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

 /*
  *  sparc helpers
  *
  *  Copyright (c) 2003 Fabrice Bellard
  *
  * This library is free software; you can redistribute it and/or
  * modify it under the terms of the GNU Lesser General Public
  * License as published by the Free Software Foundation; either
  * version 2 of the License, or (at your option) any later version.
  *
  * This library 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
  * Lesser General Public License for more details.
  *
  * You should have received a copy of the GNU Lesser General Public
  * License along with this library; if not, write to the Free Software
  * Foundation, Inc., 59 Temple Place, Suite 330, Boston, MA  02111-1307  USA
  */
 #include "exec.h"

 //#define DEBUG_PCALL
 //#define DEBUG_MMU

 /* Sparc MMU emulation */

 /* thread support */

 spinlock_t global_cpu_lock = SPIN_LOCK_UNLOCKED;

 void cpu_lock(void)
 {
     spin_lock(&global_cpu_lock);
 }

 void cpu_unlock(void)
 {
     spin_unlock(&global_cpu_lock);
 }

 #if defined(CONFIG_USER_ONLY)

 int cpu_sparc_handle_mmu_fault(CPUState *env, target_ulong address, int rw,
                                int is_user, int is_softmmu)
 {
     env->mmuregs[4] = address;
     if (rw & 2)
         env->exception_index = TT_TFAULT;
     else
         env->exception_index = TT_DFAULT;
     return 1;
 }

 #else

 #define MMUSUFFIX _mmu
 #define GETPC() (__builtin_return_address(0))

 #define SHIFT 0
 #include "softmmu_template.h"

 #define SHIFT 1
 #include "softmmu_template.h"

 #define SHIFT 2
 #include "softmmu_template.h"

 #define SHIFT 3
 #include "softmmu_template.h"


 /* try to fill the TLB and return an exception if error. If retaddr is
    NULL, it means that the function was called in C code (i.e. not
    from generated code or from helper.c) */
 /* XXX: fix it to restore all registers */
 void tlb_fill(target_ulong addr, int is_write, int is_user, void *retaddr)
 {
     TranslationBlock *tb;
     int ret;
     unsigned long pc;
     CPUState *saved_env;

     /* XXX: hack to restore env in all cases, even if not called from
        generated code */
     saved_env = env;
     env = cpu_single_env;

     ret = cpu_sparc_handle_mmu_fault(env, addr, is_write, is_user, 1);
     if (ret) {
         if (retaddr) {
             /* now we have a real cpu fault */
             pc = (unsigned long)retaddr;
             tb = tb_find_pc(pc);
             if (tb) {
                 /* the PC is inside the translated code. It means that we have
                    a virtual CPU fault */
                 cpu_restore_state(tb, env, pc, (void *)T2);
             }
         }
         cpu_loop_exit();
     }
     env = saved_env;
 }

 static const int access_table[8][8] = {
     { 0, 0, 0, 0, 2, 0, 3, 3 },
     { 0, 0, 0, 0, 2, 0, 0, 0 },
     { 2, 2, 0, 0, 0, 2, 3, 3 },
     { 2, 2, 0, 0, 0, 2, 0, 0 },
     { 2, 0, 2, 0, 2, 2, 3, 3 },
     { 2, 0, 2, 0, 2, 0, 2, 0 },
     { 2, 2, 2, 0, 2, 2, 3, 3 },
     { 2, 2, 2, 0, 2, 2, 2, 0 }
 };

 /* 1 = write OK */
 static const int rw_table[2][8] = {
     { 0, 1, 0, 1, 0, 1, 0, 1 },
     { 0, 1, 0, 1, 0, 0, 0, 0 }
 };

 int get_physical_address (CPUState *env, target_phys_addr_t *physical, int *prot,
 			  int *access_index, target_ulong address, int rw,
 			  int is_user)
 {
     int access_perms = 0;
     target_phys_addr_t pde_ptr;
     uint32_t pde;
     target_ulong virt_addr;
     int error_code = 0, is_dirty;
     unsigned long page_offset;

     virt_addr = address & TARGET_PAGE_MASK;
     if ((env->mmuregs[0] & MMU_E) == 0) { /* MMU disabled */
 	*physical = address;
         *prot = PAGE_READ | PAGE_WRITE;
         return 0;
     }

