xref: /openbmc/linux/arch/powerpc/kernel/traps.c (revision 172ae2e7f8ff9053905a36672453a6d2ff95b182)
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) __read_mostly;
64 int (*__debugger_ipi)(struct pt_regs *regs) __read_mostly;
65 int (*__debugger_bpt)(struct pt_regs *regs) __read_mostly;
66 int (*__debugger_sstep)(struct pt_regs *regs) __read_mostly;
67 int (*__debugger_iabr_match)(struct pt_regs *regs) __read_mostly;
68 int (*__debugger_dabr_match)(struct pt_regs *regs) __read_mostly;
69 int (*__debugger_fault_handler)(struct pt_regs *regs) __read_mostly;
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 		sysfs_printk_last_file();
150 		if (notify_die(DIE_OOPS, str, regs, err, 255,
151 			       SIGSEGV) == NOTIFY_STOP)
152 			return 1;
153 
154 		print_modules();
155 		show_regs(regs);
156 	} else {
157 		printk("Recursive die() failure, output suppressed\n");
158 	}
159 
160 	bust_spinlocks(0);
161 	die.lock_owner = -1;
162 	add_taint(TAINT_DIE);
163 	spin_unlock_irqrestore(&die.lock, flags);
164 
165 	if (kexec_should_crash(current) ||
166 		kexec_sr_activated(smp_processor_id()))
167 		crash_kexec(regs);
168 	crash_kexec_secondary(regs);
169 
170 	if (in_interrupt())
171 		panic("Fatal exception in interrupt");
172 
173 	if (panic_on_oops)
174 		panic("Fatal exception");
175 
176 	oops_exit();
177 	do_exit(err);
178 
179 	return 0;
180 }
181 
182 void user_single_step_siginfo(struct task_struct *tsk,
183 				struct pt_regs *regs, siginfo_t *info)
184 {
185 	memset(info, 0, sizeof(*info));
186 	info->si_signo = SIGTRAP;
187 	info->si_code = TRAP_TRACE;
188 	info->si_addr = (void __user *)regs->nip;
189 }
190 
191 void _exception(int signr, struct pt_regs *regs, int code, unsigned long addr)
192 {
193 	siginfo_t info;
194 	const char fmt32[] = KERN_INFO "%s[%d]: unhandled signal %d " \
195 			"at %08lx nip %08lx lr %08lx code %x\n";
196 	const char fmt64[] = KERN_INFO "%s[%d]: unhandled signal %d " \
197 			"at %016lx nip %016lx lr %016lx code %x\n";
198 
199 	if (!user_mode(regs)) {
200 		if (die("Exception in kernel mode", regs, signr))
201 			return;
202 	} else if (show_unhandled_signals &&
203 		    unhandled_signal(current, signr) &&
204 		    printk_ratelimit()) {
205 			printk(regs->msr & MSR_SF ? fmt64 : fmt32,
206 				current->comm, current->pid, signr,
207 				addr, regs->nip, regs->link, code);
208 		}
209 
210 	memset(&info, 0, sizeof(info));
211 	info.si_signo = signr;
212 	info.si_code = code;
213 	info.si_addr = (void __user *) addr;
214 	force_sig_info(signr, &info, current);
215 }
216 
217 #ifdef CONFIG_PPC64
218 void system_reset_exception(struct pt_regs *regs)
219 {
220 	/* See if any machine dependent calls */
221 	if (ppc_md.system_reset_exception) {
222 		if (ppc_md.system_reset_exception(regs))
223 			return;
224 	}
225 
226 #ifdef CONFIG_KEXEC
227 	cpu_set(smp_processor_id(), cpus_in_sr);
228 #endif
229 
230 	die("System Reset", regs, SIGABRT);
231 
232 	/*
233 	 * Some CPUs when released from the debugger will execute this path.
234 	 * These CPUs entered the debugger via a soft-reset. If the CPU was
235 	 * hung before entering the debugger it will return to the hung
236 	 * state when exiting this function.  This causes a problem in
237 	 * kdump since the hung CPU(s) will not respond to the IPI sent
238 	 * from kdump. To prevent the problem we call crash_kexec_secondary()
239 	 * here. If a kdump had not been initiated or we exit the debugger
240 	 * with the "exit and recover" command (x) crash_kexec_secondary()
241 	 * will return after 5ms and the CPU returns to its previous state.
242 	 */
243 	crash_kexec_secondary(regs);
244 
245 	/* Must die if the interrupt is not recoverable */
246 	if (!(regs->msr & MSR_RI))
247 		panic("Unrecoverable System Reset");
248 
249 	/* What should we do here? We could issue a shutdown or hard reset. */
250 }
251 #endif
252 
253 /*
254  * I/O accesses can cause machine checks on powermacs.
255  * Check if the NIP corresponds to the address of a sync
256  * instruction for which there is an entry in the exception
257  * table.
258  * Note that the 601 only takes a machine check on TEA
259  * (transfer error ack) signal assertion, and does not
260  * set any of the top 16 bits of SRR1.
261  *  -- paulus.
262  */
263 static inline int check_io_access(struct pt_regs *regs)
264 {
265 #ifdef CONFIG_PPC32
266 	unsigned long msr = regs->msr;
267 	const struct exception_table_entry *entry;
268 	unsigned int *nip = (unsigned int *)regs->nip;
269 
270 	if (((msr & 0xffff0000) == 0 || (msr & (0x80000 | 0x40000)))
271 	    && (entry = search_exception_tables(regs->nip)) != NULL) {
272 		/*
273 		 * Check that it's a sync instruction, or somewhere
274 		 * in the twi; isync; nop sequence that inb/inw/inl uses.
275 		 * As the address is in the exception table
276 		 * we should be able to read the instr there.
277 		 * For the debug message, we look at the preceding
278 		 * load or store.
