xref: /openbmc/linux/arch/mips/kernel/traps.c (revision 384740dc)
1 /*
2  * This file is subject to the terms and conditions of the GNU General Public
3  * License.  See the file "COPYING" in the main directory of this archive
4  * for more details.
5  *
6  * Copyright (C) 1994 - 1999, 2000, 01, 06 Ralf Baechle
7  * Copyright (C) 1995, 1996 Paul M. Antoine
8  * Copyright (C) 1998 Ulf Carlsson
9  * Copyright (C) 1999 Silicon Graphics, Inc.
10  * Kevin D. Kissell, kevink@mips.com and Carsten Langgaard, carstenl@mips.com
11  * Copyright (C) 2000, 01 MIPS Technologies, Inc.
12  * Copyright (C) 2002, 2003, 2004, 2005, 2007  Maciej W. Rozycki
13  */
14 #include <linux/bug.h>
15 #include <linux/compiler.h>
16 #include <linux/init.h>
17 #include <linux/mm.h>
18 #include <linux/module.h>
19 #include <linux/sched.h>
20 #include <linux/smp.h>
21 #include <linux/spinlock.h>
22 #include <linux/kallsyms.h>
23 #include <linux/bootmem.h>
24 #include <linux/interrupt.h>
25 #include <linux/ptrace.h>
26 #include <linux/kgdb.h>
27 #include <linux/kdebug.h>
28 
29 #include <asm/bootinfo.h>
30 #include <asm/branch.h>
31 #include <asm/break.h>
32 #include <asm/cpu.h>
33 #include <asm/dsp.h>
34 #include <asm/fpu.h>
35 #include <asm/mipsregs.h>
36 #include <asm/mipsmtregs.h>
37 #include <asm/module.h>
38 #include <asm/pgtable.h>
39 #include <asm/ptrace.h>
40 #include <asm/sections.h>
41 #include <asm/system.h>
42 #include <asm/tlbdebug.h>
43 #include <asm/traps.h>
44 #include <asm/uaccess.h>
45 #include <asm/mmu_context.h>
46 #include <asm/types.h>
47 #include <asm/stacktrace.h>
48 
49 extern void check_wait(void);
50 extern asmlinkage void r4k_wait(void);
51 extern asmlinkage void rollback_handle_int(void);
52 extern asmlinkage void handle_int(void);
53 extern asmlinkage void handle_tlbm(void);
54 extern asmlinkage void handle_tlbl(void);
55 extern asmlinkage void handle_tlbs(void);
56 extern asmlinkage void handle_adel(void);
57 extern asmlinkage void handle_ades(void);
58 extern asmlinkage void handle_ibe(void);
59 extern asmlinkage void handle_dbe(void);
60 extern asmlinkage void handle_sys(void);
61 extern asmlinkage void handle_bp(void);
62 extern asmlinkage void handle_ri(void);
63 extern asmlinkage void handle_ri_rdhwr_vivt(void);
64 extern asmlinkage void handle_ri_rdhwr(void);
65 extern asmlinkage void handle_cpu(void);
66 extern asmlinkage void handle_ov(void);
67 extern asmlinkage void handle_tr(void);
68 extern asmlinkage void handle_fpe(void);
69 extern asmlinkage void handle_mdmx(void);
70 extern asmlinkage void handle_watch(void);
71 extern asmlinkage void handle_mt(void);
72 extern asmlinkage void handle_dsp(void);
73 extern asmlinkage void handle_mcheck(void);
74 extern asmlinkage void handle_reserved(void);
75 
76 extern int fpu_emulator_cop1Handler(struct pt_regs *xcp,
77 	struct mips_fpu_struct *ctx, int has_fpu);
78 
79 void (*board_be_init)(void);
80 int (*board_be_handler)(struct pt_regs *regs, int is_fixup);
81 void (*board_nmi_handler_setup)(void);
82 void (*board_ejtag_handler_setup)(void);
83 void (*board_bind_eic_interrupt)(int irq, int regset);
84 
85 
86 static void show_raw_backtrace(unsigned long reg29)
87 {
88 	unsigned long *sp = (unsigned long *)(reg29 & ~3);
89 	unsigned long addr;
90 
91 	printk("Call Trace:");
92 #ifdef CONFIG_KALLSYMS
93 	printk("\n");
94 #endif
95 	while (!kstack_end(sp)) {
96 		unsigned long __user *p =
97 			(unsigned long __user *)(unsigned long)sp++;
98 		if (__get_user(addr, p)) {
99 			printk(" (Bad stack address)");
100 			break;
101 		}
102 		if (__kernel_text_address(addr))
103 			print_ip_sym(addr);
104 	}
105 	printk("\n");
106 }
107 
108 #ifdef CONFIG_KALLSYMS
109 int raw_show_trace;
110 static int __init set_raw_show_trace(char *str)
111 {
112 	raw_show_trace = 1;
113 	return 1;
114 }
115 __setup("raw_show_trace", set_raw_show_trace);
116 #endif
117 
118 static void show_backtrace(struct task_struct *task, const struct pt_regs *regs)
119 {
120 	unsigned long sp = regs->regs[29];
121 	unsigned long ra = regs->regs[31];
122 	unsigned long pc = regs->cp0_epc;
123 
124 	if (raw_show_trace || !__kernel_text_address(pc)) {
125 		show_raw_backtrace(sp);
126 		return;
127 	}
128 	printk("Call Trace:\n");
129 	do {
130 		print_ip_sym(pc);
131 		pc = unwind_stack(task, &sp, pc, &ra);
132 	} while (pc);
133 	printk("\n");
134 }
135 
136 /*
137  * This routine abuses get_user()/put_user() to reference pointers
138  * with at least a bit of error checking ...
139  */
140 static void show_stacktrace(struct task_struct *task,
141 	const struct pt_regs *regs)
142 {
143 	const int field = 2 * sizeof(unsigned long);
144 	long stackdata;
145 	int i;
146 	unsigned long __user *sp = (unsigned long __user *)regs->regs[29];
147 
148 	printk("Stack :");
149 	i = 0;
150 	while ((unsigned long) sp & (PAGE_SIZE - 1)) {
151 		if (i && ((i % (64 / field)) == 0))
152 			printk("\n       ");
153 		if (i > 39) {
154 			printk(" ...");
155 			break;
156 		}
157 
158 		if (__get_user(stackdata, sp++)) {
159 			printk(" (Bad stack address)");
160 			break;
161 		}
162 
163 		printk(" %0*lx", field, stackdata);
164 		i++;
165 	}
166 	printk("\n");
167 	show_backtrace(task, regs);
168 }
169 
170 void show_stack(struct task_struct *task, unsigned long *sp)
171 {
172 	struct pt_regs regs;
173 	if (sp) {
174 		regs.regs[29] = (unsigned long)sp;
175 		regs.regs[31] = 0;
176 		regs.cp0_epc = 0;
177 	} else {
178 		if (task && task != current) {
179 			regs.regs[29] = task->thread.reg29;
180 			regs.regs[31] = 0;
181 			regs.cp0_epc = task->thread.reg31;
182 		} else {
183 			prepare_frametrace(&regs);
184 		}
185 	}
186 	show_stacktrace(task, &regs);
187 }
188 
189 /*
190  * The architecture-independent dump_stack generator
191  */
192 void dump_stack(void)
193 {
194 	struct pt_regs regs;
195 
196 	prepare_frametrace(&regs);
197 	show_backtrace(current, &regs);
198 }
199 
200 EXPORT_SYMBOL(dump_stack);
201 
202 static void show_code(unsigned int __user *pc)
203 {
204 	long i;
205 	unsigned short __user *pc16 = NULL;
206 
207 	printk("\nCode:");
208 
