/*
   * Copyright (C) 2004, 2005 MIPS Technologies, Inc.  All rights reserved.
   *
   *  This program is free software; you can distribute it and/or modify it
   *  under the terms of the GNU General Public License (Version 2) as
   *  published by the Free Software Foundation.
   *
   *  This program is distributed in the hope it will be useful, but WITHOUT
   *  ANY WARRANTY; without even the implied warranty of MERCHANTABILITY or
   *  FITNESS FOR A PARTICULAR PURPOSE.  See the GNU General Public License
   *  for more details.
   *
   *  You should have received a copy of the GNU General Public License along
   *  with this program; if not, write to the Free Software Foundation, Inc.,
   *  59 Temple Place - Suite 330, Boston MA 02111-1307, USA.

   */
  
  /*
   * VPE support module
   *
   * Provides support for loading a MIPS SP program on VPE1.

   * The SP environment is rather simple, no tlb's.  It needs to be relocatable

   * (or partially linked). You should initialise your stack in the startup
   * code. This loader looks for the symbol __start and sets up
   * execution to resume from there. The MIPS SDE kit contains suitable examples.
   *
   * To load and run, simply cat a SP 'program file' to /dev/vpe1.
   * i.e cat spapp >/dev/vpe1.

   */

  #include <linux/kernel.h>

  #include <linux/device.h>

  #include <linux/fs.h>
  #include <linux/init.h>
  #include <asm/uaccess.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/cpu.h>

  #include <asm/mips_mt.h>

  #include <asm/processor.h>
  #include <asm/system.h>

  #include <asm/vpe.h>
  #include <asm/kspd.h>

  
  typedef void *vpe_handle;

  #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))

  /*
   * The number of TCs and VPEs physically available on the core
   */
  static int hw_tcs, hw_vpes;

  static char module_name[] = "vpe";

  static int major;

  static const int minor = 1;	/* fixed for now  */

  #ifdef CONFIG_MIPS_APSP_KSPD

  static struct kspd_notifications kspd_events;

  static int kspd_events_reqd;

  #endif

  /* grab the likely amount of memory we will need. */
  #ifdef CONFIG_MIPS_VPE_LOADER_TOM
  #define P_SIZE (2 * 1024 * 1024)
  #else
  /* add an overhead to the max kmalloc size for non-striped symbols/etc */
  #define P_SIZE (256 * 1024)
  #endif

  extern unsigned long physical_memsize;

  #define MAX_VPES 16

  #define VPE_PATH_MAX 256

  
  enum vpe_state {
  	VPE_STATE_UNUSED = 0,
  	VPE_STATE_INUSE,
  	VPE_STATE_RUNNING
  };
  
  enum tc_state {
  	TC_STATE_UNUSED = 0,
  	TC_STATE_INUSE,
  	TC_STATE_RUNNING,
  	TC_STATE_DYNAMIC
  };

  struct vpe {

  	enum vpe_state state;
  
  	/* (device) minor associated with this vpe */
  	int minor;
  
  	/* elfloader stuff */
  	void *load_addr;

  	unsigned long len;

  	char *pbuffer;

  	unsigned long plen;

  	unsigned int uid, gid;
  	char cwd[VPE_PATH_MAX];

  
  	unsigned long __start;
  
  	/* tc's associated with this vpe */
  	struct list_head tc;
  
  	/* The list of vpe's */
  	struct list_head list;
  
  	/* shared symbol address */
  	void *shared_ptr;

  
  	/* the list of who wants to know when something major happens */
  	struct list_head notify;

  
  	unsigned int ntcs;

  };
  
  struct tc {
  	enum tc_state state;
  	int index;

  	struct vpe *pvpe;	/* parent VPE */
  	struct list_head tc;	/* The list of TC's with this VPE */
  	struct list_head list;	/* The global list of tc's */

  };

  struct {

  	spinlock_t vpe_list_lock;
  	struct list_head vpe_list;	/* Virtual processing elements */
  	spinlock_t tc_list_lock;
  	struct list_head tc_list;	/* Thread contexts */

  } 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)

  };

  
  static void release_progmem(void *ptr);

  
  /* get the vpe associated with this minor */

  static 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 == minor) {
  			res = v;
  			break;
  		}

  	}

  	spin_unlock(&vpecontrol.vpe_list_lock);

  	return res;