     *access_index = ((rw & 1) << 2) | (rw & 2) | (is_user? 0 : 1);
     *physical = 0xfffff000;

     /* SPARC reference MMU table walk: Context table->L1->L2->PTE */
     /* Context base + context number */
     pde_ptr = (env->mmuregs[1] << 4) + (env->mmuregs[2] << 2);
     pde = ldl_phys(pde_ptr);

     /* Ctx pde */
     switch (pde & PTE_ENTRYTYPE_MASK) {
     default:
     case 0: /* Invalid */
 	return 1 << 2;
     case 2: /* L0 PTE, maybe should not happen? */
     case 3: /* Reserved */
         return 4 << 2;
     case 1: /* L0 PDE */
 	pde_ptr = ((address >> 22) & ~3) + ((pde & ~3) << 4);
         pde = ldl_phys(pde_ptr);

 	switch (pde & PTE_ENTRYTYPE_MASK) {
 	default:
 	case 0: /* Invalid */
 	    return (1 << 8) | (1 << 2);
 	case 3: /* Reserved */
 	    return (1 << 8) | (4 << 2);
 	case 1: /* L1 PDE */
 	    pde_ptr = ((address & 0xfc0000) >> 16) + ((pde & ~3) << 4);
             pde = ldl_phys(pde_ptr);

 	    switch (pde & PTE_ENTRYTYPE_MASK) {
 	    default:
 	    case 0: /* Invalid */
 		return (2 << 8) | (1 << 2);
 	    case 3: /* Reserved */
 		return (2 << 8) | (4 << 2);
 	    case 1: /* L2 PDE */
 		pde_ptr = ((address & 0x3f000) >> 10) + ((pde & ~3) << 4);
                 pde = ldl_phys(pde_ptr);

 		switch (pde & PTE_ENTRYTYPE_MASK) {
 		default:
 		case 0: /* Invalid */
 		    return (3 << 8) | (1 << 2);
 		case 1: /* PDE, should not happen */
 		case 3: /* Reserved */
 		    return (3 << 8) | (4 << 2);
 		case 2: /* L3 PTE */
 		    virt_addr = address & TARGET_PAGE_MASK;
 		    page_offset = (address & TARGET_PAGE_MASK) & (TARGET_PAGE_SIZE - 1);
 		}
 		break;
 	    case 2: /* L2 PTE */
 		virt_addr = address & ~0x3ffff;
 		page_offset = address & 0x3ffff;
 	    }
 	    break;
 	case 2: /* L1 PTE */
 	    virt_addr = address & ~0xffffff;
 	    page_offset = address & 0xffffff;
 	}
     }

     /* update page modified and dirty bits */
     is_dirty = (rw & 1) && !(pde & PG_MODIFIED_MASK);
     if (!(pde & PG_ACCESSED_MASK) || is_dirty) {
 	pde |= PG_ACCESSED_MASK;
 	if (is_dirty)
 	    pde |= PG_MODIFIED_MASK;
         stl_phys_notdirty(pde_ptr, pde);
     }
     /* check access */
     access_perms = (pde & PTE_ACCESS_MASK) >> PTE_ACCESS_SHIFT;
     error_code = access_table[*access_index][access_perms];
     if (error_code && !(env->mmuregs[0] & MMU_NF))
 	return error_code;

     /* the page can be put in the TLB */
     *prot = PAGE_READ;
     if (pde & PG_MODIFIED_MASK) {
         /* only set write access if already dirty... otherwise wait
            for dirty access */
 	if (rw_table[is_user][access_perms])
 	        *prot |= PAGE_WRITE;
     }

     /* Even if large ptes, we map only one 4KB page in the cache to
        avoid filling it too fast */
     *physical = ((pde & PTE_ADDR_MASK) << 4) + page_offset;
     return error_code;
 }

