1*db405d19SRob Herring /*
2*db405d19SRob Herring * libfdt - Flat Device Tree manipulation
3*db405d19SRob Herring * Copyright (C) 2016 Free Electrons
4*db405d19SRob Herring * Copyright (C) 2016 NextThing Co.
5*db405d19SRob Herring *
6*db405d19SRob Herring * libfdt is dual licensed: you can use it either under the terms of
7*db405d19SRob Herring * the GPL, or the BSD license, at your option.
8*db405d19SRob Herring *
9*db405d19SRob Herring * a) This library is free software; you can redistribute it and/or
10*db405d19SRob Herring * modify it under the terms of the GNU General Public License as
11*db405d19SRob Herring * published by the Free Software Foundation; either version 2 of the
12*db405d19SRob Herring * License, or (at your option) any later version.
13*db405d19SRob Herring *
14*db405d19SRob Herring * This library is distributed in the hope that it will be useful,
15*db405d19SRob Herring * but WITHOUT ANY WARRANTY; without even the implied warranty of
16*db405d19SRob Herring * MERCHANTABILITY or FITNESS FOR A PARTICULAR PURPOSE. See the
17*db405d19SRob Herring * GNU General Public License for more details.
18*db405d19SRob Herring *
19*db405d19SRob Herring * You should have received a copy of the GNU General Public
20*db405d19SRob Herring * License along with this library; if not, write to the Free
21*db405d19SRob Herring * Software Foundation, Inc., 51 Franklin St, Fifth Floor, Boston,
22*db405d19SRob Herring * MA 02110-1301 USA
23*db405d19SRob Herring *
24*db405d19SRob Herring * Alternatively,
25*db405d19SRob Herring *
26*db405d19SRob Herring * b) Redistribution and use in source and binary forms, with or
27*db405d19SRob Herring * without modification, are permitted provided that the following
28*db405d19SRob Herring * conditions are met:
29*db405d19SRob Herring *
30*db405d19SRob Herring * 1. Redistributions of source code must retain the above
31*db405d19SRob Herring * copyright notice, this list of conditions and the following
32*db405d19SRob Herring * disclaimer.
33*db405d19SRob Herring * 2. Redistributions in binary form must reproduce the above
34*db405d19SRob Herring * copyright notice, this list of conditions and the following
35*db405d19SRob Herring * disclaimer in the documentation and/or other materials
36*db405d19SRob Herring * provided with the distribution.
37*db405d19SRob Herring *
38*db405d19SRob Herring * THIS SOFTWARE IS PROVIDED BY THE COPYRIGHT HOLDERS AND
39*db405d19SRob Herring * CONTRIBUTORS "AS IS" AND ANY EXPRESS OR IMPLIED WARRANTIES,
40*db405d19SRob Herring * INCLUDING, BUT NOT LIMITED TO, THE IMPLIED WARRANTIES OF
41*db405d19SRob Herring * MERCHANTABILITY AND FITNESS FOR A PARTICULAR PURPOSE ARE
42*db405d19SRob Herring * DISCLAIMED. IN NO EVENT SHALL THE COPYRIGHT OWNER OR
43*db405d19SRob Herring * CONTRIBUTORS BE LIABLE FOR ANY DIRECT, INDIRECT, INCIDENTAL,
44*db405d19SRob Herring * SPECIAL, EXEMPLARY, OR CONSEQUENTIAL DAMAGES (INCLUDING, BUT
45*db405d19SRob Herring * NOT LIMITED TO, PROCUREMENT OF SUBSTITUTE GOODS OR SERVICES;
46*db405d19SRob Herring * LOSS OF USE, DATA, OR PROFITS; OR BUSINESS INTERRUPTION)
47*db405d19SRob Herring * HOWEVER CAUSED AND ON ANY THEORY OF LIABILITY, WHETHER IN
48*db405d19SRob Herring * CONTRACT, STRICT LIABILITY, OR TORT (INCLUDING NEGLIGENCE OR
49*db405d19SRob Herring * OTHERWISE) ARISING IN ANY WAY OUT OF THE USE OF THIS SOFTWARE,
50*db405d19SRob Herring * EVEN IF ADVISED OF THE POSSIBILITY OF SUCH DAMAGE.
51*db405d19SRob Herring */
52999a78d5SMasahiro Yamada #include "libfdt_env.h"
53999a78d5SMasahiro Yamada
54999a78d5SMasahiro Yamada #include <fdt.h>
55999a78d5SMasahiro Yamada #include <libfdt.h>
56999a78d5SMasahiro Yamada
57999a78d5SMasahiro Yamada #include "libfdt_internal.h"
58999a78d5SMasahiro Yamada
59999a78d5SMasahiro Yamada /**
60999a78d5SMasahiro Yamada * overlay_get_target_phandle - retrieves the target phandle of a fragment
61999a78d5SMasahiro Yamada * @fdto: pointer to the device tree overlay blob
62999a78d5SMasahiro Yamada * @fragment: node offset of the fragment in the overlay
63999a78d5SMasahiro Yamada *
64999a78d5SMasahiro Yamada * overlay_get_target_phandle() retrieves the target phandle of an
65999a78d5SMasahiro Yamada * overlay fragment when that fragment uses a phandle (target
66999a78d5SMasahiro Yamada * property) instead of a path (target-path property).
67999a78d5SMasahiro Yamada *
68999a78d5SMasahiro Yamada * returns:
69999a78d5SMasahiro Yamada * the phandle pointed by the target property
70999a78d5SMasahiro Yamada * 0, if the phandle was not found
71999a78d5SMasahiro Yamada * -1, if the phandle was malformed
72999a78d5SMasahiro Yamada */
overlay_get_target_phandle(const void * fdto,int fragment)73999a78d5SMasahiro Yamada static uint32_t overlay_get_target_phandle(const void *fdto, int fragment)
74999a78d5SMasahiro Yamada {
75999a78d5SMasahiro Yamada const fdt32_t *val;
76999a78d5SMasahiro Yamada int len;
77999a78d5SMasahiro Yamada
78999a78d5SMasahiro Yamada val = fdt_getprop(fdto, fragment, "target", &len);
79999a78d5SMasahiro Yamada if (!val)
80999a78d5SMasahiro Yamada return 0;
81999a78d5SMasahiro Yamada
82999a78d5SMasahiro Yamada if ((len != sizeof(*val)) || (fdt32_to_cpu(*val) == (uint32_t)-1))
83999a78d5SMasahiro Yamada return (uint32_t)-1;
84999a78d5SMasahiro Yamada
85999a78d5SMasahiro Yamada return fdt32_to_cpu(*val);
86999a78d5SMasahiro Yamada }
87999a78d5SMasahiro Yamada
88999a78d5SMasahiro Yamada /**
89999a78d5SMasahiro Yamada * overlay_get_target - retrieves the offset of a fragment's target
90999a78d5SMasahiro Yamada * @fdt: Base device tree blob
91999a78d5SMasahiro Yamada * @fdto: Device tree overlay blob
92999a78d5SMasahiro Yamada * @fragment: node offset of the fragment in the overlay
93999a78d5SMasahiro Yamada * @pathp: pointer which receives the path of the target (or NULL)
94999a78d5SMasahiro Yamada *
95999a78d5SMasahiro Yamada * overlay_get_target() retrieves the target offset in the base
96999a78d5SMasahiro Yamada * device tree of a fragment, no matter how the actual targetting is
97999a78d5SMasahiro Yamada * done (through a phandle or a path)
98999a78d5SMasahiro Yamada *
99999a78d5SMasahiro Yamada * returns:
100999a78d5SMasahiro Yamada * the targetted node offset in the base device tree
101999a78d5SMasahiro Yamada * Negative error code on error
102999a78d5SMasahiro Yamada */
overlay_get_target(const void * fdt,const void * fdto,int fragment,char const ** pathp)103999a78d5SMasahiro Yamada static int overlay_get_target(const void *fdt, const void *fdto,
104999a78d5SMasahiro Yamada int fragment, char const **pathp)
105999a78d5SMasahiro Yamada {
106999a78d5SMasahiro Yamada uint32_t phandle;
107999a78d5SMasahiro Yamada const char *path = NULL;
108999a78d5SMasahiro Yamada int path_len = 0, ret;