  }
  
  /* get the vpe associated with this minor */

  static 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) */

  static struct vpe *alloc_vpe(int minor)

  {
  	struct vpe *v;

  	if ((v = kzalloc(sizeof(struct vpe), GFP_KERNEL)) == NULL)

  		return NULL;

  	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 = minor;

  	return v;
  }
  
  /* allocate a tc. At startup only tc0 is running, all other can be halted. */

  static struct tc *alloc_tc(int index)

  {

  	struct tc *tc;

  	if ((tc = kzalloc(sizeof(struct tc), GFP_KERNEL)) == 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 */

  static void release_vpe(struct vpe *v)

  {
  	list_del(&v->list);
  	if (v->load_addr)
  		release_progmem(v);
  	kfree(v);
  }

  static void __maybe_unused dump_mtregs(void)

  {
  	unsigned long val;
  
  	val = read_c0_config3();
  	printk("config3 0x%lx MT %ld
  ", val,
  	       (val & CONFIG3_MT) >> CONFIG3_MT_SHIFT);

  	val = read_c0_mvpcontrol();
  	printk("MVPControl 0x%lx, STLB %ld VPC %ld EVP %ld
  ", val,
  	       (val & MVPCONTROL_STLB) >> MVPCONTROL_STLB_SHIFT,
  	       (val & MVPCONTROL_VPC) >> MVPCONTROL_VPC_SHIFT,
  	       (val & MVPCONTROL_EVP));

  	val = read_c0_mvpconf0();
  	printk("mvpconf0 0x%lx, PVPE %ld PTC %ld M %ld
  ", val,
  	       (val & MVPCONF0_PVPE) >> MVPCONF0_PVPE_SHIFT,
  	       val & MVPCONF0_PTC, (val & MVPCONF0_M) >> MVPCONF0_M_SHIFT);

  }
  
  /* Find some VPE program space  */

  static 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;

  }
  
  static 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];
  
  			//  || strncmp(secstrings + s->sh_name, ".init", 5) == 0)
  			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_size, s);

  		}
  
  		if (m == 0)
  			mod->core_text_size = mod->core_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) ) {

  		printk(KERN_DEBUG "VPE loader: apply_r_mips_gprel16: "
  		       "relative address 0x%x out of range of gp register
  ",
  		       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) ) {

  		printk(KERN_DEBUG "VPE loader: "
   		       "apply_r_mips_pc16: relative address out of range 0x%x
  ", 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) {

  		printk(KERN_DEBUG "VPE loader: apply_r_mips_26 "
  		       " unaligned relocation
  ");

  		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
  ",
   * 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) {
  				printk(KERN_DEBUG "VPE loader: "

  				       "apply_r_mips_lo16/hi16: \t"

  				       "inconsistent value information
  ");

  				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) {
  			printk(KERN_DEBUG "%s: undefined weak symbol %s
  ",
  			       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)];
  		    	printk(KERN_WARNING "VPE loader: .text+0x%x "
  			       "relocation type %s for symbol \"%s\" failed
  ",
  			       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:

  			printk(KERN_DEBUG "simplify_symbols: ignoring SHN_MIPS_SCOMMON "

  			       "symbol <%s> st_shndx %d
  ", 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);
  
  	printk(KERN_DEBUG "dump_elfsymbols: n %d
  ", n);
  	for (i = 1; i < n; i++) {
  		printk(KERN_DEBUG " i %d name <%s> 0x%x
  ", i,
  		       strtab + sym[i].st_name, sym[i].st_value);
  	}
  }
  #endif

  /* We are prepared so configure and start the VPE... */

  static int vpe_run(struct vpe * v)

  {

  	unsigned long flags, val, dmt_flag;

  	struct vpe_notifications *n;

  	unsigned int vpeflags;

  	struct tc *t;
  
  	/* check we are the Master VPE */

  	local_irq_save(flags);

  	val = read_c0_vpeconf0();
  	if (!(val & VPECONF0_MVP)) {
  		printk(KERN_WARNING

