[deliverable/binutils-gdb.git] / sim / ppc / vm.c

/*  This file is part of the program psim.

    Copyright (C) 1994-1995, Andrew Cagney <cagney@highland.com.au>

    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; either version 2 of the License, or
    (at your option) any later version.

    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.  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.
 
    */


#ifndef _VM_C_
#define _VM_C_

#ifndef STATIC_INLINE_VM
#define STATIC_INLINE_VM STATIC_INLINE
#endif


#include "basics.h"

#include "registers.h"

#include "device_tree.h"
#include "corefile.h"

#include "vm.h"

#include "interrupts.h"

#include "mon.h"

/* OEA vs VEA

   For the VEA model, the VM layer is almost transparent.  It's only
   purpose is to maintain separate core_map's for the instruction
   and data address spaces.  This being so that writes to instruction
   space or execution of a data space is prevented.

   For the OEA model things are more complex.  The reason for separate
   instruction and data models becomes crucial.  The OEA model is
   built out of three parts.  An instruction map, a data map and an
   underlying structure that provides access to the VM data kept in
   main memory. */


/* OEA data structures:

   The OEA model maintains internal data structures that shadow the
   semantics of the various OEA VM registers (BAT, SR, etc).  This
   allows a simple efficient model of the VM to be implemented.

   Consistency between OEA registers and this model's internal data
   structures is maintained by updating the structures at
   `synchronization' points.  Of particular note is that (at the time
   of writing) the memory data types for BAT registers are rebuilt
   when ever the processor moves between problem and system states */


/* Protection table:

   Matrix of processor state, type of access and validity */

typedef enum {
  om_supervisor_state,
  om_problem_state,
  nr_om_modes
} om_processor_modes;

typedef enum {
  om_data_read, om_data_write,
  om_instruction_read, om_access_any,
  nr_om_access_types
} om_access_types;

static int om_valid_access[2][4][nr_om_access_types] = {
  /* read, write, instruction, any */
  /* K bit == 0 */
  { /*r  w  i  a       pp */
    { 1, 1, 1, 1 }, /* 00 */
    { 1, 1, 1, 1 }, /* 01 */
    { 1, 1, 1, 1 }, /* 10 */
    { 1, 0, 1, 1 }, /* 11 */
  },
  /* K bit == 1  or P bit valid */
  { /*r  w  i  a       pp */
    { 0, 0, 0, 0 }, /* 00 */
    { 1, 0, 1, 1 }, /* 01 */
    { 1, 1, 1, 1 }, /* 10 */
    { 1, 0, 1, 1 }, /* 11 */
  }
};


/* Bat translation:

   The bat data structure only contains information on valid BAT
   translations for the current processor mode and type of access. */

typedef struct _om_bat {
  unsigned_word block_effective_page_index;
  unsigned_word block_effective_page_index_mask;
  unsigned_word block_length_mask;
  unsigned_word block_real_page_number;
  int protection_bits;
} om_bat;

enum _nr_om_bat_registers {
  nr_om_bat_registers = 4
};

typedef struct _om_bats {
  int nr_valid_bat_registers;
  om_bat bat[nr_om_bat_registers];
} om_bats;


/* Segment TLB:

   In this model the 32 and 64 bit segment tables are treated in very
   similar ways.  The 32bit segment registers are treated as a
   simplification of the 64bit segment tlb */

enum _om_segment_tlb_constants {
#if (WITH_TARGET_WORD_BITSIZE == 64)
  sizeof_segment_table_entry_group = 128,
  sizeof_segment_table_entry = 16,
#endif
  om_segment_tlb_index_start_bit = 32,
  om_segment_tlb_index_stop_bit = 35,
  nr_om_segment_tlb_entries = 16,
  nr_om_segment_tlb_constants
};

typedef struct _om_segment_tlb_entry {
  int key[nr_om_modes];
  om_access_types invalid_access; /* set to instruction if no_execute bit */
  unsigned_word masked_virtual_segment_id;
#if (WITH_TARGET_WORD_BITSIZE == 64)
  int is_valid;
  unsigned_word masked_effective_segment_id;
#endif
} om_segment_tlb_entry;

typedef struct _om_segment_tlb {
  om_segment_tlb_entry entry[nr_om_segment_tlb_entries];
} om_segment_tlb;


