xref: /linux/arch/mips/kernel/traps.c (revision c145211d1f9e2ef19e7b4c2b943f68366daa97af)
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, 2007  Maciej W. Rozycki
13  */
14 #include <linux/bug.h>
15 #include <linux/compiler.h>
16 #include <linux/init.h>
17 #include <linux/mm.h>
18 #include <linux/module.h>
19 #include <linux/sched.h>
20 #include <linux/smp.h>
21 #include <linux/spinlock.h>
22 #include <linux/kallsyms.h>
23 #include <linux/bootmem.h>
24 #include <linux/interrupt.h>
25 #include <linux/ptrace.h>
26 #include <linux/kgdb.h>
27 #include <linux/kdebug.h>
28 #include <linux/notifier.h>
29 
30 #include <asm/bootinfo.h>
31 #include <asm/branch.h>
32 #include <asm/break.h>
33 #include <asm/cop2.h>
34 #include <asm/cpu.h>
35 #include <asm/dsp.h>
36 #include <asm/fpu.h>
37 #include <asm/fpu_emulator.h>
38 #include <asm/mipsregs.h>
39 #include <asm/mipsmtregs.h>
40 #include <asm/module.h>
41 #include <asm/pgtable.h>
42 #include <asm/ptrace.h>
43 #include <asm/sections.h>
44 #include <asm/system.h>
45 #include <asm/tlbdebug.h>
46 #include <asm/traps.h>
47 #include <asm/uaccess.h>
48 #include <asm/watch.h>
49 #include <asm/mmu_context.h>
50 #include <asm/types.h>
51 #include <asm/stacktrace.h>
52 #include <asm/irq.h>
53 #include <asm/uasm.h>
54 
55 extern void check_wait(void);
56 extern asmlinkage void r4k_wait(void);
57 extern asmlinkage void rollback_handle_int(void);
58 extern asmlinkage void handle_int(void);
59 extern asmlinkage void handle_tlbm(void);
60 extern asmlinkage void handle_tlbl(void);
61 extern asmlinkage void handle_tlbs(void);
62 extern asmlinkage void handle_adel(void);
63 extern asmlinkage void handle_ades(void);
64 extern asmlinkage void handle_ibe(void);
65 extern asmlinkage void handle_dbe(void);
66 extern asmlinkage void handle_sys(void);
67 extern asmlinkage void handle_bp(void);
68 extern asmlinkage void handle_ri(void);
69 extern asmlinkage void handle_ri_rdhwr_vivt(void);
70 extern asmlinkage void handle_ri_rdhwr(void);
71 extern asmlinkage void handle_cpu(void);
72 extern asmlinkage void handle_ov(void);
73 extern asmlinkage void handle_tr(void);
74 extern asmlinkage void handle_fpe(void);
75 extern asmlinkage void handle_mdmx(void);
76 extern asmlinkage void handle_watch(void);
77 extern asmlinkage void handle_mt(void);
78 extern asmlinkage void handle_dsp(void);
79 extern asmlinkage void handle_mcheck(void);
80 extern asmlinkage void handle_reserved(void);
81 
82 extern int fpu_emulator_cop1Handler(struct pt_regs *xcp,
83 	struct mips_fpu_struct *ctx, int has_fpu);
84 
85 void (*board_be_init)(void);
86 int (*board_be_handler)(struct pt_regs *regs, int is_fixup);
87 void (*board_nmi_handler_setup)(void);
88 void (*board_ejtag_handler_setup)(void);
89 void (*board_bind_eic_interrupt)(int irq, int regset);
90 
91 
92 static void show_raw_backtrace(unsigned long reg29)
93 {
94 	unsigned long *sp = (unsigned long *)(reg29 & ~3);
95 	unsigned long addr;
96 
97 	printk("Call Trace:");
98 #ifdef CONFIG_KALLSYMS
99 	printk("\n");
100 #endif
101 	while (!kstack_end(sp)) {
102 		unsigned long __user *p =
103 			(unsigned long __user *)(unsigned long)sp++;
104 		if (__get_user(addr, p)) {
105 			printk(" (Bad stack address)");
106 			break;
107 		}
108 		if (__kernel_text_address(addr))
109 			print_ip_sym(addr);
110 	}
111 	printk("\n");
112 }
113 
114 #ifdef CONFIG_KALLSYMS
115 int raw_show_trace;
116 static int __init set_raw_show_trace(char *str)
117 {
118 	raw_show_trace = 1;
119 	return 1;
120 }
121 __setup("raw_show_trace", set_raw_show_trace);
122 #endif
123 
124 static void show_backtrace(struct task_struct *task, const struct pt_regs *regs)
125 {
126 	unsigned long sp = regs->regs[29];
127 	unsigned long ra = regs->regs[31];
128 	unsigned long pc = regs->cp0_epc;
129 
130 	if (raw_show_trace || !__kernel_text_address(pc)) {
131 		show_raw_backtrace(sp);
132 		return;
133 	}
134 	printk("Call Trace:\n");
135 	do {
136 		print_ip_sym(pc);
137 		pc = unwind_stack(task, &sp, pc, &ra);
138 	} while (pc);
139 	printk("\n");
140 }
141 
142 /*
143  * This routine abuses get_user()/put_user() to reference pointers
144  * with at least a bit of error checking ...
145  */
146 static void show_stacktrace(struct task_struct *task,
147 	const struct pt_regs *regs)
148 {
149 	const int field = 2 * sizeof(unsigned long);
150 	long stackdata;
151 	int i;
152 	unsigned long __user *sp = (unsigned long __user *)regs->regs[29];
153 
154 	printk("Stack :");
155 	i = 0;
156 	while ((unsigned long) sp & (PAGE_SIZE - 1)) {
157 		if (i && ((i % (64 / field)) == 0))
158 			printk("\n       ");
159 		if (i > 39) {
160 			printk(" ...");
161 			break;
162 		}
163 
164 		if (__get_user(stackdata, sp++)) {
165 			printk(" (Bad stack address)");
166 			break;
167 		}
168 
169 		printk(" %0*lx", field, stackdata);
170 		i++;
171 	}
172 	printk("\n");
173 	show_backtrace(task, regs);
174 }
175 
176 void show_stack(struct task_struct *task, unsigned long *sp)
177 {
178 	struct pt_regs regs;
179 	if (sp) {
180 		regs.regs[29] = (unsigned long)sp;
181 		regs.regs[31] = 0;
182 		regs.cp0_epc = 0;
183 	} else {
184 		if (task && task != current) {
185 			regs.regs[29] = task->thread.reg29;
186 			regs.regs[31] = 0;
187 			regs.cp0_epc = task->thread.reg31;
188 		} else {
189 			prepare_frametrace(&regs);
190 		}
191 	}
192 	show_stacktrace(task, &regs);
193 }
194 
195 /*
196  * The architecture-independent dump_stack generator
197  */
198 void dump_stack(void)
199 {
200 	struct pt_regs regs;
201 
202 	prepare_frametrace(&regs);
203 	show_backtrace(current, &regs);
204 }
205 
206 EXPORT_SYMBOL(dump_stack);
207 
208 static void show_code(unsigned int __user *pc)
209 {
210 	long i;
211 	unsigned short __user *pc16 = NULL;
212 
213 	printk("\nCode:");
214 
215 	if ((unsigned long)pc & 1)
216 		pc16 = (unsigned short __user *)((unsigned long)pc & ~1);
217 	for(i = -3 ; i < 6 ; i++) {
218 		unsigned int insn;
219 		if (pc16 ? __get_user(insn, pc16 + i) : __get_user(insn, pc + i)) {
