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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
62 extern void check_wait(void);
63 extern asmlinkage void rollback_handle_int(void);
64 extern asmlinkage void handle_int(void);
65 extern u32 handle_tlbl[];
66 extern u32 handle_tlbs[];
67 extern u32 handle_tlbm[];
68 extern asmlinkage void handle_adel(void);
69 extern asmlinkage void handle_ades(void);
70 extern asmlinkage void handle_ibe(void);
71 extern asmlinkage void handle_dbe(void);
72 extern asmlinkage void handle_sys(void);
73 extern asmlinkage void handle_bp(void);
74 extern asmlinkage void handle_ri(void);
75 extern asmlinkage void handle_ri_rdhwr_vivt(void);
76 extern asmlinkage void handle_ri_rdhwr(void);
77 extern asmlinkage void handle_cpu(void);
78 extern asmlinkage void handle_ov(void);
79 extern asmlinkage void handle_tr(void);
80 extern asmlinkage void handle_fpe(void);
81 extern asmlinkage void handle_mdmx(void);
82 extern asmlinkage void handle_watch(void);
83 extern asmlinkage void handle_mt(void);
84 extern asmlinkage void handle_dsp(void);
85 extern asmlinkage void handle_mcheck(void);
86 extern asmlinkage void handle_reserved(void);
87
88 void (*board_be_init)(void);
89 int (*board_be_handler)(struct pt_regs *regs, int is_fixup);
90 void (*board_nmi_handler_setup)(void);
91 void (*board_ejtag_handler_setup)(void);
92 void (*board_bind_eic_interrupt)(int irq, int regset);
93 void (*board_ebase_setup)(void);
94 void(*board_cache_error_setup)(void);
95
96 static 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
119 int raw_show_trace;
120 static 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
128 static 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  */
153 static 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
183 void 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
207 static 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
226 static 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  */
325 void show_regs(struct pt_regs *regs)
326 {
327         __show_regs((struct pt_regs *)regs);
328 }
329
330 void show_registers(struct pt_regs *regs)
331 {
332         const int field = 2 * sizeof(unsigned long);
333         mm_segment_t old_fs = get_fs();
334
335         __show_regs(regs);
336         print_modules();
337         printk("Process %s (pid: %d, threadinfo=%p, task=%p, tls=%0*lx)\n",
338                current->comm, current->pid, current_thread_info(), current,
339               field, current_thread_info()->tp_value);
340         if (cpu_has_userlocal) {
341                 unsigned long tls;
342
343                 tls = read_c0_userlocal();
344                 if (tls != current_thread_info()->tp_value)
345                         printk("*HwTLS: %0*lx\n", field, tls);
346         }
347
348         if (!user_mode(regs))
349                 /* Necessary for getting the correct stack content */
350                 set_fs(KERNEL_DS);
351         show_stacktrace(current, regs);
352         show_code((unsigned int __user *) regs->cp0_epc);
353         printk("\n");
354         set_fs(old_fs);
355 }
356
357 static int regs_to_trapnr(struct pt_regs *regs)
358 {
359         return (regs->cp0_cause >> 2) & 0x1f;
360 }
361
362 static DEFINE_RAW_SPINLOCK(die_lock);
363
364 void __noreturn die(const char *str, struct pt_regs *regs)
365 {
366         static int die_counter;
367         int sig = SIGSEGV;
368 #ifdef CONFIG_MIPS_MT_SMTC
369         unsigned long dvpret;
370 #endif /* CONFIG_MIPS_MT_SMTC */
371
372         oops_enter();
373
374         if (notify_die(DIE_OOPS, str, regs, 0, regs_to_trapnr(regs),
375                        SIGSEGV) == NOTIFY_STOP)
376                 sig = 0;
377
378         console_verbose();
379         raw_spin_lock_irq(&die_lock);
380 #ifdef CONFIG_MIPS_MT_SMTC
381         dvpret = dvpe();
382 #endif /* CONFIG_MIPS_MT_SMTC */
383         bust_spinlocks(1);
384 #ifdef CONFIG_MIPS_MT_SMTC
385         mips_mt_regdump(dvpret);
386 #endif /* CONFIG_MIPS_MT_SMTC */
387
388         printk("%s[#%d]:\n", str, ++die_counter);
389         show_registers(regs);
390         add_taint(TAINT_DIE, LOCKDEP_NOW_UNRELIABLE);
391         raw_spin_unlock_irq(&die_lock);
392
393         oops_exit();
394
395         if (in_interrupt())
396                 panic("Fatal exception in interrupt");
397
398         if (panic_on_oops) {
399                 printk(KERN_EMERG "Fatal exception: panic in 5 seconds");
400                 ssleep(5);
401                 panic("Fatal exception");
402         }
403
404         if (regs && kexec_should_crash(current))
405                 crash_kexec(regs);
406
407         do_exit(sig);
408 }
409
410 extern struct exception_table_entry __start___dbe_table[];
411 extern struct exception_table_entry __stop___dbe_table[];
412
413 __asm__(
414 "       .section        __dbe_table, \"a\"\n"
415 "       .previous                       \n");
416
417 /* Given an address, look for it in the exception tables. */
418 static const struct exception_table_entry *search_dbe_tables(unsigned long addr)
419 {
420         const struct exception_table_entry *e;
421
422         e = search_extable(__start___dbe_table, __stop___dbe_table - 1, addr);
423         if (!e)
424                 e = search_module_dbetables(addr);
425         return e;
426 }
427
428 asmlinkage void do_be(struct pt_regs *regs)
429 {
430         const int field = 2 * sizeof(unsigned long);
431         const struct exception_table_entry *fixup = NULL;
432         int data = regs->cp0_cause & 4;
433         int action = MIPS_BE_FATAL;
434         enum ctx_state prev_state;
435
436         prev_state = exception_enter();
437         /* XXX For now.  Fixme, this searches the wrong table ...  */
438         if (data && !user_mode(regs))
439                 fixup = search_dbe_tables(exception_epc(regs));
440
441         if (fixup)
442                 action = MIPS_BE_FIXUP;
443
444         if (board_be_handler)
445                 action = board_be_handler(regs, fixup != NULL);
446
447         switch (action) {
448         case MIPS_BE_DISCARD:
449                 goto out;
450         case MIPS_BE_FIXUP:
451                 if (fixup) {
452                         regs->cp0_epc = fixup->nextinsn;
453                         goto out;
454                 }
455                 break;
456         default:
457                 break;
458         }
459
460         /*
461          * Assume it would be too dangerous to continue ...
462          */
463         printk(KERN_ALERT "%s bus error, epc == %0*lx, ra == %0*lx\n",
464                data ? "Data" : "Instruction",
465                field, regs->cp0_epc, field, regs->regs[31]);
466         if (notify_die(DIE_OOPS, "bus error", regs, 0, regs_to_trapnr(regs),
467                        SIGBUS) == NOTIFY_STOP)
468                 goto out;
469
470         die_if_kernel("Oops", regs);
471         force_sig(SIGBUS, current);
472
473 out:
474         exception_exit(prev_state);
475 }
476
477 /*
478  * ll/sc, rdhwr, sync emulation
479  */
480
481 #define OPCODE 0xfc000000
482 #define BASE   0x03e00000
483 #define RT     0x001f0000
484 #define OFFSET 0x0000ffff
485 #define LL     0xc0000000
486 #define SC     0xe0000000
487 #define SPEC0  0x00000000
488 #define SPEC3  0x7c000000
489 #define RD     0x0000f800
490 #define FUNC   0x0000003f
491 #define SYNC   0x0000000f
492 #define RDHWR  0x0000003b
493
494 /*  microMIPS definitions   */
495 #define MM_POOL32A_FUNC 0xfc00ffff
496 #define MM_RDHWR        0x00006b3c
497 #define MM_RS           0x001f0000
498 #define MM_RT           0x03e00000
499
500 /*
501  * The ll_bit is cleared by r*_switch.S
502  */
503
504 unsigned int ll_bit;
505 struct task_struct *ll_task;
506
507 static inline int simulate_ll(struct pt_regs *regs, unsigned int opcode)
508 {
509         unsigned long value, __user *vaddr;
510         long offset;
511
512         /*
513          * analyse the ll instruction that just caused a ri exception
514          * and put the referenced address to addr.
