xref: /openbmc/linux/arch/mips/kernel/traps.c (revision 6c870213d6f3a25981c10728f46294a3bed1703f)
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  * Copyright (C) 2014, Imagination Technologies Ltd.
14  */
15 #include <linux/bug.h>
16 #include <linux/compiler.h>
17 #include <linux/context_tracking.h>
18 #include <linux/kexec.h>
19 #include <linux/init.h>
20 #include <linux/kernel.h>
21 #include <linux/module.h>
22 #include <linux/mm.h>
23 #include <linux/sched.h>
24 #include <linux/smp.h>
25 #include <linux/spinlock.h>
26 #include <linux/kallsyms.h>
27 #include <linux/bootmem.h>
28 #include <linux/interrupt.h>
29 #include <linux/ptrace.h>
30 #include <linux/kgdb.h>
31 #include <linux/kdebug.h>
32 #include <linux/kprobes.h>
33 #include <linux/notifier.h>
34 #include <linux/kdb.h>
35 #include <linux/irq.h>
36 #include <linux/perf_event.h>
37 
38 #include <asm/bootinfo.h>
39 #include <asm/branch.h>
40 #include <asm/break.h>
41 #include <asm/cop2.h>
42 #include <asm/cpu.h>
43 #include <asm/cpu-type.h>
44 #include <asm/dsp.h>
45 #include <asm/fpu.h>
46 #include <asm/fpu_emulator.h>
47 #include <asm/idle.h>
48 #include <asm/mipsregs.h>
49 #include <asm/mipsmtregs.h>
50 #include <asm/module.h>
51 #include <asm/msa.h>
52 #include <asm/pgtable.h>
53 #include <asm/ptrace.h>
54 #include <asm/sections.h>
55 #include <asm/tlbdebug.h>
56 #include <asm/traps.h>
57 #include <asm/uaccess.h>
58 #include <asm/watch.h>
59 #include <asm/mmu_context.h>
60 #include <asm/types.h>
61 #include <asm/stacktrace.h>
62 #include <asm/uasm.h>
63 
64 extern void check_wait(void);
65 extern asmlinkage void rollback_handle_int(void);
66 extern asmlinkage void handle_int(void);
67 extern u32 handle_tlbl[];
68 extern u32 handle_tlbs[];
69 extern u32 handle_tlbm[];
70 extern asmlinkage void handle_adel(void);
71 extern asmlinkage void handle_ades(void);
72 extern asmlinkage void handle_ibe(void);
73 extern asmlinkage void handle_dbe(void);
74 extern asmlinkage void handle_sys(void);
75 extern asmlinkage void handle_bp(void);
76 extern asmlinkage void handle_ri(void);
77 extern asmlinkage void handle_ri_rdhwr_vivt(void);
78 extern asmlinkage void handle_ri_rdhwr(void);
79 extern asmlinkage void handle_cpu(void);
80 extern asmlinkage void handle_ov(void);
81 extern asmlinkage void handle_tr(void);
82 extern asmlinkage void handle_msa_fpe(void);
83 extern asmlinkage void handle_fpe(void);
84 extern asmlinkage void handle_ftlb(void);
85 extern asmlinkage void handle_msa(void);
86 extern asmlinkage void handle_mdmx(void);
87 extern asmlinkage void handle_watch(void);
88 extern asmlinkage void handle_mt(void);
89 extern asmlinkage void handle_dsp(void);
90 extern asmlinkage void handle_mcheck(void);
91 extern asmlinkage void handle_reserved(void);
92 
93 void (*board_be_init)(void);
94 int (*board_be_handler)(struct pt_regs *regs, int is_fixup);
95 void (*board_nmi_handler_setup)(void);
96 void (*board_ejtag_handler_setup)(void);
97 void (*board_bind_eic_interrupt)(int irq, int regset);
98 void (*board_ebase_setup)(void);
99 void(*board_cache_error_setup)(void);
100 
101 static void show_raw_backtrace(unsigned long reg29)
102 {
103 	unsigned long *sp = (unsigned long *)(reg29 & ~3);
104 	unsigned long addr;
105 
106 	printk("Call Trace:");
107 #ifdef CONFIG_KALLSYMS
108 	printk("\n");
109 #endif
110 	while (!kstack_end(sp)) {
111 		unsigned long __user *p =
112 			(unsigned long __user *)(unsigned long)sp++;
113 		if (__get_user(addr, p)) {
114 			printk(" (Bad stack address)");
115 			break;
116 		}
117 		if (__kernel_text_address(addr))
118 			print_ip_sym(addr);
119 	}
120 	printk("\n");
121 }
122 
123 #ifdef CONFIG_KALLSYMS
124 int raw_show_trace;
125 static int __init set_raw_show_trace(char *str)
126 {
127 	raw_show_trace = 1;
128 	return 1;
129 }
130 __setup("raw_show_trace", set_raw_show_trace);
131 #endif
132 
133 static void show_backtrace(struct task_struct *task, const struct pt_regs *regs)
134 {
135 	unsigned long sp = regs->regs[29];
136 	unsigned long ra = regs->regs[31];
137 	unsigned long pc = regs->cp0_epc;
138 
139 	if (!task)
140 		task = current;
141 
142 	if (raw_show_trace || !__kernel_text_address(pc)) {
143 		show_raw_backtrace(sp);
144 		return;
145 	}
146 	printk("Call Trace:\n");
147 	do {
148 		print_ip_sym(pc);
149 		pc = unwind_stack(task, &sp, pc, &ra);
150 	} while (pc);
151 	printk("\n");
152 }
153 
154 /*
155  * This routine abuses get_user()/put_user() to reference pointers
156  * with at least a bit of error checking ...
157  */
158 static void show_stacktrace(struct task_struct *task,
159 	const struct pt_regs *regs)
160 {
161 	const int field = 2 * sizeof(unsigned long);
162 	long stackdata;
163 	int i;
164 	unsigned long __user *sp = (unsigned long __user *)regs->regs[29];
165 
166 	printk("Stack :");
167 	i = 0;
168 	while ((unsigned long) sp & (PAGE_SIZE - 1)) {
169 		if (i && ((i % (64 / field)) == 0))
170 			printk("\n	 ");
171 		if (i > 39) {
172 			printk(" ...");
173 			break;
174 		}
175 
176 		if (__get_user(stackdata, sp++)) {
177 			printk(" (Bad stack address)");
178 			break;
179 		}
180 
181 		printk(" %0*lx", field, stackdata);
182 		i++;
183 	}
184 	printk("\n");
185 	show_backtrace(task, regs);
186 }
187 
188 void show_stack(struct task_struct *task, unsigned long *sp)
189 {
190 	struct pt_regs regs;
191 	if (sp) {
192 		regs.regs[29] = (unsigned long)sp;
193 		regs.regs[31] = 0;
194 		regs.cp0_epc = 0;
195 	} else {
196 		if (task && task != current) {
197 			regs.regs[29] = task->thread.reg29;
198 			regs.regs[31] = 0;
199 			regs.cp0_epc = task->thread.reg31;
200 #ifdef CONFIG_KGDB_KDB
201 		} else if (atomic_read(&kgdb_active) != -1 &&
202 			   kdb_current_regs) {
203 			memcpy(&regs, kdb_current_regs, sizeof(regs));
204 #endif /* CONFIG_KGDB_KDB */
205 		} else {
206 			prepare_frametrace(&regs);
207 		}
208 	}
209 	show_stacktrace(task, &regs);
210 }
211 
212 static void show_code(unsigned int __user *pc)
213 {
214 	long i;
215 	unsigned short __user *pc16 = NULL;
216 
217 	printk("\nCode:");
218 
219 	if ((unsigned long)pc & 1)
220 		pc16 = (unsigned short __user *)((unsigned long)pc & ~1);
221 	for(i = -3 ; i < 6 ; i++) {
222 		unsigned int insn;
223 		if (pc16 ? __get_user(insn, pc16 + i) : __get_user(insn, pc + i)) {
224 			printk(" (Bad address in epc)\n");
225 			break;
226 		}
227 		printk("%c%0*x%c", (i?' ':'<'), pc16 ? 4 : 8, insn, (i?' ':'>'));
228 	}
229 }
230 
231 static void __show_regs(const struct pt_regs *regs)
232 {
233 	const int field = 2 * sizeof(unsigned long);
234 	unsigned int cause = regs->cp0_cause;
235 	int i;
236 
237 	show_regs_print_info(KERN_DEFAULT);
238 
239 	/*
240 	 * Saved main processor registers
241 	 */
242 	for (i = 0; i < 32; ) {
243 		if ((i % 4) == 0)
244 			printk("$%2d   :", i);
245 		if (i == 0)
246 			printk(" %0*lx", field, 0UL);
247 		else if (i == 26 || i == 27)
248 			printk(" %*s", field, "");
249 		else
250 			printk(" %0*lx", field, regs->regs[i]);
251 
252 		i++;
253 		if ((i % 4) == 0)
254 			printk("\n");
255 	}
256 
257 #ifdef CONFIG_CPU_HAS_SMARTMIPS
258 	printk("Acx    : %0*lx\n", field, regs->acx);
259 #endif
260 	printk("Hi    : %0*lx\n", field, regs->hi);
261 	printk("Lo    : %0*lx\n", field, regs->lo);
262 
263 	/*
264 	 * Saved cp0 registers
265 	 */
266 	printk("epc   : %0*lx %pS\n", field, regs->cp0_epc,
267 	       (void *) regs->cp0_epc);
268 	printk("    %s\n", print_tainted());
269 	printk("ra    : %0*lx %pS\n", field, regs->regs[31],
270 	       (void *) regs->regs[31]);
271 
272 	printk("Status: %08x	", (uint32_t) regs->cp0_status);
273 
274 	if (cpu_has_3kex) {
275 		if (regs->cp0_status & ST0_KUO)
276 			printk("KUo ");
277 		if (regs->cp0_status & ST0_IEO)
278 			printk("IEo ");
279 		if (regs->cp0_status & ST0_KUP)
280 			printk("KUp ");
281 		if (regs->cp0_status & ST0_IEP)
282 			printk("IEp ");
283 		if (regs->cp0_status & ST0_KUC)
284 			printk("KUc ");
285 		if (regs->cp0_status & ST0_IEC)
286 			printk("IEc ");
287 	} else if (cpu_has_4kex) {
288 		if (regs->cp0_status & ST0_KX)
289 			printk("KX ");
290 		if (regs->cp0_status & ST0_SX)
291 			printk("SX ");
292 		if (regs->cp0_status & ST0_UX)
293 			printk("UX ");
294 		switch (regs->cp0_status & ST0_KSU) {
295 		case KSU_USER:
296 			printk("USER ");
297 			break;
298 		case KSU_SUPERVISOR:
299 			printk("SUPERVISOR ");
300 			break;
301 		case KSU_KERNEL:
302 			printk("KERNEL ");
303 			break;
304 		default:
305 			printk("BAD_MODE ");
306 			break;
307 		}
308 		if (regs->cp0_status & ST0_ERL)
309 			printk("ERL ");
310 		if (regs->cp0_status & ST0_EXL)
311 			printk("EXL ");
312 		if (regs->cp0_status & ST0_IE)
313 			printk("IE ");
314 	}
315 	printk("\n");
316 
317 	printk("Cause : %08x\n", cause);
318 
319 	cause = (cause & CAUSEF_EXCCODE) >> CAUSEB_EXCCODE;
320 	if (1 <= cause && cause <= 5)
321 		printk("BadVA : %0*lx\n", field, regs->cp0_badvaddr);
322 
323 	printk("PrId  : %08x (%s)\n", read_c0_prid(),
324 	       cpu_name_string());
325 }
326 
327 /*
328  * FIXME: really the generic show_regs should take a const pointer argument.