220 			printk(" (Bad address in epc)\n");
221 			break;
222 		}
223 		printk("%c%0*x%c", (i?' ':'<'), pc16 ? 4 : 8, insn, (i?' ':'>'));
224 	}
225 }
226 
227 static void __show_regs(const struct pt_regs *regs)
228 {
229 	const int field = 2 * sizeof(unsigned long);
230 	unsigned int cause = regs->cp0_cause;
231 	int i;
232 
233 	printk("Cpu %d\n", smp_processor_id());
234 
235 	/*
236 	 * Saved main processor registers
237 	 */
238 	for (i = 0; i < 32; ) {
239 		if ((i % 4) == 0)
240 			printk("$%2d   :", i);
241 		if (i == 0)
242 			printk(" %0*lx", field, 0UL);
243 		else if (i == 26 || i == 27)
244 			printk(" %*s", field, "");
245 		else
246 			printk(" %0*lx", field, regs->regs[i]);
247 
248 		i++;
249 		if ((i % 4) == 0)
250 			printk("\n");
251 	}
252 
253 #ifdef CONFIG_CPU_HAS_SMARTMIPS
254 	printk("Acx    : %0*lx\n", field, regs->acx);
255 #endif
256 	printk("Hi    : %0*lx\n", field, regs->hi);
257 	printk("Lo    : %0*lx\n", field, regs->lo);
258 
259 	/*
260 	 * Saved cp0 registers
261 	 */
262 	printk("epc   : %0*lx %pS\n", field, regs->cp0_epc,
263 	       (void *) regs->cp0_epc);
264 	printk("    %s\n", print_tainted());
265 	printk("ra    : %0*lx %pS\n", field, regs->regs[31],
266 	       (void *) regs->regs[31]);
267 
268 	printk("Status: %08x    ", (uint32_t) regs->cp0_status);
269 
270 	if (current_cpu_data.isa_level == MIPS_CPU_ISA_I) {
271 		if (regs->cp0_status & ST0_KUO)
272 			printk("KUo ");
273 		if (regs->cp0_status & ST0_IEO)
274 			printk("IEo ");
275 		if (regs->cp0_status & ST0_KUP)
276 			printk("KUp ");
277 		if (regs->cp0_status & ST0_IEP)
278 			printk("IEp ");
279 		if (regs->cp0_status & ST0_KUC)
280 			printk("KUc ");
281 		if (regs->cp0_status & ST0_IEC)
282 			printk("IEc ");
283 	} else {
284 		if (regs->cp0_status & ST0_KX)
285 			printk("KX ");
286 		if (regs->cp0_status & ST0_SX)
287 			printk("SX ");
288 		if (regs->cp0_status & ST0_UX)
289 			printk("UX ");
290 		switch (regs->cp0_status & ST0_KSU) {
291 		case KSU_USER:
292 			printk("USER ");
293 			break;
294 		case KSU_SUPERVISOR:
295 			printk("SUPERVISOR ");
296 			break;
297 		case KSU_KERNEL:
298 			printk("KERNEL ");
299 			break;
300 		default:
301 			printk("BAD_MODE ");
302 			break;
303 		}
304 		if (regs->cp0_status & ST0_ERL)
305 			printk("ERL ");
306 		if (regs->cp0_status & ST0_EXL)
307 			printk("EXL ");
308 		if (regs->cp0_status & ST0_IE)
309 			printk("IE ");
310 	}
311 	printk("\n");
312 
313 	printk("Cause : %08x\n", cause);
314 
315 	cause = (cause & CAUSEF_EXCCODE) >> CAUSEB_EXCCODE;
316 	if (1 <= cause && cause <= 5)
317 		printk("BadVA : %0*lx\n", field, regs->cp0_badvaddr);
318 
319 	printk("PrId  : %08x (%s)\n", read_c0_prid(),
320 	       cpu_name_string());
321 }
322 
323 /*
324  * FIXME: really the generic show_regs should take a const pointer argument.
325  */
326 void show_regs(struct pt_regs *regs)
327 {
328 	__show_regs((struct pt_regs *)regs);
329 }
330 
331 void show_registers(const struct pt_regs *regs)
332 {
333 	const int field = 2 * sizeof(unsigned long);
334 
335 	__show_regs(regs);
336 	print_modules();
337 	printk("Process %s (pid: %d, threadinfo=%p, task=%p, tls=%0*lx)\n",
338 	       current->comm, current->pid, current_thread_info(), current,
339 	      field, current_thread_info()->tp_value);
340 	if (cpu_has_userlocal) {
341 		unsigned long tls;
342 
343 		tls = read_c0_userlocal();
344 		if (tls != current_thread_info()->tp_value)
345 			printk("*HwTLS: %0*lx\n", field, tls);
346 	}
347 
348 	show_stacktrace(current, regs);
349 	show_code((unsigned int __user *) regs->cp0_epc);
350 	printk("\n");
351 }
352 
353 static DEFINE_SPINLOCK(die_lock);
354 
355 void __noreturn die(const char * str, struct pt_regs * regs)
356 {
357 	static int die_counter;
358 	int sig = SIGSEGV;
359 #ifdef CONFIG_MIPS_MT_SMTC
360 	unsigned long dvpret = dvpe();
361 #endif /* CONFIG_MIPS_MT_SMTC */
362 
363 	console_verbose();
364 	spin_lock_irq(&die_lock);
365 	bust_spinlocks(1);
366 #ifdef CONFIG_MIPS_MT_SMTC
367 	mips_mt_regdump(dvpret);
368 #endif /* CONFIG_MIPS_MT_SMTC */
369 
370 	if (notify_die(DIE_OOPS, str, regs, 0, current->thread.trap_no, SIGSEGV) == NOTIFY_STOP)
371 		sig = 0;
372 
373 	printk("%s[#%d]:\n", str, ++die_counter);
374 	show_registers(regs);
375 	add_taint(TAINT_DIE);
376 	spin_unlock_irq(&die_lock);
377 
378 	if (in_interrupt())
379 		panic("Fatal exception in interrupt");
380 
381 	if (panic_on_oops) {
382 		printk(KERN_EMERG "Fatal exception: panic in 5 seconds\n");
383 		ssleep(5);
384 		panic("Fatal exception");
385 	}
386 
387 	do_exit(sig);
388 }
389 
390 extern struct exception_table_entry __start___dbe_table[];
391 extern struct exception_table_entry __stop___dbe_table[];
392 
393 __asm__(
394 "	.section	__dbe_table, \"a\"\n"
395 "	.previous			\n");
396 
397 /* Given an address, look for it in the exception tables. */
398 static const struct exception_table_entry *search_dbe_tables(unsigned long addr)
399 {
400 	const struct exception_table_entry *e;
401 
402 	e = search_extable(__start___dbe_table, __stop___dbe_table - 1, addr);
403 	if (!e)
404 		e = search_module_dbetables(addr);
405 	return e;
406 }
407 
408 asmlinkage void do_be(struct pt_regs *regs)
409 {
410 	const int field = 2 * sizeof(unsigned long);
411 	const struct exception_table_entry *fixup = NULL;
412 	int data = regs->cp0_cause & 4;
413 	int action = MIPS_BE_FATAL;
414 
415 	/* XXX For now.  Fixme, this searches the wrong table ...  */
416 	if (data && !user_mode(regs))
417 		fixup = search_dbe_tables(exception_epc(regs));
418 
419 	if (fixup)
420 		action = MIPS_BE_FIXUP;
421 
422 	if (board_be_handler)
423 		action = board_be_handler(regs, fixup != NULL);
424 
425 	switch (action) {
426 	case MIPS_BE_DISCARD:
427 		return;
428 	case MIPS_BE_FIXUP:
429 		if (fixup) {
430 			regs->cp0_epc = fixup->nextinsn;
431 			return;
432 		}
433 		break;
434 	default:
435 		break;
436 	}
437 
438 	/*
439 	 * Assume it would be too dangerous to continue ...
