target-unicore32/softmmu.c

   1 /*
   2  * Softmmu related functions
   3  *
   4  * Copyright (C) 2010-2012 Guan Xuetao
   5  *
   6  * This program is free software; you can redistribute it and/or modify
   7  * it under the terms of the GNU General Public License version 2 as
   8  * published by the Free Software Foundation, or any later version.
   9  * See the COPYING file in the top-level directory.
  10  */
  11 #ifdef CONFIG_USER_ONLY
  12 #error This file only exist under softmmu circumstance
  13 #endif
  14
  15 #include <cpu.h>
  16
  17 #undef DEBUG_UC32
  18
  19 #ifdef DEBUG_UC32
  20 #define DPRINTF(fmt, ...) printf("%s: " fmt , __func__, ## __VA_ARGS__)
  21 #else
  22 #define DPRINTF(fmt, ...) do {} while (0)
  23 #endif
  24
  25 #define SUPERPAGE_SIZE             (1 << 22)
  26 #define UC32_PAGETABLE_READ        (1 << 8)
  27 #define UC32_PAGETABLE_WRITE       (1 << 7)
  28 #define UC32_PAGETABLE_EXEC        (1 << 6)
  29 #define UC32_PAGETABLE_EXIST       (1 << 2)
  30 #define PAGETABLE_TYPE(x)          ((x) & 3)
  31
  32
  33 /* Map CPU modes onto saved register banks.  */
  34 static inline int bank_number(CPUUniCore32State *env, int mode)
  35 {
  36     switch (mode) {
  37     case ASR_MODE_USER:
  38     case ASR_MODE_SUSR:
  39         return 0;
  40     case ASR_MODE_PRIV:
  41         return 1;
  42     case ASR_MODE_TRAP:
  43         return 2;
  44     case ASR_MODE_EXTN:
  45         return 3;
  46     case ASR_MODE_INTR:
  47         return 4;
  48     }
  49     cpu_abort(env, "Bad mode %x\n", mode);
  50     return -1;
  51 }
  52
  53 void switch_mode(CPUUniCore32State *env, int mode)
  54 {
  55     int old_mode;
  56     int i;
  57
  58     old_mode = env->uncached_asr & ASR_M;
  59     if (mode == old_mode) {
  60         return;
  61     }
  62
  63     i = bank_number(env, old_mode);
  64     env->banked_r29[i] = env->regs[29];
  65     env->banked_r30[i] = env->regs[30];
  66     env->banked_bsr[i] = env->bsr;
  67
  68     i = bank_number(env, mode);
  69     env->regs[29] = env->banked_r29[i];
  70     env->regs[30] = env->banked_r30[i];
  71     env->bsr = env->banked_bsr[i];
  72 }
  73
  74 /* Handle a CPU exception.  */
  75 void uc32_cpu_do_interrupt(CPUState *cs)
  76 {
  77     UniCore32CPU *cpu = UNICORE32_CPU(cs);
  78     CPUUniCore32State *env = &cpu->env;
  79     uint32_t addr;
  80     int new_mode;
  81
  82     switch (env->exception_index) {
  83     case UC32_EXCP_PRIV:
  84         new_mode = ASR_MODE_PRIV;
  85         addr = 0x08;
  86         break;
  87     case UC32_EXCP_ITRAP:
  88         DPRINTF("itrap happened at %x\n", env->regs[31]);
  89         new_mode = ASR_MODE_TRAP;
  90         addr = 0x0c;
  91         break;
  92     case UC32_EXCP_DTRAP:
  93         DPRINTF("dtrap happened at %x\n", env->regs[31]);
  94         new_mode = ASR_MODE_TRAP;
  95         addr = 0x10;
  96         break;
  97     case UC32_EXCP_INTR:
  98         new_mode = ASR_MODE_INTR;
  99         addr = 0x18;
 100         break;
 101     default:
 102         cpu_abort(env, "Unhandled exception 0x%x\n", env->exception_index);
 103         return;
 104     }
 105     /* High vectors.  */
 106     if (env->cp0.c1_sys & (1 << 13)) {
 107         addr += 0xffff0000;
 108     }
 109
 110     switch_mode(env, new_mode);
 111     env->bsr = cpu_asr_read(env);
 112     env->uncached_asr = (env->uncached_asr & ~ASR_M) | new_mode;
 113     env->uncached_asr |= ASR_I;
 114     /* The PC already points to the proper instruction.  */
 115     env->regs[30] = env->regs[31];
 116     env->regs[31] = addr;
 117     cs->interrupt_request |= CPU_INTERRUPT_EXITTB;
 118 }
 119
 120 static int get_phys_addr_ucv2(CPUUniCore32State *env, uint32_t address,
 121         int access_type, int is_user, uint32_t *phys_ptr, int *prot,
 122         target_ulong *page_size)
 123 {
 124     int code;
 125     uint32_t table;
 126     uint32_t desc;
 127     uint32_t phys_addr;
 128
 129     /* Pagetable walk.  */
 130     /* Lookup l1 descriptor.  */
 131     table = env->cp0.c2_base & 0xfffff000;
 132     table |= (address >> 20) & 0xffc;
 133     desc = ldl_phys(table);
 134     code = 0;
 135     switch (PAGETABLE_TYPE(desc)) {
 136     case 3:
 137         /* Superpage  */
 138         if (!(desc & UC32_PAGETABLE_EXIST)) {
