xref: /openbmc/linux/arch/powerpc/kernel/traps.c (revision fd589a8f)
1 /*
2  *  Copyright (C) 1995-1996  Gary Thomas (gdt@linuxppc.org)
3  *
4  *  This program is free software; you can redistribute it and/or
5  *  modify it under the terms of the GNU General Public License
6  *  as published by the Free Software Foundation; either version
7  *  2 of the License, or (at your option) any later version.
8  *
9  *  Modified by Cort Dougan (cort@cs.nmt.edu)
10  *  and Paul Mackerras (paulus@samba.org)
11  */
12 
13 /*
14  * This file handles the architecture-dependent parts of hardware exceptions
15  */
16 
17 #include <linux/errno.h>
18 #include <linux/sched.h>
19 #include <linux/kernel.h>
20 #include <linux/mm.h>
21 #include <linux/stddef.h>
22 #include <linux/unistd.h>
23 #include <linux/ptrace.h>
24 #include <linux/slab.h>
25 #include <linux/user.h>
26 #include <linux/interrupt.h>
27 #include <linux/init.h>
28 #include <linux/module.h>
29 #include <linux/prctl.h>
30 #include <linux/delay.h>
31 #include <linux/kprobes.h>
32 #include <linux/kexec.h>
33 #include <linux/backlight.h>
34 #include <linux/bug.h>
35 #include <linux/kdebug.h>
36 #include <linux/debugfs.h>
37 
38 #include <asm/emulated_ops.h>
39 #include <asm/pgtable.h>
40 #include <asm/uaccess.h>
41 #include <asm/system.h>
42 #include <asm/io.h>
43 #include <asm/machdep.h>
44 #include <asm/rtas.h>
45 #include <asm/pmc.h>
46 #ifdef CONFIG_PPC32
47 #include <asm/reg.h>
48 #endif
49 #ifdef CONFIG_PMAC_BACKLIGHT
50 #include <asm/backlight.h>
51 #endif
52 #ifdef CONFIG_PPC64
53 #include <asm/firmware.h>
54 #include <asm/processor.h>
55 #endif
56 #include <asm/kexec.h>
57 #include <asm/ppc-opcode.h>
58 #ifdef CONFIG_FSL_BOOKE
59 #include <asm/dbell.h>
60 #endif
61 
62 #if defined(CONFIG_DEBUGGER) || defined(CONFIG_KEXEC)
63 int (*__debugger)(struct pt_regs *regs);
64 int (*__debugger_ipi)(struct pt_regs *regs);
65 int (*__debugger_bpt)(struct pt_regs *regs);
66 int (*__debugger_sstep)(struct pt_regs *regs);
67 int (*__debugger_iabr_match)(struct pt_regs *regs);
68 int (*__debugger_dabr_match)(struct pt_regs *regs);
69 int (*__debugger_fault_handler)(struct pt_regs *regs);
70 
71 EXPORT_SYMBOL(__debugger);
72 EXPORT_SYMBOL(__debugger_ipi);
73 EXPORT_SYMBOL(__debugger_bpt);
74 EXPORT_SYMBOL(__debugger_sstep);
75 EXPORT_SYMBOL(__debugger_iabr_match);
76 EXPORT_SYMBOL(__debugger_dabr_match);
77 EXPORT_SYMBOL(__debugger_fault_handler);
78 #endif
79 
80 /*
81  * Trap & Exception support
82  */
83 
84 #ifdef CONFIG_PMAC_BACKLIGHT
85 static void pmac_backlight_unblank(void)
86 {
87 	mutex_lock(&pmac_backlight_mutex);
88 	if (pmac_backlight) {
89 		struct backlight_properties *props;
90 
91 		props = &pmac_backlight->props;
92 		props->brightness = props->max_brightness;
93 		props->power = FB_BLANK_UNBLANK;
94 		backlight_update_status(pmac_backlight);
95 	}
96 	mutex_unlock(&pmac_backlight_mutex);
97 }
98 #else
99 static inline void pmac_backlight_unblank(void) { }
100 #endif
101 
102 int die(const char *str, struct pt_regs *regs, long err)
103 {
104 	static struct {
105 		spinlock_t lock;
106 		u32 lock_owner;
107 		int lock_owner_depth;
108 	} die = {
109 		.lock =			__SPIN_LOCK_UNLOCKED(die.lock),
110 		.lock_owner =		-1,
111 		.lock_owner_depth =	0
112 	};
113 	static int die_counter;
114 	unsigned long flags;
115 
116 	if (debugger(regs))
117 		return 1;
118 
119 	oops_enter();
120 
121 	if (die.lock_owner != raw_smp_processor_id()) {
122 		console_verbose();
123 		spin_lock_irqsave(&die.lock, flags);
124 		die.lock_owner = smp_processor_id();
125 		die.lock_owner_depth = 0;
126 		bust_spinlocks(1);
127 		if (machine_is(powermac))
128 			pmac_backlight_unblank();
129 	} else {
130 		local_save_flags(flags);
131 	}
132 
133 	if (++die.lock_owner_depth < 3) {
134 		printk("Oops: %s, sig: %ld [#%d]\n", str, err, ++die_counter);
135 #ifdef CONFIG_PREEMPT
136 		printk("PREEMPT ");
137 #endif
138 #ifdef CONFIG_SMP
139 		printk("SMP NR_CPUS=%d ", NR_CPUS);
140 #endif
141 #ifdef CONFIG_DEBUG_PAGEALLOC
142 		printk("DEBUG_PAGEALLOC ");
143 #endif
144 #ifdef CONFIG_NUMA
145 		printk("NUMA ");
146 #endif
147 		printk("%s\n", ppc_md.name ? ppc_md.name : "");
148 
149 		print_modules();
150 		show_regs(regs);
151 	} else {
152 		printk("Recursive die() failure, output suppressed\n");
153 	}
154 
155 	bust_spinlocks(0);
156 	die.lock_owner = -1;
157 	add_taint(TAINT_DIE);
158 	spin_unlock_irqrestore(&die.lock, flags);
159 
160 	if (kexec_should_crash(current) ||
161 		kexec_sr_activated(smp_processor_id()))
162 		crash_kexec(regs);
163 	crash_kexec_secondary(regs);
164 
165 	if (in_interrupt())
166 		panic("Fatal exception in interrupt");
167 
168 	if (panic_on_oops)
169 		panic("Fatal exception");
170 
171 	oops_exit();
172 	do_exit(err);
173 
174 	return 0;
175 }
176 
177 void _exception(int signr, struct pt_regs *regs, int code, unsigned long addr)
178 {
179 	siginfo_t info;
180 	const char fmt32[] = KERN_INFO "%s[%d]: unhandled signal %d " \
181 			"at %08lx nip %08lx lr %08lx code %x\n";
182 	const char fmt64[] = KERN_INFO "%s[%d]: unhandled signal %d " \
183 			"at %016lx nip %016lx lr %016lx code %x\n";
184 
185 	if (!user_mode(regs)) {
186 		if (die("Exception in kernel mode", regs, signr))
187 			return;
188 	} else if (show_unhandled_signals &&
189 		    unhandled_signal(current, signr) &&
190 		    printk_ratelimit()) {
191 			printk(regs->msr & MSR_SF ? fmt64 : fmt32,
192 				current->comm, current->pid, signr,
193 				addr, regs->nip, regs->link, code);
194 		}
195 
196 	memset(&info, 0, sizeof(info));
197 	info.si_signo = signr;
198 	info.si_code = code;
199 	info.si_addr = (void __user *) addr;
200 	force_sig_info(signr, &info, current);
201 
202 	/*
203 	 * Init gets no signals that it doesn't have a handler for.
