1 files changed, 153 insertions, 205 deletions

diff --git a/drivers/of/resolver.c b/drivers/of/resolver.c
index 46325d6394cf..8bf12e904fd2 100644
--- a/drivers/of/resolver.c
+++ b/drivers/of/resolver.c
@@ -28,20 +28,19 @@
  * Find a node with the give full name by recursively following any of
  * the child node links.
  */
-static struct device_node *__of_find_node_by_full_name(struct device_node *node,
+static struct device_node *find_node_by_full_name(struct device_node *node,
 		const char *full_name)
 {
 	struct device_node *child, *found;
 
-	if (node == NULL)
+	if (!node)
 		return NULL;
 
-	/* check */
-	if (of_node_cmp(node->full_name, full_name) == 0)
+	if (!of_node_cmp(node->full_name, full_name))
 		return of_node_get(node);
 
 	for_each_child_of_node(node, child) {
-		found = __of_find_node_by_full_name(child, full_name);
+		found = find_node_by_full_name(child, full_name);
 		if (found != NULL) {
 			of_node_put(child);
 			return found;
@@ -51,16 +50,12 @@ static struct device_node *__of_find_node_by_full_name(struct device_node *node,
 	return NULL;
 }
 
-/*
- * Find live tree's maximum phandle value.
- */
-static phandle of_get_tree_max_phandle(void)
+static phandle live_tree_max_phandle(void)
 {
 	struct device_node *node;
 	phandle phandle;
 	unsigned long flags;
 
-	/* now search recursively */
 	raw_spin_lock_irqsave(&devtree_lock, flags);
 	phandle = 0;
 	for_each_of_allnodes(node) {
@@ -73,131 +68,102 @@ static phandle of_get_tree_max_phandle(void)
 	return phandle;
 }
 
-/*
- * Adjust a subtree's phandle values by a given delta.
- * Makes sure not to just adjust the device node's phandle value,
- * but modify the phandle properties values as well.
- */
-static void __of_adjust_tree_phandles(struct device_node *node,
+static void adjust_overlay_phandles(struct device_node *overlay,
 		int phandle_delta)
 {
 	struct device_node *child;
 	struct property *prop;
 	phandle phandle;
 
-	/* first adjust the node's phandle direct value */
-	if (node->phandle != 0 && node->phandle != OF_PHANDLE_ILLEGAL)
-		node->phandle += phandle_delta;
+	/* adjust node's phandle in node */
+	if (overlay->phandle != 0 && overlay->phandle != OF_PHANDLE_ILLEGAL)
+		overlay->phandle += phandle_delta;
 
-	/* now adjust phandle & linux,phandle values */
-	for_each_property_of_node(node, prop) {
+	/* copy adjusted phandle into *phandle properties */
+	for_each_property_of_node(overlay, prop) {
 
-		/* only look for these two */
-		if (of_prop_cmp(prop->name, "phandle") != 0 &&
-		    of_prop_cmp(prop->name, "linux,phandle") != 0)
+		if (of_prop_cmp(prop->name, "phandle") &&
+		    of_prop_cmp(prop->name, "linux,phandle"))
 			continue;
 
-		/* must be big enough */
 		if (prop->length < 4)
 			continue;
 
-		/* read phandle value */
 		phandle = be32_to_cpup(prop->value);
-		if (phandle == OF_PHANDLE_ILLEGAL)	/* unresolved */
+		if (phandle == OF_PHANDLE_ILLEGAL)
 			continue;
 
-		/* adjust */
-		*(uint32_t *)prop->value = cpu_to_be32(node->phandle);
+		*(uint32_t *)prop->value = cpu_to_be32(overlay->phandle);
 	}
 
-	/* now do the children recursively */
-	for_each_child_of_node(node, child)
-		__of_adjust_tree_phandles(child, phandle_delta);
+	for_each_child_of_node(overlay, child)
+		adjust_overlay_phandles(child, phandle_delta);
 }
 
