xref: /linux/arch/mips/kernel/traps.c (revision 04c71976500352d02f60616d2b960267d8c5fe24)
1 /*
2  * This file is subject to the terms and conditions of the GNU General Public
3  * License.  See the file "COPYING" in the main directory of this archive
4  * for more details.
5  *
6  * Copyright (C) 1994 - 1999, 2000, 01, 06 Ralf Baechle
7  * Copyright (C) 1995, 1996 Paul M. Antoine
8  * Copyright (C) 1998 Ulf Carlsson
9  * Copyright (C) 1999 Silicon Graphics, Inc.
10  * Kevin D. Kissell, kevink@mips.com and Carsten Langgaard, carstenl@mips.com
11  * Copyright (C) 2000, 01 MIPS Technologies, Inc.
12  * Copyright (C) 2002, 2003, 2004, 2005  Maciej W. Rozycki
13  */
14 #include <linux/bug.h>
15 #include <linux/init.h>
16 #include <linux/mm.h>
17 #include <linux/module.h>
18 #include <linux/sched.h>
19 #include <linux/smp.h>
20 #include <linux/spinlock.h>
21 #include <linux/kallsyms.h>
22 #include <linux/bootmem.h>
23 #include <linux/interrupt.h>
24 
25 #include <asm/bootinfo.h>
26 #include <asm/branch.h>
27 #include <asm/break.h>
28 #include <asm/cpu.h>
29 #include <asm/dsp.h>
30 #include <asm/fpu.h>
31 #include <asm/mipsregs.h>
32 #include <asm/mipsmtregs.h>
33 #include <asm/module.h>
34 #include <asm/pgtable.h>
35 #include <asm/ptrace.h>
36 #include <asm/sections.h>
37 #include <asm/system.h>
38 #include <asm/tlbdebug.h>
39 #include <asm/traps.h>
40 #include <asm/uaccess.h>
41 #include <asm/mmu_context.h>
42 #include <asm/types.h>
43 #include <asm/stacktrace.h>
44 
45 extern asmlinkage void handle_int(void);
46 extern asmlinkage void handle_tlbm(void);
47 extern asmlinkage void handle_tlbl(void);
48 extern asmlinkage void handle_tlbs(void);
49 extern asmlinkage void handle_adel(void);
50 extern asmlinkage void handle_ades(void);
51 extern asmlinkage void handle_ibe(void);
52 extern asmlinkage void handle_dbe(void);
53 extern asmlinkage void handle_sys(void);
54 extern asmlinkage void handle_bp(void);
55 extern asmlinkage void handle_ri(void);
56 extern asmlinkage void handle_ri_rdhwr_vivt(void);
57 extern asmlinkage void handle_ri_rdhwr(void);
58 extern asmlinkage void handle_cpu(void);
59 extern asmlinkage void handle_ov(void);
60 extern asmlinkage void handle_tr(void);
61 extern asmlinkage void handle_fpe(void);
62 extern asmlinkage void handle_mdmx(void);
63 extern asmlinkage void handle_watch(void);
64 extern asmlinkage void handle_mt(void);
65 extern asmlinkage void handle_dsp(void);
66 extern asmlinkage void handle_mcheck(void);
67 extern asmlinkage void handle_reserved(void);
68 
69 extern int fpu_emulator_cop1Handler(struct pt_regs *xcp,
70 	struct mips_fpu_struct *ctx, int has_fpu);
71 
72 void (*board_watchpoint_handler)(struct pt_regs *regs);
73 void (*board_be_init)(void);
74 int (*board_be_handler)(struct pt_regs *regs, int is_fixup);
75 void (*board_nmi_handler_setup)(void);
76 void (*board_ejtag_handler_setup)(void);
77 void (*board_bind_eic_interrupt)(int irq, int regset);
78 
79 
80 static void show_raw_backtrace(unsigned long reg29)
81 {
82 	unsigned long *sp = (unsigned long *)reg29;
83 	unsigned long addr;
84 
85 	printk("Call Trace:");
86 #ifdef CONFIG_KALLSYMS
87 	printk("\n");
88 #endif
89 	while (!kstack_end(sp)) {
90 		addr = *sp++;
91 		if (__kernel_text_address(addr))
92 			print_ip_sym(addr);
93 	}
94 	printk("\n");
95 }
96 
97 #ifdef CONFIG_KALLSYMS
98 int raw_show_trace;
99 static int __init set_raw_show_trace(char *str)
100 {
101 	raw_show_trace = 1;
102 	return 1;
103 }
104 __setup("raw_show_trace", set_raw_show_trace);
105 #endif
106 
107 static void show_backtrace(struct task_struct *task, const struct pt_regs *regs)
108 {
109 	unsigned long sp = regs->regs[29];
110 	unsigned long ra = regs->regs[31];
111 	unsigned long pc = regs->cp0_epc;
112 
113 	if (raw_show_trace || !__kernel_text_address(pc)) {
114 		show_raw_backtrace(sp);
115 		return;
116 	}
117 	printk("Call Trace:\n");
118 	do {
119 		print_ip_sym(pc);
120 		pc = unwind_stack(task, &sp, pc, &ra);
121 	} while (pc);
122 	printk("\n");
123 }
124 
125 /*
126  * This routine abuses get_user()/put_user() to reference pointers
127  * with at least a bit of error checking ...
