[PATCH] avr32 architecture

This adds support for the Atmel AVR32 architecture as well as the AT32AP7000
CPU and the AT32STK1000 development board.

AVR32 is a new high-performance 32-bit RISC microprocessor core, designed for
cost-sensitive embedded applications, with particular emphasis on low power
consumption and high code density.  The AVR32 architecture is not binary
compatible with earlier 8-bit AVR architectures.

The AVR32 architecture, including the instruction set, is described by the
AVR32 Architecture Manual, available from

http://www.atmel.com/dyn/resources/prod_documents/doc32000.pdf

The Atmel AT32AP7000 is the first CPU implementing the AVR32 architecture.  It
features a 7-stage pipeline, 16KB instruction and data caches and a full
Memory Management Unit.  It also comes with a large set of integrated
peripherals, many of which are shared with the AT91 ARM-based controllers from
Atmel.

Full data sheet is available from

http://www.atmel.com/dyn/resources/prod_documents/doc32003.pdf

while the CPU core implementation including caches and MMU is documented by
the AVR32 AP Technical Reference, available from

http://www.atmel.com/dyn/resources/prod_documents/doc32001.pdf

Information about the AT32STK1000 development board can be found at

http://www.atmel.com/dyn/products/tools_card.asp?tool_id=3918

including a BSP CD image with an earlier version of this patch, development
tools (binaries and source/patches) and a root filesystem image suitable for
booting from SD card.

Alternatively, there's a preliminary "getting started" guide available at
http://avr32linux.org/twiki/bin/view/Main/GettingStarted which provides links
to the sources and patches you will need in order to set up a cross-compiling
environment for avr32-linux.

This patch, as well as the other patches included with the BSP and the
toolchain patches, is actively supported by Atmel Corporation.

[dmccr@us.ibm.com: Fix more pxx_page macro locations]
[bunk@stusta.de: fix `make defconfig']
Signed-off-by: Haavard Skinnemoen <hskinnemoen@atmel.com>
Signed-off-by: Adrian Bunk <bunk@stusta.de>
Signed-off-by: Dave McCracken <dmccr@us.ibm.com>
Signed-off-by: Andrew Morton <akpm@osdl.org>
Signed-off-by: Linus Torvalds <torvalds@osdl.org>

