target/riscv/csr.c

   1 /*
   2  * RISC-V Control and Status Registers.
   3  *
   4  * Copyright (c) 2016-2017 Sagar Karandikar, sagark@eecs.berkeley.edu
   5  * Copyright (c) 2017-2018 SiFive, Inc.
   6  *
   7  * This program is free software; you can redistribute it and/or modify it
   8  * under the terms and conditions of the GNU General Public License,
   9  * version 2 or later, as published by the Free Software Foundation.
  10  *
  11  * This program is distributed in the hope it will be useful, but WITHOUT
  12  * ANY WARRANTY; without even the implied warranty of MERCHANTABILITY or
  13  * FITNESS FOR A PARTICULAR PURPOSE.  See the GNU General Public License for
  14  * more details.
  15  *
  16  * You should have received a copy of the GNU General Public License along with
  17  * this program.  If not, see <http://www.gnu.org/licenses/>.
  18  */
  19
  20 #include "qemu/osdep.h"
  21 #include "qemu/log.h"
  22 #include "cpu.h"
  23 #include "qemu/main-loop.h"
  24 #include "exec/exec-all.h"
  25
  26 /* CSR function table */
  27 static riscv_csr_operations csr_ops[];
  28
  29 /* CSR function table constants */
  30 enum {
  31     CSR_TABLE_SIZE = 0x1000
  32 };
  33
  34 /* CSR function table public API */
  35 void riscv_get_csr_ops(int csrno, riscv_csr_operations *ops)
  36 {
  37     *ops = csr_ops[csrno & (CSR_TABLE_SIZE - 1)];
  38 }
  39
  40 void riscv_set_csr_ops(int csrno, riscv_csr_operations *ops)
  41 {
  42     csr_ops[csrno & (CSR_TABLE_SIZE - 1)] = *ops;
  43 }
  44
  45 /* Predicates */
  46 static int fs(CPURISCVState *env, int csrno)
  47 {
  48 #if !defined(CONFIG_USER_ONLY)
  49     if (!env->debugger && !riscv_cpu_fp_enabled(env)) {
  50         return -1;
  51     }
  52 #endif
  53     return 0;
  54 }
  55
  56 static int ctr(CPURISCVState *env, int csrno)
  57 {
  58 #if !defined(CONFIG_USER_ONLY)
  59     CPUState *cs = env_cpu(env);
  60     RISCVCPU *cpu = RISCV_CPU(cs);
  61     uint32_t ctr_en = ~0u;
  62
  63     if (!cpu->cfg.ext_counters) {
  64         /* The Counters extensions is not enabled */
  65         return -1;
  66     }
  67
  68     /*
  69      * The counters are always enabled at run time on newer priv specs, as the
  70      * CSR has changed from controlling that the counters can be read to
  71      * controlling that the counters increment.
  72      */
  73     if (env->priv_ver > PRIV_VERSION_1_09_1) {
  74         return 0;
  75     }
  76
  77     if (env->priv < PRV_M) {
  78         ctr_en &= env->mcounteren;
  79     }
  80     if (env->priv < PRV_S) {
  81         ctr_en &= env->scounteren;
  82     }
  83     if (!(ctr_en & (1u << (csrno & 31)))) {
  84         return -1;
  85     }
  86 #endif
  87     return 0;
  88 }
  89
  90 #if !defined(CONFIG_USER_ONLY)
  91 static int any(CPURISCVState *env, int csrno)
  92 {
  93     return 0;
  94 }
  95
  96 static int smode(CPURISCVState *env, int csrno)
  97 {
  98     return -!riscv_has_ext(env, RVS);
  99 }
 100
 101 static int pmp(CPURISCVState *env, int csrno)
 102 {
 103     return -!riscv_feature(env, RISCV_FEATURE_PMP);
 104 }
 105 #endif
 106
 107 /* User Floating-Point CSRs */
 108 static int read_fflags(CPURISCVState *env, int csrno, target_ulong *val)
 109 {
 110 #if !defined(CONFIG_USER_ONLY)
 111     if (!env->debugger && !riscv_cpu_fp_enabled(env)) {
 112         return -1;
 113     }
 114 #endif
 115     *val = riscv_cpu_get_fflags(env);
 116     return 0;
 117 }
 118
 119 static int write_fflags(CPURISCVState *env, int csrno, target_ulong val)
 120 {
 121 #if !defined(CONFIG_USER_ONLY)
 122     if (!env->debugger && !riscv_cpu_fp_enabled(env)) {
