// SPDX-License-Identifier: GPL-2.0/* * Functions for working with device tree overlays * * Copyright (C) 2012 Pantelis Antoniou <panto@antoniou-consulting.com> * Copyright (C) 2012 Texas Instruments Inc. */ #define pr_fmt(fmt) "OF: overlay: " fmt #include <linux/kernel.h>#include <linux/module.h>#include <linux/of.h>#include <linux/of_device.h>#include <linux/of_fdt.h>#include <linux/string.h>#include <linux/ctype.h>#include <linux/errno.h>#include <linux/slab.h>#include <linux/libfdt.h>#include <linux/err.h>#include <linux/idr.h> #include "of_private.h" /** * struct target - info about current target node as recursing through overlay * @np: node where current level of overlay will be applied * @in_livetree: @np is a node in the live devicetree * * Used in the algorithm to create the portion of a changeset that describes * an overlay fragment, which is a devicetree subtree. Initially @np is a node * in the live devicetree where the overlay subtree is targeted to be grafted * into. When recursing to the next level of the overlay subtree, the target * also recurses to the next level of the live devicetree, as long as overlay * subtree node also exists in the live devicetree. When a node in the overlay * subtree does not exist at the same level in the live devicetree, target->np * points to a newly allocated node, and all subsequent targets in the subtree * will be newly allocated nodes. */struct target { struct device_node *np; bool in_livetree;}; /** * struct fragment - info about fragment nodes in overlay expanded device tree * @overlay: pointer to the __overlay__ node * @target: target of the overlay operation */struct fragment { struct device_node *overlay; struct device_node *target;}; /** * struct overlay_changeset * @id: changeset identifier * @ovcs_list: list on which we are located * @new_fdt: Memory allocated to hold unflattened aligned FDT * @overlay_mem: the memory chunk that contains @overlay_root * @overlay_root: expanded device tree that contains the fragment nodes * @notify_state: most recent notify action used on overlay * @count: count of fragment structures * @fragments: fragment nodes in the overlay expanded device tree * @symbols_fragment: last element of @fragments[] is the __symbols__ node * @cset: changeset to apply fragments to live device tree */struct overlay_changeset { int id; struct list_head ovcs_list; const void *new_fdt; const void *overlay_mem; struct device_node *overlay_root; enum of_overlay_notify_action notify_state; int count; struct fragment *fragments; bool symbols_fragment; struct of_changeset cset;}; /* flags are sticky - once set, do not reset */static int devicetree_state_flags;#define DTSF_APPLY_FAIL 0x01#define DTSF_REVERT_FAIL 0x02 static int of_prop_val_eq(const struct property *p1, const struct property *p2){ return p1->length == p2->length && !memcmp(p1->value, p2->value, (size_t)p1->length);} /* * If a changeset apply or revert encounters an error, an attempt will * be made to undo partial changes, but may fail. If the undo fails * we do not know the state of the devicetree. */static int devicetree_corrupt(void){ return devicetree_state_flags & (DTSF_APPLY_FAIL | DTSF_REVERT_FAIL);} static int build_changeset_next_level(struct overlay_changeset *ovcs, struct target *target, const struct device_node *overlay_node); /* * of_resolve_phandles() finds the largest phandle in the live tree. * of_overlay_apply() may add a larger phandle to the live tree. * Do not allow race between two overlays being applied simultaneously: * mutex_lock(&of_overlay_phandle_mutex) * of_resolve_phandles() * of_overlay_apply() * mutex_unlock(&of_overlay_phandle_mutex) */static DEFINE_MUTEX(of_overlay_phandle_mutex); void of_overlay_mutex_lock(void){ mutex_lock(&of_overlay_phandle_mutex);} void of_overlay_mutex_unlock(void){ mutex_unlock(&of_overlay_phandle_mutex);} static LIST_HEAD(ovcs_list);static DEFINE_IDR(ovcs_idr); static BLOCKING_NOTIFIER_HEAD(overlay_notify_chain); /** * of_overlay_notifier_register() - Register notifier for overlay operations * @nb: Notifier block to register * * Register for notification on overlay