xref: /openbmc/linux/arch/mips/kernel/traps.c (revision a1e58bbd)
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 
26 #include <asm/bootinfo.h>
27 #include <asm/branch.h>
28 #include <asm/break.h>
29 #include <asm/cpu.h>
30 #include <asm/dsp.h>
31 #include <asm/fpu.h>
32 #include <asm/mipsregs.h>
33 #include <asm/mipsmtregs.h>
34 #include <asm/module.h>
35 #include <asm/pgtable.h>
36 #include <asm/ptrace.h>
37 #include <asm/sections.h>
38 #include <asm/system.h>
39 #include <asm/tlbdebug.h>
40 #include <asm/traps.h>
41 #include <asm/uaccess.h>
42 #include <asm/mmu_context.h>
43 #include <asm/types.h>
44 #include <asm/stacktrace.h>
45 
46 extern asmlinkage void handle_int(void);
47 extern asmlinkage void handle_tlbm(void);
48 extern asmlinkage void handle_tlbl(void);
49 extern asmlinkage void handle_tlbs(void);
50 extern asmlinkage void handle_adel(void);
51 extern asmlinkage void handle_ades(void);
52 extern asmlinkage void handle_ibe(void);
53 extern asmlinkage void handle_dbe(void);
54 extern asmlinkage void handle_sys(void);
55 extern asmlinkage void handle_bp(void);
56 extern asmlinkage void handle_ri(void);
57 extern asmlinkage void handle_ri_rdhwr_vivt(void);
58 extern asmlinkage void handle_ri_rdhwr(void);
59 extern asmlinkage void handle_cpu(void);
60 extern asmlinkage void handle_ov(void);
61 extern asmlinkage void handle_tr(void);
62 extern asmlinkage void handle_fpe(void);
63 extern asmlinkage void handle_mdmx(void);
64 extern asmlinkage void handle_watch(void);
65 extern asmlinkage void handle_mt(void);
66 extern asmlinkage void handle_dsp(void);
67 extern asmlinkage void handle_mcheck(void);
68 extern asmlinkage void handle_reserved(void);
69 
70 extern int fpu_emulator_cop1Handler(struct pt_regs *xcp,
71 	struct mips_fpu_struct *ctx, int has_fpu);
72 
73 void (*board_watchpoint_handler)(struct pt_regs *regs);
74 void (*board_be_init)(void);
75 int (*board_be_handler)(struct pt_regs *regs, int is_fixup);
76 void (*board_nmi_handler_setup)(void);
77 void (*board_ejtag_handler_setup)(void);
78 void (*board_bind_eic_interrupt)(int irq, int regset);
79 
80 
81 static void show_raw_backtrace(unsigned long reg29)
82 {
83 	unsigned long *sp = (unsigned long *)reg29;
84 	unsigned long addr;
85 
86 	printk("Call Trace:");
87 #ifdef CONFIG_KALLSYMS
88 	printk("\n");
89 #endif
90 	while (!kstack_end(sp)) {
91 		addr = *sp++;
92 		if (__kernel_text_address(addr))
93 			print_ip_sym(addr);
94 	}
95 	printk("\n");
96 }
97 
98 #ifdef CONFIG_KALLSYMS
99 int raw_show_trace;
100 static int __init set_raw_show_trace(char *str)
101 {
102 	raw_show_trace = 1;
103 	return 1;
104 }
105 __setup("raw_show_trace", set_raw_show_trace);
106 #endif
107 
108 static void show_backtrace(struct task_struct *task, const struct pt_regs *regs)
109 {
110 	unsigned long sp = regs->regs[29];
111 	unsigned long ra = regs->regs[31];
112 	unsigned long pc = regs->cp0_epc;
113 
114 	if (raw_show_trace || !__kernel_text_address(pc)) {
115 		show_raw_backtrace(sp);
116 		return;
117 	}
118 	printk("Call Trace:\n");
119 	do {
120 		print_ip_sym(pc);
121 		pc = unwind_stack(task, &sp, pc, &ra);
122 	} while (pc);
123 	printk("\n");
124 }
125 
126 /*
127  * This routine abuses get_user()/put_user() to reference pointers
128  * with at least a bit of error checking ...
129  */
130 static void show_stacktrace(struct task_struct *task,
131 	const struct pt_regs *regs)
132 {
133 	const int field = 2 * sizeof(unsigned long);
134 	long stackdata;
135 	int i;
136 	unsigned long __user *sp = (unsigned long __user *)regs->regs[29];
137 
138 	printk("Stack :");
139 	i = 0;
140 	while ((unsigned long) sp & (PAGE_SIZE - 1)) {
141 		if (i && ((i % (64 / field)) == 0))
142 			printk("\n       ");
143 		if (i > 39) {
144 			printk(" ...");
145 			break;
146 		}
147 
148 		if (__get_user(stackdata, sp++)) {
149 			printk(" (Bad stack address)");
150 			break;
151 		}
152 
153 		printk(" %0*lx", field, stackdata);
154 		i++;
155 	}
156 	printk("\n");
157 	show_backtrace(task, regs);
158 }
159 
160 void show_stack(struct task_struct *task, unsigned long *sp)
161 {
162 	struct pt_regs regs;
163 	if (sp) {
164 		regs.regs[29] = (unsigned long)sp;
165 		regs.regs[31] = 0;
166 		regs.cp0_epc = 0;
167 	} else {
168 		if (task && task != current) {
169 			regs.regs[29] = task->thread.reg29;
170 			regs.regs[31] = 0;
171 			regs.cp0_epc = task->thread.reg31;
172 		} else {
173 			prepare_frametrace(&regs);
174 		}
175 	}
176 	show_stacktrace(task, &regs);
177 }
178 
179 /*
180  * The architecture-independent dump_stack generator
181  */
182 void dump_stack(void)
183 {
184 	struct pt_regs regs;
185 
186 	prepare_frametrace(&regs);
187 	show_backtrace(current, &regs);
188 }
189 
190 EXPORT_SYMBOL(dump_stack);
191 
192 static void show_code(unsigned int __user *pc)
193 {
194 	long i;
195 
196 	printk("\nCode:");
197 
198 	for(i = -3 ; i < 6 ; i++) {
199 		unsigned int insn;
200 		if (__get_user(insn, pc + i)) {
201 			printk(" (Bad address in epc)\n");
202 			break;
203 		}
204 		printk("%c%08x%c", (i?' ':'<'), insn, (i?' ':'>'));
205 	}
206 }
207 
208 static void __show_regs(const struct pt_regs *regs)
209 {
210 	const int field = 2 * sizeof(unsigned long);
211 	unsigned int cause = regs->cp0_cause;
212 	int i;
213 
214 	printk("Cpu %d\n", smp_processor_id());
215 
216 	/*
217 	 * Saved main processor registers
218 	 */
219 	for (i = 0; i < 32; ) {
220 		if ((i % 4) == 0)
221 			printk("$%2d   :", i);
222 		if (i == 0)
223 			printk(" %0*lx", field, 0UL);
224 		else if (i == 26 || i == 27)
225 			printk(" %*s", field, "");
226 		else
227 			printk(" %0*lx", field, regs->regs[i]);
228 
229 		i++;
230 		if ((i % 4) == 0)
231 			printk("\n");
232 	}
233 
234 #ifdef CONFIG_CPU_HAS_SMARTMIPS
235 	printk("Acx    : %0*lx\n", field, regs->acx);
