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 	uint32_t 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 > FDT_MAX_NCELLS)
29 		return -FDT_ERR_BADNCELLS;
30 
31 	return (int)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 == 0)
40 		return -FDT_ERR_BADNCELLS;
41 	if (val == -FDT_ERR_NOTFOUND)
42 		return 2;
43 	return val;
44 }
45 
46 int fdt_size_cells(const void *fdt, int nodeoffset)
47 {
48 	int val;
49 
50 	val = fdt_cells(fdt, nodeoffset, "#size-cells");
51 	if (val == -FDT_ERR_NOTFOUND)
52 		return 1;
53 	return val;
54 }
55 
56 /* This function assumes that [address|size]_cells is 1 or 2 */
57 int fdt_appendprop_addrrange(void *fdt, int parent, int nodeoffset,
58 			     const char *name, uint64_t addr, uint64_t size)
59 {
60 	int addr_cells, size_cells, ret;
61 	uint8_t data[sizeof(fdt64_t) * 2], *prop;
62 
63 	ret = fdt_address_cells(fdt, parent);
64 	if (ret < 0)
65 		return ret;
66 	addr_cells = ret;
67 
68 	ret = fdt_size_cells(fdt, parent);
69 	if (ret < 0)
70 		return ret;
71 	size_cells = ret;
72 
73 	/* check validity of address */
74 	prop = data;
75 	if (addr_cells == 1) {
76 		if ((addr > UINT32_MAX) || ((UINT32_MAX + 1 - addr) < size))
77 			return -FDT_ERR_BADVALUE;
78 
79 		fdt32_st(prop, (uint32_t)addr);
80 	} else if (addr_cells == 2) {
81 		fdt64_st(prop, addr);
82 	} else {
83 		return -FDT_ERR_BADNCELLS;
84 	}
85 
86 	/* check validity of size */
87 	prop += addr_cells * sizeof(fdt32_t);
88 	if (size_cells == 1) {
89 		if (size > UINT32_MAX)
90 			return -FDT_ERR_BADVALUE;
91 
92 		fdt32_st(prop, (uint32_t)size);
93 	} else if (size_cells == 2) {
94 		fdt64_st(prop, size);
95 	} else {
96 		return -FDT_ERR_BADNCELLS;
97 	}
98 
99 	return fdt_appendprop(fdt, nodeoffset, name, data,
100 			      (addr_cells + size_cells) * sizeof(fdt32_t));
101 }
102