204 	 * That's all very well, but if it has caused a synchronous
205 	 * exception and we ignore the resulting signal, it will just
206 	 * generate the same exception over and over again and we get
207 	 * nowhere.  Better to kill it and let the kernel panic.
208 	 */
209 	if (is_global_init(current)) {
210 		__sighandler_t handler;
211 
212 		spin_lock_irq(&current->sighand->siglock);
213 		handler = current->sighand->action[signr-1].sa.sa_handler;
214 		spin_unlock_irq(&current->sighand->siglock);
215 		if (handler == SIG_DFL) {
216 			/* init has generated a synchronous exception
217 			   and it doesn't have a handler for the signal */
218 			printk(KERN_CRIT "init has generated signal %d "
219 			       "but has no handler for it\n", signr);
220 			do_exit(signr);
221 		}
222 	}
223 }
224 
225 #ifdef CONFIG_PPC64
226 void system_reset_exception(struct pt_regs *regs)
227 {
228 	/* See if any machine dependent calls */
229 	if (ppc_md.system_reset_exception) {
230 		if (ppc_md.system_reset_exception(regs))
231 			return;
232 	}
233 
234 #ifdef CONFIG_KEXEC
235 	cpu_set(smp_processor_id(), cpus_in_sr);
236 #endif
237 
238 	die("System Reset", regs, SIGABRT);
239 
240 	/*
241 	 * Some CPUs when released from the debugger will execute this path.
242 	 * These CPUs entered the debugger via a soft-reset. If the CPU was
243 	 * hung before entering the debugger it will return to the hung
244 	 * state when exiting this function.  This causes a problem in
245 	 * kdump since the hung CPU(s) will not respond to the IPI sent
246 	 * from kdump. To prevent the problem we call crash_kexec_secondary()
247 	 * here. If a kdump had not been initiated or we exit the debugger
248 	 * with the "exit and recover" command (x) crash_kexec_secondary()
249 	 * will return after 5ms and the CPU returns to its previous state.
250 	 */
251 	crash_kexec_secondary(regs);
252 
253 	/* Must die if the interrupt is not recoverable */
254 	if (!(regs->msr & MSR_RI))
255 		panic("Unrecoverable System Reset");
256 
257 	/* What should we do here? We could issue a shutdown or hard reset. */
258 }
259 #endif
260 
261 /*
262  * I/O accesses can cause machine checks on powermacs.
263  * Check if the NIP corresponds to the address of a sync
264  * instruction for which there is an entry in the exception
265  * table.
266  * Note that the 601 only takes a machine check on TEA
267  * (transfer error ack) signal assertion, and does not
268  * set any of the top 16 bits of SRR1.
269  *  -- paulus.
270  */
271 static inline int check_io_access(struct pt_regs *regs)
272 {
273 #ifdef CONFIG_PPC32
274 	unsigned long msr = regs->msr;
275 	const struct exception_table_entry *entry;
276 	unsigned int *nip = (unsigned int *)regs->nip;
277 
278 	if (((msr & 0xffff0000) == 0 || (msr & (0x80000 | 0x40000)))
279 	    && (entry = search_exception_tables(regs->nip)) != NULL) {
280 		/*
281 		 * Check that it's a sync instruction, or somewhere
282 		 * in the twi; isync; nop sequence that inb/inw/inl uses.
283 		 * As the address is in the exception table
284 		 * we should be able to read the instr there.
285 		 * For the debug message, we look at the preceding
286 		 * load or store.
287 		 */
288 		if (*nip == 0x60000000)		/* nop */
289 			nip -= 2;
290 		else if (*nip == 0x4c00012c)	/* isync */
291 			--nip;
292 		if (*nip == 0x7c0004ac || (*nip >> 26) == 3) {
293 			/* sync or twi */
294 			unsigned int rb;
295 
296 			--nip;
297 			rb = (*nip >> 11) & 0x1f;
298 			printk(KERN_DEBUG "%s bad port %lx at %p\n",
299 			       (*nip & 0x100)? "OUT to": "IN from",
300 			       regs->gpr[rb] - _IO_BASE, nip);
301 			regs->msr |= MSR_RI;
302 			regs->nip = entry->fixup;
303 			return 1;
304 		}
305 	}
306 #endif /* CONFIG_PPC32 */
307 	return 0;
308 }
309 
310 #if defined(CONFIG_4xx) || defined(CONFIG_BOOKE)
311 /* On 4xx, the reason for the machine check or program exception
312    is in the ESR. */
313 #define get_reason(regs)	((regs)->dsisr)
314 #ifndef CONFIG_FSL_BOOKE
315 #define get_mc_reason(regs)	((regs)->dsisr)
316 #else
317 #define get_mc_reason(regs)	(mfspr(SPRN_MCSR) & MCSR_MASK)
318 #endif
319 #define REASON_FP		ESR_FP
320 #define REASON_ILLEGAL		(ESR_PIL | ESR_PUO)
321 #define REASON_PRIVILEGED	ESR_PPR
322 #define REASON_TRAP		ESR_PTR
323 
324 /* single-step stuff */
325 #define single_stepping(regs)	(current->thread.dbcr0 & DBCR0_IC)
326 #define clear_single_step(regs)	(current->thread.dbcr0 &= ~DBCR0_IC)
327 
328 #else
329 /* On non-4xx, the reason for the machine check or program
330    exception is in the MSR. */
331 #define get_reason(regs)	((regs)->msr)
332 #define get_mc_reason(regs)	((regs)->msr)
333 #define REASON_FP		0x100000
334 #define REASON_ILLEGAL		0x80000
335 #define REASON_PRIVILEGED	0x40000
336 #define REASON_TRAP		0x20000
337 
338 #define single_stepping(regs)	((regs)->msr & MSR_SE)
339 #define clear_single_step(regs)	((regs)->msr &= ~MSR_SE)
340 #endif
341 
342 #if defined(CONFIG_4xx)
343 int machine_check_4xx(struct pt_regs *regs)
344 {
345 	unsigned long reason = get_mc_reason(regs);
346 
347 	if (reason & ESR_IMCP) {
348 		printk("Instruction");
349 		mtspr(SPRN_ESR, reason & ~ESR_IMCP);
350 	} else
351 		printk("Data");
352 	printk(" machine check in kernel mode.\n");
353 
