1287 lines
34 KiB
C
1287 lines
34 KiB
C
// SPDX-License-Identifier: GPL-2.0
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/*
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* Functions for working with device tree overlays
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*
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* Copyright (C) 2012 Pantelis Antoniou <panto@antoniou-consulting.com>
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* Copyright (C) 2012 Texas Instruments Inc.
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*/
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#define pr_fmt(fmt) "OF: overlay: " fmt
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#include <linux/kernel.h>
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#include <linux/module.h>
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#include <linux/of.h>
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#include <linux/of_device.h>
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#include <linux/of_fdt.h>
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#include <linux/string.h>
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#include <linux/ctype.h>
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#include <linux/errno.h>
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#include <linux/slab.h>
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#include <linux/libfdt.h>
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#include <linux/err.h>
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#include <linux/idr.h>
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#include "of_private.h"
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/**
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* struct target - info about current target node as recursing through overlay
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* @np: node where current level of overlay will be applied
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* @in_livetree: @np is a node in the live devicetree
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*
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* Used in the algorithm to create the portion of a changeset that describes
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* an overlay fragment, which is a devicetree subtree. Initially @np is a node
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* in the live devicetree where the overlay subtree is targeted to be grafted
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* into. When recursing to the next level of the overlay subtree, the target
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* also recurses to the next level of the live devicetree, as long as overlay
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* subtree node also exists in the live devicetree. When a node in the overlay
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* subtree does not exist at the same level in the live devicetree, target->np
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* points to a newly allocated node, and all subsequent targets in the subtree
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* will be newly allocated nodes.
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*/
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struct target {
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struct device_node *np;
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bool in_livetree;
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};
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/**
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* struct fragment - info about fragment nodes in overlay expanded device tree
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* @target: target of the overlay operation
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* @overlay: pointer to the __overlay__ node
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*/
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struct fragment {
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struct device_node *overlay;
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struct device_node *target;
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};
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/**
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* struct overlay_changeset
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* @id: changeset identifier
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* @ovcs_list: list on which we are located
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* @fdt: FDT that was unflattened to create @overlay_tree
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* @overlay_tree: expanded device tree that contains the fragment nodes
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* @count: count of fragment structures
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* @fragments: fragment nodes in the overlay expanded device tree
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* @symbols_fragment: last element of @fragments[] is the __symbols__ node
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* @cset: changeset to apply fragments to live device tree
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*/
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struct overlay_changeset {
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int id;
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struct list_head ovcs_list;
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const void *fdt;
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struct device_node *overlay_tree;
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int count;
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struct fragment *fragments;
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bool symbols_fragment;
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struct of_changeset cset;
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};
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/* flags are sticky - once set, do not reset */
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static int devicetree_state_flags;
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#define DTSF_APPLY_FAIL 0x01
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#define DTSF_REVERT_FAIL 0x02
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/*
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* If a changeset apply or revert encounters an error, an attempt will
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* be made to undo partial changes, but may fail. If the undo fails
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* we do not know the state of the devicetree.
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*/
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static int devicetree_corrupt(void)
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{
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return devicetree_state_flags &
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(DTSF_APPLY_FAIL | DTSF_REVERT_FAIL);
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}
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static int build_changeset_next_level(struct overlay_changeset *ovcs,
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struct target *target, const struct device_node *overlay_node);
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/*
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* of_resolve_phandles() finds the largest phandle in the live tree.
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* of_overlay_apply() may add a larger phandle to the live tree.
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* Do not allow race between two overlays being applied simultaneously:
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* mutex_lock(&of_overlay_phandle_mutex)
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* of_resolve_phandles()
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* of_overlay_apply()
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* mutex_unlock(&of_overlay_phandle_mutex)
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*/
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static DEFINE_MUTEX(of_overlay_phandle_mutex);
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void of_overlay_mutex_lock(void)
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{
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mutex_lock(&of_overlay_phandle_mutex);
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}
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void of_overlay_mutex_unlock(void)
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{
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mutex_unlock(&of_overlay_phandle_mutex);
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}
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static LIST_HEAD(ovcs_list);
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static DEFINE_IDR(ovcs_idr);
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static BLOCKING_NOTIFIER_HEAD(overlay_notify_chain);
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/**
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* of_overlay_notifier_register() - Register notifier for overlay operations
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* @nb: Notifier block to register
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*
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* Register for notification on overlay operations on device tree nodes. The
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* reported actions definied by @of_reconfig_change. The notifier callback
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* furthermore receives a pointer to the affected device tree node.
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*
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* Note that a notifier callback is not supposed to store pointers to a device
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* tree node or its content beyond @OF_OVERLAY_POST_REMOVE corresponding to the
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* respective node it received.
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*/
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int of_overlay_notifier_register(struct notifier_block *nb)
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{
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return blocking_notifier_chain_register(&overlay_notify_chain, nb);
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}
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EXPORT_SYMBOL_GPL(of_overlay_notifier_register);
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/**
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* of_overlay_notifier_register() - Unregister notifier for overlay operations
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* @nb: Notifier block to unregister
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*/
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int of_overlay_notifier_unregister(struct notifier_block *nb)
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{
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return blocking_notifier_chain_unregister(&overlay_notify_chain, nb);
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}
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EXPORT_SYMBOL_GPL(of_overlay_notifier_unregister);
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static char *of_overlay_action_name[] = {
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"pre-apply",
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"post-apply",
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"pre-remove",
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"post-remove",
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};
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static int overlay_notify(struct overlay_changeset *ovcs,
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enum of_overlay_notify_action action)
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{
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struct of_overlay_notify_data nd;
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int i, ret;
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for (i = 0; i < ovcs->count; i++) {
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struct fragment *fragment = &ovcs->fragments[i];
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nd.target = fragment->target;
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nd.overlay = fragment->overlay;
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ret = blocking_notifier_call_chain(&overlay_notify_chain,
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action, &nd);
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if (ret == NOTIFY_OK || ret == NOTIFY_STOP)
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return 0;
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if (ret) {
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ret = notifier_to_errno(ret);
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pr_err("overlay changeset %s notifier error %d, target: %pOF\n",
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of_overlay_action_name[action], ret, nd.target);
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return ret;
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}
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}
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return 0;
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}
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/*
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* The values of properties in the "/__symbols__" node are paths in
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* the ovcs->overlay_tree. When duplicating the properties, the paths
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* need to be adjusted to be the correct path for the live device tree.