 123         return -1;
 124     }
 125     env->mstatus |= MSTATUS_FS;
 126 #endif
 127     riscv_cpu_set_fflags(env, val & (FSR_AEXC >> FSR_AEXC_SHIFT));
 128     return 0;
 129 }
 130
 131 static int read_frm(CPURISCVState *env, int csrno, target_ulong *val)
 132 {
 133 #if !defined(CONFIG_USER_ONLY)
 134     if (!env->debugger && !riscv_cpu_fp_enabled(env)) {
 135         return -1;
 136     }
 137 #endif
 138     *val = env->frm;
 139     return 0;
 140 }
 141
 142 static int write_frm(CPURISCVState *env, int csrno, target_ulong val)
 143 {
 144 #if !defined(CONFIG_USER_ONLY)
 145     if (!env->debugger && !riscv_cpu_fp_enabled(env)) {
 146         return -1;
 147     }
 148     env->mstatus |= MSTATUS_FS;
 149 #endif
 150     env->frm = val & (FSR_RD >> FSR_RD_SHIFT);
 151     return 0;
 152 }
 153
 154 static int read_fcsr(CPURISCVState *env, int csrno, target_ulong *val)
 155 {
 156 #if !defined(CONFIG_USER_ONLY)
 157     if (!env->debugger && !riscv_cpu_fp_enabled(env)) {
 158         return -1;
 159     }
 160 #endif
 161     *val = (riscv_cpu_get_fflags(env) << FSR_AEXC_SHIFT)
 162         | (env->frm << FSR_RD_SHIFT);
 163     return 0;
 164 }
 165
 166 static int write_fcsr(CPURISCVState *env, int csrno, target_ulong val)
 167 {
 168 #if !defined(CONFIG_USER_ONLY)
 169     if (!env->debugger && !riscv_cpu_fp_enabled(env)) {
 170         return -1;
 171     }
 172     env->mstatus |= MSTATUS_FS;
 173 #endif
 174     env->frm = (val & FSR_RD) >> FSR_RD_SHIFT;
 175     riscv_cpu_set_fflags(env, (val & FSR_AEXC) >> FSR_AEXC_SHIFT);
 176     return 0;
 177 }
 178
 179 /* User Timers and Counters */
 180 static int read_instret(CPURISCVState *env, int csrno, target_ulong *val)
 181 {
 182 #if !defined(CONFIG_USER_ONLY)
 183     if (use_icount) {
 184         *val = cpu_get_icount();
 185     } else {
 186         *val = cpu_get_host_ticks();
 187     }
 188 #else
 189     *val = cpu_get_host_ticks();
 190 #endif
 191     return 0;
 192 }
 193
 194 #if defined(TARGET_RISCV32)
 195 static int read_instreth(CPURISCVState *env, int csrno, target_ulong *val)
 196 {
 197 #if !defined(CONFIG_USER_ONLY)
 198     if (use_icount) {
 199         *val = cpu_get_icount() >> 32;
 200     } else {
 201         *val = cpu_get_host_ticks() >> 32;
 202     }
 203 #else
 204     *val = cpu_get_host_ticks() >> 32;
 205 #endif
 206     return 0;
 207 }
 208 #endif /* TARGET_RISCV32 */
 209
 210 #if defined(CONFIG_USER_ONLY)
 211 static int read_time(CPURISCVState *env, int csrno, target_ulong *val)
 212 {
 213     *val = cpu_get_host_ticks();
 214     return 0;
 215 }
 216
 217 #if defined(TARGET_RISCV32)
 218 static int read_timeh(CPURISCVState *env, int csrno, target_ulong *val)
 219 {
 220     *val = cpu_get_host_ticks() >> 32;
 221     return 0;
 222 }
 223 #endif
 224
 225 #else /* CONFIG_USER_ONLY */
 226
 227 /* Machine constants */
 228
 229 #define M_MODE_INTERRUPTS (MIP_MSIP | MIP_MTIP | MIP_MEIP)
 230 #define S_MODE_INTERRUPTS (MIP_SSIP | MIP_STIP | MIP_SEIP)
 231
 232 static const target_ulong delegable_ints = S_MODE_INTERRUPTS;
 233 static const target_ulong all_ints = M_MODE_INTERRUPTS | S_MODE_INTERRUPTS;
 234 static const target_ulong delegable_excps =
 235     (1ULL << (RISCV_EXCP_INST_ADDR_MIS)) |
 236     (1ULL << (RISCV_EXCP_INST_ACCESS_FAULT)) |
 237     (1ULL << (RISCV_EXCP_ILLEGAL_INST)) |
 238     (1ULL << (RISCV_EXCP_BREAKPOINT)) |
 239     (1ULL << (RISCV_EXCP_LOAD_ADDR_MIS)) |
 240     (1ULL << (RISCV_EXCP_LOAD_ACCESS_FAULT)) |
 241     (1ULL << (RISCV_EXCP_STORE_AMO_ADDR_MIS)) |
 242     (1ULL << (RISCV_EXCP_STORE_AMO_ACCESS_FAULT)) |