operations on device tree nodes. The * reported actions defined by @of_reconfig_change. The notifier callback * furthermore receives a pointer to the affected device tree node. * * Note that a notifier callback is not supposed to store pointers to a device * tree node or its content beyond @OF_OVERLAY_POST_REMOVE corresponding to the * respective node it received. */int of_overlay_notifier_register(struct notifier_block *nb){ return blocking_notifier_chain_register(&overlay_notify_chain, nb);}EXPORT_SYMBOL_GPL(of_overlay_notifier_register); /** * of_overlay_notifier_unregister() - Unregister notifier for overlay operations * @nb: Notifier block to unregister */int of_overlay_notifier_unregister(struct notifier_block *nb){ return blocking_notifier_chain_unregister(&overlay_notify_chain, nb);}EXPORT_SYMBOL_GPL(of_overlay_notifier_unregister); static int overlay_notify(struct overlay_changeset *ovcs, enum of_overlay_notify_action action){ struct of_overlay_notify_data nd; int i, ret; ovcs->notify_state = action; for (i = 0; i < ovcs->count; i++) { struct fragment *fragment = &ovcs->fragments[i]; nd.target = fragment->target; nd.overlay = fragment->overlay; ret = blocking_notifier_call_chain(&overlay_notify_chain, action, &nd); if (notifier_to_errno(ret)) { ret = notifier_to_errno(ret); pr_err("overlay changeset %s notifier error %d, target: %pOF\n", of_overlay_action_name(action), ret, nd.target); return ret; } } return 0;} static void overlay_fw_devlink_refresh(struct overlay_changeset *ovcs){ for (int i = 0; i < ovcs->count; i++) { struct device_node *np = ovcs->fragments[i].target; fw_devlink_refresh_fwnode(of_fwnode_handle(np)); }} /* * The values of properties in the "/__symbols__" node are paths in * the ovcs->overlay_root. When duplicating the properties, the paths * need to be adjusted to be the correct path for the live device tree. * * The paths refer to a node in the subtree of a fragment node's "__overlay__" * node, for example "/fragment@0/__overlay__/symbol_path_tail", * where symbol_path_tail can be a single node or it may be a multi-node path. * * The duplicated property value will be modified by replacing the * "/fragment_name/__overlay/" portion of the value with the target * path from the fragment node. */static struct property *dup_and_fixup_symbol_prop( struct overlay_changeset *ovcs, const struct property *prop){ struct fragment *fragment; struct property *new_prop; struct device_node *fragment_node; struct device_node *overlay_node; const char *path; const char *path_tail; const char *target_path; int k; int overlay_name_len; int path_len; int path_tail_len; int target_path_len; if (!prop->value) return NULL; if (strnlen(prop->value, prop->length) >= prop->length) return NULL; path = prop->value; path_len = strlen(path); if (path_len < 1) return NULL; fragment_node = __of_find_node_by_path(ovcs->overlay_root, path + 1); overlay_node = __of_find_node_by_path(fragment_node, "__overlay__/"); of_node_put(fragment_node); of_node_put(overlay_node); for (k = 0; k < ovcs->count; k++) { fragment = &ovcs->fragments[k]; if (fragment->overlay == overlay_node) break; } if (k >= ovcs->count) return NULL; overlay_name_len = snprintf(NULL, 0, "%pOF", fragment->overlay); if (overlay_name_len > path_len) return NULL; path_tail = path + overlay_name_len; path_tail_len = strlen(path_tail); target_path = kasprintf(GFP_KERNEL, "%pOF", fragment->target); if (!target_path) return NULL; target_path_len = strlen(target_path); new_prop = kzalloc_obj(*new_prop); if (!new_prop) goto err_free_target_path; new_prop->name = kstrdup(prop->name, GFP_KERNEL); new_prop->length = target_path_len + path_tail_len + 1; new_prop->value = kzalloc(new_prop->length, GFP_KERNEL); if (!new_prop->name || !new_prop->value) goto err_free_new_prop; memcpy(new_prop->value, target_path, target_path_len); memcpy(new_prop->value + target_path_len, path_tail, path_tail_len); of_property_set_flag(new_prop, OF_DYNAMIC); kfree(target_path); return new_prop; err_free_new_prop: __of_prop_free(new_prop);err_free_target_path: kfree(target_path); return NULL;} /** * add_changeset_property() - add @overlay_prop to overlay changeset * @ovcs: overlay changeset * @target: where @overlay_prop will be placed * @overlay_prop: property to add or update, from overlay tree * @is_symbols_prop: 1 if @overlay_prop is from node "/__symbols__" * * If @overlay_prop does not already exist in live devicetree, add changeset * entry to add @overlay_prop in @target, else add changeset entry to update * value of @overlay_prop. * * @target may be either in the live devicetree or in a new subtree that * is contained in the changeset. * * Some special properties are not added or updated (no error returned): * "name", "phandle", "linux,phandle". * * Properties "#address-cells" and "#size-cells" are not updated if they * are already in the live tree, but if present in the live tree, the values * in the overlay must match the values in the live tree. * * Update of property in symbols node is not allowed. * * Return: 0 on success, -ENOMEM if memory allocation failure, or -EINVAL if * invalid @overlay. */static int add_changeset_property(struct overlay_changeset *ovcs, struct target *target, const struct property *overlay_prop, bool is_symbols_prop){ struct property *new_prop = NULL; const struct property *prop; int ret = 0; if (target->in_livetree) if (is_pseudo_property(overlay_prop->name)) return 0; if (target->in_livetree) prop = of_find_property(target->np, overlay_prop->name, NULL); else prop = NULL; if (prop) { if (!of_prop_cmp(prop->name, "#address-cells")) { if (!of_prop_val_eq(prop, overlay_prop)) { pr_err("ERROR: changing value of #address-cells is not allowed in %pOF\n", target->np); ret = -EINVAL; } return ret; } else if (!of_prop_cmp(prop->name, "#size-cells")) { if (!of_prop_val_eq(prop, overlay_prop)) { pr_err("ERROR: changing value of #size-cells is not allowed in %pOF\n", target->np); ret = -EINVAL; } return ret; } } if (is_symbols_prop) { if (prop) return -EINVAL; new_prop = dup_and_fixup_symbol_prop(ovcs, overlay_prop); } else { new_prop = __of_prop_dup(overlay_prop, GFP_KERNEL); } if (!new_prop) return -ENOMEM; if (!prop) { if (!target->in_livetree) { new_prop->next = target->np->deadprops; target->np->deadprops = new_prop; } ret = of_changeset_add_property(&ovcs->cset, target->np, new_prop); } else { ret = of_changeset_update_property(&ovcs->cset, target->np, new_prop); } if (!of_node_check_flag(target->np, OF_OVERLAY)) pr_err("WARNING: memory leak will occur if overlay removed, property: %pOF/%s\n", target->np, new_prop->name); if (ret) __of_prop_free(new_prop); return ret;} /** * add_changeset_node() - add @node (and children) to overlay changeset * @ovcs: overlay changeset * @target: where @node will be placed in live tree or changeset * @node: node from within overlay device tree fragment * * If @node does not already exist in @target, add changeset entry * to add @node in @target. * * If @node already exists in @target, and the existing node has * a phandle, the overlay node is not allowed to have a phandle. * * If @node has child nodes, add the children recursively via * build_changeset_next_level(). * * NOTE_1: A live devicetree created from a flattened device tree (FDT) will * not contain the full path in node->full_name. Thus an overlay * created from an FDT also will not contain the full path in * node->full_name. However, a live devicetree created from Open * Firmware may have the full path in node->full_name. * * add_changeset_node() follows the FDT convention and does not include * the full path in node->full_name. Even though it expects the overlay * to not contain the full path, it uses kbasename() to remove the * full path should it exist. It also uses kbasename() in comparisons * to nodes in the live devicetree so that it can apply an overlay to * a live devicetree created from Open Firmware. * * NOTE_2: Multiple mods of created nodes not supported. * * Return: 0 on success, -ENOMEM if memory allocation failure, or -EINVAL if * invalid @overlay. */static int add_changeset_node(struct overlay_changeset *ovcs, struct target *target, const struct device_node *node){ const char *node_kbasename; const __be32 *phandle; struct