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*
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* The paths refer to a node in the subtree of a fragment node's "__overlay__"
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* node, for example "/fragment@0/__overlay__/symbol_path_tail",
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* where symbol_path_tail can be a single node or it may be a multi-node path.
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*
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* The duplicated property value will be modified by replacing the
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* "/fragment_name/__overlay/" portion of the value with the target
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* path from the fragment node.
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*/
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static struct property *dup_and_fixup_symbol_prop(
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struct overlay_changeset *ovcs, const struct property *prop)
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{
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struct fragment *fragment;
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struct property *new_prop;
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struct device_node *fragment_node;
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struct device_node *overlay_node;
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const char *path;
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const char *path_tail;
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const char *target_path;
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int k;
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int overlay_name_len;
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int path_len;
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int path_tail_len;
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int target_path_len;
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if (!prop->value)
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return NULL;
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if (strnlen(prop->value, prop->length) >= prop->length)
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return NULL;
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path = prop->value;
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path_len = strlen(path);
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if (path_len < 1)
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return NULL;
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fragment_node = __of_find_node_by_path(ovcs->overlay_tree, path + 1);
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overlay_node = __of_find_node_by_path(fragment_node, "__overlay__/");
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of_node_put(fragment_node);
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of_node_put(overlay_node);
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for (k = 0; k < ovcs->count; k++) {
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fragment = &ovcs->fragments[k];
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if (fragment->overlay == overlay_node)
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break;
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}
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if (k >= ovcs->count)
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return NULL;
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overlay_name_len = snprintf(NULL, 0, "%pOF", fragment->overlay);
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if (overlay_name_len > path_len)
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return NULL;
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path_tail = path + overlay_name_len;
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path_tail_len = strlen(path_tail);
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target_path = kasprintf(GFP_KERNEL, "%pOF", fragment->target);
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if (!target_path)
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return NULL;
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target_path_len = strlen(target_path);
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new_prop = kzalloc(sizeof(*new_prop), GFP_KERNEL);
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if (!new_prop)
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goto err_free_target_path;
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new_prop->name = kstrdup(prop->name, GFP_KERNEL);
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new_prop->length = target_path_len + path_tail_len + 1;
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new_prop->value = kzalloc(new_prop->length, GFP_KERNEL);
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if (!new_prop->name || !new_prop->value)
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goto err_free_new_prop;
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strcpy(new_prop->value, target_path);
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strcpy(new_prop->value + target_path_len, path_tail);
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of_property_set_flag(new_prop, OF_DYNAMIC);
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return new_prop;
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err_free_new_prop:
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kfree(new_prop->name);
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kfree(new_prop->value);
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kfree(new_prop);
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err_free_target_path:
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kfree(target_path);
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return NULL;
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}
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/**
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* add_changeset_property() - add @overlay_prop to overlay changeset
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* @ovcs: overlay changeset
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* @target: where @overlay_prop will be placed
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* @overlay_prop: property to add or update, from overlay tree
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* @is_symbols_prop: 1 if @overlay_prop is from node "/__symbols__"
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*
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* If @overlay_prop does not already exist in live devicetree, add changeset
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* entry to add @overlay_prop in @target, else add changeset entry to update
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* value of @overlay_prop.
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*
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* @target may be either in the live devicetree or in a new subtree that
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* is contained in the changeset.
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*
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* Some special properties are not added or updated (no error returned):
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* "name", "phandle", "linux,phandle".
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*
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* Properties "#address-cells" and "#size-cells" are not updated if they
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* are already in the live tree, but if present in the live tree, the values
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* in the overlay must match the values in the live tree.
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*
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* Update of property in symbols node is not allowed.
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*
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* Returns 0 on success, -ENOMEM if memory allocation failure, or -EINVAL if
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* invalid @overlay.
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*/
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static int add_changeset_property(struct overlay_changeset *ovcs,
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struct target *target, struct property *overlay_prop,
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bool is_symbols_prop)
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{
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struct property *new_prop = NULL, *prop;
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int ret = 0;
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if (target->in_livetree)
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if (!of_prop_cmp(overlay_prop->name, "name") ||
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!of_prop_cmp(overlay_prop->name, "phandle") ||
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!of_prop_cmp(overlay_prop->name, "linux,phandle"))
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return 0;
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if (target->in_livetree)
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prop = of_find_property(target->np, overlay_prop->name, NULL);
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else
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prop = NULL;
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if (prop) {
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if (!of_prop_cmp(prop->name, "#address-cells")) {
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if (!of_prop_val_eq(prop, overlay_prop)) {
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pr_err("ERROR: changing value of #address-cells is not allowed in %pOF\n",
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target->np);
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ret = -EINVAL;
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}
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return ret;
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} else if (!of_prop_cmp(prop->name, "#size-cells")) {
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if (!of_prop_val_eq(prop, overlay_prop)) {
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pr_err("ERROR: changing value of #size-cells is not allowed in %pOF\n",
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target->np);
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ret = -EINVAL;
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}
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return ret;
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}
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}
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if (is_symbols_prop) {
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if (prop)
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return -EINVAL;
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new_prop = dup_and_fixup_symbol_prop(ovcs, overlay_prop);
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} else {
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new_prop = __of_prop_dup(overlay_prop, GFP_KERNEL);
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}
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if (!new_prop)
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return -ENOMEM;
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if (!prop) {
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if (!target->in_livetree) {
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new_prop->next = target->np->deadprops;
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target->np->deadprops = new_prop;
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}
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ret = of_changeset_add_property(&ovcs->cset, target->np,
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new_prop);
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} else {
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ret = of_changeset_update_property(&ovcs->cset, target->np,
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new_prop);
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}
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if (!of_node_check_flag(target->np, OF_OVERLAY))
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pr_err("WARNING: memory leak will occur if overlay removed, property: %pOF/%s\n",
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target->np, new_prop->name);
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if (ret) {
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kfree(new_prop->name);
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kfree(new_prop->value);
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kfree(new_prop);
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}
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return ret;
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}
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/**
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* add_changeset_node() - add @node (and children) to overlay changeset
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* @ovcs: overlay changeset
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* @target: where @node will be placed in live tree or changeset
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* @node: node from within overlay device tree fragment
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*
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* If @node does not already exist in @target, add changeset entry
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* to add @node in @target.