/* Page TLB:

   This OEA model includes a small direct map Page TLB.  The tlb is to
   cut down on the need for the OEA to perform walks of the page hash
   table. */

enum _om_page_tlb_constants {
  om_page_tlb_index_start_bit = 46,
  om_page_tlb_index_stop_bit = 51,
  nr_om_page_tlb_entries = 64,
#if (WITH_TARGET_WORD_BITSIZE == 64)
  sizeof_pte_group = 128,
  sizeof_pte = 16,
#endif
#if (WITH_TARGET_WORD_BITSIZE == 32)
  sizeof_pte_group = 64,
  sizeof_pte = 8,
#endif
  nr_om_page_tlb_constants
};

typedef struct _om_page_tlb_entry {
  int valid;
  int protection;
  unsigned_word masked_virtual_segment_id;
  unsigned_word masked_page;
  unsigned_word masked_real_page_number;
} om_page_tlb_entry;

typedef struct _om_page_tlb {
  om_page_tlb_entry entry[nr_om_page_tlb_entries];
} om_page_tlb;


/* memory translation:

   OEA memory translation possibly involves BAT, SR, TLB and HTAB
   information*/

typedef struct _om_map {

  /* local cache of register values */
  int is_relocate;
  int is_problem_state;

  /* block address translation */
  om_bats *bat_registers;

  /* failing that, translate ea to va using segment tlb */
#if (WITH_TARGET_WORD_BITSIZE == 64)
  unsigned_word real_address_of_segment_table;
#endif
  om_segment_tlb *segment_tlb;

  /* then va to ra using hashed page table and tlb */
  unsigned_word real_address_of_page_table;
  unsigned_word page_table_hash_mask;
  om_page_tlb *page_tlb;

  /* physical memory for fetching page table entries */
  core_map *physical;

} om_map;


/* VM objects:

   External objects defined by vm.h */

struct _vm_instruction_map {
  /* real memory for last part */
  core_map *code;
  /* translate effective to real */
  om_map translation;
};

struct _vm_data_map {
  /* translate effective to real */
  om_map translation;
  /* real memory for translated address */
  core_map *read;
  core_map *write;
};


/* VM:

   Underlying memory object.  For the VEA this is just the
   core_map. For OEA it is the instruction and data memory
   translation's */

struct _vm {

  /* OEA: base address registers */
  om_bats ibats;
  om_bats dbats;

  /* OEA: segment registers */
  om_segment_tlb segment_tlb;

  /* OEA: translation lookaside buffers */
  om_page_tlb instruction_tlb;
  om_page_tlb data_tlb;

  /* real memory */
  core *physical;

  /* memory maps */
  vm_instruction_map instruction_map;
  vm_data_map data_map;

};


/* OEA Support procedures */


STATIC_INLINE_VM unsigned_word
om_segment_tlb_index(unsigned_word ea)
{
  unsigned_word index = EXTRACTED(ea,
				  om_segment_tlb_index_start_bit,
				  om_segment_tlb_index_stop_bit);
  return index;
}

STATIC_INLINE_VM unsigned_word
om_page_tlb_index(unsigned_word ea)
{
  unsigned_word index = EXTRACTED(ea,
				  om_page_tlb_index_start_bit,
				  om_page_tlb_index_stop_bit);
  return index;
}

STATIC_INLINE_VM unsigned_word
om_masked_page(unsigned_word ea)
{
  unsigned_word masked_page = MASKED(ea, 36, 51);
  return masked_page;
}

STATIC_INLINE_VM unsigned_word
om_masked_byte(unsigned_word ea)
{
  unsigned_word masked_byte = MASKED(ea, 52, 63);
  return masked_byte;
}


INLINE_VM vm *
vm_create(core *physical)
{
  vm *virtual;

  /* internal checks */
  if (nr_om_segment_tlb_entries
      != (1 << (om_segment_tlb_index_stop_bit
		- om_segment_tlb_index_start_bit + 1)))
    error("new_vm() - internal error with om_segment constants\n");
  if (nr_om_page_tlb_entries
      != (1 << (om_page_tlb_index_stop_bit
		- om_page_tlb_index_start_bit + 1)))
    error("new_vm() - internal error with om_page constants\n");