128  */
129 static void show_stacktrace(struct task_struct *task,
130 	const struct pt_regs *regs)
131 {
132 	const int field = 2 * sizeof(unsigned long);
133 	long stackdata;
134 	int i;
135 	unsigned long __user *sp = (unsigned long __user *)regs->regs[29];
136 
137 	printk("Stack :");
138 	i = 0;
139 	while ((unsigned long) sp & (PAGE_SIZE - 1)) {
140 		if (i && ((i % (64 / field)) == 0))
141 			printk("\n       ");
142 		if (i > 39) {
143 			printk(" ...");
144 			break;
145 		}
146 
147 		if (__get_user(stackdata, sp++)) {
148 			printk(" (Bad stack address)");
149 			break;
150 		}
151 
152 		printk(" %0*lx", field, stackdata);
153 		i++;
154 	}
155 	printk("\n");
156 	show_backtrace(task, regs);
157 }
158 
159 void show_stack(struct task_struct *task, unsigned long *sp)
160 {
161 	struct pt_regs regs;
162 	if (sp) {
163 		regs.regs[29] = (unsigned long)sp;
164 		regs.regs[31] = 0;
165 		regs.cp0_epc = 0;
166 	} else {
167 		if (task && task != current) {
168 			regs.regs[29] = task->thread.reg29;
169 			regs.regs[31] = 0;
170 			regs.cp0_epc = task->thread.reg31;
171 		} else {
172 			prepare_frametrace(&regs);
173 		}
174 	}
175 	show_stacktrace(task, &regs);
176 }
177 
178 /*
179  * The architecture-independent dump_stack generator
180  */
181 void dump_stack(void)
182 {
183 	struct pt_regs regs;
184 
185 	prepare_frametrace(&regs);
186 	show_backtrace(current, &regs);
187 }
188 
189 EXPORT_SYMBOL(dump_stack);
190 
191 static void show_code(unsigned int __user *pc)
192 {
193 	long i;
194 
195 	printk("\nCode:");
196 
197 	for(i = -3 ; i < 6 ; i++) {
198 		unsigned int insn;
199 		if (__get_user(insn, pc + i)) {
200 			printk(" (Bad address in epc)\n");
201 			break;
202 		}
203 		printk("%c%08x%c", (i?' ':'<'), insn, (i?' ':'>'));
204 	}
205 }
206 
207 static void __show_regs(const struct pt_regs *regs)
208 {
209 	const int field = 2 * sizeof(unsigned long);
210 	unsigned int cause = regs->cp0_cause;
211 	int i;
212 
213 	printk("Cpu %d\n", smp_processor_id());
214 
215 	/*
216 	 * Saved main processor registers
217 	 */
218 	for (i = 0; i < 32; ) {
219 		if ((i % 4) == 0)
220 			printk("$%2d   :", i);
221 		if (i == 0)
222 			printk(" %0*lx", field, 0UL);
223 		else if (i == 26 || i == 27)
224 			printk(" %*s", field, "");
225 		else
226 			printk(" %0*lx", field, regs->regs[i]);
227 
228 		i++;
229 		if ((i % 4) == 0)
230 			printk("\n");
231 	}
232 
233 #ifdef CONFIG_CPU_HAS_SMARTMIPS
234 	printk("Acx    : %0*lx\n", field, regs->acx);
235 #endif
236 	printk("Hi    : %0*lx\n", field, regs->hi);
237 	printk("Lo    : %0*lx\n", field, regs->lo);
238 
239 	/*
240 	 * Saved cp0 registers
241 	 */
242 	printk("epc   : %0*lx ", field, regs->cp0_epc);
243 	print_symbol("%s ", regs->cp0_epc);
244 	printk("    %s\n", print_tainted());
245 	printk("ra    : %0*lx ", field, regs->regs[31]);
246 	print_symbol("%s\n", regs->regs[31]);
247 
248 	printk("Status: %08x    ", (uint32_t) regs->cp0_status);
249 
250 	if (current_cpu_data.isa_level == MIPS_CPU_ISA_I) {
251 		if (regs->cp0_status & ST0_KUO)
252 			printk("KUo ");
253 		if (regs->cp0_status & ST0_IEO)
254 			printk("IEo ");
255 		if (regs->cp0_status & ST0_KUP)
256 			printk("KUp ");
257 		if (regs->cp0_status & ST0_IEP)
258 			printk("IEp ");
259 		if (regs->cp0_status & ST0_KUC)
260 			printk("KUc ");
261 		if (regs->cp0_status & ST0_IEC)
262 			printk("IEc ");
263 	} else {
264 		if (regs->cp0_status & ST0_KX)
265 			printk("KX ");
266 		if (regs->cp0_status & ST0_SX)
267 			printk("SX ");
268 		if (regs->cp0_status & ST0_UX)
269 			printk("UX ");
270 		switch (regs->cp0_status & ST0_KSU) {
271 		case KSU_USER:
272 			printk("USER ");
273 			break;
274 		case KSU_SUPERVISOR:
275 			printk("SUPERVISOR ");
276 			break;
277 		case KSU_KERNEL:
278 			printk("KERNEL ");
279 			break;
280 		default:
281 			printk("BAD_MODE ");
282 			break;
283 		}
284 		if (regs->cp0_status & ST0_ERL)
285 			printk("ERL ");
286 		if (regs->cp0_status & ST0_EXL)
287 			printk("EXL ");
288 		if (regs->cp0_status & ST0_IE)
289 			printk("IE ");
290 	}
291 	printk("\n");
292 
293 	printk("Cause : %08x\n", cause);
294 
295 	cause = (cause & CAUSEF_EXCCODE) >> CAUSEB_EXCCODE;
296 	if (1 <= cause && cause <= 5)
297 		printk("BadVA : %0*lx\n", field, regs->cp0_badvaddr);
298 
299 	printk("PrId  : %08x (%s)\n", read_c0_prid(),
300 	       cpu_name_string());
301 }
302 
303 /*
304  * FIXME: really the generic show_regs should take a const pointer argument.
305  */
306 void show_regs(struct pt_regs *regs)
307 {
308 	__show_regs((struct pt_regs *)regs);
309 }
310 
311 void show_registers(const struct pt_regs *regs)
312 {
313 	__show_regs(regs);
314 	print_modules();
315 	printk("Process %s (pid: %d, threadinfo=%p, task=%p)\n",
316 	        current->comm, current->pid, current_thread_info(), current);
317 	show_stacktrace(current, regs);
318 	show_code((unsigned int __user *) regs->cp0_epc);
319 	printk("\n");
320 }
321 
322 static DEFINE_SPINLOCK(die_lock);
323 
324 void __noreturn die(const char * str, const struct pt_regs * regs)
325 {
326 	static int die_counter;
327 #ifdef CONFIG_MIPS_MT_SMTC
328 	unsigned long dvpret = dvpe();
329 #endif /* CONFIG_MIPS_MT_SMTC */
330 
331 	console_verbose();
332 	spin_lock_irq(&die_lock);
333 	bust_spinlocks(1);
334 #ifdef CONFIG_MIPS_MT_SMTC
335 	mips_mt_regdump(dvpret);
336 #endif /* CONFIG_MIPS_MT_SMTC */
337 	printk("%s[#%d]:\n", str, ++die_counter);
338 	show_registers(regs);
339 	add_taint(TAINT_DIE);
340 	spin_unlock_irq(&die_lock);
341 
342 	if (in_interrupt())
343 		panic("Fatal exception in interrupt");
344 
345 	if (panic_on_oops) {
346 		printk(KERN_EMERG "Fatal exception: panic in 5 seconds\n");
347 		ssleep(5);
348 		panic("Fatal exception");
349 	}
350 
351 	do_exit(SIGSEGV);
352 }
353 
354 extern const struct exception_table_entry __start___dbe_table[];
355 extern const struct exception_table_entry __stop___dbe_table[];
356 
357 __asm__(
358 "	.section	__dbe_table, \"a\"\n"
359 "	.previous			\n");
360 
361 /* Given an address, look for it in the exception tables. */
362 static const struct exception_table_entry *search_dbe_tables(unsigned long addr)
363 {
364 	const struct exception_table_entry *e;
365 
366 	e = search_extable(__start___dbe_table, __stop___dbe_table - 1, addr);
367 	if (!e)
368 		e = search_module_dbetables(addr);
369 	return e;
370 }
371 
372 asmlinkage void do_be(struct pt_regs *regs)
373 {
374 	const int field = 2 * sizeof(unsigned long);
375 	const struct exception_table_entry *fixup = NULL;
376 	int data = regs->cp0_cause & 4;
377 	int action = MIPS_BE_FATAL;
378 
379 	/* XXX For now.  Fixme, this searches the wrong table ...  */
380 	if (data && !user_mode(regs))
381 		fixup = search_dbe_tables(exception_epc(regs));
382 
383 	if (fixup)
384 		action = MIPS_BE_FIXUP;
385 
386 	if (board_be_handler)
387 		action = board_be_handler(regs, fixup != NULL);
388 
389 	switch (action) {
390 	case MIPS_BE_DISCARD:
391 		return;
392 	case MIPS_BE_FIXUP:
393 		if (fixup) {
394 			regs->cp0_epc = fixup->nextinsn;
395 			return;
396 		}
397 		break;
398 	default:
399 		break;
400 	}
401 
402 	/*
403 	 * Assume it would be too dangerous to continue ...
