1 files changed, 933 insertions, 0 deletions

diff --git a/arch/mips/kernel/vpe.c b/arch/mips/kernel/vpe.c
new file mode 100644
index 000000000..0d5f9c8f5
--- /dev/null
+++ b/arch/mips/kernel/vpe.c
@@ -0,0 +1,933 @@
+/*
+ * 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.
+ *
+ * Copyright (C) 2004, 2005 MIPS Technologies, Inc.  All rights reserved.
+ * Copyright (C) 2013 Imagination Technologies Ltd.
+ *
+ * VPE spport module for loading a MIPS SP program into VPE1. The SP
+ * environment is rather simple since there are no TLBs. It needs
+ * to be relocatable (or partiall linked). Initialize your stack in
+ * the startup-code. The loader looks for the symbol __start and sets
+ * up the execution to resume from there. To load and run, simply do
+ * a cat SP 'binary' to the /dev/vpe1 device.
+ */
+#include <linux/kernel.h>
+#include <linux/device.h>
+#include <linux/fs.h>
+#include <linux/init.h>
+#include <linux/slab.h>
+#include <linux/list.h>
+#include <linux/vmalloc.h>
+#include <linux/elf.h>
+#include <linux/seq_file.h>
+#include <linux/syscalls.h>
+#include <linux/moduleloader.h>
+#include <linux/interrupt.h>
+#include <linux/poll.h>
+#include <linux/bootmem.h>
+#include <asm/mipsregs.h>
+#include <asm/mipsmtregs.h>
+#include <asm/cacheflush.h>
+#include <linux/atomic.h>
+#include <asm/mips_mt.h>
+#include <asm/processor.h>
+#include <asm/vpe.h>
+
+#ifndef ARCH_SHF_SMALL
+#define ARCH_SHF_SMALL 0
+#endif
+
+/* If this is set, the section belongs in the init part of the module */
+#define INIT_OFFSET_MASK (1UL << (BITS_PER_LONG-1))
+
+struct vpe_control vpecontrol = {
+	.vpe_list_lock	= __SPIN_LOCK_UNLOCKED(vpe_list_lock),
+	.vpe_list	= LIST_HEAD_INIT(vpecontrol.vpe_list),
+	.tc_list_lock	= __SPIN_LOCK_UNLOCKED(tc_list_lock),
+	.tc_list	= LIST_HEAD_INIT(vpecontrol.tc_list)
+};
+
+/* get the vpe associated with this minor */
+struct vpe *get_vpe(int minor)
+{
+	struct vpe *res, *v;
+
+	if (!cpu_has_mipsmt)
+		return NULL;
+
+	res = NULL;
+	spin_lock(&vpecontrol.vpe_list_lock);
+	list_for_each_entry(v, &vpecontrol.vpe_list, list) {
+		if (v->minor == VPE_MODULE_MINOR) {
+			res = v;
+			break;
+		}
+	}
+	spin_unlock(&vpecontrol.vpe_list_lock);
+
+	return res;
+}
+
+/* get the vpe associated with this minor */
+struct tc *get_tc(int index)
+{
+	struct tc *res, *t;
+
+	res = NULL;
+	spin_lock(&vpecontrol.tc_list_lock);
+	list_for_each_entry(t, &vpecontrol.tc_list, list) {
+		if (t->index == index) {
+			res = t;
+			break;
+		}
+	}
+	spin_unlock(&vpecontrol.tc_list_lock);
+
+	return res;
+}
+
+/* allocate a vpe and associate it with this minor (or index) */
+struct vpe *alloc_vpe(int minor)
+{
+	struct vpe *v;
+
+	v = kzalloc(sizeof(struct vpe), GFP_KERNEL);
+	if (v == NULL)
+		goto out;
+
+	INIT_LIST_HEAD(&v->tc);
+	spin_lock(&vpecontrol.vpe_list_lock);
+	list_add_tail(&v->list, &vpecontrol.vpe_list);
+	spin_unlock(&vpecontrol.vpe_list_lock);
+
+	INIT_LIST_HEAD(&v->notify);
