Archipelago » qemu

/*

 *  CRIS mmu emulation.

 *

 *  Copyright (c) 2007 AXIS Communications AB

 *  Written by Edgar E. Iglesias.

 *

 * 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

 */

#ifndef CONFIG_USER_ONLY

#include <stdio.h>

#include <string.h>

#include <stdlib.h>

#include "config.h"

#include "cpu.h"

#include "mmu.h"

#include "exec-all.h"

static int cris_mmu_enabled(uint32_t rw_gc_cfg)

{

        return (rw_gc_cfg & 12) != 0;

}

static int cris_mmu_segmented_addr(int seg, uint32_t rw_mm_cfg)

{

        return (1 << seg) & rw_mm_cfg;

}

static uint32_t cris_mmu_translate_seg(CPUState *env, int seg)

{

        uint32_t base;

        int i;

        if (seg < 8)

                base = env->sregs[SFR_RW_MM_KBASE_LO];

        else

                base = env->sregs[SFR_RW_MM_KBASE_HI];

        i = seg & 7;

        base >>= i * 4;

        base &= 15;

        base <<= 28;

        return base;

}

/* Used by the tlb decoder.  */

#define EXTRACT_FIELD(src, start, end) \

            (((src) >> start) & ((1 << (end - start + 1)) - 1))

static int cris_mmu_translate_page(struct cris_mmu_result_t *res,

                                   CPUState *env, uint32_t vaddr,

                                   int rw, int usermode)

{

        unsigned int vpage;

        unsigned int idx;

        uint32_t lo, hi;

        uint32_t vpn, pfn = 0, pid, fg, fv, fk, fw, fx;

        int i, match = 0;

        vpage = vaddr >> 13;

        idx = vpage & 31;

        vpage >>= 4;

        /* We know the index which to check on each set.

           Scan both I and D.  */

        for (i = 0; i < 4; i++)

        {

                lo = env->tlbsets[0][i][idx].lo;

                hi = env->tlbsets[0][i][idx].hi;

                vpn = EXTRACT_FIELD(hi, 13, 31);

                pid = EXTRACT_FIELD(hi, 0, 7);

                if (vpn == vpage

                    && pid == env->pregs[SR_PID]) {

                        match = 1;

                        break;

                }

        }

        if (match) {

                pfn = EXTRACT_FIELD(lo, 13, 31);

                fg = EXTRACT_FIELD(lo, 4, 4);

                fv = EXTRACT_FIELD(lo, 3, 3);

                fk = EXTRACT_FIELD(lo, 2, 2);

                fw = EXTRACT_FIELD(lo, 1, 1);

                fx = EXTRACT_FIELD(lo, 0, 0);

        }

        printf ("%s match=%d vaddr=%x vpage=%x vpn=%x pfn=%x pid=%x %x\n",

                __func__, match,

                vaddr, vpage,

                vpn, pfn, pid, env->pregs[SR_PID]);

        res->pfn = pfn;

        return !match;

}

int cris_mmu_translate(struct cris_mmu_result_t *res,

                       CPUState *env, uint32_t vaddr,

                       int rw, int is_user)

{

        uint32_t phy = vaddr;

        int seg;

        int miss = 0;

        if (!cris_mmu_enabled(env->sregs[SFR_RW_GC_CFG])) {

                res->phy = vaddr;

                return 0;

        }

        seg = vaddr >> 28;

        if (cris_mmu_segmented_addr(seg, env->sregs[SFR_RW_MM_CFG]))

        {

                uint32_t base;

                miss = 0;

                base = cris_mmu_translate_seg(env, seg);

                phy = base | (0x0fffffff & vaddr);

                res->phy = phy;

        }

        else

        {

                miss = cris_mmu_translate_page(res, env, vaddr, rw, is_user);

                if (!miss) {

                        phy &= 8191;

                        phy |= (res->pfn << 13);

                        res->phy = phy;

                }

        }

//        printf ("miss=%d v=%x -> p=%x\n", miss, vaddr, phy);

        return miss;

}

#endif