404 	 */
405 	printk(KERN_ALERT "%s bus error, epc == %0*lx, ra == %0*lx\n",
406 	       data ? "Data" : "Instruction",
407 	       field, regs->cp0_epc, field, regs->regs[31]);
408 	die_if_kernel("Oops", regs);
409 	force_sig(SIGBUS, current);
410 }
411 
412 /*
413  * ll/sc emulation
414  */
415 
416 #define OPCODE 0xfc000000
417 #define BASE   0x03e00000
418 #define RT     0x001f0000
419 #define OFFSET 0x0000ffff
420 #define LL     0xc0000000
421 #define SC     0xe0000000
422 #define SPEC3  0x7c000000
423 #define RD     0x0000f800
424 #define FUNC   0x0000003f
425 #define RDHWR  0x0000003b
426 
427 /*
428  * The ll_bit is cleared by r*_switch.S
429  */
430 
431 unsigned long ll_bit;
432 
433 static struct task_struct *ll_task = NULL;
434 
435 static inline void simulate_ll(struct pt_regs *regs, unsigned int opcode)
436 {
437 	unsigned long value, __user *vaddr;
438 	long offset;
439 	int signal = 0;
440 
441 	/*
442 	 * analyse the ll instruction that just caused a ri exception
443 	 * and put the referenced address to addr.
444 	 */
445 
446 	/* sign extend offset */
447 	offset = opcode & OFFSET;
448 	offset <<= 16;
449 	offset >>= 16;
450 
451 	vaddr = (unsigned long __user *)
452 	        ((unsigned long)(regs->regs[(opcode & BASE) >> 21]) + offset);
453 
454 	if ((unsigned long)vaddr & 3) {
455 		signal = SIGBUS;
456 		goto sig;
457 	}
458 	if (get_user(value, vaddr)) {
459 		signal = SIGSEGV;
460 		goto sig;
461 	}
462 
463 	preempt_disable();
464 
465 	if (ll_task == NULL || ll_task == current) {
466 		ll_bit = 1;
467 	} else {
468 		ll_bit = 0;
469 	}
470 	ll_task = current;
471 
472 	preempt_enable();
473 
474 	compute_return_epc(regs);
475 
476 	regs->regs[(opcode & RT) >> 16] = value;
477 
478 	return;
479 
480 sig:
481 	force_sig(signal, current);
482 }
483 
484 static inline void simulate_sc(struct pt_regs *regs, unsigned int opcode)
485 {
486 	unsigned long __user *vaddr;
487 	unsigned long reg;
488 	long offset;
489 	int signal = 0;
490 
491 	/*
492 	 * analyse the sc instruction that just caused a ri exception
493 	 * and put the referenced address to addr.
494 	 */
495 
496 	/* sign extend offset */
497 	offset = opcode & OFFSET;
498 	offset <<= 16;
499 	offset >>= 16;
500 
501 	vaddr = (unsigned long __user *)
502 	        ((unsigned long)(regs->regs[(opcode & BASE) >> 21]) + offset);
503 	reg = (opcode & RT) >> 16;
504 
505 	if ((unsigned long)vaddr & 3) {
506 		signal = SIGBUS;
507 		goto sig;
508 	}
509 
510 	preempt_disable();
511 
512 	if (ll_bit == 0 || ll_task != current) {
513 		compute_return_epc(regs);
514 		regs->regs[reg] = 0;
515 		preempt_enable();
516 		return;
517 	}
518 
519 	preempt_enable();
520 
521 	if (put_user(regs->regs[reg], vaddr)) {
522 		signal = SIGSEGV;
523 		goto sig;
524 	}
525 
526 	compute_return_epc(regs);
527 	regs->regs[reg] = 1;
528 
529 	return;
530 
531 sig:
532 	force_sig(signal, current);
533 }
534 
535 /*
536  * ll uses the opcode of lwc0 and sc uses the opcode of swc0.  That is both
537  * opcodes are supposed to result in coprocessor unusable exceptions if
538  * executed on ll/sc-less processors.  That's the theory.  In practice a
539  * few processors such as NEC's VR4100 throw reserved instruction exceptions
540  * instead, so we're doing the emulation thing in both exception handlers.
541  */
542 static inline int simulate_llsc(struct pt_regs *regs)
543 {
544 	unsigned int opcode;
545 
546 	if (get_user(opcode, (unsigned int __user *) exception_epc(regs)))
547 		goto out_sigsegv;
548 
549 	if ((opcode & OPCODE) == LL) {
550 		simulate_ll(regs, opcode);
551 		return 0;
552 	}
553 	if ((opcode & OPCODE) == SC) {
554 		simulate_sc(regs, opcode);
555 		return 0;
556 	}
557 
558 	return -EFAULT;			/* Strange things going on ... */
559 
560 out_sigsegv:
561 	force_sig(SIGSEGV, current);
562 	return -EFAULT;
563 }
564 
565 /*
566  * Simulate trapping 'rdhwr' instructions to provide user accessible
567  * registers not implemented in hardware.  The only current use of this
568  * is the thread area pointer.
569  */
570 static inline int simulate_rdhwr(struct pt_regs *regs)
571 {
572 	struct thread_info *ti = task_thread_info(current);
573 	unsigned int opcode;
574 
575 	if (get_user(opcode, (unsigned int __user *) exception_epc(regs)))
576 		goto out_sigsegv;
577 
578 	if (unlikely(compute_return_epc(regs)))
579 		return -EFAULT;
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 29:
586 				regs->regs[rt] = ti->tp_value;
587 				return 0;
588 			default:
589 				return -EFAULT;
590 		}
591 	}
592 
593 	/* Not ours.  */
594 	return -EFAULT;
595 
596 out_sigsegv:
597 	force_sig(SIGSEGV, current);
598 	return -EFAULT;
599 }
600 
601 asmlinkage void do_ov(struct pt_regs *regs)
602 {
603 	siginfo_t info;
604 
605 	die_if_kernel("Integer overflow", regs);
606 
607 	info.si_code = FPE_INTOVF;
608 	info.si_signo = SIGFPE;
609 	info.si_errno = 0;
610 	info.si_addr = (void __user *) regs->cp0_epc;
611 	force_sig_info(SIGFPE, &info, current);
612 }
613 
614 /*
615  * XXX Delayed fp exceptions when doing a lazy ctx switch XXX
616  */
617 asmlinkage void do_fpe(struct pt_regs *regs, unsigned long fcr31)
618 {
619 	siginfo_t info;
620 
621 	die_if_kernel("FP exception in kernel code", regs);
622 
623 	if (fcr31 & FPU_CSR_UNI_X) {
624 		int sig;
625 
626 		/*
627 		 * Unimplemented operation exception.  If we've got the full
628 		 * software emulator on-board, let's use it...
629 		 *
630 		 * Force FPU to dump state into task/thread context.  We're
631 		 * moving a lot of data here for what is probably a single
632 		 * instruction, but the alternative is to pre-decode the FP
633 		 * register operands before invoking the emulator, which seems
634 		 * a bit extreme for what should be an infrequent event.
635 		 */
636 		/* Ensure 'resume' not overwrite saved fp context again. */
637 		lose_fpu(1);
638 
639 		/* Run the emulator */
640 		sig = fpu_emulator_cop1Handler(regs, &current->thread.fpu, 1);
641 
642 		/*
643 		 * We can't allow the emulated instruction to leave any of
644 		 * the cause bit set in $fcr31.