1 files changed, 324 insertions, 0 deletions

diff --git a/arch/avr32/kernel/module.c b/arch/avr32/kernel/module.c
new file mode 100644
index 000000000000..dfc32f2817b6
--- /dev/null
+++ b/arch/avr32/kernel/module.c
@@ -0,0 +1,324 @@
+/*
+ * AVR32-specific kernel module loader
+ *
+ * Copyright (C) 2005-2006 Atmel Corporation
+ *
+ * GOT initialization parts are based on the s390 version
+ *   Copyright (C) 2002, 2003 IBM Deutschland Entwicklung GmbH,
+ *                            IBM Corporation
+ *
+ * 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/module.h>
+#include <linux/kernel.h>
+#include <linux/elf.h>
+#include <linux/vmalloc.h>
+
+void *module_alloc(unsigned long size)
+{
+	if (size == 0)
+		return NULL;
+	return vmalloc(size);
+}
+
+void module_free(struct module *mod, void *module_region)
+{
+	vfree(mod->arch.syminfo);
+	mod->arch.syminfo = NULL;
+
+	vfree(module_region);
+	/* FIXME: if module_region == mod->init_region, trim exception
+	 * table entries. */
+}
+
+static inline int check_rela(Elf32_Rela *rela, struct module *module,
+			     char *strings, Elf32_Sym *symbols)
+{
+	struct mod_arch_syminfo *info;
+
+	info = module->arch.syminfo + ELF32_R_SYM(rela->r_info);
+	switch (ELF32_R_TYPE(rela->r_info)) {
+	case R_AVR32_GOT32:
+	case R_AVR32_GOT16:
+	case R_AVR32_GOT8:
+	case R_AVR32_GOT21S:
+	case R_AVR32_GOT18SW:	/* mcall */
+	case R_AVR32_GOT16S:	/* ld.w */
+		if (rela->r_addend != 0) {
+			printk(KERN_ERR
+			       "GOT relocation against %s at offset %u with addend\n",
+			       strings + symbols[ELF32_R_SYM(rela->r_info)].st_name,
+			       rela->r_offset);
+			return -ENOEXEC;
+		}
+		if (info->got_offset == -1UL) {
+			info->got_offset = module->arch.got_size;
+			module->arch.got_size += sizeof(void *);
+		}
+		pr_debug("GOT[%3lu] %s\n", info->got_offset,
+			 strings + symbols[ELF32_R_SYM(rela->r_info)].st_name);
+		break;
+	}
+
+	return 0;
+}
+
+int module_frob_arch_sections(Elf_Ehdr *hdr, Elf_Shdr *sechdrs,
+			      char *secstrings, struct module *module)
+{
+	Elf32_Shdr *symtab;
+	Elf32_Sym *symbols;
+	Elf32_Rela *rela;
+	char *strings;
+	int nrela, i, j;
+	int ret;
+
+	/* Find the symbol table */
+	symtab = NULL;
+	for (i = 0; i < hdr->e_shnum; i++)
+		switch (sechdrs[i].sh_type) {
+		case SHT_SYMTAB:
+			symtab = &sechdrs[i];
+			break;
+		}
+	if (!symtab) {
+		printk(KERN_ERR "module %s: no symbol table\n", module->name);
+		return -ENOEXEC;
+	}
+
+	/* Allocate room for one syminfo structure per symbol. */
+	module->arch.nsyms = symtab->sh_size / sizeof(Elf_Sym);
+	module->arch.syminfo = vmalloc(module->arch.nsyms
+				   * sizeof(struct mod_arch_syminfo));
+	if (!module->arch.syminfo)
+		return -ENOMEM;
+
+	symbols = (void *)hdr + symtab->sh_offset;
+	strings = (void *)hdr + sechdrs[symtab->sh_link].sh_offset;
+	for (i = 0; i < module->arch.nsyms; i++) {
+		if (symbols[i].st_shndx == SHN_UNDEF &&
+		    strcmp(strings + symbols[i].st_name,
+			   "_GLOBAL_OFFSET_TABLE_") == 0)
+			/* "Define" it as absolute. */
+			symbols[i].st_shndx = SHN_ABS;
+		module->arch.syminfo[i].got_offset = -1UL;
+		module->arch.syminfo[i].got_initialized = 0;
+	}
+
+	/* Allocate GOT entries for symbols that need it. */
+	module->arch.got_size = 0;
+	for (i = 0; i < hdr->e_shnum; i++) {
+		if (sechdrs[i].sh_type != SHT_RELA)
+			continue;
+		nrela = sechdrs[i].sh_size / sizeof(Elf32_Rela);
+		rela = (void *)hdr + sechdrs[i].sh_offset;
+		for (j = 0; j < nrela; j++) {
+			ret = check_rela(rela + j, module,
+					 strings, symbols);
+			if (ret)
+				goto out_free_syminfo;
+		}
+	}
+
+	/*
+	 * Increase core size to make room for GOT and set start
+	 * offset for GOT.
+	 */
+	module->core_size = ALIGN(module->core_size, 4);
+	module->arch.got_offset = module->core_size;
+	module->core_size += module->arch.got_size;
+
+	return 0;
+
+out_free_syminfo:
+	vfree(module->arch.syminfo);
+	module->arch.syminfo = NULL;
+
+	return ret;
+}
+
+static inline int reloc_overflow(struct module *module, const char *reloc_name,
+				 Elf32_Addr relocation)
+{
+	printk(KERN_ERR "module %s: Value %lx does not fit relocation %s\n",
+	       module->name, (unsigned long)relocation, reloc_name);
+	return -ENOEXEC;
+}
+
+#define get_u16(loc)		(*((uint16_t *)loc))
+#define put_u16(loc, val)	(*((uint16_t *)loc) = (val))
+
+int apply_relocate_add(Elf32_Shdr *sechdrs, const char *strtab,
+		       unsigned int symindex, unsigned int relindex,
+		       struct module *module)
+{
+	Elf32_Shdr *symsec = sechdrs + symindex;
+	Elf32_Shdr *relsec = sechdrs + relindex;
+	Elf32_Shdr *dstsec = sechdrs + relsec->sh_info;
