diff --git a/drivers/of/overlay.c b/drivers/of/overlay.c index af3b9a16df26..a42dd7b094c4 100644 --- a/drivers/of/overlay.c +++ b/drivers/of/overlay.c @@ -143,7 +143,6 @@ static struct property *dup_and_fixup_symbol_prop(struct of_overlay *ov, 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; @@ -157,6 +156,10 @@ static struct property *dup_and_fixup_symbol_prop(struct of_overlay *ov, } +/* + * Some special properties are not updated (no error returned). + * Update of property in symbols node is not allowed. + */ static int of_overlay_apply_single_property(struct of_overlay *ov, struct device_node *target, struct property *prop, bool is_symbols_node) @@ -164,17 +167,14 @@ static int of_overlay_apply_single_property(struct of_overlay *ov, struct property *propn = NULL, *tprop; int ret = 0; - /* NOTE: Multiple changes of single properties not supported */ tprop = of_find_property(target, prop->name, NULL); - /* special properties are not meant to be updated (silent NOP) */ if (of_prop_cmp(prop->name, "name") == 0 || of_prop_cmp(prop->name, "phandle") == 0 || 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); @@ -185,10 +185,9 @@ static int of_overlay_apply_single_property(struct of_overlay *ov, if (propn == NULL) return -ENOMEM; - /* not found? add */ if (tprop == NULL) ret = of_changeset_add_property(&ov->cset, target, propn); - else /* found? update */ + else ret = of_changeset_update_property(&ov->cset, target, propn); if (ret) { @@ -210,13 +209,11 @@ static int of_overlay_apply_single_device_node(struct of_overlay *ov, if (cname == NULL) return -ENOMEM; - /* NOTE: Multiple mods of created nodes not supported */ for_each_child_of_node(target, tchild) if (!of_node_cmp(cname, kbasename(tchild->full_name))) break; if (tchild != NULL) { - /* new overlay phandle value conflicts with existing value */ if (child->phandle) return -EINVAL; @@ -224,12 +221,10 @@ static int of_overlay_apply_single_device_node(struct of_overlay *ov, ret = of_overlay_apply_one(ov, tchild, child, 0); of_node_put(tchild); } else { - /* create empty tree as a target */ tchild = __of_node_dup(child, "%pOF/%s", target, cname); if (!tchild) return -ENOMEM; - /* point to parent */ tchild->parent = target; ret = of_changeset_attach_node(&ov->cset, tchild); @@ -250,6 +245,8 @@ static int of_overlay_apply_single_device_node(struct of_overlay *ov, * Note that the in case of an error the target node is left * in a inconsistent state. Error recovery should be performed * by using the changeset. + * + * Do not allow symbols node to have any children. */ static int of_overlay_apply_one(struct of_overlay *ov, struct device_node *target, const struct device_node *overlay, @@ -269,7 +266,6 @@ 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; @@ -299,7 +295,6 @@ static int of_overlay_apply(struct of_overlay *ov) { int i, err; - /* first we apply the overlays atomically */ for (i = 0; i < ov->count; i++) { struct of_overlay_info *ovinfo = &ov->ovinfo_tab[i]; @@ -316,10 +311,10 @@ static int of_overlay_apply(struct of_overlay *ov) /* * Find the target node using a number of different strategies - * in order of preference + * in order of preference: * - * "target" property containing the phandle of the target - * "target-path" property containing the path of the target + * 1) "target" property containing the phandle of the target + * 2) "target-path" property containing the path of the target */ static struct device_node *find_target_node(struct device_node *info_node) { @@ -327,12 +322,10 @@ static struct device_node *find_target_node(struct device_node *info_node) u32 val; int ret; - /* first try to go by using the target as a phandle */ ret = of_property_read_u32(info_node, "target", &val); if (ret == 0) return of_find_node_by_phandle(val); - /* now try to locate by path */ ret = of_property_read_string(info_node, "target-path", &path); if (ret == 0) return of_find_node_by_path(path); @@ -397,7 +390,6 @@ static int of_build_overlay_info(struct of_overlay *ov, struct of_overlay_info *ovinfo; int cnt, err; - /* worst case; every child is a node */ cnt = 0; for_each_child_of_node(tree, node) cnt++; @@ -430,7 +422,6 @@ static int of_build_overlay_info(struct of_overlay *ov, cnt++; } - /* if nothing filled, return error */ if (cnt == 0) { kfree(ovinfo); return -ENODEV; @@ -486,7 +477,6 @@ int of_overlay_create(struct device_node *tree) struct of_overlay *ov; int err, id; - /* allocate the overlay structure */ ov = kzalloc(sizeof(*ov), GFP_KERNEL); if (ov == NULL) return -ENOMEM; @@ -505,7 +495,6 @@ int of_overlay_create(struct device_node *tree) } ov->id = id; - /* build the overlay info structures */ err = of_build_overlay_info(ov, tree); if (err) { pr_err("of_build_overlay_info() failed for tree@%pOF\n", @@ -520,18 +509,15 @@ int of_overlay_create(struct device_node *tree) goto err_free_idr; } - /* apply the overlay */ err = of_overlay_apply(ov); if (err) goto err_abort_trans; - /* apply the changeset */ err = __of_changeset_apply(&ov->cset); if (err) goto err_revert_overlay; - /* add to the tail of the overlay list */ list_add_tail(&ov->node, &ov_list); of_overlay_notify(ov, OF_OVERLAY_POST_APPLY); @@ -554,13 +540,15 @@ int of_overlay_create(struct device_node *tree) } EXPORT_SYMBOL_GPL(of_overlay_create); -/* check whether the given node, lies under the given tree */ +/* + * check whether the given node, lies under the given tree + * return 1 if under tree, else 0 + */ static int overlay_subtree_check(struct device_node *tree, struct device_node *dn) { struct device_node *child; - /* match? */ if (tree == dn) return 1; @@ -574,7 +562,10 @@ static int overlay_subtree_check(struct device_node *tree, return 0; } -/* check whether this overlay is the topmost */ +/* + * check whether this overlay is the topmost + * return 1 if topmost, else 0 + */ static int overlay_is_topmost(struct of_overlay *ov, struct device_node *dn) { struct of_overlay *ovt; @@ -595,7 +586,6 @@ static int overlay_is_topmost(struct of_overlay *ov, struct device_node *dn) } } - /* overlay is topmost */ return 1; } @@ -645,7 +635,6 @@ int of_overlay_destroy(int id) goto out; } - /* check whether the overlay is safe to remove */ if (!overlay_removal_is_ok(ov)) { err = -EBUSY; goto out;