279 		 */
280 		if (*nip == 0x60000000)		/* nop */
281 			nip -= 2;
282 		else if (*nip == 0x4c00012c)	/* isync */
283 			--nip;
284 		if (*nip == 0x7c0004ac || (*nip >> 26) == 3) {
285 			/* sync or twi */
286 			unsigned int rb;
287 
288 			--nip;
289 			rb = (*nip >> 11) & 0x1f;
290 			printk(KERN_DEBUG "%s bad port %lx at %p\n",
291 			       (*nip & 0x100)? "OUT to": "IN from",
292 			       regs->gpr[rb] - _IO_BASE, nip);
293 			regs->msr |= MSR_RI;
294 			regs->nip = entry->fixup;
295 			return 1;
296 		}
297 	}
298 #endif /* CONFIG_PPC32 */
299 	return 0;
300 }
301 
302 #ifdef CONFIG_PPC_ADV_DEBUG_REGS
303 /* On 4xx, the reason for the machine check or program exception
304    is in the ESR. */
305 #define get_reason(regs)	((regs)->dsisr)
306 #ifndef CONFIG_FSL_BOOKE
307 #define get_mc_reason(regs)	((regs)->dsisr)
308 #else
309 #define get_mc_reason(regs)	(mfspr(SPRN_MCSR) & MCSR_MASK)
310 #endif
311 #define REASON_FP		ESR_FP
312 #define REASON_ILLEGAL		(ESR_PIL | ESR_PUO)
313 #define REASON_PRIVILEGED	ESR_PPR
314 #define REASON_TRAP		ESR_PTR
315 
316 /* single-step stuff */
317 #define single_stepping(regs)	(current->thread.dbcr0 & DBCR0_IC)
318 #define clear_single_step(regs)	(current->thread.dbcr0 &= ~DBCR0_IC)
319 
320 #else
321 /* On non-4xx, the reason for the machine check or program
322    exception is in the MSR. */
323 #define get_reason(regs)	((regs)->msr)
324 #define get_mc_reason(regs)	((regs)->msr)
325 #define REASON_FP		0x100000
326 #define REASON_ILLEGAL		0x80000
327 #define REASON_PRIVILEGED	0x40000
328 #define REASON_TRAP		0x20000
329 
330 #define single_stepping(regs)	((regs)->msr & MSR_SE)
331 #define clear_single_step(regs)	((regs)->msr &= ~MSR_SE)
332 #endif
333 
334 #if defined(CONFIG_4xx)
335 int machine_check_4xx(struct pt_regs *regs)
336 {
337 	unsigned long reason = get_mc_reason(regs);
338 
339 	if (reason & ESR_IMCP) {
340 		printk("Instruction");
341 		mtspr(SPRN_ESR, reason & ~ESR_IMCP);
342 	} else
343 		printk("Data");
344 	printk(" machine check in kernel mode.\n");
345 
346 	return 0;
347 }
348 
349 int machine_check_440A(struct pt_regs *regs)
350 {
351 	unsigned long reason = get_mc_reason(regs);
352 
353 	printk("Machine check in kernel mode.\n");
354 	if (reason & ESR_IMCP){
355 		printk("Instruction Synchronous Machine Check exception\n");
356 		mtspr(SPRN_ESR, reason & ~ESR_IMCP);
357 	}
358 	else {
359 		u32 mcsr = mfspr(SPRN_MCSR);
360 		if (mcsr & MCSR_IB)
361 			printk("Instruction Read PLB Error\n");
362 		if (mcsr & MCSR_DRB)
363 			printk("Data Read PLB Error\n");
364 		if (mcsr & MCSR_DWB)
365 			printk("Data Write PLB Error\n");
366 		if (mcsr & MCSR_TLBP)
367 			printk("TLB Parity Error\n");
368 		if (mcsr & MCSR_ICP){
369 			flush_instruction_cache();
370 			printk("I-Cache Parity Error\n");
371 		}
372 		if (mcsr & MCSR_DCSP)
373 			printk("D-Cache Search Parity Error\n");
374 		if (mcsr & MCSR_DCFP)
375 			printk("D-Cache Flush Parity Error\n");
376 		if (mcsr & MCSR_IMPE)
377 			printk("Machine Check exception is imprecise\n");
378 
379 		/* Clear MCSR */
380 		mtspr(SPRN_MCSR, mcsr);
381 	}
382 	return 0;
383 }
384 #elif defined(CONFIG_E500)
385 int machine_check_e500(struct pt_regs *regs)
386 {
387 	unsigned long reason = get_mc_reason(regs);
388 
389 	printk("Machine check in kernel mode.\n");
390 	printk("Caused by (from MCSR=%lx): ", reason);
391 
392 	if (reason & MCSR_MCP)
393 		printk("Machine Check Signal\n");
394 	if (reason & MCSR_ICPERR)
395 		printk("Instruction Cache Parity Error\n");
396 	if (reason & MCSR_DCP_PERR)
397 		printk("Data Cache Push Parity Error\n");
398 	if (reason & MCSR_DCPERR)
399 		printk("Data Cache Parity Error\n");
400 	if (reason & MCSR_BUS_IAERR)
401 		printk("Bus - Instruction Address Error\n");
402 	if (reason & MCSR_BUS_RAERR)
403 		printk("Bus - Read Address Error\n");
404 	if (reason & MCSR_BUS_WAERR)
405 		printk("Bus - Write Address Error\n");
406 	if (reason & MCSR_BUS_IBERR)
407 		printk("Bus - Instruction Data Error\n");
408 	if (reason & MCSR_BUS_RBERR)
409 		printk("Bus - Read Data Bus Error\n");
410 	if (reason & MCSR_BUS_WBERR)
411 		printk("Bus - Read Data Bus Error\n");
412 	if (reason & MCSR_BUS_IPERR)
413 		printk("Bus - Instruction Parity Error\n");
414 	if (reason & MCSR_BUS_RPERR)
415 		printk("Bus - Read Parity Error\n");
416 
417 	return 0;
418 }
419 #elif defined(CONFIG_E200)
420 int machine_check_e200(struct pt_regs *regs)
421 {
422 	unsigned long reason = get_mc_reason(regs);
423 
424 	printk("Machine check in kernel mode.\n");
425 	printk("Caused by (from MCSR=%lx): ", reason);
426 
427 	if (reason & MCSR_MCP)
428 		printk("Machine Check Signal\n");
429 	if (reason & MCSR_CP_PERR)
430 		printk("Cache Push Parity Error\n");
431 	if (reason & MCSR_CPERR)
432 		printk("Cache Parity Error\n");
433 	if (reason & MCSR_EXCP_ERR)
434 		printk("ISI, ITLB, or Bus Error on first instruction fetch for an exception handler\n");
435 	if (reason & MCSR_BUS_IRERR)
436 		printk("Bus - Read Bus Error on instruction fetch\n");
437 	if (reason & MCSR_BUS_DRERR)
438 		printk("Bus - Read Bus Error on data load\n");
439 	if (reason & MCSR_BUS_WRERR)
440 		printk("Bus - Write Bus Error on buffered store or cache line push\n");
441 
442 	return 0;
443 }
444 #else
445 int machine_check_generic(struct pt_regs *regs)
446 {
447 	unsigned long reason = get_mc_reason(regs);
448 
449 	printk("Machine check in kernel mode.\n");
450 	printk("Caused by (from SRR1=%lx): ", reason);
451 	switch (reason & 0x601F0000) {
452 	case 0x80000:
453 		printk("Machine check signal\n");
454 		break;
455 	case 0:		/* for 601 */
456 	case 0x40000:
457 	case 0x140000:	/* 7450 MSS error and TEA */
458 		printk("Transfer error ack signal\n");
459 		break;
460 	case 0x20000:
461 		printk("Data parity error signal\n");
462 		break;
463 	case 0x10000:
464 		printk("Address parity error signal\n");
465 		break;
466 	case 0x20000000:
467 		printk("L1 Data Cache error\n");
468 		break;
469 	case 0x40000000:
470 		printk("L1 Instruction Cache error\n");
471 		break;
472 	case 0x00100000:
473 		printk("L2 data cache parity error\n");
474 		break;
475 	default:
476 		printk("Unknown values in msr\n");
477 	}
478 	return 0;
479 }
480 #endif /* everything else */
481 
482 void machine_check_exception(struct pt_regs *regs)
483 {
484 	int recover = 0;
485 
486 	__get_cpu_var(irq_stat).mce_exceptions++;
487 
488 	/* See if any machine dependent calls. In theory, we would want
489 	 * to call the CPU first, and call the ppc_md. one if the CPU
490 	 * one returns a positive number. However there is existing code
491 	 * that assumes the board gets a first chance, so let's keep it
492 	 * that way for now and fix things later. --BenH.
