[qemu.git] / target-microblaze / mmu.c

/*
 *  Microblaze MMU emulation for qemu.
 *
 *  Copyright (c) 2009 Edgar E. Iglesias
 *  Copyright (c) 2009-2012 PetaLogix Qld Pty Ltd.
 *
 * 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, see <http://www.gnu.org/licenses/>.
 */

#include "cpu.h"

#define D(x)

static unsigned int tlb_decode_size(unsigned int f)
{
    static const unsigned int sizes[] = {
        1 * 1024, 4 * 1024, 16 * 1024, 64 * 1024, 256 * 1024,
        1 * 1024 * 1024, 4 * 1024 * 1024, 16 * 1024 * 1024
    };
    assert(f < ARRAY_SIZE(sizes));
    return sizes[f];
}

static void mmu_flush_idx(CPUMBState *env, unsigned int idx)
{
    struct microblaze_mmu *mmu = &env->mmu;
    unsigned int tlb_size;
    uint32_t tlb_tag, end, t;

    t = mmu->rams[RAM_TAG][idx];
    if (!(t & TLB_VALID))
        return;

    tlb_tag = t & TLB_EPN_MASK;
    tlb_size = tlb_decode_size((t & TLB_PAGESZ_MASK) >> 7);
    end = tlb_tag + tlb_size;

    while (tlb_tag < end) {
        tlb_flush_page(env, tlb_tag);
        tlb_tag += TARGET_PAGE_SIZE;
    }
}

static void mmu_change_pid(CPUMBState *env, unsigned int newpid) 
{
    struct microblaze_mmu *mmu = &env->mmu;
    unsigned int i;
    uint32_t t;

    if (newpid & ~0xff)
        qemu_log("Illegal rpid=%x\n", newpid);

    for (i = 0; i < ARRAY_SIZE(mmu->rams[RAM_TAG]); i++) {
        /* Lookup and decode.  */
        t = mmu->rams[RAM_TAG][i];
        if (t & TLB_VALID) {
            if (mmu->tids[i] && ((mmu->regs[MMU_R_PID] & 0xff) == mmu->tids[i]))
                mmu_flush_idx(env, i);
        }
    }
}

/* rw - 0 = read, 1 = write, 2 = fetch.  */
unsigned int mmu_translate(struct microblaze_mmu *mmu,
                           struct microblaze_mmu_lookup *lu,
                           target_ulong vaddr, int rw, int mmu_idx)
{
    unsigned int i, hit = 0;
    unsigned int tlb_ex = 0, tlb_wr = 0, tlb_zsel;
    unsigned int tlb_size;
    uint32_t tlb_tag, tlb_rpn, mask, t0;

    lu->err = ERR_MISS;
    for (i = 0; i < ARRAY_SIZE(mmu->rams[RAM_TAG]); i++) {
        uint32_t t, d;

        /* Lookup and decode.  */
        t = mmu->rams[RAM_TAG][i];
        D(qemu_log("TLB %d valid=%d\n", i, t & TLB_VALID));
        if (t & TLB_VALID) {
            tlb_size = tlb_decode_size((t & TLB_PAGESZ_MASK) >> 7);
            if (tlb_size < TARGET_PAGE_SIZE) {
                qemu_log("%d pages not supported\n", tlb_size);
                abort();
            }

            mask = ~(tlb_size - 1);
            tlb_tag = t & TLB_EPN_MASK;
            if ((vaddr & mask) != (tlb_tag & mask)) {
                D(qemu_log("TLB %d vaddr=%x != tag=%x\n",
                           i, vaddr & mask, tlb_tag & mask));
                continue;
            }
            if (mmu->tids[i]
                && ((mmu->regs[MMU_R_PID] & 0xff) != mmu->tids[i])) {
                D(qemu_log("TLB %d pid=%x != tid=%x\n",
                           i, mmu->regs[MMU_R_PID], mmu->tids[i]));
                continue;
            }