440 	 */
441 	printk(KERN_ALERT "%s bus error, epc == %0*lx, ra == %0*lx\n",
442 	       data ? "Data" : "Instruction",
443 	       field, regs->cp0_epc, field, regs->regs[31]);
444 	if (notify_die(DIE_OOPS, "bus error", regs, SIGBUS, 0, 0)
445 	    == NOTIFY_STOP)
446 		return;
447 
448 	die_if_kernel("Oops", regs);
449 	force_sig(SIGBUS, current);
450 }
451 
452 /*
453  * ll/sc, rdhwr, sync emulation
454  */
455 
456 #define OPCODE 0xfc000000
457 #define BASE   0x03e00000
458 #define RT     0x001f0000
459 #define OFFSET 0x0000ffff
460 #define LL     0xc0000000
461 #define SC     0xe0000000
462 #define SPEC0  0x00000000
463 #define SPEC3  0x7c000000
464 #define RD     0x0000f800
465 #define FUNC   0x0000003f
466 #define SYNC   0x0000000f
467 #define RDHWR  0x0000003b
468 
469 /*
470  * The ll_bit is cleared by r*_switch.S
471  */
472 
473 unsigned int ll_bit;
474 struct task_struct *ll_task;
475 
476 static inline int simulate_ll(struct pt_regs *regs, unsigned int opcode)
477 {
478 	unsigned long value, __user *vaddr;
479 	long offset;
480 
481 	/*
482 	 * analyse the ll instruction that just caused a ri exception
483 	 * and put the referenced address to addr.
484 	 */
485 
486 	/* sign extend offset */
487 	offset = opcode & OFFSET;
488 	offset <<= 16;
489 	offset >>= 16;
490 
491 	vaddr = (unsigned long __user *)
492 	        ((unsigned long)(regs->regs[(opcode & BASE) >> 21]) + offset);
493 
494 	if ((unsigned long)vaddr & 3)
495 		return SIGBUS;
496 	if (get_user(value, vaddr))
497 		return SIGSEGV;
498 
499 	preempt_disable();
500 
501 	if (ll_task == NULL || ll_task == current) {
502 		ll_bit = 1;
503 	} else {
504 		ll_bit = 0;
505 	}
506 	ll_task = current;
507 
508 	preempt_enable();
509 
510 	regs->regs[(opcode & RT) >> 16] = value;
511 
512 	return 0;
513 }
514 
515 static inline int simulate_sc(struct pt_regs *regs, unsigned int opcode)
516 {
517 	unsigned long __user *vaddr;
518 	unsigned long reg;
519 	long offset;
520 
521 	/*
522 	 * analyse the sc instruction that just caused a ri exception
523 	 * and put the referenced address to addr.
524 	 */
525 
526 	/* sign extend offset */
527 	offset = opcode & OFFSET;
528 	offset <<= 16;
529 	offset >>= 16;
530 
531 	vaddr = (unsigned long __user *)
532 	        ((unsigned long)(regs->regs[(opcode & BASE) >> 21]) + offset);
533 	reg = (opcode & RT) >> 16;
534 
535 	if ((unsigned long)vaddr & 3)
536 		return SIGBUS;
537 
538 	preempt_disable();
539 
540 	if (ll_bit == 0 || ll_task != current) {
541 		regs->regs[reg] = 0;
542 		preempt_enable();
543 		return 0;
544 	}
545 
546 	preempt_enable();
547 
548 	if (put_user(regs->regs[reg], vaddr))
549 		return SIGSEGV;
550 
551 	regs->regs[reg] = 1;
552 
553 	return 0;
554 }
555 
556 /*
557  * ll uses the opcode of lwc0 and sc uses the opcode of swc0.  That is both
558  * opcodes are supposed to result in coprocessor unusable exceptions if
559  * executed on ll/sc-less processors.  That's the theory.  In practice a
560  * few processors such as NEC's VR4100 throw reserved instruction exceptions
561  * instead, so we're doing the emulation thing in both exception handlers.
562  */
563 static int simulate_llsc(struct pt_regs *regs, unsigned int opcode)
564 {
565 	if ((opcode & OPCODE) == LL)
566 		return simulate_ll(regs, opcode);
567 	if ((opcode & OPCODE) == SC)
568 		return simulate_sc(regs, opcode);
569 
570 	return -1;			/* Must be something else ... */
571 }
572 
573 /*
574  * Simulate trapping 'rdhwr' instructions to provide user accessible
575  * registers not implemented in hardware.
576  */
577 static int simulate_rdhwr(struct pt_regs *regs, unsigned int opcode)
578 {
579 	struct thread_info *ti = task_thread_info(current);
580 
581 	if ((opcode & OPCODE) == SPEC3 && (opcode & FUNC) == RDHWR) {
582 		int rd = (opcode & RD) >> 11;
583 		int rt = (opcode & RT) >> 16;
584 		switch (rd) {
585 		case 0:		/* CPU number */
586 			regs->regs[rt] = smp_processor_id();
587 			return 0;
588 		case 1:		/* SYNCI length */
589 			regs->regs[rt] = min(current_cpu_data.dcache.linesz,
590 					     current_cpu_data.icache.linesz);
591 			return 0;
592 		case 2:		/* Read count register */
593 			regs->regs[rt] = read_c0_count();
594 			return 0;
595 		case 3:		/* Count register resolution */
596 			switch (current_cpu_data.cputype) {
597 			case CPU_20KC:
598 			case CPU_25KF:
599 				regs->regs[rt] = 1;
600 				break;
601 			default:
602 				regs->regs[rt] = 2;
603 			}
604 			return 0;
605 		case 29:
606 			regs->regs[rt] = ti->tp_value;
607 			return 0;
608 		default:
609 			return -1;
610 		}
611 	}
612 
613 	/* Not ours.  */
614 	return -1;
615 }
616 
617 static int simulate_sync(struct pt_regs *regs, unsigned int opcode)
618 {
619 	if ((opcode & OPCODE) == SPEC0 && (opcode & FUNC) == SYNC)
620 		return 0;
621 
622 	return -1;			/* Must be something else ... */
623 }
624 
625 asmlinkage void do_ov(struct pt_regs *regs)
626 {
627 	siginfo_t info;
628 
629 	die_if_kernel("Integer overflow", regs);
630 
631 	info.si_code = FPE_INTOVF;
632 	info.si_signo = SIGFPE;
633 	info.si_errno = 0;
634 	info.si_addr = (void __user *) regs->cp0_epc;
635 	force_sig_info(SIGFPE, &info, current);
636 }
637 
638 /*
639  * XXX Delayed fp exceptions when doing a lazy ctx switch XXX
640  */
641 asmlinkage void do_fpe(struct pt_regs *regs, unsigned long fcr31)
642 {
643 	siginfo_t info;
644 
645 	if (notify_die(DIE_FP, "FP exception", regs, SIGFPE, 0, 0)
646 	    == NOTIFY_STOP)
647 		return;
648 	die_if_kernel("FP exception in kernel code", regs);
649 
650 	if (fcr31 & FPU_CSR_UNI_X) {
651 		int sig;
652 
653 		/*
654 		 * Unimplemented operation exception.  If we've got the full
655 		 * software emulator on-board, let's use it...
656 		 *
657 		 * Force FPU to dump state into task/thread context.  We're
658 		 * moving a lot of data here for what is probably a single
659 		 * instruction, but the alternative is to pre-decode the FP
660 		 * register operands before invoking the emulator, which seems
661 		 * a bit extreme for what should be an infrequent event.
662 		 */
663 		/* Ensure 'resume' not overwrite saved fp context again. */
664 		lose_fpu(1);
665 
666 		/* Run the emulator */
667 		sig = fpu_emulator_cop1Handler(regs, &current->thread.fpu, 1);
668 
669 		/*
670 		 * We can't allow the emulated instruction to leave any of
671 		 * the cause bit set in $fcr31.
672 		 */
673 		current->thread.fpu.fcr31 &= ~FPU_CSR_ALL_X;
674 
675 		/* Restore the hardware register state */
676 		own_fpu(1);	/* Using the FPU again.  */
677 
678 		/* If something went wrong, signal */
679 		if (sig)
680 			force_sig(sig, current);
681 
682 		return;
683 	} else if (fcr31 & FPU_CSR_INV_X)
684 		info.si_code = FPE_FLTINV;
685 	else if (fcr31 & FPU_CSR_DIV_X)
686 		info.si_code = FPE_FLTDIV;
687 	else if (fcr31 & FPU_CSR_OVF_X)
688 		info.si_code = FPE_FLTOVF;
689 	else if (fcr31 & FPU_CSR_UDF_X)
690 		info.si_code = FPE_FLTUND;
691 	else if (fcr31 & FPU_CSR_INE_X)
692 		info.si_code = FPE_FLTRES;
693 	else
694 		info.si_code = __SI_FAULT;
695 	info.si_signo = SIGFPE;
696 	info.si_errno = 0;
697 	info.si_addr = (void __user *) regs->cp0_epc;
698 	force_sig_info(SIGFPE, &info, current);
699 }
700 
701 static void do_trap_or_bp(struct pt_regs *regs, unsigned int code,
702 	const char *str)
703 {
704 	siginfo_t info;
705 	char b[40];
706 
707 	if (notify_die(DIE_TRAP, str, regs, code, 0, 0) == NOTIFY_STOP)
708 		return;
709 
710 	/*
711 	 * A short test says that IRIX 5.3 sends SIGTRAP for all trap
712 	 * insns, even for trap and break codes that indicate arithmetic
713 	 * failures.  Weird ...
