Andrew's latest changes & print all instruction counts if -I

1 files changed, 938 insertions, 0 deletions

diff --git a/sim/ppc/vm.c b/sim/ppc/vm.c
new file mode 100644
index 0000000..f15e0bf
--- /dev/null
+++ b/sim/ppc/vm.c
@@ -0,0 +1,938 @@
+/*  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 "core.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\n");
+	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_ */