target/xtensa/helper.c - qemu - Git at Google

 /*
  * Copyright (c) 2011, Max Filippov, Open Source and Linux Lab.
  * All rights reserved.
  *
  * Redistribution and use in source and binary forms, with or without
  * modification, are permitted provided that the following conditions are met:
  *     * Redistributions of source code must retain the above copyright
  *       notice, this list of conditions and the following disclaimer.
  *     * Redistributions in binary form must reproduce the above copyright
  *       notice, this list of conditions and the following disclaimer in the
  *       documentation and/or other materials provided with the distribution.
  *     * Neither the name of the Open Source and Linux Lab nor the
  *       names of its contributors may be used to endorse or promote products
  *       derived from this software without specific prior written permission.
  *
  * THIS SOFTWARE IS PROVIDED BY THE COPYRIGHT HOLDERS AND CONTRIBUTORS "AS IS"
  * AND ANY EXPRESS OR IMPLIED WARRANTIES, INCLUDING, BUT NOT LIMITED TO, THE
  * IMPLIED WARRANTIES OF MERCHANTABILITY AND FITNESS FOR A PARTICULAR PURPOSE
  * ARE DISCLAIMED. IN NO EVENT SHALL THE AUTHOR BE LIABLE FOR ANY
  * DIRECT, INDIRECT, INCIDENTAL, SPECIAL, EXEMPLARY, OR CONSEQUENTIAL DAMAGES
  * (INCLUDING, BUT NOT LIMITED TO, PROCUREMENT OF SUBSTITUTE GOODS OR SERVICES;
  * LOSS OF USE, DATA, OR PROFITS; OR BUSINESS INTERRUPTION) HOWEVER CAUSED AND
  * ON ANY THEORY OF LIABILITY, WHETHER IN CONTRACT, STRICT LIABILITY, OR TORT
  * (INCLUDING NEGLIGENCE OR OTHERWISE) ARISING IN ANY WAY OUT OF THE USE OF THIS
  * SOFTWARE, EVEN IF ADVISED OF THE POSSIBILITY OF SUCH DAMAGE.
  */

 #include "qemu/osdep.h"
 #include "cpu.h"
 #include "exec/exec-all.h"
 #include "exec/gdbstub.h"
 #include "exec/helper-proto.h"
 #include "qemu/error-report.h"
 #include "qemu/qemu-print.h"
 #include "qemu/host-utils.h"

 static struct XtensaConfigList *xtensa_cores;

 static void add_translator_to_hash(GHashTable *translator,
                                    const char *name,
                                    const XtensaOpcodeOps *opcode)
 {
     if (!g_hash_table_insert(translator, (void *)name, (void *)opcode)) {
         error_report("Multiple definitions of '%s' opcode in a single table",
                      name);
     }
 }

 static GHashTable *hash_opcode_translators(const XtensaOpcodeTranslators *t)
 {
     unsigned i, j;
     GHashTable *translator = g_hash_table_new(g_str_hash, g_str_equal);

     for (i = 0; i < t->num_opcodes; ++i) {
         if (t->opcode[i].op_flags & XTENSA_OP_NAME_ARRAY) {
             const char * const *name = t->opcode[i].name;

             for (j = 0; name[j]; ++j) {
                 add_translator_to_hash(translator,
                                        (void *)name[j],
                                        (void *)(t->opcode + i));
             }
         } else {
             add_translator_to_hash(translator,
                                    (void *)t->opcode[i].name,
                                    (void *)(t->opcode + i));
         }
     }
     return translator;
 }

 static XtensaOpcodeOps *
 xtensa_find_opcode_ops(const XtensaOpcodeTranslators *t,
                        const char *name)
 {
     static GHashTable *translators;
     GHashTable *translator;

     if (translators == NULL) {
         translators = g_hash_table_new(g_direct_hash, g_direct_equal);
     }
     translator = g_hash_table_lookup(translators, t);
     if (translator == NULL) {
         translator = hash_opcode_translators(t);
         g_hash_table_insert(translators, (void *)t, translator);
     }
     return g_hash_table_lookup(translator, name);
 }

 static void init_libisa(XtensaConfig *config)
 {
     unsigned i, j;
     unsigned opcodes;
     unsigned formats;
     unsigned regfiles;