236 #endif
237 	printk("Hi    : %0*lx\n", field, regs->hi);
238 	printk("Lo    : %0*lx\n", field, regs->lo);
239 
240 	/*
241 	 * Saved cp0 registers
242 	 */
243 	printk("epc   : %0*lx ", field, regs->cp0_epc);
244 	print_symbol("%s ", regs->cp0_epc);
245 	printk("    %s\n", print_tainted());
246 	printk("ra    : %0*lx ", field, regs->regs[31]);
247 	print_symbol("%s\n", regs->regs[31]);
248 
249 	printk("Status: %08x    ", (uint32_t) regs->cp0_status);
250 
251 	if (current_cpu_data.isa_level == MIPS_CPU_ISA_I) {
252 		if (regs->cp0_status & ST0_KUO)
253 			printk("KUo ");
254 		if (regs->cp0_status & ST0_IEO)
255 			printk("IEo ");
256 		if (regs->cp0_status & ST0_KUP)
257 			printk("KUp ");
258 		if (regs->cp0_status & ST0_IEP)
259 			printk("IEp ");
260 		if (regs->cp0_status & ST0_KUC)
261 			printk("KUc ");
262 		if (regs->cp0_status & ST0_IEC)
263 			printk("IEc ");
264 	} else {
265 		if (regs->cp0_status & ST0_KX)
266 			printk("KX ");
267 		if (regs->cp0_status & ST0_SX)
268 			printk("SX ");
269 		if (regs->cp0_status & ST0_UX)
270 			printk("UX ");
271 		switch (regs->cp0_status & ST0_KSU) {
272 		case KSU_USER:
273 			printk("USER ");
274 			break;
275 		case KSU_SUPERVISOR:
276 			printk("SUPERVISOR ");
277 			break;
278 		case KSU_KERNEL:
279 			printk("KERNEL ");
280 			break;
281 		default:
282 			printk("BAD_MODE ");
283 			break;
284 		}
285 		if (regs->cp0_status & ST0_ERL)
286 			printk("ERL ");
287 		if (regs->cp0_status & ST0_EXL)
288 			printk("EXL ");
289 		if (regs->cp0_status & ST0_IE)
290 			printk("IE ");
291 	}
292 	printk("\n");
293 
294 	printk("Cause : %08x\n", cause);
295 
296 	cause = (cause & CAUSEF_EXCCODE) >> CAUSEB_EXCCODE;
297 	if (1 <= cause && cause <= 5)
298 		printk("BadVA : %0*lx\n", field, regs->cp0_badvaddr);
299 
300 	printk("PrId  : %08x (%s)\n", read_c0_prid(),
301 	       cpu_name_string());
302 }
303 
304 /*
305  * FIXME: really the generic show_regs should take a const pointer argument.
306  */
307 void show_regs(struct pt_regs *regs)
308 {
309 	__show_regs((struct pt_regs *)regs);
310 }
311 
312 void show_registers(const struct pt_regs *regs)
313 {
314 	__show_regs(regs);
315 	print_modules();
316 	printk("Process %s (pid: %d, threadinfo=%p, task=%p)\n",
317 	        current->comm, task_pid_nr(current), current_thread_info(), current);
318 	show_stacktrace(current, regs);
319 	show_code((unsigned int __user *) regs->cp0_epc);
320 	printk("\n");
321 }
322 
323 static DEFINE_SPINLOCK(die_lock);
324 
325 void __noreturn die(const char * str, const struct pt_regs * regs)
326 {
327 	static int die_counter;
328 #ifdef CONFIG_MIPS_MT_SMTC
329 	unsigned long dvpret = dvpe();
330 #endif /* CONFIG_MIPS_MT_SMTC */
331 
332 	console_verbose();
333 	spin_lock_irq(&die_lock);
334 	bust_spinlocks(1);
335 #ifdef CONFIG_MIPS_MT_SMTC
336 	mips_mt_regdump(dvpret);
337 #endif /* CONFIG_MIPS_MT_SMTC */
338 	printk("%s[#%d]:\n", str, ++die_counter);
339 	show_registers(regs);
340 	add_taint(TAINT_DIE);
341 	spin_unlock_irq(&die_lock);
342 
343 	if (in_interrupt())
344 		panic("Fatal exception in interrupt");
345 
346 	if (panic_on_oops) {
347 		printk(KERN_EMERG "Fatal exception: panic in 5 seconds\n");
348 		ssleep(5);
349 		panic("Fatal exception");
350 	}
351 
352 	do_exit(SIGSEGV);
353 }
354 
355 extern const struct exception_table_entry __start___dbe_table[];
356 extern const struct exception_table_entry __stop___dbe_table[];
357 
358 __asm__(
359 "	.section	__dbe_table, \"a\"\n"
360 "	.previous			\n");
361 
362 /* Given an address, look for it in the exception tables. */
363 static const struct exception_table_entry *search_dbe_tables(unsigned long addr)
364 {
365 	const struct exception_table_entry *e;
366 
367 	e = search_extable(__start___dbe_table, __stop___dbe_table - 1, addr);
368 	if (!e)
369 		e = search_module_dbetables(addr);
370 	return e;
371 }
372 
373 asmlinkage void do_be(struct pt_regs *regs)
374 {
375 	const int field = 2 * sizeof(unsigned long);
376 	const struct exception_table_entry *fixup = NULL;
377 	int data = regs->cp0_cause & 4;
378 	int action = MIPS_BE_FATAL;
379 
380 	/* XXX For now.  Fixme, this searches the wrong table ...  */
381 	if (data && !user_mode(regs))
382 		fixup = search_dbe_tables(exception_epc(regs));
383 
384 	if (fixup)
385 		action = MIPS_BE_FIXUP;
386 
387 	if (board_be_handler)
388 		action = board_be_handler(regs, fixup != NULL);
389 
390 	switch (action) {
391 	case MIPS_BE_DISCARD:
392 		return;
393 	case MIPS_BE_FIXUP:
394 		if (fixup) {
395 			regs->cp0_epc = fixup->nextinsn;
396 			return;
397 		}
398 		break;
399 	default:
400 		break;
401 	}
402 
403 	/*
404 	 * Assume it would be too dangerous to continue ...
405 	 */
406 	printk(KERN_ALERT "%s bus error, epc == %0*lx, ra == %0*lx\n",
407 	       data ? "Data" : "Instruction",
408 	       field, regs->cp0_epc, field, regs->regs[31]);
409 	die_if_kernel("Oops", regs);
410 	force_sig(SIGBUS, current);
411 }
412 
413 /*
414  * ll/sc, rdhwr, sync emulation
415  */
416 
417 #define OPCODE 0xfc000000
418 #define BASE   0x03e00000
419 #define RT     0x001f0000
420 #define OFFSET 0x0000ffff
421 #define LL     0xc0000000
422 #define SC     0xe0000000
423 #define SPEC0  0x00000000
424 #define SPEC3  0x7c000000
425 #define RD     0x0000f800
426 #define FUNC   0x0000003f
427 #define SYNC   0x0000000f
428 #define RDHWR  0x0000003b
429 
430 /*
431  * The ll_bit is cleared by r*_switch.S
432  */
433 
434 unsigned long ll_bit;
435 
436 static struct task_struct *ll_task = NULL;
437 
438 static inline int simulate_ll(struct pt_regs *regs, unsigned int opcode)
439 {
440 	unsigned long value, __user *vaddr;
441 	long offset;
442 
443 	/*
444 	 * analyse the ll instruction that just caused a ri exception
445 	 * and put the referenced address to addr.
