xref: /linux/arch/mips/kernel/traps.c (revision 63870295de9adb365cd121dab94379b8cfdf986a)
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 asmlinkage void handle_int(void);
50 extern asmlinkage void handle_tlbm(void);
51 extern asmlinkage void handle_tlbl(void);
52 extern asmlinkage void handle_tlbs(void);
53 extern asmlinkage void handle_adel(void);
54 extern asmlinkage void handle_ades(void);
55 extern asmlinkage void handle_ibe(void);
56 extern asmlinkage void handle_dbe(void);
57 extern asmlinkage void handle_sys(void);
58 extern asmlinkage void handle_bp(void);
59 extern asmlinkage void handle_ri(void);
60 extern asmlinkage void handle_ri_rdhwr_vivt(void);
61 extern asmlinkage void handle_ri_rdhwr(void);
62 extern asmlinkage void handle_cpu(void);
63 extern asmlinkage void handle_ov(void);
64 extern asmlinkage void handle_tr(void);
65 extern asmlinkage void handle_fpe(void);
66 extern asmlinkage void handle_mdmx(void);
67 extern asmlinkage void handle_watch(void);
68 extern asmlinkage void handle_mt(void);
69 extern asmlinkage void handle_dsp(void);
70 extern asmlinkage void handle_mcheck(void);
71 extern asmlinkage void handle_reserved(void);
72 
73 extern int fpu_emulator_cop1Handler(struct pt_regs *xcp,
74 	struct mips_fpu_struct *ctx, int has_fpu);
75 
76 void (*board_be_init)(void);
77 int (*board_be_handler)(struct pt_regs *regs, int is_fixup);
78 void (*board_nmi_handler_setup)(void);
79 void (*board_ejtag_handler_setup)(void);
80 void (*board_bind_eic_interrupt)(int irq, int regset);
81 
82 
83 static void show_raw_backtrace(unsigned long reg29)
84 {
85 	unsigned long *sp = (unsigned long *)(reg29 & ~3);
86 	unsigned long addr;
87 
88 	printk("Call Trace:");
89 #ifdef CONFIG_KALLSYMS
90 	printk("\n");
91 #endif
92 	while (!kstack_end(sp)) {
93 		unsigned long __user *p =
94 			(unsigned long __user *)(unsigned long)sp++;
95 		if (__get_user(addr, p)) {
96 			printk(" (Bad stack address)");
97 			break;
98 		}
99 		if (__kernel_text_address(addr))
100 			print_ip_sym(addr);
101 	}
102 	printk("\n");
103 }
104 
105 #ifdef CONFIG_KALLSYMS
106 int raw_show_trace;
107 static int __init set_raw_show_trace(char *str)
108 {
109 	raw_show_trace = 1;
110 	return 1;
111 }
112 __setup("raw_show_trace", set_raw_show_trace);
113 #endif
114 
115 static void show_backtrace(struct task_struct *task, const struct pt_regs *regs)
116 {
117 	unsigned long sp = regs->regs[29];
118 	unsigned long ra = regs->regs[31];
119 	unsigned long pc = regs->cp0_epc;
120 
121 	if (raw_show_trace || !__kernel_text_address(pc)) {
122 		show_raw_backtrace(sp);
123 		return;
124 	}
125 	printk("Call Trace:\n");
126 	do {
127 		print_ip_sym(pc);
128 		pc = unwind_stack(task, &sp, pc, &ra);
129 	} while (pc);
130 	printk("\n");
131 }
132 
133 /*
134  * This routine abuses get_user()/put_user() to reference pointers
135  * with at least a bit of error checking ...
136  */
137 static void show_stacktrace(struct task_struct *task,
138 	const struct pt_regs *regs)
139 {
140 	const int field = 2 * sizeof(unsigned long);
141 	long stackdata;
142 	int i;
143 	unsigned long __user *sp = (unsigned long __user *)regs->regs[29];
144 
145 	printk("Stack :");
146 	i = 0;
147 	while ((unsigned long) sp & (PAGE_SIZE - 1)) {
148 		if (i && ((i % (64 / field)) == 0))
149 			printk("\n       ");
150 		if (i > 39) {
151 			printk(" ...");
152 			break;
153 		}
154 
155 		if (__get_user(stackdata, sp++)) {
156 			printk(" (Bad stack address)");
157 			break;
158 		}
159 
160 		printk(" %0*lx", field, stackdata);
161 		i++;
162 	}
163 	printk("\n");
164 	show_backtrace(task, regs);
165 }
166 
167 void show_stack(struct task_struct *task, unsigned long *sp)
168 {
169 	struct pt_regs regs;
170 	if (sp) {
171 		regs.regs[29] = (unsigned long)sp;
172 		regs.regs[31] = 0;
173 		regs.cp0_epc = 0;
174 	} else {
175 		if (task && task != current) {
176 			regs.regs[29] = task->thread.reg29;
177 			regs.regs[31] = 0;
178 			regs.cp0_epc = task->thread.reg31;
179 		} else {
180 			prepare_frametrace(&regs);
181 		}
182 	}
183 	show_stacktrace(task, &regs);
184 }
185 
186 /*
187  * The architecture-independent dump_stack generator
188  */
189 void dump_stack(void)
190 {
191 	struct pt_regs regs;
192 
193 	prepare_frametrace(&regs);
194 	show_backtrace(current, &regs);
195 }
196 
197 EXPORT_SYMBOL(dump_stack);
198 
199 static void show_code(unsigned int __user *pc)
200 {
201 	long i;
202 	unsigned short __user *pc16 = NULL;
203 
204 	printk("\nCode:");
205 
206 	if ((unsigned long)pc & 1)
207 		pc16 = (unsigned short __user *)((unsigned long)pc & ~1);
208 	for(i = -3 ; i < 6 ; i++) {
209 		unsigned int insn;
210 		if (pc16 ? __get_user(insn, pc16 + i) : __get_user(insn, pc + i)) {
211 			printk(" (Bad address in epc)\n");
212 			break;
213 		}
214 		printk("%c%0*x%c", (i?' ':'<'), pc16 ? 4 : 8, insn, (i?' ':'>'));
215 	}
216 }
217 
218 static void __show_regs(const struct pt_regs *regs)
219 {
220 	const int field = 2 * sizeof(unsigned long);
221 	unsigned int cause = regs->cp0_cause;
222 	int i;
223 
224 	printk("Cpu %d\n", smp_processor_id());
225 
226 	/*
227 	 * Saved main processor registers
228 	 */
229 	for (i = 0; i < 32; ) {
230 		if ((i % 4) == 0)
231 			printk("$%2d   :", i);
232 		if (i == 0)
233 			printk(" %0*lx", field, 0UL);
234 		else if (i == 26 || i == 27)
235 			printk(" %*s", field, "");
236 		else
237 			printk(" %0*lx", field, regs->regs[i]);
238 
239 		i++;
240 		if ((i % 4) == 0)
241 			printk("\n");
242 	}
243 
244 #ifdef CONFIG_CPU_HAS_SMARTMIPS
245 	printk("Acx    : %0*lx\n", field, regs->acx);
246 #endif
247 	printk("Hi    : %0*lx\n", field, regs->hi);
248 	printk("Lo    : %0*lx\n", field, regs->lo);
249 
250 	/*
251 	 * Saved cp0 registers
252 	 */
253 	printk("epc   : %0*lx %pS\n", field, regs->cp0_epc,
254 	       (void *) regs->cp0_epc);
255 	printk("    %s\n", print_tainted());
256 	printk("ra    : %0*lx %pS\n", field, regs->regs[31],
257 	       (void *) regs->regs[31]);
258 
259 	printk("Status: %08x    ", (uint32_t) regs->cp0_status);
260 
261 	if (current_cpu_data.isa_level == MIPS_CPU_ISA_I) {
262 		if (regs->cp0_status & ST0_KUO)
263 			printk("KUo ");
264 		if (regs->cp0_status & ST0_IEO)
265 			printk("IEo ");
266 		if (regs->cp0_status & ST0_KUP)
267 			printk("KUp ");
268 		if (regs->cp0_status & ST0_IEP)
269 			printk("IEp ");
270 		if (regs->cp0_status & ST0_KUC)
271 			printk("KUc ");
272 		if (regs->cp0_status & ST0_IEC)
273 			printk("IEc ");
274 	} else {
275 		if (regs->cp0_status & ST0_KX)
276 			printk("KX ");
277 		if (regs->cp0_status & ST0_SX)
278 			printk("SX ");
279 		if (regs->cp0_status & ST0_UX)
280 			printk("UX ");
281 		switch (regs->cp0_status & ST0_KSU) {
282 		case KSU_USER:
283 			printk("USER ");
284 			break;
285 		case KSU_SUPERVISOR:
286 			printk("SUPERVISOR ");
287 			break;
288 		case KSU_KERNEL:
289 			printk("KERNEL ");
290 			break;
291 		default:
292 			printk("BAD_MODE ");
293 			break;
294 		}
295 		if (regs->cp0_status & ST0_ERL)
296 			printk("ERL ");
297 		if (regs->cp0_status & ST0_EXL)
298 			printk("EXL ");
299 		if (regs->cp0_status & ST0_IE)
300 			printk("IE ");
301 	}
302 	printk("\n");
303 
304 	printk("Cause : %08x\n", cause);
305 
306 	cause = (cause & CAUSEF_EXCCODE) >> CAUSEB_EXCCODE;
307 	if (1 <= cause && cause <= 5)
308 		printk("BadVA : %0*lx\n", field, regs->cp0_badvaddr);
309 
310 	printk("PrId  : %08x (%s)\n", read_c0_prid(),
311 	       cpu_name_string());
312 }
313 
314 /*
315  * FIXME: really the generic show_regs should take a const pointer argument.