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*
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* If @node already exists in @target, and the existing node has
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* a phandle, the overlay node is not allowed to have a phandle.
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*
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* If @node has child nodes, add the children recursively via
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* build_changeset_next_level().
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*
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* NOTE_1: A live devicetree created from a flattened device tree (FDT) will
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* not contain the full path in node->full_name. Thus an overlay
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* created from an FDT also will not contain the full path in
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* node->full_name. However, a live devicetree created from Open
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* Firmware may have the full path in node->full_name.
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*
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* add_changeset_node() follows the FDT convention and does not include
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* the full path in node->full_name. Even though it expects the overlay
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* to not contain the full path, it uses kbasename() to remove the
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* full path should it exist. It also uses kbasename() in comparisons
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* to nodes in the live devicetree so that it can apply an overlay to
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* a live devicetree created from Open Firmware.
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*
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* NOTE_2: Multiple mods of created nodes not supported.
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*
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* Returns 0 on success, -ENOMEM if memory allocation failure, or -EINVAL if
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* invalid @overlay.
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*/
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static int add_changeset_node(struct overlay_changeset *ovcs,
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struct target *target, struct device_node *node)
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{
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const char *node_kbasename;
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const __be32 *phandle;
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struct device_node *tchild;
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struct target target_child;
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int ret = 0, size;
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node_kbasename = kbasename(node->full_name);
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for_each_child_of_node(target->np, tchild)
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if (!of_node_cmp(node_kbasename, kbasename(tchild->full_name)))
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break;
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if (!tchild) {
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tchild = __of_node_dup(NULL, node_kbasename);
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if (!tchild)
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return -ENOMEM;
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tchild->parent = target->np;
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tchild->name = __of_get_property(node, "name", NULL);
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if (!tchild->name)
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tchild->name = "<NULL>";
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/* ignore obsolete "linux,phandle" */
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phandle = __of_get_property(node, "phandle", &size);
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if (phandle && (size == 4))
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tchild->phandle = be32_to_cpup(phandle);
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of_node_set_flag(tchild, OF_OVERLAY);
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ret = of_changeset_attach_node(&ovcs->cset, tchild);
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if (ret)
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return ret;
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target_child.np = tchild;
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target_child.in_livetree = false;
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ret = build_changeset_next_level(ovcs, &target_child, node);
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of_node_put(tchild);
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return ret;
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}
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if (node->phandle && tchild->phandle) {
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ret = -EINVAL;
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} else {
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target_child.np = tchild;
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target_child.in_livetree = target->in_livetree;
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ret = build_changeset_next_level(ovcs, &target_child, node);
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}
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of_node_put(tchild);
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return ret;
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}
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/**
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* build_changeset_next_level() - add level of overlay changeset
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* @ovcs: overlay changeset
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* @target: where to place @overlay_node in live tree
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* @overlay_node: node from within an overlay device tree fragment
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*
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* Add the properties (if any) and nodes (if any) from @overlay_node to the
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* @ovcs->cset changeset. If an added node has child nodes, they will
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* be added recursively.
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*
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* Do not allow symbols node to have any children.
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*
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* Returns 0 on success, -ENOMEM if memory allocation failure, or -EINVAL if
|
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* invalid @overlay_node.
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*/
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static int build_changeset_next_level(struct overlay_changeset *ovcs,
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struct target *target, const struct device_node *overlay_node)
|
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{
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struct device_node *child;
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struct property *prop;
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int ret;
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for_each_property_of_node(overlay_node, prop) {
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ret = add_changeset_property(ovcs, target, prop, 0);
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if (ret) {
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pr_debug("Failed to apply prop @%pOF/%s, err=%d\n",
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target->np, prop->name, ret);
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return ret;
|
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}
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}
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|
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for_each_child_of_node(overlay_node, child) {
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ret = add_changeset_node(ovcs, target, child);
|
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if (ret) {
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pr_debug("Failed to apply node @%pOF/%pOFn, err=%d\n",
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target->np, child, ret);
|
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of_node_put(child);
|
|
return ret;
|
|
}
|
|
}
|
|
|
|
return 0;
|
|
}
|
|
|
|
/*
|
|
* Add the properties from __overlay__ node to the @ovcs->cset changeset.
