
 	struct sctp_ssnmap *retval;
+	int order;
 
-	retval = kmalloc(sctp_ssnmap_size(in, out), gfp);
+	order = get_order(sctp_ssnmap_size(in,out));
+	retval = (struct sctp_ssnmap *)__get_free_pages(gfp, order);
 
 	if (!retval)
 		goto fail;
@@ -71,7 +73,7 @@ struct sctp_ssnmap *sctp_ssnmap_new(__u16 in, __u16 out, int gfp)
 	return retval;
 
 fail_map:
-	kfree(retval);
+	free_pages((unsigned long)retval, order);
 fail:
 	return NULL;
 }
@@ -107,7 +109,9 @@ void sctp_ssnmap_clear(struct sctp_ssnmap *map)
 void sctp_ssnmap_free(struct sctp_ssnmap *map)
 {
 	if (map && map->malloced) {
-		kfree(map);
+		free_pages((unsigned long)map,
+			   get_order(sctp_ssnmap_size(map->in.len,
+						      map->out.len)));
 		SCTP_DBG_OBJCNT_DEC(ssnmap);
 	}
 }