xref: /openbmc/linux/arch/powerpc/kernel/traps.c (revision f5b06569)
1 /*
2  *  Copyright (C) 1995-1996  Gary Thomas (gdt@linuxppc.org)
3  *  Copyright 2007-2010 Freescale Semiconductor, Inc.
4  *
5  *  This program is free software; you can redistribute it and/or
6  *  modify it under the terms of the GNU General Public License
7  *  as published by the Free Software Foundation; either version
8  *  2 of the License, or (at your option) any later version.
9  *
10  *  Modified by Cort Dougan (cort@cs.nmt.edu)
11  *  and Paul Mackerras (paulus@samba.org)
12  */
13 
14 /*
15  * This file handles the architecture-dependent parts of hardware exceptions
16  */
17 
18 #include <linux/errno.h>
19 #include <linux/sched.h>
20 #include <linux/kernel.h>
21 #include <linux/mm.h>
22 #include <linux/stddef.h>
23 #include <linux/unistd.h>
24 #include <linux/ptrace.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 #include <linux/ratelimit.h>
38 #include <linux/context_tracking.h>
39 
40 #include <asm/emulated_ops.h>
41 #include <asm/pgtable.h>
42 #include <asm/uaccess.h>
43 #include <asm/io.h>
44 #include <asm/machdep.h>
45 #include <asm/rtas.h>
46 #include <asm/pmc.h>
47 #include <asm/reg.h>
48 #ifdef CONFIG_PMAC_BACKLIGHT
49 #include <asm/backlight.h>
50 #endif
51 #ifdef CONFIG_PPC64
52 #include <asm/firmware.h>
53 #include <asm/processor.h>
54 #include <asm/tm.h>
55 #endif
56 #include <asm/kexec.h>
57 #include <asm/ppc-opcode.h>
58 #include <asm/rio.h>
59 #include <asm/fadump.h>
60 #include <asm/switch_to.h>
61 #include <asm/tm.h>
62 #include <asm/debug.h>
63 #include <asm/asm-prototypes.h>
64 #include <asm/hmi.h>
65 #include <sysdev/fsl_pci.h>
66 
67 #if defined(CONFIG_DEBUGGER) || defined(CONFIG_KEXEC)
68 int (*__debugger)(struct pt_regs *regs) __read_mostly;
69 int (*__debugger_ipi)(struct pt_regs *regs) __read_mostly;
70 int (*__debugger_bpt)(struct pt_regs *regs) __read_mostly;
71 int (*__debugger_sstep)(struct pt_regs *regs) __read_mostly;
72 int (*__debugger_iabr_match)(struct pt_regs *regs) __read_mostly;
73 int (*__debugger_break_match)(struct pt_regs *regs) __read_mostly;
74 int (*__debugger_fault_handler)(struct pt_regs *regs) __read_mostly;
75 
76 EXPORT_SYMBOL(__debugger);
77 EXPORT_SYMBOL(__debugger_ipi);
78 EXPORT_SYMBOL(__debugger_bpt);
79 EXPORT_SYMBOL(__debugger_sstep);
80 EXPORT_SYMBOL(__debugger_iabr_match);
81 EXPORT_SYMBOL(__debugger_break_match);
82 EXPORT_SYMBOL(__debugger_fault_handler);
83 #endif
84 
85 /* Transactional Memory trap debug */
86 #ifdef TM_DEBUG_SW
87 #define TM_DEBUG(x...) printk(KERN_INFO x)
88 #else
89 #define TM_DEBUG(x...) do { } while(0)