109999a78d5SMasahiro Yamada
110999a78d5SMasahiro Yamada /* Try first to do a phandle based lookup */
111999a78d5SMasahiro Yamada phandle = overlay_get_target_phandle(fdto, fragment);
112999a78d5SMasahiro Yamada if (phandle == (uint32_t)-1)
113999a78d5SMasahiro Yamada return -FDT_ERR_BADPHANDLE;
114999a78d5SMasahiro Yamada
115999a78d5SMasahiro Yamada /* no phandle, try path */
116999a78d5SMasahiro Yamada if (!phandle) {
117999a78d5SMasahiro Yamada /* And then a path based lookup */
118999a78d5SMasahiro Yamada path = fdt_getprop(fdto, fragment, "target-path", &path_len);
119999a78d5SMasahiro Yamada if (path)
120999a78d5SMasahiro Yamada ret = fdt_path_offset(fdt, path);
121999a78d5SMasahiro Yamada else
122999a78d5SMasahiro Yamada ret = path_len;
123999a78d5SMasahiro Yamada } else
124999a78d5SMasahiro Yamada ret = fdt_node_offset_by_phandle(fdt, phandle);
125999a78d5SMasahiro Yamada
126999a78d5SMasahiro Yamada /*
127999a78d5SMasahiro Yamada * If we haven't found either a target or a
128999a78d5SMasahiro Yamada * target-path property in a node that contains a
129999a78d5SMasahiro Yamada * __overlay__ subnode (we wouldn't be called
130999a78d5SMasahiro Yamada * otherwise), consider it a improperly written
131999a78d5SMasahiro Yamada * overlay
132999a78d5SMasahiro Yamada */
133999a78d5SMasahiro Yamada if (ret < 0 && path_len == -FDT_ERR_NOTFOUND)
134999a78d5SMasahiro Yamada ret = -FDT_ERR_BADOVERLAY;
135999a78d5SMasahiro Yamada
136999a78d5SMasahiro Yamada /* return on error */
137999a78d5SMasahiro Yamada if (ret < 0)
138999a78d5SMasahiro Yamada return ret;
139999a78d5SMasahiro Yamada
140999a78d5SMasahiro Yamada /* return pointer to path (if available) */
141999a78d5SMasahiro Yamada if (pathp)
142999a78d5SMasahiro Yamada *pathp = path ? path : NULL;
143999a78d5SMasahiro Yamada
144999a78d5SMasahiro Yamada return ret;
145999a78d5SMasahiro Yamada }
146999a78d5SMasahiro Yamada
147999a78d5SMasahiro Yamada /**
148999a78d5SMasahiro Yamada * overlay_phandle_add_offset - Increases a phandle by an offset
149999a78d5SMasahiro Yamada * @fdt: Base device tree blob
150999a78d5SMasahiro Yamada * @node: Device tree overlay blob
151999a78d5SMasahiro Yamada * @name: Name of the property to modify (phandle or linux,phandle)
152999a78d5SMasahiro Yamada * @delta: offset to apply
153999a78d5SMasahiro Yamada *
154999a78d5SMasahiro Yamada * overlay_phandle_add_offset() increments a node phandle by a given
155999a78d5SMasahiro Yamada * offset.
156999a78d5SMasahiro Yamada *
157999a78d5SMasahiro Yamada * returns:
158999a78d5SMasahiro Yamada * 0 on success.
159999a78d5SMasahiro Yamada * Negative error code on error
160999a78d5SMasahiro Yamada */
overlay_phandle_add_offset(void * fdt,int node,const char * name,uint32_t delta)161999a78d5SMasahiro Yamada static int overlay_phandle_add_offset(void *fdt, int node,
162999a78d5SMasahiro Yamada const char *name, uint32_t delta)
163999a78d5SMasahiro Yamada {
164999a78d5SMasahiro Yamada const fdt32_t *val;
165999a78d5SMasahiro Yamada uint32_t adj_val;
166999a78d5SMasahiro Yamada int len;
167999a78d5SMasahiro Yamada
168999a78d5SMasahiro Yamada val = fdt_getprop(fdt, node, name, &len);
169999a78d5SMasahiro Yamada if (!val)
170999a78d5SMasahiro Yamada return len;
171999a78d5SMasahiro Yamada
172999a78d5SMasahiro Yamada if (len != sizeof(*val))
173999a78d5SMasahiro Yamada return -FDT_ERR_BADPHANDLE;
174999a78d5SMasahiro Yamada
175999a78d5SMasahiro Yamada adj_val = fdt32_to_cpu(*val);
176999a78d5SMasahiro Yamada if ((adj_val + delta) < adj_val)
177999a78d5SMasahiro Yamada return -FDT_ERR_NOPHANDLES;
178999a78d5SMasahiro Yamada
179999a78d5SMasahiro Yamada adj_val += delta;
180999a78d5SMasahiro Yamada if (adj_val == (uint32_t)-1)
181999a78d5SMasahiro Yamada return -FDT_ERR_NOPHANDLES;
182999a78d5SMasahiro Yamada
183999a78d5SMasahiro Yamada return fdt_setprop_inplace_u32(fdt, node, name, adj_val);
184999a78d5SMasahiro Yamada }
185999a78d5SMasahiro Yamada
186999a78d5SMasahiro Yamada /**
187999a78d5SMasahiro Yamada * overlay_adjust_node_phandles - Offsets the phandles of a node
188999a78d5SMasahiro Yamada * @fdto: Device tree overlay blob
189999a78d5SMasahiro Yamada * @node: Offset of the node we want to adjust
190999a78d5SMasahiro Yamada * @delta: Offset to shift the phandles of
191999a78d5SMasahiro Yamada *
192999a78d5SMasahiro Yamada * overlay_adjust_node_phandles() adds a constant to all the phandles
193999a78d5SMasahiro Yamada * of a given node. This is mainly use as part of the overlay
194999a78d5SMasahiro Yamada * application process, when we want to update all the overlay
195999a78d5SMasahiro Yamada * phandles to not conflict with the overlays of the base device tree.
196999a78d5SMasahiro Yamada *
197999a78d5SMasahiro Yamada * returns:
198999a78d5SMasahiro Yamada * 0 on success
199999a78d5SMasahiro Yamada * Negative error code on failure
200999a78d5SMasahiro Yamada */
overlay_adjust_node_phandles(void * fdto,int node,uint32_t delta)201999a78d5SMasahiro Yamada static int overlay_adjust_node_phandles(void *fdto, int node,
202999a78d5SMasahiro Yamada uint32_t delta)
203999a78d5SMasahiro Yamada {
204999a78d5SMasahiro Yamada int child;
205999a78d5SMasahiro Yamada int ret;
206999a78d5SMasahiro Yamada
207999a78d5SMasahiro Yamada ret = overlay_phandle_add_offset(fdto, node, "phandle", delta);
208999a78d5SMasahiro Yamada if (ret && ret != -FDT_ERR_NOTFOUND)
209999a78d5SMasahiro Yamada return ret;
210999a78d5SMasahiro Yamada
211999a78d5SMasahiro Yamada ret = overlay_phandle_add_offset(fdto, node, "linux,phandle", delta);
212999a78d5SMasahiro Yamada if (ret && ret != -FDT_ERR_NOTFOUND)
213999a78d5SMasahiro Yamada return ret;
214999a78d5SMasahiro Yamada
215999a78d5SMasahiro Yamada fdt_for_each_subnode(child, fdto, node) {
216999a78d5SMasahiro Yamada ret = overlay_adjust_node_phandles(fdto, child, delta);
217999a78d5SMasahiro Yamada if (ret)
218999a78d5SMasahiro Yamada return ret;
219999a78d5SMasahiro Yamada }
220999a78d5SMasahiro Yamada
221999a78d5SMasahiro Yamada return 0;
222999a78d5SMasahiro Yamada }
223999a78d5SMasahiro Yamada
224999a78d5SMasahiro Yamada /**
225999a78d5SMasahiro Yamada * overlay_adjust_local_phandles - Adjust the phandles of a whole overlay
226999a78d5SMasahiro Yamada * @fdto: Device tree overlay blob
227999a78d5SMasahiro Yamada * @delta: Offset to shift the phandles of
228999a78d5SMasahiro Yamada *
229999a78d5SMasahiro Yamada * overlay_adjust_local_phandles() adds a constant to all the
230999a78d5SMasahiro Yamada * phandles of an overlay. This is mainly use as part of the overlay
231999a78d5SMasahiro Yamada * application process, when we want to update all the overlay
232999a78d5SMasahiro Yamada * phandles to not conflict with the overlays of the base device tree.
