+++ /dev/null
-// SPDX-License-Identifier: GPL-2.0+ OR BSD-2-Clause
-/*
- * libfdt - Flat Device Tree manipulation
- * Copyright (C) 2013 Google, Inc
- * Written by Simon Glass <sjg@chromium.org>
- */
-
-#include <linux/libfdt_env.h>
-
-#ifndef USE_HOSTCC
-#include <fdt.h>
-#include <linux/libfdt.h>
-#else
-#include "fdt_host.h"
-#endif
-
-#define FDT_MAX_DEPTH 32
-
-static int str_in_list(const char *str, char * const list[], int count)
-{
- int i;
-
- for (i = 0; i < count; i++)
- if (!strcmp(list[i], str))
- return 1;
-
- return 0;
-}
-
-int fdt_find_regions(const void *fdt, char * const inc[], int inc_count,
- char * const exc_prop[], int exc_prop_count,
- struct fdt_region region[], int max_regions,
- char *path, int path_len, int add_string_tab)
-{
- int stack[FDT_MAX_DEPTH] = { 0 };
- char *end;
- int nextoffset = 0;
- uint32_t tag;
- int count = 0;
- int start = -1;
- int depth = -1;
- int want = 0;
- int base = fdt_off_dt_struct(fdt);
-
- end = path;
- *end = '\0';
- do {
- const struct fdt_property *prop;
- const char *name;
- const char *str;
- int include = 0;
- int stop_at = 0;
- int offset;
- int len;
-
- offset = nextoffset;
- tag = fdt_next_tag(fdt, offset, &nextoffset);
- stop_at = nextoffset;
-
- switch (tag) {
- case FDT_PROP:
- include = want >= 2;
- stop_at = offset;
- prop = fdt_get_property_by_offset(fdt, offset, NULL);
- str = fdt_string(fdt, fdt32_to_cpu(prop->nameoff));
- if (str_in_list(str, exc_prop, exc_prop_count))
- include = 0;
- break;
-
- case FDT_NOP:
- include = want >= 2;
- stop_at = offset;
- break;
-
- case FDT_BEGIN_NODE:
- depth++;
- if (depth == FDT_MAX_DEPTH)
- return -FDT_ERR_BADSTRUCTURE;
- name = fdt_get_name(fdt, offset, &len);
- if (end - path + 2 + len >= path_len)
- return -FDT_ERR_NOSPACE;
- if (end != path + 1)
- *end++ = '/';
- strcpy(end, name);
- end += len;
- stack[depth] = want;
- if (want == 1)
- stop_at = offset;
- if (str_in_list(path, inc, inc_count))
- want = 2;
- else if (want)
- want--;
- else
- stop_at = offset;
- include = want;
- break;
-
- case FDT_END_NODE:
- /* Depth must never go below -1 */
- if (depth < 0)
- return -FDT_ERR_BADSTRUCTURE;
- include = want;
- want = stack[depth--];
- while (end > path && *--end != '/')
- ;
- *end = '\0';
- break;
-
- case FDT_END:
- include = 1;
- break;
- }
-
- if (include && start == -1) {
- /* Should we merge with previous? */
- if (count && count <= max_regions &&
- offset == region[count - 1].offset +
- region[count - 1].size - base)
- start = region[--count].offset - base;
- else
- start = offset;
- }
-
- if (!include && start != -1) {
- if (count < max_regions) {
- region[count].offset = base + start;
- region[count].size = stop_at - start;
- }
- count++;
- start = -1;
- }
- } while (tag != FDT_END);
-
- if (nextoffset != fdt_size_dt_struct(fdt))
- return -FDT_ERR_BADLAYOUT;
-
- /* Add a region for the END tag and the string table */
- if (count < max_regions) {
- region[count].offset = base + start;
- region[count].size = nextoffset - start;
- if (add_string_tab)
- region[count].size += fdt_size_dt_strings(fdt);
- }
- count++;
-
- return count;
-}
-
-/**
- * fdt_add_region() - Add a new region to our list
- * @info: State information
- * @offset: Start offset of region
- * @size: Size of region
- *
- * The region is added if there is space, but in any case we increment the
- * count. If permitted, and the new region overlaps the last one, we merge
- * them.