209 	if ((unsigned long)pc & 1)
210 		pc16 = (unsigned short __user *)((unsigned long)pc & ~1);
211 	for(i = -3 ; i < 6 ; i++) {
212 		unsigned int insn;
213 		if (pc16 ? __get_user(insn, pc16 + i) : __get_user(insn, pc + i)) {
214 			printk(" (Bad address in epc)\n");
215 			break;
216 		}
217 		printk("%c%0*x%c", (i?' ':'<'), pc16 ? 4 : 8, insn, (i?' ':'>'));
218 	}
219 }
220 
221 static void __show_regs(const struct pt_regs *regs)
222 {
223 	const int field = 2 * sizeof(unsigned long);
224 	unsigned int cause = regs->cp0_cause;
225 	int i;
226 
227 	printk("Cpu %d\n", smp_processor_id());
228 
229 	/*
230 	 * Saved main processor registers
231 	 */
232 	for (i = 0; i < 32; ) {
233 		if ((i % 4) == 0)
234 			printk("$%2d   :", i);
235 		if (i == 0)
236 			printk(" %0*lx", field, 0UL);
237 		else if (i == 26 || i == 27)
238 			printk(" %*s", field, "");
239 		else
240 			printk(" %0*lx", field, regs->regs[i]);
241 
242 		i++;
243 		if ((i % 4) == 0)
244 			printk("\n");
245 	}
246 
247 #ifdef CONFIG_CPU_HAS_SMARTMIPS
248 	printk("Acx    : %0*lx\n", field, regs->acx);
249 #endif
250 	printk("Hi    : %0*lx\n", field, regs->hi);
251 	printk("Lo    : %0*lx\n", field, regs->lo);
252 
253 	/*
254 	 * Saved cp0 registers
255 	 */
256 	printk("epc   : %0*lx %pS\n", field, regs->cp0_epc,
257 	       (void *) regs->cp0_epc);
258 	printk("    %s\n", print_tainted());
259 	printk("ra    : %0*lx %pS\n", field, regs->regs[31],
260 	       (void *) regs->regs[31]);
261 
262 	printk("Status: %08x    ", (uint32_t) regs->cp0_status);
263 
264 	if (current_cpu_data.isa_level == MIPS_CPU_ISA_I) {
265 		if (regs->cp0_status & ST0_KUO)
266 			printk("KUo ");
267 		if (regs->cp0_status & ST0_IEO)
268 			printk("IEo ");
269 		if (regs->cp0_status & ST0_KUP)
270 			printk("KUp ");
271 		if (regs->cp0_status & ST0_IEP)
272 			printk("IEp ");
273 		if (regs->cp0_status & ST0_KUC)
274 			printk("KUc ");
275 		if (regs->cp0_status & ST0_IEC)
276 			printk("IEc ");
277 	} else {
278 		if (regs->cp0_status & ST0_KX)
279 			printk("KX ");
280 		if (regs->cp0_status & ST0_SX)
281 			printk("SX ");
282 		if (regs->cp0_status & ST0_UX)
283 			printk("UX ");
284 		switch (regs->cp0_status & ST0_KSU) {
285 		case KSU_USER:
286 			printk("USER ");
287 			break;
288 		case KSU_SUPERVISOR:
289 			printk("SUPERVISOR ");
290 			break;
291 		case KSU_KERNEL:
292 			printk("KERNEL ");
293 			break;
294 		default:
295 			printk("BAD_MODE ");
296 			break;
297 		}
298 		if (regs->cp0_status & ST0_ERL)
299 			printk("ERL ");
300 		if (regs->cp0_status & ST0_EXL)
301 			printk("EXL ");
302 		if (regs->cp0_status & ST0_IE)
303 			printk("IE ");
304 	}
305 	printk("\n");
306 
307 	printk("Cause : %08x\n", cause);
308 
309 	cause = (cause & CAUSEF_EXCCODE) >> CAUSEB_EXCCODE;
310 	if (1 <= cause && cause <= 5)
311 		printk("BadVA : %0*lx\n", field, regs->cp0_badvaddr);
312 
313 	printk("PrId  : %08x (%s)\n", read_c0_prid(),
314 	       cpu_name_string());
315 }
316 
317 /*
318  * FIXME: really the generic show_regs should take a const pointer argument.
319  */
320 void show_regs(struct pt_regs *regs)
321 {
322 	__show_regs((struct pt_regs *)regs);
323 }
324 
325 void show_registers(const struct pt_regs *regs)
326 {
327 	const int field = 2 * sizeof(unsigned long);
328 
329 	__show_regs(regs);
330 	print_modules();
331 	printk("Process %s (pid: %d, threadinfo=%p, task=%p, tls=%0*lx)\n",
332 	       current->comm, current->pid, current_thread_info(), current,
333 	      field, current_thread_info()->tp_value);
334 	if (cpu_has_userlocal) {
335 		unsigned long tls;
336 
337 		tls = read_c0_userlocal();
338 		if (tls != current_thread_info()->tp_value)
339 			printk("*HwTLS: %0*lx\n", field, tls);
340 	}
341 
342 	show_stacktrace(current, regs);
343 	show_code((unsigned int __user *) regs->cp0_epc);
344 	printk("\n");
345 }
346 
347 static DEFINE_SPINLOCK(die_lock);
348 
349 void __noreturn die(const char * str, const struct pt_regs * regs)
350 {
351 	static int die_counter;
352 #ifdef CONFIG_MIPS_MT_SMTC
353 	unsigned long dvpret = dvpe();
354 #endif /* CONFIG_MIPS_MT_SMTC */
355 
356 	console_verbose();
357 	spin_lock_irq(&die_lock);
358 	bust_spinlocks(1);
359 #ifdef CONFIG_MIPS_MT_SMTC
360 	mips_mt_regdump(dvpret);
361 #endif /* CONFIG_MIPS_MT_SMTC */
362 	printk("%s[#%d]:\n", str, ++die_counter);
363 	show_registers(regs);
364 	add_taint(TAINT_DIE);
365 	spin_unlock_irq(&die_lock);
366 
367 	if (in_interrupt())
368 		panic("Fatal exception in interrupt");
369 
370 	if (panic_on_oops) {
371 		printk(KERN_EMERG "Fatal exception: panic in 5 seconds\n");
372 		ssleep(5);
373 		panic("Fatal exception");
374 	}
375 
376 	do_exit(SIGSEGV);
377 }
378 
379 extern struct exception_table_entry __start___dbe_table[];
380 extern struct exception_table_entry __stop___dbe_table[];
381 
382 __asm__(
383 "	.section	__dbe_table, \"a\"\n"
384 "	.previous			\n");
385 
386 /* Given an address, look for it in the exception tables. */
387 static const struct exception_table_entry *search_dbe_tables(unsigned long addr)
388 {
389 	const struct exception_table_entry *e;
390 
391 	e = search_extable(__start___dbe_table, __stop___dbe_table - 1, addr);
392 	if (!e)
393 		e = search_module_dbetables(addr);
394 	return e;
395 }
396 
397 asmlinkage void do_be(struct pt_regs *regs)
398 {
399 	const int field = 2 * sizeof(unsigned long);
400 	const struct exception_table_entry *fixup = NULL;
401 	int data = regs->cp0_cause & 4;
402 	int action = MIPS_BE_FATAL;
403 
404 	/* XXX For now.  Fixme, this searches the wrong table ...  */
405 	if (data && !user_mode(regs))
406 		fixup = search_dbe_tables(exception_epc(regs));
407 
408 	if (fixup)
409 		action = MIPS_BE_FIXUP;
410 
411 	if (board_be_handler)
412 		action = board_be_handler(regs, fixup != NULL);
413 
414 	switch (action) {
415 	case MIPS_BE_DISCARD:
416 		return;
417 	case MIPS_BE_FIXUP:
418 		if (fixup) {
419 			regs->cp0_epc = fixup->nextinsn;
420 			return;
421 		}
422 		break;
423 	default:
424 		break;
425 	}
426 
427 	/*
428 	 * Assume it would be too dangerous to continue ...