  		       "VPE loader: only Master VPE's are allowed to configure MT
  ");

  		local_irq_restore(flags);

  		return -1;
  	}

  	dmt_flag = dmt();
  	vpeflags = dvpe();

  	if (!list_empty(&v->tc)) {

  		if ((t = list_entry(v->tc.next, struct tc, tc)) == NULL) {

  			evpe(vpeflags);
  			emt(dmt_flag);
  			local_irq_restore(flags);
  
  			printk(KERN_WARNING
  			       "VPE loader: TC %d is already in use.
  ",
                                 t->index);

  			return -ENOEXEC;
  		}
  	} else {

  		evpe(vpeflags);
  		emt(dmt_flag);
  		local_irq_restore(flags);
  
  		printk(KERN_WARNING
  		       "VPE loader: No TC's associated with VPE %d
  ",

  		       v->minor);

  		return -ENOEXEC;
  	}

  	/* Put MVPE's into 'configuration state' */

  	set_c0_mvpcontrol(MVPCONTROL_VPC);

  	settc(t->index);

  	/* should check it is halted, and not activated */
  	if ((read_tc_c0_tcstatus() & TCSTATUS_A) || !(read_tc_c0_tchalt() & TCHALT_H)) {

  		evpe(vpeflags);
  		emt(dmt_flag);
  		local_irq_restore(flags);
  
  		printk(KERN_WARNING "VPE loader: TC %d is already active!
  ",

  		       t->index);

  		return -ENOEXEC;
  	}
  
  	/* Write the address we want it to start running from in the TCPC register. */
  	write_tc_c0_tcrestart((unsigned long)v->__start);

  	write_tc_c0_tccontext((unsigned long)0);

  	/*
  	 * Mark the TC as activated, not interrupt exempt and not dynamically
  	 * allocatable
  	 */

  	val = read_tc_c0_tcstatus();
  	val = (val & ~(TCSTATUS_DA | TCSTATUS_IXMT)) | TCSTATUS_A;
  	write_tc_c0_tcstatus(val);
  
  	write_tc_c0_tchalt(read_tc_c0_tchalt() & ~TCHALT_H);

  	/*
  	 * The sde-kit passes 'memsize' to __start in $a3, so set something

  	 * here...  Or set $a3 to zero and define DFLT_STACK_SIZE and

  	 * DFLT_HEAP_SIZE when you compile your program
  	 */

  	mttgpr(6, v->ntcs);

  	mttgpr(7, physical_memsize);

  
  	/* set up VPE1 */
  	/*
  	 * bind the TC to VPE 1 as late as possible so we only have the final
  	 * VPE registers to set up, and so an EJTAG probe can trigger on it
  	 */

  	write_tc_c0_tcbind((read_tc_c0_tcbind() & ~TCBIND_CURVPE) | 1);

  	write_vpe_c0_vpeconf0(read_vpe_c0_vpeconf0() & ~(VPECONF0_VPA));
  
  	back_to_back_c0_hazard();

  	/* Set up the XTC bit in vpeconf0 to point at our tc */
  	write_vpe_c0_vpeconf0( (read_vpe_c0_vpeconf0() & ~(VPECONF0_XTC))
  	                      | (t->index << VPECONF0_XTC_SHIFT));

  	back_to_back_c0_hazard();

  	/* enable this VPE */
  	write_vpe_c0_vpeconf0(read_vpe_c0_vpeconf0() | VPECONF0_VPA);

  
  	/* clear out any left overs from a previous program */

  	write_vpe_c0_status(0);

  	write_vpe_c0_cause(0);
  
  	/* take system out of configuration state */

  	clear_c0_mvpcontrol(MVPCONTROL_VPC);

  	/*
  	 * SMTC/SMVP kernels manage VPE enable independently,
  	 * but uniprocessor kernels need to turn it on, even
  	 * if that wasn't the pre-dvpe() state.
  	 */

  #ifdef CONFIG_SMP

  	evpe(vpeflags);

  #else
  	evpe(EVPE_ENABLE);

  #endif
  	emt(dmt_flag);
  	local_irq_restore(flags);

  	list_for_each_entry(n, &v->notify, list)
  		n->start(minor);

  	return 0;
  }

  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)) {
  		printk(KERN_WARNING