645 		 */
646 		current->thread.fpu.fcr31 &= ~FPU_CSR_ALL_X;
647 
648 		/* Restore the hardware register state */
649 		own_fpu(1);	/* Using the FPU again.  */
650 
651 		/* If something went wrong, signal */
652 		if (sig)
653 			force_sig(sig, current);
654 
655 		return;
656 	} else if (fcr31 & FPU_CSR_INV_X)
657 		info.si_code = FPE_FLTINV;
658 	else if (fcr31 & FPU_CSR_DIV_X)
659 		info.si_code = FPE_FLTDIV;
660 	else if (fcr31 & FPU_CSR_OVF_X)
661 		info.si_code = FPE_FLTOVF;
662 	else if (fcr31 & FPU_CSR_UDF_X)
663 		info.si_code = FPE_FLTUND;
664 	else if (fcr31 & FPU_CSR_INE_X)
665 		info.si_code = FPE_FLTRES;
666 	else
667 		info.si_code = __SI_FAULT;
668 	info.si_signo = SIGFPE;
669 	info.si_errno = 0;
670 	info.si_addr = (void __user *) regs->cp0_epc;
671 	force_sig_info(SIGFPE, &info, current);
672 }
673 
674 asmlinkage void do_bp(struct pt_regs *regs)
675 {
676 	unsigned int opcode, bcode;
677 	siginfo_t info;
678 
679 	if (__get_user(opcode, (unsigned int __user *) exception_epc(regs)))
680 		goto out_sigsegv;
681 
682 	/*
683 	 * There is the ancient bug in the MIPS assemblers that the break
684 	 * code starts left to bit 16 instead to bit 6 in the opcode.
685 	 * Gas is bug-compatible, but not always, grrr...
686 	 * We handle both cases with a simple heuristics.  --macro
687 	 */
688 	bcode = ((opcode >> 6) & ((1 << 20) - 1));
689 	if (bcode < (1 << 10))
690 		bcode <<= 10;
691 
692 	/*
693 	 * (A short test says that IRIX 5.3 sends SIGTRAP for all break
694 	 * insns, even for break codes that indicate arithmetic failures.
695 	 * Weird ...)
696 	 * But should we continue the brokenness???  --macro
697 	 */
698 	switch (bcode) {
699 	case BRK_OVERFLOW << 10:
700 	case BRK_DIVZERO << 10:
701 		die_if_kernel("Break instruction in kernel code", regs);
702 		if (bcode == (BRK_DIVZERO << 10))
703 			info.si_code = FPE_INTDIV;
704 		else
705 			info.si_code = FPE_INTOVF;
706 		info.si_signo = SIGFPE;
707 		info.si_errno = 0;
708 		info.si_addr = (void __user *) regs->cp0_epc;
709 		force_sig_info(SIGFPE, &info, current);
710 		break;
711 	case BRK_BUG:
712 		die("Kernel bug detected", regs);
713 		break;
714 	default:
715 		die_if_kernel("Break instruction in kernel code", regs);
716 		force_sig(SIGTRAP, current);
717 	}
718 	return;
719 
720 out_sigsegv:
721 	force_sig(SIGSEGV, current);
722 }
723 
724 asmlinkage void do_tr(struct pt_regs *regs)
725 {
726 	unsigned int opcode, tcode = 0;
727 	siginfo_t info;
728 
729 	if (__get_user(opcode, (unsigned int __user *) exception_epc(regs)))
730 		goto out_sigsegv;
731 
732 	/* Immediate versions don't provide a code.  */
733 	if (!(opcode & OPCODE))
734 		tcode = ((opcode >> 6) & ((1 << 10) - 1));
735 
736 	/*
737 	 * (A short test says that IRIX 5.3 sends SIGTRAP for all trap
738 	 * insns, even for trap codes that indicate arithmetic failures.
739 	 * Weird ...)
740 	 * But should we continue the brokenness???  --macro
741 	 */
742 	switch (tcode) {
743 	case BRK_OVERFLOW:
744 	case BRK_DIVZERO:
745 		die_if_kernel("Trap instruction in kernel code", regs);
746 		if (tcode == BRK_DIVZERO)
747 			info.si_code = FPE_INTDIV;
748 		else
749 			info.si_code = FPE_INTOVF;
750 		info.si_signo = SIGFPE;
751 		info.si_errno = 0;
752 		info.si_addr = (void __user *) regs->cp0_epc;
753 		force_sig_info(SIGFPE, &info, current);
754 		break;
755 	case BRK_BUG:
756 		die("Kernel bug detected", regs);
757 		break;
758 	default:
759 		die_if_kernel("Trap instruction in kernel code", regs);
760 		force_sig(SIGTRAP, current);
761 	}
762 	return;
763 
764 out_sigsegv:
765 	force_sig(SIGSEGV, current);
766 }
767 
768 asmlinkage void do_ri(struct pt_regs *regs)
769 {
770 	die_if_kernel("Reserved instruction in kernel code", regs);
771 
772 	if (!cpu_has_llsc)
773 		if (!simulate_llsc(regs))
774 			return;
775 
776 	if (!simulate_rdhwr(regs))
777 		return;
778 
779 	force_sig(SIGILL, current);
780 }
781 
782 /*
783  * MIPS MT processors may have fewer FPU contexts than CPU threads. If we've
784  * emulated more than some threshold number of instructions, force migration to
785  * a "CPU" that has FP support.
786  */
787 static void mt_ase_fp_affinity(void)
788 {
789 #ifdef CONFIG_MIPS_MT_FPAFF
790 	if (mt_fpemul_threshold > 0 &&
791 	     ((current->thread.emulated_fp++ > mt_fpemul_threshold))) {
792 		/*
793 		 * If there's no FPU present, or if the application has already
794 		 * restricted the allowed set to exclude any CPUs with FPUs,
795 		 * we'll skip the procedure.
796 		 */
797 		if (cpus_intersects(current->cpus_allowed, mt_fpu_cpumask)) {
798 			cpumask_t tmask;
799 
800 			cpus_and(tmask, current->thread.user_cpus_allowed,
801 			         mt_fpu_cpumask);
802 			set_cpus_allowed(current, tmask);
803 			set_thread_flag(TIF_FPUBOUND);
804 		}
805 	}
806 #endif /* CONFIG_MIPS_MT_FPAFF */
807 }
808 
809 asmlinkage void do_cpu(struct pt_regs *regs)
810 {
811 	unsigned int cpid;
812 
813 	die_if_kernel("do_cpu invoked from kernel context!", regs);
814 
815 	cpid = (regs->cp0_cause >> CAUSEB_CE) & 3;
816 
817 	switch (cpid) {
818 	case 0:
819 		if (!cpu_has_llsc)
820 			if (!simulate_llsc(regs))
821 				return;
822 
823 		if (!simulate_rdhwr(regs))
824 			return;
825 
826 		break;
827 
828 	case 1:
829 		if (used_math())	/* Using the FPU again.  */
830 			own_fpu(1);
831 		else {			/* First time FPU user.  */
832 			init_fpu();
833 			set_used_math();
834 		}
835 
836 		if (!raw_cpu_has_fpu) {
837 			int sig;
838 			sig = fpu_emulator_cop1Handler(regs,
839 						&current->thread.fpu, 0);
840 			if (sig)
841 				force_sig(sig, current);
842 			else
843 				mt_ase_fp_affinity();
844 		}
845 
846 		return;
847 
848 	case 2:
849 	case 3:
850 		break;
851 	}
852 
853 	force_sig(SIGILL, current);
854 }
855 
856 asmlinkage void do_mdmx(struct pt_regs *regs)
857 {
858 	force_sig(SIGILL, current);
859 }
860 
861 asmlinkage void do_watch(struct pt_regs *regs)
862 {
863 	if (board_watchpoint_handler) {
864 		(*board_watchpoint_handler)(regs);
865 		return;
866 	}
867 
868 	/*
869 	 * We use the watch exception where available to detect stack
870 	 * overflows.