714 	 * But should we continue the brokenness???  --macro
715 	 */
716 	switch (code) {
717 	case BRK_OVERFLOW:
718 	case BRK_DIVZERO:
719 		scnprintf(b, sizeof(b), "%s instruction in kernel code", str);
720 		die_if_kernel(b, regs);
721 		if (code == BRK_DIVZERO)
722 			info.si_code = FPE_INTDIV;
723 		else
724 			info.si_code = FPE_INTOVF;
725 		info.si_signo = SIGFPE;
726 		info.si_errno = 0;
727 		info.si_addr = (void __user *) regs->cp0_epc;
728 		force_sig_info(SIGFPE, &info, current);
729 		break;
730 	case BRK_BUG:
731 		die_if_kernel("Kernel bug detected", regs);
732 		force_sig(SIGTRAP, current);
733 		break;
734 	case BRK_MEMU:
735 		/*
736 		 * Address errors may be deliberately induced by the FPU
737 		 * emulator to retake control of the CPU after executing the
738 		 * instruction in the delay slot of an emulated branch.
739 		 *
740 		 * Terminate if exception was recognized as a delay slot return
741 		 * otherwise handle as normal.
742 		 */
743 		if (do_dsemulret(regs))
744 			return;
745 
746 		die_if_kernel("Math emu break/trap", regs);
747 		force_sig(SIGTRAP, current);
748 		break;
749 	default:
750 		scnprintf(b, sizeof(b), "%s instruction in kernel code", str);
751 		die_if_kernel(b, regs);
752 		force_sig(SIGTRAP, current);
753 	}
754 }
755 
756 asmlinkage void do_bp(struct pt_regs *regs)
757 {
758 	unsigned int opcode, bcode;
759 
760 	if (__get_user(opcode, (unsigned int __user *) exception_epc(regs)))
761 		goto out_sigsegv;
762 
763 	/*
764 	 * There is the ancient bug in the MIPS assemblers that the break
765 	 * code starts left to bit 16 instead to bit 6 in the opcode.
766 	 * Gas is bug-compatible, but not always, grrr...
767 	 * We handle both cases with a simple heuristics.  --macro
768 	 */
769 	bcode = ((opcode >> 6) & ((1 << 20) - 1));
770 	if (bcode >= (1 << 10))
771 		bcode >>= 10;
772 
773 	do_trap_or_bp(regs, bcode, "Break");
774 	return;
775 
776 out_sigsegv:
777 	force_sig(SIGSEGV, current);
778 }
779 
780 asmlinkage void do_tr(struct pt_regs *regs)
781 {
782 	unsigned int opcode, tcode = 0;
783 
784 	if (__get_user(opcode, (unsigned int __user *) exception_epc(regs)))
785 		goto out_sigsegv;
786 
787 	/* Immediate versions don't provide a code.  */
788 	if (!(opcode & OPCODE))
789 		tcode = ((opcode >> 6) & ((1 << 10) - 1));
790 
791 	do_trap_or_bp(regs, tcode, "Trap");
792 	return;
793 
794 out_sigsegv:
795 	force_sig(SIGSEGV, current);
796 }
797 
798 asmlinkage void do_ri(struct pt_regs *regs)
799 {
800 	unsigned int __user *epc = (unsigned int __user *)exception_epc(regs);
801 	unsigned long old_epc = regs->cp0_epc;
802 	unsigned int opcode = 0;
803 	int status = -1;
804 
805 	if (notify_die(DIE_RI, "RI Fault", regs, SIGSEGV, 0, 0)
806 	    == NOTIFY_STOP)
807 		return;
808 
809 	die_if_kernel("Reserved instruction in kernel code", regs);
810 
811 	if (unlikely(compute_return_epc(regs) < 0))
812 		return;
813 
814 	if (unlikely(get_user(opcode, epc) < 0))
815 		status = SIGSEGV;
816 
817 	if (!cpu_has_llsc && status < 0)
818 		status = simulate_llsc(regs, opcode);
819 
820 	if (status < 0)
821 		status = simulate_rdhwr(regs, opcode);
822 
823 	if (status < 0)
824 		status = simulate_sync(regs, opcode);
825 
826 	if (status < 0)
827 		status = SIGILL;
828 
829 	if (unlikely(status > 0)) {
830 		regs->cp0_epc = old_epc;		/* Undo skip-over.  */
831 		force_sig(status, current);
832 	}
833 }
834 
835 /*
836  * MIPS MT processors may have fewer FPU contexts than CPU threads. If we've
837  * emulated more than some threshold number of instructions, force migration to
838  * a "CPU" that has FP support.
839  */
840 static void mt_ase_fp_affinity(void)
841 {
842 #ifdef CONFIG_MIPS_MT_FPAFF
843 	if (mt_fpemul_threshold > 0 &&
844 	     ((current->thread.emulated_fp++ > mt_fpemul_threshold))) {
845 		/*
846 		 * If there's no FPU present, or if the application has already
847 		 * restricted the allowed set to exclude any CPUs with FPUs,
848 		 * we'll skip the procedure.
849 		 */
850 		if (cpus_intersects(current->cpus_allowed, mt_fpu_cpumask)) {
851 			cpumask_t tmask;
852 
853 			current->thread.user_cpus_allowed
854 				= current->cpus_allowed;
855 			cpus_and(tmask, current->cpus_allowed,
856 				mt_fpu_cpumask);
857 			set_cpus_allowed(current, tmask);
858 			set_thread_flag(TIF_FPUBOUND);
859 		}
860 	}
861 #endif /* CONFIG_MIPS_MT_FPAFF */
862 }
863 
864 /*
865  * No lock; only written during early bootup by CPU 0.
866  */
867 static RAW_NOTIFIER_HEAD(cu2_chain);
868 
869 int __ref register_cu2_notifier(struct notifier_block *nb)
870 {
871 	return raw_notifier_chain_register(&cu2_chain, nb);
872 }
873 
874 int cu2_notifier_call_chain(unsigned long val, void *v)
875 {
876 	return raw_notifier_call_chain(&cu2_chain, val, v);
877 }
878 
879 static int default_cu2_call(struct notifier_block *nfb, unsigned long action,
880         void *data)
881 {
882 	struct pt_regs *regs = data;
883 
884 	switch (action) {
885 	default:
886 		die_if_kernel("Unhandled kernel unaligned access or invalid "
887 			      "instruction", regs);
888 		/* Fall through  */
889 
890 	case CU2_EXCEPTION:
891 		force_sig(SIGILL, current);
892 	}
893 
894 	return NOTIFY_OK;
895 }
896 
897 static struct notifier_block default_cu2_notifier = {
898 	.notifier_call	= default_cu2_call,
899 	.priority	= 0x80000000,		/* Run last  */
900 };
901 
902 asmlinkage void do_cpu(struct pt_regs *regs)
903 {
904 	unsigned int __user *epc;
905 	unsigned long old_epc;
906 	unsigned int opcode;
907 	unsigned int cpid;
908 	int status;
909 	unsigned long __maybe_unused flags;
910 
911 	die_if_kernel("do_cpu invoked from kernel context!", regs);
912 
913 	cpid = (regs->cp0_cause >> CAUSEB_CE) & 3;
914 
915 	switch (cpid) {
916 	case 0:
917 		epc = (unsigned int __user *)exception_epc(regs);
918 		old_epc = regs->cp0_epc;
919 		opcode = 0;
920 		status = -1;
921 
922 		if (unlikely(compute_return_epc(regs) < 0))
923 			return;
924 
925 		if (unlikely(get_user(opcode, epc) < 0))
926 			status = SIGSEGV;
927 
928 		if (!cpu_has_llsc && status < 0)
929 			status = simulate_llsc(regs, opcode);
930 
931 		if (status < 0)
932 			status = simulate_rdhwr(regs, opcode);
933 
934 		if (status < 0)
935 			status = SIGILL;
936 
937 		if (unlikely(status > 0)) {
938 			regs->cp0_epc = old_epc;	/* Undo skip-over.  */
939 			force_sig(status, current);
940 		}
941 
942 		return;
943 
944 	case 1:
945 		if (used_math())	/* Using the FPU again.  */
946 			own_fpu(1);
947 		else {			/* First time FPU user.  */
948 			init_fpu();
949 			set_used_math();
950 		}
951 
952 		if (!raw_cpu_has_fpu) {
953 			int sig;
954 			sig = fpu_emulator_cop1Handler(regs,
955 						&current->thread.fpu, 0);
956 			if (sig)
957 				force_sig(sig, current);
958 			else
959 				mt_ase_fp_affinity();
960 		}
961 
962 		return;
963 
964 	case 2:
965 		raw_notifier_call_chain(&cu2_chain, CU2_EXCEPTION, regs);
966 		break;
967 
968 	case 3:
969 		break;
970 	}
971 
972 	force_sig(SIGILL, current);
973 }
974 
975 asmlinkage void do_mdmx(struct pt_regs *regs)
976 {
977 	force_sig(SIGILL, current);
978 }
979 
980 /*
981  * Called with interrupts disabled.
