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-rw-r--r--src/target-cris/mmu.c363
1 files changed, 363 insertions, 0 deletions
diff --git a/src/target-cris/mmu.c b/src/target-cris/mmu.c
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--- /dev/null
+++ b/src/target-cris/mmu.c
@@ -0,0 +1,363 @@
+/*
+ * CRIS mmu emulation.
+ *
+ * Copyright (c) 2007 AXIS Communications AB
+ * Written by 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/>.
+ */
+
+#ifndef CONFIG_USER_ONLY
+
+#include "cpu.h"
+#include "mmu.h"
+
+#ifdef DEBUG
+#define D(x) x
+#define D_LOG(...) qemu_log(__VA_ARGS__)
+#else
+#define D(x) do { } while (0)
+#define D_LOG(...) do { } while (0)
+#endif
+
+void cris_mmu_init(CPUCRISState *env)
+{
+ env->mmu_rand_lfsr = 0xcccc;
+}
+
+#define SR_POLYNOM 0x8805
+static inline unsigned int compute_polynom(unsigned int sr)
+{
+ unsigned int i;
+ unsigned int f;
+
+ f = 0;
+ for (i = 0; i < 16; i++)
+ f += ((SR_POLYNOM >> i) & 1) & ((sr >> i) & 1);
+
+ return f;
+}
+
+static void cris_mmu_update_rand_lfsr(CPUCRISState *env)
+{
+ unsigned int f;
+
+ /* Update lfsr at every fault. */
+ f = compute_polynom(env->mmu_rand_lfsr);
+ env->mmu_rand_lfsr >>= 1;
+ env->mmu_rand_lfsr |= (f << 15);
+ env->mmu_rand_lfsr &= 0xffff;
+}
+
+static inline int cris_mmu_enabled(uint32_t rw_gc_cfg)
+{
+ return (rw_gc_cfg & 12) != 0;
+}
+
+static inline int cris_mmu_segmented_addr(int seg, uint32_t rw_mm_cfg)
+{
+ return (1 << seg) & rw_mm_cfg;
+}
+
+static uint32_t cris_mmu_translate_seg(CPUCRISState *env, int seg)
+{
+ uint32_t base;
+ int i;
+
+ if (seg < 8)
+ base = env->sregs[SFR_RW_MM_KBASE_LO];
+ else
+ base = env->sregs[SFR_RW_MM_KBASE_HI];
+
+ i = seg & 7;
+ base >>= i * 4;
+ base &= 15;
+
+ base <<= 28;
+ return base;
+}
+/* Used by the tlb decoder. */
+#define EXTRACT_FIELD(src, start, end) \
+ (((src) >> start) & ((1 << (end - start + 1)) - 1))
+
+static inline void set_field(uint32_t *dst, unsigned int val,
+ unsigned int offset, unsigned int width)
+{
+ uint32_t mask;
+
+ mask = (1 << width) - 1;
+ mask <<= offset;
+ val <<= offset;
+
+ val &= mask;
+ *dst &= ~(mask);
+ *dst |= val;
+}
+
+#ifdef DEBUG
+static void dump_tlb(CPUCRISState *env, int mmu)
+{
+ int set;
+ int idx;
+ uint32_t hi, lo, tlb_vpn, tlb_pfn;
+
+ for (set = 0; set < 4; set++) {
+ for (idx = 0; idx < 16; idx++) {
+ lo = env->tlbsets[mmu][set][idx].lo;
+ hi = env->tlbsets[mmu][set][idx].hi;
+ tlb_vpn = EXTRACT_FIELD(hi, 13, 31);
+ tlb_pfn = EXTRACT_FIELD(lo, 13, 31);
+
+ printf ("TLB: [%d][%d] hi=%x lo=%x v=%x p=%x\n",
+ set, idx, hi, lo, tlb_vpn, tlb_pfn);
+ }
+ }
+}
+#endif
+
+/* rw 0 = read, 1 = write, 2 = exec. */
+static int cris_mmu_translate_page(struct cris_mmu_result *res,
+ CPUCRISState *env, uint32_t vaddr,
+ int rw, int usermode, int debug)
+{
+ unsigned int vpage;
+ unsigned int idx;
+ uint32_t pid, lo, hi;
+ uint32_t tlb_vpn, tlb_pfn = 0;
+ int tlb_pid, tlb_g, tlb_v, tlb_k, tlb_w, tlb_x;
+ int cfg_v, cfg_k, cfg_w, cfg_x;
+ int set, match = 0;
+ uint32_t r_cause;
+ uint32_t r_cfg;
+ int rwcause;
+ int mmu = 1; /* Data mmu is default. */
+ int vect_base;
+
+ r_cause = env->sregs[SFR_R_MM_CAUSE];
+ r_cfg = env->sregs[SFR_RW_MM_CFG];
+ pid = env->pregs[PR_PID] & 0xff;
+
+ switch (rw) {
+ case 2: rwcause = CRIS_MMU_ERR_EXEC; mmu = 0; break;
+ case 1: rwcause = CRIS_MMU_ERR_WRITE; break;
+ default:
+ case 0: rwcause = CRIS_MMU_ERR_READ; break;
+ }
+
+ /* I exception vectors 4 - 7, D 8 - 11. */
+ vect_base = (mmu + 1) * 4;
+
+ vpage = vaddr >> 13;
+
+ /* We know the index which to check on each set.