 /* Perform address translation */
 int cpu_sparc_handle_mmu_fault (CPUState *env, target_ulong address, int rw,
                               int is_user, int is_softmmu)
 {
     target_ulong virt_addr;
     target_phys_addr_t paddr;
     unsigned long vaddr;
     int error_code = 0, prot, ret = 0, access_index;

     error_code = get_physical_address(env, &paddr, &prot, &access_index, address, rw, is_user);
     if (error_code == 0) {
 	virt_addr = address & TARGET_PAGE_MASK;
 	vaddr = virt_addr + ((address & TARGET_PAGE_MASK) & (TARGET_PAGE_SIZE - 1));
 	ret = tlb_set_page(env, vaddr, paddr, prot, is_user, is_softmmu);
 	return ret;
     }

     if (env->mmuregs[3]) /* Fault status register */
 	env->mmuregs[3] = 1; /* overflow (not read before another fault) */
     env->mmuregs[3] |= (access_index << 5) | error_code | 2;
     env->mmuregs[4] = address; /* Fault address register */

     if ((env->mmuregs[0] & MMU_NF) || env->psret == 0)  {
         // No fault mode: if a mapping is available, just override
         // permissions. If no mapping is available, redirect accesses to
         // neverland. Fake/overridden mappings will be flushed when
         // switching to normal mode.
 	vaddr = address & TARGET_PAGE_MASK;
         prot = PAGE_READ | PAGE_WRITE;
         ret = tlb_set_page(env, vaddr, paddr, prot, is_user, is_softmmu);
 	return ret;
     } else {
         if (rw & 2)
             env->exception_index = TT_TFAULT;
         else
             env->exception_index = TT_DFAULT;
         return 1;
     }
 }
 #endif

 void memcpy32(target_ulong *dst, const target_ulong *src)
 {
     dst[0] = src[0];
     dst[1] = src[1];
     dst[2] = src[2];
     dst[3] = src[3];
     dst[4] = src[4];
     dst[5] = src[5];
     dst[6] = src[6];
     dst[7] = src[7];
 }

 void set_cwp(int new_cwp)
 {
     /* put the modified wrap registers at their proper location */
     if (env->cwp == (NWINDOWS - 1))
         memcpy32(env->regbase, env->regbase + NWINDOWS * 16);
     env->cwp = new_cwp;
     /* put the wrap registers at their temporary location */
     if (new_cwp == (NWINDOWS - 1))
         memcpy32(env->regbase + NWINDOWS * 16, env->regbase);
     env->regwptr = env->regbase + (new_cwp * 16);
 }

 void cpu_set_cwp(CPUState *env1, int new_cwp)
 {
     CPUState *saved_env;
     saved_env = env;
     env = env1;
     set_cwp(new_cwp);
     env = saved_env;
 }

 void do_interrupt(int intno)
 {
     int cwp;

 #ifdef DEBUG_PCALL
     if (loglevel & CPU_LOG_INT) {
 	static int count;
 	fprintf(logfile, "%6d: v=%02x pc=%08x npc=%08x SP=%08x\n",
                 count, intno,
                 env->pc,
                 env->npc, env->regwptr[6]);
 	cpu_dump_state(env, logfile, fprintf, 0);
 #if 0
 	{
 	    int i;
 	    uint8_t *ptr;

 	    fprintf(logfile, "       code=");
 	    ptr = (uint8_t *)env->pc;
 	    for(i = 0; i < 16; i++) {
 		fprintf(logfile, " %02x", ldub(ptr + i));
 	    }
 	    fprintf(logfile, "\n");
 	}
 #endif
 	count++;
     }
 #endif
 #if !defined(CONFIG_USER_ONLY)
     if (env->psret == 0) {
         cpu_abort(cpu_single_env, "Trap 0x%02x while interrupts disabled, Error state", env->exception_index);
 	return;
     }
 #endif
     env->psret = 0;
     cwp = (env->cwp - 1) & (NWINDOWS - 1);
     set_cwp(cwp);
     env->regwptr[9] = env->pc;
     env->regwptr[10] = env->npc;
     env->psrps = env->psrs;
     env->psrs = 1;
     env->tbr = (env->tbr & TBR_BASE_MASK) | (intno << 4);
     env->pc = env->tbr;
     env->npc = env->pc + 4;
     env->exception_index = 0;
 }

 target_ulong mmu_probe(target_ulong address, int mmulev)
 {
     target_phys_addr_t pde_ptr;
     uint32_t pde;

