diff options
author | Simon Glass <sjg@chromium.org> | 2015-06-23 15:38:27 -0600 |
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committer | Simon Glass <sjg@chromium.org> | 2015-07-21 17:39:20 -0600 |
commit | c3c4c00563abfca63f5b846f4f4f6fc390e58563 (patch) | |
tree | 756cd781da4f729c2fb3cc5f63ff06f8a18d101a /lib/libfdt | |
parent | 8f6e2e1ee17bb1ecce03518b8eceda6965617477 (diff) | |
download | u-boot-c3c4c00563abfca63f5b846f4f4f6fc390e58563.zip u-boot-c3c4c00563abfca63f5b846f4f4f6fc390e58563.tar.gz u-boot-c3c4c00563abfca63f5b846f4f4f6fc390e58563.tar.bz2 |
fdt: Add fdt_first/next_region() functions
These have been sent upstream but not accepted to libfdt. For now, bring
these into U-Boot to enable fdtgrep to operate. We will use fdtgrep to
cut device tree files down for SPL.
Signed-off-by: Simon Glass <sjg@chromium.org>
Diffstat (limited to 'lib/libfdt')
-rw-r--r-- | lib/libfdt/Makefile | 2 | ||||
-rw-r--r-- | lib/libfdt/fdt_region.c | 492 |
2 files changed, 493 insertions, 1 deletions
diff --git a/lib/libfdt/Makefile b/lib/libfdt/Makefile index 2f5413f..934d614 100644 --- a/lib/libfdt/Makefile +++ b/lib/libfdt/Makefile @@ -6,4 +6,4 @@ # obj-y += fdt.o fdt_ro.o fdt_rw.o fdt_strerror.o fdt_sw.o fdt_wip.o \ - fdt_empty_tree.o fdt_addresses.o + fdt_empty_tree.o fdt_addresses.o fdt_region.o diff --git a/lib/libfdt/fdt_region.c b/lib/libfdt/fdt_region.c new file mode 100644 index 0000000..9fea775 --- /dev/null +++ b/lib/libfdt/fdt_region.c @@ -0,0 +1,492 @@ +/* + * libfdt - Flat Device Tree manipulation + * Copyright (C) 2013 Google, Inc + * Written by Simon Glass <sjg@chromium.org> + * SPDX-License-Identifier: GPL-2.0+ BSD-2-Clause + */ + +#include "libfdt_env.h" + +#ifndef USE_HOSTCC +#include <fdt.h> +#include <libfdt.h> +#else +#include "fdt_host.h" +#endif + +#include "libfdt_internal.h" + +/** + * fdt_add_region() - Add a new region to our list + * + * 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. + * + * @info: State information + * @offset: Start offset of region + * @size: Size of region + */ +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; +} + +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; + + /* The aliases node must come before the others */ + node_end = fdt_next_subnode(fdt, node); + if (node_end <= 0) + return -FDT_ERR_BADLAYOUT; + node_end -= sizeof(fdt32_t); + + 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 - sizeof(fdt32_t); + + 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 'end' 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 + * + * 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. + * + * @info: State information + * @depth: Current stack depth + */ +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_TOODEEP; + 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; +} |