C6X: loadable module support

Original port to early 2.6 kernel using TI COFF toolchain.
Brought up to date by Mark Salter <msalter@redhat.com>

Signed-off-by: Aurelien Jacquiot <a-jacquiot@ti.com>
Signed-off-by: Mark Salter <msalter@redhat.com>
Acked-by: Arnd Bergmann <arnd@arndb.de>

1 files changed, 123 insertions, 0 deletions

diff --git a/arch/c6x/kernel/module.c b/arch/c6x/kernel/module.c
new file mode 100644
index 000000000000..5fc03f18f56c
--- /dev/null
+++ b/arch/c6x/kernel/module.c
@@ -0,0 +1,123 @@
+/*
+ *  Port on Texas Instruments TMS320C6x architecture
+ *
+ *  Copyright (C) 2005, 2009, 2010, 2011 Texas Instruments Incorporated
+ *  Author: Thomas Charleux (thomas.charleux@jaluna.com)
+ *
+ *  This program is free software; you can redistribute it and/or modify
+ *  it under the terms of the GNU General Public License version 2 as
+ *  published by the Free Software Foundation.
+ *
+ */
+#include <linux/moduleloader.h>
+#include <linux/elf.h>
+#include <linux/vmalloc.h>
+#include <linux/kernel.h>
+
+static inline int fixup_pcr(u32 *ip, Elf32_Addr dest, u32 maskbits, int shift)
+{
+	u32 opcode;
+	long ep = (long)ip & ~31;
+	long delta = ((long)dest - ep) >> 2;
+	long mask = (1 << maskbits) - 1;
+
+	if ((delta >> (maskbits - 1)) == 0 ||
+	    (delta >> (maskbits - 1)) == -1) {
+		opcode = *ip;
+		opcode &= ~(mask << shift);
+		opcode |= ((delta & mask) << shift);
+		*ip = opcode;
+
+		pr_debug("REL PCR_S%d[%p] dest[%p] opcode[%08x]\n",
+			 maskbits, ip, (void *)dest, opcode);
+
+		return 0;
+	}
+	pr_err("PCR_S%d reloc %p -> %p out of range!\n",
+	       maskbits, ip, (void *)dest);
+
+	return -1;
+}
+
+/*
+ * apply a RELA relocation
+ */
+int apply_relocate_add(Elf32_Shdr *sechdrs,
+		       const char *strtab,
+		       unsigned int symindex,
+		       unsigned int relsec,
+		       struct module *me)
+{
+	Elf32_Rela *rel = (void *) sechdrs[relsec].sh_addr;
+	Elf_Sym *sym;
+	u32 *location, opcode;
+	unsigned int i;
+	Elf32_Addr v;
+	Elf_Addr offset = 0;
+
+	pr_debug("Applying relocate section %u to %u with offset 0x%x\n",
+		 relsec, sechdrs[relsec].sh_info, offset);
+
+	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 - offset;
+
+		/* This is the symbol it is referring to.  Note that all
+		   undefined symbols have been resolved.  */
+		sym = (Elf_Sym *)sechdrs[symindex].sh_addr
+			+ ELF32_R_SYM(rel[i].r_info);
+
+		/* this is the adjustment to be made */
+		v = sym->st_value + rel[i].r_addend;
+
+		switch (ELF32_R_TYPE(rel[i].r_info)) {
+		case R_C6000_ABS32:
+			pr_debug("RELA ABS32: [%p] = 0x%x\n", location, v);
+			*location = v;
+			break;
+		case R_C6000_ABS16:
+			pr_debug("RELA ABS16: [%p] = 0x%x\n", location, v);
+			*(u16 *)location = v;
+			break;
+		case R_C6000_ABS8:
+			pr_debug("RELA ABS8: [%p] = 0x%x\n", location, v);
+			*(u8 *)location = v;
+			break;
+		case R_C6000_ABS_L16:
+			opcode = *location;
+			opcode &= ~0x7fff80;
+			opcode |= ((v & 0xffff) << 7);
+			pr_debug("RELA ABS_L16[%p] v[0x%x] opcode[0x%x]\n",
+				 location, v, opcode);
+			*location = opcode;
+			break;
+		case R_C6000_ABS_H16:
+			opcode = *location;
+			opcode &= ~0x7fff80;
+			opcode |= ((v >> 9) & 0x7fff80);
+			pr_debug("RELA ABS_H16[%p] v[0x%x] opcode[0x%x]\n",
+				 location, v, opcode);
+			*location = opcode;
+			break;
+		case R_C6000_PCR_S21:
+			if (fixup_pcr(location, v, 21, 7))
+				return -ENOEXEC;
+			break;
+		case R_C6000_PCR_S12:
+			if (fixup_pcr(location, v, 12, 16))
+				return -ENOEXEC;
+			break;
+		case R_C6000_PCR_S10:
+			if (fixup_pcr(location, v, 10, 13))
+				return -ENOEXEC;
+			break;
+		default:
+			pr_err("module %s: Unknown RELA relocation: %u\n",
+			       me->name, ELF32_R_TYPE(rel[i].r_info));
+			return -ENOEXEC;
+		}
+	}
+
+	return 0;
+}