329  */
330 void show_regs(struct pt_regs *regs)
331 {
332 	__show_regs((struct pt_regs *)regs);
333 }
334 
335 void show_registers(struct pt_regs *regs)
336 {
337 	const int field = 2 * sizeof(unsigned long);
338 	mm_segment_t old_fs = get_fs();
339 
340 	__show_regs(regs);
341 	print_modules();
342 	printk("Process %s (pid: %d, threadinfo=%p, task=%p, tls=%0*lx)\n",
343 	       current->comm, current->pid, current_thread_info(), current,
344 	      field, current_thread_info()->tp_value);
345 	if (cpu_has_userlocal) {
346 		unsigned long tls;
347 
348 		tls = read_c0_userlocal();
349 		if (tls != current_thread_info()->tp_value)
350 			printk("*HwTLS: %0*lx\n", field, tls);
351 	}
352 
353 	if (!user_mode(regs))
354 		/* Necessary for getting the correct stack content */
355 		set_fs(KERNEL_DS);
356 	show_stacktrace(current, regs);
357 	show_code((unsigned int __user *) regs->cp0_epc);
358 	printk("\n");
359 	set_fs(old_fs);
360 }
361 
362 static int regs_to_trapnr(struct pt_regs *regs)
363 {
364 	return (regs->cp0_cause >> 2) & 0x1f;
365 }
366 
367 static DEFINE_RAW_SPINLOCK(die_lock);
368 
369 void __noreturn die(const char *str, struct pt_regs *regs)
370 {
371 	static int die_counter;
372 	int sig = SIGSEGV;
373 #ifdef CONFIG_MIPS_MT_SMTC
374 	unsigned long dvpret;
375 #endif /* CONFIG_MIPS_MT_SMTC */
376 
377 	oops_enter();
378 
379 	if (notify_die(DIE_OOPS, str, regs, 0, regs_to_trapnr(regs),
380 		       SIGSEGV) == NOTIFY_STOP)
381 		sig = 0;
382 
383 	console_verbose();
384 	raw_spin_lock_irq(&die_lock);
385 #ifdef CONFIG_MIPS_MT_SMTC
386 	dvpret = dvpe();
387 #endif /* CONFIG_MIPS_MT_SMTC */
388 	bust_spinlocks(1);
389 #ifdef CONFIG_MIPS_MT_SMTC
390 	mips_mt_regdump(dvpret);
391 #endif /* CONFIG_MIPS_MT_SMTC */
392 
393 	printk("%s[#%d]:\n", str, ++die_counter);
394 	show_registers(regs);
395 	add_taint(TAINT_DIE, LOCKDEP_NOW_UNRELIABLE);
396 	raw_spin_unlock_irq(&die_lock);
397 
398 	oops_exit();
399 
400 	if (in_interrupt())
401 		panic("Fatal exception in interrupt");
402 
403 	if (panic_on_oops) {
404 		printk(KERN_EMERG "Fatal exception: panic in 5 seconds");
405 		ssleep(5);
406 		panic("Fatal exception");
407 	}
408 
409 	if (regs && kexec_should_crash(current))
410 		crash_kexec(regs);
411 
412 	do_exit(sig);
413 }
414 
415 extern struct exception_table_entry __start___dbe_table[];
416 extern struct exception_table_entry __stop___dbe_table[];
417 
418 __asm__(
419 "	.section	__dbe_table, \"a\"\n"
420 "	.previous			\n");
421 
422 /* Given an address, look for it in the exception tables. */
423 static const struct exception_table_entry *search_dbe_tables(unsigned long addr)
424 {
425 	const struct exception_table_entry *e;
426 
427 	e = search_extable(__start___dbe_table, __stop___dbe_table - 1, addr);
428 	if (!e)
429 		e = search_module_dbetables(addr);
430 	return e;
431 }
432 
433 asmlinkage void do_be(struct pt_regs *regs)
434 {
435 	const int field = 2 * sizeof(unsigned long);
436 	const struct exception_table_entry *fixup = NULL;
437 	int data = regs->cp0_cause & 4;
438 	int action = MIPS_BE_FATAL;
439 	enum ctx_state prev_state;
440 
441 	prev_state = exception_enter();
442 	/* XXX For now.	 Fixme, this searches the wrong table ...  */
443 	if (data && !user_mode(regs))
444 		fixup = search_dbe_tables(exception_epc(regs));
445 
446 	if (fixup)
447 		action = MIPS_BE_FIXUP;
448 
449 	if (board_be_handler)
450 		action = board_be_handler(regs, fixup != NULL);
451 
452 	switch (action) {
453 	case MIPS_BE_DISCARD:
454 		goto out;
455 	case MIPS_BE_FIXUP:
456 		if (fixup) {
457 			regs->cp0_epc = fixup->nextinsn;
458 			goto out;
459 		}
460 		break;
461 	default:
462 		break;
463 	}
464 
465 	/*
466 	 * Assume it would be too dangerous to continue ...
467 	 */
468 	printk(KERN_ALERT "%s bus error, epc == %0*lx, ra == %0*lx\n",
469 	       data ? "Data" : "Instruction",
470 	       field, regs->cp0_epc, field, regs->regs[31]);
471 	if (notify_die(DIE_OOPS, "bus error", regs, 0, regs_to_trapnr(regs),
472 		       SIGBUS) == NOTIFY_STOP)
473 		goto out;
474 
475 	die_if_kernel("Oops", regs);
476 	force_sig(SIGBUS, current);
477 
478 out:
479 	exception_exit(prev_state);
480 }
481 
482 /*
483  * ll/sc, rdhwr, sync emulation
484  */
485 
486 #define OPCODE 0xfc000000
487 #define BASE   0x03e00000
488 #define RT     0x001f0000
489 #define OFFSET 0x0000ffff
490 #define LL     0xc0000000
491 #define SC     0xe0000000
492 #define SPEC0  0x00000000
493 #define SPEC3  0x7c000000
494 #define RD     0x0000f800
495 #define FUNC   0x0000003f
496 #define SYNC   0x0000000f
497 #define RDHWR  0x0000003b
498 
499 /*  microMIPS definitions   */
500 #define MM_POOL32A_FUNC 0xfc00ffff
501 #define MM_RDHWR        0x00006b3c
502 #define MM_RS           0x001f0000
503 #define MM_RT           0x03e00000
504 
505 /*
506  * The ll_bit is cleared by r*_switch.S
507  */
508 
509 unsigned int ll_bit;
510 struct task_struct *ll_task;
511 
512 static inline int simulate_ll(struct pt_regs *regs, unsigned int opcode)
513 {
514 	unsigned long value, __user *vaddr;
515 	long offset;
516 
517 	/*
518 	 * analyse the ll instruction that just caused a ri exception
519 	 * and put the referenced address to addr.
520 	 */
521 
522 	/* sign extend offset */
523 	offset = opcode & OFFSET;
524 	offset <<= 16;
525 	offset >>= 16;
526 
527 	vaddr = (unsigned long __user *)
528 		((unsigned long)(regs->regs[(opcode & BASE) >> 21]) + offset);
529 
530 	if ((unsigned long)vaddr & 3)
531 		return SIGBUS;
532 	if (get_user(value, vaddr))
533 		return SIGSEGV;
534 
535 	preempt_disable();
536 
537 	if (ll_task == NULL || ll_task == current) {
538 		ll_bit = 1;
539 	} else {
540 		ll_bit = 0;
541 	}
542 	ll_task = current;
543 
544 	preempt_enable();
545 
546 	regs->regs[(opcode & RT) >> 16] = value;
547 
548 	return 0;
549 }
550 
551 static inline int simulate_sc(struct pt_regs *regs, unsigned int opcode)
552 {
553 	unsigned long __user *vaddr;
554 	unsigned long reg;
555 	long offset;
556 
557 	/*
558 	 * analyse the sc instruction that just caused a ri exception
559 	 * and put the referenced address to addr.
560 	 */
561 
562 	/* sign extend offset */
563 	offset = opcode & OFFSET;
564 	offset <<= 16;
565 	offset >>= 16;
566 
567 	vaddr = (unsigned long __user *)
568 		((unsigned long)(regs->regs[(opcode & BASE) >> 21]) + offset);
569 	reg = (opcode & RT) >> 16;
570 
571 	if ((unsigned long)vaddr & 3)
572 		return SIGBUS;
573 
574 	preempt_disable();
575 
576 	if (ll_bit == 0 || ll_task != current) {
577 		regs->regs[reg] = 0;
578 		preempt_enable();
579 		return 0;
580 	}
581 
582 	preempt_enable();
583 
584 	if (put_user(regs->regs[reg], vaddr))
585 		return SIGSEGV;
586 
587 	regs->regs[reg] = 1;
588 
589 	return 0;
590 }
591 
592 /*
593  * ll uses the opcode of lwc0 and sc uses the opcode of swc0.  That is both
594  * opcodes are supposed to result in coprocessor unusable exceptions if
595  * executed on ll/sc-less processors.  That's the theory.  In practice a
596  * few processors such as NEC's VR4100 throw reserved instruction exceptions
597  * instead, so we're doing the emulation thing in both exception handlers.