+	v->minor = VPE_MODULE_MINOR;
+
+out:
+	return v;
+}
+
+/* allocate a tc. At startup only tc0 is running, all other can be halted. */
+struct tc *alloc_tc(int index)
+{
+	struct tc *tc;
+
+	tc = kzalloc(sizeof(struct tc), GFP_KERNEL);
+	if (tc == NULL)
+		goto out;
+
+	INIT_LIST_HEAD(&tc->tc);
+	tc->index = index;
+
+	spin_lock(&vpecontrol.tc_list_lock);
+	list_add_tail(&tc->list, &vpecontrol.tc_list);
+	spin_unlock(&vpecontrol.tc_list_lock);
+
+out:
+	return tc;
+}
+
+/* clean up and free everything */
+void release_vpe(struct vpe *v)
+{
+	list_del(&v->list);
+	if (v->load_addr)
+		release_progmem(v->load_addr);
+	kfree(v);
+}
+
+/* Find some VPE program space */
+void *alloc_progmem(unsigned long len)
+{
+	void *addr;
+
+#ifdef CONFIG_MIPS_VPE_LOADER_TOM
+	/*
+	 * This means you must tell Linux to use less memory than you
+	 * physically have, for example by passing a mem= boot argument.
+	 */
+	addr = pfn_to_kaddr(max_low_pfn);
+	memset(addr, 0, len);
+#else
+	/* simple grab some mem for now */
+	addr = kzalloc(len, GFP_KERNEL);
+#endif
+
+	return addr;
+}
+
+void release_progmem(void *ptr)
+{
+#ifndef CONFIG_MIPS_VPE_LOADER_TOM
+	kfree(ptr);
+#endif
+}
+
+/* Update size with this section: return offset. */
+static long get_offset(unsigned long *size, Elf_Shdr *sechdr)
+{
+	long ret;
+
+	ret = ALIGN(*size, sechdr->sh_addralign ? : 1);
+	*size = ret + sechdr->sh_size;
+	return ret;
+}
+
+/* Lay out the SHF_ALLOC sections in a way not dissimilar to how ld
+   might -- code, read-only data, read-write data, small data.	Tally
+   sizes, and place the offsets into sh_entsize fields: high bit means it
+   belongs in init. */
+static void layout_sections(struct module *mod, const Elf_Ehdr *hdr,
+			    Elf_Shdr *sechdrs, const char *secstrings)
+{
+	static unsigned long const masks[][2] = {
+		/* NOTE: all executable code must be the first section
+		 * in this array; otherwise modify the text_size
+		 * finder in the two loops below */
+		{SHF_EXECINSTR | SHF_ALLOC, ARCH_SHF_SMALL},
+		{SHF_ALLOC, SHF_WRITE | ARCH_SHF_SMALL},
+		{SHF_WRITE | SHF_ALLOC, ARCH_SHF_SMALL},
+		{ARCH_SHF_SMALL | SHF_ALLOC, 0}
+	};
+	unsigned int m, i;
+
+	for (i = 0; i < hdr->e_shnum; i++)
+		sechdrs[i].sh_entsize = ~0UL;
+
+	for (m = 0; m < ARRAY_SIZE(masks); ++m) {
+		for (i = 0; i < hdr->e_shnum; ++i) {
+			Elf_Shdr *s = &sechdrs[i];
+
+			if ((s->sh_flags & masks[m][0]) != masks[m][0]
+			    || (s->sh_flags & masks[m][1])
+			    || s->sh_entsize != ~0UL)
+				continue;
+			s->sh_entsize =
+				get_offset((unsigned long *)&mod->core_layout.size, s);
+		}
+
+		if (m == 0)
+			mod->core_layout.text_size = mod->core_layout.size;
+
+	}
+}
+
+/* from module-elf32.c, but subverted a little */
+
+struct mips_hi16 {
+	struct mips_hi16 *next;
+	Elf32_Addr *addr;
+	Elf32_Addr value;
+};
+
+static struct mips_hi16 *mips_hi16_list;
+static unsigned int gp_offs, gp_addr;
+
+static int apply_r_mips_none(struct module *me, uint32_t *location,
