Enabling OF selftest to run without machine's devicetree

If there is no devicetree present, this patch adds the selftest
data as a live devicetree. It also removes the same after the
testcase execution is complete.

Tested with and without machine's devicetree.

Signed-off-by: Gaurav Minocha <gaurav.minocha.os@gmail.com>
Signed-off-by: Grant Likely <grant.likely@linaro.org>

1 files changed, 31 insertions, 9 deletions

diff --git a/drivers/of/selftest.c b/drivers/of/selftest.c
index d41002667833..a737cb5974de 100644
--- a/drivers/of/selftest.c
+++ b/drivers/of/selftest.c
@@ -27,6 +27,7 @@ static struct selftest_results {
 #define NO_OF_NODES 2
 static struct device_node *nodes[NO_OF_NODES];
 static int last_node_index;
+static bool selftest_live_tree;
 
 #define selftest(result, fmt, ...) { \
         if (!(result)) { \
@@ -630,13 +631,6 @@ static int attach_node_and_children(struct device_node *np)
 {
         struct device_node *next, *root = np, *dup;
 
-        if (!np) {
-                pr_warn("%s: No tree to attach; not running tests\n",
-                        __func__);
-                return -ENODATA;
-        }
-
-
         /* skip root node */
         np = np->child;
         /* storing a copy in temporary node */
@@ -672,12 +666,12 @@ static int attach_node_and_children(struct device_node *np)
 static int __init selftest_data_add(void)
 {
         void *selftest_data;
-        struct device_node *selftest_data_node;
+        struct device_node *selftest_data_node, *np;
         extern uint8_t __dtb_testcases_begin[];
         extern uint8_t __dtb_testcases_end[];
         const int size = __dtb_testcases_end - __dtb_testcases_begin;
 
-        if (!size || !of_allnodes) {
+        if (!size) {
                 pr_warn("%s: No testcase data to attach; not running tests\n",
                         __func__);
                 return -ENODATA;
@@ -692,6 +686,22 @@ static int __init selftest_data_add(void)
                 return -ENOMEM;
         }
         of_fdt_unflatten_tree(selftest_data, &selftest_data_node);
+        if (!selftest_data_node) {
+                pr_warn("%s: No tree to attach; not running tests\n", __func__);
+                return -ENODATA;
+        }
+
+        if (!of_allnodes) {
+                /* enabling flag for removing nodes */
+                selftest_live_tree = true;
+                of_allnodes = selftest_data_node;
+
+                for_each_of_allnodes(np)
+                        __of_attach_node_sysfs(np);
+                of_aliases = of_find_node_by_path("/aliases");
+                of_chosen = of_find_node_by_path("/chosen");
+                return 0;
+        }
 
         /* attach the sub-tree to live tree */
         return attach_node_and_children(selftest_data_node);
@@ -723,6 +733,18 @@ static void selftest_data_remove(void)
         struct device_node *np;
         struct property *prop;
 
+        if (selftest_live_tree) {
+                of_node_put(of_aliases);
+                of_node_put(of_chosen);
+                of_aliases = NULL;
+                of_chosen = NULL;
+                for_each_child_of_node(of_allnodes, np)
+                        detach_node_and_children(np);
+                __of_detach_node_sysfs(of_allnodes);
+                of_allnodes = NULL;
+                return;
+        }
+
         while (last_node_index >= 0) {
                 if (nodes[last_node_index]) {
                         np = of_find_node_by_path(nodes[last_node_index]->full_name);