|
|
*/
|
|
static int build_changeset_symbols_node(struct overlay_changeset *ovcs,
|
|
struct target *target,
|
|
const struct device_node *overlay_symbols_node)
|
|
{
|
|
struct property *prop;
|
|
int ret;
|
|
|
|
for_each_property_of_node(overlay_symbols_node, prop) {
|
|
ret = add_changeset_property(ovcs, target, prop, 1);
|
|
if (ret) {
|
|
pr_debug("Failed to apply symbols prop @%pOF/%s, err=%d\n",
|
|
target->np, prop->name, ret);
|
|
return ret;
|
|
}
|
|
}
|
|
|
|
return 0;
|
|
}
|
|
|
|
static int find_dup_cset_node_entry(struct overlay_changeset *ovcs,
|
|
struct of_changeset_entry *ce_1)
|
|
{
|
|
struct of_changeset_entry *ce_2;
|
|
char *fn_1, *fn_2;
|
|
int node_path_match;
|
|
|
|
if (ce_1->action != OF_RECONFIG_ATTACH_NODE &&
|
|
ce_1->action != OF_RECONFIG_DETACH_NODE)
|
|
return 0;
|
|
|
|
ce_2 = ce_1;
|
|
list_for_each_entry_continue(ce_2, &ovcs->cset.entries, node) {
|
|
if ((ce_2->action != OF_RECONFIG_ATTACH_NODE &&
|
|
ce_2->action != OF_RECONFIG_DETACH_NODE) ||
|
|
of_node_cmp(ce_1->np->full_name, ce_2->np->full_name))
|
|
continue;
|
|
|
|
fn_1 = kasprintf(GFP_KERNEL, "%pOF", ce_1->np);
|
|
fn_2 = kasprintf(GFP_KERNEL, "%pOF", ce_2->np);
|
|
node_path_match = !strcmp(fn_1, fn_2);
|
|
kfree(fn_1);
|
|
kfree(fn_2);
|
|
if (node_path_match) {
|
|
pr_err("ERROR: multiple fragments add and/or delete node %pOF\n",
|
|
ce_1->np);
|
|
return -EINVAL;
|
|
}
|
|
}
|
|
|
|
return 0;
|
|
}
|
|
|
|
static int find_dup_cset_prop(struct overlay_changeset *ovcs,
|
|
struct of_changeset_entry *ce_1)
|
|
{
|
|
struct of_changeset_entry *ce_2;
|
|
char *fn_1, *fn_2;
|
|
int node_path_match;
|
|
|
|
if (ce_1->action != OF_RECONFIG_ADD_PROPERTY &&
|
|
ce_1->action != OF_RECONFIG_REMOVE_PROPERTY &&
|
|
ce_1->action != OF_RECONFIG_UPDATE_PROPERTY)
|
|
return 0;
|
|
|
|
ce_2 = ce_1;
|
|
list_for_each_entry_continue(ce_2, &ovcs->cset.entries, node) {
|
|
if ((ce_2->action != OF_RECONFIG_ADD_PROPERTY &&
|
|
ce_2->action != OF_RECONFIG_REMOVE_PROPERTY &&
|
|
ce_2->action != OF_RECONFIG_UPDATE_PROPERTY) ||
|
|
of_node_cmp(ce_1->np->full_name, ce_2->np->full_name))
|
|
continue;
|
|
|
|
fn_1 = kasprintf(GFP_KERNEL, "%pOF", ce_1->np);
|
|
fn_2 = kasprintf(GFP_KERNEL, "%pOF", ce_2->np);
|
|
node_path_match = !strcmp(fn_1, fn_2);
|
|
kfree(fn_1);
|
|
kfree(fn_2);
|
|
if (node_path_match &&
|
|
!of_prop_cmp(ce_1->prop->name, ce_2->prop->name)) {
|
|
pr_err("ERROR: multiple fragments add, update, and/or delete property %pOF/%s\n",
|
|
ce_1->np, ce_1->prop->name);
|
|
return -EINVAL;
|
|
}
|
|
}
|
|
|
|
return 0;
|
|
}
|
|
|
|
/**
|
|
* changeset_dup_entry_check() - check for duplicate entries
|
|
* @ovcs: Overlay changeset
|
|
*
|
|
* Check changeset @ovcs->cset for multiple {add or delete} node entries for
|
|
* the same node or duplicate {add, delete, or update} properties entries
|
|
* for the same property.
|
|
*
|
|
* Returns 0 on success, or -EINVAL if duplicate changeset entry found.
|
|
*/
|
|
static int changeset_dup_entry_check(struct overlay_changeset *ovcs)
|
|
{
|
|
struct of_changeset_entry *ce_1;
|
|
int dup_entry = 0;
|
|
|
|
list_for_each_entry(ce_1, &ovcs->cset.entries, node) {
|
|
dup_entry |= find_dup_cset_node_entry(ovcs, ce_1);
|
|
dup_entry |= find_dup_cset_prop(ovcs, ce_1);
|
|
}
|
|
|
|
return dup_entry ? -EINVAL : 0;
|
|
}
|
|
|
|
/**
|
|
* build_changeset() - populate overlay changeset in @ovcs from @ovcs->fragments
|
|
* @ovcs: Overlay changeset
|
|
*
|
|
* Create changeset @ovcs->cset to contain the nodes and properties of the
|
|
* overlay device tree fragments in @ovcs->fragments[]. If an error occurs,
|
|
* any portions of the changeset that were successfully created will remain
|
|
* in @ovcs->cset.
|
|
*
|
|
* Returns 0 on success, -ENOMEM if memory allocation failure, or -EINVAL if
|
|
* invalid overlay in @ovcs->fragments[].