354 	return 0;
355 }
356 
357 int machine_check_440A(struct pt_regs *regs)
358 {
359 	unsigned long reason = get_mc_reason(regs);
360 
361 	printk("Machine check in kernel mode.\n");
362 	if (reason & ESR_IMCP){
363 		printk("Instruction Synchronous Machine Check exception\n");
364 		mtspr(SPRN_ESR, reason & ~ESR_IMCP);
365 	}
366 	else {
367 		u32 mcsr = mfspr(SPRN_MCSR);
368 		if (mcsr & MCSR_IB)
369 			printk("Instruction Read PLB Error\n");
370 		if (mcsr & MCSR_DRB)
371 			printk("Data Read PLB Error\n");
372 		if (mcsr & MCSR_DWB)
373 			printk("Data Write PLB Error\n");
374 		if (mcsr & MCSR_TLBP)
375 			printk("TLB Parity Error\n");
376 		if (mcsr & MCSR_ICP){
377 			flush_instruction_cache();
378 			printk("I-Cache Parity Error\n");
379 		}
380 		if (mcsr & MCSR_DCSP)
381 			printk("D-Cache Search Parity Error\n");
382 		if (mcsr & MCSR_DCFP)
383 			printk("D-Cache Flush Parity Error\n");
384 		if (mcsr & MCSR_IMPE)
385 			printk("Machine Check exception is imprecise\n");
386 
387 		/* Clear MCSR */
388 		mtspr(SPRN_MCSR, mcsr);
389 	}
390 	return 0;
391 }
392 #elif defined(CONFIG_E500)
393 int machine_check_e500(struct pt_regs *regs)
394 {
395 	unsigned long reason = get_mc_reason(regs);
396 
397 	printk("Machine check in kernel mode.\n");
398 	printk("Caused by (from MCSR=%lx): ", reason);
399 
400 	if (reason & MCSR_MCP)
401 		printk("Machine Check Signal\n");
402 	if (reason & MCSR_ICPERR)
403 		printk("Instruction Cache Parity Error\n");
404 	if (reason & MCSR_DCP_PERR)
405 		printk("Data Cache Push Parity Error\n");
406 	if (reason & MCSR_DCPERR)
407 		printk("Data Cache Parity Error\n");
408 	if (reason & MCSR_BUS_IAERR)
409 		printk("Bus - Instruction Address Error\n");
410 	if (reason & MCSR_BUS_RAERR)
411 		printk("Bus - Read Address Error\n");
412 	if (reason & MCSR_BUS_WAERR)
413 		printk("Bus - Write Address Error\n");
414 	if (reason & MCSR_BUS_IBERR)
415 		printk("Bus - Instruction Data Error\n");
416 	if (reason & MCSR_BUS_RBERR)
417 		printk("Bus - Read Data Bus Error\n");
418 	if (reason & MCSR_BUS_WBERR)
419 		printk("Bus - Read Data Bus Error\n");
420 	if (reason & MCSR_BUS_IPERR)
421 		printk("Bus - Instruction Parity Error\n");
422 	if (reason & MCSR_BUS_RPERR)
423 		printk("Bus - Read Parity Error\n");
424 
425 	return 0;
426 }
427 #elif defined(CONFIG_E200)
428 int machine_check_e200(struct pt_regs *regs)
429 {
430 	unsigned long reason = get_mc_reason(regs);
431 
432 	printk("Machine check in kernel mode.\n");
433 	printk("Caused by (from MCSR=%lx): ", reason);
434 
435 	if (reason & MCSR_MCP)
436 		printk("Machine Check Signal\n");
437 	if (reason & MCSR_CP_PERR)
438 		printk("Cache Push Parity Error\n");
439 	if (reason & MCSR_CPERR)
440 		printk("Cache Parity Error\n");
441 	if (reason & MCSR_EXCP_ERR)
442 		printk("ISI, ITLB, or Bus Error on first instruction fetch for an exception handler\n");
443 	if (reason & MCSR_BUS_IRERR)
444 		printk("Bus - Read Bus Error on instruction fetch\n");
445 	if (reason & MCSR_BUS_DRERR)
446 		printk("Bus - Read Bus Error on data load\n");
447 	if (reason & MCSR_BUS_WRERR)
448 		printk("Bus - Write Bus Error on buffered store or cache line push\n");
449 
450 	return 0;
451 }
452 #else
453 int machine_check_generic(struct pt_regs *regs)
454 {
455 	unsigned long reason = get_mc_reason(regs);
456 
457 	printk("Machine check in kernel mode.\n");
458 	printk("Caused by (from SRR1=%lx): ", reason);
459 	switch (reason & 0x601F0000) {
460 	case 0x80000:
461 		printk("Machine check signal\n");
462 		break;
463 	case 0:		/* for 601 */
464 	case 0x40000:
465 	case 0x140000:	/* 7450 MSS error and TEA */
466 		printk("Transfer error ack signal\n");
467 		break;
468 	case 0x20000:
469 		printk("Data parity error signal\n");
470 		break;
471 	case 0x10000:
472 		printk("Address parity error signal\n");
473 		break;
474 	case 0x20000000:
475 		printk("L1 Data Cache error\n");
476 		break;
477 	case 0x40000000:
478 		printk("L1 Instruction Cache error\n");
479 		break;
480 	case 0x00100000:
481 		printk("L2 data cache parity error\n");
482 		break;
483 	default:
484 		printk("Unknown values in msr\n");
485 	}
486 	return 0;
487 }
488 #endif /* everything else */
489 
490 void machine_check_exception(struct pt_regs *regs)
491 {
492 	int recover = 0;
493 
494 	/* See if any machine dependent calls. In theory, we would want
495 	 * to call the CPU first, and call the ppc_md. one if the CPU
496 	 * one returns a positive number. However there is existing code
497 	 * that assumes the board gets a first chance, so let's keep it
498 	 * that way for now and fix things later. --BenH.
499 	 */
500 	if (ppc_md.machine_check_exception)
501 		recover = ppc_md.machine_check_exception(regs);
502 	else if (cur_cpu_spec->machine_check)
503 		recover = cur_cpu_spec->machine_check(regs);
504 
505 	if (recover > 0)
506 		return;
507 
508 	if (user_mode(regs)) {
509 		regs->msr |= MSR_RI;
510 		_exception(SIGBUS, regs, BUS_ADRERR, regs->nip);
511 		return;
512 	}
513 
514 #if defined(CONFIG_8xx) && defined(CONFIG_PCI)
515 	/* the qspan pci read routines can cause machine checks -- Cort
516 	 *
517 	 * yuck !!! that totally needs to go away ! There are better ways
518 	 * to deal with that than having a wart in the mcheck handler.
