litmus-rt.git - The LITMUS^RT kernel.

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Diffstat (limited to 'fs/btrfs/async-thread.h')

0 files changed, 0 insertions, 0 deletions

/* * Functions for working with device tree overlays * * Copyright (C) 2012 Pantelis Antoniou <panto@antoniou-consulting.com> * Copyright (C) 2012 Texas Instruments Inc. * * This program is free software; you can redistribute it and/or * modify it under the terms of the GNU General Public License * version 2 as published by the Free Software Foundation. */ #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/string.h> #include <linux/ctype.h> #include <linux/errno.h> #include <linux/slab.h> #include <linux/err.h> #include <linux/idr.h> #include "of_private.h" /** * struct fragment - info about fragment nodes in overlay expanded device tree * @target: target of the overlay operation * @overlay: pointer to the __overlay__ node */ struct fragment { struct device_node *target; struct device_node *overlay; }; /** * struct overlay_changeset * @ovcs_list: list on which we are located * @overlay_tree: expanded device tree that contains the fragment nodes * @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; struct device_node *overlay_tree; 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 /* * 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 device_node *target_node, 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); 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); 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 char *of_overlay_action_name[] = { "pre-apply", "post-apply", "pre-remove", "post-remove", }; static int overlay_notify(struct overlay_changeset *ovcs, enum of_overlay_notify_action action) { struct of_overlay_notify_data nd; int i, ret; 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 (ret == NOTIFY_OK || ret == NOTIFY_STOP) return 0; if (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; } /* * The values of properties in the "/__symbols__" node are paths in * the ovcs->overlay_tree. 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_tree, 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(sizeof(*new_prop), GFP_KERNEL); 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; strcpy(new_prop->value, target_path); strcpy(new_prop->value + target_path_len, path_tail); of_property_set_flag(new_prop, OF_DYNAMIC); return new_prop; err_free_new_prop: kfree(new_prop->name); kfree(new_prop->value); kfree(new_prop); err_free_target_path: kfree(target_path); return NULL; } /** * add_changeset_property() - add @overlay_prop to overlay changeset * @ovcs: overlay changeset * @target_node: where to place @overlay_prop in live tree * @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 @target_node, add changeset entry * to add @overlay_prop in @target_node, else add changeset entry to update * value of @overlay_prop. * * Some special properties are not updated (no error returned). * * Update of property in symbols node is not allowed. * * Returns 0 on success, -ENOMEM if memory allocation failure, or -EINVAL if * invalid @overlay. */ static int add_changeset_property(struct overlay_changeset *ovcs, struct device_node *target_node, struct property *overlay_prop, bool is_symbols_prop) { struct property *new_prop = NULL, *prop; int ret = 0; prop = of_find_property(target_node, overlay_prop->name, NULL); if (!of_prop_cmp(overlay_prop->name, "name") || !of_prop_cmp(overlay_prop->name, "phandle") || !of_prop_cmp(overlay_prop->name, "linux,phandle")) return 0; 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) ret = of_changeset_add_property(&ovcs->cset, target_node, new_prop); else ret = of_changeset_update_property(&ovcs->cset, target_node, new_prop); if (ret) { kfree(new_prop->name); kfree(new_prop->value); kfree(new_prop); } return ret; } /** * add_changeset_node() - add @node (and children) to overlay changeset * @ovcs: overlay changeset * @target_node: where to place @node in live tree * @node: node from within overlay device tree fragment * * If @node does not already exist in @target_node, add changeset entry * to add @node in @target_node. * * If @node already exists in @target_node, 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: Multiple mods of created nodes not supported. * If more than one fragment contains a node that does not already exist * in the live tree, then for each fragment of_changeset_attach_node() * will add a changeset entry to add the node. When the changeset is * applied, __of_attach_node() will attach the node twice (once for * each fragment). At this point the device tree will be corrupted. * * TODO: add integrity check to ensure that multiple fragments do not * create the same node. * * Returns 0 on success, -ENOMEM if memory allocation failure, or -EINVAL if * invalid @overlay. */ static int add_changeset_node(struct overlay_changeset *ovcs, struct device_node *target_node, struct device_node *node) { const char *node_kbasename; struct device_node *tchild; int ret = 0; node_kbasename = kbasename(node->full_name); for_each_child_of_node(target_node, tchild) if (!of_node_cmp(node_kbasename, kbasename(tchild->full_name))) break; if (!tchild) { tchild = __of_node_dup(node, "%pOF/%s", target_node, node_kbasename); if (!tchild) return -ENOMEM; tchild->parent = target_node; ret = of_changeset_attach_node(&ovcs->cset, tchild); if (ret) return ret; return build_changeset_next_level(ovcs, tchild, node); } if (node->phandle && tchild->phandle) ret = -EINVAL; else ret = build_changeset_next_level(ovcs, tchild, node); of_node_put(tchild); return ret; } /** * build_changeset_next_level() - add level of overlay changeset * @ovcs: overlay changeset * @target_node: 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. * * Returns 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 device_node *target_node, const struct device_node *overlay_node) { struct device_node *child; struct property *prop; int ret; for_each_property_of_node(overlay_node, prop) { ret = add_changeset_property(ovcs, target_node, prop, 0); if (ret) { pr_debug("Failed to apply prop @%pOF/%s, err=%d\n", target_node, prop->name, ret); return ret; } } for_each_child_of_node(overlay_node, child) { ret = add_changeset_node(ovcs, target_node, child); if (ret) { pr_debug("Failed to apply node @%pOF/%s, err=%d\n", target_node, child->name, ret); 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 device_node *target_node, 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_node, prop, 1); if (ret) { pr_debug("Failed to apply prop @%pOF/%s, err=%d\n", target_node, prop->name, ret); return ret; } } return 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; 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]; ret = build_changeset_next_level(ovcs, fragment->target, fragment->overlay); if (ret) { pr_debug("apply failed '%pOF'\n", fragment->target); return ret; } } if (ovcs->symbols_fragment) { fragment = &ovcs->fragments[ovcs->count - 1]; ret = build_changeset_symbols_node(ovcs, fragment->target, fragment->overlay); if (ret) { pr_debug("apply failed '%pOF'\n", fragment->target); return ret; } } return 0; } /* * 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_node(struct device_node *info_node) { const char *path; u32 val; int ret; ret = of_property_read_u32(info_node, "target", &val); if (!ret) return of_find_node_by_phandle(val); ret = of_property_read_string(info_node, "target-path", &path); if (!ret) return of_find_node_by_path(path); pr_err("Failed to find target for node %p (%s)\n", info_node, info_node->name); return NULL; } /** * init_overlay_changeset() - initialize overlay changeset from overlay tree * @ovcs Overlay changeset to build * @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, struct device_node *tree) { struct device_node *node, *overlay_node; struct fragment *fragment; struct fragment *fragments; int cnt, 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; INIT_LIST_HEAD(&ovcs->ovcs_list); of_changeset_init(&ovcs->cset); ovcs->id = idr_alloc(&ovcs_idr, ovcs, 1, 0, GFP_KERNEL); if (ovcs->id <= 0) return ovcs->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) { fragment = &fragments[cnt]; fragment->overlay = of_get_child_by_name(node, "__overlay__"); if (fragment->overlay) { fragment->target = find_target_node(node); if (!fragment->target) { of_node_put(fragment->overlay); ret = -EINVAL; goto err_free_fragments; } else { cnt++; }


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