     config->isa = xtensa_isa_init(config->isa_internal, NULL, NULL);
     assert(xtensa_isa_maxlength(config->isa) <= MAX_INSN_LENGTH);
     opcodes = xtensa_isa_num_opcodes(config->isa);
     formats = xtensa_isa_num_formats(config->isa);
     regfiles = xtensa_isa_num_regfiles(config->isa);
     config->opcode_ops = g_new(XtensaOpcodeOps *, opcodes);

     for (i = 0; i < formats; ++i) {
         assert(xtensa_format_num_slots(config->isa, i) <= MAX_INSN_SLOTS);
     }

     for (i = 0; i < opcodes; ++i) {
         const char *opc_name = xtensa_opcode_name(config->isa, i);
         XtensaOpcodeOps *ops = NULL;

         assert(xtensa_opcode_num_operands(config->isa, i) <= MAX_OPCODE_ARGS);
         if (!config->opcode_translators) {
             ops = xtensa_find_opcode_ops(&xtensa_core_opcodes, opc_name);
         } else {
             for (j = 0; !ops && config->opcode_translators[j]; ++j) {
                 ops = xtensa_find_opcode_ops(config->opcode_translators[j],
                                              opc_name);
             }
         }
 #ifdef DEBUG
         if (ops == NULL) {
             fprintf(stderr,
                     "opcode translator not found for %s's opcode '%s'\n",
                     config->name, opc_name);
         }
 #endif
         config->opcode_ops[i] = ops;
     }
     config->a_regfile = xtensa_regfile_lookup(config->isa, "AR");

     config->regfile = g_new(void **, regfiles);
     for (i = 0; i < regfiles; ++i) {
         const char *name = xtensa_regfile_name(config->isa, i);

         config->regfile[i] = xtensa_get_regfile_by_name(name);
 #ifdef DEBUG
         if (config->regfile[i] == NULL) {
             fprintf(stderr, "regfile '%s' not found for %s\n",
                     name, config->name);
         }
 #endif
     }
     xtensa_collect_sr_names(config);
 }

 static void xtensa_finalize_config(XtensaConfig *config)
 {
     if (config->isa_internal) {
         init_libisa(config);
     }

     if (config->gdb_regmap.num_regs == 0 ||
         config->gdb_regmap.num_core_regs == 0) {
         unsigned n_regs = 0;
         unsigned n_core_regs = 0;

         xtensa_count_regs(config, &n_regs, &n_core_regs);
         if (config->gdb_regmap.num_regs == 0) {
             config->gdb_regmap.num_regs = n_regs;
         }
         if (config->gdb_regmap.num_core_regs == 0) {
             config->gdb_regmap.num_core_regs = n_core_regs;
         }
     }
 }

 static void xtensa_core_class_init(ObjectClass *oc, void *data)
 {
     CPUClass *cc = CPU_CLASS(oc);
     XtensaCPUClass *xcc = XTENSA_CPU_CLASS(oc);
     XtensaConfig *config = data;

     xtensa_finalize_config(config);
     xcc->config = config;

     /*
      * Use num_core_regs to see only non-privileged registers in an unmodified
      * gdb. Use num_regs to see all registers. gdb modification is required
      * for that: reset bit 0 in the 'flags' field of the registers definitions
      * in the gdb/xtensa-config.c inside gdb source tree or inside gdb overlay.
      */
     cc->gdb_num_core_regs = config->gdb_regmap.num_regs;
 }

 void xtensa_register_core(XtensaConfigList *node)
 {
     TypeInfo type = {
         .parent = TYPE_XTENSA_CPU,
         .class_init = xtensa_core_class_init,
         .class_data = (void *)node->config,
     };

     node->next = xtensa_cores;
     xtensa_cores = node;
     type.name = g_strdup_printf(XTENSA_CPU_TYPE_NAME("%s"), node->config->name);
     type_register(&type);
     g_free((gpointer)type.name);
 }

 static uint32_t check_hw_breakpoints(CPUXtensaState *env)
 {
     unsigned i;

     for (i = 0; i < env->config->ndbreak; ++i) {
         if (env->cpu_watchpoint[i] &&
                 env->cpu_watchpoint[i]->flags & BP_WATCHPOINT_HIT) {
             return DEBUGCAUSE_DB | (i << DEBUGCAUSE_DBNUM_SHIFT);
         }
     }
     return 0;
 }

 void xtensa_breakpoint_handler(CPUState *cs)
 {
     XtensaCPU *cpu = XTENSA_CPU(cs);
     CPUXtensaState *env = &cpu->env;

     if (cs->watchpoint_hit) {
         if (cs->watchpoint_hit->flags & BP_CPU) {
             uint32_t cause;

             cs->watchpoint_hit = NULL;
             cause = check_hw_breakpoints(env);
             if (cause) {
                 debug_exception_env(env, cause);
             }
             cpu_loop_exit_noexc(cs);
         }
     }
 }

 void xtensa_cpu_list(void)
 {
     XtensaConfigList *core = xtensa_cores;
     qemu_printf("Available CPUs:\n");
     for (; core; core = core->next) {
         qemu_printf("  %s\n", core->config->name);
     }
 }