519 	 * -- BenH
520 	 */
521 	bad_page_fault(regs, regs->dar, SIGBUS);
522 	return;
523 #endif
524 
525 	if (debugger_fault_handler(regs)) {
526 		regs->msr |= MSR_RI;
527 		return;
528 	}
529 
530 	if (check_io_access(regs))
531 		return;
532 
533 	if (debugger_fault_handler(regs))
534 		return;
535 	die("Machine check", regs, SIGBUS);
536 
537 	/* Must die if the interrupt is not recoverable */
538 	if (!(regs->msr & MSR_RI))
539 		panic("Unrecoverable Machine check");
540 }
541 
542 void SMIException(struct pt_regs *regs)
543 {
544 	die("System Management Interrupt", regs, SIGABRT);
545 }
546 
547 void unknown_exception(struct pt_regs *regs)
548 {
549 	printk("Bad trap at PC: %lx, SR: %lx, vector=%lx\n",
550 	       regs->nip, regs->msr, regs->trap);
551 
552 	_exception(SIGTRAP, regs, 0, 0);
553 }
554 
555 void instruction_breakpoint_exception(struct pt_regs *regs)
556 {
557 	if (notify_die(DIE_IABR_MATCH, "iabr_match", regs, 5,
558 					5, SIGTRAP) == NOTIFY_STOP)
559 		return;
560 	if (debugger_iabr_match(regs))
561 		return;
562 	_exception(SIGTRAP, regs, TRAP_BRKPT, regs->nip);
563 }
564 
565 void RunModeException(struct pt_regs *regs)
566 {
567 	_exception(SIGTRAP, regs, 0, 0);
568 }
569 
570 void __kprobes single_step_exception(struct pt_regs *regs)
571 {
572 	regs->msr &= ~(MSR_SE | MSR_BE);  /* Turn off 'trace' bits */
573 
574 	if (notify_die(DIE_SSTEP, "single_step", regs, 5,
575 					5, SIGTRAP) == NOTIFY_STOP)
576 		return;
577 	if (debugger_sstep(regs))
578 		return;
579 
580 	_exception(SIGTRAP, regs, TRAP_TRACE, regs->nip);
581 }
582 
583 /*
584  * After we have successfully emulated an instruction, we have to
585  * check if the instruction was being single-stepped, and if so,
586  * pretend we got a single-step exception.  This was pointed out
587  * by Kumar Gala.  -- paulus
588  */
589 static void emulate_single_step(struct pt_regs *regs)
590 {
591 	if (single_stepping(regs)) {
592 		clear_single_step(regs);
593 		_exception(SIGTRAP, regs, TRAP_TRACE, 0);
594 	}
595 }
596 
597 static inline int __parse_fpscr(unsigned long fpscr)
598 {
599 	int ret = 0;
600 
601 	/* Invalid operation */
602 	if ((fpscr & FPSCR_VE) && (fpscr & FPSCR_VX))
603 		ret = FPE_FLTINV;
604 
605 	/* Overflow */
606 	else if ((fpscr & FPSCR_OE) && (fpscr & FPSCR_OX))
607 		ret = FPE_FLTOVF;
608 
609 	/* Underflow */
610 	else if ((fpscr & FPSCR_UE) && (fpscr & FPSCR_UX))
611 		ret = FPE_FLTUND;
612 
613 	/* Divide by zero */
614 	else if ((fpscr & FPSCR_ZE) && (fpscr & FPSCR_ZX))
615 		ret = FPE_FLTDIV;
616 
617 	/* Inexact result */
618 	else if ((fpscr & FPSCR_XE) && (fpscr & FPSCR_XX))
619 		ret = FPE_FLTRES;
620 
621 	return ret;
622 }
623 
624 static void parse_fpe(struct pt_regs *regs)
625 {
626 	int code = 0;
627 
628 	flush_fp_to_thread(current);
629 
630 	code = __parse_fpscr(current->thread.fpscr.val);
631 
632 	_exception(SIGFPE, regs, code, regs->nip);
633 }
634 
635 /*
636  * Illegal instruction emulation support.  Originally written to
637  * provide the PVR to user applications using the mfspr rd, PVR.
638  * Return non-zero if we can't emulate, or -EFAULT if the associated
639  * memory access caused an access fault.  Return zero on success.
640  *
641  * There are a couple of ways to do this, either "decode" the instruction
642  * or directly match lots of bits.  In this case, matching lots of
643  * bits is faster and easier.
644  *
645  */
646 static int emulate_string_inst(struct pt_regs *regs, u32 instword)
647 {
648 	u8 rT = (instword >> 21) & 0x1f;
649 	u8 rA = (instword >> 16) & 0x1f;
650 	u8 NB_RB = (instword >> 11) & 0x1f;
651 	u32 num_bytes;
652 	unsigned long EA;
653 	int pos = 0;
654 
655 	/* Early out if we are an invalid form of lswx */
656 	if ((instword & PPC_INST_STRING_MASK) == PPC_INST_LSWX)
657 		if ((rT == rA) || (rT == NB_RB))
658 			return -EINVAL;
659 
660 	EA = (rA == 0) ? 0 : regs->gpr[rA];
661 
662 	switch (instword & PPC_INST_STRING_MASK) {
663 		case PPC_INST_LSWX:
664 		case PPC_INST_STSWX:
665 			EA += NB_RB;
666 			num_bytes = regs->xer & 0x7f;
667 			break;
668 		case PPC_INST_LSWI:
669 		case PPC_INST_STSWI:
670 			num_bytes = (NB_RB == 0) ? 32 : NB_RB;
671 			break;
672 		default:
673 			return -EINVAL;
674 	}
675 
676 	while (num_bytes != 0)
677 	{
678 		u8 val;
679 		u32 shift = 8 * (3 - (pos & 0x3));
680 
681 		switch ((instword & PPC_INST_STRING_MASK)) {
682 			case PPC_INST_LSWX:
683 			case PPC_INST_LSWI:
684 				if (get_user(val, (u8 __user *)EA))
685 					return -EFAULT;
686 				/* first time updating this reg,
687 				 * zero it out */
688 				if (pos == 0)
689 					regs->gpr[rT] = 0;
690 				regs->gpr[rT] |= val << shift;
691 				break;
692 			case PPC_INST_STSWI:
693 			case PPC_INST_STSWX:
694 				val = regs->gpr[rT] >> shift;
695 				if (put_user(val, (u8 __user *)EA))
696 					return -EFAULT;
697 				break;
698 		}
699 		/* move EA to next address */
700 		EA += 1;
701 		num_bytes--;
702 
703 		/* manage our position within the register */
704 		if (++pos == 4) {
705 			pos = 0;
706 			if (++rT == 32)
707 				rT = 0;
708 		}
709 	}
710 
711 	return 0;
712 }
713 
