xref: /linux/arch/mips/kernel/traps.c (revision 48c36c8f9a3e881953bb72deb55623a53795a684)
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/kprobes.h>
29 #include <linux/notifier.h>
30 #include <linux/kdb.h>
31 #include <linux/irq.h>
32 #include <linux/perf_event.h>
33 
34 #include <asm/bootinfo.h>
35 #include <asm/branch.h>
36 #include <asm/break.h>
37 #include <asm/cop2.h>
38 #include <asm/cpu.h>
39 #include <asm/dsp.h>
40 #include <asm/fpu.h>
41 #include <asm/fpu_emulator.h>
42 #include <asm/mipsregs.h>
43 #include <asm/mipsmtregs.h>
44 #include <asm/module.h>
45 #include <asm/pgtable.h>
46 #include <asm/ptrace.h>
47 #include <asm/sections.h>
48 #include <asm/system.h>
49 #include <asm/tlbdebug.h>
50 #include <asm/traps.h>
51 #include <asm/uaccess.h>
52 #include <asm/watch.h>
53 #include <asm/mmu_context.h>
54 #include <asm/types.h>
55 #include <asm/stacktrace.h>
56 #include <asm/uasm.h>
57 
58 extern void check_wait(void);
59 extern asmlinkage void r4k_wait(void);
60 extern asmlinkage void rollback_handle_int(void);
61 extern asmlinkage void handle_int(void);
62 extern asmlinkage void handle_tlbm(void);
63 extern asmlinkage void handle_tlbl(void);
64 extern asmlinkage void handle_tlbs(void);
65 extern asmlinkage void handle_adel(void);
66 extern asmlinkage void handle_ades(void);
67 extern asmlinkage void handle_ibe(void);
68 extern asmlinkage void handle_dbe(void);
69 extern asmlinkage void handle_sys(void);
70 extern asmlinkage void handle_bp(void);
71 extern asmlinkage void handle_ri(void);
72 extern asmlinkage void handle_ri_rdhwr_vivt(void);
73 extern asmlinkage void handle_ri_rdhwr(void);
74 extern asmlinkage void handle_cpu(void);
75 extern asmlinkage void handle_ov(void);
76 extern asmlinkage void handle_tr(void);
77 extern asmlinkage void handle_fpe(void);
78 extern asmlinkage void handle_mdmx(void);
79 extern asmlinkage void handle_watch(void);
80 extern asmlinkage void handle_mt(void);
81 extern asmlinkage void handle_dsp(void);
82 extern asmlinkage void handle_mcheck(void);
83 extern asmlinkage void handle_reserved(void);
84 
85 extern int fpu_emulator_cop1Handler(struct pt_regs *xcp,
86 	struct mips_fpu_struct *ctx, int has_fpu);
87 
88 void (*board_be_init)(void);
89 int (*board_be_handler)(struct pt_regs *regs, int is_fixup);
90 void (*board_nmi_handler_setup)(void);
91 void (*board_ejtag_handler_setup)(void);
92 void (*board_bind_eic_interrupt)(int irq, int regset);
93 
94 
95 static void show_raw_backtrace(unsigned long reg29)
96 {
97 	unsigned long *sp = (unsigned long *)(reg29 & ~3);
98 	unsigned long addr;
99 
100 	printk("Call Trace:");
101 #ifdef CONFIG_KALLSYMS
102 	printk("\n");
103 #endif
104 	while (!kstack_end(sp)) {
105 		unsigned long __user *p =
106 			(unsigned long __user *)(unsigned long)sp++;
107 		if (__get_user(addr, p)) {
108 			printk(" (Bad stack address)");
109 			break;
110 		}
111 		if (__kernel_text_address(addr))
112 			print_ip_sym(addr);
113 	}
114 	printk("\n");
115 }
116 
117 #ifdef CONFIG_KALLSYMS
118 int raw_show_trace;
119 static int __init set_raw_show_trace(char *str)
120 {
121 	raw_show_trace = 1;
122 	return 1;
123 }
124 __setup("raw_show_trace", set_raw_show_trace);
125 #endif
126 
127 static void show_backtrace(struct task_struct *task, const struct pt_regs *regs)
128 {
129 	unsigned long sp = regs->regs[29];
130 	unsigned long ra = regs->regs[31];
131 	unsigned long pc = regs->cp0_epc;
132 
133 	if (raw_show_trace || !__kernel_text_address(pc)) {
134 		show_raw_backtrace(sp);
135 		return;
136 	}
137 	printk("Call Trace:\n");
138 	do {
139 		print_ip_sym(pc);
140 		pc = unwind_stack(task, &sp, pc, &ra);
141 	} while (pc);
142 	printk("\n");
143 }
144 
145 /*
146  * This routine abuses get_user()/put_user() to reference pointers
147  * with at least a bit of error checking ...
148  */
149 static void show_stacktrace(struct task_struct *task,
150 	const struct pt_regs *regs)
151 {
152 	const int field = 2 * sizeof(unsigned long);
153 	long stackdata;
154 	int i;
155 	unsigned long __user *sp = (unsigned long __user *)regs->regs[29];
156 
157 	printk("Stack :");
158 	i = 0;
159 	while ((unsigned long) sp & (PAGE_SIZE - 1)) {
160 		if (i && ((i % (64 / field)) == 0))
161 			printk("\n       ");
162 		if (i > 39) {
163 			printk(" ...");
164 			break;
165 		}
166 
167 		if (__get_user(stackdata, sp++)) {
168 			printk(" (Bad stack address)");
169 			break;
170 		}
171 
172 		printk(" %0*lx", field, stackdata);
173 		i++;
174 	}
175 	printk("\n");
176 	show_backtrace(task, regs);
177 }
178 
179 void show_stack(struct task_struct *task, unsigned long *sp)
180 {
181 	struct pt_regs regs;
182 	if (sp) {
183 		regs.regs[29] = (unsigned long)sp;
184 		regs.regs[31] = 0;
185 		regs.cp0_epc = 0;
186 	} else {
187 		if (task && task != current) {
188 			regs.regs[29] = task->thread.reg29;
189 			regs.regs[31] = 0;
190 			regs.cp0_epc = task->thread.reg31;
191 #ifdef CONFIG_KGDB_KDB
192 		} else if (atomic_read(&kgdb_active) != -1 &&
193 			   kdb_current_regs) {
194 			memcpy(&regs, kdb_current_regs, sizeof(regs));
195 #endif /* CONFIG_KGDB_KDB */
196 		} else {
197 			prepare_frametrace(&regs);
198 		}
199 	}
200 	show_stacktrace(task, &regs);
201 }
202 
203 /*
204  * The architecture-independent dump_stack generator
205  */
206 void dump_stack(void)
207 {
208 	struct pt_regs regs;
209 
210 	prepare_frametrace(&regs);
211 	show_backtrace(current, &regs);
212 }
213 
214 EXPORT_SYMBOL(dump_stack);
215 
216 static void show_code(unsigned int __user *pc)
217 {
218 	long i;
219 	unsigned short __user *pc16 = NULL;
220 
221 	printk("\nCode:");
222 
223 	if ((unsigned long)pc & 1)
224 		pc16 = (unsigned short __user *)((unsigned long)pc & ~1);
225 	for(i = -3 ; i < 6 ; i++) {
226 		unsigned int insn;
227 		if (pc16 ? __get_user(insn, pc16 + i) : __get_user(insn, pc + i)) {
228 			printk(" (Bad address in epc)\n");
229 			break;
230 		}
231 		printk("%c%0*x%c", (i?' ':'<'), pc16 ? 4 : 8, insn, (i?' ':'>'));
232 	}
233 }
234 
235 static void __show_regs(const struct pt_regs *regs)
236 {
237 	const int field = 2 * sizeof(unsigned long);
238 	unsigned int cause = regs->cp0_cause;
239 	int i;
240 
241 	printk("Cpu %d\n", smp_processor_id());
242 
243 	/*
244 	 * Saved main processor registers
245 	 */
246 	for (i = 0; i < 32; ) {
247 		if ((i % 4) == 0)
248 			printk("$%2d   :", i);
249 		if (i == 0)
250 			printk(" %0*lx", field, 0UL);
251 		else if (i == 26 || i == 27)
252 			printk(" %*s", field, "");
253 		else
254 			printk(" %0*lx", field, regs->regs[i]);
255 
256 		i++;
257 		if ((i % 4) == 0)
258 			printk("\n");
259 	}