 243     (1ULL << (RISCV_EXCP_U_ECALL)) |
 244     (1ULL << (RISCV_EXCP_S_ECALL)) |
 245     (1ULL << (RISCV_EXCP_H_ECALL)) |
 246     (1ULL << (RISCV_EXCP_M_ECALL)) |
 247     (1ULL << (RISCV_EXCP_INST_PAGE_FAULT)) |
 248     (1ULL << (RISCV_EXCP_LOAD_PAGE_FAULT)) |
 249     (1ULL << (RISCV_EXCP_STORE_PAGE_FAULT));
 250 static const target_ulong sstatus_v1_9_mask = SSTATUS_SIE | SSTATUS_SPIE |
 251     SSTATUS_UIE | SSTATUS_UPIE | SSTATUS_SPP | SSTATUS_FS | SSTATUS_XS |
 252     SSTATUS_SUM | SSTATUS_SD;
 253 static const target_ulong sstatus_v1_10_mask = SSTATUS_SIE | SSTATUS_SPIE |
 254     SSTATUS_UIE | SSTATUS_UPIE | SSTATUS_SPP | SSTATUS_FS | SSTATUS_XS |
 255     SSTATUS_SUM | SSTATUS_MXR | SSTATUS_SD;
 256 static const target_ulong sip_writable_mask = SIP_SSIP | MIP_USIP | MIP_UEIP;
 257
 258 #if defined(TARGET_RISCV32)
 259 static const char valid_vm_1_09[16] = {
 260     [VM_1_09_MBARE] = 1,
 261     [VM_1_09_SV32] = 1,
 262 };
 263 static const char valid_vm_1_10[16] = {
 264     [VM_1_10_MBARE] = 1,
 265     [VM_1_10_SV32] = 1
 266 };
 267 #elif defined(TARGET_RISCV64)
 268 static const char valid_vm_1_09[16] = {
 269     [VM_1_09_MBARE] = 1,
 270     [VM_1_09_SV39] = 1,
 271     [VM_1_09_SV48] = 1,
 272 };
 273 static const char valid_vm_1_10[16] = {
 274     [VM_1_10_MBARE] = 1,
 275     [VM_1_10_SV39] = 1,
 276     [VM_1_10_SV48] = 1,
 277     [VM_1_10_SV57] = 1
 278 };
 279 #endif /* CONFIG_USER_ONLY */
 280
 281 /* Machine Information Registers */
 282 static int read_zero(CPURISCVState *env, int csrno, target_ulong *val)
 283 {
 284     return *val = 0;
 285 }
 286
 287 static int read_mhartid(CPURISCVState *env, int csrno, target_ulong *val)
 288 {
 289     *val = env->mhartid;
 290     return 0;
 291 }
 292
 293 /* Machine Trap Setup */
 294 static int read_mstatus(CPURISCVState *env, int csrno, target_ulong *val)
 295 {
 296     *val = env->mstatus;
 297     return 0;
 298 }
 299
 300 static int validate_vm(CPURISCVState *env, target_ulong vm)
 301 {
 302     return (env->priv_ver >= PRIV_VERSION_1_10_0) ?
 303         valid_vm_1_10[vm & 0xf] : valid_vm_1_09[vm & 0xf];
 304 }
 305
 306 static int write_mstatus(CPURISCVState *env, int csrno, target_ulong val)
 307 {
 308     target_ulong mstatus = env->mstatus;
 309     target_ulong mask = 0;
 310     int dirty;
 311
 312     /* flush tlb on mstatus fields that affect VM */
 313     if (env->priv_ver <= PRIV_VERSION_1_09_1) {
 314         if ((val ^ mstatus) & (MSTATUS_MXR | MSTATUS_MPP |
 315                 MSTATUS_MPRV | MSTATUS_SUM | MSTATUS_VM)) {
 316             tlb_flush(env_cpu(env));
 317         }
 318         mask = MSTATUS_SIE | MSTATUS_SPIE | MSTATUS_MIE | MSTATUS_MPIE |
 319             MSTATUS_SPP | MSTATUS_FS | MSTATUS_MPRV | MSTATUS_SUM |
 320             MSTATUS_MPP | MSTATUS_MXR |
 321             (validate_vm(env, get_field(val, MSTATUS_VM)) ?
 322                 MSTATUS_VM : 0);
 323     }
 324     if (env->priv_ver >= PRIV_VERSION_1_10_0) {
 325         if ((val ^ mstatus) & (MSTATUS_MXR | MSTATUS_MPP | MSTATUS_MPV |
 326                 MSTATUS_MPRV | MSTATUS_SUM)) {
 327             tlb_flush(env_cpu(env));
 328         }
 329         mask = MSTATUS_SIE | MSTATUS_SPIE | MSTATUS_MIE | MSTATUS_MPIE |
 330             MSTATUS_SPP | MSTATUS_FS | MSTATUS_MPRV | MSTATUS_SUM |
 331             MSTATUS_MPP | MSTATUS_MXR | MSTATUS_TVM | MSTATUS_TSR |
 332             MSTATUS_TW;
 333 #if defined(TARGET_RISCV64)
 334             /*
 335              * RV32: MPV and MTL are not in mstatus. The current plan is to
 336              * add them to mstatush. For now, we just don't support it.
