diff options
Diffstat (limited to 'target-microblaze')
| -rw-r--r-- | target-microblaze/mmu.c | 250 | ||||
| -rw-r--r-- | target-microblaze/mmu.h | 88 |
2 files changed, 338 insertions, 0 deletions
diff --git a/target-microblaze/mmu.c b/target-microblaze/mmu.c new file mode 100644 index 000000000..f3dfa89bc --- /dev/null +++ b/target-microblaze/mmu.c @@ -0,0 +1,250 @@ +/* + * 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, write to the Free Software + * Foundation, Inc., 51 Franklin Street, Fifth Floor, Boston MA 02110-1301 USA + */ +#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 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; + 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; + } + + + 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; + + switch (rn) { + /* Reads to HI/LO trig reads from the mmu rams. */ + case MMU_R_TLBLO: + case MMU_R_TLBHI: + 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; + 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])); + + 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: + case MMU_R_PID: + 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; + 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) +{ + memset(mmu, 0, sizeof *mmu); +} diff --git a/target-microblaze/mmu.h b/target-microblaze/mmu.h new file mode 100644 index 000000000..975933396 --- /dev/null +++ b/target-microblaze/mmu.h @@ -0,0 +1,88 @@ +/* + * 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, write to the Free Software + * Foundation, Inc., 51 Franklin Street, Fifth Floor, Boston MA 02110-1301 USA + */ + +#define MMU_R_PID 0 +#define MMU_R_ZPR 1 +#define MMU_R_TLBX 2 +#define MMU_R_TLBLO 3 +#define MMU_R_TLBHI 4 +#define MMU_R_TLBSX 5 + +#define RAM_DATA 1 +#define RAM_TAG 0 + +/* Tag portion */ +#define TLB_EPN_MASK 0xFFFFFC00 /* Effective Page Number */ +#define TLB_PAGESZ_MASK 0x00000380 +#define TLB_PAGESZ(x) (((x) & 0x7) << 7) +#define PAGESZ_1K 0 +#define PAGESZ_4K 1 +#define PAGESZ_16K 2 +#define PAGESZ_64K 3 +#define PAGESZ_256K 4 +#define PAGESZ_1M 5 +#define PAGESZ_4M 6 +#define PAGESZ_16M 7 +#define TLB_VALID 0x00000040 /* Entry is valid */ + +/* Data portion */ +#define TLB_RPN_MASK 0xFFFFFC00 /* Real Page Number */ +#define TLB_PERM_MASK 0x00000300 +#define TLB_EX 0x00000200 /* Instruction execution allowed */ +#define TLB_WR 0x00000100 /* Writes permitted */ +#define TLB_ZSEL_MASK 0x000000F0 +#define TLB_ZSEL(x) (((x) & 0xF) << 4) +#define TLB_ATTR_MASK 0x0000000F +#define TLB_W 0x00000008 /* Caching is write-through */ +#define TLB_I 0x00000004 /* Caching is inhibited */ +#define TLB_M 0x00000002 /* Memory is coherent */ +#define TLB_G 0x00000001 /* Memory is guarded from prefetch */ + +#define TLB_ENTRIES 64 + +struct microblaze_mmu +{ + /* Data and tag brams. */ + uint32_t rams[2][TLB_ENTRIES]; + /* We keep a separate ram for the tids to avoid the 48 bit tag width. */ + uint8_t tids[TLB_ENTRIES]; + /* Control flops. */ + uint32_t regs[8];; +}; + +struct microblaze_mmu_lookup +{ + uint32_t paddr; + uint32_t vaddr; + unsigned int size; + unsigned int idx; + int prot; + enum { + ERR_PROT, ERR_MISS, ERR_HIT + } err; +}; + +void mmu_flip_um(CPUState *env, unsigned int um); +unsigned int mmu_translate(struct microblaze_mmu *mmu, + struct microblaze_mmu_lookup *lu, + target_ulong vaddr, int rw, int mmu_idx); +uint32_t mmu_read(CPUState *env, uint32_t rn); +void mmu_write(CPUState *env, uint32_t rn, uint32_t v); +void mmu_init(struct microblaze_mmu *mmu); |