xref: /linux/arch/mips/kernel/traps.c (revision 14b42963f64b98ab61fa9723c03d71aa5ef4f862)
1 /*
2  * This file is subject to the terms and conditions of the GNU General Public
3  * License.  See the file "COPYING" in the main directory of this archive
4  * for more details.
5  *
6  * Copyright (C) 1994 - 1999, 2000, 01, 06 Ralf Baechle
7  * Copyright (C) 1995, 1996 Paul M. Antoine
8  * Copyright (C) 1998 Ulf Carlsson
9  * Copyright (C) 1999 Silicon Graphics, Inc.
10  * Kevin D. Kissell, kevink@mips.com and Carsten Langgaard, carstenl@mips.com
11  * Copyright (C) 2000, 01 MIPS Technologies, Inc.
12  * Copyright (C) 2002, 2003, 2004, 2005  Maciej W. Rozycki
13  */
14 #include <linux/init.h>
15 #include <linux/mm.h>
16 #include <linux/module.h>
17 #include <linux/sched.h>
18 #include <linux/smp.h>
19 #include <linux/smp_lock.h>
20 #include <linux/spinlock.h>
21 #include <linux/kallsyms.h>
22 #include <linux/bootmem.h>
23 
24 #include <asm/bootinfo.h>
25 #include <asm/branch.h>
26 #include <asm/break.h>
27 #include <asm/cpu.h>
28 #include <asm/dsp.h>
29 #include <asm/fpu.h>
30 #include <asm/mipsregs.h>
31 #include <asm/mipsmtregs.h>
32 #include <asm/module.h>
33 #include <asm/pgtable.h>
34 #include <asm/ptrace.h>
35 #include <asm/sections.h>
36 #include <asm/system.h>
37 #include <asm/tlbdebug.h>
38 #include <asm/traps.h>
39 #include <asm/uaccess.h>
40 #include <asm/mmu_context.h>
41 #include <asm/watch.h>
42 #include <asm/types.h>
43 
44 extern asmlinkage void handle_int(void);
45 extern asmlinkage void handle_tlbm(void);
46 extern asmlinkage void handle_tlbl(void);
47 extern asmlinkage void handle_tlbs(void);
48 extern asmlinkage void handle_adel(void);
49 extern asmlinkage void handle_ades(void);
50 extern asmlinkage void handle_ibe(void);
51 extern asmlinkage void handle_dbe(void);
52 extern asmlinkage void handle_sys(void);
53 extern asmlinkage void handle_bp(void);
54 extern asmlinkage void handle_ri(void);
55 extern asmlinkage void handle_cpu(void);
56 extern asmlinkage void handle_ov(void);
57 extern asmlinkage void handle_tr(void);
58 extern asmlinkage void handle_fpe(void);
59 extern asmlinkage void handle_mdmx(void);
60 extern asmlinkage void handle_watch(void);
61 extern asmlinkage void handle_mt(void);
62 extern asmlinkage void handle_dsp(void);
63 extern asmlinkage void handle_mcheck(void);
64 extern asmlinkage void handle_reserved(void);
65 
66 extern int fpu_emulator_cop1Handler(struct pt_regs *xcp,
67 	struct mips_fpu_struct *ctx);
68 
69 void (*board_be_init)(void);
70 int (*board_be_handler)(struct pt_regs *regs, int is_fixup);
71 void (*board_nmi_handler_setup)(void);
72 void (*board_ejtag_handler_setup)(void);
73 void (*board_bind_eic_interrupt)(int irq, int regset);
74 
75 /*
76  * These constant is for searching for possible module text segments.
77  * MODULE_RANGE is a guess of how much space is likely to be vmalloced.
78  */
79 #define MODULE_RANGE (8*1024*1024)
80 
81 /*
82  * This routine abuses get_user()/put_user() to reference pointers
83  * with at least a bit of error checking ...
84  */
85 void show_stack(struct task_struct *task, unsigned long *sp)
86 {
87 	const int field = 2 * sizeof(unsigned long);
88 	long stackdata;
89 	int i;
90 
91 	if (!sp) {
92 		if (task && task != current)
93 			sp = (unsigned long *) task->thread.reg29;
94 		else
95 			sp = (unsigned long *) &sp;
96 	}
97 
98 	printk("Stack :");
99 	i = 0;
100 	while ((unsigned long) sp & (PAGE_SIZE - 1)) {
101 		if (i && ((i % (64 / field)) == 0))
102 			printk("\n       ");
103 		if (i > 39) {
104 			printk(" ...");
105 			break;
106 		}
107 
108 		if (__get_user(stackdata, sp++)) {
109 			printk(" (Bad stack address)");
110 			break;
111 		}
112 
113 		printk(" %0*lx", field, stackdata);
114 		i++;
115 	}
116 	printk("\n");
117 }
118 
119 void show_trace(struct task_struct *task, unsigned long *stack)
120 {
121 	const int field = 2 * sizeof(unsigned long);
122 	unsigned long addr;
123 
124 	if (!stack) {
125 		if (task && task != current)
126 			stack = (unsigned long *) task->thread.reg29;
127 		else
128 			stack = (unsigned long *) &stack;
129 	}
130 
131 	printk("Call Trace:");
132 #ifdef CONFIG_KALLSYMS
133 	printk("\n");
134 #endif
135 	while (!kstack_end(stack)) {
136 		addr = *stack++;
137 		if (__kernel_text_address(addr)) {
138 			printk(" [<%0*lx>] ", field, addr);
139 			print_symbol("%s\n", addr);
140 		}
141 	}
142 	printk("\n");
143 }
144 
145 /*
146  * The architecture-independent dump_stack generator
147  */
148 void dump_stack(void)
149 {
150 	unsigned long stack;
151 
152 	show_trace(current, &stack);
153 }
154 
155 EXPORT_SYMBOL(dump_stack);
156 
157 void show_code(unsigned int *pc)
158 {
159 	long i;
160 
161 	printk("\nCode:");
162 
163 	for(i = -3 ; i < 6 ; i++) {
164 		unsigned int insn;
165 		if (__get_user(insn, pc + i)) {
166 			printk(" (Bad address in epc)\n");
167 			break;
168 		}
169 		printk("%c%08x%c", (i?' ':'<'), insn, (i?' ':'>'));
170 	}
171 }
172 
173 void show_regs(struct pt_regs *regs)
174 {
175 	const int field = 2 * sizeof(unsigned long);
176 	unsigned int cause = regs->cp0_cause;
177 	int i;
178 
179 	printk("Cpu %d\n", smp_processor_id());
180 
181 	/*
182 	 * Saved main processor registers
183 	 */
184 	for (i = 0; i < 32; ) {
185 		if ((i % 4) == 0)
186 			printk("$%2d   :", i);
187 		if (i == 0)
188 			printk(" %0*lx", field, 0UL);
189 		else if (i == 26 || i == 27)
190 			printk(" %*s", field, "");
191 		else
192 			printk(" %0*lx", field, regs->regs[i]);
193 
194 		i++;
195 		if ((i % 4) == 0)
196 			printk("\n");
197 	}
198 
199 	printk("Hi    : %0*lx\n", field, regs->hi);