982  */
983 asmlinkage void do_watch(struct pt_regs *regs)
984 {
985 	u32 cause;
986 
987 	/*
988 	 * Clear WP (bit 22) bit of cause register so we don't loop
989 	 * forever.
990 	 */
991 	cause = read_c0_cause();
992 	cause &= ~(1 << 22);
993 	write_c0_cause(cause);
994 
995 	/*
996 	 * If the current thread has the watch registers loaded, save
997 	 * their values and send SIGTRAP.  Otherwise another thread
998 	 * left the registers set, clear them and continue.
999 	 */
1000 	if (test_tsk_thread_flag(current, TIF_LOAD_WATCH)) {
1001 		mips_read_watch_registers();
1002 		local_irq_enable();
1003 		force_sig(SIGTRAP, current);
1004 	} else {
1005 		mips_clear_watch_registers();
1006 		local_irq_enable();
1007 	}
1008 }
1009 
1010 asmlinkage void do_mcheck(struct pt_regs *regs)
1011 {
1012 	const int field = 2 * sizeof(unsigned long);
1013 	int multi_match = regs->cp0_status & ST0_TS;
1014 
1015 	show_regs(regs);
1016 
1017 	if (multi_match) {
1018 		printk("Index   : %0x\n", read_c0_index());
1019 		printk("Pagemask: %0x\n", read_c0_pagemask());
1020 		printk("EntryHi : %0*lx\n", field, read_c0_entryhi());
1021 		printk("EntryLo0: %0*lx\n", field, read_c0_entrylo0());
1022 		printk("EntryLo1: %0*lx\n", field, read_c0_entrylo1());
1023 		printk("\n");
1024 		dump_tlb_all();
1025 	}
1026 
1027 	show_code((unsigned int __user *) regs->cp0_epc);
1028 
1029 	/*
1030 	 * Some chips may have other causes of machine check (e.g. SB1
1031 	 * graduation timer)
1032 	 */
1033 	panic("Caught Machine Check exception - %scaused by multiple "
1034 	      "matching entries in the TLB.",
1035 	      (multi_match) ? "" : "not ");
1036 }
1037 
1038 asmlinkage void do_mt(struct pt_regs *regs)
1039 {
1040 	int subcode;
1041 
1042 	subcode = (read_vpe_c0_vpecontrol() & VPECONTROL_EXCPT)
1043 			>> VPECONTROL_EXCPT_SHIFT;
1044 	switch (subcode) {
1045 	case 0:
1046 		printk(KERN_DEBUG "Thread Underflow\n");
1047 		break;
1048 	case 1:
1049 		printk(KERN_DEBUG "Thread Overflow\n");
1050 		break;
1051 	case 2:
1052 		printk(KERN_DEBUG "Invalid YIELD Qualifier\n");
1053 		break;
1054 	case 3:
1055 		printk(KERN_DEBUG "Gating Storage Exception\n");
1056 		break;
1057 	case 4:
1058 		printk(KERN_DEBUG "YIELD Scheduler Exception\n");
1059 		break;
1060 	case 5:
1061 		printk(KERN_DEBUG "Gating Storage Schedulier Exception\n");
1062 		break;
1063 	default:
1064 		printk(KERN_DEBUG "*** UNKNOWN THREAD EXCEPTION %d ***\n",
1065 			subcode);
1066 		break;
1067 	}
1068 	die_if_kernel("MIPS MT Thread exception in kernel", regs);
1069 
1070 	force_sig(SIGILL, current);
1071 }
1072 
1073 
1074 asmlinkage void do_dsp(struct pt_regs *regs)
1075 {
1076 	if (cpu_has_dsp)
1077 		panic("Unexpected DSP exception\n");
1078 
1079 	force_sig(SIGILL, current);
1080 }
1081 
1082 asmlinkage void do_reserved(struct pt_regs *regs)
1083 {
1084 	/*
1085 	 * Game over - no way to handle this if it ever occurs.  Most probably
1086 	 * caused by a new unknown cpu type or after another deadly
1087 	 * hard/software error.
1088 	 */
1089 	show_regs(regs);
1090 	panic("Caught reserved exception %ld - should not happen.",
1091 	      (regs->cp0_cause & 0x7f) >> 2);
1092 }
1093 
1094 static int __initdata l1parity = 1;
1095 static int __init nol1parity(char *s)
1096 {
1097 	l1parity = 0;
1098 	return 1;
1099 }
1100 __setup("nol1par", nol1parity);
1101 static int __initdata l2parity = 1;
1102 static int __init nol2parity(char *s)
1103 {
1104 	l2parity = 0;
1105 	return 1;
1106 }
1107 __setup("nol2par", nol2parity);
1108 
1109 /*
1110  * Some MIPS CPUs can enable/disable for cache parity detection, but do
1111  * it different ways.