871 	 */
872 	dump_tlb_all();
873 	show_regs(regs);
874 	panic("Caught WATCH exception - probably caused by stack overflow.");
875 }
876 
877 asmlinkage void do_mcheck(struct pt_regs *regs)
878 {
879 	const int field = 2 * sizeof(unsigned long);
880 	int multi_match = regs->cp0_status & ST0_TS;
881 
882 	show_regs(regs);
883 
884 	if (multi_match) {
885 		printk("Index   : %0x\n", read_c0_index());
886 		printk("Pagemask: %0x\n", read_c0_pagemask());
887 		printk("EntryHi : %0*lx\n", field, read_c0_entryhi());
888 		printk("EntryLo0: %0*lx\n", field, read_c0_entrylo0());
889 		printk("EntryLo1: %0*lx\n", field, read_c0_entrylo1());
890 		printk("\n");
891 		dump_tlb_all();
892 	}
893 
894 	show_code((unsigned int __user *) regs->cp0_epc);
895 
896 	/*
897 	 * Some chips may have other causes of machine check (e.g. SB1
898 	 * graduation timer)
899 	 */
900 	panic("Caught Machine Check exception - %scaused by multiple "
901 	      "matching entries in the TLB.",
902 	      (multi_match) ? "" : "not ");
903 }
904 
905 asmlinkage void do_mt(struct pt_regs *regs)
906 {
907 	int subcode;
908 
909 	subcode = (read_vpe_c0_vpecontrol() & VPECONTROL_EXCPT)
910 			>> VPECONTROL_EXCPT_SHIFT;
911 	switch (subcode) {
912 	case 0:
913 		printk(KERN_DEBUG "Thread Underflow\n");
914 		break;
915 	case 1:
916 		printk(KERN_DEBUG "Thread Overflow\n");
917 		break;
918 	case 2:
919 		printk(KERN_DEBUG "Invalid YIELD Qualifier\n");
920 		break;
921 	case 3:
922 		printk(KERN_DEBUG "Gating Storage Exception\n");
923 		break;
924 	case 4:
925 		printk(KERN_DEBUG "YIELD Scheduler Exception\n");
926 		break;
927 	case 5:
928 		printk(KERN_DEBUG "Gating Storage Schedulier Exception\n");
929 		break;
930 	default:
931 		printk(KERN_DEBUG "*** UNKNOWN THREAD EXCEPTION %d ***\n",
932 			subcode);
933 		break;
934 	}
935 	die_if_kernel("MIPS MT Thread exception in kernel", regs);
936 
937 	force_sig(SIGILL, current);
938 }
939 
940 
941 asmlinkage void do_dsp(struct pt_regs *regs)
942 {
943 	if (cpu_has_dsp)
944 		panic("Unexpected DSP exception\n");
945 
946 	force_sig(SIGILL, current);
947 }
948 
949 asmlinkage void do_reserved(struct pt_regs *regs)
950 {
951 	/*
952 	 * Game over - no way to handle this if it ever occurs.  Most probably
953 	 * caused by a new unknown cpu type or after another deadly
954 	 * hard/software error.
955 	 */
956 	show_regs(regs);
957 	panic("Caught reserved exception %ld - should not happen.",
958 	      (regs->cp0_cause & 0x7f) >> 2);
959 }
960 
961 /*
962  * Some MIPS CPUs can enable/disable for cache parity detection, but do
963  * it different ways.
964  */
965 static inline void parity_protection_init(void)
966 {
967 	switch (current_cpu_type()) {
968 	case CPU_24K:
969 	case CPU_34K:
970 	case CPU_5KC:
971 		write_c0_ecc(0x80000000);
972 		back_to_back_c0_hazard();
973 		/* Set the PE bit (bit 31) in the c0_errctl register. */
974 		printk(KERN_INFO "Cache parity protection %sabled\n",
975 		       (read_c0_ecc() & 0x80000000) ? "en" : "dis");
976 		break;
977 	case CPU_20KC:
978 	case CPU_25KF:
979 		/* Clear the DE bit (bit 16) in the c0_status register. */
980 		printk(KERN_INFO "Enable cache parity protection for "
981 		       "MIPS 20KC/25KF CPUs.\n");
982 		clear_c0_status(ST0_DE);
983 		break;
984 	default:
985 		break;
986 	}
987 }
988 
989 asmlinkage void cache_parity_error(void)
990 {
991 	const int field = 2 * sizeof(unsigned long);
992 	unsigned int reg_val;
993 
994 	/* For the moment, report the problem and hang. */
995 	printk("Cache error exception:\n");
996 	printk("cp0_errorepc == %0*lx\n", field, read_c0_errorepc());
997 	reg_val = read_c0_cacheerr();
998 	printk("c0_cacheerr == %08x\n", reg_val);
999 
1000 	printk("Decoded c0_cacheerr: %s cache fault in %s reference.\n",
1001 	       reg_val & (1<<30) ? "secondary" : "primary",
1002 	       reg_val & (1<<31) ? "data" : "insn");
1003 	printk("Error bits: %s%s%s%s%s%s%s\n",
1004 	       reg_val & (1<<29) ? "ED " : "",
1005 	       reg_val & (1<<28) ? "ET " : "",
1006 	       reg_val & (1<<26) ? "EE " : "",
1007 	       reg_val & (1<<25) ? "EB " : "",
1008 	       reg_val & (1<<24) ? "EI " : "",
1009 	       reg_val & (1<<23) ? "E1 " : "",
1010 	       reg_val & (1<<22) ? "E0 " : "");
1011 	printk("IDX: 0x%08x\n", reg_val & ((1<<22)-1));
1012 
1013 #if defined(CONFIG_CPU_MIPS32) || defined(CONFIG_CPU_MIPS64)
1014 	if (reg_val & (1<<22))
1015 		printk("DErrAddr0: 0x%0*lx\n", field, read_c0_derraddr0());
1016 
1017 	if (reg_val & (1<<23))
1018 		printk("DErrAddr1: 0x%0*lx\n", field, read_c0_derraddr1());
1019 #endif
1020 
1021 	panic("Can't handle the cache error!");
1022 }
1023 
1024 /*
1025  * SDBBP EJTAG debug exception handler.
1026  * We skip the instruction and return to the next instruction.
1027  */
1028 void ejtag_exception_handler(struct pt_regs *regs)
1029 {
1030 	const int field = 2 * sizeof(unsigned long);
1031 	unsigned long depc, old_epc;
1032 	unsigned int debug;
1033 
1034 	printk(KERN_DEBUG "SDBBP EJTAG debug exception - not handled yet, just ignored!\n");
1035 	depc = read_c0_depc();
1036 	debug = read_c0_debug();
1037 	printk(KERN_DEBUG "c0_depc = %0*lx, DEBUG = %08x\n", field, depc, debug);
1038 	if (debug & 0x80000000) {
1039 		/*
1040 		 * In branch delay slot.
1041 		 * We cheat a little bit here and use EPC to calculate the
1042 		 * debug return address (DEPC). EPC is restored after the
1043 		 * calculation.
1044 		 */
1045 		old_epc = regs->cp0_epc;
1046 		regs->cp0_epc = depc;
1047 		__compute_return_epc(regs);
1048 		depc = regs->cp0_epc;
1049 		regs->cp0_epc = old_epc;
1050 	} else
1051 		depc += 4;
1052 	write_c0_depc(depc);
1053 
1054 #if 0
1055 	printk(KERN_DEBUG "\n\n----- Enable EJTAG single stepping ----\n\n");
1056 	write_c0_debug(debug | 0x100);
1057 #endif
1058 }
1059 
1060 /*
1061  * NMI exception handler.