515          */
516
517         /* sign extend offset */
518         offset = opcode & OFFSET;
519         offset <<= 16;
520         offset >>= 16;
521
522         vaddr = (unsigned long __user *)
523                 ((unsigned long)(regs->regs[(opcode & BASE) >> 21]) + offset);
524
525         if ((unsigned long)vaddr & 3)
526                 return SIGBUS;
527         if (get_user(value, vaddr))
528                 return SIGSEGV;
529
530         preempt_disable();
531
532         if (ll_task == NULL || ll_task == current) {
533                 ll_bit = 1;
534         } else {
535                 ll_bit = 0;
536         }
537         ll_task = current;
538
539         preempt_enable();
540
541         regs->regs[(opcode & RT) >> 16] = value;
542
543         return 0;
544 }
545
546 static inline int simulate_sc(struct pt_regs *regs, unsigned int opcode)
547 {
548         unsigned long __user *vaddr;
549         unsigned long reg;
550         long offset;
551
552         /*
553          * analyse the sc instruction that just caused a ri exception
554          * and put the referenced address to addr.
555          */
556
557         /* sign extend offset */
558         offset = opcode & OFFSET;
559         offset <<= 16;
560         offset >>= 16;
561
562         vaddr = (unsigned long __user *)
563                 ((unsigned long)(regs->regs[(opcode & BASE) >> 21]) + offset);
564         reg = (opcode & RT) >> 16;
565
566         if ((unsigned long)vaddr & 3)
567                 return SIGBUS;
568
569         preempt_disable();
570
571         if (ll_bit == 0 || ll_task != current) {
572                 regs->regs[reg] = 0;
573                 preempt_enable();
574                 return 0;
575         }
576
577         preempt_enable();
578
579         if (put_user(regs->regs[reg], vaddr))
580                 return SIGSEGV;
581
582         regs->regs[reg] = 1;
583
584         return 0;
585 }
586
587 /*
588  * ll uses the opcode of lwc0 and sc uses the opcode of swc0.  That is both
589  * opcodes are supposed to result in coprocessor unusable exceptions if
590  * executed on ll/sc-less processors.  That's the theory.  In practice a
591  * few processors such as NEC's VR4100 throw reserved instruction exceptions
592  * instead, so we're doing the emulation thing in both exception handlers.
593  */
594 static int simulate_llsc(struct pt_regs *regs, unsigned int opcode)
595 {
596         if ((opcode & OPCODE) == LL) {
597                 perf_sw_event(PERF_COUNT_SW_EMULATION_FAULTS,
598                                 1, regs, 0);
599                 return simulate_ll(regs, opcode);
600         }
601         if ((opcode & OPCODE) == SC) {
602                 perf_sw_event(PERF_COUNT_SW_EMULATION_FAULTS,
603                                 1, regs, 0);
604                 return simulate_sc(regs, opcode);
605         }
606
607         return -1;                      /* Must be something else ... */
608 }
609
610 /*
611  * Simulate trapping 'rdhwr' instructions to provide user accessible
612  * registers not implemented in hardware.
613  */
614 static int simulate_rdhwr(struct pt_regs *regs, int rd, int rt)
615 {
616         struct thread_info *ti = task_thread_info(current);
617
618         perf_sw_event(PERF_COUNT_SW_EMULATION_FAULTS,
619                         1, regs, 0);
620         switch (rd) {
621         case 0:         /* CPU number */
622                 regs->regs[rt] = smp_processor_id();
623                 return 0;
624         case 1:         /* SYNCI length */
625                 regs->regs[rt] = min(current_cpu_data.dcache.linesz,
626                                      current_cpu_data.icache.linesz);
627                 return 0;
628         case 2:         /* Read count register */
629                 regs->regs[rt] = read_c0_count();
630                 return 0;
631         case 3:         /* Count register resolution */
632                 switch (current_cpu_type()) {
633                 case CPU_20KC:
634                 case CPU_25KF:
635                         regs->regs[rt] = 1;
636                         break;
637                 default:
638                         regs->regs[rt] = 2;
639                 }
640                 return 0;
641         case 29:
642                 regs->regs[rt] = ti->tp_value;
643                 return 0;
644         default:
645                 return -1;
646         }
647 }
648
649 static int simulate_rdhwr_normal(struct pt_regs *regs, unsigned int opcode)
650 {
651         if ((opcode & OPCODE) == SPEC3 && (opcode & FUNC) == RDHWR) {
652                 int rd = (opcode & RD) >> 11;
653                 int rt = (opcode & RT) >> 16;
654
655                 simulate_rdhwr(regs, rd, rt);
656                 return 0;
657         }
658
659         /* Not ours.  */
660         return -1;
661 }
662
663 static int simulate_rdhwr_mm(struct pt_regs *regs, unsigned short opcode)
664 {
665         if ((opcode & MM_POOL32A_FUNC) == MM_RDHWR) {
666                 int rd = (opcode & MM_RS) >> 16;
667                 int rt = (opcode & MM_RT) >> 21;
668                 simulate_rdhwr(regs, rd, rt);
669                 return 0;
670         }
671
672         /* Not ours.  */
673         return -1;
674 }
675
676 static int simulate_sync(struct pt_regs *regs, unsigned int opcode)
677 {
678         if ((opcode & OPCODE) == SPEC0 && (opcode & FUNC) == SYNC) {
679                 perf_sw_event(PERF_COUNT_SW_EMULATION_FAULTS,
680                                 1, regs, 0);
681                 return 0;
682         }
683
684         return -1;                      /* Must be something else ... */
685 }
686
687 asmlinkage void do_ov(struct pt_regs *regs)
688 {
689         enum ctx_state prev_state;
690         siginfo_t info;
691
692         prev_state = exception_enter();
693         die_if_kernel("Integer overflow", regs);
694
695         info.si_code = FPE_INTOVF;
696         info.si_signo = SIGFPE;
697         info.si_errno = 0;
698         info.si_addr = (void __user *) regs->cp0_epc;
699         force_sig_info(SIGFPE, &info, current);
700         exception_exit(prev_state);
701 }
702
703 int process_fpemu_return(int sig, void __user *fault_addr)
704 {
705         if (sig == SIGSEGV || sig == SIGBUS) {
706                 struct siginfo si = {0};
707                 si.si_addr = fault_addr;
708                 si.si_signo = sig;
709                 if (sig == SIGSEGV) {
710                         if (find_vma(current->mm, (unsigned long)fault_addr))
711                                 si.si_code = SEGV_ACCERR;
712                         else
713                                 si.si_code = SEGV_MAPERR;
714                 } else {
715                         si.si_code = BUS_ADRERR;
716                 }
717                 force_sig_info(sig, &si, current);
718                 return 1;
719         } else if (sig) {
720                 force_sig(sig, current);
721                 return 1;
722         } else {
723                 return 0;
724         }
725 }
726
727 /*
728  * XXX Delayed fp exceptions when doing a lazy ctx switch XXX
729  */
730 asmlinkage void do_fpe(struct pt_regs *regs, unsigned long fcr31)
731 {
732         enum ctx_state prev_state;
733         siginfo_t info = {0};
734
735         prev_state = exception_enter();
736         if (notify_die(DIE_FP, "FP exception", regs, 0, regs_to_trapnr(regs),
737                        SIGFPE) == NOTIFY_STOP)
738                 goto out;
739         die_if_kernel("FP exception in kernel code", regs);
740
741         if (fcr31 & FPU_CSR_UNI_X) {
742                 int sig;
743                 void __user *fault_addr = NULL;
744
745                 /*
746                  * Unimplemented operation exception.  If we've got the full
747                  * software emulator on-board, let's use it...
748                  *
749                  * Force FPU to dump state into task/thread context.  We're
750                  * moving a lot of data here for what is probably a single
751                  * instruction, but the alternative is to pre-decode the FP
752                  * register operands before invoking the emulator, which seems
753                  * a bit extreme for what should be an infrequent event.
754                  */
755                 /* Ensure 'resume' not overwrite saved fp context again. */
756                 lose_fpu(1);
757
758                 /* Run the emulator */
759                 sig = fpu_emulator_cop1Handler(regs, &current->thread.fpu, 1,
760                                                &fault_addr);
761
762                 /*
763                  * We can't allow the emulated instruction to leave any of
764                  * the cause bit set in $fcr31.