|
|
*/
|
|
static int build_changeset(struct overlay_changeset *ovcs)
|
|
{
|
|
struct fragment *fragment;
|
|
struct target target;
|
|
int fragments_count, i, ret;
|
|
|
|
/*
|
|
* if there is a symbols fragment in ovcs->fragments[i] it is
|
|
* the final element in the array
|
|
*/
|
|
if (ovcs->symbols_fragment)
|
|
fragments_count = ovcs->count - 1;
|
|
else
|
|
fragments_count = ovcs->count;
|
|
|
|
for (i = 0; i < fragments_count; i++) {
|
|
fragment = &ovcs->fragments[i];
|
|
|
|
target.np = fragment->target;
|
|
target.in_livetree = true;
|
|
ret = build_changeset_next_level(ovcs, &target,
|
|
fragment->overlay);
|
|
if (ret) {
|
|
pr_debug("fragment apply failed '%pOF'\n",
|
|
fragment->target);
|
|
return ret;
|
|
}
|
|
}
|
|
|
|
if (ovcs->symbols_fragment) {
|
|
fragment = &ovcs->fragments[ovcs->count - 1];
|
|
|
|
target.np = fragment->target;
|
|
target.in_livetree = true;
|
|
ret = build_changeset_symbols_node(ovcs, &target,
|
|
fragment->overlay);
|
|
if (ret) {
|
|
pr_debug("symbols fragment apply failed '%pOF'\n",
|
|
fragment->target);
|
|
return ret;
|
|
}
|
|
}
|
|
|
|
return changeset_dup_entry_check(ovcs);
|
|
}
|
|
|
|
/*
|
|
* Find the target node using a number of different strategies
|
|
* in order of preference:
|
|
*
|
|
* 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(struct device_node *info_node)
|
|
{
|
|
struct device_node *node;
|
|
const char *path;
|
|
u32 val;
|
|
int ret;
|
|
|
|
ret = of_property_read_u32(info_node, "target", &val);
|
|
if (!ret) {
|
|
node = of_find_node_by_phandle(val);
|
|
if (!node)
|
|
pr_err("find target, node: %pOF, phandle 0x%x not found\n",
|
|
info_node, val);
|
|
return node;
|
|
}
|
|
|
|
ret = of_property_read_string(info_node, "target-path", &path);
|
|
if (!ret) {
|
|
node = of_find_node_by_path(path);
|
|
if (!node)
|
|
pr_err("find target, node: %pOF, path '%s' not found\n",
|
|
info_node, path);
|
|
return node;
|
|
}
|
|
|
|
pr_err("find target, node: %pOF, no target property\n", info_node);
|
|
|
|
return NULL;
|
|
}
|
|
|
|
/**
|
|
* init_overlay_changeset() - initialize overlay changeset from overlay tree
|
|
* @ovcs: Overlay changeset to build
|
|
* @fdt: the FDT that was unflattened to create @tree
|
|
* @tree: Contains all the overlay fragments and overlay fixup nodes
|
|
*
|
|
* Initialize @ovcs. Populate @ovcs->fragments with node information from
|
|
* the top level of @tree. The relevant top level nodes are the fragment
|
|
* nodes and the __symbols__ node. Any other top level node will be ignored.
|
|
*
|
|
* Returns 0 on success, -ENOMEM if memory allocation failure, -EINVAL if error
|
|
* detected in @tree, or -ENOSPC if idr_alloc() error.
|
|
*/
|
|
static int init_overlay_changeset(struct overlay_changeset *ovcs,
|
|
const void *fdt, struct device_node *tree)
|
|
{
|
|
struct device_node *node, *overlay_node;
|
|
struct fragment *fragment;
|
|
struct fragment *fragments;
|
|
int cnt, id, ret;
|
|
|
|
/*
|
|
* Warn for some issues. Can not return -EINVAL for these until
|
|
* of_unittest_apply_overlay() is fixed to pass these checks.
|
|
*/
|
|
if (!of_node_check_flag(tree, OF_DYNAMIC))
|
|
pr_debug("%s() tree is not dynamic\n", __func__);
|
|
|
|
if (!of_node_check_flag(tree, OF_DETACHED))
|
|
pr_debug("%s() tree is not detached\n", __func__);
|
|
|
|
if (!of_node_is_root(tree))
|
|
pr_debug("%s() tree is not root\n", __func__);
|
|
|
|
ovcs->overlay_tree = tree;
|
|
ovcs->fdt = fdt;
|
|
|
|
INIT_LIST_HEAD(&ovcs->ovcs_list);
|
|
|
|
of_changeset_init(&ovcs->cset);
|
|
|
|
id = idr_alloc(&ovcs_idr, ovcs, 1, 0, GFP_KERNEL);
|
|
if (id <= 0)
|
|
return id;
|
|
|
|
cnt = 0;
|
|
|
|
/* fragment nodes */
|
|
for_each_child_of_node(tree, node) {
|
|
overlay_node = of_get_child_by_name(node, "__overlay__");
|
|
if (overlay_node) {
|
|
cnt++;
|
|
of_node_put(overlay_node);
|
|
}
|
|
}
|
|
|
|
node = of_get_child_by_name(tree, "__symbols__");
|
|
if (node) {
|
|
cnt++;
|
|
of_node_put(node);
|
|
}
|
|
|
|
fragments = kcalloc(cnt, sizeof(*fragments), GFP_KERNEL);
|
|
if (!fragments) {
|
|
ret = -ENOMEM;
|
|
goto err_free_idr;
|
|
}
|
|
|
|
cnt = 0;
|
|
for_each_child_of_node(tree, node) {
|
|
overlay_node = of_get_child_by_name(node, "__overlay__");
|
|
if (!overlay_node)
|
|
continue;
|
|
|
|
fragment = &fragments[cnt];
|
|
fragment->overlay = overlay_node;
|
|
fragment->target = find_target(node);
|
|
if (!fragment->target) {
|
|
of_node_put(fragment->overlay);
|
|
ret = -EINVAL;
|
|
goto err_free_fragments;
|
|
}
|
|
|
|
cnt++;
|
|
}
|
|
|
|
/*
|
|
* if there is a symbols fragment in ovcs->fragments[i] it is
|
|
* the final element in the array
|
|
*/
|
|
node = of_get_child_by_name(tree, "__symbols__");
|
|
if (node) {
|
|
ovcs->symbols_fragment = 1;
|
|
fragment = &fragments[cnt];
|
|
fragment->overlay = node;
|
|
fragment->target = of_find_node_by_path("/__symbols__");
|
|
|
|
if (!fragment->target) {
|
|
pr_err("symbols in overlay, but not in live tree\n");
|
|
ret = -EINVAL;
|
|
goto err_free_fragments;
|
|
}
|
|
|
|
cnt++;
|
|
}
|
|
|
|
if (!cnt) {
|
|
pr_err("no fragments or symbols in overlay\n");
|
|
ret = -EINVAL;
|
|
goto err_free_fragments;
|
|
}
|
|
|
|
ovcs->id = id;
|
|
ovcs->count = cnt;
|
|
ovcs->fragments = fragments;
|
|
|
|
return 0;
|
|
|
|
err_free_fragments:
|
|
kfree(fragments);
|
|
err_free_idr:
|
|
idr_remove(&ovcs_idr, id);
|
|
|
|
pr_err("%s() failed, ret = %d\n", __func__, ret);
|
|
|
|
return ret;
|
|
}
|
|
|
|
static void free_overlay_changeset(struct overlay_changeset *ovcs)
|
|
{
|
|
int i;
|
|
|
|
if (ovcs->cset.entries.next)
|
|
of_changeset_destroy(&ovcs->cset);
|
|
|
|
if (ovcs->id)
|
|
idr_remove(&ovcs_idr, ovcs->id);
|
|
|
|
for (i = 0; i < ovcs->count; i++) {
|
|
of_node_put(ovcs->fragments[i].target);
|
|
of_node_put(ovcs->fragments[i].overlay);
|
|
}
|
|
kfree(ovcs->fragments);
|
|
/*
|
|
* There should be no live pointers into ovcs->overlay_tree and
|
|
* ovcs->fdt due to the policy that overlay notifiers are not allowed
|
|
* to retain pointers into the overlay devicetree.