 #ifdef CONFIG_USER_ONLY

 bool xtensa_cpu_tlb_fill(CPUState *cs, vaddr address, int size,
                          MMUAccessType access_type, int mmu_idx,
                          bool probe, uintptr_t retaddr)
 {
     XtensaCPU *cpu = XTENSA_CPU(cs);
     CPUXtensaState *env = &cpu->env;

     qemu_log_mask(CPU_LOG_INT,
                   "%s: rw = %d, address = 0x%08" VADDR_PRIx ", size = %d\n",
                   __func__, access_type, address, size);
     env->sregs[EXCVADDR] = address;
     env->sregs[EXCCAUSE] = (access_type == MMU_DATA_STORE ?
                             STORE_PROHIBITED_CAUSE : LOAD_PROHIBITED_CAUSE);
     cs->exception_index = EXC_USER;
     cpu_loop_exit_restore(cs, retaddr);
 }

 #else

 void xtensa_cpu_do_unaligned_access(CPUState *cs,
                                     vaddr addr, MMUAccessType access_type,
                                     int mmu_idx, uintptr_t retaddr)
 {
     XtensaCPU *cpu = XTENSA_CPU(cs);
     CPUXtensaState *env = &cpu->env;

     if (xtensa_option_enabled(env->config, XTENSA_OPTION_UNALIGNED_EXCEPTION) &&
         !xtensa_option_enabled(env->config, XTENSA_OPTION_HW_ALIGNMENT)) {
         cpu_restore_state(CPU(cpu), retaddr, true);
         HELPER(exception_cause_vaddr)(env,
                                       env->pc, LOAD_STORE_ALIGNMENT_CAUSE,
                                       addr);
     }
 }

 bool xtensa_cpu_tlb_fill(CPUState *cs, vaddr address, int size,
                          MMUAccessType access_type, int mmu_idx,
                          bool probe, uintptr_t retaddr)
 {
     XtensaCPU *cpu = XTENSA_CPU(cs);
     CPUXtensaState *env = &cpu->env;
     uint32_t paddr;
     uint32_t page_size;
     unsigned access;
     int ret = xtensa_get_physical_addr(env, true, address, access_type,
                                        mmu_idx, &paddr, &page_size, &access);

     qemu_log_mask(CPU_LOG_MMU, "%s(%08" VADDR_PRIx
                   ", %d, %d) -> %08x, ret = %d\n",
                   __func__, address, access_type, mmu_idx, paddr, ret);

     if (ret == 0) {
         tlb_set_page(cs,
                      address & TARGET_PAGE_MASK,
                      paddr & TARGET_PAGE_MASK,
                      access, mmu_idx, page_size);
         return true;
     } else if (probe) {
         return false;
     } else {
         cpu_restore_state(cs, retaddr, true);
         HELPER(exception_cause_vaddr)(env, env->pc, ret, address);
     }
 }

 void xtensa_cpu_do_transaction_failed(CPUState *cs, hwaddr physaddr, vaddr addr,
                                       unsigned size, MMUAccessType access_type,
                                       int mmu_idx, MemTxAttrs attrs,
                                       MemTxResult response, uintptr_t retaddr)
 {
     XtensaCPU *cpu = XTENSA_CPU(cs);
     CPUXtensaState *env = &cpu->env;

     cpu_restore_state(cs, retaddr, true);
     HELPER(exception_cause_vaddr)(env, env->pc,
                                   access_type == MMU_INST_FETCH ?
                                   INSTR_PIF_ADDR_ERROR_CAUSE :
                                   LOAD_STORE_PIF_ADDR_ERROR_CAUSE,
                                   addr);
 }

 void xtensa_runstall(CPUXtensaState *env, bool runstall)
 {
     CPUState *cpu = env_cpu(env);