446 	 */
447 
448 	/* sign extend offset */
449 	offset = opcode & OFFSET;
450 	offset <<= 16;
451 	offset >>= 16;
452 
453 	vaddr = (unsigned long __user *)
454 	        ((unsigned long)(regs->regs[(opcode & BASE) >> 21]) + offset);
455 
456 	if ((unsigned long)vaddr & 3)
457 		return SIGBUS;
458 	if (get_user(value, vaddr))
459 		return SIGSEGV;
460 
461 	preempt_disable();
462 
463 	if (ll_task == NULL || ll_task == current) {
464 		ll_bit = 1;
465 	} else {
466 		ll_bit = 0;
467 	}
468 	ll_task = current;
469 
470 	preempt_enable();
471 
472 	regs->regs[(opcode & RT) >> 16] = value;
473 
474 	return 0;
475 }
476 
477 static inline int simulate_sc(struct pt_regs *regs, unsigned int opcode)
478 {
479 	unsigned long __user *vaddr;
480 	unsigned long reg;
481 	long offset;
482 
483 	/*
484 	 * analyse the sc instruction that just caused a ri exception
485 	 * and put the referenced address to addr.
486 	 */
487 
488 	/* sign extend offset */
489 	offset = opcode & OFFSET;
490 	offset <<= 16;
491 	offset >>= 16;
492 
493 	vaddr = (unsigned long __user *)
494 	        ((unsigned long)(regs->regs[(opcode & BASE) >> 21]) + offset);
495 	reg = (opcode & RT) >> 16;
496 
497 	if ((unsigned long)vaddr & 3)
498 		return SIGBUS;
499 
500 	preempt_disable();
501 
502 	if (ll_bit == 0 || ll_task != current) {
503 		regs->regs[reg] = 0;
504 		preempt_enable();
505 		return 0;
506 	}
507 
508 	preempt_enable();
509 
510 	if (put_user(regs->regs[reg], vaddr))
511 		return SIGSEGV;
512 
513 	regs->regs[reg] = 1;
514 
515 	return 0;
516 }
517 
518 /*
519  * ll uses the opcode of lwc0 and sc uses the opcode of swc0.  That is both
520  * opcodes are supposed to result in coprocessor unusable exceptions if
521  * executed on ll/sc-less processors.  That's the theory.  In practice a
522  * few processors such as NEC's VR4100 throw reserved instruction exceptions
523  * instead, so we're doing the emulation thing in both exception handlers.
524  */
525 static int simulate_llsc(struct pt_regs *regs, unsigned int opcode)
526 {
527 	if ((opcode & OPCODE) == LL)
528 		return simulate_ll(regs, opcode);
529 	if ((opcode & OPCODE) == SC)
530 		return simulate_sc(regs, opcode);
531 
532 	return -1;			/* Must be something else ... */
533 }
534 
535 /*
536  * Simulate trapping 'rdhwr' instructions to provide user accessible
537  * registers not implemented in hardware.
538  */
539 static int simulate_rdhwr(struct pt_regs *regs, unsigned int opcode)
540 {
541 	struct thread_info *ti = task_thread_info(current);
542 
543 	if ((opcode & OPCODE) == SPEC3 && (opcode & FUNC) == RDHWR) {
544 		int rd = (opcode & RD) >> 11;
545 		int rt = (opcode & RT) >> 16;
546 		switch (rd) {
547 		case 0:		/* CPU number */
548 			regs->regs[rt] = smp_processor_id();
549 			return 0;
550 		case 1:		/* SYNCI length */
551 			regs->regs[rt] = min(current_cpu_data.dcache.linesz,
552 					     current_cpu_data.icache.linesz);
553 			return 0;
554 		case 2:		/* Read count register */
555 			regs->regs[rt] = read_c0_count();
556 			return 0;
557 		case 3:		/* Count register resolution */
558 			switch (current_cpu_data.cputype) {
559 			case CPU_20KC:
560 			case CPU_25KF:
561 				regs->regs[rt] = 1;
562 				break;
563 			default:
564 				regs->regs[rt] = 2;
565 			}
566 			return 0;
567 		case 29:
568 			regs->regs[rt] = ti->tp_value;
569 			return 0;
570 		default:
571 			return -1;
572 		}
573 	}
574 
575 	/* Not ours.  */
576 	return -1;
577 }
578 
579 static int simulate_sync(struct pt_regs *regs, unsigned int opcode)
580 {
581 	if ((opcode & OPCODE) == SPEC0 && (opcode & FUNC) == SYNC)
582 		return 0;
583 
584 	return -1;			/* Must be something else ... */
585 }
586 
587 asmlinkage void do_ov(struct pt_regs *regs)
588 {
589 	siginfo_t info;
590 
591 	die_if_kernel("Integer overflow", regs);
592 
593 	info.si_code = FPE_INTOVF;
594 	info.si_signo = SIGFPE;
595 	info.si_errno = 0;
596 	info.si_addr = (void __user *) regs->cp0_epc;
597 	force_sig_info(SIGFPE, &info, current);
598 }
599 
600 /*
601  * XXX Delayed fp exceptions when doing a lazy ctx switch XXX
602  */
603 asmlinkage void do_fpe(struct pt_regs *regs, unsigned long fcr31)
604 {
605 	siginfo_t info;
606 
607 	die_if_kernel("FP exception in kernel code", regs);
608 
609 	if (fcr31 & FPU_CSR_UNI_X) {
610 		int sig;
611 
612 		/*
613 		 * Unimplemented operation exception.  If we've got the full
614 		 * software emulator on-board, let's use it...
615 		 *
616 		 * Force FPU to dump state into task/thread context.  We're
617 		 * moving a lot of data here for what is probably a single
618 		 * instruction, but the alternative is to pre-decode the FP
619 		 * register operands before invoking the emulator, which seems
620 		 * a bit extreme for what should be an infrequent event.
621 		 */
622 		/* Ensure 'resume' not overwrite saved fp context again. */
623 		lose_fpu(1);
624 
625 		/* Run the emulator */
626 		sig = fpu_emulator_cop1Handler(regs, &current->thread.fpu, 1);
627 
628 		/*
629 		 * We can't allow the emulated instruction to leave any of
630 		 * the cause bit set in $fcr31.
631 		 */
632 		current->thread.fpu.fcr31 &= ~FPU_CSR_ALL_X;
633 
634 		/* Restore the hardware register state */
635 		own_fpu(1);	/* Using the FPU again.  */
636 
637 		/* If something went wrong, signal */
638 		if (sig)
639 			force_sig(sig, current);
640 
641 		return;
642 	} else if (fcr31 & FPU_CSR_INV_X)
643 		info.si_code = FPE_FLTINV;
644 	else if (fcr31 & FPU_CSR_DIV_X)
645 		info.si_code = FPE_FLTDIV;
646 	else if (fcr31 & FPU_CSR_OVF_X)
647 		info.si_code = FPE_FLTOVF;
648 	else if (fcr31 & FPU_CSR_UDF_X)
649 		info.si_code = FPE_FLTUND;
650 	else if (fcr31 & FPU_CSR_INE_X)
651 		info.si_code = FPE_FLTRES;
652 	else
653 		info.si_code = __SI_FAULT;
654 	info.si_signo = SIGFPE;
655 	info.si_errno = 0;
656 	info.si_addr = (void __user *) regs->cp0_epc;
657 	force_sig_info(SIGFPE, &info, current);
658 }
659 
660 asmlinkage void do_bp(struct pt_regs *regs)
661 {
662 	unsigned int opcode, bcode;
663 	siginfo_t info;
664 
665 	if (__get_user(opcode, (unsigned int __user *) exception_epc(regs)))
666 		goto out_sigsegv;
667 
668 	/*
669 	 * There is the ancient bug in the MIPS assemblers that the break
670 	 * code starts left to bit 16 instead to bit 6 in the opcode.