90 #endif
91 
92 /*
93  * Trap & Exception support
94  */
95 
96 #ifdef CONFIG_PMAC_BACKLIGHT
97 static void pmac_backlight_unblank(void)
98 {
99 	mutex_lock(&pmac_backlight_mutex);
100 	if (pmac_backlight) {
101 		struct backlight_properties *props;
102 
103 		props = &pmac_backlight->props;
104 		props->brightness = props->max_brightness;
105 		props->power = FB_BLANK_UNBLANK;
106 		backlight_update_status(pmac_backlight);
107 	}
108 	mutex_unlock(&pmac_backlight_mutex);
109 }
110 #else
111 static inline void pmac_backlight_unblank(void) { }
112 #endif
113 
114 static arch_spinlock_t die_lock = __ARCH_SPIN_LOCK_UNLOCKED;
115 static int die_owner = -1;
116 static unsigned int die_nest_count;
117 static int die_counter;
118 
119 static unsigned __kprobes long oops_begin(struct pt_regs *regs)
120 {
121 	int cpu;
122 	unsigned long flags;
123 
124 	if (debugger(regs))
125 		return 1;
126 
127 	oops_enter();
128 
129 	/* racy, but better than risking deadlock. */
130 	raw_local_irq_save(flags);
131 	cpu = smp_processor_id();
132 	if (!arch_spin_trylock(&die_lock)) {
133 		if (cpu == die_owner)
134 			/* nested oops. should stop eventually */;
135 		else
136 			arch_spin_lock(&die_lock);
137 	}
138 	die_nest_count++;
139 	die_owner = cpu;
140 	console_verbose();
141 	bust_spinlocks(1);
142 	if (machine_is(powermac))
143 		pmac_backlight_unblank();
144 	return flags;
145 }
146 
147 static void __kprobes oops_end(unsigned long flags, struct pt_regs *regs,
148 			       int signr)
149 {
150 	bust_spinlocks(0);
151 	die_owner = -1;
152 	add_taint(TAINT_DIE, LOCKDEP_NOW_UNRELIABLE);
153 	die_nest_count--;
154 	oops_exit();
155 	printk("\n");
156 	if (!die_nest_count)
157 		/* Nest count reaches zero, release the lock. */
158 		arch_spin_unlock(&die_lock);
159 	raw_local_irq_restore(flags);
160 
161 	crash_fadump(regs, "die oops");
162 
163 	/*
164 	 * A system reset (0x100) is a request to dump, so we always send
165 	 * it through the crashdump code.
166 	 */
167 	if (kexec_should_crash(current) || (TRAP(regs) == 0x100)) {
168 		crash_kexec(regs);
169 
170 		/*
171 		 * We aren't the primary crash CPU. We need to send it
172 		 * to a holding pattern to avoid it ending up in the panic
173 		 * code.
174 		 */
175 		crash_kexec_secondary(regs);
176 	}
177 
178 	if (!signr)
179 		return;
180 
181 	/*
182 	 * While our oops output is serialised by a spinlock, output
183 	 * from panic() called below can race and corrupt it. If we
184 	 * know we are going to panic, delay for 1 second so we have a
185 	 * chance to get clean backtraces from all CPUs that are oopsing.
