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1
/*
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 *  MIPS emulation helpers for qemu.
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 * 
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 *  Copyright (c) 2004-2005 Jocelyn Mayer
5
 *
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 * This library is free software; you can redistribute it and/or
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 * modify it under the terms of the GNU Lesser General Public
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 * License as published by the Free Software Foundation; either
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 * version 2 of the License, or (at your option) any later version.
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 *
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 * This library is distributed in the hope that it will be useful,
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 * but WITHOUT ANY WARRANTY; without even the implied warranty of
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 * MERCHANTABILITY or FITNESS FOR A PARTICULAR PURPOSE.  See the GNU
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 * Lesser General Public License for more details.
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 *
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 * You should have received a copy of the GNU Lesser General Public
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 * License along with this library; if not, write to the Free Software
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 * Foundation, Inc., 59 Temple Place, Suite 330, Boston, MA  02111-1307  USA
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 */
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#include "exec.h"
21

    
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/* MIPS32 4K MMU emulation */
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#ifdef MIPS_USES_R4K_TLB
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static int map_address (CPUState *env, target_ulong *physical, int *prot,
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                        target_ulong address, int rw, int access_type)
26
{
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    tlb_t *tlb;
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    target_ulong tag;
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    uint8_t ASID;
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    int i, n;
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    int ret;
32

    
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    ret = -2;
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    tag = (address & 0xFFFFE000);
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    ASID = env->CP0_EntryHi & 0x000000FF;
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    for (i = 0; i < MIPS_TLB_NB; i++) {
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        tlb = &env->tlb[i];
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        /* Check ASID, virtual page number & size */
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        if ((tlb->G == 1 || tlb->ASID == ASID) &&
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            tlb->VPN == tag && address < tlb->end) {
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            /* TLB match */
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            n = (address >> 12) & 1;
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            /* Check access rights */
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            if ((tlb->V[n] & 2) && (rw == 0 || (tlb->D[n] & 4))) {
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                *physical = tlb->PFN[n] | (address & 0xFFF);
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                *prot = PAGE_READ;
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                if (tlb->D[n])
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                    *prot |= PAGE_WRITE;
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                return 0;
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            } else if (!(tlb->V[n] & 2)) {
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                return -3;
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            } else {
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                return -4;
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            }
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        }
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    }
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    return ret;
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}
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#endif
61

    
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int get_physical_address (CPUState *env, target_ulong *physical, int *prot,
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                          target_ulong address, int rw, int access_type)
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{
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    int user_mode;
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    int ret;
67

    
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    /* User mode can only access useg */
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    user_mode = ((env->hflags & MIPS_HFLAG_MODE) == MIPS_HFLAG_UM) ? 1 : 0;
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#if 0
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    if (logfile) {
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        fprintf(logfile, "user mode %d h %08x\n",
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                user_mode, env->hflags);
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    }
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#endif
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    if (user_mode && address > 0x7FFFFFFFUL)
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        return -1;
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    ret = 0;
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    if (address < 0x80000000UL) {
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        if (!(env->hflags & MIPS_HFLAG_ERL)) {
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#ifdef MIPS_USES_R4K_TLB
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            ret = map_address(env, physical, prot, address, rw, access_type);
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#else
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            *physical = address + 0x40000000UL;
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            *prot = PAGE_READ | PAGE_WRITE;
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#endif
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        } else {
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            *physical = address;
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            *prot = PAGE_READ | PAGE_WRITE;
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        }
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    } else if (address < 0xA0000000UL) {
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        /* kseg0 */
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        /* XXX: check supervisor mode */
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        *physical = address - 0x80000000UL;
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        *prot = PAGE_READ | PAGE_WRITE;
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    } else if (address < 0xC0000000UL) {
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        /* kseg1 */
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        /* XXX: check supervisor mode */
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        *physical = address - 0xA0000000UL;
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        *prot = PAGE_READ | PAGE_WRITE;
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    } else if (address < 0xE0000000UL) {
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        /* kseg2 */
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#ifdef MIPS_USES_R4K_TLB
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        ret = map_address(env, physical, prot, address, rw, access_type);
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#else
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        *physical = address;
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        *prot = PAGE_READ | PAGE_WRITE;
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#endif
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    } else {
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        /* kseg3 */
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        /* XXX: check supervisor mode */
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        /* XXX: debug segment is not emulated */
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#ifdef MIPS_USES_R4K_TLB
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        ret = map_address(env, physical, prot, address, rw, access_type);
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#else
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        *physical = address;
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        *prot = PAGE_READ | PAGE_WRITE;
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#endif
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    }
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#if 0
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    if (logfile) {
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        fprintf(logfile, "%08x %d %d => %08x %d (%d)\n", address, rw,
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                access_type, *physical, *prot, ret);
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    }
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#endif
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    return ret;
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}
129

