xref: /linux/arch/mips/kernel/traps.c (revision a17627ef8833ac30622a7b39b7be390e1b174405)
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) 2000, 01 MIPS Technologies, Inc.
12  * Copyright (C) 2002, 2003, 2004, 2005  Maciej W. Rozycki
13  */
14 #include <linux/init.h>
15 #include <linux/mm.h>
16 #include <linux/module.h>
17 #include <linux/sched.h>
18 #include <linux/smp.h>
19 #include <linux/spinlock.h>
20 #include <linux/kallsyms.h>
21 #include <linux/bootmem.h>
22 #include <linux/interrupt.h>
23 
24 #include <asm/bootinfo.h>
25 #include <asm/branch.h>
26 #include <asm/break.h>
27 #include <asm/cpu.h>
28 #include <asm/dsp.h>
29 #include <asm/fpu.h>
30 #include <asm/mipsregs.h>
31 #include <asm/mipsmtregs.h>
32 #include <asm/module.h>
33 #include <asm/pgtable.h>
34 #include <asm/ptrace.h>
35 #include <asm/sections.h>
36 #include <asm/system.h>
37 #include <asm/tlbdebug.h>
38 #include <asm/traps.h>
39 #include <asm/uaccess.h>
40 #include <asm/mmu_context.h>
41 #include <asm/watch.h>
42 #include <asm/types.h>
43 #include <asm/stacktrace.h>
44 
45 extern asmlinkage void handle_int(void);
46 extern asmlinkage void handle_tlbm(void);
47 extern asmlinkage void handle_tlbl(void);
48 extern asmlinkage void handle_tlbs(void);
49 extern asmlinkage void handle_adel(void);
50 extern asmlinkage void handle_ades(void);
51 extern asmlinkage void handle_ibe(void);
52 extern asmlinkage void handle_dbe(void);
53 extern asmlinkage void handle_sys(void);
54 extern asmlinkage void handle_bp(void);
55 extern asmlinkage void handle_ri(void);
56 extern asmlinkage void handle_ri_rdhwr_vivt(void);
57 extern asmlinkage void handle_ri_rdhwr(void);
58 extern asmlinkage void handle_cpu(void);
59 extern asmlinkage void handle_ov(void);
60 extern asmlinkage void handle_tr(void);
61 extern asmlinkage void handle_fpe(void);
62 extern asmlinkage void handle_mdmx(void);
63 extern asmlinkage void handle_watch(void);
64 extern asmlinkage void handle_mt(void);
65 extern asmlinkage void handle_dsp(void);
66 extern asmlinkage void handle_mcheck(void);
67 extern asmlinkage void handle_reserved(void);
68 
69 extern int fpu_emulator_cop1Handler(struct pt_regs *xcp,
70 	struct mips_fpu_struct *ctx, int has_fpu);
71 
72 void (*board_be_init)(void);
73 int (*board_be_handler)(struct pt_regs *regs, int is_fixup);
74 void (*board_nmi_handler_setup)(void);
75 void (*board_ejtag_handler_setup)(void);
76 void (*board_bind_eic_interrupt)(int irq, int regset);
77 
78 
79 static void show_raw_backtrace(unsigned long reg29)
80 {
81 	unsigned long *sp = (unsigned long *)reg29;
82 	unsigned long addr;
83 
84 	printk("Call Trace:");
85 #ifdef CONFIG_KALLSYMS
86 	printk("\n");
87 #endif
88 	while (!kstack_end(sp)) {
89 		addr = *sp++;
90 		if (__kernel_text_address(addr))
91 			print_ip_sym(addr);
92 	}
93 	printk("\n");
94 }
95 
96 #ifdef CONFIG_KALLSYMS
97 int raw_show_trace;
98 static int __init set_raw_show_trace(char *str)
99 {
100 	raw_show_trace = 1;
101 	return 1;
102 }
103 __setup("raw_show_trace", set_raw_show_trace);
104 #endif
105 
106 static void show_backtrace(struct task_struct *task, struct pt_regs *regs)
107 {
108 	unsigned long sp = regs->regs[29];
109 	unsigned long ra = regs->regs[31];
110 	unsigned long pc = regs->cp0_epc;
111 
112 	if (raw_show_trace || !__kernel_text_address(pc)) {
113 		show_raw_backtrace(sp);
114 		return;
115 	}
116 	printk("Call Trace:\n");
117 	do {
118 		print_ip_sym(pc);
119 		pc = unwind_stack(task, &sp, pc, &ra);
120 	} while (pc);
121 	printk("\n");
122 }
123 
124 /*
125  * This routine abuses get_user()/put_user() to reference pointers
126  * with at least a bit of error checking ...
127  */
128 static void show_stacktrace(struct task_struct *task, struct pt_regs *regs)
129 {
130 	const int field = 2 * sizeof(unsigned long);
131 	long stackdata;
132 	int i;
133 	unsigned long *sp = (unsigned long *)regs->regs[29];
134 
135 	printk("Stack :");
136 	i = 0;
137 	while ((unsigned long) sp & (PAGE_SIZE - 1)) {
138 		if (i && ((i % (64 / field)) == 0))
139 			printk("\n       ");
140 		if (i > 39) {
141 			printk(" ...");
142 			break;
143 		}
144 
145 		if (__get_user(stackdata, sp++)) {
146 			printk(" (Bad stack address)");
147 			break;
148 		}
149 
150 		printk(" %0*lx", field, stackdata);
151 		i++;
152 	}
153 	printk("\n");
154 	show_backtrace(task, regs);
155 }
156 
157 void show_stack(struct task_struct *task, unsigned long *sp)
158 {
159 	struct pt_regs regs;
160 	if (sp) {
161 		regs.regs[29] = (unsigned long)sp;
162 		regs.regs[31] = 0;
163 		regs.cp0_epc = 0;
164 	} else {
165 		if (task && task != current) {
166 			regs.regs[29] = task->thread.reg29;
167 			regs.regs[31] = 0;
168 			regs.cp0_epc = task->thread.reg31;
169 		} else {
170 			prepare_frametrace(&regs);
171 		}
172 	}
173 	show_stacktrace(task, &regs);
174 }
175 
176 /*
177  * The architecture-independent dump_stack generator
178  */
179 void dump_stack(void)
180 {
181 	struct pt_regs regs;
182 
183 	prepare_frametrace(&regs);
184 	show_backtrace(current, &regs);
185 }
186 
187 EXPORT_SYMBOL(dump_stack);
188 
189 void show_code(unsigned int *pc)
190 {
191 	long i;
192 
193 	printk("\nCode:");
194 
195 	for(i = -3 ; i < 6 ; i++) {
196 		unsigned int insn;
197 		if (__get_user(insn, pc + i)) {
