target-xtensa/helper.c

   1 /*
   2  * Copyright (c) 2011, Max Filippov, Open Source and Linux Lab.
   3  * All rights reserved.
   4  *
   5  * Redistribution and use in source and binary forms, with or without
   6  * modification, are permitted provided that the following conditions are met:
   7  *     * Redistributions of source code must retain the above copyright
   8  *       notice, this list of conditions and the following disclaimer.
   9  *     * Redistributions in binary form must reproduce the above copyright
  10  *       notice, this list of conditions and the following disclaimer in the
  11  *       documentation and/or other materials provided with the distribution.
  12  *     * Neither the name of the Open Source and Linux Lab nor the
  13  *       names of its contributors may be used to endorse or promote products
  14  *       derived from this software without specific prior written permission.
  15  *
  16  * THIS SOFTWARE IS PROVIDED BY THE COPYRIGHT HOLDERS AND CONTRIBUTORS "AS IS"
  17  * AND ANY EXPRESS OR IMPLIED WARRANTIES, INCLUDING, BUT NOT LIMITED TO, THE
  18  * IMPLIED WARRANTIES OF MERCHANTABILITY AND FITNESS FOR A PARTICULAR PURPOSE
  19  * ARE DISCLAIMED. IN NO EVENT SHALL THE AUTHOR BE LIABLE FOR ANY
  20  * DIRECT, INDIRECT, INCIDENTAL, SPECIAL, EXEMPLARY, OR CONSEQUENTIAL DAMAGES
  21  * (INCLUDING, BUT NOT LIMITED TO, PROCUREMENT OF SUBSTITUTE GOODS OR SERVICES;
  22  * LOSS OF USE, DATA, OR PROFITS; OR BUSINESS INTERRUPTION) HOWEVER CAUSED AND
  23  * ON ANY THEORY OF LIABILITY, WHETHER IN CONTRACT, STRICT LIABILITY, OR TORT
  24  * (INCLUDING NEGLIGENCE OR OTHERWISE) ARISING IN ANY WAY OUT OF THE USE OF THIS
  25  * SOFTWARE, EVEN IF ADVISED OF THE POSSIBILITY OF SUCH DAMAGE.
  26  */
  27
  28 #include "cpu.h"
  29 #include "exec-all.h"
  30 #include "gdbstub.h"
  31 #include "qemu-common.h"
  32 #include "host-utils.h"
  33 #if !defined(CONFIG_USER_ONLY)
  34 #include "hw/loader.h"
  35 #endif
  36
  37 static void reset_mmu(CPUState *env);
  38
  39 void cpu_reset(CPUXtensaState *env)
  40 {
  41     env->exception_taken = 0;
  42     env->pc = env->config->exception_vector[EXC_RESET];
  43     env->sregs[LITBASE] &= ~1;
  44     env->sregs[PS] = xtensa_option_enabled(env->config,
  45             XTENSA_OPTION_INTERRUPT) ? 0x1f : 0x10;
  46     env->sregs[VECBASE] = env->config->vecbase;
  47
  48     env->pending_irq_level = 0;
  49     reset_mmu(env);
  50 }
  51
  52 static struct XtensaConfigList *xtensa_cores;
  53
  54 void xtensa_register_core(XtensaConfigList *node)
  55 {
  56     node->next = xtensa_cores;
  57     xtensa_cores = node;
  58 }
  59
  60 CPUXtensaState *cpu_xtensa_init(const char *cpu_model)
  61 {
  62     static int tcg_inited;
  63     CPUXtensaState *env;
  64     const XtensaConfig *config = NULL;
  65     XtensaConfigList *core = xtensa_cores;
  66
  67     for (; core; core = core->next)
  68         if (strcmp(core->config->name, cpu_model) == 0) {
  69             config = core->config;
  70             break;
  71         }
  72
  73     if (config == NULL) {
  74         return NULL;
  75     }
  76
  77     env = g_malloc0(sizeof(*env));
  78     env->config = config;
  79     cpu_exec_init(env);
  80
  81     if (!tcg_inited) {
  82         tcg_inited = 1;
  83         xtensa_translate_init();
  84     }
  85
  86     xtensa_irq_init(env);
  87     qemu_init_vcpu(env);
  88     return env;
  89 }
  90
  91
  92 void xtensa_cpu_list(FILE *f, fprintf_function cpu_fprintf)
  93 {
  94     XtensaConfigList *core = xtensa_cores;
  95     cpu_fprintf(f, "Available CPUs:\n");
  96     for (; core; core = core->next) {
  97         cpu_fprintf(f, "  %s\n", core->config->name);
  98     }
  99 }
 100
 101 target_phys_addr_t cpu_get_phys_page_debug(CPUState *env, target_ulong addr)
 102 {
 103     uint32_t paddr;
 104     uint32_t page_size;
 105     unsigned access;
 106
 107     if (xtensa_get_physical_addr(env, addr, 0, 0,
 108                 &paddr, &page_size, &access) == 0) {
 109         return paddr;
 110     }
 111     if (xtensa_get_physical_addr(env, addr, 2, 0,
 112                 &paddr, &page_size, &access) == 0) {
 113         return paddr;
 114     }
 115     return ~0;
 116 }
 117
 118 static uint32_t relocated_vector(CPUState *env, uint32_t vector)
 119 {
 120     if (xtensa_option_enabled(env->config,
 121                 XTENSA_OPTION_RELOCATABLE_VECTOR)) {
 122         return vector - env->config->vecbase + env->sregs[VECBASE];
 123     } else {
 124         return vector;
 125     }
 126 }
 127
 128 /*!
