[PATCH v2 24/29] nios2: Module support

Ley Foon Tan
2014-07-15T08:48:34Z

This patch adds support for loadable modules.

Signed-off-by: Ley Foon Tan <lftan@altera.com>
---
arch/nios2/kernel/module.c | 135 +++++++++++++++++++++++++++++++++++++++++++++
1 file changed, 135 insertions(+)
create mode 100644 arch/nios2/kernel/module.c

diff --git a/arch/nios2/kernel/module.c b/arch/nios2/kernel/module.c
new file mode 100644
index 0000000..360c53a
--- /dev/null
+++ b/arch/nios2/kernel/module.c
@@ -0,0 +1,135 @@
+/*
+ * 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>
+
+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;
+}
+
+void module_arch_cleanup(struct module *mod)
+{
+}
--
1.8.2.1