helper.c

qemu虚拟机代码

/*
 *  PowerPC emulation helpers for qemu.
 * 
 *  Copyright (c) 2003-2005 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"

//#define DEBUG_MMU
//#define DEBUG_BATS
//#define DEBUG_EXCEPTIONS
//#define FLUSH_ALL_TLBS

/*****************************************************************************/
/* PowerPC MMU emulation */

#if defined(CONFIG_USER_ONLY) 
int cpu_ppc_handle_mmu_fault (CPUState *env, uint32_t address, int rw,
                              int is_user, int is_softmmu)
{
    int exception, error_code;
    
    if (rw == 2) {
        exception = EXCP_ISI;
        error_code = 0;
    } else {
        exception = EXCP_DSI;
        error_code = 0;
        if (rw)
            error_code |= 0x02000000;
        env->spr[SPR_DAR] = address;
        env->spr[SPR_DSISR] = error_code;
    }
    env->exception_index = exception;
    env->error_code = error_code;
    return 1;
}
target_ulong cpu_get_phys_page_debug(CPUState *env, target_ulong addr)
{
    return addr;
}
#else
/* Perform BAT hit & translation */
static int get_bat (CPUState *env, uint32_t *real, int *prot,
                    uint32_t virtual, int rw, int type)
{
    uint32_t *BATlt, *BATut, *BATu, *BATl;
    uint32_t base, BEPIl, BEPIu, bl;
    int i;
    int ret = -1;

#if defined (DEBUG_BATS)
    if (loglevel > 0) {
        fprintf(logfile, "%s: %cBAT v 0x%08x\n", __func__,
               type == ACCESS_CODE ? 'I' : 'D', virtual);
    }
#endif
    switch (type) {
    case ACCESS_CODE:
        BATlt = env->IBAT[1];
        BATut = env->IBAT[0];
        break;
    default:
        BATlt = env->DBAT[1];
        BATut = env->DBAT[0];
        break;
    }
#if defined (DEBUG_BATS)
    if (loglevel > 0) {
        fprintf(logfile, "%s...: %cBAT v 0x%08x\n", __func__,
               type == ACCESS_CODE ? 'I' : 'D', virtual);
    }
#endif
    base = virtual & 0xFFFC0000;
    for (i = 0; i < 4; i++) {
        BATu = &BATut[i];
        BATl = &BATlt[i];
        BEPIu = *BATu & 0xF0000000;
        BEPIl = *BATu & 0x0FFE0000;
        bl = (*BATu & 0x00001FFC) << 15;
#if defined (DEBUG_BATS)
        if (loglevel > 0) {
            fprintf(logfile, "%s: %cBAT%d v 0x%08x BATu 0x%08x BATl 0x%08x\n",
                    __func__, type == ACCESS_CODE ? 'I' : 'D', i, virtual,
                    *BATu, *BATl);
        }
#endif
        if ((virtual & 0xF0000000) == BEPIu &&
            ((virtual & 0x0FFE0000) & ~bl) == BEPIl) {
            /* BAT matches */
            if ((msr_pr == 0 && (*BATu & 0x00000002)) ||
                (msr_pr == 1 && (*BATu & 0x00000001))) {
                /* Get physical address */
                *real = (*BATl & 0xF0000000) |
                    ((virtual & 0x0FFE0000 & bl) | (*BATl & 0x0FFE0000)) |
                    (virtual & 0x0001F000);
                if (*BATl & 0x00000001)
                    *prot = PAGE_READ;
                if (*BATl & 0x00000002)
                    *prot = PAGE_WRITE | PAGE_READ;
#if defined (DEBUG_BATS)
                if (loglevel > 0) {
                    fprintf(logfile, "BAT %d match: r 0x%08x prot=%c%c\n",
                            i, *real, *prot & PAGE_READ ? 'R' : '-',
                            *prot & PAGE_WRITE ? 'W' : '-');
                }
#endif
                ret = 0;
                break;
            }
        }
    }
    if (ret < 0) {
#if defined (DEBUG_BATS)
        printf("no BAT match for 0x%08x:\n", virtual);
        for (i = 0; i < 4; i++) {
            BATu = &BATut[i];
            BATl = &BATlt[i];
            BEPIu = *BATu & 0xF0000000;
            BEPIl = *BATu & 0x0FFE0000;
            bl = (*BATu & 0x00001FFC) << 15;
            printf("%s: %cBAT%d v 0x%08x BATu 0x%08x BATl 0x%08x \n\t"
                   "0x%08x 0x%08x 0x%08x\n",
                   __func__, type == ACCESS_CODE ? 'I' : 'D', i, virtual,
                   *BATu, *BATl, BEPIu, BEPIl, bl);
        }
#endif
    }
    /* No hit */
    return ret;
}

