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qemu-patch-raspberry4/target-microblaze/mmu.c
Benjamin Herrenschmidt 97ed5ccdee tlb: Add "ifetch" argument to cpu_mmu_index() 
This is set to true when the index is for an instruction fetch
translation.

The core get_page_addr_code() sets it, as do the SOFTMMU_CODE_ACCESS
acessors.

All targets ignore it for now, and all other callers pass "false".

This will allow targets who wish to split the mmu index between
instruction and data accesses to do so. A subsequent patch will
do just that for PowerPC.

Signed-off-by: Benjamin Herrenschmidt <benh@kernel.crashing.org>
Message-Id: <1439796853-4410-2-git-send-email-benh@kernel.crashing.org>
Signed-off-by: Richard Henderson <rth@twiddle.net>
2015-09-11 08:15:28 -07:00

302 lines
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/*
* 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)
{
CPUState *cs = CPU(mb_env_get_cpu(env));
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(cs, 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)
{
MicroBlazeCPU *cpu = mb_env_get_cpu(env);
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(CPU(cpu), 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, false));
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;
}
}
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