671 	 * Gas is bug-compatible, but not always, grrr...
672 	 * We handle both cases with a simple heuristics.  --macro
673 	 */
674 	bcode = ((opcode >> 6) & ((1 << 20) - 1));
675 	if (bcode < (1 << 10))
676 		bcode <<= 10;
677 
678 	/*
679 	 * (A short test says that IRIX 5.3 sends SIGTRAP for all break
680 	 * insns, even for break codes that indicate arithmetic failures.
681 	 * Weird ...)
682 	 * But should we continue the brokenness???  --macro
683 	 */
684 	switch (bcode) {
685 	case BRK_OVERFLOW << 10:
686 	case BRK_DIVZERO << 10:
687 		die_if_kernel("Break instruction in kernel code", regs);
688 		if (bcode == (BRK_DIVZERO << 10))
689 			info.si_code = FPE_INTDIV;
690 		else
691 			info.si_code = FPE_INTOVF;
692 		info.si_signo = SIGFPE;
693 		info.si_errno = 0;
694 		info.si_addr = (void __user *) regs->cp0_epc;
695 		force_sig_info(SIGFPE, &info, current);
696 		break;
697 	case BRK_BUG:
698 		die("Kernel bug detected", regs);
699 		break;
700 	default:
701 		die_if_kernel("Break instruction in kernel code", regs);
702 		force_sig(SIGTRAP, current);
703 	}
704 	return;
705 
706 out_sigsegv:
707 	force_sig(SIGSEGV, current);
708 }
709 
710 asmlinkage void do_tr(struct pt_regs *regs)
711 {
712 	unsigned int opcode, tcode = 0;
713 	siginfo_t info;
714 
715 	if (__get_user(opcode, (unsigned int __user *) exception_epc(regs)))
716 		goto out_sigsegv;
717 
718 	/* Immediate versions don't provide a code.  */
719 	if (!(opcode & OPCODE))
720 		tcode = ((opcode >> 6) & ((1 << 10) - 1));
721 
722 	/*
723 	 * (A short test says that IRIX 5.3 sends SIGTRAP for all trap
724 	 * insns, even for trap codes that indicate arithmetic failures.
725 	 * Weird ...)
726 	 * But should we continue the brokenness???  --macro
727 	 */
728 	switch (tcode) {
729 	case BRK_OVERFLOW:
730 	case BRK_DIVZERO:
731 		die_if_kernel("Trap instruction in kernel code", regs);
732 		if (tcode == BRK_DIVZERO)
733 			info.si_code = FPE_INTDIV;
734 		else
735 			info.si_code = FPE_INTOVF;
736 		info.si_signo = SIGFPE;
737 		info.si_errno = 0;
738 		info.si_addr = (void __user *) regs->cp0_epc;
739 		force_sig_info(SIGFPE, &info, current);
740 		break;
741 	case BRK_BUG:
742 		die("Kernel bug detected", regs);
743 		break;
744 	default:
745 		die_if_kernel("Trap instruction in kernel code", regs);
746 		force_sig(SIGTRAP, current);
747 	}
748 	return;
749 
750 out_sigsegv:
751 	force_sig(SIGSEGV, current);
752 }
753 
754 asmlinkage void do_ri(struct pt_regs *regs)
755 {
756 	unsigned int __user *epc = (unsigned int __user *)exception_epc(regs);
757 	unsigned long old_epc = regs->cp0_epc;
758 	unsigned int opcode = 0;
759 	int status = -1;
760 
761 	die_if_kernel("Reserved instruction in kernel code", regs);
762 
763 	if (unlikely(compute_return_epc(regs) < 0))
764 		return;
765 
766 	if (unlikely(get_user(opcode, epc) < 0))
767 		status = SIGSEGV;
768 
769 	if (!cpu_has_llsc && status < 0)
770 		status = simulate_llsc(regs, opcode);
771 
772 	if (status < 0)
773 		status = simulate_rdhwr(regs, opcode);
774 
775 	if (status < 0)
776 		status = simulate_sync(regs, opcode);
777 
778 	if (status < 0)
779 		status = SIGILL;
780 
781 	if (unlikely(status > 0)) {
782 		regs->cp0_epc = old_epc;		/* Undo skip-over.  */
783 		force_sig(status, current);
784 	}
785 }
786 
787 /*
788  * MIPS MT processors may have fewer FPU contexts than CPU threads. If we've
789  * emulated more than some threshold number of instructions, force migration to
790  * a "CPU" that has FP support.
791  */
792 static void mt_ase_fp_affinity(void)
793 {
794 #ifdef CONFIG_MIPS_MT_FPAFF
795 	if (mt_fpemul_threshold > 0 &&
796 	     ((current->thread.emulated_fp++ > mt_fpemul_threshold))) {
797 		/*
798 		 * If there's no FPU present, or if the application has already
799 		 * restricted the allowed set to exclude any CPUs with FPUs,
800 		 * we'll skip the procedure.
801 		 */
802 		if (cpus_intersects(current->cpus_allowed, mt_fpu_cpumask)) {
803 			cpumask_t tmask;
804 
805 			cpus_and(tmask, current->thread.user_cpus_allowed,
806 			         mt_fpu_cpumask);
807 			set_cpus_allowed(current, tmask);
808 			set_thread_flag(TIF_FPUBOUND);
809 		}
810 	}
811 #endif /* CONFIG_MIPS_MT_FPAFF */
812 }
813 
814 asmlinkage void do_cpu(struct pt_regs *regs)
815 {
816 	unsigned int __user *epc;
817 	unsigned long old_epc;
818 	unsigned int opcode;
819 	unsigned int cpid;
820 	int status;
821 
822 	die_if_kernel("do_cpu invoked from kernel context!", regs);
823 
824 	cpid = (regs->cp0_cause >> CAUSEB_CE) & 3;
825 
826 	switch (cpid) {
827 	case 0:
828 		epc = (unsigned int __user *)exception_epc(regs);
829 		old_epc = regs->cp0_epc;
830 		opcode = 0;
831 		status = -1;
832 
833 		if (unlikely(compute_return_epc(regs) < 0))
834 			return;
835 
836 		if (unlikely(get_user(opcode, epc) < 0))
837 			status = SIGSEGV;
838 
839 		if (!cpu_has_llsc && status < 0)
840 			status = simulate_llsc(regs, opcode);
841 
842 		if (status < 0)
843 			status = simulate_rdhwr(regs, opcode);
844 
845 		if (status < 0)
846 			status = SIGILL;
847 
848 		if (unlikely(status > 0)) {
849 			regs->cp0_epc = old_epc;	/* Undo skip-over.  */
850 			force_sig(status, current);
851 		}
852 
853 		return;
854 
855 	case 1:
856 		if (used_math())	/* Using the FPU again.  */
857 			own_fpu(1);
858 		else {			/* First time FPU user.  */
859 			init_fpu();
860 			set_used_math();
861 		}
862 
863 		if (!raw_cpu_has_fpu) {
864 			int sig;
865 			sig = fpu_emulator_cop1Handler(regs,
866 						&current->thread.fpu, 0);
867 			if (sig)
868 				force_sig(sig, current);
869 			else
870 				mt_ase_fp_affinity();
871 		}
872 
873 		return;
874 
875 	case 2:
876 	case 3:
877 		break;
878 	}
879 
880 	force_sig(SIGILL, current);
881 }
882 
883 asmlinkage void do_mdmx(struct pt_regs *regs)
884 {
885 	force_sig(SIGILL, current);
886 }
887 
888 asmlinkage void do_watch(struct pt_regs *regs)
889 {
890 	if (board_watchpoint_handler) {
891 		(*board_watchpoint_handler)(regs);
892 		return;
893 	}
894 
895 	/*
896 	 * We use the watch exception where available to detect stack
897 	 * overflows.
