1 /*
2 * Port on Texas Instruments TMS320C6x architecture
3 *
4 * Copyright (C) 2005, 2009, 2010, 2011 Texas Instruments Incorporated
5 * Author: Thomas Charleux (thomas.charleux@jaluna.com)
6 *
7 * This program is free software; you can redistribute it and/or modify
8 * it under the terms of the GNU General Public License version 2 as
9 * published by the Free Software Foundation.
10 *
11 */
12 #include <linux/moduleloader.h>
13 #include <linux/elf.h>
14 #include <linux/vmalloc.h>
15 #include <linux/kernel.h>
16
fixup_pcr(u32 * ip,Elf32_Addr dest,u32 maskbits,int shift)17 static inline int fixup_pcr(u32 *ip, Elf32_Addr dest, u32 maskbits, int shift)
18 {
19 u32 opcode;
20 long ep = (long)ip & ~31;
21 long delta = ((long)dest - ep) >> 2;
22 long mask = (1 << maskbits) - 1;
23
24 if ((delta >> (maskbits - 1)) == 0 ||
25 (delta >> (maskbits - 1)) == -1) {
26 opcode = *ip;
27 opcode &= ~(mask << shift);
28 opcode |= ((delta & mask) << shift);
29 *ip = opcode;
30
31 pr_debug("REL PCR_S%d[%p] dest[%p] opcode[%08x]\n",
32 maskbits, ip, (void *)dest, opcode);
33
34 return 0;
35 }
36 pr_err("PCR_S%d reloc %p -> %p out of range!\n",
37 maskbits, ip, (void *)dest);
38
39 return -1;
40 }
41
42 /*
43 * apply a RELA relocation
44 */
apply_relocate_add(Elf32_Shdr * sechdrs,const char * strtab,unsigned int symindex,unsigned int relsec,struct module * me)45 int apply_relocate_add(Elf32_Shdr *sechdrs,
46 const char *strtab,
47 unsigned int symindex,
48 unsigned int relsec,
49 struct module *me)
50 {
51 Elf32_Rela *rel = (void *) sechdrs[relsec].sh_addr;
52 Elf_Sym *sym;
53 u32 *location, opcode;
54 unsigned int i;
55 Elf32_Addr v;
56 Elf_Addr offset = 0;
57
58 pr_debug("Applying relocate section %u to %u with offset 0x%x\n",
59 relsec, sechdrs[relsec].sh_info, offset);
60
61 for (i = 0; i < sechdrs[relsec].sh_size / sizeof(*rel); i++) {
62 /* This is where to make the change */
63 location = (void *)sechdrs[sechdrs[relsec].sh_info].sh_addr
64 + rel[i].r_offset - offset;
65
66 /* This is the symbol it is referring to. Note that all
67 undefined symbols have been resolved. */
68 sym = (Elf_Sym *)sechdrs[symindex].sh_addr
69 + ELF32_R_SYM(rel[i].r_info);
70
71 /* this is the adjustment to be made */
72 v = sym->st_value + rel[i].r_addend;
73
74 switch (ELF32_R_TYPE(rel[i].r_info)) {
75 case R_C6000_ABS32:
76 pr_debug("RELA ABS32: [%p] = 0x%x\n", location, v);
77 *location = v;
78 break;
79 case R_C6000_ABS16:
80 pr_debug("RELA ABS16: [%p] = 0x%x\n", location, v);
81 *(u16 *)location = v;
82 break;
83 case R_C6000_ABS8:
84 pr_debug("RELA ABS8: [%p] = 0x%x\n", location, v);
85 *(u8 *)location = v;
86 break;
87 case R_C6000_ABS_L16:
88 opcode = *location;
89 opcode &= ~0x7fff80;
90 opcode |= ((v & 0xffff) << 7);
91 pr_debug("RELA ABS_L16[%p] v[0x%x] opcode[0x%x]\n",
92 location, v, opcode);
93 *location = opcode;
94 break;
95 case R_C6000_ABS_H16:
96 opcode = *location;
97 opcode &= ~0x7fff80;
98 opcode |= ((v >> 9) & 0x7fff80);
99 pr_debug("RELA ABS_H16[%p] v[0x%x] opcode[0x%x]\n",
100 location, v, opcode);
101 *location = opcode;
102 break;
103 case R_C6000_PCR_S21:
104 if (fixup_pcr(location, v, 21, 7))
105 return -ENOEXEC;
106 break;
107 case R_C6000_PCR_S12:
108 if (fixup_pcr(location, v, 12, 16))
109 return -ENOEXEC;
110 break;
111 case R_C6000_PCR_S10:
112 if (fixup_pcr(location, v, 10, 13))
113 return -ENOEXEC;
114 break;
115 default:
116 pr_err("module %s: Unknown RELA relocation: %u\n",
117 me->name, ELF32_R_TYPE(rel[i].r_info));
118 return -ENOEXEC;
119 }
120 }
121
122 return 0;
123 }
124