    
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#if defined(CONFIG_USER_ONLY) 
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target_ulong cpu_get_phys_page_debug(CPUState *env, target_ulong addr)
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{
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    return addr;
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}
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#else
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target_ulong cpu_get_phys_page_debug(CPUState *env, target_ulong addr)
137
{
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    target_ulong phys_addr;
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    int prot;
140

    
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    if (get_physical_address(env, &phys_addr, &prot, addr, 0, ACCESS_INT) != 0)
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        return -1;
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    return phys_addr;
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}
145
#endif
146

    
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#if !defined(CONFIG_USER_ONLY) 
148

    
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#define MMUSUFFIX _mmu
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#define GETPC() (__builtin_return_address(0))
151

    
152
#define SHIFT 0
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#include "softmmu_template.h"
154

    
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#define SHIFT 1
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#include "softmmu_template.h"
157

    
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#define SHIFT 2
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#include "softmmu_template.h"
160

    
161
#define SHIFT 3
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#include "softmmu_template.h"
163

    
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void tlb_fill (target_ulong addr, int is_write, int is_user, void *retaddr)
165
{
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    TranslationBlock *tb;
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    CPUState *saved_env;
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    unsigned long pc;
169
    int ret;
170

    
171
    /* XXX: hack to restore env in all cases, even if not called from
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       generated code */
173
    saved_env = env;
174
    env = cpu_single_env;
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    ret = cpu_mips_handle_mmu_fault(env, addr, is_write, is_user, 1);
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    if (ret) {
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        if (retaddr) {
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            /* now we have a real cpu fault */
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            pc = (unsigned long)retaddr;
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            tb = tb_find_pc(pc);
181
            if (tb) {
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                /* the PC is inside the translated code. It means that we have
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                   a virtual CPU fault */
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                cpu_restore_state(tb, env, pc, NULL);
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            }
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        }
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        do_raise_exception_err(env->exception_index, env->error_code);
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    }
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    env = saved_env;
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}
191

    
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void cpu_mips_init_mmu (CPUState *env)
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{
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}
195

    
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#endif /* !defined(CONFIG_USER_ONLY) */
197

    
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int cpu_mips_handle_mmu_fault (CPUState *env, target_ulong address, int rw,
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                               int is_user, int is_softmmu)
200
{
201
    target_ulong physical;
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    int prot;
203
    int exception = 0, error_code = 0;
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    int access_type;
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    int ret = 0;
206

    
207
    if (logfile) {
208
        cpu_dump_state(env, logfile, fprintf, 0);
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        fprintf(logfile, "%s pc %08x ad %08x rw %d is_user %d smmu %d\n",
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                __func__, env->PC, address, rw, is_user, is_softmmu);
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    }
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    /* data access */
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    /* XXX: put correct access by using cpu_restore_state()
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       correctly */
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    access_type = ACCESS_INT;
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    if (env->user_mode_only) {
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        /* user mode only emulation */
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        ret = -2;
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        goto do_fault;
220
    }
221
    ret = get_physical_address(env, &physical, &prot,
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                               address, rw, access_type);
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    if (logfile) {
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        fprintf(logfile, "%s address=%08x ret %d physical %08x prot %d\n",
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                __func__, address, ret, physical, prot);
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    }
227
    if (ret == 0) {
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        ret = tlb_set_page(env, address & ~0xFFF, physical & ~0xFFF, prot,
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                           is_user, is_softmmu);
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    } else if (ret < 0) {
231
    do_fault:
232
        switch (ret) {
233
        default:
234
        case -1:
235
            /* Reference to kernel address from user mode or supervisor mode */
236
            /* Reference to supervisor address from user mode */
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            if (rw)
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                exception = EXCP_AdES;
239
            else
240
                exception = EXCP_AdEL;
241
            break;
242
        case -2:
243
            /* No TLB match for a mapped address */
244
            if (rw)
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                exception = EXCP_TLBS;
246
            else
247
                exception = EXCP_TLBL;
248
            error_code = 1;
249
            break;
250
        case -3:
251
            /* TLB match with no valid bit */
252
            if (rw)
253
                exception = EXCP_TLBS;
254
            else
255
                exception = EXCP_TLBL;
256
            error_code = 0;
257
            break;
258
        case -4:
259
            /* TLB match but 'D' bit is cleared */
260
            exception = EXCP_LTLBL;
261
            break;
262
                