429 	 */
430 	printk(KERN_ALERT "%s bus error, epc == %0*lx, ra == %0*lx\n",
431 	       data ? "Data" : "Instruction",
432 	       field, regs->cp0_epc, field, regs->regs[31]);
433 	if (notify_die(DIE_OOPS, "bus error", regs, SIGBUS, 0, 0)
434 	    == NOTIFY_STOP)
435 		return;
436 
437 	die_if_kernel("Oops", regs);
438 	force_sig(SIGBUS, current);
439 }
440 
441 /*
442  * ll/sc, rdhwr, sync emulation
443  */
444 
445 #define OPCODE 0xfc000000
446 #define BASE   0x03e00000
447 #define RT     0x001f0000
448 #define OFFSET 0x0000ffff
449 #define LL     0xc0000000
450 #define SC     0xe0000000
451 #define SPEC0  0x00000000
452 #define SPEC3  0x7c000000
453 #define RD     0x0000f800
454 #define FUNC   0x0000003f
455 #define SYNC   0x0000000f
456 #define RDHWR  0x0000003b
457 
458 /*
459  * The ll_bit is cleared by r*_switch.S
460  */
461 
462 unsigned long ll_bit;
463 
464 static struct task_struct *ll_task = NULL;
465 
466 static inline int simulate_ll(struct pt_regs *regs, unsigned int opcode)
467 {
468 	unsigned long value, __user *vaddr;
469 	long offset;
470 
471 	/*
472 	 * analyse the ll instruction that just caused a ri exception
473 	 * and put the referenced address to addr.
474 	 */
475 
476 	/* sign extend offset */
477 	offset = opcode & OFFSET;
478 	offset <<= 16;
479 	offset >>= 16;
480 
481 	vaddr = (unsigned long __user *)
482 	        ((unsigned long)(regs->regs[(opcode & BASE) >> 21]) + offset);
483 
484 	if ((unsigned long)vaddr & 3)
485 		return SIGBUS;
486 	if (get_user(value, vaddr))
487 		return SIGSEGV;
488 
489 	preempt_disable();
490 
491 	if (ll_task == NULL || ll_task == current) {
492 		ll_bit = 1;
493 	} else {
494 		ll_bit = 0;
495 	}
496 	ll_task = current;
497 
498 	preempt_enable();
499 
500 	regs->regs[(opcode & RT) >> 16] = value;
501 
502 	return 0;
503 }
504 
505 static inline int simulate_sc(struct pt_regs *regs, unsigned int opcode)
506 {
507 	unsigned long __user *vaddr;
508 	unsigned long reg;
509 	long offset;
510 
511 	/*
512 	 * analyse the sc instruction that just caused a ri exception
513 	 * and put the referenced address to addr.
514 	 */
515 
516 	/* sign extend offset */
517 	offset = opcode & OFFSET;
518 	offset <<= 16;
519 	offset >>= 16;
520 
521 	vaddr = (unsigned long __user *)
522 	        ((unsigned long)(regs->regs[(opcode & BASE) >> 21]) + offset);
523 	reg = (opcode & RT) >> 16;
524 
525 	if ((unsigned long)vaddr & 3)
526 		return SIGBUS;
527 
528 	preempt_disable();
529 
530 	if (ll_bit == 0 || ll_task != current) {
531 		regs->regs[reg] = 0;
532 		preempt_enable();
533 		return 0;
534 	}
535 
536 	preempt_enable();
537 
538 	if (put_user(regs->regs[reg], vaddr))
539 		return SIGSEGV;
540 
541 	regs->regs[reg] = 1;
542 
543 	return 0;
544 }
545 
546 /*
547  * ll uses the opcode of lwc0 and sc uses the opcode of swc0.  That is both
548  * opcodes are supposed to result in coprocessor unusable exceptions if
549  * executed on ll/sc-less processors.  That's the theory.  In practice a
550  * few processors such as NEC's VR4100 throw reserved instruction exceptions
551  * instead, so we're doing the emulation thing in both exception handlers.
552  */
553 static int simulate_llsc(struct pt_regs *regs, unsigned int opcode)
554 {
555 	if ((opcode & OPCODE) == LL)
556 		return simulate_ll(regs, opcode);
557 	if ((opcode & OPCODE) == SC)
558 		return simulate_sc(regs, opcode);
559 
560 	return -1;			/* Must be something else ... */
561 }
562 
563 /*
564  * Simulate trapping 'rdhwr' instructions to provide user accessible
565  * registers not implemented in hardware.
566  */
567 static int simulate_rdhwr(struct pt_regs *regs, unsigned int opcode)
568 {
569 	struct thread_info *ti = task_thread_info(current);
570 
571 	if ((opcode & OPCODE) == SPEC3 && (opcode & FUNC) == RDHWR) {
572 		int rd = (opcode & RD) >> 11;
573 		int rt = (opcode & RT) >> 16;
574 		switch (rd) {
575 		case 0:		/* CPU number */
576 			regs->regs[rt] = smp_processor_id();
577 			return 0;
578 		case 1:		/* SYNCI length */
579 			regs->regs[rt] = min(current_cpu_data.dcache.linesz,
580 					     current_cpu_data.icache.linesz);
581 			return 0;
582 		case 2:		/* Read count register */
583 			regs->regs[rt] = read_c0_count();
584 			return 0;
585 		case 3:		/* Count register resolution */
586 			switch (current_cpu_data.cputype) {
587 			case CPU_20KC:
588 			case CPU_25KF:
589 				regs->regs[rt] = 1;
590 				break;
591 			default:
592 				regs->regs[rt] = 2;
593 			}
594 			return 0;
595 		case 29:
596 			regs->regs[rt] = ti->tp_value;
597 			return 0;
598 		default:
599 			return -1;
600 		}
601 	}
602 
603 	/* Not ours.  */
604 	return -1;
605 }
606 
607 static int simulate_sync(struct pt_regs *regs, unsigned int opcode)
608 {
609 	if ((opcode & OPCODE) == SPEC0 && (opcode & FUNC) == SYNC)
610 		return 0;
611 
612 	return -1;			/* Must be something else ... */
613 }
614 
615 asmlinkage void do_ov(struct pt_regs *regs)
616 {
617 	siginfo_t info;
618 
619 	die_if_kernel("Integer overflow", regs);
620 
621 	info.si_code = FPE_INTOVF;
622 	info.si_signo = SIGFPE;
623 	info.si_errno = 0;
624 	info.si_addr = (void __user *) regs->cp0_epc;
625 	force_sig_info(SIGFPE, &info, current);
626 }
627 
628 /*
629  * XXX Delayed fp exceptions when doing a lazy ctx switch XXX
630  */
631 asmlinkage void do_fpe(struct pt_regs *regs, unsigned long fcr31)
632 {
633 	siginfo_t info;
634 
635 	if (notify_die(DIE_FP, "FP exception", regs, SIGFPE, 0, 0)
636 	    == NOTIFY_STOP)
637 		return;
638 	die_if_kernel("FP exception in kernel code", regs);
639 
640 	if (fcr31 & FPU_CSR_UNI_X) {
641 		int sig;
642 
643 		/*
644 		 * Unimplemented operation exception.  If we've got the full
645 		 * software emulator on-board, let's use it...
646 		 *
647 		 * Force FPU to dump state into task/thread context.  We're
648 		 * moving a lot of data here for what is probably a single
649 		 * instruction, but the alternative is to pre-decode the FP
650 		 * register operands before invoking the emulator, which seems
651 		 * a bit extreme for what should be an infrequent event.
652 		 */
653 		/* Ensure 'resume' not overwrite saved fp context again. */
654 		lose_fpu(1);
655 
656 		/* Run the emulator */
657 		sig = fpu_emulator_cop1Handler(regs, &current->thread.fpu, 1);
658 
659 		/*
660 		 * We can't allow the emulated instruction to leave any of
661 		 * the cause bit set in $fcr31.