714 static int emulate_popcntb_inst(struct pt_regs *regs, u32 instword)
715 {
716 	u32 ra,rs;
717 	unsigned long tmp;
718 
719 	ra = (instword >> 16) & 0x1f;
720 	rs = (instword >> 21) & 0x1f;
721 
722 	tmp = regs->gpr[rs];
723 	tmp = tmp - ((tmp >> 1) & 0x5555555555555555ULL);
724 	tmp = (tmp & 0x3333333333333333ULL) + ((tmp >> 2) & 0x3333333333333333ULL);
725 	tmp = (tmp + (tmp >> 4)) & 0x0f0f0f0f0f0f0f0fULL;
726 	regs->gpr[ra] = tmp;
727 
728 	return 0;
729 }
730 
731 static int emulate_isel(struct pt_regs *regs, u32 instword)
732 {
733 	u8 rT = (instword >> 21) & 0x1f;
734 	u8 rA = (instword >> 16) & 0x1f;
735 	u8 rB = (instword >> 11) & 0x1f;
736 	u8 BC = (instword >> 6) & 0x1f;
737 	u8 bit;
738 	unsigned long tmp;
739 
740 	tmp = (rA == 0) ? 0 : regs->gpr[rA];
741 	bit = (regs->ccr >> (31 - BC)) & 0x1;
742 
743 	regs->gpr[rT] = bit ? tmp : regs->gpr[rB];
744 
745 	return 0;
746 }
747 
748 static int emulate_instruction(struct pt_regs *regs)
749 {
750 	u32 instword;
751 	u32 rd;
752 
753 	if (!user_mode(regs) || (regs->msr & MSR_LE))
754 		return -EINVAL;
755 	CHECK_FULL_REGS(regs);
756 
757 	if (get_user(instword, (u32 __user *)(regs->nip)))
758 		return -EFAULT;
759 
760 	/* Emulate the mfspr rD, PVR. */
761 	if ((instword & PPC_INST_MFSPR_PVR_MASK) == PPC_INST_MFSPR_PVR) {
762 		PPC_WARN_EMULATED(mfpvr);
763 		rd = (instword >> 21) & 0x1f;
764 		regs->gpr[rd] = mfspr(SPRN_PVR);
765 		return 0;
766 	}
767 
768 	/* Emulating the dcba insn is just a no-op.  */
769 	if ((instword & PPC_INST_DCBA_MASK) == PPC_INST_DCBA) {
770 		PPC_WARN_EMULATED(dcba);
771 		return 0;
772 	}
773 
774 	/* Emulate the mcrxr insn.  */
775 	if ((instword & PPC_INST_MCRXR_MASK) == PPC_INST_MCRXR) {
776 		int shift = (instword >> 21) & 0x1c;
777 		unsigned long msk = 0xf0000000UL >> shift;
778 
779 		PPC_WARN_EMULATED(mcrxr);
780 		regs->ccr = (regs->ccr & ~msk) | ((regs->xer >> shift) & msk);
781 		regs->xer &= ~0xf0000000UL;
782 		return 0;
783 	}
784 
785 	/* Emulate load/store string insn. */
786 	if ((instword & PPC_INST_STRING_GEN_MASK) == PPC_INST_STRING) {
787 		PPC_WARN_EMULATED(string);
788 		return emulate_string_inst(regs, instword);
789 	}
790 
791 	/* Emulate the popcntb (Population Count Bytes) instruction. */
792 	if ((instword & PPC_INST_POPCNTB_MASK) == PPC_INST_POPCNTB) {
793 		PPC_WARN_EMULATED(popcntb);
794 		return emulate_popcntb_inst(regs, instword);
795 	}
796 
797 	/* Emulate isel (Integer Select) instruction */
798 	if ((instword & PPC_INST_ISEL_MASK) == PPC_INST_ISEL) {
799 		PPC_WARN_EMULATED(isel);
800 		return emulate_isel(regs, instword);
801 	}
802 
803 	return -EINVAL;
804 }
805 
806 int is_valid_bugaddr(unsigned long addr)
807 {
808 	return is_kernel_addr(addr);
809 }
810 
811 void __kprobes program_check_exception(struct pt_regs *regs)
812 {
813 	unsigned int reason = get_reason(regs);
814 	extern int do_mathemu(struct pt_regs *regs);
815 
816 	/* We can now get here via a FP Unavailable exception if the core
817 	 * has no FPU, in that case the reason flags will be 0 */
818 
819 	if (reason & REASON_FP) {
820 		/* IEEE FP exception */
821 		parse_fpe(regs);
822 		return;
823 	}
824 	if (reason & REASON_TRAP) {
825 		/* trap exception */
826 		if (notify_die(DIE_BPT, "breakpoint", regs, 5, 5, SIGTRAP)
827 				== NOTIFY_STOP)
828 			return;
829 		if (debugger_bpt(regs))
830 			return;
831 
832 		if (!(regs->msr & MSR_PR) &&  /* not user-mode */
833 		    report_bug(regs->nip, regs) == BUG_TRAP_TYPE_WARN) {
834 			regs->nip += 4;
835 			return;
836 		}
837 		_exception(SIGTRAP, regs, TRAP_BRKPT, regs->nip);
838 		return;
839 	}
840 
841 	local_irq_enable();
842 
843 #ifdef CONFIG_MATH_EMULATION
844 	/* (reason & REASON_ILLEGAL) would be the obvious thing here,
845 	 * but there seems to be a hardware bug on the 405GP (RevD)
846 	 * that means ESR is sometimes set incorrectly - either to
847 	 * ESR_DST (!?) or 0.  In the process of chasing this with the
848 	 * hardware people - not sure if it can happen on any illegal
849 	 * instruction or only on FP instructions, whether there is a
850 	 * pattern to occurences etc. -dgibson 31/Mar/2003 */
851 	switch (do_mathemu(regs)) {
852 	case 0:
853 		emulate_single_step(regs);
854 		return;
855 	case 1: {
856 			int code = 0;
857 			code = __parse_fpscr(current->thread.fpscr.val);
858 			_exception(SIGFPE, regs, code, regs->nip);
859 			return;
860 		}
861 	case -EFAULT:
862 		_exception(SIGSEGV, regs, SEGV_MAPERR, regs->nip);
863 		return;
864 	}
865 	/* fall through on any other errors */
866 #endif /* CONFIG_MATH_EMULATION */
867 
868 	/* Try to emulate it if we should. */
869 	if (reason & (REASON_ILLEGAL | REASON_PRIVILEGED)) {
870 		switch (emulate_instruction(regs)) {
871 		case 0:
872 			regs->nip += 4;
873 			emulate_single_step(regs);
874 			return;
875 		case -EFAULT:
876 			_exception(SIGSEGV, regs, SEGV_MAPERR, regs->nip);
877 			return;
878 		}
879 	}
880 
881 	if (reason & REASON_PRIVILEGED)
882 		_exception(SIGILL, regs, ILL_PRVOPC, regs->nip);
883 	else
884 		_exception(SIGILL, regs, ILL_ILLOPC, regs->nip);
885 }
886 
887 void alignment_exception(struct pt_regs *regs)
888 {
889 	int sig, code, fixed = 0;
890 