/* PTE table lookup */
static int find_pte (uint32_t *RPN, int *prot, uint32_t base, uint32_t va,
                     int h, int key, int rw)
{
    uint32_t pte0, pte1, keep = 0, access = 0;
    int i, good = -1, store = 0;
    int ret = -1; /* No entry found */

    for (i = 0; i < 8; i++) {
        pte0 = ldl_phys(base + (i * 8));
        pte1 =  ldl_phys(base + (i * 8) + 4);
#if defined (DEBUG_MMU)
        if (loglevel > 0) {
	    fprintf(logfile, "Load pte from 0x%08x => 0x%08x 0x%08x "
		    "%d %d %d 0x%08x\n", base + (i * 8), pte0, pte1,
		    pte0 >> 31, h, (pte0 >> 6) & 1, va);
	}
#endif
        /* Check validity and table match */
        if (pte0 & 0x80000000 && (h == ((pte0 >> 6) & 1))) {
            /* Check vsid & api */
            if ((pte0 & 0x7FFFFFBF) == va) {
                if (good == -1) {
                    good = i;
                    keep = pte1;
                } else {
                    /* All matches should have equal RPN, WIMG & PP */
                    if ((keep & 0xFFFFF07B) != (pte1 & 0xFFFFF07B)) {
			if (loglevel > 0)
			    fprintf(logfile, "Bad RPN/WIMG/PP\n");
                        return -1;
                    }
                }
                /* Check access rights */
                if (key == 0) {
                    access = PAGE_READ;
                    if ((pte1 & 0x00000003) != 0x3)
                        access |= PAGE_WRITE;
                } else {
                    switch (pte1 & 0x00000003) {
                    case 0x0:
                        access = 0;
                        break;
                    case 0x1:
                    case 0x3:
                        access = PAGE_READ;
                        break;
                    case 0x2:
                        access = PAGE_READ | PAGE_WRITE;
                        break;
                    }
                }
                if (ret < 0) {
		    if ((rw == 0 && (access & PAGE_READ)) ||
			(rw == 1 && (access & PAGE_WRITE))) {
#if defined (DEBUG_MMU)
			if (loglevel > 0)
			    fprintf(logfile, "PTE access granted !\n");
#endif
                        good = i;
                        keep = pte1;
                        ret = 0;
		    } else {
			/* Access right violation */
                        ret = -2;
#if defined (DEBUG_MMU)
			if (loglevel > 0)
			    fprintf(logfile, "PTE access rejected\n");
#endif
                    }
		    *prot = access;
		}
            }
        }
    }
    if (good != -1) {
        *RPN = keep & 0xFFFFF000;
#if defined (DEBUG_MMU)
        if (loglevel > 0) {
	    fprintf(logfile, "found PTE at addr 0x%08x prot=0x%01x ret=%d\n",
               *RPN, *prot, ret);
	}
#endif
        /* Update page flags */
        if (!(keep & 0x00000100)) {
	    /* Access flag */
            keep |= 0x00000100;
            store = 1;
        }
        if (!(keep & 0x00000080)) {
	    if (rw && ret == 0) {
		/* Change flag */
                keep |= 0x00000080;
                store = 1;
	    } else {
		/* Force page fault for first write access */
		*prot &= ~PAGE_WRITE;
            }
        }
        if (store) {
	    stl_phys_notdirty(base + (good * 8) + 4, keep);
	}
    }

    return ret;
}

static inline uint32_t get_pgaddr (uint32_t sdr1, uint32_t hash, uint32_t mask)
{
    return (sdr1 & 0xFFFF0000) | (hash & mask);
}