233999a78d5SMasahiro Yamada *
234999a78d5SMasahiro Yamada * returns:
235999a78d5SMasahiro Yamada * 0 on success
236999a78d5SMasahiro Yamada * Negative error code on failure
237999a78d5SMasahiro Yamada */
overlay_adjust_local_phandles(void * fdto,uint32_t delta)238999a78d5SMasahiro Yamada static int overlay_adjust_local_phandles(void *fdto, uint32_t delta)
239999a78d5SMasahiro Yamada {
240999a78d5SMasahiro Yamada /*
241999a78d5SMasahiro Yamada * Start adjusting the phandles from the overlay root
242999a78d5SMasahiro Yamada */
243999a78d5SMasahiro Yamada return overlay_adjust_node_phandles(fdto, 0, delta);
244999a78d5SMasahiro Yamada }
245999a78d5SMasahiro Yamada
246999a78d5SMasahiro Yamada /**
247999a78d5SMasahiro Yamada * overlay_update_local_node_references - Adjust the overlay references
248999a78d5SMasahiro Yamada * @fdto: Device tree overlay blob
249999a78d5SMasahiro Yamada * @tree_node: Node offset of the node to operate on
250999a78d5SMasahiro Yamada * @fixup_node: Node offset of the matching local fixups node
251999a78d5SMasahiro Yamada * @delta: Offset to shift the phandles of
252999a78d5SMasahiro Yamada *
253999a78d5SMasahiro Yamada * overlay_update_local_nodes_references() update the phandles
254999a78d5SMasahiro Yamada * pointing to a node within the device tree overlay by adding a
255999a78d5SMasahiro Yamada * constant delta.
256999a78d5SMasahiro Yamada *
257999a78d5SMasahiro Yamada * This is mainly used as part of a device tree application process,
258999a78d5SMasahiro Yamada * where you want the device tree overlays phandles to not conflict
259999a78d5SMasahiro Yamada * with the ones from the base device tree before merging them.
260999a78d5SMasahiro Yamada *
261999a78d5SMasahiro Yamada * returns:
262999a78d5SMasahiro Yamada * 0 on success
263999a78d5SMasahiro Yamada * Negative error code on failure
264999a78d5SMasahiro Yamada */
overlay_update_local_node_references(void * fdto,int tree_node,int fixup_node,uint32_t delta)265999a78d5SMasahiro Yamada static int overlay_update_local_node_references(void *fdto,
266999a78d5SMasahiro Yamada int tree_node,
267999a78d5SMasahiro Yamada int fixup_node,
268999a78d5SMasahiro Yamada uint32_t delta)
269999a78d5SMasahiro Yamada {
270999a78d5SMasahiro Yamada int fixup_prop;
271999a78d5SMasahiro Yamada int fixup_child;
272999a78d5SMasahiro Yamada int ret;
273999a78d5SMasahiro Yamada
274999a78d5SMasahiro Yamada fdt_for_each_property_offset(fixup_prop, fdto, fixup_node) {
275999a78d5SMasahiro Yamada const fdt32_t *fixup_val;
276999a78d5SMasahiro Yamada const char *tree_val;
277999a78d5SMasahiro Yamada const char *name;
278999a78d5SMasahiro Yamada int fixup_len;
279999a78d5SMasahiro Yamada int tree_len;
280999a78d5SMasahiro Yamada int i;
281999a78d5SMasahiro Yamada
282999a78d5SMasahiro Yamada fixup_val = fdt_getprop_by_offset(fdto, fixup_prop,
283999a78d5SMasahiro Yamada &name, &fixup_len);
284999a78d5SMasahiro Yamada if (!fixup_val)
285999a78d5SMasahiro Yamada return fixup_len;
286999a78d5SMasahiro Yamada
287999a78d5SMasahiro Yamada if (fixup_len % sizeof(uint32_t))
288999a78d5SMasahiro Yamada return -FDT_ERR_BADOVERLAY;
289999a78d5SMasahiro Yamada
290999a78d5SMasahiro Yamada tree_val = fdt_getprop(fdto, tree_node, name, &tree_len);
291999a78d5SMasahiro Yamada if (!tree_val) {
292999a78d5SMasahiro Yamada if (tree_len == -FDT_ERR_NOTFOUND)
293999a78d5SMasahiro Yamada return -FDT_ERR_BADOVERLAY;
294999a78d5SMasahiro Yamada
295999a78d5SMasahiro Yamada return tree_len;
296999a78d5SMasahiro Yamada }
297999a78d5SMasahiro Yamada
298999a78d5SMasahiro Yamada for (i = 0; i < (fixup_len / sizeof(uint32_t)); i++) {
299999a78d5SMasahiro Yamada fdt32_t adj_val;
300999a78d5SMasahiro Yamada uint32_t poffset;
301999a78d5SMasahiro Yamada
302999a78d5SMasahiro Yamada poffset = fdt32_to_cpu(fixup_val[i]);
303999a78d5SMasahiro Yamada
304999a78d5SMasahiro Yamada /*
305999a78d5SMasahiro Yamada * phandles to fixup can be unaligned.
306999a78d5SMasahiro Yamada *
307999a78d5SMasahiro Yamada * Use a memcpy for the architectures that do
308999a78d5SMasahiro Yamada * not support unaligned accesses.