316  */
317 void show_regs(struct pt_regs *regs)
318 {
319 	__show_regs((struct pt_regs *)regs);
320 }
321 
322 void show_registers(const struct pt_regs *regs)
323 {
324 	const int field = 2 * sizeof(unsigned long);
325 
326 	__show_regs(regs);
327 	print_modules();
328 	printk("Process %s (pid: %d, threadinfo=%p, task=%p, tls=%0*lx)\n",
329 	       current->comm, current->pid, current_thread_info(), current,
330 	      field, current_thread_info()->tp_value);
331 	if (cpu_has_userlocal) {
332 		unsigned long tls;
333 
334 		tls = read_c0_userlocal();
335 		if (tls != current_thread_info()->tp_value)
336 			printk("*HwTLS: %0*lx\n", field, tls);
337 	}
338 
339 	show_stacktrace(current, regs);
340 	show_code((unsigned int __user *) regs->cp0_epc);
341 	printk("\n");
342 }
343 
344 static DEFINE_SPINLOCK(die_lock);
345 
346 void __noreturn die(const char * str, const struct pt_regs * regs)
347 {
348 	static int die_counter;
349 #ifdef CONFIG_MIPS_MT_SMTC
350 	unsigned long dvpret = dvpe();
351 #endif /* CONFIG_MIPS_MT_SMTC */
352 
353 	console_verbose();
354 	spin_lock_irq(&die_lock);
355 	bust_spinlocks(1);
356 #ifdef CONFIG_MIPS_MT_SMTC
357 	mips_mt_regdump(dvpret);
358 #endif /* CONFIG_MIPS_MT_SMTC */
359 	printk("%s[#%d]:\n", str, ++die_counter);
360 	show_registers(regs);
361 	add_taint(TAINT_DIE);
362 	spin_unlock_irq(&die_lock);
363 
364 	if (in_interrupt())
365 		panic("Fatal exception in interrupt");
366 
367 	if (panic_on_oops) {
368 		printk(KERN_EMERG "Fatal exception: panic in 5 seconds\n");
369 		ssleep(5);
370 		panic("Fatal exception");
371 	}
372 
373 	do_exit(SIGSEGV);
374 }
375 
376 extern const struct exception_table_entry __start___dbe_table[];
377 extern const struct exception_table_entry __stop___dbe_table[];
378 
379 __asm__(
380 "	.section	__dbe_table, \"a\"\n"
381 "	.previous			\n");
382 
383 /* Given an address, look for it in the exception tables. */
384 static const struct exception_table_entry *search_dbe_tables(unsigned long addr)
385 {
386 	const struct exception_table_entry *e;
387 
388 	e = search_extable(__start___dbe_table, __stop___dbe_table - 1, addr);
389 	if (!e)
390 		e = search_module_dbetables(addr);
391 	return e;
392 }
393 
394 asmlinkage void do_be(struct pt_regs *regs)
395 {
396 	const int field = 2 * sizeof(unsigned long);
397 	const struct exception_table_entry *fixup = NULL;
398 	int data = regs->cp0_cause & 4;
399 	int action = MIPS_BE_FATAL;
400 
401 	/* XXX For now.  Fixme, this searches the wrong table ...  */
402 	if (data && !user_mode(regs))
403 		fixup = search_dbe_tables(exception_epc(regs));
404 
405 	if (fixup)
406 		action = MIPS_BE_FIXUP;
407 
408 	if (board_be_handler)
409 		action = board_be_handler(regs, fixup != NULL);
410 
411 	switch (action) {
412 	case MIPS_BE_DISCARD:
413 		return;
414 	case MIPS_BE_FIXUP:
415 		if (fixup) {
416 			regs->cp0_epc = fixup->nextinsn;
417 			return;
418 		}
419 		break;
420 	default:
421 		break;
422 	}
423 
424 	/*
425 	 * Assume it would be too dangerous to continue ...
426 	 */
427 	printk(KERN_ALERT "%s bus error, epc == %0*lx, ra == %0*lx\n",
428 	       data ? "Data" : "Instruction",
429 	       field, regs->cp0_epc, field, regs->regs[31]);
430 	if (notify_die(DIE_OOPS, "bus error", regs, SIGBUS, 0, 0)
431 	    == NOTIFY_STOP)
432 		return;
433 
434 	die_if_kernel("Oops", regs);
435 	force_sig(SIGBUS, current);
436 }
437 
438 /*
439  * ll/sc, rdhwr, sync emulation
440  */
441 
442 #define OPCODE 0xfc000000
443 #define BASE   0x03e00000
444 #define RT     0x001f0000
445 #define OFFSET 0x0000ffff
446 #define LL     0xc0000000
447 #define SC     0xe0000000
448 #define SPEC0  0x00000000
449 #define SPEC3  0x7c000000
450 #define RD     0x0000f800
451 #define FUNC   0x0000003f
452 #define SYNC   0x0000000f
453 #define RDHWR  0x0000003b
454 
455 /*
456  * The ll_bit is cleared by r*_switch.S
457  */
458 
459 unsigned long ll_bit;
460 
461 static struct task_struct *ll_task = NULL;
462 
463 static inline int simulate_ll(struct pt_regs *regs, unsigned int opcode)
464 {
465 	unsigned long value, __user *vaddr;
466 	long offset;
467 
468 	/*
469 	 * analyse the ll instruction that just caused a ri exception
470 	 * and put the referenced address to addr.