 129  * Handle penging IRQ.
 130  * For the high priority interrupt jump to the corresponding interrupt vector.
 131  * For the level-1 interrupt convert it to either user, kernel or double
 132  * exception with the 'level-1 interrupt' exception cause.
 133  */
 134 static void handle_interrupt(CPUState *env)
 135 {
 136     int level = env->pending_irq_level;
 137
 138     if (level > xtensa_get_cintlevel(env) &&
 139             level <= env->config->nlevel &&
 140             (env->config->level_mask[level] &
 141              env->sregs[INTSET] &
 142              env->sregs[INTENABLE])) {
 143         if (level > 1) {
 144             env->sregs[EPC1 + level - 1] = env->pc;
 145             env->sregs[EPS2 + level - 2] = env->sregs[PS];
 146             env->sregs[PS] =
 147                 (env->sregs[PS] & ~PS_INTLEVEL) | level | PS_EXCM;
 148             env->pc = relocated_vector(env,
 149                     env->config->interrupt_vector[level]);
 150         } else {
 151             env->sregs[EXCCAUSE] = LEVEL1_INTERRUPT_CAUSE;
 152
 153             if (env->sregs[PS] & PS_EXCM) {
 154                 if (env->config->ndepc) {
 155                     env->sregs[DEPC] = env->pc;
 156                 } else {
 157                     env->sregs[EPC1] = env->pc;
 158                 }
 159                 env->exception_index = EXC_DOUBLE;
 160             } else {
 161                 env->sregs[EPC1] = env->pc;
 162                 env->exception_index =
 163                     (env->sregs[PS] & PS_UM) ? EXC_USER : EXC_KERNEL;
 164             }
 165             env->sregs[PS] |= PS_EXCM;
 166         }
 167         env->exception_taken = 1;
 168     }
 169 }
 170
 171 void do_interrupt(CPUState *env)
 172 {
 173     if (env->exception_index == EXC_IRQ) {
 174         qemu_log_mask(CPU_LOG_INT,
 175                 "%s(EXC_IRQ) level = %d, cintlevel = %d, "
 176                 "pc = %08x, a0 = %08x, ps = %08x, "
 177                 "intset = %08x, intenable = %08x, "
 178                 "ccount = %08x\n",
 179                 __func__, env->pending_irq_level, xtensa_get_cintlevel(env),
 180                 env->pc, env->regs[0], env->sregs[PS],
 181                 env->sregs[INTSET], env->sregs[INTENABLE],
 182                 env->sregs[CCOUNT]);
 183         handle_interrupt(env);
 184     }
 185
 186     switch (env->exception_index) {
 187     case EXC_WINDOW_OVERFLOW4:
 188     case EXC_WINDOW_UNDERFLOW4:
 189     case EXC_WINDOW_OVERFLOW8:
 190     case EXC_WINDOW_UNDERFLOW8:
 191     case EXC_WINDOW_OVERFLOW12:
 192     case EXC_WINDOW_UNDERFLOW12:
 193     case EXC_KERNEL:
 194     case EXC_USER:
 195     case EXC_DOUBLE:
 196         qemu_log_mask(CPU_LOG_INT, "%s(%d) "
 197                 "pc = %08x, a0 = %08x, ps = %08x, ccount = %08x\n",
 198                 __func__, env->exception_index,
 199                 env->pc, env->regs[0], env->sregs[PS], env->sregs[CCOUNT]);
 200         if (env->config->exception_vector[env->exception_index]) {
 201             env->pc = relocated_vector(env,
 202                     env->config->exception_vector[env->exception_index]);
 203             env->exception_taken = 1;
 204         } else {
 205             qemu_log("%s(pc = %08x) bad exception_index: %d\n",
 206                     __func__, env->pc, env->exception_index);
 207         }
 208         break;
 209
 210     case EXC_IRQ:
 211         break;
 212
 213     default:
 214         qemu_log("%s(pc = %08x) unknown exception_index: %d\n",