198 			printk(" (Bad address in epc)\n");
199 			break;
200 		}
201 		printk("%c%08x%c", (i?' ':'<'), insn, (i?' ':'>'));
202 	}
203 }
204 
205 void show_regs(struct pt_regs *regs)
206 {
207 	const int field = 2 * sizeof(unsigned long);
208 	unsigned int cause = regs->cp0_cause;
209 	int i;
210 
211 	printk("Cpu %d\n", smp_processor_id());
212 
213 	/*
214 	 * Saved main processor registers
215 	 */
216 	for (i = 0; i < 32; ) {
217 		if ((i % 4) == 0)
218 			printk("$%2d   :", i);
219 		if (i == 0)
220 			printk(" %0*lx", field, 0UL);
221 		else if (i == 26 || i == 27)
222 			printk(" %*s", field, "");
223 		else
224 			printk(" %0*lx", field, regs->regs[i]);
225 
226 		i++;
227 		if ((i % 4) == 0)
228 			printk("\n");
229 	}
230 
231 #ifdef CONFIG_CPU_HAS_SMARTMIPS
232 	printk("Acx    : %0*lx\n", field, regs->acx);
233 #endif
234 	printk("Hi    : %0*lx\n", field, regs->hi);
235 	printk("Lo    : %0*lx\n", field, regs->lo);
236 
237 	/*
238 	 * Saved cp0 registers
239 	 */
240 	printk("epc   : %0*lx ", field, regs->cp0_epc);
241 	print_symbol("%s ", regs->cp0_epc);
242 	printk("    %s\n", print_tainted());
243 	printk("ra    : %0*lx ", field, regs->regs[31]);
244 	print_symbol("%s\n", regs->regs[31]);
245 
246 	printk("Status: %08x    ", (uint32_t) regs->cp0_status);
247 
248 	if (current_cpu_data.isa_level == MIPS_CPU_ISA_I) {
249 		if (regs->cp0_status & ST0_KUO)
250 			printk("KUo ");
251 		if (regs->cp0_status & ST0_IEO)
252 			printk("IEo ");
253 		if (regs->cp0_status & ST0_KUP)
254 			printk("KUp ");
255 		if (regs->cp0_status & ST0_IEP)
256 			printk("IEp ");
257 		if (regs->cp0_status & ST0_KUC)
258 			printk("KUc ");
259 		if (regs->cp0_status & ST0_IEC)
260 			printk("IEc ");
261 	} else {
262 		if (regs->cp0_status & ST0_KX)
263 			printk("KX ");
264 		if (regs->cp0_status & ST0_SX)
265 			printk("SX ");
266 		if (regs->cp0_status & ST0_UX)
267 			printk("UX ");
268 		switch (regs->cp0_status & ST0_KSU) {
269 		case KSU_USER:
270 			printk("USER ");
271 			break;
272 		case KSU_SUPERVISOR:
273 			printk("SUPERVISOR ");
274 			break;
275 		case KSU_KERNEL:
276 			printk("KERNEL ");
277 			break;
278 		default:
279 			printk("BAD_MODE ");
280 			break;
281 		}
282 		if (regs->cp0_status & ST0_ERL)
283 			printk("ERL ");
284 		if (regs->cp0_status & ST0_EXL)
285 			printk("EXL ");
286 		if (regs->cp0_status & ST0_IE)
287 			printk("IE ");
288 	}
289 	printk("\n");
290 
291 	printk("Cause : %08x\n", cause);
292 
293 	cause = (cause & CAUSEF_EXCCODE) >> CAUSEB_EXCCODE;
294 	if (1 <= cause && cause <= 5)
295 		printk("BadVA : %0*lx\n", field, regs->cp0_badvaddr);
296 
297 	printk("PrId  : %08x\n", read_c0_prid());
298 }
299 
300 void show_registers(struct pt_regs *regs)
301 {
302 	show_regs(regs);
303 	print_modules();
304 	printk("Process %s (pid: %d, threadinfo=%p, task=%p)\n",
305 	        current->comm, current->pid, current_thread_info(), current);
306 	show_stacktrace(current, regs);
307 	show_code((unsigned int *) regs->cp0_epc);
308 	printk("\n");
309 }
310 
311 static DEFINE_SPINLOCK(die_lock);
312 
313 NORET_TYPE void ATTRIB_NORET die(const char * str, struct pt_regs * regs)
314 {
315 	static int die_counter;
316 #ifdef CONFIG_MIPS_MT_SMTC
317 	unsigned long dvpret = dvpe();
318 #endif /* CONFIG_MIPS_MT_SMTC */
319 
320 	console_verbose();
321 	spin_lock_irq(&die_lock);
322 	bust_spinlocks(1);
323 #ifdef CONFIG_MIPS_MT_SMTC
324 	mips_mt_regdump(dvpret);
325 #endif /* CONFIG_MIPS_MT_SMTC */
326 	printk("%s[#%d]:\n", str, ++die_counter);
327 	show_registers(regs);
328 	spin_unlock_irq(&die_lock);
329 
330 	if (in_interrupt())
331 		panic("Fatal exception in interrupt");
332 
333 	if (panic_on_oops) {
334 		printk(KERN_EMERG "Fatal exception: panic in 5 seconds\n");
335 		ssleep(5);
336 		panic("Fatal exception");
337 	}
338 
339 	do_exit(SIGSEGV);
340 }
341 
342 extern const struct exception_table_entry __start___dbe_table[];
343 extern const struct exception_table_entry __stop___dbe_table[];
344 
345 __asm__(
346 "	.section	__dbe_table, \"a\"\n"
347 "	.previous			\n");
348 
349 /* Given an address, look for it in the exception tables. */
350 static const struct exception_table_entry *search_dbe_tables(unsigned long addr)
351 {
352 	const struct exception_table_entry *e;
353 
354 	e = search_extable(__start___dbe_table, __stop___dbe_table - 1, addr);
355 	if (!e)
356 		e = search_module_dbetables(addr);
357 	return e;
358 }
359 
360 asmlinkage void do_be(struct pt_regs *regs)
361 {
362 	const int field = 2 * sizeof(unsigned long);
363 	const struct exception_table_entry *fixup = NULL;
364 	int data = regs->cp0_cause & 4;
365 	int action = MIPS_BE_FATAL;
366 
367 	/* XXX For now.  Fixme, this searches the wrong table ...  */
368 	if (data && !user_mode(regs))
369 		fixup = search_dbe_tables(exception_epc(regs));
370 
371 	if (fixup)
372 		action = MIPS_BE_FIXUP;
373 
374 	if (board_be_handler)
375 		action = board_be_handler(regs, fixup != 0);
376 
377 	switch (action) {
378 	case MIPS_BE_DISCARD:
379 		return;
380 	case MIPS_BE_FIXUP:
381 		if (fixup) {
382 			regs->cp0_epc = fixup->nextinsn;
383 			return;
384 		}
385 		break;
386 	default:
387 		break;
388 	}
389 
390 	/*
391 	 * Assume it would be too dangerous to continue ...