     env->runstall = runstall;
     cpu->halted = runstall;
     if (runstall) {
         cpu_interrupt(cpu, CPU_INTERRUPT_HALT);
     } else {
         qemu_cpu_kick(cpu);
     }
 }
 #endif
	/*
	* Copyright (c) 2011, Max Filippov, Open Source and Linux Lab.
	* All rights reserved.
	*
	* Redistribution and use in source and binary forms, with or without
	* modification, are permitted provided that the following conditions are met:
	* * Redistributions of source code must retain the above copyright
	* notice, this list of conditions and the following disclaimer.
	* * Redistributions in binary form must reproduce the above copyright
	* notice, this list of conditions and the following disclaimer in the
	* documentation and/or other materials provided with the distribution.
	* * Neither the name of the Open Source and Linux Lab nor the
	* names of its contributors may be used to endorse or promote products
	* derived from this software without specific prior written permission.
	*
	* THIS SOFTWARE IS PROVIDED BY THE COPYRIGHT HOLDERS AND CONTRIBUTORS "AS IS"
	* AND ANY EXPRESS OR IMPLIED WARRANTIES, INCLUDING, BUT NOT LIMITED TO, THE
	* IMPLIED WARRANTIES OF MERCHANTABILITY AND FITNESS FOR A PARTICULAR PURPOSE
	* ARE DISCLAIMED. IN NO EVENT SHALL THE AUTHOR BE LIABLE FOR ANY
	* DIRECT, INDIRECT, INCIDENTAL, SPECIAL, EXEMPLARY, OR CONSEQUENTIAL DAMAGES
	* (INCLUDING, BUT NOT LIMITED TO, PROCUREMENT OF SUBSTITUTE GOODS OR SERVICES;
	* LOSS OF USE, DATA, OR PROFITS; OR BUSINESS INTERRUPTION) HOWEVER CAUSED AND
	* ON ANY THEORY OF LIABILITY, WHETHER IN CONTRACT, STRICT LIABILITY, OR TORT
	* (INCLUDING NEGLIGENCE OR OTHERWISE) ARISING IN ANY WAY OUT OF THE USE OF THIS
	* SOFTWARE, EVEN IF ADVISED OF THE POSSIBILITY OF SUCH DAMAGE.
	*/

	#include "qemu/osdep.h"
	#include "cpu.h"
	#include "exec/exec-all.h"
	#include "exec/gdbstub.h"
	#include "exec/helper-proto.h"
	#include "qemu/error-report.h"
	#include "qemu/qemu-print.h"
	#include "qemu/host-utils.h"

	static struct XtensaConfigList *xtensa_cores;

	static void add_translator_to_hash(GHashTable *translator,
	const char *name,
	const XtensaOpcodeOps *opcode)
	{
	if (!g_hash_table_insert(translator, (void )name, (void )opcode)) {
	error_report("Multiple definitions of '%s' opcode in a single table",
	name);
	}
	}

	static GHashTable hash_opcode_translators(const XtensaOpcodeTranslators t)
	{
	unsigned i, j;
	GHashTable *translator = g_hash_table_new(g_str_hash, g_str_equal);

	for (i = 0; i < t->num_opcodes; ++i) {
	if (t->opcode[i].op_flags & XTENSA_OP_NAME_ARRAY) {
	const char * const *name = t->opcode[i].name;

	for (j = 0; name[j]; ++j) {
	add_translator_to_hash(translator,
	(void *)name[j],
	(void *)(t->opcode + i));
	}
	} else {
	add_translator_to_hash(translator,
	(void *)t->opcode[i].name,
	(void *)(t->opcode + i));
	}
	}
	return translator;
	}

	static XtensaOpcodeOps *
	xtensa_find_opcode_ops(const XtensaOpcodeTranslators *t,
	const char *name)
	{
	static GHashTable *translators;
	GHashTable *translator;

	if (translators == NULL) {
	translators = g_hash_table_new(g_direct_hash, g_direct_equal);
	}
	translator = g_hash_table_lookup(translators, t);
	if (translator == NULL) {
	translator = hash_opcode_translators(t);
	g_hash_table_insert(translators, (void *)t, translator);
	}
	return g_hash_table_lookup(translator, name);
	}

	static void init_libisa(XtensaConfig *config)
	{
	unsigned i, j;
	unsigned opcodes;
	unsigned formats;
	unsigned regfiles;

