linux/arch/mips/kernel/traps.c
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   1/*
   2 * This file is subject to the terms and conditions of the GNU General Public
   3 * License.  See the file "COPYING" in the main directory of this archive
   4 * for more details.
   5 *
   6 * Copyright (C) 1994 - 1999, 2000, 01, 06 Ralf Baechle
   7 * Copyright (C) 1995, 1996 Paul M. Antoine
   8 * Copyright (C) 1998 Ulf Carlsson
   9 * Copyright (C) 1999 Silicon Graphics, Inc.
  10 * Kevin D. Kissell, kevink@mips.com and Carsten Langgaard, carstenl@mips.com
  11 * Copyright (C) 2002, 2003, 2004, 2005, 2007  Maciej W. Rozycki
  12 * Copyright (C) 2000, 2001, 2012 MIPS Technologies, Inc.  All rights reserved.
  13 */
  14#include <linux/bug.h>
  15#include <linux/compiler.h>
  16#include <linux/context_tracking.h>
  17#include <linux/kexec.h>
  18#include <linux/init.h>
  19#include <linux/kernel.h>
  20#include <linux/module.h>
  21#include <linux/mm.h>
  22#include <linux/sched.h>
  23#include <linux/smp.h>
  24#include <linux/spinlock.h>
  25#include <linux/kallsyms.h>
  26#include <linux/bootmem.h>
  27#include <linux/interrupt.h>
  28#include <linux/ptrace.h>
  29#include <linux/kgdb.h>
  30#include <linux/kdebug.h>
  31#include <linux/kprobes.h>
  32#include <linux/notifier.h>
  33#include <linux/kdb.h>
  34#include <linux/irq.h>
  35#include <linux/perf_event.h>
  36
  37#include <asm/bootinfo.h>
  38#include <asm/branch.h>
  39#include <asm/break.h>
  40#include <asm/cop2.h>
  41#include <asm/cpu.h>
  42#include <asm/cpu-type.h>
  43#include <asm/dsp.h>
  44#include <asm/fpu.h>
  45#include <asm/fpu_emulator.h>
  46#include <asm/idle.h>
  47#include <asm/mipsregs.h>
  48#include <asm/mipsmtregs.h>
  49#include <asm/module.h>
  50#include <asm/pgtable.h>
  51#include <asm/ptrace.h>
  52#include <asm/sections.h>
  53#include <asm/tlbdebug.h>
  54#include <asm/traps.h>
  55#include <asm/uaccess.h>
  56#include <asm/watch.h>
  57#include <asm/mmu_context.h>
  58#include <asm/types.h>
  59#include <asm/stacktrace.h>
  60#include <asm/uasm.h>
  61
  62extern void check_wait(void);
  63extern asmlinkage void rollback_handle_int(void);
  64extern asmlinkage void handle_int(void);
  65extern u32 handle_tlbl[];
  66extern u32 handle_tlbs[];
  67extern u32 handle_tlbm[];
  68extern asmlinkage void handle_adel(void);
  69extern asmlinkage void handle_ades(void);
  70extern asmlinkage void handle_ibe(void);
  71extern asmlinkage void handle_dbe(void);
  72extern asmlinkage void handle_sys(void);
  73extern asmlinkage void handle_bp(void);
  74extern asmlinkage void handle_ri(void);
  75extern asmlinkage void handle_ri_rdhwr_vivt(void);
  76extern asmlinkage void handle_ri_rdhwr(void);
  77extern asmlinkage void handle_cpu(void);
  78extern asmlinkage void handle_ov(void);
  79extern asmlinkage void handle_tr(void);
  80extern asmlinkage void handle_fpe(void);
  81extern asmlinkage void handle_mdmx(void);
  82extern asmlinkage void handle_watch(void);
  83extern asmlinkage void handle_mt(void);
  84extern asmlinkage void handle_dsp(void);
  85extern asmlinkage void handle_mcheck(void);
  86extern asmlinkage void handle_reserved(void);
  87
  88void (*board_be_init)(void);
  89int (*board_be_handler)(struct pt_regs *regs, int is_fixup);
  90void (*board_nmi_handler_setup)(void);
  91void (*board_ejtag_handler_setup)(void);
  92void (*board_bind_eic_interrupt)(int irq, int regset);
  93void (*board_ebase_setup)(void);
  94void(*board_cache_error_setup)(void);
  95
  96static void show_raw_backtrace(unsigned long reg29)
  97{
  98        unsigned long *sp = (unsigned long *)(reg29 & ~3);
  99        unsigned long addr;
 100
 101        printk("Call Trace:");
 102#ifdef CONFIG_KALLSYMS
 103        printk("\n");
 104#endif
 105        while (!kstack_end(sp)) {
 106                unsigned long __user *p =
 107                        (unsigned long __user *)(unsigned long)sp++;
 108                if (__get_user(addr, p)) {
 109                        printk(" (Bad stack address)");
 110                        break;
 111                }
 112                if (__kernel_text_address(addr))
 113                        print_ip_sym(addr);
 114        }
 115        printk("\n");
 116}
 117
 118#ifdef CONFIG_KALLSYMS
 119int raw_show_trace;
 120static int __init set_raw_show_trace(char *str)
 121{
 122        raw_show_trace = 1;
 123        return 1;
 124}
 125__setup("raw_show_trace", set_raw_show_trace);
 126#endif
 127
 128static void show_backtrace(struct task_struct *task, const struct pt_regs *regs)
 129{
 130        unsigned long sp = regs->regs[29];
 131        unsigned long ra = regs->regs[31];
 132        unsigned long pc = regs->cp0_epc;
 133
 134        if (!task)
 135                task = current;
 136
 137        if (raw_show_trace || !__kernel_text_address(pc)) {
 138                show_raw_backtrace(sp);
 139                return;
 140        }
 141        printk("Call Trace:\n");
 142        do {
 143                print_ip_sym(pc);
 144                pc = unwind_stack(task, &sp, pc, &ra);
 145        } while (pc);
 146        printk("\n");
 147}
 148
 149/*
 150 * This routine abuses get_user()/put_user() to reference pointers
 151 * with at least a bit of error checking ...
 152 */
 153static void show_stacktrace(struct task_struct *task,
 154        const struct pt_regs *regs)
 155{
 156        const int field = 2 * sizeof(unsigned long);
 157        long stackdata;
 158        int i;
 159        unsigned long __user *sp = (unsigned long __user *)regs->regs[29];
 160
 161        printk("Stack :");
 162        i = 0;
 163        while ((unsigned long) sp & (PAGE_SIZE - 1)) {
 164                if (i && ((i % (64 / field)) == 0))
 165                        printk("\n       ");
 166                if (i > 39) {
 167                        printk(" ...");
 168                        break;
 169                }
 170
 171                if (__get_user(stackdata, sp++)) {
 172                        printk(" (Bad stack address)");
 173                        break;
 174                }
 175
 176                printk(" %0*lx", field, stackdata);
 177                i++;
 178        }
 179        printk("\n");
 180        show_backtrace(task, regs);
 181}
 182
 183void show_stack(struct task_struct *task, unsigned long *sp)
 184{
 185        struct pt_regs regs;
 186        if (sp) {
 187                regs.regs[29] = (unsigned long)sp;
 188                regs.regs[31] = 0;
 189                regs.cp0_epc = 0;
 190        } else {
 191                if (task && task != current) {
 192                        regs.regs[29] = task->thread.reg29;
 193                        regs.regs[31] = 0;
 194                        regs.cp0_epc = task->thread.reg31;
 195#ifdef CONFIG_KGDB_KDB
 196                } else if (atomic_read(&kgdb_active) != -1 &&
 197                           kdb_current_regs) {
 198                        memcpy(&regs, kdb_current_regs, sizeof(regs));
 199#endif /* CONFIG_KGDB_KDB */
 200                } else {
 201                        prepare_frametrace(&regs);
 202                }
 203        }
 204        show_stacktrace(task, &regs);
 205}
 206
 207static void show_code(unsigned int __user *pc)
 208{
 209        long i;
 210        unsigned short __user *pc16 = NULL;
 211
 212        printk("\nCode:");
 213
 214        if ((unsigned long)pc & 1)
 215                pc16 = (unsigned short __user *)((unsigned long)pc & ~1);
 216        for(i = -3 ; i < 6 ; i++) {
 217                unsigned int insn;
 218                if (pc16 ? __get_user(insn, pc16 + i) : __get_user(insn, pc + i)) {
 219                        printk(" (Bad address in epc)\n");
 220                        break;
 221                }
 222                printk("%c%0*x%c", (i?' ':'<'), pc16 ? 4 : 8, insn, (i?' ':'>'));
 223        }
 224}
 225
 226static void __show_regs(const struct pt_regs *regs)
 227{
 228        const int field = 2 * sizeof(unsigned long);
 229        unsigned int cause = regs->cp0_cause;
 230        int i;
 231
 232        show_regs_print_info(KERN_DEFAULT);
 233
 234        /*
 235         * Saved main processor registers
 236         */
 237        for (i = 0; i < 32; ) {
 238                if ((i % 4) == 0)
 239                        printk("$%2d   :", i);
 240                if (i == 0)
 241                        printk(" %0*lx", field, 0UL);
 242                else if (i == 26 || i == 27)
 243                        printk(" %*s", field, "");
 244                else
 245                        printk(" %0*lx", field, regs->regs[i]);
 246
 247                i++;
 248                if ((i % 4) == 0)
 249                        printk("\n");
