target/nios2/helper.c

   1 /*
   2  * Altera Nios II helper routines.
   3  *
   4  * Copyright (c) 2012 Chris Wulff <crwulff@gmail.com>
   5  *
   6  * This library is free software; you can redistribute it and/or
   7  * modify it under the terms of the GNU Lesser General Public
   8  * License as published by the Free Software Foundation; either
   9  * version 2.1 of the License, or (at your option) any later version.
  10  *
  11  * This library is distributed in the hope that it will be useful,
  12  * but WITHOUT ANY WARRANTY; without even the implied warranty of
  13  * MERCHANTABILITY or FITNESS FOR A PARTICULAR PURPOSE.  See the GNU
  14  * Lesser General Public License for more details.
  15  *
  16  * You should have received a copy of the GNU Lesser General Public
  17  * License along with this library; if not, see
  18  * <http://www.gnu.org/licenses/lgpl-2.1.html>
  19  */
  20
  21 #include "qemu/osdep.h"
  22
  23 #include "cpu.h"
  24 #include "qemu/host-utils.h"
  25 #include "qapi/error.h"
  26 #include "exec/exec-all.h"
  27 #include "exec/log.h"
  28 #include "exec/helper-proto.h"
  29
  30 #if defined(CONFIG_USER_ONLY)
  31
  32 void nios2_cpu_do_interrupt(CPUState *cs)
  33 {
  34     Nios2CPU *cpu = NIOS2_CPU(cs);
  35     CPUNios2State *env = &cpu->env;
  36     cs->exception_index = -1;
  37     env->regs[R_EA] = env->regs[R_PC] + 4;
  38 }
  39
  40 int nios2_cpu_handle_mmu_fault(CPUState *cs, vaddr address, int rw, int mmu_idx)
  41 {
  42     cs->exception_index = 0xaa;
  43     /* Page 0x1000 is kuser helper */
  44     if (address < 0x1000 || address >= 0x2000) {
  45         cpu_dump_state(cs, stderr, fprintf, 0);
  46     }
  47     return 1;
  48 }
  49
  50 #else /* !CONFIG_USER_ONLY */
  51
  52 void nios2_cpu_do_interrupt(CPUState *cs)
  53 {
  54     Nios2CPU *cpu = NIOS2_CPU(cs);
  55     CPUNios2State *env = &cpu->env;
  56
  57     switch (cs->exception_index) {
  58     case EXCP_IRQ:
  59         assert(env->regs[CR_STATUS] & CR_STATUS_PIE);
  60
  61         qemu_log_mask(CPU_LOG_INT, "interrupt at pc=%x\n", env->regs[R_PC]);
  62
  63         env->regs[CR_ESTATUS] = env->regs[CR_STATUS];
  64         env->regs[CR_STATUS] |= CR_STATUS_IH;
  65         env->regs[CR_STATUS] &= ~(CR_STATUS_PIE | CR_STATUS_U);
  66
  67         env->regs[CR_EXCEPTION] &= ~(0x1F << 2);
  68         env->regs[CR_EXCEPTION] |= (cs->exception_index & 0x1F) << 2;
  69
  70         env->regs[R_EA] = env->regs[R_PC] + 4;
  71         env->regs[R_PC] = cpu->exception_addr;
  72         break;
  73
  74     case EXCP_TLBD:
  75         if ((env->regs[CR_STATUS] & CR_STATUS_EH) == 0) {
  76             qemu_log_mask(CPU_LOG_INT, "TLB MISS (fast) at pc=%x\n",
  77                           env->regs[R_PC]);
  78
  79             /* Fast TLB miss */
  80             /* Variation from the spec. Table 3-35 of the cpu reference shows
  81              * estatus not being changed for TLB miss but this appears to
  82              * be incorrect. */
  83             env->regs[CR_ESTATUS] = env->regs[CR_STATUS];
  84             env->regs[CR_STATUS] |= CR_STATUS_EH;
  85             env->regs[CR_STATUS] &= ~(CR_STATUS_PIE | CR_STATUS_U);
  86
  87             env->regs[CR_EXCEPTION] &= ~(0x1F << 2);
  88             env->regs[CR_EXCEPTION] |= (cs->exception_index & 0x1F) << 2;
  89
  90             env->regs[CR_TLBMISC] &= ~CR_TLBMISC_DBL;
  91             env->regs[CR_TLBMISC] |= CR_TLBMISC_WR;
  92
  93             env->regs[R_EA] = env->regs[R_PC] + 4;
  94             env->regs[R_PC] = cpu->fast_tlb_miss_addr;
  95         } else {
  96             qemu_log_mask(CPU_LOG_INT, "TLB MISS (double) at pc=%x\n",
  97                           env->regs[R_PC]);
  98
  99             /* Double TLB miss */
 100             env->regs[CR_STATUS] |= CR_STATUS_EH;