device_node *tchild; struct target target_child; int ret = 0, size; node_kbasename = kbasename(node->full_name); for_each_child_of_node(target->np, tchild) if (!of_node_cmp(node_kbasename, kbasename(tchild->full_name))) break; if (!tchild) { tchild = __of_node_dup(NULL, node_kbasename); if (!tchild) return -ENOMEM; tchild->parent = target->np; tchild->name = __of_get_property(node, "name", NULL); if (!tchild->name) tchild->name = "<NULL>"; /* ignore obsolete "linux,phandle" */ phandle = __of_get_property(node, "phandle", &size); if (phandle && (size == 4)) tchild->phandle = be32_to_cpup(phandle); of_node_set_flag(tchild, OF_OVERLAY); ret = of_changeset_attach_node(&ovcs->cset, tchild); if (ret) return ret; target_child.np = tchild; target_child.in_livetree = false; ret = build_changeset_next_level(ovcs, &target_child, node); of_node_put(tchild); return ret; } if (node->phandle && tchild->phandle) { ret = -EINVAL; } else { target_child.np = tchild; target_child.in_livetree = target->in_livetree; ret = build_changeset_next_level(ovcs, &target_child, node); } of_node_put(tchild); return ret;} /** * build_changeset_next_level() - add level of overlay changeset * @ovcs: overlay changeset * @target: where to place @overlay_node in live tree * @overlay_node: node from within an overlay device tree fragment * * Add the properties (if any) and nodes (if any) from @overlay_node to the * @ovcs->cset changeset. If an added node has child nodes, they will * be added recursively. * * Do not allow symbols node to have any children. * * Return: 0 on success, -ENOMEM if memory allocation failure, or -EINVAL if * invalid @overlay_node. */static int build_changeset_next_level(struct overlay_changeset *ovcs, struct target *target, const struct device_node *overlay_node){ struct property *prop; int ret; for_each_property_of_node(overlay_node, prop) { ret = add_changeset_property(ovcs, target, prop, 0); if (ret) { pr_debug("Failed to apply prop @%pOF/%s, err=%d\n", target->np, prop->name, ret); return ret; } } Lines 1–500 of 1298. Load more
// SPDX-License-Identifier: GPL-2.0 /* * Functions for working with device tree overlays * * Copyright (C) 2012 Pantelis Antoniou <panto@antoniou-consulting.com> * Copyright (C) 2012 Texas Instruments Inc. */ #define pr_fmt(fmt) "OF: overlay: " fmt #include <linux/kernel.h> #include <linux/module.h> #include <linux/of.h> #include <linux/of_device.h> #include <linux/of_fdt.h> #include <linux/string.h> #include <linux/ctype.h> #include <linux/errno.h> #include <linux/slab.h> #include <linux/libfdt.h> #include <linux/err.h> #include <linux/idr.h> #include "of_private.h" /** * struct target - info about current target node as recursing through overlay * @np: node where current level of overlay will be applied * @in_livetree: @np is a node in the live devicetree * * Used in the algorithm to create the portion of a changeset that describes * an overlay fragment, which is a devicetree subtree. Initially @np is a node * in the live devicetree where the overlay subtree is targeted to be grafted * into. When recursing to the next level of the overlay subtree, the target * also recurses to the next level of the live devicetree, as long as overlay * subtree node also exists in the live devicetree. When a node in the overlay * subtree does not exist at the same level in the live devicetree, target->np * points to a newly allocated node, and all subsequent targets in the subtree * will be newly allocated nodes. */ struct target { struct device_node *np; bool in_livetree; }; /** * struct fragment - info about fragment nodes in overlay expanded device tree * @overlay: pointer to the __overlay__ node * @target: target of the overlay operation */ struct fragment { struct device_node *overlay; struct device_node *target; }; /** * struct overlay_changeset * @id: changeset identifier * @ovcs_list: list on which we are located * @new_fdt: Memory allocated to hold unflattened aligned FDT * @overlay_mem: the memory chunk that contains @overlay_root * @overlay_root: expanded device tree that contains the fragment nodes * @notify_state: most recent notify action