-static int __of_adjust_phandle_ref(struct device_node *node,
-		struct property *rprop, int value)
+static int update_usages_of_a_phandle_reference(struct device_node *overlay,
+		struct property *prop_fixup, phandle phandle)
 {
-	phandle phandle;
 	struct device_node *refnode;
-	struct property *sprop;
-	char *propval, *propcur, *propend, *nodestr, *propstr, *s;
-	int offset, propcurlen;
+	struct property *prop;
+	char *value, *cur, *end, *node_path, *prop_name, *s;
+	int offset, len;
 	int err = 0;
 
-	/* make a copy */
-	propval = kmalloc(rprop->length, GFP_KERNEL);
-	if (!propval) {
-		pr_err("%s: Could not copy value of '%s'\n",
-				__func__, rprop->name);
+	value = kmalloc(prop_fixup->length, GFP_KERNEL);
+	if (!value)
 		return -ENOMEM;
-	}
-	memcpy(propval, rprop->value, rprop->length);
+	memcpy(value, prop_fixup->value, prop_fixup->length);
 
-	propend = propval + rprop->length;
-	for (propcur = propval; propcur < propend; propcur += propcurlen + 1) {
-		propcurlen = strlen(propcur);
+	/* prop_fixup contains a list of tuples of path:property_name:offset */
+	end = value + prop_fixup->length;
+	for (cur = value; cur < end; cur += len + 1) {
+		len = strlen(cur);
 
-		nodestr = propcur;
-		s = strchr(propcur, ':');
+		node_path = cur;
+		s = strchr(cur, ':');
 		if (!s) {
-			pr_err("%s: Illegal symbol entry '%s' (1)\n",
-				__func__, propcur);
 			err = -EINVAL;
 			goto err_fail;
 		}
 		*s++ = '\0';
 
-		propstr = s;
+		prop_name = s;
 		s = strchr(s, ':');
 		if (!s) {
-			pr_err("%s: Illegal symbol entry '%s' (2)\n",
-				__func__, (char *)rprop->value);
 			err = -EINVAL;
 			goto err_fail;
 		}
-
 		*s++ = '\0';
+
 		err = kstrtoint(s, 10, &offset);
-		if (err != 0) {
-			pr_err("%s: Could get offset '%s'\n",
-				__func__, (char *)rprop->value);
+		if (err)
 			goto err_fail;
-		}
 
-		/* look into the resolve node for the full path */
-		refnode = __of_find_node_by_full_name(node, nodestr);
-		if (!refnode) {
-			pr_warn("%s: Could not find refnode '%s'\n",
-				__func__, (char *)rprop->value);
+		refnode = find_node_by_full_name(overlay, node_path);
+		if (!refnode)
 			continue;
-		}
 
-		/* now find the property */
-		for_each_property_of_node(refnode, sprop) {
-			if (of_prop_cmp(sprop->name, propstr) == 0)
+		for_each_property_of_node(refnode, prop) {
+			if (!of_prop_cmp(prop->name, prop_name))
 				break;
 		}
 		of_node_put(refnode);
 
-		if (!sprop) {
-			pr_err("%s: Could not find property '%s'\n",
-				__func__, (char *)rprop->value);
+		if (!prop) {
 			err = -ENOENT;
 			goto err_fail;
 		}
 
-		phandle = value;
-		*(__be32 *)(sprop->value + offset) = cpu_to_be32(phandle);
+		*(__be32 *)(prop->value + offset) = cpu_to_be32(phandle);
 	}
 
 err_fail:
-	kfree(propval);
+	kfree(value);
 	return err;
 }
 
 /* compare nodes taking into account that 'name' strips out the @ part */
-static int __of_node_name_cmp(const struct device_node *dn1,
+static int node_name_cmp(const struct device_node *dn1,
 		const struct device_node *dn2)
 {
 	const char *n1 = strrchr(dn1->full_name, '/') ? : "/";
@@ -208,85 +174,77 @@ static int __of_node_name_cmp(const struct device_node *dn1,
 
