xref: /openbmc/linux/arch/microblaze/kernel/module.c (revision b04b4f78)
1 /*
2  * Copyright (C) 2007-2009 Michal Simek <monstr@monstr.eu>
3  * Copyright (C) 2007-2009 PetaLogix
4  *
5  * This program is free software; you can redistribute it and/or modify
6  * it under the terms of the GNU General Public License version 2 as
7  * published by the Free Software Foundation.
8  */
9 
10 #include <linux/module.h>
11 #include <linux/moduleloader.h>
12 #include <linux/kernel.h>
13 #include <linux/elf.h>
14 #include <linux/vmalloc.h>
15 #include <linux/slab.h>
16 #include <linux/fs.h>
17 #include <linux/string.h>
18 
19 #include <asm/pgtable.h>
20 
21 void *module_alloc(unsigned long size)
22 {
23 	void *ret;
24 	ret = (size == 0) ? NULL : vmalloc(size);
25 	pr_debug("module_alloc (%08lx@%08lx)\n", size, (unsigned long int)ret);
26 	return ret;
27 }
28 
29 void module_free(struct module *module, void *region)
30 {
31 	pr_debug("module_free(%s,%08lx)\n", module->name,
32 					(unsigned long)region);
33 	vfree(region);
34 }
35 
36 int module_frob_arch_sections(Elf_Ehdr *hdr,
37 				Elf_Shdr *sechdrs,
38 				char *secstrings,
39 				struct module *mod)
40 {
41 	return 0;
42 }
43 
44 int apply_relocate(Elf32_Shdr *sechdrs, const char *strtab,
45 	unsigned int symindex, unsigned int relsec, struct module *module)
46 {
47 	printk(KERN_ERR "module %s: ADD RELOCATION unsupported\n",
48 		module->name);
49 	return -ENOEXEC;
50 }
51 
52 int apply_relocate_add(Elf32_Shdr *sechdrs, const char *strtab,
53 	unsigned int symindex, unsigned int relsec, struct module *module)
54 {
55 
56 	unsigned int i;
57 	Elf32_Rela *rela = (void *)sechdrs[relsec].sh_addr;
58 	Elf32_Sym *sym;
59 	unsigned long int *location;
60 	unsigned long int locoffs;
61 	unsigned long int value;
62 #if __GNUC__ < 4
63 	unsigned long int old_value;
64 #endif
65 
66 	pr_debug("Applying add relocation section %u to %u\n",
67 		relsec, sechdrs[relsec].sh_info);
68 
69 	for (i = 0; i < sechdrs[relsec].sh_size / sizeof(*rela); i++) {
70 
71 		location = (void *)sechdrs[sechdrs[relsec].sh_info].sh_addr +
72 				rela[i].r_offset;
73 		sym = (Elf32_Sym *)sechdrs[symindex].sh_addr +
74 			ELF32_R_SYM(rela[i].r_info);
75 		value = sym->st_value + rela[i].r_addend;
76 
77 		switch (ELF32_R_TYPE(rela[i].r_info)) {
78 
79 		/*
80 		 * Be careful! mb-gcc / mb-ld splits the relocs between the
81 		 * text and the reloc table. In general this means we must
82 		 * read the current contents of (*location), add any offset
83 		 * then store the result back in
84 		 */
85 
86 		case R_MICROBLAZE_32:
87 #if __GNUC__ < 4
88 			old_value = *location;
89 			*location = value + old_value;
90 
91 			pr_debug("R_MICROBLAZE_32 (%08lx->%08lx)\n",
92 				old_value, value);
93 #else
94 			*location = value;
95 #endif
96 			break;
97 
98 		case R_MICROBLAZE_64:
99 #if __GNUC__ < 4
100 			/* Split relocs only required/used pre gcc4.1.1 */
101 			old_value = ((location[0] & 0x0000FFFF) << 16) |
102 					(location[1] & 0x0000FFFF);
103 			value += old_value;
104 #endif
105 			location[0] = (location[0] & 0xFFFF0000) |
106 					(value >> 16);
107 			location[1] = (location[1] & 0xFFFF0000) |
108 					(value & 0xFFFF);
109 #if __GNUC__ < 4
110 			pr_debug("R_MICROBLAZE_64 (%08lx->%08lx)\n",
111 				old_value, value);
112 #endif
113 			break;
114 
115 		case R_MICROBLAZE_64_PCREL:
116 			locoffs = (location[0] & 0xFFFF) << 16 |
117 				(location[1] & 0xFFFF);
118 			value -= (unsigned long int)(location) + 4 +
119 				locoffs;
120 			location[0] = (location[0] & 0xFFFF0000) |
121 					(value >> 16);
122 			location[1] = (location[1] & 0xFFFF0000) |
123 					(value & 0xFFFF);
124 			pr_debug("R_MICROBLAZE_64_PCREL (%08lx)\n",
125 				value);
126 			break;
127 
128 		case R_MICROBLAZE_NONE:
129 			pr_debug("R_MICROBLAZE_NONE\n");
130 			break;
131 
132 		default:
133 			printk(KERN_ERR "module %s: "
134 				"Unknown relocation: %u\n",
135 				module->name,
136 				ELF32_R_TYPE(rela->r_info));
137 			return -ENOEXEC;
138 		}
139 	}
140 	return 0;
141 }
142 
143 int module_finalize(const Elf32_Ehdr *hdr, const Elf_Shdr *sechdrs,
144 		struct module *module)
145 {
146 	return 0;
147 }
148 
149 void module_arch_cleanup(struct module *mod)
150 {
151 }
152