- */
-static int fdt_add_region(struct fdt_region_state *info, int offset, int size)
-{
- struct fdt_region *reg;
-
- reg = info->region ? &info->region[info->count - 1] : NULL;
- if (info->can_merge && info->count &&
- info->count <= info->max_regions &&
- reg && offset <= reg->offset + reg->size) {
- reg->size = offset + size - reg->offset;
- } else if (info->count++ < info->max_regions) {
- if (reg) {
- reg++;
- reg->offset = offset;
- reg->size = size;
- }
- } else {
- return -1;
- }
-
- return 0;
-}
-
-static int region_list_contains_offset(struct fdt_region_state *info,
- const void *fdt, int target)
-{
- struct fdt_region *reg;
- int num;
-
- target += fdt_off_dt_struct(fdt);
- for (reg = info->region, num = 0; num < info->count; reg++, num++) {
- if (target >= reg->offset && target < reg->offset + reg->size)
- return 1;
- }
-
- return 0;
-}
-
-/**
- * fdt_add_alias_regions() - Add regions covering the aliases that we want
- *
- * The /aliases node is not automatically included by fdtgrep unless the
- * command-line arguments cause to be included (or not excluded). However
- * aliases are special in that we generally want to include those which
- * reference a node that fdtgrep includes.
- *
- * In fact we want to include only aliases for those nodes still included in
- * the fdt, and drop the other aliases since they point to nodes that will not
- * be present.
- *
- * This function scans the aliases and adds regions for those which we want
- * to keep.
- *
- * @fdt: Device tree to scan
- * @region: List of regions
- * @count: Number of regions in the list so far (i.e. starting point for this
- * function)
- * @max_regions: Maximum number of regions in @region list
- * @info: Place to put the region state
- * @return number of regions after processing, or -FDT_ERR_NOSPACE if we did
- * not have enough room in the regions table for the regions we wanted to add.
- */
-int fdt_add_alias_regions(const void *fdt, struct fdt_region *region, int count,
- int max_regions, struct fdt_region_state *info)
-{
- int base = fdt_off_dt_struct(fdt);
- int node, node_end, offset;
- int did_alias_header;
-
- node = fdt_subnode_offset(fdt, 0, "aliases");
- if (node < 0)
- return -FDT_ERR_NOTFOUND;
-
- /*
- * Find the next node so that we know where the /aliases node ends. We
- * need special handling if /aliases is the last node.
- */
- node_end = fdt_next_subnode(fdt, node);
- if (node_end == -FDT_ERR_NOTFOUND)
- /* Move back to the FDT_END_NODE tag of '/' */
- node_end = fdt_size_dt_struct(fdt) - sizeof(fdt32_t) * 2;
- else if (node_end < 0) /* other error */
- return node_end;
- node_end -= sizeof(fdt32_t); /* Move to FDT_END_NODE tag of /aliases */
-
- did_alias_header = 0;
- info->region = region;
- info->count = count;
- info->can_merge = 0;
- info->max_regions = max_regions;
-
- for (offset = fdt_first_property_offset(fdt, node);
- offset >= 0;
- offset = fdt_next_property_offset(fdt, offset)) {
- const struct fdt_property *prop;
- const char *name;
- int target, next;
-
- prop = fdt_get_property_by_offset(fdt, offset, NULL);
- name = fdt_string(fdt, fdt32_to_cpu(prop->nameoff));
- target = fdt_path_offset(fdt, name);
- if (!region_list_contains_offset(info, fdt, target))
- continue;
- next = fdt_next_property_offset(fdt, offset);
- if (next < 0)
- next = node_end;
-
- if (!did_alias_header) {
- fdt_add_region(info, base + node, 12);
- did_alias_header = 1;
- }
- fdt_add_region(info, base + offset, next - offset);
- }
-
- /* Add the FDT_END_NODE tag */
- if (did_alias_header)
- fdt_add_region(info, base + node_end, sizeof(fdt32_t));
-
- return info->count < max_regions ? info->count : -FDT_ERR_NOSPACE;
-}
-
-/**
- * fdt_include_supernodes() - Include supernodes required by this node
- * @info: State information
- * @depth: Current stack depth
- *
- * When we decided to include a node or property which is not at the top
- * level, this function forces the inclusion of higher level nodes. For
- * example, given this tree:
- *
- * / {
- * testing {
- * }
- * }
- *
- * If we decide to include testing then we need the root node to have a valid
- * tree. This function adds those regions.