1112  */
1113 static inline void parity_protection_init(void)
1114 {
1115 	switch (current_cpu_type()) {
1116 	case CPU_24K:
1117 	case CPU_34K:
1118 	case CPU_74K:
1119 	case CPU_1004K:
1120 		{
1121 #define ERRCTL_PE	0x80000000
1122 #define ERRCTL_L2P	0x00800000
1123 			unsigned long errctl;
1124 			unsigned int l1parity_present, l2parity_present;
1125 
1126 			errctl = read_c0_ecc();
1127 			errctl &= ~(ERRCTL_PE|ERRCTL_L2P);
1128 
1129 			/* probe L1 parity support */
1130 			write_c0_ecc(errctl | ERRCTL_PE);
1131 			back_to_back_c0_hazard();
1132 			l1parity_present = (read_c0_ecc() & ERRCTL_PE);
1133 
1134 			/* probe L2 parity support */
1135 			write_c0_ecc(errctl|ERRCTL_L2P);
1136 			back_to_back_c0_hazard();
1137 			l2parity_present = (read_c0_ecc() & ERRCTL_L2P);
1138 
1139 			if (l1parity_present && l2parity_present) {
1140 				if (l1parity)
1141 					errctl |= ERRCTL_PE;
1142 				if (l1parity ^ l2parity)
1143 					errctl |= ERRCTL_L2P;
1144 			} else if (l1parity_present) {
1145 				if (l1parity)
1146 					errctl |= ERRCTL_PE;
1147 			} else if (l2parity_present) {
1148 				if (l2parity)
1149 					errctl |= ERRCTL_L2P;
1150 			} else {
1151 				/* No parity available */
1152 			}
1153 
1154 			printk(KERN_INFO "Writing ErrCtl register=%08lx\n", errctl);
1155 
1156 			write_c0_ecc(errctl);
1157 			back_to_back_c0_hazard();
1158 			errctl = read_c0_ecc();
1159 			printk(KERN_INFO "Readback ErrCtl register=%08lx\n", errctl);
1160 
1161 			if (l1parity_present)
1162 				printk(KERN_INFO "Cache parity protection %sabled\n",
1163 				       (errctl & ERRCTL_PE) ? "en" : "dis");
1164 
1165 			if (l2parity_present) {
1166 				if (l1parity_present && l1parity)
1167 					errctl ^= ERRCTL_L2P;
1168 				printk(KERN_INFO "L2 cache parity protection %sabled\n",
1169 				       (errctl & ERRCTL_L2P) ? "en" : "dis");
1170 			}
1171 		}
1172 		break;
1173 
1174 	case CPU_5KC:
1175 		write_c0_ecc(0x80000000);
1176 		back_to_back_c0_hazard();
1177 		/* Set the PE bit (bit 31) in the c0_errctl register. */
1178 		printk(KERN_INFO "Cache parity protection %sabled\n",
1179 		       (read_c0_ecc() & 0x80000000) ? "en" : "dis");
1180 		break;
1181 	case CPU_20KC:
1182 	case CPU_25KF:
1183 		/* Clear the DE bit (bit 16) in the c0_status register. */
1184 		printk(KERN_INFO "Enable cache parity protection for "
1185 		       "MIPS 20KC/25KF CPUs.\n");
1186 		clear_c0_status(ST0_DE);
1187 		break;
1188 	default:
1189 		break;
1190 	}
1191 }
1192 
1193 asmlinkage void cache_parity_error(void)
1194 {
1195 	const int field = 2 * sizeof(unsigned long);
1196 	unsigned int reg_val;
1197 
1198 	/* For the moment, report the problem and hang. */
1199 	printk("Cache error exception:\n");
1200 	printk("cp0_errorepc == %0*lx\n", field, read_c0_errorepc());
1201 	reg_val = read_c0_cacheerr();
1202 	printk("c0_cacheerr == %08x\n", reg_val);
1203 
1204 	printk("Decoded c0_cacheerr: %s cache fault in %s reference.\n",
1205 	       reg_val & (1<<30) ? "secondary" : "primary",
1206 	       reg_val & (1<<31) ? "data" : "insn");
1207 	printk("Error bits: %s%s%s%s%s%s%s\n",
1208 	       reg_val & (1<<29) ? "ED " : "",
1209 	       reg_val & (1<<28) ? "ET " : "",
1210 	       reg_val & (1<<26) ? "EE " : "",
1211 	       reg_val & (1<<25) ? "EB " : "",
1212 	       reg_val & (1<<24) ? "EI " : "",
1213 	       reg_val & (1<<23) ? "E1 " : "",
1214 	       reg_val & (1<<22) ? "E0 " : "");
1215 	printk("IDX: 0x%08x\n", reg_val & ((1<<22)-1));
1216 
1217 #if defined(CONFIG_CPU_MIPS32) || defined(CONFIG_CPU_MIPS64)
1218 	if (reg_val & (1<<22))
1219 		printk("DErrAddr0: 0x%0*lx\n", field, read_c0_derraddr0());
1220 
1221 	if (reg_val & (1<<23))
1222 		printk("DErrAddr1: 0x%0*lx\n", field, read_c0_derraddr1());
1223 #endif
1224 
1225 	panic("Can't handle the cache error!");
1226 }
1227 
1228 /*
1229  * SDBBP EJTAG debug exception handler.
1230  * We skip the instruction and return to the next instruction.
1231  */
1232 void ejtag_exception_handler(struct pt_regs *regs)
1233 {
1234 	const int field = 2 * sizeof(unsigned long);
1235 	unsigned long depc, old_epc;
1236 	unsigned int debug;
1237 
1238 	printk(KERN_DEBUG "SDBBP EJTAG debug exception - not handled yet, just ignored!\n");
1239 	depc = read_c0_depc();
1240 	debug = read_c0_debug();
1241 	printk(KERN_DEBUG "c0_depc = %0*lx, DEBUG = %08x\n", field, depc, debug);
1242 	if (debug & 0x80000000) {
1243 		/*
1244 		 * In branch delay slot.
1245 		 * We cheat a little bit here and use EPC to calculate the
1246 		 * debug return address (DEPC). EPC is restored after the
1247 		 * calculation.
1248 		 */
1249 		old_epc = regs->cp0_epc;
1250 		regs->cp0_epc = depc;
1251 		__compute_return_epc(regs);
1252 		depc = regs->cp0_epc;
1253 		regs->cp0_epc = old_epc;
1254 	} else
1255 		depc += 4;
1256 	write_c0_depc(depc);
1257 
1258 #if 0
1259 	printk(KERN_DEBUG "\n\n----- Enable EJTAG single stepping ----\n\n");
1260 	write_c0_debug(debug | 0x100);
1261 #endif
1262 }
1263 
1264 /*
1265  * NMI exception handler.
1266  */
1267 NORET_TYPE void ATTRIB_NORET nmi_exception_handler(struct pt_regs *regs)
1268 {
1269 	bust_spinlocks(1);
1270 	printk("NMI taken!!!!\n");
1271 	die("NMI", regs);
1272 }
1273 
1274 #define VECTORSPACING 0x100	/* for EI/VI mode */
1275 
1276 unsigned long ebase;
1277 unsigned long exception_handlers[32];
1278 unsigned long vi_handlers[64];
1279 
1280 void __init *set_except_vector(int n, void *addr)
1281 {
1282 	unsigned long handler = (unsigned long) addr;
1283 	unsigned long old_handler = exception_handlers[n];
1284 
1285 	exception_handlers[n] = handler;
1286 	if (n == 0 && cpu_has_divec) {
1287 		unsigned long jump_mask = ~((1 << 28) - 1);
1288 		u32 *buf = (u32 *)(ebase + 0x200);
1289 		unsigned int k0 = 26;
1290 		if ((handler & jump_mask) == ((ebase + 0x200) & jump_mask)) {
1291 			uasm_i_j(&buf, handler & ~jump_mask);
1292 			uasm_i_nop(&buf);
1293 		} else {
1294 			UASM_i_LA(&buf, k0, handler);
1295 			uasm_i_jr(&buf, k0);
1296 			uasm_i_nop(&buf);
1297 		}
1298 		local_flush_icache_range(ebase + 0x200, (unsigned long)buf);
1299 	}
1300 	return (void *)old_handler;
1301 }
1302 
1303 static asmlinkage void do_default_vi(void)
1304 {
1305 	show_regs(get_irq_regs());
1306 	panic("Caught unexpected vectored interrupt.");
1307 }
1308 
1309 static void *set_vi_srs_handler(int n, vi_handler_t addr, int srs)
1310 {
1311 	unsigned long handler;
1312 	unsigned long old_handler = vi_handlers[n];
1313 	int srssets = current_cpu_data.srsets;
1314 	u32 *w;
1315 	unsigned char *b;
1316 
1317 	BUG_ON(!cpu_has_veic && !cpu_has_vint);
1318 
1319 	if (addr == NULL) {
1320 		handler = (unsigned long) do_default_vi;
1321 		srs = 0;
1322 	} else
1323 		handler = (unsigned long) addr;
1324 	vi_handlers[n] = (unsigned long) addr;
1325 
1326 	b = (unsigned char *)(ebase + 0x200 + n*VECTORSPACING);
1327 
1328 	if (srs >= srssets)
1329 		panic("Shadow register set %d not supported", srs);
1330 
1331 	if (cpu_has_veic) {
1332 		if (board_bind_eic_interrupt)
1333 			board_bind_eic_interrupt(n, srs);
1334 	} else if (cpu_has_vint) {
1335 		/* SRSMap is only defined if shadow sets are implemented */
1336 		if (srssets > 1)
1337 			change_c0_srsmap(0xf << n*4, srs << n*4);
1338 	}
1339 
1340 	if (srs == 0) {
1341 		/*
1342 		 * If no shadow set is selected then use the default handler
1343 		 * that does normal register saving and a standard interrupt exit
1344 		 */
1345 
1346 		extern char except_vec_vi, except_vec_vi_lui;
1347 		extern char except_vec_vi_ori, except_vec_vi_end;
1348 		extern char rollback_except_vec_vi;
1349 		char *vec_start = (cpu_wait == r4k_wait) ?