260 
261 #ifdef CONFIG_CPU_HAS_SMARTMIPS
262 	printk("Acx    : %0*lx\n", field, regs->acx);
263 #endif
264 	printk("Hi    : %0*lx\n", field, regs->hi);
265 	printk("Lo    : %0*lx\n", field, regs->lo);
266 
267 	/*
268 	 * Saved cp0 registers
269 	 */
270 	printk("epc   : %0*lx %pS\n", field, regs->cp0_epc,
271 	       (void *) regs->cp0_epc);
272 	printk("    %s\n", print_tainted());
273 	printk("ra    : %0*lx %pS\n", field, regs->regs[31],
274 	       (void *) regs->regs[31]);
275 
276 	printk("Status: %08x    ", (uint32_t) regs->cp0_status);
277 
278 	if (current_cpu_data.isa_level == MIPS_CPU_ISA_I) {
279 		if (regs->cp0_status & ST0_KUO)
280 			printk("KUo ");
281 		if (regs->cp0_status & ST0_IEO)
282 			printk("IEo ");
283 		if (regs->cp0_status & ST0_KUP)
284 			printk("KUp ");
285 		if (regs->cp0_status & ST0_IEP)
286 			printk("IEp ");
287 		if (regs->cp0_status & ST0_KUC)
288 			printk("KUc ");
289 		if (regs->cp0_status & ST0_IEC)
290 			printk("IEc ");
291 	} else {
292 		if (regs->cp0_status & ST0_KX)
293 			printk("KX ");
294 		if (regs->cp0_status & ST0_SX)
295 			printk("SX ");
296 		if (regs->cp0_status & ST0_UX)
297 			printk("UX ");
298 		switch (regs->cp0_status & ST0_KSU) {
299 		case KSU_USER:
300 			printk("USER ");
301 			break;
302 		case KSU_SUPERVISOR:
303 			printk("SUPERVISOR ");
304 			break;
305 		case KSU_KERNEL:
306 			printk("KERNEL ");
307 			break;
308 		default:
309 			printk("BAD_MODE ");
310 			break;
311 		}
312 		if (regs->cp0_status & ST0_ERL)
313 			printk("ERL ");
314 		if (regs->cp0_status & ST0_EXL)
315 			printk("EXL ");
316 		if (regs->cp0_status & ST0_IE)
317 			printk("IE ");
318 	}
319 	printk("\n");
320 
321 	printk("Cause : %08x\n", cause);
322 
323 	cause = (cause & CAUSEF_EXCCODE) >> CAUSEB_EXCCODE;
324 	if (1 <= cause && cause <= 5)
325 		printk("BadVA : %0*lx\n", field, regs->cp0_badvaddr);
326 
327 	printk("PrId  : %08x (%s)\n", read_c0_prid(),
328 	       cpu_name_string());
329 }
330 
331 /*
332  * FIXME: really the generic show_regs should take a const pointer argument.
333  */
334 void show_regs(struct pt_regs *regs)
335 {
336 	__show_regs((struct pt_regs *)regs);
337 }
338 
339 void show_registers(struct pt_regs *regs)
340 {
341 	const int field = 2 * sizeof(unsigned long);
342 
343 	__show_regs(regs);
344 	print_modules();
345 	printk("Process %s (pid: %d, threadinfo=%p, task=%p, tls=%0*lx)\n",
346 	       current->comm, current->pid, current_thread_info(), current,
347 	      field, current_thread_info()->tp_value);
348 	if (cpu_has_userlocal) {
349 		unsigned long tls;
350 
351 		tls = read_c0_userlocal();
352 		if (tls != current_thread_info()->tp_value)
353 			printk("*HwTLS: %0*lx\n", field, tls);
354 	}
355 
356 	show_stacktrace(current, regs);
357 	show_code((unsigned int __user *) regs->cp0_epc);
358 	printk("\n");
359 }
360 
361 static int regs_to_trapnr(struct pt_regs *regs)
362 {
363 	return (regs->cp0_cause >> 2) & 0x1f;
364 }
365 
366 static DEFINE_SPINLOCK(die_lock);
367 
368 void __noreturn die(const char *str, struct pt_regs *regs)
369 {
370 	static int die_counter;
371 	int sig = SIGSEGV;
372 #ifdef CONFIG_MIPS_MT_SMTC
373 	unsigned long dvpret = dvpe();
374 #endif /* CONFIG_MIPS_MT_SMTC */
375 
376 	notify_die(DIE_OOPS, str, regs, 0, regs_to_trapnr(regs), SIGSEGV);
377 
378 	console_verbose();
379 	spin_lock_irq(&die_lock);
380 	bust_spinlocks(1);
381 #ifdef CONFIG_MIPS_MT_SMTC
382 	mips_mt_regdump(dvpret);
383 #endif /* CONFIG_MIPS_MT_SMTC */
384 
385 	if (notify_die(DIE_OOPS, str, regs, 0, regs_to_trapnr(regs), SIGSEGV) == NOTIFY_STOP)
386 		sig = 0;
387 
388 	printk("%s[#%d]:\n", str, ++die_counter);
389 	show_registers(regs);
390 	add_taint(TAINT_DIE);
391 	spin_unlock_irq(&die_lock);
392 
393 	if (in_interrupt())
394 		panic("Fatal exception in interrupt");
395 
396 	if (panic_on_oops) {
397 		printk(KERN_EMERG "Fatal exception: panic in 5 seconds\n");
398 		ssleep(5);
399 		panic("Fatal exception");
400 	}
401 
402 	do_exit(sig);
403 }
404 
405 extern struct exception_table_entry __start___dbe_table[];
406 extern struct exception_table_entry __stop___dbe_table[];
407 
408 __asm__(
409 "	.section	__dbe_table, \"a\"\n"
410 "	.previous			\n");
411 
412 /* Given an address, look for it in the exception tables. */
413 static const struct exception_table_entry *search_dbe_tables(unsigned long addr)
414 {
415 	const struct exception_table_entry *e;
416 
417 	e = search_extable(__start___dbe_table, __stop___dbe_table - 1, addr);
418 	if (!e)
419 		e = search_module_dbetables(addr);
420 	return e;
421 }
422 
423 asmlinkage void do_be(struct pt_regs *regs)
424 {
425 	const int field = 2 * sizeof(unsigned long);
426 	const struct exception_table_entry *fixup = NULL;
427 	int data = regs->cp0_cause & 4;
428 	int action = MIPS_BE_FATAL;
429 
430 	/* XXX For now.  Fixme, this searches the wrong table ...  */
431 	if (data && !user_mode(regs))
432 		fixup = search_dbe_tables(exception_epc(regs));
433 
434 	if (fixup)
435 		action = MIPS_BE_FIXUP;
436 
437 	if (board_be_handler)
438 		action = board_be_handler(regs, fixup != NULL);
439 
440 	switch (action) {
441 	case MIPS_BE_DISCARD:
442 		return;
443 	case MIPS_BE_FIXUP:
444 		if (fixup) {
445 			regs->cp0_epc = fixup->nextinsn;
446 			return;
447 		}
448 		break;
449 	default:
450 		break;
451 	}
452 
453 	/*
454 	 * Assume it would be too dangerous to continue ...
455 	 */
456 	printk(KERN_ALERT "%s bus error, epc == %0*lx, ra == %0*lx\n",
457 	       data ? "Data" : "Instruction",
458 	       field, regs->cp0_epc, field, regs->regs[31]);
459 	if (notify_die(DIE_OOPS, "bus error", regs, 0, regs_to_trapnr(regs), SIGBUS)
460 	    == NOTIFY_STOP)
461 		return;
462 
463 	die_if_kernel("Oops", regs);
464 	force_sig(SIGBUS, current);
465 }
466 
467 /*
468  * ll/sc, rdhwr, sync emulation
469  */
470 
471 #define OPCODE 0xfc000000
472 #define BASE   0x03e00000
473 #define RT     0x001f0000
474 #define OFFSET 0x0000ffff
475 #define LL     0xc0000000
476 #define SC     0xe0000000
477 #define SPEC0  0x00000000
478 #define SPEC3  0x7c000000
479 #define RD     0x0000f800
480 #define FUNC   0x0000003f
481 #define SYNC   0x0000000f
482 #define RDHWR  0x0000003b
483 
484 /*
485  * The ll_bit is cleared by r*_switch.S
486  */
487 
488 unsigned int ll_bit;
489 struct task_struct *ll_task;
490 
491 static inline int simulate_ll(struct pt_regs *regs, unsigned int opcode)
492 {
493 	unsigned long value, __user *vaddr;
494 	long offset;
495 
496 	/*
497 	 * analyse the ll instruction that just caused a ri exception
498 	 * and put the referenced address to addr.