598  */
599 static int simulate_llsc(struct pt_regs *regs, unsigned int opcode)
600 {
601 	if ((opcode & OPCODE) == LL) {
602 		perf_sw_event(PERF_COUNT_SW_EMULATION_FAULTS,
603 				1, regs, 0);
604 		return simulate_ll(regs, opcode);
605 	}
606 	if ((opcode & OPCODE) == SC) {
607 		perf_sw_event(PERF_COUNT_SW_EMULATION_FAULTS,
608 				1, regs, 0);
609 		return simulate_sc(regs, opcode);
610 	}
611 
612 	return -1;			/* Must be something else ... */
613 }
614 
615 /*
616  * Simulate trapping 'rdhwr' instructions to provide user accessible
617  * registers not implemented in hardware.
618  */
619 static int simulate_rdhwr(struct pt_regs *regs, int rd, int rt)
620 {
621 	struct thread_info *ti = task_thread_info(current);
622 
623 	perf_sw_event(PERF_COUNT_SW_EMULATION_FAULTS,
624 			1, regs, 0);
625 	switch (rd) {
626 	case 0:		/* CPU number */
627 		regs->regs[rt] = smp_processor_id();
628 		return 0;
629 	case 1:		/* SYNCI length */
630 		regs->regs[rt] = min(current_cpu_data.dcache.linesz,
631 				     current_cpu_data.icache.linesz);
632 		return 0;
633 	case 2:		/* Read count register */
634 		regs->regs[rt] = read_c0_count();
635 		return 0;
636 	case 3:		/* Count register resolution */
637 		switch (current_cpu_type()) {
638 		case CPU_20KC:
639 		case CPU_25KF:
640 			regs->regs[rt] = 1;
641 			break;
642 		default:
643 			regs->regs[rt] = 2;
644 		}
645 		return 0;
646 	case 29:
647 		regs->regs[rt] = ti->tp_value;
648 		return 0;
649 	default:
650 		return -1;
651 	}
652 }
653 
654 static int simulate_rdhwr_normal(struct pt_regs *regs, unsigned int opcode)
655 {
656 	if ((opcode & OPCODE) == SPEC3 && (opcode & FUNC) == RDHWR) {
657 		int rd = (opcode & RD) >> 11;
658 		int rt = (opcode & RT) >> 16;
659 
660 		simulate_rdhwr(regs, rd, rt);
661 		return 0;
662 	}
663 
664 	/* Not ours.  */
665 	return -1;
666 }
667 
668 static int simulate_rdhwr_mm(struct pt_regs *regs, unsigned short opcode)
669 {
670 	if ((opcode & MM_POOL32A_FUNC) == MM_RDHWR) {
671 		int rd = (opcode & MM_RS) >> 16;
672 		int rt = (opcode & MM_RT) >> 21;
673 		simulate_rdhwr(regs, rd, rt);
674 		return 0;
675 	}
676 
677 	/* Not ours.  */
678 	return -1;
679 }
680 
681 static int simulate_sync(struct pt_regs *regs, unsigned int opcode)
682 {
683 	if ((opcode & OPCODE) == SPEC0 && (opcode & FUNC) == SYNC) {
684 		perf_sw_event(PERF_COUNT_SW_EMULATION_FAULTS,
685 				1, regs, 0);
686 		return 0;
687 	}
688 
689 	return -1;			/* Must be something else ... */
690 }
691 
692 asmlinkage void do_ov(struct pt_regs *regs)
693 {
694 	enum ctx_state prev_state;
695 	siginfo_t info;
696 
697 	prev_state = exception_enter();
698 	die_if_kernel("Integer overflow", regs);
699 
700 	info.si_code = FPE_INTOVF;
701 	info.si_signo = SIGFPE;
702 	info.si_errno = 0;
703 	info.si_addr = (void __user *) regs->cp0_epc;
704 	force_sig_info(SIGFPE, &info, current);
705 	exception_exit(prev_state);
706 }
707 
708 int process_fpemu_return(int sig, void __user *fault_addr)
709 {
710 	if (sig == SIGSEGV || sig == SIGBUS) {
711 		struct siginfo si = {0};
712 		si.si_addr = fault_addr;
713 		si.si_signo = sig;
714 		if (sig == SIGSEGV) {
715 			if (find_vma(current->mm, (unsigned long)fault_addr))
716 				si.si_code = SEGV_ACCERR;
717 			else
718 				si.si_code = SEGV_MAPERR;
719 		} else {
720 			si.si_code = BUS_ADRERR;
721 		}
722 		force_sig_info(sig, &si, current);
723 		return 1;
724 	} else if (sig) {
725 		force_sig(sig, current);
726 		return 1;
727 	} else {
728 		return 0;
729 	}
730 }
731 
732 /*
733  * XXX Delayed fp exceptions when doing a lazy ctx switch XXX
734  */
735 asmlinkage void do_fpe(struct pt_regs *regs, unsigned long fcr31)
736 {
737 	enum ctx_state prev_state;
738 	siginfo_t info = {0};
739 
740 	prev_state = exception_enter();
741 	if (notify_die(DIE_FP, "FP exception", regs, 0, regs_to_trapnr(regs),
742 		       SIGFPE) == NOTIFY_STOP)
743 		goto out;
744 	die_if_kernel("FP exception in kernel code", regs);
745 
746 	if (fcr31 & FPU_CSR_UNI_X) {
747 		int sig;
748 		void __user *fault_addr = NULL;
749 
750 		/*
751 		 * Unimplemented operation exception.  If we've got the full
752 		 * software emulator on-board, let's use it...
753 		 *
754 		 * Force FPU to dump state into task/thread context.  We're
755 		 * moving a lot of data here for what is probably a single
756 		 * instruction, but the alternative is to pre-decode the FP
757 		 * register operands before invoking the emulator, which seems
758 		 * a bit extreme for what should be an infrequent event.
759 		 */
760 		/* Ensure 'resume' not overwrite saved fp context again. */
761 		lose_fpu(1);
762 
763 		/* Run the emulator */
764 		sig = fpu_emulator_cop1Handler(regs, &current->thread.fpu, 1,
765 					       &fault_addr);
766 
767 		/*
768 		 * We can't allow the emulated instruction to leave any of
769 		 * the cause bit set in $fcr31.
770 		 */
771 		current->thread.fpu.fcr31 &= ~FPU_CSR_ALL_X;
772 
773 		/* Restore the hardware register state */
774 		own_fpu(1);	/* Using the FPU again.	 */
775 
776 		/* If something went wrong, signal */
777 		process_fpemu_return(sig, fault_addr);
778 
779 		goto out;
780 	} else if (fcr31 & FPU_CSR_INV_X)
781 		info.si_code = FPE_FLTINV;
782 	else if (fcr31 & FPU_CSR_DIV_X)
783 		info.si_code = FPE_FLTDIV;
784 	else if (fcr31 & FPU_CSR_OVF_X)
785 		info.si_code = FPE_FLTOVF;
786 	else if (fcr31 & FPU_CSR_UDF_X)
787 		info.si_code = FPE_FLTUND;
788 	else if (fcr31 & FPU_CSR_INE_X)
789 		info.si_code = FPE_FLTRES;
790 	else
791 		info.si_code = __SI_FAULT;
792 	info.si_signo = SIGFPE;
793 	info.si_errno = 0;
794 	info.si_addr = (void __user *) regs->cp0_epc;
795 	force_sig_info(SIGFPE, &info, current);
796 
797 out:
798 	exception_exit(prev_state);
799 }
800 
801 static void do_trap_or_bp(struct pt_regs *regs, unsigned int code,
802 	const char *str)
803 {
804 	siginfo_t info;
805 	char b[40];
806 
807 #ifdef CONFIG_KGDB_LOW_LEVEL_TRAP
808 	if (kgdb_ll_trap(DIE_TRAP, str, regs, code, regs_to_trapnr(regs), SIGTRAP) == NOTIFY_STOP)
809 		return;
810 #endif /* CONFIG_KGDB_LOW_LEVEL_TRAP */
811 
812 	if (notify_die(DIE_TRAP, str, regs, code, regs_to_trapnr(regs),
813 		       SIGTRAP) == NOTIFY_STOP)
814 		return;
815 
816 	/*
817 	 * A short test says that IRIX 5.3 sends SIGTRAP for all trap
818 	 * insns, even for trap and break codes that indicate arithmetic
819 	 * failures.  Weird ...
820 	 * But should we continue the brokenness???  --macro
821 	 */
822 	switch (code) {
823 	case BRK_OVERFLOW:
824 	case BRK_DIVZERO:
825 		scnprintf(b, sizeof(b), "%s instruction in kernel code", str);
826 		die_if_kernel(b, regs);
827 		if (code == BRK_DIVZERO)
828 			info.si_code = FPE_INTDIV;
829 		else
830 			info.si_code = FPE_INTOVF;
831 		info.si_signo = SIGFPE;
832 		info.si_errno = 0;
833 		info.si_addr = (void __user *) regs->cp0_epc;
834 		force_sig_info(SIGFPE, &info, current);
835 		break;
836 	case BRK_BUG:
837 		die_if_kernel("Kernel bug detected", regs);
838 		force_sig(SIGTRAP, current);
839 		break;
840 	case BRK_MEMU:
841 		/*
842 		 * Address errors may be deliberately induced by the FPU
843 		 * emulator to retake control of the CPU after executing the
844 		 * instruction in the delay slot of an emulated branch.
845 		 *
846 		 * Terminate if exception was recognized as a delay slot return
847 		 * otherwise handle as normal.
848 		 */
849 		if (do_dsemulret(regs))
850 			return;
851 
852 		die_if_kernel("Math emu break/trap", regs);
853 		force_sig(SIGTRAP, current);
854 		break;
855 	default:
856 		scnprintf(b, sizeof(b), "%s instruction in kernel code", str);
857 		die_if_kernel(b, regs);
858 		force_sig(SIGTRAP, current);
859 	}
860 }
861 
862 asmlinkage void do_bp(struct pt_regs *regs)
863 {
864 	unsigned int opcode, bcode;
865 	enum ctx_state prev_state;
866 	unsigned long epc;
867 	u16 instr[2];
868 	mm_segment_t seg;
869 
870 	seg = get_fs();
871 	if (!user_mode(regs))
872 		set_fs(KERNEL_DS);
873 
874 	prev_state = exception_enter();
875 	if (get_isa16_mode(regs->cp0_epc)) {
876 		/* Calculate EPC. */
877 		epc = exception_epc(regs);
878 		if (cpu_has_mmips) {
879 			if ((__get_user(instr[0], (u16 __user *)msk_isa16_mode(epc)) ||
880 			    (__get_user(instr[1], (u16 __user *)msk_isa16_mode(epc + 2)))))
881 				goto out_sigsegv;
882 			opcode = (instr[0] << 16) | instr[1];
883 		} else {
884 			/* MIPS16e mode */
885 			if (__get_user(instr[0],
886 				       (u16 __user *)msk_isa16_mode(epc)))
887 				goto out_sigsegv;
888 			bcode = (instr[0] >> 6) & 0x3f;
889 			do_trap_or_bp(regs, bcode, "Break");
890 			goto out;
891 		}
892 	} else {
893 		if (__get_user(opcode,
894 			       (unsigned int __user *) exception_epc(regs)))
895 			goto out_sigsegv;
896 	}
897 
898 	/*
899 	 * There is the ancient bug in the MIPS assemblers that the break
900 	 * code starts left to bit 16 instead to bit 6 in the opcode.