  /* create the new vm register file */
  virtual = ZALLOC(vm);

  /* set up core */
  virtual->physical = physical;

  /* set up the address decoders */
  virtual->instruction_map.translation.bat_registers = &virtual->ibats;
  virtual->instruction_map.translation.segment_tlb = &virtual->segment_tlb;
  virtual->instruction_map.translation.page_tlb = &virtual->instruction_tlb;
  virtual->instruction_map.translation.is_relocate = 0;
  virtual->instruction_map.translation.is_problem_state = 0;
  virtual->instruction_map.translation.physical = core_readable(physical);
  virtual->instruction_map.code = core_readable(physical);

  virtual->data_map.translation.bat_registers = &virtual->dbats;
  virtual->data_map.translation.segment_tlb = &virtual->segment_tlb;
  virtual->data_map.translation.page_tlb = &virtual->data_tlb;
  virtual->data_map.translation.is_relocate = 0;
  virtual->data_map.translation.is_problem_state = 0;
  virtual->data_map.translation.physical = core_readable(physical);
  virtual->data_map.read = core_readable(physical);
  virtual->data_map.write = core_writeable(physical);

  return virtual;
}


STATIC_INLINE_VM om_bat *
om_effective_to_bat(om_map *map,
		    unsigned_word ea)
{
  int curr_bat = 0;
  om_bats *bats = map->bat_registers;
  int nr_bats = bats->nr_valid_bat_registers;

  for (curr_bat = 0; curr_bat < nr_bats; curr_bat++) {
    om_bat *bat = bats->bat + curr_bat;
    if ((ea & bat->block_effective_page_index_mask)
	!= bat->block_effective_page_index)
      continue;
    return bat;
  }

  return NULL;
}


STATIC_INLINE_VM om_segment_tlb_entry *
om_effective_to_virtual(om_map *map, 
			unsigned_word ea,
			cpu *processor,
			unsigned_word cia)
{
  /* first try the segment tlb */
  om_segment_tlb_entry *segment_tlb_entry = (map->segment_tlb->entry
					     + om_segment_tlb_index(ea));

#if (WITH_TARGET_WORD_BITSIZE == 32)
  return segment_tlb_entry;
#endif

#if (WITH_TARGET_WORD_BITSIZE == 64)
  if (segment_tlb_entry->is_valid
      && (segment_tlb_entry->masked_effective_segment_id == MASKED(ea, 0, 35))) {
    error("fixme - is there a need to update any bits\n");
    return segment_tlb_entry;
  }

  /* drats, segment tlb missed */
  {
    unsigned_word segment_id_hash = ea;
    int current_hash = 0;
    for (current_hash = 0; current_hash < 2; current_hash += 1) {
      unsigned_word segment_table_entry_group =
	(map->real_address_of_segment_table
	 | (MASKED64(segment_id_hash, 31, 35) >> (56-35)));
      unsigned_word segment_table_entry;
      for (segment_table_entry = segment_table_entry_group;
	   segment_table_entry < (segment_table_entry_group
				  + sizeof_segment_table_entry_group);
	   segment_table_entry += sizeof_segment_table_entry) {
	/* byte order? */
	unsigned_word segment_table_entry_dword_0 =
	  core_map_read_8(map->physical, segment_table_entry, processor, cia);
	unsigned_word segment_table_entry_dword_1 =
	  core_map_read_8(map->physical, segment_table_entry + 8, processor, cia);
	int is_valid = MASKED64(segment_table_entry_dword_0, 56, 56) != 0;
	unsigned_word masked_effective_segment_id =
	  MASKED64(segment_table_entry_dword_0, 0, 35);
	if (is_valid && masked_effective_segment_id == MASKED64(ea, 0, 35)) {
	  /* don't permit some things */
	  if (MASKED64(segment_table_entry_dword_0, 57, 57))
	    error("om_effective_to_virtual() - T=1 in STE not supported\n");
	  /* update segment tlb */
	  segment_tlb_entry->is_valid = is_valid;
	  segment_tlb_entry->masked_effective_segment_id =
	    masked_effective_segment_id;
	  segment_tlb_entry->key[om_supervisor_state] =
	    EXTRACTED64(segment_table_entry_dword_0, 58, 58);
	  segment_tlb_entry->key[om_problem_state] =
	    EXTRACTED64(segment_table_entry_dword_0, 59, 59);
	  segment_tlb_entry->invalid_access =
	    (MASKED64(segment_table_entry_dword_0, 60, 60)
	     ? om_instruction_read
	     : om_access_any);
	  segment_tlb_entry->masked_virtual_segment_id =
	    MASKED(segment_table_entry_dword_1, 0, 51);
	  return segment_tlb_entry;
	}
      }
      segment_id_hash = ~segment_id_hash;
    }
  }
  return NULL;
#endif
}