662 		 */
663 		current->thread.fpu.fcr31 &= ~FPU_CSR_ALL_X;
664 
665 		/* Restore the hardware register state */
666 		own_fpu(1);	/* Using the FPU again.  */
667 
668 		/* If something went wrong, signal */
669 		if (sig)
670 			force_sig(sig, current);
671 
672 		return;
673 	} else if (fcr31 & FPU_CSR_INV_X)
674 		info.si_code = FPE_FLTINV;
675 	else if (fcr31 & FPU_CSR_DIV_X)
676 		info.si_code = FPE_FLTDIV;
677 	else if (fcr31 & FPU_CSR_OVF_X)
678 		info.si_code = FPE_FLTOVF;
679 	else if (fcr31 & FPU_CSR_UDF_X)
680 		info.si_code = FPE_FLTUND;
681 	else if (fcr31 & FPU_CSR_INE_X)
682 		info.si_code = FPE_FLTRES;
683 	else
684 		info.si_code = __SI_FAULT;
685 	info.si_signo = SIGFPE;
686 	info.si_errno = 0;
687 	info.si_addr = (void __user *) regs->cp0_epc;
688 	force_sig_info(SIGFPE, &info, current);
689 }
690 
691 static void do_trap_or_bp(struct pt_regs *regs, unsigned int code,
692 	const char *str)
693 {
694 	siginfo_t info;
695 	char b[40];
696 
697 	if (notify_die(DIE_TRAP, str, regs, code, 0, 0) == NOTIFY_STOP)
698 		return;
699 
700 	/*
701 	 * A short test says that IRIX 5.3 sends SIGTRAP for all trap
702 	 * insns, even for trap and break codes that indicate arithmetic
703 	 * failures.  Weird ...
704 	 * But should we continue the brokenness???  --macro
705 	 */
706 	switch (code) {
707 	case BRK_OVERFLOW:
708 	case BRK_DIVZERO:
709 		scnprintf(b, sizeof(b), "%s instruction in kernel code", str);
710 		die_if_kernel(b, regs);
711 		if (code == BRK_DIVZERO)
712 			info.si_code = FPE_INTDIV;
713 		else
714 			info.si_code = FPE_INTOVF;
715 		info.si_signo = SIGFPE;
716 		info.si_errno = 0;
717 		info.si_addr = (void __user *) regs->cp0_epc;
718 		force_sig_info(SIGFPE, &info, current);
719 		break;
720 	case BRK_BUG:
721 		die_if_kernel("Kernel bug detected", regs);
722 		force_sig(SIGTRAP, current);
723 		break;
724 	default:
725 		scnprintf(b, sizeof(b), "%s instruction in kernel code", str);
726 		die_if_kernel(b, regs);
727 		force_sig(SIGTRAP, current);
728 	}
729 }
730 
731 asmlinkage void do_bp(struct pt_regs *regs)
732 {
733 	unsigned int opcode, bcode;
734 
735 	if (__get_user(opcode, (unsigned int __user *) exception_epc(regs)))
736 		goto out_sigsegv;
737 
738 	/*
739 	 * There is the ancient bug in the MIPS assemblers that the break
740 	 * code starts left to bit 16 instead to bit 6 in the opcode.
741 	 * Gas is bug-compatible, but not always, grrr...
742 	 * We handle both cases with a simple heuristics.  --macro
743 	 */
744 	bcode = ((opcode >> 6) & ((1 << 20) - 1));
745 	if (bcode >= (1 << 10))
746 		bcode >>= 10;
747 
748 	do_trap_or_bp(regs, bcode, "Break");
749 	return;
750 
751 out_sigsegv:
752 	force_sig(SIGSEGV, current);
753 }
754 
755 asmlinkage void do_tr(struct pt_regs *regs)
756 {
757 	unsigned int opcode, tcode = 0;
758 
759 	if (__get_user(opcode, (unsigned int __user *) exception_epc(regs)))
760 		goto out_sigsegv;
761 
762 	/* Immediate versions don't provide a code.  */
763 	if (!(opcode & OPCODE))
764 		tcode = ((opcode >> 6) & ((1 << 10) - 1));
765 
766 	do_trap_or_bp(regs, tcode, "Trap");
767 	return;
768 
769 out_sigsegv:
770 	force_sig(SIGSEGV, current);
771 }
772 
773 asmlinkage void do_ri(struct pt_regs *regs)
774 {
775 	unsigned int __user *epc = (unsigned int __user *)exception_epc(regs);
776 	unsigned long old_epc = regs->cp0_epc;
777 	unsigned int opcode = 0;
778 	int status = -1;
779 
780 	if (notify_die(DIE_RI, "RI Fault", regs, SIGSEGV, 0, 0)
781 	    == NOTIFY_STOP)
782 		return;
783 
784 	die_if_kernel("Reserved instruction in kernel code", regs);
785 
786 	if (unlikely(compute_return_epc(regs) < 0))
787 		return;
788 
789 	if (unlikely(get_user(opcode, epc) < 0))
790 		status = SIGSEGV;
791 
792 	if (!cpu_has_llsc && status < 0)
793 		status = simulate_llsc(regs, opcode);
794 
795 	if (status < 0)
796 		status = simulate_rdhwr(regs, opcode);
797 
798 	if (status < 0)
799 		status = simulate_sync(regs, opcode);
800 
801 	if (status < 0)
802 		status = SIGILL;
803 
804 	if (unlikely(status > 0)) {
805 		regs->cp0_epc = old_epc;		/* Undo skip-over.  */
806 		force_sig(status, current);
807 	}
808 }
809 
810 /*
811  * MIPS MT processors may have fewer FPU contexts than CPU threads. If we've
812  * emulated more than some threshold number of instructions, force migration to
813  * a "CPU" that has FP support.
814  */
815 static void mt_ase_fp_affinity(void)
816 {
817 #ifdef CONFIG_MIPS_MT_FPAFF
818 	if (mt_fpemul_threshold > 0 &&
819 	     ((current->thread.emulated_fp++ > mt_fpemul_threshold))) {
820 		/*
821 		 * If there's no FPU present, or if the application has already
822 		 * restricted the allowed set to exclude any CPUs with FPUs,
823 		 * we'll skip the procedure.
824 		 */
825 		if (cpus_intersects(current->cpus_allowed, mt_fpu_cpumask)) {
826 			cpumask_t tmask;
827 
828 			current->thread.user_cpus_allowed
829 				= current->cpus_allowed;
830 			cpus_and(tmask, current->cpus_allowed,
831 				mt_fpu_cpumask);
832 			set_cpus_allowed(current, tmask);
833 			set_thread_flag(TIF_FPUBOUND);
834 		}
835 	}
836 #endif /* CONFIG_MIPS_MT_FPAFF */
837 }
838 
839 asmlinkage void do_cpu(struct pt_regs *regs)
840 {
841 	unsigned int __user *epc;
842 	unsigned long old_epc;
843 	unsigned int opcode;
844 	unsigned int cpid;
845 	int status;
846 
847 	die_if_kernel("do_cpu invoked from kernel context!", regs);
848 
849 	cpid = (regs->cp0_cause >> CAUSEB_CE) & 3;
850 
851 	switch (cpid) {
852 	case 0:
853 		epc = (unsigned int __user *)exception_epc(regs);
854 		old_epc = regs->cp0_epc;
855 		opcode = 0;
856 		status = -1;
857 
858 		if (unlikely(compute_return_epc(regs) < 0))
859 			return;
860 
861 		if (unlikely(get_user(opcode, epc) < 0))
862 			status = SIGSEGV;
863 
864 		if (!cpu_has_llsc && status < 0)
865 			status = simulate_llsc(regs, opcode);
866 
867 		if (status < 0)
868 			status = simulate_rdhwr(regs, opcode);
869 
870 		if (status < 0)
871 			status = SIGILL;
872 
873 		if (unlikely(status > 0)) {
874 			regs->cp0_epc = old_epc;	/* Undo skip-over.  */
875 			force_sig(status, current);
876 		}
877 
878 		return;
879 
880 	case 1:
881 		if (used_math())	/* Using the FPU again.  */
882 			own_fpu(1);
883 		else {			/* First time FPU user.  */
884 			init_fpu();
885 			set_used_math();
886 		}
887 
888 		if (!raw_cpu_has_fpu) {
889 			int sig;
890 			sig = fpu_emulator_cop1Handler(regs,
891 						&current->thread.fpu, 0);
892 			if (sig)
893 				force_sig(sig, current);
894 			else
895 				mt_ase_fp_affinity();
896 		}
897 
898 		return;
899 
900 	case 2:
901 	case 3:
902 		break;
903 	}
904 
905 	force_sig(SIGILL, current);
906 }
907 
908 asmlinkage void do_mdmx(struct pt_regs *regs)
909 {
910 	force_sig(SIGILL, current);
911 }
912 
913 asmlinkage void do_watch(struct pt_regs *regs)
914 {
915 	/*
916 	 * We use the watch exception where available to detect stack
917 	 * overflows.