1062  */
1063 NORET_TYPE void ATTRIB_NORET nmi_exception_handler(struct pt_regs *regs)
1064 {
1065 	bust_spinlocks(1);
1066 	printk("NMI taken!!!!\n");
1067 	die("NMI", regs);
1068 }
1069 
1070 #define VECTORSPACING 0x100	/* for EI/VI mode */
1071 
1072 unsigned long ebase;
1073 unsigned long exception_handlers[32];
1074 unsigned long vi_handlers[64];
1075 
1076 /*
1077  * As a side effect of the way this is implemented we're limited
1078  * to interrupt handlers in the address range from
1079  * KSEG0 <= x < KSEG0 + 256mb on the Nevada.  Oh well ...
1080  */
1081 void *set_except_vector(int n, void *addr)
1082 {
1083 	unsigned long handler = (unsigned long) addr;
1084 	unsigned long old_handler = exception_handlers[n];
1085 
1086 	exception_handlers[n] = handler;
1087 	if (n == 0 && cpu_has_divec) {
1088 		*(u32 *)(ebase + 0x200) = 0x08000000 |
1089 					  (0x03ffffff & (handler >> 2));
1090 		flush_icache_range(ebase + 0x200, ebase + 0x204);
1091 	}
1092 	return (void *)old_handler;
1093 }
1094 
1095 #ifdef CONFIG_CPU_MIPSR2_SRS
1096 /*
1097  * MIPSR2 shadow register set allocation
1098  * FIXME: SMP...
1099  */
1100 
1101 static struct shadow_registers {
1102 	/*
1103 	 * Number of shadow register sets supported
1104 	 */
1105 	unsigned long sr_supported;
1106 	/*
1107 	 * Bitmap of allocated shadow registers
1108 	 */
1109 	unsigned long sr_allocated;
1110 } shadow_registers;
1111 
1112 static void mips_srs_init(void)
1113 {
1114 	shadow_registers.sr_supported = ((read_c0_srsctl() >> 26) & 0x0f) + 1;
1115 	printk(KERN_INFO "%ld MIPSR2 register sets available\n",
1116 	       shadow_registers.sr_supported);
1117 	shadow_registers.sr_allocated = 1;	/* Set 0 used by kernel */
1118 }
1119 
1120 int mips_srs_max(void)
1121 {
1122 	return shadow_registers.sr_supported;
1123 }
1124 
1125 int mips_srs_alloc(void)
1126 {
1127 	struct shadow_registers *sr = &shadow_registers;
1128 	int set;
1129 
1130 again:
1131 	set = find_first_zero_bit(&sr->sr_allocated, sr->sr_supported);
1132 	if (set >= sr->sr_supported)
1133 		return -1;
1134 
1135 	if (test_and_set_bit(set, &sr->sr_allocated))
1136 		goto again;
1137 
1138 	return set;
1139 }
1140 
1141 void mips_srs_free(int set)
1142 {
1143 	struct shadow_registers *sr = &shadow_registers;
1144 
1145 	clear_bit(set, &sr->sr_allocated);
1146 }
1147 
1148 static asmlinkage void do_default_vi(void)
1149 {
1150 	show_regs(get_irq_regs());
1151 	panic("Caught unexpected vectored interrupt.");
1152 }
1153 
1154 static void *set_vi_srs_handler(int n, vi_handler_t addr, int srs)
1155 {
1156 	unsigned long handler;
1157 	unsigned long old_handler = vi_handlers[n];
1158 	u32 *w;
1159 	unsigned char *b;
1160 
1161 	if (!cpu_has_veic && !cpu_has_vint)
1162 		BUG();
1163 
1164 	if (addr == NULL) {
1165 		handler = (unsigned long) do_default_vi;
1166 		srs = 0;
1167 	} else
1168 		handler = (unsigned long) addr;
1169 	vi_handlers[n] = (unsigned long) addr;
1170 
1171 	b = (unsigned char *)(ebase + 0x200 + n*VECTORSPACING);
1172 
1173 	if (srs >= mips_srs_max())
1174 		panic("Shadow register set %d not supported", srs);
1175 
1176 	if (cpu_has_veic) {
1177 		if (board_bind_eic_interrupt)
1178 			board_bind_eic_interrupt(n, srs);
1179 	} else if (cpu_has_vint) {
1180 		/* SRSMap is only defined if shadow sets are implemented */
1181 		if (mips_srs_max() > 1)
1182 			change_c0_srsmap(0xf << n*4, srs << n*4);
1183 	}
1184 
1185 	if (srs == 0) {
1186 		/*
1187 		 * If no shadow set is selected then use the default handler
1188 		 * that does normal register saving and a standard interrupt exit
1189 		 */
1190 
1191 		extern char except_vec_vi, except_vec_vi_lui;
1192 		extern char except_vec_vi_ori, except_vec_vi_end;
1193 #ifdef CONFIG_MIPS_MT_SMTC
1194 		/*
1195 		 * We need to provide the SMTC vectored interrupt handler
1196 		 * not only with the address of the handler, but with the
1197 		 * Status.IM bit to be masked before going there.
1198 		 */
1199 		extern char except_vec_vi_mori;
1200 		const int mori_offset = &except_vec_vi_mori - &except_vec_vi;
1201 #endif /* CONFIG_MIPS_MT_SMTC */
1202 		const int handler_len = &except_vec_vi_end - &except_vec_vi;
1203 		const int lui_offset = &except_vec_vi_lui - &except_vec_vi;
1204 		const int ori_offset = &except_vec_vi_ori - &except_vec_vi;
1205 
1206 		if (handler_len > VECTORSPACING) {
1207 			/*
1208 			 * Sigh... panicing won't help as the console
1209 			 * is probably not configured :(
1210 			 */
1211 			panic("VECTORSPACING too small");
1212 		}
1213 
1214 		memcpy(b, &except_vec_vi, handler_len);
1215 #ifdef CONFIG_MIPS_MT_SMTC
1216 		BUG_ON(n > 7);	/* Vector index %d exceeds SMTC maximum. */
1217 
1218 		w = (u32 *)(b + mori_offset);
1219 		*w = (*w & 0xffff0000) | (0x100 << n);
1220 #endif /* CONFIG_MIPS_MT_SMTC */
1221 		w = (u32 *)(b + lui_offset);
1222 		*w = (*w & 0xffff0000) | (((u32)handler >> 16) & 0xffff);
1223 		w = (u32 *)(b + ori_offset);
1224 		*w = (*w & 0xffff0000) | ((u32)handler & 0xffff);
1225 		flush_icache_range((unsigned long)b, (unsigned long)(b+handler_len));
1226 	}
1227 	else {
1228 		/*
1229 		 * In other cases jump directly to the interrupt handler
1230 		 *
1231 		 * It is the handlers responsibility to save registers if required
1232 		 * (eg hi/lo) and return from the exception using "eret"
1233 		 */
1234 		w = (u32 *)b;
1235 		*w++ = 0x08000000 | (((u32)handler >> 2) & 0x03fffff); /* j handler */
1236 		*w = 0;
1237 		flush_icache_range((unsigned long)b, (unsigned long)(b+8));
1238 	}
1239 
1240 	return (void *)old_handler;
1241 }
1242 
1243 void *set_vi_handler(int n, vi_handler_t addr)
1244 {
1245 	return set_vi_srs_handler(n, addr, 0);
1246 }
1247 
1248 #else
1249 
1250 static inline void mips_srs_init(void)
1251 {
1252 }
1253 
1254 #endif /* CONFIG_CPU_MIPSR2_SRS */
1255 