            /* Bring in the data part.  */
            d = mmu->rams[RAM_DATA][i];
            tlb_ex = d & TLB_EX;
            tlb_wr = d & TLB_WR;

            /* Now let's see if there is a zone that overrides the protbits.  */
            tlb_zsel = (d >> 4) & 0xf;
            t0 = mmu->regs[MMU_R_ZPR] >> (30 - (tlb_zsel * 2));
            t0 &= 0x3;

            if (tlb_zsel > mmu->c_mmu_zones) {
                qemu_log("tlb zone select out of range! %d\n", tlb_zsel);
                t0 = 1; /* Ignore.  */
            }

            if (mmu->c_mmu == 1) {
                t0 = 1; /* Zones are disabled.  */
            }

            switch (t0) {
                case 0:
                    if (mmu_idx == MMU_USER_IDX)
                        continue;
                    break;
                case 2:
                    if (mmu_idx != MMU_USER_IDX) {
                        tlb_ex = 1;
                        tlb_wr = 1;
                    }
                    break;
                case 3:
                    tlb_ex = 1;
                    tlb_wr = 1;
                    break;
                default: break;
            }

            lu->err = ERR_PROT;
            lu->prot = PAGE_READ;
            if (tlb_wr)
                lu->prot |= PAGE_WRITE;
            else if (rw == 1)
                goto done;
            if (tlb_ex)
                lu->prot |=PAGE_EXEC;
            else if (rw == 2) {
                goto done;
            }

            tlb_rpn = d & TLB_RPN_MASK;

            lu->vaddr = tlb_tag;
            lu->paddr = tlb_rpn;
            lu->size = tlb_size;
            lu->err = ERR_HIT;
            lu->idx = i;
            hit = 1;
            goto done;
        }
    }
done:
    D(qemu_log("MMU vaddr=%x rw=%d tlb_wr=%d tlb_ex=%d hit=%d\n",
              vaddr, rw, tlb_wr, tlb_ex, hit));
    return hit;
}

/* Writes/reads to the MMU's special regs end up here.  */
uint32_t mmu_read(CPUMBState *env, uint32_t rn)
{
    unsigned int i;
    uint32_t r;

    if (env->mmu.c_mmu < 2 || !env->mmu.c_mmu_tlb_access) {
        qemu_log("MMU access on MMU-less system\n");
        return 0;
    }

    switch (rn) {
        /* Reads to HI/LO trig reads from the mmu rams.  */
        case MMU_R_TLBLO:
        case MMU_R_TLBHI:
            if (!(env->mmu.c_mmu_tlb_access & 1)) {
                qemu_log("Invalid access to MMU reg %d\n", rn);
                return 0;
            }

            i = env->mmu.regs[MMU_R_TLBX] & 0xff;
            r = env->mmu.rams[rn & 1][i];
            if (rn == MMU_R_TLBHI)
                env->mmu.regs[MMU_R_PID] = env->mmu.tids[i];
            break;
        case MMU_R_PID:
        case MMU_R_ZPR:
            if (!(env->mmu.c_mmu_tlb_access & 1)) {
                qemu_log("Invalid access to MMU reg %d\n", rn);
                return 0;
            }
            r = env->mmu.regs[rn];
            break;
        default:
            r = env->mmu.regs[rn];
            break;
    }
    D(qemu_log("%s rn=%d=%x\n", __func__, rn, r));
    return r;
}

void mmu_write(CPUMBState *env, uint32_t rn, uint32_t v)
{
    unsigned int i;
    D(qemu_log("%s rn=%d=%x old=%x\n", __func__, rn, v, env->mmu.regs[rn]));

    if (env->mmu.c_mmu < 2 || !env->mmu.c_mmu_tlb_access) {
        qemu_log("MMU access on MMU-less system\n");
        return;
    }