     /* Context base + context number */
     pde_ptr = (env->mmuregs[1] << 4) + (env->mmuregs[2] << 2);
     pde = ldl_phys(pde_ptr);

     switch (pde & PTE_ENTRYTYPE_MASK) {
     default:
     case 0: /* Invalid */
     case 2: /* PTE, maybe should not happen? */
     case 3: /* Reserved */
 	return 0;
     case 1: /* L1 PDE */
 	if (mmulev == 3)
 	    return pde;
 	pde_ptr = ((address >> 22) & ~3) + ((pde & ~3) << 4);
         pde = ldl_phys(pde_ptr);

 	switch (pde & PTE_ENTRYTYPE_MASK) {
 	default:
 	case 0: /* Invalid */
 	case 3: /* Reserved */
 	    return 0;
 	case 2: /* L1 PTE */
 	    return pde;
 	case 1: /* L2 PDE */
 	    if (mmulev == 2)
 		return pde;
 	    pde_ptr = ((address & 0xfc0000) >> 16) + ((pde & ~3) << 4);
             pde = ldl_phys(pde_ptr);

 	    switch (pde & PTE_ENTRYTYPE_MASK) {
 	    default:
 	    case 0: /* Invalid */
 	    case 3: /* Reserved */
 		return 0;
 	    case 2: /* L2 PTE */
 		return pde;
 	    case 1: /* L3 PDE */
 		if (mmulev == 1)
 		    return pde;
 		pde_ptr = ((address & 0x3f000) >> 10) + ((pde & ~3) << 4);
                 pde = ldl_phys(pde_ptr);

 		switch (pde & PTE_ENTRYTYPE_MASK) {
 		default:
 		case 0: /* Invalid */
 		case 1: /* PDE, should not happen */
 		case 3: /* Reserved */
 		    return 0;
 		case 2: /* L3 PTE */
 		    return pde;
 		}
 	    }
 	}
     }
     return 0;
 }

 #ifdef DEBUG_MMU
 void dump_mmu(void)
 {
      target_ulong va, va1, va2;
      unsigned int n, m, o;
      target_phys_addr_t pde_ptr, pa;
     uint32_t pde;

     printf("MMU dump:\n");
     pde_ptr = (env->mmuregs[1] << 4) + (env->mmuregs[2] << 2);
     pde = ldl_phys(pde_ptr);
     printf("Root ptr: " TARGET_FMT_lx ", ctx: %d\n", env->mmuregs[1] << 4, env->mmuregs[2]);
     for (n = 0, va = 0; n < 256; n++, va += 16 * 1024 * 1024) {
 	pde_ptr = mmu_probe(va, 2);
 	if (pde_ptr) {
 	    pa = cpu_get_phys_page_debug(env, va);
  	    printf("VA: " TARGET_FMT_lx ", PA: " TARGET_FMT_lx " PDE: " TARGET_FMT_lx "\n", va, pa, pde_ptr);
 	    for (m = 0, va1 = va; m < 64; m++, va1 += 256 * 1024) {
 		pde_ptr = mmu_probe(va1, 1);
 		if (pde_ptr) {
 		    pa = cpu_get_phys_page_debug(env, va1);
  		    printf(" VA: " TARGET_FMT_lx ", PA: " TARGET_FMT_lx " PDE: " TARGET_FMT_lx "\n", va1, pa, pde_ptr);
 		    for (o = 0, va2 = va1; o < 64; o++, va2 += 4 * 1024) {
 			pde_ptr = mmu_probe(va2, 0);
 			if (pde_ptr) {
 			    pa = cpu_get_phys_page_debug(env, va2);
  			    printf("  VA: " TARGET_FMT_lx ", PA: " TARGET_FMT_lx " PTE: " TARGET_FMT_lx "\n", va2, pa, pde_ptr);
 			}
 		    }
 		}
 	    }
 	}
     }
     printf("MMU dump ends\n");
 }
 #endif
	/*
	* sparc helpers
	*
	* Copyright (c) 2003 Fabrice Bellard
	*
	* This library is free software; you can redistribute it and/or
	* modify it under the terms of the GNU Lesser General Public
	* License as published by the Free Software Foundation; either
	* version 2 of the License, or (at your option) any later version.
	*
	* This library 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
	* Lesser General Public License for more details.
	*
	* You should have received a copy of the GNU Lesser General Public
	* License along with this library; if not, write to the Free Software
	* Foundation, Inc., 59 Temple Place, Suite 330, Boston, MA 02111-1307 USA
	*/
	#include "exec.h"