493 	 */
494 	if (ppc_md.machine_check_exception)
495 		recover = ppc_md.machine_check_exception(regs);
496 	else if (cur_cpu_spec->machine_check)
497 		recover = cur_cpu_spec->machine_check(regs);
498 
499 	if (recover > 0)
500 		return;
501 
502 	if (user_mode(regs)) {
503 		regs->msr |= MSR_RI;
504 		_exception(SIGBUS, regs, BUS_ADRERR, regs->nip);
505 		return;
506 	}
507 
508 #if defined(CONFIG_8xx) && defined(CONFIG_PCI)
509 	/* the qspan pci read routines can cause machine checks -- Cort
510 	 *
511 	 * yuck !!! that totally needs to go away ! There are better ways
512 	 * to deal with that than having a wart in the mcheck handler.
513 	 * -- BenH
514 	 */
515 	bad_page_fault(regs, regs->dar, SIGBUS);
516 	return;
517 #endif
518 
519 	if (debugger_fault_handler(regs)) {
520 		regs->msr |= MSR_RI;
521 		return;
522 	}
523 
524 	if (check_io_access(regs))
525 		return;
526 
527 	if (debugger_fault_handler(regs))
528 		return;
529 	die("Machine check", regs, SIGBUS);
530 
531 	/* Must die if the interrupt is not recoverable */
532 	if (!(regs->msr & MSR_RI))
533 		panic("Unrecoverable Machine check");
534 }
535 
536 void SMIException(struct pt_regs *regs)
537 {
538 	die("System Management Interrupt", regs, SIGABRT);
539 }
540 
541 void unknown_exception(struct pt_regs *regs)
542 {
543 	printk("Bad trap at PC: %lx, SR: %lx, vector=%lx\n",
544 	       regs->nip, regs->msr, regs->trap);
545 
546 	_exception(SIGTRAP, regs, 0, 0);
547 }
548 
549 void instruction_breakpoint_exception(struct pt_regs *regs)
550 {
551 	if (notify_die(DIE_IABR_MATCH, "iabr_match", regs, 5,
552 					5, SIGTRAP) == NOTIFY_STOP)
553 		return;
554 	if (debugger_iabr_match(regs))
555 		return;
556 	_exception(SIGTRAP, regs, TRAP_BRKPT, regs->nip);
557 }
558 
559 void RunModeException(struct pt_regs *regs)
560 {
561 	_exception(SIGTRAP, regs, 0, 0);
562 }
563 
564 void __kprobes single_step_exception(struct pt_regs *regs)
565 {
566 	regs->msr &= ~(MSR_SE | MSR_BE);  /* Turn off 'trace' bits */
567 
568 	if (notify_die(DIE_SSTEP, "single_step", regs, 5,
569 					5, SIGTRAP) == NOTIFY_STOP)
570 		return;
571 	if (debugger_sstep(regs))
572 		return;
573 
574 	_exception(SIGTRAP, regs, TRAP_TRACE, regs->nip);
575 }
576 
577 /*
578  * After we have successfully emulated an instruction, we have to
579  * check if the instruction was being single-stepped, and if so,
580  * pretend we got a single-step exception.  This was pointed out
581  * by Kumar Gala.  -- paulus
582  */
583 static void emulate_single_step(struct pt_regs *regs)
584 {
585 	if (single_stepping(regs)) {
586 		clear_single_step(regs);
587 		_exception(SIGTRAP, regs, TRAP_TRACE, 0);
588 	}
589 }
590 
591 static inline int __parse_fpscr(unsigned long fpscr)
592 {
593 	int ret = 0;
594 
595 	/* Invalid operation */
596 	if ((fpscr & FPSCR_VE) && (fpscr & FPSCR_VX))
597 		ret = FPE_FLTINV;
598 
599 	/* Overflow */
600 	else if ((fpscr & FPSCR_OE) && (fpscr & FPSCR_OX))
601 		ret = FPE_FLTOVF;
602 
603 	/* Underflow */
604 	else if ((fpscr & FPSCR_UE) && (fpscr & FPSCR_UX))
605 		ret = FPE_FLTUND;
606 
607 	/* Divide by zero */
608 	else if ((fpscr & FPSCR_ZE) && (fpscr & FPSCR_ZX))
609 		ret = FPE_FLTDIV;
610 
611 	/* Inexact result */
612 	else if ((fpscr & FPSCR_XE) && (fpscr & FPSCR_XX))
613 		ret = FPE_FLTRES;
614 
615 	return ret;
616 }
617 
618 static void parse_fpe(struct pt_regs *regs)
619 {
620 	int code = 0;
621 
622 	flush_fp_to_thread(current);
623 
624 	code = __parse_fpscr(current->thread.fpscr.val);
625 
626 	_exception(SIGFPE, regs, code, regs->nip);
627 }
628 
629 /*
630  * Illegal instruction emulation support.  Originally written to
631  * provide the PVR to user applications using the mfspr rd, PVR.
