]>
git.ipfire.org Git - people/ms/u-boot.git/blob - lib/libfdt/fdt_region.c
2 * libfdt - Flat Device Tree manipulation
3 * Copyright (C) 2013 Google, Inc
4 * Written by Simon Glass <sjg@chromium.org>
5 * SPDX-License-Identifier: GPL-2.0+ BSD-2-Clause
8 #include <libfdt_env.h>
17 #include "libfdt_internal.h"
19 #define FDT_MAX_DEPTH 32
21 static int str_in_list(const char *str
, char * const list
[], int count
)
25 for (i
= 0; i
< count
; i
++)
26 if (!strcmp(list
[i
], str
))
32 int fdt_find_regions(const void *fdt
, char * const inc
[], int inc_count
,
33 char * const exc_prop
[], int exc_prop_count
,
34 struct fdt_region region
[], int max_regions
,
35 char *path
, int path_len
, int add_string_tab
)
37 int stack
[FDT_MAX_DEPTH
] = { 0 };
45 int base
= fdt_off_dt_struct(fdt
);
50 const struct fdt_property
*prop
;
59 tag
= fdt_next_tag(fdt
, offset
, &nextoffset
);
66 prop
= fdt_get_property_by_offset(fdt
, offset
, NULL
);
67 str
= fdt_string(fdt
, fdt32_to_cpu(prop
->nameoff
));
68 if (str_in_list(str
, exc_prop
, exc_prop_count
))
79 if (depth
== FDT_MAX_DEPTH
)
80 return -FDT_ERR_BADSTRUCTURE
;
81 name
= fdt_get_name(fdt
, offset
, &len
);
82 if (end
- path
+ 2 + len
>= path_len
)
83 return -FDT_ERR_NOSPACE
;
91 if (str_in_list(path
, inc
, inc_count
))
102 want
= stack
[depth
--];
103 while (end
> path
&& *--end
!= '/')
113 if (include
&& start
== -1) {
114 /* Should we merge with previous? */
115 if (count
&& count
<= max_regions
&&
116 offset
== region
[count
- 1].offset
+
117 region
[count
- 1].size
- base
)
118 start
= region
[--count
].offset
- base
;
123 if (!include
&& start
!= -1) {
124 if (count
< max_regions
) {
125 region
[count
].offset
= base
+ start
;
126 region
[count
].size
= stop_at
- start
;
131 } while (tag
!= FDT_END
);
133 if (nextoffset
!= fdt_size_dt_struct(fdt
))
134 return -FDT_ERR_BADLAYOUT
;
136 /* Add a region for the END tag and the string table */
137 if (count
< max_regions
) {
138 region
[count
].offset
= base
+ start
;
139 region
[count
].size
= nextoffset
- start
;
141 region
[count
].size
+= fdt_size_dt_strings(fdt
);
149 * fdt_add_region() - Add a new region to our list
150 * @info: State information
151 * @offset: Start offset of region
152 * @size: Size of region
154 * The region is added if there is space, but in any case we increment the
155 * count. If permitted, and the new region overlaps the last one, we merge
158 static int fdt_add_region(struct fdt_region_state
*info
, int offset
, int size
)
160 struct fdt_region
*reg
;
162 reg
= info
->region
? &info
->region
[info
->count
- 1] : NULL
;
163 if (info
->can_merge
&& info
->count
&&
164 info
->count
<= info
->max_regions
&&
165 reg
&& offset
<= reg
->offset
+ reg
->size
) {
166 reg
->size
= offset
+ size
- reg
->offset
;
167 } else if (info
->count
++ < info
->max_regions
) {
170 reg
->offset
= offset
;
180 static int region_list_contains_offset(struct fdt_region_state
*info
,
181 const void *fdt
, int target
)
183 struct fdt_region
*reg
;
186 target
+= fdt_off_dt_struct(fdt
);
187 for (reg
= info
->region
, num
= 0; num
< info
->count
; reg
++, num
++) {
188 if (target
>= reg
->offset
&& target
< reg
->offset
+ reg
->size
)
196 * fdt_add_alias_regions() - Add regions covering the aliases that we want
198 * The /aliases node is not automatically included by fdtgrep unless the
199 * command-line arguments cause to be included (or not excluded). However
200 * aliases are special in that we generally want to include those which
201 * reference a node that fdtgrep includes.
203 * In fact we want to include only aliases for those nodes still included in
204 * the fdt, and drop the other aliases since they point to nodes that will not
207 * This function scans the aliases and adds regions for those which we want
210 * @fdt: Device tree to scan
211 * @region: List of regions
212 * @count: Number of regions in the list so far (i.e. starting point for this
214 * @max_regions: Maximum number of regions in @region list
215 * @info: Place to put the region state
216 * @return number of regions after processing, or -FDT_ERR_NOSPACE if we did
217 * not have enough room in the regions table for the regions we wanted to add.