1350 			&rollback_except_vec_vi : &except_vec_vi;
1351 #ifdef CONFIG_MIPS_MT_SMTC
1352 		/*
1353 		 * We need to provide the SMTC vectored interrupt handler
1354 		 * not only with the address of the handler, but with the
1355 		 * Status.IM bit to be masked before going there.
1356 		 */
1357 		extern char except_vec_vi_mori;
1358 		const int mori_offset = &except_vec_vi_mori - vec_start;
1359 #endif /* CONFIG_MIPS_MT_SMTC */
1360 		const int handler_len = &except_vec_vi_end - vec_start;
1361 		const int lui_offset = &except_vec_vi_lui - vec_start;
1362 		const int ori_offset = &except_vec_vi_ori - vec_start;
1363 
1364 		if (handler_len > VECTORSPACING) {
1365 			/*
1366 			 * Sigh... panicing won't help as the console
1367 			 * is probably not configured :(
1368 			 */
1369 			panic("VECTORSPACING too small");
1370 		}
1371 
1372 		memcpy(b, vec_start, handler_len);
1373 #ifdef CONFIG_MIPS_MT_SMTC
1374 		BUG_ON(n > 7);	/* Vector index %d exceeds SMTC maximum. */
1375 
1376 		w = (u32 *)(b + mori_offset);
1377 		*w = (*w & 0xffff0000) | (0x100 << n);
1378 #endif /* CONFIG_MIPS_MT_SMTC */
1379 		w = (u32 *)(b + lui_offset);
1380 		*w = (*w & 0xffff0000) | (((u32)handler >> 16) & 0xffff);
1381 		w = (u32 *)(b + ori_offset);
1382 		*w = (*w & 0xffff0000) | ((u32)handler & 0xffff);
1383 		local_flush_icache_range((unsigned long)b,
1384 					 (unsigned long)(b+handler_len));
1385 	}
1386 	else {
1387 		/*
1388 		 * In other cases jump directly to the interrupt handler
1389 		 *
1390 		 * It is the handlers responsibility to save registers if required
1391 		 * (eg hi/lo) and return from the exception using "eret"
1392 		 */
1393 		w = (u32 *)b;
1394 		*w++ = 0x08000000 | (((u32)handler >> 2) & 0x03fffff); /* j handler */
1395 		*w = 0;
1396 		local_flush_icache_range((unsigned long)b,
1397 					 (unsigned long)(b+8));
1398 	}
1399 
1400 	return (void *)old_handler;
1401 }
1402 
1403 void *set_vi_handler(int n, vi_handler_t addr)
1404 {
1405 	return set_vi_srs_handler(n, addr, 0);
1406 }
1407 
1408 extern void cpu_cache_init(void);
1409 extern void tlb_init(void);
1410 extern void flush_tlb_handlers(void);
1411 
1412 /*
1413  * Timer interrupt
1414  */
1415 int cp0_compare_irq;
1416 int cp0_compare_irq_shift;
1417 
1418 /*
1419  * Performance counter IRQ or -1 if shared with timer
1420  */
1421 int cp0_perfcount_irq;
1422 EXPORT_SYMBOL_GPL(cp0_perfcount_irq);
1423 
1424 static int __cpuinitdata noulri;
1425 
1426 static int __init ulri_disable(char *s)
1427 {
1428 	pr_info("Disabling ulri\n");
1429 	noulri = 1;
1430 
1431 	return 1;
1432 }
1433 __setup("noulri", ulri_disable);
1434 
1435 void __cpuinit per_cpu_trap_init(void)
1436 {
1437 	unsigned int cpu = smp_processor_id();
1438 	unsigned int status_set = ST0_CU0;
1439 #ifdef CONFIG_MIPS_MT_SMTC
1440 	int secondaryTC = 0;
1441 	int bootTC = (cpu == 0);
1442 
1443 	/*
1444 	 * Only do per_cpu_trap_init() for first TC of Each VPE.
1445 	 * Note that this hack assumes that the SMTC init code
1446 	 * assigns TCs consecutively and in ascending order.
1447 	 */
1448 
1449 	if (((read_c0_tcbind() & TCBIND_CURTC) != 0) &&
1450 	    ((read_c0_tcbind() & TCBIND_CURVPE) == cpu_data[cpu - 1].vpe_id))
1451 		secondaryTC = 1;
1452 #endif /* CONFIG_MIPS_MT_SMTC */
1453 
1454 	/*
1455 	 * Disable coprocessors and select 32-bit or 64-bit addressing
1456 	 * and the 16/32 or 32/32 FPR register model.  Reset the BEV
1457 	 * flag that some firmware may have left set and the TS bit (for
1458 	 * IP27).  Set XX for ISA IV code to work.
1459 	 */
1460 #ifdef CONFIG_64BIT
1461 	status_set |= ST0_FR|ST0_KX|ST0_SX|ST0_UX;
1462 #endif
1463 	if (current_cpu_data.isa_level == MIPS_CPU_ISA_IV)
1464 		status_set |= ST0_XX;
1465 	if (cpu_has_dsp)
1466 		status_set |= ST0_MX;
1467 
1468 	change_c0_status(ST0_CU|ST0_MX|ST0_RE|ST0_FR|ST0_BEV|ST0_TS|ST0_KX|ST0_SX|ST0_UX,
1469 			 status_set);
1470 
1471 	if (cpu_has_mips_r2) {
1472 		unsigned int enable = 0x0000000f | cpu_hwrena_impl_bits;
1473 
1474 		if (!noulri && cpu_has_userlocal)
1475 			enable |= (1 << 29);
1476 
1477 		write_c0_hwrena(enable);
1478 	}
1479 
1480 #ifdef CONFIG_MIPS_MT_SMTC
1481 	if (!secondaryTC) {
1482 #endif /* CONFIG_MIPS_MT_SMTC */
1483 
1484 	if (cpu_has_veic || cpu_has_vint) {
1485 		unsigned long sr = set_c0_status(ST0_BEV);
1486 		write_c0_ebase(ebase);
1487 		write_c0_status(sr);
1488 		/* Setting vector spacing enables EI/VI mode  */
1489 		change_c0_intctl(0x3e0, VECTORSPACING);
1490 	}
1491 	if (cpu_has_divec) {
1492 		if (cpu_has_mipsmt) {
1493 			unsigned int vpflags = dvpe();
1494 			set_c0_cause(CAUSEF_IV);
1495 			evpe(vpflags);
1496 		} else
1497 			set_c0_cause(CAUSEF_IV);
1498 	}
1499 
1500 	/*
1501 	 * Before R2 both interrupt numbers were fixed to 7, so on R2 only:
1502 	 *
1503 	 *  o read IntCtl.IPTI to determine the timer interrupt
1504 	 *  o read IntCtl.IPPCI to determine the performance counter interrupt
1505 	 */
1506 	if (cpu_has_mips_r2) {
1507 		cp0_compare_irq_shift = CAUSEB_TI - CAUSEB_IP;
1508 		cp0_compare_irq = (read_c0_intctl() >> INTCTLB_IPTI) & 7;
1509 		cp0_perfcount_irq = (read_c0_intctl() >> INTCTLB_IPPCI) & 7;
1510 		if (cp0_perfcount_irq == cp0_compare_irq)
1511 			cp0_perfcount_irq = -1;
1512 	} else {
1513 		cp0_compare_irq = CP0_LEGACY_COMPARE_IRQ;
1514 		cp0_compare_irq_shift = cp0_compare_irq;
1515 		cp0_perfcount_irq = -1;
1516 	}
1517 
1518 #ifdef CONFIG_MIPS_MT_SMTC
1519 	}
1520 #endif /* CONFIG_MIPS_MT_SMTC */
1521 
1522 	cpu_data[cpu].asid_cache = ASID_FIRST_VERSION;
1523 	TLBMISS_HANDLER_SETUP();
1524 
1525 	atomic_inc(&init_mm.mm_count);
1526 	current->active_mm = &init_mm;
1527 	BUG_ON(current->mm);
1528 	enter_lazy_tlb(&init_mm, current);
1529 
1530 #ifdef CONFIG_MIPS_MT_SMTC
1531 	if (bootTC) {
1532 #endif /* CONFIG_MIPS_MT_SMTC */
1533 		cpu_cache_init();
1534 		tlb_init();
1535 #ifdef CONFIG_MIPS_MT_SMTC
1536 	} else if (!secondaryTC) {
1537 		/*
1538 		 * First TC in non-boot VPE must do subset of tlb_init()
1539 		 * for MMU countrol registers.