|
|
*/
|
|
kfree(ovcs->overlay_tree);
|
|
kfree(ovcs->fdt);
|
|
kfree(ovcs);
|
|
}
|
|
|
|
/*
|
|
* internal documentation
|
|
*
|
|
* of_overlay_apply() - Create and apply an overlay changeset
|
|
* @fdt: the FDT that was unflattened to create @tree
|
|
* @tree: Expanded overlay device tree
|
|
* @ovcs_id: Pointer to overlay changeset id
|
|
*
|
|
* Creates and applies an overlay changeset.
|
|
*
|
|
* If an error occurs in a pre-apply notifier, then no changes are made
|
|
* to the device tree.
|
|
*
|
|
|
|
* A non-zero return value will not have created the changeset if error is from:
|
|
* - parameter checks
|
|
* - building the changeset
|
|
* - overlay changeset pre-apply notifier
|
|
*
|
|
* If an error is returned by an overlay changeset pre-apply notifier
|
|
* then no further overlay changeset pre-apply notifier will be called.
|
|
*
|
|
* A non-zero return value will have created the changeset if error is from:
|
|
* - overlay changeset entry notifier
|
|
* - overlay changeset post-apply notifier
|
|
*
|
|
* If an error is returned by an overlay changeset post-apply notifier
|
|
* then no further overlay changeset post-apply notifier will be called.
|
|
*
|
|
* If more than one notifier returns an error, then the last notifier
|
|
* error to occur is returned.
|
|
*
|
|
* If an error occurred while applying the overlay changeset, then an
|
|
* attempt is made to revert any changes that were made to the
|
|
* device tree. If there were any errors during the revert attempt
|
|
* then the state of the device tree can not be determined, and any
|
|
* following attempt to apply or remove an overlay changeset will be
|
|
* refused.
|
|
*
|
|
* Returns 0 on success, or a negative error number. Overlay changeset
|
|
* id is returned to *ovcs_id.
|
|
*/
|
|
|
|
static int of_overlay_apply(const void *fdt, struct device_node *tree,
|
|
int *ovcs_id)
|
|
{
|
|
struct overlay_changeset *ovcs;
|
|
int ret = 0, ret_revert, ret_tmp;
|
|
|
|
/*
|
|
* As of this point, fdt and tree belong to the overlay changeset.
|
|
* overlay changeset code is responsible for freeing them.
|
|
*/
|
|
|
|
if (devicetree_corrupt()) {
|
|
pr_err("devicetree state suspect, refuse to apply overlay\n");
|
|
kfree(fdt);
|
|
kfree(tree);
|
|
ret = -EBUSY;
|
|
goto out;
|
|
}
|
|
|
|
ovcs = kzalloc(sizeof(*ovcs), GFP_KERNEL);
|
|
if (!ovcs) {
|
|
kfree(fdt);
|
|
kfree(tree);
|
|
ret = -ENOMEM;
|
|
goto out;
|
|
}
|
|
|
|
of_overlay_mutex_lock();
|
|
mutex_lock(&of_mutex);
|
|
|
|
ret = of_resolve_phandles(tree);
|
|
if (ret)
|
|
goto err_free_tree;
|
|
|
|
ret = init_overlay_changeset(ovcs, fdt, tree);
|
|
if (ret)
|
|
goto err_free_tree;
|
|
|
|
/*
|
|
* after overlay_notify(), ovcs->overlay_tree related pointers may have
|
|
* leaked to drivers, so can not kfree() tree, aka ovcs->overlay_tree;
|
|
* and can not free fdt, aka ovcs->fdt
|
|
*/
|
|
ret = overlay_notify(ovcs, OF_OVERLAY_PRE_APPLY);
|
|
if (ret) {
|
|
pr_err("overlay changeset pre-apply notify error %d\n", ret);
|
|
goto err_free_overlay_changeset;
|
|
}
|
|
|
|
ret = build_changeset(ovcs);
|
|
if (ret)
|
|
goto err_free_overlay_changeset;
|
|
|
|
ret_revert = 0;
|
|
ret = __of_changeset_apply_entries(&ovcs->cset, &ret_revert);
|
|
if (ret) {
|
|
if (ret_revert) {
|
|
pr_debug("overlay changeset revert error %d\n",
|
|
ret_revert);
|
|
devicetree_state_flags |= DTSF_APPLY_FAIL;
|
|
}
|
|
goto err_free_overlay_changeset;
|
|
}
|
|
|
|
of_populate_phandle_cache();
|
|
|
|
ret = __of_changeset_apply_notify(&ovcs->cset);
|
|
if (ret)
|
|
pr_err("overlay apply changeset entry notify error %d\n", ret);
|
|
/* notify failure is not fatal, continue */
|
|
|
|
list_add_tail(&ovcs->ovcs_list, &ovcs_list);
|
|
*ovcs_id = ovcs->id;