309999a78d5SMasahiro Yamada */
310999a78d5SMasahiro Yamada memcpy(&adj_val, tree_val + poffset, sizeof(adj_val));
311999a78d5SMasahiro Yamada
312999a78d5SMasahiro Yamada adj_val = cpu_to_fdt32(fdt32_to_cpu(adj_val) + delta);
313999a78d5SMasahiro Yamada
314999a78d5SMasahiro Yamada ret = fdt_setprop_inplace_namelen_partial(fdto,
315999a78d5SMasahiro Yamada tree_node,
316999a78d5SMasahiro Yamada name,
317999a78d5SMasahiro Yamada strlen(name),
318999a78d5SMasahiro Yamada poffset,
319999a78d5SMasahiro Yamada &adj_val,
320999a78d5SMasahiro Yamada sizeof(adj_val));
321999a78d5SMasahiro Yamada if (ret == -FDT_ERR_NOSPACE)
322999a78d5SMasahiro Yamada return -FDT_ERR_BADOVERLAY;
323999a78d5SMasahiro Yamada
324999a78d5SMasahiro Yamada if (ret)
325999a78d5SMasahiro Yamada return ret;
326999a78d5SMasahiro Yamada }
327999a78d5SMasahiro Yamada }
328999a78d5SMasahiro Yamada
329999a78d5SMasahiro Yamada fdt_for_each_subnode(fixup_child, fdto, fixup_node) {
330999a78d5SMasahiro Yamada const char *fixup_child_name = fdt_get_name(fdto, fixup_child,
331999a78d5SMasahiro Yamada NULL);
332999a78d5SMasahiro Yamada int tree_child;
333999a78d5SMasahiro Yamada
334999a78d5SMasahiro Yamada tree_child = fdt_subnode_offset(fdto, tree_node,
335999a78d5SMasahiro Yamada fixup_child_name);
336999a78d5SMasahiro Yamada if (tree_child == -FDT_ERR_NOTFOUND)
337999a78d5SMasahiro Yamada return -FDT_ERR_BADOVERLAY;
338999a78d5SMasahiro Yamada if (tree_child < 0)
339999a78d5SMasahiro Yamada return tree_child;
340999a78d5SMasahiro Yamada
341999a78d5SMasahiro Yamada ret = overlay_update_local_node_references(fdto,
342999a78d5SMasahiro Yamada tree_child,
343999a78d5SMasahiro Yamada fixup_child,
344999a78d5SMasahiro Yamada delta);
345999a78d5SMasahiro Yamada if (ret)
346999a78d5SMasahiro Yamada return ret;
347999a78d5SMasahiro Yamada }
348999a78d5SMasahiro Yamada
349999a78d5SMasahiro Yamada return 0;
350999a78d5SMasahiro Yamada }
351999a78d5SMasahiro Yamada
352999a78d5SMasahiro Yamada /**
353999a78d5SMasahiro Yamada * overlay_update_local_references - Adjust the overlay references
354999a78d5SMasahiro Yamada * @fdto: Device tree overlay blob
355999a78d5SMasahiro Yamada * @delta: Offset to shift the phandles of
356999a78d5SMasahiro Yamada *
357999a78d5SMasahiro Yamada * overlay_update_local_references() update all the phandles pointing
358999a78d5SMasahiro Yamada * to a node within the device tree overlay by adding a constant
359999a78d5SMasahiro Yamada * delta to not conflict with the base overlay.
360999a78d5SMasahiro Yamada *
361999a78d5SMasahiro Yamada * This is mainly used as part of a device tree application process,
362999a78d5SMasahiro Yamada * where you want the device tree overlays phandles to not conflict
363999a78d5SMasahiro Yamada * with the ones from the base device tree before merging them.
364999a78d5SMasahiro Yamada *
365999a78d5SMasahiro Yamada * returns:
366999a78d5SMasahiro Yamada * 0 on success
367999a78d5SMasahiro Yamada * Negative error code on failure
368999a78d5SMasahiro Yamada */
overlay_update_local_references(void * fdto,uint32_t delta)369999a78d5SMasahiro Yamada static int overlay_update_local_references(void *fdto, uint32_t delta)
370999a78d5SMasahiro Yamada {
371999a78d5SMasahiro Yamada int fixups;
372999a78d5SMasahiro Yamada
373999a78d5SMasahiro Yamada fixups = fdt_path_offset(fdto, "/__local_fixups__");
374999a78d5SMasahiro Yamada if (fixups < 0) {
375999a78d5SMasahiro Yamada /* There's no local phandles to adjust, bail out */
376999a78d5SMasahiro Yamada if (fixups == -FDT_ERR_NOTFOUND)
377999a78d5SMasahiro Yamada return 0;
378999a78d5SMasahiro Yamada
379999a78d5SMasahiro Yamada return fixups;
380999a78d5SMasahiro Yamada }
381999a78d5SMasahiro Yamada
382999a78d5SMasahiro Yamada /*
383999a78d5SMasahiro Yamada * Update our local references from the root of the tree
384999a78d5SMasahiro Yamada */
385999a78d5SMasahiro Yamada return overlay_update_local_node_references(fdto, 0, fixups,
386999a78d5SMasahiro Yamada delta);
387999a78d5SMasahiro Yamada }
388999a78d5SMasahiro Yamada
389999a78d5SMasahiro Yamada /**
390999a78d5SMasahiro Yamada * overlay_fixup_one_phandle - Set an overlay phandle to the base one
391999a78d5SMasahiro Yamada * @fdt: Base Device Tree blob
392999a78d5SMasahiro Yamada * @fdto: Device tree overlay blob
393999a78d5SMasahiro Yamada * @symbols_off: Node offset of the symbols node in the base device tree
394999a78d5SMasahiro Yamada * @path: Path to a node holding a phandle in the overlay
395999a78d5SMasahiro Yamada * @path_len: number of path characters to consider
396999a78d5SMasahiro Yamada * @name: Name of the property holding the phandle reference in the overlay
397999a78d5SMasahiro Yamada * @name_len: number of name characters to consider
398999a78d5SMasahiro Yamada * @poffset: Offset within the overlay property where the phandle is stored
399999a78d5SMasahiro Yamada * @label: Label of the node referenced by the phandle
400999a78d5SMasahiro Yamada *
401999a78d5SMasahiro Yamada * overlay_fixup_one_phandle() resolves an overlay phandle pointing to
402999a78d5SMasahiro Yamada * a node in the base device tree.
403999a78d5SMasahiro Yamada *
404999a78d5SMasahiro Yamada * This is part of the device tree overlay application process, when
405999a78d5SMasahiro Yamada * you want all the phandles in the overlay to point to the actual
406999a78d5SMasahiro Yamada * base dt nodes.
407999a78d5SMasahiro Yamada *
408999a78d5SMasahiro Yamada * returns:
409999a78d5SMasahiro Yamada * 0 on success
410999a78d5SMasahiro Yamada * Negative error code on failure
411999a78d5SMasahiro Yamada */
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)412999a78d5SMasahiro Yamada static int overlay_fixup_one_phandle(void *fdt, void *fdto,
413999a78d5SMasahiro Yamada int symbols_off,
414999a78d5SMasahiro Yamada const char *path, uint32_t path_len,
415999a78d5SMasahiro Yamada const char *name, uint32_t name_len,
416999a78d5SMasahiro Yamada int poffset, const char *label)
417999a78d5SMasahiro Yamada {
418999a78d5SMasahiro Yamada const char *symbol_path;
419999a78d5SMasahiro Yamada uint32_t phandle;
420999a78d5SMasahiro Yamada fdt32_t phandle_prop;
421999a78d5SMasahiro Yamada int symbol_off, fixup_off;
422999a78d5SMasahiro Yamada int prop_len;
423999a78d5SMasahiro Yamada
424999a78d5SMasahiro Yamada if (symbols_off < 0)
425999a78d5SMasahiro Yamada return symbols_off;
426999a78d5SMasahiro Yamada
427999a78d5SMasahiro Yamada symbol_path = fdt_getprop(fdt, symbols_off, label,
428999a78d5SMasahiro Yamada &prop_len);
429999a78d5SMasahiro Yamada if (!symbol_path)
430999a78d5SMasahiro Yamada return prop_len;
431999a78d5SMasahiro Yamada
432999a78d5SMasahiro Yamada symbol_off = fdt_path_offset(fdt, symbol_path);
433999a78d5SMasahiro Yamada if (symbol_off < 0)
434999a78d5SMasahiro Yamada return symbol_off;
435999a78d5SMasahiro Yamada
436999a78d5SMasahiro Yamada phandle = fdt_get_phandle(fdt, symbol_off);
437999a78d5SMasahiro Yamada if (!phandle)
438999a78d5SMasahiro Yamada return -FDT_ERR_NOTFOUND;
439999a78d5SMasahiro Yamada
440999a78d5SMasahiro Yamada fixup_off = fdt_path_offset_namelen(fdto, path, path_len);
441999a78d5SMasahiro Yamada if (fixup_off == -FDT_ERR_NOTFOUND)
442999a78d5SMasahiro Yamada return -FDT_ERR_BADOVERLAY;
443999a78d5SMasahiro Yamada if (fixup_off < 0)
444999a78d5SMasahiro Yamada return fixup_off;
445999a78d5SMasahiro Yamada
446999a78d5SMasahiro Yamada phandle_prop = cpu_to_fdt32(phandle);
447999a78d5SMasahiro Yamada return fdt_setprop_inplace_namelen_partial(fdto, fixup_off,
448999a78d5SMasahiro Yamada name, name_len, poffset,
449999a78d5SMasahiro Yamada &phandle_prop,
450999a78d5SMasahiro Yamada sizeof(phandle_prop));
451999a78d5SMasahiro Yamada };
452999a78d5SMasahiro Yamada
453999a78d5SMasahiro Yamada /**
454999a78d5SMasahiro Yamada * overlay_fixup_phandle - Set an overlay phandle to the base one
455999a78d5SMasahiro Yamada * @fdt: Base Device Tree blob
456999a78d5SMasahiro Yamada * @fdto: Device tree overlay blob
457999a78d5SMasahiro Yamada * @symbols_off: Node offset of the symbols node in the base device tree
458999a78d5SMasahiro Yamada * @property: Property offset in the overlay holding the list of fixups
459999a78d5SMasahiro Yamada *
460999a78d5SMasahiro Yamada * overlay_fixup_phandle() resolves all the overlay phandles pointed
461999a78d5SMasahiro Yamada * to in a __fixups__ property, and updates them to match the phandles
462999a78d5SMasahiro Yamada * in use in the base device tree.