765                  */
766                 current->thread.fpu.fcr31 &= ~FPU_CSR_ALL_X;
767
768                 /* Restore the hardware register state */
769                 own_fpu(1);     /* Using the FPU again.  */
770
771                 /* If something went wrong, signal */
772                 process_fpemu_return(sig, fault_addr);
773
774                 goto out;
775         } else if (fcr31 & FPU_CSR_INV_X)
776                 info.si_code = FPE_FLTINV;
777         else if (fcr31 & FPU_CSR_DIV_X)
778                 info.si_code = FPE_FLTDIV;
779         else if (fcr31 & FPU_CSR_OVF_X)
780                 info.si_code = FPE_FLTOVF;
781         else if (fcr31 & FPU_CSR_UDF_X)
782                 info.si_code = FPE_FLTUND;
783         else if (fcr31 & FPU_CSR_INE_X)
784                 info.si_code = FPE_FLTRES;
785         else
786                 info.si_code = __SI_FAULT;
787         info.si_signo = SIGFPE;
788         info.si_errno = 0;
789         info.si_addr = (void __user *) regs->cp0_epc;
790         force_sig_info(SIGFPE, &info, current);
791
792 out:
793         exception_exit(prev_state);
794 }
795
796 static void do_trap_or_bp(struct pt_regs *regs, unsigned int code,
797         const char *str)
798 {
799         siginfo_t info;
800         char b[40];
801
802 #ifdef CONFIG_KGDB_LOW_LEVEL_TRAP
803         if (kgdb_ll_trap(DIE_TRAP, str, regs, code, regs_to_trapnr(regs), SIGTRAP) == NOTIFY_STOP)
804                 return;
805 #endif /* CONFIG_KGDB_LOW_LEVEL_TRAP */
806
807         if (notify_die(DIE_TRAP, str, regs, code, regs_to_trapnr(regs),
808                        SIGTRAP) == NOTIFY_STOP)
809                 return;
810
811         /*
812          * A short test says that IRIX 5.3 sends SIGTRAP for all trap
813          * insns, even for trap and break codes that indicate arithmetic
814          * failures.  Weird ...
815          * But should we continue the brokenness???  --macro
816          */
817         switch (code) {
818         case BRK_OVERFLOW:
819         case BRK_DIVZERO:
820                 scnprintf(b, sizeof(b), "%s instruction in kernel code", str);
821                 die_if_kernel(b, regs);
822                 if (code == BRK_DIVZERO)
823                         info.si_code = FPE_INTDIV;
824                 else
825                         info.si_code = FPE_INTOVF;
826                 info.si_signo = SIGFPE;
827                 info.si_errno = 0;
828                 info.si_addr = (void __user *) regs->cp0_epc;
829                 force_sig_info(SIGFPE, &info, current);
830                 break;
831         case BRK_BUG:
832                 die_if_kernel("Kernel bug detected", regs);
833                 force_sig(SIGTRAP, current);
834                 break;
835         case BRK_MEMU:
836                 /*
837                  * Address errors may be deliberately induced by the FPU
838                  * emulator to retake control of the CPU after executing the
839                  * instruction in the delay slot of an emulated branch.
840                  *
841                  * Terminate if exception was recognized as a delay slot return
842                  * otherwise handle as normal.
843                  */
844                 if (do_dsemulret(regs))
845                         return;
846
847                 die_if_kernel("Math emu break/trap", regs);
848                 force_sig(SIGTRAP, current);
849                 break;
850         default:
851                 scnprintf(b, sizeof(b), "%s instruction in kernel code", str);
852                 die_if_kernel(b, regs);
853                 force_sig(SIGTRAP, current);
854         }
855 }
856
857 asmlinkage void do_bp(struct pt_regs *regs)
858 {
859         unsigned int opcode, bcode;
860         enum ctx_state prev_state;
861         unsigned long epc;
862         u16 instr[2];
863
864         prev_state = exception_enter();
865         if (get_isa16_mode(regs->cp0_epc)) {
866                 /* Calculate EPC. */
867                 epc = exception_epc(regs);
868                 if (cpu_has_mmips) {
869                         if ((__get_user(instr[0], (u16 __user *)msk_isa16_mode(epc)) ||
870                             (__get_user(instr[1], (u16 __user *)msk_isa16_mode(epc + 2)))))
871                                 goto out_sigsegv;
872                     opcode = (instr[0] << 16) | instr[1];
873                 } else {
874                     /* MIPS16e mode */
875                     if (__get_user(instr[0], (u16 __user *)msk_isa16_mode(epc)))
876                                 goto out_sigsegv;
877                     bcode = (instr[0] >> 6) & 0x3f;
878                     do_trap_or_bp(regs, bcode, "Break");
879                     goto out;
880                 }
881         } else {
882                 if (__get_user(opcode, (unsigned int __user *) exception_epc(regs)))
883                         goto out_sigsegv;
884         }
885
886         /*
887          * There is the ancient bug in the MIPS assemblers that the break
888          * code starts left to bit 16 instead to bit 6 in the opcode.
889          * Gas is bug-compatible, but not always, grrr...
890          * We handle both cases with a simple heuristics.  --macro
891          */
892         bcode = ((opcode >> 6) & ((1 << 20) - 1));
893         if (bcode >= (1 << 10))
894                 bcode >>= 10;
895
896         /*
897          * notify the kprobe handlers, if instruction is likely to
898          * pertain to them.
899          */
900         switch (bcode) {
901         case BRK_KPROBE_BP:
902                 if (notify_die(DIE_BREAK, "debug", regs, bcode,
903                                regs_to_trapnr(regs), SIGTRAP) == NOTIFY_STOP)
904                         goto out;
905                 else
906                         break;
907         case BRK_KPROBE_SSTEPBP:
908                 if (notify_die(DIE_SSTEPBP, "single_step", regs, bcode,
909                                regs_to_trapnr(regs), SIGTRAP) == NOTIFY_STOP)
910                         goto out;
911                 else
912                         break;
913         default:
914                 break;
915         }
916
917         do_trap_or_bp(regs, bcode, "Break");
918
919 out:
920         exception_exit(prev_state);
921         return;
922
923 out_sigsegv:
924         force_sig(SIGSEGV, current);
925         goto out;
926 }
927
928 asmlinkage void do_tr(struct pt_regs *regs)
929 {
930         u32 opcode, tcode = 0;
931         enum ctx_state prev_state;
932         u16 instr[2];
933         unsigned long epc = msk_isa16_mode(exception_epc(regs));
934
935         prev_state = exception_enter();
936         if (get_isa16_mode(regs->cp0_epc)) {
937                 if (__get_user(instr[0], (u16 __user *)(epc + 0)) ||
938                     __get_user(instr[1], (u16 __user *)(epc + 2)))
939                         goto out_sigsegv;
940                 opcode = (instr[0] << 16) | instr[1];
941                 /* Immediate versions don't provide a code.  */
942                 if (!(opcode & OPCODE))
943                         tcode = (opcode >> 12) & ((1 << 4) - 1);
944         } else {
945                 if (__get_user(opcode, (u32 __user *)epc))
946                         goto out_sigsegv;
947                 /* Immediate versions don't provide a code.  */
948                 if (!(opcode & OPCODE))
949                         tcode = (opcode >> 6) & ((1 << 10) - 1);
950         }
951
952         do_trap_or_bp(regs, tcode, "Trap");
953
954 out:
955         exception_exit(prev_state);
956         return;
957
958 out_sigsegv:
959         force_sig(SIGSEGV, current);
960         goto out;
961 }
962
963 asmlinkage void do_ri(struct pt_regs *regs)
964 {
965         unsigned int __user *epc = (unsigned int __user *)exception_epc(regs);
966         unsigned long old_epc = regs->cp0_epc;
967         unsigned long old31 = regs->regs[31];
968         enum ctx_state prev_state;
969         unsigned int opcode = 0;
970         int status = -1;
971
972         prev_state = exception_enter();
973         if (notify_die(DIE_RI, "RI Fault", regs, 0, regs_to_trapnr(regs),
974                        SIGILL) == NOTIFY_STOP)
975                 goto out;
976
977         die_if_kernel("Reserved instruction in kernel code", regs);
978
979         if (unlikely(compute_return_epc(regs) < 0))
980                 goto out;
981
982         if (get_isa16_mode(regs->cp0_epc)) {
983                 unsigned short mmop[2] = { 0 };
984
985                 if (unlikely(get_user(mmop[0], epc) < 0))
986                         status = SIGSEGV;
987                 if (unlikely(get_user(mmop[1], epc) < 0))
988                         status = SIGSEGV;
989                 opcode = (mmop[0] << 16) | mmop[1];
990
991                 if (status < 0)
992                         status = simulate_rdhwr_mm(regs, opcode);
993         } else {
994                 if (unlikely(get_user(opcode, epc) < 0))
995                         status = SIGSEGV;
996
997                 if (!cpu_has_llsc && status < 0)
998                         status = simulate_llsc(regs, opcode);
999
1000                 if (status < 0)
1001                         status = simulate_rdhwr_normal(regs, opcode);
1002
1003                 if (status < 0)
1004                         status = simulate_sync(regs, opcode);
1005         }
1006
1007         if (status < 0)
1008                 status = SIGILL;
1009
1010         if (unlikely(status > 0)) {
1011                 regs->cp0_epc = old_epc;                /* Undo skip-over.  */
1012                 regs->regs[31] = old31;
1013                 force_sig(status, current);
1014         }
1015
1016 out:
1017         exception_exit(prev_state);
1018 }
1019
1020 /*
1021  * MIPS MT processors may have fewer FPU contexts than CPU threads. If we've
1022  * emulated more than some threshold number of instructions, force migration to
1023  * a "CPU" that has FP support.