918 	 */
919 	dump_tlb_all();
920 	show_regs(regs);
921 	panic("Caught WATCH exception - probably caused by stack overflow.");
922 }
923 
924 asmlinkage void do_mcheck(struct pt_regs *regs)
925 {
926 	const int field = 2 * sizeof(unsigned long);
927 	int multi_match = regs->cp0_status & ST0_TS;
928 
929 	show_regs(regs);
930 
931 	if (multi_match) {
932 		printk("Index   : %0x\n", read_c0_index());
933 		printk("Pagemask: %0x\n", read_c0_pagemask());
934 		printk("EntryHi : %0*lx\n", field, read_c0_entryhi());
935 		printk("EntryLo0: %0*lx\n", field, read_c0_entrylo0());
936 		printk("EntryLo1: %0*lx\n", field, read_c0_entrylo1());
937 		printk("\n");
938 		dump_tlb_all();
939 	}
940 
941 	show_code((unsigned int __user *) regs->cp0_epc);
942 
943 	/*
944 	 * Some chips may have other causes of machine check (e.g. SB1
945 	 * graduation timer)
946 	 */
947 	panic("Caught Machine Check exception - %scaused by multiple "
948 	      "matching entries in the TLB.",
949 	      (multi_match) ? "" : "not ");
950 }
951 
952 asmlinkage void do_mt(struct pt_regs *regs)
953 {
954 	int subcode;
955 
956 	subcode = (read_vpe_c0_vpecontrol() & VPECONTROL_EXCPT)
957 			>> VPECONTROL_EXCPT_SHIFT;
958 	switch (subcode) {
959 	case 0:
960 		printk(KERN_DEBUG "Thread Underflow\n");
961 		break;
962 	case 1:
963 		printk(KERN_DEBUG "Thread Overflow\n");
964 		break;
965 	case 2:
966 		printk(KERN_DEBUG "Invalid YIELD Qualifier\n");
967 		break;
968 	case 3:
969 		printk(KERN_DEBUG "Gating Storage Exception\n");
970 		break;
971 	case 4:
972 		printk(KERN_DEBUG "YIELD Scheduler Exception\n");
973 		break;
974 	case 5:
975 		printk(KERN_DEBUG "Gating Storage Schedulier Exception\n");
976 		break;
977 	default:
978 		printk(KERN_DEBUG "*** UNKNOWN THREAD EXCEPTION %d ***\n",
979 			subcode);
980 		break;
981 	}
982 	die_if_kernel("MIPS MT Thread exception in kernel", regs);
983 
984 	force_sig(SIGILL, current);
985 }
986 
987 
988 asmlinkage void do_dsp(struct pt_regs *regs)
989 {
990 	if (cpu_has_dsp)
991 		panic("Unexpected DSP exception\n");
992 
993 	force_sig(SIGILL, current);
994 }
995 
996 asmlinkage void do_reserved(struct pt_regs *regs)
997 {
998 	/*
999 	 * Game over - no way to handle this if it ever occurs.  Most probably
1000 	 * caused by a new unknown cpu type or after another deadly
1001 	 * hard/software error.
1002 	 */
1003 	show_regs(regs);
1004 	panic("Caught reserved exception %ld - should not happen.",
1005 	      (regs->cp0_cause & 0x7f) >> 2);
1006 }
1007 
1008 static int __initdata l1parity = 1;
1009 static int __init nol1parity(char *s)
1010 {
1011 	l1parity = 0;
1012 	return 1;
1013 }
1014 __setup("nol1par", nol1parity);
1015 static int __initdata l2parity = 1;
1016 static int __init nol2parity(char *s)
1017 {
1018 	l2parity = 0;
1019 	return 1;
1020 }
1021 __setup("nol2par", nol2parity);
1022 
1023 /*
1024  * Some MIPS CPUs can enable/disable for cache parity detection, but do
1025  * it different ways.
1026  */
1027 static inline void parity_protection_init(void)
1028 {
1029 	switch (current_cpu_type()) {
1030 	case CPU_24K:
1031 	case CPU_34K:
1032 	case CPU_74K:
1033 	case CPU_1004K:
1034 		{
1035 #define ERRCTL_PE	0x80000000
1036 #define ERRCTL_L2P	0x00800000
1037 			unsigned long errctl;
1038 			unsigned int l1parity_present, l2parity_present;
1039 
1040 			errctl = read_c0_ecc();
1041 			errctl &= ~(ERRCTL_PE|ERRCTL_L2P);
1042 
1043 			/* probe L1 parity support */
1044 			write_c0_ecc(errctl | ERRCTL_PE);
1045 			back_to_back_c0_hazard();
1046 			l1parity_present = (read_c0_ecc() & ERRCTL_PE);
1047 
1048 			/* probe L2 parity support */
1049 			write_c0_ecc(errctl|ERRCTL_L2P);
1050 			back_to_back_c0_hazard();
1051 			l2parity_present = (read_c0_ecc() & ERRCTL_L2P);
1052 
1053 			if (l1parity_present && l2parity_present) {
1054 				if (l1parity)
1055 					errctl |= ERRCTL_PE;
1056 				if (l1parity ^ l2parity)
1057 					errctl |= ERRCTL_L2P;
1058 			} else if (l1parity_present) {
1059 				if (l1parity)
1060 					errctl |= ERRCTL_PE;
1061 			} else if (l2parity_present) {
1062 				if (l2parity)
1063 					errctl |= ERRCTL_L2P;
1064 			} else {
1065 				/* No parity available */
1066 			}
1067 
1068 			printk(KERN_INFO "Writing ErrCtl register=%08lx\n", errctl);
1069 
1070 			write_c0_ecc(errctl);
1071 			back_to_back_c0_hazard();
1072 			errctl = read_c0_ecc();
1073 			printk(KERN_INFO "Readback ErrCtl register=%08lx\n", errctl);
1074 
1075 			if (l1parity_present)
1076 				printk(KERN_INFO "Cache parity protection %sabled\n",
1077 				       (errctl & ERRCTL_PE) ? "en" : "dis");
1078 
1079 			if (l2parity_present) {
1080 				if (l1parity_present && l1parity)
1081 					errctl ^= ERRCTL_L2P;
1082 				printk(KERN_INFO "L2 cache parity protection %sabled\n",
1083 				       (errctl & ERRCTL_L2P) ? "en" : "dis");
1084 			}
1085 		}
1086 		break;
1087 
1088 	case CPU_5KC:
1089 		write_c0_ecc(0x80000000);
1090 		back_to_back_c0_hazard();
1091 		/* Set the PE bit (bit 31) in the c0_errctl register. */
1092 		printk(KERN_INFO "Cache parity protection %sabled\n",
1093 		       (read_c0_ecc() & 0x80000000) ? "en" : "dis");
1094 		break;
1095 	case CPU_20KC:
1096 	case CPU_25KF:
1097 		/* Clear the DE bit (bit 16) in the c0_status register. */
1098 		printk(KERN_INFO "Enable cache parity protection for "
1099 		       "MIPS 20KC/25KF CPUs.\n");
1100 		clear_c0_status(ST0_DE);
1101 		break;
1102 	default:
1103 		break;
1104 	}
1105 }
1106 
1107 asmlinkage void cache_parity_error(void)
1108 {
1109 	const int field = 2 * sizeof(unsigned long);
1110 	unsigned int reg_val;
1111 
1112 	/* For the moment, report the problem and hang. */
1113 	printk("Cache error exception:\n");
1114 	printk("cp0_errorepc == %0*lx\n", field, read_c0_errorepc());
1115 	reg_val = read_c0_cacheerr();
1116 	printk("c0_cacheerr == %08x\n", reg_val);
1117 
1118 	printk("Decoded c0_cacheerr: %s cache fault in %s reference.\n",
1119 	       reg_val & (1<<30) ? "secondary" : "primary",
1120 	       reg_val & (1<<31) ? "data" : "insn");
1121 	printk("Error bits: %s%s%s%s%s%s%s\n",
1122 	       reg_val & (1<<29) ? "ED " : "",
1123 	       reg_val & (1<<28) ? "ET " : "",
1124 	       reg_val & (1<<26) ? "EE " : "",
1125 	       reg_val & (1<<25) ? "EB " : "",
1126 	       reg_val & (1<<24) ? "EI " : "",
1127 	       reg_val & (1<<23) ? "E1 " : "",
1128 	       reg_val & (1<<22) ? "E0 " : "");
1129 	printk("IDX: 0x%08x\n", reg_val & ((1<<22)-1));
1130 
1131 #if defined(CONFIG_CPU_MIPS32) || defined(CONFIG_CPU_MIPS64)
1132 	if (reg_val & (1<<22))
1133 		printk("DErrAddr0: 0x%0*lx\n", field, read_c0_derraddr0());
1134 
1135 	if (reg_val & (1<<23))
1136 		printk("DErrAddr1: 0x%0*lx\n", field, read_c0_derraddr1());
1137 #endif
1138 
1139 	panic("Can't handle the cache error!");
1140 }
1141 
1142 /*
1143  * SDBBP EJTAG debug exception handler.
