diff options
Diffstat (limited to 'lib/libfdt/fdt_overlay.c')
-rw-r--r-- | lib/libfdt/fdt_overlay.c | 863 |
1 files changed, 2 insertions, 861 deletions
diff --git a/lib/libfdt/fdt_overlay.c b/lib/libfdt/fdt_overlay.c index bd81241..575c827 100644 --- a/lib/libfdt/fdt_overlay.c +++ b/lib/libfdt/fdt_overlay.c @@ -1,861 +1,2 @@ -#include "libfdt_env.h" - -#include <fdt.h> -#include <libfdt.h> - -#include "libfdt_internal.h" - -/** - * overlay_get_target_phandle - retrieves the target phandle of a fragment - * @fdto: pointer to the device tree overlay blob - * @fragment: node offset of the fragment in the overlay - * - * overlay_get_target_phandle() retrieves the target phandle of an - * overlay fragment when that fragment uses a phandle (target - * property) instead of a path (target-path property). - * - * returns: - * the phandle pointed by the target property - * 0, if the phandle was not found - * -1, if the phandle was malformed - */ -static uint32_t overlay_get_target_phandle(const void *fdto, int fragment) -{ - const fdt32_t *val; - int len; - - val = fdt_getprop(fdto, fragment, "target", &len); - if (!val) - return 0; - - if ((len != sizeof(*val)) || (fdt32_to_cpu(*val) == (uint32_t)-1)) - return (uint32_t)-1; - - return fdt32_to_cpu(*val); -} - -/** - * overlay_get_target - retrieves the offset of a fragment's target - * @fdt: Base device tree blob - * @fdto: Device tree overlay blob - * @fragment: node offset of the fragment in the overlay - * @pathp: pointer which receives the path of the target (or NULL) - * - * overlay_get_target() retrieves the target offset in the base - * device tree of a fragment, no matter how the actual targetting is - * done (through a phandle or a path) - * - * returns: - * the targetted node offset in the base device tree - * Negative error code on error - */ -static int overlay_get_target(const void *fdt, const void *fdto, - int fragment, char const **pathp) -{ - uint32_t phandle; - const char *path = NULL; - int path_len = 0, ret; - - /* Try first to do a phandle based lookup */ - phandle = overlay_get_target_phandle(fdto, fragment); - if (phandle == (uint32_t)-1) - return -FDT_ERR_BADPHANDLE; - - /* no phandle, try path */ - if (!phandle) { - /* And then a path based lookup */ - path = fdt_getprop(fdto, fragment, "target-path", &path_len); - if (path) - ret = fdt_path_offset(fdt, path); - else - ret = path_len; - } else - ret = fdt_node_offset_by_phandle(fdt, phandle); - - /* - * If we haven't found either a target or a - * target-path property in a node that contains a - * __overlay__ subnode (we wouldn't be called - * otherwise), consider it a improperly written - * overlay - */ - if (ret < 0 && path_len == -FDT_ERR_NOTFOUND) - ret = -FDT_ERR_BADOVERLAY; - - /* return on error */ - if (ret < 0) - return ret; - - /* return pointer to path (if available) */ - if (pathp) - *pathp = path ? path : NULL; - - return ret; -} - -/** - * overlay_phandle_add_offset - Increases a phandle by an offset - * @fdt: Base device tree blob - * @node: Device tree overlay blob - * @name: Name of the property to modify (phandle or linux,phandle) - * @delta: offset to apply - * - * overlay_phandle_add_offset() increments a node phandle by a given - * offset. - * - * returns: - * 0 on success. - * Negative error code on error - */ -static int overlay_phandle_add_offset(void *fdt, int node, - const char *name, uint32_t delta) -{ - const fdt32_t *val; - uint32_t adj_val; - int len; - - val = fdt_getprop(fdt, node, name, &len); - if (!val) - return len; - - if (len != sizeof(*val)) - return -FDT_ERR_BADPHANDLE; - - adj_val = fdt32_to_cpu(*val); - if ((adj_val + delta) < adj_val) - return -FDT_ERR_NOPHANDLES; - - adj_val += delta; - if (adj_val == (uint32_t)-1) - return -FDT_ERR_NOPHANDLES; - - return fdt_setprop_inplace_u32(fdt, node, name, adj_val); -} - -/** - * overlay_adjust_node_phandles - Offsets the phandles of a node - * @fdto: Device tree overlay blob - * @node: Offset of the node we want to adjust - * @delta: Offset to shift the phandles of - * - * overlay_adjust_node_phandles() adds a constant to all the phandles - * of a given node. This is mainly use as part of the overlay - * application process, when we want to update all the overlay - * phandles to not conflict with the overlays of the base device tree. - * - * returns: - * 0 on success - * Negative error code on failure - */ -static int overlay_adjust_node_phandles(void *fdto, int node, - uint32_t delta) -{ - int child; - int ret; - - ret = overlay_phandle_add_offset(fdto, node, "phandle", delta); - if (ret && ret != -FDT_ERR_NOTFOUND) - return ret; - - ret = overlay_phandle_add_offset(fdto, node, "linux,phandle", delta); - if (ret && ret != -FDT_ERR_NOTFOUND) - return ret; - - fdt_for_each_subnode(child, fdto, node) { - ret = overlay_adjust_node_phandles(fdto, child, delta); - if (ret) - return ret; - } - - return 0; -} - -/** - * overlay_adjust_local_phandles - Adjust the phandles of a whole overlay - * @fdto: Device tree overlay blob - * @delta: Offset to shift the phandles of - * - * overlay_adjust_local_phandles() adds a constant to all the - * phandles of an overlay. This is mainly use as part of the overlay - * application process, when we want to update all the overlay - * phandles to not conflict with the overlays of the base device tree. - * - * returns: - * 0 on success - * Negative error code on failure - */ -static int overlay_adjust_local_phandles(void *fdto, uint32_t delta) -{ - /* - * Start adjusting the phandles from the overlay root - */ - return overlay_adjust_node_phandles(fdto, 0, delta); -} - -/** - * overlay_update_local_node_references - Adjust the overlay references - * @fdto: Device tree overlay blob - * @tree_node: Node offset of the node to operate on - * @fixup_node: Node offset of the matching local fixups node - * @delta: Offset to shift the phandles of - * - * overlay_update_local_nodes_references() update the phandles - * pointing to a node within the device tree overlay by adding a - * constant delta. - * - * This is mainly used as part of a device tree application process, - * where you want the device tree overlays phandles to not conflict - * with the ones from the base device tree before merging them. - * - * returns: - * 0 on success - * Negative error code on failure - */ -static int overlay_update_local_node_references(void *fdto, - int tree_node, - int fixup_node, - uint32_t delta) -{ - int fixup_prop; - int fixup_child; - int ret; - - fdt_for_each_property_offset(fixup_prop, fdto, fixup_node) { - const fdt32_t *fixup_val; - const char *tree_val; - const char *name; - int fixup_len; - int tree_len; - int i; - - fixup_val = fdt_getprop_by_offset(fdto, fixup_prop, - &name, &fixup_len); - if (!fixup_val) - return fixup_len; - - if (fixup_len % sizeof(uint32_t)) - return -FDT_ERR_BADOVERLAY; - - tree_val = fdt_getprop(fdto, tree_node, name, &tree_len); - if (!tree_val) { - if (tree_len == -FDT_ERR_NOTFOUND) - return -FDT_ERR_BADOVERLAY; - - return tree_len; - } - - for (i = 0; i < (fixup_len / sizeof(uint32_t)); i++) { - fdt32_t adj_val; - uint32_t poffset; - - poffset = fdt32_to_cpu(fixup_val[i]); - - /* - * phandles to fixup can be unaligned. - * - * Use a memcpy for the architectures that do - * not support unaligned accesses. - */ - memcpy(&adj_val, tree_val + poffset, sizeof(adj_val)); - - adj_val = cpu_to_fdt32(fdt32_to_cpu(adj_val) + delta); - - ret = fdt_setprop_inplace_namelen_partial(fdto, - tree_node, - name, - strlen(name), - poffset, - &adj_val, - sizeof(adj_val)); - if (ret == -FDT_ERR_NOSPACE) - return -FDT_ERR_BADOVERLAY; - - if (ret) - return ret; - } - } - - fdt_for_each_subnode(fixup_child, fdto, fixup_node) { - const char *fixup_child_name = fdt_get_name(fdto, fixup_child, - NULL); - int tree_child; - - tree_child = fdt_subnode_offset(fdto, tree_node, - fixup_child_name); - if (tree_child == -FDT_ERR_NOTFOUND) - return -FDT_ERR_BADOVERLAY; - if (tree_child < 0) - return tree_child; - - ret = overlay_update_local_node_references(fdto, - tree_child, - fixup_child, - delta); - if (ret) - return ret; - } - - return 0; -} - -/** - * overlay_update_local_references - Adjust the overlay references - * @fdto: Device tree overlay blob - * @delta: Offset to shift the phandles of - * - * overlay_update_local_references() update all the phandles pointing - * to a node within the device tree overlay by adding a constant - * delta to not conflict with the base overlay. - * - * This is mainly used as part of a device tree application process, - * where you want the device tree overlays phandles to not conflict - * with the ones from the base device tree before merging them. - * - * returns: - * 0 on success - * Negative error code on failure - */ -static int overlay_update_local_references(void *fdto, uint32_t delta) -{ - int fixups; - - fixups = fdt_path_offset(fdto, "/__local_fixups__"); - if (fixups < 0) { - /* There's no local phandles to adjust, bail out */ - if (fixups == -FDT_ERR_NOTFOUND) - return 0; - - return fixups; - } - - /* - * Update our local references from the root of the tree - */ - return overlay_update_local_node_references(fdto, 0, fixups, - delta); -} - -/** - * overlay_fixup_one_phandle - Set an overlay phandle to the base one - * @fdt: Base Device Tree blob - * @fdto: Device tree overlay blob - * @symbols_off: Node offset of the symbols node in the base device tree - * @path: Path to a node holding a phandle in the overlay - * @path_len: number of path characters to consider - * @name: Name of the property holding the phandle reference in the overlay - * @name_len: number of name characters to consider - * @poffset: Offset within the overlay property where the phandle is stored - * @label: Label of the node referenced by the phandle - * - * overlay_fixup_one_phandle() resolves an overlay phandle pointing to - * a node in the base device tree. - * - * This is part of the device tree overlay application process, when - * you want all the phandles in the overlay to point to the actual - * base dt nodes. - * - * returns: - * 0 on success - * Negative error code on failure - */ -static int overlay_fixup_one_phandle(void *fdt, void *fdto, - int symbols_off, - const char *path, uint32_t path_len, - const char *name, uint32_t name_len, - int poffset, const char *label) -{ - const char *symbol_path; - uint32_t phandle; - fdt32_t phandle_prop; - int symbol_off, fixup_off; - int prop_len; - - if (symbols_off < 0) - return symbols_off; - - symbol_path = fdt_getprop(fdt, symbols_off, label, - &prop_len); - if (!symbol_path) - return prop_len; - - symbol_off = fdt_path_offset(fdt, symbol_path); - if (symbol_off < 0) - return symbol_off; - - phandle = fdt_get_phandle(fdt, symbol_off); - if (!phandle) - return -FDT_ERR_NOTFOUND; - - fixup_off = fdt_path_offset_namelen(fdto, path, path_len); - if (fixup_off == -FDT_ERR_NOTFOUND) - return -FDT_ERR_BADOVERLAY; - if (fixup_off < 0) - return fixup_off; - - phandle_prop = cpu_to_fdt32(phandle); - return