1/*
  2 * arch/score/kernel/module.c
  3 *
  4 * Score Processor version.
  5 *
  6 * Copyright (C) 2009 Sunplus Core Technology Co., Ltd.
  7 *  Chen Liqin <liqin.chen@sunplusct.com>
  8 *  Lennox Wu <lennox.wu@sunplusct.com>
  9 *
 10 * This program is free software; you can redistribute it and/or modify
 11 * it under the terms of the GNU General Public License as published by
 12 * the Free Software Foundation; either version 2 of the License, or
 13 * (at your option) any later version.
 14 *
 15 * This program is distributed in the hope that it will be useful,
 16 * but WITHOUT ANY WARRANTY; without even the implied warranty of
 17 * MERCHANTABILITY or FITNESS FOR A PARTICULAR PURPOSE.  See the
 18 * GNU General Public License for more details.
 19 *
 20 * You should have received a copy of the GNU General Public License
 21 * along with this program; if not, see the file COPYING, or write
 22 * to the Free Software Foundation, Inc.,
 23 * 51 Franklin St, Fifth Floor, Boston, MA  02110-1301  USA
 24 */
 25
 26#include <linux/moduleloader.h>
 27#include <linux/module.h>
 28#include <linux/vmalloc.h>
 29
 30int apply_relocate(Elf_Shdr *sechdrs, const char *strtab,
 31		unsigned int symindex, unsigned int relindex,
 32		struct module *me)
 33{
 34	Elf32_Shdr *symsec = sechdrs + symindex;
 35	Elf32_Shdr *relsec = sechdrs + relindex;
 36	Elf32_Shdr *dstsec = sechdrs + relsec->sh_info;
 37	Elf32_Rel *rel = (void *)relsec->sh_addr;
 38	unsigned int i;
 39
 40	for (i = 0; i < relsec->sh_size / sizeof(Elf32_Rel); i++, rel++) {
 41		unsigned long loc;
 42		Elf32_Sym *sym;
 43		s32 r_offset;
 44
 45		r_offset = ELF32_R_SYM(rel->r_info);
 46		if ((r_offset < 0) ||
 47		    (r_offset > (symsec->sh_size / sizeof(Elf32_Sym)))) {
 48			printk(KERN_ERR "%s: bad relocation, section %d reloc %d\n",
 49				me->name, relindex, i);
 50				return -ENOEXEC;
 51		}
 52
 53		sym = ((Elf32_Sym *)symsec->sh_addr) + r_offset;
 54
 55		if ((rel->r_offset < 0) ||
 56		    (rel->r_offset > dstsec->sh_size - sizeof(u32))) {
 57			printk(KERN_ERR "%s: out of bounds relocation, "
 58				"section %d reloc %d offset %d size %d\n",
 59				me->name, relindex, i, rel->r_offset,
 60				dstsec->sh_size);
 61			return -ENOEXEC;
 62		}
 63
 64		loc = dstsec->sh_addr + rel->r_offset;
 65		switch (ELF32_R_TYPE(rel->r_info)) {
 66		case R_SCORE_NONE:
 67			break;
 68		case R_SCORE_ABS32:
 69			*(unsigned long *)loc += sym->st_value;
 70			break;
 71		case R_SCORE_HI16:
 72			break;
 73		case R_SCORE_LO16: {
 74			unsigned long hi16_offset, offset;
 75			unsigned long uvalue;
 76			unsigned long temp, temp_hi;
 77			temp_hi = *((unsigned long *)loc - 1);
 78			temp = *(unsigned long *)loc;
 79
 80			hi16_offset = (((((temp_hi) >> 16) & 0x3) << 15) |
 81					((temp_hi) & 0x7fff)) >> 1;
 82			offset = ((temp >> 16 & 0x03) << 15) |
 83					((temp & 0x7fff) >> 1);
 84			offset = (hi16_offset << 16) | (offset & 0xffff);
 85			uvalue = sym->st_value + offset;
 86			hi16_offset = (uvalue >> 16) << 1;
 87
 88			temp_hi = ((temp_hi) & (~(0x37fff))) |
 89					(hi16_offset & 0x7fff) |
 90					((hi16_offset << 1) & 0x30000);
 91			*((unsigned long *)loc - 1) = temp_hi;
 92
 93			offset = (uvalue & 0xffff) << 1;
 94			temp = (temp & (~(0x37fff))) | (offset & 0x7fff) |
 95				((offset << 1) & 0x30000);
 96			*(unsigned long *)loc = temp;
 97			break;
 98		}
 99		case R_SCORE_24: {
100			unsigned long hi16_offset, offset;
101			unsigned long uvalue;
102			unsigned long temp;
103
104			temp = *(unsigned long *)loc;
105			offset = (temp & 0x03FF7FFE);
106			hi16_offset = (offset & 0xFFFF0000);
107			offset = (hi16_offset | ((offset & 0xFFFF) << 1)) >> 2;
108
109			uvalue = (sym->st_value + offset) >> 1;
110			uvalue = uvalue & 0x00ffffff;
111
112			temp = (temp & 0xfc008001) |
113				((uvalue << 2) & 0x3ff0000) |
114				((uvalue & 0x3fff) << 1);
115			*(unsigned long *)loc = temp;
116			break;
117		}
118		default:
119			printk(KERN_ERR "%s: unknown relocation: %u\n",
120				me->name, ELF32_R_TYPE(rel->r_info));
121			return -ENOEXEC;
122		}
123	}
124
125	return 0;
126}
127
128int apply_relocate_add(Elf_Shdr *sechdrs, const char *strtab,
129		unsigned int symindex, unsigned int relsec,
130		struct module *me)
131{
132	/* Non-standard return value... most other arch's return -ENOEXEC
133	 * for an unsupported relocation variant
134	 */
135	return 0;
136}
137
138/* Given an address, look for it in the module exception tables. */
139const struct exception_table_entry *search_module_dbetables(unsigned long addr)
140{
141	return NULL;
142}