STATIC_INLINE_VM om_page_tlb_entry *
om_virtual_to_real(om_map *map, 
		   unsigned_word ea,
		   om_segment_tlb_entry *segment_tlb_entry,
		   om_access_types access,
		   cpu *processor,
		   unsigned_word cia)
{
  om_page_tlb_entry *page_tlb_entry = (map->page_tlb->entry
				       + om_page_tlb_index(ea));

  /* is it a tlb hit? */
  if (page_tlb_entry->valid
      && (page_tlb_entry->masked_virtual_segment_id ==
	  segment_tlb_entry->masked_virtual_segment_id)
      && (page_tlb_entry->masked_page == om_masked_page(ea))) {
    error("fixme - it is not a hit if direction/update bits do not match\n");
    return page_tlb_entry;
  }
      
  /* drats, it is a tlb miss */
  {
    unsigned_word page_hash = (segment_tlb_entry->masked_virtual_segment_id 
			       ^ om_masked_page(ea));
    int current_hash;
    for (current_hash = 0; current_hash < 2; current_hash += 1) {
      unsigned_word real_address_of_pte_group =
	(map->real_address_of_page_table
	 | (page_hash & map->page_table_hash_mask));
      unsigned_word real_address_of_pte;
      for (real_address_of_pte = real_address_of_pte_group;
	   real_address_of_pte < (real_address_of_pte_group
				  + sizeof_pte_group);
	   real_address_of_pte += sizeof_pte) {
	unsigned_word pte_word_0 =
	  core_map_read_word(map->physical,
			     real_address_of_pte,
			     processor, cia);
	unsigned_word pte_word_1 =
	  core_map_read_word(map->physical,
			     real_address_of_pte + sizeof_pte / 2,
			     processor, cia);
	error("fixme - check pte hit %ld %ld\n",
	      (long)pte_word_0,
	      (long)pte_word_1);
	if (1) {
	  error("fixme - update the page_tlb\n");
	  page_tlb_entry->valid = 1;
	  page_tlb_entry->protection = 0;
	  page_tlb_entry->masked_virtual_segment_id = 0;
	  page_tlb_entry->masked_page = 0;
	  page_tlb_entry->masked_real_page_number = 0;
	  return page_tlb_entry;
	}
      }
      page_hash = ~page_hash; /*???*/
    }
  }
  return NULL;
}


static void
om_interrupt(cpu *processor,
	     unsigned_word cia,
	     unsigned_word ea,
	     om_access_types access,
	     storage_interrupt_reasons reason)
{
  switch (access) {
  case om_data_read:
    data_storage_interrupt(processor, cia, ea, reason, 0/*!is_store*/);
    break;
  case om_data_write:
    data_storage_interrupt(processor, cia, ea, reason, 1/*is_store*/);
    break;
  case om_instruction_read:
    instruction_storage_interrupt(processor, cia, reason);
    break;
  default:
    error("om_interrupt - unexpected access type %d, cia=0x%x, ea=0x%x\n",
	  access, cia, ea);
  }
}


STATIC_INLINE_VM unsigned_word
om_translate_effective_to_real(om_map *map,
			       unsigned_word ea,
			       om_access_types access,
			       cpu *processor,
			       unsigned_word cia,
			       int abort)
{
  om_bat *bat = NULL;
  om_segment_tlb_entry *segment_tlb_entry = NULL;
  om_page_tlb_entry *page_tlb_entry = NULL;
  unsigned_word ra;

  if (!map->is_relocate) {
    ra = ea;
    TRACE(trace_vm, ("%s, direct map, ea=0x%x\n",
		     "om_translate_effective_to_real",
		     ea));
    return ra;
  }