186 	 */
187 	if (in_interrupt() || panic_on_oops || !current->pid ||
188 	    is_global_init(current)) {
189 		mdelay(MSEC_PER_SEC);
190 	}
191 
192 	if (in_interrupt())
193 		panic("Fatal exception in interrupt");
194 	if (panic_on_oops)
195 		panic("Fatal exception");
196 	do_exit(signr);
197 }
198 
199 static int __kprobes __die(const char *str, struct pt_regs *regs, long err)
200 {
201 	printk("Oops: %s, sig: %ld [#%d]\n", str, err, ++die_counter);
202 #ifdef CONFIG_PREEMPT
203 	printk("PREEMPT ");
204 #endif
205 #ifdef CONFIG_SMP
206 	printk("SMP NR_CPUS=%d ", NR_CPUS);
207 #endif
208 	if (debug_pagealloc_enabled())
209 		printk("DEBUG_PAGEALLOC ");
210 #ifdef CONFIG_NUMA
211 	printk("NUMA ");
212 #endif
213 	printk("%s\n", ppc_md.name ? ppc_md.name : "");
214 
215 	if (notify_die(DIE_OOPS, str, regs, err, 255, SIGSEGV) == NOTIFY_STOP)
216 		return 1;
217 
218 	print_modules();
219 	show_regs(regs);
220 
221 	return 0;
222 }
223 
224 void die(const char *str, struct pt_regs *regs, long err)
225 {
226 	unsigned long flags = oops_begin(regs);
227 
228 	if (__die(str, regs, err))
229 		err = 0;
230 	oops_end(flags, regs, err);
231 }
232 
233 void user_single_step_siginfo(struct task_struct *tsk,
234 				struct pt_regs *regs, siginfo_t *info)
235 {
236 	memset(info, 0, sizeof(*info));
237 	info->si_signo = SIGTRAP;
238 	info->si_code = TRAP_TRACE;
239 	info->si_addr = (void __user *)regs->nip;
240 }
241 
242 void _exception(int signr, struct pt_regs *regs, int code, unsigned long addr)
243 {
244 	siginfo_t info;
245 	const char fmt32[] = KERN_INFO "%s[%d]: unhandled signal %d " \
246 			"at %08lx nip %08lx lr %08lx code %x\n";
247 	const char fmt64[] = KERN_INFO "%s[%d]: unhandled signal %d " \
248 			"at %016lx nip %016lx lr %016lx code %x\n";
249 
250 	if (!user_mode(regs)) {
251 		die("Exception in kernel mode", regs, signr);
252 		return;
253 	}
254 
255 	if (show_unhandled_signals && unhandled_signal(current, signr)) {
256 		printk_ratelimited(regs->msr & MSR_64BIT ? fmt64 : fmt32,
257 				   current->comm, current->pid, signr,
258 				   addr, regs->nip, regs->link, code);
259 	}
260 
261 	if (arch_irqs_disabled() && !arch_irq_disabled_regs(regs))
262 		local_irq_enable();
263 
264 	current->thread.trap_nr = code;
265 	memset(&info, 0, sizeof(info));
266 	info.si_signo = signr;
267 	info.si_code = code;
268 	info.si_addr = (void __user *) addr;
269 	force_sig_info(signr, &info, current);
270 }
271 
272 #ifdef CONFIG_PPC64
273 void system_reset_exception(struct pt_regs *regs)
274 {
275 	/* See if any machine dependent calls */
276 	if (ppc_md.system_reset_exception) {
277 		if (ppc_md.system_reset_exception(regs))
278 			return;
279 	}
280 
281 	die("System Reset", regs, SIGABRT);
282 
283 	/* Must die if the interrupt is not recoverable */
284 	if (!(regs->msr & MSR_RI))
285 		panic("Unrecoverable System Reset");
286 
287 	/* What should we do here? We could issue a shutdown or hard reset. */
288 }
289 
290 /*
291  * This function is called in real mode. Strictly no printk's please.
292  *
293  * regs->nip and regs->msr contains srr0 and ssr1.
294  */
295 long machine_check_early(struct pt_regs *regs)
296 {
297 	long handled = 0;
298 
299 	__this_cpu_inc(irq_stat.mce_exceptions);
300 
301 	add_taint(TAINT_MACHINE_CHECK, LOCKDEP_NOW_UNRELIABLE);
302 
303 	if (cur_cpu_spec && cur_cpu_spec->machine_check_early)
304 		handled = cur_cpu_spec->machine_check_early(regs);
305 	return handled;
306 }
307 
308 long hmi_exception_realmode(struct pt_regs *regs)
309 {
310 	__this_cpu_inc(irq_stat.hmi_exceptions);
311 
312 	wait_for_subcore_guest_exit();
313 
314 	if (ppc_md.hmi_exception_early)
315 		ppc_md.hmi_exception_early(regs);
316 
317 	wait_for_tb_resync();
318 
319 	return 0;
320 }
321 
322 #endif
323 
324 /*
325  * I/O accesses can cause machine checks on powermacs.