 337              */
 338             mask |= MSTATUS_MTL | MSTATUS_MPV;
 339 #endif
 340     }
 341
 342     mstatus = (mstatus & ~mask) | (val & mask);
 343
 344     dirty = (riscv_cpu_fp_enabled(env) &&
 345              ((mstatus & MSTATUS_FS) == MSTATUS_FS)) |
 346             ((mstatus & MSTATUS_XS) == MSTATUS_XS);
 347     mstatus = set_field(mstatus, MSTATUS_SD, dirty);
 348     env->mstatus = mstatus;
 349
 350     return 0;
 351 }
 352
 353 static int read_misa(CPURISCVState *env, int csrno, target_ulong *val)
 354 {
 355     *val = env->misa;
 356     return 0;
 357 }
 358
 359 static int write_misa(CPURISCVState *env, int csrno, target_ulong val)
 360 {
 361     if (!riscv_feature(env, RISCV_FEATURE_MISA)) {
 362         /* drop write to misa */
 363         return 0;
 364     }
 365
 366     /* 'I' or 'E' must be present */
 367     if (!(val & (RVI | RVE))) {
 368         /* It is not, drop write to misa */
 369         return 0;
 370     }
 371
 372     /* 'E' excludes all other extensions */
 373     if (val & RVE) {
 374         /* when we support 'E' we can do "val = RVE;" however
 375          * for now we just drop writes if 'E' is present.
 376          */
 377         return 0;
 378     }
 379
 380     /* Mask extensions that are not supported by this hart */
 381     val &= env->misa_mask;
 382
 383     /* Mask extensions that are not supported by QEMU */
 384     val &= (RVI | RVE | RVM | RVA | RVF | RVD | RVC | RVS | RVU);
 385
 386     /* 'D' depends on 'F', so clear 'D' if 'F' is not present */
 387     if ((val & RVD) && !(val & RVF)) {
 388         val &= ~RVD;
 389     }
 390
 391     /* Suppress 'C' if next instruction is not aligned
 392      * TODO: this should check next_pc
 393      */
 394     if ((val & RVC) && (GETPC() & ~3) != 0) {
 395         val &= ~RVC;
 396     }
 397
 398     /* misa.MXL writes are not supported by QEMU */
 399     val = (env->misa & MISA_MXL) | (val & ~MISA_MXL);
 400
 401     /* flush translation cache */
 402     if (val != env->misa) {
 403         tb_flush(env_cpu(env));
 404     }
 405
 406     env->misa = val;
 407
 408     return 0;
 409 }
 410
 411 static int read_medeleg(CPURISCVState *env, int csrno, target_ulong *val)
 412 {
 413     *val = env->medeleg;
 414     return 0;
 415 }
 416
 417 static int write_medeleg(CPURISCVState *env, int csrno, target_ulong val)
 418 {
 419     env->medeleg = (env->medeleg & ~delegable_excps) | (val & delegable_excps);
 420     return 0;
 421 }
 422
 423 static int read_mideleg(CPURISCVState *env, int csrno, target_ulong *val)
 424 {
 425     *val = env->mideleg;
 426     return 0;
 427 }
 428
 429 static int write_mideleg(CPURISCVState *env, int csrno, target_ulong val)
 430 {
 431     env->mideleg = (env->mideleg & ~delegable_ints) | (val & delegable_ints);
 432     return 0;
 433 }
 434
 435 static int read_mie(CPURISCVState *env, int csrno, target_ulong *val)
 436 {
 437     *val = env->mie;
 438     return 0;
 439 }
 440
 441 static int write_mie(CPURISCVState *env, int csrno, target_ulong val)
 442 {
 443     env->mie = (env->mie & ~all_ints) | (val & all_ints);
 444     return 0;
 445 }
 446
 447 static int read_mtvec(CPURISCVState *env, int csrno, target_ulong *val)
 448 {
 449     *val = env->mtvec;
 450     return 0;
 451 }
 452
 453 static int write_mtvec(CPURISCVState *env, int csrno, target_ulong val)
 454 {
 455     /* bits [1:0] encode mode; 0 = direct, 1 = vectored, 2 >= reserved */
 456     if ((val & 3) < 2) {
 457         env->mtvec = val;
 458     } else {
 459         qemu_log_mask(LOG_UNIMP, "CSR_MTVEC: reserved mode not supported\n");
 460     }
 461     return 0;
 462 }
 463
 464 static int read_mcounteren(CPURISCVState *env, int csrno, target_ulong *val)
 465 {
 466     if (env->priv_ver < PRIV_VERSION_1_10_0) {
 467         return -1;
 468     }