392 	 */
393 	printk(KERN_ALERT "%s bus error, epc == %0*lx, ra == %0*lx\n",
394 	       data ? "Data" : "Instruction",
395 	       field, regs->cp0_epc, field, regs->regs[31]);
396 	die_if_kernel("Oops", regs);
397 	force_sig(SIGBUS, current);
398 }
399 
400 /*
401  * ll/sc emulation
402  */
403 
404 #define OPCODE 0xfc000000
405 #define BASE   0x03e00000
406 #define RT     0x001f0000
407 #define OFFSET 0x0000ffff
408 #define LL     0xc0000000
409 #define SC     0xe0000000
410 #define SPEC3  0x7c000000
411 #define RD     0x0000f800
412 #define FUNC   0x0000003f
413 #define RDHWR  0x0000003b
414 
415 /*
416  * The ll_bit is cleared by r*_switch.S
417  */
418 
419 unsigned long ll_bit;
420 
421 static struct task_struct *ll_task = NULL;
422 
423 static inline void simulate_ll(struct pt_regs *regs, unsigned int opcode)
424 {
425 	unsigned long value, __user *vaddr;
426 	long offset;
427 	int signal = 0;
428 
429 	/*
430 	 * analyse the ll instruction that just caused a ri exception
431 	 * and put the referenced address to addr.
432 	 */
433 
434 	/* sign extend offset */
435 	offset = opcode & OFFSET;
436 	offset <<= 16;
437 	offset >>= 16;
438 
439 	vaddr = (unsigned long __user *)
440 	        ((unsigned long)(regs->regs[(opcode & BASE) >> 21]) + offset);
441 
442 	if ((unsigned long)vaddr & 3) {
443 		signal = SIGBUS;
444 		goto sig;
445 	}
446 	if (get_user(value, vaddr)) {
447 		signal = SIGSEGV;
448 		goto sig;
449 	}
450 
451 	preempt_disable();
452 
453 	if (ll_task == NULL || ll_task == current) {
454 		ll_bit = 1;
455 	} else {
456 		ll_bit = 0;
457 	}
458 	ll_task = current;
459 
460 	preempt_enable();
461 
462 	compute_return_epc(regs);
463 
464 	regs->regs[(opcode & RT) >> 16] = value;
465 
466 	return;
467 
468 sig:
469 	force_sig(signal, current);
470 }
471 
472 static inline void simulate_sc(struct pt_regs *regs, unsigned int opcode)
473 {
474 	unsigned long __user *vaddr;
475 	unsigned long reg;
476 	long offset;
477 	int signal = 0;
478 
479 	/*
480 	 * analyse the sc instruction that just caused a ri exception
481 	 * and put the referenced address to addr.
482 	 */
483 
484 	/* sign extend offset */
485 	offset = opcode & OFFSET;
486 	offset <<= 16;
487 	offset >>= 16;
488 
489 	vaddr = (unsigned long __user *)
490 	        ((unsigned long)(regs->regs[(opcode & BASE) >> 21]) + offset);
491 	reg = (opcode & RT) >> 16;
492 
493 	if ((unsigned long)vaddr & 3) {
494 		signal = SIGBUS;
495 		goto sig;
496 	}
497 
498 	preempt_disable();
499 
500 	if (ll_bit == 0 || ll_task != current) {
501 		compute_return_epc(regs);
502 		regs->regs[reg] = 0;
503 		preempt_enable();
504 		return;
505 	}
506 
507 	preempt_enable();
508 
509 	if (put_user(regs->regs[reg], vaddr)) {
510 		signal = SIGSEGV;
511 		goto sig;
512 	}
513 
514 	compute_return_epc(regs);
515 	regs->regs[reg] = 1;
516 
517 	return;
518 
519 sig:
520 	force_sig(signal, current);
521 }
522 
523 /*
524  * ll uses the opcode of lwc0 and sc uses the opcode of swc0.  That is both
525  * opcodes are supposed to result in coprocessor unusable exceptions if
526  * executed on ll/sc-less processors.  That's the theory.  In practice a
527  * few processors such as NEC's VR4100 throw reserved instruction exceptions
528  * instead, so we're doing the emulation thing in both exception handlers.
529  */
530 static inline int simulate_llsc(struct pt_regs *regs)
531 {
532 	unsigned int opcode;
533 
534 	if (get_user(opcode, (unsigned int __user *) exception_epc(regs)))
535 		goto out_sigsegv;
536 
537 	if ((opcode & OPCODE) == LL) {
538 		simulate_ll(regs, opcode);
539 		return 0;
540 	}
541 	if ((opcode & OPCODE) == SC) {
542 		simulate_sc(regs, opcode);
543 		return 0;
544 	}
545 
546 	return -EFAULT;			/* Strange things going on ... */
547 
548 out_sigsegv:
549 	force_sig(SIGSEGV, current);
550 	return -EFAULT;
551 }
552 
553 /*
554  * Simulate trapping 'rdhwr' instructions to provide user accessible
555  * registers not implemented in hardware.  The only current use of this
556  * is the thread area pointer.
557  */
558 static inline int simulate_rdhwr(struct pt_regs *regs)
559 {
560 	struct thread_info *ti = task_thread_info(current);
561 	unsigned int opcode;
562 
563 	if (get_user(opcode, (unsigned int __user *) exception_epc(regs)))
564 		goto out_sigsegv;
565 
566 	if (unlikely(compute_return_epc(regs)))
567 		return -EFAULT;
568 
569 	if ((opcode & OPCODE) == SPEC3 && (opcode & FUNC) == RDHWR) {
570 		int rd = (opcode & RD) >> 11;
571 		int rt = (opcode & RT) >> 16;
572 		switch (rd) {
573 			case 29:
574 				regs->regs[rt] = ti->tp_value;
575 				return 0;
576 			default:
577 				return -EFAULT;
578 		}
579 	}
580 
581 	/* Not ours.  */
582 	return -EFAULT;
583 
584 out_sigsegv:
585 	force_sig(SIGSEGV, current);
586 	return -EFAULT;
587 }
588 
589 asmlinkage void do_ov(struct pt_regs *regs)
590 {
591 	siginfo_t info;
592 
593 	die_if_kernel("Integer overflow", regs);
594 
595 	info.si_code = FPE_INTOVF;
596 	info.si_signo = SIGFPE;
597 	info.si_errno = 0;
598 	info.si_addr = (void __user *) regs->cp0_epc;
599 	force_sig_info(SIGFPE, &info, current);
600 }
601 
602 /*
603  * XXX Delayed fp exceptions when doing a lazy ctx switch XXX
604  */
605 asmlinkage void do_fpe(struct pt_regs *regs, unsigned long fcr31)
606 {
607 	die_if_kernel("FP exception in kernel code", regs);
608 
609 	if (fcr31 & FPU_CSR_UNI_X) {
610 		int sig;
611 
612 		/*
613 		 * Unimplemented operation exception.  If we've got the full
614 		 * software emulator on-board, let's use it...
615 		 *
616 		 * Force FPU to dump state into task/thread context.  We're
617 		 * moving a lot of data here for what is probably a single
618 		 * instruction, but the alternative is to pre-decode the FP
619 		 * register operands before invoking the emulator, which seems
620 		 * a bit extreme for what should be an infrequent event.
621 		 */
622 		/* Ensure 'resume' not overwrite saved fp context again. */
623 		lose_fpu(1);
624 
625 		/* Run the emulator */
626 		sig = fpu_emulator_cop1Handler (regs, &current->thread.fpu, 1);
627 
628 		/*
629 		 * We can't allow the emulated instruction to leave any of
630 		 * the cause bit set in $fcr31.