471 	 */
472 
473 	/* sign extend offset */
474 	offset = opcode & OFFSET;
475 	offset <<= 16;
476 	offset >>= 16;
477 
478 	vaddr = (unsigned long __user *)
479 	        ((unsigned long)(regs->regs[(opcode & BASE) >> 21]) + offset);
480 
481 	if ((unsigned long)vaddr & 3)
482 		return SIGBUS;
483 	if (get_user(value, vaddr))
484 		return SIGSEGV;
485 
486 	preempt_disable();
487 
488 	if (ll_task == NULL || ll_task == current) {
489 		ll_bit = 1;
490 	} else {
491 		ll_bit = 0;
492 	}
493 	ll_task = current;
494 
495 	preempt_enable();
496 
497 	regs->regs[(opcode & RT) >> 16] = value;
498 
499 	return 0;
500 }
501 
502 static inline int simulate_sc(struct pt_regs *regs, unsigned int opcode)
503 {
504 	unsigned long __user *vaddr;
505 	unsigned long reg;
506 	long offset;
507 
508 	/*
509 	 * analyse the sc instruction that just caused a ri exception
510 	 * and put the referenced address to addr.
511 	 */
512 
513 	/* sign extend offset */
514 	offset = opcode & OFFSET;
515 	offset <<= 16;
516 	offset >>= 16;
517 
518 	vaddr = (unsigned long __user *)
519 	        ((unsigned long)(regs->regs[(opcode & BASE) >> 21]) + offset);
520 	reg = (opcode & RT) >> 16;
521 
522 	if ((unsigned long)vaddr & 3)
523 		return SIGBUS;
524 
525 	preempt_disable();
526 
527 	if (ll_bit == 0 || ll_task != current) {
528 		regs->regs[reg] = 0;
529 		preempt_enable();
530 		return 0;
531 	}
532 
533 	preempt_enable();
534 
535 	if (put_user(regs->regs[reg], vaddr))
536 		return SIGSEGV;
537 
538 	regs->regs[reg] = 1;
539 
540 	return 0;
541 }
542 
543 /*
544  * ll uses the opcode of lwc0 and sc uses the opcode of swc0.  That is both
545  * opcodes are supposed to result in coprocessor unusable exceptions if
546  * executed on ll/sc-less processors.  That's the theory.  In practice a
547  * few processors such as NEC's VR4100 throw reserved instruction exceptions
548  * instead, so we're doing the emulation thing in both exception handlers.
549  */
550 static int simulate_llsc(struct pt_regs *regs, unsigned int opcode)
551 {
552 	if ((opcode & OPCODE) == LL)
553 		return simulate_ll(regs, opcode);
554 	if ((opcode & OPCODE) == SC)
555 		return simulate_sc(regs, opcode);
556 
557 	return -1;			/* Must be something else ... */
558 }
559 
560 /*
561  * Simulate trapping 'rdhwr' instructions to provide user accessible
562  * registers not implemented in hardware.
563  */
564 static int simulate_rdhwr(struct pt_regs *regs, unsigned int opcode)
565 {
566 	struct thread_info *ti = task_thread_info(current);
567 
568 	if ((opcode & OPCODE) == SPEC3 && (opcode & FUNC) == RDHWR) {
569 		int rd = (opcode & RD) >> 11;
570 		int rt = (opcode & RT) >> 16;
571 		switch (rd) {
572 		case 0:		/* CPU number */
573 			regs->regs[rt] = smp_processor_id();
574 			return 0;
575 		case 1:		/* SYNCI length */
576 			regs->regs[rt] = min(current_cpu_data.dcache.linesz,
577 					     current_cpu_data.icache.linesz);
578 			return 0;
579 		case 2:		/* Read count register */
580 			regs->regs[rt] = read_c0_count();
581 			return 0;
582 		case 3:		/* Count register resolution */
583 			switch (current_cpu_data.cputype) {
584 			case CPU_20KC:
585 			case CPU_25KF:
586 				regs->regs[rt] = 1;
587 				break;
588 			default:
589 				regs->regs[rt] = 2;
590 			}
591 			return 0;
592 		case 29:
593 			regs->regs[rt] = ti->tp_value;
594 			return 0;
595 		default:
596 			return -1;
597 		}
598 	}
599 
600 	/* Not ours.  */
601 	return -1;
602 }
603 
604 static int simulate_sync(struct pt_regs *regs, unsigned int opcode)
605 {
606 	if ((opcode & OPCODE) == SPEC0 && (opcode & FUNC) == SYNC)
607 		return 0;
608 
609 	return -1;			/* Must be something else ... */
610 }
611 
612 asmlinkage void do_ov(struct pt_regs *regs)
613 {
614 	siginfo_t info;
615 
616 	die_if_kernel("Integer overflow", regs);
617 
618 	info.si_code = FPE_INTOVF;
619 	info.si_signo = SIGFPE;
620 	info.si_errno = 0;
621 	info.si_addr = (void __user *) regs->cp0_epc;
622 	force_sig_info(SIGFPE, &info, current);
623 }
624 
625 /*
626  * XXX Delayed fp exceptions when doing a lazy ctx switch XXX
627  */
628 asmlinkage void do_fpe(struct pt_regs *regs, unsigned long fcr31)
629 {
630 	siginfo_t info;
631 
632 	if (notify_die(DIE_FP, "FP exception", regs, SIGFPE, 0, 0)
633 	    == NOTIFY_STOP)
634 		return;
635 	die_if_kernel("FP exception in kernel code", regs);
636 
637 	if (fcr31 & FPU_CSR_UNI_X) {
638 		int sig;
639 
640 		/*
641 		 * Unimplemented operation exception.  If we've got the full
642 		 * software emulator on-board, let's use it...
643 		 *
644 		 * Force FPU to dump state into task/thread context.  We're
645 		 * moving a lot of data here for what is probably a single
646 		 * instruction, but the alternative is to pre-decode the FP
647 		 * register operands before invoking the emulator, which seems
648 		 * a bit extreme for what should be an infrequent event.
649 		 */
650 		/* Ensure 'resume' not overwrite saved fp context again. */
651 		lose_fpu(1);
652 
653 		/* Run the emulator */
654 		sig = fpu_emulator_cop1Handler(regs, &current->thread.fpu, 1);
655 
656 		/*
657 		 * We can't allow the emulated instruction to leave any of
658 		 * the cause bit set in $fcr31.
659 		 */
660 		current->thread.fpu.fcr31 &= ~FPU_CSR_ALL_X;
661 
662 		/* Restore the hardware register state */
663 		own_fpu(1);	/* Using the FPU again.  */
664 
665 		/* If something went wrong, signal */
666 		if (sig)
667 			force_sig(sig, current);
668 
669 		return;
670 	} else if (fcr31 & FPU_CSR_INV_X)
671 		info.si_code = FPE_FLTINV;
672 	else if (fcr31 & FPU_CSR_DIV_X)
673 		info.si_code = FPE_FLTDIV;
674 	else if (fcr31 & FPU_CSR_OVF_X)
675 		info.si_code = FPE_FLTOVF;
676 	else if (fcr31 & FPU_CSR_UDF_X)
677 		info.si_code = FPE_FLTUND;
678 	else if (fcr31 & FPU_CSR_INE_X)
679 		info.si_code = FPE_FLTRES;
680 	else
681 		info.si_code = __SI_FAULT;
682 	info.si_signo = SIGFPE;
683 	info.si_errno = 0;
684 	info.si_addr = (void __user *) regs->cp0_epc;
685 	force_sig_info(SIGFPE, &info, current);
686 }
687 
688 static void do_trap_or_bp(struct pt_regs *regs, unsigned int code,
689 	const char *str)
690 {
691 	siginfo_t info;
692 	char b[40];
693 
694 	if (notify_die(DIE_TRAP, str, regs, code, 0, 0) == NOTIFY_STOP)
695 		return;
696 
697 	/*
698 	 * A short test says that IRIX 5.3 sends SIGTRAP for all trap
699 	 * insns, even for trap and break codes that indicate arithmetic
700 	 * failures.  Weird ...
