OpenRISC: Module support

Signed-off-by: Jonas Bonn <jonas@southpole.se>
Reviewed-by: Arnd Bergmann <arnd@arndb.de>

1 files changed, 72 insertions, 0 deletions

diff --git a/arch/openrisc/kernel/module.c b/arch/openrisc/kernel/module.c
new file mode 100644
index 000000000000..10ff50f0202a
--- /dev/null
+++ b/arch/openrisc/kernel/module.c
@@ -0,0 +1,72 @@
+/*
+ * OpenRISC module.c
+ *
+ * Linux architectural port borrowing liberally from similar works of
+ * others.  All original copyrights apply as per the original source
+ * declaration.
+ *
+ * Modifications for the OpenRISC architecture:
+ * Copyright (C) 2010-2011 Jonas Bonn <jonas@southpole.se>
+ *
+ *      This program is free software; you can redistribute it and/or
+ *      modify it under the terms of the GNU General Public License
+ *      as published by the Free Software Foundation; either version
+ *      2 of the License, or (at your option) any later version.
+ */
+
+#include <linux/moduleloader.h>
+#include <linux/elf.h>
+
+int apply_relocate_add(Elf32_Shdr *sechdrs,
+                       const char *strtab,
+                       unsigned int symindex,
+                       unsigned int relsec,
+                       struct module *me)
+{
+        unsigned int i;
+        Elf32_Rela *rel = (void *)sechdrs[relsec].sh_addr;
+        Elf32_Sym *sym;
+        uint32_t *location;
+        uint32_t value;
+
+        pr_debug("Applying relocate section %u to %u\n", relsec,
+                 sechdrs[relsec].sh_info);
+        for (i = 0; i < sechdrs[relsec].sh_size / sizeof(*rel); i++) {
+                /* This is where to make the change */
+                location = (void *)sechdrs[sechdrs[relsec].sh_info].sh_addr
+                        + rel[i].r_offset;
+
+                /* This is the symbol it is referring to.  Note that all
+                   undefined symbols have been resolved.  */
+                sym = (Elf32_Sym *)sechdrs[symindex].sh_addr
+                        + ELF32_R_SYM(rel[i].r_info);
+                value = sym->st_value + rel[i].r_addend;
+
+                switch (ELF32_R_TYPE(rel[i].r_info)) {
+                case R_OR32_32:
+                        *location = value;
+                        break;
+                case R_OR32_CONST:
+                        location = (uint16_t *)location + 1;
+                        *((uint16_t *)location) = (uint16_t) (value);
+                        break;
+                case R_OR32_CONSTH:
+                        location = (uint16_t *)location + 1;
+                        *((uint16_t *)location) = (uint16_t) (value >> 16);
+                        break;
+                case R_OR32_JUMPTARG:
+                        value -= (uint32_t)location;
+                        value >>= 2;
+                        value &= 0x03ffffff;
+                        value |= *location & 0xfc000000;
+                        *location = value;
+                        break;
+                default:
+                        pr_err("module %s: Unknown relocation: %u\n",
+                               me->name, ELF32_R_TYPE(rel[i].r_info));
+                        break;
+                }
+        }
+
+        return 0;
+}