1024  */
1025 static void mt_ase_fp_affinity(void)
1026 {
1027 #ifdef CONFIG_MIPS_MT_FPAFF
1028         if (mt_fpemul_threshold > 0 &&
1029              ((current->thread.emulated_fp++ > mt_fpemul_threshold))) {
1030                 /*
1031                  * If there's no FPU present, or if the application has already
1032                  * restricted the allowed set to exclude any CPUs with FPUs,
1033                  * we'll skip the procedure.
1034                  */
1035                 if (cpus_intersects(current->cpus_allowed, mt_fpu_cpumask)) {
1036                         cpumask_t tmask;
1037
1038                         current->thread.user_cpus_allowed
1039                                 = current->cpus_allowed;
1040                         cpus_and(tmask, current->cpus_allowed,
1041                                 mt_fpu_cpumask);
1042                         set_cpus_allowed_ptr(current, &tmask);
1043                         set_thread_flag(TIF_FPUBOUND);
1044                 }
1045         }
1046 #endif /* CONFIG_MIPS_MT_FPAFF */
1047 }
1048
1049 /*
1050  * No lock; only written during early bootup by CPU 0.
1051  */
1052 static RAW_NOTIFIER_HEAD(cu2_chain);
1053
1054 int __ref register_cu2_notifier(struct notifier_block *nb)
1055 {
1056         return raw_notifier_chain_register(&cu2_chain, nb);
1057 }
1058
1059 int cu2_notifier_call_chain(unsigned long val, void *v)
1060 {
1061         return raw_notifier_call_chain(&cu2_chain, val, v);
1062 }
1063
1064 static int default_cu2_call(struct notifier_block *nfb, unsigned long action,
1065         void *data)
1066 {
1067         struct pt_regs *regs = data;
1068
1069         die_if_kernel("COP2: Unhandled kernel unaligned access or invalid "
1070                               "instruction", regs);
1071         force_sig(SIGILL, current);
1072
1073         return NOTIFY_OK;
1074 }
1075
1076 asmlinkage void do_cpu(struct pt_regs *regs)
1077 {
1078         enum ctx_state prev_state;
1079         unsigned int __user *epc;
1080         unsigned long old_epc, old31;
1081         unsigned int opcode;
1082         unsigned int cpid;
1083         int status;
1084         unsigned long __maybe_unused flags;
1085
1086         prev_state = exception_enter();
1087         cpid = (regs->cp0_cause >> CAUSEB_CE) & 3;
1088
1089         if (cpid != 2)
1090                 die_if_kernel("do_cpu invoked from kernel context!", regs);
1091
1092         switch (cpid) {
1093         case 0:
1094                 epc = (unsigned int __user *)exception_epc(regs);
1095                 old_epc = regs->cp0_epc;
1096                 old31 = regs->regs[31];
1097                 opcode = 0;
1098                 status = -1;
1099
1100                 if (unlikely(compute_return_epc(regs) < 0))
1101                         goto out;
1102
1103                 if (get_isa16_mode(regs->cp0_epc)) {
1104                         unsigned short mmop[2] = { 0 };
1105
1106                         if (unlikely(get_user(mmop[0], epc) < 0))
1107                                 status = SIGSEGV;
1108                         if (unlikely(get_user(mmop[1], epc) < 0))
1109                                 status = SIGSEGV;
1110                         opcode = (mmop[0] << 16) | mmop[1];
1111
1112                         if (status < 0)
1113                                 status = simulate_rdhwr_mm(regs, opcode);
1114                 } else {
1115                         if (unlikely(get_user(opcode, epc) < 0))
1116                                 status = SIGSEGV;
1117
1118                         if (!cpu_has_llsc && status < 0)
1119                                 status = simulate_llsc(regs, opcode);
1120
1121                         if (status < 0)
1122                                 status = simulate_rdhwr_normal(regs, opcode);
1123                 }
1124
1125                 if (status < 0)
1126                         status = SIGILL;
1127
1128                 if (unlikely(status > 0)) {
1129                         regs->cp0_epc = old_epc;        /* Undo skip-over.  */
1130                         regs->regs[31] = old31;
1131                         force_sig(status, current);
1132                 }
1133
1134                 goto out;
1135
1136         case 3:
1137                 /*
1138                  * Old (MIPS I and MIPS II) processors will set this code
1139                  * for COP1X opcode instructions that replaced the original
1140                  * COP3 space.  We don't limit COP1 space instructions in
1141                  * the emulator according to the CPU ISA, so we want to
1142                  * treat COP1X instructions consistently regardless of which
1143                  * code the CPU chose.  Therefore we redirect this trap to
1144                  * the FP emulator too.
1145                  *
1146                  * Then some newer FPU-less processors use this code
1147                  * erroneously too, so they are covered by this choice
1148                  * as well.
1149                  */
1150                 if (raw_cpu_has_fpu)
1151                         break;
1152                 /* Fall through.  */
1153
1154         case 1:
1155                 if (used_math())        /* Using the FPU again.  */
1156                         own_fpu(1);
1157                 else {                  /* First time FPU user.  */
1158                         init_fpu();
1159                         set_used_math();
1160                 }
1161
1162                 if (!raw_cpu_has_fpu) {
1163                         int sig;
1164                         void __user *fault_addr = NULL;
1165                         sig = fpu_emulator_cop1Handler(regs,
1166                                                        &current->thread.fpu,
1167                                                        0, &fault_addr);
1168                         if (!process_fpemu_return(sig, fault_addr))
1169                                 mt_ase_fp_affinity();
1170                 }
1171
1172                 goto out;
1173
1174         case 2:
1175                 raw_notifier_call_chain(&cu2_chain, CU2_EXCEPTION, regs);
1176                 goto out;
1177         }
1178
1179         force_sig(SIGILL, current);
1180
1181 out:
1182         exception_exit(prev_state);
1183 }
1184
1185 asmlinkage void do_mdmx(struct pt_regs *regs)
1186 {
1187         enum ctx_state prev_state;
1188
1189         prev_state = exception_enter();
1190         force_sig(SIGILL, current);
1191         exception_exit(prev_state);
1192 }
1193
1194 /*
1195  * Called with interrupts disabled.
1196  */
1197 asmlinkage void do_watch(struct pt_regs *regs)
1198 {
1199         enum ctx_state prev_state;
1200         u32 cause;
1201
1202         prev_state = exception_enter();
1203         /*
1204          * Clear WP (bit 22) bit of cause register so we don't loop
1205          * forever.