	//#define DEBUG_PCALL
	//#define DEBUG_MMU

	/* Sparc MMU emulation */

	/* thread support */

	spinlock_t global_cpu_lock = SPIN_LOCK_UNLOCKED;

	void cpu_lock(void)
	{
	spin_lock(&global_cpu_lock);
	}

	void cpu_unlock(void)
	{
	spin_unlock(&global_cpu_lock);
	}

	#if defined(CONFIG_USER_ONLY)

	int cpu_sparc_handle_mmu_fault(CPUState *env, target_ulong address, int rw,
	int is_user, int is_softmmu)
	{
	env->mmuregs[4] = address;
	if (rw & 2)
	env->exception_index = TT_TFAULT;
	else
	env->exception_index = TT_DFAULT;
	return 1;
	}

	#else

	#define MMUSUFFIX _mmu
	#define GETPC() (__builtin_return_address(0))

	#define SHIFT 0
	#include "softmmu_template.h"

	#define SHIFT 1
	#include "softmmu_template.h"

	#define SHIFT 2
	#include "softmmu_template.h"

	#define SHIFT 3
	#include "softmmu_template.h"


	/* try to fill the TLB and return an exception if error. If retaddr is
	NULL, it means that the function was called in C code (i.e. not
	from generated code or from helper.c) */
	/* XXX: fix it to restore all registers */
	void tlb_fill(target_ulong addr, int is_write, int is_user, void *retaddr)
	{
	TranslationBlock *tb;
	int ret;
	unsigned long pc;
	CPUState *saved_env;

	/* XXX: hack to restore env in all cases, even if not called from
	generated code */
	saved_env = env;
	env = cpu_single_env;

	ret = cpu_sparc_handle_mmu_fault(env, addr, is_write, is_user, 1);
	if (ret) {
	if (retaddr) {
	/* now we have a real cpu fault */
	pc = (unsigned long)retaddr;
	tb = tb_find_pc(pc);
	if (tb) {
	/* the PC is inside the translated code. It means that we have
	a virtual CPU fault */
	cpu_restore_state(tb, env, pc, (void *)T2);
	}
	}
	cpu_loop_exit();
	}
	env = saved_env;
	}

	static const int access_table[8][8] = {
	{ 0, 0, 0, 0, 2, 0, 3, 3 },
	{ 0, 0, 0, 0, 2, 0, 0, 0 },
	{ 2, 2, 0, 0, 0, 2, 3, 3 },
	{ 2, 2, 0, 0, 0, 2, 0, 0 },
	{ 2, 0, 2, 0, 2, 2, 3, 3 },
	{ 2, 0, 2, 0, 2, 0, 2, 0 },
	{ 2, 2, 2, 0, 2, 2, 3, 3 },
	{ 2, 2, 2, 0, 2, 2, 2, 0 }
	};

	/* 1 = write OK */
	static const int rw_table[2][8] = {
	{ 0, 1, 0, 1, 0, 1, 0, 1 },
	{ 0, 1, 0, 1, 0, 0, 0, 0 }
	};

	int get_physical_address (CPUState env, target_phys_addr_t physical, int *prot,
	int *access_index, target_ulong address, int rw,
	int is_user)
	{
	int access_perms = 0;
	target_phys_addr_t pde_ptr;
	uint32_t pde;
	target_ulong virt_addr;
	int error_code = 0, is_dirty;
	unsigned long page_offset;

	virt_addr = address & TARGET_PAGE_MASK;
	if ((env->mmuregs[0] & MMU_E) == 0) { /* MMU disabled */
	*physical = address;
	*prot = PAGE_READ \| PAGE_WRITE;
	return 0;
	}