499 	 */
500 
501 	/* sign extend offset */
502 	offset = opcode & OFFSET;
503 	offset <<= 16;
504 	offset >>= 16;
505 
506 	vaddr = (unsigned long __user *)
507 	        ((unsigned long)(regs->regs[(opcode & BASE) >> 21]) + offset);
508 
509 	if ((unsigned long)vaddr & 3)
510 		return SIGBUS;
511 	if (get_user(value, vaddr))
512 		return SIGSEGV;
513 
514 	preempt_disable();
515 
516 	if (ll_task == NULL || ll_task == current) {
517 		ll_bit = 1;
518 	} else {
519 		ll_bit = 0;
520 	}
521 	ll_task = current;
522 
523 	preempt_enable();
524 
525 	regs->regs[(opcode & RT) >> 16] = value;
526 
527 	return 0;
528 }
529 
530 static inline int simulate_sc(struct pt_regs *regs, unsigned int opcode)
531 {
532 	unsigned long __user *vaddr;
533 	unsigned long reg;
534 	long offset;
535 
536 	/*
537 	 * analyse the sc instruction that just caused a ri exception
538 	 * and put the referenced address to addr.
539 	 */
540 
541 	/* sign extend offset */
542 	offset = opcode & OFFSET;
543 	offset <<= 16;
544 	offset >>= 16;
545 
546 	vaddr = (unsigned long __user *)
547 	        ((unsigned long)(regs->regs[(opcode & BASE) >> 21]) + offset);
548 	reg = (opcode & RT) >> 16;
549 
550 	if ((unsigned long)vaddr & 3)
551 		return SIGBUS;
552 
553 	preempt_disable();
554 
555 	if (ll_bit == 0 || ll_task != current) {
556 		regs->regs[reg] = 0;
557 		preempt_enable();
558 		return 0;
559 	}
560 
561 	preempt_enable();
562 
563 	if (put_user(regs->regs[reg], vaddr))
564 		return SIGSEGV;
565 
566 	regs->regs[reg] = 1;
567 
568 	return 0;
569 }
570 
571 /*
572  * ll uses the opcode of lwc0 and sc uses the opcode of swc0.  That is both
573  * opcodes are supposed to result in coprocessor unusable exceptions if
574  * executed on ll/sc-less processors.  That's the theory.  In practice a
575  * few processors such as NEC's VR4100 throw reserved instruction exceptions
576  * instead, so we're doing the emulation thing in both exception handlers.
577  */
578 static int simulate_llsc(struct pt_regs *regs, unsigned int opcode)
579 {
580 	if ((opcode & OPCODE) == LL) {
581 		perf_sw_event(PERF_COUNT_SW_EMULATION_FAULTS,
582 				1, 0, regs, 0);
583 		return simulate_ll(regs, opcode);
584 	}
585 	if ((opcode & OPCODE) == SC) {
586 		perf_sw_event(PERF_COUNT_SW_EMULATION_FAULTS,
587 				1, 0, regs, 0);
588 		return simulate_sc(regs, opcode);
589 	}
590 
591 	return -1;			/* Must be something else ... */
592 }
593 
594 /*
595  * Simulate trapping 'rdhwr' instructions to provide user accessible
596  * registers not implemented in hardware.
597  */
598 static int simulate_rdhwr(struct pt_regs *regs, unsigned int opcode)
599 {
600 	struct thread_info *ti = task_thread_info(current);
601 
602 	if ((opcode & OPCODE) == SPEC3 && (opcode & FUNC) == RDHWR) {
603 		int rd = (opcode & RD) >> 11;
604 		int rt = (opcode & RT) >> 16;
605 		perf_sw_event(PERF_COUNT_SW_EMULATION_FAULTS,
606 				1, 0, regs, 0);
607 		switch (rd) {
608 		case 0:		/* CPU number */
609 			regs->regs[rt] = smp_processor_id();
610 			return 0;
611 		case 1:		/* SYNCI length */
612 			regs->regs[rt] = min(current_cpu_data.dcache.linesz,
613 					     current_cpu_data.icache.linesz);
614 			return 0;
615 		case 2:		/* Read count register */
616 			regs->regs[rt] = read_c0_count();
617 			return 0;
618 		case 3:		/* Count register resolution */
619 			switch (current_cpu_data.cputype) {
620 			case CPU_20KC:
621 			case CPU_25KF:
622 				regs->regs[rt] = 1;
623 				break;
624 			default:
625 				regs->regs[rt] = 2;
626 			}
627 			return 0;
628 		case 29:
629 			regs->regs[rt] = ti->tp_value;
630 			return 0;
631 		default:
632 			return -1;
633 		}
634 	}
635 
636 	/* Not ours.  */
637 	return -1;
638 }
639 
640 static int simulate_sync(struct pt_regs *regs, unsigned int opcode)
641 {
642 	if ((opcode & OPCODE) == SPEC0 && (opcode & FUNC) == SYNC) {
643 		perf_sw_event(PERF_COUNT_SW_EMULATION_FAULTS,
644 				1, 0, regs, 0);
645 		return 0;
646 	}
647 
648 	return -1;			/* Must be something else ... */
649 }
650 
651 asmlinkage void do_ov(struct pt_regs *regs)
652 {
653 	siginfo_t info;
654 
655 	die_if_kernel("Integer overflow", regs);
656 
657 	info.si_code = FPE_INTOVF;
658 	info.si_signo = SIGFPE;
659 	info.si_errno = 0;
660 	info.si_addr = (void __user *) regs->cp0_epc;
661 	force_sig_info(SIGFPE, &info, current);
662 }
663 
664 /*
665  * XXX Delayed fp exceptions when doing a lazy ctx switch XXX
666  */
667 asmlinkage void do_fpe(struct pt_regs *regs, unsigned long fcr31)
668 {
669 	siginfo_t info;
670 
671 	if (notify_die(DIE_FP, "FP exception", regs, 0, regs_to_trapnr(regs), SIGFPE)
672 	    == NOTIFY_STOP)
673 		return;
674 	die_if_kernel("FP exception in kernel code", regs);
675 
676 	if (fcr31 & FPU_CSR_UNI_X) {
677 		int sig;
678 
679 		/*
680 		 * Unimplemented operation exception.  If we've got the full
681 		 * software emulator on-board, let's use it...
682 		 *
683 		 * Force FPU to dump state into task/thread context.  We're
684 		 * moving a lot of data here for what is probably a single
685 		 * instruction, but the alternative is to pre-decode the FP
686 		 * register operands before invoking the emulator, which seems
687 		 * a bit extreme for what should be an infrequent event.
688 		 */
689 		/* Ensure 'resume' not overwrite saved fp context again. */
690 		lose_fpu(1);
691 
692 		/* Run the emulator */
693 		sig = fpu_emulator_cop1Handler(regs, &current->thread.fpu, 1);
694 
695 		/*
696 		 * We can't allow the emulated instruction to leave any of
697 		 * the cause bit set in $fcr31.