 /*
  * Adjust the local phandle references by the given phandle delta.
- * Assumes the existances of a __local_fixups__ node at the root.
- * Assumes that __of_verify_tree_phandle_references has been called.
- * Does not take any devtree locks so make sure you call this on a tree
- * which is at the detached state.
+ *
+ * Subtree @local_fixups, which is overlay node __local_fixups__,
+ * mirrors the fragment node structure at the root of the overlay.
+ *
+ * For each property in the fragments that contains a phandle reference,
+ * @local_fixups has a property of the same name that contains a list
+ * of offsets of the phandle reference(s) within the respective property
+ * value(s).  The values at these offsets will be fixed up.
  */
-static int __of_adjust_tree_phandle_references(struct device_node *node,
-		struct device_node *target, int phandle_delta)
+static int adjust_local_phandle_references(struct device_node *local_fixups,
+		struct device_node *overlay, int phandle_delta)
 {
-	struct device_node *child, *childtarget;
-	struct property *rprop, *sprop;
+	struct device_node *child, *overlay_child;
+	struct property *prop_fix, *prop;
 	int err, i, count;
 	unsigned int off;
 	phandle phandle;
 
-	if (node == NULL)
+	if (!local_fixups)
 		return 0;
 
-	for_each_property_of_node(node, rprop) {
+	for_each_property_of_node(local_fixups, prop_fix) {
 
 		/* skip properties added automatically */
-		if (of_prop_cmp(rprop->name, "name") == 0 ||
-		    of_prop_cmp(rprop->name, "phandle") == 0 ||
-		    of_prop_cmp(rprop->name, "linux,phandle") == 0)
+		if (!of_prop_cmp(prop_fix->name, "name") ||
+		    !of_prop_cmp(prop_fix->name, "phandle") ||
+		    !of_prop_cmp(prop_fix->name, "linux,phandle"))
 			continue;
 
-		if ((rprop->length % 4) != 0 || rprop->length == 0) {
-			pr_err("%s: Illegal property (size) '%s' @%s\n",
-					__func__, rprop->name, node->full_name);
+		if ((prop_fix->length % 4) != 0 || prop_fix->length == 0)
 			return -EINVAL;
-		}
-		count = rprop->length / sizeof(__be32);
+		count = prop_fix->length / sizeof(__be32);
 
-		/* now find the target property */
-		for_each_property_of_node(target, sprop) {
-			if (of_prop_cmp(sprop->name, rprop->name) == 0)
+		for_each_property_of_node(overlay, prop) {
+			if (!of_prop_cmp(prop->name, prop_fix->name))
 				break;
 		}
 
-		if (sprop == NULL) {
-			pr_err("%s: Could not find target property '%s' @%s\n",
-					__func__, rprop->name, node->full_name);
+		if (!prop)
 			return -EINVAL;
-		}
 
 		for (i = 0; i < count; i++) {
-			off = be32_to_cpu(((__be32 *)rprop->value)[i]);
-			/* make sure the offset doesn't overstep (even wrap) */
-			if (off >= sprop->length ||
-					(off + 4) > sprop->length) {
-				pr_err("%s: Illegal property '%s' @%s\n",
-						__func__, rprop->name,
-						node->full_name);
+			off = be32_to_cpu(((__be32 *)prop_fix->value)[i]);
+			if ((off + 4) > prop->length)
 				return -EINVAL;
-			}
-
-			if (phandle_delta) {
-				/* adjust */
-				phandle = be32_to_cpu(*(__be32 *)(sprop->value + off));
-				phandle += phandle_delta;
-				*(__be32 *)(sprop->value + off) = cpu_to_be32(phandle);
-			}
+
+			phandle = be32_to_cpu(*(__be32 *)(prop->value + off));
+			phandle += phandle_delta;
+			*(__be32 *)(prop->value + off) = cpu_to_be32(phandle);
 		}
 	}
 
-	for_each_child_of_node(node, child) {
-
-		for_each_child_of_node(target, childtarget)
-			if (__of_node_name_cmp(child, childtarget) == 0)
+	/*
+	 * 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 (!node_name_cmp(child, overlay_child))
 				break;
 