632  * Return non-zero if we can't emulate, or -EFAULT if the associated
633  * memory access caused an access fault.  Return zero on success.
634  *
635  * There are a couple of ways to do this, either "decode" the instruction
636  * or directly match lots of bits.  In this case, matching lots of
637  * bits is faster and easier.
638  *
639  */
640 static int emulate_string_inst(struct pt_regs *regs, u32 instword)
641 {
642 	u8 rT = (instword >> 21) & 0x1f;
643 	u8 rA = (instword >> 16) & 0x1f;
644 	u8 NB_RB = (instword >> 11) & 0x1f;
645 	u32 num_bytes;
646 	unsigned long EA;
647 	int pos = 0;
648 
649 	/* Early out if we are an invalid form of lswx */
650 	if ((instword & PPC_INST_STRING_MASK) == PPC_INST_LSWX)
651 		if ((rT == rA) || (rT == NB_RB))
652 			return -EINVAL;
653 
654 	EA = (rA == 0) ? 0 : regs->gpr[rA];
655 
656 	switch (instword & PPC_INST_STRING_MASK) {
657 		case PPC_INST_LSWX:
658 		case PPC_INST_STSWX:
659 			EA += NB_RB;
660 			num_bytes = regs->xer & 0x7f;
661 			break;
662 		case PPC_INST_LSWI:
663 		case PPC_INST_STSWI:
664 			num_bytes = (NB_RB == 0) ? 32 : NB_RB;
665 			break;
666 		default:
667 			return -EINVAL;
668 	}
669 
670 	while (num_bytes != 0)
671 	{
672 		u8 val;
673 		u32 shift = 8 * (3 - (pos & 0x3));
674 
675 		switch ((instword & PPC_INST_STRING_MASK)) {
676 			case PPC_INST_LSWX:
677 			case PPC_INST_LSWI:
678 				if (get_user(val, (u8 __user *)EA))
679 					return -EFAULT;
680 				/* first time updating this reg,
681 				 * zero it out */
682 				if (pos == 0)
683 					regs->gpr[rT] = 0;
684 				regs->gpr[rT] |= val << shift;
685 				break;
686 			case PPC_INST_STSWI:
687 			case PPC_INST_STSWX:
688 				val = regs->gpr[rT] >> shift;
689 				if (put_user(val, (u8 __user *)EA))
690 					return -EFAULT;
691 				break;
692 		}
693 		/* move EA to next address */
694 		EA += 1;
695 		num_bytes--;
696 
697 		/* manage our position within the register */
698 		if (++pos == 4) {
699 			pos = 0;
700 			if (++rT == 32)
701 				rT = 0;
702 		}
703 	}
704 
705 	return 0;
706 }
707 
708 static int emulate_popcntb_inst(struct pt_regs *regs, u32 instword)
709 {
710 	u32 ra,rs;
711 	unsigned long tmp;
712 
713 	ra = (instword >> 16) & 0x1f;
714 	rs = (instword >> 21) & 0x1f;
715 
716 	tmp = regs->gpr[rs];
717 	tmp = tmp - ((tmp >> 1) & 0x5555555555555555ULL);
718 	tmp = (tmp & 0x3333333333333333ULL) + ((tmp >> 2) & 0x3333333333333333ULL);
719 	tmp = (tmp + (tmp >> 4)) & 0x0f0f0f0f0f0f0f0fULL;
720 	regs->gpr[ra] = tmp;
721 
722 	return 0;
723 }
724 
725 static int emulate_isel(struct pt_regs *regs, u32 instword)
726 {
727 	u8 rT = (instword >> 21) & 0x1f;
728 	u8 rA = (instword >> 16) & 0x1f;
729 	u8 rB = (instword >> 11) & 0x1f;
730 	u8 BC = (instword >> 6) & 0x1f;
731 	u8 bit;
732 	unsigned long tmp;
733 
734 	tmp = (rA == 0) ? 0 : regs->gpr[rA];
735 	bit = (regs->ccr >> (31 - BC)) & 0x1;
736 
737 	regs->gpr[rT] = bit ? tmp : regs->gpr[rB];
738 
739 	return 0;
740 }
741 
742 static int emulate_instruction(struct pt_regs *regs)
743 {
744 	u32 instword;
745 	u32 rd;
746 
747 	if (!user_mode(regs) || (regs->msr & MSR_LE))
748 		return -EINVAL;
749 	CHECK_FULL_REGS(regs);
750 
751 	if (get_user(instword, (u32 __user *)(regs->nip)))
752 		return -EFAULT;
753 
754 	/* Emulate the mfspr rD, PVR. */
755 	if ((instword & PPC_INST_MFSPR_PVR_MASK) == PPC_INST_MFSPR_PVR) {
756 		PPC_WARN_EMULATED(mfpvr, regs);
757 		rd = (instword >> 21) & 0x1f;
758 		regs->gpr[rd] = mfspr(SPRN_PVR);
759 		return 0;
760 	}
761 
762 	/* Emulating the dcba insn is just a no-op.  */
763 	if ((instword & PPC_INST_DCBA_MASK) == PPC_INST_DCBA) {
764 		PPC_WARN_EMULATED(dcba, regs);
765 		return 0;
766 	}
767 
768 	/* Emulate the mcrxr insn.  */
769 	if ((instword & PPC_INST_MCRXR_MASK) == PPC_INST_MCRXR) {
770 		int shift = (instword >> 21) & 0x1c;
771 		unsigned long msk = 0xf0000000UL >> shift;
772 
773 		PPC_WARN_EMULATED(mcrxr, regs);
774 		regs->ccr = (regs->ccr & ~msk) | ((regs->xer >> shift) & msk);
775 		regs->xer &= ~0xf0000000UL;
776 		return 0;
777 	}
778 
779 	/* Emulate load/store string insn. */
780 	if ((instword & PPC_INST_STRING_GEN_MASK) == PPC_INST_STRING) {
781 		PPC_WARN_EMULATED(string, regs);
782 		return emulate_string_inst(regs, instword);
783 	}
784 
785 	/* Emulate the popcntb (Population Count Bytes) instruction. */
786 	if ((instword & PPC_INST_POPCNTB_MASK) == PPC_INST_POPCNTB) {
787 		PPC_WARN_EMULATED(popcntb, regs);
788 		return emulate_popcntb_inst(regs, instword);
789 	}
790 
791 	/* Emulate isel (Integer Select) instruction */
792 	if ((instword & PPC_INST_ISEL_MASK) == PPC_INST_ISEL) {
793 		PPC_WARN_EMULATED(isel, regs);
794 		return emulate_isel(regs, instword);
795 	}
796 
797 	return -EINVAL;
798 }
799 
800 int is_valid_bugaddr(unsigned long addr)
801 {
802 	return is_kernel_addr(addr);
803 }
804 
805 void __kprobes program_check_exception(struct pt_regs *regs)