	*access_index = ((rw & 1) << 2) \| (rw & 2) \| (is_user? 0 : 1);
	*physical = 0xfffff000;

	/* SPARC reference MMU table walk: Context table->L1->L2->PTE */
	/* Context base + context number */
	pde_ptr = (env->mmuregs[1] << 4) + (env->mmuregs[2] << 2);
	pde = ldl_phys(pde_ptr);

	/* Ctx pde */
	switch (pde & PTE_ENTRYTYPE_MASK) {
	default:
	case 0: /* Invalid */
	return 1 << 2;
	case 2: /* L0 PTE, maybe should not happen? */
	case 3: /* Reserved */
	return 4 << 2;
	case 1: /* L0 PDE */
	pde_ptr = ((address >> 22) & ~3) + ((pde & ~3) << 4);
	pde = ldl_phys(pde_ptr);

	switch (pde & PTE_ENTRYTYPE_MASK) {
	default:
	case 0: /* Invalid */
	return (1 << 8) \| (1 << 2);
	case 3: /* Reserved */
	return (1 << 8) \| (4 << 2);
	case 1: /* L1 PDE */
	pde_ptr = ((address & 0xfc0000) >> 16) + ((pde & ~3) << 4);
	pde = ldl_phys(pde_ptr);

	switch (pde & PTE_ENTRYTYPE_MASK) {
	default:
	case 0: /* Invalid */
	return (2 << 8) \| (1 << 2);
	case 3: /* Reserved */
	return (2 << 8) \| (4 << 2);
	case 1: /* L2 PDE */
	pde_ptr = ((address & 0x3f000) >> 10) + ((pde & ~3) << 4);
	pde = ldl_phys(pde_ptr);

	switch (pde & PTE_ENTRYTYPE_MASK) {
	default:
	case 0: /* Invalid */
	return (3 << 8) \| (1 << 2);
	case 1: /* PDE, should not happen */
	case 3: /* Reserved */
	return (3 << 8) \| (4 << 2);
	case 2: /* L3 PTE */
	virt_addr = address & TARGET_PAGE_MASK;
	page_offset = (address & TARGET_PAGE_MASK) & (TARGET_PAGE_SIZE - 1);
	}
	break;
	case 2: /* L2 PTE */
	virt_addr = address & ~0x3ffff;
	page_offset = address & 0x3ffff;
	}
	break;
	case 2: /* L1 PTE */
	virt_addr = address & ~0xffffff;
	page_offset = address & 0xffffff;
	}
	}

	/* update page modified and dirty bits */
	is_dirty = (rw & 1) && !(pde & PG_MODIFIED_MASK);
	if (!(pde & PG_ACCESSED_MASK) \|\| is_dirty) {
	pde \|= PG_ACCESSED_MASK;
	if (is_dirty)
	pde \|= PG_MODIFIED_MASK;
	stl_phys_notdirty(pde_ptr, pde);
	}
	/* check access */
	access_perms = (pde & PTE_ACCESS_MASK) >> PTE_ACCESS_SHIFT;
	error_code = access_table[*access_index][access_perms];
	if (error_code && !(env->mmuregs[0] & MMU_NF))
	return error_code;

	/* the page can be put in the TLB */
	*prot = PAGE_READ;
	if (pde & PG_MODIFIED_MASK) {
	/* only set write access if already dirty... otherwise wait
	for dirty access */
	if (rw_table[is_user][access_perms])
	*prot \|= PAGE_WRITE;
	}

	/* Even if large ptes, we map only one 4KB page in the cache to
	avoid filling it too fast */
	*physical = ((pde & PTE_ADDR_MASK) << 4) + page_offset;
	return error_code;
	}