+			     Elf32_Addr v)
+{
+	return 0;
+}
+
+static int apply_r_mips_gprel16(struct module *me, uint32_t *location,
+				Elf32_Addr v)
+{
+	int rel;
+
+	if (!(*location & 0xffff)) {
+		rel = (int)v - gp_addr;
+	} else {
+		/* .sbss + gp(relative) + offset */
+		/* kludge! */
+		rel =  (int)(short)((int)v + gp_offs +
+				    (int)(short)(*location & 0xffff) - gp_addr);
+	}
+
+	if ((rel > 32768) || (rel < -32768)) {
+		pr_debug("VPE loader: apply_r_mips_gprel16: relative address 0x%x out of range of gp register\n",
+			 rel);
+		return -ENOEXEC;
+	}
+
+	*location = (*location & 0xffff0000) | (rel & 0xffff);
+
+	return 0;
+}
+
+static int apply_r_mips_pc16(struct module *me, uint32_t *location,
+			     Elf32_Addr v)
+{
+	int rel;
+	rel = (((unsigned int)v - (unsigned int)location));
+	rel >>= 2; /* because the offset is in _instructions_ not bytes. */
+	rel -= 1;  /* and one instruction less due to the branch delay slot. */
+
+	if ((rel > 32768) || (rel < -32768)) {
+		pr_debug("VPE loader: apply_r_mips_pc16: relative address out of range 0x%x\n",
+			 rel);
+		return -ENOEXEC;
+	}
+
+	*location = (*location & 0xffff0000) | (rel & 0xffff);
+
+	return 0;
+}
+
+static int apply_r_mips_32(struct module *me, uint32_t *location,
+			   Elf32_Addr v)
+{
+	*location += v;
+
+	return 0;
+}
+
+static int apply_r_mips_26(struct module *me, uint32_t *location,
+			   Elf32_Addr v)
+{
+	if (v % 4) {
+		pr_debug("VPE loader: apply_r_mips_26: unaligned relocation\n");
+		return -ENOEXEC;
+	}
+
+/*
+ * Not desperately convinced this is a good check of an overflow condition
+ * anyway. But it gets in the way of handling undefined weak symbols which
+ * we want to set to zero.
+ * if ((v & 0xf0000000) != (((unsigned long)location + 4) & 0xf0000000)) {
+ * printk(KERN_ERR
+ * "module %s: relocation overflow\n",
+ * me->name);
+ * return -ENOEXEC;
+ * }
+ */
+
+	*location = (*location & ~0x03ffffff) |
+		((*location + (v >> 2)) & 0x03ffffff);
+	return 0;
+}
+
+static int apply_r_mips_hi16(struct module *me, uint32_t *location,
+			     Elf32_Addr v)
+{
+	struct mips_hi16 *n;
+
+	/*
+	 * We cannot relocate this one now because we don't know the value of
+	 * the carry we need to add.  Save the information, and let LO16 do the
+	 * actual relocation.
+	 */
+	n = kmalloc(sizeof(*n), GFP_KERNEL);
+	if (!n)
+		return -ENOMEM;
+
+	n->addr = location;
+	n->value = v;
+	n->next = mips_hi16_list;
+	mips_hi16_list = n;
+
+	return 0;
+}
+
+static int apply_r_mips_lo16(struct module *me, uint32_t *location,
+			     Elf32_Addr v)
+{
+	unsigned long insnlo = *location;
+	Elf32_Addr val, vallo;
+	struct mips_hi16 *l, *next;
+
+	/* Sign extend the addend we extract from the lo insn.	*/
+	vallo = ((insnlo & 0xffff) ^ 0x8000) - 0x8000;
+
+	if (mips_hi16_list != NULL) {
+
+		l = mips_hi16_list;
+		while (l != NULL) {
+			unsigned long insn;
+
+			/*
+			 * The value for the HI16 had best be the same.
