| /* |
| * Microblaze MMU emulation for qemu. |
| * |
| * Copyright (c) 2009 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, see <http://www.gnu.org/licenses/>. |
| */ |
| #include <stdio.h> |
| #include <stdlib.h> |
| #include <assert.h> |
| |
| #include "config.h" |
| #include "cpu.h" |
| #include "exec-all.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(CPUState *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(CPUState *env, unsigned int newpid) |
| { |
| struct microblaze_mmu *mmu = &env->mmu; |
| unsigned int i; |
| unsigned int tlb_size; |
| uint32_t tlb_tag, mask, 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) { |
| tlb_size = tlb_decode_size((t & TLB_PAGESZ_MASK) >> 7); |
| mask = ~(tlb_size - 1); |
| |
| tlb_tag = t & TLB_EPN_MASK; |
| 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 lets 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(CPUState *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(CPUState *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; |
| } |
| } |
