mtd: ofpart: move ofpart partitions to a dedicated dt node

Parsing direct subnodes of a mtd device as partitions is unreliable
since the mtd device is also part of its bus subsystem and can contain
bus data in subnodes.

Move ofpart data to a subnode of its own so it is clear which data is
part of the partition layout.

Signed-off-by: Michal Suchanek <hramrach@gmail.com>
Signed-off-by: Brian Norris <computersforpeace@gmail.com>

1 files changed, 46 insertions, 17 deletions

diff --git a/drivers/mtd/ofpart.c b/drivers/mtd/ofpart.c
index aa26c32e1bc2..669c3452f278 100644
--- a/drivers/mtd/ofpart.c
+++ b/drivers/mtd/ofpart.c
@@ -29,23 +29,33 @@ static int parse_ofpart_partitions(struct mtd_info *master,
                                    struct mtd_partition **pparts,
                                    struct mtd_part_parser_data *data)
 {
-        struct device_node *node;
+        struct device_node *mtd_node;
+        struct device_node *ofpart_node;
         const char *partname;
         struct device_node *pp;
-        int nr_parts, i;
+        int nr_parts, i, ret = 0;
+        bool dedicated = true;
 
 
         if (!data)
                 return 0;
 
-        node = data->of_node;
-        if (!node)
+        mtd_node = data->of_node;
+        if (!mtd_node)
                 return 0;
 
+        ofpart_node = of_get_child_by_name(mtd_node, "partitions");
+        if (!ofpart_node) {
+                pr_warn("%s: 'partitions' subnode not found on %s. Trying to parse direct subnodes as partitions.\n",
+                        master->name, mtd_node->full_name);
+                ofpart_node = mtd_node;
+                dedicated = false;
+        }
+
         /* First count the subnodes */
         nr_parts = 0;
-        for_each_child_of_node(node,  pp) {
-                if (node_has_compatible(pp))
+        for_each_child_of_node(ofpart_node,  pp) {
+                if (!dedicated && node_has_compatible(pp))
                         continue;
 
                 nr_parts++;
@@ -59,22 +69,36 @@ static int parse_ofpart_partitions(struct mtd_info *master,
                 return -ENOMEM;
 
         i = 0;
-        for_each_child_of_node(node,  pp) {
+        for_each_child_of_node(ofpart_node,  pp) {
                 const __be32 *reg;
                 int len;
                 int a_cells, s_cells;
 
-                if (node_has_compatible(pp))
+                if (!dedicated && node_has_compatible(pp))
                         continue;
 
                 reg = of_get_property(pp, "reg", &len);
                 if (!reg) {
-                        nr_parts--;
-                        continue;
+                        if (dedicated) {
+                                pr_debug("%s: ofpart partition %s (%s) missing reg property.\n",
+                                         master->name, pp->full_name,
+                                         mtd_node->full_name);
+                                goto ofpart_fail;
+                        } else {
+                                nr_parts--;
+                                continue;
+                        }
                 }
 
                 a_cells = of_n_addr_cells(pp);
                 s_cells = of_n_size_cells(pp);
+                if (len / 4 != a_cells + s_cells) {
+                        pr_debug("%s: ofpart partition %s (%s) error parsing reg property.\n",
+                                 master->name, pp->full_name,
+                                 mtd_node->full_name);
+                        goto ofpart_fail;
+                }
+
                 (*pparts)[i].offset = of_read_number(reg, a_cells);
                 (*pparts)[i].size = of_read_number(reg + a_cells, s_cells);
 
@@ -92,15 +116,20 @@ static int parse_ofpart_partitions(struct mtd_info *master,
                 i++;
         }
 
-        if (!i) {
-                of_node_put(pp);
-                pr_err("No valid partition found on %s\n", node->full_name);
-                kfree(*pparts);
-                *pparts = NULL;
-                return -EINVAL;
-        }
+        if (!nr_parts)
+                goto ofpart_none;
 
         return nr_parts;
+
+ofpart_fail:
+        pr_err("%s: error parsing ofpart partition %s (%s)\n",
+               master->name, pp->full_name, mtd_node->full_name);
+        ret = -EINVAL;
+ofpart_none:
+        of_node_put(pp);
+        kfree(*pparts);
+        *pparts = NULL;
+        return ret;
 }
 
 static struct mtd_part_parser ofpart_parser = {