 250        }
 251
 252#ifdef CONFIG_CPU_HAS_SMARTMIPS
 253        printk("Acx    : %0*lx\n", field, regs->acx);
 254#endif
 255        printk("Hi    : %0*lx\n", field, regs->hi);
 256        printk("Lo    : %0*lx\n", field, regs->lo);
 257
 258        /*
 259         * Saved cp0 registers
 260         */
 261        printk("epc   : %0*lx %pS\n", field, regs->cp0_epc,
 262               (void *) regs->cp0_epc);
 263        printk("    %s\n", print_tainted());
 264        printk("ra    : %0*lx %pS\n", field, regs->regs[31],
 265               (void *) regs->regs[31]);
 266
 267        printk("Status: %08x    ", (uint32_t) regs->cp0_status);
 268
 269        if (cpu_has_3kex) {
 270                if (regs->cp0_status & ST0_KUO)
 271                        printk("KUo ");
 272                if (regs->cp0_status & ST0_IEO)
 273                        printk("IEo ");
 274                if (regs->cp0_status & ST0_KUP)
 275                        printk("KUp ");
 276                if (regs->cp0_status & ST0_IEP)
 277                        printk("IEp ");
 278                if (regs->cp0_status & ST0_KUC)
 279                        printk("KUc ");
 280                if (regs->cp0_status & ST0_IEC)
 281                        printk("IEc ");
 282        } else if (cpu_has_4kex) {
 283                if (regs->cp0_status & ST0_KX)
 284                        printk("KX ");
 285                if (regs->cp0_status & ST0_SX)
 286                        printk("SX ");
 287                if (regs->cp0_status & ST0_UX)
 288                        printk("UX ");
 289                switch (regs->cp0_status & ST0_KSU) {
 290                case KSU_USER:
 291                        printk("USER ");
 292                        break;
 293                case KSU_SUPERVISOR:
 294                        printk("SUPERVISOR ");
 295                        break;
 296                case KSU_KERNEL:
 297                        printk("KERNEL ");
 298                        break;
 299                default:
 300                        printk("BAD_MODE ");
 301                        break;
 302                }
 303                if (regs->cp0_status & ST0_ERL)
 304                        printk("ERL ");
 305                if (regs->cp0_status & ST0_EXL)
 306                        printk("EXL ");
 307                if (regs->cp0_status & ST0_IE)
 308                        printk("IE ");
 309        }
 310        printk("\n");
 311
 312        printk("Cause : %08x\n", cause);
 313
 314        cause = (cause & CAUSEF_EXCCODE) >> CAUSEB_EXCCODE;
 315        if (1 <= cause && cause <= 5)
 316                printk("BadVA : %0*lx\n", field, regs->cp0_badvaddr);
 317
 318        printk("PrId  : %08x (%s)\n", read_c0_prid(),
 319               cpu_name_string());
 320}
 321
 322/*
 323 * FIXME: really the generic show_regs should take a const pointer argument.
 324 */
 325void show_regs(struct pt_regs *regs)
 326{
 327        __show_regs((struct pt_regs *)regs);
 328}
 329
 330void show_registers(struct pt_regs *regs)
 331{
 332        const int field = 2 * sizeof(unsigned long);
 333
 334        __show_regs(regs);
 335        print_modules();
 336        printk("Process %s (pid: %d, threadinfo=%p, task=%p, tls=%0*lx)\n",
 337               current->comm, current->pid, current_thread_info(), current,
 338              field, current_thread_info()->tp_value);
 339        if (cpu_has_userlocal) {
 340                unsigned long tls;
 341
 342                tls = read_c0_userlocal();
 343                if (tls != current_thread_info()->tp_value)
 344                        printk("*HwTLS: %0*lx\n", field, tls);
 345        }
 346
 347        show_stacktrace(current, regs);
 348        show_code((unsigned int __user *) regs->cp0_epc);
 349        printk("\n");
 350}
 351
 352static int regs_to_trapnr(struct pt_regs *regs)
 353{
 354        return (regs->cp0_cause >> 2) & 0x1f;
 355}
 356
 357static DEFINE_RAW_SPINLOCK(die_lock);
 358
 359void __noreturn die(const char *str, struct pt_regs *regs)
 360{
 361        static int die_counter;
 362        int sig = SIGSEGV;
 363#ifdef CONFIG_MIPS_MT_SMTC
 364        unsigned long dvpret;
 365#endif /* CONFIG_MIPS_MT_SMTC */
 366
 367        oops_enter();
 368
 369        if (notify_die(DIE_OOPS, str, regs, 0, regs_to_trapnr(regs), SIGSEGV) == NOTIFY_STOP)
 370                sig = 0;
 371
 372        console_verbose();
 373        raw_spin_lock_irq(&die_lock);
 374#ifdef CONFIG_MIPS_MT_SMTC
 375        dvpret = dvpe();
 376#endif /* CONFIG_MIPS_MT_SMTC */
 377        bust_spinlocks(1);
 378#ifdef CONFIG_MIPS_MT_SMTC
 379        mips_mt_regdump(dvpret);
 380#endif /* CONFIG_MIPS_MT_SMTC */
 381
 382        printk("%s[#%d]:\n", str, ++die_counter);
 383        show_registers(regs);
 384        add_taint(TAINT_DIE, LOCKDEP_NOW_UNRELIABLE);
 385        raw_spin_unlock_irq(&die_lock);
 386
 387        oops_exit();
 388
 389        if (in_interrupt())
 390                panic("Fatal exception in interrupt");
 391
 392        if (panic_on_oops) {
 393                printk(KERN_EMERG "Fatal exception: panic in 5 seconds");
 394                ssleep(5);
 395                panic("Fatal exception");
 396        }
 397
 398        if (regs && kexec_should_crash(current))
 399                crash_kexec(regs);
 400
 401        do_exit(sig);
 402}
 403
 404extern struct exception_table_entry __start___dbe_table[];
 405extern struct exception_table_entry __stop___dbe_table[];
 406
 407__asm__(
 408"       .section        __dbe_table, \"a\"\n"
 409"       .previous                       \n");
 410
 411/* Given an address, look for it in the exception tables. */
 412static const struct exception_table_entry *search_dbe_tables(unsigned long addr)
 413{
 414        const struct exception_table_entry *e;
 415
 416        e = search_extable(__start___dbe_table, __stop___dbe_table - 1, addr);
 417        if (!e)
 418                e = search_module_dbetables(addr);
 419        return e;
 420}
 421
 422asmlinkage void do_be(struct pt_regs *regs)
 423{
 424        const int field = 2 * sizeof(unsigned long);
 425        const struct exception_table_entry *fixup = NULL;
 426        int data = regs->cp0_cause & 4;
 427        int action = MIPS_BE_FATAL;
 428        enum ctx_state prev_state;
 429
 430        prev_state = exception_enter();
 431        /* XXX For now.  Fixme, this searches the wrong table ...  */
 432        if (data && !user_mode(regs))
 433                fixup = search_dbe_tables(exception_epc(regs));
 434
 435        if (fixup)
 436                action = MIPS_BE_FIXUP;
 437
 438        if (board_be_handler)
 439                action = board_be_handler(regs, fixup != NULL);
 440
 441        switch (action) {
 442        case MIPS_BE_DISCARD:
 443                goto out;
 444        case MIPS_BE_FIXUP:
 445                if (fixup) {
 446                        regs->cp0_epc = fixup->nextinsn;
 447                        goto out;
 448                }
 449                break;
 450        default:
 451                break;
 452        }
 453
 454        /*
 455         * Assume it would be too dangerous to continue ...
 456         */
 457        printk(KERN_ALERT "%s bus error, epc == %0*lx, ra == %0*lx\n",
 458               data ? "Data" : "Instruction",
 459               field, regs->cp0_epc, field, regs->regs[31]);
 460        if (notify_die(DIE_OOPS, "bus error", regs, 0, regs_to_trapnr(regs), SIGBUS)
 461            == NOTIFY_STOP)
 462                goto out;
 463
 464        die_if_kernel("Oops", regs);
 465        force_sig(SIGBUS, current);
 466
 467out:
 468        exception_exit(prev_state);
 469}
 470
 471/*
 472 * ll/sc, rdhwr, sync emulation
 473 */
 474
 475#define OPCODE 0xfc000000
 476#define BASE   0x03e00000
 477#define RT     0x001f0000
 478#define OFFSET 0x0000ffff
 479#define LL     0xc0000000
 480#define SC     0xe0000000
 481#define SPEC0  0x00000000
 482#define SPEC3  0x7c000000
 483#define RD     0x0000f800
 484#define FUNC   0x0000003f
 485#define SYNC   0x0000000f
 486#define RDHWR  0x0000003b
 487
 488/*  microMIPS definitions   */
 489#define MM_POOL32A_FUNC 0xfc00ffff
 490#define MM_RDHWR        0x00006b3c
 491#define MM_RS           0x001f0000
 492#define MM_RT           0x03e00000
 493
 494/*
 495 * The ll_bit is cleared by r*_switch.S
 496 */
 497
 498unsigned int ll_bit;
 499struct task_struct *ll_task;
 500
 501static inline int simulate_ll(struct pt_regs *regs, unsigned int opcode)
 502{
 503        unsigned long value, __user *vaddr;
 504        long offset;
 505
 506        /*
 507         * analyse the ll instruction that just caused a ri exception
 508         * and put the referenced address to addr.