1144  * We skip the instruction and return to the next instruction.
1145  */
1146 void ejtag_exception_handler(struct pt_regs *regs)
1147 {
1148 	const int field = 2 * sizeof(unsigned long);
1149 	unsigned long depc, old_epc;
1150 	unsigned int debug;
1151 
1152 	printk(KERN_DEBUG "SDBBP EJTAG debug exception - not handled yet, just ignored!\n");
1153 	depc = read_c0_depc();
1154 	debug = read_c0_debug();
1155 	printk(KERN_DEBUG "c0_depc = %0*lx, DEBUG = %08x\n", field, depc, debug);
1156 	if (debug & 0x80000000) {
1157 		/*
1158 		 * In branch delay slot.
1159 		 * We cheat a little bit here and use EPC to calculate the
1160 		 * debug return address (DEPC). EPC is restored after the
1161 		 * calculation.
1162 		 */
1163 		old_epc = regs->cp0_epc;
1164 		regs->cp0_epc = depc;
1165 		__compute_return_epc(regs);
1166 		depc = regs->cp0_epc;
1167 		regs->cp0_epc = old_epc;
1168 	} else
1169 		depc += 4;
1170 	write_c0_depc(depc);
1171 
1172 #if 0
1173 	printk(KERN_DEBUG "\n\n----- Enable EJTAG single stepping ----\n\n");
1174 	write_c0_debug(debug | 0x100);
1175 #endif
1176 }
1177 
1178 /*
1179  * NMI exception handler.
1180  */
1181 NORET_TYPE void ATTRIB_NORET nmi_exception_handler(struct pt_regs *regs)
1182 {
1183 	bust_spinlocks(1);
1184 	printk("NMI taken!!!!\n");
1185 	die("NMI", regs);
1186 }
1187 
1188 #define VECTORSPACING 0x100	/* for EI/VI mode */
1189 
1190 unsigned long ebase;
1191 unsigned long exception_handlers[32];
1192 unsigned long vi_handlers[64];
1193 
1194 /*
1195  * As a side effect of the way this is implemented we're limited
1196  * to interrupt handlers in the address range from
1197  * KSEG0 <= x < KSEG0 + 256mb on the Nevada.  Oh well ...
1198  */
1199 void *set_except_vector(int n, void *addr)
1200 {
1201 	unsigned long handler = (unsigned long) addr;
1202 	unsigned long old_handler = exception_handlers[n];
1203 
1204 	exception_handlers[n] = handler;
1205 	if (n == 0 && cpu_has_divec) {
1206 		*(u32 *)(ebase + 0x200) = 0x08000000 |
1207 					  (0x03ffffff & (handler >> 2));
1208 		local_flush_icache_range(ebase + 0x200, ebase + 0x204);
1209 	}
1210 	return (void *)old_handler;
1211 }
1212 
1213 static asmlinkage void do_default_vi(void)
1214 {
1215 	show_regs(get_irq_regs());
1216 	panic("Caught unexpected vectored interrupt.");
1217 }
1218 
1219 static void *set_vi_srs_handler(int n, vi_handler_t addr, int srs)
1220 {
1221 	unsigned long handler;
1222 	unsigned long old_handler = vi_handlers[n];
1223 	int srssets = current_cpu_data.srsets;
1224 	u32 *w;
1225 	unsigned char *b;
1226 
1227 	if (!cpu_has_veic && !cpu_has_vint)
1228 		BUG();
1229 
1230 	if (addr == NULL) {
1231 		handler = (unsigned long) do_default_vi;
1232 		srs = 0;
1233 	} else
1234 		handler = (unsigned long) addr;
1235 	vi_handlers[n] = (unsigned long) addr;
1236 
1237 	b = (unsigned char *)(ebase + 0x200 + n*VECTORSPACING);
1238 
1239 	if (srs >= srssets)
1240 		panic("Shadow register set %d not supported", srs);
1241 
1242 	if (cpu_has_veic) {
1243 		if (board_bind_eic_interrupt)
1244 			board_bind_eic_interrupt(n, srs);
1245 	} else if (cpu_has_vint) {
1246 		/* SRSMap is only defined if shadow sets are implemented */
1247 		if (srssets > 1)
1248 			change_c0_srsmap(0xf << n*4, srs << n*4);
1249 	}
1250 
1251 	if (srs == 0) {
1252 		/*
1253 		 * If no shadow set is selected then use the default handler
1254 		 * that does normal register saving and a standard interrupt exit
1255 		 */
1256 
1257 		extern char except_vec_vi, except_vec_vi_lui;
1258 		extern char except_vec_vi_ori, except_vec_vi_end;
1259 		extern char rollback_except_vec_vi;
1260 		char *vec_start = (cpu_wait == r4k_wait) ?
1261 			&rollback_except_vec_vi : &except_vec_vi;
1262 #ifdef CONFIG_MIPS_MT_SMTC
1263 		/*
1264 		 * We need to provide the SMTC vectored interrupt handler
1265 		 * not only with the address of the handler, but with the
1266 		 * Status.IM bit to be masked before going there.