+			 */
+			if (v != l->value) {
+				pr_debug("VPE loader: apply_r_mips_lo16/hi16: inconsistent value information\n");
+				goto out_free;
+			}
+
+			/*
+			 * Do the HI16 relocation.  Note that we actually don't
+			 * need to know anything about the LO16 itself, except
+			 * where to find the low 16 bits of the addend needed
+			 * by the LO16.
+			 */
+			insn = *l->addr;
+			val = ((insn & 0xffff) << 16) + vallo;
+			val += v;
+
+			/*
+			 * Account for the sign extension that will happen in
+			 * the low bits.
+			 */
+			val = ((val >> 16) + ((val & 0x8000) != 0)) & 0xffff;
+
+			insn = (insn & ~0xffff) | val;
+			*l->addr = insn;
+
+			next = l->next;
+			kfree(l);
+			l = next;
+		}
+
+		mips_hi16_list = NULL;
+	}
+
+	/*
+	 * Ok, we're done with the HI16 relocs.	 Now deal with the LO16.
+	 */
+	val = v + vallo;
+	insnlo = (insnlo & ~0xffff) | (val & 0xffff);
+	*location = insnlo;
+
+	return 0;
+
+out_free:
+	while (l != NULL) {
+		next = l->next;
+		kfree(l);
+		l = next;
+	}
+	mips_hi16_list = NULL;
+
+	return -ENOEXEC;
+}
+
+static int (*reloc_handlers[]) (struct module *me, uint32_t *location,
+				Elf32_Addr v) = {
+	[R_MIPS_NONE]	= apply_r_mips_none,
+	[R_MIPS_32]	= apply_r_mips_32,
+	[R_MIPS_26]	= apply_r_mips_26,
+	[R_MIPS_HI16]	= apply_r_mips_hi16,
+	[R_MIPS_LO16]	= apply_r_mips_lo16,
+	[R_MIPS_GPREL16] = apply_r_mips_gprel16,
+	[R_MIPS_PC16] = apply_r_mips_pc16
+};
+
+static char *rstrs[] = {
+	[R_MIPS_NONE]	= "MIPS_NONE",
+	[R_MIPS_32]	= "MIPS_32",
+	[R_MIPS_26]	= "MIPS_26",
+	[R_MIPS_HI16]	= "MIPS_HI16",
+	[R_MIPS_LO16]	= "MIPS_LO16",
+	[R_MIPS_GPREL16] = "MIPS_GPREL16",
+	[R_MIPS_PC16] = "MIPS_PC16"
+};
+
+static int apply_relocations(Elf32_Shdr *sechdrs,
+		      const char *strtab,
+		      unsigned int symindex,
+		      unsigned int relsec,
+		      struct module *me)
+{
+	Elf32_Rel *rel = (void *) sechdrs[relsec].sh_addr;
+	Elf32_Sym *sym;
+	uint32_t *location;
+	unsigned int i;
+	Elf32_Addr v;
+	int res;
+
+	for (i = 0; i < sechdrs[relsec].sh_size / sizeof(*rel); i++) {
+		Elf32_Word r_info = rel[i].r_info;
+
+		/* 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 */
+		sym = (Elf32_Sym *)sechdrs[symindex].sh_addr
+			+ ELF32_R_SYM(r_info);
+
+		if (!sym->st_value) {
+			pr_debug("%s: undefined weak symbol %s\n",
+				 me->name, strtab + sym->st_name);
+			/* just print the warning, dont barf */
+		}
+
+		v = sym->st_value;
+
+		res = reloc_handlers[ELF32_R_TYPE(r_info)](me, location, v);
+		if (res) {
+			char *r = rstrs[ELF32_R_TYPE(r_info)];
+			pr_warn("VPE loader: .text+0x%x relocation type %s for symbol \"%s\" failed\n",
+				rel[i].r_offset, r ? r : "UNKNOWN",
+				strtab + sym->st_name);
+			return res;
+		}
+	}
+
+	return 0;
+}
+
+static inline void save_gp_address(unsigned int secbase, unsigned int rel)
+{
+	gp_addr = secbase + rel;
+	gp_offs = gp_addr - (secbase & 0xffff0000);
+}
+/* end module-elf32.c */
+
+/* Change all symbols so that sh_value encodes the pointer directly. */
+static void simplify_symbols(Elf_Shdr *sechdrs,
+			    unsigned int symindex,
+			    const char *strtab,
+			    const char *secstrings,
+			    unsigned int nsecs, struct module *mod)
+{
+	Elf_Sym *sym = (void *)sechdrs[symindex].sh_addr;
+	unsigned long secbase, bssbase = 0;
+	unsigned int i, n = sechdrs[symindex].sh_size / sizeof(Elf_Sym);
+	int size;
+
+	/* find the .bss section for COMMON symbols */
+	for (i = 0; i < nsecs; i++) {
+		if (strncmp(secstrings + sechdrs[i].sh_name, ".bss", 4) == 0) {
+			bssbase = sechdrs[i].sh_addr;
+			break;
+		}
+	}
+
+	for (i = 1; i < n; i++) {
+		switch (sym[i].st_shndx) {
+		case SHN_COMMON:
+			/* Allocate space for the symbol in the .bss section.