  		       "VPE loader: program wrong arch or weird elf version
  ");

  
  		return -ENOEXEC;
  	}

  	if (hdr->e_type == ET_REL)
  		relocate = 1;

  	if (len < hdr->e_shoff + hdr->e_shnum * sizeof(Elf_Shdr)) {

  		printk(KERN_ERR "VPE loader: program length %u truncated
  ",
  		       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) {
  				printk(KERN_ERR "VPE program length %u truncated
  ",
  				       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_size);

  	if (!v->load_addr)
  		return -ENOMEM;

  	pr_info("VPE loader: loading to %p
  ", 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;

  			printk(KERN_DEBUG " section sh_name %s sh_addr 0x%x
  ",
  			       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 the 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) {
  			printk(KERN_WARNING "VPE loader: program does not contain "
  			       "a __start symbol
  ");
  			return -ENOEXEC;
  		}

  		if (v->shared_ptr == NULL)
  			printk(KERN_WARNING "VPE loader: "
  			       "program does not contain vpe_shared symbol.
  "
  			       " Unable to use AMVP (AP/SP) facilities.
  ");

  	}
  
  	printk(" elf loaded
  ");

  	return 0;

  }

  static void cleanup_tc(struct tc *tc)
  {

  	unsigned long flags;
  	unsigned int mtflags, vpflags;

  	int tmp;

  	local_irq_save(flags);
  	mtflags = dmt();
  	vpflags = dvpe();

  	/* Put MVPE's into 'configuration state' */
  	set_c0_mvpcontrol(MVPCONTROL_VPC);
  
  	settc(tc->index);
  	tmp = read_tc_c0_tcstatus();
  
  	/* mark not allocated and not dynamically allocatable */
  	tmp &= ~(TCSTATUS_A | TCSTATUS_DA);
  	tmp |= TCSTATUS_IXMT;	/* interrupt exempt */
  	write_tc_c0_tcstatus(tmp);
  
  	write_tc_c0_tchalt(TCHALT_H);

  	mips_ihb();

  
  	/* bind it to anything other than VPE1 */

  //	write_tc_c0_tcbind(read_tc_c0_tcbind() & ~TCBIND_CURVPE); // | TCBIND_CURVPE

  
  	clear_c0_mvpcontrol(MVPCONTROL_VPC);

  	evpe(vpflags);
  	emt(mtflags);
  	local_irq_restore(flags);

  }
  
  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 *not;

  	struct vpe *v;

  	int ret;

  	if (minor != iminor(inode)) {
  		/* assume only 1 device at the moment. */

  		pr_warning("VPE loader: only vpe1 is supported
  ");
  
  		return -ENODEV;

  	}

  	if ((v = get_vpe(tclimit)) == NULL) {

  		pr_warning("VPE loader: unable to get vpe
  ");
  
  		return -ENODEV;

  	}

  	state = xchg(&v->state, VPE_STATE_INUSE);
  	if (state != VPE_STATE_UNUSED) {

  		printk(KERN_DEBUG "VPE loader: tc in use dumping regs
  ");

  		list_for_each_entry(not, &v->notify, list) {

  			not->stop(tclimit);

  		}

  		release_progmem(v->load_addr);

  		cleanup_tc(get_tc(tclimit));

  	}

  	/* this of-course trashes what was there before... */
  	v->pbuffer = vmalloc(P_SIZE);

  	if (!v->pbuffer) {
  		pr_warning("VPE loader: unable to allocate memory
  ");
  		return -ENOMEM;
  	}

  	v->plen = P_SIZE;
  	v->load_addr = NULL;
  	v->len = 0;

  	v->uid = filp->f_cred->fsuid;
  	v->gid = filp->f_cred->fsgid;

  
  #ifdef CONFIG_MIPS_APSP_KSPD
  	/* get kspd to tell us when a syscall_exit happens */
  	if (!kspd_events_reqd) {
  		kspd_notify(&kspd_events);
  		kspd_events_reqd++;
  	}
  #endif
  
  	v->cwd[0] = 0;
  	ret = getcwd(v->cwd, VPE_PATH_MAX);
  	if (ret < 0)
  		printk(KERN_WARNING "VPE loader: open, getcwd returned %d
  ", ret);
  
  	v->shared_ptr = NULL;
  	v->__start = 0;

  	return 0;
  }
  
  static int vpe_release(struct inode *inode, struct file *filp)
  {

  	struct vpe *v;

  	Elf_Ehdr *hdr;

  	int ret = 0;

  	v = get_vpe(tclimit);
  	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 {

   			printk(KERN_WARNING "VPE loader: ELF load failed.
  ");

  			ret = -ENOEXEC;
  		}
  	} else {

   		printk(KERN_WARNING "VPE loader: only elf files are supported
  ");