463999a78d5SMasahiro Yamada *
464999a78d5SMasahiro Yamada * This is part of the device tree overlay application process, when
465999a78d5SMasahiro Yamada * you want all the phandles in the overlay to point to the actual
466999a78d5SMasahiro Yamada * base dt nodes.
467999a78d5SMasahiro Yamada *
468999a78d5SMasahiro Yamada * returns:
469999a78d5SMasahiro Yamada * 0 on success
470999a78d5SMasahiro Yamada * Negative error code on failure
471999a78d5SMasahiro Yamada */
overlay_fixup_phandle(void * fdt,void * fdto,int symbols_off,int property)472999a78d5SMasahiro Yamada static int overlay_fixup_phandle(void *fdt, void *fdto, int symbols_off,
473999a78d5SMasahiro Yamada int property)
474999a78d5SMasahiro Yamada {
475999a78d5SMasahiro Yamada const char *value;
476999a78d5SMasahiro Yamada const char *label;
477999a78d5SMasahiro Yamada int len;
478999a78d5SMasahiro Yamada
479999a78d5SMasahiro Yamada value = fdt_getprop_by_offset(fdto, property,
480999a78d5SMasahiro Yamada &label, &len);
481999a78d5SMasahiro Yamada if (!value) {
482999a78d5SMasahiro Yamada if (len == -FDT_ERR_NOTFOUND)
483999a78d5SMasahiro Yamada return -FDT_ERR_INTERNAL;
484999a78d5SMasahiro Yamada
485999a78d5SMasahiro Yamada return len;
486999a78d5SMasahiro Yamada }
487999a78d5SMasahiro Yamada
488999a78d5SMasahiro Yamada do {
489999a78d5SMasahiro Yamada const char *path, *name, *fixup_end;
490999a78d5SMasahiro Yamada const char *fixup_str = value;
491999a78d5SMasahiro Yamada uint32_t path_len, name_len;
492999a78d5SMasahiro Yamada uint32_t fixup_len;
493999a78d5SMasahiro Yamada char *sep, *endptr;
494999a78d5SMasahiro Yamada int poffset, ret;
495999a78d5SMasahiro Yamada
496999a78d5SMasahiro Yamada fixup_end = memchr(value, '\0', len);
497999a78d5SMasahiro Yamada if (!fixup_end)
498999a78d5SMasahiro Yamada return -FDT_ERR_BADOVERLAY;
499999a78d5SMasahiro Yamada fixup_len = fixup_end - fixup_str;
500999a78d5SMasahiro Yamada
501999a78d5SMasahiro Yamada len -= fixup_len + 1;
502999a78d5SMasahiro Yamada value += fixup_len + 1;
503999a78d5SMasahiro Yamada
504999a78d5SMasahiro Yamada path = fixup_str;
505999a78d5SMasahiro Yamada sep = memchr(fixup_str, ':', fixup_len);
506999a78d5SMasahiro Yamada if (!sep || *sep != ':')
507999a78d5SMasahiro Yamada return -FDT_ERR_BADOVERLAY;
508999a78d5SMasahiro Yamada
509999a78d5SMasahiro Yamada path_len = sep - path;
510999a78d5SMasahiro Yamada if (path_len == (fixup_len - 1))
511999a78d5SMasahiro Yamada return -FDT_ERR_BADOVERLAY;
512999a78d5SMasahiro Yamada
513999a78d5SMasahiro Yamada fixup_len -= path_len + 1;
514999a78d5SMasahiro Yamada name = sep + 1;
515999a78d5SMasahiro Yamada sep = memchr(name, ':', fixup_len);
516999a78d5SMasahiro Yamada if (!sep || *sep != ':')
517999a78d5SMasahiro Yamada return -FDT_ERR_BADOVERLAY;
518999a78d5SMasahiro Yamada
519999a78d5SMasahiro Yamada name_len = sep - name;
520999a78d5SMasahiro Yamada if (!name_len)
521999a78d5SMasahiro Yamada return -FDT_ERR_BADOVERLAY;
522999a78d5SMasahiro Yamada
523999a78d5SMasahiro Yamada poffset = strtoul(sep + 1, &endptr, 10);
524999a78d5SMasahiro Yamada if ((*endptr != '\0') || (endptr <= (sep + 1)))
525999a78d5SMasahiro Yamada return -FDT_ERR_BADOVERLAY;
526999a78d5SMasahiro Yamada
527999a78d5SMasahiro Yamada ret = overlay_fixup_one_phandle(fdt, fdto, symbols_off,
528999a78d5SMasahiro Yamada path, path_len, name, name_len,
529999a78d5SMasahiro Yamada poffset, label);
530999a78d5SMasahiro Yamada if (ret)
531999a78d5SMasahiro Yamada return ret;
532999a78d5SMasahiro Yamada } while (len > 0);
533999a78d5SMasahiro Yamada
534999a78d5SMasahiro Yamada return 0;
535999a78d5SMasahiro Yamada }
536999a78d5SMasahiro Yamada
537999a78d5SMasahiro Yamada /**
538999a78d5SMasahiro Yamada * overlay_fixup_phandles - Resolve the overlay phandles to the base
539999a78d5SMasahiro Yamada * device tree
540999a78d5SMasahiro Yamada * @fdt: Base Device Tree blob
541999a78d5SMasahiro Yamada * @fdto: Device tree overlay blob
542999a78d5SMasahiro Yamada *
543999a78d5SMasahiro Yamada * overlay_fixup_phandles() resolves all the overlay phandles pointing
544999a78d5SMasahiro Yamada * to nodes in the base device tree.
545999a78d5SMasahiro Yamada *
546999a78d5SMasahiro Yamada * This is one of the steps of the device tree overlay application
547999a78d5SMasahiro Yamada * process, when you want all the phandles in the overlay to point to
548999a78d5SMasahiro Yamada * the actual base dt nodes.