698 		 */
699 		current->thread.fpu.fcr31 &= ~FPU_CSR_ALL_X;
700 
701 		/* Restore the hardware register state */
702 		own_fpu(1);	/* Using the FPU again.  */
703 
704 		/* If something went wrong, signal */
705 		if (sig)
706 			force_sig(sig, current);
707 
708 		return;
709 	} else if (fcr31 & FPU_CSR_INV_X)
710 		info.si_code = FPE_FLTINV;
711 	else if (fcr31 & FPU_CSR_DIV_X)
712 		info.si_code = FPE_FLTDIV;
713 	else if (fcr31 & FPU_CSR_OVF_X)
714 		info.si_code = FPE_FLTOVF;
715 	else if (fcr31 & FPU_CSR_UDF_X)
716 		info.si_code = FPE_FLTUND;
717 	else if (fcr31 & FPU_CSR_INE_X)
718 		info.si_code = FPE_FLTRES;
719 	else
720 		info.si_code = __SI_FAULT;
721 	info.si_signo = SIGFPE;
722 	info.si_errno = 0;
723 	info.si_addr = (void __user *) regs->cp0_epc;
724 	force_sig_info(SIGFPE, &info, current);
725 }
726 
727 static void do_trap_or_bp(struct pt_regs *regs, unsigned int code,
728 	const char *str)
729 {
730 	siginfo_t info;
731 	char b[40];
732 
733 #ifdef CONFIG_KGDB_LOW_LEVEL_TRAP
734 	if (kgdb_ll_trap(DIE_TRAP, str, regs, code, regs_to_trapnr(regs), SIGTRAP) == NOTIFY_STOP)
735 		return;
736 #endif /* CONFIG_KGDB_LOW_LEVEL_TRAP */
737 
738 	if (notify_die(DIE_TRAP, str, regs, code, regs_to_trapnr(regs), SIGTRAP) == NOTIFY_STOP)
739 		return;
740 
741 	/*
742 	 * A short test says that IRIX 5.3 sends SIGTRAP for all trap
743 	 * insns, even for trap and break codes that indicate arithmetic
744 	 * failures.  Weird ...
745 	 * But should we continue the brokenness???  --macro
746 	 */
747 	switch (code) {
748 	case BRK_OVERFLOW:
749 	case BRK_DIVZERO:
750 		scnprintf(b, sizeof(b), "%s instruction in kernel code", str);
751 		die_if_kernel(b, regs);
752 		if (code == BRK_DIVZERO)
753 			info.si_code = FPE_INTDIV;
754 		else
755 			info.si_code = FPE_INTOVF;
756 		info.si_signo = SIGFPE;
757 		info.si_errno = 0;
758 		info.si_addr = (void __user *) regs->cp0_epc;
759 		force_sig_info(SIGFPE, &info, current);
760 		break;
761 	case BRK_BUG:
762 		die_if_kernel("Kernel bug detected", regs);
763 		force_sig(SIGTRAP, current);
764 		break;
765 	case BRK_MEMU:
766 		/*
767 		 * Address errors may be deliberately induced by the FPU
768 		 * emulator to retake control of the CPU after executing the
769 		 * instruction in the delay slot of an emulated branch.
770 		 *
771 		 * Terminate if exception was recognized as a delay slot return
772 		 * otherwise handle as normal.
773 		 */
774 		if (do_dsemulret(regs))
775 			return;
776 
777 		die_if_kernel("Math emu break/trap", regs);
778 		force_sig(SIGTRAP, current);
779 		break;
780 	default:
781 		scnprintf(b, sizeof(b), "%s instruction in kernel code", str);
782 		die_if_kernel(b, regs);
783 		force_sig(SIGTRAP, current);
784 	}
785 }
786 
787 asmlinkage void do_bp(struct pt_regs *regs)
788 {
789 	unsigned int opcode, bcode;
790 
791 	if (__get_user(opcode, (unsigned int __user *) exception_epc(regs)))
792 		goto out_sigsegv;
793 
794 	/*
795 	 * There is the ancient bug in the MIPS assemblers that the break
796 	 * code starts left to bit 16 instead to bit 6 in the opcode.
797 	 * Gas is bug-compatible, but not always, grrr...
798 	 * We handle both cases with a simple heuristics.  --macro
799 	 */
800 	bcode = ((opcode >> 6) & ((1 << 20) - 1));
801 	if (bcode >= (1 << 10))
802 		bcode >>= 10;
803 
804 	/*
805 	 * notify the kprobe handlers, if instruction is likely to
806 	 * pertain to them.
807 	 */
808 	switch (bcode) {
809 	case BRK_KPROBE_BP:
810 		if (notify_die(DIE_BREAK, "debug", regs, bcode, regs_to_trapnr(regs), SIGTRAP) == NOTIFY_STOP)
811 			return;
812 		else
813 			break;
814 	case BRK_KPROBE_SSTEPBP:
815 		if (notify_die(DIE_SSTEPBP, "single_step", regs, bcode, regs_to_trapnr(regs), SIGTRAP) == NOTIFY_STOP)
816 			return;
817 		else
818 			break;
819 	default:
820 		break;
821 	}
822 
823 	do_trap_or_bp(regs, bcode, "Break");
824 	return;
825 
826 out_sigsegv:
827 	force_sig(SIGSEGV, current);
828 }
829 
830 asmlinkage void do_tr(struct pt_regs *regs)
831 {
832 	unsigned int opcode, tcode = 0;
833 
834 	if (__get_user(opcode, (unsigned int __user *) exception_epc(regs)))
835 		goto out_sigsegv;
836 
837 	/* Immediate versions don't provide a code.  */
838 	if (!(opcode & OPCODE))
839 		tcode = ((opcode >> 6) & ((1 << 10) - 1));
840 
841 	do_trap_or_bp(regs, tcode, "Trap");
842 	return;
843 
844 out_sigsegv:
845 	force_sig(SIGSEGV, current);
846 }
847 
848 asmlinkage void do_ri(struct pt_regs *regs)
849 {
850 	unsigned int __user *epc = (unsigned int __user *)exception_epc(regs);
851 	unsigned long old_epc = regs->cp0_epc;
852 	unsigned int opcode = 0;
853 	int status = -1;
854 
855 	if (notify_die(DIE_RI, "RI Fault", regs, 0, regs_to_trapnr(regs), SIGILL)
856 	    == NOTIFY_STOP)
857 		return;
858 
859 	die_if_kernel("Reserved instruction in kernel code", regs);
860 
861 	if (unlikely(compute_return_epc(regs) < 0))
862 		return;
863 
864 	if (unlikely(get_user(opcode, epc) < 0))
865 		status = SIGSEGV;
866 
867 	if (!cpu_has_llsc && status < 0)
868 		status = simulate_llsc(regs, opcode);
869 
870 	if (status < 0)
871 		status = simulate_rdhwr(regs, opcode);
872 
873 	if (status < 0)
874 		status = simulate_sync(regs, opcode);
875 
876 	if (status < 0)
877 		status = SIGILL;
878 
879 	if (unlikely(status > 0)) {
880 		regs->cp0_epc = old_epc;		/* Undo skip-over.  */
881 		force_sig(status, current);
882 	}
883 }
884 
885 /*
886  * MIPS MT processors may have fewer FPU contexts than CPU threads. If we've
887  * emulated more than some threshold number of instructions, force migration to
888  * a "CPU" that has FP support.
889  */
890 static void mt_ase_fp_affinity(void)
891 {
892 #ifdef CONFIG_MIPS_MT_FPAFF
893 	if (mt_fpemul_threshold > 0 &&
894 	     ((current->thread.emulated_fp++ > mt_fpemul_threshold))) {
895 		/*
896 		 * If there's no FPU present, or if the application has already
897 		 * restricted the allowed set to exclude any CPUs with FPUs,
898 		 * we'll skip the procedure.
899 		 */
900 		if (cpus_intersects(current->cpus_allowed, mt_fpu_cpumask)) {
901 			cpumask_t tmask;
902 
903 			current->thread.user_cpus_allowed
904 				= current->cpus_allowed;
905 			cpus_and(tmask, current->cpus_allowed,
906 				mt_fpu_cpumask);
907 			set_cpus_allowed_ptr(current, &tmask);
908 			set_thread_flag(TIF_FPUBOUND);
909 		}
910 	}
911 #endif /* CONFIG_MIPS_MT_FPAFF */
912 }
913 
914 /*
915  * No lock; only written during early bootup by CPU 0.