263
        }
264
        /* Raise exception */
265
        env->CP0_BadVAddr = address;
266
        env->CP0_Context = (env->CP0_Context & 0xff800000) |
267
                           ((address >> 8) &   0x007ffff0);
268
        env->CP0_EntryHi =
269
            (env->CP0_EntryHi & 0x000000FF) | (address & 0xFFFFF000);
270
        env->exception_index = exception;
271
        env->error_code = error_code;
272
        ret = 1;
273
    }
274

    
275
    return ret;
276
}
277

    
278
void do_interrupt (CPUState *env)
279
{
280
    target_ulong pc, offset;
281
    int cause = -1;
282

    
283
    if (logfile && env->exception_index != EXCP_EXT_INTERRUPT) {
284
        fprintf(logfile, "%s enter: PC %08x EPC %08x cause %d excp %d\n",
285
                __func__, env->PC, env->CP0_EPC, cause, env->exception_index);
286
    }
287
    if (env->exception_index == EXCP_EXT_INTERRUPT &&
288
        (env->hflags & MIPS_HFLAG_DM))
289
        env->exception_index = EXCP_DINT;
290
    offset = 0x180;
291
    switch (env->exception_index) {
292
    case EXCP_DSS:
293
        env->CP0_Debug |= 1 << CP0DB_DSS;
294
        /* Debug single step cannot be raised inside a delay slot and
295
         * resume will always occur on the next instruction
296
         * (but we assume the pc has always been updated during
297
         *  code translation).
298
         */
299
        env->CP0_DEPC = env->PC;
300
        goto enter_debug_mode;
301
    case EXCP_DINT:
302
        env->CP0_Debug |= 1 << CP0DB_DINT;
303
        goto set_DEPC;
304
    case EXCP_DIB:
305
        env->CP0_Debug |= 1 << CP0DB_DIB;
306
        goto set_DEPC;
307
    case EXCP_DBp:
308
        env->CP0_Debug |= 1 << CP0DB_DBp;
309
        goto set_DEPC;
310
    case EXCP_DDBS:
311
        env->CP0_Debug |= 1 << CP0DB_DDBS;
312
        goto set_DEPC;
313
    case EXCP_DDBL:
314
        env->CP0_Debug |= 1 << CP0DB_DDBL;
315
        goto set_DEPC;
316
    set_DEPC:
317
        if (env->hflags & MIPS_HFLAG_DS) {
318
            /* If the exception was raised from a delay slot,
319
             * come back to the jump
320
             */
321
            env->CP0_DEPC = env->PC - 4;
322
        } else {
323
            env->CP0_DEPC = env->PC;
324
        }
325
    enter_debug_mode:
326
        env->hflags |= MIPS_HFLAG_DM;
327
        /* EJTAG probe trap enable is not implemented... */
328
        pc = 0xBFC00480;
329
        break;
330
    case EXCP_RESET:
331
#ifdef MIPS_USES_R4K_TLB
332
        env->CP0_random = MIPS_TLB_NB - 1;
333
#endif
334
        env->CP0_Wired = 0;
335
        env->CP0_Config0 = MIPS_CONFIG0;
336
#if defined (MIPS_CONFIG1)
337
        env->CP0_Config1 = MIPS_CONFIG1;
338
#endif
339
#if defined (MIPS_CONFIG2)
340
        env->CP0_Config2 = MIPS_CONFIG2;
341
#endif
342
#if defined (MIPS_CONFIG3)
343
        env->CP0_Config3 = MIPS_CONFIG3;
344
#endif
345
        env->CP0_WatchLo = 0;
346
        env->CP0_Status = (1 << CP0St_CU0) | (1 << CP0St_BEV);
347
        goto set_error_EPC;
348
    case EXCP_SRESET:
349
        env->CP0_Status = (1 << CP0St_CU0) | (1 << CP0St_BEV) |
350
            (1 << CP0St_SR);
351
        env->CP0_WatchLo = 0;
352
        goto set_error_EPC;
353
    case EXCP_NMI:
354
        env->CP0_Status = (1 << CP0St_CU0) | (1 << CP0St_BEV) |
355
            (1 << CP0St_NMI);
356
    set_error_EPC:
357
        env->hflags = MIPS_HFLAG_ERL;