1206          */
1207         cause = read_c0_cause();
1208         cause &= ~(1 << 22);
1209         write_c0_cause(cause);
1210
1211         /*
1212          * If the current thread has the watch registers loaded, save
1213          * their values and send SIGTRAP.  Otherwise another thread
1214          * left the registers set, clear them and continue.
1215          */
1216         if (test_tsk_thread_flag(current, TIF_LOAD_WATCH)) {
1217                 mips_read_watch_registers();
1218                 local_irq_enable();
1219                 force_sig(SIGTRAP, current);
1220         } else {
1221                 mips_clear_watch_registers();
1222                 local_irq_enable();
1223         }
1224         exception_exit(prev_state);
1225 }
1226
1227 asmlinkage void do_mcheck(struct pt_regs *regs)
1228 {
1229         const int field = 2 * sizeof(unsigned long);
1230         int multi_match = regs->cp0_status & ST0_TS;
1231         enum ctx_state prev_state;
1232
1233         prev_state = exception_enter();
1234         show_regs(regs);
1235
1236         if (multi_match) {
1237                 printk("Index   : %0x\n", read_c0_index());
1238                 printk("Pagemask: %0x\n", read_c0_pagemask());
1239                 printk("EntryHi : %0*lx\n", field, read_c0_entryhi());
1240                 printk("EntryLo0: %0*lx\n", field, read_c0_entrylo0());
1241                 printk("EntryLo1: %0*lx\n", field, read_c0_entrylo1());
1242                 printk("\n");
1243                 dump_tlb_all();
1244         }
1245
1246         show_code((unsigned int __user *) regs->cp0_epc);
1247
1248         /*
1249          * Some chips may have other causes of machine check (e.g. SB1
1250          * graduation timer)
1251          */
1252         panic("Caught Machine Check exception - %scaused by multiple "
1253               "matching entries in the TLB.",
1254               (multi_match) ? "" : "not ");
1255 }
1256
1257 asmlinkage void do_mt(struct pt_regs *regs)
1258 {
1259         int subcode;
1260
1261         subcode = (read_vpe_c0_vpecontrol() & VPECONTROL_EXCPT)
1262                         >> VPECONTROL_EXCPT_SHIFT;
1263         switch (subcode) {
1264         case 0:
1265                 printk(KERN_DEBUG "Thread Underflow\n");
1266                 break;
1267         case 1:
1268                 printk(KERN_DEBUG "Thread Overflow\n");
1269                 break;
1270         case 2:
1271                 printk(KERN_DEBUG "Invalid YIELD Qualifier\n");
1272                 break;
1273         case 3:
1274                 printk(KERN_DEBUG "Gating Storage Exception\n");
1275                 break;
1276         case 4:
1277                 printk(KERN_DEBUG "YIELD Scheduler Exception\n");
1278                 break;
1279         case 5:
1280                 printk(KERN_DEBUG "Gating Storage Scheduler Exception\n");
1281                 break;
1282         default:
1283                 printk(KERN_DEBUG "*** UNKNOWN THREAD EXCEPTION %d ***\n",
1284                         subcode);
1285                 break;
1286         }
1287         die_if_kernel("MIPS MT Thread exception in kernel", regs);
1288
1289         force_sig(SIGILL, current);
1290 }
1291
1292
1293 asmlinkage void do_dsp(struct pt_regs *regs)
1294 {
1295         if (cpu_has_dsp)
1296                 panic("Unexpected DSP exception");
1297
1298         force_sig(SIGILL, current);
1299 }
1300
1301 asmlinkage void do_reserved(struct pt_regs *regs)
1302 {
1303         /*
1304          * Game over - no way to handle this if it ever occurs.  Most probably
1305          * caused by a new unknown cpu type or after another deadly
1306          * hard/software error.
1307          */
1308         show_regs(regs);
1309         panic("Caught reserved exception %ld - should not happen.",
1310               (regs->cp0_cause & 0x7f) >> 2);
1311 }
1312
1313 static int __initdata l1parity = 1;
1314 static int __init nol1parity(char *s)
1315 {
1316         l1parity = 0;
1317         return 1;
1318 }
1319 __setup("nol1par", nol1parity);
1320 static int __initdata l2parity = 1;
1321 static int __init nol2parity(char *s)
1322 {
1323         l2parity = 0;
1324         return 1;
1325 }
1326 __setup("nol2par", nol2parity);
1327
1328 /*
1329  * Some MIPS CPUs can enable/disable for cache parity detection, but do
1330  * it different ways.
1331  */
1332 static inline void parity_protection_init(void)
1333 {
1334         switch (current_cpu_type()) {
1335         case CPU_24K:
1336         case CPU_34K:
1337         case CPU_74K:
1338         case CPU_1004K:
1339                 {
1340 #define ERRCTL_PE       0x80000000
1341 #define ERRCTL_L2P      0x00800000
1342                         unsigned long errctl;
1343                         unsigned int l1parity_present, l2parity_present;
1344
1345                         errctl = read_c0_ecc();
1346                         errctl &= ~(ERRCTL_PE|ERRCTL_L2P);
1347
1348                         /* probe L1 parity support */
1349                         write_c0_ecc(errctl | ERRCTL_PE);
1350                         back_to_back_c0_hazard();
1351                         l1parity_present = (read_c0_ecc() & ERRCTL_PE);
1352
1353                         /* probe L2 parity support */
1354                         write_c0_ecc(errctl|ERRCTL_L2P);
1355                         back_to_back_c0_hazard();
1356                         l2parity_present = (read_c0_ecc() & ERRCTL_L2P);
1357
1358                         if (l1parity_present && l2parity_present) {
1359                                 if (l1parity)
1360                                         errctl |= ERRCTL_PE;
1361                                 if (l1parity ^ l2parity)
1362                                         errctl |= ERRCTL_L2P;
1363                         } else if (l1parity_present) {
1364                                 if (l1parity)
1365                                         errctl |= ERRCTL_PE;
1366                         } else if (l2parity_present) {
1367                                 if (l2parity)
1368                                         errctl |= ERRCTL_L2P;
1369                         } else {
1370                                 /* No parity available */
1371                         }
1372
1373                         printk(KERN_INFO "Writing ErrCtl register=%08lx\n", errctl);
1374
1375                         write_c0_ecc(errctl);
1376                         back_to_back_c0_hazard();
1377                         errctl = read_c0_ecc();
1378                         printk(KERN_INFO "Readback ErrCtl register=%08lx\n", errctl);
1379
1380                         if (l1parity_present)
1381                                 printk(KERN_INFO "Cache parity protection %sabled\n",
1382                                        (errctl & ERRCTL_PE) ? "en" : "dis");
1383
1384                         if (l2parity_present) {
1385                                 if (l1parity_present && l1parity)
1386                                         errctl ^= ERRCTL_L2P;
1387                                 printk(KERN_INFO "L2 cache parity protection %sabled\n",
1388                                        (errctl & ERRCTL_L2P) ? "en" : "dis");
1389                         }
1390                 }
1391                 break;
1392
1393         case CPU_5KC:
1394         case CPU_5KE:
1395         case CPU_LOONGSON1:
1396                 write_c0_ecc(0x80000000);
1397                 back_to_back_c0_hazard();
1398                 /* Set the PE bit (bit 31) in the c0_errctl register. */
1399                 printk(KERN_INFO "Cache parity protection %sabled\n",
1400                        (read_c0_ecc() & 0x80000000) ? "en" : "dis");
1401                 break;
1402         case CPU_20KC:
1403         case CPU_25KF:
1404                 /* Clear the DE bit (bit 16) in the c0_status register. */
1405                 printk(KERN_INFO "Enable cache parity protection for "
1406                        "MIPS 20KC/25KF CPUs.\n");
1407                 clear_c0_status(ST0_DE);
1408                 break;
1409         default:
1410                 break;
1411         }
1412 }
1413
1414 asmlinkage void cache_parity_error(void)
1415 {
1416         const int field = 2 * sizeof(unsigned long);
1417         unsigned int reg_val;
1418
1419         /* For the moment, report the problem and hang. */
1420         printk("Cache error exception:\n");
1421         printk("cp0_errorepc == %0*lx\n", field, read_c0_errorepc());
1422         reg_val = read_c0_cacheerr();
1423         printk("c0_cacheerr == %08x\n", reg_val);
1424
1425         printk("Decoded c0_cacheerr: %s cache fault in %s reference.\n",
1426                reg_val & (1<<30) ? "secondary" : "primary",
1427                reg_val & (1<<31) ? "data" : "insn");
1428         printk("Error bits: %s%s%s%s%s%s%s\n",
1429                reg_val & (1<<29) ? "ED " : "",
1430                reg_val & (1<<28) ? "ET " : "",
1431                reg_val & (1<<26) ? "EE " : "",
1432                reg_val & (1<<25) ? "EB " : "",
1433                reg_val & (1<<24) ? "EI " : "",
1434                reg_val & (1<<23) ? "E1 " : "",
1435                reg_val & (1<<22) ? "E0 " : "");
1436         printk("IDX: 0x%08x\n", reg_val & ((1<<22)-1));
1437
1438 #if defined(CONFIG_CPU_MIPS32) || defined(CONFIG_CPU_MIPS64)
1439         if (reg_val & (1<<22))
1440                 printk("DErrAddr0: 0x%0*lx\n", field, read_c0_derraddr0());
1441
1442         if (reg_val & (1<<23))
1443                 printk("DErrAddr1: 0x%0*lx\n", field, read_c0_derraddr1());
1444 #endif
1445
1446         panic("Can't handle the cache error!");
1447 }
1448
1449 /*
1450  * SDBBP EJTAG debug exception handler.