  		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;
  }
  
  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->f_path.dentry->d_inode) != minor)
  		return -ENODEV;
  
  	v = get_vpe(tclimit);
  	if (v == NULL)

  		return -ENODEV;

  	if ((count + v->len) > v->plen) {
  		printk(KERN_WARNING

  		       "VPE loader: elf size too big. Perhaps strip uneeded symbols
  ");

  		return -ENOMEM;
  	}
  
  	count -= copy_from_user(v->pbuffer + v->len, buffer, count);

  	if (!count)

  		return -EFAULT;

  
  	v->len += count;
  	return ret;
  }

  static const struct file_operations vpe_fops = {

  	.owner = THIS_MODULE,
  	.open = vpe_open,
  	.release = vpe_release,

  	.write = vpe_write,
  	.llseek = noop_llseek,

  };
  
  /* module wrapper entry points */
  /* give me a vpe */
  vpe_handle vpe_alloc(void)
  {
  	int i;
  	struct vpe *v;
  
  	/* find a vpe */
  	for (i = 1; i < MAX_VPES; i++) {
  		if ((v = get_vpe(i)) != NULL) {
  			v->state = VPE_STATE_INUSE;
  			return v;
  		}
  	}
  	return NULL;
  }
  
  EXPORT_SYMBOL(vpe_alloc);
  
  /* start running from here */
  int vpe_start(vpe_handle vpe, unsigned long start)
  {
  	struct vpe *v = vpe;
  
  	v->__start = start;
  	return vpe_run(v);
  }
  
  EXPORT_SYMBOL(vpe_start);
  
  /* halt it for now */
  int vpe_stop(vpe_handle vpe)
  {
  	struct vpe *v = vpe;
  	struct tc *t;
  	unsigned int evpe_flags;
  
  	evpe_flags = dvpe();
  
  	if ((t = list_entry(v->tc.next, struct tc, tc)) != NULL) {
  
  		settc(t->index);
  		write_vpe_c0_vpeconf0(read_vpe_c0_vpeconf0() & ~VPECONF0_VPA);
  	}
  
  	evpe(evpe_flags);
  
  	return 0;
  }
  
  EXPORT_SYMBOL(vpe_stop);
  
  /* I've done with it thank you */
  int vpe_free(vpe_handle vpe)
  {
  	struct vpe *v = vpe;
  	struct tc *t;
  	unsigned int evpe_flags;
  
  	if ((t = list_entry(v->tc.next, struct tc, tc)) == NULL) {
  		return -ENOEXEC;
  	}
  
  	evpe_flags = dvpe();
  
  	/* Put MVPE's into 'configuration state' */

  	set_c0_mvpcontrol(MVPCONTROL_VPC);

  
  	settc(t->index);
  	write_vpe_c0_vpeconf0(read_vpe_c0_vpeconf0() & ~VPECONF0_VPA);

  	/* halt the TC */

  	write_tc_c0_tchalt(TCHALT_H);

  	mips_ihb();
  
  	/* mark the TC unallocated */
  	write_tc_c0_tcstatus(read_tc_c0_tcstatus() & ~TCSTATUS_A);

  
  	v->state = VPE_STATE_UNUSED;

  	clear_c0_mvpcontrol(MVPCONTROL_VPC);

  	evpe(evpe_flags);
  
  	return 0;
  }
  
  EXPORT_SYMBOL(vpe_free);
  
  void *vpe_get_shared(int index)
  {
  	struct vpe *v;

  	if ((v = get_vpe(index)) == NULL)

  		return NULL;

  
  	return v->shared_ptr;
  }
  
  EXPORT_SYMBOL(vpe_get_shared);

  int vpe_getuid(int index)
  {
  	struct vpe *v;
  
  	if ((v = get_vpe(index)) == NULL)
  		return -1;
  
  	return v->uid;
  }
  
  EXPORT_SYMBOL(vpe_getuid);
  
  int vpe_getgid(int index)
  {
  	struct vpe *v;
  
  	if ((v = get_vpe(index)) == NULL)
  		return -1;
  
  	return v->gid;
  }
  
  EXPORT_SYMBOL(vpe_getgid);
  
  int vpe_notify(int index, struct vpe_notifications *notify)
  {
  	struct vpe *v;
  
  	if ((v = get_vpe(index)) == NULL)
  		return -1;
  
  	list_add(&notify->list, &v->notify);
  	return 0;
  }
  
  EXPORT_SYMBOL(vpe_notify);
  
  char *vpe_getcwd(int index)
  {
  	struct vpe *v;
  
  	if ((v = get_vpe(index)) == NULL)
  		return NULL;
  
  	return v->cwd;
  }
  
  EXPORT_SYMBOL(vpe_getcwd);
  