    switch (rn) {
        /* Writes to HI/LO trig writes to the mmu rams.  */
        case MMU_R_TLBLO:
        case MMU_R_TLBHI:
            i = env->mmu.regs[MMU_R_TLBX] & 0xff;
            if (rn == MMU_R_TLBHI) {
                if (i < 3 && !(v & TLB_VALID) && qemu_loglevel_mask(~0))
                    qemu_log("invalidating index %x at pc=%x\n",
                             i, env->sregs[SR_PC]);
                env->mmu.tids[i] = env->mmu.regs[MMU_R_PID] & 0xff;
                mmu_flush_idx(env, i);
            }
            env->mmu.rams[rn & 1][i] = v;

            D(qemu_log("%s ram[%d][%d]=%x\n", __func__, rn & 1, i, v));
            break;
        case MMU_R_ZPR:
            if (env->mmu.c_mmu_tlb_access <= 1) {
                qemu_log("Invalid access to MMU reg %d\n", rn);
                return;
            }

            /* Changes to the zone protection reg flush the QEMU TLB.
               Fortunately, these are very uncommon.  */
            if (v != env->mmu.regs[rn]) {
                tlb_flush(env, 1);
            }
            env->mmu.regs[rn] = v;
            break;
        case MMU_R_PID:
            if (env->mmu.c_mmu_tlb_access <= 1) {
                qemu_log("Invalid access to MMU reg %d\n", rn);
                return;
            }

            if (v != env->mmu.regs[rn]) {
                mmu_change_pid(env, v);
                env->mmu.regs[rn] = v;
            }
            break;
        case MMU_R_TLBSX:
        {
            struct microblaze_mmu_lookup lu;
            int hit;

            if (env->mmu.c_mmu_tlb_access <= 1) {
                qemu_log("Invalid access to MMU reg %d\n", rn);
                return;
            }

            hit = mmu_translate(&env->mmu, &lu,
                                v & TLB_EPN_MASK, 0, cpu_mmu_index(env));
            if (hit) {
                env->mmu.regs[MMU_R_TLBX] = lu.idx;
            } else
                env->mmu.regs[MMU_R_TLBX] |= 0x80000000;
            break;
        }
        default:
            env->mmu.regs[rn] = v;
            break;
   }
}