326  * Check if the NIP corresponds to the address of a sync
327  * instruction for which there is an entry in the exception
328  * table.
329  * Note that the 601 only takes a machine check on TEA
330  * (transfer error ack) signal assertion, and does not
331  * set any of the top 16 bits of SRR1.
332  *  -- paulus.
333  */
334 static inline int check_io_access(struct pt_regs *regs)
335 {
336 #ifdef CONFIG_PPC32
337 	unsigned long msr = regs->msr;
338 	const struct exception_table_entry *entry;
339 	unsigned int *nip = (unsigned int *)regs->nip;
340 
341 	if (((msr & 0xffff0000) == 0 || (msr & (0x80000 | 0x40000)))
342 	    && (entry = search_exception_tables(regs->nip)) != NULL) {
343 		/*
344 		 * Check that it's a sync instruction, or somewhere
345 		 * in the twi; isync; nop sequence that inb/inw/inl uses.
346 		 * As the address is in the exception table
347 		 * we should be able to read the instr there.
348 		 * For the debug message, we look at the preceding
349 		 * load or store.
350 		 */
351 		if (*nip == 0x60000000)		/* nop */
352 			nip -= 2;
353 		else if (*nip == 0x4c00012c)	/* isync */
354 			--nip;
355 		if (*nip == 0x7c0004ac || (*nip >> 26) == 3) {
356 			/* sync or twi */
357 			unsigned int rb;
358 
359 			--nip;
360 			rb = (*nip >> 11) & 0x1f;
361 			printk(KERN_DEBUG "%s bad port %lx at %p\n",
362 			       (*nip & 0x100)? "OUT to": "IN from",
363 			       regs->gpr[rb] - _IO_BASE, nip);
364 			regs->msr |= MSR_RI;
365 			regs->nip = entry->fixup;
366 			return 1;
367 		}
368 	}
369 #endif /* CONFIG_PPC32 */
370 	return 0;
371 }
372 
373 #ifdef CONFIG_PPC_ADV_DEBUG_REGS
374 /* On 4xx, the reason for the machine check or program exception
375    is in the ESR. */
376 #define get_reason(regs)	((regs)->dsisr)
377 #ifndef CONFIG_FSL_BOOKE
378 #define get_mc_reason(regs)	((regs)->dsisr)
379 #else
380 #define get_mc_reason(regs)	(mfspr(SPRN_MCSR))
381 #endif
382 #define REASON_FP		ESR_FP
383 #define REASON_ILLEGAL		(ESR_PIL | ESR_PUO)
384 #define REASON_PRIVILEGED	ESR_PPR
385 #define REASON_TRAP		ESR_PTR
386 
387 /* single-step stuff */
388 #define single_stepping(regs)	(current->thread.debug.dbcr0 & DBCR0_IC)
389 #define clear_single_step(regs)	(current->thread.debug.dbcr0 &= ~DBCR0_IC)
390 
391 #else
392 /* On non-4xx, the reason for the machine check or program
393    exception is in the MSR. */
394 #define get_reason(regs)	((regs)->msr)
395 #define get_mc_reason(regs)	((regs)->msr)
396 #define REASON_TM		0x200000
397 #define REASON_FP		0x100000
398 #define REASON_ILLEGAL		0x80000
399 #define REASON_PRIVILEGED	0x40000
400 #define REASON_TRAP		0x20000
401 
402 #define single_stepping(regs)	((regs)->msr & MSR_SE)
403 #define clear_single_step(regs)	((regs)->msr &= ~MSR_SE)
404 #endif
405 
406 #if defined(CONFIG_4xx)
407 int machine_check_4xx(struct pt_regs *regs)
408 {
409 	unsigned long reason = get_mc_reason(regs);
410 
411 	if (reason & ESR_IMCP) {
412 		printk("Instruction");
413 		mtspr(SPRN_ESR, reason & ~ESR_IMCP);
414 	} else
415 		printk("Data");