358
        if (env->hflags & MIPS_HFLAG_DS) {
359
            /* If the exception was raised from a delay slot,
360
             * come back to the jump
361
             */
362
            env->CP0_ErrorEPC = env->PC - 4;
363
        } else {
364
            env->CP0_ErrorEPC = env->PC;
365
        }
366
        pc = 0xBFC00000;
367
        break;
368
    case EXCP_MCHECK:
369
        cause = 24;
370
        goto set_EPC;
371
    case EXCP_EXT_INTERRUPT:
372
        cause = 0;
373
        if (env->CP0_Cause & (1 << CP0Ca_IV))
374
            offset = 0x200;
375
        goto set_EPC;
376
    case EXCP_DWATCH:
377
        cause = 23;
378
        /* XXX: TODO: manage defered watch exceptions */
379
        goto set_EPC;
380
    case EXCP_AdEL:
381
    case EXCP_AdES:
382
        cause = 4;
383
        goto set_EPC;
384
    case EXCP_TLBL:
385
    case EXCP_TLBF:
386
        cause = 2;
387
        if (env->error_code == 1 && !(env->hflags & MIPS_HFLAG_EXL))
388
            offset = 0x000;
389
        goto set_EPC;
390
    case EXCP_IBE:
391
        cause = 6;
392
        goto set_EPC;
393
    case EXCP_DBE:
394
        cause = 7;
395
        goto set_EPC;
396
    case EXCP_SYSCALL:
397
        cause = 8;
398
        goto set_EPC;
399
    case EXCP_BREAK:
400
        cause = 9;
401
        goto set_EPC;
402
    case EXCP_RI:
403
        cause = 10;
404
        goto set_EPC;
405
    case EXCP_CpU:
406
        cause = 11;
407
        /* XXX: fill in the faulty unit number */
408
        goto set_EPC;
409
    case EXCP_OVERFLOW:
410
        cause = 12;
411
        goto set_EPC;
412
    case EXCP_TRAP:
413
        cause = 13;
414
        goto set_EPC;
415
    case EXCP_LTLBL:
416
        cause = 1;
417
        goto set_EPC;
418
    case EXCP_TLBS:
419
        cause = 3;
420
        if (env->error_code == 1 && !(env->hflags & MIPS_HFLAG_EXL))
421
            offset = 0x000;
422
        goto set_EPC;
423
    set_EPC:
424
        if (env->CP0_Status & (1 << CP0St_BEV)) {
425
            pc = 0xBFC00200;
426
        } else {
427
            pc = 0x80000000;
428
        }
429
        env->hflags |= MIPS_HFLAG_EXL;
430
        pc += offset;
431
        env->CP0_Cause = (env->CP0_Cause & ~0x7C) | (cause << 2);
432
        if (env->hflags & MIPS_HFLAG_DS) {
433
            /* If the exception was raised from a delay slot,
434
             * come back to the jump
435
             */
436
            env->CP0_EPC = env->PC - 4;
437
            env->CP0_Cause |= 0x80000000;
438
        } else {
439
            env->CP0_EPC = env->PC;
440
            env->CP0_Cause &= ~0x80000000;
441
        }
442
        break;
443
    default:
444
        if (logfile) {
445
            fprintf(logfile, "Invalid MIPS exception %d. Exiting\n",
446
                    env->exception_index);
447
        }
448
        printf("Invalid MIPS exception %d. Exiting\n", env->exception_index);
449
        exit(1);
450
    }
451
    env->PC = pc;
452
    if (logfile && env->exception_index != EXCP_EXT_INTERRUPT) {
453
        fprintf(logfile, "%s: PC %08x EPC %08x cause %d excp %d\n"
454
                "    S %08x C %08x A %08x D %08x\n",
455
                __func__, env->PC, env->CP0_EPC, cause, env->exception_index,
456
                env->CP0_Status, env->CP0_Cause, env->CP0_BadVAddr,
457
                env->CP0_DEPC);
458
    }
459
    env->exception_index = EXCP_NONE;
460
}