void mmu_init(struct microblaze_mmu *mmu)
{
    int i;
    for (i = 0; i < ARRAY_SIZE(mmu->regs); i++) {
        mmu->regs[i] = 0;
    }
}
Commit	Line	Data
afeeceb0 EI	1	/*
	2	* Microblaze MMU emulation for qemu.
	3	*
	4	* Copyright (c) 2009 Edgar E. Iglesias
dadc1064	5	* Copyright (c) 2009-2012 PetaLogix Qld Pty Ltd.
afeeceb0 EI	6	*
	7	* This library is free software; you can redistribute it and/or
	8	* modify it under the terms of the GNU Lesser General Public
	9	* License as published by the Free Software Foundation; either
	10	* version 2 of the License, or (at your option) any later version.
	11	*
	12	* This library is distributed in the hope that it will be useful,
	13	* but WITHOUT ANY WARRANTY; without even the implied warranty of
	14	* MERCHANTABILITY or FITNESS FOR A PARTICULAR PURPOSE. See the GNU
	15	* Lesser General Public License for more details.
	16	*
	17	* You should have received a copy of the GNU Lesser General Public
8167ee88	18	* License along with this library; if not, see <http://www.gnu.org/licenses/>.
afeeceb0	19	*/
afeeceb0	20
afeeceb0	21	#include "cpu.h"
afeeceb0 EI	22
	23	#define D(x)
	24
	25	static unsigned int tlb_decode_size(unsigned int f)
	26	{
	27	static const unsigned int sizes[] = {
	28	1 * 1024, 4 * 1024, 16 * 1024, 64 * 1024, 256 * 1024,
	29	1 * 1024 * 1024, 4 * 1024 * 1024, 16 * 1024 * 1024
	30	};
	31	assert(f < ARRAY_SIZE(sizes));
	32	return sizes[f];
	33	}
	34
68cee38a	35	static void mmu_flush_idx(CPUMBState *env, unsigned int idx)
afeeceb0 EI	36	{
	37	struct microblaze_mmu *mmu = &env->mmu;
	38	unsigned int tlb_size;
	39	uint32_t tlb_tag, end, t;
	40
	41	t = mmu->rams[RAM_TAG][idx];
	42	if (!(t & TLB_VALID))
	43	return;
	44
	45	tlb_tag = t & TLB_EPN_MASK;
	46	tlb_size = tlb_decode_size((t & TLB_PAGESZ_MASK) >> 7);
	47	end = tlb_tag + tlb_size;
	48
	49	while (tlb_tag < end) {
	50	tlb_flush_page(env, tlb_tag);
	51	tlb_tag += TARGET_PAGE_SIZE;
	52	}
	53	}
	54
68cee38a	55	static void mmu_change_pid(CPUMBState *env, unsigned int newpid)
afeeceb0 EI	56	{
	57	struct microblaze_mmu *mmu = &env->mmu;
	58	unsigned int i;
183aa454	59	uint32_t t;
afeeceb0 EI	60
	61	if (newpid & ~0xff)
	62	qemu_log("Illegal rpid=%x\n", newpid);
	63
	64	for (i = 0; i < ARRAY_SIZE(mmu->rams[RAM_TAG]); i++) {
	65	/* Lookup and decode. */
	66	t = mmu->rams[RAM_TAG][i];
	67	if (t & TLB_VALID) {
afeeceb0 EI	68	if (mmu->tids[i] && ((mmu->regs[MMU_R_PID] & 0xff) == mmu->tids[i]))
	69	mmu_flush_idx(env, i);
	70	}
	71	}
	72	}
	73
	74	/* rw - 0 = read, 1 = write, 2 = fetch. */
	75	unsigned int mmu_translate(struct microblaze_mmu *mmu,
	76	struct microblaze_mmu_lookup *lu,
	77	target_ulong vaddr, int rw, int mmu_idx)
	78	{
	79	unsigned int i, hit = 0;
	80	unsigned int tlb_ex = 0, tlb_wr = 0, tlb_zsel;
	81	unsigned int tlb_size;
	82	uint32_t tlb_tag, tlb_rpn, mask, t0;
	83
	84	lu->err = ERR_MISS;