549999a78d5SMasahiro Yamada *
550999a78d5SMasahiro Yamada * returns:
551999a78d5SMasahiro Yamada * 0 on success
552999a78d5SMasahiro Yamada * Negative error code on failure
553999a78d5SMasahiro Yamada */
overlay_fixup_phandles(void * fdt,void * fdto)554999a78d5SMasahiro Yamada static int overlay_fixup_phandles(void *fdt, void *fdto)
555999a78d5SMasahiro Yamada {
556999a78d5SMasahiro Yamada int fixups_off, symbols_off;
557999a78d5SMasahiro Yamada int property;
558999a78d5SMasahiro Yamada
559999a78d5SMasahiro Yamada /* We can have overlays without any fixups */
560999a78d5SMasahiro Yamada fixups_off = fdt_path_offset(fdto, "/__fixups__");
561999a78d5SMasahiro Yamada if (fixups_off == -FDT_ERR_NOTFOUND)
562999a78d5SMasahiro Yamada return 0; /* nothing to do */
563999a78d5SMasahiro Yamada if (fixups_off < 0)
564999a78d5SMasahiro Yamada return fixups_off;
565999a78d5SMasahiro Yamada
566999a78d5SMasahiro Yamada /* And base DTs without symbols */
567999a78d5SMasahiro Yamada symbols_off = fdt_path_offset(fdt, "/__symbols__");
568999a78d5SMasahiro Yamada if ((symbols_off < 0 && (symbols_off != -FDT_ERR_NOTFOUND)))
569999a78d5SMasahiro Yamada return symbols_off;
570999a78d5SMasahiro Yamada
571999a78d5SMasahiro Yamada fdt_for_each_property_offset(property, fdto, fixups_off) {
572999a78d5SMasahiro Yamada int ret;
573999a78d5SMasahiro Yamada
574999a78d5SMasahiro Yamada ret = overlay_fixup_phandle(fdt, fdto, symbols_off, property);
575999a78d5SMasahiro Yamada if (ret)
576999a78d5SMasahiro Yamada return ret;
577999a78d5SMasahiro Yamada }
578999a78d5SMasahiro Yamada
579999a78d5SMasahiro Yamada return 0;
580999a78d5SMasahiro Yamada }
581999a78d5SMasahiro Yamada
582999a78d5SMasahiro Yamada /**
583999a78d5SMasahiro Yamada * overlay_apply_node - Merges a node into the base device tree
584999a78d5SMasahiro Yamada * @fdt: Base Device Tree blob
585999a78d5SMasahiro Yamada * @target: Node offset in the base device tree to apply the fragment to
586999a78d5SMasahiro Yamada * @fdto: Device tree overlay blob
587999a78d5SMasahiro Yamada * @node: Node offset in the overlay holding the changes to merge
588999a78d5SMasahiro Yamada *
589999a78d5SMasahiro Yamada * overlay_apply_node() merges a node into a target base device tree
590999a78d5SMasahiro Yamada * node pointed.
591999a78d5SMasahiro Yamada *
592999a78d5SMasahiro Yamada * This is part of the final step in the device tree overlay
593999a78d5SMasahiro Yamada * application process, when all the phandles have been adjusted and
594999a78d5SMasahiro Yamada * resolved and you just have to merge overlay into the base device
595999a78d5SMasahiro Yamada * tree.
596999a78d5SMasahiro Yamada *
597999a78d5SMasahiro Yamada * returns:
598999a78d5SMasahiro Yamada * 0 on success
599999a78d5SMasahiro Yamada * Negative error code on failure
600999a78d5SMasahiro Yamada */
overlay_apply_node(void * fdt,int target,void * fdto,int node)601999a78d5SMasahiro Yamada static int overlay_apply_node(void *fdt, int target,
602999a78d5SMasahiro Yamada void *fdto, int node)
603999a78d5SMasahiro Yamada {
604999a78d5SMasahiro Yamada int property;
605999a78d5SMasahiro Yamada int subnode;
606999a78d5SMasahiro Yamada
607999a78d5SMasahiro Yamada fdt_for_each_property_offset(property, fdto, node) {
608999a78d5SMasahiro Yamada const char *name;
609999a78d5SMasahiro Yamada const void *prop;
610999a78d5SMasahiro Yamada int prop_len;
611999a78d5SMasahiro Yamada int ret;
612999a78d5SMasahiro Yamada
613999a78d5SMasahiro Yamada prop = fdt_getprop_by_offset(fdto, property, &name,
614999a78d5SMasahiro Yamada &prop_len);
615999a78d5SMasahiro Yamada if (prop_len == -FDT_ERR_NOTFOUND)
616999a78d5SMasahiro Yamada return -FDT_ERR_INTERNAL;
617999a78d5SMasahiro Yamada if (prop_len < 0)
618999a78d5SMasahiro Yamada return prop_len;
619999a78d5SMasahiro Yamada
620999a78d5SMasahiro Yamada ret = fdt_setprop(fdt, target, name, prop, prop_len);
621999a78d5SMasahiro Yamada if (ret)
622999a78d5SMasahiro Yamada return ret;
623999a78d5SMasahiro Yamada }
624999a78d5SMasahiro Yamada
625999a78d5SMasahiro Yamada fdt_for_each_subnode(subnode, fdto, node) {
626999a78d5SMasahiro Yamada const char *name = fdt_get_name(fdto, subnode, NULL);
627999a78d5SMasahiro Yamada int nnode;
628999a78d5SMasahiro Yamada int ret;
629999a78d5SMasahiro Yamada
630999a78d5SMasahiro Yamada nnode = fdt_add_subnode(fdt, target, name);
631999a78d5SMasahiro Yamada if (nnode == -FDT_ERR_EXISTS) {
632999a78d5SMasahiro Yamada nnode = fdt_subnode_offset(fdt, target, name);
633999a78d5SMasahiro Yamada if (nnode == -FDT_ERR_NOTFOUND)
634999a78d5SMasahiro Yamada return -FDT_ERR_INTERNAL;
635999a78d5SMasahiro Yamada }
636999a78d5SMasahiro Yamada
637999a78d5SMasahiro Yamada if (nnode < 0)
638999a78d5SMasahiro Yamada return nnode;
639999a78d5SMasahiro Yamada
640999a78d5SMasahiro Yamada ret = overlay_apply_node(fdt, nnode, fdto, subnode);
641999a78d5SMasahiro Yamada if (ret)
642999a78d5SMasahiro Yamada return ret;
643999a78d5SMasahiro Yamada }
644999a78d5SMasahiro Yamada
645999a78d5SMasahiro Yamada return 0;
646999a78d5SMasahiro Yamada }
647999a78d5SMasahiro Yamada
648999a78d5SMasahiro Yamada /**
649999a78d5SMasahiro Yamada * overlay_merge - Merge an overlay into its base device tree
650999a78d5SMasahiro Yamada * @fdt: Base Device Tree blob
651999a78d5SMasahiro Yamada * @fdto: Device tree overlay blob
652999a78d5SMasahiro Yamada *
653999a78d5SMasahiro Yamada * overlay_merge() merges an overlay into its base device tree.
654999a78d5SMasahiro Yamada *
655999a78d5SMasahiro Yamada * This is the next to last step in the device tree overlay application
656999a78d5SMasahiro Yamada * process, when all the phandles have been adjusted and resolved and
657999a78d5SMasahiro Yamada * you just have to merge overlay into the base device tree.