901 	 * Gas is bug-compatible, but not always, grrr...
902 	 * We handle both cases with a simple heuristics.  --macro
903 	 */
904 	bcode = ((opcode >> 6) & ((1 << 20) - 1));
905 	if (bcode >= (1 << 10))
906 		bcode >>= 10;
907 
908 	/*
909 	 * notify the kprobe handlers, if instruction is likely to
910 	 * pertain to them.
911 	 */
912 	switch (bcode) {
913 	case BRK_KPROBE_BP:
914 		if (notify_die(DIE_BREAK, "debug", regs, bcode,
915 			       regs_to_trapnr(regs), SIGTRAP) == NOTIFY_STOP)
916 			goto out;
917 		else
918 			break;
919 	case BRK_KPROBE_SSTEPBP:
920 		if (notify_die(DIE_SSTEPBP, "single_step", regs, bcode,
921 			       regs_to_trapnr(regs), SIGTRAP) == NOTIFY_STOP)
922 			goto out;
923 		else
924 			break;
925 	default:
926 		break;
927 	}
928 
929 	do_trap_or_bp(regs, bcode, "Break");
930 
931 out:
932 	set_fs(seg);
933 	exception_exit(prev_state);
934 	return;
935 
936 out_sigsegv:
937 	force_sig(SIGSEGV, current);
938 	goto out;
939 }
940 
941 asmlinkage void do_tr(struct pt_regs *regs)
942 {
943 	u32 opcode, tcode = 0;
944 	enum ctx_state prev_state;
945 	u16 instr[2];
946 	mm_segment_t seg;
947 	unsigned long epc = msk_isa16_mode(exception_epc(regs));
948 
949 	seg = get_fs();
950 	if (!user_mode(regs))
951 		set_fs(get_ds());
952 
953 	prev_state = exception_enter();
954 	if (get_isa16_mode(regs->cp0_epc)) {
955 		if (__get_user(instr[0], (u16 __user *)(epc + 0)) ||
956 		    __get_user(instr[1], (u16 __user *)(epc + 2)))
957 			goto out_sigsegv;
958 		opcode = (instr[0] << 16) | instr[1];
959 		/* Immediate versions don't provide a code.  */
960 		if (!(opcode & OPCODE))
961 			tcode = (opcode >> 12) & ((1 << 4) - 1);
962 	} else {
963 		if (__get_user(opcode, (u32 __user *)epc))
964 			goto out_sigsegv;
965 		/* Immediate versions don't provide a code.  */
966 		if (!(opcode & OPCODE))
967 			tcode = (opcode >> 6) & ((1 << 10) - 1);
968 	}
969 
970 	do_trap_or_bp(regs, tcode, "Trap");
971 
972 out:
973 	set_fs(seg);
974 	exception_exit(prev_state);
975 	return;
976 
977 out_sigsegv:
978 	force_sig(SIGSEGV, current);
979 	goto out;
980 }
981 
982 asmlinkage void do_ri(struct pt_regs *regs)
983 {
984 	unsigned int __user *epc = (unsigned int __user *)exception_epc(regs);
985 	unsigned long old_epc = regs->cp0_epc;
986 	unsigned long old31 = regs->regs[31];
987 	enum ctx_state prev_state;
988 	unsigned int opcode = 0;
989 	int status = -1;
990 
991 	prev_state = exception_enter();
992 	if (notify_die(DIE_RI, "RI Fault", regs, 0, regs_to_trapnr(regs),
993 		       SIGILL) == NOTIFY_STOP)
994 		goto out;
995 
996 	die_if_kernel("Reserved instruction in kernel code", regs);
997 
998 	if (unlikely(compute_return_epc(regs) < 0))
999 		goto out;
1000 
1001 	if (get_isa16_mode(regs->cp0_epc)) {
1002 		unsigned short mmop[2] = { 0 };
1003 
1004 		if (unlikely(get_user(mmop[0], epc) < 0))
1005 			status = SIGSEGV;
1006 		if (unlikely(get_user(mmop[1], epc) < 0))
1007 			status = SIGSEGV;
1008 		opcode = (mmop[0] << 16) | mmop[1];
1009 
1010 		if (status < 0)
1011 			status = simulate_rdhwr_mm(regs, opcode);
1012 	} else {
1013 		if (unlikely(get_user(opcode, epc) < 0))
1014 			status = SIGSEGV;
1015 
1016 		if (!cpu_has_llsc && status < 0)
1017 			status = simulate_llsc(regs, opcode);
1018 
1019 		if (status < 0)
1020 			status = simulate_rdhwr_normal(regs, opcode);
1021 
1022 		if (status < 0)
1023 			status = simulate_sync(regs, opcode);
1024 	}
1025 
1026 	if (status < 0)
1027 		status = SIGILL;
1028 
1029 	if (unlikely(status > 0)) {
1030 		regs->cp0_epc = old_epc;		/* Undo skip-over.  */
1031 		regs->regs[31] = old31;
1032 		force_sig(status, current);
1033 	}
1034 
1035 out:
1036 	exception_exit(prev_state);
1037 }
1038 
1039 /*
1040  * MIPS MT processors may have fewer FPU contexts than CPU threads. If we've
1041  * emulated more than some threshold number of instructions, force migration to
1042  * a "CPU" that has FP support.
1043  */
1044 static void mt_ase_fp_affinity(void)
1045 {
1046 #ifdef CONFIG_MIPS_MT_FPAFF
1047 	if (mt_fpemul_threshold > 0 &&
1048 	     ((current->thread.emulated_fp++ > mt_fpemul_threshold))) {
1049 		/*
1050 		 * If there's no FPU present, or if the application has already
1051 		 * restricted the allowed set to exclude any CPUs with FPUs,
1052 		 * we'll skip the procedure.
1053 		 */
1054 		if (cpus_intersects(current->cpus_allowed, mt_fpu_cpumask)) {
1055 			cpumask_t tmask;
1056 
1057 			current->thread.user_cpus_allowed
1058 				= current->cpus_allowed;
1059 			cpus_and(tmask, current->cpus_allowed,
1060 				mt_fpu_cpumask);
1061 			set_cpus_allowed_ptr(current, &tmask);
1062 			set_thread_flag(TIF_FPUBOUND);
1063 		}
1064 	}
1065 #endif /* CONFIG_MIPS_MT_FPAFF */
1066 }
1067 
1068 /*
1069  * No lock; only written during early bootup by CPU 0.
1070  */
1071 static RAW_NOTIFIER_HEAD(cu2_chain);
1072 
1073 int __ref register_cu2_notifier(struct notifier_block *nb)
1074 {
1075 	return raw_notifier_chain_register(&cu2_chain, nb);
1076 }
1077 
1078 int cu2_notifier_call_chain(unsigned long val, void *v)
1079 {
1080 	return raw_notifier_call_chain(&cu2_chain, val, v);
1081 }
1082 
1083 static int default_cu2_call(struct notifier_block *nfb, unsigned long action,
1084 	void *data)
1085 {
1086 	struct pt_regs *regs = data;
1087 
1088 	die_if_kernel("COP2: Unhandled kernel unaligned access or invalid "
1089 			      "instruction", regs);
1090 	force_sig(SIGILL, current);
1091 
1092 	return NOTIFY_OK;
1093 }
1094 
1095 static int enable_restore_fp_context(int msa)
1096 {
1097 	int err, was_fpu_owner;
1098 
1099 	if (!used_math()) {
1100 		/* First time FP context user. */
1101 		err = init_fpu();
1102 		if (msa && !err)
1103 			enable_msa();
1104 		if (!err)
1105 			set_used_math();
1106 		return err;
1107 	}
1108 
1109 	/*
1110 	 * This task has formerly used the FP context.
1111 	 *
1112 	 * If this thread has no live MSA vector context then we can simply
1113 	 * restore the scalar FP context. If it has live MSA vector context
1114 	 * (that is, it has or may have used MSA since last performing a
1115 	 * function call) then we'll need to restore the vector context. This
1116 	 * applies even if we're currently only executing a scalar FP
1117 	 * instruction. This is because if we were to later execute an MSA
1118 	 * instruction then we'd either have to:
1119 	 *
1120 	 *  - Restore the vector context & clobber any registers modified by
1121 	 *    scalar FP instructions between now & then.
1122 	 *
1123 	 * or
1124 	 *
1125 	 *  - Not restore the vector context & lose the most significant bits
1126 	 *    of all vector registers.
1127 	 *
1128 	 * Neither of those options is acceptable. We cannot restore the least
1129 	 * significant bits of the registers now & only restore the most
1130 	 * significant bits later because the most significant bits of any
1131 	 * vector registers whose aliased FP register is modified now will have
1132 	 * been zeroed. We'd have no way to know that when restoring the vector
1133 	 * context & thus may load an outdated value for the most significant
1134 	 * bits of a vector register.
1135 	 */
1136 	if (!msa && !thread_msa_context_live())
1137 		return own_fpu(1);
1138 
1139 	/*
1140 	 * This task is using or has previously used MSA. Thus we require
1141 	 * that Status.FR == 1.
1142 	 */
1143 	was_fpu_owner = is_fpu_owner();
1144 	err = own_fpu(0);
1145 	if (err)
1146 		return err;
1147 
1148 	enable_msa();
1149 	write_msa_csr(current->thread.fpu.msacsr);
1150 	set_thread_flag(TIF_USEDMSA);
1151 
1152 	/*
1153 	 * If this is the first time that the task is using MSA and it has
1154 	 * previously used scalar FP in this time slice then we already nave
1155 	 * FP context which we shouldn't clobber.