 469     *val = env->mcounteren;
 470     return 0;
 471 }
 472
 473 static int write_mcounteren(CPURISCVState *env, int csrno, target_ulong val)
 474 {
 475     if (env->priv_ver < PRIV_VERSION_1_10_0) {
 476         return -1;
 477     }
 478     env->mcounteren = val;
 479     return 0;
 480 }
 481
 482 /* This regiser is replaced with CSR_MCOUNTINHIBIT in 1.11.0 */
 483 static int read_mscounteren(CPURISCVState *env, int csrno, target_ulong *val)
 484 {
 485     if (env->priv_ver > PRIV_VERSION_1_09_1
 486         && env->priv_ver < PRIV_VERSION_1_11_0) {
 487         return -1;
 488     }
 489     *val = env->mcounteren;
 490     return 0;
 491 }
 492
 493 /* This regiser is replaced with CSR_MCOUNTINHIBIT in 1.11.0 */
 494 static int write_mscounteren(CPURISCVState *env, int csrno, target_ulong val)
 495 {
 496     if (env->priv_ver > PRIV_VERSION_1_09_1
 497         && env->priv_ver < PRIV_VERSION_1_11_0) {
 498         return -1;
 499     }
 500     env->mcounteren = val;
 501     return 0;
 502 }
 503
 504 static int read_mucounteren(CPURISCVState *env, int csrno, target_ulong *val)
 505 {
 506     if (env->priv_ver > PRIV_VERSION_1_09_1) {
 507         return -1;
 508     }
 509     *val = env->scounteren;
 510     return 0;
 511 }
 512
 513 static int write_mucounteren(CPURISCVState *env, int csrno, target_ulong val)
 514 {
 515     if (env->priv_ver > PRIV_VERSION_1_09_1) {
 516         return -1;
 517     }
 518     env->scounteren = val;
 519     return 0;
 520 }
 521
 522 /* Machine Trap Handling */
 523 static int read_mscratch(CPURISCVState *env, int csrno, target_ulong *val)
 524 {
 525     *val = env->mscratch;
 526     return 0;
 527 }
 528
 529 static int write_mscratch(CPURISCVState *env, int csrno, target_ulong val)
 530 {
 531     env->mscratch = val;
 532     return 0;
 533 }
 534
 535 static int read_mepc(CPURISCVState *env, int csrno, target_ulong *val)
 536 {
 537     *val = env->mepc;
 538     return 0;
 539 }
 540
 541 static int write_mepc(CPURISCVState *env, int csrno, target_ulong val)
 542 {
 543     env->mepc = val;
 544     return 0;
 545 }
 546
 547 static int read_mcause(CPURISCVState *env, int csrno, target_ulong *val)
 548 {
 549     *val = env->mcause;
 550     return 0;
 551 }
 552
 553 static int write_mcause(CPURISCVState *env, int csrno, target_ulong val)
 554 {
 555     env->mcause = val;
 556     return 0;
 557 }
 558
 559 static int read_mbadaddr(CPURISCVState *env, int csrno, target_ulong *val)
 560 {
 561     *val = env->mbadaddr;
 562     return 0;
 563 }
 564
 565 static int write_mbadaddr(CPURISCVState *env, int csrno, target_ulong val)
 566 {
 567     env->mbadaddr = val;
 568     return 0;
 569 }
 570
 571 static int rmw_mip(CPURISCVState *env, int csrno, target_ulong *ret_value,
 572                    target_ulong new_value, target_ulong write_mask)
 573 {
 574     RISCVCPU *cpu = env_archcpu(env);
 575     /* Allow software control of delegable interrupts not claimed by hardware */
 576     target_ulong mask = write_mask & delegable_ints & ~env->miclaim;
 577     uint32_t old_mip;
 578
 579     if (mask) {
 580         old_mip = riscv_cpu_update_mip(cpu, mask, (new_value & mask));
 581     } else {
 582         old_mip = atomic_read(&env->mip);
 583     }
 584
 585     if (ret_value) {
 586         *ret_value = old_mip;
 587     }
 588
 589     return 0;
 590 }
 591
 592 /* Supervisor Trap Setup */
 593 static int read_sstatus(CPURISCVState *env, int csrno, target_ulong *val)
 594 {
 595     target_ulong mask = ((env->priv_ver >= PRIV_VERSION_1_10_0) ?
 596                          sstatus_v1_10_mask : sstatus_v1_9_mask);
 597     *val = env->mstatus & mask;
 598     return 0;
 599 }
 600
 601 static int write_sstatus(CPURISCVState *env, int csrno, target_ulong val)
 602 {
 603     target_ulong mask = ((env->priv_ver >= PRIV_VERSION_1_10_0) ?