891 	/* we don't implement logging of alignment exceptions */
892 	if (!(current->thread.align_ctl & PR_UNALIGN_SIGBUS))
893 		fixed = fix_alignment(regs);
894 
895 	if (fixed == 1) {
896 		regs->nip += 4;	/* skip over emulated instruction */
897 		emulate_single_step(regs);
898 		return;
899 	}
900 
901 	/* Operand address was bad */
902 	if (fixed == -EFAULT) {
903 		sig = SIGSEGV;
904 		code = SEGV_ACCERR;
905 	} else {
906 		sig = SIGBUS;
907 		code = BUS_ADRALN;
908 	}
909 	if (user_mode(regs))
910 		_exception(sig, regs, code, regs->dar);
911 	else
912 		bad_page_fault(regs, regs->dar, sig);
913 }
914 
915 void StackOverflow(struct pt_regs *regs)
916 {
917 	printk(KERN_CRIT "Kernel stack overflow in process %p, r1=%lx\n",
918 	       current, regs->gpr[1]);
919 	debugger(regs);
920 	show_regs(regs);
921 	panic("kernel stack overflow");
922 }
923 
924 void nonrecoverable_exception(struct pt_regs *regs)
925 {
926 	printk(KERN_ERR "Non-recoverable exception at PC=%lx MSR=%lx\n",
927 	       regs->nip, regs->msr);
928 	debugger(regs);
929 	die("nonrecoverable exception", regs, SIGKILL);
930 }
931 
932 void trace_syscall(struct pt_regs *regs)
933 {
934 	printk("Task: %p(%d), PC: %08lX/%08lX, Syscall: %3ld, Result: %s%ld    %s\n",
935 	       current, task_pid_nr(current), regs->nip, regs->link, regs->gpr[0],
936 	       regs->ccr&0x10000000?"Error=":"", regs->gpr[3], print_tainted());
937 }
938 
939 void kernel_fp_unavailable_exception(struct pt_regs *regs)
940 {
941 	printk(KERN_EMERG "Unrecoverable FP Unavailable Exception "
942 			  "%lx at %lx\n", regs->trap, regs->nip);
943 	die("Unrecoverable FP Unavailable Exception", regs, SIGABRT);
944 }
945 
946 void altivec_unavailable_exception(struct pt_regs *regs)
947 {
948 	if (user_mode(regs)) {
949 		/* A user program has executed an altivec instruction,
950 		   but this kernel doesn't support altivec. */
951 		_exception(SIGILL, regs, ILL_ILLOPC, regs->nip);
952 		return;
953 	}
954 
955 	printk(KERN_EMERG "Unrecoverable VMX/Altivec Unavailable Exception "
956 			"%lx at %lx\n", regs->trap, regs->nip);
957 	die("Unrecoverable VMX/Altivec Unavailable Exception", regs, SIGABRT);
958 }
959 
960 void vsx_unavailable_exception(struct pt_regs *regs)
961 {
962 	if (user_mode(regs)) {
963 		/* A user program has executed an vsx instruction,
964 		   but this kernel doesn't support vsx. */
965 		_exception(SIGILL, regs, ILL_ILLOPC, regs->nip);
966 		return;
967 	}
968 
969 	printk(KERN_EMERG "Unrecoverable VSX Unavailable Exception "
970 			"%lx at %lx\n", regs->trap, regs->nip);
971 	die("Unrecoverable VSX Unavailable Exception", regs, SIGABRT);
972 }
973 
974 void performance_monitor_exception(struct pt_regs *regs)
975 {
976 	perf_irq(regs);
977 }
978 
979 #ifdef CONFIG_8xx
980 void SoftwareEmulation(struct pt_regs *regs)
981 {
982 	extern int do_mathemu(struct pt_regs *);
983 	extern int Soft_emulate_8xx(struct pt_regs *);
984 #if defined(CONFIG_MATH_EMULATION) || defined(CONFIG_8XX_MINIMAL_FPEMU)
985 	int errcode;
986 #endif
987 
988 	CHECK_FULL_REGS(regs);
989 
990 	if (!user_mode(regs)) {
991 		debugger(regs);
992 		die("Kernel Mode Software FPU Emulation", regs, SIGFPE);
993 	}
994 
995 #ifdef CONFIG_MATH_EMULATION
996 	errcode = do_mathemu(regs);
997 	if (errcode >= 0)
998 		PPC_WARN_EMULATED(math);
999 
1000 	switch (errcode) {
1001 	case 0:
1002 		emulate_single_step(regs);
1003 		return;
1004 	case 1: {
1005 			int code = 0;
1006 			code = __parse_fpscr(current->thread.fpscr.val);
1007 			_exception(SIGFPE, regs, code, regs->nip);
1008 			return;
1009 		}
1010 	case -EFAULT:
1011 		_exception(SIGSEGV, regs, SEGV_MAPERR, regs->nip);
1012 		return;
1013 	default:
1014 		_exception(SIGILL, regs, ILL_ILLOPC, regs->nip);
1015 		return;
1016 	}
1017 
1018 #elif defined(CONFIG_8XX_MINIMAL_FPEMU)
1019 	errcode = Soft_emulate_8xx(regs);
1020 	if (errcode >= 0)
1021 		PPC_WARN_EMULATED(8xx);
1022 
1023 	switch (errcode) {
1024 	case 0:
1025 		emulate_single_step(regs);
1026 		return;
1027 	case 1:
1028 		_exception(SIGILL, regs, ILL_ILLOPC, regs->nip);
1029 		return;
1030 	case -EFAULT:
1031 		_exception(SIGSEGV, regs, SEGV_MAPERR, regs->nip);
1032 		return;
1033 	}
1034 #else
1035 	_exception(SIGILL, regs, ILL_ILLOPC, regs->nip);
1036 #endif
1037 }
1038 #endif /* CONFIG_8xx */
1039 
1040 #if defined(CONFIG_40x) || defined(CONFIG_BOOKE)
1041 
1042 void __kprobes DebugException(struct pt_regs *regs, unsigned long debug_status)
1043 {
1044 	/* Hack alert: On BookE, Branch Taken stops on the branch itself, while
1045 	 * on server, it stops on the target of the branch. In order to simulate
1046 	 * the server behaviour, we thus restart right away with a single step
1047 	 * instead of stopping here when hitting a BT
1048 	 */
1049 	if (debug_status & DBSR_BT) {
1050 		regs->msr &= ~MSR_DE;
1051 
1052 		/* Disable BT */
1053 		mtspr(SPRN_DBCR0, mfspr(SPRN_DBCR0) & ~DBCR0_BT);
1054 		/* Clear the BT event */
1055 		mtspr(SPRN_DBSR, DBSR_BT);
1056 
1057 		/* Do the single step trick only when coming from userspace */
1058 		if (user_mode(regs)) {
1059 			current->thread.dbcr0 &= ~DBCR0_BT;
