1 // SPDX-License-Identifier: (GPL-2.0-or-later OR BSD-2-Clause)
2 /*
3  * libfdt - Flat Device Tree manipulation
4  * Copyright (C) 2014 David Gibson <david@gibson.dropbear.id.au>
5  * Copyright (C) 2018 embedded brains GmbH
6  */
7 #include "libfdt_env.h"
8 
9 #include <fdt.h>
10 #include <libfdt.h>
11 
12 #include "libfdt_internal.h"
13 
14 static int fdt_cells(const void *fdt, int nodeoffset, const char *name)
15 {
16 	const fdt32_t *c;
17 	int val;
18 	int len;
19 
20 	c = fdt_getprop(fdt, nodeoffset, name, &len);
21 	if (!c)
22 		return len;
23 
24 	if (len != sizeof(*c))
25 		return -FDT_ERR_BADNCELLS;
26 
27 	val = fdt32_to_cpu(*c);
28 	if ((val <= 0) || (val > FDT_MAX_NCELLS))
29 		return -FDT_ERR_BADNCELLS;
30 
31 	return val;
32 }
33 
34 int fdt_address_cells(const void *fdt, int nodeoffset)
35 {
36 	int val;
37 
38 	val = fdt_cells(fdt, nodeoffset, "#address-cells");
39 	if (val == -FDT_ERR_NOTFOUND)
40 		return 2;
41 	return val;
42 }
43 
44 int fdt_size_cells(const void *fdt, int nodeoffset)
45 {
46 	int val;
47 
48 	val = fdt_cells(fdt, nodeoffset, "#size-cells");
49 	if (val == -FDT_ERR_NOTFOUND)
50 		return 1;
51 	return val;
52 }
53 
54 /* This function assumes that [address|size]_cells is 1 or 2 */
55 int fdt_appendprop_addrrange(void *fdt, int parent, int nodeoffset,
56 			     const char *name, uint64_t addr, uint64_t size)
57 {
58 	int addr_cells, size_cells, ret;
59 	uint8_t data[sizeof(fdt64_t) * 2], *prop;
60 
61 	ret = fdt_address_cells(fdt, parent);
62 	if (ret < 0)
63 		return ret;
64 	addr_cells = ret;
65 
66 	ret = fdt_size_cells(fdt, parent);
67 	if (ret < 0)
68 		return ret;
69 	size_cells = ret;
70 
71 	/* check validity of address */
72 	prop = data;
73 	if (addr_cells == 1) {
74 		if ((addr > UINT32_MAX) || ((UINT32_MAX + 1 - addr) < size))
75 			return -FDT_ERR_BADVALUE;
76 
77 		fdt32_st(prop, (uint32_t)addr);
78 	} else if (addr_cells == 2) {
79 		fdt64_st(prop, addr);
80 	} else {
81 		return -FDT_ERR_BADNCELLS;
82 	}
83 
84 	/* check validity of size */
85 	prop += addr_cells * sizeof(fdt32_t);
86 	if (size_cells == 1) {
87 		if (size > UINT32_MAX)
88 			return -FDT_ERR_BADVALUE;
89 
90 		fdt32_st(prop, (uint32_t)size);
91 	} else if (size_cells == 2) {
92 		fdt64_st(prop, size);
93 	} else {
94 		return -FDT_ERR_BADNCELLS;
95 	}
96 
97 	return fdt_appendprop(fdt, nodeoffset, name, data,
98 			      (addr_cells + size_cells) * sizeof(fdt32_t));
99 }
100