-		if (!childtarget) {
-			pr_err("%s: Could not find target child '%s' @%s\n",
-					__func__, child->name, node->full_name);
+		if (!overlay_child)
 			return -EINVAL;
-		}
 
-		err = __of_adjust_tree_phandle_references(child, childtarget,
+		err = adjust_local_phandle_references(child, overlay_child,
 				phandle_delta);
-		if (err != 0)
+		if (err)
 			return err;
 	}
 
@@ -294,111 +252,103 @@ static int __of_adjust_tree_phandle_references(struct device_node *node,
 }
 
 /**
- * of_resolve	- Resolve the given node against the live tree.
+ * of_resolve_phandles - Relocate and resolve overlay against live tree
  *
- * @resolve:	Node to resolve
+ * @overlay:	Pointer to devicetree overlay to relocate and resolve
  *
- * Perform dynamic Device Tree resolution against the live tree
- * to the given node to resolve. This depends on the live tree
- * having a __symbols__ node, and the resolve node the __fixups__ &
- * __local_fixups__ nodes (if needed).
- * The result of the operation is a resolve node that it's contents
- * are fit to be inserted or operate upon the live tree.
- * Returns 0 on success or a negative error value on error.
+ * Modify (relocate) values of local phandles in @overlay to a range that
+ * does not conflict with the live expanded devicetree.  Update references
+ * to the local phandles in @overlay.  Update (resolve) phandle references
+ * in @overlay that refer to the live expanded devicetree.
+ *
+ * Phandle values in the live tree are in the range of
+ * 1 .. live_tree_max_phandle().  The range of phandle values in the overlay
+ * also begin with at 1.  Adjust the phandle values in the overlay to begin
+ * at live_tree_max_phandle() + 1.  Update references to the phandles to
+ * the adjusted phandle values.
+ *
+ * The name of each property in the "__fixups__" node in the overlay matches
+ * the name of a symbol (a label) in the live tree.  The values of each
+ * property in the "__fixups__" node is a list of the property values in the
+ * overlay that need to be updated to contain the phandle reference
+ * corresponding to that symbol in the live tree.  Update the references in
+ * the overlay with the phandle values in the live tree.
+ *
+ * @overlay must be detached.
+ *
+ * Resolving and applying @overlay to the live expanded devicetree must be
+ * protected by a mechanism to ensure that multiple overlays are processed
+ * in a single threaded manner so that multiple overlays will not relocate
+ * phandles to overlapping ranges.  The mechanism to enforce this is not
+ * yet implemented.
+ *
+ * Return: %0 on success or a negative error value on error.
  */
-int of_resolve_phandles(struct device_node *resolve)
+int of_resolve_phandles(struct device_node *overlay)
 {
-	struct device_node *child, *childroot, *refnode;
-	struct device_node *root_sym, *resolve_sym, *resolve_fix;
-	struct property *rprop;
+	struct device_node *child, *local_fixups, *refnode;
+	struct device_node *tree_symbols, *overlay_fixups;
+	struct property *prop;
 	const char *refpath;
 	phandle phandle, phandle_delta;
 	int err;
 
-	if (!resolve)
-		pr_err("%s: null node\n", __func__);
-	if (resolve && !of_node_check_flag(resolve, OF_DETACHED))
-		pr_err("%s: node %s not detached\n", __func__,
-			 resolve->full_name);
-	/* the resolve node must exist, and be detached */
-	if (!resolve || !of_node_check_flag(resolve, OF_DETACHED))
-		return -EINVAL;
-
-	/* first we need to adjust the phandles */
-	phandle_delta = of_get_tree_max_phandle() + 1;
-	__of_adjust_tree_phandles(resolve, phandle_delta);
-
-	/* locate the local fixups */
-	childroot = NULL;
-	for_each_child_of_node(resolve, childroot)
-		if (of_node_cmp(childroot->name, "__local_fixups__") == 0)
-			break;
-
-	if (childroot != NULL) {
-		/* resolve root is guaranteed to be the '/' */
-		err = __of_adjust_tree_phandle_references(childroot,
-				resolve, 0);
-		if (err != 0)
-			return err;
+	tree_symbols = NULL;
 