/* Perform segment based translation */
static int get_segment (CPUState *env, uint32_t *real, int *prot,
                        uint32_t virtual, int rw, int type)
{
    uint32_t pg_addr, sdr, ptem, vsid, pgidx;
    uint32_t hash, mask;
    uint32_t sr;
    int key;
    int ret = -1, ret2;

    sr = env->sr[virtual >> 28];
#if defined (DEBUG_MMU)
    if (loglevel > 0) {
	fprintf(logfile, "Check segment v=0x%08x %d 0x%08x nip=0x%08x "
		"lr=0x%08x ir=%d dr=%d pr=%d %d t=%d\n",
		virtual, virtual >> 28, sr, env->nip,
		env->lr, msr_ir, msr_dr, msr_pr, rw, type);
    }
#endif
    key = (((sr & 0x20000000) && msr_pr == 1) ||
        ((sr & 0x40000000) && msr_pr == 0)) ? 1 : 0;
    if ((sr & 0x80000000) == 0) {
#if defined (DEBUG_MMU)
    if (loglevel > 0) 
	    fprintf(logfile, "pte segment: key=%d n=0x%08x\n",
		    key, sr & 0x10000000);
#endif
        /* Check if instruction fetch is allowed, if needed */
        if (type != ACCESS_CODE || (sr & 0x10000000) == 0) {
            /* Page address translation */
            vsid = sr & 0x00FFFFFF;
            pgidx = (virtual >> 12) & 0xFFFF;
            sdr = env->sdr1;
            hash = ((vsid ^ pgidx) & 0x0007FFFF) << 6;
            mask = ((sdr & 0x000001FF) << 16) | 0xFFC0;
            pg_addr = get_pgaddr(sdr, hash, mask);
            ptem = (vsid << 7) | (pgidx >> 10);
#if defined (DEBUG_MMU)
	    if (loglevel > 0) {
		fprintf(logfile, "0 sdr1=0x%08x vsid=0x%06x api=0x%04x "
			"hash=0x%07x pg_addr=0x%08x\n", sdr, vsid, pgidx, hash,
			pg_addr);
	    }
#endif
            /* Primary table lookup */
            ret = find_pte(real, prot, pg_addr, ptem, 0, key, rw);
            if (ret < 0) {
                /* Secondary table lookup */
                hash = (~hash) & 0x01FFFFC0;
                pg_addr = get_pgaddr(sdr, hash, mask);
#if defined (DEBUG_MMU)
		if (virtual != 0xEFFFFFFF && loglevel > 0) {
		    fprintf(logfile, "1 sdr1=0x%08x vsid=0x%06x api=0x%04x "
			    "hash=0x%05x pg_addr=0x%08x\n", sdr, vsid, pgidx,
			    hash, pg_addr);
		}
#endif
                ret2 = find_pte(real, prot, pg_addr, ptem, 1, key, rw);
                if (ret2 != -1)
                    ret = ret2;
            }
        } else {
#if defined (DEBUG_MMU)
	    if (loglevel > 0)
		fprintf(logfile, "No access allowed\n");
#endif
	    ret = -3;
        }
    } else {
#if defined (DEBUG_MMU)
        if (loglevel > 0)
	    fprintf(logfile, "direct store...\n");
#endif
        /* Direct-store segment : absolutely *BUGGY* for now */
        switch (type) {
        case ACCESS_INT:
            /* Integer load/store : only access allowed */
            break;
        case ACCESS_CODE:
            /* No code fetch is allowed in direct-store areas */
            return -4;
        case ACCESS_FLOAT:
            /* Floating point load/store */
            return -4;
        case ACCESS_RES:
            /* lwarx, ldarx or srwcx. */
            return -4;
        case ACCESS_CACHE:
            /* dcba, dcbt, dcbtst, dcbf, dcbi, dcbst, dcbz, or icbi */
            /* Should make the instruction do no-op.
             * As it already do no-op, it's quite easy :-)
             */
            *real = virtual;
            return 0;
        case ACCESS_EXT:
            /* eciwx or ecowx */
            return -4;
        default:
            if (logfile) {
                fprintf(logfile, "ERROR: instruction should not need "
                        "address translation\n");
            }
            printf("ERROR: instruction should not need "
                   "address translation\n");
            return -4;
        }
        if ((rw == 1 || key != 1) && (rw == 0 || key != 0)) {
            *real = virtual;
            ret = 2;
        } else {
            ret = -2;
        }
    }