701 	 * But should we continue the brokenness???  --macro
702 	 */
703 	switch (code) {
704 	case BRK_OVERFLOW:
705 	case BRK_DIVZERO:
706 		scnprintf(b, sizeof(b), "%s instruction in kernel code", str);
707 		die_if_kernel(b, regs);
708 		if (code == BRK_DIVZERO)
709 			info.si_code = FPE_INTDIV;
710 		else
711 			info.si_code = FPE_INTOVF;
712 		info.si_signo = SIGFPE;
713 		info.si_errno = 0;
714 		info.si_addr = (void __user *) regs->cp0_epc;
715 		force_sig_info(SIGFPE, &info, current);
716 		break;
717 	case BRK_BUG:
718 		die_if_kernel("Kernel bug detected", regs);
719 		force_sig(SIGTRAP, current);
720 		break;
721 	default:
722 		scnprintf(b, sizeof(b), "%s instruction in kernel code", str);
723 		die_if_kernel(b, regs);
724 		force_sig(SIGTRAP, current);
725 	}
726 }
727 
728 asmlinkage void do_bp(struct pt_regs *regs)
729 {
730 	unsigned int opcode, bcode;
731 
732 	if (__get_user(opcode, (unsigned int __user *) exception_epc(regs)))
733 		goto out_sigsegv;
734 
735 	/*
736 	 * There is the ancient bug in the MIPS assemblers that the break
737 	 * code starts left to bit 16 instead to bit 6 in the opcode.
738 	 * Gas is bug-compatible, but not always, grrr...
739 	 * We handle both cases with a simple heuristics.  --macro
740 	 */
741 	bcode = ((opcode >> 6) & ((1 << 20) - 1));
742 	if (bcode >= (1 << 10))
743 		bcode >>= 10;
744 
745 	do_trap_or_bp(regs, bcode, "Break");
746 	return;
747 
748 out_sigsegv:
749 	force_sig(SIGSEGV, current);
750 }
751 
752 asmlinkage void do_tr(struct pt_regs *regs)
753 {
754 	unsigned int opcode, tcode = 0;
755 
756 	if (__get_user(opcode, (unsigned int __user *) exception_epc(regs)))
757 		goto out_sigsegv;
758 
759 	/* Immediate versions don't provide a code.  */
760 	if (!(opcode & OPCODE))
761 		tcode = ((opcode >> 6) & ((1 << 10) - 1));
762 
763 	do_trap_or_bp(regs, tcode, "Trap");
764 	return;
765 
766 out_sigsegv:
767 	force_sig(SIGSEGV, current);
768 }
769 
770 asmlinkage void do_ri(struct pt_regs *regs)
771 {
772 	unsigned int __user *epc = (unsigned int __user *)exception_epc(regs);
773 	unsigned long old_epc = regs->cp0_epc;
774 	unsigned int opcode = 0;
775 	int status = -1;
776 
777 	if (notify_die(DIE_RI, "RI Fault", regs, SIGSEGV, 0, 0)
778 	    == NOTIFY_STOP)
779 		return;
780 
781 	die_if_kernel("Reserved instruction in kernel code", regs);
782 
783 	if (unlikely(compute_return_epc(regs) < 0))
784 		return;
785 
786 	if (unlikely(get_user(opcode, epc) < 0))
787 		status = SIGSEGV;
788 
789 	if (!cpu_has_llsc && status < 0)
790 		status = simulate_llsc(regs, opcode);
791 
792 	if (status < 0)
793 		status = simulate_rdhwr(regs, opcode);
794 
795 	if (status < 0)
796 		status = simulate_sync(regs, opcode);
797 
798 	if (status < 0)
799 		status = SIGILL;
800 
801 	if (unlikely(status > 0)) {
802 		regs->cp0_epc = old_epc;		/* Undo skip-over.  */
803 		force_sig(status, current);
804 	}
805 }
806 
807 /*
808  * MIPS MT processors may have fewer FPU contexts than CPU threads. If we've
809  * emulated more than some threshold number of instructions, force migration to
810  * a "CPU" that has FP support.
811  */
812 static void mt_ase_fp_affinity(void)
813 {
814 #ifdef CONFIG_MIPS_MT_FPAFF
815 	if (mt_fpemul_threshold > 0 &&
816 	     ((current->thread.emulated_fp++ > mt_fpemul_threshold))) {
817 		/*
818 		 * If there's no FPU present, or if the application has already
819 		 * restricted the allowed set to exclude any CPUs with FPUs,
820 		 * we'll skip the procedure.
821 		 */
822 		if (cpus_intersects(current->cpus_allowed, mt_fpu_cpumask)) {
823 			cpumask_t tmask;
824 
825 			cpus_and(tmask, current->thread.user_cpus_allowed,
826 			         mt_fpu_cpumask);
827 			set_cpus_allowed(current, tmask);
828 			set_thread_flag(TIF_FPUBOUND);
829 		}
830 	}
831 #endif /* CONFIG_MIPS_MT_FPAFF */
832 }
833 
834 asmlinkage void do_cpu(struct pt_regs *regs)
835 {
836 	unsigned int __user *epc;
837 	unsigned long old_epc;
838 	unsigned int opcode;
839 	unsigned int cpid;
840 	int status;
841 
842 	die_if_kernel("do_cpu invoked from kernel context!", regs);
843 
844 	cpid = (regs->cp0_cause >> CAUSEB_CE) & 3;
845 
846 	switch (cpid) {
847 	case 0:
848 		epc = (unsigned int __user *)exception_epc(regs);
849 		old_epc = regs->cp0_epc;
850 		opcode = 0;
851 		status = -1;
852 
853 		if (unlikely(compute_return_epc(regs) < 0))
854 			return;
855 
856 		if (unlikely(get_user(opcode, epc) < 0))
857 			status = SIGSEGV;
858 
859 		if (!cpu_has_llsc && status < 0)
860 			status = simulate_llsc(regs, opcode);
861 
862 		if (status < 0)
863 			status = simulate_rdhwr(regs, opcode);
864 
865 		if (status < 0)
866 			status = SIGILL;
867 
868 		if (unlikely(status > 0)) {
869 			regs->cp0_epc = old_epc;	/* Undo skip-over.  */
870 			force_sig(status, current);
871 		}
872 
873 		return;
874 
875 	case 1:
876 		if (used_math())	/* Using the FPU again.  */
877 			own_fpu(1);
878 		else {			/* First time FPU user.  */
879 			init_fpu();
880 			set_used_math();
881 		}
882 
883 		if (!raw_cpu_has_fpu) {
884 			int sig;
885 			sig = fpu_emulator_cop1Handler(regs,
886 						&current->thread.fpu, 0);
887 			if (sig)
888 				force_sig(sig, current);
889 			else
890 				mt_ase_fp_affinity();
891 		}
892 
893 		return;
894 
895 	case 2:
896 	case 3:
897 		break;
898 	}
899 
900 	force_sig(SIGILL, current);
901 }
902 
903 asmlinkage void do_mdmx(struct pt_regs *regs)
904 {
905 	force_sig(SIGILL, current);
906 }
907 
908 asmlinkage void do_watch(struct pt_regs *regs)
909 {
910 	/*
911 	 * We use the watch exception where available to detect stack
912 	 * overflows.