200 	printk("Lo    : %0*lx\n", field, regs->lo);
201 
202 	/*
203 	 * Saved cp0 registers
204 	 */
205 	printk("epc   : %0*lx ", field, regs->cp0_epc);
206 	print_symbol("%s ", regs->cp0_epc);
207 	printk("    %s\n", print_tainted());
208 	printk("ra    : %0*lx ", field, regs->regs[31]);
209 	print_symbol("%s\n", regs->regs[31]);
210 
211 	printk("Status: %08x    ", (uint32_t) regs->cp0_status);
212 
213 	if (current_cpu_data.isa_level == MIPS_CPU_ISA_I) {
214 		if (regs->cp0_status & ST0_KUO)
215 			printk("KUo ");
216 		if (regs->cp0_status & ST0_IEO)
217 			printk("IEo ");
218 		if (regs->cp0_status & ST0_KUP)
219 			printk("KUp ");
220 		if (regs->cp0_status & ST0_IEP)
221 			printk("IEp ");
222 		if (regs->cp0_status & ST0_KUC)
223 			printk("KUc ");
224 		if (regs->cp0_status & ST0_IEC)
225 			printk("IEc ");
226 	} else {
227 		if (regs->cp0_status & ST0_KX)
228 			printk("KX ");
229 		if (regs->cp0_status & ST0_SX)
230 			printk("SX ");
231 		if (regs->cp0_status & ST0_UX)
232 			printk("UX ");
233 		switch (regs->cp0_status & ST0_KSU) {
234 		case KSU_USER:
235 			printk("USER ");
236 			break;
237 		case KSU_SUPERVISOR:
238 			printk("SUPERVISOR ");
239 			break;
240 		case KSU_KERNEL:
241 			printk("KERNEL ");
242 			break;
243 		default:
244 			printk("BAD_MODE ");
245 			break;
246 		}
247 		if (regs->cp0_status & ST0_ERL)
248 			printk("ERL ");
249 		if (regs->cp0_status & ST0_EXL)
250 			printk("EXL ");
251 		if (regs->cp0_status & ST0_IE)
252 			printk("IE ");
253 	}
254 	printk("\n");
255 
256 	printk("Cause : %08x\n", cause);
257 
258 	cause = (cause & CAUSEF_EXCCODE) >> CAUSEB_EXCCODE;
259 	if (1 <= cause && cause <= 5)
260 		printk("BadVA : %0*lx\n", field, regs->cp0_badvaddr);
261 
262 	printk("PrId  : %08x\n", read_c0_prid());
263 }
264 
265 void show_registers(struct pt_regs *regs)
266 {
267 	show_regs(regs);
268 	print_modules();
269 	printk("Process %s (pid: %d, threadinfo=%p, task=%p)\n",
270 	        current->comm, current->pid, current_thread_info(), current);
271 	show_stack(current, (long *) regs->regs[29]);
272 	show_trace(current, (long *) regs->regs[29]);
273 	show_code((unsigned int *) regs->cp0_epc);
274 	printk("\n");
275 }
276 
277 static DEFINE_SPINLOCK(die_lock);
278 
279 NORET_TYPE void ATTRIB_NORET die(const char * str, struct pt_regs * regs)
280 {
281 	static int die_counter;
282 #ifdef CONFIG_MIPS_MT_SMTC
283 	unsigned long dvpret = dvpe();
284 #endif /* CONFIG_MIPS_MT_SMTC */
285 
286 	console_verbose();
287 	spin_lock_irq(&die_lock);
288 	bust_spinlocks(1);
289 #ifdef CONFIG_MIPS_MT_SMTC
290 	mips_mt_regdump(dvpret);
291 #endif /* CONFIG_MIPS_MT_SMTC */
292 	printk("%s[#%d]:\n", str, ++die_counter);
293 	show_registers(regs);
294 	spin_unlock_irq(&die_lock);
295 	do_exit(SIGSEGV);
296 }
297 
298 extern const struct exception_table_entry __start___dbe_table[];
299 extern const struct exception_table_entry __stop___dbe_table[];
300 
301 void __declare_dbe_table(void)
302 {
303 	__asm__ __volatile__(
304 	".section\t__dbe_table,\"a\"\n\t"
305 	".previous"
306 	);
307 }
308 
309 /* Given an address, look for it in the exception tables. */
310 static const struct exception_table_entry *search_dbe_tables(unsigned long addr)
311 {
312 	const struct exception_table_entry *e;
313 
314 	e = search_extable(__start___dbe_table, __stop___dbe_table - 1, addr);
315 	if (!e)
316 		e = search_module_dbetables(addr);
317 	return e;
318 }
319 
320 asmlinkage void do_be(struct pt_regs *regs)
321 {
322 	const int field = 2 * sizeof(unsigned long);
323 	const struct exception_table_entry *fixup = NULL;
324 	int data = regs->cp0_cause & 4;
325 	int action = MIPS_BE_FATAL;
326 
327 	/* XXX For now.  Fixme, this searches the wrong table ...  */
328 	if (data && !user_mode(regs))
329 		fixup = search_dbe_tables(exception_epc(regs));
330 
331 	if (fixup)
332 		action = MIPS_BE_FIXUP;
333 
334 	if (board_be_handler)
335 		action = board_be_handler(regs, fixup != 0);
336 
337 	switch (action) {
338 	case MIPS_BE_DISCARD:
339 		return;
340 	case MIPS_BE_FIXUP:
341 		if (fixup) {
342 			regs->cp0_epc = fixup->nextinsn;
343 			return;
344 		}
345 		break;
346 	default:
347 		break;
348 	}
349 
350 	/*
351 	 * Assume it would be too dangerous to continue ...
352 	 */
353 	printk(KERN_ALERT "%s bus error, epc == %0*lx, ra == %0*lx\n",
354 	       data ? "Data" : "Instruction",
355 	       field, regs->cp0_epc, field, regs->regs[31]);
356 	die_if_kernel("Oops", regs);
357 	force_sig(SIGBUS, current);
358 }
359 
360 static inline int get_insn_opcode(struct pt_regs *regs, unsigned int *opcode)
361 {
362 	unsigned int __user *epc;
363 
364 	epc = (unsigned int __user *) regs->cp0_epc +
365 	      ((regs->cp0_cause & CAUSEF_BD) != 0);
366 	if (!get_user(*opcode, epc))
367 		return 0;
368 
369 	force_sig(SIGSEGV, current);
370 	return 1;
371 }
372 
373 /*
374  * ll/sc emulation
375  */
376 
377 #define OPCODE 0xfc000000
378 #define BASE   0x03e00000
379 #define RT     0x001f0000
380 #define OFFSET 0x0000ffff
381 #define LL     0xc0000000
382 #define SC     0xe0000000
383 #define SPEC3  0x7c000000
384 #define RD     0x0000f800
385 #define FUNC   0x0000003f
386 #define RDHWR  0x0000003b
387 
388 /*
389  * The ll_bit is cleared by r*_switch.S
390  */
391 
392 unsigned long ll_bit;
393 
394 static struct task_struct *ll_task = NULL;
395 
396 static inline void simulate_ll(struct pt_regs *regs, unsigned int opcode)
397 {
398 	unsigned long value, __user *vaddr;
399 	long offset;
400 	int signal = 0;
401 
402 	/*
403 	 * analyse the ll instruction that just caused a ri exception
404 	 * and put the referenced address to addr.