 509         */
 510
 511        /* sign extend offset */
 512        offset = opcode & OFFSET;
 513        offset <<= 16;
 514        offset >>= 16;
 515
 516        vaddr = (unsigned long __user *)
 517                ((unsigned long)(regs->regs[(opcode & BASE) >> 21]) + offset);
 518
 519        if ((unsigned long)vaddr & 3)
 520                return SIGBUS;
 521        if (get_user(value, vaddr))
 522                return SIGSEGV;
 523
 524        preempt_disable();
 525
 526        if (ll_task == NULL || ll_task == current) {
 527                ll_bit = 1;
 528        } else {
 529                ll_bit = 0;
 530        }
 531        ll_task = current;
 532
 533        preempt_enable();
 534
 535        regs->regs[(opcode & RT) >> 16] = value;
 536
 537        return 0;
 538}
 539
 540static inline int simulate_sc(struct pt_regs *regs, unsigned int opcode)
 541{
 542        unsigned long __user *vaddr;
 543        unsigned long reg;
 544        long offset;
 545
 546        /*
 547         * analyse the sc instruction that just caused a ri exception
 548         * and put the referenced address to addr.
 549         */
 550
 551        /* sign extend offset */
 552        offset = opcode & OFFSET;
 553        offset <<= 16;
 554        offset >>= 16;
 555
 556        vaddr = (unsigned long __user *)
 557                ((unsigned long)(regs->regs[(opcode & BASE) >> 21]) + offset);
 558        reg = (opcode & RT) >> 16;
 559
 560        if ((unsigned long)vaddr & 3)
 561                return SIGBUS;
 562
 563        preempt_disable();
 564
 565        if (ll_bit == 0 || ll_task != current) {
 566                regs->regs[reg] = 0;
 567                preempt_enable();
 568                return 0;
 569        }
 570
 571        preempt_enable();
 572
 573        if (put_user(regs->regs[reg], vaddr))
 574                return SIGSEGV;
 575
 576        regs->regs[reg] = 1;
 577
 578        return 0;
 579}
 580
 581/*
 582 * ll uses the opcode of lwc0 and sc uses the opcode of swc0.  That is both
 583 * opcodes are supposed to result in coprocessor unusable exceptions if
 584 * executed on ll/sc-less processors.  That's the theory.  In practice a
 585 * few processors such as NEC's VR4100 throw reserved instruction exceptions
 586 * instead, so we're doing the emulation thing in both exception handlers.
 587 */
 588static int simulate_llsc(struct pt_regs *regs, unsigned int opcode)
 589{
 590        if ((opcode & OPCODE) == LL) {
 591                perf_sw_event(PERF_COUNT_SW_EMULATION_FAULTS,
 592                                1, regs, 0);
 593                return simulate_ll(regs, opcode);
 594        }
 595        if ((opcode & OPCODE) == SC) {
 596                perf_sw_event(PERF_COUNT_SW_EMULATION_FAULTS,
 597                                1, regs, 0);
 598                return simulate_sc(regs, opcode);
 599        }
 600
 601        return -1;                      /* Must be something else ... */
 602}
 603
 604/*
 605 * Simulate trapping 'rdhwr' instructions to provide user accessible
 606 * registers not implemented in hardware.
 607 */
 608static int simulate_rdhwr(struct pt_regs *regs, int rd, int rt)
 609{
 610        struct thread_info *ti = task_thread_info(current);
 611
 612        perf_sw_event(PERF_COUNT_SW_EMULATION_FAULTS,
 613                        1, regs, 0);
 614        switch (rd) {
 615        case 0:         /* CPU number */
 616                regs->regs[rt] = smp_processor_id();
 617                return 0;
 618        case 1:         /* SYNCI length */
 619                regs->regs[rt] = min(current_cpu_data.dcache.linesz,
 620                                     current_cpu_data.icache.linesz);
 621                return 0;
 622        case 2:         /* Read count register */
 623                regs->regs[rt] = read_c0_count();
 624                return 0;
 625        case 3:         /* Count register resolution */
 626                switch (current_cpu_type()) {
 627                case CPU_20KC:
 628                case CPU_25KF:
 629                        regs->regs[rt] = 1;
 630                        break;
 631                default:
 632                        regs->regs[rt] = 2;
 633                }
 634                return 0;
 635        case 29:
 636                regs->regs[rt] = ti->tp_value;
 637                return 0;
 638        default:
 639                return -1;
 640        }
 641}
 642
 643static int simulate_rdhwr_normal(struct pt_regs *regs, unsigned int opcode)
 644{
 645        if ((opcode & OPCODE) == SPEC3 && (opcode & FUNC) == RDHWR) {
 646                int rd = (opcode & RD) >> 11;
 647                int rt = (opcode & RT) >> 16;
 648
 649                simulate_rdhwr(regs, rd, rt);
 650                return 0;
 651        }
 652
 653        /* Not ours.  */
 654        return -1;
 655}
 656
 657static int simulate_rdhwr_mm(struct pt_regs *regs, unsigned short opcode)
 658{
 659        if ((opcode & MM_POOL32A_FUNC) == MM_RDHWR) {
 660                int rd = (opcode & MM_RS) >> 16;
 661                int rt = (opcode & MM_RT) >> 21;
 662                simulate_rdhwr(regs, rd, rt);
 663                return 0;
 664        }
 665
 666        /* Not ours.  */
 667        return -1;
 668}
 669
 670static int simulate_sync(struct pt_regs *regs, unsigned int opcode)
 671{
 672        if ((opcode & OPCODE) == SPEC0 && (opcode & FUNC) == SYNC) {
 673                perf_sw_event(PERF_COUNT_SW_EMULATION_FAULTS,
 674                                1, regs, 0);
 675                return 0;
 676        }
 677
 678        return -1;                      /* Must be something else ... */
 679}
 680
 681asmlinkage void do_ov(struct pt_regs *regs)
 682{
 683        enum ctx_state prev_state;
 684        siginfo_t info;
 685
 686        prev_state = exception_enter();
 687        die_if_kernel("Integer overflow", regs);
 688
 689        info.si_code = FPE_INTOVF;
 690        info.si_signo = SIGFPE;
 691        info.si_errno = 0;
 692        info.si_addr = (void __user *) regs->cp0_epc;
 693        force_sig_info(SIGFPE, &info, current);
 694        exception_exit(prev_state);
 695}
 696
 697int process_fpemu_return(int sig, void __user *fault_addr)
 698{
 699        if (sig == SIGSEGV || sig == SIGBUS) {
 700                struct siginfo si = {0};
 701                si.si_addr = fault_addr;
 702                si.si_signo = sig;
 703                if (sig == SIGSEGV) {
 704                        if (find_vma(current->mm, (unsigned long)fault_addr))
 705                                si.si_code = SEGV_ACCERR;
 706                        else
 707                                si.si_code = SEGV_MAPERR;
 708                } else {
 709                        si.si_code = BUS_ADRERR;
 710                }
 711                force_sig_info(sig, &si, current);
 712                return 1;
 713        } else if (sig) {
 714                force_sig(sig, current);
 715                return 1;
 716        } else {
 717                return 0;
 718        }
 719}
 720
 721/*
 722 * XXX Delayed fp exceptions when doing a lazy ctx switch XXX
 723 */
 724asmlinkage void do_fpe(struct pt_regs *regs, unsigned long fcr31)
 725{
 726        enum ctx_state prev_state;
 727        siginfo_t info = {0};
 728
 729        prev_state = exception_enter();
 730        if (notify_die(DIE_FP, "FP exception", regs, 0, regs_to_trapnr(regs), SIGFPE)
 731            == NOTIFY_STOP)
 732                goto out;
 733        die_if_kernel("FP exception in kernel code", regs);
 734
 735        if (fcr31 & FPU_CSR_UNI_X) {
 736                int sig;
 737                void __user *fault_addr = NULL;
 738
 739                /*
 740                 * Unimplemented operation exception.  If we've got the full
 741                 * software emulator on-board, let's use it...
 742                 *
 743                 * Force FPU to dump state into task/thread context.  We're
 744                 * moving a lot of data here for what is probably a single
 745                 * instruction, but the alternative is to pre-decode the FP
 746                 * register operands before invoking the emulator, which seems
 747                 * a bit extreme for what should be an infrequent event.
 748                 */
 749                /* Ensure 'resume' not overwrite saved fp context again. */
 750                lose_fpu(1);
 751
 752                /* Run the emulator */
 753                sig = fpu_emulator_cop1Handler(regs, &current->thread.fpu, 1,
 754                                               &fault_addr);
 755
 756                /*
 757                 * We can't allow the emulated instruction to leave any of
 758                 * the cause bit set in $fcr31.