+			   st_value is currently size.
+			   We want it to have the address of the symbol. */
+
+			size = sym[i].st_value;
+			sym[i].st_value = bssbase;
+
+			bssbase += size;
+			break;
+
+		case SHN_ABS:
+			/* Don't need to do anything */
+			break;
+
+		case SHN_UNDEF:
+			/* ret = -ENOENT; */
+			break;
+
+		case SHN_MIPS_SCOMMON:
+			pr_debug("simplify_symbols: ignoring SHN_MIPS_SCOMMON symbol <%s> st_shndx %d\n",
+				 strtab + sym[i].st_name, sym[i].st_shndx);
+			/* .sbss section */
+			break;
+
+		default:
+			secbase = sechdrs[sym[i].st_shndx].sh_addr;
+
+			if (strncmp(strtab + sym[i].st_name, "_gp", 3) == 0)
+				save_gp_address(secbase, sym[i].st_value);
+
+			sym[i].st_value += secbase;
+			break;
+		}
+	}
+}
+
+#ifdef DEBUG_ELFLOADER
+static void dump_elfsymbols(Elf_Shdr *sechdrs, unsigned int symindex,
+			    const char *strtab, struct module *mod)
+{
+	Elf_Sym *sym = (void *)sechdrs[symindex].sh_addr;
+	unsigned int i, n = sechdrs[symindex].sh_size / sizeof(Elf_Sym);
+
+	pr_debug("dump_elfsymbols: n %d\n", n);
+	for (i = 1; i < n; i++) {
+		pr_debug(" i %d name <%s> 0x%x\n", i, strtab + sym[i].st_name,
+			 sym[i].st_value);
+	}
+}
+#endif
+
+static int find_vpe_symbols(struct vpe *v, Elf_Shdr *sechdrs,
+				      unsigned int symindex, const char *strtab,
+				      struct module *mod)
+{
+	Elf_Sym *sym = (void *)sechdrs[symindex].sh_addr;
+	unsigned int i, n = sechdrs[symindex].sh_size / sizeof(Elf_Sym);
+
+	for (i = 1; i < n; i++) {
+		if (strcmp(strtab + sym[i].st_name, "__start") == 0)
+			v->__start = sym[i].st_value;
+
+		if (strcmp(strtab + sym[i].st_name, "vpe_shared") == 0)
+			v->shared_ptr = (void *)sym[i].st_value;
+	}
+
+	if ((v->__start == 0) || (v->shared_ptr == NULL))
+		return -1;
+
+	return 0;
+}
+
+/*
+ * Allocates a VPE with some program code space(the load address), copies the
+ * contents of the program (p)buffer performing relocatations/etc, free's it
+ * when finished.