  #ifdef CONFIG_MIPS_APSP_KSPD
  static void kspd_sp_exit( int sp_id)
  {
  	cleanup_tc(get_tc(sp_id));
  }
  #endif

  static ssize_t store_kill(struct device *dev, struct device_attribute *attr,
  			  const char *buf, size_t len)

  {
  	struct vpe *vpe = get_vpe(tclimit);
  	struct vpe_notifications *not;
  
  	list_for_each_entry(not, &vpe->notify, list) {
  		not->stop(tclimit);
  	}
  
  	release_progmem(vpe->load_addr);
  	cleanup_tc(get_tc(tclimit));
  	vpe_stop(vpe);
  	vpe_free(vpe);
  
  	return len;
  }

  static ssize_t show_ntcs(struct device *cd, struct device_attribute *attr,
  			 char *buf)

  {
  	struct vpe *vpe = get_vpe(tclimit);
  
  	return sprintf(buf, "%d
  ", vpe->ntcs);
  }

  static ssize_t store_ntcs(struct device *dev, struct device_attribute *attr,
  			  const char *buf, size_t len)

  {
  	struct vpe *vpe = get_vpe(tclimit);
  	unsigned long new;
  	char *endp;
  
  	new = simple_strtoul(buf, &endp, 0);
  	if (endp == buf)
  		goto out_einval;
  
  	if (new == 0 || new > (hw_tcs - tclimit))
  		goto out_einval;
  
  	vpe->ntcs = new;
  
  	return len;
  
  out_einval:

  	return -EINVAL;

  }

  static struct device_attribute vpe_class_attributes[] = {

  	__ATTR(kill, S_IWUSR, NULL, store_kill),

  	__ATTR(ntcs, S_IRUGO | S_IWUSR, show_ntcs, store_ntcs),
  	{}
  };

  static void vpe_device_release(struct device *cd)

  {
  	kfree(cd);
  }
  
  struct class vpe_class = {
  	.name = "vpe",
  	.owner = THIS_MODULE,

  	.dev_release = vpe_device_release,
  	.dev_attrs = vpe_class_attributes,

  };

  struct device vpe_device;

  static int __init vpe_module_init(void)
  {

  	unsigned int mtflags, vpflags;

  	unsigned long flags, val;

  	struct vpe *v = NULL;
  	struct tc *t;

  	int tc, err;

  
  	if (!cpu_has_mipsmt) {
  		printk("VPE loader: not a MIPS MT capable processor
  ");
  		return -ENODEV;
  	}

  	if (vpelimit == 0) {
  		printk(KERN_WARNING "No VPEs reserved for AP/SP, not "
  		       "initializing VPE loader.
  Pass maxvpes=<n> argument as "
  		       "kernel argument
  ");
  
  		return -ENODEV;
  	}
  
  	if (tclimit == 0) {
  		printk(KERN_WARNING "No TCs reserved for AP/SP, not "
  		       "initializing VPE loader.
  Pass maxtcs=<n> argument as "
  		       "kernel argument
  ");
  
  		return -ENODEV;
  	}

  	major = register_chrdev(0, module_name, &vpe_fops);
  	if (major < 0) {

  		printk("VPE loader: unable to register character device
  ");

  		return major;

  	}

  	err = class_register(&vpe_class);
  	if (err) {
  		printk(KERN_ERR "vpe_class registration failed
  ");

  		goto out_chrdev;
  	}

  	device_initialize(&vpe_device);

  	vpe_device.class	= &vpe_class,
  	vpe_device.parent	= NULL,

  	dev_set_name(&vpe_device, "vpe1");

  	vpe_device.devt = MKDEV(major, minor);

  	err = device_add(&vpe_device);

  	if (err) {
  		printk(KERN_ERR "Adding vpe_device failed
  ");
  		goto out_class;
  	}

  	local_irq_save(flags);
  	mtflags = dmt();
  	vpflags = dvpe();

  
  	/* Put MVPE's into 'configuration state' */

  	set_c0_mvpcontrol(MVPCONTROL_VPC);