 215                 __func__, env->pc, env->exception_index);
 216         break;
 217     }
 218     check_interrupts(env);
 219 }
 220
 221 static void reset_tlb_mmu_all_ways(CPUState *env,
 222         const xtensa_tlb *tlb, xtensa_tlb_entry entry[][MAX_TLB_WAY_SIZE])
 223 {
 224     unsigned wi, ei;
 225
 226     for (wi = 0; wi < tlb->nways; ++wi) {
 227         for (ei = 0; ei < tlb->way_size[wi]; ++ei) {
 228             entry[wi][ei].asid = 0;
 229             entry[wi][ei].variable = true;
 230         }
 231     }
 232 }
 233
 234 static void reset_tlb_mmu_ways56(CPUState *env,
 235         const xtensa_tlb *tlb, xtensa_tlb_entry entry[][MAX_TLB_WAY_SIZE])
 236 {
 237     if (!tlb->varway56) {
 238         static const xtensa_tlb_entry way5[] = {
 239             {
 240                 .vaddr = 0xd0000000,
 241                 .paddr = 0,
 242                 .asid = 1,
 243                 .attr = 7,
 244                 .variable = false,
 245             }, {
 246                 .vaddr = 0xd8000000,
 247                 .paddr = 0,
 248                 .asid = 1,
 249                 .attr = 3,
 250                 .variable = false,
 251             }
 252         };
 253         static const xtensa_tlb_entry way6[] = {
 254             {
 255                 .vaddr = 0xe0000000,
 256                 .paddr = 0xf0000000,
 257                 .asid = 1,
 258                 .attr = 7,
 259                 .variable = false,
 260             }, {
 261                 .vaddr = 0xf0000000,
 262                 .paddr = 0xf0000000,
 263                 .asid = 1,
 264                 .attr = 3,
 265                 .variable = false,
 266             }
 267         };
 268         memcpy(entry[5], way5, sizeof(way5));
 269         memcpy(entry[6], way6, sizeof(way6));
 270     } else {
 271         uint32_t ei;
 272         for (ei = 0; ei < 8; ++ei) {
 273             entry[6][ei].vaddr = ei << 29;
 274             entry[6][ei].paddr = ei << 29;
 275             entry[6][ei].asid = 1;
 276             entry[6][ei].attr = 2;
 277         }
 278     }
 279 }
 280
 281 static void reset_tlb_region_way0(CPUState *env,
 282         xtensa_tlb_entry entry[][MAX_TLB_WAY_SIZE])
 283 {
 284     unsigned ei;
 285
 286     for (ei = 0; ei < 8; ++ei) {
 287         entry[0][ei].vaddr = ei << 29;
 288         entry[0][ei].paddr = ei << 29;
 289         entry[0][ei].asid = 1;
 290         entry[0][ei].attr = 2;
 291         entry[0][ei].variable = true;
 292     }
 293 }
 294
 295 static void reset_mmu(CPUState *env)
 296 {
 297     if (xtensa_option_enabled(env->config, XTENSA_OPTION_MMU)) {
 298         env->sregs[RASID] = 0x04030201;
 299         env->sregs[ITLBCFG] = 0;
 300         env->sregs[DTLBCFG] = 0;
 301         env->autorefill_idx = 0;
 302         reset_tlb_mmu_all_ways(env, &env->config->itlb, env->itlb);
 303         reset_tlb_mmu_all_ways(env, &env->config->dtlb, env->dtlb);
 304         reset_tlb_mmu_ways56(env, &env->config->itlb, env->itlb);
 305         reset_tlb_mmu_ways56(env, &env->config->dtlb, env->dtlb);
 306     } else {
 307         reset_tlb_region_way0(env, env->itlb);
 308         reset_tlb_region_way0(env, env->dtlb);
 309     }
 310 }
 311
 312 static unsigned get_ring(const CPUState *env, uint8_t asid)
 313 {
 314     unsigned i;
 315     for (i = 0; i < 4; ++i) {
 316         if (((env->sregs[RASID] >> i * 8) & 0xff) == asid) {
 317             return i;
 318         }
 319     }
 320     return 0xff;
 321 }
 322
 323 /*!
 324  * Lookup xtensa TLB for the given virtual address.