916  */
917 static RAW_NOTIFIER_HEAD(cu2_chain);
918 
919 int __ref register_cu2_notifier(struct notifier_block *nb)
920 {
921 	return raw_notifier_chain_register(&cu2_chain, nb);
922 }
923 
924 int cu2_notifier_call_chain(unsigned long val, void *v)
925 {
926 	return raw_notifier_call_chain(&cu2_chain, val, v);
927 }
928 
929 static int default_cu2_call(struct notifier_block *nfb, unsigned long action,
930         void *data)
931 {
932 	struct pt_regs *regs = data;
933 
934 	switch (action) {
935 	default:
936 		die_if_kernel("Unhandled kernel unaligned access or invalid "
937 			      "instruction", regs);
938 		/* Fall through  */
939 
940 	case CU2_EXCEPTION:
941 		force_sig(SIGILL, current);
942 	}
943 
944 	return NOTIFY_OK;
945 }
946 
947 asmlinkage void do_cpu(struct pt_regs *regs)
948 {
949 	unsigned int __user *epc;
950 	unsigned long old_epc;
951 	unsigned int opcode;
952 	unsigned int cpid;
953 	int status;
954 	unsigned long __maybe_unused flags;
955 
956 	die_if_kernel("do_cpu invoked from kernel context!", regs);
957 
958 	cpid = (regs->cp0_cause >> CAUSEB_CE) & 3;
959 
960 	switch (cpid) {
961 	case 0:
962 		epc = (unsigned int __user *)exception_epc(regs);
963 		old_epc = regs->cp0_epc;
964 		opcode = 0;
965 		status = -1;
966 
967 		if (unlikely(compute_return_epc(regs) < 0))
968 			return;
969 
970 		if (unlikely(get_user(opcode, epc) < 0))
971 			status = SIGSEGV;
972 
973 		if (!cpu_has_llsc && status < 0)
974 			status = simulate_llsc(regs, opcode);
975 
976 		if (status < 0)
977 			status = simulate_rdhwr(regs, opcode);
978 
979 		if (status < 0)
980 			status = SIGILL;
981 
982 		if (unlikely(status > 0)) {
983 			regs->cp0_epc = old_epc;	/* Undo skip-over.  */
984 			force_sig(status, current);
985 		}
986 
987 		return;
988 
989 	case 1:
990 		if (used_math())	/* Using the FPU again.  */
991 			own_fpu(1);
992 		else {			/* First time FPU user.  */
993 			init_fpu();
994 			set_used_math();
995 		}
996 
997 		if (!raw_cpu_has_fpu) {
998 			int sig;
999 			sig = fpu_emulator_cop1Handler(regs,
1000 						&current->thread.fpu, 0);
1001 			if (sig)
1002 				force_sig(sig, current);
1003 			else
1004 				mt_ase_fp_affinity();
1005 		}
1006 
1007 		return;
1008 
1009 	case 2:
1010 		raw_notifier_call_chain(&cu2_chain, CU2_EXCEPTION, regs);
1011 		return;
1012 
1013 	case 3:
1014 		break;
1015 	}
1016 
1017 	force_sig(SIGILL, current);
1018 }
1019 
1020 asmlinkage void do_mdmx(struct pt_regs *regs)
1021 {
1022 	force_sig(SIGILL, current);
1023 }
1024 
1025 /*
1026  * Called with interrupts disabled.
1027  */
1028 asmlinkage void do_watch(struct pt_regs *regs)
1029 {
1030 	u32 cause;
1031 
1032 	/*
1033 	 * Clear WP (bit 22) bit of cause register so we don't loop
1034 	 * forever.
1035 	 */
1036 	cause = read_c0_cause();
1037 	cause &= ~(1 << 22);
1038 	write_c0_cause(cause);
1039 
1040 	/*
1041 	 * If the current thread has the watch registers loaded, save
1042 	 * their values and send SIGTRAP.  Otherwise another thread
1043 	 * left the registers set, clear them and continue.
1044 	 */
1045 	if (test_tsk_thread_flag(current, TIF_LOAD_WATCH)) {
1046 		mips_read_watch_registers();
1047 		local_irq_enable();
1048 		force_sig(SIGTRAP, current);
1049 	} else {
1050 		mips_clear_watch_registers();
1051 		local_irq_enable();
1052 	}
1053 }
1054 
1055 asmlinkage void do_mcheck(struct pt_regs *regs)
1056 {
1057 	const int field = 2 * sizeof(unsigned long);
1058 	int multi_match = regs->cp0_status & ST0_TS;
1059 
1060 	show_regs(regs);
1061 
1062 	if (multi_match) {
1063 		printk("Index   : %0x\n", read_c0_index());
1064 		printk("Pagemask: %0x\n", read_c0_pagemask());
1065 		printk("EntryHi : %0*lx\n", field, read_c0_entryhi());
1066 		printk("EntryLo0: %0*lx\n", field, read_c0_entrylo0());
1067 		printk("EntryLo1: %0*lx\n", field, read_c0_entrylo1());
1068 		printk("\n");
1069 		dump_tlb_all();
1070 	}
1071 
1072 	show_code((unsigned int __user *) regs->cp0_epc);
1073 
1074 	/*
1075 	 * Some chips may have other causes of machine check (e.g. SB1
1076 	 * graduation timer)
1077 	 */
1078 	panic("Caught Machine Check exception - %scaused by multiple "
1079 	      "matching entries in the TLB.",
1080 	      (multi_match) ? "" : "not ");
1081 }
1082 
1083 asmlinkage void do_mt(struct pt_regs *regs)
1084 {
1085 	int subcode;
1086 
1087 	subcode = (read_vpe_c0_vpecontrol() & VPECONTROL_EXCPT)
1088 			>> VPECONTROL_EXCPT_SHIFT;
1089 	switch (subcode) {
1090 	case 0:
1091 		printk(KERN_DEBUG "Thread Underflow\n");
1092 		break;
1093 	case 1:
1094 		printk(KERN_DEBUG "Thread Overflow\n");
1095 		break;
1096 	case 2:
1097 		printk(KERN_DEBUG "Invalid YIELD Qualifier\n");
1098 		break;
1099 	case 3:
1100 		printk(KERN_DEBUG "Gating Storage Exception\n");
1101 		break;
1102 	case 4:
1103 		printk(KERN_DEBUG "YIELD Scheduler Exception\n");
1104 		break;
1105 	case 5:
1106 		printk(KERN_DEBUG "Gating Storage Schedulier Exception\n");
1107 		break;
1108 	default:
1109 		printk(KERN_DEBUG "*** UNKNOWN THREAD EXCEPTION %d ***\n",
1110 			subcode);
1111 		break;
1112 	}
1113 	die_if_kernel("MIPS MT Thread exception in kernel", regs);
1114 
1115 	force_sig(SIGILL, current);
1116 }
1117 
1118 
1119 asmlinkage void do_dsp(struct pt_regs *regs)
1120 {
1121 	if (cpu_has_dsp)
1122 		panic("Unexpected DSP exception\n");
1123 
1124 	force_sig(SIGILL, current);
1125 }
1126 
1127 asmlinkage void do_reserved(struct pt_regs *regs)
1128 {
1129 	/*
1130 	 * Game over - no way to handle this if it ever occurs.  Most probably
1131 	 * caused by a new unknown cpu type or after another deadly
1132 	 * hard/software error.
1133 	 */
1134 	show_regs(regs);
1135 	panic("Caught reserved exception %ld - should not happen.",
1136 	      (regs->cp0_cause & 0x7f) >> 2);
1137 }
1138 
1139 static int __initdata l1parity = 1;
1140 static int __init nol1parity(char *s)
1141 {
1142 	l1parity = 0;
1143 	return 1;
1144 }
1145 __setup("nol1par", nol1parity);
1146 static int __initdata l2parity = 1;
1147 static int __init nol2parity(char *s)
1148 {
1149 	l2parity = 0;
1150 	return 1;
1151 }
1152 __setup("nol2par", nol2parity);
1153 
1154 /*
1155  * Some MIPS CPUs can enable/disable for cache parity detection, but do
1156  * it different ways.