	/* Perform address translation */
	int cpu_sparc_handle_mmu_fault (CPUState *env, target_ulong address, int rw,
	int is_user, int is_softmmu)
	{
	target_ulong virt_addr;
	target_phys_addr_t paddr;
	unsigned long vaddr;
	int error_code = 0, prot, ret = 0, access_index;

	error_code = get_physical_address(env, &paddr, &prot, &access_index, address, rw, is_user);
	if (error_code == 0) {
	virt_addr = address & TARGET_PAGE_MASK;
	vaddr = virt_addr + ((address & TARGET_PAGE_MASK) & (TARGET_PAGE_SIZE - 1));
	ret = tlb_set_page(env, vaddr, paddr, prot, is_user, is_softmmu);
	return ret;
	}

	if (env->mmuregs[3]) /* Fault status register */
	env->mmuregs[3] = 1; /* overflow (not read before another fault) */
	env->mmuregs[3] \|= (access_index << 5) \| error_code \| 2;
	env->mmuregs[4] = address; /* Fault address register */

	if ((env->mmuregs[0] & MMU_NF) \|\| env->psret == 0) {
	// No fault mode: if a mapping is available, just override
	// permissions. If no mapping is available, redirect accesses to
	// neverland. Fake/overridden mappings will be flushed when
	// switching to normal mode.
	vaddr = address & TARGET_PAGE_MASK;
	prot = PAGE_READ \| PAGE_WRITE;
	ret = tlb_set_page(env, vaddr, paddr, prot, is_user, is_softmmu);
	return ret;
	} else {
	if (rw & 2)
	env->exception_index = TT_TFAULT;
	else
	env->exception_index = TT_DFAULT;
	return 1;
	}
	}
	#endif

	void memcpy32(target_ulong dst, const target_ulong src)
	{
	dst[0] = src[0];
	dst[1] = src[1];
	dst[2] = src[2];
	dst[3] = src[3];
	dst[4] = src[4];
	dst[5] = src[5];
	dst[6] = src[6];
	dst[7] = src[7];
	}

	void set_cwp(int new_cwp)
	{
	/* put the modified wrap registers at their proper location */
	if (env->cwp == (NWINDOWS - 1))
	memcpy32(env->regbase, env->regbase + NWINDOWS * 16);
	env->cwp = new_cwp;
	/* put the wrap registers at their temporary location */
	if (new_cwp == (NWINDOWS - 1))
	memcpy32(env->regbase + NWINDOWS * 16, env->regbase);
	env->regwptr = env->regbase + (new_cwp * 16);
	}

	void cpu_set_cwp(CPUState *env1, int new_cwp)
	{
	CPUState *saved_env;
	saved_env = env;
	env = env1;
	set_cwp(new_cwp);
	env = saved_env;
	}

	void do_interrupt(int intno)
	{
	int cwp;

	#ifdef DEBUG_PCALL
	if (loglevel & CPU_LOG_INT) {
	static int count;
	fprintf(logfile, "%6d: v=%02x pc=%08x npc=%08x SP=%08x\n",
	count, intno,
	env->pc,
	env->npc, env->regwptr[6]);
	cpu_dump_state(env, logfile, fprintf, 0);
	#if 0
	{
	int i;
	uint8_t *ptr;

	fprintf(logfile, " code=");
	ptr = (uint8_t *)env->pc;
	for(i = 0; i < 16; i++) {
	fprintf(logfile, " %02x", ldub(ptr + i));
	}
	fprintf(logfile, "\n");
	}
	#endif
	count++;
	}
	#endif
	#if !defined(CONFIG_USER_ONLY)
	if (env->psret == 0) {
	cpu_abort(cpu_single_env, "Trap 0x%02x while interrupts disabled, Error state", env->exception_index);
	return;
	}
	#endif
	env->psret = 0;
	cwp = (env->cwp - 1) & (NWINDOWS - 1);
	set_cwp(cwp);
	env->regwptr[9] = env->pc;
	env->regwptr[10] = env->npc;
	env->psrps = env->psrs;
	env->psrs = 1;
	env->tbr = (env->tbr & TBR_BASE_MASK) \| (intno << 4);
	env->pc = env->tbr;
	env->npc = env->pc + 4;
	env->exception_index = 0;
	}

	target_ulong mmu_probe(target_ulong address, int mmulev)
	{
	target_phys_addr_t pde_ptr;
	uint32_t pde;