+ */
+static int vpe_elfload(struct vpe *v)
+{
+	Elf_Ehdr *hdr;
+	Elf_Shdr *sechdrs;
+	long err = 0;
+	char *secstrings, *strtab = NULL;
+	unsigned int len, i, symindex = 0, strindex = 0, relocate = 0;
+	struct module mod; /* so we can re-use the relocations code */
+
+	memset(&mod, 0, sizeof(struct module));
+	strcpy(mod.name, "VPE loader");
+
+	hdr = (Elf_Ehdr *) v->pbuffer;
+	len = v->plen;
+
+	/* Sanity checks against insmoding binaries or wrong arch,
+	   weird elf version */
+	if (memcmp(hdr->e_ident, ELFMAG, SELFMAG) != 0
+	    || (hdr->e_type != ET_REL && hdr->e_type != ET_EXEC)
+	    || !elf_check_arch(hdr)
+	    || hdr->e_shentsize != sizeof(*sechdrs)) {
+		pr_warn("VPE loader: program wrong arch or weird elf version\n");
+
+		return -ENOEXEC;
+	}
+
+	if (hdr->e_type == ET_REL)
+		relocate = 1;
+
+	if (len < hdr->e_shoff + hdr->e_shnum * sizeof(Elf_Shdr)) {
+		pr_err("VPE loader: program length %u truncated\n", len);
+
+		return -ENOEXEC;
+	}
+
+	/* Convenience variables */
+	sechdrs = (void *)hdr + hdr->e_shoff;
+	secstrings = (void *)hdr + sechdrs[hdr->e_shstrndx].sh_offset;
+	sechdrs[0].sh_addr = 0;
+
+	/* And these should exist, but gcc whinges if we don't init them */
+	symindex = strindex = 0;
+
+	if (relocate) {
+		for (i = 1; i < hdr->e_shnum; i++) {
+			if ((sechdrs[i].sh_type != SHT_NOBITS) &&
+			    (len < sechdrs[i].sh_offset + sechdrs[i].sh_size)) {
+				pr_err("VPE program length %u truncated\n",
+				       len);
+				return -ENOEXEC;
+			}
+
+			/* Mark all sections sh_addr with their address in the
+			   temporary image. */
+			sechdrs[i].sh_addr = (size_t) hdr +
+				sechdrs[i].sh_offset;
+
+			/* Internal symbols and strings. */
+			if (sechdrs[i].sh_type == SHT_SYMTAB) {
+				symindex = i;
+				strindex = sechdrs[i].sh_link;
+				strtab = (char *)hdr +
+					sechdrs[strindex].sh_offset;
+			}
+		}
+		layout_sections(&mod, hdr, sechdrs, secstrings);
+	}
+
+	v->load_addr = alloc_progmem(mod.core_layout.size);
+	if (!v->load_addr)
+		return -ENOMEM;
+
+	pr_info("VPE loader: loading to %p\n", v->load_addr);
+
+	if (relocate) {
+		for (i = 0; i < hdr->e_shnum; i++) {
+			void *dest;
+
+			if (!(sechdrs[i].sh_flags & SHF_ALLOC))
+				continue;
+
+			dest = v->load_addr + sechdrs[i].sh_entsize;
+
+			if (sechdrs[i].sh_type != SHT_NOBITS)
+				memcpy(dest, (void *)sechdrs[i].sh_addr,
+				       sechdrs[i].sh_size);
+			/* Update sh_addr to point to copy in image. */
+			sechdrs[i].sh_addr = (unsigned long)dest;
+
+			pr_debug(" section sh_name %s sh_addr 0x%x\n",
+				 secstrings + sechdrs[i].sh_name,
+				 sechdrs[i].sh_addr);
+		}
+
+		/* Fix up syms, so that st_value is a pointer to location. */
+		simplify_symbols(sechdrs, symindex, strtab, secstrings,
+				 hdr->e_shnum, &mod);
+
+		/* Now do relocations. */
+		for (i = 1; i < hdr->e_shnum; i++) {
+			const char *strtab = (char *)sechdrs[strindex].sh_addr;
+			unsigned int info = sechdrs[i].sh_info;