631 		 */
632 		current->thread.fpu.fcr31 &= ~FPU_CSR_ALL_X;
633 
634 		/* Restore the hardware register state */
635 		own_fpu(1);	/* Using the FPU again.  */
636 
637 		/* If something went wrong, signal */
638 		if (sig)
639 			force_sig(sig, current);
640 
641 		return;
642 	}
643 
644 	force_sig(SIGFPE, current);
645 }
646 
647 asmlinkage void do_bp(struct pt_regs *regs)
648 {
649 	unsigned int opcode, bcode;
650 	siginfo_t info;
651 
652 	if (__get_user(opcode, (unsigned int __user *) exception_epc(regs)))
653 		goto out_sigsegv;
654 
655 	/*
656 	 * There is the ancient bug in the MIPS assemblers that the break
657 	 * code starts left to bit 16 instead to bit 6 in the opcode.
658 	 * Gas is bug-compatible, but not always, grrr...
659 	 * We handle both cases with a simple heuristics.  --macro
660 	 */
661 	bcode = ((opcode >> 6) & ((1 << 20) - 1));
662 	if (bcode < (1 << 10))
663 		bcode <<= 10;
664 
665 	/*
666 	 * (A short test says that IRIX 5.3 sends SIGTRAP for all break
667 	 * insns, even for break codes that indicate arithmetic failures.
668 	 * Weird ...)
669 	 * But should we continue the brokenness???  --macro
670 	 */
671 	switch (bcode) {
672 	case BRK_OVERFLOW << 10:
673 	case BRK_DIVZERO << 10:
674 		die_if_kernel("Break instruction in kernel code", regs);
675 		if (bcode == (BRK_DIVZERO << 10))
676 			info.si_code = FPE_INTDIV;
677 		else
678 			info.si_code = FPE_INTOVF;
679 		info.si_signo = SIGFPE;
680 		info.si_errno = 0;
681 		info.si_addr = (void __user *) regs->cp0_epc;
682 		force_sig_info(SIGFPE, &info, current);
683 		break;
684 	case BRK_BUG:
685 		die("Kernel bug detected", regs);
686 		break;
687 	default:
688 		die_if_kernel("Break instruction in kernel code", regs);
689 		force_sig(SIGTRAP, current);
690 	}
691 	return;
692 
693 out_sigsegv:
694 	force_sig(SIGSEGV, current);
695 }
696 
697 asmlinkage void do_tr(struct pt_regs *regs)
698 {
699 	unsigned int opcode, tcode = 0;
700 	siginfo_t info;
701 
702 	if (__get_user(opcode, (unsigned int __user *) exception_epc(regs)))
703 		goto out_sigsegv;
704 
705 	/* Immediate versions don't provide a code.  */
706 	if (!(opcode & OPCODE))
707 		tcode = ((opcode >> 6) & ((1 << 10) - 1));
708 
709 	/*
710 	 * (A short test says that IRIX 5.3 sends SIGTRAP for all trap
711 	 * insns, even for trap codes that indicate arithmetic failures.
712 	 * Weird ...)
713 	 * But should we continue the brokenness???  --macro
714 	 */
715 	switch (tcode) {
716 	case BRK_OVERFLOW:
717 	case BRK_DIVZERO:
718 		die_if_kernel("Trap instruction in kernel code", regs);
719 		if (tcode == BRK_DIVZERO)
720 			info.si_code = FPE_INTDIV;
721 		else
722 			info.si_code = FPE_INTOVF;
723 		info.si_signo = SIGFPE;
724 		info.si_errno = 0;
725 		info.si_addr = (void __user *) regs->cp0_epc;
726 		force_sig_info(SIGFPE, &info, current);
727 		break;
728 	case BRK_BUG:
729 		die("Kernel bug detected", regs);
730 		break;
731 	default:
732 		die_if_kernel("Trap instruction in kernel code", regs);
733 		force_sig(SIGTRAP, current);
734 	}
735 	return;
736 
737 out_sigsegv:
738 	force_sig(SIGSEGV, current);
739 }
740 
741 asmlinkage void do_ri(struct pt_regs *regs)
742 {
743 	die_if_kernel("Reserved instruction in kernel code", regs);
744 
745 	if (!cpu_has_llsc)
746 		if (!simulate_llsc(regs))
747 			return;
748 
749 	if (!simulate_rdhwr(regs))
750 		return;
751 
752 	force_sig(SIGILL, current);
753 }
754 
755 asmlinkage void do_cpu(struct pt_regs *regs)
756 {
757 	unsigned int cpid;
758 
759 	die_if_kernel("do_cpu invoked from kernel context!", regs);
760 
761 	cpid = (regs->cp0_cause >> CAUSEB_CE) & 3;
762 
763 	switch (cpid) {
764 	case 0:
765 		if (!cpu_has_llsc)
766 			if (!simulate_llsc(regs))
767 				return;
768 
769 		if (!simulate_rdhwr(regs))
770 			return;
771 
772 		break;
773 
774 	case 1:
775 		if (used_math())	/* Using the FPU again.  */
776 			own_fpu(1);
777 		else {			/* First time FPU user.  */
778 			init_fpu();
779 			set_used_math();
780 		}
781 
782 		if (!raw_cpu_has_fpu) {
783 			int sig;
784 			sig = fpu_emulator_cop1Handler(regs,
785 						&current->thread.fpu, 0);
786 			if (sig)
787 				force_sig(sig, current);
788 #ifdef CONFIG_MIPS_MT_FPAFF
789 			else {
790 			/*
791 			 * MIPS MT processors may have fewer FPU contexts
792 			 * than CPU threads. If we've emulated more than
793 			 * some threshold number of instructions, force
794 			 * migration to a "CPU" that has FP support.
795 			 */
796 			 if(mt_fpemul_threshold > 0
797 			 && ((current->thread.emulated_fp++
798 			    > mt_fpemul_threshold))) {
799 			  /*
800 			   * If there's no FPU present, or if the
801 			   * application has already restricted
802 			   * the allowed set to exclude any CPUs
803 			   * with FPUs, we'll skip the procedure.
804 			   */
805 			  if (cpus_intersects(current->cpus_allowed,
806 			  			mt_fpu_cpumask)) {
807 			    cpumask_t tmask;
808 
809 			    cpus_and(tmask,
810 					current->thread.user_cpus_allowed,
811 					mt_fpu_cpumask);
812 			    set_cpus_allowed(current, tmask);
813 			    current->thread.mflags |= MF_FPUBOUND;
814 			  }
815 			 }
816 			}
817 #endif /* CONFIG_MIPS_MT_FPAFF */
818 		}
819 
820 		return;
821 
822 	case 2:
823 	case 3:
824 		break;
825 	}
826 
827 	force_sig(SIGILL, current);
828 }
829 
830 asmlinkage void do_mdmx(struct pt_regs *regs)
831 {
832 	force_sig(SIGILL, current);
833 }
834 
835 asmlinkage void do_watch(struct pt_regs *regs)
836 {
837 	/*
838 	 * We use the watch exception where available to detect stack
839 	 * overflows.