1267 		 */
1268 		extern char except_vec_vi_mori;
1269 		const int mori_offset = &except_vec_vi_mori - vec_start;
1270 #endif /* CONFIG_MIPS_MT_SMTC */
1271 		const int handler_len = &except_vec_vi_end - vec_start;
1272 		const int lui_offset = &except_vec_vi_lui - vec_start;
1273 		const int ori_offset = &except_vec_vi_ori - vec_start;
1274 
1275 		if (handler_len > VECTORSPACING) {
1276 			/*
1277 			 * Sigh... panicing won't help as the console
1278 			 * is probably not configured :(
1279 			 */
1280 			panic("VECTORSPACING too small");
1281 		}
1282 
1283 		memcpy(b, vec_start, handler_len);
1284 #ifdef CONFIG_MIPS_MT_SMTC
1285 		BUG_ON(n > 7);	/* Vector index %d exceeds SMTC maximum. */
1286 
1287 		w = (u32 *)(b + mori_offset);
1288 		*w = (*w & 0xffff0000) | (0x100 << n);
1289 #endif /* CONFIG_MIPS_MT_SMTC */
1290 		w = (u32 *)(b + lui_offset);
1291 		*w = (*w & 0xffff0000) | (((u32)handler >> 16) & 0xffff);
1292 		w = (u32 *)(b + ori_offset);
1293 		*w = (*w & 0xffff0000) | ((u32)handler & 0xffff);
1294 		local_flush_icache_range((unsigned long)b,
1295 					 (unsigned long)(b+handler_len));
1296 	}
1297 	else {
1298 		/*
1299 		 * In other cases jump directly to the interrupt handler
1300 		 *
1301 		 * It is the handlers responsibility to save registers if required
1302 		 * (eg hi/lo) and return from the exception using "eret"
1303 		 */
1304 		w = (u32 *)b;
1305 		*w++ = 0x08000000 | (((u32)handler >> 2) & 0x03fffff); /* j handler */
1306 		*w = 0;
1307 		local_flush_icache_range((unsigned long)b,
1308 					 (unsigned long)(b+8));
1309 	}
1310 
1311 	return (void *)old_handler;
1312 }
1313 
1314 void *set_vi_handler(int n, vi_handler_t addr)
1315 {
1316 	return set_vi_srs_handler(n, addr, 0);
1317 }
1318 
1319 /*
1320  * This is used by native signal handling
1321  */
1322 asmlinkage int (*save_fp_context)(struct sigcontext __user *sc);
1323 asmlinkage int (*restore_fp_context)(struct sigcontext __user *sc);
1324 
1325 extern asmlinkage int _save_fp_context(struct sigcontext __user *sc);
1326 extern asmlinkage int _restore_fp_context(struct sigcontext __user *sc);
1327 
1328 extern asmlinkage int fpu_emulator_save_context(struct sigcontext __user *sc);
1329 extern asmlinkage int fpu_emulator_restore_context(struct sigcontext __user *sc);
1330 
1331 #ifdef CONFIG_SMP
1332 static int smp_save_fp_context(struct sigcontext __user *sc)
1333 {
1334 	return raw_cpu_has_fpu
1335 	       ? _save_fp_context(sc)
1336 	       : fpu_emulator_save_context(sc);
1337 }
1338 
1339 static int smp_restore_fp_context(struct sigcontext __user *sc)
1340 {
1341 	return raw_cpu_has_fpu
1342 	       ? _restore_fp_context(sc)
1343 	       : fpu_emulator_restore_context(sc);
1344 }
1345 #endif
1346 
1347 static inline void signal_init(void)
1348 {
1349 #ifdef CONFIG_SMP
1350 	/* For now just do the cpu_has_fpu check when the functions are invoked */
1351 	save_fp_context = smp_save_fp_context;
1352 	restore_fp_context = smp_restore_fp_context;
1353 #else
1354 	if (cpu_has_fpu) {
1355 		save_fp_context = _save_fp_context;
1356 		restore_fp_context = _restore_fp_context;
1357 	} else {
1358 		save_fp_context = fpu_emulator_save_context;
1359 		restore_fp_context = fpu_emulator_restore_context;
1360 	}
1361 #endif
1362 }
1363 
1364 #ifdef CONFIG_MIPS32_COMPAT
1365 
1366 /*
1367  * This is used by 32-bit signal stuff on the 64-bit kernel
1368  */
1369 asmlinkage int (*save_fp_context32)(struct sigcontext32 __user *sc);
1370 asmlinkage int (*restore_fp_context32)(struct sigcontext32 __user *sc);
1371 
1372 extern asmlinkage int _save_fp_context32(struct sigcontext32 __user *sc);
1373 extern asmlinkage int _restore_fp_context32(struct sigcontext32 __user *sc);
1374 
1375 extern asmlinkage int fpu_emulator_save_context32(struct sigcontext32 __user *sc);
1376 extern asmlinkage int fpu_emulator_restore_context32(struct sigcontext32 __user *sc);
1377 
1378 static inline void signal32_init(void)
1379 {
1380 	if (cpu_has_fpu) {
1381 		save_fp_context32 = _save_fp_context32;
1382 		restore_fp_context32 = _restore_fp_context32;
1383 	} else {
1384 		save_fp_context32 = fpu_emulator_save_context32;
1385 		restore_fp_context32 = fpu_emulator_restore_context32;
1386 	}
1387 }
1388 #endif
1389 
1390 extern void cpu_cache_init(void);
1391 extern void tlb_init(void);
1392 extern void flush_tlb_handlers(void);
1393 
1394 /*
1395  * Timer interrupt
1396  */
1397 int cp0_compare_irq;
1398 
1399 /*
1400  * Performance counter IRQ or -1 if shared with timer
1401  */
1402 int cp0_perfcount_irq;
1403 EXPORT_SYMBOL_GPL(cp0_perfcount_irq);
1404 
1405 static int __cpuinitdata noulri;
1406 
1407 static int __init ulri_disable(char *s)
1408 {
1409 	pr_info("Disabling ulri\n");
1410 	noulri = 1;
1411 
1412 	return 1;
1413 }
1414 __setup("noulri", ulri_disable);
1415 
1416 void __cpuinit per_cpu_trap_init(void)
1417 {
1418 	unsigned int cpu = smp_processor_id();
1419 	unsigned int status_set = ST0_CU0;
1420 #ifdef CONFIG_MIPS_MT_SMTC
1421 	int secondaryTC = 0;
1422 	int bootTC = (cpu == 0);
1423 
1424 	/*
1425 	 * Only do per_cpu_trap_init() for first TC of Each VPE.
1426 	 * Note that this hack assumes that the SMTC init code
1427 	 * assigns TCs consecutively and in ascending order.
1428 	 */
1429 
1430 	if (((read_c0_tcbind() & TCBIND_CURTC) != 0) &&
1431 	    ((read_c0_tcbind() & TCBIND_CURVPE) == cpu_data[cpu - 1].vpe_id))
1432 		secondaryTC = 1;
1433 #endif /* CONFIG_MIPS_MT_SMTC */
1434 
1435 	/*
1436 	 * Disable coprocessors and select 32-bit or 64-bit addressing
1437 	 * and the 16/32 or 32/32 FPR register model.  Reset the BEV
1438 	 * flag that some firmware may have left set and the TS bit (for
1439 	 * IP27).  Set XX for ISA IV code to work.
1440 	 */
1441 #ifdef CONFIG_64BIT
1442 	status_set |= ST0_FR|ST0_KX|ST0_SX|ST0_UX;
1443 #endif
1444 	if (current_cpu_data.isa_level == MIPS_CPU_ISA_IV)
1445 		status_set |= ST0_XX;
1446 	if (cpu_has_dsp)
1447 		status_set |= ST0_MX;
1448 
1449 	change_c0_status(ST0_CU|ST0_MX|ST0_RE|ST0_FR|ST0_BEV|ST0_TS|ST0_KX|ST0_SX|ST0_UX,
1450 			 status_set);
1451 
1452 	if (cpu_has_mips_r2) {
1453 		unsigned int enable = 0x0000000f;
1454 
1455 		if (!noulri && cpu_has_userlocal)
1456 			enable |= (1 << 29);
1457 
1458 		write_c0_hwrena(enable);
1459 	}
1460 
1461 #ifdef CONFIG_MIPS_MT_SMTC
1462 	if (!secondaryTC) {
1463 #endif /* CONFIG_MIPS_MT_SMTC */
1464 
1465 	if (cpu_has_veic || cpu_has_vint) {
1466 		write_c0_ebase(ebase);
1467 		/* Setting vector spacing enables EI/VI mode  */
1468 		change_c0_intctl(0x3e0, VECTORSPACING);
1469 	}
1470 	if (cpu_has_divec) {
1471 		if (cpu_has_mipsmt) {
1472 			unsigned int vpflags = dvpe();
1473 			set_c0_cause(CAUSEF_IV);
1474 			evpe(vpflags);
1475 		} else
1476 			set_c0_cause(CAUSEF_IV);
1477 	}
1478 
1479 	/*
1480 	 * Before R2 both interrupt numbers were fixed to 7, so on R2 only:
1481 	 *
1482 	 *  o read IntCtl.IPTI to determine the timer interrupt
1483 	 *  o read IntCtl.IPPCI to determine the performance counter interrupt
1484 	 */
1485 	if (cpu_has_mips_r2) {
1486 		cp0_compare_irq = (read_c0_intctl() >> 29) & 7;
1487 		cp0_perfcount_irq = (read_c0_intctl() >> 26) & 7;
1488 		if (cp0_perfcount_irq == cp0_compare_irq)
1489 			cp0_perfcount_irq = -1;
1490 	} else {
1491 		cp0_compare_irq = CP0_LEGACY_COMPARE_IRQ;
1492 		cp0_perfcount_irq = -1;
1493 	}
1494 
1495 #ifdef CONFIG_MIPS_MT_SMTC
1496 	}
1497 #endif /* CONFIG_MIPS_MT_SMTC */
1498 
1499 	cpu_data[cpu].asid_cache = ASID_FIRST_VERSION;
1500 	TLBMISS_HANDLER_SETUP();
1501 
1502 	atomic_inc(&init_mm.mm_count);
1503 	current->active_mm = &init_mm;
1504 	BUG_ON(current->mm);
1505 	enter_lazy_tlb(&init_mm, current);
1506 
1507 #ifdef CONFIG_MIPS_MT_SMTC
1508 	if (bootTC) {
1509 #endif /* CONFIG_MIPS_MT_SMTC */
1510 		cpu_cache_init();
1511 		tlb_init();
1512 #ifdef CONFIG_MIPS_MT_SMTC
1513 	} else if (!secondaryTC) {
1514 		/*
1515 		 * First TC in non-boot VPE must do subset of tlb_init()
1516 		 * for MMU countrol registers.