219 int fdt_add_alias_regions(const void *fdt
, struct fdt_region
*region
, int count
,
220 int max_regions
, struct fdt_region_state
*info
)
222 int base
= fdt_off_dt_struct(fdt
);
223 int node
, node_end
, offset
;
224 int did_alias_header
;
226 node
= fdt_subnode_offset(fdt
, 0, "aliases");
228 return -FDT_ERR_NOTFOUND
;
231 * Find the next node so that we know where the /aliases node ends. We
232 * need special handling if /aliases is the last node.
234 node_end
= fdt_next_subnode(fdt
, node
);
235 if (node_end
== -FDT_ERR_NOTFOUND
)
236 /* Move back to the FDT_END_NODE tag of '/' */
237 node_end
= fdt_size_dt_struct(fdt
) - sizeof(fdt32_t
) * 2;
238 else if (node_end
< 0) /* other error */
240 node_end
-= sizeof(fdt32_t
); /* Move to FDT_END_NODE tag of /aliases */
242 did_alias_header
= 0;
243 info
->region
= region
;
246 info
->max_regions
= max_regions
;
248 for (offset
= fdt_first_property_offset(fdt
, node
);
250 offset
= fdt_next_property_offset(fdt
, offset
)) {
251 const struct fdt_property
*prop
;
255 prop
= fdt_get_property_by_offset(fdt
, offset
, NULL
);
256 name
= fdt_string(fdt
, fdt32_to_cpu(prop
->nameoff
));
257 target
= fdt_path_offset(fdt
, name
);
258 if (!region_list_contains_offset(info
, fdt
, target
))
260 next
= fdt_next_property_offset(fdt
, offset
);
264 if (!did_alias_header
) {
265 fdt_add_region(info
, base
+ node
, 12);
266 did_alias_header
= 1;
268 fdt_add_region(info
, base
+ offset
, next
- offset
);
271 /* Add the FDT_END_NODE tag */
272 if (did_alias_header
)
273 fdt_add_region(info
, base
+ node_end
, sizeof(fdt32_t
));
275 return info
->count
< max_regions
? info
->count
: -FDT_ERR_NOSPACE
;
279 * fdt_include_supernodes() - Include supernodes required by this node
280 * @info: State information
281 * @depth: Current stack depth
283 * When we decided to include a node or property which is not at the top
284 * level, this function forces the inclusion of higher level nodes. For
285 * example, given this tree:
292 * If we decide to include testing then we need the root node to have a valid
293 * tree. This function adds those regions.
295 static int fdt_include_supernodes(struct fdt_region_state
*info
, int depth
)
297 int base
= fdt_off_dt_struct(info
->fdt
);
302 * Work down the stack looking for supernodes that we didn't include.
303 * The algortihm here is actually pretty simple, since we know that
304 * no previous subnode had to include these nodes, or if it did, we
305 * marked them as included (on the stack) already.
307 for (i
= 0; i
<= depth
; i
++) {
308 if (!info
->stack
[i
].included
) {
309 start
= info
->stack
[i
].offset
;
311 /* Add the FDT_BEGIN_NODE tag of this supernode */
312 fdt_next_tag(info
->fdt
, start
, &stop_at
);
313 if (fdt_add_region(info
, base
+ start
, stop_at
- start
))
316 /* Remember that this supernode is now included */
317 info
->stack
[i
].included
= 1;
321 /* Force (later) generation of the FDT_END_NODE tag */
322 if (!info
->stack
[i
].want
)
323 info
->stack
[i
].want
= WANT_NODES_ONLY
;
338 int fdt_first_region(const void *fdt
,
339 int (*h_include
)(void *priv
, const void *fdt
, int offset
,
340 int type
, const char *data
, int size
),
341 void *priv
, struct fdt_region
*region
,
342 char *path
, int path_len
, int flags
,
343 struct fdt_region_state
*info
)
345 struct fdt_region_ptrs
*p
= &info
->ptrs
;
347 /* Set up our state */
350 info
->max_regions
= 1;
352 p
->want
= WANT_NOTHING
;
357 p
->done
= FDT_DONE_NOTHING
;
359 return fdt_next_region(fdt
, h_include
, priv
, region
,
360 path
, path_len
, flags
, info
);
363 /***********************************************************************
365 * Theory of operation
367 * Note: in this description 'included' means that a node (or other part
368 * of the tree) should be included in the region list, i.e. it will have
369 * a region which covers its part of the tree.