fdt_setprop_inplace_namelen_partial(fdto, fixup_off, - name, name_len, poffset, - &phandle_prop, - sizeof(phandle_prop)); -}; - -/** - * overlay_fixup_phandle - Set an overlay phandle to the base one - * @fdt: Base Device Tree blob - * @fdto: Device tree overlay blob - * @symbols_off: Node offset of the symbols node in the base device tree - * @property: Property offset in the overlay holding the list of fixups - * - * overlay_fixup_phandle() resolves all the overlay phandles pointed - * to in a __fixups__ property, and updates them to match the phandles - * in use in the base device tree. - * - * This is part of the device tree overlay application process, when - * you want all the phandles in the overlay to point to the actual - * base dt nodes. - * - * returns: - * 0 on success - * Negative error code on failure - */ -static int overlay_fixup_phandle(void *fdt, void *fdto, int symbols_off, - int property) -{ - const char *value; - const char *label; - int len; - - value = fdt_getprop_by_offset(fdto, property, - &label, &len); - if (!value) { - if (len == -FDT_ERR_NOTFOUND) - return -FDT_ERR_INTERNAL; - - return len; - } - - do { - const char *path, *name, *fixup_end; - const char *fixup_str = value; - uint32_t path_len, name_len; - uint32_t fixup_len; - char *sep, *endptr; - int poffset, ret; - - fixup_end = memchr(value, '\0', len); - if (!fixup_end) - return -FDT_ERR_BADOVERLAY; - fixup_len = fixup_end - fixup_str; - - len -= fixup_len + 1; - value += fixup_len + 1; - - path = fixup_str; - sep = memchr(fixup_str, ':', fixup_len); - if (!sep || *sep != ':') - return -FDT_ERR_BADOVERLAY; - - path_len = sep - path; - if (path_len == (fixup_len - 1)) - return -FDT_ERR_BADOVERLAY; - - fixup_len -= path_len + 1; - name = sep + 1; - sep = memchr(name, ':', fixup_len); - if (!sep || *sep != ':') - return -FDT_ERR_BADOVERLAY; - - name_len = sep - name; - if (!name_len) - return -FDT_ERR_BADOVERLAY; - - poffset = strtoul(sep + 1, &endptr, 10); - if ((*endptr != '\0') || (endptr <= (sep + 1))) - return -FDT_ERR_BADOVERLAY; - - ret = overlay_fixup_one_phandle(fdt, fdto, symbols_off, - path, path_len, name, name_len, - poffset, label); - if (ret) - return ret; - } while (len > 0); - - return 0; -} - -/** - * overlay_fixup_phandles - Resolve the overlay phandles to the base - * device tree - * @fdt: Base Device Tree blob - * @fdto: Device tree overlay blob - * - * overlay_fixup_phandles() resolves all the overlay phandles pointing - * to nodes in the base device tree. - * - * This is one of the steps of the device tree overlay application - * process, when you want all the phandles in the overlay to point to - * the actual base dt nodes. - * - * returns: - * 0 on success - * Negative error code on failure - */ -static int overlay_fixup_phandles(void *fdt, void *fdto) -{ - int fixups_off, symbols_off; - int property; - - /* We can have overlays without any fixups */ - fixups_off = fdt_path_offset(fdto, "/__fixups__"); - if (fixups_off == -FDT_ERR_NOTFOUND) - return 0; /* nothing to do */ - if (fixups_off < 0) - return fixups_off; - - /* And base DTs without symbols */ - symbols_off = fdt_path_offset(fdt, "/__symbols__"); - if ((symbols_off < 0 && (symbols_off != -FDT_ERR_NOTFOUND))) - return symbols_off; - - fdt_for_each_property_offset(property, fdto, fixups_off) { - int ret; - - ret = overlay_fixup_phandle(fdt, fdto, symbols_off, property); - if (ret) - return ret; - } - - return 0; -} - -/** - * overlay_apply_node - Merges a node into the base device tree - * @fdt: Base Device Tree blob - * @target: Node offset in the base device tree to apply the fragment to - * @fdto: Device tree overlay blob - * @node: Node offset in the overlay holding the changes to merge - * - * overlay_apply_node() merges a