[PATCH 3/3] drivers: of: bugfix local fixups resolving

Pascal Vizeli pvizeli at syshack.ch
Sat Jun 2 14:17:15 PDT 2018


Signed-off-by: Pascal Vizeli <pvizeli at syshack.ch>
---
 drivers/of/resolver.c | 144 +++++++++++++++++-------------------------
 1 file changed, 58 insertions(+), 86 deletions(-)

diff --git a/drivers/of/resolver.c b/drivers/of/resolver.c
index 62476093c..03c61e959 100644
--- a/drivers/of/resolver.c
+++ b/drivers/of/resolver.c
@@ -66,108 +66,72 @@ static void of_adjust_tree_phandles(struct device_node *node,
  * of the tree. Does not take any devtree locks so make sure you
  * call this on a tree which is at the detached state.
  */
-static int of_adjust_tree_phandle_references(struct device_node *node,
-		int phandle_delta)
+static int of_adjust_tree_phandle_references(struct device_node *local_fixups,
+		struct device_node *overlay, int phandle_delta)
 {
 	phandle phandle;
-	struct device_node *refnode, *child;
-	struct property *rprop, *sprop;
-	char *propval, *propcur, *propend, *nodestr, *propstr, *s;
-	int offset, propcurlen;
-	int err;
-	bool found = false;
+	struct device_node *child, *overlay_child;
+	struct property *fixprop, *prop;
+	int i, count, err;
+	unsigned int off;
 
 	/* locate the symbols & fixups nodes on resolve */
-	for_each_child_of_node(node, child)
-		if (of_node_cmp(child->name, "__local_fixups__") == 0) {
-			found = true;
-			break;
-		}
-
-	/* no local fixups */
-	if (!found)
+	if (!local_fixups)
 		return 0;
 
-	/* find the local fixups property */
-	for_each_property_of_node(child, rprop) {
+	for_each_property_of_node(local_fixups, fixprop) {
 		/* skip properties added automatically */
-		if (of_prop_cmp(rprop->name, "name") == 0)
+		if (of_prop_cmp(fixprop->name, "name") == 0 ||
+		    of_prop_cmp(fixprop->name, "phandle") == 0 ||
+		    of_prop_cmp(fixprop->name, "linux,phandle") == 0)
 			continue;
 
-		/* make a copy */
-		propval = kmalloc(rprop->length, GFP_KERNEL);
-		if (propval == NULL) {
-			pr_err("%s: Could not copy value of '%s'\n",
-					__func__, rprop->name);
-			return -ENOMEM;
-		}
-		memcpy(propval, rprop->value, rprop->length);
-
-		propend = propval + rprop->length;
-		for (propcur = propval; propcur < propend;
-				propcur += propcurlen + 1) {
-
-			propcurlen = strlen(propcur);
-
-			nodestr = propcur;
-			s = strchr(propcur, ':');
-			if (s == NULL) {
-				pr_err("%s: Illegal symbol entry '%s' (1)\n",
-					__func__, propcur);
-				err = -EINVAL;
-				goto err_fail;
-			}
-			*s++ = '\0';
+		if ((fixprop->length % 4) != 0 || fixprop->length == 0)
+			return -EINVAL;
+		count = fixprop->length / sizeof(uint32_t);
 
-			propstr = s;
-			s = strchr(s, ':');
-			if (s == NULL) {
-				pr_err("%s: Illegal symbol entry '%s' (2)\n",
-					__func__, (char *)rprop->value);
-				err = -EINVAL;
-				goto err_fail;
-			}
-
-			*s++ = '\0';
-			offset = simple_strtoul(s, NULL, 10);
+		for_each_property_of_node(overlay, prop) {
+			if (!of_prop_cmp(fixprop->name, prop->name))
+				break;
+		}
 
-			/* look into the resolve node for the full path */
-			refnode = of_find_node_by_path_from(node, nodestr);
-			if (refnode == NULL) {
-				pr_warn("%s: Could not find refnode '%s'\n",
-					__func__, (char *)rprop->value);
-				continue;
-			}
+		if (!prop)
+			return -EINVAL;
 
-			/* now find the property */
-			found = false;
-			for_each_property_of_node(refnode, sprop)
-				if (of_prop_cmp(sprop->name, propstr) == 0) {
-					found = true;
-					break;
-				}
+		for (i=0; i < count; i++) {
+			off = be32_to_cpu(((uint32_t *)fixprop->value)[i]);
+			if ((off + 4) > prop->length)
+				return -EINVAL;
 
-			if (!found) {
-				pr_err("%s: Could not find property '%s'\n",
-					__func__, (char *)rprop->value);
-				err = -ENOENT;
-				goto err_fail;
-			}
-
-			phandle = be32_to_cpu(*(uint32_t *)
-					(sprop->value + offset));
-			*(uint32_t *)(sprop->value + offset) =
-				cpu_to_be32(phandle + phandle_delta);
+			phandle = be32_to_cpu(*(uint32_t *)(prop->value + off));
+			phandle += phandle_delta;
+			*(uint32_t *)(prop->value + off) = cpu_to_be32(phandle);
 		}
+	}
 
-		kfree(propval);
+	/*
+	 * These nested loops recurse down two subtrees in parallel, where the
+	 * node names in the two subtrees match.
+	 *
+	 * The roots of the subtrees are the overlay's __local_fixups__ node
+	 * and the overlay's root node.
+	 */
+	for_each_child_of_node(local_fixups, child) {
+
+		for_each_child_of_node(overlay, overlay_child)
+			if (!of_node_cmp(child->name, overlay_child->name))
+				break;
+
+		if (!overlay_child)
+			return -EINVAL;
+
+		err = of_adjust_tree_phandle_references(child, overlay_child,
+				phandle_delta);
+		if (err)
+			return err;
 	}
 
 	return 0;
-
-err_fail:
-	kfree(propval);
-	return err;
 }
 
 /**
@@ -185,7 +149,7 @@ err_fail:
  */
 int of_resolve(struct device_node *resolve)
 {
-	struct device_node *child, *refnode;
+	struct device_node *child, *refnode, *local_fixups;
 	struct device_node *root_sym, *resolve_sym, *resolve_fix;
 	struct property *rprop, *sprop;
 	const char *refpath;
@@ -203,7 +167,15 @@ int of_resolve(struct device_node *resolve)
 	/* first we need to adjust the phandles */
 	phandle_delta = of_get_tree_max_phandle(NULL) + 1;
 	of_adjust_tree_phandles(resolve, phandle_delta);
-	err = of_adjust_tree_phandle_references(resolve, phandle_delta);
+
+	/* second we need lookup local fixups of phandles */
+	for_each_child_of_node(resolve, local_fixups) {
+		if (!of_node_cmp(local_fixups->name, "__local_fixups__"))
+			break;
+	}
+
+	err = of_adjust_tree_phandle_references(local_fixups, resolve,
+			phandle_delta);
 	if (err != 0)
 		return err;
 
-- 
2.17.0




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