405 	 */
406 
407 	/* sign extend offset */
408 	offset = opcode & OFFSET;
409 	offset <<= 16;
410 	offset >>= 16;
411 
412 	vaddr = (unsigned long __user *)
413 	        ((unsigned long)(regs->regs[(opcode & BASE) >> 21]) + offset);
414 
415 	if ((unsigned long)vaddr & 3) {
416 		signal = SIGBUS;
417 		goto sig;
418 	}
419 	if (get_user(value, vaddr)) {
420 		signal = SIGSEGV;
421 		goto sig;
422 	}
423 
424 	preempt_disable();
425 
426 	if (ll_task == NULL || ll_task == current) {
427 		ll_bit = 1;
428 	} else {
429 		ll_bit = 0;
430 	}
431 	ll_task = current;
432 
433 	preempt_enable();
434 
435 	compute_return_epc(regs);
436 
437 	regs->regs[(opcode & RT) >> 16] = value;
438 
439 	return;
440 
441 sig:
442 	force_sig(signal, current);
443 }
444 
445 static inline void simulate_sc(struct pt_regs *regs, unsigned int opcode)
446 {
447 	unsigned long __user *vaddr;
448 	unsigned long reg;
449 	long offset;
450 	int signal = 0;
451 
452 	/*
453 	 * analyse the sc instruction that just caused a ri exception
454 	 * and put the referenced address to addr.
455 	 */
456 
457 	/* sign extend offset */
458 	offset = opcode & OFFSET;
459 	offset <<= 16;
460 	offset >>= 16;
461 
462 	vaddr = (unsigned long __user *)
463 	        ((unsigned long)(regs->regs[(opcode & BASE) >> 21]) + offset);
464 	reg = (opcode & RT) >> 16;
465 
466 	if ((unsigned long)vaddr & 3) {
467 		signal = SIGBUS;
468 		goto sig;
469 	}
470 
471 	preempt_disable();
472 
473 	if (ll_bit == 0 || ll_task != current) {
474 		compute_return_epc(regs);
475 		regs->regs[reg] = 0;
476 		preempt_enable();
477 		return;
478 	}
479 
480 	preempt_enable();
481 
482 	if (put_user(regs->regs[reg], vaddr)) {
483 		signal = SIGSEGV;
484 		goto sig;
485 	}
486 
487 	compute_return_epc(regs);
488 	regs->regs[reg] = 1;
489 
490 	return;
491 
492 sig:
493 	force_sig(signal, current);
494 }
495 
496 /*
497  * ll uses the opcode of lwc0 and sc uses the opcode of swc0.  That is both
498  * opcodes are supposed to result in coprocessor unusable exceptions if
499  * executed on ll/sc-less processors.  That's the theory.  In practice a
500  * few processors such as NEC's VR4100 throw reserved instruction exceptions
501  * instead, so we're doing the emulation thing in both exception handlers.
502  */
503 static inline int simulate_llsc(struct pt_regs *regs)
504 {
505 	unsigned int opcode;
506 
507 	if (unlikely(get_insn_opcode(regs, &opcode)))
508 		return -EFAULT;
509 
510 	if ((opcode & OPCODE) == LL) {
511 		simulate_ll(regs, opcode);
512 		return 0;
513 	}
514 	if ((opcode & OPCODE) == SC) {
515 		simulate_sc(regs, opcode);
516 		return 0;
517 	}
518 
519 	return -EFAULT;			/* Strange things going on ... */
520 }
521 
522 /*
523  * Simulate trapping 'rdhwr' instructions to provide user accessible
524  * registers not implemented in hardware.  The only current use of this
525  * is the thread area pointer.
526  */
527 static inline int simulate_rdhwr(struct pt_regs *regs)
528 {
529 	struct thread_info *ti = task_thread_info(current);
530 	unsigned int opcode;
531 
532 	if (unlikely(get_insn_opcode(regs, &opcode)))
533 		return -EFAULT;
534 
535 	if (unlikely(compute_return_epc(regs)))
536 		return -EFAULT;
537 
538 	if ((opcode & OPCODE) == SPEC3 && (opcode & FUNC) == RDHWR) {
539 		int rd = (opcode & RD) >> 11;
540 		int rt = (opcode & RT) >> 16;
541 		switch (rd) {
542 			case 29:
543 				regs->regs[rt] = ti->tp_value;
544 				return 0;
545 			default:
546 				return -EFAULT;
547 		}
548 	}
549 
550 	/* Not ours.  */
551 	return -EFAULT;
552 }
553 
554 asmlinkage void do_ov(struct pt_regs *regs)
555 {
556 	siginfo_t info;
557 
558 	die_if_kernel("Integer overflow", regs);
559 
560 	info.si_code = FPE_INTOVF;
561 	info.si_signo = SIGFPE;
562 	info.si_errno = 0;
563 	info.si_addr = (void __user *) regs->cp0_epc;
564 	force_sig_info(SIGFPE, &info, current);
565 }
566 
567 /*
568  * XXX Delayed fp exceptions when doing a lazy ctx switch XXX
569  */
570 asmlinkage void do_fpe(struct pt_regs *regs, unsigned long fcr31)
571 {
572 	if (fcr31 & FPU_CSR_UNI_X) {
573 		int sig;
574 
575 		preempt_disable();
576 
577 #ifdef CONFIG_PREEMPT
578 		if (!is_fpu_owner()) {
579 			/* We might lose fpu before disabling preempt... */
580 			own_fpu();
581 			BUG_ON(!used_math());
582 			restore_fp(current);
583 		}
584 #endif
585 		/*
586 		 * Unimplemented operation exception.  If we've got the full
587 		 * software emulator on-board, let's use it...
588 		 *
589 		 * Force FPU to dump state into task/thread context.  We're
590 		 * moving a lot of data here for what is probably a single
591 		 * instruction, but the alternative is to pre-decode the FP
592 		 * register operands before invoking the emulator, which seems
593 		 * a bit extreme for what should be an infrequent event.
594 		 */
595 		save_fp(current);
596 		/* Ensure 'resume' not overwrite saved fp context again. */
597 		lose_fpu();
598 
599 		preempt_enable();
600 
601 		/* Run the emulator */
602 		sig = fpu_emulator_cop1Handler (regs, &current->thread.fpu);
603 
604 		preempt_disable();
605 
606 		own_fpu();	/* Using the FPU again.  */
607 		/*
608 		 * We can't allow the emulated instruction to leave any of
609 		 * the cause bit set in $fcr31.