913 	 */
914 	dump_tlb_all();
915 	show_regs(regs);
916 	panic("Caught WATCH exception - probably caused by stack overflow.");
917 }
918 
919 asmlinkage void do_mcheck(struct pt_regs *regs)
920 {
921 	const int field = 2 * sizeof(unsigned long);
922 	int multi_match = regs->cp0_status & ST0_TS;
923 
924 	show_regs(regs);
925 
926 	if (multi_match) {
927 		printk("Index   : %0x\n", read_c0_index());
928 		printk("Pagemask: %0x\n", read_c0_pagemask());
929 		printk("EntryHi : %0*lx\n", field, read_c0_entryhi());
930 		printk("EntryLo0: %0*lx\n", field, read_c0_entrylo0());
931 		printk("EntryLo1: %0*lx\n", field, read_c0_entrylo1());
932 		printk("\n");
933 		dump_tlb_all();
934 	}
935 
936 	show_code((unsigned int __user *) regs->cp0_epc);
937 
938 	/*
939 	 * Some chips may have other causes of machine check (e.g. SB1
940 	 * graduation timer)
941 	 */
942 	panic("Caught Machine Check exception - %scaused by multiple "
943 	      "matching entries in the TLB.",
944 	      (multi_match) ? "" : "not ");
945 }
946 
947 asmlinkage void do_mt(struct pt_regs *regs)
948 {
949 	int subcode;
950 
951 	subcode = (read_vpe_c0_vpecontrol() & VPECONTROL_EXCPT)
952 			>> VPECONTROL_EXCPT_SHIFT;
953 	switch (subcode) {
954 	case 0:
955 		printk(KERN_DEBUG "Thread Underflow\n");
956 		break;
957 	case 1:
958 		printk(KERN_DEBUG "Thread Overflow\n");
959 		break;
960 	case 2:
961 		printk(KERN_DEBUG "Invalid YIELD Qualifier\n");
962 		break;
963 	case 3:
964 		printk(KERN_DEBUG "Gating Storage Exception\n");
965 		break;
966 	case 4:
967 		printk(KERN_DEBUG "YIELD Scheduler Exception\n");
968 		break;
969 	case 5:
970 		printk(KERN_DEBUG "Gating Storage Schedulier Exception\n");
971 		break;
972 	default:
973 		printk(KERN_DEBUG "*** UNKNOWN THREAD EXCEPTION %d ***\n",
974 			subcode);
975 		break;
976 	}
977 	die_if_kernel("MIPS MT Thread exception in kernel", regs);
978 
979 	force_sig(SIGILL, current);
980 }
981 
982 
983 asmlinkage void do_dsp(struct pt_regs *regs)
984 {
985 	if (cpu_has_dsp)
986 		panic("Unexpected DSP exception\n");
987 
988 	force_sig(SIGILL, current);
989 }
990 
991 asmlinkage void do_reserved(struct pt_regs *regs)
992 {
993 	/*
994 	 * Game over - no way to handle this if it ever occurs.  Most probably
995 	 * caused by a new unknown cpu type or after another deadly
996 	 * hard/software error.
997 	 */
998 	show_regs(regs);
999 	panic("Caught reserved exception %ld - should not happen.",
1000 	      (regs->cp0_cause & 0x7f) >> 2);
1001 }
1002 
1003 static int __initdata l1parity = 1;
1004 static int __init nol1parity(char *s)
1005 {
1006 	l1parity = 0;
1007 	return 1;
1008 }
1009 __setup("nol1par", nol1parity);
1010 static int __initdata l2parity = 1;
1011 static int __init nol2parity(char *s)
1012 {
1013 	l2parity = 0;
1014 	return 1;
1015 }
1016 __setup("nol2par", nol2parity);
1017 
1018 /*
1019  * Some MIPS CPUs can enable/disable for cache parity detection, but do
1020  * it different ways.
1021  */
1022 static inline void parity_protection_init(void)
1023 {
1024 	switch (current_cpu_type()) {
1025 	case CPU_24K:
1026 	case CPU_34K:
1027 	case CPU_74K:
1028 	case CPU_1004K:
1029 		{
1030 #define ERRCTL_PE	0x80000000
1031 #define ERRCTL_L2P	0x00800000
1032 			unsigned long errctl;
1033 			unsigned int l1parity_present, l2parity_present;
1034 
1035 			errctl = read_c0_ecc();
1036 			errctl &= ~(ERRCTL_PE|ERRCTL_L2P);
1037 
1038 			/* probe L1 parity support */
1039 			write_c0_ecc(errctl | ERRCTL_PE);
1040 			back_to_back_c0_hazard();
1041 			l1parity_present = (read_c0_ecc() & ERRCTL_PE);
1042 
1043 			/* probe L2 parity support */
1044 			write_c0_ecc(errctl|ERRCTL_L2P);
1045 			back_to_back_c0_hazard();
1046 			l2parity_present = (read_c0_ecc() & ERRCTL_L2P);
1047 
1048 			if (l1parity_present && l2parity_present) {
1049 				if (l1parity)
1050 					errctl |= ERRCTL_PE;
1051 				if (l1parity ^ l2parity)
1052 					errctl |= ERRCTL_L2P;
1053 			} else if (l1parity_present) {
1054 				if (l1parity)
1055 					errctl |= ERRCTL_PE;
1056 			} else if (l2parity_present) {
1057 				if (l2parity)
1058 					errctl |= ERRCTL_L2P;
1059 			} else {
1060 				/* No parity available */
1061 			}
1062 
1063 			printk(KERN_INFO "Writing ErrCtl register=%08lx\n", errctl);
1064 
1065 			write_c0_ecc(errctl);
1066 			back_to_back_c0_hazard();
1067 			errctl = read_c0_ecc();
1068 			printk(KERN_INFO "Readback ErrCtl register=%08lx\n", errctl);
1069 
1070 			if (l1parity_present)
1071 				printk(KERN_INFO "Cache parity protection %sabled\n",
1072 				       (errctl & ERRCTL_PE) ? "en" : "dis");
1073 
1074 			if (l2parity_present) {
1075 				if (l1parity_present && l1parity)
1076 					errctl ^= ERRCTL_L2P;
1077 				printk(KERN_INFO "L2 cache parity protection %sabled\n",
1078 				       (errctl & ERRCTL_L2P) ? "en" : "dis");
1079 			}
1080 		}
1081 		break;
1082 
1083 	case CPU_5KC:
1084 		write_c0_ecc(0x80000000);
1085 		back_to_back_c0_hazard();
1086 		/* Set the PE bit (bit 31) in the c0_errctl register. */
1087 		printk(KERN_INFO "Cache parity protection %sabled\n",
1088 		       (read_c0_ecc() & 0x80000000) ? "en" : "dis");
1089 		break;
1090 	case CPU_20KC:
1091 	case CPU_25KF:
1092 		/* Clear the DE bit (bit 16) in the c0_status register. */
1093 		printk(KERN_INFO "Enable cache parity protection for "
1094 		       "MIPS 20KC/25KF CPUs.\n");
1095 		clear_c0_status(ST0_DE);
1096 		break;
1097 	default:
1098 		break;
1099 	}
1100 }
1101 
1102 asmlinkage void cache_parity_error(void)
1103 {
1104 	const int field = 2 * sizeof(unsigned long);
1105 	unsigned int reg_val;
1106 
1107 	/* For the moment, report the problem and hang. */
1108 	printk("Cache error exception:\n");
1109 	printk("cp0_errorepc == %0*lx\n", field, read_c0_errorepc());
1110 	reg_val = read_c0_cacheerr();
1111 	printk("c0_cacheerr == %08x\n", reg_val);
1112 
1113 	printk("Decoded c0_cacheerr: %s cache fault in %s reference.\n",
1114 	       reg_val & (1<<30) ? "secondary" : "primary",
1115 	       reg_val & (1<<31) ? "data" : "insn");
1116 	printk("Error bits: %s%s%s%s%s%s%s\n",
1117 	       reg_val & (1<<29) ? "ED " : "",
1118 	       reg_val & (1<<28) ? "ET " : "",
1119 	       reg_val & (1<<26) ? "EE " : "",
1120 	       reg_val & (1<<25) ? "EB " : "",
1121 	       reg_val & (1<<24) ? "EI " : "",
1122 	       reg_val & (1<<23) ? "E1 " : "",
1123 	       reg_val & (1<<22) ? "E0 " : "");
1124 	printk("IDX: 0x%08x\n", reg_val & ((1<<22)-1));
1125 
1126 #if defined(CONFIG_CPU_MIPS32) || defined(CONFIG_CPU_MIPS64)
1127 	if (reg_val & (1<<22))
1128 		printk("DErrAddr0: 0x%0*lx\n", field, read_c0_derraddr0());
1129 
1130 	if (reg_val & (1<<23))
1131 		printk("DErrAddr1: 0x%0*lx\n", field, read_c0_derraddr1());
1132 #endif
1133 
1134 	panic("Can't handle the cache error!");
1135 }
1136 
1137 /*
1138  * SDBBP EJTAG debug exception handler.