node into a target base device tree - * node pointed. - * - * This is part of the final step in the device tree overlay - * application process, when all the phandles have been adjusted and - * resolved and you just have to merge overlay into the base device - * tree. - * - * returns: - * 0 on success - * Negative error code on failure - */ -static int overlay_apply_node(void *fdt, int target, - void *fdto, int node) -{ - int property; - int subnode; - - fdt_for_each_property_offset(property, fdto, node) { - const char *name; - const void *prop; - int prop_len; - int ret; - - prop = fdt_getprop_by_offset(fdto, property, &name, - &prop_len); - if (prop_len == -FDT_ERR_NOTFOUND) - return -FDT_ERR_INTERNAL; - if (prop_len < 0) - return prop_len; - - ret = fdt_setprop(fdt, target, name, prop, prop_len); - if (ret) - return ret; - } - - fdt_for_each_subnode(subnode, fdto, node) { - const char *name = fdt_get_name(fdto, subnode, NULL); - int nnode; - int ret; - - nnode = fdt_add_subnode(fdt, target, name); - if (nnode == -FDT_ERR_EXISTS) { - nnode = fdt_subnode_offset(fdt, target, name); - if (nnode == -FDT_ERR_NOTFOUND) - return -FDT_ERR_INTERNAL; - } - - if (nnode < 0) - return nnode; - - ret = overlay_apply_node(fdt, nnode, fdto, subnode); - if (ret) - return ret; - } - - return 0; -} - -/** - * overlay_merge - Merge an overlay into its base device tree - * @fdt: Base Device Tree blob - * @fdto: Device tree overlay blob - * - * overlay_merge() merges an overlay into its base device tree. - * - * This is the next to last step in the device tree overlay application - * process, when all the phandles have been adjusted and resolved and - * you just have to merge overlay into the base device tree. - * - * returns: - * 0 on success - * Negative error code on failure - */ -static int overlay_merge(void *fdt, void *fdto) -{ - int fragment; - - fdt_for_each_subnode(fragment, fdto, 0) { - int overlay; - int target; - int ret; - - /* - * Each fragments will have an __overlay__ node. If - * they don't, it's not supposed to be merged - */ - overlay = fdt_subnode_offset(fdto, fragment, "__overlay__"); - if (overlay == -FDT_ERR_NOTFOUND) - continue; - - if (overlay < 0) - return overlay; - - target = overlay_get_target(fdt, fdto, fragment, NULL); - if (target < 0) - return target; - - ret = overlay_apply_node(fdt, target, fdto, overlay); - if (ret) - return ret; - } - - return 0; -} - -static int get_path_len(const void *fdt, int nodeoffset) -{ - int len = 0, namelen; - const char *name; - - FDT_CHECK_HEADER(fdt); - - for (;;) { - name = fdt_get_name(fdt, nodeoffset, &namelen); - if (!name) - return namelen; - - /* root? we're done */ - if (namelen == 0) - break; - - nodeoffset = fdt_parent_offset(fdt, nodeoffset); - if (nodeoffset < 0) - return nodeoffset; - len += namelen + 1; - } - - /* in case of root pretend it's "/" */ - if (len == 0) - len++; - return len; -} - -/** - * overlay_symbol_update - Update the symbols of base tree after a merge - * @fdt: Base Device Tree blob - * @fdto: Device tree overlay blob - * - * overlay_symbol_update() updates the symbols of the base tree with the - * symbols of the applied overlay - * - * This is the last step in the device tree overlay application - * process, allowing the reference of overlay symbols by subsequent - * overlay operations. - * - * returns: - * 0 on success - * Negative error code on failure - */ -static int overlay_symbol_update(void *fdt, void *fdto) -{ - int root_sym, ov_sym, prop, path_len, fragment, target; - int len, frag_name_len, ret, rel_path_len; - const char *s, *e; - const char *path; - const char *name; - const char *frag_name; - const char *rel_path; - const char *target_path; - char *buf; - void *p; - - ov_sym = fdt_subnode_offset(fdto, 0, "__symbols__"); - - /* if no overlay symbols exist no problem */ - if (ov_sym < 0) - return 0; - - root_sym = fdt_subnode_offset(fdt, 0, "__symbols__"); - - /* it no root symbols exist we should create them */ - if (root_sym == -FDT_ERR_NOTFOUND) - root_sym = fdt_add_subnode(fdt, 0, "__symbols__"); - - /* any error is fatal now */ - if (root_sym < 0) - return root_sym; - - /* iterate over each overlay symbol */ - fdt_for_each_property_offset(prop, fdto, ov_sym) { - path = fdt_getprop_by_offset(fdto, prop, &name, &path_len); - if (!path) - return path_len; - - /* verify it's a string property (terminated by a single \0) */ - if (path_len < 1 || memchr(path, '\0', path_len) != &path[path_len - 1]) - return -FDT_ERR_BADVALUE; - - /* keep end marker to avoid strlen() */ - e = path + path_len; - - /* format: /<fragment-name>/__overlay__/<relative-subnode-path> */ - - if (*path != '/') - return -FDT_ERR_BADVALUE; - - /* get fragment name first */ - s = strchr(path + 1, '/'); - if (!s) - return -FDT_ERR_BADOVERLAY; - - frag_name = path + 1; - frag_name_len = s - path - 1; - - /* verify format; safe since "s" lies in \0 terminated prop */ - len = sizeof("/__overlay__/") - 1; - if ((e - s) < len || memcmp(s, "/__overlay__/", len)) - return -FDT_ERR_BADOVERLAY; - - rel_path = s + len; - rel_path_len = e - rel_path; - - /* find the fragment index in which the symbol lies */ - ret = fdt_subnode_offset_namelen(fdto, 0, frag_name, - frag_name_len); - /* not found? */ - if (ret < 0) - return -FDT_ERR_BADOVERLAY; - fragment = ret; - - /* an __overlay__ subnode must exist */ - ret = fdt_subnode_offset(fdto, fragment, "__overlay__"); - if (ret < 0) - return -FDT_ERR_BADOVERLAY; - - /* get the target of the fragment */ - ret = overlay_get_target(fdt, fdto, fragment, &target_path); - if (ret < 0) - return ret; - target = ret; - - /* if we have a target path use */ - if (!target_path) { - ret = get_path_len(fdt, target); - if (ret < 0) - return ret; - len = ret; - } else { - len = strlen(target_path); - } - - ret = fdt_setprop_placeholder(fdt, root_sym, name, - len + (len > 1) + rel_path_len + 1, &p); - if (ret < 0) - return ret; - - if (!target_path) { - /* again in case setprop_placeholder changed it */ - ret = overlay_get_target(fdt, fdto, fragment, &target_path); - if (ret < 0) - return ret; - target = ret; - } - - buf = p; - if (len > 1) { /* target is not root */ - if (!target_path) { - ret = fdt_get_path(fdt, target, buf, len + 1); - if (ret < 0) - return ret; - } else - memcpy(buf, target_path, len + 1); - - } else - len--; - - buf[len] = '/'; - memcpy(buf + len + 1, rel_path, rel_path_len); - buf[len + 1 + rel_path_len] = '\0'; - } - - return 0; -} - -int fdt_overlay_apply(void *fdt, void *fdto) -{ - uint32_t delta = fdt_get_max_phandle(fdt); - int ret; - - FDT_CHECK_HEADER(fdt); - FDT_CHECK_HEADER(fdto); - - ret = overlay_adjust_local_phandles(fdto, delta); - if (ret) - goto err; - - ret = overlay_update_local_references(fdto, delta); - if (ret) - goto err; - - ret = overlay_fixup_phandles(fdt, fdto); - if (ret) - goto err; - - ret = overlay_merge(fdt, fdto); - if (ret) - goto err; - - ret = overlay_symbol_update(fdt, fdto); - if (ret) - goto err; - - /* - * The overlay has been damaged, erase its magic. - */ - fdt_set_magic(fdto, ~0); - - return 0; - -err: - /* - * The overlay might have been damaged, erase its magic. - */ - fdt_set_magic(fdto, ~0); - - /* - * The base device tree might have been damaged, erase its - * magic. - */ - fdt_set_magic(fdt, ~0); - - return ret; -} +#include <linux/libfdt_env.h> +#include "../../scripts/dtc/libfdt/fdt_overlay.c" |