416 	printk(" machine check in kernel mode.\n");
417 
418 	return 0;
419 }
420 
421 int machine_check_440A(struct pt_regs *regs)
422 {
423 	unsigned long reason = get_mc_reason(regs);
424 
425 	printk("Machine check in kernel mode.\n");
426 	if (reason & ESR_IMCP){
427 		printk("Instruction Synchronous Machine Check exception\n");
428 		mtspr(SPRN_ESR, reason & ~ESR_IMCP);
429 	}
430 	else {
431 		u32 mcsr = mfspr(SPRN_MCSR);
432 		if (mcsr & MCSR_IB)
433 			printk("Instruction Read PLB Error\n");
434 		if (mcsr & MCSR_DRB)
435 			printk("Data Read PLB Error\n");
436 		if (mcsr & MCSR_DWB)
437 			printk("Data Write PLB Error\n");
438 		if (mcsr & MCSR_TLBP)
439 			printk("TLB Parity Error\n");
440 		if (mcsr & MCSR_ICP){
441 			flush_instruction_cache();
442 			printk("I-Cache Parity Error\n");
443 		}
444 		if (mcsr & MCSR_DCSP)
445 			printk("D-Cache Search Parity Error\n");
446 		if (mcsr & MCSR_DCFP)
447 			printk("D-Cache Flush Parity Error\n");
448 		if (mcsr & MCSR_IMPE)
449 			printk("Machine Check exception is imprecise\n");
450 
451 		/* Clear MCSR */
452 		mtspr(SPRN_MCSR, mcsr);
453 	}
454 	return 0;
455 }
456 
457 int machine_check_47x(struct pt_regs *regs)
458 {
459 	unsigned long reason = get_mc_reason(regs);
460 	u32 mcsr;
461 
462 	printk(KERN_ERR "Machine check in kernel mode.\n");
463 	if (reason & ESR_IMCP) {
464 		printk(KERN_ERR
465 		       "Instruction Synchronous Machine Check exception\n");
466 		mtspr(SPRN_ESR, reason & ~ESR_IMCP);
467 		return 0;
468 	}
469 	mcsr = mfspr(SPRN_MCSR);
470 	if (mcsr & MCSR_IB)
471 		printk(KERN_ERR "Instruction Read PLB Error\n");
472 	if (mcsr & MCSR_DRB)
473 		printk(KERN_ERR "Data Read PLB Error\n");
474 	if (mcsr & MCSR_DWB)
475 		printk(KERN_ERR "Data Write PLB Error\n");
476 	if (mcsr & MCSR_TLBP)
477 		printk(KERN_ERR "TLB Parity Error\n");
478 	if (mcsr & MCSR_ICP) {
479 		flush_instruction_cache();
480 		printk(KERN_ERR "I-Cache Parity Error\n");
481 	}
482 	if (mcsr & MCSR_DCSP)
483 		printk(KERN_ERR "D-Cache Search Parity Error\n");
484 	if (mcsr & PPC47x_MCSR_GPR)
485 		printk(KERN_ERR "GPR Parity Error\n");
486 	if (mcsr & PPC47x_MCSR_FPR)
487 		printk(KERN_ERR "FPR Parity Error\n");
488 	if (mcsr & PPC47x_MCSR_IPR)
489 		printk(KERN_ERR "Machine Check exception is imprecise\n");
490 
491 	/* Clear MCSR */
492 	mtspr(SPRN_MCSR, mcsr);
493 
494 	return 0;
495 }
496 #elif defined(CONFIG_E500)
497 int machine_check_e500mc(struct pt_regs *regs)
498 {
499 	unsigned long mcsr = mfspr(SPRN_MCSR);
500 	unsigned long reason = mcsr;
501 	int recoverable = 1;
502 
503 	if (reason & MCSR_LD) {
504 		recoverable = fsl_rio_mcheck_exception(regs);
505 		if (recoverable == 1)
506 			goto silent_out;
507 	}
508 
509 	printk("Machine check in kernel mode.\n");
510 	printk("Caused by (from MCSR=%lx): ", reason);
511 
512 	if (reason & MCSR_MCP)
513 		printk("Machine Check Signal\n");
514 
515 	if (reason & MCSR_ICPERR) {
516 		printk("Instruction Cache Parity Error\n");
517 
518 		/*
519 		 * This is recoverable by invalidating the i-cache.