1157  */
1158 static inline void parity_protection_init(void)
1159 {
1160 	switch (current_cpu_type()) {
1161 	case CPU_24K:
1162 	case CPU_34K:
1163 	case CPU_74K:
1164 	case CPU_1004K:
1165 		{
1166 #define ERRCTL_PE	0x80000000
1167 #define ERRCTL_L2P	0x00800000
1168 			unsigned long errctl;
1169 			unsigned int l1parity_present, l2parity_present;
1170 
1171 			errctl = read_c0_ecc();
1172 			errctl &= ~(ERRCTL_PE|ERRCTL_L2P);
1173 
1174 			/* probe L1 parity support */
1175 			write_c0_ecc(errctl | ERRCTL_PE);
1176 			back_to_back_c0_hazard();
1177 			l1parity_present = (read_c0_ecc() & ERRCTL_PE);
1178 
1179 			/* probe L2 parity support */
1180 			write_c0_ecc(errctl|ERRCTL_L2P);
1181 			back_to_back_c0_hazard();
1182 			l2parity_present = (read_c0_ecc() & ERRCTL_L2P);
1183 
1184 			if (l1parity_present && l2parity_present) {
1185 				if (l1parity)
1186 					errctl |= ERRCTL_PE;
1187 				if (l1parity ^ l2parity)
1188 					errctl |= ERRCTL_L2P;
1189 			} else if (l1parity_present) {
1190 				if (l1parity)
1191 					errctl |= ERRCTL_PE;
1192 			} else if (l2parity_present) {
1193 				if (l2parity)
1194 					errctl |= ERRCTL_L2P;
1195 			} else {
1196 				/* No parity available */
1197 			}
1198 
1199 			printk(KERN_INFO "Writing ErrCtl register=%08lx\n", errctl);
1200 
1201 			write_c0_ecc(errctl);
1202 			back_to_back_c0_hazard();
1203 			errctl = read_c0_ecc();
1204 			printk(KERN_INFO "Readback ErrCtl register=%08lx\n", errctl);
1205 
1206 			if (l1parity_present)
1207 				printk(KERN_INFO "Cache parity protection %sabled\n",
1208 				       (errctl & ERRCTL_PE) ? "en" : "dis");
1209 
1210 			if (l2parity_present) {
1211 				if (l1parity_present && l1parity)
1212 					errctl ^= ERRCTL_L2P;
1213 				printk(KERN_INFO "L2 cache parity protection %sabled\n",
1214 				       (errctl & ERRCTL_L2P) ? "en" : "dis");
1215 			}
1216 		}
1217 		break;
1218 
1219 	case CPU_5KC:
1220 		write_c0_ecc(0x80000000);
1221 		back_to_back_c0_hazard();
1222 		/* Set the PE bit (bit 31) in the c0_errctl register. */
1223 		printk(KERN_INFO "Cache parity protection %sabled\n",
1224 		       (read_c0_ecc() & 0x80000000) ? "en" : "dis");
1225 		break;
1226 	case CPU_20KC:
1227 	case CPU_25KF:
1228 		/* Clear the DE bit (bit 16) in the c0_status register. */
1229 		printk(KERN_INFO "Enable cache parity protection for "
1230 		       "MIPS 20KC/25KF CPUs.\n");
1231 		clear_c0_status(ST0_DE);
1232 		break;
1233 	default:
1234 		break;
1235 	}
1236 }
1237 
1238 asmlinkage void cache_parity_error(void)
1239 {
1240 	const int field = 2 * sizeof(unsigned long);
1241 	unsigned int reg_val;
1242 
1243 	/* For the moment, report the problem and hang. */
1244 	printk("Cache error exception:\n");
1245 	printk("cp0_errorepc == %0*lx\n", field, read_c0_errorepc());
1246 	reg_val = read_c0_cacheerr();
1247 	printk("c0_cacheerr == %08x\n", reg_val);
1248 
1249 	printk("Decoded c0_cacheerr: %s cache fault in %s reference.\n",
1250 	       reg_val & (1<<30) ? "secondary" : "primary",
1251 	       reg_val & (1<<31) ? "data" : "insn");
1252 	printk("Error bits: %s%s%s%s%s%s%s\n",
1253 	       reg_val & (1<<29) ? "ED " : "",
1254 	       reg_val & (1<<28) ? "ET " : "",
1255 	       reg_val & (1<<26) ? "EE " : "",
1256 	       reg_val & (1<<25) ? "EB " : "",
1257 	       reg_val & (1<<24) ? "EI " : "",
1258 	       reg_val & (1<<23) ? "E1 " : "",
1259 	       reg_val & (1<<22) ? "E0 " : "");
1260 	printk("IDX: 0x%08x\n", reg_val & ((1<<22)-1));
1261 
1262 #if defined(CONFIG_CPU_MIPS32) || defined(CONFIG_CPU_MIPS64)
1263 	if (reg_val & (1<<22))
1264 		printk("DErrAddr0: 0x%0*lx\n", field, read_c0_derraddr0());
1265 
1266 	if (reg_val & (1<<23))
1267 		printk("DErrAddr1: 0x%0*lx\n", field, read_c0_derraddr1());
1268 #endif
1269 
1270 	panic("Can't handle the cache error!");
1271 }
1272 
1273 /*
1274  * SDBBP EJTAG debug exception handler.
1275  * We skip the instruction and return to the next instruction.
1276  */
1277 void ejtag_exception_handler(struct pt_regs *regs)
1278 {
1279 	const int field = 2 * sizeof(unsigned long);
1280 	unsigned long depc, old_epc;
1281 	unsigned int debug;
1282 
1283 	printk(KERN_DEBUG "SDBBP EJTAG debug exception - not handled yet, just ignored!\n");
1284 	depc = read_c0_depc();
1285 	debug = read_c0_debug();
1286 	printk(KERN_DEBUG "c0_depc = %0*lx, DEBUG = %08x\n", field, depc, debug);
1287 	if (debug & 0x80000000) {
1288 		/*
1289 		 * In branch delay slot.
1290 		 * We cheat a little bit here and use EPC to calculate the
1291 		 * debug return address (DEPC). EPC is restored after the
1292 		 * calculation.
1293 		 */
1294 		old_epc = regs->cp0_epc;
1295 		regs->cp0_epc = depc;
1296 		__compute_return_epc(regs);
1297 		depc = regs->cp0_epc;
1298 		regs->cp0_epc = old_epc;
1299 	} else
1300 		depc += 4;
1301 	write_c0_depc(depc);
1302 
1303 #if 0
1304 	printk(KERN_DEBUG "\n\n----- Enable EJTAG single stepping ----\n\n");
1305 	write_c0_debug(debug | 0x100);
1306 #endif
1307 }
1308 
1309 /*
1310  * NMI exception handler.
1311  */
1312 NORET_TYPE void ATTRIB_NORET nmi_exception_handler(struct pt_regs *regs)
1313 {
1314 	bust_spinlocks(1);
1315 	printk("NMI taken!!!!\n");
1316 	die("NMI", regs);
1317 }
1318 
1319 #define VECTORSPACING 0x100	/* for EI/VI mode */
1320 
1321 unsigned long ebase;
1322 unsigned long exception_handlers[32];
1323 unsigned long vi_handlers[64];
1324 
1325 void __init *set_except_vector(int n, void *addr)
1326 {
1327 	unsigned long handler = (unsigned long) addr;
1328 	unsigned long old_handler = exception_handlers[n];
1329 
1330 	exception_handlers[n] = handler;
1331 	if (n == 0 && cpu_has_divec) {
1332 		unsigned long jump_mask = ~((1 << 28) - 1);
1333 		u32 *buf = (u32 *)(ebase + 0x200);
1334 		unsigned int k0 = 26;
1335 		if ((handler & jump_mask) == ((ebase + 0x200) & jump_mask)) {
1336 			uasm_i_j(&buf, handler & ~jump_mask);
1337 			uasm_i_nop(&buf);
1338 		} else {
1339 			UASM_i_LA(&buf, k0, handler);
1340 			uasm_i_jr(&buf, k0);
1341 			uasm_i_nop(&buf);
1342 		}
1343 		local_flush_icache_range(ebase + 0x200, (unsigned long)buf);
1344 	}
1345 	return (void *)old_handler;
1346 }
1347 
1348 static asmlinkage void do_default_vi(void)
1349 {
1350 	show_regs(get_irq_regs());
1351 	panic("Caught unexpected vectored interrupt.");
1352 }
1353 
1354 static void *set_vi_srs_handler(int n, vi_handler_t addr, int srs)
1355 {
1356 	unsigned long handler;
1357 	unsigned long old_handler = vi_handlers[n];
1358 	int srssets = current_cpu_data.srsets;
1359 	u32 *w;
1360 	unsigned char *b;
1361 
1362 	BUG_ON(!cpu_has_veic && !cpu_has_vint);
1363 
1364 	if (addr == NULL) {
1365 		handler = (unsigned long) do_default_vi;
1366 		srs = 0;
1367 	} else
1368 		handler = (unsigned long) addr;
1369 	vi_handlers[n] = (unsigned long) addr;
1370 
1371 	b = (unsigned char *)(ebase + 0x200 + n*VECTORSPACING);
1372 
1373 	if (srs >= srssets)
1374 		panic("Shadow register set %d not supported", srs);
1375 
1376 	if (cpu_has_veic) {
1377 		if (board_bind_eic_interrupt)
1378 			board_bind_eic_interrupt(n, srs);
1379 	} else if (cpu_has_vint) {
1380 		/* SRSMap is only defined if shadow sets are implemented */
1381 		if (srssets > 1)
1382 			change_c0_srsmap(0xf << n*4, srs << n*4);
1383 	}
1384 
1385 	if (srs == 0) {
1386 		/*
1387 		 * If no shadow set is selected then use the default handler
1388 		 * that does normal register saving and a standard interrupt exit
1389 		 */
1390 
1391 		extern char except_vec_vi, except_vec_vi_lui;
1392 		extern char except_vec_vi_ori, except_vec_vi_end;
1393 		extern char rollback_except_vec_vi;
1394 		char *vec_start = (cpu_wait == r4k_wait) ?