371 * This function maintains some state from the last time it is called.
372 * It checks the next part of the tree that it is supposed to look at
373 * (p.nextoffset) to see if that should be included or not. When it
374 * finds something to include, it sets info->start to its offset. This
375 * marks the start of the region we want to include.
377 * Once info->start is set to the start (i.e. not -1), we continue
378 * scanning until we find something that we don't want included. This
379 * will be the end of a region. At this point we can close off the
380 * region and add it to the list. So we do so, and reset info->start
383 * One complication here is that we want to merge regions. So when we
384 * come to add another region later, we may in fact merge it with the
385 * previous one if one ends where the other starts.
387 * The function fdt_add_region() will return -1 if it fails to add the
388 * region, because we already have a region ready to be returned, and
389 * the new one cannot be merged in with it. In this case, we must return
390 * the region we found, and wait for another call to this function.
391 * When it comes, we will repeat the processing of the tag and again
392 * try to add a region. This time it will succeed.
394 * The current state of the pointers (stack, offset, etc.) is maintained
395 * in a ptrs member. At the start of every loop iteration we make a copy
396 * of it. The copy is then updated as the tag is processed. Only if we
397 * get to the end of the loop iteration (and successfully call
398 * fdt_add_region() if we need to) can we commit the changes we have
399 * made to these pointers. For example, if we see an FDT_END_NODE tag,
400 * we will decrement the depth value. But if we need to add a region
401 * for this tag (let's say because the previous tag is included and this
402 * FDT_END_NODE tag is not included) then we will only commit the result
403 * if we were able to add the region. That allows us to retry again next
406 * We keep track of a variable called 'want' which tells us what we want
407 * to include when there is no specific information provided by the
408 * h_include function for a particular property. This basically handles
409 * the inclusion of properties which are pulled in by virtue of the node
410 * they are in. So if you include a node, its properties are also
411 * included. In this case 'want' will be WANT_NODES_AND_PROPS. The
412 * FDT_REG_DIRECT_SUBNODES feature also makes use of 'want'. While we
413 * are inside the subnode, 'want' will be set to WANT_NODES_ONLY, so
414 * that only the subnode's FDT_BEGIN_NODE and FDT_END_NODE tags will be
415 * included, and properties will be skipped. If WANT_NOTHING is
416 * selected, then we will just rely on what the h_include() function
419 * Using 'want' we work out 'include', which tells us whether this
420 * current tag should be included or not. As you can imagine, if the
421 * value of 'include' changes, that means we are on a boundary between
422 * nodes to include and nodes to exclude. At this point we either close
423 * off a previous region and add it to the list, or mark the start of a
426 * Apart from the nodes, we have mem_rsvmap, the FDT_END tag and the
427 * string list. Each of these dealt with as a whole (i.e. we create a
428 * region for each if it is to be included). For mem_rsvmap we don't
429 * allow it to merge with the first struct region. For the stringlist,
430 * we don't allow it to merge with the last struct region (which
431 * contains at minimum the FDT_END tag).
433 *********************************************************************/
435 int fdt_next_region(const void *fdt
,
436 int (*h_include
)(void *priv
, const void *fdt
, int offset
,
437 int type
, const char *data
, int size
),
438 void *priv
, struct fdt_region
*region
,
439 char *path
, int path_len
, int flags
,
440 struct fdt_region_state
*info
)
442 int base
= fdt_off_dt_struct(fdt
);
446 info
->region
= region
;
448 if (info
->ptrs
.done
< FDT_DONE_MEM_RSVMAP
&&
449 (flags
& FDT_REG_ADD_MEM_RSVMAP
)) {
450 /* Add the memory reserve map into its own region */
451 if (fdt_add_region(info
, fdt_off_mem_rsvmap(fdt
),
452 fdt_off_dt_struct(fdt
) -
453 fdt_off_mem_rsvmap(fdt
)))
455 info
->can_merge
= 0; /* Don't allow merging with this */
456 info
->ptrs
.done
= FDT_DONE_MEM_RSVMAP
;
460 * Work through the tags one by one, deciding whether each needs to
461 * be included or not. We set the variable 'include' to indicate our
462 * decision. 'want' is used to track what we want to include - it
463 * allows us to pick up all the properties (and/or subnode tags) of
466 while (info
->ptrs
.done
< FDT_DONE_STRUCT
) {
467 const struct fdt_property
*prop
;
468 struct fdt_region_ptrs p
;
478 * Make a copy of our pointers. If we make it to the end of
479 * this block then we will commit them back to info->ptrs.
480 * Otherwise we can try again from the same starting state
481 * next time we are called.