+ Scan both I and D. */
+#if 0
+ for (set = 0; set < 4; set++) {
+ for (idx = 0; idx < 16; idx++) {
+ lo = env->tlbsets[mmu][set][idx].lo;
+ hi = env->tlbsets[mmu][set][idx].hi;
+ tlb_vpn = EXTRACT_FIELD(hi, 13, 31);
+ tlb_pfn = EXTRACT_FIELD(lo, 13, 31);
+
+ printf ("TLB: [%d][%d] hi=%x lo=%x v=%x p=%x\n",
+ set, idx, hi, lo, tlb_vpn, tlb_pfn);
+ }
+ }
+#endif
+
+ idx = vpage & 15;
+ for (set = 0; set < 4; set++)
+ {
+ lo = env->tlbsets[mmu][set][idx].lo;
+ hi = env->tlbsets[mmu][set][idx].hi;
+
+ tlb_vpn = hi >> 13;
+ tlb_pid = EXTRACT_FIELD(hi, 0, 7);
+ tlb_g = EXTRACT_FIELD(lo, 4, 4);
+
+ D_LOG("TLB[%d][%d][%d] v=%x vpage=%x lo=%x hi=%x\n",
+ mmu, set, idx, tlb_vpn, vpage, lo, hi);
+ if ((tlb_g || (tlb_pid == pid))
+ && tlb_vpn == vpage) {
+ match = 1;
+ break;
+ }
+ }
+
+ res->bf_vec = vect_base;
+ if (match) {
+ cfg_w = EXTRACT_FIELD(r_cfg, 19, 19);
+ cfg_k = EXTRACT_FIELD(r_cfg, 18, 18);
+ cfg_x = EXTRACT_FIELD(r_cfg, 17, 17);
+ cfg_v = EXTRACT_FIELD(r_cfg, 16, 16);
+
+ tlb_pfn = EXTRACT_FIELD(lo, 13, 31);
+ tlb_v = EXTRACT_FIELD(lo, 3, 3);
+ tlb_k = EXTRACT_FIELD(lo, 2, 2);
+ tlb_w = EXTRACT_FIELD(lo, 1, 1);
+ tlb_x = EXTRACT_FIELD(lo, 0, 0);
+
+ /*
+ set_exception_vector(0x04, i_mmu_refill);
+ set_exception_vector(0x05, i_mmu_invalid);
+ set_exception_vector(0x06, i_mmu_access);
+ set_exception_vector(0x07, i_mmu_execute);
+ set_exception_vector(0x08, d_mmu_refill);
+ set_exception_vector(0x09, d_mmu_invalid);
+ set_exception_vector(0x0a, d_mmu_access);
+ set_exception_vector(0x0b, d_mmu_write);
+ */
+ if (cfg_k && tlb_k && usermode) {
+ D(printf ("tlb: kernel protected %x lo=%x pc=%x\n",
+ vaddr, lo, env->pc));
+ match = 0;
+ res->bf_vec = vect_base + 2;
+ } else if (rw == 1 && cfg_w && !tlb_w) {
+ D(printf ("tlb: write protected %x lo=%x pc=%x\n",
+ vaddr, lo, env->pc));
+ match = 0;
+ /* write accesses never go through the I mmu. */
+ res->bf_vec = vect_base + 3;
+ } else if (rw == 2 && cfg_x && !tlb_x) {
+ D(printf ("tlb: exec protected %x lo=%x pc=%x\n",
+ vaddr, lo, env->pc));
+ match = 0;
+ res->bf_vec = vect_base + 3;
+ } else if (cfg_v && !tlb_v) {
+ D(printf ("tlb: invalid %x\n", vaddr));
+ match = 0;
+ res->bf_vec = vect_base + 1;
+ }
+
+ res->prot = 0;
+ if (match) {
+ res->prot |= PAGE_READ;
+ if (tlb_w)
+ res->prot |= PAGE_WRITE;
+ if (mmu == 0 && (cfg_x || tlb_x))
+ res->prot |= PAGE_EXEC;
+ }
+ else
+ D(dump_tlb(env, mmu));
+ } else {
+ /* If refill, provide a randomized set. */
+ set = env->mmu_rand_lfsr & 3;
+ }
+
+ if (!match && !debug) {
+ cris_mmu_update_rand_lfsr(env);