|
|
|
|
ret_tmp = overlay_notify(ovcs, OF_OVERLAY_POST_APPLY);
|
|
if (ret_tmp) {
|
|
pr_err("overlay changeset post-apply notify error %d\n",
|
|
ret_tmp);
|
|
if (!ret)
|
|
ret = ret_tmp;
|
|
}
|
|
|
|
goto out_unlock;
|
|
|
|
err_free_tree:
|
|
kfree(fdt);
|
|
kfree(tree);
|
|
|
|
err_free_overlay_changeset:
|
|
free_overlay_changeset(ovcs);
|
|
|
|
out_unlock:
|
|
mutex_unlock(&of_mutex);
|
|
of_overlay_mutex_unlock();
|
|
|
|
out:
|
|
pr_debug("%s() err=%d\n", __func__, ret);
|
|
|
|
return ret;
|
|
}
|
|
|
|
int of_overlay_fdt_apply(const void *overlay_fdt, u32 overlay_fdt_size,
|
|
int *ovcs_id)
|
|
{
|
|
const void *new_fdt;
|
|
int ret;
|
|
u32 size;
|
|
struct device_node *overlay_root;
|
|
|
|
*ovcs_id = 0;
|
|
ret = 0;
|
|
|
|
if (overlay_fdt_size < sizeof(struct fdt_header) ||
|
|
fdt_check_header(overlay_fdt)) {
|
|
pr_err("Invalid overlay_fdt header\n");
|
|
return -EINVAL;
|
|
}
|
|
|
|
size = fdt_totalsize(overlay_fdt);
|
|
if (overlay_fdt_size < size)
|
|
return -EINVAL;
|
|
|
|
/*
|
|
* Must create permanent copy of FDT because of_fdt_unflatten_tree()
|
|
* will create pointers to the passed in FDT in the unflattened tree.
|
|
*/
|
|
new_fdt = kmemdup(overlay_fdt, size, GFP_KERNEL);
|
|
if (!new_fdt)
|
|
return -ENOMEM;
|
|
|
|
of_fdt_unflatten_tree(new_fdt, NULL, &overlay_root);
|
|
if (!overlay_root) {
|
|
pr_err("unable to unflatten overlay_fdt\n");
|
|
ret = -EINVAL;
|
|
goto out_free_new_fdt;
|
|
}
|
|
|
|
ret = of_overlay_apply(new_fdt, overlay_root, ovcs_id);
|
|
if (ret < 0) {
|
|
/*
|
|
* new_fdt and overlay_root now belong to the overlay
|
|
* changeset.
|
|
* overlay changeset code is responsible for freeing them.
|
|
*/
|
|
goto out;
|
|
}
|
|
|
|
return 0;
|
|
|
|
|
|
out_free_new_fdt:
|
|
kfree(new_fdt);
|
|
|
|
out:
|
|
return ret;
|
|
}
|
|
EXPORT_SYMBOL_GPL(of_overlay_fdt_apply);
|
|
|
|
/*
|
|
* Find @np in @tree.
|
|
*
|
|
* Returns 1 if @np is @tree or is contained in @tree, else 0
|
|
*/
|
|
static int find_node(struct device_node *tree, struct device_node *np)
|
|
{
|
|
struct device_node *child;
|
|
|
|
if (tree == np)
|
|
return 1;
|
|
|
|
for_each_child_of_node(tree, child) {
|
|
if (find_node(child, np)) {
|
|
of_node_put(child);
|
|
return 1;
|
|
}
|
|
}
|
|
|
|
return 0;
|
|
}
|
|
|
|
/*
|
|
* Is @remove_ce_node a child of, a parent of, or the same as any
|
|
* node in an overlay changeset more topmost than @remove_ovcs?
|
|
*
|
|
* Returns 1 if found, else 0
|
|
*/
|
|
static int node_overlaps_later_cs(struct overlay_changeset *remove_ovcs,
|
|
struct device_node *remove_ce_node)
|
|
{
|
|
struct overlay_changeset *ovcs;
|
|
struct of_changeset_entry *ce;
|
|
|
|
list_for_each_entry_reverse(ovcs, &ovcs_list, ovcs_list) {
|
|
if (ovcs == remove_ovcs)
|
|
break;
|
|
|
|
list_for_each_entry(ce, &ovcs->cset.entries, node) {
|
|
if (find_node(ce->np, remove_ce_node)) {
|
|
pr_err("%s: #%d overlaps with #%d @%pOF\n",
|
|
__func__, remove_ovcs->id, ovcs->id,
|
|
remove_ce_node);
|
|
return 1;
|
|
}
|
|
if (find_node(remove_ce_node, ce->np)) {
|
|
pr_err("%s: #%d overlaps with #%d @%pOF\n",
|
|
__func__, remove_ovcs->id, ovcs->id,
|
|
remove_ce_node);
|
|
return 1;
|
|
}
|
|
}
|
|
}
|
|
|
|
return 0;
|
|
}
|
|
|
|
/*
|
|
* We can safely remove the overlay only if it's the top-most one.
|
|
* Newly applied overlays are inserted at the tail of the overlay list,
|
|
* so a top most overlay is the one that is closest to the tail.
|
|
*
|
|
* The topmost check is done by exploiting this property. For each
|
|
* affected device node in the log list we check if this overlay is
|
|
* the one closest to the tail. If another overlay has affected this
|
|
* device node and is closest to the tail, then removal is not permited.