 139             code = 0x0b; /* superpage miss */
 140             goto do_fault;
 141         }
 142         phys_addr = (desc & 0xffc00000) | (address & 0x003fffff);
 143         *page_size = SUPERPAGE_SIZE;
 144         break;
 145     case 0:
 146         /* Lookup l2 entry.  */
 147         if (is_user) {
 148             DPRINTF("PGD address %x, desc %x\n", table, desc);
 149         }
 150         if (!(desc & UC32_PAGETABLE_EXIST)) {
 151             code = 0x05; /* second pagetable miss */
 152             goto do_fault;
 153         }
 154         table = (desc & 0xfffff000) | ((address >> 10) & 0xffc);
 155         desc = ldl_phys(table);
 156         /* 4k page.  */
 157         if (is_user) {
 158             DPRINTF("PTE address %x, desc %x\n", table, desc);
 159         }
 160         if (!(desc & UC32_PAGETABLE_EXIST)) {
 161             code = 0x08; /* page miss */
 162             goto do_fault;
 163         }
 164         switch (PAGETABLE_TYPE(desc)) {
 165         case 0:
 166             phys_addr = (desc & 0xfffff000) | (address & 0xfff);
 167             *page_size = TARGET_PAGE_SIZE;
 168             break;
 169         default:
 170             cpu_abort(env, "wrong page type!");
 171         }
 172         break;
 173     default:
 174         cpu_abort(env, "wrong page type!");
 175     }
 176
 177     *phys_ptr = phys_addr;
 178     *prot = 0;
 179     /* Check access permissions.  */
 180     if (desc & UC32_PAGETABLE_READ) {
 181         *prot |= PAGE_READ;
 182     } else {
 183         if (is_user && (access_type == 0)) {
 184             code = 0x11; /* access unreadable area */
 185             goto do_fault;
 186         }
 187     }
 188
 189     if (desc & UC32_PAGETABLE_WRITE) {
 190         *prot |= PAGE_WRITE;
 191     } else {
 192         if (is_user && (access_type == 1)) {
 193             code = 0x12; /* access unwritable area */
 194             goto do_fault;
 195         }
 196     }
 197
 198     if (desc & UC32_PAGETABLE_EXEC) {
 199         *prot |= PAGE_EXEC;
 200     } else {
 201         if (is_user && (access_type == 2)) {
 202             code = 0x13; /* access unexecutable area */
 203             goto do_fault;
 204         }
 205     }
 206
 207 do_fault:
 208     return code;
 209 }
 210
 211 int uc32_cpu_handle_mmu_fault(CPUUniCore32State *env, target_ulong address,
 212                               int access_type, int mmu_idx)
 213 {
 214     uint32_t phys_addr;
 215     target_ulong page_size;
 216     int prot;
 217     int ret, is_user;
 218
 219     ret = 1;
 220     is_user = mmu_idx == MMU_USER_IDX;
 221
 222     if ((env->cp0.c1_sys & 1) == 0) {
 223         /* MMU disabled.  */
 224         phys_addr = address;
 225         prot = PAGE_READ | PAGE_WRITE | PAGE_EXEC;
 226         page_size = TARGET_PAGE_SIZE;
 227         ret = 0;
 228     } else {
 229         if ((address & (1 << 31)) || (is_user)) {
 230             ret = get_phys_addr_ucv2(env, address, access_type, is_user,
 231                                     &phys_addr, &prot, &page_size);
 232             if (is_user) {
 233                 DPRINTF("user space access: ret %x, address %x, "
 234                         "access_type %x, phys_addr %x, prot %x\n",
 235                         ret, address, access_type, phys_addr, prot);
 236             }
 237         } else {
 238             /*IO memory */
 239             phys_addr = address | (1 << 31);
 240             prot = PAGE_READ | PAGE_WRITE | PAGE_EXEC;
 241             page_size = TARGET_PAGE_SIZE;
 242             ret = 0;
 243         }
 244     }
 245
 246     if (ret == 0) {
 247         /* Map a single page.  */
 248         phys_addr &= TARGET_PAGE_MASK;
 249         address &= TARGET_PAGE_MASK;
 250         tlb_set_page(env, address, phys_addr, prot, mmu_idx, page_size);
 251         return 0;
 252     }
 253
 254     env->cp0.c3_faultstatus = ret;
 255     env->cp0.c4_faultaddr = address;
 256     if (access_type == 2) {
 257         env->exception_index = UC32_EXCP_ITRAP;
 258     } else {
 259         env->exception_index = UC32_EXCP_DTRAP;
 260     }
 261     return ret;
 262 }
 263
 264 hwaddr cpu_get_phys_page_debug(CPUUniCore32State *env,
 265         target_ulong addr)
 266 {
 267     cpu_abort(env, "%s not supported yet\n", __func__);
 268     return addr;
 269 }