1// SPDX-License-Identifier: GPL-2.0-or-later
2/*
3 * This file does the necessary interface mapping between the bootwrapper
4 * device tree operations and the interface provided by shared source
5 * files flatdevicetree.[ch].
6 *
7 * Copyright 2007 David Gibson, IBM Corporation.
8 */
9
10#include <stddef.h>
11#include <stdio.h>
12#include <page.h>
13#include <libfdt.h>
14#include "ops.h"
15
16#define DEBUG	0
17#define BAD_ERROR(err)	(((err) < 0) \
18			 && ((err) != -FDT_ERR_NOTFOUND) \
19			 && ((err) != -FDT_ERR_EXISTS))
20
21#define check_err(err) \
22	({ \
23		if (BAD_ERROR(err) || ((err < 0) && DEBUG)) \
24			printf("%s():%d  %s\n\r", __func__, __LINE__, \
25			       fdt_strerror(err)); \
26		if (BAD_ERROR(err)) \
27			exit(); \
28		(err < 0) ? -1 : 0; \
29	})
30
31#define offset_devp(off)	\
32	({ \
33		unsigned long _offset = (off); \
34		check_err(_offset) ? NULL : (void *)(_offset+1); \
35	})
36
37#define devp_offset_find(devp)	(((unsigned long)(devp))-1)
38#define devp_offset(devp)	(devp ? ((unsigned long)(devp))-1 : 0)
39
40static void *fdt;
41static void *buf; /* = NULL */
42
43#define EXPAND_GRANULARITY	1024
44
45static void expand_buf(int minexpand)
46{
47	int size = fdt_totalsize(fdt);
48	int rc;
49
50	size = _ALIGN(size + minexpand, EXPAND_GRANULARITY);
51	buf = platform_ops.realloc(buf, size);
52	if (!buf)
53		fatal("Couldn't find %d bytes to expand device tree\n\r", size);
54	rc = fdt_open_into(fdt, buf, size);
55	if (rc != 0)
56		fatal("Couldn't expand fdt into new buffer: %s\n\r",
57		      fdt_strerror(rc));
58
59	fdt = buf;
60}
61
62static void *fdt_wrapper_finddevice(const char *path)
63{
64	return offset_devp(fdt_path_offset(fdt, path));
65}
66
67static int fdt_wrapper_getprop(const void *devp, const char *name,
68			       void *buf, const int buflen)
69{
70	const void *p;
71	int len;
72
73	p = fdt_getprop(fdt, devp_offset(devp), name, &len);
74	if (!p)
75		return check_err(len);
76	memcpy(buf, p, min(len, buflen));
77	return len;
78}
79
80static int fdt_wrapper_setprop(const void *devp, const char *name,
81			       const void *buf, const int len)
82{
83	int rc;
84
85	rc = fdt_setprop(fdt, devp_offset(devp), name, buf, len);
86	if (rc == -FDT_ERR_NOSPACE) {
87		expand_buf(len + 16);
88		rc = fdt_setprop(fdt, devp_offset(devp), name, buf, len);
89	}
90
91	return check_err(rc);
92}
93
94static int fdt_wrapper_del_node(const void *devp)
95{
96	return fdt_del_node(fdt, devp_offset(devp));
97}
98
99static void *fdt_wrapper_get_parent(const void *devp)
100{
101	return offset_devp(fdt_parent_offset(fdt, devp_offset(devp)));
102}
103
104static void *fdt_wrapper_create_node(const void *devp, const char *name)
105{
106	int offset;
107
108	offset = fdt_add_subnode(fdt, devp_offset(devp), name);
109	if (offset == -FDT_ERR_NOSPACE) {
110		expand_buf(strlen(name) + 16);
111		offset = fdt_add_subnode(fdt, devp_offset(devp), name);
112	}
113
114	return offset_devp(offset);
115}
116
117static void *fdt_wrapper_find_node_by_prop_value(const void *prev,
118						 const char *name,
119						 const char *val,
120						 int len)
121{
122	int offset = fdt_node_offset_by_prop_value(fdt, devp_offset_find(prev),
123	                                           name, val, len);
124	return offset_devp(offset);
125}
126
127static void *fdt_wrapper_find_node_by_compatible(const void *prev,
128						 const char *val)
129{
130	int offset = fdt_node_offset_by_compatible(fdt, devp_offset_find(prev),
131	                                           val);
132	return offset_devp(offset);
133}
134
135static char *fdt_wrapper_get_path(const void *devp, char *buf, int len)
136{
137	int rc;
138
139	rc = fdt_get_path(fdt, devp_offset(devp), buf, len);
140	if (check_err(rc))
141		return NULL;
142	return buf;
143}
144
145static unsigned long fdt_wrapper_finalize(void)
146{
147	int rc;
148
149	rc = fdt_pack(fdt);
150	if (rc != 0)
151		fatal("Couldn't pack flat tree: %s\n\r",
152		      fdt_strerror(rc));
153	return (unsigned long)fdt;
154}
155
156void fdt_init(void *blob)
157{
158	int err;
159	int bufsize;
160
161	dt_ops.finddevice = fdt_wrapper_finddevice;
162	dt_ops.getprop = fdt_wrapper_getprop;
163	dt_ops.setprop = fdt_wrapper_setprop;
164	dt_ops.get_parent = fdt_wrapper_get_parent;
165	dt_ops.create_node = fdt_wrapper_create_node;
166	dt_ops.find_node_by_prop_value = fdt_wrapper_find_node_by_prop_value;
167	dt_ops.find_node_by_compatible = fdt_wrapper_find_node_by_compatible;
168	dt_ops.del_node = fdt_wrapper_del_node;
169	dt_ops.get_path = fdt_wrapper_get_path;
170	dt_ops.finalize = fdt_wrapper_finalize;
171
172	/* Make sure the dt blob is the right version and so forth */
173	fdt = blob;
174	bufsize = fdt_totalsize(fdt) + EXPAND_GRANULARITY;
175	buf = malloc(bufsize);
176	if(!buf)
177		fatal("malloc failed. can't relocate the device tree\n\r");
178
179	err = fdt_open_into(fdt, buf, bufsize);
180
181	if (err != 0)
182		fatal("fdt_init(): %s\n\r", fdt_strerror(err));
183
184	fdt = buf;
185}
186