610 		 */
611 		current->thread.fpu.fcr31 &= ~FPU_CSR_ALL_X;
612 
613 		/* Restore the hardware register state */
614 		restore_fp(current);
615 
616 		preempt_enable();
617 
618 		/* If something went wrong, signal */
619 		if (sig)
620 			force_sig(sig, current);
621 
622 		return;
623 	}
624 
625 	force_sig(SIGFPE, current);
626 }
627 
628 asmlinkage void do_bp(struct pt_regs *regs)
629 {
630 	unsigned int opcode, bcode;
631 	siginfo_t info;
632 
633 	die_if_kernel("Break instruction in kernel code", regs);
634 
635 	if (get_insn_opcode(regs, &opcode))
636 		return;
637 
638 	/*
639 	 * There is the ancient bug in the MIPS assemblers that the break
640 	 * code starts left to bit 16 instead to bit 6 in the opcode.
641 	 * Gas is bug-compatible, but not always, grrr...
642 	 * We handle both cases with a simple heuristics.  --macro
643 	 */
644 	bcode = ((opcode >> 6) & ((1 << 20) - 1));
645 	if (bcode < (1 << 10))
646 		bcode <<= 10;
647 
648 	/*
649 	 * (A short test says that IRIX 5.3 sends SIGTRAP for all break
650 	 * insns, even for break codes that indicate arithmetic failures.
651 	 * Weird ...)
652 	 * But should we continue the brokenness???  --macro
653 	 */
654 	switch (bcode) {
655 	case BRK_OVERFLOW << 10:
656 	case BRK_DIVZERO << 10:
657 		if (bcode == (BRK_DIVZERO << 10))
658 			info.si_code = FPE_INTDIV;
659 		else
660 			info.si_code = FPE_INTOVF;
661 		info.si_signo = SIGFPE;
662 		info.si_errno = 0;
663 		info.si_addr = (void __user *) regs->cp0_epc;
664 		force_sig_info(SIGFPE, &info, current);
665 		break;
666 	default:
667 		force_sig(SIGTRAP, current);
668 	}
669 }
670 
671 asmlinkage void do_tr(struct pt_regs *regs)
672 {
673 	unsigned int opcode, tcode = 0;
674 	siginfo_t info;
675 
676 	die_if_kernel("Trap instruction in kernel code", regs);
677 
678 	if (get_insn_opcode(regs, &opcode))
679 		return;
680 
681 	/* Immediate versions don't provide a code.  */
682 	if (!(opcode & OPCODE))
683 		tcode = ((opcode >> 6) & ((1 << 10) - 1));
684 
685 	/*
686 	 * (A short test says that IRIX 5.3 sends SIGTRAP for all trap
687 	 * insns, even for trap codes that indicate arithmetic failures.
688 	 * Weird ...)
689 	 * But should we continue the brokenness???  --macro
690 	 */
691 	switch (tcode) {
692 	case BRK_OVERFLOW:
693 	case BRK_DIVZERO:
694 		if (tcode == BRK_DIVZERO)
695 			info.si_code = FPE_INTDIV;
696 		else
697 			info.si_code = FPE_INTOVF;
698 		info.si_signo = SIGFPE;
699 		info.si_errno = 0;
700 		info.si_addr = (void __user *) regs->cp0_epc;
701 		force_sig_info(SIGFPE, &info, current);
702 		break;
703 	default:
704 		force_sig(SIGTRAP, current);
705 	}
706 }
707 
708 asmlinkage void do_ri(struct pt_regs *regs)
709 {
710 	die_if_kernel("Reserved instruction in kernel code", regs);
711 
712 	if (!cpu_has_llsc)
713 		if (!simulate_llsc(regs))
714 			return;
715 
716 	if (!simulate_rdhwr(regs))
717 		return;
718 
719 	force_sig(SIGILL, current);
720 }
721 
722 asmlinkage void do_cpu(struct pt_regs *regs)
723 {
724 	unsigned int cpid;
725 
726 	die_if_kernel("do_cpu invoked from kernel context!", regs);
727 
728 	cpid = (regs->cp0_cause >> CAUSEB_CE) & 3;
729 
730 	switch (cpid) {
731 	case 0:
732 		if (!cpu_has_llsc)
733 			if (!simulate_llsc(regs))
734 				return;
735 
736 		if (!simulate_rdhwr(regs))
737 			return;
738 
739 		break;
740 
741 	case 1:
742 		preempt_disable();
743 
744 		own_fpu();
745 		if (used_math()) {	/* Using the FPU again.  */
746 			restore_fp(current);
747 		} else {			/* First time FPU user.  */
748 			init_fpu();
749 			set_used_math();
750 		}
751 
752 		preempt_enable();
753 
754 		if (!cpu_has_fpu) {
755 			int sig = fpu_emulator_cop1Handler(regs,
756 						&current->thread.fpu);
757 			if (sig)
758 				force_sig(sig, current);
759 #ifdef CONFIG_MIPS_MT_FPAFF
760 			else {
761 			/*
762 			 * MIPS MT processors may have fewer FPU contexts
763 			 * than CPU threads. If we've emulated more than
764 			 * some threshold number of instructions, force
765 			 * migration to a "CPU" that has FP support.
766 			 */
767 			 if(mt_fpemul_threshold > 0
768 			 && ((current->thread.emulated_fp++
769 			    > mt_fpemul_threshold))) {
770 			  /*
771 			   * If there's no FPU present, or if the
772 			   * application has already restricted
773 			   * the allowed set to exclude any CPUs
774 			   * with FPUs, we'll skip the procedure.
775 			   */
776 			  if (cpus_intersects(current->cpus_allowed,
777 			  			mt_fpu_cpumask)) {
778 			    cpumask_t tmask;
779 
780 			    cpus_and(tmask,
781 					current->thread.user_cpus_allowed,
782 					mt_fpu_cpumask);
783 			    set_cpus_allowed(current, tmask);
784 			    current->thread.mflags |= MF_FPUBOUND;
785 			  }
786 			 }
787 			}
788 #endif /* CONFIG_MIPS_MT_FPAFF */
789 		}
790 
791 		return;
792 
793 	case 2:
794 	case 3:
795 		die_if_kernel("do_cpu invoked from kernel context!", regs);
796 		break;
797 	}
798 
799 	force_sig(SIGILL, current);
800 }
801 
802 asmlinkage void do_mdmx(struct pt_regs *regs)
803 {
804 	force_sig(SIGILL, current);
805 }
806 
807 asmlinkage void do_watch(struct pt_regs *regs)
808 {
809 	/*
810 	 * We use the watch exception where available to detect stack
811 	 * overflows.