1540 		 */
1541 		write_c0_pagemask(PM_DEFAULT_MASK);
1542 		write_c0_wired(0);
1543 	}
1544 #endif /* CONFIG_MIPS_MT_SMTC */
1545 }
1546 
1547 /* Install CPU exception handler */
1548 void __init set_handler(unsigned long offset, void *addr, unsigned long size)
1549 {
1550 	memcpy((void *)(ebase + offset), addr, size);
1551 	local_flush_icache_range(ebase + offset, ebase + offset + size);
1552 }
1553 
1554 static char panic_null_cerr[] __cpuinitdata =
1555 	"Trying to set NULL cache error exception handler";
1556 
1557 /*
1558  * Install uncached CPU exception handler.
1559  * This is suitable only for the cache error exception which is the only
1560  * exception handler that is being run uncached.
1561  */
1562 void __cpuinit set_uncached_handler(unsigned long offset, void *addr,
1563 	unsigned long size)
1564 {
1565 	unsigned long uncached_ebase = CKSEG1ADDR(ebase);
1566 
1567 	if (!addr)
1568 		panic(panic_null_cerr);
1569 
1570 	memcpy((void *)(uncached_ebase + offset), addr, size);
1571 }
1572 
1573 static int __initdata rdhwr_noopt;
1574 static int __init set_rdhwr_noopt(char *str)
1575 {
1576 	rdhwr_noopt = 1;
1577 	return 1;
1578 }
1579 
1580 __setup("rdhwr_noopt", set_rdhwr_noopt);
1581 
1582 void __init trap_init(void)
1583 {
1584 	extern char except_vec3_generic, except_vec3_r4000;
1585 	extern char except_vec4;
1586 	unsigned long i;
1587 	int rollback;
1588 
1589 	check_wait();
1590 	rollback = (cpu_wait == r4k_wait);
1591 
1592 #if defined(CONFIG_KGDB)
1593 	if (kgdb_early_setup)
1594 		return;	/* Already done */
1595 #endif
1596 
1597 	if (cpu_has_veic || cpu_has_vint) {
1598 		unsigned long size = 0x200 + VECTORSPACING*64;
1599 		ebase = (unsigned long)
1600 			__alloc_bootmem(size, 1 << fls(size), 0);
1601 	} else {
1602 		ebase = CKSEG0;
1603 		if (cpu_has_mips_r2)
1604 			ebase += (read_c0_ebase() & 0x3ffff000);
1605 	}
1606 
1607 	per_cpu_trap_init();
1608 
1609 	/*
1610 	 * Copy the generic exception handlers to their final destination.
1611 	 * This will be overriden later as suitable for a particular
1612 	 * configuration.
1613 	 */
1614 	set_handler(0x180, &except_vec3_generic, 0x80);
1615 
1616 	/*
1617 	 * Setup default vectors
1618 	 */
1619 	for (i = 0; i <= 31; i++)
1620 		set_except_vector(i, handle_reserved);
1621 
1622 	/*
1623 	 * Copy the EJTAG debug exception vector handler code to it's final
1624 	 * destination.
1625 	 */
1626 	if (cpu_has_ejtag && board_ejtag_handler_setup)
1627 		board_ejtag_handler_setup();
1628 
1629 	/*
1630 	 * Only some CPUs have the watch exceptions.
1631 	 */
1632 	if (cpu_has_watch)
1633 		set_except_vector(23, handle_watch);
1634 
1635 	/*
1636 	 * Initialise interrupt handlers
1637 	 */
1638 	if (cpu_has_veic || cpu_has_vint) {
1639 		int nvec = cpu_has_veic ? 64 : 8;
1640 		for (i = 0; i < nvec; i++)
1641 			set_vi_handler(i, NULL);
1642 	}
1643 	else if (cpu_has_divec)
1644 		set_handler(0x200, &except_vec4, 0x8);
1645 
1646 	/*
1647 	 * Some CPUs can enable/disable for cache parity detection, but does
1648 	 * it different ways.
1649 	 */
1650 	parity_protection_init();
1651 
1652 	/*
1653 	 * The Data Bus Errors / Instruction Bus Errors are signaled
1654 	 * by external hardware.  Therefore these two exceptions
1655 	 * may have board specific handlers.
1656 	 */
1657 	if (board_be_init)
1658 		board_be_init();
1659 
1660 	set_except_vector(0, rollback ? rollback_handle_int : handle_int);
1661 	set_except_vector(1, handle_tlbm);
1662 	set_except_vector(2, handle_tlbl);
1663 	set_except_vector(3, handle_tlbs);
1664 
1665 	set_except_vector(4, handle_adel);
1666 	set_except_vector(5, handle_ades);
1667 
1668 	set_except_vector(6, handle_ibe);
1669 	set_except_vector(7, handle_dbe);
1670 
1671 	set_except_vector(8, handle_sys);
1672 	set_except_vector(9, handle_bp);
1673 	set_except_vector(10, rdhwr_noopt ? handle_ri :
1674 			  (cpu_has_vtag_icache ?
1675 			   handle_ri_rdhwr_vivt : handle_ri_rdhwr));
1676 	set_except_vector(11, handle_cpu);
1677 	set_except_vector(12, handle_ov);
1678 	set_except_vector(13, handle_tr);
1679 
1680 	if (current_cpu_type() == CPU_R6000 ||
1681 	    current_cpu_type() == CPU_R6000A) {
1682 		/*
1683 		 * The R6000 is the only R-series CPU that features a machine
1684 		 * check exception (similar to the R4000 cache error) and
1685 		 * unaligned ldc1/sdc1 exception.  The handlers have not been
1686 		 * written yet.  Well, anyway there is no R6000 machine on the
1687 		 * current list of targets for Linux/MIPS.
1688 		 * (Duh, crap, there is someone with a triple R6k machine)
1689 		 */
1690 		//set_except_vector(14, handle_mc);
1691 		//set_except_vector(15, handle_ndc);
1692 	}
1693 
1694 
1695 	if (board_nmi_handler_setup)
1696 		board_nmi_handler_setup();
1697 
1698 	if (cpu_has_fpu && !cpu_has_nofpuex)
1699 		set_except_vector(15, handle_fpe);
1700 
1701 	set_except_vector(22, handle_mdmx);
1702 
1703 	if (cpu_has_mcheck)
1704 		set_except_vector(24, handle_mcheck);
1705 
1706 	if (cpu_has_mipsmt)
1707 		set_except_vector(25, handle_mt);
1708 
1709 	set_except_vector(26, handle_dsp);
1710 
1711 	if (cpu_has_vce)
1712 		/* Special exception: R4[04]00 uses also the divec space. */
1713 		memcpy((void *)(ebase + 0x180), &except_vec3_r4000, 0x100);
1714 	else if (cpu_has_4kex)
1715 		memcpy((void *)(ebase + 0x180), &except_vec3_generic, 0x80);
1716 	else
1717 		memcpy((void *)(ebase + 0x080), &except_vec3_generic, 0x80);
1718 
1719 	local_flush_icache_range(ebase, ebase + 0x400);
1720 	flush_tlb_handlers();
1721 
1722 	sort_extable(__start___dbe_table, __stop___dbe_table);
1723 
1724 	register_cu2_notifier(&default_cu2_notifier);
1725 }
1726