806 {
807 	unsigned int reason = get_reason(regs);
808 	extern int do_mathemu(struct pt_regs *regs);
809 
810 	/* We can now get here via a FP Unavailable exception if the core
811 	 * has no FPU, in that case the reason flags will be 0 */
812 
813 	if (reason & REASON_FP) {
814 		/* IEEE FP exception */
815 		parse_fpe(regs);
816 		return;
817 	}
818 	if (reason & REASON_TRAP) {
819 		/* trap exception */
820 		if (notify_die(DIE_BPT, "breakpoint", regs, 5, 5, SIGTRAP)
821 				== NOTIFY_STOP)
822 			return;
823 		if (debugger_bpt(regs))
824 			return;
825 
826 		if (!(regs->msr & MSR_PR) &&  /* not user-mode */
827 		    report_bug(regs->nip, regs) == BUG_TRAP_TYPE_WARN) {
828 			regs->nip += 4;
829 			return;
830 		}
831 		_exception(SIGTRAP, regs, TRAP_BRKPT, regs->nip);
832 		return;
833 	}
834 
835 	local_irq_enable();
836 
837 #ifdef CONFIG_MATH_EMULATION
838 	/* (reason & REASON_ILLEGAL) would be the obvious thing here,
839 	 * but there seems to be a hardware bug on the 405GP (RevD)
840 	 * that means ESR is sometimes set incorrectly - either to
841 	 * ESR_DST (!?) or 0.  In the process of chasing this with the
842 	 * hardware people - not sure if it can happen on any illegal
843 	 * instruction or only on FP instructions, whether there is a
844 	 * pattern to occurences etc. -dgibson 31/Mar/2003 */
845 	switch (do_mathemu(regs)) {
846 	case 0:
847 		emulate_single_step(regs);
848 		return;
849 	case 1: {
850 			int code = 0;
851 			code = __parse_fpscr(current->thread.fpscr.val);
852 			_exception(SIGFPE, regs, code, regs->nip);
853 			return;
854 		}
855 	case -EFAULT:
856 		_exception(SIGSEGV, regs, SEGV_MAPERR, regs->nip);
857 		return;
858 	}
859 	/* fall through on any other errors */
860 #endif /* CONFIG_MATH_EMULATION */
861 
862 	/* Try to emulate it if we should. */
863 	if (reason & (REASON_ILLEGAL | REASON_PRIVILEGED)) {
864 		switch (emulate_instruction(regs)) {
865 		case 0:
866 			regs->nip += 4;
867 			emulate_single_step(regs);
868 			return;
869 		case -EFAULT:
870 			_exception(SIGSEGV, regs, SEGV_MAPERR, regs->nip);
871 			return;
872 		}
873 	}
874 
875 	if (reason & REASON_PRIVILEGED)
876 		_exception(SIGILL, regs, ILL_PRVOPC, regs->nip);
877 	else
878 		_exception(SIGILL, regs, ILL_ILLOPC, regs->nip);
879 }
880 
881 void alignment_exception(struct pt_regs *regs)
882 {
883 	int sig, code, fixed = 0;
884 
885 	/* we don't implement logging of alignment exceptions */
886 	if (!(current->thread.align_ctl & PR_UNALIGN_SIGBUS))
887 		fixed = fix_alignment(regs);
888 
889 	if (fixed == 1) {
890 		regs->nip += 4;	/* skip over emulated instruction */
891 		emulate_single_step(regs);
892 		return;
893 	}
894 
895 	/* Operand address was bad */
896 	if (fixed == -EFAULT) {
897 		sig = SIGSEGV;
898 		code = SEGV_ACCERR;
899 	} else {
900 		sig = SIGBUS;
901 		code = BUS_ADRALN;
902 	}
903 	if (user_mode(regs))
904 		_exception(sig, regs, code, regs->dar);
905 	else
906 		bad_page_fault(regs, regs->dar, sig);
907 }
908 
909 void StackOverflow(struct pt_regs *regs)
910 {
911 	printk(KERN_CRIT "Kernel stack overflow in process %p, r1=%lx\n",
912 	       current, regs->gpr[1]);
913 	debugger(regs);
914 	show_regs(regs);
915 	panic("kernel stack overflow");
916 }
917 
918 void nonrecoverable_exception(struct pt_regs *regs)
919 {
920 	printk(KERN_ERR "Non-recoverable exception at PC=%lx MSR=%lx\n",
921 	       regs->nip, regs->msr);
922 	debugger(regs);
923 	die("nonrecoverable exception", regs, SIGKILL);
924 }
925 
926 void trace_syscall(struct pt_regs *regs)
927 {
928 	printk("Task: %p(%d), PC: %08lX/%08lX, Syscall: %3ld, Result: %s%ld    %s\n",
929 	       current, task_pid_nr(current), regs->nip, regs->link, regs->gpr[0],
930 	       regs->ccr&0x10000000?"Error=":"", regs->gpr[3], print_tainted());
931 }
932 
933 void kernel_fp_unavailable_exception(struct pt_regs *regs)
934 {
935 	printk(KERN_EMERG "Unrecoverable FP Unavailable Exception "
936 			  "%lx at %lx\n", regs->trap, regs->nip);
937 	die("Unrecoverable FP Unavailable Exception", regs, SIGABRT);
938 }
939 
940 void altivec_unavailable_exception(struct pt_regs *regs)
941 {
942 	if (user_mode(regs)) {
943 		/* A user program has executed an altivec instruction,
944 		   but this kernel doesn't support altivec. */
945 		_exception(SIGILL, regs, ILL_ILLOPC, regs->nip);
946 		return;
947 	}
948 
949 	printk(KERN_EMERG "Unrecoverable VMX/Altivec Unavailable Exception "
950 			"%lx at %lx\n", regs->trap, regs->nip);
951 	die("Unrecoverable VMX/Altivec Unavailable Exception", regs, SIGABRT);
952 }
953 
954 void vsx_unavailable_exception(struct pt_regs *regs)
955 {
956 	if (user_mode(regs)) {
957 		/* A user program has executed an vsx instruction,
958 		   but this kernel doesn't support vsx. */
959 		_exception(SIGILL, regs, ILL_ILLOPC, regs->nip);
960 		return;
961 	}
962 
963 	printk(KERN_EMERG "Unrecoverable VSX Unavailable Exception "