812 	 */
813 	dump_tlb_all();
814 	show_regs(regs);
815 	panic("Caught WATCH exception - probably caused by stack overflow.");
816 }
817 
818 asmlinkage void do_mcheck(struct pt_regs *regs)
819 {
820 	const int field = 2 * sizeof(unsigned long);
821 	int multi_match = regs->cp0_status & ST0_TS;
822 
823 	show_regs(regs);
824 
825 	if (multi_match) {
826 		printk("Index   : %0x\n", read_c0_index());
827 		printk("Pagemask: %0x\n", read_c0_pagemask());
828 		printk("EntryHi : %0*lx\n", field, read_c0_entryhi());
829 		printk("EntryLo0: %0*lx\n", field, read_c0_entrylo0());
830 		printk("EntryLo1: %0*lx\n", field, read_c0_entrylo1());
831 		printk("\n");
832 		dump_tlb_all();
833 	}
834 
835 	show_code((unsigned int *) regs->cp0_epc);
836 
837 	/*
838 	 * Some chips may have other causes of machine check (e.g. SB1
839 	 * graduation timer)
840 	 */
841 	panic("Caught Machine Check exception - %scaused by multiple "
842 	      "matching entries in the TLB.",
843 	      (multi_match) ? "" : "not ");
844 }
845 
846 asmlinkage void do_mt(struct pt_regs *regs)
847 {
848 	int subcode;
849 
850 	die_if_kernel("MIPS MT Thread exception in kernel", regs);
851 
852 	subcode = (read_vpe_c0_vpecontrol() & VPECONTROL_EXCPT)
853 			>> VPECONTROL_EXCPT_SHIFT;
854 	switch (subcode) {
855 	case 0:
856 		printk(KERN_ERR "Thread Underflow\n");
857 		break;
858 	case 1:
859 		printk(KERN_ERR "Thread Overflow\n");
860 		break;
861 	case 2:
862 		printk(KERN_ERR "Invalid YIELD Qualifier\n");
863 		break;
864 	case 3:
865 		printk(KERN_ERR "Gating Storage Exception\n");
866 		break;
867 	case 4:
868 		printk(KERN_ERR "YIELD Scheduler Exception\n");
869 		break;
870 	case 5:
871 		printk(KERN_ERR "Gating Storage Schedulier Exception\n");
872 		break;
873 	default:
874 		printk(KERN_ERR "*** UNKNOWN THREAD EXCEPTION %d ***\n",
875 			subcode);
876 		break;
877 	}
878 	die_if_kernel("MIPS MT Thread exception in kernel", regs);
879 
880 	force_sig(SIGILL, current);
881 }
882 
883 
884 asmlinkage void do_dsp(struct pt_regs *regs)
885 {
886 	if (cpu_has_dsp)
887 		panic("Unexpected DSP exception\n");
888 
889 	force_sig(SIGILL, current);
890 }
891 
892 asmlinkage void do_reserved(struct pt_regs *regs)
893 {
894 	/*
895 	 * Game over - no way to handle this if it ever occurs.  Most probably
896 	 * caused by a new unknown cpu type or after another deadly
897 	 * hard/software error.
898 	 */
899 	show_regs(regs);
900 	panic("Caught reserved exception %ld - should not happen.",
901 	      (regs->cp0_cause & 0x7f) >> 2);
902 }
903 
904 asmlinkage void do_default_vi(struct pt_regs *regs)
905 {
906 	show_regs(regs);
907 	panic("Caught unexpected vectored interrupt.");
908 }
909 
910 /*
911  * Some MIPS CPUs can enable/disable for cache parity detection, but do
912  * it different ways.
913  */
914 static inline void parity_protection_init(void)
915 {
916 	switch (current_cpu_data.cputype) {
917 	case CPU_24K:
918 	case CPU_34K:
919 	case CPU_5KC:
920 		write_c0_ecc(0x80000000);
921 		back_to_back_c0_hazard();
922 		/* Set the PE bit (bit 31) in the c0_errctl register. */
923 		printk(KERN_INFO "Cache parity protection %sabled\n",
924 		       (read_c0_ecc() & 0x80000000) ? "en" : "dis");
925 		break;
926 	case CPU_20KC:
927 	case CPU_25KF:
928 		/* Clear the DE bit (bit 16) in the c0_status register. */
929 		printk(KERN_INFO "Enable cache parity protection for "
930 		       "MIPS 20KC/25KF CPUs.\n");
931 		clear_c0_status(ST0_DE);
932 		break;
933 	default:
934 		break;
935 	}
936 }
937 
938 asmlinkage void cache_parity_error(void)
939 {
940 	const int field = 2 * sizeof(unsigned long);
941 	unsigned int reg_val;
942 
943 	/* For the moment, report the problem and hang. */
944 	printk("Cache error exception:\n");
945 	printk("cp0_errorepc == %0*lx\n", field, read_c0_errorepc());
946 	reg_val = read_c0_cacheerr();
947 	printk("c0_cacheerr == %08x\n", reg_val);
948 
949 	printk("Decoded c0_cacheerr: %s cache fault in %s reference.\n",
950 	       reg_val & (1<<30) ? "secondary" : "primary",
951 	       reg_val & (1<<31) ? "data" : "insn");
952 	printk("Error bits: %s%s%s%s%s%s%s\n",
953 	       reg_val & (1<<29) ? "ED " : "",
954 	       reg_val & (1<<28) ? "ET " : "",
955 	       reg_val & (1<<26) ? "EE " : "",
956 	       reg_val & (1<<25) ? "EB " : "",
957 	       reg_val & (1<<24) ? "EI " : "",
958 	       reg_val & (1<<23) ? "E1 " : "",
959 	       reg_val & (1<<22) ? "E0 " : "");
960 	printk("IDX: 0x%08x\n", reg_val & ((1<<22)-1));
961 
962 #if defined(CONFIG_CPU_MIPS32) || defined(CONFIG_CPU_MIPS64)
963 	if (reg_val & (1<<22))
964 		printk("DErrAddr0: 0x%0*lx\n", field, read_c0_derraddr0());
965 
966 	if (reg_val & (1<<23))
967 		printk("DErrAddr1: 0x%0*lx\n", field, read_c0_derraddr1());
968 #endif
969 
970 	panic("Can't handle the cache error!");
971 }
972 
973 /*
974  * SDBBP EJTAG debug exception handler.
975  * We skip the instruction and return to the next instruction.
976  */
977 void ejtag_exception_handler(struct pt_regs *regs)
978 {
979 	const int field = 2 * sizeof(unsigned long);
980 	unsigned long depc, old_epc;
981 	unsigned int debug;
982 
983 	printk("SDBBP EJTAG debug exception - not handled yet, just ignored!\n");
984 	depc = read_c0_depc();
985 	debug = read_c0_debug();
986 	printk("c0_depc = %0*lx, DEBUG = %08x\n", field, depc, debug);
987 	if (debug & 0x80000000) {
988 		/*
989 		 * In branch delay slot.
990 		 * We cheat a little bit here and use EPC to calculate the
991 		 * debug return address (DEPC). EPC is restored after the
992 		 * calculation.