 759                 */
 760                current->thread.fpu.fcr31 &= ~FPU_CSR_ALL_X;
 761
 762                /* Restore the hardware register state */
 763                own_fpu(1);     /* Using the FPU again.  */
 764
 765                /* If something went wrong, signal */
 766                process_fpemu_return(sig, fault_addr);
 767
 768                goto out;
 769        } else if (fcr31 & FPU_CSR_INV_X)
 770                info.si_code = FPE_FLTINV;
 771        else if (fcr31 & FPU_CSR_DIV_X)
 772                info.si_code = FPE_FLTDIV;
 773        else if (fcr31 & FPU_CSR_OVF_X)
 774                info.si_code = FPE_FLTOVF;
 775        else if (fcr31 & FPU_CSR_UDF_X)
 776                info.si_code = FPE_FLTUND;
 777        else if (fcr31 & FPU_CSR_INE_X)
 778                info.si_code = FPE_FLTRES;
 779        else
 780                info.si_code = __SI_FAULT;
 781        info.si_signo = SIGFPE;
 782        info.si_errno = 0;
 783        info.si_addr = (void __user *) regs->cp0_epc;
 784        force_sig_info(SIGFPE, &info, current);
 785
 786out:
 787        exception_exit(prev_state);
 788}
 789
 790static void do_trap_or_bp(struct pt_regs *regs, unsigned int code,
 791        const char *str)
 792{
 793        siginfo_t info;
 794        char b[40];
 795
 796#ifdef CONFIG_KGDB_LOW_LEVEL_TRAP
 797        if (kgdb_ll_trap(DIE_TRAP, str, regs, code, regs_to_trapnr(regs), SIGTRAP) == NOTIFY_STOP)
 798                return;
 799#endif /* CONFIG_KGDB_LOW_LEVEL_TRAP */
 800
 801        if (notify_die(DIE_TRAP, str, regs, code, regs_to_trapnr(regs), SIGTRAP) == NOTIFY_STOP)
 802                return;
 803
 804        /*
 805         * A short test says that IRIX 5.3 sends SIGTRAP for all trap
 806         * insns, even for trap and break codes that indicate arithmetic
 807         * failures.  Weird ...
 808         * But should we continue the brokenness???  --macro
 809         */
 810        switch (code) {
 811        case BRK_OVERFLOW:
 812        case BRK_DIVZERO:
 813                scnprintf(b, sizeof(b), "%s instruction in kernel code", str);
 814                die_if_kernel(b, regs);
 815                if (code == BRK_DIVZERO)
 816                        info.si_code = FPE_INTDIV;
 817                else
 818                        info.si_code = FPE_INTOVF;
 819                info.si_signo = SIGFPE;
 820                info.si_errno = 0;
 821                info.si_addr = (void __user *) regs->cp0_epc;
 822                force_sig_info(SIGFPE, &info, current);
 823                break;
 824        case BRK_BUG:
 825                die_if_kernel("Kernel bug detected", regs);
 826                force_sig(SIGTRAP, current);
 827                break;
 828        case BRK_MEMU:
 829                /*
 830                 * Address errors may be deliberately induced by the FPU
 831                 * emulator to retake control of the CPU after executing the
 832                 * instruction in the delay slot of an emulated branch.
 833                 *
 834                 * Terminate if exception was recognized as a delay slot return
 835                 * otherwise handle as normal.
 836                 */
 837                if (do_dsemulret(regs))
 838                        return;
 839
 840                die_if_kernel("Math emu break/trap", regs);
 841                force_sig(SIGTRAP, current);
 842                break;
 843        default:
 844                scnprintf(b, sizeof(b), "%s instruction in kernel code", str);
 845                die_if_kernel(b, regs);
 846                force_sig(SIGTRAP, current);
 847        }
 848}
 849
 850asmlinkage void do_bp(struct pt_regs *regs)
 851{
 852        unsigned int opcode, bcode;
 853        enum ctx_state prev_state;
 854        unsigned long epc;
 855        u16 instr[2];
 856
 857        prev_state = exception_enter();
 858        if (get_isa16_mode(regs->cp0_epc)) {
 859                /* Calculate EPC. */
 860                epc = exception_epc(regs);
 861                if (cpu_has_mmips) {
 862                        if ((__get_user(instr[0], (u16 __user *)msk_isa16_mode(epc)) ||
 863                            (__get_user(instr[1], (u16 __user *)msk_isa16_mode(epc + 2)))))
 864                                goto out_sigsegv;
 865                    opcode = (instr[0] << 16) | instr[1];
 866                } else {
 867                    /* MIPS16e mode */
 868                    if (__get_user(instr[0], (u16 __user *)msk_isa16_mode(epc)))
 869                                goto out_sigsegv;
 870                    bcode = (instr[0] >> 6) & 0x3f;
 871                    do_trap_or_bp(regs, bcode, "Break");
 872                    goto out;
 873                }
 874        } else {
 875                if (__get_user(opcode, (unsigned int __user *) exception_epc(regs)))
 876                        goto out_sigsegv;
 877        }
 878
 879        /*
 880         * There is the ancient bug in the MIPS assemblers that the break
 881         * code starts left to bit 16 instead to bit 6 in the opcode.
 882         * Gas is bug-compatible, but not always, grrr...
 883         * We handle both cases with a simple heuristics.  --macro
 884         */
 885        bcode = ((opcode >> 6) & ((1 << 20) - 1));
 886        if (bcode >= (1 << 10))
 887                bcode >>= 10;
 888
 889        /*
 890         * notify the kprobe handlers, if instruction is likely to
 891         * pertain to them.
 892         */
 893        switch (bcode) {
 894        case BRK_KPROBE_BP:
 895                if (notify_die(DIE_BREAK, "debug", regs, bcode, regs_to_trapnr(regs), SIGTRAP) == NOTIFY_STOP)
 896                        goto out;
 897                else
 898                        break;
 899        case BRK_KPROBE_SSTEPBP:
 900                if (notify_die(DIE_SSTEPBP, "single_step", regs, bcode, regs_to_trapnr(regs), SIGTRAP) == NOTIFY_STOP)
 901                        goto out;
 902                else
 903                        break;
 904        default:
 905                break;
 906        }
 907
 908        do_trap_or_bp(regs, bcode, "Break");
 909
 910out:
 911        exception_exit(prev_state);
 912        return;
 913
 914out_sigsegv:
 915        force_sig(SIGSEGV, current);
 916        goto out;
 917}
 918
 919asmlinkage void do_tr(struct pt_regs *regs)
 920{
 921        u32 opcode, tcode = 0;
 922        enum ctx_state prev_state;
 923        u16 instr[2];
 924        unsigned long epc = msk_isa16_mode(exception_epc(regs));
 925
 926        prev_state = exception_enter();
 927        if (get_isa16_mode(regs->cp0_epc)) {
 928                if (__get_user(instr[0], (u16 __user *)(epc + 0)) ||
 929                    __get_user(instr[1], (u16 __user *)(epc + 2)))
 930                        goto out_sigsegv;
 931                opcode = (instr[0] << 16) | instr[1];
 932                /* Immediate versions don't provide a code.  */
 933                if (!(opcode & OPCODE))
 934                        tcode = (opcode >> 12) & ((1 << 4) - 1);
 935        } else {
 936                if (__get_user(opcode, (u32 __user *)epc))
 937                        goto out_sigsegv;
 938                /* Immediate versions don't provide a code.  */
 939                if (!(opcode & OPCODE))
 940                        tcode = (opcode >> 6) & ((1 << 10) - 1);
 941        }
 942
 943        do_trap_or_bp(regs, tcode, "Trap");
 944
 945out:
 946        exception_exit(prev_state);
 947        return;
 948
 949out_sigsegv:
 950        force_sig(SIGSEGV, current);
 951        goto out;
 952}
 953
 954asmlinkage void do_ri(struct pt_regs *regs)
 955{
 956        unsigned int __user *epc = (unsigned int __user *)exception_epc(regs);
 957        unsigned long old_epc = regs->cp0_epc;
 958        unsigned long old31 = regs->regs[31];
 959        enum ctx_state prev_state;
 960        unsigned int opcode = 0;
 961        int status = -1;
 962
 963        prev_state = exception_enter();
 964        if (notify_die(DIE_RI, "RI Fault", regs, 0, regs_to_trapnr(regs), SIGILL)
 965            == NOTIFY_STOP)
 966                goto out;
 967
 968        die_if_kernel("Reserved instruction in kernel code", regs);
 969
 970        if (unlikely(compute_return_epc(regs) < 0))
 971                goto out;
 972
 973        if (get_isa16_mode(regs->cp0_epc)) {
 974                unsigned short mmop[2] = { 0 };
 975
 976                if (unlikely(get_user(mmop[0], epc) < 0))
 977                        status = SIGSEGV;
 978                if (unlikely(get_user(mmop[1], epc) < 0))
 979                        status = SIGSEGV;
 980                opcode = (mmop[0] << 16) | mmop[1];
 981
 982                if (status < 0)
 983                        status = simulate_rdhwr_mm(regs, opcode);
 984        } else {
 985                if (unlikely(get_user(opcode, epc) < 0))
 986                        status = SIGSEGV;
 987
 988                if (!cpu_has_llsc && status < 0)
 989                        status = simulate_llsc(regs, opcode);
 990
 991                if (status < 0)
 992                        status = simulate_rdhwr_normal(regs, opcode);
 993
 994                if (status < 0)
 995                        status = simulate_sync(regs, opcode);
 996        }
 997
 998        if (status < 0)
 999                status = SIGILL;
1000
1001        if (unlikely(status > 0)) {
1002                regs->cp0_epc = old_epc;                /* Undo skip-over.  */
1003                regs->regs[31] = old31;
1004                force_sig(status, current);
1005        }
1006
1007out:
1008        exception_exit(prev_state);
1009}
1010
1011/*
1012 * MIPS MT processors may have fewer FPU contexts than CPU threads. If we've
1013 * emulated more than some threshold number of instructions, force migration to
1014 * a "CPU" that has FP support.
1015 */
1016static void mt_ase_fp_affinity(void)
1017{
1018#ifdef CONFIG_MIPS_MT_FPAFF
1019        if (mt_fpemul_threshold > 0 &&
1020             ((current->thread.emulated_fp++ > mt_fpemul_threshold))) {
1021                /*
1022                 * If there's no FPU present, or if the application has already
1023                 * restricted the allowed set to exclude any CPUs with FPUs,
1024                 * we'll skip the procedure.