1451  * We skip the instruction and return to the next instruction.
1452  */
1453 void ejtag_exception_handler(struct pt_regs *regs)
1454 {
1455         const int field = 2 * sizeof(unsigned long);
1456         unsigned long depc, old_epc, old_ra;
1457         unsigned int debug;
1458
1459         printk(KERN_DEBUG "SDBBP EJTAG debug exception - not handled yet, just ignored!\n");
1460         depc = read_c0_depc();
1461         debug = read_c0_debug();
1462         printk(KERN_DEBUG "c0_depc = %0*lx, DEBUG = %08x\n", field, depc, debug);
1463         if (debug & 0x80000000) {
1464                 /*
1465                  * In branch delay slot.
1466                  * We cheat a little bit here and use EPC to calculate the
1467                  * debug return address (DEPC). EPC is restored after the
1468                  * calculation.
1469                  */
1470                 old_epc = regs->cp0_epc;
1471                 old_ra = regs->regs[31];
1472                 regs->cp0_epc = depc;
1473                 compute_return_epc(regs);
1474                 depc = regs->cp0_epc;
1475                 regs->cp0_epc = old_epc;
1476                 regs->regs[31] = old_ra;
1477         } else
1478                 depc += 4;
1479         write_c0_depc(depc);
1480
1481 #if 0
1482         printk(KERN_DEBUG "\n\n----- Enable EJTAG single stepping ----\n\n");
1483         write_c0_debug(debug | 0x100);
1484 #endif
1485 }
1486
1487 /*
1488  * NMI exception handler.
1489  * No lock; only written during early bootup by CPU 0.
1490  */
1491 static RAW_NOTIFIER_HEAD(nmi_chain);
1492
1493 int register_nmi_notifier(struct notifier_block *nb)
1494 {
1495         return raw_notifier_chain_register(&nmi_chain, nb);
1496 }
1497
1498 void __noreturn nmi_exception_handler(struct pt_regs *regs)
1499 {
1500         char str[100];
1501
1502         raw_notifier_call_chain(&nmi_chain, 0, regs);
1503         bust_spinlocks(1);
1504         snprintf(str, 100, "CPU%d NMI taken, CP0_EPC=%lx\n",
1505                  smp_processor_id(), regs->cp0_epc);
1506         regs->cp0_epc = read_c0_errorepc();
1507         die(str, regs);
1508 }
1509
1510 #define VECTORSPACING 0x100     /* for EI/VI mode */
1511
1512 unsigned long ebase;
1513 unsigned long exception_handlers[32];
1514 unsigned long vi_handlers[64];
1515
1516 void __init *set_except_vector(int n, void *addr)
1517 {
1518         unsigned long handler = (unsigned long) addr;
1519         unsigned long old_handler;
1520
1521 #ifdef CONFIG_CPU_MICROMIPS
1522         /*
1523          * Only the TLB handlers are cache aligned with an even
1524          * address. All other handlers are on an odd address and
1525          * require no modification. Otherwise, MIPS32 mode will
1526          * be entered when handling any TLB exceptions. That
1527          * would be bad...since we must stay in microMIPS mode.
1528          */
1529         if (!(handler & 0x1))
1530                 handler |= 1;
1531 #endif
1532         old_handler = xchg(&exception_handlers[n], handler);
1533
1534         if (n == 0 && cpu_has_divec) {
1535 #ifdef CONFIG_CPU_MICROMIPS
1536                 unsigned long jump_mask = ~((1 << 27) - 1);
1537 #else
1538                 unsigned long jump_mask = ~((1 << 28) - 1);
1539 #endif
1540                 u32 *buf = (u32 *)(ebase + 0x200);
1541                 unsigned int k0 = 26;
1542                 if ((handler & jump_mask) == ((ebase + 0x200) & jump_mask)) {
1543                         uasm_i_j(&buf, handler & ~jump_mask);
1544                         uasm_i_nop(&buf);
1545                 } else {
1546                         UASM_i_LA(&buf, k0, handler);
1547                         uasm_i_jr(&buf, k0);
1548                         uasm_i_nop(&buf);
1549                 }
1550                 local_flush_icache_range(ebase + 0x200, (unsigned long)buf);
1551         }
1552         return (void *)old_handler;
1553 }
1554
1555 static void do_default_vi(void)
1556 {
1557         show_regs(get_irq_regs());
1558         panic("Caught unexpected vectored interrupt.");
1559 }
1560
1561 static void *set_vi_srs_handler(int n, vi_handler_t addr, int srs)
1562 {
1563         unsigned long handler;
1564         unsigned long old_handler = vi_handlers[n];
1565         int srssets = current_cpu_data.srsets;
1566         u16 *h;
1567         unsigned char *b;
1568
1569         BUG_ON(!cpu_has_veic && !cpu_has_vint);
1570
1571         if (addr == NULL) {
1572                 handler = (unsigned long) do_default_vi;
1573                 srs = 0;
1574         } else
1575                 handler = (unsigned long) addr;
1576         vi_handlers[n] = handler;
1577
1578         b = (unsigned char *)(ebase + 0x200 + n*VECTORSPACING);
1579
1580         if (srs >= srssets)
1581                 panic("Shadow register set %d not supported", srs);
1582
1583         if (cpu_has_veic) {
1584                 if (board_bind_eic_interrupt)
1585                         board_bind_eic_interrupt(n, srs);
1586         } else if (cpu_has_vint) {
1587                 /* SRSMap is only defined if shadow sets are implemented */
1588                 if (srssets > 1)
1589                         change_c0_srsmap(0xf << n*4, srs << n*4);
1590         }
1591
1592         if (srs == 0) {
1593                 /*
1594                  * If no shadow set is selected then use the default handler
1595                  * that does normal register saving and standard interrupt exit
1596                  */
1597                 extern char except_vec_vi, except_vec_vi_lui;
1598                 extern char except_vec_vi_ori, except_vec_vi_end;
1599                 extern char rollback_except_vec_vi;
1600                 char *vec_start = using_rollback_handler() ?
1601                         &rollback_except_vec_vi : &except_vec_vi;
1602 #ifdef CONFIG_MIPS_MT_SMTC
1603                 /*
1604                  * We need to provide the SMTC vectored interrupt handler
1605                  * not only with the address of the handler, but with the
1606                  * Status.IM bit to be masked before going there.