  /* match with BAT? */
  bat = om_effective_to_bat(map, ea);
  if (bat != NULL) {
    if (!om_valid_access[1][bat->protection_bits][access]) {
      TRACE(trace_vm, ("%s, bat protection violation, ea=0x%x\n",
		       "om_translate_effective_to_real",
		       ea));
      if (abort)
	om_interrupt(processor, cia, ea, access,
		     protection_violation_storage_interrupt);
      else
	return MASK(0, 63);
    }

    ra = ((ea & bat->block_length_mask) | bat->block_real_page_number);
    TRACE(trace_vm, ("%s, bat translation, ea=0x%x, ra=0x%x\n",
		     "om_translate_effective_to_real",
		     ea, ra));
    return ra;
  }

  /* translate ea to va using segment map */
  segment_tlb_entry = om_effective_to_virtual(map, ea, processor, cia);
#if (WITH_TARGET_WORD_BITSIZE == 64)
  if (segment_tlb_entry == NULL) {
    TRACE(trace_vm, ("%s, segment tlb lookup failed - ea=0x%x\n",
		     "om_translate_effective_to_real",
		     ea));
    if (abort)
      om_interrupt(processor, cia, ea, access,
		   segment_table_miss_storage_interrupt);
    else
      return MASK(0, 63);
  }
#endif
  /* check for invalid segment access type */
  if (segment_tlb_entry->invalid_access == access) {
    TRACE(trace_vm, ("%s, segment tlb access invalid - ea=0x%x\n",
		     "om_translate_effective_to_real",
		     ea));
    if (abort)
      om_interrupt(processor, cia, ea, access,
		   protection_violation_storage_interrupt);
    else
      return MASK(0, 63);
  }

  /* lookup in PTE */
  page_tlb_entry = om_virtual_to_real(map, ea, segment_tlb_entry,
				      access,
				      processor, cia);
  if (page_tlb_entry == NULL) {
    TRACE(trace_vm, ("%s, page tlb lookup failed - ea=0x%x\n",
		     "om_translate_effective_to_real",
		     ea));
    if (abort)
      om_interrupt(processor, cia, ea, access,
		   hash_table_miss_storage_interrupt);
    else
      return MASK(0, 63);
  }
  if (!(om_valid_access
	[segment_tlb_entry->key[map->is_problem_state]]
	[page_tlb_entry->protection]
	[access])) {
    TRACE(trace_vm, ("%s, page tlb access invalid - ea=0x%x\n",
		     "om_translate_effective_to_real",
		     ea));
    if (abort)
      om_interrupt(processor, cia, ea, access,
		   protection_violation_storage_interrupt);
    else
      return MASK(0, 63);
  }

  ra = (page_tlb_entry->masked_real_page_number
	| om_masked_byte(ea));
  TRACE(trace_vm, ("%s, page - ea=0x%x, ra=0x%x\n",
		   "om_translate_effective_to_real",
		   ea, ra));
  return ra;
}


/*
 * Definition of operations for memory management
 */


/* rebuild all the relevant bat information */
STATIC_INLINE_VM void
om_unpack_bat(om_bat *bat,
	      spreg ubat,
	      spreg lbat)
{
  /* for extracting out the offset within a page */
  bat->block_length_mask = ((MASKED(ubat, 51, 61) << (17-2))
			    | MASK(63-17+1, 63));

  /* for checking the effective page index */
  bat->block_effective_page_index = MASKED(ubat, 0, 46);
  bat->block_effective_page_index_mask = ~bat->block_length_mask;

  /* protection information */
  bat->protection_bits = EXTRACTED(lbat, 62, 63);
  bat->block_real_page_number = MASKED(lbat, 0, 46);
}