993 		 */
994 		old_epc = regs->cp0_epc;
995 		regs->cp0_epc = depc;
996 		__compute_return_epc(regs);
997 		depc = regs->cp0_epc;
998 		regs->cp0_epc = old_epc;
999 	} else
1000 		depc += 4;
1001 	write_c0_depc(depc);
1002 
1003 #if 0
1004 	printk("\n\n----- Enable EJTAG single stepping ----\n\n");
1005 	write_c0_debug(debug | 0x100);
1006 #endif
1007 }
1008 
1009 /*
1010  * NMI exception handler.
1011  */
1012 void nmi_exception_handler(struct pt_regs *regs)
1013 {
1014 #ifdef CONFIG_MIPS_MT_SMTC
1015 	unsigned long dvpret = dvpe();
1016 	bust_spinlocks(1);
1017 	printk("NMI taken!!!!\n");
1018 	mips_mt_regdump(dvpret);
1019 #else
1020 	bust_spinlocks(1);
1021 	printk("NMI taken!!!!\n");
1022 #endif /* CONFIG_MIPS_MT_SMTC */
1023 	die("NMI", regs);
1024 	while(1) ;
1025 }
1026 
1027 #define VECTORSPACING 0x100	/* for EI/VI mode */
1028 
1029 unsigned long ebase;
1030 unsigned long exception_handlers[32];
1031 unsigned long vi_handlers[64];
1032 
1033 /*
1034  * As a side effect of the way this is implemented we're limited
1035  * to interrupt handlers in the address range from
1036  * KSEG0 <= x < KSEG0 + 256mb on the Nevada.  Oh well ...
1037  */
1038 void *set_except_vector(int n, void *addr)
1039 {
1040 	unsigned long handler = (unsigned long) addr;
1041 	unsigned long old_handler = exception_handlers[n];
1042 
1043 	exception_handlers[n] = handler;
1044 	if (n == 0 && cpu_has_divec) {
1045 		*(volatile u32 *)(ebase + 0x200) = 0x08000000 |
1046 		                                 (0x03ffffff & (handler >> 2));
1047 		flush_icache_range(ebase + 0x200, ebase + 0x204);
1048 	}
1049 	return (void *)old_handler;
1050 }
1051 
1052 #ifdef CONFIG_CPU_MIPSR2_SRS
1053 /*
1054  * MIPSR2 shadow register set allocation
1055  * FIXME: SMP...
1056  */
1057 
1058 static struct shadow_registers {
1059 	/*
1060 	 * Number of shadow register sets supported
1061 	 */
1062 	unsigned long sr_supported;
1063 	/*
1064 	 * Bitmap of allocated shadow registers
1065 	 */
1066 	unsigned long sr_allocated;
1067 } shadow_registers;
1068 
1069 static void mips_srs_init(void)
1070 {
1071 	shadow_registers.sr_supported = ((read_c0_srsctl() >> 26) & 0x0f) + 1;
1072 	printk(KERN_INFO "%d MIPSR2 register sets available\n",
1073 	       shadow_registers.sr_supported);
1074 	shadow_registers.sr_allocated = 1;	/* Set 0 used by kernel */
1075 }
1076 
1077 int mips_srs_max(void)
1078 {
1079 	return shadow_registers.sr_supported;
1080 }
1081 
1082 int mips_srs_alloc(void)
1083 {
1084 	struct shadow_registers *sr = &shadow_registers;
1085 	int set;
1086 
1087 again:
1088 	set = find_first_zero_bit(&sr->sr_allocated, sr->sr_supported);
1089 	if (set >= sr->sr_supported)
1090 		return -1;
1091 
1092 	if (test_and_set_bit(set, &sr->sr_allocated))
1093 		goto again;
1094 
1095 	return set;
1096 }
1097 
1098 void mips_srs_free(int set)
1099 {
1100 	struct shadow_registers *sr = &shadow_registers;
1101 
1102 	clear_bit(set, &sr->sr_allocated);
1103 }
1104 
1105 static void *set_vi_srs_handler(int n, void *addr, int srs)
1106 {
1107 	unsigned long handler;
1108 	unsigned long old_handler = vi_handlers[n];
1109 	u32 *w;
1110 	unsigned char *b;
1111 
1112 	if (!cpu_has_veic && !cpu_has_vint)
1113 		BUG();
1114 
1115 	if (addr == NULL) {
1116 		handler = (unsigned long) do_default_vi;
1117 		srs = 0;
1118 	} else
1119 		handler = (unsigned long) addr;
1120 	vi_handlers[n] = (unsigned long) addr;
1121 
1122 	b = (unsigned char *)(ebase + 0x200 + n*VECTORSPACING);
1123 
1124 	if (srs >= mips_srs_max())
1125 		panic("Shadow register set %d not supported", srs);
1126 
1127 	if (cpu_has_veic) {
1128 		if (board_bind_eic_interrupt)
1129 			board_bind_eic_interrupt (n, srs);
1130 	} else if (cpu_has_vint) {
1131 		/* SRSMap is only defined if shadow sets are implemented */
1132 		if (mips_srs_max() > 1)
1133 			change_c0_srsmap (0xf << n*4, srs << n*4);
1134 	}
1135 
1136 	if (srs == 0) {
1137 		/*
1138 		 * If no shadow set is selected then use the default handler
1139 		 * that does normal register saving and a standard interrupt exit
1140 		 */
1141 
1142 		extern char except_vec_vi, except_vec_vi_lui;
1143 		extern char except_vec_vi_ori, except_vec_vi_end;
1144 #ifdef CONFIG_MIPS_MT_SMTC
1145 		/*
1146 		 * We need to provide the SMTC vectored interrupt handler
1147 		 * not only with the address of the handler, but with the
1148 		 * Status.IM bit to be masked before going there.