520 		 */
521 		mtspr(SPRN_L1CSR1, mfspr(SPRN_L1CSR1) | L1CSR1_ICFI);
522 		while (mfspr(SPRN_L1CSR1) & L1CSR1_ICFI)
523 			;
524 
525 		/*
526 		 * This will generally be accompanied by an instruction
527 		 * fetch error report -- only treat MCSR_IF as fatal
528 		 * if it wasn't due to an L1 parity error.
529 		 */
530 		reason &= ~MCSR_IF;
531 	}
532 
533 	if (reason & MCSR_DCPERR_MC) {
534 		printk("Data Cache Parity Error\n");
535 
536 		/*
537 		 * In write shadow mode we auto-recover from the error, but it
538 		 * may still get logged and cause a machine check.  We should
539 		 * only treat the non-write shadow case as non-recoverable.
540 		 */
541 		if (!(mfspr(SPRN_L1CSR2) & L1CSR2_DCWS))
542 			recoverable = 0;
543 	}
544 
545 	if (reason & MCSR_L2MMU_MHIT) {
546 		printk("Hit on multiple TLB entries\n");
547 		recoverable = 0;
548 	}
549 
550 	if (reason & MCSR_NMI)
551 		printk("Non-maskable interrupt\n");
552 
553 	if (reason & MCSR_IF) {
554 		printk("Instruction Fetch Error Report\n");
555 		recoverable = 0;
556 	}
557 
558 	if (reason & MCSR_LD) {
559 		printk("Load Error Report\n");
560 		recoverable = 0;
561 	}
562 
563 	if (reason & MCSR_ST) {
564 		printk("Store Error Report\n");
565 		recoverable = 0;
566 	}
567 
568 	if (reason & MCSR_LDG) {
569 		printk("Guarded Load Error Report\n");
570 		recoverable = 0;
571 	}
572 
573 	if (reason & MCSR_TLBSYNC)
574 		printk("Simultaneous tlbsync operations\n");
575 
576 	if (reason & MCSR_BSL2_ERR) {
577 		printk("Level 2 Cache Error\n");
578 		recoverable = 0;
579 	}
580 
581 	if (reason & MCSR_MAV) {
582 		u64 addr;
583 
584 		addr = mfspr(SPRN_MCAR);
585 		addr |= (u64)mfspr(SPRN_MCARU) << 32;
586 
587 		printk("Machine Check %s Address: %#llx\n",
588 		       reason & MCSR_MEA ? "Effective" : "Physical", addr);
589 	}
590 
591 silent_out:
592 	mtspr(SPRN_MCSR, mcsr);
593 	return mfspr(SPRN_MCSR) == 0 && recoverable;
594 }
595 
596 int machine_check_e500(struct pt_regs *regs)
597 {
598 	unsigned long reason = get_mc_reason(regs);
599 
600 	if (reason & MCSR_BUS_RBERR) {
601 		if (fsl_rio_mcheck_exception(regs))
602 			return 1;
603 		if (fsl_pci_mcheck_exception(regs))
604 			return 1;
605 	}
606 
607 	printk("Machine check in kernel mode.\n");
608 	printk("Caused by (from MCSR=%lx): ", reason);
609 
610 	if (reason & MCSR_MCP)
611 		printk("Machine Check Signal\n");
612 	if (reason & MCSR_ICPERR)
613 		printk("Instruction Cache Parity Error\n");
614 	if (reason & MCSR_DCP_PERR)
615 		printk("Data Cache Push Parity Error\n");
616 	if (reason & MCSR_DCPERR)
617 		printk("Data Cache Parity Error\n");
618 	if (reason & MCSR_BUS_IAERR)
619 		printk("Bus - Instruction Address Error\n");
620 	if (reason & MCSR_BUS_RAERR)
621 		printk("Bus - Read Address Error\n");
622 	if (reason & MCSR_BUS_WAERR)
623 		printk("Bus - Write Address Error\n");
624 	if (reason & MCSR_BUS_IBERR)