1025                 */
1026                if (cpus_intersects(current->cpus_allowed, mt_fpu_cpumask)) {
1027                        cpumask_t tmask;
1028
1029                        current->thread.user_cpus_allowed
1030                                = current->cpus_allowed;
1031                        cpus_and(tmask, current->cpus_allowed,
1032                                mt_fpu_cpumask);
1033                        set_cpus_allowed_ptr(current, &tmask);
1034                        set_thread_flag(TIF_FPUBOUND);
1035                }
1036        }
1037#endif /* CONFIG_MIPS_MT_FPAFF */
1038}
1039
1040/*
1041 * No lock; only written during early bootup by CPU 0.
1042 */
1043static RAW_NOTIFIER_HEAD(cu2_chain);
1044
1045int __ref register_cu2_notifier(struct notifier_block *nb)
1046{
1047        return raw_notifier_chain_register(&cu2_chain, nb);
1048}
1049
1050int cu2_notifier_call_chain(unsigned long val, void *v)
1051{
1052        return raw_notifier_call_chain(&cu2_chain, val, v);
1053}
1054
1055static int default_cu2_call(struct notifier_block *nfb, unsigned long action,
1056        void *data)
1057{
1058        struct pt_regs *regs = data;
1059
1060        die_if_kernel("COP2: Unhandled kernel unaligned access or invalid "
1061                              "instruction", regs);
1062        force_sig(SIGILL, current);
1063
1064        return NOTIFY_OK;
1065}
1066
1067asmlinkage void do_cpu(struct pt_regs *regs)
1068{
1069        enum ctx_state prev_state;
1070        unsigned int __user *epc;
1071        unsigned long old_epc, old31;
1072        unsigned int opcode;
1073        unsigned int cpid;
1074        int status;
1075        unsigned long __maybe_unused flags;
1076
1077        prev_state = exception_enter();
1078        cpid = (regs->cp0_cause >> CAUSEB_CE) & 3;
1079
1080        if (cpid != 2)
1081                die_if_kernel("do_cpu invoked from kernel context!", regs);
1082
1083        switch (cpid) {
1084        case 0:
1085                epc = (unsigned int __user *)exception_epc(regs);
1086                old_epc = regs->cp0_epc;
1087                old31 = regs->regs[31];
1088                opcode = 0;
1089                status = -1;
1090
1091                if (unlikely(compute_return_epc(regs) < 0))
1092                        goto out;
1093
1094                if (get_isa16_mode(regs->cp0_epc)) {
1095                        unsigned short mmop[2] = { 0 };
1096
1097                        if (unlikely(get_user(mmop[0], epc) < 0))
1098                                status = SIGSEGV;
1099                        if (unlikely(get_user(mmop[1], epc) < 0))
1100                                status = SIGSEGV;
1101                        opcode = (mmop[0] << 16) | mmop[1];
1102
1103                        if (status < 0)
1104                                status = simulate_rdhwr_mm(regs, opcode);
1105                } else {
1106                        if (unlikely(get_user(opcode, epc) < 0))
1107                                status = SIGSEGV;
1108
1109                        if (!cpu_has_llsc && status < 0)
1110                                status = simulate_llsc(regs, opcode);
1111
1112                        if (status < 0)
1113                                status = simulate_rdhwr_normal(regs, opcode);
1114                }
1115
1116                if (status < 0)
1117                        status = SIGILL;
1118
1119                if (unlikely(status > 0)) {
1120                        regs->cp0_epc = old_epc;        /* Undo skip-over.  */
1121                        regs->regs[31] = old31;
1122                        force_sig(status, current);
1123                }
1124
1125                goto out;
1126
1127        case 3:
1128                /*
1129                 * Old (MIPS I and MIPS II) processors will set this code
1130                 * for COP1X opcode instructions that replaced the original
1131                 * COP3 space.  We don't limit COP1 space instructions in
1132                 * the emulator according to the CPU ISA, so we want to
1133                 * treat COP1X instructions consistently regardless of which
1134                 * code the CPU chose.  Therefore we redirect this trap to
1135                 * the FP emulator too.
1136                 *
1137                 * Then some newer FPU-less processors use this code
1138                 * erroneously too, so they are covered by this choice
1139                 * as well.
1140                 */
1141                if (raw_cpu_has_fpu)
1142                        break;
1143                /* Fall through.  */
1144
1145        case 1:
1146                if (used_math())        /* Using the FPU again.  */
1147                        own_fpu(1);
1148                else {                  /* First time FPU user.  */
1149                        init_fpu();
1150                        set_used_math();
1151                }
1152
1153                if (!raw_cpu_has_fpu) {
1154                        int sig;
1155                        void __user *fault_addr = NULL;
1156                        sig = fpu_emulator_cop1Handler(regs,
1157                                                       &current->thread.fpu,
1158                                                       0, &fault_addr);
1159                        if (!process_fpemu_return(sig, fault_addr))
1160                                mt_ase_fp_affinity();
1161                }
1162
1163                goto out;
1164
1165        case 2:
1166                raw_notifier_call_chain(&cu2_chain, CU2_EXCEPTION, regs);
1167                goto out;
1168        }
1169
1170        force_sig(SIGILL, current);
1171
1172out:
1173        exception_exit(prev_state);
1174}
1175
1176asmlinkage void do_mdmx(struct pt_regs *regs)
1177{
1178        enum ctx_state prev_state;
1179
1180        prev_state = exception_enter();
1181        force_sig(SIGILL, current);
1182        exception_exit(prev_state);
1183}
1184
1185/*
1186 * Called with interrupts disabled.
1187 */
1188asmlinkage void do_watch(struct pt_regs *regs)
1189{
1190        enum ctx_state prev_state;
1191        u32 cause;
1192
1193        prev_state = exception_enter();
1194        /*
1195         * Clear WP (bit 22) bit of cause register so we don't loop
1196         * forever.
1197         */
1198        cause = read_c0_cause();
1199        cause &= ~(1 << 22);
1200        write_c0_cause(cause);
1201
1202        /*
1203         * If the current thread has the watch registers loaded, save
1204         * their values and send SIGTRAP.  Otherwise another thread
1205         * left the registers set, clear them and continue.
1206         */
1207        if (test_tsk_thread_flag(current, TIF_LOAD_WATCH)) {
1208                mips_read_watch_registers();
1209                local_irq_enable();
1210                force_sig(SIGTRAP, current);
1211        } else {
1212                mips_clear_watch_registers();
1213                local_irq_enable();
1214        }
1215        exception_exit(prev_state);
1216}
1217
1218asmlinkage void do_mcheck(struct pt_regs *regs)
1219{
1220        const int field = 2 * sizeof(unsigned long);
1221        int multi_match = regs->cp0_status & ST0_TS;
1222        enum ctx_state prev_state;
1223
1224        prev_state = exception_enter();
1225        show_regs(regs);
1226
1227        if (multi_match) {
1228                printk("Index   : %0x\n", read_c0_index());
1229                printk("Pagemask: %0x\n", read_c0_pagemask());
1230                printk("EntryHi : %0*lx\n", field, read_c0_entryhi());
1231                printk("EntryLo0: %0*lx\n", field, read_c0_entrylo0());
1232                printk("EntryLo1: %0*lx\n", field, read_c0_entrylo1());
1233                printk("\n");
1234                dump_tlb_all();
1235        }
1236
1237        show_code((unsigned int __user *) regs->cp0_epc);
1238
1239        /*
1240         * Some chips may have other causes of machine check (e.g. SB1
1241         * graduation timer)
1242         */
1243        panic("Caught Machine Check exception - %scaused by multiple "
1244              "matching entries in the TLB.",
1245              (multi_match) ? "" : "not ");
1246}
1247
1248asmlinkage void do_mt(struct pt_regs *regs)
1249{
1250        int subcode;
1251
1252        subcode = (read_vpe_c0_vpecontrol() & VPECONTROL_EXCPT)
1253                        >> VPECONTROL_EXCPT_SHIFT;
1254        switch (subcode) {
1255        case 0:
1256                printk(KERN_DEBUG "Thread Underflow\n");
1257                break;
1258        case 1:
1259                printk(KERN_DEBUG "Thread Overflow\n");
1260                break;
1261        case 2:
1262                printk(KERN_DEBUG "Invalid YIELD Qualifier\n");
1263                break;
1264        case 3:
1265                printk(KERN_DEBUG "Gating Storage Exception\n");
1266                break;
1267        case 4:
1268                printk(KERN_DEBUG "YIELD Scheduler Exception\n");
1269                break;
1270        case 5:
1271                printk(KERN_DEBUG "Gating Storage Scheduler Exception\n");
1272                break;
1273        default:
1274                printk(KERN_DEBUG "*** UNKNOWN THREAD EXCEPTION %d ***\n",
1275                        subcode);
1276                break;
1277        }
1278        die_if_kernel("MIPS MT Thread exception in kernel", regs);
1279
1280        force_sig(SIGILL, current);
1281}
1282
1283
1284asmlinkage void do_dsp(struct pt_regs *regs)
1285{
1286        if (cpu_has_dsp)
1287                panic("Unexpected DSP exception");
1288
1289        force_sig(SIGILL, current);
1290}
1291
1292asmlinkage void do_reserved(struct pt_regs *regs)
1293{
1294        /*
1295         * Game over - no way to handle this if it ever occurs.  Most probably
1296         * caused by a new unknown cpu type or after another deadly
1297         * hard/software error.