+
+			/* Not a valid relocation section? */
+			if (info >= hdr->e_shnum)
+				continue;
+
+			/* Don't bother with non-allocated sections */
+			if (!(sechdrs[info].sh_flags & SHF_ALLOC))
+				continue;
+
+			if (sechdrs[i].sh_type == SHT_REL)
+				err = apply_relocations(sechdrs, strtab,
+							symindex, i, &mod);
+			else if (sechdrs[i].sh_type == SHT_RELA)
+				err = apply_relocate_add(sechdrs, strtab,
+							 symindex, i, &mod);
+			if (err < 0)
+				return err;
+
+		}
+	} else {
+		struct elf_phdr *phdr = (struct elf_phdr *)
+						((char *)hdr + hdr->e_phoff);
+
+		for (i = 0; i < hdr->e_phnum; i++) {
+			if (phdr->p_type == PT_LOAD) {
+				memcpy((void *)phdr->p_paddr,
+				       (char *)hdr + phdr->p_offset,
+				       phdr->p_filesz);
+				memset((void *)phdr->p_paddr + phdr->p_filesz,
+				       0, phdr->p_memsz - phdr->p_filesz);
+		    }
+		    phdr++;
+		}
+
+		for (i = 0; i < hdr->e_shnum; i++) {
+			/* Internal symbols and strings. */
+			if (sechdrs[i].sh_type == SHT_SYMTAB) {
+				symindex = i;
+				strindex = sechdrs[i].sh_link;
+				strtab = (char *)hdr +
+					sechdrs[strindex].sh_offset;
+
+				/*
+				 * mark symtab's address for when we try
+				 * to find the magic symbols
+				 */
+				sechdrs[i].sh_addr = (size_t) hdr +
+					sechdrs[i].sh_offset;
+			}
+		}
+	}
+
+	/* make sure it's physically written out */
+	flush_icache_range((unsigned long)v->load_addr,
+			   (unsigned long)v->load_addr + v->len);
+
+	if ((find_vpe_symbols(v, sechdrs, symindex, strtab, &mod)) < 0) {
+		if (v->__start == 0) {
+			pr_warn("VPE loader: program does not contain a __start symbol\n");
+			return -ENOEXEC;
+		}
+
+		if (v->shared_ptr == NULL)
+			pr_warn("VPE loader: program does not contain vpe_shared symbol.\n"
+				" Unable to use AMVP (AP/SP) facilities.\n");
+	}
+
+	pr_info(" elf loaded\n");
+	return 0;
+}
+
+static int getcwd(char *buff, int size)
+{
+	mm_segment_t old_fs;
+	int ret;
+
+	old_fs = get_fs();
+	set_fs(KERNEL_DS);
+
+	ret = sys_getcwd(buff, size);
+
+	set_fs(old_fs);
+
+	return ret;
+}
+
+/* checks VPE is unused and gets ready to load program	*/
+static int vpe_open(struct inode *inode, struct file *filp)
+{
+	enum vpe_state state;
+	struct vpe_notifications *notifier;
+	struct vpe *v;
+	int ret;
+
+	if (VPE_MODULE_MINOR != iminor(inode)) {
+		/* assume only 1 device at the moment. */
+		pr_warn("VPE loader: only vpe1 is supported\n");
+
+		return -ENODEV;
+	}
+
+	v = get_vpe(aprp_cpu_index());
+	if (v == NULL) {
+		pr_warn("VPE loader: unable to get vpe\n");
+
+		return -ENODEV;
+	}
+
+	state = xchg(&v->state, VPE_STATE_INUSE);
+	if (state != VPE_STATE_UNUSED) {
+		pr_debug("VPE loader: tc in use dumping regs\n");
+
+		list_for_each_entry(notifier, &v->notify, list)
+			notifier->stop(aprp_cpu_index());
+
+		release_progmem(v->load_addr);
+		cleanup_tc(get_tc(aprp_cpu_index()));
+	}
+
+	/* this of-course trashes what was there before... */