+
+ /* Compute index. */
+ idx = vpage & 15;
+
+ /* Update RW_MM_TLB_SEL. */
+ env->sregs[SFR_RW_MM_TLB_SEL] = 0;
+ set_field(&env->sregs[SFR_RW_MM_TLB_SEL], idx, 0, 4);
+ set_field(&env->sregs[SFR_RW_MM_TLB_SEL], set, 4, 2);
+
+ /* Update RW_MM_CAUSE. */
+ set_field(&r_cause, rwcause, 8, 2);
+ set_field(&r_cause, vpage, 13, 19);
+ set_field(&r_cause, pid, 0, 8);
+ env->sregs[SFR_R_MM_CAUSE] = r_cause;
+ D(printf("refill vaddr=%x pc=%x\n", vaddr, env->pc));
+ }
+
+ D(printf ("%s rw=%d mtch=%d pc=%x va=%x vpn=%x tlbvpn=%x pfn=%x pid=%x"
+ " %x cause=%x sel=%x sp=%x %x %x\n",
+ __func__, rw, match, env->pc,
+ vaddr, vpage,
+ tlb_vpn, tlb_pfn, tlb_pid,
+ pid,
+ r_cause,
+ env->sregs[SFR_RW_MM_TLB_SEL],
+ env->regs[R_SP], env->pregs[PR_USP], env->ksp));
+
+ res->phy = tlb_pfn << TARGET_PAGE_BITS;
+ return !match;
+}
+
+void cris_mmu_flush_pid(CPUCRISState *env, uint32_t pid)
+{
+ CRISCPU *cpu = cris_env_get_cpu(env);
+ target_ulong vaddr;
+ unsigned int idx;
+ uint32_t lo, hi;
+ uint32_t tlb_vpn;
+ int tlb_pid, tlb_g, tlb_v;
+ unsigned int set;
+ unsigned int mmu;
+
+ pid &= 0xff;
+ for (mmu = 0; mmu < 2; mmu++) {
+ for (set = 0; set < 4; set++)
+ {
+ for (idx = 0; idx < 16; idx++) {
+ lo = env->tlbsets[mmu][set][idx].lo;
+ hi = env->tlbsets[mmu][set][idx].hi;
+
+ tlb_vpn = EXTRACT_FIELD(hi, 13, 31);
+ tlb_pid = EXTRACT_FIELD(hi, 0, 7);
+ tlb_g = EXTRACT_FIELD(lo, 4, 4);
+ tlb_v = EXTRACT_FIELD(lo, 3, 3);
+
+ if (tlb_v && !tlb_g && (tlb_pid == pid)) {
+ vaddr = tlb_vpn << TARGET_PAGE_BITS;
+ D_LOG("flush pid=%x vaddr=%x\n",
+ pid, vaddr);
+ tlb_flush_page(CPU(cpu), vaddr);
+ }
+ }
+ }
+ }
+}
+
+int cris_mmu_translate(struct cris_mmu_result *res,
+ CPUCRISState *env, uint32_t vaddr,
+ int rw, int mmu_idx, int debug)
+{
+ int seg;
+ int miss = 0;
+ int is_user = mmu_idx == MMU_USER_IDX;
+ uint32_t old_srs;
+
+ old_srs= env->pregs[PR_SRS];
+
+ /* rw == 2 means exec, map the access to the insn mmu. */
+ env->pregs[PR_SRS] = rw == 2 ? 1 : 2;
+
+ if (!cris_mmu_enabled(env->sregs[SFR_RW_GC_CFG])) {
+ res->phy = vaddr;
+ res->prot = PAGE_BITS;
+ goto done;
+ }
+
+ seg = vaddr >> 28;
+ if (!is_user && cris_mmu_segmented_addr(seg, env->sregs[SFR_RW_MM_CFG]))
+ {
+ uint32_t base;
+
+ miss = 0;
+ base = cris_mmu_translate_seg(env, seg);
+ res->phy = base | (0x0fffffff & vaddr);
+ res->prot = PAGE_BITS;
+ } else {
+ miss = cris_mmu_translate_page(res, env, vaddr, rw,
+ is_user, debug);
+ }
+ done:
+ env->pregs[PR_SRS] = old_srs;
+ return miss;
+}
+#endif
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