1060 			current->thread.dbcr0 |= DBCR0_IDM | DBCR0_IC;
1061 			regs->msr |= MSR_DE;
1062 			return;
1063 		}
1064 
1065 		if (notify_die(DIE_SSTEP, "block_step", regs, 5,
1066 			       5, SIGTRAP) == NOTIFY_STOP) {
1067 			return;
1068 		}
1069 		if (debugger_sstep(regs))
1070 			return;
1071 	} else if (debug_status & DBSR_IC) { 	/* Instruction complete */
1072 		regs->msr &= ~MSR_DE;
1073 
1074 		/* Disable instruction completion */
1075 		mtspr(SPRN_DBCR0, mfspr(SPRN_DBCR0) & ~DBCR0_IC);
1076 		/* Clear the instruction completion event */
1077 		mtspr(SPRN_DBSR, DBSR_IC);
1078 
1079 		if (notify_die(DIE_SSTEP, "single_step", regs, 5,
1080 			       5, SIGTRAP) == NOTIFY_STOP) {
1081 			return;
1082 		}
1083 
1084 		if (debugger_sstep(regs))
1085 			return;
1086 
1087 		if (user_mode(regs))
1088 			current->thread.dbcr0 &= ~(DBCR0_IC);
1089 
1090 		_exception(SIGTRAP, regs, TRAP_TRACE, regs->nip);
1091 	} else if (debug_status & (DBSR_DAC1R | DBSR_DAC1W)) {
1092 		regs->msr &= ~MSR_DE;
1093 
1094 		if (user_mode(regs)) {
1095 			current->thread.dbcr0 &= ~(DBSR_DAC1R | DBSR_DAC1W |
1096 								DBCR0_IDM);
1097 		} else {
1098 			/* Disable DAC interupts */
1099 			mtspr(SPRN_DBCR0, mfspr(SPRN_DBCR0) & ~(DBSR_DAC1R |
1100 						DBSR_DAC1W | DBCR0_IDM));
1101 
1102 			/* Clear the DAC event */
1103 			mtspr(SPRN_DBSR, (DBSR_DAC1R | DBSR_DAC1W));
1104 		}
1105 		/* Setup and send the trap to the handler */
1106 		do_dabr(regs, mfspr(SPRN_DAC1), debug_status);
1107 	}
1108 }
1109 #endif /* CONFIG_4xx || CONFIG_BOOKE */
1110 
1111 #if !defined(CONFIG_TAU_INT)
1112 void TAUException(struct pt_regs *regs)
1113 {
1114 	printk("TAU trap at PC: %lx, MSR: %lx, vector=%lx    %s\n",
1115 	       regs->nip, regs->msr, regs->trap, print_tainted());
1116 }
1117 #endif /* CONFIG_INT_TAU */
1118 
1119 #ifdef CONFIG_ALTIVEC
1120 void altivec_assist_exception(struct pt_regs *regs)
1121 {
1122 	int err;
1123 
1124 	if (!user_mode(regs)) {
1125 		printk(KERN_EMERG "VMX/Altivec assist exception in kernel mode"
1126 		       " at %lx\n", regs->nip);
1127 		die("Kernel VMX/Altivec assist exception", regs, SIGILL);
1128 	}
1129 
1130 	flush_altivec_to_thread(current);
1131 
1132 	PPC_WARN_EMULATED(altivec);
1133 	err = emulate_altivec(regs);
1134 	if (err == 0) {
1135 		regs->nip += 4;		/* skip emulated instruction */
1136 		emulate_single_step(regs);
1137 		return;
1138 	}
1139 
1140 	if (err == -EFAULT) {
1141 		/* got an error reading the instruction */
1142 		_exception(SIGSEGV, regs, SEGV_ACCERR, regs->nip);
1143 	} else {
1144 		/* didn't recognize the instruction */
1145 		/* XXX quick hack for now: set the non-Java bit in the VSCR */
1146 		if (printk_ratelimit())
1147 			printk(KERN_ERR "Unrecognized altivec instruction "
1148 			       "in %s at %lx\n", current->comm, regs->nip);
1149 		current->thread.vscr.u[3] |= 0x10000;
1150 	}
1151 }
1152 #endif /* CONFIG_ALTIVEC */
1153 
1154 #ifdef CONFIG_VSX
1155 void vsx_assist_exception(struct pt_regs *regs)
1156 {
1157 	if (!user_mode(regs)) {
1158 		printk(KERN_EMERG "VSX assist exception in kernel mode"
1159 		       " at %lx\n", regs->nip);
1160 		die("Kernel VSX assist exception", regs, SIGILL);
1161 	}
1162 
1163 	flush_vsx_to_thread(current);
1164 	printk(KERN_INFO "VSX assist not supported at %lx\n", regs->nip);
1165 	_exception(SIGILL, regs, ILL_ILLOPC, regs->nip);
1166 }
1167 #endif /* CONFIG_VSX */
1168 
1169 #ifdef CONFIG_FSL_BOOKE
1170 
1171 void doorbell_exception(struct pt_regs *regs)
1172 {
1173 #ifdef CONFIG_SMP
1174 	int cpu = smp_processor_id();
1175 	int msg;
1176 
1177 	if (num_online_cpus() < 2)
1178 		return;
1179 
1180 	for (msg = 0; msg < 4; msg++)
1181 		if (test_and_clear_bit(msg, &dbell_smp_message[cpu]))
1182 			smp_message_recv(msg);
1183 #else
1184 	printk(KERN_WARNING "Received doorbell on non-smp system\n");
1185 #endif
1186 }
1187 
1188 void CacheLockingException(struct pt_regs *regs, unsigned long address,
1189 			   unsigned long error_code)
1190 {
1191 	/* We treat cache locking instructions from the user
1192 	 * as priv ops, in the future we could try to do
1193 	 * something smarter
1194 	 */
1195 	if (error_code & (ESR_DLK|ESR_ILK))
1196 		_exception(SIGILL, regs, ILL_PRVOPC, regs->nip);
1197 	return;
1198 }
1199 #endif /* CONFIG_FSL_BOOKE */
1200 
1201 #ifdef CONFIG_SPE
1202 void SPEFloatingPointException(struct pt_regs *regs)
1203 {
1204 	extern int do_spe_mathemu(struct pt_regs *regs);
1205 	unsigned long spefscr;
1206 	int fpexc_mode;
1207 	int code = 0;
1208 	int err;
1209 
1210 	preempt_disable();
1211 	if (regs->msr & MSR_SPE)
1212 		giveup_spe(current);
1213 	preempt_enable();
1214 
1215 	spefscr = current->thread.spefscr;
1216 	fpexc_mode = current->thread.fpexc_mode;
1217 
1218 	if ((spefscr & SPEFSCR_FOVF) && (fpexc_mode & PR_FP_EXC_OVF)) {
1219 		code = FPE_FLTOVF;
1220 	}
1221 	else if ((spefscr & SPEFSCR_FUNF) && (fpexc_mode & PR_FP_EXC_UND)) {
1222 		code = FPE_FLTUND;
1223 	}
1224 	else if ((spefscr & SPEFSCR_FDBZ) && (fpexc_mode & PR_FP_EXC_DIV))
1225 		code = FPE_FLTDIV;
1226 	else if ((spefscr & SPEFSCR_FINV) && (fpexc_mode & PR_FP_EXC_INV)) {
1227 		code = FPE_FLTINV;
1228 	}