1156 	 */
1157 	if (!test_and_set_thread_flag(TIF_MSA_CTX_LIVE) && was_fpu_owner)
1158 		return 0;
1159 
1160 	/* We need to restore the vector context. */
1161 	restore_msa(current);
1162 	return 0;
1163 }
1164 
1165 asmlinkage void do_cpu(struct pt_regs *regs)
1166 {
1167 	enum ctx_state prev_state;
1168 	unsigned int __user *epc;
1169 	unsigned long old_epc, old31;
1170 	unsigned int opcode;
1171 	unsigned int cpid;
1172 	int status, err;
1173 	unsigned long __maybe_unused flags;
1174 
1175 	prev_state = exception_enter();
1176 	cpid = (regs->cp0_cause >> CAUSEB_CE) & 3;
1177 
1178 	if (cpid != 2)
1179 		die_if_kernel("do_cpu invoked from kernel context!", regs);
1180 
1181 	switch (cpid) {
1182 	case 0:
1183 		epc = (unsigned int __user *)exception_epc(regs);
1184 		old_epc = regs->cp0_epc;
1185 		old31 = regs->regs[31];
1186 		opcode = 0;
1187 		status = -1;
1188 
1189 		if (unlikely(compute_return_epc(regs) < 0))
1190 			goto out;
1191 
1192 		if (get_isa16_mode(regs->cp0_epc)) {
1193 			unsigned short mmop[2] = { 0 };
1194 
1195 			if (unlikely(get_user(mmop[0], epc) < 0))
1196 				status = SIGSEGV;
1197 			if (unlikely(get_user(mmop[1], epc) < 0))
1198 				status = SIGSEGV;
1199 			opcode = (mmop[0] << 16) | mmop[1];
1200 
1201 			if (status < 0)
1202 				status = simulate_rdhwr_mm(regs, opcode);
1203 		} else {
1204 			if (unlikely(get_user(opcode, epc) < 0))
1205 				status = SIGSEGV;
1206 
1207 			if (!cpu_has_llsc && status < 0)
1208 				status = simulate_llsc(regs, opcode);
1209 
1210 			if (status < 0)
1211 				status = simulate_rdhwr_normal(regs, opcode);
1212 		}
1213 
1214 		if (status < 0)
1215 			status = SIGILL;
1216 
1217 		if (unlikely(status > 0)) {
1218 			regs->cp0_epc = old_epc;	/* Undo skip-over.  */
1219 			regs->regs[31] = old31;
1220 			force_sig(status, current);
1221 		}
1222 
1223 		goto out;
1224 
1225 	case 3:
1226 		/*
1227 		 * Old (MIPS I and MIPS II) processors will set this code
1228 		 * for COP1X opcode instructions that replaced the original
1229 		 * COP3 space.	We don't limit COP1 space instructions in
1230 		 * the emulator according to the CPU ISA, so we want to
1231 		 * treat COP1X instructions consistently regardless of which
1232 		 * code the CPU chose.	Therefore we redirect this trap to
1233 		 * the FP emulator too.
1234 		 *
1235 		 * Then some newer FPU-less processors use this code
1236 		 * erroneously too, so they are covered by this choice
1237 		 * as well.
1238 		 */
1239 		if (raw_cpu_has_fpu)
1240 			break;
1241 		/* Fall through.  */
1242 
1243 	case 1:
1244 		err = enable_restore_fp_context(0);
1245 
1246 		if (!raw_cpu_has_fpu || err) {
1247 			int sig;
1248 			void __user *fault_addr = NULL;
1249 			sig = fpu_emulator_cop1Handler(regs,
1250 						       &current->thread.fpu,
1251 						       0, &fault_addr);
1252 			if (!process_fpemu_return(sig, fault_addr) && !err)
1253 				mt_ase_fp_affinity();
1254 		}
1255 
1256 		goto out;
1257 
1258 	case 2:
1259 		raw_notifier_call_chain(&cu2_chain, CU2_EXCEPTION, regs);
1260 		goto out;
1261 	}
1262 
1263 	force_sig(SIGILL, current);
1264 
1265 out:
1266 	exception_exit(prev_state);
1267 }
1268 
1269 asmlinkage void do_msa_fpe(struct pt_regs *regs)
1270 {
1271 	enum ctx_state prev_state;
1272 
1273 	prev_state = exception_enter();
1274 	die_if_kernel("do_msa_fpe invoked from kernel context!", regs);
1275 	force_sig(SIGFPE, current);
1276 	exception_exit(prev_state);
1277 }
1278 
1279 asmlinkage void do_msa(struct pt_regs *regs)
1280 {
1281 	enum ctx_state prev_state;
1282 	int err;
1283 
1284 	prev_state = exception_enter();
1285 
1286 	if (!cpu_has_msa || test_thread_flag(TIF_32BIT_FPREGS)) {
1287 		force_sig(SIGILL, current);
1288 		goto out;
1289 	}
1290 
1291 	die_if_kernel("do_msa invoked from kernel context!", regs);
1292 
1293 	err = enable_restore_fp_context(1);
1294 	if (err)
1295 		force_sig(SIGILL, current);
1296 out:
1297 	exception_exit(prev_state);
1298 }
1299 
1300 asmlinkage void do_mdmx(struct pt_regs *regs)
1301 {
1302 	enum ctx_state prev_state;
1303 
1304 	prev_state = exception_enter();
1305 	force_sig(SIGILL, current);
1306 	exception_exit(prev_state);
1307 }
1308 
1309 /*
1310  * Called with interrupts disabled.
1311  */
1312 asmlinkage void do_watch(struct pt_regs *regs)
1313 {
1314 	enum ctx_state prev_state;
1315 	u32 cause;
1316 
1317 	prev_state = exception_enter();
1318 	/*
1319 	 * Clear WP (bit 22) bit of cause register so we don't loop
1320 	 * forever.
1321 	 */
1322 	cause = read_c0_cause();
1323 	cause &= ~(1 << 22);
1324 	write_c0_cause(cause);
1325 
1326 	/*
1327 	 * If the current thread has the watch registers loaded, save
1328 	 * their values and send SIGTRAP.  Otherwise another thread
1329 	 * left the registers set, clear them and continue.
1330 	 */
1331 	if (test_tsk_thread_flag(current, TIF_LOAD_WATCH)) {
1332 		mips_read_watch_registers();
1333 		local_irq_enable();
1334 		force_sig(SIGTRAP, current);
1335 	} else {
1336 		mips_clear_watch_registers();
1337 		local_irq_enable();
1338 	}
1339 	exception_exit(prev_state);
1340 }
1341 
1342 asmlinkage void do_mcheck(struct pt_regs *regs)
1343 {
1344 	const int field = 2 * sizeof(unsigned long);
1345 	int multi_match = regs->cp0_status & ST0_TS;
1346 	enum ctx_state prev_state;
1347 
1348 	prev_state = exception_enter();
1349 	show_regs(regs);
1350 
1351 	if (multi_match) {
1352 		printk("Index	: %0x\n", read_c0_index());
1353 		printk("Pagemask: %0x\n", read_c0_pagemask());
1354 		printk("EntryHi : %0*lx\n", field, read_c0_entryhi());
1355 		printk("EntryLo0: %0*lx\n", field, read_c0_entrylo0());
1356 		printk("EntryLo1: %0*lx\n", field, read_c0_entrylo1());
1357 		printk("\n");
1358 		dump_tlb_all();
1359 	}
1360 
1361 	show_code((unsigned int __user *) regs->cp0_epc);
1362 
1363 	/*
1364 	 * Some chips may have other causes of machine check (e.g. SB1
1365 	 * graduation timer)
1366 	 */
1367 	panic("Caught Machine Check exception - %scaused by multiple "
1368 	      "matching entries in the TLB.",
1369 	      (multi_match) ? "" : "not ");
1370 }
1371 
1372 asmlinkage void do_mt(struct pt_regs *regs)
1373 {
1374 	int subcode;
1375 
1376 	subcode = (read_vpe_c0_vpecontrol() & VPECONTROL_EXCPT)
1377 			>> VPECONTROL_EXCPT_SHIFT;
1378 	switch (subcode) {
1379 	case 0:
1380 		printk(KERN_DEBUG "Thread Underflow\n");
1381 		break;
1382 	case 1:
1383 		printk(KERN_DEBUG "Thread Overflow\n");
1384 		break;
1385 	case 2:
1386 		printk(KERN_DEBUG "Invalid YIELD Qualifier\n");
1387 		break;
1388 	case 3:
1389 		printk(KERN_DEBUG "Gating Storage Exception\n");
1390 		break;
1391 	case 4:
1392 		printk(KERN_DEBUG "YIELD Scheduler Exception\n");
1393 		break;
1394 	case 5:
1395 		printk(KERN_DEBUG "Gating Storage Scheduler Exception\n");
1396 		break;
1397 	default:
1398 		printk(KERN_DEBUG "*** UNKNOWN THREAD EXCEPTION %d ***\n",
1399 			subcode);
1400 		break;
1401 	}
1402 	die_if_kernel("MIPS MT Thread exception in kernel", regs);
1403 
1404 	force_sig(SIGILL, current);
1405 }
1406 
1407 
1408 asmlinkage void do_dsp(struct pt_regs *regs)
1409 {
1410 	if (cpu_has_dsp)
1411 		panic("Unexpected DSP exception");
1412 
1413 	force_sig(SIGILL, current);
1414 }
1415 
1416 asmlinkage void do_reserved(struct pt_regs *regs)
1417 {
1418 	/*
1419 	 * Game over - no way to handle this if it ever occurs.	 Most probably
1420 	 * caused by a new unknown cpu type or after another deadly
1421 	 * hard/software error.
1422 	 */
1423 	show_regs(regs);
1424 	panic("Caught reserved exception %ld - should not happen.",
1425 	      (regs->cp0_cause & 0x7f) >> 2);
1426 }
1427 
1428 static int __initdata l1parity = 1;
1429 static int __init nol1parity(char *s)
1430 {
1431 	l1parity = 0;
1432 	return 1;
1433 }
1434 __setup("nol1par", nol1parity);
1435 static int __initdata l2parity = 1;
1436 static int __init nol2parity(char *s)
1437 {
1438 	l2parity = 0;
1439 	return 1;
1440 }
1441 __setup("nol2par", nol2parity);
1442 
1443 /*
1444  * Some MIPS CPUs can enable/disable for cache parity detection, but do
1445  * it different ways.