1256 /*
1257  * This is used by native signal handling
1258  */
1259 asmlinkage int (*save_fp_context)(struct sigcontext __user *sc);
1260 asmlinkage int (*restore_fp_context)(struct sigcontext __user *sc);
1261 
1262 extern asmlinkage int _save_fp_context(struct sigcontext __user *sc);
1263 extern asmlinkage int _restore_fp_context(struct sigcontext __user *sc);
1264 
1265 extern asmlinkage int fpu_emulator_save_context(struct sigcontext __user *sc);
1266 extern asmlinkage int fpu_emulator_restore_context(struct sigcontext __user *sc);
1267 
1268 #ifdef CONFIG_SMP
1269 static int smp_save_fp_context(struct sigcontext __user *sc)
1270 {
1271 	return raw_cpu_has_fpu
1272 	       ? _save_fp_context(sc)
1273 	       : fpu_emulator_save_context(sc);
1274 }
1275 
1276 static int smp_restore_fp_context(struct sigcontext __user *sc)
1277 {
1278 	return raw_cpu_has_fpu
1279 	       ? _restore_fp_context(sc)
1280 	       : fpu_emulator_restore_context(sc);
1281 }
1282 #endif
1283 
1284 static inline void signal_init(void)
1285 {
1286 #ifdef CONFIG_SMP
1287 	/* For now just do the cpu_has_fpu check when the functions are invoked */
1288 	save_fp_context = smp_save_fp_context;
1289 	restore_fp_context = smp_restore_fp_context;
1290 #else
1291 	if (cpu_has_fpu) {
1292 		save_fp_context = _save_fp_context;
1293 		restore_fp_context = _restore_fp_context;
1294 	} else {
1295 		save_fp_context = fpu_emulator_save_context;
1296 		restore_fp_context = fpu_emulator_restore_context;
1297 	}
1298 #endif
1299 }
1300 
1301 #ifdef CONFIG_MIPS32_COMPAT
1302 
1303 /*
1304  * This is used by 32-bit signal stuff on the 64-bit kernel
1305  */
1306 asmlinkage int (*save_fp_context32)(struct sigcontext32 __user *sc);
1307 asmlinkage int (*restore_fp_context32)(struct sigcontext32 __user *sc);
1308 
1309 extern asmlinkage int _save_fp_context32(struct sigcontext32 __user *sc);
1310 extern asmlinkage int _restore_fp_context32(struct sigcontext32 __user *sc);
1311 
1312 extern asmlinkage int fpu_emulator_save_context32(struct sigcontext32 __user *sc);
1313 extern asmlinkage int fpu_emulator_restore_context32(struct sigcontext32 __user *sc);
1314 
1315 static inline void signal32_init(void)
1316 {
1317 	if (cpu_has_fpu) {
1318 		save_fp_context32 = _save_fp_context32;
1319 		restore_fp_context32 = _restore_fp_context32;
1320 	} else {
1321 		save_fp_context32 = fpu_emulator_save_context32;
1322 		restore_fp_context32 = fpu_emulator_restore_context32;
1323 	}
1324 }
1325 #endif
1326 
1327 extern void cpu_cache_init(void);
1328 extern void tlb_init(void);
1329 extern void flush_tlb_handlers(void);
1330 
1331 void __init per_cpu_trap_init(void)
1332 {
1333 	unsigned int cpu = smp_processor_id();
1334 	unsigned int status_set = ST0_CU0;
1335 #ifdef CONFIG_MIPS_MT_SMTC
1336 	int secondaryTC = 0;
1337 	int bootTC = (cpu == 0);
1338 
1339 	/*
1340 	 * Only do per_cpu_trap_init() for first TC of Each VPE.
1341 	 * Note that this hack assumes that the SMTC init code
1342 	 * assigns TCs consecutively and in ascending order.
1343 	 */
1344 
1345 	if (((read_c0_tcbind() & TCBIND_CURTC) != 0) &&
1346 	    ((read_c0_tcbind() & TCBIND_CURVPE) == cpu_data[cpu - 1].vpe_id))
1347 		secondaryTC = 1;
1348 #endif /* CONFIG_MIPS_MT_SMTC */
1349 
1350 	/*
1351 	 * Disable coprocessors and select 32-bit or 64-bit addressing
1352 	 * and the 16/32 or 32/32 FPR register model.  Reset the BEV
1353 	 * flag that some firmware may have left set and the TS bit (for
1354 	 * IP27).  Set XX for ISA IV code to work.
1355 	 */
1356 #ifdef CONFIG_64BIT
1357 	status_set |= ST0_FR|ST0_KX|ST0_SX|ST0_UX;
1358 #endif
1359 	if (current_cpu_data.isa_level == MIPS_CPU_ISA_IV)
1360 		status_set |= ST0_XX;
1361 	change_c0_status(ST0_CU|ST0_MX|ST0_RE|ST0_FR|ST0_BEV|ST0_TS|ST0_KX|ST0_SX|ST0_UX,
1362 			 status_set);
1363 
1364 	if (cpu_has_dsp)
1365 		set_c0_status(ST0_MX);
1366 
1367 #ifdef CONFIG_CPU_MIPSR2
1368 	if (cpu_has_mips_r2) {
1369 		unsigned int enable = 0x0000000f;
1370 
1371 		if (cpu_has_userlocal)
1372 			enable |= (1 << 29);
1373 
1374 		write_c0_hwrena(enable);
1375 	}
1376 #endif
1377 
1378 #ifdef CONFIG_MIPS_MT_SMTC
1379 	if (!secondaryTC) {
1380 #endif /* CONFIG_MIPS_MT_SMTC */
1381 
1382 	if (cpu_has_veic || cpu_has_vint) {
1383 		write_c0_ebase(ebase);
1384 		/* Setting vector spacing enables EI/VI mode  */
1385 		change_c0_intctl(0x3e0, VECTORSPACING);
1386 	}
1387 	if (cpu_has_divec) {
1388 		if (cpu_has_mipsmt) {
1389 			unsigned int vpflags = dvpe();
1390 			set_c0_cause(CAUSEF_IV);
1391 			evpe(vpflags);
1392 		} else
1393 			set_c0_cause(CAUSEF_IV);
1394 	}
1395 
1396 	/*
1397 	 * Before R2 both interrupt numbers were fixed to 7, so on R2 only:
1398 	 *
1399 	 *  o read IntCtl.IPTI to determine the timer interrupt
1400 	 *  o read IntCtl.IPPCI to determine the performance counter interrupt
1401 	 */
1402 	if (cpu_has_mips_r2) {
1403 		cp0_compare_irq = (read_c0_intctl() >> 29) & 7;
1404 		cp0_perfcount_irq = (read_c0_intctl() >> 26) & 7;
1405 		if (cp0_perfcount_irq == cp0_compare_irq)
1406 			cp0_perfcount_irq = -1;
1407 	} else {
1408 		cp0_compare_irq = CP0_LEGACY_COMPARE_IRQ;
1409 		cp0_perfcount_irq = -1;
1410 	}
1411 
1412 #ifdef CONFIG_MIPS_MT_SMTC
1413 	}
1414 #endif /* CONFIG_MIPS_MT_SMTC */
1415 
1416 	cpu_data[cpu].asid_cache = ASID_FIRST_VERSION;
1417 	TLBMISS_HANDLER_SETUP();
1418 
1419 	atomic_inc(&init_mm.mm_count);
1420 	current->active_mm = &init_mm;
1421 	BUG_ON(current->mm);
1422 	enter_lazy_tlb(&init_mm, current);
1423 
1424 #ifdef CONFIG_MIPS_MT_SMTC
1425 	if (bootTC) {
1426 #endif /* CONFIG_MIPS_MT_SMTC */
1427 		cpu_cache_init();
1428 		tlb_init();
1429 #ifdef CONFIG_MIPS_MT_SMTC
1430 	} else if (!secondaryTC) {
1431 		/*
1432 		 * First TC in non-boot VPE must do subset of tlb_init()
1433 		 * for MMU countrol registers.