 101             env->regs[CR_STATUS] &= ~(CR_STATUS_PIE | CR_STATUS_U);
 102
 103             env->regs[CR_EXCEPTION] &= ~(0x1F << 2);
 104             env->regs[CR_EXCEPTION] |= (cs->exception_index & 0x1F) << 2;
 105
 106             env->regs[CR_TLBMISC] |= CR_TLBMISC_DBL;
 107
 108             env->regs[R_PC] = cpu->exception_addr;
 109         }
 110         break;
 111
 112     case EXCP_TLBR:
 113     case EXCP_TLBW:
 114     case EXCP_TLBX:
 115         qemu_log_mask(CPU_LOG_INT, "TLB PERM at pc=%x\n", env->regs[R_PC]);
 116
 117         env->regs[CR_ESTATUS] = env->regs[CR_STATUS];
 118         env->regs[CR_STATUS] |= CR_STATUS_EH;
 119         env->regs[CR_STATUS] &= ~(CR_STATUS_PIE | CR_STATUS_U);
 120
 121         env->regs[CR_EXCEPTION] &= ~(0x1F << 2);
 122         env->regs[CR_EXCEPTION] |= (cs->exception_index & 0x1F) << 2;
 123
 124         if ((env->regs[CR_STATUS] & CR_STATUS_EH) == 0) {
 125             env->regs[CR_TLBMISC] |= CR_TLBMISC_WR;
 126         }
 127
 128         env->regs[R_EA] = env->regs[R_PC] + 4;
 129         env->regs[R_PC] = cpu->exception_addr;
 130         break;
 131
 132     case EXCP_SUPERA:
 133     case EXCP_SUPERI:
 134     case EXCP_SUPERD:
 135         qemu_log_mask(CPU_LOG_INT, "SUPERVISOR exception at pc=%x\n",
 136                       env->regs[R_PC]);
 137
 138         if ((env->regs[CR_STATUS] & CR_STATUS_EH) == 0) {
 139             env->regs[CR_ESTATUS] = env->regs[CR_STATUS];
 140             env->regs[R_EA] = env->regs[R_PC] + 4;
 141         }
 142
 143         env->regs[CR_STATUS] |= CR_STATUS_EH;
 144         env->regs[CR_STATUS] &= ~(CR_STATUS_PIE | CR_STATUS_U);
 145
 146         env->regs[CR_EXCEPTION] &= ~(0x1F << 2);
 147         env->regs[CR_EXCEPTION] |= (cs->exception_index & 0x1F) << 2;
 148
 149         env->regs[R_PC] = cpu->exception_addr;
 150         break;
 151
 152     case EXCP_ILLEGAL:
 153     case EXCP_TRAP:
 154         qemu_log_mask(CPU_LOG_INT, "TRAP exception at pc=%x\n",
 155                       env->regs[R_PC]);
 156
 157         if ((env->regs[CR_STATUS] & CR_STATUS_EH) == 0) {
 158             env->regs[CR_ESTATUS] = env->regs[CR_STATUS];
 159             env->regs[R_EA] = env->regs[R_PC] + 4;
 160         }
 161
 162         env->regs[CR_STATUS] |= CR_STATUS_EH;
 163         env->regs[CR_STATUS] &= ~(CR_STATUS_PIE | CR_STATUS_U);
 164
 165         env->regs[CR_EXCEPTION] &= ~(0x1F << 2);
 166         env->regs[CR_EXCEPTION] |= (cs->exception_index & 0x1F) << 2;
 167
 168         env->regs[R_PC] = cpu->exception_addr;
 169         break;
 170
 171     case EXCP_BREAK:
 172         if ((env->regs[CR_STATUS] & CR_STATUS_EH) == 0) {
 173             env->regs[CR_BSTATUS] = env->regs[CR_STATUS];
 174             env->regs[R_BA] = env->regs[R_PC] + 4;
 175         }
 176
 177         env->regs[CR_STATUS] |= CR_STATUS_EH;
 178         env->regs[CR_STATUS] &= ~(CR_STATUS_PIE | CR_STATUS_U);
 179
 180         env->regs[CR_EXCEPTION] &= ~(0x1F << 2);
 181         env->regs[CR_EXCEPTION] |= (cs->exception_index & 0x1F) << 2;
 182
 183         env->regs[R_PC] = cpu->exception_addr;
 184         break;
 185
 186     default:
 187         cpu_abort(cs, "unhandled exception type=%d\n",
 188                   cs->exception_index);
 189         break;
 190     }
 191 }
 192
 193 static int cpu_nios2_handle_virtual_page(
 194     CPUState *cs, target_ulong address, int rw, int mmu_idx)
 195 {
 196     Nios2CPU *cpu = NIOS2_CPU(cs);
 197     CPUNios2State *env = &cpu->env;
 198     target_ulong vaddr, paddr;
 199     Nios2MMULookup lu;
 200     unsigned int hit;
 201     hit = mmu_translate(env, &lu, address, rw, mmu_idx);
 202     if (hit) {
 203         vaddr = address & TARGET_PAGE_MASK;
 204         paddr = lu.paddr + vaddr - lu.vaddr;
 205
 206         if (((rw == 0) && (lu.prot & PAGE_READ)) ||
 207             ((rw == 1) && (lu.prot & PAGE_WRITE)) ||
