/*
* MIPS emulation helpers for qemu.
*
* Copyright (c) 2004-2005 Jocelyn Mayer
*
* 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 <stdarg.h>
#include <stdlib.h>
#include <stdio.h>
#include <string.h>
#include <inttypes.h>
#include <signal.h>
#include <assert.h>
#include "cpu.h"
#include "exec-all.h"
enum {
TLBRET_DIRTY = -4,
TLBRET_INVALID = -3,
TLBRET_NOMATCH = -2,
TLBRET_BADADDR = -1,
TLBRET_MATCH = 0
};
/* MIPS32 4K MMU emulation */
#ifdef MIPS_USES_R4K_TLB
static int map_address (CPUState *env, target_ulong *physical, int *prot,
target_ulong address, int rw, int access_type)
{
target_ulong tag = address & (TARGET_PAGE_MASK << 1);
uint8_t ASID = env->CP0_EntryHi & 0xFF;
tlb_t *tlb;
int i, n;
for (i = 0; i < env->tlb_in_use; i++) {
tlb = &env->tlb[i];
/* Check ASID, virtual page number & size */
if ((tlb->G == 1 || tlb->ASID == ASID) &&
tlb->VPN == tag && address < tlb->end2) {
/* TLB match */
n = (address >> TARGET_PAGE_BITS) & 1;
/* Check access rights */
if (!(n ? tlb->V1 : tlb->V0))
return TLBRET_INVALID;
if (rw == 0 || (n ? tlb->D1 : tlb->D0)) {
*physical = tlb->PFN[n] | (address & ~TARGET_PAGE_MASK);
*prot = PAGE_READ;
if (n ? tlb->D1 : tlb->D0)
*prot |= PAGE_WRITE;
return TLBRET_MATCH;
}
return TLBRET_DIRTY;
}
}
return TLBRET_NOMATCH;
}
#endif
static int get_physical_address (CPUState *env, target_ulong *physical,
int *prot, target_ulong address,
int rw, int access_type)
{
/* User mode can only access useg */
int user_mode = (env->hflags & MIPS_HFLAG_MODE) == MIPS_HFLAG_UM;
int ret = TLBRET_MATCH;
#if 0
if (logfile) {
fprintf(logfile, "user mode %d h %08x\n",
user_mode, env->hflags);
}
#endif
if (user_mode && address > 0x7FFFFFFFUL)
return TLBRET_BADADDR;
if (address < (int32_t)0x80000000UL) {
if (!(env->hflags & MIPS_HFLAG_ERL)) {
#ifdef MIPS_USES_R4K_TLB
ret = map_address(env, physical, prot, address, rw, access_type);
#else
*physical = address + 0x40000000UL;
*prot = PAGE_READ | PAGE_WRITE;
#endif
} else {
*physical = address;
*prot = PAGE_READ | PAGE_WRITE;
}
} else if (address < (int32_t)0xA0000000UL) {
/* kseg0 */
/* XXX: check supervisor mode */
*physical = address - (int32_t)0x80000000UL;
*prot = PAGE_READ | PAGE_WRITE;
} else if (address < (int32_t)0xC0000000UL) {
/* kseg1 */
/* XXX: check supervisor mode */
*physical = address - (int32_t)0xA0000000UL;
*prot = PAGE_READ | PAGE_WRITE;
} else if (address < (int32_t)0xE0000000UL) {
/* kseg2 */
#ifdef MIPS_USES_R4K_TLB
ret = map_address(env, physical, prot, address, rw, access_type);
#else
*physical = address;
*prot = PAGE_READ | PAGE_WRITE;
#endif
} else {
/* kseg3 */
/* XXX: check supervisor mode */
/* XXX: debug segment is not emulated */
#ifdef MIPS_USES_R4K_TLB
ret = map_address(env, physical, prot, address, rw, access_type);
#else
*physical = address;
*prot = PAGE_READ | PAGE_WRITE;
#endif
}
#if 0
if (logfile) {
fprintf(logfile, TLSZ " %d %d => " TLSZ " %d (%d)\n",
address, rw, access_type, *physical, *prot, ret);
}
#endif
return ret;
}
#if defined(CONFIG_USER_ONLY)
target_ulong cpu_get_phys_page_debug(CPUState *env, target_ulong addr)
