diff options
Diffstat (limited to 'drivers/of/overlay.c')
| -rw-r--r-- | drivers/of/overlay.c | 152 |
1 files changed, 134 insertions, 18 deletions
diff --git a/drivers/of/overlay.c b/drivers/of/overlay.c index 3397d7642958..30d91f907026 100644 --- a/drivers/of/overlay.c +++ b/drivers/of/overlay.c @@ -12,10 +12,12 @@ #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> @@ -33,7 +35,9 @@ struct fragment { /** * struct overlay_changeset + * @id: changeset identifier * @ovcs_list: list on which we are located + * @fdt: FDT that was unflattened to create @overlay_tree * @overlay_tree: expanded device tree that contains the fragment nodes * @count: count of fragment structures * @fragments: fragment nodes in the overlay expanded device tree @@ -43,6 +47,7 @@ struct fragment { struct overlay_changeset { int id; struct list_head ovcs_list; + const void *fdt; struct device_node *overlay_tree; int count; struct fragment *fragments; @@ -307,7 +312,20 @@ static int add_changeset_property(struct overlay_changeset *ovcs, * If @node has child nodes, add the children recursively via * build_changeset_next_level(). * - * NOTE: Multiple mods of created nodes not supported. + * 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. * 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 @@ -334,8 +352,7 @@ static int add_changeset_node(struct overlay_changeset *ovcs, break; if (!tchild) { - tchild = __of_node_dup(node, "%pOF/%s", - target_node, node_kbasename); + tchild = __of_node_dup(node, node_kbasename); if (!tchild) return -ENOMEM; @@ -483,27 +500,38 @@ static int build_changeset(struct overlay_changeset *ovcs) */ static struct device_node *find_target_node(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) - return of_find_node_by_phandle(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) - return of_find_node_by_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("Failed to find target for node %p (%s)\n", - info_node, info_node->name); + 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 + * @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 @@ -514,7 +542,7 @@ static struct device_node *find_target_node(struct device_node *info_node) * detected in @tree, or -ENOSPC if idr_alloc() error. */ static int init_overlay_changeset(struct overlay_changeset *ovcs, - struct device_node *tree) + const void *fdt, struct device_node *tree) { struct device_node *node, *overlay_node; struct fragment *fragment; @@ -535,6 +563,7 @@ static int init_overlay_changeset(struct overlay_changeset *ovcs, pr_debug("%s() tree is not root\n", __func__); ovcs->overlay_tree = tree; + ovcs->fdt = fdt; INIT_LIST_HEAD(&ovcs->ovcs_list); @@ -606,6 +635,7 @@ static int init_overlay_changeset(struct overlay_changeset *ovcs, } if (!cnt) { + pr_err("no fragments or symbols in overlay\n"); ret = -EINVAL; goto err_free_fragments; } @@ -642,11 +672,24 @@ static void free_overlay_changeset(struct overlay_changeset *ovcs) } kfree(ovcs->fragments); + /* + * TODO + * + * would like to: kfree(ovcs->overlay_tree); + * but can not since drivers may have pointers into this data + * + * would like to: kfree(ovcs->fdt); + * but can not since drivers may have pointers into this data + */ + 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 * @@ -685,21 +728,29 @@ static void free_overlay_changeset(struct overlay_changeset *ovcs) * id is returned to *ovcs_id. */ -int of_overlay_apply(struct device_node *tree, int *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; - *ovcs_id = 0; + /* + * 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; } @@ -709,12 +760,17 @@ int of_overlay_apply(struct device_node *tree, int *ovcs_id) ret = of_resolve_phandles(tree); if (ret) - goto err_free_overlay_changeset; + goto err_free_tree; - ret = init_overlay_changeset(ovcs, tree); + ret = init_overlay_changeset(ovcs, fdt, tree); if (ret) - goto err_free_overlay_changeset; + 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); @@ -754,6 +810,10 @@ int of_overlay_apply(struct device_node *tree, int *ovcs_id) goto out_unlock; +err_free_tree: + kfree(fdt); + kfree(tree); + err_free_overlay_changeset: free_overlay_changeset(ovcs); @@ -766,7 +826,63 @@ out: return ret; } -EXPORT_SYMBOL_GPL(of_overlay_apply); + +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. |