-		BUG_ON(__of_adjust_tree_phandle_references(childroot,
-				resolve, phandle_delta));
+	if (!overlay) {
+		pr_err("null overlay\n");
+		err = -EINVAL;
+		goto out;
+	}
+	if (!of_node_check_flag(overlay, OF_DETACHED)) {
+		pr_err("overlay not detached\n");
+		err = -EINVAL;
+		goto out;
 	}
 
-	root_sym = NULL;
-	resolve_sym = NULL;
-	resolve_fix = NULL;
-
-	/* this may fail (if no fixups are required) */
-	root_sym = of_find_node_by_path("/__symbols__");
+	phandle_delta = live_tree_max_phandle() + 1;
+	adjust_overlay_phandles(overlay, phandle_delta);
 
-	/* locate the symbols & fixups nodes on resolve */
-	for_each_child_of_node(resolve, child) {
+	for_each_child_of_node(overlay, local_fixups)
+		if (!of_node_cmp(local_fixups->name, "__local_fixups__"))
+			break;
 
-		if (!resolve_sym &&
-				of_node_cmp(child->name, "__symbols__") == 0)
-			resolve_sym = child;
+	err = adjust_local_phandle_references(local_fixups, overlay, phandle_delta);
+	if (err)
+		goto out;
 
-		if (!resolve_fix &&
-				of_node_cmp(child->name, "__fixups__") == 0)
-			resolve_fix = child;
+	overlay_fixups = NULL;
 
-		/* both found, don't bother anymore */
-		if (resolve_sym && resolve_fix)
-			break;
+	for_each_child_of_node(overlay, child) {
+		if (!of_node_cmp(child->name, "__fixups__"))
+			overlay_fixups = child;
 	}
 
-	/* we do allow for the case where no fixups are needed */
-	if (!resolve_fix) {
-		err = 0;	/* no error */
+	if (!overlay_fixups) {
+		err = 0;
 		goto out;
 	}
 
-	/* we need to fixup, but no root symbols... */
-	if (!root_sym) {
-		pr_err("%s: no symbols in root of device tree.\n", __func__);
+	tree_symbols = of_find_node_by_path("/__symbols__");
+	if (!tree_symbols) {
+		pr_err("no symbols in root of device tree.\n");
 		err = -EINVAL;
 		goto out;
 	}
 
-	for_each_property_of_node(resolve_fix, rprop) {
+	for_each_property_of_node(overlay_fixups, prop) {
 
 		/* skip properties added automatically */
-		if (of_prop_cmp(rprop->name, "name") == 0)
+		if (!of_prop_cmp(prop->name, "name"))
 			continue;
 
-		err = of_property_read_string(root_sym,
-				rprop->name, &refpath);
-		if (err != 0) {
-			pr_err("%s: Could not find symbol '%s'\n",
-					__func__, rprop->name);
+		err = of_property_read_string(tree_symbols,
+				prop->name, &refpath);
+		if (err)
 			goto out;
-		}
 
 		refnode = of_find_node_by_path(refpath);
 		if (!refnode) {
-			pr_err("%s: Could not find node by path '%s'\n",
-					__func__, refpath);
 			err = -ENOENT;
 			goto out;
 		}
@@ -406,17 +356,15 @@ int of_resolve_phandles(struct device_node *resolve)
 		phandle = refnode->phandle;
 		of_node_put(refnode);
 
-		pr_debug("%s: %s phandle is 0x%08x\n",
-				__func__, rprop->name, phandle);
-
-		err = __of_adjust_phandle_ref(resolve, rprop, phandle);
+		err = update_usages_of_a_phandle_reference(overlay, prop, phandle);
 		if (err)
 			break;
 	}
 
 out:
-	/* NULL is handled by of_node_put as NOP */
-	of_node_put(root_sym);
+	if (err)
+		pr_err("overlay phandle fixup failed: %d\n", err);
+	of_node_put(tree_symbols);
 
 	return err;
 }