840 	 */
841 	dump_tlb_all();
842 	show_regs(regs);
843 	panic("Caught WATCH exception - probably caused by stack overflow.");
844 }
845 
846 asmlinkage void do_mcheck(struct pt_regs *regs)
847 {
848 	const int field = 2 * sizeof(unsigned long);
849 	int multi_match = regs->cp0_status & ST0_TS;
850 
851 	show_regs(regs);
852 
853 	if (multi_match) {
854 		printk("Index   : %0x\n", read_c0_index());
855 		printk("Pagemask: %0x\n", read_c0_pagemask());
856 		printk("EntryHi : %0*lx\n", field, read_c0_entryhi());
857 		printk("EntryLo0: %0*lx\n", field, read_c0_entrylo0());
858 		printk("EntryLo1: %0*lx\n", field, read_c0_entrylo1());
859 		printk("\n");
860 		dump_tlb_all();
861 	}
862 
863 	show_code((unsigned int *) regs->cp0_epc);
864 
865 	/*
866 	 * Some chips may have other causes of machine check (e.g. SB1
867 	 * graduation timer)
868 	 */
869 	panic("Caught Machine Check exception - %scaused by multiple "
870 	      "matching entries in the TLB.",
871 	      (multi_match) ? "" : "not ");
872 }
873 
874 asmlinkage void do_mt(struct pt_regs *regs)
875 {
876 	int subcode;
877 
878 	subcode = (read_vpe_c0_vpecontrol() & VPECONTROL_EXCPT)
879 			>> VPECONTROL_EXCPT_SHIFT;
880 	switch (subcode) {
881 	case 0:
882 		printk(KERN_DEBUG "Thread Underflow\n");
883 		break;
884 	case 1:
885 		printk(KERN_DEBUG "Thread Overflow\n");
886 		break;
887 	case 2:
888 		printk(KERN_DEBUG "Invalid YIELD Qualifier\n");
889 		break;
890 	case 3:
891 		printk(KERN_DEBUG "Gating Storage Exception\n");
892 		break;
893 	case 4:
894 		printk(KERN_DEBUG "YIELD Scheduler Exception\n");
895 		break;
896 	case 5:
897 		printk(KERN_DEBUG "Gating Storage Schedulier Exception\n");
898 		break;
899 	default:
900 		printk(KERN_DEBUG "*** UNKNOWN THREAD EXCEPTION %d ***\n",
901 			subcode);
902 		break;
903 	}
904 	die_if_kernel("MIPS MT Thread exception in kernel", regs);
905 
906 	force_sig(SIGILL, current);
907 }
908 
909 
910 asmlinkage void do_dsp(struct pt_regs *regs)
911 {
912 	if (cpu_has_dsp)
913 		panic("Unexpected DSP exception\n");
914 
915 	force_sig(SIGILL, current);
916 }
917 
918 asmlinkage void do_reserved(struct pt_regs *regs)
919 {
920 	/*
921 	 * Game over - no way to handle this if it ever occurs.  Most probably
922 	 * caused by a new unknown cpu type or after another deadly
923 	 * hard/software error.
924 	 */
925 	show_regs(regs);
926 	panic("Caught reserved exception %ld - should not happen.",
927 	      (regs->cp0_cause & 0x7f) >> 2);
928 }
929 
930 /*
931  * Some MIPS CPUs can enable/disable for cache parity detection, but do
932  * it different ways.
933  */
934 static inline void parity_protection_init(void)
935 {
936 	switch (current_cpu_data.cputype) {
937 	case CPU_24K:
938 	case CPU_34K:
939 	case CPU_5KC:
940 		write_c0_ecc(0x80000000);
941 		back_to_back_c0_hazard();
942 		/* Set the PE bit (bit 31) in the c0_errctl register. */
943 		printk(KERN_INFO "Cache parity protection %sabled\n",
944 		       (read_c0_ecc() & 0x80000000) ? "en" : "dis");
945 		break;
946 	case CPU_20KC:
947 	case CPU_25KF:
948 		/* Clear the DE bit (bit 16) in the c0_status register. */
949 		printk(KERN_INFO "Enable cache parity protection for "
950 		       "MIPS 20KC/25KF CPUs.\n");
951 		clear_c0_status(ST0_DE);
952 		break;
953 	default:
954 		break;
955 	}
956 }
957 
958 asmlinkage void cache_parity_error(void)
959 {
960 	const int field = 2 * sizeof(unsigned long);
961 	unsigned int reg_val;
962 
963 	/* For the moment, report the problem and hang. */
964 	printk("Cache error exception:\n");
965 	printk("cp0_errorepc == %0*lx\n", field, read_c0_errorepc());
966 	reg_val = read_c0_cacheerr();
967 	printk("c0_cacheerr == %08x\n", reg_val);
968 
969 	printk("Decoded c0_cacheerr: %s cache fault in %s reference.\n",
970 	       reg_val & (1<<30) ? "secondary" : "primary",
971 	       reg_val & (1<<31) ? "data" : "insn");
972 	printk("Error bits: %s%s%s%s%s%s%s\n",
973 	       reg_val & (1<<29) ? "ED " : "",
974 	       reg_val & (1<<28) ? "ET " : "",
975 	       reg_val & (1<<26) ? "EE " : "",
976 	       reg_val & (1<<25) ? "EB " : "",
977 	       reg_val & (1<<24) ? "EI " : "",
978 	       reg_val & (1<<23) ? "E1 " : "",
979 	       reg_val & (1<<22) ? "E0 " : "");
980 	printk("IDX: 0x%08x\n", reg_val & ((1<<22)-1));
981 
982 #if defined(CONFIG_CPU_MIPS32) || defined(CONFIG_CPU_MIPS64)
983 	if (reg_val & (1<<22))
984 		printk("DErrAddr0: 0x%0*lx\n", field, read_c0_derraddr0());
985 
986 	if (reg_val & (1<<23))
987 		printk("DErrAddr1: 0x%0*lx\n", field, read_c0_derraddr1());
988 #endif
989 
990 	panic("Can't handle the cache error!");
991 }
992 
993 /*
994  * SDBBP EJTAG debug exception handler.
995  * We skip the instruction and return to the next instruction.
996  */
997 void ejtag_exception_handler(struct pt_regs *regs)
998 {
999 	const int field = 2 * sizeof(unsigned long);
1000 	unsigned long depc, old_epc;
1001 	unsigned int debug;
1002 
1003 	printk(KERN_DEBUG "SDBBP EJTAG debug exception - not handled yet, just ignored!\n");
1004 	depc = read_c0_depc();
1005 	debug = read_c0_debug();
1006 	printk(KERN_DEBUG "c0_depc = %0*lx, DEBUG = %08x\n", field, depc, debug);
1007 	if (debug & 0x80000000) {
1008 		/*
1009 		 * In branch delay slot.
1010 		 * We cheat a little bit here and use EPC to calculate the
1011 		 * debug return address (DEPC). EPC is restored after the
1012 		 * calculation.
1013 		 */
1014 		old_epc = regs->cp0_epc;
1015 		regs->cp0_epc = depc;
1016 		__compute_return_epc(regs);
1017 		depc = regs->cp0_epc;
1018 		regs->cp0_epc = old_epc;
1019 	} else
1020 		depc += 4;
1021 	write_c0_depc(depc);
1022 
1023 #if 0
1024 	printk(KERN_DEBUG "\n\n----- Enable EJTAG single stepping ----\n\n");
1025 	write_c0_debug(debug | 0x100);
1026 #endif
1027 }
1028 
1029 /*
1030  * NMI exception handler.