625 		printk("Bus - Instruction Data Error\n");
626 	if (reason & MCSR_BUS_RBERR)
627 		printk("Bus - Read Data Bus Error\n");
628 	if (reason & MCSR_BUS_WBERR)
629 		printk("Bus - Write Data Bus Error\n");
630 	if (reason & MCSR_BUS_IPERR)
631 		printk("Bus - Instruction Parity Error\n");
632 	if (reason & MCSR_BUS_RPERR)
633 		printk("Bus - Read Parity Error\n");
634 
635 	return 0;
636 }
637 
638 int machine_check_generic(struct pt_regs *regs)
639 {
640 	return 0;
641 }
642 #elif defined(CONFIG_E200)
643 int machine_check_e200(struct pt_regs *regs)
644 {
645 	unsigned long reason = get_mc_reason(regs);
646 
647 	printk("Machine check in kernel mode.\n");
648 	printk("Caused by (from MCSR=%lx): ", reason);
649 
650 	if (reason & MCSR_MCP)
651 		printk("Machine Check Signal\n");
652 	if (reason & MCSR_CP_PERR)
653 		printk("Cache Push Parity Error\n");
654 	if (reason & MCSR_CPERR)
655 		printk("Cache Parity Error\n");
656 	if (reason & MCSR_EXCP_ERR)
657 		printk("ISI, ITLB, or Bus Error on first instruction fetch for an exception handler\n");
658 	if (reason & MCSR_BUS_IRERR)
659 		printk("Bus - Read Bus Error on instruction fetch\n");
660 	if (reason & MCSR_BUS_DRERR)
661 		printk("Bus - Read Bus Error on data load\n");
662 	if (reason & MCSR_BUS_WRERR)
663 		printk("Bus - Write Bus Error on buffered store or cache line push\n");
664 
665 	return 0;
666 }
667 #else
668 int machine_check_generic(struct pt_regs *regs)
669 {
670 	unsigned long reason = get_mc_reason(regs);
671 
672 	printk("Machine check in kernel mode.\n");
673 	printk("Caused by (from SRR1=%lx): ", reason);
674 	switch (reason & 0x601F0000) {
675 	case 0x80000:
676 		printk("Machine check signal\n");
677 		break;
678 	case 0:		/* for 601 */
679 	case 0x40000:
680 	case 0x140000:	/* 7450 MSS error and TEA */
681 		printk("Transfer error ack signal\n");
682 		break;
683 	case 0x20000:
684 		printk("Data parity error signal\n");
685 		break;
686 	case 0x10000:
687 		printk("Address parity error signal\n");
688 		break;
689 	case 0x20000000:
690 		printk("L1 Data Cache error\n");
691 		break;
692 	case 0x40000000:
693 		printk("L1 Instruction Cache error\n");
694 		break;
695 	case 0x00100000:
696 		printk("L2 data cache parity error\n");
697 		break;
698 	default:
699 		printk("Unknown values in msr\n");
700 	}
701 	return 0;
702 }
703 #endif /* everything else */
704 
705 void machine_check_exception(struct pt_regs *regs)
706 {
707 	enum ctx_state prev_state = exception_enter();
708 	int recover = 0;
709 
710 	__this_cpu_inc(irq_stat.mce_exceptions);
711 
712 	/* See if any machine dependent calls. In theory, we would want
713 	 * to call the CPU first, and call the ppc_md. one if the CPU
714 	 * one returns a positive number. However there is existing code
715 	 * that assumes the board gets a first chance, so let's keep it
716 	 * that way for now and fix things later. --BenH.
