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 "qemu/osdep.h"
  16 #include "cpu.h"
  17 #include "exec/exec-all.h"
  18 #include "qemu/error-report.h"
  19
  20 #undef DEBUG_UC32
  21
  22 #ifdef DEBUG_UC32
  23 #define DPRINTF(fmt, ...) printf("%s: " fmt , __func__, ## __VA_ARGS__)
  24 #else
  25 #define DPRINTF(fmt, ...) do {} while (0)
  26 #endif
  27
  28 #define SUPERPAGE_SIZE             (1 << 22)
  29 #define UC32_PAGETABLE_READ        (1 << 8)
  30 #define UC32_PAGETABLE_WRITE       (1 << 7)
  31 #define UC32_PAGETABLE_EXEC        (1 << 6)
  32 #define UC32_PAGETABLE_EXIST       (1 << 2)
  33 #define PAGETABLE_TYPE(x)          ((x) & 3)
  34
  35
  36 /* Map CPU modes onto saved register banks.  */
  37 static inline int bank_number(CPUUniCore32State *env, int mode)
  38 {
  39     UniCore32CPU *cpu = uc32_env_get_cpu(env);
  40
  41     switch (mode) {
  42     case ASR_MODE_USER:
  43     case ASR_MODE_SUSR:
  44         return 0;
  45     case ASR_MODE_PRIV:
  46         return 1;
  47     case ASR_MODE_TRAP:
  48         return 2;
  49     case ASR_MODE_EXTN:
  50         return 3;
  51     case ASR_MODE_INTR:
  52         return 4;
  53     }
  54     cpu_abort(CPU(cpu), "Bad mode %x\n", mode);
  55     return -1;
  56 }
  57
  58 void switch_mode(CPUUniCore32State *env, int mode)
  59 {
  60     int old_mode;
  61     int i;
  62
  63     old_mode = env->uncached_asr & ASR_M;
  64     if (mode == old_mode) {
  65         return;
  66     }
  67
  68     i = bank_number(env, old_mode);
  69     env->banked_r29[i] = env->regs[29];
  70     env->banked_r30[i] = env->regs[30];
  71     env->banked_bsr[i] = env->bsr;
  72
  73     i = bank_number(env, mode);
  74     env->regs[29] = env->banked_r29[i];
  75     env->regs[30] = env->banked_r30[i];
  76     env->bsr = env->banked_bsr[i];
  77 }
  78
  79 /* Handle a CPU exception.  */
  80 void uc32_cpu_do_interrupt(CPUState *cs)
  81 {
  82     UniCore32CPU *cpu = UNICORE32_CPU(cs);
  83     CPUUniCore32State *env = &cpu->env;
  84     uint32_t addr;
  85     int new_mode;
  86
  87     switch (cs->exception_index) {
  88     case UC32_EXCP_PRIV:
  89         new_mode = ASR_MODE_PRIV;
  90         addr = 0x08;
  91         break;
  92     case UC32_EXCP_ITRAP:
  93         DPRINTF("itrap happened at %x\n", env->regs[31]);
  94         new_mode = ASR_MODE_TRAP;
  95         addr = 0x0c;
  96         break;
  97     case UC32_EXCP_DTRAP:
  98         DPRINTF("dtrap happened at %x\n", env->regs[31]);
  99         new_mode = ASR_MODE_TRAP;
 100         addr = 0x10;
 101         break;
 102     case UC32_EXCP_INTR:
 103         new_mode = ASR_MODE_INTR;
 104         addr = 0x18;
 105         break;
 106     default:
 107         cpu_abort(cs, "Unhandled exception 0x%x\n", cs->exception_index);
 108         return;
 109     }
 110     /* High vectors.  */
 111     if (env->cp0.c1_sys & (1 << 13)) {
 112         addr += 0xffff0000;
 113     }
 114
 115     switch_mode(env, new_mode);
 116     env->bsr = cpu_asr_read(env);
 117     env->uncached_asr = (env->uncached_asr & ~ASR_M) | new_mode;
 118     env->uncached_asr |= ASR_I;
 119     /* The PC already points to the proper instruction.  */
 120     env->regs[30] = env->regs[31];
 121     env->regs[31] = addr;
 122     cs->interrupt_request |= CPU_INTERRUPT_EXITTB;
 123 }
 124
 125 static int get_phys_addr_ucv2(CPUUniCore32State *env, uint32_t address,
 126         int access_type, int is_user, uint32_t *phys_ptr, int *prot,
 127         target_ulong *page_size)
 128 {
 129     UniCore32CPU *cpu = uc32_env_get_cpu(env);
 130     CPUState *cs = CPU(cpu);
 131     int code;
 132     uint32_t table;
 133     uint32_t desc;
 134     uint32_t phys_addr;
 135
 136     /* Pagetable walk.  */
 137     /* Lookup l1 descriptor.  */
 138     table = env->cp0.c2_base & 0xfffff000;
 139     table |= (address >> 20) & 0xffc;
 140     desc = ldl_phys(cs->as, table);
 141     code = 0;
 142     switch (PAGETABLE_TYPE(desc)) {
 143     case 3:
 144         /* Superpage  */
 145         if (!(desc & UC32_PAGETABLE_EXIST)) {
 146             code = 0x0b; /* superpage miss */
 147             goto do_fault;
 148         }
 149         phys_addr = (desc & 0xffc00000) | (address & 0x003fffff);
 150         *page_size = SUPERPAGE_SIZE;