486 * Find the tag, and the offset of the next one. If we need to
487 * stop including tags, then by default we stop *after*
488 * including the current tag
490 offset
= p
.nextoffset
;
491 tag
= fdt_next_tag(fdt
, offset
, &p
.nextoffset
);
492 stop_at
= p
.nextoffset
;
497 prop
= fdt_get_property_by_offset(fdt
, offset
, NULL
);
498 str
= fdt_string(fdt
, fdt32_to_cpu(prop
->nameoff
));
499 val
= h_include(priv
, fdt
, last_node
, FDT_IS_PROP
, str
,
502 include
= p
.want
>= WANT_NODES_AND_PROPS
;
506 * Make sure we include the } for this block.
507 * It might be more correct to have this done
508 * by the call to fdt_include_supernodes() in
509 * the case where it adds the node we are
510 * currently in, but this is equivalent.
512 if ((flags
& FDT_REG_SUPERNODES
) && val
&&
514 p
.want
= WANT_NODES_ONLY
;
517 /* Value grepping is not yet supported */
521 include
= p
.want
>= WANT_NODES_AND_PROPS
;
528 if (p
.depth
== FDT_MAX_DEPTH
)
529 return -FDT_ERR_BADSTRUCTURE
;
530 name
= fdt_get_name(fdt
, offset
, &len
);
531 if (p
.end
- path
+ 2 + len
>= path_len
)
532 return -FDT_ERR_NOSPACE
;
534 /* Build the full path of this node */
535 if (p
.end
!= path
+ 1)
539 info
->stack
[p
.depth
].want
= p
.want
;
540 info
->stack
[p
.depth
].offset
= offset
;
543 * If we are not intending to include this node unless
544 * it matches, make sure we stop *before* its tag.
546 if (p
.want
== WANT_NODES_ONLY
||
547 !(flags
& (FDT_REG_DIRECT_SUBNODES
|
548 FDT_REG_ALL_SUBNODES
))) {
550 p
.want
= WANT_NOTHING
;
552 val
= h_include(priv
, fdt
, offset
, FDT_IS_NODE
, path
,
555 /* Include this if requested */
557 p
.want
= (flags
& FDT_REG_ALL_SUBNODES
) ?
558 WANT_ALL_NODES_AND_PROPS
:
559 WANT_NODES_AND_PROPS
;
562 /* If not requested, decay our 'p.want' value */
564 if (p
.want
!= WANT_ALL_NODES_AND_PROPS
)
567 /* Not including this tag, so stop now */
573 * Decide whether to include this tag, and update our
574 * stack with the state for this node
577 info
->stack
[p
.depth
].included
= include
;
583 return -FDT_ERR_BADSTRUCTURE
;
586 * If we don't want this node, stop right away, unless
587 * we are including subnodes
589 if (!p
.want
&& !(flags
& FDT_REG_DIRECT_SUBNODES
))
591 p
.want
= info
->stack
[p
.depth
].want
;
593 while (p
.end
> path
&& *--p
.end
!= '/')
599 /* We always include the end tag */
601 p
.done
= FDT_DONE_STRUCT
;
605 /* If this tag is to be included, mark it as region start */
606 if (include
&& info
->start
== -1) {
607 /* Include any supernodes required by this one */
608 if (flags
& FDT_REG_SUPERNODES
) {
609 if (fdt_include_supernodes(info
, p
.depth
))
612 info
->start
= offset
;
616 * If this tag is not to be included, finish up the current
619 if (!include
&& info
->start
!= -1) {
620 if (fdt_add_region(info
, base
+ info
->start
,
621 stop_at
- info
->start
))
627 /* If we have made it this far, we can commit our pointers */
631 /* Add a region for the END tag and a separate one for string table */
632 if (info
->ptrs
.done
< FDT_DONE_END
) {
633 if (info
->ptrs
.nextoffset
!= fdt_size_dt_struct(fdt
))
634 return -FDT_ERR_BADSTRUCTURE
;
636 if (fdt_add_region(info
, base
+ info
->start
,
637 info
->ptrs
.nextoffset
- info
->start
))
641 if (info
->ptrs
.done
< FDT_DONE_STRINGS
) {
642 if (flags
& FDT_REG_ADD_STRING_TAB
) {
644 if (fdt_off_dt_strings(fdt
) <
645 base
+ info
->ptrs
.nextoffset
)
646 return -FDT_ERR_BADLAYOUT
;
647 if (fdt_add_region(info
, fdt_off_dt_strings(fdt
),
648 fdt_size_dt_strings(fdt
)))
654 return info
->count
> 0 ? 0 : -FDT_ERR_NOTFOUND
;