658999a78d5SMasahiro Yamada *
659999a78d5SMasahiro Yamada * returns:
660999a78d5SMasahiro Yamada * 0 on success
661999a78d5SMasahiro Yamada * Negative error code on failure
662999a78d5SMasahiro Yamada */
overlay_merge(void * fdt,void * fdto)663999a78d5SMasahiro Yamada static int overlay_merge(void *fdt, void *fdto)
664999a78d5SMasahiro Yamada {
665999a78d5SMasahiro Yamada int fragment;
666999a78d5SMasahiro Yamada
667999a78d5SMasahiro Yamada fdt_for_each_subnode(fragment, fdto, 0) {
668999a78d5SMasahiro Yamada int overlay;
669999a78d5SMasahiro Yamada int target;
670999a78d5SMasahiro Yamada int ret;
671999a78d5SMasahiro Yamada
672999a78d5SMasahiro Yamada /*
673999a78d5SMasahiro Yamada * Each fragments will have an __overlay__ node. If
674999a78d5SMasahiro Yamada * they don't, it's not supposed to be merged
675999a78d5SMasahiro Yamada */
676999a78d5SMasahiro Yamada overlay = fdt_subnode_offset(fdto, fragment, "__overlay__");
677999a78d5SMasahiro Yamada if (overlay == -FDT_ERR_NOTFOUND)
678999a78d5SMasahiro Yamada continue;
679999a78d5SMasahiro Yamada
680999a78d5SMasahiro Yamada if (overlay < 0)
681999a78d5SMasahiro Yamada return overlay;
682999a78d5SMasahiro Yamada
683999a78d5SMasahiro Yamada target = overlay_get_target(fdt, fdto, fragment, NULL);
684999a78d5SMasahiro Yamada if (target < 0)
685999a78d5SMasahiro Yamada return target;
686999a78d5SMasahiro Yamada
687999a78d5SMasahiro Yamada ret = overlay_apply_node(fdt, target, fdto, overlay);
688999a78d5SMasahiro Yamada if (ret)
689999a78d5SMasahiro Yamada return ret;
690999a78d5SMasahiro Yamada }
691999a78d5SMasahiro Yamada
692999a78d5SMasahiro Yamada return 0;
693999a78d5SMasahiro Yamada }
694999a78d5SMasahiro Yamada
get_path_len(const void * fdt,int nodeoffset)695999a78d5SMasahiro Yamada static int get_path_len(const void *fdt, int nodeoffset)
696999a78d5SMasahiro Yamada {
697999a78d5SMasahiro Yamada int len = 0, namelen;
698999a78d5SMasahiro Yamada const char *name;
699999a78d5SMasahiro Yamada
700999a78d5SMasahiro Yamada FDT_CHECK_HEADER(fdt);
701999a78d5SMasahiro Yamada
702999a78d5SMasahiro Yamada for (;;) {
703999a78d5SMasahiro Yamada name = fdt_get_name(fdt, nodeoffset, &namelen);
704999a78d5SMasahiro Yamada if (!name)
705999a78d5SMasahiro Yamada return namelen;
706999a78d5SMasahiro Yamada
707999a78d5SMasahiro Yamada /* root? we're done */
708999a78d5SMasahiro Yamada if (namelen == 0)
709999a78d5SMasahiro Yamada break;
710999a78d5SMasahiro Yamada
711999a78d5SMasahiro Yamada nodeoffset = fdt_parent_offset(fdt, nodeoffset);
712999a78d5SMasahiro Yamada if (nodeoffset < 0)
713999a78d5SMasahiro Yamada return nodeoffset;
714999a78d5SMasahiro Yamada len += namelen + 1;
715999a78d5SMasahiro Yamada }
716999a78d5SMasahiro Yamada
717999a78d5SMasahiro Yamada /* in case of root pretend it's "/" */
718999a78d5SMasahiro Yamada if (len == 0)
719999a78d5SMasahiro Yamada len++;
720999a78d5SMasahiro Yamada return len;
721999a78d5SMasahiro Yamada }
722999a78d5SMasahiro Yamada
723999a78d5SMasahiro Yamada /**
724999a78d5SMasahiro Yamada * overlay_symbol_update - Update the symbols of base tree after a merge
725999a78d5SMasahiro Yamada * @fdt: Base Device Tree blob
726999a78d5SMasahiro Yamada * @fdto: Device tree overlay blob
727999a78d5SMasahiro Yamada *
728999a78d5SMasahiro Yamada * overlay_symbol_update() updates the symbols of the base tree with the
729999a78d5SMasahiro Yamada * symbols of the applied overlay
730999a78d5SMasahiro Yamada *
731999a78d5SMasahiro Yamada * This is the last step in the device tree overlay application
732999a78d5SMasahiro Yamada * process, allowing the reference of overlay symbols by subsequent
733999a78d5SMasahiro Yamada * overlay operations.
734999a78d5SMasahiro Yamada *
735999a78d5SMasahiro Yamada * returns:
736999a78d5SMasahiro Yamada * 0 on success
737999a78d5SMasahiro Yamada * Negative error code on failure
738999a78d5SMasahiro Yamada */
overlay_symbol_update(void * fdt,void * fdto)739999a78d5SMasahiro Yamada static int overlay_symbol_update(void *fdt, void *fdto)
740999a78d5SMasahiro Yamada {
741999a78d5SMasahiro Yamada int root_sym, ov_sym, prop, path_len, fragment, target;
742999a78d5SMasahiro Yamada int len, frag_name_len, ret, rel_path_len;
743999a78d5SMasahiro Yamada const char *s, *e;
744999a78d5SMasahiro Yamada const char *path;
745999a78d5SMasahiro Yamada const char *name;
746999a78d5SMasahiro Yamada const char *frag_name;
747999a78d5SMasahiro Yamada const char *rel_path;
748999a78d5SMasahiro Yamada const char *target_path;
749999a78d5SMasahiro Yamada char *buf;
750999a78d5SMasahiro Yamada void *p;
751999a78d5SMasahiro Yamada
752999a78d5SMasahiro Yamada ov_sym = fdt_subnode_offset(fdto, 0, "__symbols__");
753999a78d5SMasahiro Yamada
754999a78d5SMasahiro Yamada /* if no overlay symbols exist no problem */
755999a78d5SMasahiro Yamada if (ov_sym < 0)
756999a78d5SMasahiro Yamada return 0;
757999a78d5SMasahiro Yamada
758999a78d5SMasahiro Yamada root_sym = fdt_subnode_offset(fdt, 0, "__symbols__");
759999a78d5SMasahiro Yamada
760999a78d5SMasahiro Yamada /* it no root symbols exist we should create them */
761999a78d5SMasahiro Yamada if (root_sym == -FDT_ERR_NOTFOUND)
762999a78d5SMasahiro Yamada root_sym = fdt_add_subnode(fdt, 0, "__symbols__");
763999a78d5SMasahiro Yamada
764999a78d5SMasahiro Yamada /* any error is fatal now */
765999a78d5SMasahiro Yamada if (root_sym < 0)
766999a78d5SMasahiro Yamada return root_sym;
767999a78d5SMasahiro Yamada
768999a78d5SMasahiro Yamada /* iterate over each overlay symbol */
769999a78d5SMasahiro Yamada fdt_for_each_property_offset(prop, fdto, ov_sym) {
770999a78d5SMasahiro Yamada path = fdt_getprop_by_offset(fdto, prop, &name, &path_len);
771999a78d5SMasahiro Yamada if (!path)
772999a78d5SMasahiro Yamada return path_len;
773999a78d5SMasahiro Yamada
774999a78d5SMasahiro Yamada /* verify it's a string property (terminated by a single \0) */
775999a78d5SMasahiro Yamada if (path_len < 1 || memchr(path, '\0', path_len) != &path[path_len - 1])
776999a78d5SMasahiro Yamada return -FDT_ERR_BADVALUE;
777999a78d5SMasahiro Yamada
778999a78d5SMasahiro Yamada /* keep end marker to avoid strlen() */
779999a78d5SMasahiro Yamada e = path + path_len;
780999a78d5SMasahiro Yamada