 151         break;
 152     case 0:
 153         /* Lookup l2 entry.  */
 154         if (is_user) {
 155             DPRINTF("PGD address %x, desc %x\n", table, desc);
 156         }
 157         if (!(desc & UC32_PAGETABLE_EXIST)) {
 158             code = 0x05; /* second pagetable miss */
 159             goto do_fault;
 160         }
 161         table = (desc & 0xfffff000) | ((address >> 10) & 0xffc);
 162         desc = ldl_phys(cs->as, table);
 163         /* 4k page.  */
 164         if (is_user) {
 165             DPRINTF("PTE address %x, desc %x\n", table, desc);
 166         }
 167         if (!(desc & UC32_PAGETABLE_EXIST)) {
 168             code = 0x08; /* page miss */
 169             goto do_fault;
 170         }
 171         switch (PAGETABLE_TYPE(desc)) {
 172         case 0:
 173             phys_addr = (desc & 0xfffff000) | (address & 0xfff);
 174             *page_size = TARGET_PAGE_SIZE;
 175             break;
 176         default:
 177             cpu_abort(CPU(cpu), "wrong page type!");
 178         }
 179         break;
 180     default:
 181         cpu_abort(CPU(cpu), "wrong page type!");
 182     }
 183
 184     *phys_ptr = phys_addr;
 185     *prot = 0;
 186     /* Check access permissions.  */
 187     if (desc & UC32_PAGETABLE_READ) {
 188         *prot |= PAGE_READ;
 189     } else {
 190         if (is_user && (access_type == 0)) {
 191             code = 0x11; /* access unreadable area */
 192             goto do_fault;
 193         }
 194     }
 195
 196     if (desc & UC32_PAGETABLE_WRITE) {
 197         *prot |= PAGE_WRITE;
 198     } else {
 199         if (is_user && (access_type == 1)) {
 200             code = 0x12; /* access unwritable area */
 201             goto do_fault;
 202         }
 203     }
 204
 205     if (desc & UC32_PAGETABLE_EXEC) {
 206         *prot |= PAGE_EXEC;
 207     } else {
 208         if (is_user && (access_type == 2)) {
 209             code = 0x13; /* access unexecutable area */
 210             goto do_fault;
 211         }
 212     }
 213
 214 do_fault:
 215     return code;
 216 }
 217
 218 int uc32_cpu_handle_mmu_fault(CPUState *cs, vaddr address, int size,
 219                               int access_type, int mmu_idx)
 220 {
 221     UniCore32CPU *cpu = UNICORE32_CPU(cs);
 222     CPUUniCore32State *env = &cpu->env;
 223     uint32_t phys_addr;
 224     target_ulong page_size;
 225     int prot;
 226     int ret, is_user;
 227
 228     ret = 1;
 229     is_user = mmu_idx == MMU_USER_IDX;
 230
 231     if ((env->cp0.c1_sys & 1) == 0) {
 232         /* MMU disabled.  */
 233         phys_addr = address;
 234         prot = PAGE_READ | PAGE_WRITE | PAGE_EXEC;
 235         page_size = TARGET_PAGE_SIZE;
 236         ret = 0;
 237     } else {
 238         if ((address & (1 << 31)) || (is_user)) {
 239             ret = get_phys_addr_ucv2(env, address, access_type, is_user,
 240                                     &phys_addr, &prot, &page_size);
 241             if (is_user) {
 242                 DPRINTF("user space access: ret %x, address %" VADDR_PRIx ", "
 243                         "access_type %x, phys_addr %x, prot %x\n",
 244                         ret, address, access_type, phys_addr, prot);
 245             }
 246         } else {
 247             /*IO memory */
 248             phys_addr = address | (1 << 31);
 249             prot = PAGE_READ | PAGE_WRITE | PAGE_EXEC;
 250             page_size = TARGET_PAGE_SIZE;
 251             ret = 0;
 252         }
 253     }
 254
 255     if (ret == 0) {
 256         /* Map a single page.  */
 257         phys_addr &= TARGET_PAGE_MASK;
 258         address &= TARGET_PAGE_MASK;
 259         tlb_set_page(cs, address, phys_addr, prot, mmu_idx, page_size);
 260         return 0;
 261     }
 262
 263     env->cp0.c3_faultstatus = ret;
 264     env->cp0.c4_faultaddr = address;
 265     if (access_type == 2) {
 266         cs->exception_index = UC32_EXCP_ITRAP;
 267     } else {
 268         cs->exception_index = UC32_EXCP_DTRAP;
 269     }
 270     return ret;
 271 }
 272
 273 hwaddr uc32_cpu_get_phys_page_debug(CPUState *cs, vaddr addr)
 274 {
 275     error_report("function uc32_cpu_get_phys_page_debug not "
 276                     "implemented, aborting");
 277     return -1;
 278 }