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/*
* Kernel module support for Nios II.
*
* Copyright (C) 2004 Microtronix Datacom Ltd.
* Written by Wentao Xu <xuwentao@microtronix.com>
* Copyright (C) 2001, 2003 Rusty Russell
*
* This file is subject to the terms and conditions of the GNU General
* Public License. See the file COPYING in the main directory of this
* archive for more details.
*/
#include <linux/moduleloader.h>
#include <linux/elf.h>
#include <linux/mm.h>
#include <linux/vmalloc.h>
#include <linux/slab.h>
#include <linux/fs.h>
#include <linux/string.h>
#include <linux/kernel.h>
#include <asm/pgtable.h>
#include <asm/cacheflush.h>
/*
* Modules should NOT be allocated with kmalloc for (obvious) reasons.
* But we do it for now to avoid relocation issues. CALL26/PCREL26 cannot reach
* from 0x80000000 (vmalloc area) to 0xc00000000 (kernel) (kmalloc returns
* addresses in 0xc0000000)
*/
void *module_alloc(unsigned long size)
{
if (size == 0)
return NULL;
return kmalloc(size, GFP_KERNEL);
}
/* Free memory returned from module_alloc */
void module_memfree(void *module_region)
{
kfree(module_region);
}
int apply_relocate_add(Elf32_Shdr *sechdrs, const char *strtab,
unsigned int symindex, unsigned int relsec,
struct module *mod)
{
unsigned int i;
Elf32_Rela *rela = (void *)sechdrs[relsec].sh_addr;
pr_debug("Applying relocate section %u to %u\n", relsec,
sechdrs[relsec].sh_info);
for (i = 0; i < sechdrs[relsec].sh_size / sizeof(*rela); i++) {
/* This is where to make the change */
uint32_t word;
uint32_t *loc
= ((void *)sechdrs[sechdrs[relsec].sh_info].sh_addr
+ rela[i].r_offset);
/* This is the symbol it is referring to. Note that all
undefined symbols have been resolved. */
Elf32_Sym *sym
= ((Elf32_Sym *)sechdrs[symindex].sh_addr
+ ELF32_R_SYM(rela[i].r_info));
uint32_t v = sym->st_value + rela[i].r_addend;
pr_debug("reltype %d 0x%x name:<%s>\n",
ELF32_R_TYPE(rela[i].r_info),
rela[i].r_offset, strtab + sym->st_name);
switch (ELF32_R_TYPE(rela[i].r_info)) {
case R_NIOS2_NONE:
break;
case R_NIOS2_BFD_RELOC_32:
*loc += v;
break;
case R_NIOS2_PCREL16:
v -= (uint32_t)loc + 4;
if ((int32_t)v > 0x7fff ||
(int32_t)v < -(int32_t)0x8000) {
pr_err("module %s: relocation overflow\n",
mod->name);
return -ENOEXEC;
}
word = *loc;
*loc = ((((word >> 22) << 16) | (v & 0xffff)) << 6) |
(word & 0x3f);
break;
case R_NIOS2_CALL26:
if (v & 3) {
pr_err("module %s: dangerous relocation\n",
mod->name);
return -ENOEXEC;
}
if ((v >> 28) != ((uint32_t)loc >> 28)) {
pr_err("module %s: relocation overflow\n",
mod->name);
return -ENOEXEC;
}
*loc = (*loc & 0x3f) | ((v >> 2) << 6);
break;
case R_NIOS2_HI16:
word = *loc;
*loc = ((((word >> 22) << 16) |
((v >> 16) & 0xffff)) << 6) | (word & 0x3f);
break;
case R_NIOS2_LO16:
word = *loc;
*loc = ((((word >> 22) << 16) | (v & 0xffff)) << 6) |
(word & 0x3f);
break;
case R_NIOS2_HIADJ16:
{
Elf32_Addr word2;
word = *loc;
word2 = ((v >> 16) + ((v >> 15) & 1)) & 0xffff;
*loc = ((((word >> 22) << 16) | word2) << 6) |
(word & 0x3f);
}
break;
default:
pr_err("module %s: Unknown reloc: %u\n",
mod->name, ELF32_R_TYPE(rela[i].r_info));
return -ENOEXEC;
}
}
return 0;
}
int module_finalize(const Elf_Ehdr *hdr, const Elf_Shdr *sechdrs,
struct module *me)
{
flush_cache_all();
return 0;
}
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