781999a78d5SMasahiro Yamada /* format: /<fragment-name>/__overlay__/<relative-subnode-path> */
782999a78d5SMasahiro Yamada
783999a78d5SMasahiro Yamada if (*path != '/')
784999a78d5SMasahiro Yamada return -FDT_ERR_BADVALUE;
785999a78d5SMasahiro Yamada
786999a78d5SMasahiro Yamada /* get fragment name first */
787999a78d5SMasahiro Yamada s = strchr(path + 1, '/');
788999a78d5SMasahiro Yamada if (!s)
789999a78d5SMasahiro Yamada return -FDT_ERR_BADOVERLAY;
790999a78d5SMasahiro Yamada
791999a78d5SMasahiro Yamada frag_name = path + 1;
792999a78d5SMasahiro Yamada frag_name_len = s - path - 1;
793999a78d5SMasahiro Yamada
794999a78d5SMasahiro Yamada /* verify format; safe since "s" lies in \0 terminated prop */
795999a78d5SMasahiro Yamada len = sizeof("/__overlay__/") - 1;
796999a78d5SMasahiro Yamada if ((e - s) < len || memcmp(s, "/__overlay__/", len))
797999a78d5SMasahiro Yamada return -FDT_ERR_BADOVERLAY;
798999a78d5SMasahiro Yamada
799999a78d5SMasahiro Yamada rel_path = s + len;
800999a78d5SMasahiro Yamada rel_path_len = e - rel_path;
801999a78d5SMasahiro Yamada
802999a78d5SMasahiro Yamada /* find the fragment index in which the symbol lies */
803999a78d5SMasahiro Yamada ret = fdt_subnode_offset_namelen(fdto, 0, frag_name,
804999a78d5SMasahiro Yamada frag_name_len);
805999a78d5SMasahiro Yamada /* not found? */
806999a78d5SMasahiro Yamada if (ret < 0)
807999a78d5SMasahiro Yamada return -FDT_ERR_BADOVERLAY;
808999a78d5SMasahiro Yamada fragment = ret;
809999a78d5SMasahiro Yamada
810999a78d5SMasahiro Yamada /* an __overlay__ subnode must exist */
811999a78d5SMasahiro Yamada ret = fdt_subnode_offset(fdto, fragment, "__overlay__");
812999a78d5SMasahiro Yamada if (ret < 0)
813999a78d5SMasahiro Yamada return -FDT_ERR_BADOVERLAY;
814999a78d5SMasahiro Yamada
815999a78d5SMasahiro Yamada /* get the target of the fragment */
816999a78d5SMasahiro Yamada ret = overlay_get_target(fdt, fdto, fragment, &target_path);
817999a78d5SMasahiro Yamada if (ret < 0)
818999a78d5SMasahiro Yamada return ret;
819999a78d5SMasahiro Yamada target = ret;
820999a78d5SMasahiro Yamada
821999a78d5SMasahiro Yamada /* if we have a target path use */
822999a78d5SMasahiro Yamada if (!target_path) {
823999a78d5SMasahiro Yamada ret = get_path_len(fdt, target);
824999a78d5SMasahiro Yamada if (ret < 0)
825999a78d5SMasahiro Yamada return ret;
826999a78d5SMasahiro Yamada len = ret;
827999a78d5SMasahiro Yamada } else {
828999a78d5SMasahiro Yamada len = strlen(target_path);
829999a78d5SMasahiro Yamada }
830999a78d5SMasahiro Yamada
831999a78d5SMasahiro Yamada ret = fdt_setprop_placeholder(fdt, root_sym, name,
832999a78d5SMasahiro Yamada len + (len > 1) + rel_path_len + 1, &p);
833999a78d5SMasahiro Yamada if (ret < 0)
834999a78d5SMasahiro Yamada return ret;
835999a78d5SMasahiro Yamada
836999a78d5SMasahiro Yamada if (!target_path) {
837999a78d5SMasahiro Yamada /* again in case setprop_placeholder changed it */
838999a78d5SMasahiro Yamada ret = overlay_get_target(fdt, fdto, fragment, &target_path);
839999a78d5SMasahiro Yamada if (ret < 0)
840999a78d5SMasahiro Yamada return ret;
841999a78d5SMasahiro Yamada target = ret;
842999a78d5SMasahiro Yamada }
843999a78d5SMasahiro Yamada
844999a78d5SMasahiro Yamada buf = p;
845999a78d5SMasahiro Yamada if (len > 1) { /* target is not root */
846999a78d5SMasahiro Yamada if (!target_path) {
847999a78d5SMasahiro Yamada ret = fdt_get_path(fdt, target, buf, len + 1);
848999a78d5SMasahiro Yamada if (ret < 0)
849999a78d5SMasahiro Yamada return ret;
850999a78d5SMasahiro Yamada } else
851999a78d5SMasahiro Yamada memcpy(buf, target_path, len + 1);
852999a78d5SMasahiro Yamada
853999a78d5SMasahiro Yamada } else
854999a78d5SMasahiro Yamada len--;
855999a78d5SMasahiro Yamada
856999a78d5SMasahiro Yamada buf[len] = '/';
857999a78d5SMasahiro Yamada memcpy(buf + len + 1, rel_path, rel_path_len);
858999a78d5SMasahiro Yamada buf[len + 1 + rel_path_len] = '\0';
859999a78d5SMasahiro Yamada }
860999a78d5SMasahiro Yamada
861999a78d5SMasahiro Yamada return 0;
862999a78d5SMasahiro Yamada }
863999a78d5SMasahiro Yamada
fdt_overlay_apply(void * fdt,void * fdto)864999a78d5SMasahiro Yamada int fdt_overlay_apply(void *fdt, void *fdto)
865999a78d5SMasahiro Yamada {
866999a78d5SMasahiro Yamada uint32_t delta = fdt_get_max_phandle(fdt);
867999a78d5SMasahiro Yamada int ret;
868999a78d5SMasahiro Yamada
869999a78d5SMasahiro Yamada FDT_CHECK_HEADER(fdt);
870999a78d5SMasahiro Yamada FDT_CHECK_HEADER(fdto);
871999a78d5SMasahiro Yamada
872999a78d5SMasahiro Yamada ret = overlay_adjust_local_phandles(fdto, delta);
873999a78d5SMasahiro Yamada if (ret)
874999a78d5SMasahiro Yamada goto err;
875999a78d5SMasahiro Yamada
876999a78d5SMasahiro Yamada ret = overlay_update_local_references(fdto, delta);
877999a78d5SMasahiro Yamada if (ret)
878999a78d5SMasahiro Yamada goto err;
879999a78d5SMasahiro Yamada
880999a78d5SMasahiro Yamada ret = overlay_fixup_phandles(fdt, fdto);
881999a78d5SMasahiro Yamada if (ret)
882999a78d5SMasahiro Yamada goto err;
883999a78d5SMasahiro Yamada
884999a78d5SMasahiro Yamada ret = overlay_merge(fdt, fdto);
885999a78d5SMasahiro Yamada if (ret)
886999a78d5SMasahiro Yamada goto err;
887999a78d5SMasahiro Yamada
888999a78d5SMasahiro Yamada ret = overlay_symbol_update(fdt, fdto);
889999a78d5SMasahiro Yamada if (ret)
890999a78d5SMasahiro Yamada goto err;
891999a78d5SMasahiro Yamada
892999a78d5SMasahiro Yamada /*
893999a78d5SMasahiro Yamada * The overlay has been damaged, erase its magic.
894999a78d5SMasahiro Yamada */
895999a78d5SMasahiro Yamada fdt_set_magic(fdto, ~0);
896999a78d5SMasahiro Yamada
897999a78d5SMasahiro Yamada return 0;
898999a78d5SMasahiro Yamada
899999a78d5SMasahiro Yamada err:
900999a78d5SMasahiro Yamada /*
901999a78d5SMasahiro Yamada * The overlay might have been damaged, erase its magic.
902999a78d5SMasahiro Yamada */
903999a78d5SMasahiro Yamada fdt_set_magic(fdto, ~0);
904999a78d5SMasahiro Yamada
905999a78d5SMasahiro Yamada /*
906999a78d5SMasahiro Yamada * The base device tree might have been damaged, erase its
907999a78d5SMasahiro Yamada * magic.
908999a78d5SMasahiro Yamada */
909999a78d5SMasahiro Yamada fdt_set_magic(fdt, ~0);
910999a78d5SMasahiro Yamada
911999a78d5SMasahiro Yamada return ret;
912999a78d5SMasahiro Yamada }
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