Commit d1651b03 authored by Frank Rowand's avatar Frank Rowand Committed by Rob Herring
Browse files

of: overlay: add overlay symbols to live device tree 



Add overlay __symbols__ properties to live tree when an overlay
is added to the live tree so that the symbols are available to
subsequent overlays.

Expected test result is new __symbols__ entries for labels from
the overlay after this commit.

Before this commit:

   Console error message near end of unittest:
      ### dt-test ### FAIL of_unittest_overlay_high_level():2296 Adding overlay 'overlay_bad_symbol' failed
      ### dt-test ### end of unittest - 190 passed, 1 failed

   The new unittest "fails" because the expected result of loading the
   new overlay is an error instead of success.

   $ # node hvac-medium-2 exists because the overlay loaded
   $ # since the duplicate symbol was not detected
   $ cd /proc/device-tree/testcase-data-2/substation@100/
   $ ls
   compatible     hvac-medium-2  motor-8        reg
   hvac-large-1   linux,phandle  name           status
   hvac-medium-1  motor-1        phandle

   $ cd /proc/device-tree/__symbols__/
   $ ls
   electric_1   lights_1     name         rides_1      spin_ctrl_2
   hvac_1       lights_2     retail_1     spin_ctrl_1

After this commit:

   Previous console error message no longer occurs, but expected error
   occurs:
      OF: overlay: Failed to apply prop @/__symbols__/hvac_1
      OF: overlay: apply failed '/__symbols__'
      ### dt-test ### end of unittest - 191 passed, 0 failed

   $ # node hvac-medium-2 does not exist because the overlay
   $ # properly failed to load due to the duplicate symbol
   $ cd /proc/device-tree/testcase-data-2/substation@100/
   $ ls
   compatible     hvac-medium-1  motor-1        name           reg
   hvac-large-1   linux,phandle  motor-8        phandle        status

   $ cd /proc/device-tree/__symbols__/
   $ ls
   electric_1      lights_1        retail_1        ride_200_right  spin_ctrl_2
   hvac_1          lights_2        ride_200        rides_1
   hvac_2          name            ride_200_left   spin_ctrl_1
   $ cat ride_200; echo
   /testcase-data-2/fairway-1/ride@200
   $ cat ride_200_left ; echo
   /testcase-data-2/fairway-1/ride@200/track@10
   $ cat ride_200_right ; echo
   /testcase-data-2/fairway-1/ride@200/track@20

Signed-off-by: default avatarFrank Rowand <frank.rowand@sony.com>
Signed-off-by: default avatarRob Herring <robh@kernel.org>
parent c1cd1e01

drivers/of/overlay.c

+107 −9
Original line number Diff line number Diff line
@@ -35,6 +35,7 @@ 
struct of_overlay_info {

	struct device_node *target;

	struct device_node *overlay;

	bool is_symbols_node;

};



/**
@@ -55,7 +56,8 @@ struct of_overlay { 
};



static int of_overlay_apply_one(struct of_overlay *ov,

		struct device_node *target, const struct device_node *overlay);

		struct device_node *target, const struct device_node *overlay,

		bool is_symbols_node);



static BLOCKING_NOTIFIER_HEAD(of_overlay_chain);
@@ -92,10 +94,74 @@ static int of_overlay_notify(struct of_overlay *ov, 
	return 0;

}



static struct property *dup_and_fixup_symbol_prop(struct of_overlay *ov,

		const struct property *prop)

{

	struct of_overlay_info *ovinfo;

	struct property *new;

	const char *overlay_name;

	char *label_path;

	char *symbol_path;

	const char *target_path;

	int k;

	int label_path_len;

	int overlay_name_len;

	int target_path_len;



	if (!prop->value)

		return NULL;

	symbol_path = prop->value;



	new = kzalloc(sizeof(*new), GFP_KERNEL);

	if (!new)

		return NULL;



	for (k = 0; k < ov->count; k++) {

		ovinfo = &ov->ovinfo_tab[k];

		overlay_name = ovinfo->overlay->full_name;

		overlay_name_len = strlen(overlay_name);

		if (!strncasecmp(symbol_path, overlay_name, overlay_name_len))

			break;

	}



	if (k >= ov->count)

		goto err_free;



	target_path = ovinfo->target->full_name;

	target_path_len = strlen(target_path);



	label_path = symbol_path + overlay_name_len;

	label_path_len = strlen(label_path);



	new->name = kstrdup(prop->name, GFP_KERNEL);

	new->length = target_path_len + label_path_len + 1;

	new->value = kzalloc(new->length, GFP_KERNEL);



	if (!new->name || !new->value)

		goto err_free;



	strcpy(new->value, target_path);

	strcpy(new->value + target_path_len, label_path);