1395 			&rollback_except_vec_vi : &except_vec_vi;
1396 #ifdef CONFIG_MIPS_MT_SMTC
1397 		/*
1398 		 * We need to provide the SMTC vectored interrupt handler
1399 		 * not only with the address of the handler, but with the
1400 		 * Status.IM bit to be masked before going there.
1401 		 */
1402 		extern char except_vec_vi_mori;
1403 		const int mori_offset = &except_vec_vi_mori - vec_start;
1404 #endif /* CONFIG_MIPS_MT_SMTC */
1405 		const int handler_len = &except_vec_vi_end - vec_start;
1406 		const int lui_offset = &except_vec_vi_lui - vec_start;
1407 		const int ori_offset = &except_vec_vi_ori - vec_start;
1408 
1409 		if (handler_len > VECTORSPACING) {
1410 			/*
1411 			 * Sigh... panicing won't help as the console
1412 			 * is probably not configured :(
1413 			 */
1414 			panic("VECTORSPACING too small");
1415 		}
1416 
1417 		memcpy(b, vec_start, handler_len);
1418 #ifdef CONFIG_MIPS_MT_SMTC
1419 		BUG_ON(n > 7);	/* Vector index %d exceeds SMTC maximum. */
1420 
1421 		w = (u32 *)(b + mori_offset);
1422 		*w = (*w & 0xffff0000) | (0x100 << n);
1423 #endif /* CONFIG_MIPS_MT_SMTC */
1424 		w = (u32 *)(b + lui_offset);
1425 		*w = (*w & 0xffff0000) | (((u32)handler >> 16) & 0xffff);
1426 		w = (u32 *)(b + ori_offset);
1427 		*w = (*w & 0xffff0000) | ((u32)handler & 0xffff);
1428 		local_flush_icache_range((unsigned long)b,
1429 					 (unsigned long)(b+handler_len));
1430 	}
1431 	else {
1432 		/*
1433 		 * In other cases jump directly to the interrupt handler
1434 		 *
1435 		 * It is the handlers responsibility to save registers if required
1436 		 * (eg hi/lo) and return from the exception using "eret"
1437 		 */
1438 		w = (u32 *)b;
1439 		*w++ = 0x08000000 | (((u32)handler >> 2) & 0x03fffff); /* j handler */
1440 		*w = 0;
1441 		local_flush_icache_range((unsigned long)b,
1442 					 (unsigned long)(b+8));
1443 	}
1444 
1445 	return (void *)old_handler;
1446 }
1447 
1448 void *set_vi_handler(int n, vi_handler_t addr)
1449 {
1450 	return set_vi_srs_handler(n, addr, 0);
1451 }
1452 
1453 extern void cpu_cache_init(void);
1454 extern void tlb_init(void);
1455 extern void flush_tlb_handlers(void);
1456 
1457 /*
1458  * Timer interrupt
1459  */
1460 int cp0_compare_irq;
1461 int cp0_compare_irq_shift;
1462 
1463 /*
1464  * Performance counter IRQ or -1 if shared with timer
1465  */
1466 int cp0_perfcount_irq;
1467 EXPORT_SYMBOL_GPL(cp0_perfcount_irq);
1468 
1469 static int __cpuinitdata noulri;
1470 
1471 static int __init ulri_disable(char *s)
1472 {
1473 	pr_info("Disabling ulri\n");
1474 	noulri = 1;
1475 
1476 	return 1;
1477 }
1478 __setup("noulri", ulri_disable);
1479 
1480 void __cpuinit per_cpu_trap_init(void)
1481 {
1482 	unsigned int cpu = smp_processor_id();
1483 	unsigned int status_set = ST0_CU0;
1484 	unsigned int hwrena = cpu_hwrena_impl_bits;
1485 #ifdef CONFIG_MIPS_MT_SMTC
1486 	int secondaryTC = 0;
1487 	int bootTC = (cpu == 0);
1488 
1489 	/*
1490 	 * Only do per_cpu_trap_init() for first TC of Each VPE.
1491 	 * Note that this hack assumes that the SMTC init code
1492 	 * assigns TCs consecutively and in ascending order.
1493 	 */
1494 
1495 	if (((read_c0_tcbind() & TCBIND_CURTC) != 0) &&
1496 	    ((read_c0_tcbind() & TCBIND_CURVPE) == cpu_data[cpu - 1].vpe_id))
1497 		secondaryTC = 1;
1498 #endif /* CONFIG_MIPS_MT_SMTC */
1499 
1500 	/*
1501 	 * Disable coprocessors and select 32-bit or 64-bit addressing
1502 	 * and the 16/32 or 32/32 FPR register model.  Reset the BEV
1503 	 * flag that some firmware may have left set and the TS bit (for
1504 	 * IP27).  Set XX for ISA IV code to work.
1505 	 */
1506 #ifdef CONFIG_64BIT
1507 	status_set |= ST0_FR|ST0_KX|ST0_SX|ST0_UX;
1508 #endif
1509 	if (current_cpu_data.isa_level == MIPS_CPU_ISA_IV)
1510 		status_set |= ST0_XX;
1511 	if (cpu_has_dsp)
1512 		status_set |= ST0_MX;
1513 
1514 	change_c0_status(ST0_CU|ST0_MX|ST0_RE|ST0_FR|ST0_BEV|ST0_TS|ST0_KX|ST0_SX|ST0_UX,
1515 			 status_set);
1516 
1517 	if (cpu_has_mips_r2)
1518 		hwrena |= 0x0000000f;
1519 
1520 	if (!noulri && cpu_has_userlocal)
1521 		hwrena |= (1 << 29);
1522 
1523 	if (hwrena)
1524 		write_c0_hwrena(hwrena);
1525 
1526 #ifdef CONFIG_MIPS_MT_SMTC
1527 	if (!secondaryTC) {
1528 #endif /* CONFIG_MIPS_MT_SMTC */
1529 
1530 	if (cpu_has_veic || cpu_has_vint) {
1531 		unsigned long sr = set_c0_status(ST0_BEV);
1532 		write_c0_ebase(ebase);
1533 		write_c0_status(sr);
1534 		/* Setting vector spacing enables EI/VI mode  */
1535 		change_c0_intctl(0x3e0, VECTORSPACING);
1536 	}
1537 	if (cpu_has_divec) {
1538 		if (cpu_has_mipsmt) {
1539 			unsigned int vpflags = dvpe();
1540 			set_c0_cause(CAUSEF_IV);
1541 			evpe(vpflags);
1542 		} else
1543 			set_c0_cause(CAUSEF_IV);
1544 	}
1545 
1546 	/*
1547 	 * Before R2 both interrupt numbers were fixed to 7, so on R2 only:
1548 	 *
1549 	 *  o read IntCtl.IPTI to determine the timer interrupt
1550 	 *  o read IntCtl.IPPCI to determine the performance counter interrupt
1551 	 */
1552 	if (cpu_has_mips_r2) {
1553 		cp0_compare_irq_shift = CAUSEB_TI - CAUSEB_IP;
1554 		cp0_compare_irq = (read_c0_intctl() >> INTCTLB_IPTI) & 7;
1555 		cp0_perfcount_irq = (read_c0_intctl() >> INTCTLB_IPPCI) & 7;
1556 		if (cp0_perfcount_irq == cp0_compare_irq)
1557 			cp0_perfcount_irq = -1;
1558 	} else {
1559 		cp0_compare_irq = CP0_LEGACY_COMPARE_IRQ;
1560 		cp0_compare_irq_shift = cp0_compare_irq;
1561 		cp0_perfcount_irq = -1;
1562 	}
1563 
1564 #ifdef CONFIG_MIPS_MT_SMTC
1565 	}
1566 #endif /* CONFIG_MIPS_MT_SMTC */
1567 
1568 	cpu_data[cpu].asid_cache = ASID_FIRST_VERSION;
1569 	TLBMISS_HANDLER_SETUP();
1570 
1571 	atomic_inc(&init_mm.mm_count);
1572 	current->active_mm = &init_mm;
1573 	BUG_ON(current->mm);
1574 	enter_lazy_tlb(&init_mm, current);
1575 
1576 #ifdef CONFIG_MIPS_MT_SMTC
1577 	if (bootTC) {
1578 #endif /* CONFIG_MIPS_MT_SMTC */
1579 		cpu_cache_init();
1580 		tlb_init();
1581 #ifdef CONFIG_MIPS_MT_SMTC
1582 	} else if (!secondaryTC) {
1583 		/*
1584 		 * First TC in non-boot VPE must do subset of tlb_init()
1585 		 * for MMU countrol registers.