1517 		 */
1518 		write_c0_pagemask(PM_DEFAULT_MASK);
1519 		write_c0_wired(0);
1520 	}
1521 #endif /* CONFIG_MIPS_MT_SMTC */
1522 }
1523 
1524 /* Install CPU exception handler */
1525 void __init set_handler(unsigned long offset, void *addr, unsigned long size)
1526 {
1527 	memcpy((void *)(ebase + offset), addr, size);
1528 	local_flush_icache_range(ebase + offset, ebase + offset + size);
1529 }
1530 
1531 static char panic_null_cerr[] __cpuinitdata =
1532 	"Trying to set NULL cache error exception handler";
1533 
1534 /* Install uncached CPU exception handler */
1535 void __cpuinit set_uncached_handler(unsigned long offset, void *addr,
1536 	unsigned long size)
1537 {
1538 #ifdef CONFIG_32BIT
1539 	unsigned long uncached_ebase = KSEG1ADDR(ebase);
1540 #endif
1541 #ifdef CONFIG_64BIT
1542 	unsigned long uncached_ebase = TO_UNCAC(ebase);
1543 #endif
1544 
1545 	if (!addr)
1546 		panic(panic_null_cerr);
1547 
1548 	memcpy((void *)(uncached_ebase + offset), addr, size);
1549 }
1550 
1551 static int __initdata rdhwr_noopt;
1552 static int __init set_rdhwr_noopt(char *str)
1553 {
1554 	rdhwr_noopt = 1;
1555 	return 1;
1556 }
1557 
1558 __setup("rdhwr_noopt", set_rdhwr_noopt);
1559 
1560 void __init trap_init(void)
1561 {
1562 	extern char except_vec3_generic, except_vec3_r4000;
1563 	extern char except_vec4;
1564 	unsigned long i;
1565 	int rollback;
1566 
1567 	check_wait();
1568 	rollback = (cpu_wait == r4k_wait);
1569 
1570 #if defined(CONFIG_KGDB)
1571 	if (kgdb_early_setup)
1572 		return;	/* Already done */
1573 #endif
1574 
1575 	if (cpu_has_veic || cpu_has_vint)
1576 		ebase = (unsigned long) alloc_bootmem_low_pages(0x200 + VECTORSPACING*64);
1577 	else
1578 		ebase = CAC_BASE;
1579 
1580 	per_cpu_trap_init();
1581 
1582 	/*
1583 	 * Copy the generic exception handlers to their final destination.
1584 	 * This will be overriden later as suitable for a particular
1585 	 * configuration.
1586 	 */
1587 	set_handler(0x180, &except_vec3_generic, 0x80);
1588 
1589 	/*
1590 	 * Setup default vectors
1591 	 */
1592 	for (i = 0; i <= 31; i++)
1593 		set_except_vector(i, handle_reserved);
1594 
1595 	/*
1596 	 * Copy the EJTAG debug exception vector handler code to it's final
1597 	 * destination.
1598 	 */
1599 	if (cpu_has_ejtag && board_ejtag_handler_setup)
1600 		board_ejtag_handler_setup();
1601 
1602 	/*
1603 	 * Only some CPUs have the watch exceptions.
1604 	 */
1605 	if (cpu_has_watch)
1606 		set_except_vector(23, handle_watch);
1607 
1608 	/*
1609 	 * Initialise interrupt handlers
1610 	 */
1611 	if (cpu_has_veic || cpu_has_vint) {
1612 		int nvec = cpu_has_veic ? 64 : 8;
1613 		for (i = 0; i < nvec; i++)
1614 			set_vi_handler(i, NULL);
1615 	}
1616 	else if (cpu_has_divec)
1617 		set_handler(0x200, &except_vec4, 0x8);
1618 
1619 	/*
1620 	 * Some CPUs can enable/disable for cache parity detection, but does
1621 	 * it different ways.
1622 	 */
1623 	parity_protection_init();
1624 
1625 	/*
1626 	 * The Data Bus Errors / Instruction Bus Errors are signaled
1627 	 * by external hardware.  Therefore these two exceptions
1628 	 * may have board specific handlers.
1629 	 */
1630 	if (board_be_init)
1631 		board_be_init();
1632 
1633 	set_except_vector(0, rollback ? rollback_handle_int : handle_int);
1634 	set_except_vector(1, handle_tlbm);
1635 	set_except_vector(2, handle_tlbl);
1636 	set_except_vector(3, handle_tlbs);
1637 
1638 	set_except_vector(4, handle_adel);
1639 	set_except_vector(5, handle_ades);
1640 
1641 	set_except_vector(6, handle_ibe);
1642 	set_except_vector(7, handle_dbe);
1643 
1644 	set_except_vector(8, handle_sys);
1645 	set_except_vector(9, handle_bp);
1646 	set_except_vector(10, rdhwr_noopt ? handle_ri :
1647 			  (cpu_has_vtag_icache ?
1648 			   handle_ri_rdhwr_vivt : handle_ri_rdhwr));
1649 	set_except_vector(11, handle_cpu);
1650 	set_except_vector(12, handle_ov);
1651 	set_except_vector(13, handle_tr);
1652 
1653 	if (current_cpu_type() == CPU_R6000 ||
1654 	    current_cpu_type() == CPU_R6000A) {
1655 		/*
1656 		 * The R6000 is the only R-series CPU that features a machine
1657 		 * check exception (similar to the R4000 cache error) and
1658 		 * unaligned ldc1/sdc1 exception.  The handlers have not been
1659 		 * written yet.  Well, anyway there is no R6000 machine on the
1660 		 * current list of targets for Linux/MIPS.
1661 		 * (Duh, crap, there is someone with a triple R6k machine)
1662 		 */
1663 		//set_except_vector(14, handle_mc);
1664 		//set_except_vector(15, handle_ndc);
1665 	}
1666 
1667 
1668 	if (board_nmi_handler_setup)
1669 		board_nmi_handler_setup();
1670 
1671 	if (cpu_has_fpu && !cpu_has_nofpuex)
1672 		set_except_vector(15, handle_fpe);
1673 
1674 	set_except_vector(22, handle_mdmx);
1675 
1676 	if (cpu_has_mcheck)
1677 		set_except_vector(24, handle_mcheck);
1678 
1679 	if (cpu_has_mipsmt)
1680 		set_except_vector(25, handle_mt);
1681 
1682 	set_except_vector(26, handle_dsp);
1683 
1684 	if (cpu_has_vce)
1685 		/* Special exception: R4[04]00 uses also the divec space. */
1686 		memcpy((void *)(CAC_BASE + 0x180), &except_vec3_r4000, 0x100);
1687 	else if (cpu_has_4kex)
1688 		memcpy((void *)(CAC_BASE + 0x180), &except_vec3_generic, 0x80);
1689 	else
1690 		memcpy((void *)(CAC_BASE + 0x080), &except_vec3_generic, 0x80);
1691 
1692 	signal_init();
1693 #ifdef CONFIG_MIPS32_COMPAT
1694 	signal32_init();
1695 #endif
1696 
1697 	local_flush_icache_range(ebase, ebase + 0x400);
1698 	flush_tlb_handlers();
1699 
1700 	sort_extable(__start___dbe_table, __stop___dbe_table);
1701 }
1702