	85	for (i = 0; i < ARRAY_SIZE(mmu->rams[RAM_TAG]); i++) {
	86	uint32_t t, d;
	87
	88	/* Lookup and decode. */
	89	t = mmu->rams[RAM_TAG][i];
	90	D(qemu_log("TLB %d valid=%d\n", i, t & TLB_VALID));
	91	if (t & TLB_VALID) {
	92	tlb_size = tlb_decode_size((t & TLB_PAGESZ_MASK) >> 7);
	93	if (tlb_size < TARGET_PAGE_SIZE) {
	94	qemu_log("%d pages not supported\n", tlb_size);
	95	abort();
	96	}
	97
	98	mask = ~(tlb_size - 1);
	99	tlb_tag = t & TLB_EPN_MASK;
	100	if ((vaddr & mask) != (tlb_tag & mask)) {
	101	D(qemu_log("TLB %d vaddr=%x != tag=%x\n",
	102	i, vaddr & mask, tlb_tag & mask));
	103	continue;
	104	}
	105	if (mmu->tids[i]
	106	&& ((mmu->regs[MMU_R_PID] & 0xff) != mmu->tids[i])) {
	107	D(qemu_log("TLB %d pid=%x != tid=%x\n",
	108	i, mmu->regs[MMU_R_PID], mmu->tids[i]));
	109	continue;
	110	}
	111
	112	/* Bring in the data part. */
	113	d = mmu->rams[RAM_DATA][i];
	114	tlb_ex = d & TLB_EX;
	115	tlb_wr = d & TLB_WR;
	116
e03ba136	117	/* Now let's see if there is a zone that overrides the protbits. */
afeeceb0 EI	118	tlb_zsel = (d >> 4) & 0xf;
	119	t0 = mmu->regs[MMU_R_ZPR] >> (30 - (tlb_zsel * 2));
	120	t0 &= 0x3;
3c50a71f EI	121
	122	if (tlb_zsel > mmu->c_mmu_zones) {
	123	qemu_log("tlb zone select out of range! %d\n", tlb_zsel);
	124	t0 = 1; /* Ignore. */
	125	}
	126
	127	if (mmu->c_mmu == 1) {
	128	t0 = 1; /* Zones are disabled. */
	129	}
	130
afeeceb0 EI	131	switch (t0) {
	132	case 0:
	133	if (mmu_idx == MMU_USER_IDX)
	134	continue;
	135	break;
	136	case 2:
	137	if (mmu_idx != MMU_USER_IDX) {
	138	tlb_ex = 1;
	139	tlb_wr = 1;
	140	}
	141	break;
	142	case 3:
	143	tlb_ex = 1;
	144	tlb_wr = 1;
	145	break;
3c50a71f	146	default: break;
afeeceb0 EI	147	}
afeeceb0 EI	148
afeeceb0 EI	149	lu->err = ERR_PROT;
	150	lu->prot = PAGE_READ;
	151	if (tlb_wr)
	152	lu->prot \|= PAGE_WRITE;
	153	else if (rw == 1)
	154	goto done;
	155	if (tlb_ex)
	156	lu->prot \|=PAGE_EXEC;
	157	else if (rw == 2) {
	158	goto done;
	159	}
	160
	161	tlb_rpn = d & TLB_RPN_MASK;
	162
	163	lu->vaddr = tlb_tag;
	164	lu->paddr = tlb_rpn;
	165	lu->size = tlb_size;
	166	lu->err = ERR_HIT;
	167	lu->idx = i;
	168	hit = 1;
	169	goto done;
	170	}
	171	}
	172	done:
	173	D(qemu_log("MMU vaddr=%x rw=%d tlb_wr=%d tlb_ex=%d hit=%d\n",
	174	vaddr, rw, tlb_wr, tlb_ex, hit));
	175	return hit;
	176	}
	177
	178	/* Writes/reads to the MMU's special regs end up here. */
68cee38a	179	uint32_t mmu_read(CPUMBState *env, uint32_t rn)
afeeceb0 EI	180	{
	181	unsigned int i;
	182	uint32_t r;
	183
3c50a71f EI	184	if (env->mmu.c_mmu < 2 \|\| !env->mmu.c_mmu_tlb_access) {
	185	qemu_log("MMU access on MMU-less system\n");
	186	return 0;
	187	}
	188
afeeceb0 EI	189	switch (rn) {
	190	/* Reads to HI/LO trig reads from the mmu rams. */
	191	case MMU_R_TLBLO:
	192	case MMU_R_TLBHI:
3c50a71f EI	193	if (!(env->mmu.c_mmu_tlb_access & 1)) {
	194	qemu_log("Invalid access to MMU reg %d\n", rn);