 325  * See ISA, 4.6.2.2
 326  *
 327  * \param pwi: [out] way index
 328  * \param pei: [out] entry index
 329  * \param pring: [out] access ring
 330  * \return 0 if ok, exception cause code otherwise
 331  */
 332 int xtensa_tlb_lookup(const CPUState *env, uint32_t addr, bool dtlb,
 333         uint32_t *pwi, uint32_t *pei, uint8_t *pring)
 334 {
 335     const xtensa_tlb *tlb = dtlb ?
 336         &env->config->dtlb : &env->config->itlb;
 337     const xtensa_tlb_entry (*entry)[MAX_TLB_WAY_SIZE] = dtlb ?
 338         env->dtlb : env->itlb;
 339
 340     int nhits = 0;
 341     unsigned wi;
 342
 343     for (wi = 0; wi < tlb->nways; ++wi) {
 344         uint32_t vpn;
 345         uint32_t ei;
 346         split_tlb_entry_spec_way(env, addr, dtlb, &vpn, wi, &ei);
 347         if (entry[wi][ei].vaddr == vpn && entry[wi][ei].asid) {
 348             unsigned ring = get_ring(env, entry[wi][ei].asid);
 349             if (ring < 4) {
 350                 if (++nhits > 1) {
 351                     return dtlb ?
 352                         LOAD_STORE_TLB_MULTI_HIT_CAUSE :
 353                         INST_TLB_MULTI_HIT_CAUSE;
 354                 }
 355                 *pwi = wi;
 356                 *pei = ei;
 357                 *pring = ring;
 358             }
 359         }
 360     }
 361     return nhits ? 0 :
 362         (dtlb ? LOAD_STORE_TLB_MISS_CAUSE : INST_TLB_MISS_CAUSE);
 363 }
 364
 365 /*!
 366  * Convert MMU ATTR to PAGE_{READ,WRITE,EXEC} mask.
 367  * See ISA, 4.6.5.10
 368  */
 369 static unsigned mmu_attr_to_access(uint32_t attr)
 370 {
 371     unsigned access = 0;
 372     if (attr < 12) {
 373         access |= PAGE_READ;
 374         if (attr & 0x1) {
 375             access |= PAGE_EXEC;
 376         }
 377         if (attr & 0x2) {
 378             access |= PAGE_WRITE;
 379         }
 380     } else if (attr == 13) {
 381         access |= PAGE_READ | PAGE_WRITE;
 382     }
 383     return access;
 384 }
 385
 386 /*!
 387  * Convert region protection ATTR to PAGE_{READ,WRITE,EXEC} mask.
 388  * See ISA, 4.6.3.3
 389  */
 390 static unsigned region_attr_to_access(uint32_t attr)
 391 {
 392     unsigned access = 0;
 393     if ((attr < 6 && attr != 3) || attr == 14) {
 394         access |= PAGE_READ | PAGE_WRITE;
 395     }
 396     if (attr > 0 && attr < 6) {
 397         access |= PAGE_EXEC;
 398     }
 399     return access;
 400 }
 401
 402 static bool is_access_granted(unsigned access, int is_write)
 403 {
 404     switch (is_write) {
 405     case 0:
 406         return access & PAGE_READ;
 407
 408     case 1:
 409         return access & PAGE_WRITE;
 410
 411     case 2:
 412         return access & PAGE_EXEC;
 413
 414     default:
 415         return 0;
 416     }
 417 }
 418
 419 static int autorefill_mmu(CPUState *env, uint32_t vaddr, bool dtlb,
 420         uint32_t *wi, uint32_t *ei, uint8_t *ring);
 421
 422 static int get_physical_addr_mmu(CPUState *env,
 423         uint32_t vaddr, int is_write, int mmu_idx,
 424         uint32_t *paddr, uint32_t *page_size, unsigned *access)
 425 {
 426     bool dtlb = is_write != 2;
 427     uint32_t wi;
 428     uint32_t ei;
 429     uint8_t ring;
 430     int ret = xtensa_tlb_lookup(env, vaddr, dtlb, &wi, &ei, &ring);
 431
 432     if ((ret == INST_TLB_MISS_CAUSE || ret == LOAD_STORE_TLB_MISS_CAUSE) &&
 433             (mmu_idx != 0 || ((vaddr ^ env->sregs[PTEVADDR]) & 0xffc00000)) &&
 434             autorefill_mmu(env, vaddr, dtlb, &wi, &ei, &ring) == 0) {
 435         ret = 0;
 436     }
 437     if (ret != 0) {
 438         return ret;
 439     }
 440
 441     const xtensa_tlb_entry *entry =
 442         xtensa_tlb_get_entry(env, dtlb, wi, ei);
 443
 444     if (ring < mmu_idx) {
 445         return dtlb ?