1607                  */
1608                 extern char except_vec_vi_mori;
1609 #if defined(CONFIG_CPU_MICROMIPS) || defined(CONFIG_CPU_BIG_ENDIAN)
1610                 const int mori_offset = &except_vec_vi_mori - vec_start + 2;
1611 #else
1612                 const int mori_offset = &except_vec_vi_mori - vec_start;
1613 #endif
1614 #endif /* CONFIG_MIPS_MT_SMTC */
1615 #if defined(CONFIG_CPU_MICROMIPS) || defined(CONFIG_CPU_BIG_ENDIAN)
1616                 const int lui_offset = &except_vec_vi_lui - vec_start + 2;
1617                 const int ori_offset = &except_vec_vi_ori - vec_start + 2;
1618 #else
1619                 const int lui_offset = &except_vec_vi_lui - vec_start;
1620                 const int ori_offset = &except_vec_vi_ori - vec_start;
1621 #endif
1622                 const int handler_len = &except_vec_vi_end - vec_start;
1623
1624                 if (handler_len > VECTORSPACING) {
1625                         /*
1626                          * Sigh... panicing won't help as the console
1627                          * is probably not configured :(
1628                          */
1629                         panic("VECTORSPACING too small");
1630                 }
1631
1632                 set_handler(((unsigned long)b - ebase), vec_start,
1633 #ifdef CONFIG_CPU_MICROMIPS
1634                                 (handler_len - 1));
1635 #else
1636                                 handler_len);
1637 #endif
1638 #ifdef CONFIG_MIPS_MT_SMTC
1639                 BUG_ON(n > 7);  /* Vector index %d exceeds SMTC maximum. */
1640
1641                 h = (u16 *)(b + mori_offset);
1642                 *h = (0x100 << n);
1643 #endif /* CONFIG_MIPS_MT_SMTC */
1644                 h = (u16 *)(b + lui_offset);
1645                 *h = (handler >> 16) & 0xffff;
1646                 h = (u16 *)(b + ori_offset);
1647                 *h = (handler & 0xffff);
1648                 local_flush_icache_range((unsigned long)b,
1649                                          (unsigned long)(b+handler_len));
1650         }
1651         else {
1652                 /*
1653                  * In other cases jump directly to the interrupt handler. It
1654                  * is the handler's responsibility to save registers if required
1655                  * (eg hi/lo) and return from the exception using "eret".
1656                  */
1657                 u32 insn;
1658
1659                 h = (u16 *)b;
1660                 /* j handler */
1661 #ifdef CONFIG_CPU_MICROMIPS
1662                 insn = 0xd4000000 | (((u32)handler & 0x07ffffff) >> 1);
1663 #else
1664                 insn = 0x08000000 | (((u32)handler & 0x0fffffff) >> 2);
1665 #endif
1666                 h[0] = (insn >> 16) & 0xffff;
1667                 h[1] = insn & 0xffff;
1668                 h[2] = 0;
1669                 h[3] = 0;
1670                 local_flush_icache_range((unsigned long)b,
1671                                          (unsigned long)(b+8));
1672         }
1673
1674         return (void *)old_handler;
1675 }
1676
1677 void *set_vi_handler(int n, vi_handler_t addr)
1678 {
1679         return set_vi_srs_handler(n, addr, 0);
1680 }
1681
1682 extern void tlb_init(void);
1683
1684 /*
1685  * Timer interrupt
1686  */
1687 int cp0_compare_irq;
1688 EXPORT_SYMBOL_GPL(cp0_compare_irq);
1689 int cp0_compare_irq_shift;
1690
1691 /*
1692  * Performance counter IRQ or -1 if shared with timer
1693  */
1694 int cp0_perfcount_irq;
1695 EXPORT_SYMBOL_GPL(cp0_perfcount_irq);
1696
1697 static int noulri;
1698
1699 static int __init ulri_disable(char *s)
1700 {
1701         pr_info("Disabling ulri\n");
1702         noulri = 1;
1703
1704         return 1;
1705 }
1706 __setup("noulri", ulri_disable);
1707
1708 void per_cpu_trap_init(bool is_boot_cpu)
1709 {
1710         unsigned int cpu = smp_processor_id();
1711         unsigned int status_set = ST0_CU0;
1712         unsigned int hwrena = cpu_hwrena_impl_bits;
1713 #ifdef CONFIG_MIPS_MT_SMTC
1714         int secondaryTC = 0;
1715         int bootTC = (cpu == 0);
1716
1717         /*
1718          * Only do per_cpu_trap_init() for first TC of Each VPE.
1719          * Note that this hack assumes that the SMTC init code
1720          * assigns TCs consecutively and in ascending order.
1721          */
1722
1723         if (((read_c0_tcbind() & TCBIND_CURTC) != 0) &&
1724             ((read_c0_tcbind() & TCBIND_CURVPE) == cpu_data[cpu - 1].vpe_id))
1725                 secondaryTC = 1;
1726 #endif /* CONFIG_MIPS_MT_SMTC */
1727
1728         /*
1729          * Disable coprocessors and select 32-bit or 64-bit addressing
1730          * and the 16/32 or 32/32 FPR register model.  Reset the BEV
1731          * flag that some firmware may have left set and the TS bit (for
1732          * IP27).  Set XX for ISA IV code to work.
1733          */
1734 #ifdef CONFIG_64BIT
1735         status_set |= ST0_FR|ST0_KX|ST0_SX|ST0_UX;
1736 #endif
1737         if (current_cpu_data.isa_level & MIPS_CPU_ISA_IV)
1738                 status_set |= ST0_XX;
1739         if (cpu_has_dsp)
1740                 status_set |= ST0_MX;
1741
1742         change_c0_status(ST0_CU|ST0_MX|ST0_RE|ST0_FR|ST0_BEV|ST0_TS|ST0_KX|ST0_SX|ST0_UX,
1743                          status_set);
1744
1745         if (cpu_has_mips_r2)
1746                 hwrena |= 0x0000000f;
1747
1748         if (!noulri && cpu_has_userlocal)
1749                 hwrena |= (1 << 29);
1750
1751         if (hwrena)
1752                 write_c0_hwrena(hwrena);
1753
1754 #ifdef CONFIG_MIPS_MT_SMTC
1755         if (!secondaryTC) {
1756 #endif /* CONFIG_MIPS_MT_SMTC */
1757
1758         if (cpu_has_veic || cpu_has_vint) {
1759                 unsigned long sr = set_c0_status(ST0_BEV);
1760                 write_c0_ebase(ebase);
1761                 write_c0_status(sr);
1762                 /* Setting vector spacing enables EI/VI mode  */
1763                 change_c0_intctl(0x3e0, VECTORSPACING);
1764         }
1765         if (cpu_has_divec) {
1766                 if (cpu_has_mipsmt) {
1767                         unsigned int vpflags = dvpe();
1768                         set_c0_cause(CAUSEF_IV);
1769                         evpe(vpflags);
1770                 } else
1771                         set_c0_cause(CAUSEF_IV);
1772         }
1773
1774         /*
1775          * Before R2 both interrupt numbers were fixed to 7, so on R2 only:
1776          *
1777          *  o read IntCtl.IPTI to determine the timer interrupt
1778          *  o read IntCtl.IPPCI to determine the performance counter interrupt
1779          */
1780         if (cpu_has_mips_r2) {
1781                 cp0_compare_irq_shift = CAUSEB_TI - CAUSEB_IP;
1782                 cp0_compare_irq = (read_c0_intctl() >> INTCTLB_IPTI) & 7;
1783                 cp0_perfcount_irq = (read_c0_intctl() >> INTCTLB_IPPCI) & 7;
1784                 if (cp0_perfcount_irq == cp0_compare_irq)
1785                         cp0_perfcount_irq = -1;
1786         } else {
1787                 cp0_compare_irq = CP0_LEGACY_COMPARE_IRQ;
1788                 cp0_compare_irq_shift = CP0_LEGACY_PERFCNT_IRQ;
1789                 cp0_perfcount_irq = -1;
1790         }
1791
1792 #ifdef CONFIG_MIPS_MT_SMTC
1793         }
1794 #endif /* CONFIG_MIPS_MT_SMTC */
1795
1796         if (!cpu_data[cpu].asid_cache)
1797                 cpu_data[cpu].asid_cache = ASID_FIRST_VERSION;
1798
1799         atomic_inc(&init_mm.mm_count);
1800         current->active_mm = &init_mm;
1801         BUG_ON(current->mm);
1802         enter_lazy_tlb(&init_mm, current);
1803
1804 #ifdef CONFIG_MIPS_MT_SMTC
1805         if (bootTC) {
1806 #endif /* CONFIG_MIPS_MT_SMTC */
1807                 /* Boot CPU's cache setup in setup_arch(). */
1808                 if (!is_boot_cpu)
1809                         cpu_cache_init();
1810                 tlb_init();
1811 #ifdef CONFIG_MIPS_MT_SMTC
1812         } else if (!secondaryTC) {
1813                 /*
1814                  * First TC in non-boot VPE must do subset of tlb_init()
1815                  * for MMU countrol registers.