1031  */
1032 void nmi_exception_handler(struct pt_regs *regs)
1033 {
1034 #ifdef CONFIG_MIPS_MT_SMTC
1035 	unsigned long dvpret = dvpe();
1036 	bust_spinlocks(1);
1037 	printk("NMI taken!!!!\n");
1038 	mips_mt_regdump(dvpret);
1039 #else
1040 	bust_spinlocks(1);
1041 	printk("NMI taken!!!!\n");
1042 #endif /* CONFIG_MIPS_MT_SMTC */
1043 	die("NMI", regs);
1044 	while(1) ;
1045 }
1046 
1047 #define VECTORSPACING 0x100	/* for EI/VI mode */
1048 
1049 unsigned long ebase;
1050 unsigned long exception_handlers[32];
1051 unsigned long vi_handlers[64];
1052 
1053 /*
1054  * As a side effect of the way this is implemented we're limited
1055  * to interrupt handlers in the address range from
1056  * KSEG0 <= x < KSEG0 + 256mb on the Nevada.  Oh well ...
1057  */
1058 void *set_except_vector(int n, void *addr)
1059 {
1060 	unsigned long handler = (unsigned long) addr;
1061 	unsigned long old_handler = exception_handlers[n];
1062 
1063 	exception_handlers[n] = handler;
1064 	if (n == 0 && cpu_has_divec) {
1065 		*(volatile u32 *)(ebase + 0x200) = 0x08000000 |
1066 		                                 (0x03ffffff & (handler >> 2));
1067 		flush_icache_range(ebase + 0x200, ebase + 0x204);
1068 	}
1069 	return (void *)old_handler;
1070 }
1071 
1072 #ifdef CONFIG_CPU_MIPSR2_SRS
1073 /*
1074  * MIPSR2 shadow register set allocation
1075  * FIXME: SMP...
1076  */
1077 
1078 static struct shadow_registers {
1079 	/*
1080 	 * Number of shadow register sets supported
1081 	 */
1082 	unsigned long sr_supported;
1083 	/*
1084 	 * Bitmap of allocated shadow registers
1085 	 */
1086 	unsigned long sr_allocated;
1087 } shadow_registers;
1088 
1089 static void mips_srs_init(void)
1090 {
1091 	shadow_registers.sr_supported = ((read_c0_srsctl() >> 26) & 0x0f) + 1;
1092 	printk(KERN_INFO "%ld MIPSR2 register sets available\n",
1093 	       shadow_registers.sr_supported);
1094 	shadow_registers.sr_allocated = 1;	/* Set 0 used by kernel */
1095 }
1096 
1097 int mips_srs_max(void)
1098 {
1099 	return shadow_registers.sr_supported;
1100 }
1101 
1102 int mips_srs_alloc(void)
1103 {
1104 	struct shadow_registers *sr = &shadow_registers;
1105 	int set;
1106 
1107 again:
1108 	set = find_first_zero_bit(&sr->sr_allocated, sr->sr_supported);
1109 	if (set >= sr->sr_supported)
1110 		return -1;
1111 
1112 	if (test_and_set_bit(set, &sr->sr_allocated))
1113 		goto again;
1114 
1115 	return set;
1116 }
1117 
1118 void mips_srs_free(int set)
1119 {
1120 	struct shadow_registers *sr = &shadow_registers;
1121 
1122 	clear_bit(set, &sr->sr_allocated);
1123 }
1124 
1125 static asmlinkage void do_default_vi(void)
1126 {
1127 	show_regs(get_irq_regs());
1128 	panic("Caught unexpected vectored interrupt.");
1129 }
1130 
1131 static void *set_vi_srs_handler(int n, vi_handler_t addr, int srs)
1132 {
1133 	unsigned long handler;
1134 	unsigned long old_handler = vi_handlers[n];
1135 	u32 *w;
1136 	unsigned char *b;
1137 
1138 	if (!cpu_has_veic && !cpu_has_vint)
1139 		BUG();
1140 
1141 	if (addr == NULL) {
1142 		handler = (unsigned long) do_default_vi;
1143 		srs = 0;
1144 	} else
1145 		handler = (unsigned long) addr;
1146 	vi_handlers[n] = (unsigned long) addr;
1147 
1148 	b = (unsigned char *)(ebase + 0x200 + n*VECTORSPACING);
1149 
1150 	if (srs >= mips_srs_max())
1151 		panic("Shadow register set %d not supported", srs);
1152 
1153 	if (cpu_has_veic) {
1154 		if (board_bind_eic_interrupt)
1155 			board_bind_eic_interrupt (n, srs);
1156 	} else if (cpu_has_vint) {
1157 		/* SRSMap is only defined if shadow sets are implemented */
1158 		if (mips_srs_max() > 1)
1159 			change_c0_srsmap (0xf << n*4, srs << n*4);
1160 	}
1161 
1162 	if (srs == 0) {
1163 		/*
1164 		 * If no shadow set is selected then use the default handler
1165 		 * that does normal register saving and a standard interrupt exit
1166 		 */
1167 
1168 		extern char except_vec_vi, except_vec_vi_lui;
1169 		extern char except_vec_vi_ori, except_vec_vi_end;
1170 #ifdef CONFIG_MIPS_MT_SMTC
1171 		/*
1172 		 * We need to provide the SMTC vectored interrupt handler
1173 		 * not only with the address of the handler, but with the
1174 		 * Status.IM bit to be masked before going there.