used on overlay * @count: count of fragment structures * @fragments: fragment nodes in the overlay expanded device tree * @symbols_fragment: last element of @fragments[] is the __symbols__ node * @cset: changeset to apply fragments to live device tree */ struct overlay_changeset { int id; struct list_head ovcs_list; const void *new_fdt; const void *overlay_mem; struct device_node *overlay_root; enum of_overlay_notify_action notify_state; int count; struct fragment *fragments; bool symbols_fragment; struct of_changeset cset; }; /* flags are sticky - once set, do not reset */ static int devicetree_state_flags; #define DTSF_APPLY_FAIL 0x01 #define DTSF_REVERT_FAIL 0x02 static int of_prop_val_eq(const struct property *p1, const struct property *p2) { return p1->length == p2->length && !memcmp(p1->value, p2->value, (size_t)p1->length); } /* * If a changeset apply or revert encounters an error, an attempt will * be made to undo partial changes, but may fail. If the undo fails * we do not know the state of the devicetree. */ static int devicetree_corrupt(void) { return devicetree_state_flags & (DTSF_APPLY_FAIL | DTSF_REVERT_FAIL); } static int build_changeset_next_level(struct overlay_changeset *ovcs, struct target *target, const struct device_node *overlay_node); /* * of_resolve_phandles() finds the largest phandle in the live tree. * of_overlay_apply() may add a larger phandle to the live tree. * Do not allow race between two overlays being applied simultaneously: * mutex_lock(&of_overlay_phandle_mutex) * of_resolve_phandles() * of_overlay_apply() * mutex_unlock(&of_overlay_phandle_mutex) */ static DEFINE_MUTEX(of_overlay_phandle_mutex); void of_overlay_mutex_lock(void) { mutex_lock(&of_overlay_phandle_mutex); } void of_overlay_mutex_unlock(void) { mutex_unlock(&of_overlay_phandle_mutex); } static LIST_HEAD(ovcs_list); static DEFINE_IDR(ovcs_idr); static BLOCKING_NOTIFIER_HEAD(overlay_notify_chain); /** * of_overlay_notifier_register() - Register notifier for overlay operations * @nb: Notifier block to register * * Register for notification on overlay operations on device tree nodes. The * reported actions defined by @of_reconfig_change. The notifier callback * furthermore receives a pointer to the affected device tree node. * * Note that a notifier callback is not supposed to store pointers to a device * tree node or its content beyond @OF_OVERLAY_POST_REMOVE corresponding to the * respective node it received. */ int of_overlay_notifier_register(struct notifier_block *nb) { return blocking_notifier_chain_register(&overlay_notify_chain, nb); } EXPORT_SYMBOL_GPL(of_overlay_notifier_register); /** * of_overlay_notifier_unregister() - Unregister notifier for overlay operations * @nb: Notifier block to unregister */ int of_overlay_notifier_unregister(struct notifier_block *nb) { return blocking_notifier_chain_unregister(&overlay_notify_chain, nb); } EXPORT_SYMBOL_GPL(of_overlay_notifier_unregister); static int overlay_notify(struct overlay_changeset *ovcs, enum of_overlay_notify_action action) { struct of_overlay_notify_data nd; int i, ret; ovcs->notify_state = action; for (i = 0; i < ovcs->count; i++) { struct fragment *fragment = &ovcs->fragments[i]; nd.target = fragment->target; nd.overlay = fragment->overlay; ret = blocking_notifier_call_chain(&overlay_notify_chain, action, &nd); if (notifier_to_errno(ret)) { ret = notifier_to_errno(ret); pr_err("overlay changeset %s notifier error %d, target: %pOF\n", of_overlay_action_name(action), ret, nd.target); return ret; } } return 0; } static void overlay_fw_devlink_refresh(struct overlay_changeset *ovcs) { for (int i = 0; i < ovcs->count; i++) { struct device_node *np = ovcs->fragments[i].target; fw_devlink_refresh_fwnode(of_fwnode_handle(np)); } } /* * The values of properties in the "/__symbols__" node are paths in * the ovcs->overlay_root. When duplicating the properties, the paths * need to be adjusted to be the correct path for the live device tree. * * The paths refer to a node in the subtree of a fragment node's "__overlay__" * node, for example "/fragment@0/__overlay__/symbol_path_tail", * where