	config->isa = xtensa_isa_init(config->isa_internal, NULL, NULL);
	assert(xtensa_isa_maxlength(config->isa) <= MAX_INSN_LENGTH);
	opcodes = xtensa_isa_num_opcodes(config->isa);
	formats = xtensa_isa_num_formats(config->isa);
	regfiles = xtensa_isa_num_regfiles(config->isa);
	config->opcode_ops = g_new(XtensaOpcodeOps *, opcodes);

	for (i = 0; i < formats; ++i) {
	assert(xtensa_format_num_slots(config->isa, i) <= MAX_INSN_SLOTS);
	}

	for (i = 0; i < opcodes; ++i) {
	const char *opc_name = xtensa_opcode_name(config->isa, i);
	XtensaOpcodeOps *ops = NULL;

	assert(xtensa_opcode_num_operands(config->isa, i) <= MAX_OPCODE_ARGS);
	if (!config->opcode_translators) {
	ops = xtensa_find_opcode_ops(&xtensa_core_opcodes, opc_name);
	} else {
	for (j = 0; !ops && config->opcode_translators[j]; ++j) {
	ops = xtensa_find_opcode_ops(config->opcode_translators[j],
	opc_name);
	}
	}
	#ifdef DEBUG
	if (ops == NULL) {
	fprintf(stderr,
	"opcode translator not found for %s's opcode '%s'\n",
	config->name, opc_name);
	}
	#endif
	config->opcode_ops[i] = ops;
	}
	config->a_regfile = xtensa_regfile_lookup(config->isa, "AR");

	config->regfile = g_new(void **, regfiles);
	for (i = 0; i < regfiles; ++i) {
	const char *name = xtensa_regfile_name(config->isa, i);

	config->regfile[i] = xtensa_get_regfile_by_name(name);
	#ifdef DEBUG
	if (config->regfile[i] == NULL) {
	fprintf(stderr, "regfile '%s' not found for %s\n",
	name, config->name);
	}
	#endif
	}
	xtensa_collect_sr_names(config);
	}

	static void xtensa_finalize_config(XtensaConfig *config)
	{
	if (config->isa_internal) {
	init_libisa(config);
	}

	if (config->gdb_regmap.num_regs == 0 \|\|
	config->gdb_regmap.num_core_regs == 0) {
	unsigned n_regs = 0;
	unsigned n_core_regs = 0;

	xtensa_count_regs(config, &n_regs, &n_core_regs);
	if (config->gdb_regmap.num_regs == 0) {
	config->gdb_regmap.num_regs = n_regs;
	}
	if (config->gdb_regmap.num_core_regs == 0) {
	config->gdb_regmap.num_core_regs = n_core_regs;
	}
	}
	}

	static void xtensa_core_class_init(ObjectClass oc, void data)
	{
	CPUClass *cc = CPU_CLASS(oc);
	XtensaCPUClass *xcc = XTENSA_CPU_CLASS(oc);
	XtensaConfig *config = data;

	xtensa_finalize_config(config);
	xcc->config = config;

	/*
	* Use num_core_regs to see only non-privileged registers in an unmodified
	* gdb. Use num_regs to see all registers. gdb modification is required
	* for that: reset bit 0 in the 'flags' field of the registers definitions
	* in the gdb/xtensa-config.c inside gdb source tree or inside gdb overlay.
	*/
	cc->gdb_num_core_regs = config->gdb_regmap.num_regs;
	}

	void xtensa_register_core(XtensaConfigList *node)
	{
	TypeInfo type = {
	.parent = TYPE_XTENSA_CPU,
	.class_init = xtensa_core_class_init,
	.class_data = (void *)node->config,
	};

	node->next = xtensa_cores;
	xtensa_cores = node;
	type.name = g_strdup_printf(XTENSA_CPU_TYPE_NAME("%s"), node->config->name);
	type_register(&type);
	g_free((gpointer)type.name);
	}

	static uint32_t check_hw_breakpoints(CPUXtensaState *env)
	{
	unsigned i;

	for (i = 0; i < env->config->ndbreak; ++i) {
	if (env->cpu_watchpoint[i] &&
	env->cpu_watchpoint[i]->flags & BP_WATCHPOINT_HIT) {
	return DEBUGCAUSE_DB \| (i << DEBUGCAUSE_DBNUM_SHIFT);
	}
	}
	return 0;
	}

	void xtensa_breakpoint_handler(CPUState *cs)
	{
	XtensaCPU *cpu = XTENSA_CPU(cs);
	CPUXtensaState *env = &cpu->env;

	if (cs->watchpoint_hit) {
	if (cs->watchpoint_hit->flags & BP_CPU) {
	uint32_t cause;

	cs->watchpoint_hit = NULL;
	cause = check_hw_breakpoints(env);
	if (cause) {
	debug_exception_env(env, cause);
	}
	cpu_loop_exit_noexc(cs);
	}
	}
	}

	void xtensa_cpu_list(void)
	{
	XtensaConfigList *core = xtensa_cores;
	qemu_printf("Available CPUs:\n");
	for (; core; core = core->next) {
	qemu_printf(" %s\n", core->config->name);
	}
	}

