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authorEdgar E. Iglesias <edgar.iglesias@gmail.com>2009-05-20 20:08:24 +0200
committerEdgar E. Iglesias <edgar.iglesias@gmail.com>2009-05-26 21:10:34 +0200
commitafeeceb0d79be886e83b56fb91cc6a2ca99888be (patch)
tree97a04630baccdadfb6a364b380d6092ae9698e27 /target-microblaze
parente90e390c2b8368d534cccfd2aaca1f6a0ae5d53d (diff)
microblaze: Add MMU emulation.
Signed-off-by: Edgar E. Iglesias <edgar.iglesias@gmail.com>
Diffstat (limited to 'target-microblaze')
-rw-r--r--target-microblaze/mmu.c250
-rw-r--r--target-microblaze/mmu.h88
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);