    return ret;
}

static int get_physical_address (CPUState *env, uint32_t *physical, int *prot,
                                 uint32_t address, int rw, int access_type)
{
    int ret;
#if 0
    if (loglevel > 0) {
        fprintf(logfile, "%s\n", __func__);
    }
#endif    
    if ((access_type == ACCESS_CODE && msr_ir == 0) ||
        (access_type != ACCESS_CODE && msr_dr == 0)) {
        /* No address translation */
        *physical = address & ~0xFFF;
        *prot = PAGE_READ | PAGE_WRITE;
        ret = 0;
    } else {
        /* Try to find a BAT */
        ret = get_bat(env, physical, prot, address, rw, access_type);
        if (ret < 0) {
            /* We didn't match any BAT entry */
            ret = get_segment(env, physical, prot, address, rw, access_type);
        }
    }
#if 0
    if (loglevel > 0) {
        fprintf(logfile, "%s address %08x => %08x\n",
		__func__, address, *physical);
    }
#endif    
    return ret;
}

target_ulong cpu_get_phys_page_debug(CPUState *env, target_ulong addr)
{
    uint32_t phys_addr;
    int prot;

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

/* Perform address translation */
int cpu_ppc_handle_mmu_fault (CPUState *env, uint32_t address, int rw,
                              int is_user, int is_softmmu)
{
    uint32_t physical;
    int prot;
    int exception = 0, error_code = 0;
    int access_type;
    int ret = 0;

    if (rw == 2) {
        /* code access */
        rw = 0;
        access_type = ACCESS_CODE;
    } else {
        /* data access */
        /* XXX: put correct access by using cpu_restore_state()
           correctly */
        access_type = ACCESS_INT;
        //        access_type = env->access_type;
    }
    if (env->user_mode_only) {
        /* user mode only emulation */
        ret = -2;
        goto do_fault;
    }
    ret = get_physical_address(env, &physical, &prot,
                               address, rw, access_type);
    if (ret == 0) {
	ret = tlb_set_page(env, address & ~0xFFF, physical, prot,
			   is_user, is_softmmu);
    } else if (ret < 0) {
    do_fault:
#if defined (DEBUG_MMU)
	if (loglevel > 0)
	    cpu_dump_state(env, logfile, fprintf, 0);
#endif
        if (access_type == ACCESS_CODE) {
            exception = EXCP_ISI;
            switch (ret) {
            case -1:
                /* No matches in page tables */
                error_code = 0x40000000;
                break;
            case -2:
                /* Access rights violation */
                error_code = 0x08000000;
                break;
            case -3:
		/* No execute protection violation */
                error_code = 0x10000000;
                break;
            case -4:
                /* Direct store exception */
                /* No code fetch is allowed in direct-store areas */
                error_code = 0x10000000;
                break;
            case -5:
                /* No match in segment table */
                exception = EXCP_ISEG;
                error_code = 0;
                break;