898 	 */
899 	dump_tlb_all();
900 	show_regs(regs);
901 	panic("Caught WATCH exception - probably caused by stack overflow.");
902 }
903 
904 asmlinkage void do_mcheck(struct pt_regs *regs)
905 {
906 	const int field = 2 * sizeof(unsigned long);
907 	int multi_match = regs->cp0_status & ST0_TS;
908 
909 	show_regs(regs);
910 
911 	if (multi_match) {
912 		printk("Index   : %0x\n", read_c0_index());
913 		printk("Pagemask: %0x\n", read_c0_pagemask());
914 		printk("EntryHi : %0*lx\n", field, read_c0_entryhi());
915 		printk("EntryLo0: %0*lx\n", field, read_c0_entrylo0());
916 		printk("EntryLo1: %0*lx\n", field, read_c0_entrylo1());
917 		printk("\n");
918 		dump_tlb_all();
919 	}
920 
921 	show_code((unsigned int __user *) regs->cp0_epc);
922 
923 	/*
924 	 * Some chips may have other causes of machine check (e.g. SB1
925 	 * graduation timer)
926 	 */
927 	panic("Caught Machine Check exception - %scaused by multiple "
928 	      "matching entries in the TLB.",
929 	      (multi_match) ? "" : "not ");
930 }
931 
932 asmlinkage void do_mt(struct pt_regs *regs)
933 {
934 	int subcode;
935 
936 	subcode = (read_vpe_c0_vpecontrol() & VPECONTROL_EXCPT)
937 			>> VPECONTROL_EXCPT_SHIFT;
938 	switch (subcode) {
939 	case 0:
940 		printk(KERN_DEBUG "Thread Underflow\n");
941 		break;
942 	case 1:
943 		printk(KERN_DEBUG "Thread Overflow\n");
944 		break;
945 	case 2:
946 		printk(KERN_DEBUG "Invalid YIELD Qualifier\n");
947 		break;
948 	case 3:
949 		printk(KERN_DEBUG "Gating Storage Exception\n");
950 		break;
951 	case 4:
952 		printk(KERN_DEBUG "YIELD Scheduler Exception\n");
953 		break;
954 	case 5:
955 		printk(KERN_DEBUG "Gating Storage Schedulier Exception\n");
956 		break;
957 	default:
958 		printk(KERN_DEBUG "*** UNKNOWN THREAD EXCEPTION %d ***\n",
959 			subcode);
960 		break;
961 	}
962 	die_if_kernel("MIPS MT Thread exception in kernel", regs);
963 
964 	force_sig(SIGILL, current);
965 }
966 
967 
968 asmlinkage void do_dsp(struct pt_regs *regs)
969 {
970 	if (cpu_has_dsp)
971 		panic("Unexpected DSP exception\n");
972 
973 	force_sig(SIGILL, current);
974 }
975 
976 asmlinkage void do_reserved(struct pt_regs *regs)
977 {
978 	/*
979 	 * Game over - no way to handle this if it ever occurs.  Most probably
980 	 * caused by a new unknown cpu type or after another deadly
981 	 * hard/software error.
982 	 */
983 	show_regs(regs);
984 	panic("Caught reserved exception %ld - should not happen.",
985 	      (regs->cp0_cause & 0x7f) >> 2);
986 }
987 
988 /*
989  * Some MIPS CPUs can enable/disable for cache parity detection, but do
990  * it different ways.
991  */
992 static inline void parity_protection_init(void)
993 {
994 	switch (current_cpu_type()) {
995 	case CPU_24K:
996 	case CPU_34K:
997 	case CPU_5KC:
998 		write_c0_ecc(0x80000000);
999 		back_to_back_c0_hazard();
1000 		/* Set the PE bit (bit 31) in the c0_errctl register. */
1001 		printk(KERN_INFO "Cache parity protection %sabled\n",
1002 		       (read_c0_ecc() & 0x80000000) ? "en" : "dis");
1003 		break;
1004 	case CPU_20KC:
1005 	case CPU_25KF:
1006 		/* Clear the DE bit (bit 16) in the c0_status register. */
1007 		printk(KERN_INFO "Enable cache parity protection for "
1008 		       "MIPS 20KC/25KF CPUs.\n");
1009 		clear_c0_status(ST0_DE);
1010 		break;
1011 	default:
1012 		break;
1013 	}
1014 }
1015 
1016 asmlinkage void cache_parity_error(void)
1017 {
1018 	const int field = 2 * sizeof(unsigned long);
1019 	unsigned int reg_val;
1020 
1021 	/* For the moment, report the problem and hang. */
1022 	printk("Cache error exception:\n");
1023 	printk("cp0_errorepc == %0*lx\n", field, read_c0_errorepc());
1024 	reg_val = read_c0_cacheerr();
1025 	printk("c0_cacheerr == %08x\n", reg_val);
1026 
1027 	printk("Decoded c0_cacheerr: %s cache fault in %s reference.\n",
1028 	       reg_val & (1<<30) ? "secondary" : "primary",
1029 	       reg_val & (1<<31) ? "data" : "insn");
1030 	printk("Error bits: %s%s%s%s%s%s%s\n",
1031 	       reg_val & (1<<29) ? "ED " : "",
1032 	       reg_val & (1<<28) ? "ET " : "",
1033 	       reg_val & (1<<26) ? "EE " : "",
1034 	       reg_val & (1<<25) ? "EB " : "",
1035 	       reg_val & (1<<24) ? "EI " : "",
1036 	       reg_val & (1<<23) ? "E1 " : "",
1037 	       reg_val & (1<<22) ? "E0 " : "");
1038 	printk("IDX: 0x%08x\n", reg_val & ((1<<22)-1));
1039 
1040 #if defined(CONFIG_CPU_MIPS32) || defined(CONFIG_CPU_MIPS64)
1041 	if (reg_val & (1<<22))
1042 		printk("DErrAddr0: 0x%0*lx\n", field, read_c0_derraddr0());
1043 
1044 	if (reg_val & (1<<23))
1045 		printk("DErrAddr1: 0x%0*lx\n", field, read_c0_derraddr1());
1046 #endif
1047 
1048 	panic("Can't handle the cache error!");
1049 }
1050 
1051 /*
1052  * SDBBP EJTAG debug exception handler.
1053  * We skip the instruction and return to the next instruction.