1298         */
1299        show_regs(regs);
1300        panic("Caught reserved exception %ld - should not happen.",
1301              (regs->cp0_cause & 0x7f) >> 2);
1302}
1303
1304static int __initdata l1parity = 1;
1305static int __init nol1parity(char *s)
1306{
1307        l1parity = 0;
1308        return 1;
1309}
1310__setup("nol1par", nol1parity);
1311static int __initdata l2parity = 1;
1312static int __init nol2parity(char *s)
1313{
1314        l2parity = 0;
1315        return 1;
1316}
1317__setup("nol2par", nol2parity);
1318
1319/*
1320 * Some MIPS CPUs can enable/disable for cache parity detection, but do
1321 * it different ways.
1322 */
1323static inline void parity_protection_init(void)
1324{
1325        switch (current_cpu_type()) {
1326        case CPU_24K:
1327        case CPU_34K:
1328        case CPU_74K:
1329        case CPU_1004K:
1330                {
1331#define ERRCTL_PE       0x80000000
1332#define ERRCTL_L2P      0x00800000
1333                        unsigned long errctl;
1334                        unsigned int l1parity_present, l2parity_present;
1335
1336                        errctl = read_c0_ecc();
1337                        errctl &= ~(ERRCTL_PE|ERRCTL_L2P);
1338
1339                        /* probe L1 parity support */
1340                        write_c0_ecc(errctl | ERRCTL_PE);
1341                        back_to_back_c0_hazard();
1342                        l1parity_present = (read_c0_ecc() & ERRCTL_PE);
1343
1344                        /* probe L2 parity support */
1345                        write_c0_ecc(errctl|ERRCTL_L2P);
1346                        back_to_back_c0_hazard();
1347                        l2parity_present = (read_c0_ecc() & ERRCTL_L2P);
1348
1349                        if (l1parity_present && l2parity_present) {
1350                                if (l1parity)
1351                                        errctl |= ERRCTL_PE;
1352                                if (l1parity ^ l2parity)
1353                                        errctl |= ERRCTL_L2P;
1354                        } else if (l1parity_present) {
1355                                if (l1parity)
1356                                        errctl |= ERRCTL_PE;
1357                        } else if (l2parity_present) {
1358                                if (l2parity)
1359                                        errctl |= ERRCTL_L2P;
1360                        } else {
1361                                /* No parity available */
1362                        }
1363
1364                        printk(KERN_INFO "Writing ErrCtl register=%08lx\n", errctl);
1365
1366                        write_c0_ecc(errctl);
1367                        back_to_back_c0_hazard();
1368                        errctl = read_c0_ecc();
1369                        printk(KERN_INFO "Readback ErrCtl register=%08lx\n", errctl);
1370
1371                        if (l1parity_present)
1372                                printk(KERN_INFO "Cache parity protection %sabled\n",
1373                                       (errctl & ERRCTL_PE) ? "en" : "dis");
1374
1375                        if (l2parity_present) {
1376                                if (l1parity_present && l1parity)
1377                                        errctl ^= ERRCTL_L2P;
1378                                printk(KERN_INFO "L2 cache parity protection %sabled\n",
1379                                       (errctl & ERRCTL_L2P) ? "en" : "dis");
1380                        }
1381                }
1382                break;
1383
1384        case CPU_5KC:
1385        case CPU_5KE:
1386        case CPU_LOONGSON1:
1387                write_c0_ecc(0x80000000);
1388                back_to_back_c0_hazard();
1389                /* Set the PE bit (bit 31) in the c0_errctl register. */
1390                printk(KERN_INFO "Cache parity protection %sabled\n",
1391                       (read_c0_ecc() & 0x80000000) ? "en" : "dis");
1392                break;
1393        case CPU_20KC:
1394        case CPU_25KF:
1395                /* Clear the DE bit (bit 16) in the c0_status register. */
1396                printk(KERN_INFO "Enable cache parity protection for "
1397                       "MIPS 20KC/25KF CPUs.\n");
1398                clear_c0_status(ST0_DE);
1399                break;
1400        default:
1401                break;
1402        }
1403}
1404
1405asmlinkage void cache_parity_error(void)
1406{
1407        const int field = 2 * sizeof(unsigned long);
1408        unsigned int reg_val;
1409
1410        /* For the moment, report the problem and hang. */
1411        printk("Cache error exception:\n");
1412        printk("cp0_errorepc == %0*lx\n", field, read_c0_errorepc());
1413        reg_val = read_c0_cacheerr();
1414        printk("c0_cacheerr == %08x\n", reg_val);
1415
1416        printk("Decoded c0_cacheerr: %s cache fault in %s reference.\n",
1417               reg_val & (1<<30) ? "secondary" : "primary",
1418               reg_val & (1<<31) ? "data" : "insn");
1419        printk("Error bits: %s%s%s%s%s%s%s\n",
1420               reg_val & (1<<29) ? "ED " : "",
1421               reg_val & (1<<28) ? "ET " : "",
1422               reg_val & (1<<26) ? "EE " : "",
1423               reg_val & (1<<25) ? "EB " : "",
1424               reg_val & (1<<24) ? "EI " : "",
1425               reg_val & (1<<23) ? "E1 " : "",
1426               reg_val & (1<<22) ? "E0 " : "");
1427        printk("IDX: 0x%08x\n", reg_val & ((1<<22)-1));
1428
1429#if defined(CONFIG_CPU_MIPS32) || defined(CONFIG_CPU_MIPS64)
1430        if (reg_val & (1<<22))
1431                printk("DErrAddr0: 0x%0*lx\n", field, read_c0_derraddr0());
1432
1433        if (reg_val & (1<<23))
1434                printk("DErrAddr1: 0x%0*lx\n", field, read_c0_derraddr1());
1435#endif
1436
1437        panic("Can't handle the cache error!");
1438}
1439
1440/*
1441 * SDBBP EJTAG debug exception handler.
1442 * We skip the instruction and return to the next instruction.
1443 */
1444void ejtag_exception_handler(struct pt_regs *regs)
1445{
1446        const int field = 2 * sizeof(unsigned long);
1447        unsigned long depc, old_epc, old_ra;
1448        unsigned int debug;
1449
1450        printk(KERN_DEBUG "SDBBP EJTAG debug exception - not handled yet, just ignored!\n");
1451        depc = read_c0_depc();
1452        debug = read_c0_debug();
1453        printk(KERN_DEBUG "c0_depc = %0*lx, DEBUG = %08x\n", field, depc, debug);
1454        if (debug & 0x80000000) {
1455                /*
1456                 * In branch delay slot.
1457                 * We cheat a little bit here and use EPC to calculate the
1458                 * debug return address (DEPC). EPC is restored after the
1459                 * calculation.
1460                 */
1461                old_epc = regs->cp0_epc;
1462                old_ra = regs->regs[31];
1463                regs->cp0_epc = depc;
1464                compute_return_epc(regs);
1465                depc = regs->cp0_epc;
1466                regs->cp0_epc = old_epc;
1467                regs->regs[31] = old_ra;
1468        } else
1469                depc += 4;
1470        write_c0_depc(depc);
1471
1472#if 0
1473        printk(KERN_DEBUG "\n\n----- Enable EJTAG single stepping ----\n\n");
1474        write_c0_debug(debug | 0x100);
1475#endif
1476}
1477
1478/*
1479 * NMI exception handler.
1480 * No lock; only written during early bootup by CPU 0.
1481 */
1482static RAW_NOTIFIER_HEAD(nmi_chain);
1483
1484int register_nmi_notifier(struct notifier_block *nb)
1485{
1486        return raw_notifier_chain_register(&nmi_chain, nb);
1487}
1488
1489void __noreturn nmi_exception_handler(struct pt_regs *regs)
1490{
1491        raw_notifier_call_chain(&nmi_chain, 0, regs);
1492        bust_spinlocks(1);
1493        printk("NMI taken!!!!\n");
1494        die("NMI", regs);
1495}
1496
1497#define VECTORSPACING 0x100     /* for EI/VI mode */
1498
1499unsigned long ebase;
1500unsigned long exception_handlers[32];
1501unsigned long vi_handlers[64];
1502
1503void __init *set_except_vector(int n, void *addr)
1504{
1505        unsigned long handler = (unsigned long) addr;
1506        unsigned long old_handler;
1507
1508#ifdef CONFIG_CPU_MICROMIPS
1509        /*
1510         * Only the TLB handlers are cache aligned with an even
1511         * address. All other handlers are on an odd address and
1512         * require no modification. Otherwise, MIPS32 mode will
1513         * be entered when handling any TLB exceptions. That
1514         * would be bad...since we must stay in microMIPS mode.