	/* mark the property as dynamic */

	of_property_set_flag(new, OF_DYNAMIC);



	return new;



 err_free:

	kfree(new->name);

	kfree(new->value);

	kfree(new);

	return NULL;





}



static int of_overlay_apply_single_property(struct of_overlay *ov,

		struct device_node *target, struct property *prop)

		struct device_node *target, struct property *prop,

		bool is_symbols_node)

{

	struct property *propn, *tprop;

	struct property *propn = NULL, *tprop;



	/* NOTE: Multiple changes of single properties not supported */

	tprop = of_find_property(target, prop->name, NULL);
@@ -106,7 +172,15 @@ static int of_overlay_apply_single_property(struct of_overlay *ov, 
	    of_prop_cmp(prop->name, "linux,phandle") == 0)

		return 0;



	if (is_symbols_node) {

		/* changing a property in __symbols__ node not allowed */

		if (tprop)

			return -EINVAL;

		propn = dup_and_fixup_symbol_prop(ov, prop);

	} else {

		propn = __of_prop_dup(prop, GFP_KERNEL);

	}



	if (propn == NULL)

		return -ENOMEM;
@@ -140,7 +214,7 @@ static int of_overlay_apply_single_device_node(struct of_overlay *ov, 
			return -EINVAL;



		/* apply overlay recursively */

		ret = of_overlay_apply_one(ov, tchild, child);

		ret = of_overlay_apply_one(ov, tchild, child, 0);

		of_node_put(tchild);

	} else {

		/* create empty tree as a target */
@@ -155,7 +229,7 @@ static int of_overlay_apply_single_device_node(struct of_overlay *ov, 
		if (ret)

			return ret;



		ret = of_overlay_apply_one(ov, tchild, child);

		ret = of_overlay_apply_one(ov, tchild, child, 0);

		if (ret)

			return ret;

	}
@@ -171,14 +245,16 @@ static int of_overlay_apply_single_device_node(struct of_overlay *ov, 
 * by using the changeset.

 */

static int of_overlay_apply_one(struct of_overlay *ov,

		struct device_node *target, const struct device_node *overlay)

		struct device_node *target, const struct device_node *overlay,

		bool is_symbols_node)

{

	struct device_node *child;

	struct property *prop;

	int ret;



	for_each_property_of_node(overlay, prop) {

		ret = of_overlay_apply_single_property(ov, target, prop);

		ret = of_overlay_apply_single_property(ov, target, prop,

						       is_symbols_node);

		if (ret) {

			pr_err("Failed to apply prop @%pOF/%s\n",

			       target, prop->name);
@@ -186,6 +262,10 @@ static int of_overlay_apply_one(struct of_overlay *ov, 
		}

	}



	/* do not allow symbols node to have any children */

	if (is_symbols_node)

		return 0;



	for_each_child_of_node(overlay, child) {

		ret = of_overlay_apply_single_device_node(ov, target, child);

		if (ret != 0) {
@@ -216,7 +296,8 @@ static int of_overlay_apply(struct of_overlay *ov) 
	for (i = 0; i < ov->count; i++) {

		struct of_overlay_info *ovinfo = &ov->ovinfo_tab[i];



		err = of_overlay_apply_one(ov, ovinfo->target, ovinfo->overlay);

		err = of_overlay_apply_one(ov, ovinfo->target, ovinfo->overlay,

					   ovinfo->is_symbols_node);

		if (err != 0) {

			pr_err("apply failed '%pOF'\n", ovinfo->target);

			return err;
@@ -314,6 +395,9 @@ static int of_build_overlay_info(struct of_overlay *ov, 
	for_each_child_of_node(tree, node)

		cnt++;



	if (of_get_child_by_name(tree, "__symbols__"))

		cnt++;



	ovinfo = kcalloc(cnt, sizeof(*ovinfo), GFP_KERNEL);

	if (ovinfo == NULL)

		return -ENOMEM;
@@ -325,6 +409,20 @@ static int of_build_overlay_info(struct of_overlay *ov, 
			cnt++;

	}



	node = of_get_child_by_name(tree, "__symbols__");

	if (node) {

		ovinfo[cnt].overlay = node;

		ovinfo[cnt].target = of_find_node_by_path("/__symbols__");

		ovinfo[cnt].is_symbols_node = 1;



		if (!ovinfo[cnt].target) {

			pr_err("no symbols in root of device tree.\n");

			return -EINVAL;

		}



		cnt++;

	}



	/* if nothing filled, return error */

	if (cnt == 0) {

		kfree(ovinfo);

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