1434 		 */
1435 		write_c0_pagemask(PM_DEFAULT_MASK);
1436 		write_c0_wired(0);
1437 	}
1438 #endif /* CONFIG_MIPS_MT_SMTC */
1439 }
1440 
1441 /* Install CPU exception handler */
1442 void __init set_handler(unsigned long offset, void *addr, unsigned long size)
1443 {
1444 	memcpy((void *)(ebase + offset), addr, size);
1445 	flush_icache_range(ebase + offset, ebase + offset + size);
1446 }
1447 
1448 static char panic_null_cerr[] __initdata =
1449 	"Trying to set NULL cache error exception handler";
1450 
1451 /* Install uncached CPU exception handler */
1452 void __init set_uncached_handler(unsigned long offset, void *addr, unsigned long size)
1453 {
1454 #ifdef CONFIG_32BIT
1455 	unsigned long uncached_ebase = KSEG1ADDR(ebase);
1456 #endif
1457 #ifdef CONFIG_64BIT
1458 	unsigned long uncached_ebase = TO_UNCAC(ebase);
1459 #endif
1460 
1461 	if (!addr)
1462 		panic(panic_null_cerr);
1463 
1464 	memcpy((void *)(uncached_ebase + offset), addr, size);
1465 }
1466 
1467 static int __initdata rdhwr_noopt;
1468 static int __init set_rdhwr_noopt(char *str)
1469 {
1470 	rdhwr_noopt = 1;
1471 	return 1;
1472 }
1473 
1474 __setup("rdhwr_noopt", set_rdhwr_noopt);
1475 
1476 void __init trap_init(void)
1477 {
1478 	extern char except_vec3_generic, except_vec3_r4000;
1479 	extern char except_vec4;
1480 	unsigned long i;
1481 
1482 	if (cpu_has_veic || cpu_has_vint)
1483 		ebase = (unsigned long) alloc_bootmem_low_pages(0x200 + VECTORSPACING*64);
1484 	else
1485 		ebase = CAC_BASE;
1486 
1487 	mips_srs_init();
1488 
1489 	per_cpu_trap_init();
1490 
1491 	/*
1492 	 * Copy the generic exception handlers to their final destination.
1493 	 * This will be overriden later as suitable for a particular
1494 	 * configuration.
1495 	 */
1496 	set_handler(0x180, &except_vec3_generic, 0x80);
1497 
1498 	/*
1499 	 * Setup default vectors
1500 	 */
1501 	for (i = 0; i <= 31; i++)
1502 		set_except_vector(i, handle_reserved);
1503 
1504 	/*
1505 	 * Copy the EJTAG debug exception vector handler code to it's final
1506 	 * destination.
1507 	 */
1508 	if (cpu_has_ejtag && board_ejtag_handler_setup)
1509 		board_ejtag_handler_setup();
1510 
1511 	/*
1512 	 * Only some CPUs have the watch exceptions.
1513 	 */
1514 	if (cpu_has_watch)
1515 		set_except_vector(23, handle_watch);
1516 
1517 	/*
1518 	 * Initialise interrupt handlers
1519 	 */
1520 	if (cpu_has_veic || cpu_has_vint) {
1521 		int nvec = cpu_has_veic ? 64 : 8;
1522 		for (i = 0; i < nvec; i++)
1523 			set_vi_handler(i, NULL);
1524 	}
1525 	else if (cpu_has_divec)
1526 		set_handler(0x200, &except_vec4, 0x8);
1527 
1528 	/*
1529 	 * Some CPUs can enable/disable for cache parity detection, but does
1530 	 * it different ways.
1531 	 */
1532 	parity_protection_init();
1533 
1534 	/*
1535 	 * The Data Bus Errors / Instruction Bus Errors are signaled
1536 	 * by external hardware.  Therefore these two exceptions
1537 	 * may have board specific handlers.
1538 	 */
1539 	if (board_be_init)
1540 		board_be_init();
1541 
1542 	set_except_vector(0, handle_int);
1543 	set_except_vector(1, handle_tlbm);
1544 	set_except_vector(2, handle_tlbl);
1545 	set_except_vector(3, handle_tlbs);
1546 
1547 	set_except_vector(4, handle_adel);
1548 	set_except_vector(5, handle_ades);
1549 
1550 	set_except_vector(6, handle_ibe);
1551 	set_except_vector(7, handle_dbe);
1552 
1553 	set_except_vector(8, handle_sys);
1554 	set_except_vector(9, handle_bp);
1555 	set_except_vector(10, rdhwr_noopt ? handle_ri :
1556 			  (cpu_has_vtag_icache ?
1557 			   handle_ri_rdhwr_vivt : handle_ri_rdhwr));
1558 	set_except_vector(11, handle_cpu);
1559 	set_except_vector(12, handle_ov);
1560 	set_except_vector(13, handle_tr);
1561 
1562 	if (current_cpu_type() == CPU_R6000 ||
1563 	    current_cpu_type() == CPU_R6000A) {
1564 		/*
1565 		 * The R6000 is the only R-series CPU that features a machine
1566 		 * check exception (similar to the R4000 cache error) and
1567 		 * unaligned ldc1/sdc1 exception.  The handlers have not been
1568 		 * written yet.  Well, anyway there is no R6000 machine on the
1569 		 * current list of targets for Linux/MIPS.
1570 		 * (Duh, crap, there is someone with a triple R6k machine)
1571 		 */
1572 		//set_except_vector(14, handle_mc);
1573 		//set_except_vector(15, handle_ndc);
1574 	}
1575 
1576 
1577 	if (board_nmi_handler_setup)
1578 		board_nmi_handler_setup();
1579 
1580 	if (cpu_has_fpu && !cpu_has_nofpuex)
1581 		set_except_vector(15, handle_fpe);
1582 
1583 	set_except_vector(22, handle_mdmx);
1584 
1585 	if (cpu_has_mcheck)
1586 		set_except_vector(24, handle_mcheck);
1587 
1588 	if (cpu_has_mipsmt)
1589 		set_except_vector(25, handle_mt);
1590 
1591 	set_except_vector(26, handle_dsp);
1592 
1593 	if (cpu_has_vce)
1594 		/* Special exception: R4[04]00 uses also the divec space. */
1595 		memcpy((void *)(CAC_BASE + 0x180), &except_vec3_r4000, 0x100);
1596 	else if (cpu_has_4kex)
1597 		memcpy((void *)(CAC_BASE + 0x180), &except_vec3_generic, 0x80);
1598 	else
1599 		memcpy((void *)(CAC_BASE + 0x080), &except_vec3_generic, 0x80);
1600 
1601 	signal_init();
1602 #ifdef CONFIG_MIPS32_COMPAT
1603 	signal32_init();
1604 #endif
1605 
1606 	flush_icache_range(ebase, ebase + 0x400);
1607 	flush_tlb_handlers();
1608 }
1609