1054  */
1055 void ejtag_exception_handler(struct pt_regs *regs)
1056 {
1057 	const int field = 2 * sizeof(unsigned long);
1058 	unsigned long depc, old_epc;
1059 	unsigned int debug;
1060 
1061 	printk(KERN_DEBUG "SDBBP EJTAG debug exception - not handled yet, just ignored!\n");
1062 	depc = read_c0_depc();
1063 	debug = read_c0_debug();
1064 	printk(KERN_DEBUG "c0_depc = %0*lx, DEBUG = %08x\n", field, depc, debug);
1065 	if (debug & 0x80000000) {
1066 		/*
1067 		 * In branch delay slot.
1068 		 * We cheat a little bit here and use EPC to calculate the
1069 		 * debug return address (DEPC). EPC is restored after the
1070 		 * calculation.
1071 		 */
1072 		old_epc = regs->cp0_epc;
1073 		regs->cp0_epc = depc;
1074 		__compute_return_epc(regs);
1075 		depc = regs->cp0_epc;
1076 		regs->cp0_epc = old_epc;
1077 	} else
1078 		depc += 4;
1079 	write_c0_depc(depc);
1080 
1081 #if 0
1082 	printk(KERN_DEBUG "\n\n----- Enable EJTAG single stepping ----\n\n");
1083 	write_c0_debug(debug | 0x100);
1084 #endif
1085 }
1086 
1087 /*
1088  * NMI exception handler.
1089  */
1090 NORET_TYPE void ATTRIB_NORET nmi_exception_handler(struct pt_regs *regs)
1091 {
1092 	bust_spinlocks(1);
1093 	printk("NMI taken!!!!\n");
1094 	die("NMI", regs);
1095 }
1096 
1097 #define VECTORSPACING 0x100	/* for EI/VI mode */
1098 
1099 unsigned long ebase;
1100 unsigned long exception_handlers[32];
1101 unsigned long vi_handlers[64];
1102 
1103 /*
1104  * As a side effect of the way this is implemented we're limited
1105  * to interrupt handlers in the address range from
1106  * KSEG0 <= x < KSEG0 + 256mb on the Nevada.  Oh well ...
1107  */
1108 void *set_except_vector(int n, void *addr)
1109 {
1110 	unsigned long handler = (unsigned long) addr;
1111 	unsigned long old_handler = exception_handlers[n];
1112 
1113 	exception_handlers[n] = handler;
1114 	if (n == 0 && cpu_has_divec) {
1115 		*(u32 *)(ebase + 0x200) = 0x08000000 |
1116 					  (0x03ffffff & (handler >> 2));
1117 		flush_icache_range(ebase + 0x200, ebase + 0x204);
1118 	}
1119 	return (void *)old_handler;
1120 }
1121 
1122 static asmlinkage void do_default_vi(void)
1123 {
1124 	show_regs(get_irq_regs());
1125 	panic("Caught unexpected vectored interrupt.");
1126 }
1127 
1128 static void *set_vi_srs_handler(int n, vi_handler_t addr, int srs)
1129 {
1130 	unsigned long handler;
1131 	unsigned long old_handler = vi_handlers[n];
1132 	int srssets = current_cpu_data.srsets;
1133 	u32 *w;
1134 	unsigned char *b;
1135 
1136 	if (!cpu_has_veic && !cpu_has_vint)
1137 		BUG();
1138 
1139 	if (addr == NULL) {
1140 		handler = (unsigned long) do_default_vi;
1141 		srs = 0;
1142 	} else
1143 		handler = (unsigned long) addr;
1144 	vi_handlers[n] = (unsigned long) addr;
1145 
1146 	b = (unsigned char *)(ebase + 0x200 + n*VECTORSPACING);
1147 
1148 	if (srs >= srssets)
1149 		panic("Shadow register set %d not supported", srs);
1150 
1151 	if (cpu_has_veic) {
1152 		if (board_bind_eic_interrupt)
1153 			board_bind_eic_interrupt(n, srs);
1154 	} else if (cpu_has_vint) {
1155 		/* SRSMap is only defined if shadow sets are implemented */
1156 		if (srssets > 1)
1157 			change_c0_srsmap(0xf << n*4, srs << n*4);
1158 	}
1159 
1160 	if (srs == 0) {
1161 		/*
1162 		 * If no shadow set is selected then use the default handler
1163 		 * that does normal register saving and a standard interrupt exit
1164 		 */
1165 
1166 		extern char except_vec_vi, except_vec_vi_lui;
1167 		extern char except_vec_vi_ori, except_vec_vi_end;
1168 #ifdef CONFIG_MIPS_MT_SMTC
1169 		/*
1170 		 * We need to provide the SMTC vectored interrupt handler
1171 		 * not only with the address of the handler, but with the
1172 		 * Status.IM bit to be masked before going there.
1173 		 */
1174 		extern char except_vec_vi_mori;
1175 		const int mori_offset = &except_vec_vi_mori - &except_vec_vi;
1176 #endif /* CONFIG_MIPS_MT_SMTC */
1177 		const int handler_len = &except_vec_vi_end - &except_vec_vi;
1178 		const int lui_offset = &except_vec_vi_lui - &except_vec_vi;
1179 		const int ori_offset = &except_vec_vi_ori - &except_vec_vi;
1180 
1181 		if (handler_len > VECTORSPACING) {
1182 			/*
1183 			 * Sigh... panicing won't help as the console
1184 			 * is probably not configured :(
1185 			 */
1186 			panic("VECTORSPACING too small");
1187 		}
1188 
1189 		memcpy(b, &except_vec_vi, handler_len);
1190 #ifdef CONFIG_MIPS_MT_SMTC
1191 		BUG_ON(n > 7);	/* Vector index %d exceeds SMTC maximum. */
1192 
1193 		w = (u32 *)(b + mori_offset);
1194 		*w = (*w & 0xffff0000) | (0x100 << n);
1195 #endif /* CONFIG_MIPS_MT_SMTC */
1196 		w = (u32 *)(b + lui_offset);
1197 		*w = (*w & 0xffff0000) | (((u32)handler >> 16) & 0xffff);
1198 		w = (u32 *)(b + ori_offset);
1199 		*w = (*w & 0xffff0000) | ((u32)handler & 0xffff);
1200 		flush_icache_range((unsigned long)b, (unsigned long)(b+handler_len));
1201 	}
1202 	else {
1203 		/*
1204 		 * In other cases jump directly to the interrupt handler
1205 		 *
1206 		 * It is the handlers responsibility to save registers if required
1207 		 * (eg hi/lo) and return from the exception using "eret"
1208 		 */
1209 		w = (u32 *)b;
1210 		*w++ = 0x08000000 | (((u32)handler >> 2) & 0x03fffff); /* j handler */
1211 		*w = 0;
1212 		flush_icache_range((unsigned long)b, (unsigned long)(b+8));
1213 	}
1214 
1215 	return (void *)old_handler;
1216 }
1217 
1218 void *set_vi_handler(int n, vi_handler_t addr)
1219 {
1220 	return set_vi_srs_handler(n, addr, 0);
1221 }
1222 
1223 /*
1224  * This is used by native signal handling
1225  */
1226 asmlinkage int (*save_fp_context)(struct sigcontext __user *sc);
1227 asmlinkage int (*restore_fp_context)(struct sigcontext __user *sc);
1228 
1229 extern asmlinkage int _save_fp_context(struct sigcontext __user *sc);