	#ifdef CONFIG_USER_ONLY

	bool xtensa_cpu_tlb_fill(CPUState *cs, vaddr address, int size,
	MMUAccessType access_type, int mmu_idx,
	bool probe, uintptr_t retaddr)
	{
	XtensaCPU *cpu = XTENSA_CPU(cs);
	CPUXtensaState *env = &cpu->env;

	qemu_log_mask(CPU_LOG_INT,
	"%s: rw = %d, address = 0x%08" VADDR_PRIx ", size = %d\n",
	__func__, access_type, address, size);
	env->sregs[EXCVADDR] = address;
	env->sregs[EXCCAUSE] = (access_type == MMU_DATA_STORE ?
	STORE_PROHIBITED_CAUSE : LOAD_PROHIBITED_CAUSE);
	cs->exception_index = EXC_USER;
	cpu_loop_exit_restore(cs, retaddr);
	}

	#else

	void xtensa_cpu_do_unaligned_access(CPUState *cs,
	vaddr addr, MMUAccessType access_type,
	int mmu_idx, uintptr_t retaddr)
	{
	XtensaCPU *cpu = XTENSA_CPU(cs);
	CPUXtensaState *env = &cpu->env;

	if (xtensa_option_enabled(env->config, XTENSA_OPTION_UNALIGNED_EXCEPTION) &&
	!xtensa_option_enabled(env->config, XTENSA_OPTION_HW_ALIGNMENT)) {
	cpu_restore_state(CPU(cpu), retaddr, true);
	HELPER(exception_cause_vaddr)(env,
	env->pc, LOAD_STORE_ALIGNMENT_CAUSE,
	addr);
	}
	}

	bool xtensa_cpu_tlb_fill(CPUState *cs, vaddr address, int size,
	MMUAccessType access_type, int mmu_idx,
	bool probe, uintptr_t retaddr)
	{
	XtensaCPU *cpu = XTENSA_CPU(cs);
	CPUXtensaState *env = &cpu->env;
	uint32_t paddr;
	uint32_t page_size;
	unsigned access;
	int ret = xtensa_get_physical_addr(env, true, address, access_type,
	mmu_idx, &paddr, &page_size, &access);

	qemu_log_mask(CPU_LOG_MMU, "%s(%08" VADDR_PRIx
	", %d, %d) -> %08x, ret = %d\n",
	__func__, address, access_type, mmu_idx, paddr, ret);

	if (ret == 0) {
	tlb_set_page(cs,
	address & TARGET_PAGE_MASK,
	paddr & TARGET_PAGE_MASK,
	access, mmu_idx, page_size);
	return true;
	} else if (probe) {
	return false;
	} else {
	cpu_restore_state(cs, retaddr, true);
	HELPER(exception_cause_vaddr)(env, env->pc, ret, address);
	}
	}

	void xtensa_cpu_do_transaction_failed(CPUState *cs, hwaddr physaddr, vaddr addr,
	unsigned size, MMUAccessType access_type,
	int mmu_idx, MemTxAttrs attrs,
	MemTxResult response, uintptr_t retaddr)
	{
	XtensaCPU *cpu = XTENSA_CPU(cs);
	CPUXtensaState *env = &cpu->env;

	cpu_restore_state(cs, retaddr, true);
	HELPER(exception_cause_vaddr)(env, env->pc,
	access_type == MMU_INST_FETCH ?
	INSTR_PIF_ADDR_ERROR_CAUSE :
	LOAD_STORE_PIF_ADDR_ERROR_CAUSE,
	addr);
	}

	void xtensa_runstall(CPUXtensaState *env, bool runstall)
	{
	CPUState *cpu = env_cpu(env);

	env->runstall = runstall;
	cpu->halted = runstall;
	if (runstall) {
	cpu_interrupt(cpu, CPU_INTERRUPT_HALT);
	} else {
	qemu_cpu_kick(cpu);
	}
	}
	#endif