|
|
*/
|
|
static int overlay_removal_is_ok(struct overlay_changeset *remove_ovcs)
|
|
{
|
|
struct of_changeset_entry *remove_ce;
|
|
|
|
list_for_each_entry(remove_ce, &remove_ovcs->cset.entries, node) {
|
|
if (node_overlaps_later_cs(remove_ovcs, remove_ce->np)) {
|
|
pr_err("overlay #%d is not topmost\n", remove_ovcs->id);
|
|
return 0;
|
|
}
|
|
}
|
|
|
|
return 1;
|
|
}
|
|
|
|
/**
|
|
* of_overlay_remove() - Revert and free an overlay changeset
|
|
* @ovcs_id: Pointer to overlay changeset id
|
|
*
|
|
* Removes an overlay if it is permissible. @ovcs_id was previously returned
|
|
* by of_overlay_fdt_apply().
|
|
*
|
|
* If an error occurred while attempting to revert the overlay changeset,
|
|
* then an attempt is made to re-apply any changeset entry that was
|
|
* reverted. If an error occurs on re-apply then the state of the device
|
|
* tree can not be determined, and any following attempt to apply or remove
|
|
* an overlay changeset will be refused.
|
|
*
|
|
* A non-zero return value will not revert the changeset if error is from:
|
|
* - parameter checks
|
|
* - overlay changeset pre-remove notifier
|
|
* - overlay changeset entry revert
|
|
*
|
|
* If an error is returned by an overlay changeset pre-remove notifier
|
|
* then no further overlay changeset pre-remove notifier will be called.
|
|
*
|
|
* If more than one notifier returns an error, then the last notifier
|
|
* error to occur is returned.
|
|
*
|
|
* A non-zero return value will revert the changeset if error is from:
|
|
* - overlay changeset entry notifier
|
|
* - overlay changeset post-remove notifier
|
|
*
|
|
* If an error is returned by an overlay changeset post-remove notifier
|
|
* then no further overlay changeset post-remove notifier will be called.
|
|
*
|
|
* Returns 0 on success, or a negative error number. *ovcs_id is set to
|
|
* zero after reverting the changeset, even if a subsequent error occurs.
|
|
*/
|
|
int of_overlay_remove(int *ovcs_id)
|
|
{
|
|
struct overlay_changeset *ovcs;
|
|
int ret, ret_apply, ret_tmp;
|
|
|
|
ret = 0;
|
|
|
|
if (devicetree_corrupt()) {
|
|
pr_err("suspect devicetree state, refuse to remove overlay\n");
|
|
ret = -EBUSY;
|
|
goto out;
|
|
}
|
|
|
|
mutex_lock(&of_mutex);
|
|
|
|
ovcs = idr_find(&ovcs_idr, *ovcs_id);
|
|
if (!ovcs) {
|
|
ret = -ENODEV;
|
|
pr_err("remove: Could not find overlay #%d\n", *ovcs_id);
|
|
goto out_unlock;
|
|
}
|
|
|
|
if (!overlay_removal_is_ok(ovcs)) {
|
|
ret = -EBUSY;
|
|
goto out_unlock;
|
|
}
|
|
|
|
ret = overlay_notify(ovcs, OF_OVERLAY_PRE_REMOVE);
|
|
if (ret) {
|
|
pr_err("overlay changeset pre-remove notify error %d\n", ret);
|
|
goto out_unlock;
|
|
}
|
|
|
|
list_del(&ovcs->ovcs_list);
|
|
|
|
/*
|
|
* Disable phandle cache. Avoids race condition that would arise
|
|
* from removing cache entry when the associated node is deleted.
|
|
*/
|
|
of_free_phandle_cache();
|
|
|
|
ret_apply = 0;
|
|
ret = __of_changeset_revert_entries(&ovcs->cset, &ret_apply);
|
|
|
|
of_populate_phandle_cache();
|
|
|
|
if (ret) {
|
|
if (ret_apply)
|
|
devicetree_state_flags |= DTSF_REVERT_FAIL;
|
|
goto out_unlock;
|
|
}
|
|
|
|
ret = __of_changeset_revert_notify(&ovcs->cset);
|
|
if (ret)
|
|
pr_err("overlay remove changeset entry notify error %d\n", ret);
|
|
/* notify failure is not fatal, continue */
|
|
|
|
*ovcs_id = 0;
|
|
|
|
ret_tmp = overlay_notify(ovcs, OF_OVERLAY_POST_REMOVE);
|
|
if (ret_tmp) {
|
|
pr_err("overlay changeset post-remove notify error %d\n",
|
|
ret_tmp);
|
|
if (!ret)
|
|
ret = ret_tmp;
|
|
}
|
|
|
|
free_overlay_changeset(ovcs);
|
|
|
|
out_unlock:
|
|
mutex_unlock(&of_mutex);
|
|
|
|
out:
|
|
pr_debug("%s() err=%d\n", __func__, ret);
|
|
|
|
return ret;
|
|
}
|
|
EXPORT_SYMBOL_GPL(of_overlay_remove);
|
|
|
|
/**
|
|
* of_overlay_remove_all() - Reverts and frees all overlay changesets
|
|
*
|
|
* Removes all overlays from the system in the correct order.
|
|
*
|
|
* Returns 0 on success, or a negative error number
|
|
*/
|
|
int of_overlay_remove_all(void)
|
|
{
|
|
struct overlay_changeset *ovcs, *ovcs_n;
|
|
int ret;
|
|
|
|
/* the tail of list is guaranteed to be safe to remove */
|
|
list_for_each_entry_safe_reverse(ovcs, ovcs_n, &ovcs_list, ovcs_list) {
|
|
ret = of_overlay_remove(&ovcs->id);
|
|
if (ret)
|
|
return ret;
|
|
}
|
|
|
|
return 0;
|
|
}
|
|
EXPORT_SYMBOL_GPL(of_overlay_remove_all);
|