/* * 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/>. */ #include "qemu/osdep.h" #include "cpu.h" #include "exec/exec-all.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; }