964 			"%lx at %lx\n", regs->trap, regs->nip);
965 	die("Unrecoverable VSX Unavailable Exception", regs, SIGABRT);
966 }
967 
968 void performance_monitor_exception(struct pt_regs *regs)
969 {
970 	__get_cpu_var(irq_stat).pmu_irqs++;
971 
972 	perf_irq(regs);
973 }
974 
975 #ifdef CONFIG_8xx
976 void SoftwareEmulation(struct pt_regs *regs)
977 {
978 	extern int do_mathemu(struct pt_regs *);
979 	extern int Soft_emulate_8xx(struct pt_regs *);
980 #if defined(CONFIG_MATH_EMULATION) || defined(CONFIG_8XX_MINIMAL_FPEMU)
981 	int errcode;
982 #endif
983 
984 	CHECK_FULL_REGS(regs);
985 
986 	if (!user_mode(regs)) {
987 		debugger(regs);
988 		die("Kernel Mode Software FPU Emulation", regs, SIGFPE);
989 	}
990 
991 #ifdef CONFIG_MATH_EMULATION
992 	errcode = do_mathemu(regs);
993 	if (errcode >= 0)
994 		PPC_WARN_EMULATED(math, regs);
995 
996 	switch (errcode) {
997 	case 0:
998 		emulate_single_step(regs);
999 		return;
1000 	case 1: {
1001 			int code = 0;
1002 			code = __parse_fpscr(current->thread.fpscr.val);
1003 			_exception(SIGFPE, regs, code, regs->nip);
1004 			return;
1005 		}
1006 	case -EFAULT:
1007 		_exception(SIGSEGV, regs, SEGV_MAPERR, regs->nip);
1008 		return;
1009 	default:
1010 		_exception(SIGILL, regs, ILL_ILLOPC, regs->nip);
1011 		return;
1012 	}
1013 
1014 #elif defined(CONFIG_8XX_MINIMAL_FPEMU)
1015 	errcode = Soft_emulate_8xx(regs);
1016 	if (errcode >= 0)
1017 		PPC_WARN_EMULATED(8xx, regs);
1018 
1019 	switch (errcode) {
1020 	case 0:
1021 		emulate_single_step(regs);
1022 		return;
1023 	case 1:
1024 		_exception(SIGILL, regs, ILL_ILLOPC, regs->nip);
1025 		return;
1026 	case -EFAULT:
1027 		_exception(SIGSEGV, regs, SEGV_MAPERR, regs->nip);
1028 		return;
1029 	}
1030 #else
1031 	_exception(SIGILL, regs, ILL_ILLOPC, regs->nip);
1032 #endif
1033 }
1034 #endif /* CONFIG_8xx */
1035 
1036 #ifdef CONFIG_PPC_ADV_DEBUG_REGS
1037 
1038 void __kprobes DebugException(struct pt_regs *regs, unsigned long debug_status)
1039 {
1040 	/* Hack alert: On BookE, Branch Taken stops on the branch itself, while
1041 	 * on server, it stops on the target of the branch. In order to simulate
1042 	 * the server behaviour, we thus restart right away with a single step
1043 	 * instead of stopping here when hitting a BT
1044 	 */
1045 	if (debug_status & DBSR_BT) {
1046 		regs->msr &= ~MSR_DE;
1047 
1048 		/* Disable BT */
1049 		mtspr(SPRN_DBCR0, mfspr(SPRN_DBCR0) & ~DBCR0_BT);
1050 		/* Clear the BT event */
1051 		mtspr(SPRN_DBSR, DBSR_BT);
1052 
1053 		/* Do the single step trick only when coming from userspace */
1054 		if (user_mode(regs)) {
1055 			current->thread.dbcr0 &= ~DBCR0_BT;
1056 			current->thread.dbcr0 |= DBCR0_IDM | DBCR0_IC;
1057 			regs->msr |= MSR_DE;
1058 			return;
1059 		}
1060 
1061 		if (notify_die(DIE_SSTEP, "block_step", regs, 5,
1062 			       5, SIGTRAP) == NOTIFY_STOP) {
1063 			return;
1064 		}
1065 		if (debugger_sstep(regs))
1066 			return;
1067 	} else if (debug_status & DBSR_IC) { 	/* Instruction complete */
1068 		regs->msr &= ~MSR_DE;
1069 
1070 		/* Disable instruction completion */
1071 		mtspr(SPRN_DBCR0, mfspr(SPRN_DBCR0) & ~DBCR0_IC);
1072 		/* Clear the instruction completion event */
1073 		mtspr(SPRN_DBSR, DBSR_IC);
1074 
1075 		if (notify_die(DIE_SSTEP, "single_step", regs, 5,
1076 			       5, SIGTRAP) == NOTIFY_STOP) {
1077 			return;
1078 		}
1079 
1080 		if (debugger_sstep(regs))
1081 			return;
1082 
1083 		if (user_mode(regs))
1084 			current->thread.dbcr0 &= ~(DBCR0_IC);
1085 
1086 		_exception(SIGTRAP, regs, TRAP_TRACE, regs->nip);
1087 	} else if (debug_status & (DBSR_DAC1R | DBSR_DAC1W)) {
1088 		regs->msr &= ~MSR_DE;
1089 
1090 		if (user_mode(regs)) {
1091 			current->thread.dbcr0 &= ~(DBSR_DAC1R | DBSR_DAC1W |
1092 								DBCR0_IDM);
1093 		} else {
1094 			/* Disable DAC interupts */
1095 			mtspr(SPRN_DBCR0, mfspr(SPRN_DBCR0) & ~(DBSR_DAC1R |
1096 						DBSR_DAC1W | DBCR0_IDM));
1097 
1098 			/* Clear the DAC event */
1099 			mtspr(SPRN_DBSR, (DBSR_DAC1R | DBSR_DAC1W));
1100 		}
1101 		/* Setup and send the trap to the handler */
1102 		do_dabr(regs, mfspr(SPRN_DAC1), debug_status);
1103 	}
1104 }
1105 #endif /* CONFIG_PPC_ADV_DEBUG_REGS */
1106 
1107 #if !defined(CONFIG_TAU_INT)
1108 void TAUException(struct pt_regs *regs)
1109 {
1110 	printk("TAU trap at PC: %lx, MSR: %lx, vector=%lx    %s\n",
1111 	       regs->nip, regs->msr, regs->trap, print_tainted());
1112 }
1113 #endif /* CONFIG_INT_TAU */
1114 
1115 #ifdef CONFIG_ALTIVEC
1116 void altivec_assist_exception(struct pt_regs *regs)
1117 {
1118 	int err;
1119 
1120 	if (!user_mode(regs)) {
1121 		printk(KERN_EMERG "VMX/Altivec assist exception in kernel mode"
1122 		       " at %lx\n", regs->nip);
1123 		die("Kernel VMX/Altivec assist exception", regs, SIGILL);
1124 	}
1125 
1126 	flush_altivec_to_thread(current);
1127 