 208             ((rw == 2) && (lu.prot & PAGE_EXEC))) {
 209
 210             tlb_set_page(cs, vaddr, paddr, lu.prot,
 211                          mmu_idx, TARGET_PAGE_SIZE);
 212             return 0;
 213         } else {
 214             /* Permission violation */
 215             cs->exception_index = (rw == 0) ? EXCP_TLBR :
 216                                                ((rw == 1) ? EXCP_TLBW :
 217                                                             EXCP_TLBX);
 218         }
 219     } else {
 220         cs->exception_index = EXCP_TLBD;
 221     }
 222
 223     if (rw == 2) {
 224         env->regs[CR_TLBMISC] &= ~CR_TLBMISC_D;
 225     } else {
 226         env->regs[CR_TLBMISC] |= CR_TLBMISC_D;
 227     }
 228     env->regs[CR_PTEADDR] &= CR_PTEADDR_PTBASE_MASK;
 229     env->regs[CR_PTEADDR] |= (address >> 10) & CR_PTEADDR_VPN_MASK;
 230     env->mmu.pteaddr_wr = env->regs[CR_PTEADDR];
 231     env->regs[CR_BADADDR] = address;
 232     return 1;
 233 }
 234
 235 int nios2_cpu_handle_mmu_fault(CPUState *cs, vaddr address, int rw, int mmu_idx)
 236 {
 237     Nios2CPU *cpu = NIOS2_CPU(cs);
 238     CPUNios2State *env = &cpu->env;
 239
 240     if (cpu->mmu_present) {
 241         if (MMU_SUPERVISOR_IDX == mmu_idx) {
 242             if (address >= 0xC0000000) {
 243                 /* Kernel physical page - TLB bypassed */
 244                 address &= TARGET_PAGE_MASK;
 245                 tlb_set_page(cs, address, address, PAGE_BITS,
 246                              mmu_idx, TARGET_PAGE_SIZE);
 247             } else if (address >= 0x80000000) {
 248                 /* Kernel virtual page */
 249                 return cpu_nios2_handle_virtual_page(cs, address, rw, mmu_idx);
 250             } else {
 251                 /* User virtual page */
 252                 return cpu_nios2_handle_virtual_page(cs, address, rw, mmu_idx);
 253             }
 254         } else {
 255             if (address >= 0x80000000) {
 256                 /* Illegal access from user mode */
 257                 cs->exception_index = EXCP_SUPERA;
 258                 env->regs[CR_BADADDR] = address;
 259                 return 1;
 260             } else {
 261                 /* User virtual page */
 262                 return cpu_nios2_handle_virtual_page(cs, address, rw, mmu_idx);
 263             }
 264         }
 265     } else {
 266         /* No MMU */
 267         address &= TARGET_PAGE_MASK;
 268         tlb_set_page(cs, address, address, PAGE_BITS,
 269                      mmu_idx, TARGET_PAGE_SIZE);
 270     }
 271
 272     return 0;
 273 }
 274
 275 hwaddr nios2_cpu_get_phys_page_debug(CPUState *cs, vaddr addr)
 276 {
 277     Nios2CPU *cpu = NIOS2_CPU(cs);
 278     CPUNios2State *env = &cpu->env;
 279     target_ulong vaddr, paddr = 0;
 280     Nios2MMULookup lu;
 281     unsigned int hit;
 282
 283     if (cpu->mmu_present && (addr < 0xC0000000)) {
 284         hit = mmu_translate(env, &lu, addr, 0, 0);
 285         if (hit) {
 286             vaddr = addr & TARGET_PAGE_MASK;
 287             paddr = lu.paddr + vaddr - lu.vaddr;
 288         } else {
 289             paddr = -1;
 290             qemu_log("cpu_get_phys_page debug MISS: %#" PRIx64 "\n", addr);
 291         }
 292     } else {
 293         paddr = addr & TARGET_PAGE_MASK;
 294     }
 295
 296     return paddr;
 297 }
 298
 299 void nios2_cpu_do_unaligned_access(CPUState *cs, vaddr addr,
 300                                    MMUAccessType access_type,
 301                                    int mmu_idx, uintptr_t retaddr)
 302 {
 303     Nios2CPU *cpu = NIOS2_CPU(cs);
 304     CPUNios2State *env = &cpu->env;
 305
 306     env->regs[CR_BADADDR] = addr;
 307     env->regs[CR_EXCEPTION] = EXCP_UNALIGN << 2;
 308     helper_raise_exception(env, EXCP_UNALIGN);
 309 }
 310 #endif /* !CONFIG_USER_ONLY */