- */
-static int fdt_include_supernodes(struct fdt_region_state *info, int depth)
-{
- int base = fdt_off_dt_struct(info->fdt);
- int start, stop_at;
- int i;
-
- /*
- * Work down the stack looking for supernodes that we didn't include.
- * The algortihm here is actually pretty simple, since we know that
- * no previous subnode had to include these nodes, or if it did, we
- * marked them as included (on the stack) already.
- */
- for (i = 0; i <= depth; i++) {
- if (!info->stack[i].included) {
- start = info->stack[i].offset;
-
- /* Add the FDT_BEGIN_NODE tag of this supernode */
- fdt_next_tag(info->fdt, start, &stop_at);
- if (fdt_add_region(info, base + start, stop_at - start))
- return -1;
-
- /* Remember that this supernode is now included */
- info->stack[i].included = 1;
- info->can_merge = 1;
- }
-
- /* Force (later) generation of the FDT_END_NODE tag */
- if (!info->stack[i].want)
- info->stack[i].want = WANT_NODES_ONLY;
- }
-
- return 0;
-}
-
-enum {
- FDT_DONE_NOTHING,
- FDT_DONE_MEM_RSVMAP,
- FDT_DONE_STRUCT,
- FDT_DONE_END,
- FDT_DONE_STRINGS,
- FDT_DONE_ALL,
-};
-
-int fdt_first_region(const void *fdt,
- int (*h_include)(void *priv, const void *fdt, int offset,
- int type, const char *data, int size),
- void *priv, struct fdt_region *region,
- char *path, int path_len, int flags,
- struct fdt_region_state *info)
-{
- struct fdt_region_ptrs *p = &info->ptrs;
-
- /* Set up our state */
- info->fdt = fdt;
- info->can_merge = 1;
- info->max_regions = 1;
- info->start = -1;
- p->want = WANT_NOTHING;
- p->end = path;
- *p->end = '\0';
- p->nextoffset = 0;
- p->depth = -1;
- p->done = FDT_DONE_NOTHING;
-
- return fdt_next_region(fdt, h_include, priv, region,
- path, path_len, flags, info);
-}
-
-/***********************************************************************
- *
- * Theory of operation
- *
- * Note: in this description 'included' means that a node (or other part
- * of the tree) should be included in the region list, i.e. it will have
- * a region which covers its part of the tree.
- *
- * This function maintains some state from the last time it is called.
- * It checks the next part of the tree that it is supposed to look at
- * (p.nextoffset) to see if that should be included or not. When it
- * finds something to include, it sets info->start to its offset. This
- * marks the start of the region we want to include.
- *
- * Once info->start is set to the start (i.e. not -1), we continue
- * scanning until we find something that we don't want included. This
- * will be the end of a region. At this point we can close off the
- * region and add it to the list. So we do so, and reset info->start
- * to -1.
- *
- * One complication here is that we want to merge regions. So when we
- * come to add another region later, we may in fact merge it with the
- * previous one if one ends where the other starts.
- *
- * The function fdt_add_region() will return -1 if it fails to add the
- * region, because we already have a region ready to be returned, and
- * the new one cannot be merged in with it. In this case, we must return
- * the region we found, and wait for another call to this function.
- * When it comes, we will repeat the processing of the tag and again
- * try to add a region. This time it will succeed.
- *
- * The current state of the pointers (stack, offset, etc.) is maintained
- * in a ptrs member. At the start of every loop iteration we make a copy
- * of it. The copy is then updated as the tag is processed. Only if we
- * get to the end of the loop iteration (and successfully call
- * fdt_add_region() if we need to) can we commit the changes we have
- * made to these pointers. For example, if we see an FDT_END_NODE tag,
- * we will decrement the depth value. But if we need to add a region
- * for this tag (let's say because the previous tag is included and this
- * FDT_END_NODE tag is not included) then we will only commit the result
- * if we were able to add the region. That allows us to retry again next
- * time.