 604                          sstatus_v1_10_mask : sstatus_v1_9_mask);
 605     target_ulong newval = (env->mstatus & ~mask) | (val & mask);
 606     return write_mstatus(env, CSR_MSTATUS, newval);
 607 }
 608
 609 static int read_sie(CPURISCVState *env, int csrno, target_ulong *val)
 610 {
 611     *val = env->mie & env->mideleg;
 612     return 0;
 613 }
 614
 615 static int write_sie(CPURISCVState *env, int csrno, target_ulong val)
 616 {
 617     target_ulong newval = (env->mie & ~env->mideleg) | (val & env->mideleg);
 618     return write_mie(env, CSR_MIE, newval);
 619 }
 620
 621 static int read_stvec(CPURISCVState *env, int csrno, target_ulong *val)
 622 {
 623     *val = env->stvec;
 624     return 0;
 625 }
 626
 627 static int write_stvec(CPURISCVState *env, int csrno, target_ulong val)
 628 {
 629     /* bits [1:0] encode mode; 0 = direct, 1 = vectored, 2 >= reserved */
 630     if ((val & 3) < 2) {
 631         env->stvec = val;
 632     } else {
 633         qemu_log_mask(LOG_UNIMP, "CSR_STVEC: reserved mode not supported\n");
 634     }
 635     return 0;
 636 }
 637
 638 static int read_scounteren(CPURISCVState *env, int csrno, target_ulong *val)
 639 {
 640     if (env->priv_ver < PRIV_VERSION_1_10_0) {
 641         return -1;
 642     }
 643     *val = env->scounteren;
 644     return 0;
 645 }
 646
 647 static int write_scounteren(CPURISCVState *env, int csrno, target_ulong val)
 648 {
 649     if (env->priv_ver < PRIV_VERSION_1_10_0) {
 650         return -1;
 651     }
 652     env->scounteren = val;
 653     return 0;
 654 }
 655
 656 /* Supervisor Trap Handling */
 657 static int read_sscratch(CPURISCVState *env, int csrno, target_ulong *val)
 658 {
 659     *val = env->sscratch;
 660     return 0;
 661 }
 662
 663 static int write_sscratch(CPURISCVState *env, int csrno, target_ulong val)
 664 {
 665     env->sscratch = val;
 666     return 0;
 667 }
 668
 669 static int read_sepc(CPURISCVState *env, int csrno, target_ulong *val)
 670 {
 671     *val = env->sepc;
 672     return 0;
 673 }
 674
 675 static int write_sepc(CPURISCVState *env, int csrno, target_ulong val)
 676 {
 677     env->sepc = val;
 678     return 0;
 679 }
 680
 681 static int read_scause(CPURISCVState *env, int csrno, target_ulong *val)
 682 {
 683     *val = env->scause;
 684     return 0;
 685 }
 686
 687 static int write_scause(CPURISCVState *env, int csrno, target_ulong val)
 688 {
 689     env->scause = val;
 690     return 0;
 691 }
 692
 693 static int read_sbadaddr(CPURISCVState *env, int csrno, target_ulong *val)
 694 {
 695     *val = env->sbadaddr;
 696     return 0;
 697 }
 698
 699 static int write_sbadaddr(CPURISCVState *env, int csrno, target_ulong val)
 700 {
 701     env->sbadaddr = val;
 702     return 0;
 703 }
 704
 705 static int rmw_sip(CPURISCVState *env, int csrno, target_ulong *ret_value,
 706                    target_ulong new_value, target_ulong write_mask)
 707 {
 708     int ret = rmw_mip(env, CSR_MSTATUS, ret_value, new_value,
 709                       write_mask & env->mideleg & sip_writable_mask);
 710     *ret_value &= env->mideleg;
 711     return ret;
 712 }
 713
 714 /* Supervisor Protection and Translation */
 715 static int read_satp(CPURISCVState *env, int csrno, target_ulong *val)
 716 {
 717     if (!riscv_feature(env, RISCV_FEATURE_MMU)) {
 718         *val = 0;
 719     } else if (env->priv_ver >= PRIV_VERSION_1_10_0) {
 720         if (env->priv == PRV_S && get_field(env->mstatus, MSTATUS_TVM)) {
 721             return -1;
 722         } else {
 723             *val = env->satp;
 724         }
 725     } else {
 726         *val = env->sptbr;
 727     }
 728     return 0;
 729 }
 730
 731 static int write_satp(CPURISCVState *env, int csrno, target_ulong val)
 732 {
 733     if (!riscv_feature(env, RISCV_FEATURE_MMU)) {
 734         return 0;
 735     }