symbol_path_tail can be a single node or it may be a multi-node path. * * The duplicated property value will be modified by replacing the * "/fragment_name/__overlay/" portion of the value with the target * path from the fragment node. */ static struct property *dup_and_fixup_symbol_prop( struct overlay_changeset *ovcs, const struct property *prop) { struct fragment *fragment; struct property *new_prop; struct device_node *fragment_node; struct device_node *overlay_node; const char *path; const char *path_tail; const char *target_path; int k; int overlay_name_len; int path_len; int path_tail_len; int target_path_len; if (!prop->value) return NULL; if (strnlen(prop->value, prop->length) >= prop->length) return NULL; path = prop->value; path_len = strlen(path); if (path_len < 1) return NULL; fragment_node = __of_find_node_by_path(ovcs->overlay_root, path + 1); overlay_node = __of_find_node_by_path(fragment_node, "__overlay__/"); of_node_put(fragment_node); of_node_put(overlay_node); for (k = 0; k < ovcs->count; k++) { fragment = &ovcs->fragments[k]; if (fragment->overlay == overlay_node) break; } if (k >= ovcs->count) return NULL; overlay_name_len = snprintf(NULL, 0, "%pOF", fragment->overlay); if (overlay_name_len > path_len) return NULL; path_tail = path + overlay_name_len; path_tail_len = strlen(path_tail); target_path = kasprintf(GFP_KERNEL, "%pOF", fragment->target); if (!target_path) return NULL; target_path_len = strlen(target_path); new_prop = kzalloc_obj(*new_prop); if (!new_prop) goto err_free_target_path; new_prop->name = kstrdup(prop->name, GFP_KERNEL); new_prop->length = target_path_len + path_tail_len + 1; new_prop->value = kzalloc(new_prop->length, GFP_KERNEL); if (!new_prop->name || !new_prop->value) goto err_free_new_prop; memcpy(new_prop->value, target_path, target_path_len); memcpy(new_prop->value + target_path_len, path_tail, path_tail_len); of_property_set_flag(new_prop, OF_DYNAMIC); kfree(target_path); return new_prop; err_free_new_prop: __of_prop_free(new_prop); err_free_target_path: kfree(target_path); return NULL; } /** * add_changeset_property() - add @overlay_prop to overlay changeset * @ovcs: overlay changeset * @target: where @overlay_prop will be placed * @overlay_prop: property to add or update, from overlay tree * @is_symbols_prop: 1 if @overlay_prop is from node "/__symbols__" * * If @overlay_prop does not already exist in live devicetree, add changeset * entry to add @overlay_prop in @target, else add changeset entry to update * value of @overlay_prop. * * @target may be either in the live devicetree or in a new subtree that * is contained in the changeset. * * Some special properties are not added or updated (no error returned): * "name", "phandle", "linux,phandle". * * Properties "#address-cells" and "#size-cells" are not updated if they * are already in the live tree, but if present in the live tree, the values * in the overlay must match the values in the live tree. * * Update of property in symbols node is not allowed. * * Return: 0 on success, -ENOMEM if memory allocation failure, or -EINVAL if * invalid @overlay. */ static int add_changeset_property(struct overlay_changeset *ovcs, struct target *target, const struct property *overlay_prop, bool is_symbols_prop) { struct property *new_prop = NULL; const struct property *prop; int ret = 0; if (target->in_livetree) if (is_pseudo_property(overlay_prop->name)) return 0; if (target->in_livetree) prop = of_find_property(target->np, overlay_prop->name, NULL); else prop = NULL; if (prop) { if (!of_prop_cmp(prop->name, "#address-cells")) { if (!of_prop_val_eq(prop, overlay_prop)) { pr_err("ERROR: changing value of #address-cells is not allowed in %pOF\n", target->np); ret = -EINVAL; } return ret; } else if (!of_prop_cmp(prop->name, "#size-cells")) { if (!of_prop_val_eq(prop, overlay_prop)) { pr_err("ERROR: changing value of #size-cells is not allowed in %pOF\n", target->np); ret = -EINVAL; } return ret; } } if (is_symbols_prop) { if (prop) return -EINVAL; new_prop = dup_and_fixup_symbol_prop(ovcs, overlay_prop); } else { new_prop = __of_prop_dup(overlay_prop, GFP_KERNEL); } if (!new_prop) return -ENOMEM; if (!prop) { if (!target->in_livetree) { new_prop->next = target->np->deadprops; target->np->deadprops = new_prop; } ret = of_changeset_add_property(&ovcs->cset, target->np, new_prop); } else { ret = of_changeset_update_property(&ovcs->cset, target->np, new_prop); } if (!of_node_check_flag(target->np, OF_OVERLAY)) pr_err("WARNING: memory leak will occur if overlay removed, property: %pOF/%s\n", target->np, new_prop->name); if (ret) __of_prop_free(new_prop); return ret; } /** * add_changeset_node() - add @node (and children) to overlay changeset * @ovcs: overlay changeset * @target: where @node will be placed in live tree or changeset * @node: node from within overlay device tree fragment * * If @node does not already exist in @target, add changeset entry * to add @node in @target. * * If @node already exists in @target, and the existing node has * a phandle, the overlay node is not allowed to have a phandle. * * If @node has child nodes, add the children recursively via * build_changeset_next_level(). * * NOTE_1: A live devicetree created from a flattened device tree (FDT) will * not contain the full path in node->full_name. Thus an overlay * created from an FDT also will not contain the full path in * node->full_name. However, a live devicetree created from Open * Firmware may have the full path in node->full_name. * * add_changeset_node() follows the FDT convention and does not include * the full path in node->full_name. Even though it expects the overlay * to not contain the full path, it uses kbasename() to remove the * full path should it exist. It also uses kbasename() in comparisons * to nodes in the live devicetree so that it can apply an overlay to * a live devicetree created from Open Firmware. * * NOTE_2: Multiple mods of created nodes not supported. * * Return: 0 on success, -ENOMEM if memory allocation failure, or -EINVAL if * invalid @overlay. */ static int add_changeset_node(struct overlay_changeset *ovcs, struct target *target, const struct device_node *node) { const char *node_kbasename; const __be32 *phandle; struct device_node *tchild; struct target target_child; int ret = 0, size; node_kbasename = kbasename(node->full_name); for_each_child_of_node(target->np, tchild) if (!of_node_cmp(node_kbasename, kbasename(tchild->full_name))) break; if (!tchild) { tchild = __of_node_dup(NULL, node_kbasename); if (!tchild) return -ENOMEM; tchild->parent = target->np; tchild->name = __of_get_property(node, "name", NULL); if (!tchild->name) tchild->name = "<NULL>"; /* ignore obsolete "linux,phandle" */ phandle = __of_get_property(node, "phandle", &size); if (phandle && (size == 4)) tchild->phandle = be32_to_cpup(phandle); of_node_set_flag(tchild, OF_OVERLAY); ret = of_changeset_attach_node(&ovcs->cset, tchild); if (ret) return ret; target_child.np = tchild; target_child.in_livetree = false; ret = build_changeset_next_level(ovcs, &target_child, node); of_node_put(tchild); return ret; } if (node->phandle && tchild->phandle) { ret = -EINVAL; } else { target_child.np = tchild; target_child.in_livetree = target->in_livetree; ret = build_changeset_next_level(ovcs, &target_child, node); } of_node_put(tchild); return ret; } /** * build_changeset_next_level() - add level of overlay changeset * @ovcs: overlay changeset * @target: where to place @overlay_node in live tree * @overlay_node: node from within an overlay device tree fragment * * Add the properties (if any) and nodes (if any) from @overlay_node to the * @ovcs->cset changeset. If an added node has child nodes, they will * be added recursively. * * Do not allow symbols node to have any children. * * Return: 0 on success, -ENOMEM if memory allocation failure, or -EINVAL if * invalid @overlay_node. */ static int build_changeset_next_level(struct overlay_changeset *ovcs, struct target *target, const struct device_node *overlay_node) { struct property *prop; int ret; for_each_property_of_node(overlay_node, prop) { ret = add_changeset_property(ovcs, target, prop, 0); if (ret) { pr_debug("Failed to apply prop @%pOF/%s, err=%d\n", target->np, prop->name, ret); return ret; } }