1128 	PPC_WARN_EMULATED(altivec, regs);
1129 	err = emulate_altivec(regs);
1130 	if (err == 0) {
1131 		regs->nip += 4;		/* skip emulated instruction */
1132 		emulate_single_step(regs);
1133 		return;
1134 	}
1135 
1136 	if (err == -EFAULT) {
1137 		/* got an error reading the instruction */
1138 		_exception(SIGSEGV, regs, SEGV_ACCERR, regs->nip);
1139 	} else {
1140 		/* didn't recognize the instruction */
1141 		/* XXX quick hack for now: set the non-Java bit in the VSCR */
1142 		if (printk_ratelimit())
1143 			printk(KERN_ERR "Unrecognized altivec instruction "
1144 			       "in %s at %lx\n", current->comm, regs->nip);
1145 		current->thread.vscr.u[3] |= 0x10000;
1146 	}
1147 }
1148 #endif /* CONFIG_ALTIVEC */
1149 
1150 #ifdef CONFIG_VSX
1151 void vsx_assist_exception(struct pt_regs *regs)
1152 {
1153 	if (!user_mode(regs)) {
1154 		printk(KERN_EMERG "VSX assist exception in kernel mode"
1155 		       " at %lx\n", regs->nip);
1156 		die("Kernel VSX assist exception", regs, SIGILL);
1157 	}
1158 
1159 	flush_vsx_to_thread(current);
1160 	printk(KERN_INFO "VSX assist not supported at %lx\n", regs->nip);
1161 	_exception(SIGILL, regs, ILL_ILLOPC, regs->nip);
1162 }
1163 #endif /* CONFIG_VSX */
1164 
1165 #ifdef CONFIG_FSL_BOOKE
1166 
1167 void doorbell_exception(struct pt_regs *regs)
1168 {
1169 #ifdef CONFIG_SMP
1170 	int cpu = smp_processor_id();
1171 	int msg;
1172 
1173 	if (num_online_cpus() < 2)
1174 		return;
1175 
1176 	for (msg = 0; msg < 4; msg++)
1177 		if (test_and_clear_bit(msg, &dbell_smp_message[cpu]))
1178 			smp_message_recv(msg);
1179 #else
1180 	printk(KERN_WARNING "Received doorbell on non-smp system\n");
1181 #endif
1182 }
1183 
1184 void CacheLockingException(struct pt_regs *regs, unsigned long address,
1185 			   unsigned long error_code)
1186 {
1187 	/* We treat cache locking instructions from the user
1188 	 * as priv ops, in the future we could try to do
1189 	 * something smarter
1190 	 */
1191 	if (error_code & (ESR_DLK|ESR_ILK))
1192 		_exception(SIGILL, regs, ILL_PRVOPC, regs->nip);
1193 	return;
1194 }
1195 #endif /* CONFIG_FSL_BOOKE */
1196 
1197 #ifdef CONFIG_SPE
1198 void SPEFloatingPointException(struct pt_regs *regs)
1199 {
1200 	extern int do_spe_mathemu(struct pt_regs *regs);
1201 	unsigned long spefscr;
1202 	int fpexc_mode;
1203 	int code = 0;
1204 	int err;
1205 
1206 	preempt_disable();
1207 	if (regs->msr & MSR_SPE)
1208 		giveup_spe(current);
1209 	preempt_enable();
1210 
1211 	spefscr = current->thread.spefscr;
1212 	fpexc_mode = current->thread.fpexc_mode;
1213 
1214 	if ((spefscr & SPEFSCR_FOVF) && (fpexc_mode & PR_FP_EXC_OVF)) {
1215 		code = FPE_FLTOVF;
1216 	}
1217 	else if ((spefscr & SPEFSCR_FUNF) && (fpexc_mode & PR_FP_EXC_UND)) {
1218 		code = FPE_FLTUND;
1219 	}
1220 	else if ((spefscr & SPEFSCR_FDBZ) && (fpexc_mode & PR_FP_EXC_DIV))
1221 		code = FPE_FLTDIV;
1222 	else if ((spefscr & SPEFSCR_FINV) && (fpexc_mode & PR_FP_EXC_INV)) {
1223 		code = FPE_FLTINV;
1224 	}
1225 	else if ((spefscr & (SPEFSCR_FG | SPEFSCR_FX)) && (fpexc_mode & PR_FP_EXC_RES))
1226 		code = FPE_FLTRES;
1227 
1228 	err = do_spe_mathemu(regs);
1229 	if (err == 0) {
1230 		regs->nip += 4;		/* skip emulated instruction */
1231 		emulate_single_step(regs);
1232 		return;
1233 	}
1234 
1235 	if (err == -EFAULT) {
1236 		/* got an error reading the instruction */
1237 		_exception(SIGSEGV, regs, SEGV_ACCERR, regs->nip);
1238 	} else if (err == -EINVAL) {
1239 		/* didn't recognize the instruction */
1240 		printk(KERN_ERR "unrecognized spe instruction "
1241 		       "in %s at %lx\n", current->comm, regs->nip);
1242 	} else {
1243 		_exception(SIGFPE, regs, code, regs->nip);
1244 	}
1245 
1246 	return;
1247 }
1248 
1249 void SPEFloatingPointRoundException(struct pt_regs *regs)
1250 {
1251 	extern int speround_handler(struct pt_regs *regs);
1252 	int err;
1253 
1254 	preempt_disable();
1255 	if (regs->msr & MSR_SPE)
1256 		giveup_spe(current);
1257 	preempt_enable();
1258 
1259 	regs->nip -= 4;
1260 	err = speround_handler(regs);
1261 	if (err == 0) {
1262 		regs->nip += 4;		/* skip emulated instruction */
1263 		emulate_single_step(regs);
1264 		return;
1265 	}
1266 
1267 	if (err == -EFAULT) {
1268 		/* got an error reading the instruction */
1269 		_exception(SIGSEGV, regs, SEGV_ACCERR, regs->nip);
1270 	} else if (err == -EINVAL) {
1271 		/* didn't recognize the instruction */
1272 		printk(KERN_ERR "unrecognized spe instruction "
1273 		       "in %s at %lx\n", current->comm, regs->nip);
1274 	} else {
1275 		_exception(SIGFPE, regs, 0, regs->nip);
1276 		return;
1277 	}
1278 }
1279 #endif
1280 
1281 /*
1282  * We enter here if we get an unrecoverable exception, that is, one
1283  * that happened at a point where the RI (recoverable interrupt) bit
1284  * in the MSR is 0.  This indicates that SRR0/1 are live, and that
1285  * we therefore lost state by taking this exception.