1139  * We skip the instruction and return to the next instruction.
1140  */
1141 void ejtag_exception_handler(struct pt_regs *regs)
1142 {
1143 	const int field = 2 * sizeof(unsigned long);
1144 	unsigned long depc, old_epc;
1145 	unsigned int debug;
1146 
1147 	printk(KERN_DEBUG "SDBBP EJTAG debug exception - not handled yet, just ignored!\n");
1148 	depc = read_c0_depc();
1149 	debug = read_c0_debug();
1150 	printk(KERN_DEBUG "c0_depc = %0*lx, DEBUG = %08x\n", field, depc, debug);
1151 	if (debug & 0x80000000) {
1152 		/*
1153 		 * In branch delay slot.
1154 		 * We cheat a little bit here and use EPC to calculate the
1155 		 * debug return address (DEPC). EPC is restored after the
1156 		 * calculation.
1157 		 */
1158 		old_epc = regs->cp0_epc;
1159 		regs->cp0_epc = depc;
1160 		__compute_return_epc(regs);
1161 		depc = regs->cp0_epc;
1162 		regs->cp0_epc = old_epc;
1163 	} else
1164 		depc += 4;
1165 	write_c0_depc(depc);
1166 
1167 #if 0
1168 	printk(KERN_DEBUG "\n\n----- Enable EJTAG single stepping ----\n\n");
1169 	write_c0_debug(debug | 0x100);
1170 #endif
1171 }
1172 
1173 /*
1174  * NMI exception handler.
1175  */
1176 NORET_TYPE void ATTRIB_NORET nmi_exception_handler(struct pt_regs *regs)
1177 {
1178 	bust_spinlocks(1);
1179 	printk("NMI taken!!!!\n");
1180 	die("NMI", regs);
1181 }
1182 
1183 #define VECTORSPACING 0x100	/* for EI/VI mode */
1184 
1185 unsigned long ebase;
1186 unsigned long exception_handlers[32];
1187 unsigned long vi_handlers[64];
1188 
1189 /*
1190  * As a side effect of the way this is implemented we're limited
1191  * to interrupt handlers in the address range from
1192  * KSEG0 <= x < KSEG0 + 256mb on the Nevada.  Oh well ...
1193  */
1194 void *set_except_vector(int n, void *addr)
1195 {
1196 	unsigned long handler = (unsigned long) addr;
1197 	unsigned long old_handler = exception_handlers[n];
1198 
1199 	exception_handlers[n] = handler;
1200 	if (n == 0 && cpu_has_divec) {
1201 		*(u32 *)(ebase + 0x200) = 0x08000000 |
1202 					  (0x03ffffff & (handler >> 2));
1203 		flush_icache_range(ebase + 0x200, ebase + 0x204);
1204 	}
1205 	return (void *)old_handler;
1206 }
1207 
1208 static asmlinkage void do_default_vi(void)
1209 {
1210 	show_regs(get_irq_regs());
1211 	panic("Caught unexpected vectored interrupt.");
1212 }
1213 
1214 static void *set_vi_srs_handler(int n, vi_handler_t addr, int srs)
1215 {
1216 	unsigned long handler;
1217 	unsigned long old_handler = vi_handlers[n];
1218 	int srssets = current_cpu_data.srsets;
1219 	u32 *w;
1220 	unsigned char *b;
1221 
1222 	if (!cpu_has_veic && !cpu_has_vint)
1223 		BUG();
1224 
1225 	if (addr == NULL) {
1226 		handler = (unsigned long) do_default_vi;
1227 		srs = 0;
1228 	} else
1229 		handler = (unsigned long) addr;
1230 	vi_handlers[n] = (unsigned long) addr;
1231 
1232 	b = (unsigned char *)(ebase + 0x200 + n*VECTORSPACING);
1233 
1234 	if (srs >= srssets)
1235 		panic("Shadow register set %d not supported", srs);
1236 
1237 	if (cpu_has_veic) {
1238 		if (board_bind_eic_interrupt)
1239 			board_bind_eic_interrupt(n, srs);
1240 	} else if (cpu_has_vint) {
1241 		/* SRSMap is only defined if shadow sets are implemented */
1242 		if (srssets > 1)
1243 			change_c0_srsmap(0xf << n*4, srs << n*4);
1244 	}
1245 
1246 	if (srs == 0) {
1247 		/*
1248 		 * If no shadow set is selected then use the default handler
1249 		 * that does normal register saving and a standard interrupt exit
1250 		 */
1251 
1252 		extern char except_vec_vi, except_vec_vi_lui;
1253 		extern char except_vec_vi_ori, except_vec_vi_end;
1254 #ifdef CONFIG_MIPS_MT_SMTC
1255 		/*
1256 		 * We need to provide the SMTC vectored interrupt handler
1257 		 * not only with the address of the handler, but with the
1258 		 * Status.IM bit to be masked before going there.