- *
- * We keep track of a variable called 'want' which tells us what we want
- * to include when there is no specific information provided by the
- * h_include function for a particular property. This basically handles
- * the inclusion of properties which are pulled in by virtue of the node
- * they are in. So if you include a node, its properties are also
- * included. In this case 'want' will be WANT_NODES_AND_PROPS. The
- * FDT_REG_DIRECT_SUBNODES feature also makes use of 'want'. While we
- * are inside the subnode, 'want' will be set to WANT_NODES_ONLY, so
- * that only the subnode's FDT_BEGIN_NODE and FDT_END_NODE tags will be
- * included, and properties will be skipped. If WANT_NOTHING is
- * selected, then we will just rely on what the h_include() function
- * tells us.
- *
- * Using 'want' we work out 'include', which tells us whether this
- * current tag should be included or not. As you can imagine, if the
- * value of 'include' changes, that means we are on a boundary between
- * nodes to include and nodes to exclude. At this point we either close
- * off a previous region and add it to the list, or mark the start of a
- * new region.
- *
- * Apart from the nodes, we have mem_rsvmap, the FDT_END tag and the
- * string list. Each of these dealt with as a whole (i.e. we create a
- * region for each if it is to be included). For mem_rsvmap we don't
- * allow it to merge with the first struct region. For the stringlist,
- * we don't allow it to merge with the last struct region (which
- * contains at minimum the FDT_END tag).
- *
- *********************************************************************/
-
-int fdt_next_region(const void *fdt,
- int (*h_include)(void *priv, const void *fdt, int offset,
- int type, const char *data, int size),
- void *priv, struct fdt_region *region,
- char *path, int path_len, int flags,
- struct fdt_region_state *info)
-{
- int base = fdt_off_dt_struct(fdt);
- int last_node = 0;
- const char *str;
-
- info->region = region;
- info->count = 0;
- if (info->ptrs.done < FDT_DONE_MEM_RSVMAP &&
- (flags & FDT_REG_ADD_MEM_RSVMAP)) {
- /* Add the memory reserve map into its own region */
- if (fdt_add_region(info, fdt_off_mem_rsvmap(fdt),
- fdt_off_dt_struct(fdt) -
- fdt_off_mem_rsvmap(fdt)))
- return 0;
- info->can_merge = 0; /* Don't allow merging with this */
- info->ptrs.done = FDT_DONE_MEM_RSVMAP;
- }
-
- /*
- * Work through the tags one by one, deciding whether each needs to
- * be included or not. We set the variable 'include' to indicate our
- * decision. 'want' is used to track what we want to include - it
- * allows us to pick up all the properties (and/or subnode tags) of
- * a node.
- */
- while (info->ptrs.done < FDT_DONE_STRUCT) {
- const struct fdt_property *prop;
- struct fdt_region_ptrs p;
- const char *name;
- int include = 0;
- int stop_at = 0;
- uint32_t tag;
- int offset;
- int val;
- int len;
-
- /*
- * Make a copy of our pointers. If we make it to the end of
- * this block then we will commit them back to info->ptrs.
- * Otherwise we can try again from the same starting state
- * next time we are called.
- */
- p = info->ptrs;
-
- /*
- * Find the tag, and the offset of the next one. If we need to
- * stop including tags, then by default we stop *after*
- * including the current tag
- */
- offset = p.nextoffset;
- tag = fdt_next_tag(fdt, offset, &p.nextoffset);
- stop_at = p.nextoffset;
-
- switch (tag) {
- case FDT_PROP:
- stop_at = offset;
- prop = fdt_get_property_by_offset(fdt, offset, NULL);
- str = fdt_string(fdt, fdt32_to_cpu(prop->nameoff));
- val = h_include(priv, fdt, last_node, FDT_IS_PROP, str,
- strlen(str) + 1);
- if (val == -1) {
- include = p.want >= WANT_NODES_AND_PROPS;
- } else {
- include = val;
- /*
- * Make sure we include the } for this block.
- * It might be more correct to have this done
- * by the call to fdt_include_supernodes() in
- * the case where it adds the node we are
- * currently in, but this is equivalent.
