Insert overlay symbols to the base tree when applied.
This makes it possible to apply an overlay that references a label
that a previously inserted overlay had.

Signed-off-by: Pantelis Antoniou <[email protected]>
---
 drivers/of/overlay.c | 93 ++++++++++++++++++++++++++++++++++++++++++++++++++++
 1 file changed, 93 insertions(+)

diff --git a/drivers/of/overlay.c b/drivers/of/overlay.c
index a274d65..89ebb70 100644
--- a/drivers/of/overlay.c
+++ b/drivers/of/overlay.c
@@ -8,6 +8,7 @@
  * modify it under the terms of the GNU General Public License
  * version 2 as published by the Free Software Foundation.
  */
+
 #undef DEBUG
 #include <linux/kernel.h>
 #include <linux/module.h>
@@ -514,6 +515,91 @@ static int of_free_overlay_info(struct of_overlay *ov)
        return 0;
 }
 
+static int of_overlay_add_symbols(
+               struct device_node *tree,
+               struct of_overlay *ov)
+{
+       struct of_overlay_info *ovinfo;
+       struct device_node *root_sym = NULL;
+       struct device_node *child = NULL;
+       struct property *prop;
+       const char *path, *s;
+       char *new_path;
+       int i, len, err;
+
+       /* both may fail (if no fixups are required) */
+       root_sym = of_find_node_by_path("/__symbols__");
+       child = of_get_child_by_name(tree, "__symbols__");
+
+       err = 0;
+       /* do nothing if either is NULL */
+       if (!root_sym || !child)
+               goto out;
+
+       for_each_property_of_node(child, prop) {
+
+               /* skip properties added automatically */
+               if (of_prop_cmp(prop->name, "name") == 0)
+                       continue;
+
+               err = of_property_read_string(child,
+                               prop->name, &path);
+               if (err != 0) {
+                       pr_err("Could not find symbol '%s'\n", prop->name);
+                       continue;
+               }
+
+               /* now find fragment index */
+               s = path;
+
+               /* compare paths to find fragment index */
+               for (i = 0, ovinfo = NULL, len = -1; i < ov->count; i++) {
+                       ovinfo = &ov->ovinfo_tab[i];
+
+                       pr_debug("#%d: overlay->name=%s target->name=%s\n",
+                                       i, ovinfo->overlay->full_name,
+                                       ovinfo->target->full_name);
+
+                       len = strlen(ovinfo->overlay->full_name);
+                       if (strncasecmp(path, ovinfo->overlay->full_name,
+                                               len) == 0 && path[len] == '/')
+                               break;
+               }
+
+               if (i >= ov->count)
+                       continue;
+
+               pr_debug("found target at #%d\n", i);
+               new_path = kasprintf(GFP_KERNEL, "%s%s",
+                               ovinfo->target->full_name,
+                               path + len);
+               if (!new_path) {
+                       pr_err("Failed to allocate propname for \"%s\"\n",
+                                       prop->name);
+                       err = -ENOMEM;
+                       break;
+               }
+
+               err = of_changeset_add_property_string(&ov->cset, root_sym,
+                               prop->name, new_path);
+
+               /* free always */
+               kfree(new_path);
+
+               if (err) {
+                       pr_err("Failed to add property for \"%s\"\n",
+                                       prop->name);
+                       break;
+               }
+       }
+
+out:
+       of_node_put(child);
+       of_node_put(root_sym);
+
+       return err;
+}
+
 static LIST_HEAD(ov_list);
 static DEFINE_IDR(ov_idr);
 
@@ -642,6 +728,13 @@ static int __of_overlay_create(struct device_node *tree,
                goto err_abort_trans;
        }
 
+       err = of_overlay_add_symbols(tree, ov);
+       if (err) {
+               pr_err("%s: of_overlay_add_symbols() failed for tree@%s\n",
+                               __func__, tree->full_name);
+               goto err_abort_trans;
+       }
+
        /* apply the changeset */
        err = __of_changeset_apply(&ov->cset);
        if (err) {
-- 
1.7.12

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