1446  */
1447 static inline void parity_protection_init(void)
1448 {
1449 	switch (current_cpu_type()) {
1450 	case CPU_24K:
1451 	case CPU_34K:
1452 	case CPU_74K:
1453 	case CPU_1004K:
1454 	case CPU_1074K:
1455 	case CPU_INTERAPTIV:
1456 	case CPU_PROAPTIV:
1457 	case CPU_P5600:
1458 		{
1459 #define ERRCTL_PE	0x80000000
1460 #define ERRCTL_L2P	0x00800000
1461 			unsigned long errctl;
1462 			unsigned int l1parity_present, l2parity_present;
1463 
1464 			errctl = read_c0_ecc();
1465 			errctl &= ~(ERRCTL_PE|ERRCTL_L2P);
1466 
1467 			/* probe L1 parity support */
1468 			write_c0_ecc(errctl | ERRCTL_PE);
1469 			back_to_back_c0_hazard();
1470 			l1parity_present = (read_c0_ecc() & ERRCTL_PE);
1471 
1472 			/* probe L2 parity support */
1473 			write_c0_ecc(errctl|ERRCTL_L2P);
1474 			back_to_back_c0_hazard();
1475 			l2parity_present = (read_c0_ecc() & ERRCTL_L2P);
1476 
1477 			if (l1parity_present && l2parity_present) {
1478 				if (l1parity)
1479 					errctl |= ERRCTL_PE;
1480 				if (l1parity ^ l2parity)
1481 					errctl |= ERRCTL_L2P;
1482 			} else if (l1parity_present) {
1483 				if (l1parity)
1484 					errctl |= ERRCTL_PE;
1485 			} else if (l2parity_present) {
1486 				if (l2parity)
1487 					errctl |= ERRCTL_L2P;
1488 			} else {
1489 				/* No parity available */
1490 			}
1491 
1492 			printk(KERN_INFO "Writing ErrCtl register=%08lx\n", errctl);
1493 
1494 			write_c0_ecc(errctl);
1495 			back_to_back_c0_hazard();
1496 			errctl = read_c0_ecc();
1497 			printk(KERN_INFO "Readback ErrCtl register=%08lx\n", errctl);
1498 
1499 			if (l1parity_present)
1500 				printk(KERN_INFO "Cache parity protection %sabled\n",
1501 				       (errctl & ERRCTL_PE) ? "en" : "dis");
1502 
1503 			if (l2parity_present) {
1504 				if (l1parity_present && l1parity)
1505 					errctl ^= ERRCTL_L2P;
1506 				printk(KERN_INFO "L2 cache parity protection %sabled\n",
1507 				       (errctl & ERRCTL_L2P) ? "en" : "dis");
1508 			}
1509 		}
1510 		break;
1511 
1512 	case CPU_5KC:
1513 	case CPU_5KE:
1514 	case CPU_LOONGSON1:
1515 		write_c0_ecc(0x80000000);
1516 		back_to_back_c0_hazard();
1517 		/* Set the PE bit (bit 31) in the c0_errctl register. */
1518 		printk(KERN_INFO "Cache parity protection %sabled\n",
1519 		       (read_c0_ecc() & 0x80000000) ? "en" : "dis");
1520 		break;
1521 	case CPU_20KC:
1522 	case CPU_25KF:
1523 		/* Clear the DE bit (bit 16) in the c0_status register. */
1524 		printk(KERN_INFO "Enable cache parity protection for "
1525 		       "MIPS 20KC/25KF CPUs.\n");
1526 		clear_c0_status(ST0_DE);
1527 		break;
1528 	default:
1529 		break;
1530 	}
1531 }
1532 
1533 asmlinkage void cache_parity_error(void)
1534 {
1535 	const int field = 2 * sizeof(unsigned long);
1536 	unsigned int reg_val;
1537 
1538 	/* For the moment, report the problem and hang. */
1539 	printk("Cache error exception:\n");
1540 	printk("cp0_errorepc == %0*lx\n", field, read_c0_errorepc());
1541 	reg_val = read_c0_cacheerr();
1542 	printk("c0_cacheerr == %08x\n", reg_val);
1543 
1544 	printk("Decoded c0_cacheerr: %s cache fault in %s reference.\n",
1545 	       reg_val & (1<<30) ? "secondary" : "primary",
1546 	       reg_val & (1<<31) ? "data" : "insn");
1547 	if (cpu_has_mips_r2 &&
1548 	    ((current_cpu_data.processor_id && 0xff0000) == PRID_COMP_MIPS)) {
1549 		pr_err("Error bits: %s%s%s%s%s%s%s%s\n",
1550 			reg_val & (1<<29) ? "ED " : "",
1551 			reg_val & (1<<28) ? "ET " : "",
1552 			reg_val & (1<<27) ? "ES " : "",
1553 			reg_val & (1<<26) ? "EE " : "",
1554 			reg_val & (1<<25) ? "EB " : "",
1555 			reg_val & (1<<24) ? "EI " : "",
1556 			reg_val & (1<<23) ? "E1 " : "",
1557 			reg_val & (1<<22) ? "E0 " : "");
1558 	} else {
1559 		pr_err("Error bits: %s%s%s%s%s%s%s\n",
1560 			reg_val & (1<<29) ? "ED " : "",
1561 			reg_val & (1<<28) ? "ET " : "",
1562 			reg_val & (1<<26) ? "EE " : "",
1563 			reg_val & (1<<25) ? "EB " : "",
1564 			reg_val & (1<<24) ? "EI " : "",
1565 			reg_val & (1<<23) ? "E1 " : "",
1566 			reg_val & (1<<22) ? "E0 " : "");
1567 	}
1568 	printk("IDX: 0x%08x\n", reg_val & ((1<<22)-1));
1569 
1570 #if defined(CONFIG_CPU_MIPS32) || defined(CONFIG_CPU_MIPS64)
1571 	if (reg_val & (1<<22))
1572 		printk("DErrAddr0: 0x%0*lx\n", field, read_c0_derraddr0());
1573 
1574 	if (reg_val & (1<<23))
1575 		printk("DErrAddr1: 0x%0*lx\n", field, read_c0_derraddr1());
1576 #endif
1577 
1578 	panic("Can't handle the cache error!");
1579 }
1580 
1581 asmlinkage void do_ftlb(void)
1582 {
1583 	const int field = 2 * sizeof(unsigned long);
1584 	unsigned int reg_val;
1585 
1586 	/* For the moment, report the problem and hang. */
1587 	if (cpu_has_mips_r2 &&
1588 	    ((current_cpu_data.processor_id && 0xff0000) == PRID_COMP_MIPS)) {
1589 		pr_err("FTLB error exception, cp0_ecc=0x%08x:\n",
1590 		       read_c0_ecc());
1591 		pr_err("cp0_errorepc == %0*lx\n", field, read_c0_errorepc());
1592 		reg_val = read_c0_cacheerr();
1593 		pr_err("c0_cacheerr == %08x\n", reg_val);
1594 
1595 		if ((reg_val & 0xc0000000) == 0xc0000000) {
1596 			pr_err("Decoded c0_cacheerr: FTLB parity error\n");
1597 		} else {
1598 			pr_err("Decoded c0_cacheerr: %s cache fault in %s reference.\n",
1599 			       reg_val & (1<<30) ? "secondary" : "primary",
1600 			       reg_val & (1<<31) ? "data" : "insn");
1601 		}
1602 	} else {
1603 		pr_err("FTLB error exception\n");
1604 	}
1605 	/* Just print the cacheerr bits for now */
1606 	cache_parity_error();
1607 }
1608 
1609 /*
1610  * SDBBP EJTAG debug exception handler.
1611  * We skip the instruction and return to the next instruction.
1612  */
1613 void ejtag_exception_handler(struct pt_regs *regs)
1614 {
1615 	const int field = 2 * sizeof(unsigned long);
1616 	unsigned long depc, old_epc, old_ra;
1617 	unsigned int debug;
1618 
1619 	printk(KERN_DEBUG "SDBBP EJTAG debug exception - not handled yet, just ignored!\n");
1620 	depc = read_c0_depc();
1621 	debug = read_c0_debug();
1622 	printk(KERN_DEBUG "c0_depc = %0*lx, DEBUG = %08x\n", field, depc, debug);
1623 	if (debug & 0x80000000) {
1624 		/*
1625 		 * In branch delay slot.
1626 		 * We cheat a little bit here and use EPC to calculate the
1627 		 * debug return address (DEPC). EPC is restored after the
1628 		 * calculation.
1629 		 */
1630 		old_epc = regs->cp0_epc;
1631 		old_ra = regs->regs[31];
1632 		regs->cp0_epc = depc;
1633 		compute_return_epc(regs);
1634 		depc = regs->cp0_epc;
1635 		regs->cp0_epc = old_epc;
1636 		regs->regs[31] = old_ra;
1637 	} else
1638 		depc += 4;
1639 	write_c0_depc(depc);
1640 
1641 #if 0
1642 	printk(KERN_DEBUG "\n\n----- Enable EJTAG single stepping ----\n\n");
1643 	write_c0_debug(debug | 0x100);
1644 #endif
1645 }
1646 
1647 /*
1648  * NMI exception handler.
1649  * No lock; only written during early bootup by CPU 0.
1650  */
1651 static RAW_NOTIFIER_HEAD(nmi_chain);
1652 
1653 int register_nmi_notifier(struct notifier_block *nb)
1654 {
1655 	return raw_notifier_chain_register(&nmi_chain, nb);
1656 }
1657 
1658 void __noreturn nmi_exception_handler(struct pt_regs *regs)
1659 {
1660 	char str[100];
1661 
1662 	raw_notifier_call_chain(&nmi_chain, 0, regs);
1663 	bust_spinlocks(1);
1664 	snprintf(str, 100, "CPU%d NMI taken, CP0_EPC=%lx\n",
1665 		 smp_processor_id(), regs->cp0_epc);
1666 	regs->cp0_epc = read_c0_errorepc();
1667 	die(str, regs);
1668 }
1669 
1670 #define VECTORSPACING 0x100	/* for EI/VI mode */
1671 
1672 unsigned long ebase;
1673 unsigned long exception_handlers[32];
1674 unsigned long vi_handlers[64];
1675 
1676 void __init *set_except_vector(int n, void *addr)
1677 {
1678 	unsigned long handler = (unsigned long) addr;
1679 	unsigned long old_handler;
1680 
1681 #ifdef CONFIG_CPU_MICROMIPS
1682 	/*
1683 	 * Only the TLB handlers are cache aligned with an even
1684 	 * address. All other handlers are on an odd address and
1685 	 * require no modification. Otherwise, MIPS32 mode will
1686 	 * be entered when handling any TLB exceptions. That
1687 	 * would be bad...since we must stay in microMIPS mode.