1230 extern asmlinkage int _restore_fp_context(struct sigcontext __user *sc);
1231 
1232 extern asmlinkage int fpu_emulator_save_context(struct sigcontext __user *sc);
1233 extern asmlinkage int fpu_emulator_restore_context(struct sigcontext __user *sc);
1234 
1235 #ifdef CONFIG_SMP
1236 static int smp_save_fp_context(struct sigcontext __user *sc)
1237 {
1238 	return raw_cpu_has_fpu
1239 	       ? _save_fp_context(sc)
1240 	       : fpu_emulator_save_context(sc);
1241 }
1242 
1243 static int smp_restore_fp_context(struct sigcontext __user *sc)
1244 {
1245 	return raw_cpu_has_fpu
1246 	       ? _restore_fp_context(sc)
1247 	       : fpu_emulator_restore_context(sc);
1248 }
1249 #endif
1250 
1251 static inline void signal_init(void)
1252 {
1253 #ifdef CONFIG_SMP
1254 	/* For now just do the cpu_has_fpu check when the functions are invoked */
1255 	save_fp_context = smp_save_fp_context;
1256 	restore_fp_context = smp_restore_fp_context;
1257 #else
1258 	if (cpu_has_fpu) {
1259 		save_fp_context = _save_fp_context;
1260 		restore_fp_context = _restore_fp_context;
1261 	} else {
1262 		save_fp_context = fpu_emulator_save_context;
1263 		restore_fp_context = fpu_emulator_restore_context;
1264 	}
1265 #endif
1266 }
1267 
1268 #ifdef CONFIG_MIPS32_COMPAT
1269 
1270 /*
1271  * This is used by 32-bit signal stuff on the 64-bit kernel
1272  */
1273 asmlinkage int (*save_fp_context32)(struct sigcontext32 __user *sc);
1274 asmlinkage int (*restore_fp_context32)(struct sigcontext32 __user *sc);
1275 
1276 extern asmlinkage int _save_fp_context32(struct sigcontext32 __user *sc);
1277 extern asmlinkage int _restore_fp_context32(struct sigcontext32 __user *sc);
1278 
1279 extern asmlinkage int fpu_emulator_save_context32(struct sigcontext32 __user *sc);
1280 extern asmlinkage int fpu_emulator_restore_context32(struct sigcontext32 __user *sc);
1281 
1282 static inline void signal32_init(void)
1283 {
1284 	if (cpu_has_fpu) {
1285 		save_fp_context32 = _save_fp_context32;
1286 		restore_fp_context32 = _restore_fp_context32;
1287 	} else {
1288 		save_fp_context32 = fpu_emulator_save_context32;
1289 		restore_fp_context32 = fpu_emulator_restore_context32;
1290 	}
1291 }
1292 #endif
1293 
1294 extern void cpu_cache_init(void);
1295 extern void tlb_init(void);
1296 extern void flush_tlb_handlers(void);
1297 
1298 /*
1299  * Timer interrupt
1300  */
1301 int cp0_compare_irq;
1302 
1303 /*
1304  * Performance counter IRQ or -1 if shared with timer
1305  */
1306 int cp0_perfcount_irq;
1307 EXPORT_SYMBOL_GPL(cp0_perfcount_irq);
1308 
1309 void __cpuinit per_cpu_trap_init(void)
1310 {
1311 	unsigned int cpu = smp_processor_id();
1312 	unsigned int status_set = ST0_CU0;
1313 #ifdef CONFIG_MIPS_MT_SMTC
1314 	int secondaryTC = 0;
1315 	int bootTC = (cpu == 0);
1316 
1317 	/*
1318 	 * Only do per_cpu_trap_init() for first TC of Each VPE.
1319 	 * Note that this hack assumes that the SMTC init code
1320 	 * assigns TCs consecutively and in ascending order.
1321 	 */
1322 
1323 	if (((read_c0_tcbind() & TCBIND_CURTC) != 0) &&
1324 	    ((read_c0_tcbind() & TCBIND_CURVPE) == cpu_data[cpu - 1].vpe_id))
1325 		secondaryTC = 1;
1326 #endif /* CONFIG_MIPS_MT_SMTC */
1327 
1328 	/*
1329 	 * Disable coprocessors and select 32-bit or 64-bit addressing
1330 	 * and the 16/32 or 32/32 FPR register model.  Reset the BEV
1331 	 * flag that some firmware may have left set and the TS bit (for
1332 	 * IP27).  Set XX for ISA IV code to work.
1333 	 */
1334 #ifdef CONFIG_64BIT
1335 	status_set |= ST0_FR|ST0_KX|ST0_SX|ST0_UX;
1336 #endif
1337 	if (current_cpu_data.isa_level == MIPS_CPU_ISA_IV)
1338 		status_set |= ST0_XX;
1339 	if (cpu_has_dsp)
1340 		status_set |= ST0_MX;
1341 
1342 	change_c0_status(ST0_CU|ST0_MX|ST0_RE|ST0_FR|ST0_BEV|ST0_TS|ST0_KX|ST0_SX|ST0_UX,
1343 			 status_set);
1344 
1345 #ifdef CONFIG_CPU_MIPSR2
1346 	if (cpu_has_mips_r2) {
1347 		unsigned int enable = 0x0000000f;
1348 
1349 		if (cpu_has_userlocal)
1350 			enable |= (1 << 29);
1351 
1352 		write_c0_hwrena(enable);
1353 	}
1354 #endif
1355 
1356 #ifdef CONFIG_MIPS_MT_SMTC
1357 	if (!secondaryTC) {
1358 #endif /* CONFIG_MIPS_MT_SMTC */
1359 
1360 	if (cpu_has_veic || cpu_has_vint) {
1361 		write_c0_ebase(ebase);
1362 		/* Setting vector spacing enables EI/VI mode  */
1363 		change_c0_intctl(0x3e0, VECTORSPACING);
1364 	}
1365 	if (cpu_has_divec) {
1366 		if (cpu_has_mipsmt) {
1367 			unsigned int vpflags = dvpe();
1368 			set_c0_cause(CAUSEF_IV);
1369 			evpe(vpflags);
1370 		} else
1371 			set_c0_cause(CAUSEF_IV);
1372 	}
1373 
1374 	/*
1375 	 * Before R2 both interrupt numbers were fixed to 7, so on R2 only:
1376 	 *
1377 	 *  o read IntCtl.IPTI to determine the timer interrupt
1378 	 *  o read IntCtl.IPPCI to determine the performance counter interrupt
1379 	 */
1380 	if (cpu_has_mips_r2) {
1381 		cp0_compare_irq = (read_c0_intctl() >> 29) & 7;
1382 		cp0_perfcount_irq = (read_c0_intctl() >> 26) & 7;
1383 		if (cp0_perfcount_irq == cp0_compare_irq)
1384 			cp0_perfcount_irq = -1;
1385 	} else {
1386 		cp0_compare_irq = CP0_LEGACY_COMPARE_IRQ;
1387 		cp0_perfcount_irq = -1;
1388 	}
1389 
1390 #ifdef CONFIG_MIPS_MT_SMTC
1391 	}
1392 #endif /* CONFIG_MIPS_MT_SMTC */
1393 
1394 	cpu_data[cpu].asid_cache = ASID_FIRST_VERSION;
1395 	TLBMISS_HANDLER_SETUP();
1396 
1397 	atomic_inc(&init_mm.mm_count);
1398 	current->active_mm = &init_mm;
1399 	BUG_ON(current->mm);
1400 	enter_lazy_tlb(&init_mm, current);
1401 
1402 #ifdef CONFIG_MIPS_MT_SMTC
1403 	if (bootTC) {
1404 #endif /* CONFIG_MIPS_MT_SMTC */
1405 		cpu_cache_init();
1406 		tlb_init();
1407 #ifdef CONFIG_MIPS_MT_SMTC
1408 	} else if (!secondaryTC) {
1409 		/*
1410 		 * First TC in non-boot VPE must do subset of tlb_init()
1411 		 * for MMU countrol registers.
