On Mon, 26 Aug 2013 16:39:17 +0200, Marek Szyprowski m.szyprowski@samsung.com 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 early boot before we can unflatten the tree.
Signed-off-by: Marek Szyprowski m.szyprowski@samsung.com Acked-by: Michal Nazarewicz mina86@mina86.com Acked-by: Tomasz Figa t.figa@samsung.com Reviewed-by: Rob Herring rob.herring@calxeda.com
Some nits below, but otherwise:
Acked-by: Grant Likely grant.likely@secretlab.ca
I'm happy to take this through the DT tree, or have you take it via the CMA tree.
drivers/of/fdt.c | 76 ++++++++++++++++++++++++++++++++++++++++++++++++ include/linux/of_fdt.h | 3 ++ 2 files changed, 79 insertions(+)
diff --git a/drivers/of/fdt.c b/drivers/of/fdt.c index b10ba00..4fb06f3 100644 --- a/drivers/of/fdt.c +++ b/drivers/of/fdt.c @@ -545,6 +545,82 @@ int __init of_flat_dt_match(unsigned long node, const char *const *compat) return of_fdt_match(initial_boot_params, node, compat); } +struct fdt_scan_status {
- const char *name;
- int namelen;
- int depth;
- int found;
- int (*iterator)(unsigned long node, const char *uname, int depth, void *data);
- void *data;
+};
+/**
- fdt_scan_node_by_path - iterator for of_scan_flat_dt_by_path function
- */
+static int __init fdt_scan_node_by_path(unsigned long node, const char *uname,
int depth, void *data)
Nit: since this is an iterator, I'd like to see "iter" in the function name.
+{
- 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 &&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;st->name = next;st->namelen = strcspn(next, "/");}return 0;
The above return statement is redundant.
- }
- /* 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)
Nit: Please match the indentation convention used by of_scan_flat_dt(). This current version is really hard to read.
+{
- struct fdt_scan_status st = {path, 0, -1, 0, it, data};
This is a little fragile. If the structure gets modified, this line will break. I know it results in more text, but please use explicit data member assignments in initializers.
- int ret = 0;
- if (initial_boot_params)
Nit: if (!initial_boot_params) return 0;
ret = of_scan_flat_dt(fdt_scan_node_by_path, &st);
Nit: inconsitent indentation (tabs vs. spaces)
- if (!st.found)
return -ENOENT;- else if (ret == -ENXIO) /* scan has been completed */
return 0;- else
return ret;
Both uses of 'else' above are redundant. The only way the execution will pass that point is if it was the else case!
+}
#ifdef CONFIG_BLK_DEV_INITRD /**
- early_init_dt_check_for_initrd - Decode initrd location from flat tree
diff --git a/include/linux/of_fdt.h b/include/linux/of_fdt.h index ed136ad..19f26f8 100644 --- a/include/linux/of_fdt.h +++ b/include/linux/of_fdt.h @@ -90,6 +90,9 @@ extern void *of_get_flat_dt_prop(unsigned long node, const char *name, extern int of_flat_dt_is_compatible(unsigned long node, const char *name); extern int of_flat_dt_match(unsigned long node, const char *const *matches); extern unsigned long of_get_flat_dt_root(void); +extern int of_scan_flat_dt_by_path(const char *path,
- int (*it)(unsigned long node, const char *name, int depth, void *data),
- void *data);
extern int early_init_dt_scan_chosen(unsigned long node, const char *uname, int depth, void *data); -- 1.7.9.5