arch/tile: core support for Tilera 32-bit chips.

This change is the core kernel support for TILEPro and TILE64 chips.
No driver support (except the console driver) is included yet.

This includes the relevant Linux headers in asm/; the low-level
low-level "Tile architecture" headers in arch/, which are
shared with the hypervisor, etc., and are build-system agnostic;
and the relevant hypervisor headers in hv/.

Signed-off-by: Chris Metcalf <cmetcalf@tilera.com>
Acked-by: Arnd Bergmann <arnd@arndb.de>
Acked-by: FUJITA Tomonori <fujita.tomonori@lab.ntt.co.jp>
Reviewed-by: Paul Mundt <lethal@linux-sh.org>

1 files changed, 257 insertions, 0 deletions

diff --git a/arch/tile/kernel/module.c b/arch/tile/kernel/module.c
new file mode 100644
index 000000000000..ed3e91161f88
--- /dev/null
+++ b/arch/tile/kernel/module.c
@@ -0,0 +1,257 @@
+/*
+ * Copyright 2010 Tilera Corporation. All Rights Reserved.
+ *
+ *   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, version 2.
+ *
+ *   This program is distributed in the hope that it will be useful, but
+ *   WITHOUT ANY WARRANTY; without even the implied warranty of
+ *   MERCHANTABILITY OR FITNESS FOR A PARTICULAR PURPOSE, GOOD TITLE or
+ *   NON INFRINGEMENT.  See the GNU General Public License for
+ *   more details.
+ *
+ * Based on i386 version, copyright (C) 2001 Rusty Russell.
+ */
+
+#include <linux/moduleloader.h>
+#include <linux/elf.h>
+#include <linux/vmalloc.h>
+#include <linux/fs.h>
+#include <linux/string.h>
+#include <linux/kernel.h>
+#include <asm/opcode-tile.h>
+#include <asm/pgtable.h>
+
+#ifdef __tilegx__
+# define Elf_Rela Elf64_Rela
+# define ELF_R_SYM ELF64_R_SYM
+# define ELF_R_TYPE ELF64_R_TYPE
+#else
+# define Elf_Rela Elf32_Rela
+# define ELF_R_SYM ELF32_R_SYM
+# define ELF_R_TYPE ELF32_R_TYPE
+#endif
+
+#ifdef MODULE_DEBUG
+#define DEBUGP printk
+#else
+#define DEBUGP(fmt...)
+#endif
+
+/*
+ * Allocate some address space in the range MEM_MODULE_START to
+ * MEM_MODULE_END and populate it with memory.
+ */
+void *module_alloc(unsigned long size)
+{
+	struct page **pages;
+	pgprot_t prot_rwx = __pgprot(_PAGE_KERNEL | _PAGE_KERNEL_EXEC);
+	struct vm_struct *area;
+	int i = 0;
+	int npages;
+
+	if (size == 0)
+		return NULL;
+	npages = (size + PAGE_SIZE - 1) / PAGE_SIZE;
+	pages = kmalloc(npages * sizeof(struct page *), GFP_KERNEL);
+	if (pages == NULL)
+		return NULL;
+	for (; i < npages; ++i) {
+		pages[i] = alloc_page(GFP_KERNEL | __GFP_HIGHMEM);
+		if (!pages[i])
+			goto error;
+	}
+
+	area = __get_vm_area(size, VM_ALLOC, MEM_MODULE_START, MEM_MODULE_END);
+	if (!area)
+		goto error;
+
+	if (map_vm_area(area, prot_rwx, &pages)) {
+		vunmap(area->addr);
+		goto error;
+	}
+
+	return area->addr;
+
+error:
+	while (--i >= 0)
+		__free_page(pages[i]);
+	kfree(pages);
+	return NULL;
+}
+
+
+/* Free memory returned from module_alloc */
+void module_free(struct module *mod, void *module_region)
+{
+	vfree(module_region);
+	/*
+	 * FIXME: If module_region == mod->init_region, trim exception
+	 * table entries.
+	 */
+}
+
+/* We don't need anything special. */
+int module_frob_arch_sections(Elf_Ehdr *hdr,
+			      Elf_Shdr *sechdrs,
+			      char *secstrings,
+			      struct module *mod)
+{
+	return 0;
+}
+
+int apply_relocate(Elf_Shdr *sechdrs,
+		   const char *strtab,
+		   unsigned int symindex,
+		   unsigned int relsec,
+		   struct module *me)
+{
+	printk(KERN_ERR "module %s: .rel relocation unsupported\n", me->name);