	195	return 0;
	196	}
	197
afeeceb0 EI	198	i = env->mmu.regs[MMU_R_TLBX] & 0xff;
	199	r = env->mmu.rams[rn & 1][i];
	200	if (rn == MMU_R_TLBHI)
	201	env->mmu.regs[MMU_R_PID] = env->mmu.tids[i];
	202	break;
3c50a71f EI	203	case MMU_R_PID:
	204	case MMU_R_ZPR:
	205	if (!(env->mmu.c_mmu_tlb_access & 1)) {
	206	qemu_log("Invalid access to MMU reg %d\n", rn);
	207	return 0;
	208	}
	209	r = env->mmu.regs[rn];
	210	break;
afeeceb0 EI	211	default:
	212	r = env->mmu.regs[rn];
	213	break;
	214	}
	215	D(qemu_log("%s rn=%d=%x\n", __func__, rn, r));
	216	return r;
	217	}
	218
68cee38a	219	void mmu_write(CPUMBState *env, uint32_t rn, uint32_t v)
afeeceb0 EI	220	{
	221	unsigned int i;
	222	D(qemu_log("%s rn=%d=%x old=%x\n", __func__, rn, v, env->mmu.regs[rn]));
	223
3c50a71f EI	224	if (env->mmu.c_mmu < 2 \|\| !env->mmu.c_mmu_tlb_access) {
	225	qemu_log("MMU access on MMU-less system\n");
	226	return;
	227	}
	228
afeeceb0 EI	229	switch (rn) {
	230	/* Writes to HI/LO trig writes to the mmu rams. */
	231	case MMU_R_TLBLO:
	232	case MMU_R_TLBHI:
	233	i = env->mmu.regs[MMU_R_TLBX] & 0xff;
	234	if (rn == MMU_R_TLBHI) {
	235	if (i < 3 && !(v & TLB_VALID) && qemu_loglevel_mask(~0))
	236	qemu_log("invalidating index %x at pc=%x\n",
	237	i, env->sregs[SR_PC]);
	238	env->mmu.tids[i] = env->mmu.regs[MMU_R_PID] & 0xff;
	239	mmu_flush_idx(env, i);
	240	}
	241	env->mmu.rams[rn & 1][i] = v;
	242
	243	D(qemu_log("%s ram[%d][%d]=%x\n", __func__, rn & 1, i, v));
	244	break;
	245	case MMU_R_ZPR:
3c50a71f EI	246	if (env->mmu.c_mmu_tlb_access <= 1) {
	247	qemu_log("Invalid access to MMU reg %d\n", rn);
	248	return;
	249	}
	250
d0f3654f EI	251	/* Changes to the zone protection reg flush the QEMU TLB.
	252	Fortunately, these are very uncommon. */
	253	if (v != env->mmu.regs[rn]) {
	254	tlb_flush(env, 1);
	255	}
	256	env->mmu.regs[rn] = v;
	257	break;
afeeceb0	258	case MMU_R_PID:
3c50a71f EI	259	if (env->mmu.c_mmu_tlb_access <= 1) {
	260	qemu_log("Invalid access to MMU reg %d\n", rn);
	261	return;
	262	}
	263
afeeceb0 EI	264	if (v != env->mmu.regs[rn]) {
	265	mmu_change_pid(env, v);
	266	env->mmu.regs[rn] = v;
	267	}
	268	break;
	269	case MMU_R_TLBSX:
	270	{
	271	struct microblaze_mmu_lookup lu;
	272	int hit;
3c50a71f EI	273
	274	if (env->mmu.c_mmu_tlb_access <= 1) {
	275	qemu_log("Invalid access to MMU reg %d\n", rn);
	276	return;
	277	}
	278
afeeceb0 EI	279	hit = mmu_translate(&env->mmu, &lu,
	280	v & TLB_EPN_MASK, 0, cpu_mmu_index(env));
	281	if (hit) {
	282	env->mmu.regs[MMU_R_TLBX] = lu.idx;
	283	} else
	284	env->mmu.regs[MMU_R_TLBX] \|= 0x80000000;
	285	break;
	286	}
	287	default:
	288	env->mmu.regs[rn] = v;
	289	break;
	290	}
	291	}
	292
	293	void mmu_init(struct microblaze_mmu *mmu)
	294	{
3c50a71f EI	295	int i;
	296	for (i = 0; i < ARRAY_SIZE(mmu->regs); i++) {
	297	mmu->regs[i] = 0;
	298	}
afeeceb0	299	}