1175 		 */
1176 		extern char except_vec_vi_mori;
1177 		const int mori_offset = &except_vec_vi_mori - &except_vec_vi;
1178 #endif /* CONFIG_MIPS_MT_SMTC */
1179 		const int handler_len = &except_vec_vi_end - &except_vec_vi;
1180 		const int lui_offset = &except_vec_vi_lui - &except_vec_vi;
1181 		const int ori_offset = &except_vec_vi_ori - &except_vec_vi;
1182 
1183 		if (handler_len > VECTORSPACING) {
1184 			/*
1185 			 * Sigh... panicing won't help as the console
1186 			 * is probably not configured :(
1187 			 */
1188 			panic ("VECTORSPACING too small");
1189 		}
1190 
1191 		memcpy (b, &except_vec_vi, handler_len);
1192 #ifdef CONFIG_MIPS_MT_SMTC
1193 		if (n > 7)
1194 			printk("Vector index %d exceeds SMTC maximum\n", n);
1195 		w = (u32 *)(b + mori_offset);
1196 		*w = (*w & 0xffff0000) | (0x100 << n);
1197 #endif /* CONFIG_MIPS_MT_SMTC */
1198 		w = (u32 *)(b + lui_offset);
1199 		*w = (*w & 0xffff0000) | (((u32)handler >> 16) & 0xffff);
1200 		w = (u32 *)(b + ori_offset);
1201 		*w = (*w & 0xffff0000) | ((u32)handler & 0xffff);
1202 		flush_icache_range((unsigned long)b, (unsigned long)(b+handler_len));
1203 	}
1204 	else {
1205 		/*
1206 		 * In other cases jump directly to the interrupt handler
1207 		 *
1208 		 * It is the handlers responsibility to save registers if required
1209 		 * (eg hi/lo) and return from the exception using "eret"
1210 		 */
1211 		w = (u32 *)b;
1212 		*w++ = 0x08000000 | (((u32)handler >> 2) & 0x03fffff); /* j handler */
1213 		*w = 0;
1214 		flush_icache_range((unsigned long)b, (unsigned long)(b+8));
1215 	}
1216 
1217 	return (void *)old_handler;
1218 }
1219 
1220 void *set_vi_handler(int n, vi_handler_t addr)
1221 {
1222 	return set_vi_srs_handler(n, addr, 0);
1223 }
1224 
1225 #else
1226 
1227 static inline void mips_srs_init(void)
1228 {
1229 }
1230 
1231 #endif /* CONFIG_CPU_MIPSR2_SRS */
1232 
1233 /*
1234  * This is used by native signal handling
1235  */
1236 asmlinkage int (*save_fp_context)(struct sigcontext __user *sc);
1237 asmlinkage int (*restore_fp_context)(struct sigcontext __user *sc);
1238 
1239 extern asmlinkage int _save_fp_context(struct sigcontext __user *sc);
1240 extern asmlinkage int _restore_fp_context(struct sigcontext __user *sc);
1241 
1242 extern asmlinkage int fpu_emulator_save_context(struct sigcontext __user *sc);
1243 extern asmlinkage int fpu_emulator_restore_context(struct sigcontext __user *sc);
1244 
1245 #ifdef CONFIG_SMP
1246 static int smp_save_fp_context(struct sigcontext __user *sc)
1247 {
1248 	return raw_cpu_has_fpu
1249 	       ? _save_fp_context(sc)
1250 	       : fpu_emulator_save_context(sc);
1251 }
1252 
1253 static int smp_restore_fp_context(struct sigcontext __user *sc)
1254 {
1255 	return raw_cpu_has_fpu
1256 	       ? _restore_fp_context(sc)
1257 	       : fpu_emulator_restore_context(sc);
1258 }
1259 #endif
1260 
1261 static inline void signal_init(void)
1262 {
1263 #ifdef CONFIG_SMP
1264 	/* For now just do the cpu_has_fpu check when the functions are invoked */
1265 	save_fp_context = smp_save_fp_context;
1266 	restore_fp_context = smp_restore_fp_context;
1267 #else
1268 	if (cpu_has_fpu) {
1269 		save_fp_context = _save_fp_context;
1270 		restore_fp_context = _restore_fp_context;
1271 	} else {
1272 		save_fp_context = fpu_emulator_save_context;
1273 		restore_fp_context = fpu_emulator_restore_context;
1274 	}
1275 #endif
1276 }
1277 
1278 #ifdef CONFIG_MIPS32_COMPAT
1279 
1280 /*
1281  * This is used by 32-bit signal stuff on the 64-bit kernel
1282  */
1283 asmlinkage int (*save_fp_context32)(struct sigcontext32 __user *sc);
1284 asmlinkage int (*restore_fp_context32)(struct sigcontext32 __user *sc);
1285 
1286 extern asmlinkage int _save_fp_context32(struct sigcontext32 __user *sc);
1287 extern asmlinkage int _restore_fp_context32(struct sigcontext32 __user *sc);
1288 
1289 extern asmlinkage int fpu_emulator_save_context32(struct sigcontext32 __user *sc);
1290 extern asmlinkage int fpu_emulator_restore_context32(struct sigcontext32 __user *sc);
1291 
1292 static inline void signal32_init(void)
1293 {
1294 	if (cpu_has_fpu) {
1295 		save_fp_context32 = _save_fp_context32;
1296 		restore_fp_context32 = _restore_fp_context32;
1297 	} else {
1298 		save_fp_context32 = fpu_emulator_save_context32;
1299 		restore_fp_context32 = fpu_emulator_restore_context32;
1300 	}
1301 }
1302 #endif
1303 
1304 extern void cpu_cache_init(void);
1305 extern void tlb_init(void);
1306 extern void flush_tlb_handlers(void);
1307 
1308 void __init per_cpu_trap_init(void)
1309 {
1310 	unsigned int cpu = smp_processor_id();
1311 	unsigned int status_set = ST0_CU0;
1312 #ifdef CONFIG_MIPS_MT_SMTC
1313 	int secondaryTC = 0;
1314 	int bootTC = (cpu == 0);
1315 
1316 	/*
1317 	 * Only do per_cpu_trap_init() for first TC of Each VPE.
1318 	 * Note that this hack assumes that the SMTC init code
1319 	 * assigns TCs consecutively and in ascending order.
1320 	 */
1321 
1322 	if (((read_c0_tcbind() & TCBIND_CURTC) != 0) &&
1323 	    ((read_c0_tcbind() & TCBIND_CURVPE) == cpu_data[cpu - 1].vpe_id))
1324 		secondaryTC = 1;
1325 #endif /* CONFIG_MIPS_MT_SMTC */
1326 
1327 	/*
1328 	 * Disable coprocessors and select 32-bit or 64-bit addressing
1329 	 * and the 16/32 or 32/32 FPR register model.  Reset the BEV
1330 	 * flag that some firmware may have left set and the TS bit (for
1331 	 * IP27).  Set XX for ISA IV code to work.
1332 	 */
1333 #ifdef CONFIG_64BIT
1334 	status_set |= ST0_FR|ST0_KX|ST0_SX|ST0_UX;
1335 #endif
1336 	if (current_cpu_data.isa_level == MIPS_CPU_ISA_IV)
1337 		status_set |= ST0_XX;
1338 	change_c0_status(ST0_CU|ST0_MX|ST0_RE|ST0_FR|ST0_BEV|ST0_TS|ST0_KX|ST0_SX|ST0_UX,
1339 			 status_set);
1340 
1341 	if (cpu_has_dsp)
1342 		set_c0_status(ST0_MX);
1343 
1344 #ifdef CONFIG_CPU_MIPSR2
1345 	write_c0_hwrena (0x0000000f); /* Allow rdhwr to all registers */
1346 #endif
1347 
1348 #ifdef CONFIG_MIPS_MT_SMTC
1349 	if (!secondaryTC) {
1350 #endif /* CONFIG_MIPS_MT_SMTC */
1351 
1352 	/*
1353 	 * Interrupt handling.