 736     if (env->priv_ver <= PRIV_VERSION_1_09_1 && (val ^ env->sptbr)) {
 737         tlb_flush(env_cpu(env));
 738         env->sptbr = val & (((target_ulong)
 739             1 << (TARGET_PHYS_ADDR_SPACE_BITS - PGSHIFT)) - 1);
 740     }
 741     if (env->priv_ver >= PRIV_VERSION_1_10_0 &&
 742         validate_vm(env, get_field(val, SATP_MODE)) &&
 743         ((val ^ env->satp) & (SATP_MODE | SATP_ASID | SATP_PPN)))
 744     {
 745         if (env->priv == PRV_S && get_field(env->mstatus, MSTATUS_TVM)) {
 746             return -1;
 747         } else {
 748             if((val ^ env->satp) & SATP_ASID) {
 749                 tlb_flush(env_cpu(env));
 750             }
 751             env->satp = val;
 752         }
 753     }
 754     return 0;
 755 }
 756
 757 /* Physical Memory Protection */
 758 static int read_pmpcfg(CPURISCVState *env, int csrno, target_ulong *val)
 759 {
 760     *val = pmpcfg_csr_read(env, csrno - CSR_PMPCFG0);
 761     return 0;
 762 }
 763
 764 static int write_pmpcfg(CPURISCVState *env, int csrno, target_ulong val)
 765 {
 766     pmpcfg_csr_write(env, csrno - CSR_PMPCFG0, val);
 767     return 0;
 768 }
 769
 770 static int read_pmpaddr(CPURISCVState *env, int csrno, target_ulong *val)
 771 {
 772     *val = pmpaddr_csr_read(env, csrno - CSR_PMPADDR0);
 773     return 0;
 774 }
 775
 776 static int write_pmpaddr(CPURISCVState *env, int csrno, target_ulong val)
 777 {
 778     pmpaddr_csr_write(env, csrno - CSR_PMPADDR0, val);
 779     return 0;
 780 }
 781
 782 #endif
 783
 784 /*
 785  * riscv_csrrw - read and/or update control and status register
 786  *
 787  * csrr   <->  riscv_csrrw(env, csrno, ret_value, 0, 0);
 788  * csrrw  <->  riscv_csrrw(env, csrno, ret_value, value, -1);
 789  * csrrs  <->  riscv_csrrw(env, csrno, ret_value, -1, value);
 790  * csrrc  <->  riscv_csrrw(env, csrno, ret_value, 0, value);
 791  */
 792
 793 int riscv_csrrw(CPURISCVState *env, int csrno, target_ulong *ret_value,
 794                 target_ulong new_value, target_ulong write_mask)
 795 {
 796     int ret;
 797     target_ulong old_value;
 798     RISCVCPU *cpu = env_archcpu(env);
 799
 800     /* check privileges and return -1 if check fails */
 801 #if !defined(CONFIG_USER_ONLY)
 802     int csr_priv = get_field(csrno, 0x300);
 803     int read_only = get_field(csrno, 0xC00) == 3;
 804     if ((write_mask && read_only) || (env->priv < csr_priv)) {
 805         return -1;
 806     }
 807 #endif
 808
 809     /* ensure the CSR extension is enabled. */
 810     if (!cpu->cfg.ext_icsr) {
 811         return -1;
 812     }
 813
 814     /* check predicate */
 815     if (!csr_ops[csrno].predicate || csr_ops[csrno].predicate(env, csrno) < 0) {
 816         return -1;
 817     }
 818
 819     /* execute combined read/write operation if it exists */
 820     if (csr_ops[csrno].op) {
 821         return csr_ops[csrno].op(env, csrno, ret_value, new_value, write_mask);
 822     }
 823
 824     /* if no accessor exists then return failure */
 825     if (!csr_ops[csrno].read) {
 826         return -1;
 827     }
 828
 829     /* read old value */
 830     ret = csr_ops[csrno].read(env, csrno, &old_value);
 831     if (ret < 0) {
 832         return ret;
 833     }
 834
 835     /* write value if writable and write mask set, otherwise drop writes */
 836     if (write_mask) {
 837         new_value = (old_value & ~write_mask) | (new_value & write_mask);
 838         if (csr_ops[csrno].write) {
 839             ret = csr_ops[csrno].write(env, csrno, new_value);
 840             if (ret < 0) {
 841                 return ret;
 842             }
 843         }
 844     }
 845
 846     /* return old value */
 847     if (ret_value) {
 848         *ret_value = old_value;
 849     }
 850
 851     return 0;
 852 }
 853
 854 /*
 855  * Debugger support.  If not in user mode, set env->debugger before the
 856  * riscv_csrrw call and clear it after the call.