1515         */
1516        if (!(handler & 0x1))
1517                handler |= 1;
1518#endif
1519        old_handler = xchg(&exception_handlers[n], handler);
1520
1521        if (n == 0 && cpu_has_divec) {
1522#ifdef CONFIG_CPU_MICROMIPS
1523                unsigned long jump_mask = ~((1 << 27) - 1);
1524#else
1525                unsigned long jump_mask = ~((1 << 28) - 1);
1526#endif
1527                u32 *buf = (u32 *)(ebase + 0x200);
1528                unsigned int k0 = 26;
1529                if ((handler & jump_mask) == ((ebase + 0x200) & jump_mask)) {
1530                        uasm_i_j(&buf, handler & ~jump_mask);
1531                        uasm_i_nop(&buf);
1532                } else {
1533                        UASM_i_LA(&buf, k0, handler);
1534                        uasm_i_jr(&buf, k0);
1535                        uasm_i_nop(&buf);
1536                }
1537                local_flush_icache_range(ebase + 0x200, (unsigned long)buf);
1538        }
1539        return (void *)old_handler;
1540}
1541
1542static void do_default_vi(void)
1543{
1544        show_regs(get_irq_regs());
1545        panic("Caught unexpected vectored interrupt.");
1546}
1547
1548static void *set_vi_srs_handler(int n, vi_handler_t addr, int srs)
1549{
1550        unsigned long handler;
1551        unsigned long old_handler = vi_handlers[n];
1552        int srssets = current_cpu_data.srsets;
1553        u16 *h;
1554        unsigned char *b;
1555
1556        BUG_ON(!cpu_has_veic && !cpu_has_vint);
1557        BUG_ON((n < 0) && (n > 9));
1558
1559        if (addr == NULL) {
1560                handler = (unsigned long) do_default_vi;
1561                srs = 0;
1562        } else
1563                handler = (unsigned long) addr;
1564        vi_handlers[n] = handler;
1565
1566        b = (unsigned char *)(ebase + 0x200 + n*VECTORSPACING);
1567
1568        if (srs >= srssets)
1569                panic("Shadow register set %d not supported", srs);
1570
1571        if (cpu_has_veic) {
1572                if (board_bind_eic_interrupt)
1573                        board_bind_eic_interrupt(n, srs);
1574        } else if (cpu_has_vint) {
1575                /* SRSMap is only defined if shadow sets are implemented */
1576                if (srssets > 1)
1577                        change_c0_srsmap(0xf << n*4, srs << n*4);
1578        }
1579
1580        if (srs == 0) {
1581                /*
1582                 * If no shadow set is selected then use the default handler
1583                 * that does normal register saving and standard interrupt exit
1584                 */
1585                extern char except_vec_vi, except_vec_vi_lui;
1586                extern char except_vec_vi_ori, except_vec_vi_end;
1587                extern char rollback_except_vec_vi;
1588                char *vec_start = using_rollback_handler() ?
1589                        &rollback_except_vec_vi : &except_vec_vi;
1590#ifdef CONFIG_MIPS_MT_SMTC
1591                /*
1592                 * We need to provide the SMTC vectored interrupt handler
1593                 * not only with the address of the handler, but with the
1594                 * Status.IM bit to be masked before going there.
1595                 */
1596                extern char except_vec_vi_mori;
1597#if defined(CONFIG_CPU_MICROMIPS) || defined(CONFIG_CPU_BIG_ENDIAN)
1598                const int mori_offset = &except_vec_vi_mori - vec_start + 2;
1599#else
1600                const int mori_offset = &except_vec_vi_mori - vec_start;
1601#endif
1602#endif /* CONFIG_MIPS_MT_SMTC */
1603#if defined(CONFIG_CPU_MICROMIPS) || defined(CONFIG_CPU_BIG_ENDIAN)
1604                const int lui_offset = &except_vec_vi_lui - vec_start + 2;
1605                const int ori_offset = &except_vec_vi_ori - vec_start + 2;
1606#else
1607                const int lui_offset = &except_vec_vi_lui - vec_start;
1608                const int ori_offset = &except_vec_vi_ori - vec_start;
1609#endif
1610                const int handler_len = &except_vec_vi_end - vec_start;
1611
1612                if (handler_len > VECTORSPACING) {
1613                        /*
1614                         * Sigh... panicing won't help as the console
1615                         * is probably not configured :(
1616                         */
1617                        panic("VECTORSPACING too small");
1618                }
1619
1620                set_handler(((unsigned long)b - ebase), vec_start,
1621#ifdef CONFIG_CPU_MICROMIPS
1622                                (handler_len - 1));
1623#else
1624                                handler_len);
1625#endif
1626#ifdef CONFIG_MIPS_MT_SMTC
1627                BUG_ON(n > 7);  /* Vector index %d exceeds SMTC maximum. */
1628
1629                h = (u16 *)(b + mori_offset);
1630                *h = (0x100 << n);
1631#endif /* CONFIG_MIPS_MT_SMTC */
1632                h = (u16 *)(b + lui_offset);
1633                *h = (handler >> 16) & 0xffff;
1634                h = (u16 *)(b + ori_offset);
1635                *h = (handler & 0xffff);
1636                local_flush_icache_range((unsigned long)b,
1637                                         (unsigned long)(b+handler_len));
1638        }
1639        else {
1640                /*
1641                 * In other cases jump directly to the interrupt handler. It
1642                 * is the handler's responsibility to save registers if required
1643                 * (eg hi/lo) and return from the exception using "eret".
1644                 */
1645                u32 insn;
1646
1647                h = (u16 *)b;
1648                /* j handler */
1649#ifdef CONFIG_CPU_MICROMIPS
1650                insn = 0xd4000000 | (((u32)handler & 0x07ffffff) >> 1);
1651#else
1652                insn = 0x08000000 | (((u32)handler & 0x0fffffff) >> 2);
1653#endif
1654                h[0] = (insn >> 16) & 0xffff;
1655                h[1] = insn & 0xffff;
1656                h[2] = 0;
1657                h[3] = 0;
1658                local_flush_icache_range((unsigned long)b,
1659                                         (unsigned long)(b+8));
1660        }
1661
1662        return (void *)old_handler;
1663}
1664
1665void *set_vi_handler(int n, vi_handler_t addr)
1666{
1667        return set_vi_srs_handler(n, addr, 0);
1668}
1669
1670extern void tlb_init(void);
1671
1672/*
1673 * Timer interrupt
1674 */
1675int cp0_compare_irq;
1676EXPORT_SYMBOL_GPL(cp0_compare_irq);
1677int cp0_compare_irq_shift;
1678
1679/*
1680 * Performance counter IRQ or -1 if shared with timer
1681 */
1682int cp0_perfcount_irq;
1683EXPORT_SYMBOL_GPL(cp0_perfcount_irq);
1684
1685static int noulri;
1686
1687static int __init ulri_disable(char *s)
1688{
1689        pr_info("Disabling ulri\n");
1690        noulri = 1;
1691
1692        return 1;
1693}
1694__setup("noulri", ulri_disable);
1695
1696void per_cpu_trap_init(bool is_boot_cpu)
1697{
1698        unsigned int cpu = smp_processor_id();
1699        unsigned int status_set = ST0_CU0;
1700        unsigned int hwrena = cpu_hwrena_impl_bits;
1701#ifdef CONFIG_MIPS_MT_SMTC
1702        int secondaryTC = 0;
1703        int bootTC = (cpu == 0);
1704
1705        /*
1706         * Only do per_cpu_trap_init() for first TC of Each VPE.
1707         * Note that this hack assumes that the SMTC init code
1708         * assigns TCs consecutively and in ascending order.
1709         */
1710
1711        if (((read_c0_tcbind() & TCBIND_CURTC) != 0) &&
1712            ((read_c0_tcbind() & TCBIND_CURVPE) == cpu_data[cpu - 1].vpe_id))
1713                secondaryTC = 1;
1714#endif /* CONFIG_MIPS_MT_SMTC */
1715
1716        /*
1717         * Disable coprocessors and select 32-bit or 64-bit addressing
1718         * and the 16/32 or 32/32 FPR register model.  Reset the BEV
1719         * flag that some firmware may have left set and the TS bit (for
1720         * IP27).  Set XX for ISA IV code to work.