1286  */
1287 void unrecoverable_exception(struct pt_regs *regs)
1288 {
1289 	printk(KERN_EMERG "Unrecoverable exception %lx at %lx\n",
1290 	       regs->trap, regs->nip);
1291 	die("Unrecoverable exception", regs, SIGABRT);
1292 }
1293 
1294 #ifdef CONFIG_BOOKE_WDT
1295 /*
1296  * Default handler for a Watchdog exception,
1297  * spins until a reboot occurs
1298  */
1299 void __attribute__ ((weak)) WatchdogHandler(struct pt_regs *regs)
1300 {
1301 	/* Generic WatchdogHandler, implement your own */
1302 	mtspr(SPRN_TCR, mfspr(SPRN_TCR)&(~TCR_WIE));
1303 	return;
1304 }
1305 
1306 void WatchdogException(struct pt_regs *regs)
1307 {
1308 	printk (KERN_EMERG "PowerPC Book-E Watchdog Exception\n");
1309 	WatchdogHandler(regs);
1310 }
1311 #endif
1312 
1313 /*
1314  * We enter here if we discover during exception entry that we are
1315  * running in supervisor mode with a userspace value in the stack pointer.
1316  */
1317 void kernel_bad_stack(struct pt_regs *regs)
1318 {
1319 	printk(KERN_EMERG "Bad kernel stack pointer %lx at %lx\n",
1320 	       regs->gpr[1], regs->nip);
1321 	die("Bad kernel stack pointer", regs, SIGABRT);
1322 }
1323 
1324 void __init trap_init(void)
1325 {
1326 }
1327 
1328 
1329 #ifdef CONFIG_PPC_EMULATED_STATS
1330 
1331 #define WARN_EMULATED_SETUP(type)	.type = { .name = #type }
1332 
1333 struct ppc_emulated ppc_emulated = {
1334 #ifdef CONFIG_ALTIVEC
1335 	WARN_EMULATED_SETUP(altivec),
1336 #endif
1337 	WARN_EMULATED_SETUP(dcba),
1338 	WARN_EMULATED_SETUP(dcbz),
1339 	WARN_EMULATED_SETUP(fp_pair),
1340 	WARN_EMULATED_SETUP(isel),
1341 	WARN_EMULATED_SETUP(mcrxr),
1342 	WARN_EMULATED_SETUP(mfpvr),
1343 	WARN_EMULATED_SETUP(multiple),
1344 	WARN_EMULATED_SETUP(popcntb),
1345 	WARN_EMULATED_SETUP(spe),
1346 	WARN_EMULATED_SETUP(string),
1347 	WARN_EMULATED_SETUP(unaligned),
1348 #ifdef CONFIG_MATH_EMULATION
1349 	WARN_EMULATED_SETUP(math),
1350 #elif defined(CONFIG_8XX_MINIMAL_FPEMU)
1351 	WARN_EMULATED_SETUP(8xx),
1352 #endif
1353 #ifdef CONFIG_VSX
1354 	WARN_EMULATED_SETUP(vsx),
1355 #endif
1356 };
1357 
1358 u32 ppc_warn_emulated;
1359 
1360 void ppc_warn_emulated_print(const char *type)
1361 {
1362 	if (printk_ratelimit())
1363 		pr_warning("%s used emulated %s instruction\n", current->comm,
1364 			   type);
1365 }
1366 
1367 static int __init ppc_warn_emulated_init(void)
1368 {
1369 	struct dentry *dir, *d;
1370 	unsigned int i;
1371 	struct ppc_emulated_entry *entries = (void *)&ppc_emulated;
1372 
1373 	if (!powerpc_debugfs_root)
1374 		return -ENODEV;
1375 
1376 	dir = debugfs_create_dir("emulated_instructions",
1377 				 powerpc_debugfs_root);
1378 	if (!dir)
1379 		return -ENOMEM;
1380 
1381 	d = debugfs_create_u32("do_warn", S_IRUGO | S_IWUSR, dir,
1382 			       &ppc_warn_emulated);
1383 	if (!d)
1384 		goto fail;
1385 
1386 	for (i = 0; i < sizeof(ppc_emulated)/sizeof(*entries); i++) {
1387 		d = debugfs_create_u32(entries[i].name, S_IRUGO | S_IWUSR, dir,
1388 				       (u32 *)&entries[i].val.counter);
1389 		if (!d)
1390 			goto fail;
1391 	}
1392 
1393 	return 0;
1394 
1395 fail:
1396 	debugfs_remove_recursive(dir);
1397 	return -ENOMEM;
1398 }
1399 
1400 device_initcall(ppc_warn_emulated_init);
1401 
1402 #endif /* CONFIG_PPC_EMULATED_STATS */
1403