- */
- if ((flags & FDT_REG_SUPERNODES) && val &&
- !p.want)
- p.want = WANT_NODES_ONLY;
- }
-
- /* Value grepping is not yet supported */
- break;
-
- case FDT_NOP:
- include = p.want >= WANT_NODES_AND_PROPS;
- stop_at = offset;
- break;
-
- case FDT_BEGIN_NODE:
- last_node = offset;
- p.depth++;
- if (p.depth == FDT_MAX_DEPTH)
- return -FDT_ERR_BADSTRUCTURE;
- name = fdt_get_name(fdt, offset, &len);
- if (p.end - path + 2 + len >= path_len)
- return -FDT_ERR_NOSPACE;
-
- /* Build the full path of this node */
- if (p.end != path + 1)
- *p.end++ = '/';
- strcpy(p.end, name);
- p.end += len;
- info->stack[p.depth].want = p.want;
- info->stack[p.depth].offset = offset;
-
- /*
- * If we are not intending to include this node unless
- * it matches, make sure we stop *before* its tag.
- */
- if (p.want == WANT_NODES_ONLY ||
- !(flags & (FDT_REG_DIRECT_SUBNODES |
- FDT_REG_ALL_SUBNODES))) {
- stop_at = offset;
- p.want = WANT_NOTHING;
- }
- val = h_include(priv, fdt, offset, FDT_IS_NODE, path,
- p.end - path + 1);
-
- /* Include this if requested */
- if (val) {
- p.want = (flags & FDT_REG_ALL_SUBNODES) ?
- WANT_ALL_NODES_AND_PROPS :
- WANT_NODES_AND_PROPS;
- }
-
- /* If not requested, decay our 'p.want' value */
- else if (p.want) {
- if (p.want != WANT_ALL_NODES_AND_PROPS)
- p.want--;
-
- /* Not including this tag, so stop now */
- } else {
- stop_at = offset;
- }
-
- /*
- * Decide whether to include this tag, and update our
- * stack with the state for this node
- */
- include = p.want;
- info->stack[p.depth].included = include;
- break;
-
- case FDT_END_NODE:
- include = p.want;
- if (p.depth < 0)
- return -FDT_ERR_BADSTRUCTURE;
-
- /*
- * If we don't want this node, stop right away, unless
- * we are including subnodes
- */
- if (!p.want && !(flags & FDT_REG_DIRECT_SUBNODES))
- stop_at = offset;
- p.want = info->stack[p.depth].want;
- p.depth--;
- while (p.end > path && *--p.end != '/')
- ;
- *p.end = '\0';
- break;
-
- case FDT_END:
- /* We always include the end tag */
- include = 1;
- p.done = FDT_DONE_STRUCT;
- break;
- }
-
- /* If this tag is to be included, mark it as region start */
- if (include && info->start == -1) {
- /* Include any supernodes required by this one */
- if (flags & FDT_REG_SUPERNODES) {
- if (fdt_include_supernodes(info, p.depth))
- return 0;
- }
- info->start = offset;
- }
-
- /*
- * If this tag is not to be included, finish up the current
- * region.
- */
- if (!include && info->start != -1) {
- if (fdt_add_region(info, base + info->start,
- stop_at - info->start))
- return 0;
- info->start = -1;
- info->can_merge = 1;
- }
-
- /* If we have made it this far, we can commit our pointers */
- info->ptrs = p;
- }
-
- /* Add a region for the END tag and a separate one for string table */
- if (info->ptrs.done < FDT_DONE_END) {
- if (info->ptrs.nextoffset != fdt_size_dt_struct(fdt))
- return -FDT_ERR_BADSTRUCTURE;
-
- if (fdt_add_region(info, base + info->start,
- info->ptrs.nextoffset - info->start))
- return 0;
- info->ptrs.done++;
- }
- if (info->ptrs.done < FDT_DONE_STRINGS) {
- if (flags & FDT_REG_ADD_STRING_TAB) {
- info->can_merge = 0;
- if (fdt_off_dt_strings(fdt) <
- base + info->ptrs.nextoffset)
- return -FDT_ERR_BADLAYOUT;
- if (fdt_add_region(info, fdt_off_dt_strings(fdt),
- fdt_size_dt_strings(fdt)))
- return 0;
- }
- info->ptrs.done++;
- }
-
- return info->count > 0 ? 0 : -FDT_ERR_NOTFOUND;
-}
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