/* rebuild the given bat table */
STATIC_INLINE_VM void
om_unpack_bats(om_bats *bats,
	       spreg *raw_bats,
	       msreg msr)
{
  int i;
  bats->nr_valid_bat_registers = 0;
  for (i = 0; i < nr_om_bat_registers*2; i += 2) {
    spreg ubat = raw_bats[i];
    spreg lbat = raw_bats[i+1];
    if ((msr & msr_problem_state)
	? EXTRACTED(ubat, 62, 62)
	: EXTRACTED(ubat, 63, 63)) {
      om_unpack_bat(&bats->bat[bats->nr_valid_bat_registers],
		    ubat, lbat);
      bats->nr_valid_bat_registers += 1;
    }
  }
}


#if (WITH_TARGET_WORD_BITSIZE == 32)
STATIC_INLINE_VM void
om_unpack_sr(vm *virtual,
	     sreg *srs,
	     int which_sr)
{
  om_segment_tlb_entry *segment_tlb_entry = 0;
  sreg new_sr_value = 0;

  /* check register in range */
  if (which_sr < 0 || which_sr > nr_om_segment_tlb_entries)
    error("om_set_sr: segment register out of bounds\n");

  /* get the working values */
  segment_tlb_entry = &virtual->segment_tlb.entry[which_sr];  
  new_sr_value = srs[which_sr];
  
  /* do we support this */
  if (MASKED32(new_sr_value, 0, 0))
    error("om_ser_sr(): unsupported value of T in segment register %d\n",
	  which_sr);

  /* update info */
  segment_tlb_entry->key[om_supervisor_state] = EXTRACTED32(new_sr_value, 1, 1);
  segment_tlb_entry->key[om_problem_state] = EXTRACTED32(new_sr_value, 2, 2);
  segment_tlb_entry->invalid_access = (MASKED32(new_sr_value, 3, 3)
				       ? om_instruction_read
				       : om_access_any);
  segment_tlb_entry->masked_virtual_segment_id = MASKED32(new_sr_value, 8, 31);
}
#endif


#if (WITH_TARGET_WORD_BITSIZE == 32)
STATIC_INLINE_VM void
om_unpack_srs(vm *virtual,
	      sreg *srs)
{
  int which_sr;
  for (which_sr = 0; which_sr < nr_om_segment_tlb_entries; which_sr++) {
    om_unpack_sr(virtual, srs, which_sr);
  }
}
#endif


/* Rebuild all the data structures for the new context as specifed by
   the passed registers */
INLINE_VM void
vm_synchronize_context(vm *virtual,
		       spreg *sprs,
		       sreg *srs,
		       msreg msr)
{

  /* enable/disable translation */
  int problem_state = (msr & msr_problem_state) != 0;
  int data_relocate = (msr & msr_data_relocate) != 0;
  int instruction_relocate = (msr & msr_instruction_relocate) != 0;

  unsigned_word page_table_hash_mask;
  unsigned_word real_address_of_page_table;


  /* update current processor mode */
  virtual->instruction_map.translation.is_relocate = instruction_relocate;
  virtual->instruction_map.translation.is_problem_state = problem_state;
  virtual->data_map.translation.is_relocate = data_relocate;
  virtual->data_map.translation.is_problem_state = problem_state;


  /* update bat registers for the new context */
  om_unpack_bats(&virtual->ibats, &sprs[spr_ibat0u], msr);
  om_unpack_bats(&virtual->dbats, &sprs[spr_dbat0u], msr);


  /* unpack SDR1 - the storage description register 1 */
#if (WITH_TARGET_WORD_BITSIZE == 64)
  real_address_of_page_table = EXTRACTED64(sprs[spr_sdr1], 0, 45);
  page_table_hash_mask = MASK64(47-EXTRACTED64(sprs[spr_sdr1], 59, 63),
				57);
#endif
#if (WITH_TARGET_WORD_BITSIZE == 32)
  real_address_of_page_table = EXTRACTED32(sprs[spr_sdr1], 0, 15);
  page_table_hash_mask = ((EXTRACTED32(sprs[spr_sdr1], 23, 31) << (10+6))
			  | MASK32(16, 25));
#endif
  virtual->instruction_map.translation.real_address_of_page_table = real_address_of_page_table;
  virtual->instruction_map.translation.page_table_hash_mask = page_table_hash_mask;
  virtual->data_map.translation.real_address_of_page_table = real_address_of_page_table;
  virtual->data_map.translation.page_table_hash_mask = page_table_hash_mask;