+	v->pbuffer = vmalloc(P_SIZE);
+	if (!v->pbuffer) {
+		pr_warn("VPE loader: unable to allocate memory\n");
+		return -ENOMEM;
+	}
+	v->plen = P_SIZE;
+	v->load_addr = NULL;
+	v->len = 0;
+
+	v->cwd[0] = 0;
+	ret = getcwd(v->cwd, VPE_PATH_MAX);
+	if (ret < 0)
+		pr_warn("VPE loader: open, getcwd returned %d\n", ret);
+
+	v->shared_ptr = NULL;
+	v->__start = 0;
+
+	return 0;
+}
+
+static int vpe_release(struct inode *inode, struct file *filp)
+{
+#if defined(CONFIG_MIPS_VPE_LOADER_MT) || defined(CONFIG_MIPS_VPE_LOADER_CMP)
+	struct vpe *v;
+	Elf_Ehdr *hdr;
+	int ret = 0;
+
+	v = get_vpe(aprp_cpu_index());
+	if (v == NULL)
+		return -ENODEV;
+
+	hdr = (Elf_Ehdr *) v->pbuffer;
+	if (memcmp(hdr->e_ident, ELFMAG, SELFMAG) == 0) {
+		if (vpe_elfload(v) >= 0) {
+			vpe_run(v);
+		} else {
+			pr_warn("VPE loader: ELF load failed.\n");
+			ret = -ENOEXEC;
+		}
+	} else {
+		pr_warn("VPE loader: only elf files are supported\n");
+		ret = -ENOEXEC;
+	}
+
+	/* It's good to be able to run the SP and if it chokes have a look at
+	   the /dev/rt?. But if we reset the pointer to the shared struct we
+	   lose what has happened. So perhaps if garbage is sent to the vpe
+	   device, use it as a trigger for the reset. Hopefully a nice
+	   executable will be along shortly. */
+	if (ret < 0)
+		v->shared_ptr = NULL;
+
+	vfree(v->pbuffer);
+	v->plen = 0;
+
+	return ret;
+#else
+	pr_warn("VPE loader: ELF load failed.\n");
+	return -ENOEXEC;
+#endif
+}
+
+static ssize_t vpe_write(struct file *file, const char __user *buffer,
+			 size_t count, loff_t *ppos)
+{
+	size_t ret = count;
+	struct vpe *v;
+
+	if (iminor(file_inode(file)) != VPE_MODULE_MINOR)
+		return -ENODEV;
+
+	v = get_vpe(aprp_cpu_index());
+
+	if (v == NULL)
+		return -ENODEV;
+
+	if ((count + v->len) > v->plen) {
+		pr_warn("VPE loader: elf size too big. Perhaps strip unneeded symbols\n");
+		return -ENOMEM;
+	}
+
+	count -= copy_from_user(v->pbuffer + v->len, buffer, count);
+	if (!count)
+		return -EFAULT;
+
+	v->len += count;
+	return ret;
+}
+
+const struct file_operations vpe_fops = {
+	.owner = THIS_MODULE,
+	.open = vpe_open,
+	.release = vpe_release,
+	.write = vpe_write,
+	.llseek = noop_llseek,
+};
+
+void *vpe_get_shared(int index)
+{
+	struct vpe *v = get_vpe(index);
+
+	if (v == NULL)
+		return NULL;
+
+	return v->shared_ptr;
+}
+EXPORT_SYMBOL(vpe_get_shared);
+
+int vpe_notify(int index, struct vpe_notifications *notify)
+{
+	struct vpe *v = get_vpe(index);
+
+	if (v == NULL)
+		return -1;
+
+	list_add(&notify->list, &v->notify);
+	return 0;
+}
+EXPORT_SYMBOL(vpe_notify);
+
+char *vpe_getcwd(int index)
+{
+	struct vpe *v = get_vpe(index);
+
+	if (v == NULL)
+		return NULL;
+
+	return v->cwd;
+}
+EXPORT_SYMBOL(vpe_getcwd);
+
+module_init(vpe_module_init);
+module_exit(vpe_module_exit);
+MODULE_DESCRIPTION("MIPS VPE Loader");
+MODULE_AUTHOR("Elizabeth Oldham, MIPS Technologies, Inc.");
+MODULE_LICENSE("GPL");