	/* Context base + context number */
	pde_ptr = (env->mmuregs[1] << 4) + (env->mmuregs[2] << 2);
	pde = ldl_phys(pde_ptr);

	switch (pde & PTE_ENTRYTYPE_MASK) {
	default:
	case 0: /* Invalid */
	case 2: /* PTE, maybe should not happen? */
	case 3: /* Reserved */
	return 0;
	case 1: /* L1 PDE */
	if (mmulev == 3)
	return pde;
	pde_ptr = ((address >> 22) & ~3) + ((pde & ~3) << 4);
	pde = ldl_phys(pde_ptr);

	switch (pde & PTE_ENTRYTYPE_MASK) {
	default:
	case 0: /* Invalid */
	case 3: /* Reserved */
	return 0;
	case 2: /* L1 PTE */
	return pde;
	case 1: /* L2 PDE */
	if (mmulev == 2)
	return pde;
	pde_ptr = ((address & 0xfc0000) >> 16) + ((pde & ~3) << 4);
	pde = ldl_phys(pde_ptr);

	switch (pde & PTE_ENTRYTYPE_MASK) {
	default:
	case 0: /* Invalid */
	case 3: /* Reserved */
	return 0;
	case 2: /* L2 PTE */
	return pde;
	case 1: /* L3 PDE */
	if (mmulev == 1)
	return pde;
	pde_ptr = ((address & 0x3f000) >> 10) + ((pde & ~3) << 4);
	pde = ldl_phys(pde_ptr);

	switch (pde & PTE_ENTRYTYPE_MASK) {
	default:
	case 0: /* Invalid */
	case 1: /* PDE, should not happen */
	case 3: /* Reserved */
	return 0;
	case 2: /* L3 PTE */
	return pde;
	}
	}
	}
	}
	return 0;
	}

	#ifdef DEBUG_MMU
	void dump_mmu(void)
	{
	target_ulong va, va1, va2;
	unsigned int n, m, o;
	target_phys_addr_t pde_ptr, pa;
	uint32_t pde;

	printf("MMU dump:\n");
	pde_ptr = (env->mmuregs[1] << 4) + (env->mmuregs[2] << 2);
	pde = ldl_phys(pde_ptr);
	printf("Root ptr: " TARGET_FMT_lx ", ctx: %d\n", env->mmuregs[1] << 4, env->mmuregs[2]);
	for (n = 0, va = 0; n < 256; n++, va += 16 * 1024 * 1024) {
	pde_ptr = mmu_probe(va, 2);
	if (pde_ptr) {
	pa = cpu_get_phys_page_debug(env, va);
	printf("VA: " TARGET_FMT_lx ", PA: " TARGET_FMT_lx " PDE: " TARGET_FMT_lx "\n", va, pa, pde_ptr);
	for (m = 0, va1 = va; m < 64; m++, va1 += 256 * 1024) {
	pde_ptr = mmu_probe(va1, 1);
	if (pde_ptr) {
	pa = cpu_get_phys_page_debug(env, va1);
	printf(" VA: " TARGET_FMT_lx ", PA: " TARGET_FMT_lx " PDE: " TARGET_FMT_lx "\n", va1, pa, pde_ptr);
	for (o = 0, va2 = va1; o < 64; o++, va2 += 4 * 1024) {
	pde_ptr = mmu_probe(va2, 0);
	if (pde_ptr) {
	pa = cpu_get_phys_page_debug(env, va2);
	printf(" VA: " TARGET_FMT_lx ", PA: " TARGET_FMT_lx " PTE: " TARGET_FMT_lx "\n", va2, pa, pde_ptr);
	}
	}
	}
	}
	}
	}
	printf("MMU dump ends\n");
	}
	#endif