1816                  */
1817                 write_c0_pagemask(PM_DEFAULT_MASK);
1818                 write_c0_wired(0);
1819         }
1820 #endif /* CONFIG_MIPS_MT_SMTC */
1821         TLBMISS_HANDLER_SETUP();
1822 }
1823
1824 /* Install CPU exception handler */
1825 void set_handler(unsigned long offset, void *addr, unsigned long size)
1826 {
1827 #ifdef CONFIG_CPU_MICROMIPS
1828         memcpy((void *)(ebase + offset), ((unsigned char *)addr - 1), size);
1829 #else
1830         memcpy((void *)(ebase + offset), addr, size);
1831 #endif
1832         local_flush_icache_range(ebase + offset, ebase + offset + size);
1833 }
1834
1835 static char panic_null_cerr[] =
1836         "Trying to set NULL cache error exception handler";
1837
1838 /*
1839  * Install uncached CPU exception handler.
1840  * This is suitable only for the cache error exception which is the only
1841  * exception handler that is being run uncached.
1842  */
1843 void set_uncached_handler(unsigned long offset, void *addr,
1844         unsigned long size)
1845 {
1846         unsigned long uncached_ebase = CKSEG1ADDR(ebase);
1847
1848         if (!addr)
1849                 panic(panic_null_cerr);
1850
1851         memcpy((void *)(uncached_ebase + offset), addr, size);
1852 }
1853
1854 static int __initdata rdhwr_noopt;
1855 static int __init set_rdhwr_noopt(char *str)
1856 {
1857         rdhwr_noopt = 1;
1858         return 1;
1859 }
1860
1861 __setup("rdhwr_noopt", set_rdhwr_noopt);
1862
1863 void __init trap_init(void)
1864 {
1865         extern char except_vec3_generic;
1866         extern char except_vec4;
1867         extern char except_vec3_r4000;
1868         unsigned long i;
1869
1870         check_wait();
1871
1872 #if defined(CONFIG_KGDB)
1873         if (kgdb_early_setup)
1874                 return; /* Already done */
1875 #endif
1876
1877         if (cpu_has_veic || cpu_has_vint) {
1878                 unsigned long size = 0x200 + VECTORSPACING*64;
1879                 ebase = (unsigned long)
1880                         __alloc_bootmem(size, 1 << fls(size), 0);
1881         } else {
1882 #ifdef CONFIG_KVM_GUEST
1883 #define KVM_GUEST_KSEG0     0x40000000
1884         ebase = KVM_GUEST_KSEG0;
1885 #else
1886         ebase = CKSEG0;
1887 #endif
1888                 if (cpu_has_mips_r2)
1889                         ebase += (read_c0_ebase() & 0x3ffff000);
1890         }
1891
1892         if (cpu_has_mmips) {
1893                 unsigned int config3 = read_c0_config3();
1894
1895                 if (IS_ENABLED(CONFIG_CPU_MICROMIPS))
1896                         write_c0_config3(config3 | MIPS_CONF3_ISA_OE);
1897                 else
1898                         write_c0_config3(config3 & ~MIPS_CONF3_ISA_OE);
1899         }
1900
1901         if (board_ebase_setup)
1902                 board_ebase_setup();
1903         per_cpu_trap_init(true);
1904
1905         /*
1906          * Copy the generic exception handlers to their final destination.
1907          * This will be overriden later as suitable for a particular
1908          * configuration.
1909          */
1910         set_handler(0x180, &except_vec3_generic, 0x80);
1911
1912         /*
1913          * Setup default vectors
1914          */
1915         for (i = 0; i <= 31; i++)
1916                 set_except_vector(i, handle_reserved);
1917
1918         /*
1919          * Copy the EJTAG debug exception vector handler code to it's final
1920          * destination.
1921          */
1922         if (cpu_has_ejtag && board_ejtag_handler_setup)
1923                 board_ejtag_handler_setup();
1924
1925         /*
1926          * Only some CPUs have the watch exceptions.
1927          */
1928         if (cpu_has_watch)
1929                 set_except_vector(23, handle_watch);
1930
1931         /*
1932          * Initialise interrupt handlers
1933          */
1934         if (cpu_has_veic || cpu_has_vint) {
1935                 int nvec = cpu_has_veic ? 64 : 8;
1936                 for (i = 0; i < nvec; i++)
1937                         set_vi_handler(i, NULL);
1938         }
1939         else if (cpu_has_divec)
1940                 set_handler(0x200, &except_vec4, 0x8);
1941
1942         /*
1943          * Some CPUs can enable/disable for cache parity detection, but does
1944          * it different ways.
1945          */
1946         parity_protection_init();
1947
1948         /*
1949          * The Data Bus Errors / Instruction Bus Errors are signaled
1950          * by external hardware.  Therefore these two exceptions
1951          * may have board specific handlers.
1952          */
1953         if (board_be_init)
1954                 board_be_init();
1955
1956         set_except_vector(0, using_rollback_handler() ? rollback_handle_int
1957                                                       : handle_int);
1958         set_except_vector(1, handle_tlbm);
1959         set_except_vector(2, handle_tlbl);
1960         set_except_vector(3, handle_tlbs);
1961
1962         set_except_vector(4, handle_adel);
1963         set_except_vector(5, handle_ades);
1964
1965         set_except_vector(6, handle_ibe);
1966         set_except_vector(7, handle_dbe);
1967
1968         set_except_vector(8, handle_sys);
1969         set_except_vector(9, handle_bp);
1970         set_except_vector(10, rdhwr_noopt ? handle_ri :
1971                           (cpu_has_vtag_icache ?
1972                            handle_ri_rdhwr_vivt : handle_ri_rdhwr));
1973         set_except_vector(11, handle_cpu);
1974         set_except_vector(12, handle_ov);
1975         set_except_vector(13, handle_tr);
1976
1977         if (current_cpu_type() == CPU_R6000 ||
1978             current_cpu_type() == CPU_R6000A) {
1979                 /*
1980                  * The R6000 is the only R-series CPU that features a machine
1981                  * check exception (similar to the R4000 cache error) and
1982                  * unaligned ldc1/sdc1 exception.  The handlers have not been
1983                  * written yet.  Well, anyway there is no R6000 machine on the
1984                  * current list of targets for Linux/MIPS.
1985                  * (Duh, crap, there is someone with a triple R6k machine)
1986                  */
1987                 //set_except_vector(14, handle_mc);
1988                 //set_except_vector(15, handle_ndc);
1989         }
1990
1991
1992         if (board_nmi_handler_setup)
1993                 board_nmi_handler_setup();
1994
1995         if (cpu_has_fpu && !cpu_has_nofpuex)
1996                 set_except_vector(15, handle_fpe);
1997
1998         set_except_vector(22, handle_mdmx);
1999
2000         if (cpu_has_mcheck)
2001                 set_except_vector(24, handle_mcheck);
2002
2003         if (cpu_has_mipsmt)
2004                 set_except_vector(25, handle_mt);
2005
2006         set_except_vector(26, handle_dsp);
2007
2008         if (board_cache_error_setup)
2009                 board_cache_error_setup();
2010
2011         if (cpu_has_vce)
2012                 /* Special exception: R4[04]00 uses also the divec space. */
2013                 set_handler(0x180, &except_vec3_r4000, 0x100);
2014         else if (cpu_has_4kex)
2015                 set_handler(0x180, &except_vec3_generic, 0x80);
2016         else
2017                 set_handler(0x080, &except_vec3_generic, 0x80);
2018
2019         local_flush_icache_range(ebase, ebase + 0x400);
2020
2021         sort_extable(__start___dbe_table, __stop___dbe_table);
2022
2023         cu2_notifier(default_cu2_call, 0x80000000);     /* Run last  */
2024 }