 857  */
 858 int riscv_csrrw_debug(CPURISCVState *env, int csrno, target_ulong *ret_value,
 859                 target_ulong new_value, target_ulong write_mask)
 860 {
 861     int ret;
 862 #if !defined(CONFIG_USER_ONLY)
 863     env->debugger = true;
 864 #endif
 865     ret = riscv_csrrw(env, csrno, ret_value, new_value, write_mask);
 866 #if !defined(CONFIG_USER_ONLY)
 867     env->debugger = false;
 868 #endif
 869     return ret;
 870 }
 871
 872 /* Control and Status Register function table */
 873 static riscv_csr_operations csr_ops[CSR_TABLE_SIZE] = {
 874     /* User Floating-Point CSRs */
 875     [CSR_FFLAGS] =              { fs,   read_fflags,      write_fflags      },
 876     [CSR_FRM] =                 { fs,   read_frm,         write_frm         },
 877     [CSR_FCSR] =                { fs,   read_fcsr,        write_fcsr        },
 878
 879     /* User Timers and Counters */
 880     [CSR_CYCLE] =               { ctr,  read_instret                        },
 881     [CSR_INSTRET] =             { ctr,  read_instret                        },
 882 #if defined(TARGET_RISCV32)
 883     [CSR_CYCLEH] =              { ctr,  read_instreth                       },
 884     [CSR_INSTRETH] =            { ctr,  read_instreth                       },
 885 #endif
 886
 887     /* User-level time CSRs are only available in linux-user
 888      * In privileged mode, the monitor emulates these CSRs */
 889 #if defined(CONFIG_USER_ONLY)
 890     [CSR_TIME] =                { ctr,  read_time                           },
 891 #if defined(TARGET_RISCV32)
 892     [CSR_TIMEH] =               { ctr,  read_timeh                          },
 893 #endif
 894 #endif
 895
 896 #if !defined(CONFIG_USER_ONLY)
 897     /* Machine Timers and Counters */
 898     [CSR_MCYCLE] =              { any,  read_instret                        },
 899     [CSR_MINSTRET] =            { any,  read_instret                        },
 900 #if defined(TARGET_RISCV32)
 901     [CSR_MCYCLEH] =             { any,  read_instreth                       },
 902     [CSR_MINSTRETH] =           { any,  read_instreth                       },
 903 #endif
 904
 905     /* Machine Information Registers */
 906     [CSR_MVENDORID] =           { any,  read_zero                           },
 907     [CSR_MARCHID] =             { any,  read_zero                           },
 908     [CSR_MIMPID] =              { any,  read_zero                           },
 909     [CSR_MHARTID] =             { any,  read_mhartid                        },
 910
 911     /* Machine Trap Setup */
 912     [CSR_MSTATUS] =             { any,  read_mstatus,     write_mstatus     },
 913     [CSR_MISA] =                { any,  read_misa,        write_misa        },
 914     [CSR_MIDELEG] =             { any,  read_mideleg,     write_mideleg     },
 915     [CSR_MEDELEG] =             { any,  read_medeleg,     write_medeleg     },
 916     [CSR_MIE] =                 { any,  read_mie,         write_mie         },
 917     [CSR_MTVEC] =               { any,  read_mtvec,       write_mtvec       },
 918     [CSR_MCOUNTEREN] =          { any,  read_mcounteren,  write_mcounteren  },
 919
 920     /* Legacy Counter Setup (priv v1.9.1) */
 921     [CSR_MUCOUNTEREN] =         { any,  read_mucounteren, write_mucounteren },
 922     [CSR_MSCOUNTEREN] =         { any,  read_mscounteren, write_mscounteren },
 923
 924     /* Machine Trap Handling */
 925     [CSR_MSCRATCH] =            { any,  read_mscratch,    write_mscratch    },
 926     [CSR_MEPC] =                { any,  read_mepc,        write_mepc        },
 927     [CSR_MCAUSE] =              { any,  read_mcause,      write_mcause      },
 928     [CSR_MBADADDR] =            { any,  read_mbadaddr,    write_mbadaddr    },
 929     [CSR_MIP] =                 { any,  NULL,     NULL,     rmw_mip         },
 930
 931     /* Supervisor Trap Setup */
 932     [CSR_SSTATUS] =             { smode, read_sstatus,     write_sstatus     },
 933     [CSR_SIE] =                 { smode, read_sie,         write_sie         },
 934     [CSR_STVEC] =               { smode, read_stvec,       write_stvec       },
 935     [CSR_SCOUNTEREN] =          { smode, read_scounteren,  write_scounteren  },
 936
 937     /* Supervisor Trap Handling */
 938     [CSR_SSCRATCH] =            { smode, read_sscratch,    write_sscratch    },
 939     [CSR_SEPC] =                { smode, read_sepc,        write_sepc        },
 940     [CSR_SCAUSE] =              { smode, read_scause,      write_scause      },
 941     [CSR_SBADADDR] =            { smode, read_sbadaddr,    write_sbadaddr    },
 942     [CSR_SIP] =                 { smode, NULL,     NULL,     rmw_sip         },
 943
 944     /* Supervisor Protection and Translation */
 945     [CSR_SATP] =                { smode, read_satp,        write_satp        },
 946
 947     /* Physical Memory Protection */
 948     [CSR_PMPCFG0  ... CSR_PMPADDR9] =  { pmp,   read_pmpcfg,  write_pmpcfg   },
 949     [CSR_PMPADDR0 ... CSR_PMPADDR15] = { pmp,   read_pmpaddr, write_pmpaddr  },
 950
 951     /* Performance Counters */
 952     [CSR_HPMCOUNTER3   ... CSR_HPMCOUNTER31] =    { ctr,  read_zero          },
 953     [CSR_MHPMCOUNTER3  ... CSR_MHPMCOUNTER31] =   { any,  read_zero          },
 954     [CSR_MHPMEVENT3    ... CSR_MHPMEVENT31] =     { any,  read_zero          },
 955 #if defined(TARGET_RISCV32)
 956     [CSR_HPMCOUNTER3H  ... CSR_HPMCOUNTER31H] =   { ctr,  read_zero          },
 957     [CSR_MHPMCOUNTER3H ... CSR_MHPMCOUNTER31H] =  { any,  read_zero          },
 958 #endif
 959 #endif /* !CONFIG_USER_ONLY */
 960 };