#if (WITH_TARGET_WORD_BITSIZE == 32)
  /* unpack the segment tlb registers */
  om_unpack_srs(virtual, srs);
#endif
}


INLINE_VM vm_data_map *
vm_create_data_map(vm *memory)
{
  return &memory->data_map;
}


INLINE_VM vm_instruction_map *
vm_create_instruction_map(vm *memory)
{
  return &memory->instruction_map;
}


STATIC_INLINE_VM unsigned_word
vm_translate(om_map *map,
	     unsigned_word ea,
	     om_access_types access,
	     cpu *processor,
	     unsigned_word cia,
	     int abort)
{
  switch (CURRENT_ENVIRONMENT) {
  case USER_ENVIRONMENT:
  case VIRTUAL_ENVIRONMENT:
    return ea;
  case OPERATING_ENVIRONMENT:
    return om_translate_effective_to_real(map, ea, access,
					  processor, cia,
					  abort);
  default:
    error("vm_translate() - unknown environment\n");
    return 0;
  }
}


INLINE_VM unsigned_word
vm_real_data_addr(vm_data_map *map,
		  unsigned_word ea,
		  int is_read,
		  cpu *processor,
		  unsigned_word cia)
{
  return vm_translate(&map->translation,
		      ea,
		      is_read ? om_data_read : om_data_write,
		      processor,
		      cia,
		      1); /*abort*/
}


INLINE_VM unsigned_word
vm_real_instruction_addr(vm_instruction_map *map,
			 cpu *processor,
			 unsigned_word cia)
{
  return vm_translate(&map->translation,
		      cia,
		      om_instruction_read,
		      processor,
		      cia,
		      1); /*abort*/
}

INLINE_VM instruction_word
vm_instruction_map_read(vm_instruction_map *map,
			cpu *processor,
			unsigned_word cia)
{
  unsigned_word ra = vm_real_instruction_addr(map, processor, cia);
  ASSERT((cia & 0x3) == 0); /* always aligned */
  return core_map_read_4(map->code, ra, processor, cia);
}


INLINE_VM int
vm_data_map_read_buffer(vm_data_map *map,
			void *target,
			unsigned_word addr,
			unsigned nr_bytes)
{
  unsigned count;
  for (count = 0; count < nr_bytes; count++) {
    unsigned_1 byte;
    unsigned_word ea = addr + count;
    unsigned_word ra = vm_translate(&map->translation,
				    ea, om_data_read,
				    NULL, /*processor*/
				    0, /*cia*/
				    0); /*dont-abort*/
    if (ra == MASK(0, 63))
      break;
    if (core_map_read_buffer(map->read, &byte, ea, sizeof(byte))
	!= sizeof(byte))
      break;
    ((unsigned_1*)target)[count] = T2H_1(byte);
  }
  return count;
}


INLINE_VM int
vm_data_map_write_buffer(vm_data_map *map,
			 const void *source,
			 unsigned_word addr,
			 unsigned nr_bytes,
			 int violate_read_only_section)
{
  unsigned count;
  unsigned_1 byte;
  for (count = 0; count < nr_bytes; count++) {
    unsigned_word ea = addr + count;
    unsigned_word ra = vm_translate(&map->translation,
				    ea, om_data_write,
				    NULL/*processor*/,
				    0, /*cia*/
				    0); /*dont-abort*/
    if (ra == MASK(0, 63))
      break;
    byte = T2H_1(((unsigned_1*)source)[count]);
    if (core_map_write_buffer((violate_read_only_section
			       ? map->read
			       : map->write),
			      &byte, ra, sizeof(byte)) != sizeof(byte))
      break;
  }
  return count;
}


/* define the read/write 1/2/4/8/word functions */

#undef N
#define N 1
#include "vm_n.h"

#undef N
#define N 2
#include "vm_n.h"

#undef N
#define N 4
#include "vm_n.h"

#undef N
#define N 8
#include "vm_n.h"

#undef N
#define N word
#include "vm_n.h"


#endif /* _VM_C_ */