1149 		 */
1150 		extern char except_vec_vi_mori;
1151 		const int mori_offset = &except_vec_vi_mori - &except_vec_vi;
1152 #endif /* CONFIG_MIPS_MT_SMTC */
1153 		const int handler_len = &except_vec_vi_end - &except_vec_vi;
1154 		const int lui_offset = &except_vec_vi_lui - &except_vec_vi;
1155 		const int ori_offset = &except_vec_vi_ori - &except_vec_vi;
1156 
1157 		if (handler_len > VECTORSPACING) {
1158 			/*
1159 			 * Sigh... panicing won't help as the console
1160 			 * is probably not configured :(
1161 			 */
1162 			panic ("VECTORSPACING too small");
1163 		}
1164 
1165 		memcpy (b, &except_vec_vi, handler_len);
1166 #ifdef CONFIG_MIPS_MT_SMTC
1167 		if (n > 7)
1168 			printk("Vector index %d exceeds SMTC maximum\n", n);
1169 		w = (u32 *)(b + mori_offset);
1170 		*w = (*w & 0xffff0000) | (0x100 << n);
1171 #endif /* CONFIG_MIPS_MT_SMTC */
1172 		w = (u32 *)(b + lui_offset);
1173 		*w = (*w & 0xffff0000) | (((u32)handler >> 16) & 0xffff);
1174 		w = (u32 *)(b + ori_offset);
1175 		*w = (*w & 0xffff0000) | ((u32)handler & 0xffff);
1176 		flush_icache_range((unsigned long)b, (unsigned long)(b+handler_len));
1177 	}
1178 	else {
1179 		/*
1180 		 * In other cases jump directly to the interrupt handler
1181 		 *
1182 		 * It is the handlers responsibility to save registers if required
1183 		 * (eg hi/lo) and return from the exception using "eret"
1184 		 */
1185 		w = (u32 *)b;
1186 		*w++ = 0x08000000 | (((u32)handler >> 2) & 0x03fffff); /* j handler */
1187 		*w = 0;
1188 		flush_icache_range((unsigned long)b, (unsigned long)(b+8));
1189 	}
1190 
1191 	return (void *)old_handler;
1192 }
1193 
1194 void *set_vi_handler(int n, void *addr)
1195 {
1196 	return set_vi_srs_handler(n, addr, 0);
1197 }
1198 
1199 #else
1200 
1201 static inline void mips_srs_init(void)
1202 {
1203 }
1204 
1205 #endif /* CONFIG_CPU_MIPSR2_SRS */
1206 
1207 /*
1208  * This is used by native signal handling
1209  */
1210 asmlinkage int (*save_fp_context)(struct sigcontext *sc);
1211 asmlinkage int (*restore_fp_context)(struct sigcontext *sc);
1212 
1213 extern asmlinkage int _save_fp_context(struct sigcontext *sc);
1214 extern asmlinkage int _restore_fp_context(struct sigcontext *sc);
1215 
1216 extern asmlinkage int fpu_emulator_save_context(struct sigcontext *sc);
1217 extern asmlinkage int fpu_emulator_restore_context(struct sigcontext *sc);
1218 
1219 #ifdef CONFIG_SMP
1220 static int smp_save_fp_context(struct sigcontext *sc)
1221 {
1222 	return cpu_has_fpu
1223 	       ? _save_fp_context(sc)
1224 	       : fpu_emulator_save_context(sc);
1225 }
1226 
1227 static int smp_restore_fp_context(struct sigcontext *sc)
1228 {
1229 	return cpu_has_fpu
1230 	       ? _restore_fp_context(sc)
1231 	       : fpu_emulator_restore_context(sc);
1232 }
1233 #endif
1234 
1235 static inline void signal_init(void)
1236 {
1237 #ifdef CONFIG_SMP
1238 	/* For now just do the cpu_has_fpu check when the functions are invoked */
1239 	save_fp_context = smp_save_fp_context;
1240 	restore_fp_context = smp_restore_fp_context;
1241 #else
1242 	if (cpu_has_fpu) {
1243 		save_fp_context = _save_fp_context;
1244 		restore_fp_context = _restore_fp_context;
1245 	} else {
1246 		save_fp_context = fpu_emulator_save_context;
1247 		restore_fp_context = fpu_emulator_restore_context;
1248 	}
1249 #endif
1250 }
1251 
1252 #ifdef CONFIG_MIPS32_COMPAT
1253 
1254 /*
1255  * This is used by 32-bit signal stuff on the 64-bit kernel
1256  */
1257 asmlinkage int (*save_fp_context32)(struct sigcontext32 *sc);
1258 asmlinkage int (*restore_fp_context32)(struct sigcontext32 *sc);
1259 
1260 extern asmlinkage int _save_fp_context32(struct sigcontext32 *sc);
1261 extern asmlinkage int _restore_fp_context32(struct sigcontext32 *sc);
1262 
1263 extern asmlinkage int fpu_emulator_save_context32(struct sigcontext32 *sc);
1264 extern asmlinkage int fpu_emulator_restore_context32(struct sigcontext32 *sc);
1265 
1266 static inline void signal32_init(void)
1267 {
1268 	if (cpu_has_fpu) {
1269 		save_fp_context32 = _save_fp_context32;
1270 		restore_fp_context32 = _restore_fp_context32;
1271 	} else {
1272 		save_fp_context32 = fpu_emulator_save_context32;
1273 		restore_fp_context32 = fpu_emulator_restore_context32;
1274 	}
1275 }
1276 #endif
1277 
1278 extern void cpu_cache_init(void);
1279 extern void tlb_init(void);
1280 extern void flush_tlb_handlers(void);
1281 
1282 void __init per_cpu_trap_init(void)
1283 {
1284 	unsigned int cpu = smp_processor_id();
1285 	unsigned int status_set = ST0_CU0;
1286 #ifdef CONFIG_MIPS_MT_SMTC
1287 	int secondaryTC = 0;
1288 	int bootTC = (cpu == 0);
1289 
1290 	/*
1291 	 * Only do per_cpu_trap_init() for first TC of Each VPE.
1292 	 * Note that this hack assumes that the SMTC init code
1293 	 * assigns TCs consecutively and in ascending order.
1294 	 */
1295 
1296 	if (((read_c0_tcbind() & TCBIND_CURTC) != 0) &&
1297 	    ((read_c0_tcbind() & TCBIND_CURVPE) == cpu_data[cpu - 1].vpe_id))
1298 		secondaryTC = 1;
1299 #endif /* CONFIG_MIPS_MT_SMTC */
1300 
1301 	/*
1302 	 * Disable coprocessors and select 32-bit or 64-bit addressing
1303 	 * and the 16/32 or 32/32 FPR register model.  Reset the BEV
1304 	 * flag that some firmware may have left set and the TS bit (for
1305 	 * IP27).  Set XX for ISA IV code to work.
1306 	 */
1307 #ifdef CONFIG_64BIT
1308 	status_set |= ST0_FR|ST0_KX|ST0_SX|ST0_UX;
1309 #endif
1310 	if (current_cpu_data.isa_level == MIPS_CPU_ISA_IV)
1311 		status_set |= ST0_XX;
1312 	change_c0_status(ST0_CU|ST0_MX|ST0_RE|ST0_FR|ST0_BEV|ST0_TS|ST0_KX|ST0_SX|ST0_UX,
1313 			 status_set);
1314 
1315 	if (cpu_has_dsp)
1316 		set_c0_status(ST0_MX);
1317 
1318 #ifdef CONFIG_CPU_MIPSR2
1319 	write_c0_hwrena (0x0000000f); /* Allow rdhwr to all registers */
1320 #endif
1321 
1322 #ifdef CONFIG_MIPS_MT_SMTC
1323 	if (!secondaryTC) {
1324 #endif /* CONFIG_MIPS_MT_SMTC */
1325 
1326 	/*
1327 	 * Interrupt handling.