1229 	else if ((spefscr & (SPEFSCR_FG | SPEFSCR_FX)) && (fpexc_mode & PR_FP_EXC_RES))
1230 		code = FPE_FLTRES;
1231 
1232 	err = do_spe_mathemu(regs);
1233 	if (err == 0) {
1234 		regs->nip += 4;		/* skip emulated instruction */
1235 		emulate_single_step(regs);
1236 		return;
1237 	}
1238 
1239 	if (err == -EFAULT) {
1240 		/* got an error reading the instruction */
1241 		_exception(SIGSEGV, regs, SEGV_ACCERR, regs->nip);
1242 	} else if (err == -EINVAL) {
1243 		/* didn't recognize the instruction */
1244 		printk(KERN_ERR "unrecognized spe instruction "
1245 		       "in %s at %lx\n", current->comm, regs->nip);
1246 	} else {
1247 		_exception(SIGFPE, regs, code, regs->nip);
1248 	}
1249 
1250 	return;
1251 }
1252 
1253 void SPEFloatingPointRoundException(struct pt_regs *regs)
1254 {
1255 	extern int speround_handler(struct pt_regs *regs);
1256 	int err;
1257 
1258 	preempt_disable();
1259 	if (regs->msr & MSR_SPE)
1260 		giveup_spe(current);
1261 	preempt_enable();
1262 
1263 	regs->nip -= 4;
1264 	err = speround_handler(regs);
1265 	if (err == 0) {
1266 		regs->nip += 4;		/* skip emulated instruction */
1267 		emulate_single_step(regs);
1268 		return;
1269 	}
1270 
1271 	if (err == -EFAULT) {
1272 		/* got an error reading the instruction */
1273 		_exception(SIGSEGV, regs, SEGV_ACCERR, regs->nip);
1274 	} else if (err == -EINVAL) {
1275 		/* didn't recognize the instruction */
1276 		printk(KERN_ERR "unrecognized spe instruction "
1277 		       "in %s at %lx\n", current->comm, regs->nip);
1278 	} else {
1279 		_exception(SIGFPE, regs, 0, regs->nip);
1280 		return;
1281 	}
1282 }
1283 #endif
1284 
1285 /*
1286  * We enter here if we get an unrecoverable exception, that is, one
1287  * that happened at a point where the RI (recoverable interrupt) bit
1288  * in the MSR is 0.  This indicates that SRR0/1 are live, and that
1289  * we therefore lost state by taking this exception.
1290  */
1291 void unrecoverable_exception(struct pt_regs *regs)
1292 {
1293 	printk(KERN_EMERG "Unrecoverable exception %lx at %lx\n",
1294 	       regs->trap, regs->nip);
1295 	die("Unrecoverable exception", regs, SIGABRT);
1296 }
1297 
1298 #ifdef CONFIG_BOOKE_WDT
1299 /*
1300  * Default handler for a Watchdog exception,
1301  * spins until a reboot occurs
1302  */
1303 void __attribute__ ((weak)) WatchdogHandler(struct pt_regs *regs)
1304 {
1305 	/* Generic WatchdogHandler, implement your own */
1306 	mtspr(SPRN_TCR, mfspr(SPRN_TCR)&(~TCR_WIE));
1307 	return;
1308 }
1309 
1310 void WatchdogException(struct pt_regs *regs)
1311 {
1312 	printk (KERN_EMERG "PowerPC Book-E Watchdog Exception\n");
1313 	WatchdogHandler(regs);
1314 }
1315 #endif
1316 
1317 /*
1318  * We enter here if we discover during exception entry that we are
1319  * running in supervisor mode with a userspace value in the stack pointer.
1320  */
1321 void kernel_bad_stack(struct pt_regs *regs)
1322 {
1323 	printk(KERN_EMERG "Bad kernel stack pointer %lx at %lx\n",
1324 	       regs->gpr[1], regs->nip);
1325 	die("Bad kernel stack pointer", regs, SIGABRT);
1326 }
1327 
1328 void __init trap_init(void)
1329 {
1330 }
1331 
1332 
1333 #ifdef CONFIG_PPC_EMULATED_STATS
1334 
1335 #define WARN_EMULATED_SETUP(type)	.type = { .name = #type }
1336 
1337 struct ppc_emulated ppc_emulated = {
1338 #ifdef CONFIG_ALTIVEC
1339 	WARN_EMULATED_SETUP(altivec),
1340 #endif
1341 	WARN_EMULATED_SETUP(dcba),
1342 	WARN_EMULATED_SETUP(dcbz),
1343 	WARN_EMULATED_SETUP(fp_pair),
1344 	WARN_EMULATED_SETUP(isel),
1345 	WARN_EMULATED_SETUP(mcrxr),
1346 	WARN_EMULATED_SETUP(mfpvr),
1347 	WARN_EMULATED_SETUP(multiple),
1348 	WARN_EMULATED_SETUP(popcntb),
1349 	WARN_EMULATED_SETUP(spe),
1350 	WARN_EMULATED_SETUP(string),
1351 	WARN_EMULATED_SETUP(unaligned),
1352 #ifdef CONFIG_MATH_EMULATION
1353 	WARN_EMULATED_SETUP(math),
1354 #elif defined(CONFIG_8XX_MINIMAL_FPEMU)
1355 	WARN_EMULATED_SETUP(8xx),
1356 #endif
1357 #ifdef CONFIG_VSX
1358 	WARN_EMULATED_SETUP(vsx),
1359 #endif
1360 };
1361 
1362 u32 ppc_warn_emulated;
1363 
1364 void ppc_warn_emulated_print(const char *type)
1365 {
1366 	if (printk_ratelimit())
1367 		pr_warning("%s used emulated %s instruction\n", current->comm,
1368 			   type);
1369 }
1370 
1371 static int __init ppc_warn_emulated_init(void)
1372 {
1373 	struct dentry *dir, *d;
1374 	unsigned int i;
1375 	struct ppc_emulated_entry *entries = (void *)&ppc_emulated;
1376 
1377 	if (!powerpc_debugfs_root)
1378 		return -ENODEV;
1379 
1380 	dir = debugfs_create_dir("emulated_instructions",
1381 				 powerpc_debugfs_root);
1382 	if (!dir)
1383 		return -ENOMEM;
1384 
1385 	d = debugfs_create_u32("do_warn", S_IRUGO | S_IWUSR, dir,
1386 			       &ppc_warn_emulated);
1387 	if (!d)
1388 		goto fail;
1389 
1390 	for (i = 0; i < sizeof(ppc_emulated)/sizeof(*entries); i++) {
1391 		d = debugfs_create_u32(entries[i].name, S_IRUGO | S_IWUSR, dir,
1392 				       (u32 *)&entries[i].val.counter);
1393 		if (!d)
1394 			goto fail;
1395 	}
1396 
1397 	return 0;
1398 
1399 fail:
1400 	debugfs_remove_recursive(dir);
1401 	return -ENOMEM;
1402 }
1403 
1404 device_initcall(ppc_warn_emulated_init);
1405 
1406 #endif /* CONFIG_PPC_EMULATED_STATS */
1407