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 #include <fdt.h>
9 #include <libfdt.h>
10 #include "libfdt_internal.h"
11 
fdt_cells(const void * fdt,int nodeoffset,const char * name)12 static int fdt_cells(const void *fdt, int nodeoffset, const char *name)
13 {
14     const fdt32_t *c;
15     uint32_t val;
16     int len;
17 
18     c = fdt_getprop(fdt, nodeoffset, name, &len);
19     if (!c)
20         return len;
21 
22     if (len != sizeof(*c))
23         return -FDT_ERR_BADNCELLS;
24 
25     val = fdt32_to_cpu(*c);
26     if (val > FDT_MAX_NCELLS)
27         return -FDT_ERR_BADNCELLS;
28 
29     return (int)val;
30 }
31 
fdt_address_cells(const void * fdt,int nodeoffset)32 int fdt_address_cells(const void *fdt, int nodeoffset)
33 {
34     int val;
35 
36     val = fdt_cells(fdt, nodeoffset, "#address-cells");
37     if (val == 0)
38         return -FDT_ERR_BADNCELLS;
39     if (val == -FDT_ERR_NOTFOUND)
40         return 2;
41     return val;
42 }
43 
fdt_size_cells(const void * fdt,int nodeoffset)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 */
fdt_appendprop_addrrange(void * fdt,int parent,int nodeoffset,const char * name,uint64_t addr,uint64_t size)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