1328 	 */
1329 	if (cpu_has_veic || cpu_has_vint) {
1330 		write_c0_ebase (ebase);
1331 		/* Setting vector spacing enables EI/VI mode  */
1332 		change_c0_intctl (0x3e0, VECTORSPACING);
1333 	}
1334 	if (cpu_has_divec) {
1335 		if (cpu_has_mipsmt) {
1336 			unsigned int vpflags = dvpe();
1337 			set_c0_cause(CAUSEF_IV);
1338 			evpe(vpflags);
1339 		} else
1340 			set_c0_cause(CAUSEF_IV);
1341 	}
1342 #ifdef CONFIG_MIPS_MT_SMTC
1343 	}
1344 #endif /* CONFIG_MIPS_MT_SMTC */
1345 
1346 	cpu_data[cpu].asid_cache = ASID_FIRST_VERSION;
1347 	TLBMISS_HANDLER_SETUP();
1348 
1349 	atomic_inc(&init_mm.mm_count);
1350 	current->active_mm = &init_mm;
1351 	BUG_ON(current->mm);
1352 	enter_lazy_tlb(&init_mm, current);
1353 
1354 #ifdef CONFIG_MIPS_MT_SMTC
1355 	if (bootTC) {
1356 #endif /* CONFIG_MIPS_MT_SMTC */
1357 		cpu_cache_init();
1358 		tlb_init();
1359 #ifdef CONFIG_MIPS_MT_SMTC
1360 	}
1361 #endif /* CONFIG_MIPS_MT_SMTC */
1362 }
1363 
1364 /* Install CPU exception handler */
1365 void __init set_handler (unsigned long offset, void *addr, unsigned long size)
1366 {
1367 	memcpy((void *)(ebase + offset), addr, size);
1368 	flush_icache_range(ebase + offset, ebase + offset + size);
1369 }
1370 
1371 /* Install uncached CPU exception handler */
1372 void __init set_uncached_handler (unsigned long offset, void *addr, unsigned long size)
1373 {
1374 #ifdef CONFIG_32BIT
1375 	unsigned long uncached_ebase = KSEG1ADDR(ebase);
1376 #endif
1377 #ifdef CONFIG_64BIT
1378 	unsigned long uncached_ebase = TO_UNCAC(ebase);
1379 #endif
1380 
1381 	memcpy((void *)(uncached_ebase + offset), addr, size);
1382 }
1383 
1384 void __init trap_init(void)
1385 {
1386 	extern char except_vec3_generic, except_vec3_r4000;
1387 	extern char except_vec4;
1388 	unsigned long i;
1389 
1390 	if (cpu_has_veic || cpu_has_vint)
1391 		ebase = (unsigned long) alloc_bootmem_low_pages (0x200 + VECTORSPACING*64);
1392 	else
1393 		ebase = CAC_BASE;
1394 
1395 	mips_srs_init();
1396 
1397 	per_cpu_trap_init();
1398 
1399 	/*
1400 	 * Copy the generic exception handlers to their final destination.
1401 	 * This will be overriden later as suitable for a particular
1402 	 * configuration.
1403 	 */
1404 	set_handler(0x180, &except_vec3_generic, 0x80);
1405 
1406 	/*
1407 	 * Setup default vectors
1408 	 */
1409 	for (i = 0; i <= 31; i++)
1410 		set_except_vector(i, handle_reserved);
1411 
1412 	/*
1413 	 * Copy the EJTAG debug exception vector handler code to it's final
1414 	 * destination.
1415 	 */
1416 	if (cpu_has_ejtag && board_ejtag_handler_setup)
1417 		board_ejtag_handler_setup ();
1418 
1419 	/*
1420 	 * Only some CPUs have the watch exceptions.
1421 	 */
1422 	if (cpu_has_watch)
1423 		set_except_vector(23, handle_watch);
1424 
1425 	/*
1426 	 * Initialise interrupt handlers
1427 	 */
1428 	if (cpu_has_veic || cpu_has_vint) {
1429 		int nvec = cpu_has_veic ? 64 : 8;
1430 		for (i = 0; i < nvec; i++)
1431 			set_vi_handler(i, NULL);
1432 	}
1433 	else if (cpu_has_divec)
1434 		set_handler(0x200, &except_vec4, 0x8);
1435 
1436 	/*
1437 	 * Some CPUs can enable/disable for cache parity detection, but does
1438 	 * it different ways.
1439 	 */
1440 	parity_protection_init();
1441 
1442 	/*
1443 	 * The Data Bus Errors / Instruction Bus Errors are signaled
1444 	 * by external hardware.  Therefore these two exceptions
1445 	 * may have board specific handlers.
1446 	 */
1447 	if (board_be_init)
1448 		board_be_init();
1449 
1450 	set_except_vector(0, handle_int);
1451 	set_except_vector(1, handle_tlbm);
1452 	set_except_vector(2, handle_tlbl);
1453 	set_except_vector(3, handle_tlbs);
1454 
1455 	set_except_vector(4, handle_adel);
1456 	set_except_vector(5, handle_ades);
1457 
1458 	set_except_vector(6, handle_ibe);
1459 	set_except_vector(7, handle_dbe);
1460 
1461 	set_except_vector(8, handle_sys);
1462 	set_except_vector(9, handle_bp);
1463 	set_except_vector(10, handle_ri);
1464 	set_except_vector(11, handle_cpu);
1465 	set_except_vector(12, handle_ov);
1466 	set_except_vector(13, handle_tr);
1467 
1468 	if (current_cpu_data.cputype == CPU_R6000 ||
1469 	    current_cpu_data.cputype == CPU_R6000A) {
1470 		/*
1471 		 * The R6000 is the only R-series CPU that features a machine
1472 		 * check exception (similar to the R4000 cache error) and
1473 		 * unaligned ldc1/sdc1 exception.  The handlers have not been
1474 		 * written yet.  Well, anyway there is no R6000 machine on the
1475 		 * current list of targets for Linux/MIPS.
1476 		 * (Duh, crap, there is someone with a triple R6k machine)
1477 		 */
1478 		//set_except_vector(14, handle_mc);
1479 		//set_except_vector(15, handle_ndc);
1480 	}
1481 
1482 
1483 	if (board_nmi_handler_setup)
1484 		board_nmi_handler_setup();
1485 
1486 	if (cpu_has_fpu && !cpu_has_nofpuex)
1487 		set_except_vector(15, handle_fpe);
1488 
1489 	set_except_vector(22, handle_mdmx);
1490 
1491 	if (cpu_has_mcheck)
1492 		set_except_vector(24, handle_mcheck);
1493 
1494 	if (cpu_has_mipsmt)
1495 		set_except_vector(25, handle_mt);
1496 
1497 	if (cpu_has_dsp)
1498 		set_except_vector(26, handle_dsp);
1499 
1500 	if (cpu_has_vce)
1501 		/* Special exception: R4[04]00 uses also the divec space. */
1502 		memcpy((void *)(CAC_BASE + 0x180), &except_vec3_r4000, 0x100);
1503 	else if (cpu_has_4kex)
1504 		memcpy((void *)(CAC_BASE + 0x180), &except_vec3_generic, 0x80);
1505 	else
1506 		memcpy((void *)(CAC_BASE + 0x080), &except_vec3_generic, 0x80);
1507 
1508 	signal_init();
1509 #ifdef CONFIG_MIPS32_COMPAT
1510 	signal32_init();
1511 #endif
1512 
1513 	flush_icache_range(ebase, ebase + 0x400);
1514 	flush_tlb_handlers();
1515 }
1516