1586 		 */
1587 		write_c0_pagemask(PM_DEFAULT_MASK);
1588 		write_c0_wired(0);
1589 	}
1590 #endif /* CONFIG_MIPS_MT_SMTC */
1591 }
1592 
1593 /* Install CPU exception handler */
1594 void __init set_handler(unsigned long offset, void *addr, unsigned long size)
1595 {
1596 	memcpy((void *)(ebase + offset), addr, size);
1597 	local_flush_icache_range(ebase + offset, ebase + offset + size);
1598 }
1599 
1600 static char panic_null_cerr[] __cpuinitdata =
1601 	"Trying to set NULL cache error exception handler";
1602 
1603 /*
1604  * Install uncached CPU exception handler.
1605  * This is suitable only for the cache error exception which is the only
1606  * exception handler that is being run uncached.
1607  */
1608 void __cpuinit set_uncached_handler(unsigned long offset, void *addr,
1609 	unsigned long size)
1610 {
1611 	unsigned long uncached_ebase = CKSEG1ADDR(ebase);
1612 
1613 	if (!addr)
1614 		panic(panic_null_cerr);
1615 
1616 	memcpy((void *)(uncached_ebase + offset), addr, size);
1617 }
1618 
1619 static int __initdata rdhwr_noopt;
1620 static int __init set_rdhwr_noopt(char *str)
1621 {
1622 	rdhwr_noopt = 1;
1623 	return 1;
1624 }
1625 
1626 __setup("rdhwr_noopt", set_rdhwr_noopt);
1627 
1628 void __init trap_init(void)
1629 {
1630 	extern char except_vec3_generic, except_vec3_r4000;
1631 	extern char except_vec4;
1632 	unsigned long i;
1633 	int rollback;
1634 
1635 	check_wait();
1636 	rollback = (cpu_wait == r4k_wait);
1637 
1638 #if defined(CONFIG_KGDB)
1639 	if (kgdb_early_setup)
1640 		return;	/* Already done */
1641 #endif
1642 
1643 	if (cpu_has_veic || cpu_has_vint) {
1644 		unsigned long size = 0x200 + VECTORSPACING*64;
1645 		ebase = (unsigned long)
1646 			__alloc_bootmem(size, 1 << fls(size), 0);
1647 	} else {
1648 		ebase = CKSEG0;
1649 		if (cpu_has_mips_r2)
1650 			ebase += (read_c0_ebase() & 0x3ffff000);
1651 	}
1652 
1653 	per_cpu_trap_init();
1654 
1655 	/*
1656 	 * Copy the generic exception handlers to their final destination.
1657 	 * This will be overriden later as suitable for a particular
1658 	 * configuration.
1659 	 */
1660 	set_handler(0x180, &except_vec3_generic, 0x80);
1661 
1662 	/*
1663 	 * Setup default vectors
1664 	 */
1665 	for (i = 0; i <= 31; i++)
1666 		set_except_vector(i, handle_reserved);
1667 
1668 	/*
1669 	 * Copy the EJTAG debug exception vector handler code to it's final
1670 	 * destination.
1671 	 */
1672 	if (cpu_has_ejtag && board_ejtag_handler_setup)
1673 		board_ejtag_handler_setup();
1674 
1675 	/*
1676 	 * Only some CPUs have the watch exceptions.
1677 	 */
1678 	if (cpu_has_watch)
1679 		set_except_vector(23, handle_watch);
1680 
1681 	/*
1682 	 * Initialise interrupt handlers
1683 	 */
1684 	if (cpu_has_veic || cpu_has_vint) {
1685 		int nvec = cpu_has_veic ? 64 : 8;
1686 		for (i = 0; i < nvec; i++)
1687 			set_vi_handler(i, NULL);
1688 	}
1689 	else if (cpu_has_divec)
1690 		set_handler(0x200, &except_vec4, 0x8);
1691 
1692 	/*
1693 	 * Some CPUs can enable/disable for cache parity detection, but does
1694 	 * it different ways.
1695 	 */
1696 	parity_protection_init();
1697 
1698 	/*
1699 	 * The Data Bus Errors / Instruction Bus Errors are signaled
1700 	 * by external hardware.  Therefore these two exceptions
1701 	 * may have board specific handlers.
1702 	 */
1703 	if (board_be_init)
1704 		board_be_init();
1705 
1706 	set_except_vector(0, rollback ? rollback_handle_int : handle_int);
1707 	set_except_vector(1, handle_tlbm);
1708 	set_except_vector(2, handle_tlbl);
1709 	set_except_vector(3, handle_tlbs);
1710 
1711 	set_except_vector(4, handle_adel);
1712 	set_except_vector(5, handle_ades);
1713 
1714 	set_except_vector(6, handle_ibe);
1715 	set_except_vector(7, handle_dbe);
1716 
1717 	set_except_vector(8, handle_sys);
1718 	set_except_vector(9, handle_bp);
1719 	set_except_vector(10, rdhwr_noopt ? handle_ri :
1720 			  (cpu_has_vtag_icache ?
1721 			   handle_ri_rdhwr_vivt : handle_ri_rdhwr));
1722 	set_except_vector(11, handle_cpu);
1723 	set_except_vector(12, handle_ov);
1724 	set_except_vector(13, handle_tr);
1725 
1726 	if (current_cpu_type() == CPU_R6000 ||
1727 	    current_cpu_type() == CPU_R6000A) {
1728 		/*
1729 		 * The R6000 is the only R-series CPU that features a machine
1730 		 * check exception (similar to the R4000 cache error) and
1731 		 * unaligned ldc1/sdc1 exception.  The handlers have not been
1732 		 * written yet.  Well, anyway there is no R6000 machine on the
1733 		 * current list of targets for Linux/MIPS.
1734 		 * (Duh, crap, there is someone with a triple R6k machine)
1735 		 */
1736 		//set_except_vector(14, handle_mc);
1737 		//set_except_vector(15, handle_ndc);
1738 	}
1739 
1740 
1741 	if (board_nmi_handler_setup)
1742 		board_nmi_handler_setup();
1743 
1744 	if (cpu_has_fpu && !cpu_has_nofpuex)
1745 		set_except_vector(15, handle_fpe);
1746 
1747 	set_except_vector(22, handle_mdmx);
1748 
1749 	if (cpu_has_mcheck)
1750 		set_except_vector(24, handle_mcheck);
1751 
1752 	if (cpu_has_mipsmt)
1753 		set_except_vector(25, handle_mt);
1754 
1755 	set_except_vector(26, handle_dsp);
1756 
1757 	if (cpu_has_vce)
1758 		/* Special exception: R4[04]00 uses also the divec space. */
1759 		memcpy((void *)(ebase + 0x180), &except_vec3_r4000, 0x100);
1760 	else if (cpu_has_4kex)
1761 		memcpy((void *)(ebase + 0x180), &except_vec3_generic, 0x80);
1762 	else
1763 		memcpy((void *)(ebase + 0x080), &except_vec3_generic, 0x80);
1764 
1765 	local_flush_icache_range(ebase, ebase + 0x400);
1766 	flush_tlb_handlers();
1767 
1768 	sort_extable(__start___dbe_table, __stop___dbe_table);
1769 
1770 	cu2_notifier(default_cu2_call, 0x80000000);	/* Run last  */
1771 }
1772