  
  	/* dump_mtregs(); */

  	val = read_c0_mvpconf0();

  	hw_tcs = (val & MVPCONF0_PTC) + 1;
  	hw_vpes = ((val & MVPCONF0_PVPE) >> MVPCONF0_PVPE_SHIFT) + 1;
  
  	for (tc = tclimit; tc < hw_tcs; tc++) {
  		/*
  		 * Must re-enable multithreading temporarily or in case we
  		 * reschedule send IPIs or similar we might hang.
  		 */
  		clear_c0_mvpcontrol(MVPCONTROL_VPC);
  		evpe(vpflags);
  		emt(mtflags);
  		local_irq_restore(flags);
  		t = alloc_tc(tc);
  		if (!t) {
  			err = -ENOMEM;
  			goto out;
  		}
  
  		local_irq_save(flags);
  		mtflags = dmt();
  		vpflags = dvpe();
  		set_c0_mvpcontrol(MVPCONTROL_VPC);

  
  		/* VPE's */

  		if (tc < hw_tcs) {
  			settc(tc);

  			if ((v = alloc_vpe(tc)) == NULL) {

  				printk(KERN_WARNING "VPE: unable to allocate VPE
  ");

  
  				goto out_reenable;

  			}

  			v->ntcs = hw_tcs - tclimit;

  			/* add the tc to the list of this vpe's tc's. */
  			list_add(&t->tc, &v->tc);

  
  			/* deactivate all but vpe0 */

  			if (tc >= tclimit) {

  				unsigned long tmp = read_vpe_c0_vpeconf0();
  
  				tmp &= ~VPECONF0_VPA;
  
  				/* master VPE */
  				tmp |= VPECONF0_MVP;
  				write_vpe_c0_vpeconf0(tmp);
  			}
  
  			/* disable multi-threading with TC's */
  			write_vpe_c0_vpecontrol(read_vpe_c0_vpecontrol() & ~VPECONTROL_TE);

  			if (tc >= vpelimit) {

  				/*
  				 * Set config to be the same as vpe0,
  				 * particularly kseg0 coherency alg
  				 */

  				write_vpe_c0_config(read_c0_config());
  			}

  		}
  
  		/* TC's */
  		t->pvpe = v;	/* set the parent vpe */

  		if (tc >= tclimit) {

  			unsigned long tmp;

  			settc(tc);

  			/* Any TC that is bound to VPE0 gets left as is - in case
  			   we are running SMTC on VPE0. A TC that is bound to any
  			   other VPE gets bound to VPE0, ideally I'd like to make
  			   it homeless but it doesn't appear to let me bind a TC
  			   to a non-existent VPE. Which is perfectly reasonable.
  
  			   The (un)bound state is visible to an EJTAG probe so may
  			   notify GDB...
  			*/
  
  			if (((tmp = read_tc_c0_tcbind()) & TCBIND_CURVPE)) {
  				/* tc is bound >vpe0 */
  				write_tc_c0_tcbind(tmp & ~TCBIND_CURVPE);
  
  				t->pvpe = get_vpe(0);	/* set the parent vpe */
  			}

  			/* halt the TC */
  			write_tc_c0_tchalt(TCHALT_H);
  			mips_ihb();

  			tmp = read_tc_c0_tcstatus();

  			/* mark not activated and not dynamically allocatable */

  			tmp &= ~(TCSTATUS_A | TCSTATUS_DA);
  			tmp |= TCSTATUS_IXMT;	/* interrupt exempt */
  			write_tc_c0_tcstatus(tmp);

  		}
  	}

  out_reenable:

  	/* release config state */

  	clear_c0_mvpcontrol(MVPCONTROL_VPC);

  	evpe(vpflags);
  	emt(mtflags);
  	local_irq_restore(flags);

  #ifdef CONFIG_MIPS_APSP_KSPD
  	kspd_events.kspd_sp_exit = kspd_sp_exit;
  #endif

  	return 0;

  out_class:
  	class_unregister(&vpe_class);

  out_chrdev:
  	unregister_chrdev(major, module_name);

  out:

  	return err;

  }
  
  static void __exit vpe_module_exit(void)
  {
  	struct vpe *v, *n;

  	device_del(&vpe_device);
  	unregister_chrdev(major, module_name);
  
  	/* No locking needed here */

  	list_for_each_entry_safe(v, n, &vpecontrol.vpe_list, list) {

  		if (v->state != VPE_STATE_UNUSED)

  			release_vpe(v);

  	}

  }
  
  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");