{
return addr;
}
#else
target_ulong cpu_get_phys_page_debug(CPUState *env, target_ulong addr)
{
target_ulong phys_addr;
int prot;
if (get_physical_address(env, &phys_addr, &prot, addr, 0, ACCESS_INT) != 0)
return -1;
return phys_addr;
}
void cpu_mips_init_mmu (CPUState *env)
{
}
#endif /* !defined(CONFIG_USER_ONLY) */
int cpu_mips_handle_mmu_fault (CPUState *env, target_ulong address, int rw,
int is_user, int is_softmmu)
{
target_ulong physical;
int prot;
int exception = 0, error_code = 0;
int access_type;
int ret = 0;
if (logfile) {
#if 0
cpu_dump_state(env, logfile, fprintf, 0);
#endif
fprintf(logfile, "%s pc " TLSZ " ad " TLSZ " rw %d is_user %d smmu %d\n",
__func__, env->PC, address, rw, is_user, is_softmmu);
}
rw &= 1;
/* data access */
/* XXX: put correct access by using cpu_restore_state()
correctly */
access_type = ACCESS_INT;
if (env->user_mode_only) {
/* user mode only emulation */
ret = TLBRET_NOMATCH;
goto do_fault;
}
ret = get_physical_address(env, &physical, &prot,
address, rw, access_type);
if (logfile) {
fprintf(logfile, "%s address=" TLSZ " ret %d physical " TLSZ " prot %d\n",
__func__, address, ret, physical, prot);
}
if (ret == TLBRET_MATCH) {
ret = tlb_set_page(env, address & TARGET_PAGE_MASK,
physical & TARGET_PAGE_MASK, prot,
is_user, is_softmmu);
} else if (ret < 0) {
do_fault:
switch (ret) {
default:
case TLBRET_BADADDR:
/* Reference to kernel address from user mode or supervisor mode */
/* Reference to supervisor address from user mode */
if (rw)
exception = EXCP_AdES;
else
exception = EXCP_AdEL;
break;
case TLBRET_NOMATCH:
/* No TLB match for a mapped address */
if (rw)
exception = EXCP_TLBS;
else
exception = EXCP_TLBL;
error_code = 1;
break;
case TLBRET_INVALID:
/* TLB match with no valid bit */
if (rw)
exception = EXCP_TLBS;
else
exception = EXCP_TLBL;
break;
case TLBRET_DIRTY:
/* TLB match but 'D' bit is cleared */
exception = EXCP_LTLBL;
break;
}
/* Raise exception */
env->CP0_BadVAddr = address;
env->CP0_Context = (env->CP0_Context & 0xff800000) |
((address >> 9) & 0x007ffff0);
env->CP0_EntryHi =
(env->CP0_EntryHi & 0xFF) | (address & (TARGET_PAGE_MASK << 1));
env->exception_index = exception;
env->error_code = error_code;
ret = 1;
}
return ret;
}
#if defined(CONFIG_USER_ONLY)
void do_interrupt (CPUState *env)
{
env->exception_index = EXCP_NONE;
}
#else
void do_interrupt (CPUState *env)
{
target_ulong offset;
int cause = -1;
if (logfile && env->exception_index != EXCP_EXT_INTERRUPT) {
fprintf(logfile, "%s enter: PC " TLSZ " EPC " TLSZ " cause %d excp %d\n",
__func__, env->PC, env->CP0_EPC, cause, env->exception_index);
}
if (env->exception_index == EXCP_EXT_INTERRUPT &&
(env->hflags & MIPS_HFLAG_DM))
env->exception_index = EXCP_DINT;
offset = 0x180;
switch (env->exception_index) {
case EXCP_DSS:
env->CP0_Debug |= 1 << CP0DB_DSS;
/* Debug single step cannot be raised inside a delay slot and
* resume will always occur on the next instruction
* (but we assume the pc has always been updated during
* code translation).
