xref: /openbmc/linux/arch/microblaze/kernel/module.c (revision 99a15348)
1 // SPDX-License-Identifier: GPL-2.0-only
2 /*
3  * Copyright (C) 2007-2009 Michal Simek <monstr@monstr.eu>
4  * Copyright (C) 2007-2009 PetaLogix
5  */
6 
7 #include <linux/export.h>
8 #include <linux/moduleloader.h>
9 #include <linux/kernel.h>
10 #include <linux/elf.h>
11 #include <linux/vmalloc.h>
12 #include <linux/fs.h>
13 #include <linux/string.h>
14 #include <linux/pgtable.h>
15 
16 #include <asm/cacheflush.h>
17 
18 int apply_relocate_add(Elf32_Shdr *sechdrs, const char *strtab,
19 	unsigned int symindex, unsigned int relsec, struct module *module)
20 {
21 
22 	unsigned int i;
23 	Elf32_Rela *rela = (void *)sechdrs[relsec].sh_addr;
24 	Elf32_Sym *sym;
25 	unsigned long int *location;
26 	unsigned long int value;
27 
28 	pr_debug("Applying add relocation section %u to %u\n",
29 		relsec, sechdrs[relsec].sh_info);
30 
31 	for (i = 0; i < sechdrs[relsec].sh_size / sizeof(*rela); i++) {
32 
33 		location = (void *)sechdrs[sechdrs[relsec].sh_info].sh_addr +
34 				rela[i].r_offset;
35 		sym = (Elf32_Sym *)sechdrs[symindex].sh_addr +
36 			ELF32_R_SYM(rela[i].r_info);
37 		value = sym->st_value + rela[i].r_addend;
38 
39 		switch (ELF32_R_TYPE(rela[i].r_info)) {
40 
41 		/*
42 		 * Be careful! mb-gcc / mb-ld splits the relocs between the
43 		 * text and the reloc table. In general this means we must
44 		 * read the current contents of (*location), add any offset
45 		 * then store the result back in
46 		 */
47 
48 		case R_MICROBLAZE_32:
49 			*location = value;
50 			break;
51 
52 		case R_MICROBLAZE_64:
53 			location[0] = (location[0] & 0xFFFF0000) |
54 					(value >> 16);
55 			location[1] = (location[1] & 0xFFFF0000) |
56 					(value & 0xFFFF);
57 			break;
58 
59 		case R_MICROBLAZE_64_PCREL:
60 			value -= (unsigned long int)(location) + 4;
61 			location[0] = (location[0] & 0xFFFF0000) |
62 					(value >> 16);
63 			location[1] = (location[1] & 0xFFFF0000) |
64 					(value & 0xFFFF);
65 			pr_debug("R_MICROBLAZE_64_PCREL (%08lx)\n",
66 				value);
67 			break;
68 
69 		case R_MICROBLAZE_32_PCREL_LO:
70 			pr_debug("R_MICROBLAZE_32_PCREL_LO\n");
71 			break;
72 
73 		case R_MICROBLAZE_64_NONE:
74 			pr_debug("R_MICROBLAZE_64_NONE\n");
75 			break;
76 
77 		case R_MICROBLAZE_NONE:
78 			pr_debug("R_MICROBLAZE_NONE\n");
79 			break;
80 
81 		default:
82 			pr_err("module %s: Unknown relocation: %u\n",
83 				module->name,
84 				ELF32_R_TYPE(rela[i].r_info));
85 			return -ENOEXEC;
86 		}
87 	}
88 	return 0;
89 }
90 
91 int module_finalize(const Elf32_Ehdr *hdr, const Elf_Shdr *sechdrs,
92 		struct module *module)
93 {
94 	flush_dcache();
95 	return 0;
96 }
97