+	return -ENOEXEC;
+}
+
+#ifdef __tilegx__
+/*
+ * Validate that the high 16 bits of "value" is just the sign-extension of
+ * the low 48 bits.
+ */
+static int validate_hw2_last(long value, struct module *me)
+{
+	if (((value << 16) >> 16) != value) {
+		printk("module %s: Out of range HW2_LAST value %#lx\n",
+		       me->name, value);
+		return 0;
+	}
+	return 1;
+}
+
+/*
+ * Validate that "value" isn't too big to hold in a JumpOff relocation.
+ */
+static int validate_jumpoff(long value)
+{
+	/* Determine size of jump offset. */
+	int shift = __builtin_clzl(get_JumpOff_X1(create_JumpOff_X1(-1)));
+
+	/* Check to see if it fits into the relocation slot. */
+	long f = get_JumpOff_X1(create_JumpOff_X1(value));
+	f = (f << shift) >> shift;
+
+	return f == value;
+}
+#endif
+
+int apply_relocate_add(Elf_Shdr *sechdrs,
+		       const char *strtab,
+		       unsigned int symindex,
+		       unsigned int relsec,
+		       struct module *me)
+{
+	unsigned int i;
+	Elf_Rela *rel = (void *)sechdrs[relsec].sh_addr;
+	Elf_Sym *sym;
+	u64 *location;
+	unsigned long value;
+
+	DEBUGP("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 = (Elf_Sym *)sechdrs[symindex].sh_addr
+			+ ELF_R_SYM(rel[i].r_info);
+		value = sym->st_value + rel[i].r_addend;
+
+		switch (ELF_R_TYPE(rel[i].r_info)) {
+
+#define MUNGE(func) (*location = ((*location & ~func(-1)) | func(value)))
+
+#ifndef __tilegx__
+		case R_TILE_32:
+			*(uint32_t *)location = value;
+			break;
+		case R_TILE_IMM16_X0_HA:
+			value = (value + 0x8000) >> 16;
+			/*FALLTHROUGH*/
+		case R_TILE_IMM16_X0_LO:
+			MUNGE(create_Imm16_X0);
+			break;
+		case R_TILE_IMM16_X1_HA:
+			value = (value + 0x8000) >> 16;
+			/*FALLTHROUGH*/
+		case R_TILE_IMM16_X1_LO:
+			MUNGE(create_Imm16_X1);
+			break;
+		case R_TILE_JOFFLONG_X1:
+			value -= (unsigned long) location;  /* pc-relative */
+			value = (long) value >> 3;     /* count by instrs */
+			MUNGE(create_JOffLong_X1);
+			break;
+#else
+		case R_TILEGX_64:
+			*location = value;
+			break;
+		case R_TILEGX_IMM16_X0_HW2_LAST:
+			if (!validate_hw2_last(value, me))
+				return -ENOEXEC;
+			value >>= 16;
+			/*FALLTHROUGH*/
+		case R_TILEGX_IMM16_X0_HW1:
+			value >>= 16;
+			/*FALLTHROUGH*/
+		case R_TILEGX_IMM16_X0_HW0:
+			MUNGE(create_Imm16_X0);
+			break;
+		case R_TILEGX_IMM16_X1_HW2_LAST:
+			if (!validate_hw2_last(value, me))
+				return -ENOEXEC;
+			value >>= 16;
+			/*FALLTHROUGH*/
+		case R_TILEGX_IMM16_X1_HW1:
+			value >>= 16;
+			/*FALLTHROUGH*/
+		case R_TILEGX_IMM16_X1_HW0:
+			MUNGE(create_Imm16_X1);
+			break;
+		case R_TILEGX_JUMPOFF_X1:
+			value -= (unsigned long) location;  /* pc-relative */
+			value = (long) value >> 3;     /* count by instrs */
+			if (!validate_jumpoff(value)) {
+				printk("module %s: Out of range jump to"
+				       " %#llx at %#llx (%p)\n", me->name,
+				       sym->st_value + rel[i].r_addend,
+				       rel[i].r_offset, location);
+				return -ENOEXEC;
+			}
+			MUNGE(create_JumpOff_X1);
+			break;
+#endif
+
+#undef MUNGE
+
+		default:
+			printk(KERN_ERR "module %s: Unknown relocation: %d\n",
+			       me->name, (int) ELF_R_TYPE(rel[i].r_info));
+			return -ENOEXEC;
+		}
+	}
+	return 0;
+}
+
+int module_finalize(const Elf_Ehdr *hdr,
+		    const Elf_Shdr *sechdrs,
+		    struct module *me)
+{
+	/* FIXME: perhaps remove the "writable" bit from the TLB? */
+	return 0;
+}
+
+void module_arch_cleanup(struct module *mod)
+{
+}