From 42381bf1f2de13bbfbdea74b78af9768ab65b80c Mon Sep 17 00:00:00 2001 From: Ley Foon Tan Date: Thu, 6 Nov 2014 15:20:11 +0800 Subject: nios2: Module support This patch adds support for loadable modules. Signed-off-by: Ley Foon Tan --- arch/nios2/kernel/module.c | 138 +++++++++++++++++++++++++++++++++++++++++++++ 1 file changed, 138 insertions(+) create mode 100644 arch/nios2/kernel/module.c (limited to 'arch') diff --git a/arch/nios2/kernel/module.c b/arch/nios2/kernel/module.c new file mode 100644 index 000000000000..cc924a38f22a --- /dev/null +++ b/arch/nios2/kernel/module.c @@ -0,0 +1,138 @@ +/* + * Kernel module support for Nios II. + * + * Copyright (C) 2004 Microtronix Datacom Ltd. + * Written by Wentao Xu + * 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 +#include +#include +#include +#include +#include +#include +#include + +#include +#include + +/* + * 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_free(struct module *mod, 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; +} -- cgit v1.2.3