+	Elf32_Rela *rel = (void *)relsec->sh_addr;
+	unsigned int i;
+	int ret = 0;
+
+	for (i = 0; i < relsec->sh_size / sizeof(Elf32_Rela); i++, rel++) {
+		struct mod_arch_syminfo *info;
+		Elf32_Sym *sym;
+		Elf32_Addr relocation;
+		uint32_t *location;
+		uint32_t value;
+
+		location = (void *)dstsec->sh_addr + rel->r_offset;
+		sym = (Elf32_Sym *)symsec->sh_addr + ELF32_R_SYM(rel->r_info);
+		relocation = sym->st_value + rel->r_addend;
+
+		info = module->arch.syminfo + ELF32_R_SYM(rel->r_info);
+
+		/* Initialize GOT entry if necessary */
+		switch (ELF32_R_TYPE(rel->r_info)) {
+		case R_AVR32_GOT32:
+		case R_AVR32_GOT16:
+		case R_AVR32_GOT8:
+		case R_AVR32_GOT21S:
+		case R_AVR32_GOT18SW:
+		case R_AVR32_GOT16S:
+			if (!info->got_initialized) {
+				Elf32_Addr *gotent;
+
+				gotent = (module->module_core
+					  + module->arch.got_offset
+					  + info->got_offset);
+				*gotent = relocation;
+				info->got_initialized = 1;
+			}
+
+			relocation = info->got_offset;
+			break;
+		}
+
+		switch (ELF32_R_TYPE(rel->r_info)) {
+		case R_AVR32_32:
+		case R_AVR32_32_CPENT:
+			*location = relocation;
+			break;
+		case R_AVR32_22H_PCREL:
+			relocation -= (Elf32_Addr)location;
+			if ((relocation & 0xffe00001) != 0
+			    && (relocation & 0xffc00001) != 0xffc00000)
+				return reloc_overflow(module,
+						      "R_AVR32_22H_PCREL",
+						      relocation);
+			relocation >>= 1;
+
+			value = *location;
+			value = ((value & 0xe1ef0000)
+				 | (relocation & 0xffff)
+				 | ((relocation & 0x10000) << 4)
+				 | ((relocation & 0x1e0000) << 8));
+			*location = value;
+			break;
+		case R_AVR32_11H_PCREL:
+			relocation -= (Elf32_Addr)location;
+			if ((relocation & 0xfffffc01) != 0
+			    && (relocation & 0xfffff801) != 0xfffff800)
+				return reloc_overflow(module,
+						      "R_AVR32_11H_PCREL",
+						      relocation);
+			value = get_u16(location);
+			value = ((value & 0xf00c)
+				 | ((relocation & 0x1fe) << 3)
+				 | ((relocation & 0x600) >> 9));
+			put_u16(location, value);
+			break;
+		case R_AVR32_9H_PCREL:
+			relocation -= (Elf32_Addr)location;
+			if ((relocation & 0xffffff01) != 0
+			    && (relocation & 0xfffffe01) != 0xfffffe00)
+				return reloc_overflow(module,
+						      "R_AVR32_9H_PCREL",
+						      relocation);
+			value = get_u16(location);
+			value = ((value & 0xf00f)
+				 | ((relocation & 0x1fe) << 3));
+			put_u16(location, value);
+			break;
+		case R_AVR32_9UW_PCREL:
+			relocation -= ((Elf32_Addr)location) & 0xfffffffc;
+			if ((relocation & 0xfffffc03) != 0)
+				return reloc_overflow(module,
+						      "R_AVR32_9UW_PCREL",
+						      relocation);
+			value = get_u16(location);
+			value = ((value & 0xf80f)
+				 | ((relocation & 0x1fc) << 2));
+			put_u16(location, value);
+			break;
+		case R_AVR32_GOTPC:
+			/*
+			 * R6 = PC - (PC - GOT)
+			 *
+			 * At this point, relocation contains the
+			 * value of PC.  Just subtract the value of
+			 * GOT, and we're done.
+			 */
+			pr_debug("GOTPC: PC=0x%lx, got_offset=0x%lx, core=0x%p\n",
+				 relocation, module->arch.got_offset,
+				 module->module_core);
+			relocation -= ((unsigned long)module->module_core
+				       + module->arch.got_offset);
+			*location = relocation;
+			break;
+		case R_AVR32_GOT18SW:
+			if ((relocation & 0xfffe0003) != 0
+			    && (relocation & 0xfffc0003) != 0xffff0000)
+				return reloc_overflow(module, "R_AVR32_GOT18SW",
+						     relocation);
+			relocation >>= 2;
+			/* fall through */
+		case R_AVR32_GOT16S:
+			if ((relocation & 0xffff8000) != 0
+			    && (relocation & 0xffff0000) != 0xffff0000)
+				return reloc_overflow(module, "R_AVR32_GOT16S",
+						      relocation);
+			pr_debug("GOT reloc @ 0x%lx -> %lu\n",
+				 rel->r_offset, relocation);
+			value = *location;
+			value = ((value & 0xffff0000)
+				 | (relocation & 0xffff));
+			*location = value;
+			break;
+
+		default:
+			printk(KERN_ERR "module %s: Unknown relocation: %u\n",
+			       module->name, ELF32_R_TYPE(rel->r_info));
+			return -ENOEXEC;
+		}
+	}
+
+	return ret;
+}
+
+int apply_relocate(Elf32_Shdr *sechdrs, const char *strtab,
+		   unsigned int symindex, unsigned int relindex,
+		   struct module *module)
+{
+	printk(KERN_ERR "module %s: REL relocations are not supported\n",
+		module->name);
+	return -ENOEXEC;
+}
+
+int module_finalize(const Elf_Ehdr *hdr, const Elf_Shdr *sechdrs,
+		    struct module *module)
+{
+	vfree(module->arch.syminfo);
+	module->arch.syminfo = NULL;
+
+	return 0;
+}
+
+void module_arch_cleanup(struct module *module)
+{
+
+}