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 
fdt_cells(const void * fdt,int nodeoffset,const char * name)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 
fdt_address_cells(const void * fdt,int nodeoffset)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 
fdt_size_cells(const void * fdt,int nodeoffset)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 */
fdt_appendprop_addrrange(void * fdt,int parent,int nodeoffset,const char * name,uint64_t addr,uint64_t size)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) || (((uint64_t) 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