1259 		 */
1260 		extern char except_vec_vi_mori;
1261 		const int mori_offset = &except_vec_vi_mori - &except_vec_vi;
1262 #endif /* CONFIG_MIPS_MT_SMTC */
1263 		const int handler_len = &except_vec_vi_end - &except_vec_vi;
1264 		const int lui_offset = &except_vec_vi_lui - &except_vec_vi;
1265 		const int ori_offset = &except_vec_vi_ori - &except_vec_vi;
1266 
1267 		if (handler_len > VECTORSPACING) {
1268 			/*
1269 			 * Sigh... panicing won't help as the console
1270 			 * is probably not configured :(
1271 			 */
1272 			panic("VECTORSPACING too small");
1273 		}
1274 
1275 		memcpy(b, &except_vec_vi, handler_len);
1276 #ifdef CONFIG_MIPS_MT_SMTC
1277 		BUG_ON(n > 7);	/* Vector index %d exceeds SMTC maximum. */
1278 
1279 		w = (u32 *)(b + mori_offset);
1280 		*w = (*w & 0xffff0000) | (0x100 << n);
1281 #endif /* CONFIG_MIPS_MT_SMTC */
1282 		w = (u32 *)(b + lui_offset);
1283 		*w = (*w & 0xffff0000) | (((u32)handler >> 16) & 0xffff);
1284 		w = (u32 *)(b + ori_offset);
1285 		*w = (*w & 0xffff0000) | ((u32)handler & 0xffff);
1286 		flush_icache_range((unsigned long)b, (unsigned long)(b+handler_len));
1287 	}
1288 	else {
1289 		/*
1290 		 * In other cases jump directly to the interrupt handler
1291 		 *
1292 		 * It is the handlers responsibility to save registers if required
1293 		 * (eg hi/lo) and return from the exception using "eret"
1294 		 */
1295 		w = (u32 *)b;
1296 		*w++ = 0x08000000 | (((u32)handler >> 2) & 0x03fffff); /* j handler */
1297 		*w = 0;
1298 		flush_icache_range((unsigned long)b, (unsigned long)(b+8));
1299 	}
1300 
1301 	return (void *)old_handler;
1302 }
1303 
1304 void *set_vi_handler(int n, vi_handler_t addr)
1305 {
1306 	return set_vi_srs_handler(n, addr, 0);
1307 }
1308 
1309 /*
1310  * This is used by native signal handling
1311  */
1312 asmlinkage int (*save_fp_context)(struct sigcontext __user *sc);
1313 asmlinkage int (*restore_fp_context)(struct sigcontext __user *sc);
1314 
1315 extern asmlinkage int _save_fp_context(struct sigcontext __user *sc);
1316 extern asmlinkage int _restore_fp_context(struct sigcontext __user *sc);
1317 
1318 extern asmlinkage int fpu_emulator_save_context(struct sigcontext __user *sc);
1319 extern asmlinkage int fpu_emulator_restore_context(struct sigcontext __user *sc);
1320 
1321 #ifdef CONFIG_SMP
1322 static int smp_save_fp_context(struct sigcontext __user *sc)
1323 {
1324 	return raw_cpu_has_fpu
1325 	       ? _save_fp_context(sc)
1326 	       : fpu_emulator_save_context(sc);
1327 }
1328 
1329 static int smp_restore_fp_context(struct sigcontext __user *sc)
1330 {
1331 	return raw_cpu_has_fpu
1332 	       ? _restore_fp_context(sc)
1333 	       : fpu_emulator_restore_context(sc);
1334 }
1335 #endif
1336 
1337 static inline void signal_init(void)
1338 {
1339 #ifdef CONFIG_SMP
1340 	/* For now just do the cpu_has_fpu check when the functions are invoked */
1341 	save_fp_context = smp_save_fp_context;
1342 	restore_fp_context = smp_restore_fp_context;
1343 #else
1344 	if (cpu_has_fpu) {
1345 		save_fp_context = _save_fp_context;
1346 		restore_fp_context = _restore_fp_context;
1347 	} else {
1348 		save_fp_context = fpu_emulator_save_context;
1349 		restore_fp_context = fpu_emulator_restore_context;
1350 	}
1351 #endif
1352 }
1353 
1354 #ifdef CONFIG_MIPS32_COMPAT
1355 
1356 /*
1357  * This is used by 32-bit signal stuff on the 64-bit kernel
1358  */
1359 asmlinkage int (*save_fp_context32)(struct sigcontext32 __user *sc);
1360 asmlinkage int (*restore_fp_context32)(struct sigcontext32 __user *sc);
1361 
1362 extern asmlinkage int _save_fp_context32(struct sigcontext32 __user *sc);
1363 extern asmlinkage int _restore_fp_context32(struct sigcontext32 __user *sc);
1364 
1365 extern asmlinkage int fpu_emulator_save_context32(struct sigcontext32 __user *sc);
1366 extern asmlinkage int fpu_emulator_restore_context32(struct sigcontext32 __user *sc);
1367 
1368 static inline void signal32_init(void)
1369 {
1370 	if (cpu_has_fpu) {
1371 		save_fp_context32 = _save_fp_context32;
1372 		restore_fp_context32 = _restore_fp_context32;
1373 	} else {
1374 		save_fp_context32 = fpu_emulator_save_context32;
1375 		restore_fp_context32 = fpu_emulator_restore_context32;
1376 	}
1377 }
1378 #endif
1379 
1380 extern void cpu_cache_init(void);
1381 extern void tlb_init(void);
1382 extern void flush_tlb_handlers(void);
1383 
1384 /*
1385  * Timer interrupt
1386  */
1387 int cp0_compare_irq;
1388 
1389 /*
1390  * Performance counter IRQ or -1 if shared with timer
1391  */
1392 int cp0_perfcount_irq;
1393 EXPORT_SYMBOL_GPL(cp0_perfcount_irq);
1394 
1395 static int __cpuinitdata noulri;
1396 
1397 static int __init ulri_disable(char *s)
1398 {
1399 	pr_info("Disabling ulri\n");
1400 	noulri = 1;
1401 
1402 	return 1;
1403 }
1404 __setup("noulri", ulri_disable);
1405 
1406 void __cpuinit per_cpu_trap_init(void)
1407 {
1408 	unsigned int cpu = smp_processor_id();
1409 	unsigned int status_set = ST0_CU0;
1410 #ifdef CONFIG_MIPS_MT_SMTC
1411 	int secondaryTC = 0;
1412 	int bootTC = (cpu == 0);
1413 
1414 	/*
1415 	 * Only do per_cpu_trap_init() for first TC of Each VPE.
1416 	 * Note that this hack assumes that the SMTC init code
1417 	 * assigns TCs consecutively and in ascending order.
1418 	 */
1419 
1420 	if (((read_c0_tcbind() & TCBIND_CURTC) != 0) &&
1421 	    ((read_c0_tcbind() & TCBIND_CURVPE) == cpu_data[cpu - 1].vpe_id))
1422 		secondaryTC = 1;
1423 #endif /* CONFIG_MIPS_MT_SMTC */
1424 
1425 	/*
1426 	 * Disable coprocessors and select 32-bit or 64-bit addressing
1427 	 * and the 16/32 or 32/32 FPR register model.  Reset the BEV
1428 	 * flag that some firmware may have left set and the TS bit (for
1429 	 * IP27).  Set XX for ISA IV code to work.
1430 	 */
1431 #ifdef CONFIG_64BIT
1432 	status_set |= ST0_FR|ST0_KX|ST0_SX|ST0_UX;
1433 #endif
1434 	if (current_cpu_data.isa_level == MIPS_CPU_ISA_IV)
1435 		status_set |= ST0_XX;
1436 	if (cpu_has_dsp)
1437 		status_set |= ST0_MX;
1438 
1439 	change_c0_status(ST0_CU|ST0_MX|ST0_RE|ST0_FR|ST0_BEV|ST0_TS|ST0_KX|ST0_SX|ST0_UX,
1440 			 status_set);
1441 
1442 	if (cpu_has_mips_r2) {
1443 		unsigned int enable = 0x0000000f;
1444 
1445 		if (!noulri && cpu_has_userlocal)
1446 			enable |= (1 << 29);
1447 
1448 		write_c0_hwrena(enable);
1449 	}
1450 
1451 #ifdef CONFIG_MIPS_MT_SMTC
1452 	if (!secondaryTC) {
1453 #endif /* CONFIG_MIPS_MT_SMTC */
1454 
1455 	if (cpu_has_veic || cpu_has_vint) {
1456 		write_c0_ebase(ebase);
1457 		/* Setting vector spacing enables EI/VI mode  */
1458 		change_c0_intctl(0x3e0, VECTORSPACING);
1459 	}
1460 	if (cpu_has_divec) {
1461 		if (cpu_has_mipsmt) {
1462 			unsigned int vpflags = dvpe();
1463 			set_c0_cause(CAUSEF_IV);
1464 			evpe(vpflags);
1465 		} else
1466 			set_c0_cause(CAUSEF_IV);
1467 	}
1468 
1469 	/*
1470 	 * Before R2 both interrupt numbers were fixed to 7, so on R2 only:
1471 	 *
1472 	 *  o read IntCtl.IPTI to determine the timer interrupt
1473 	 *  o read IntCtl.IPPCI to determine the performance counter interrupt
1474 	 */
1475 	if (cpu_has_mips_r2) {
1476 		cp0_compare_irq = (read_c0_intctl() >> 29) & 7;
1477 		cp0_perfcount_irq = (read_c0_intctl() >> 26) & 7;
1478 		if (cp0_perfcount_irq == cp0_compare_irq)
1479 			cp0_perfcount_irq = -1;
1480 	} else {
1481 		cp0_compare_irq = CP0_LEGACY_COMPARE_IRQ;
1482 		cp0_perfcount_irq = -1;
1483 	}
1484 
1485 #ifdef CONFIG_MIPS_MT_SMTC
1486 	}
1487 #endif /* CONFIG_MIPS_MT_SMTC */
1488 
1489 	cpu_data[cpu].asid_cache = ASID_FIRST_VERSION;
1490 	TLBMISS_HANDLER_SETUP();
1491 
1492 	atomic_inc(&init_mm.mm_count);
1493 	current->active_mm = &init_mm;
1494 	BUG_ON(current->mm);
1495 	enter_lazy_tlb(&init_mm, current);
1496 
1497 #ifdef CONFIG_MIPS_MT_SMTC
1498 	if (bootTC) {
1499 #endif /* CONFIG_MIPS_MT_SMTC */
1500 		cpu_cache_init();
1501 		tlb_init();
1502 #ifdef CONFIG_MIPS_MT_SMTC
1503 	} else if (!secondaryTC) {
1504 		/*
1505 		 * First TC in non-boot VPE must do subset of tlb_init()
1506 		 * for MMU countrol registers.