*/
env->CP0_DEPC = env->PC;
goto enter_debug_mode;
case EXCP_DINT:
env->CP0_Debug |= 1 << CP0DB_DINT;
goto set_DEPC;
case EXCP_DIB:
env->CP0_Debug |= 1 << CP0DB_DIB;
goto set_DEPC;
case EXCP_DBp:
env->CP0_Debug |= 1 << CP0DB_DBp;
goto set_DEPC;
case EXCP_DDBS:
env->CP0_Debug |= 1 << CP0DB_DDBS;
goto set_DEPC;
case EXCP_DDBL:
env->CP0_Debug |= 1 << CP0DB_DDBL;
goto set_DEPC;
set_DEPC:
if (env->hflags & MIPS_HFLAG_BMASK) {
/* If the exception was raised from a delay slot,
come back to the jump. */
env->CP0_DEPC = env->PC - 4;
env->hflags &= ~MIPS_HFLAG_BMASK;
} else {
env->CP0_DEPC = env->PC;
}
enter_debug_mode:
env->hflags |= MIPS_HFLAG_DM;
/* EJTAG probe trap enable is not implemented... */
env->PC = (int32_t)0xBFC00480;
break;
case EXCP_RESET:
cpu_reset(env);
break;
case EXCP_SRESET:
env->CP0_Status = (1 << CP0St_SR);
env->CP0_WatchLo = 0;
goto set_error_EPC;
case EXCP_NMI:
env->CP0_Status = (1 << CP0St_NMI);
set_error_EPC:
if (env->hflags & MIPS_HFLAG_BMASK) {
/* If the exception was raised from a delay slot,
come back to the jump. */
env->CP0_ErrorEPC = env->PC - 4;
env->hflags &= ~MIPS_HFLAG_BMASK;
} else {
env->CP0_ErrorEPC = env->PC;
}
env->hflags |= MIPS_HFLAG_ERL;
env->CP0_Status |= (1 << CP0St_ERL) | (1 << CP0St_BEV);
env->PC = (int32_t)0xBFC00000;
break;
case EXCP_MCHECK:
cause = 24;
goto set_EPC;
case EXCP_EXT_INTERRUPT:
cause = 0;
if (env->CP0_Cause & (1 << CP0Ca_IV))
offset = 0x200;
goto set_EPC;
case EXCP_DWATCH:
cause = 23;
/* XXX: TODO: manage defered watch exceptions */
goto set_EPC;
case EXCP_AdEL:
case EXCP_AdES:
cause = 4;
goto set_EPC;
case EXCP_TLBL:
cause = 2;
if (env->error_code == 1 && !(env->hflags & MIPS_HFLAG_EXL))
offset = 0x000;
goto set_EPC;
case EXCP_IBE:
cause = 6;
goto set_EPC;
case EXCP_DBE:
cause = 7;
goto set_EPC;
case EXCP_SYSCALL:
cause = 8;
goto set_EPC;
case EXCP_BREAK:
cause = 9;
goto set_EPC;
case EXCP_RI:
cause = 10;
goto set_EPC;
case EXCP_CpU:
cause = 11;
env->CP0_Cause = (env->CP0_Cause & ~0x03000000) | (env->error_code << 28);
goto set_EPC;
case EXCP_OVERFLOW:
cause = 12;
goto set_EPC;
case EXCP_TRAP:
cause = 13;
goto set_EPC;
case EXCP_LTLBL:
cause = 1;
goto set_EPC;
case EXCP_TLBS:
cause = 3;
if (env->error_code == 1 && !(env->hflags & MIPS_HFLAG_EXL))
offset = 0x000;
goto set_EPC;
set_EPC:
if (env->hflags & MIPS_HFLAG_BMASK) {
/* If the exception was raised from a delay slot,
come back to the jump. */
env->CP0_EPC = env->PC - 4;
env->CP0_Cause |= 0x80000000;
env->hflags &= ~MIPS_HFLAG_BMASK;
} else {
env->CP0_EPC = env->PC;
env->CP0_Cause &= ~0x80000000;
}
if (env->CP0_Status & (1 << CP0St_BEV)) {
env->PC = (int32_t)0xBFC00200;
} else {
env->PC = (int32_t)0x80000000;
}
env->hflags |= MIPS_HFLAG_EXL;
env->CP0_Status |= (1 << CP0St_EXL);
env->PC += offset;
env->CP0_Cause = (env->CP0_Cause & ~0x7C) | (cause << 2);
break;
default:
if (logfile) {
fprintf(logfile, "Invalid MIPS exception %d. Exiting\n",
env->exception_index);
}
printf("Invalid MIPS exception %d. Exiting\n", env->exception_index);
exit(1);
}
if (logfile && env->exception_index != EXCP_EXT_INTERRUPT) {
fprintf(logfile, "%s: PC " TLSZ " EPC " TLSZ " cause %d excp %d\n"
" S %08x C %08x A " TLSZ " D " TLSZ "\n",
__func__, env->PC, env->CP0_EPC, cause, env->exception_index,
env->CP0_Status, env->CP0_Cause, env->CP0_BadVAddr,
env->CP0_DEPC);
}
env->exception_index = EXCP_NONE;
}
#endif /* !defined(CONFIG_USER_ONLY) */