1688 	 */
1689 	if (!(handler & 0x1))
1690 		handler |= 1;
1691 #endif
1692 	old_handler = xchg(&exception_handlers[n], handler);
1693 
1694 	if (n == 0 && cpu_has_divec) {
1695 #ifdef CONFIG_CPU_MICROMIPS
1696 		unsigned long jump_mask = ~((1 << 27) - 1);
1697 #else
1698 		unsigned long jump_mask = ~((1 << 28) - 1);
1699 #endif
1700 		u32 *buf = (u32 *)(ebase + 0x200);
1701 		unsigned int k0 = 26;
1702 		if ((handler & jump_mask) == ((ebase + 0x200) & jump_mask)) {
1703 			uasm_i_j(&buf, handler & ~jump_mask);
1704 			uasm_i_nop(&buf);
1705 		} else {
1706 			UASM_i_LA(&buf, k0, handler);
1707 			uasm_i_jr(&buf, k0);
1708 			uasm_i_nop(&buf);
1709 		}
1710 		local_flush_icache_range(ebase + 0x200, (unsigned long)buf);
1711 	}
1712 	return (void *)old_handler;
1713 }
1714 
1715 static void do_default_vi(void)
1716 {
1717 	show_regs(get_irq_regs());
1718 	panic("Caught unexpected vectored interrupt.");
1719 }
1720 
1721 static void *set_vi_srs_handler(int n, vi_handler_t addr, int srs)
1722 {
1723 	unsigned long handler;
1724 	unsigned long old_handler = vi_handlers[n];
1725 	int srssets = current_cpu_data.srsets;
1726 	u16 *h;
1727 	unsigned char *b;
1728 
1729 	BUG_ON(!cpu_has_veic && !cpu_has_vint);
1730 
1731 	if (addr == NULL) {
1732 		handler = (unsigned long) do_default_vi;
1733 		srs = 0;
1734 	} else
1735 		handler = (unsigned long) addr;
1736 	vi_handlers[n] = handler;
1737 
1738 	b = (unsigned char *)(ebase + 0x200 + n*VECTORSPACING);
1739 
1740 	if (srs >= srssets)
1741 		panic("Shadow register set %d not supported", srs);
1742 
1743 	if (cpu_has_veic) {
1744 		if (board_bind_eic_interrupt)
1745 			board_bind_eic_interrupt(n, srs);
1746 	} else if (cpu_has_vint) {
1747 		/* SRSMap is only defined if shadow sets are implemented */
1748 		if (srssets > 1)
1749 			change_c0_srsmap(0xf << n*4, srs << n*4);
1750 	}
1751 
1752 	if (srs == 0) {
1753 		/*
1754 		 * If no shadow set is selected then use the default handler
1755 		 * that does normal register saving and standard interrupt exit
1756 		 */
1757 		extern char except_vec_vi, except_vec_vi_lui;
1758 		extern char except_vec_vi_ori, except_vec_vi_end;
1759 		extern char rollback_except_vec_vi;
1760 		char *vec_start = using_rollback_handler() ?
1761 			&rollback_except_vec_vi : &except_vec_vi;
1762 #ifdef CONFIG_MIPS_MT_SMTC
1763 		/*
1764 		 * We need to provide the SMTC vectored interrupt handler
1765 		 * not only with the address of the handler, but with the
1766 		 * Status.IM bit to be masked before going there.
1767 		 */
1768 		extern char except_vec_vi_mori;
1769 #if defined(CONFIG_CPU_MICROMIPS) || defined(CONFIG_CPU_BIG_ENDIAN)
1770 		const int mori_offset = &except_vec_vi_mori - vec_start + 2;
1771 #else
1772 		const int mori_offset = &except_vec_vi_mori - vec_start;
1773 #endif
1774 #endif /* CONFIG_MIPS_MT_SMTC */
1775 #if defined(CONFIG_CPU_MICROMIPS) || defined(CONFIG_CPU_BIG_ENDIAN)
1776 		const int lui_offset = &except_vec_vi_lui - vec_start + 2;
1777 		const int ori_offset = &except_vec_vi_ori - vec_start + 2;
1778 #else
1779 		const int lui_offset = &except_vec_vi_lui - vec_start;
1780 		const int ori_offset = &except_vec_vi_ori - vec_start;
1781 #endif
1782 		const int handler_len = &except_vec_vi_end - vec_start;
1783 
1784 		if (handler_len > VECTORSPACING) {
1785 			/*
1786 			 * Sigh... panicing won't help as the console
1787 			 * is probably not configured :(
1788 			 */
1789 			panic("VECTORSPACING too small");
1790 		}
1791 
1792 		set_handler(((unsigned long)b - ebase), vec_start,
1793 #ifdef CONFIG_CPU_MICROMIPS
1794 				(handler_len - 1));
1795 #else
1796 				handler_len);
1797 #endif
1798 #ifdef CONFIG_MIPS_MT_SMTC
1799 		BUG_ON(n > 7);	/* Vector index %d exceeds SMTC maximum. */
1800 
1801 		h = (u16 *)(b + mori_offset);
1802 		*h = (0x100 << n);
1803 #endif /* CONFIG_MIPS_MT_SMTC */
1804 		h = (u16 *)(b + lui_offset);
1805 		*h = (handler >> 16) & 0xffff;
1806 		h = (u16 *)(b + ori_offset);
1807 		*h = (handler & 0xffff);
1808 		local_flush_icache_range((unsigned long)b,
1809 					 (unsigned long)(b+handler_len));
1810 	}
1811 	else {
1812 		/*
1813 		 * In other cases jump directly to the interrupt handler. It
1814 		 * is the handler's responsibility to save registers if required
1815 		 * (eg hi/lo) and return from the exception using "eret".
1816 		 */
1817 		u32 insn;
1818 
1819 		h = (u16 *)b;
1820 		/* j handler */
1821 #ifdef CONFIG_CPU_MICROMIPS
1822 		insn = 0xd4000000 | (((u32)handler & 0x07ffffff) >> 1);
1823 #else
1824 		insn = 0x08000000 | (((u32)handler & 0x0fffffff) >> 2);
1825 #endif
1826 		h[0] = (insn >> 16) & 0xffff;
1827 		h[1] = insn & 0xffff;
1828 		h[2] = 0;
1829 		h[3] = 0;
1830 		local_flush_icache_range((unsigned long)b,
1831 					 (unsigned long)(b+8));
1832 	}
1833 
1834 	return (void *)old_handler;
1835 }
1836 
1837 void *set_vi_handler(int n, vi_handler_t addr)
1838 {
1839 	return set_vi_srs_handler(n, addr, 0);
1840 }
1841 
1842 extern void tlb_init(void);
1843 
1844 /*
1845  * Timer interrupt
1846  */
1847 int cp0_compare_irq;
1848 EXPORT_SYMBOL_GPL(cp0_compare_irq);
1849 int cp0_compare_irq_shift;
1850 
1851 /*
1852  * Performance counter IRQ or -1 if shared with timer
1853  */
1854 int cp0_perfcount_irq;
1855 EXPORT_SYMBOL_GPL(cp0_perfcount_irq);
1856 
1857 static int noulri;
1858 
1859 static int __init ulri_disable(char *s)
1860 {
1861 	pr_info("Disabling ulri\n");
1862 	noulri = 1;
1863 
1864 	return 1;
1865 }
1866 __setup("noulri", ulri_disable);
1867 
1868 void per_cpu_trap_init(bool is_boot_cpu)
1869 {
1870 	unsigned int cpu = smp_processor_id();
1871 	unsigned int status_set = ST0_CU0;
1872 	unsigned int hwrena = cpu_hwrena_impl_bits;
1873 #ifdef CONFIG_MIPS_MT_SMTC
1874 	int secondaryTC = 0;
1875 	int bootTC = (cpu == 0);
1876 
1877 	/*
1878 	 * Only do per_cpu_trap_init() for first TC of Each VPE.
1879 	 * Note that this hack assumes that the SMTC init code
1880 	 * assigns TCs consecutively and in ascending order.
1881 	 */
1882 
1883 	if (((read_c0_tcbind() & TCBIND_CURTC) != 0) &&
1884 	    ((read_c0_tcbind() & TCBIND_CURVPE) == cpu_data[cpu - 1].vpe_id))
1885 		secondaryTC = 1;
1886 #endif /* CONFIG_MIPS_MT_SMTC */
1887 
1888 	/*
1889 	 * Disable coprocessors and select 32-bit or 64-bit addressing
1890 	 * and the 16/32 or 32/32 FPR register model.  Reset the BEV
1891 	 * flag that some firmware may have left set and the TS bit (for
1892 	 * IP27).  Set XX for ISA IV code to work.