1354 	 */
1355 	if (cpu_has_veic || cpu_has_vint) {
1356 		write_c0_ebase (ebase);
1357 		/* Setting vector spacing enables EI/VI mode  */
1358 		change_c0_intctl (0x3e0, VECTORSPACING);
1359 	}
1360 	if (cpu_has_divec) {
1361 		if (cpu_has_mipsmt) {
1362 			unsigned int vpflags = dvpe();
1363 			set_c0_cause(CAUSEF_IV);
1364 			evpe(vpflags);
1365 		} else
1366 			set_c0_cause(CAUSEF_IV);
1367 	}
1368 #ifdef CONFIG_MIPS_MT_SMTC
1369 	}
1370 #endif /* CONFIG_MIPS_MT_SMTC */
1371 
1372 	cpu_data[cpu].asid_cache = ASID_FIRST_VERSION;
1373 	TLBMISS_HANDLER_SETUP();
1374 
1375 	atomic_inc(&init_mm.mm_count);
1376 	current->active_mm = &init_mm;
1377 	BUG_ON(current->mm);
1378 	enter_lazy_tlb(&init_mm, current);
1379 
1380 #ifdef CONFIG_MIPS_MT_SMTC
1381 	if (bootTC) {
1382 #endif /* CONFIG_MIPS_MT_SMTC */
1383 		cpu_cache_init();
1384 		tlb_init();
1385 #ifdef CONFIG_MIPS_MT_SMTC
1386 	}
1387 #endif /* CONFIG_MIPS_MT_SMTC */
1388 }
1389 
1390 /* Install CPU exception handler */
1391 void __init set_handler (unsigned long offset, void *addr, unsigned long size)
1392 {
1393 	memcpy((void *)(ebase + offset), addr, size);
1394 	flush_icache_range(ebase + offset, ebase + offset + size);
1395 }
1396 
1397 /* Install uncached CPU exception handler */
1398 void __init set_uncached_handler (unsigned long offset, void *addr, unsigned long size)
1399 {
1400 #ifdef CONFIG_32BIT
1401 	unsigned long uncached_ebase = KSEG1ADDR(ebase);
1402 #endif
1403 #ifdef CONFIG_64BIT
1404 	unsigned long uncached_ebase = TO_UNCAC(ebase);
1405 #endif
1406 
1407 	memcpy((void *)(uncached_ebase + offset), addr, size);
1408 }
1409 
1410 static int __initdata rdhwr_noopt;
1411 static int __init set_rdhwr_noopt(char *str)
1412 {
1413 	rdhwr_noopt = 1;
1414 	return 1;
1415 }
1416 
1417 __setup("rdhwr_noopt", set_rdhwr_noopt);
1418 
1419 void __init trap_init(void)
1420 {
1421 	extern char except_vec3_generic, except_vec3_r4000;
1422 	extern char except_vec4;
1423 	unsigned long i;
1424 
1425 	if (cpu_has_veic || cpu_has_vint)
1426 		ebase = (unsigned long) alloc_bootmem_low_pages (0x200 + VECTORSPACING*64);
1427 	else
1428 		ebase = CAC_BASE;
1429 
1430 	mips_srs_init();
1431 
1432 	per_cpu_trap_init();
1433 
1434 	/*
1435 	 * Copy the generic exception handlers to their final destination.
1436 	 * This will be overriden later as suitable for a particular
1437 	 * configuration.
1438 	 */
1439 	set_handler(0x180, &except_vec3_generic, 0x80);
1440 
1441 	/*
1442 	 * Setup default vectors
1443 	 */
1444 	for (i = 0; i <= 31; i++)
1445 		set_except_vector(i, handle_reserved);
1446 
1447 	/*
1448 	 * Copy the EJTAG debug exception vector handler code to it's final
1449 	 * destination.
1450 	 */
1451 	if (cpu_has_ejtag && board_ejtag_handler_setup)
1452 		board_ejtag_handler_setup ();
1453 
1454 	/*
1455 	 * Only some CPUs have the watch exceptions.
1456 	 */
1457 	if (cpu_has_watch)
1458 		set_except_vector(23, handle_watch);
1459 
1460 	/*
1461 	 * Initialise interrupt handlers
1462 	 */
1463 	if (cpu_has_veic || cpu_has_vint) {
1464 		int nvec = cpu_has_veic ? 64 : 8;
1465 		for (i = 0; i < nvec; i++)
1466 			set_vi_handler(i, NULL);
1467 	}
1468 	else if (cpu_has_divec)
1469 		set_handler(0x200, &except_vec4, 0x8);
1470 
1471 	/*
1472 	 * Some CPUs can enable/disable for cache parity detection, but does
1473 	 * it different ways.
1474 	 */
1475 	parity_protection_init();
1476 
1477 	/*
1478 	 * The Data Bus Errors / Instruction Bus Errors are signaled
1479 	 * by external hardware.  Therefore these two exceptions
1480 	 * may have board specific handlers.
1481 	 */
1482 	if (board_be_init)
1483 		board_be_init();
1484 
1485 	set_except_vector(0, handle_int);
1486 	set_except_vector(1, handle_tlbm);
1487 	set_except_vector(2, handle_tlbl);
1488 	set_except_vector(3, handle_tlbs);
1489 
1490 	set_except_vector(4, handle_adel);
1491 	set_except_vector(5, handle_ades);
1492 
1493 	set_except_vector(6, handle_ibe);
1494 	set_except_vector(7, handle_dbe);
1495 
1496 	set_except_vector(8, handle_sys);
1497 	set_except_vector(9, handle_bp);
1498 	set_except_vector(10, rdhwr_noopt ? handle_ri :
1499 			  (cpu_has_vtag_icache ?
1500 			   handle_ri_rdhwr_vivt : handle_ri_rdhwr));
1501 	set_except_vector(11, handle_cpu);
1502 	set_except_vector(12, handle_ov);
1503 	set_except_vector(13, handle_tr);
1504 
1505 	if (current_cpu_data.cputype == CPU_R6000 ||
1506 	    current_cpu_data.cputype == CPU_R6000A) {
1507 		/*
1508 		 * The R6000 is the only R-series CPU that features a machine
1509 		 * check exception (similar to the R4000 cache error) and
1510 		 * unaligned ldc1/sdc1 exception.  The handlers have not been
1511 		 * written yet.  Well, anyway there is no R6000 machine on the
1512 		 * current list of targets for Linux/MIPS.
1513 		 * (Duh, crap, there is someone with a triple R6k machine)
1514 		 */
1515 		//set_except_vector(14, handle_mc);
1516 		//set_except_vector(15, handle_ndc);
1517 	}
1518 
1519 
1520 	if (board_nmi_handler_setup)
1521 		board_nmi_handler_setup();
1522 
1523 	if (cpu_has_fpu && !cpu_has_nofpuex)
1524 		set_except_vector(15, handle_fpe);
1525 
1526 	set_except_vector(22, handle_mdmx);
1527 
1528 	if (cpu_has_mcheck)
1529 		set_except_vector(24, handle_mcheck);
1530 
1531 	if (cpu_has_mipsmt)
1532 		set_except_vector(25, handle_mt);
1533 
1534 	if (cpu_has_dsp)
1535 		set_except_vector(26, handle_dsp);
1536 
1537 	if (cpu_has_vce)
1538 		/* Special exception: R4[04]00 uses also the divec space. */
1539 		memcpy((void *)(CAC_BASE + 0x180), &except_vec3_r4000, 0x100);
1540 	else if (cpu_has_4kex)
1541 		memcpy((void *)(CAC_BASE + 0x180), &except_vec3_generic, 0x80);
1542 	else
1543 		memcpy((void *)(CAC_BASE + 0x080), &except_vec3_generic, 0x80);
1544 
1545 	signal_init();
1546 #ifdef CONFIG_MIPS32_COMPAT
1547 	signal32_init();
1548 #endif
1549 
1550 	flush_icache_range(ebase, ebase + 0x400);
1551 	flush_tlb_handlers();
1552 }
1553