1721         */
1722#ifdef CONFIG_64BIT
1723        status_set |= ST0_FR|ST0_KX|ST0_SX|ST0_UX;
1724#endif
1725        if (current_cpu_data.isa_level & MIPS_CPU_ISA_IV)
1726                status_set |= ST0_XX;
1727        if (cpu_has_dsp)
1728                status_set |= ST0_MX;
1729
1730        change_c0_status(ST0_CU|ST0_MX|ST0_RE|ST0_FR|ST0_BEV|ST0_TS|ST0_KX|ST0_SX|ST0_UX,
1731                         status_set);
1732
1733        if (cpu_has_mips_r2)
1734                hwrena |= 0x0000000f;
1735
1736        if (!noulri && cpu_has_userlocal)
1737                hwrena |= (1 << 29);
1738
1739        if (hwrena)
1740                write_c0_hwrena(hwrena);
1741
1742#ifdef CONFIG_MIPS_MT_SMTC
1743        if (!secondaryTC) {
1744#endif /* CONFIG_MIPS_MT_SMTC */
1745
1746        if (cpu_has_veic || cpu_has_vint) {
1747                unsigned long sr = set_c0_status(ST0_BEV);
1748                write_c0_ebase(ebase);
1749                write_c0_status(sr);
1750                /* Setting vector spacing enables EI/VI mode  */
1751                change_c0_intctl(0x3e0, VECTORSPACING);
1752        }
1753        if (cpu_has_divec) {
1754                if (cpu_has_mipsmt) {
1755                        unsigned int vpflags = dvpe();
1756                        set_c0_cause(CAUSEF_IV);
1757                        evpe(vpflags);
1758                } else
1759                        set_c0_cause(CAUSEF_IV);
1760        }
1761
1762        /*
1763         * Before R2 both interrupt numbers were fixed to 7, so on R2 only:
1764         *
1765         *  o read IntCtl.IPTI to determine the timer interrupt
1766         *  o read IntCtl.IPPCI to determine the performance counter interrupt
1767         */
1768        if (cpu_has_mips_r2) {
1769                cp0_compare_irq_shift = CAUSEB_TI - CAUSEB_IP;
1770                cp0_compare_irq = (read_c0_intctl() >> INTCTLB_IPTI) & 7;
1771                cp0_perfcount_irq = (read_c0_intctl() >> INTCTLB_IPPCI) & 7;
1772                if (cp0_perfcount_irq == cp0_compare_irq)
1773                        cp0_perfcount_irq = -1;
1774        } else {
1775                cp0_compare_irq = CP0_LEGACY_COMPARE_IRQ;
1776                cp0_compare_irq_shift = CP0_LEGACY_PERFCNT_IRQ;
1777                cp0_perfcount_irq = -1;
1778        }
1779
1780#ifdef CONFIG_MIPS_MT_SMTC
1781        }
1782#endif /* CONFIG_MIPS_MT_SMTC */
1783
1784        if (!cpu_data[cpu].asid_cache)
1785                cpu_data[cpu].asid_cache = ASID_FIRST_VERSION;
1786
1787        atomic_inc(&init_mm.mm_count);
1788        current->active_mm = &init_mm;
1789        BUG_ON(current->mm);
1790        enter_lazy_tlb(&init_mm, current);
1791
1792#ifdef CONFIG_MIPS_MT_SMTC
1793        if (bootTC) {
1794#endif /* CONFIG_MIPS_MT_SMTC */
1795                /* Boot CPU's cache setup in setup_arch(). */
1796                if (!is_boot_cpu)
1797                        cpu_cache_init();
1798                tlb_init();
1799#ifdef CONFIG_MIPS_MT_SMTC
1800        } else if (!secondaryTC) {
1801                /*
1802                 * First TC in non-boot VPE must do subset of tlb_init()
1803                 * for MMU countrol registers.
1804                 */
1805                write_c0_pagemask(PM_DEFAULT_MASK);
1806                write_c0_wired(0);
1807        }
1808#endif /* CONFIG_MIPS_MT_SMTC */
1809        TLBMISS_HANDLER_SETUP();
1810}
1811
1812/* Install CPU exception handler */
1813void set_handler(unsigned long offset, void *addr, unsigned long size)
1814{
1815#ifdef CONFIG_CPU_MICROMIPS
1816        memcpy((void *)(ebase + offset), ((unsigned char *)addr - 1), size);
1817#else
1818        memcpy((void *)(ebase + offset), addr, size);
1819#endif
1820        local_flush_icache_range(ebase + offset, ebase + offset + size);
1821}
1822
1823static char panic_null_cerr[] =
1824        "Trying to set NULL cache error exception handler";
1825
1826/*
1827 * Install uncached CPU exception handler.
1828 * This is suitable only for the cache error exception which is the only
1829 * exception handler that is being run uncached.
1830 */
1831void set_uncached_handler(unsigned long offset, void *addr,
1832        unsigned long size)
1833{
1834        unsigned long uncached_ebase = CKSEG1ADDR(ebase);
1835
1836        if (!addr)
1837                panic(panic_null_cerr);
1838
1839        memcpy((void *)(uncached_ebase + offset), addr, size);
1840}
1841
1842static int __initdata rdhwr_noopt;
1843static int __init set_rdhwr_noopt(char *str)
1844{
1845        rdhwr_noopt = 1;
1846        return 1;
1847}
1848
1849__setup("rdhwr_noopt", set_rdhwr_noopt);
1850
1851void __init trap_init(void)
1852{
1853        extern char except_vec3_generic;
1854        extern char except_vec4;
1855        extern char except_vec3_r4000;
1856        unsigned long i;
1857
1858        check_wait();
1859
1860#if defined(CONFIG_KGDB)
1861        if (kgdb_early_setup)
1862                return; /* Already done */
1863#endif
1864
1865        if (cpu_has_veic || cpu_has_vint) {
1866                unsigned long size = 0x200 + VECTORSPACING*64;
1867                ebase = (unsigned long)
1868                        __alloc_bootmem(size, 1 << fls(size), 0);
1869        } else {
1870#ifdef CONFIG_KVM_GUEST
1871#define KVM_GUEST_KSEG0     0x40000000
1872        ebase = KVM_GUEST_KSEG0;
1873#else
1874        ebase = CKSEG0;
1875#endif
1876                if (cpu_has_mips_r2)
1877                        ebase += (read_c0_ebase() & 0x3ffff000);
1878        }
1879
1880        if (cpu_has_mmips) {
1881                unsigned int config3 = read_c0_config3();
1882
1883                if (IS_ENABLED(CONFIG_CPU_MICROMIPS))
1884                        write_c0_config3(config3 | MIPS_CONF3_ISA_OE);
1885                else
1886                        write_c0_config3(config3 & ~MIPS_CONF3_ISA_OE);
1887        }
1888
1889        if (board_ebase_setup)
1890                board_ebase_setup();
1891        per_cpu_trap_init(true);
1892
1893        /*
1894         * Copy the generic exception handlers to their final destination.
1895         * This will be overriden later as suitable for a particular
1896         * configuration.
1897         */
1898        set_handler(0x180, &except_vec3_generic, 0x80);
1899
1900        /*
1901         * Setup default vectors
1902         */
1903        for (i = 0; i <= 31; i++)
1904                set_except_vector(i, handle_reserved);
1905
1906        /*
1907         * Copy the EJTAG debug exception vector handler code to it's final
1908         * destination.
1909         */
1910        if (cpu_has_ejtag && board_ejtag_handler_setup)
1911                board_ejtag_handler_setup();
1912
1913        /*
1914         * Only some CPUs have the watch exceptions.
1915         */
1916        if (cpu_has_watch)
1917                set_except_vector(23, handle_watch);
1918
1919        /*
1920         * Initialise interrupt handlers
1921         */
1922        if (cpu_has_veic || cpu_has_vint) {
1923                int nvec = cpu_has_veic ? 64 : 8;
1924                for (i = 0; i < nvec; i++)
1925                        set_vi_handler(i, NULL);
1926        }
1927        else if (cpu_has_divec)
1928                set_handler(0x200, &except_vec4, 0x8);
1929
1930        /*
1931         * Some CPUs can enable/disable for cache parity detection, but does
1932         * it different ways.
1933         */
1934        parity_protection_init();
1935
1936        /*
1937         * The Data Bus Errors / Instruction Bus Errors are signaled
1938         * by external hardware.  Therefore these two exceptions
1939         * may have board specific handlers.
1940         */
1941        if (board_be_init)
1942                board_be_init();
1943
1944        set_except_vector(0, using_rollback_handler() ? rollback_handle_int
1945                                                      : handle_int);
1946        set_except_vector(1, handle_tlbm);
1947        set_except_vector(2, handle_tlbl);
1948        set_except_vector(3, handle_tlbs);
1949
1950        set_except_vector(4, handle_adel);
1951        set_except_vector(5, handle_ades);
1952
1953        set_except_vector(6, handle_ibe);
1954        set_except_vector(7, handle_dbe);
1955
1956        set_except_vector(8, handle_sys);
1957        set_except_vector(9, handle_bp);
1958        set_except_vector(10, rdhwr_noopt ? handle_ri :
1959                          (cpu_has_vtag_icache ?
1960                           handle_ri_rdhwr_vivt : handle_ri_rdhwr));
1961        set_except_vector(11, handle_cpu);
1962        set_except_vector(12, handle_ov);
1963        set_except_vector(13, handle_tr);
1964
1965        if (current_cpu_type() == CPU_R6000 ||
1966            current_cpu_type() == CPU_R6000A) {
1967                /*
1968                 * The R6000 is the only R-series CPU that features a machine
1969                 * check exception (similar to the R4000 cache error) and
1970                 * unaligned ldc1/sdc1 exception.  The handlers have not been
1971                 * written yet.  Well, anyway there is no R6000 machine on the
1972                 * current list of targets for Linux/MIPS.
1973                 * (Duh, crap, there is someone with a triple R6k machine)
1974                 */
1975                //set_except_vector(14, handle_mc);
1976                //set_except_vector(15, handle_ndc);
1977        }
1978
1979
1980        if (board_nmi_handler_setup)
1981                board_nmi_handler_setup();
1982
1983        if (cpu_has_fpu && !cpu_has_nofpuex)
1984                set_except_vector(15, handle_fpe);
1985
1986        set_except_vector(22, handle_mdmx);
1987
1988        if (cpu_has_mcheck)
1989                set_except_vector(24, handle_mcheck);
1990
1991        if (cpu_has_mipsmt)
1992                set_except_vector(25, handle_mt);
1993
1994        set_except_vector(26, handle_dsp);
1995
1996        if (board_cache_error_setup)
1997                board_cache_error_setup();
1998
1999        if (cpu_has_vce)
2000                /* Special exception: R4[04]00 uses also the divec space. */
2001                set_handler(0x180, &except_vec3_r4000, 0x100);
2002        else if (cpu_has_4kex)
2003                set_handler(0x180, &except_vec3_generic, 0x80);
2004        else
2005                set_handler(0x080, &except_vec3_generic, 0x80);
2006
2007        local_flush_icache_range(ebase, ebase + 0x400);
2008
2009        sort_extable(__start___dbe_table, __stop___dbe_table);
2010
2011        cu2_notifier(default_cu2_call, 0x80000000);     /* Run last  */
2012}
2013