1893 	 */
1894 #ifdef CONFIG_64BIT
1895 	status_set |= ST0_FR|ST0_KX|ST0_SX|ST0_UX;
1896 #endif
1897 	if (current_cpu_data.isa_level & MIPS_CPU_ISA_IV)
1898 		status_set |= ST0_XX;
1899 	if (cpu_has_dsp)
1900 		status_set |= ST0_MX;
1901 
1902 	change_c0_status(ST0_CU|ST0_MX|ST0_RE|ST0_FR|ST0_BEV|ST0_TS|ST0_KX|ST0_SX|ST0_UX,
1903 			 status_set);
1904 
1905 	if (cpu_has_mips_r2)
1906 		hwrena |= 0x0000000f;
1907 
1908 	if (!noulri && cpu_has_userlocal)
1909 		hwrena |= (1 << 29);
1910 
1911 	if (hwrena)
1912 		write_c0_hwrena(hwrena);
1913 
1914 #ifdef CONFIG_MIPS_MT_SMTC
1915 	if (!secondaryTC) {
1916 #endif /* CONFIG_MIPS_MT_SMTC */
1917 
1918 	if (cpu_has_veic || cpu_has_vint) {
1919 		unsigned long sr = set_c0_status(ST0_BEV);
1920 		write_c0_ebase(ebase);
1921 		write_c0_status(sr);
1922 		/* Setting vector spacing enables EI/VI mode  */
1923 		change_c0_intctl(0x3e0, VECTORSPACING);
1924 	}
1925 	if (cpu_has_divec) {
1926 		if (cpu_has_mipsmt) {
1927 			unsigned int vpflags = dvpe();
1928 			set_c0_cause(CAUSEF_IV);
1929 			evpe(vpflags);
1930 		} else
1931 			set_c0_cause(CAUSEF_IV);
1932 	}
1933 
1934 	/*
1935 	 * Before R2 both interrupt numbers were fixed to 7, so on R2 only:
1936 	 *
1937 	 *  o read IntCtl.IPTI to determine the timer interrupt
1938 	 *  o read IntCtl.IPPCI to determine the performance counter interrupt
1939 	 */
1940 	if (cpu_has_mips_r2) {
1941 		cp0_compare_irq_shift = CAUSEB_TI - CAUSEB_IP;
1942 		cp0_compare_irq = (read_c0_intctl() >> INTCTLB_IPTI) & 7;
1943 		cp0_perfcount_irq = (read_c0_intctl() >> INTCTLB_IPPCI) & 7;
1944 		if (cp0_perfcount_irq == cp0_compare_irq)
1945 			cp0_perfcount_irq = -1;
1946 	} else {
1947 		cp0_compare_irq = CP0_LEGACY_COMPARE_IRQ;
1948 		cp0_compare_irq_shift = CP0_LEGACY_PERFCNT_IRQ;
1949 		cp0_perfcount_irq = -1;
1950 	}
1951 
1952 #ifdef CONFIG_MIPS_MT_SMTC
1953 	}
1954 #endif /* CONFIG_MIPS_MT_SMTC */
1955 
1956 	if (!cpu_data[cpu].asid_cache)
1957 		cpu_data[cpu].asid_cache = ASID_FIRST_VERSION;
1958 
1959 	atomic_inc(&init_mm.mm_count);
1960 	current->active_mm = &init_mm;
1961 	BUG_ON(current->mm);
1962 	enter_lazy_tlb(&init_mm, current);
1963 
1964 #ifdef CONFIG_MIPS_MT_SMTC
1965 	if (bootTC) {
1966 #endif /* CONFIG_MIPS_MT_SMTC */
1967 		/* Boot CPU's cache setup in setup_arch(). */
1968 		if (!is_boot_cpu)
1969 			cpu_cache_init();
1970 		tlb_init();
1971 #ifdef CONFIG_MIPS_MT_SMTC
1972 	} else if (!secondaryTC) {
1973 		/*
1974 		 * First TC in non-boot VPE must do subset of tlb_init()
1975 		 * for MMU countrol registers.
1976 		 */
1977 		write_c0_pagemask(PM_DEFAULT_MASK);
1978 		write_c0_wired(0);
1979 	}
1980 #endif /* CONFIG_MIPS_MT_SMTC */
1981 	TLBMISS_HANDLER_SETUP();
1982 }
1983 
1984 /* Install CPU exception handler */
1985 void set_handler(unsigned long offset, void *addr, unsigned long size)
1986 {
1987 #ifdef CONFIG_CPU_MICROMIPS
1988 	memcpy((void *)(ebase + offset), ((unsigned char *)addr - 1), size);
1989 #else
1990 	memcpy((void *)(ebase + offset), addr, size);
1991 #endif
1992 	local_flush_icache_range(ebase + offset, ebase + offset + size);
1993 }
1994 
1995 static char panic_null_cerr[] =
1996 	"Trying to set NULL cache error exception handler";
1997 
1998 /*
1999  * Install uncached CPU exception handler.
2000  * This is suitable only for the cache error exception which is the only
2001  * exception handler that is being run uncached.
2002  */
2003 void set_uncached_handler(unsigned long offset, void *addr,
2004 	unsigned long size)
2005 {
2006 	unsigned long uncached_ebase = CKSEG1ADDR(ebase);
2007 
2008 	if (!addr)
2009 		panic(panic_null_cerr);
2010 
2011 	memcpy((void *)(uncached_ebase + offset), addr, size);
2012 }
2013 
2014 static int __initdata rdhwr_noopt;
2015 static int __init set_rdhwr_noopt(char *str)
2016 {
2017 	rdhwr_noopt = 1;
2018 	return 1;
2019 }
2020 
2021 __setup("rdhwr_noopt", set_rdhwr_noopt);
2022 
2023 void __init trap_init(void)
2024 {
2025 	extern char except_vec3_generic;
2026 	extern char except_vec4;
2027 	extern char except_vec3_r4000;
2028 	unsigned long i;
2029 
2030 	check_wait();
2031 
2032 #if defined(CONFIG_KGDB)
2033 	if (kgdb_early_setup)
2034 		return; /* Already done */
2035 #endif
2036 
2037 	if (cpu_has_veic || cpu_has_vint) {
2038 		unsigned long size = 0x200 + VECTORSPACING*64;
2039 		ebase = (unsigned long)
2040 			__alloc_bootmem(size, 1 << fls(size), 0);
2041 	} else {
2042 #ifdef CONFIG_KVM_GUEST
2043 #define KVM_GUEST_KSEG0     0x40000000
2044         ebase = KVM_GUEST_KSEG0;
2045 #else
2046         ebase = CKSEG0;
2047 #endif
2048 		if (cpu_has_mips_r2)
2049 			ebase += (read_c0_ebase() & 0x3ffff000);
2050 	}
2051 
2052 	if (cpu_has_mmips) {
2053 		unsigned int config3 = read_c0_config3();
2054 
2055 		if (IS_ENABLED(CONFIG_CPU_MICROMIPS))
2056 			write_c0_config3(config3 | MIPS_CONF3_ISA_OE);
2057 		else
2058 			write_c0_config3(config3 & ~MIPS_CONF3_ISA_OE);
2059 	}
2060 
2061 	if (board_ebase_setup)
2062 		board_ebase_setup();
2063 	per_cpu_trap_init(true);
2064 
2065 	/*
2066 	 * Copy the generic exception handlers to their final destination.
2067 	 * This will be overriden later as suitable for a particular
2068 	 * configuration.
2069 	 */
2070 	set_handler(0x180, &except_vec3_generic, 0x80);
2071 
2072 	/*
2073 	 * Setup default vectors
2074 	 */
2075 	for (i = 0; i <= 31; i++)
2076 		set_except_vector(i, handle_reserved);
2077 
2078 	/*
2079 	 * Copy the EJTAG debug exception vector handler code to it's final
2080 	 * destination.
2081 	 */
2082 	if (cpu_has_ejtag && board_ejtag_handler_setup)
2083 		board_ejtag_handler_setup();
2084 
2085 	/*
2086 	 * Only some CPUs have the watch exceptions.
2087 	 */
2088 	if (cpu_has_watch)
2089 		set_except_vector(23, handle_watch);
2090 
2091 	/*
2092 	 * Initialise interrupt handlers
2093 	 */
2094 	if (cpu_has_veic || cpu_has_vint) {
2095 		int nvec = cpu_has_veic ? 64 : 8;
2096 		for (i = 0; i < nvec; i++)
2097 			set_vi_handler(i, NULL);
2098 	}
2099 	else if (cpu_has_divec)
2100 		set_handler(0x200, &except_vec4, 0x8);
2101 
2102 	/*
2103 	 * Some CPUs can enable/disable for cache parity detection, but does
2104 	 * it different ways.
2105 	 */
2106 	parity_protection_init();
2107 
2108 	/*
2109 	 * The Data Bus Errors / Instruction Bus Errors are signaled
2110 	 * by external hardware.  Therefore these two exceptions
2111 	 * may have board specific handlers.
2112 	 */
2113 	if (board_be_init)
2114 		board_be_init();
2115 
2116 	set_except_vector(0, using_rollback_handler() ? rollback_handle_int
2117 						      : handle_int);
2118 	set_except_vector(1, handle_tlbm);
2119 	set_except_vector(2, handle_tlbl);
2120 	set_except_vector(3, handle_tlbs);
2121 
2122 	set_except_vector(4, handle_adel);
2123 	set_except_vector(5, handle_ades);
2124 
2125 	set_except_vector(6, handle_ibe);
2126 	set_except_vector(7, handle_dbe);
2127 
2128 	set_except_vector(8, handle_sys);
2129 	set_except_vector(9, handle_bp);
2130 	set_except_vector(10, rdhwr_noopt ? handle_ri :
2131 			  (cpu_has_vtag_icache ?
2132 			   handle_ri_rdhwr_vivt : handle_ri_rdhwr));
2133 	set_except_vector(11, handle_cpu);
2134 	set_except_vector(12, handle_ov);
2135 	set_except_vector(13, handle_tr);
2136 	set_except_vector(14, handle_msa_fpe);
2137 
2138 	if (current_cpu_type() == CPU_R6000 ||
2139 	    current_cpu_type() == CPU_R6000A) {
2140 		/*
2141 		 * The R6000 is the only R-series CPU that features a machine
2142 		 * check exception (similar to the R4000 cache error) and
2143 		 * unaligned ldc1/sdc1 exception.  The handlers have not been
2144 		 * written yet.	 Well, anyway there is no R6000 machine on the
2145 		 * current list of targets for Linux/MIPS.
2146 		 * (Duh, crap, there is someone with a triple R6k machine)
2147 		 */
2148 		//set_except_vector(14, handle_mc);
2149 		//set_except_vector(15, handle_ndc);
2150 	}
2151 
2152 
2153 	if (board_nmi_handler_setup)
2154 		board_nmi_handler_setup();
2155 
2156 	if (cpu_has_fpu && !cpu_has_nofpuex)
2157 		set_except_vector(15, handle_fpe);
2158 
2159 	set_except_vector(16, handle_ftlb);
2160 	set_except_vector(21, handle_msa);
2161 	set_except_vector(22, handle_mdmx);
2162 
2163 	if (cpu_has_mcheck)
2164 		set_except_vector(24, handle_mcheck);
2165 
2166 	if (cpu_has_mipsmt)
2167 		set_except_vector(25, handle_mt);
2168 
2169 	set_except_vector(26, handle_dsp);
2170 
2171 	if (board_cache_error_setup)
2172 		board_cache_error_setup();
2173 
2174 	if (cpu_has_vce)
2175 		/* Special exception: R4[04]00 uses also the divec space. */
2176 		set_handler(0x180, &except_vec3_r4000, 0x100);
2177 	else if (cpu_has_4kex)
2178 		set_handler(0x180, &except_vec3_generic, 0x80);
2179 	else
2180 		set_handler(0x080, &except_vec3_generic, 0x80);
2181 
2182 	local_flush_icache_range(ebase, ebase + 0x400);
2183 
2184 	sort_extable(__start___dbe_table, __stop___dbe_table);
2185 
2186 	cu2_notifier(default_cu2_call, 0x80000000);	/* Run last  */
2187 }
2188