On Wed, Jul 31 2013, Marek Szyprowski wrote:
Add a function to scan the flattened device-tree starting from the node given by the path. It is used to extract information (like reserved memory), which is required on ealy boot before we can unflatten the
^^^^ early
tree.
Signed-off-by: Marek Szyprowski m.szyprowski@samsung.com Acked-by: Kyungmin Park kyungmin.park@samsung.com
Acked-by: Michal Nazarewicz mina86@mina86.com
Some minor comments inline.
+static int __init fdt_scan_node_by_path(unsigned long node, const char *uname,
int depth, void *data)+{
- struct fdt_scan_status *st = data;
- /*
* if scan at the requested fdt node has been completed,* return -ENXIO to abort further scanning*/- if (depth <= st->depth)
return -ENXIO;- /* requested fdt node has been found, so call iterator function */
- if (st->found)
return st->iterator(node, uname, depth, st->data);- /* check if scanning automata is entering next level of fdt nodes */
- if (depth == st->depth + 1 &&
strncmp(st->name, uname, st->namelen) == 0) {
+ strncmp(st->name, uname, st->namelen) == 0 && + uname[st->namelen] == 0) {
st->depth += 1;if (st->name[st->namelen] == 0) {st->found = 1;} else {const char *next = st->name + st->namelen + 1;const char *p = next;while (*p != '/' && *p != 0)p++;st->name = next;st->namelen = p - next;
+ st->namelen = strcspn(next, "/");
except this might be slightly slower since the second argument is looped over, but something to consider I guess since it get rid of few of the lines of code.
}return 0;- }
- /* scan next fdt node */
- return 0;
+}
+/**
- of_scan_flat_dt_by_path - scan flattened tree blob and call callback on each
child of the given path.
- @path: path to start searching for children
- @it: callback function
- @data: context data pointer
- This function is used to scan the flattened device-tree starting from the
- node given by path. It is used to extract information (like reserved
- memory), which is required on ealy boot before we can unflatten the tree.
- */
+int __init of_scan_flat_dt_by_path(const char *path,
- int (*it)(unsigned long node, const char *name, int depth, void *data),
- void *data)
+{
- struct fdt_scan_status st = {path, 0, -1, 0, it, data};
- int ret = 0;
- if (initial_boot_params)
ret = of_scan_flat_dt(fdt_scan_node_by_path, &st);- if (st.found && ret == -ENXIO) /* scan has been completed */
return 0;- else
return -ENOENT;
Perhaps propagate ret:
+ if (!st.found) + return -ENOENT; + else if (ret == -ENXIO) + return 0; + else + return ret;
+}
#ifdef CONFIG_BLK_DEV_INITRD /**
- early_init_dt_check_for_initrd - Decode initrd location from flat tree