 446             LOAD_STORE_PRIVILEGE_CAUSE :
 447             INST_FETCH_PRIVILEGE_CAUSE;
 448     }
 449
 450     *access = mmu_attr_to_access(entry->attr);
 451     if (!is_access_granted(*access, is_write)) {
 452         return dtlb ?
 453             (is_write ?
 454              STORE_PROHIBITED_CAUSE :
 455              LOAD_PROHIBITED_CAUSE) :
 456             INST_FETCH_PROHIBITED_CAUSE;
 457     }
 458
 459     *paddr = entry->paddr | (vaddr & ~xtensa_tlb_get_addr_mask(env, dtlb, wi));
 460     *page_size = ~xtensa_tlb_get_addr_mask(env, dtlb, wi) + 1;
 461
 462     return 0;
 463 }
 464
 465 static int autorefill_mmu(CPUState *env, uint32_t vaddr, bool dtlb,
 466         uint32_t *wi, uint32_t *ei, uint8_t *ring)
 467 {
 468     uint32_t paddr;
 469     uint32_t page_size;
 470     unsigned access;
 471     uint32_t pt_vaddr =
 472         (env->sregs[PTEVADDR] | (vaddr >> 10)) & 0xfffffffc;
 473     int ret = get_physical_addr_mmu(env, pt_vaddr, 0, 0,
 474             &paddr, &page_size, &access);
 475
 476     qemu_log("%s: trying autorefill(%08x) -> %08x\n", __func__,
 477             vaddr, ret ? ~0 : paddr);
 478
 479     if (ret == 0) {
 480         uint32_t vpn;
 481         uint32_t pte = ldl_phys(paddr);
 482
 483         *ring = (pte >> 4) & 0x3;
 484         *wi = (++env->autorefill_idx) & 0x3;
 485         split_tlb_entry_spec_way(env, vaddr, dtlb, &vpn, *wi, ei);
 486         xtensa_tlb_set_entry(env, dtlb, *wi, *ei, vpn, pte);
 487         qemu_log("%s: autorefill(%08x): %08x -> %08x\n",
 488                 __func__, vaddr, vpn, pte);
 489     }
 490     return ret;
 491 }
 492
 493 static int get_physical_addr_region(CPUState *env,
 494         uint32_t vaddr, int is_write, int mmu_idx,
 495         uint32_t *paddr, uint32_t *page_size, unsigned *access)
 496 {
 497     bool dtlb = is_write != 2;
 498     uint32_t wi = 0;
 499     uint32_t ei = (vaddr >> 29) & 0x7;
 500     const xtensa_tlb_entry *entry =
 501         xtensa_tlb_get_entry(env, dtlb, wi, ei);
 502
 503     *access = region_attr_to_access(entry->attr);
 504     if (!is_access_granted(*access, is_write)) {
 505         return dtlb ?
 506             (is_write ?
 507              STORE_PROHIBITED_CAUSE :
 508              LOAD_PROHIBITED_CAUSE) :
 509             INST_FETCH_PROHIBITED_CAUSE;
 510     }
 511
 512     *paddr = entry->paddr | (vaddr & ~REGION_PAGE_MASK);
 513     *page_size = ~REGION_PAGE_MASK + 1;
 514
 515     return 0;
 516 }
 517
 518 /*!
 519  * Convert virtual address to physical addr.
 520  * MMU may issue pagewalk and change xtensa autorefill TLB way entry.
 521  *
 522  * \return 0 if ok, exception cause code otherwise
 523  */
 524 int xtensa_get_physical_addr(CPUState *env,
 525         uint32_t vaddr, int is_write, int mmu_idx,
 526         uint32_t *paddr, uint32_t *page_size, unsigned *access)
 527 {
 528     if (xtensa_option_enabled(env->config, XTENSA_OPTION_MMU)) {
 529         return get_physical_addr_mmu(env, vaddr, is_write, mmu_idx,
 530                 paddr, page_size, access);
 531     } else if (xtensa_option_bits_enabled(env->config,
 532                 XTENSA_OPTION_BIT(XTENSA_OPTION_REGION_PROTECTION) |
 533                 XTENSA_OPTION_BIT(XTENSA_OPTION_REGION_TRANSLATION))) {
 534         return get_physical_addr_region(env, vaddr, is_write, mmu_idx,
 535                 paddr, page_size, access);
 536     } else {
 537         *paddr = vaddr;
 538         *page_size = TARGET_PAGE_SIZE;
 539         *access = PAGE_READ | PAGE_WRITE | PAGE_EXEC;
 540         return 0;
 541     }
 542 }