1507 		 */
1508 		write_c0_pagemask(PM_DEFAULT_MASK);
1509 		write_c0_wired(0);
1510 	}
1511 #endif /* CONFIG_MIPS_MT_SMTC */
1512 }
1513 
1514 /* Install CPU exception handler */
1515 void __init set_handler(unsigned long offset, void *addr, unsigned long size)
1516 {
1517 	memcpy((void *)(ebase + offset), addr, size);
1518 	flush_icache_range(ebase + offset, ebase + offset + size);
1519 }
1520 
1521 static char panic_null_cerr[] __cpuinitdata =
1522 	"Trying to set NULL cache error exception handler";
1523 
1524 /* Install uncached CPU exception handler */
1525 void __cpuinit set_uncached_handler(unsigned long offset, void *addr,
1526 	unsigned long size)
1527 {
1528 #ifdef CONFIG_32BIT
1529 	unsigned long uncached_ebase = KSEG1ADDR(ebase);
1530 #endif
1531 #ifdef CONFIG_64BIT
1532 	unsigned long uncached_ebase = TO_UNCAC(ebase);
1533 #endif
1534 
1535 	if (!addr)
1536 		panic(panic_null_cerr);
1537 
1538 	memcpy((void *)(uncached_ebase + offset), addr, size);
1539 }
1540 
1541 static int __initdata rdhwr_noopt;
1542 static int __init set_rdhwr_noopt(char *str)
1543 {
1544 	rdhwr_noopt = 1;
1545 	return 1;
1546 }
1547 
1548 __setup("rdhwr_noopt", set_rdhwr_noopt);
1549 
1550 void __init trap_init(void)
1551 {
1552 	extern char except_vec3_generic, except_vec3_r4000;
1553 	extern char except_vec4;
1554 	unsigned long i;
1555 
1556 #if defined(CONFIG_KGDB)
1557 	if (kgdb_early_setup)
1558 		return;	/* Already done */
1559 #endif
1560 
1561 	if (cpu_has_veic || cpu_has_vint)
1562 		ebase = (unsigned long) alloc_bootmem_low_pages(0x200 + VECTORSPACING*64);
1563 	else
1564 		ebase = CAC_BASE;
1565 
1566 	per_cpu_trap_init();
1567 
1568 	/*
1569 	 * Copy the generic exception handlers to their final destination.
1570 	 * This will be overriden later as suitable for a particular
1571 	 * configuration.
1572 	 */
1573 	set_handler(0x180, &except_vec3_generic, 0x80);
1574 
1575 	/*
1576 	 * Setup default vectors
1577 	 */
1578 	for (i = 0; i <= 31; i++)
1579 		set_except_vector(i, handle_reserved);
1580 
1581 	/*
1582 	 * Copy the EJTAG debug exception vector handler code to it's final
1583 	 * destination.
1584 	 */
1585 	if (cpu_has_ejtag && board_ejtag_handler_setup)
1586 		board_ejtag_handler_setup();
1587 
1588 	/*
1589 	 * Only some CPUs have the watch exceptions.
1590 	 */
1591 	if (cpu_has_watch)
1592 		set_except_vector(23, handle_watch);
1593 
1594 	/*
1595 	 * Initialise interrupt handlers
1596 	 */
1597 	if (cpu_has_veic || cpu_has_vint) {
1598 		int nvec = cpu_has_veic ? 64 : 8;
1599 		for (i = 0; i < nvec; i++)
1600 			set_vi_handler(i, NULL);
1601 	}
1602 	else if (cpu_has_divec)
1603 		set_handler(0x200, &except_vec4, 0x8);
1604 
1605 	/*
1606 	 * Some CPUs can enable/disable for cache parity detection, but does
1607 	 * it different ways.
1608 	 */
1609 	parity_protection_init();
1610 
1611 	/*
1612 	 * The Data Bus Errors / Instruction Bus Errors are signaled
1613 	 * by external hardware.  Therefore these two exceptions
1614 	 * may have board specific handlers.
1615 	 */
1616 	if (board_be_init)
1617 		board_be_init();
1618 
1619 	set_except_vector(0, handle_int);
1620 	set_except_vector(1, handle_tlbm);
1621 	set_except_vector(2, handle_tlbl);
1622 	set_except_vector(3, handle_tlbs);
1623 
1624 	set_except_vector(4, handle_adel);
1625 	set_except_vector(5, handle_ades);
1626 
1627 	set_except_vector(6, handle_ibe);
1628 	set_except_vector(7, handle_dbe);
1629 
1630 	set_except_vector(8, handle_sys);
1631 	set_except_vector(9, handle_bp);
1632 	set_except_vector(10, rdhwr_noopt ? handle_ri :
1633 			  (cpu_has_vtag_icache ?
1634 			   handle_ri_rdhwr_vivt : handle_ri_rdhwr));
1635 	set_except_vector(11, handle_cpu);
1636 	set_except_vector(12, handle_ov);
1637 	set_except_vector(13, handle_tr);
1638 
1639 	if (current_cpu_type() == CPU_R6000 ||
1640 	    current_cpu_type() == CPU_R6000A) {
1641 		/*
1642 		 * The R6000 is the only R-series CPU that features a machine
1643 		 * check exception (similar to the R4000 cache error) and
1644 		 * unaligned ldc1/sdc1 exception.  The handlers have not been
1645 		 * written yet.  Well, anyway there is no R6000 machine on the
1646 		 * current list of targets for Linux/MIPS.
1647 		 * (Duh, crap, there is someone with a triple R6k machine)
1648 		 */
1649 		//set_except_vector(14, handle_mc);
1650 		//set_except_vector(15, handle_ndc);
1651 	}
1652 
1653 
1654 	if (board_nmi_handler_setup)
1655 		board_nmi_handler_setup();
1656 
1657 	if (cpu_has_fpu && !cpu_has_nofpuex)
1658 		set_except_vector(15, handle_fpe);
1659 
1660 	set_except_vector(22, handle_mdmx);
1661 
1662 	if (cpu_has_mcheck)
1663 		set_except_vector(24, handle_mcheck);
1664 
1665 	if (cpu_has_mipsmt)
1666 		set_except_vector(25, handle_mt);
1667 
1668 	set_except_vector(26, handle_dsp);
1669 
1670 	if (cpu_has_vce)
1671 		/* Special exception: R4[04]00 uses also the divec space. */
1672 		memcpy((void *)(CAC_BASE + 0x180), &except_vec3_r4000, 0x100);
1673 	else if (cpu_has_4kex)
1674 		memcpy((void *)(CAC_BASE + 0x180), &except_vec3_generic, 0x80);
1675 	else
1676 		memcpy((void *)(CAC_BASE + 0x080), &except_vec3_generic, 0x80);
1677 
1678 	signal_init();
1679 #ifdef CONFIG_MIPS32_COMPAT
1680 	signal32_init();
1681 #endif
1682 
1683 	flush_icache_range(ebase, ebase + 0x400);
1684 	flush_tlb_handlers();
1685 }
1686