1412 		 */
1413 		write_c0_pagemask(PM_DEFAULT_MASK);
1414 		write_c0_wired(0);
1415 	}
1416 #endif /* CONFIG_MIPS_MT_SMTC */
1417 }
1418 
1419 /* Install CPU exception handler */
1420 void __init set_handler(unsigned long offset, void *addr, unsigned long size)
1421 {
1422 	memcpy((void *)(ebase + offset), addr, size);
1423 	flush_icache_range(ebase + offset, ebase + offset + size);
1424 }
1425 
1426 static char panic_null_cerr[] __cpuinitdata =
1427 	"Trying to set NULL cache error exception handler";
1428 
1429 /* Install uncached CPU exception handler */
1430 void __cpuinit set_uncached_handler(unsigned long offset, void *addr,
1431 	unsigned long size)
1432 {
1433 #ifdef CONFIG_32BIT
1434 	unsigned long uncached_ebase = KSEG1ADDR(ebase);
1435 #endif
1436 #ifdef CONFIG_64BIT
1437 	unsigned long uncached_ebase = TO_UNCAC(ebase);
1438 #endif
1439 
1440 	if (!addr)
1441 		panic(panic_null_cerr);
1442 
1443 	memcpy((void *)(uncached_ebase + offset), addr, size);
1444 }
1445 
1446 static int __initdata rdhwr_noopt;
1447 static int __init set_rdhwr_noopt(char *str)
1448 {
1449 	rdhwr_noopt = 1;
1450 	return 1;
1451 }
1452 
1453 __setup("rdhwr_noopt", set_rdhwr_noopt);
1454 
1455 void __init trap_init(void)
1456 {
1457 	extern char except_vec3_generic, except_vec3_r4000;
1458 	extern char except_vec4;
1459 	unsigned long i;
1460 
1461 	if (cpu_has_veic || cpu_has_vint)
1462 		ebase = (unsigned long) alloc_bootmem_low_pages(0x200 + VECTORSPACING*64);
1463 	else
1464 		ebase = CAC_BASE;
1465 
1466 	per_cpu_trap_init();
1467 
1468 	/*
1469 	 * Copy the generic exception handlers to their final destination.
1470 	 * This will be overriden later as suitable for a particular
1471 	 * configuration.
1472 	 */
1473 	set_handler(0x180, &except_vec3_generic, 0x80);
1474 
1475 	/*
1476 	 * Setup default vectors
1477 	 */
1478 	for (i = 0; i <= 31; i++)
1479 		set_except_vector(i, handle_reserved);
1480 
1481 	/*
1482 	 * Copy the EJTAG debug exception vector handler code to it's final
1483 	 * destination.
1484 	 */
1485 	if (cpu_has_ejtag && board_ejtag_handler_setup)
1486 		board_ejtag_handler_setup();
1487 
1488 	/*
1489 	 * Only some CPUs have the watch exceptions.
1490 	 */
1491 	if (cpu_has_watch)
1492 		set_except_vector(23, handle_watch);
1493 
1494 	/*
1495 	 * Initialise interrupt handlers
1496 	 */
1497 	if (cpu_has_veic || cpu_has_vint) {
1498 		int nvec = cpu_has_veic ? 64 : 8;
1499 		for (i = 0; i < nvec; i++)
1500 			set_vi_handler(i, NULL);
1501 	}
1502 	else if (cpu_has_divec)
1503 		set_handler(0x200, &except_vec4, 0x8);
1504 
1505 	/*
1506 	 * Some CPUs can enable/disable for cache parity detection, but does
1507 	 * it different ways.
1508 	 */
1509 	parity_protection_init();
1510 
1511 	/*
1512 	 * The Data Bus Errors / Instruction Bus Errors are signaled
1513 	 * by external hardware.  Therefore these two exceptions
1514 	 * may have board specific handlers.
1515 	 */
1516 	if (board_be_init)
1517 		board_be_init();
1518 
1519 	set_except_vector(0, handle_int);
1520 	set_except_vector(1, handle_tlbm);
1521 	set_except_vector(2, handle_tlbl);
1522 	set_except_vector(3, handle_tlbs);
1523 
1524 	set_except_vector(4, handle_adel);
1525 	set_except_vector(5, handle_ades);
1526 
1527 	set_except_vector(6, handle_ibe);
1528 	set_except_vector(7, handle_dbe);
1529 
1530 	set_except_vector(8, handle_sys);
1531 	set_except_vector(9, handle_bp);
1532 	set_except_vector(10, rdhwr_noopt ? handle_ri :
1533 			  (cpu_has_vtag_icache ?
1534 			   handle_ri_rdhwr_vivt : handle_ri_rdhwr));
1535 	set_except_vector(11, handle_cpu);
1536 	set_except_vector(12, handle_ov);
1537 	set_except_vector(13, handle_tr);
1538 
1539 	if (current_cpu_type() == CPU_R6000 ||
1540 	    current_cpu_type() == CPU_R6000A) {
1541 		/*
1542 		 * The R6000 is the only R-series CPU that features a machine
1543 		 * check exception (similar to the R4000 cache error) and
1544 		 * unaligned ldc1/sdc1 exception.  The handlers have not been
1545 		 * written yet.  Well, anyway there is no R6000 machine on the
1546 		 * current list of targets for Linux/MIPS.
1547 		 * (Duh, crap, there is someone with a triple R6k machine)
1548 		 */
1549 		//set_except_vector(14, handle_mc);
1550 		//set_except_vector(15, handle_ndc);
1551 	}
1552 
1553 
1554 	if (board_nmi_handler_setup)
1555 		board_nmi_handler_setup();
1556 
1557 	if (cpu_has_fpu && !cpu_has_nofpuex)
1558 		set_except_vector(15, handle_fpe);
1559 
1560 	set_except_vector(22, handle_mdmx);
1561 
1562 	if (cpu_has_mcheck)
1563 		set_except_vector(24, handle_mcheck);
1564 
1565 	if (cpu_has_mipsmt)
1566 		set_except_vector(25, handle_mt);
1567 
1568 	set_except_vector(26, handle_dsp);
1569 
1570 	if (cpu_has_vce)
1571 		/* Special exception: R4[04]00 uses also the divec space. */
1572 		memcpy((void *)(CAC_BASE + 0x180), &except_vec3_r4000, 0x100);
1573 	else if (cpu_has_4kex)
1574 		memcpy((void *)(CAC_BASE + 0x180), &except_vec3_generic, 0x80);
1575 	else
1576 		memcpy((void *)(CAC_BASE + 0x080), &except_vec3_generic, 0x80);
1577 
1578 	signal_init();
1579 #ifdef CONFIG_MIPS32_COMPAT
1580 	signal32_init();
1581 #endif
1582 
1583 	flush_icache_range(ebase, ebase + 0x400);
1584 	flush_tlb_handlers();
1585 }
1586