717 	 */
718 	if (ppc_md.machine_check_exception)
719 		recover = ppc_md.machine_check_exception(regs);
720 	else if (cur_cpu_spec->machine_check)
721 		recover = cur_cpu_spec->machine_check(regs);
722 
723 	if (recover > 0)
724 		goto bail;
725 
726 #if defined(CONFIG_8xx) && defined(CONFIG_PCI)
727 	/* the qspan pci read routines can cause machine checks -- Cort
728 	 *
729 	 * yuck !!! that totally needs to go away ! There are better ways
730 	 * to deal with that than having a wart in the mcheck handler.
731 	 * -- BenH
732 	 */
733 	bad_page_fault(regs, regs->dar, SIGBUS);
734 	goto bail;
735 #endif
736 
737 	if (debugger_fault_handler(regs))
738 		goto bail;
739 
740 	if (check_io_access(regs))
741 		goto bail;
742 
743 	die("Machine check", regs, SIGBUS);
744 
745 	/* Must die if the interrupt is not recoverable */
746 	if (!(regs->msr & MSR_RI))
747 		panic("Unrecoverable Machine check");
748 
749 bail:
750 	exception_exit(prev_state);
751 }
752 
753 void SMIException(struct pt_regs *regs)
754 {
755 	die("System Management Interrupt", regs, SIGABRT);
756 }
757 
758 void handle_hmi_exception(struct pt_regs *regs)
759 {
760 	struct pt_regs *old_regs;
761 
762 	old_regs = set_irq_regs(regs);
763 	irq_enter();
764 
765 	if (ppc_md.handle_hmi_exception)
766 		ppc_md.handle_hmi_exception(regs);
767 
768 	irq_exit();
769 	set_irq_regs(old_regs);
770 }
771 
772 void unknown_exception(struct pt_regs *regs)
773 {
774 	enum ctx_state prev_state = exception_enter();
775 
776 	printk("Bad trap at PC: %lx, SR: %lx, vector=%lx\n",
777 	       regs->nip, regs->msr, regs->trap);
778 
779 	_exception(SIGTRAP, regs, 0, 0);
780 
781 	exception_exit(prev_state);
782 }
783 
784 void instruction_breakpoint_exception(struct pt_regs *regs)
785 {
786 	enum ctx_state prev_state = exception_enter();
787 
788 	if (notify_die(DIE_IABR_MATCH, "iabr_match", regs, 5,
789 					5, SIGTRAP) == NOTIFY_STOP)
790 		goto bail;
791 	if (debugger_iabr_match(regs))
792 		goto bail;
793 	_exception(SIGTRAP, regs, TRAP_BRKPT, regs->nip);
794 
795 bail:
796 	exception_exit(prev_state);
797 }
798 
799 void RunModeException(struct pt_regs *regs)
800 {
801 	_exception(SIGTRAP, regs, 0, 0);
802 }
803 
804 void __kprobes single_step_exception(struct pt_regs *regs)
805 {
806 	enum ctx_state prev_state = exception_enter();
807 
808 	clear_single_step(regs);
809 
810 	if (notify_die(DIE_SSTEP, "single_step", regs, 5,
811 					5, SIGTRAP) == NOTIFY_STOP)
812 		goto bail;
813 	if (debugger_sstep(regs))
814 		goto bail;
815 
816 	_exception(SIGTRAP, regs, TRAP_TRACE, regs->nip);
817 
818 bail:
819 	exception_exit(prev_state);
820 }
821 
822 /*
823  * After we have successfully emulated an instruction, we have to
824  * check if the instruction was being single-stepped, and if so,
825  * pretend we got a single-step exception.  This was pointed out
826  * by Kumar Gala.  -- paulus
827  */
828 static void emulate_single_step(struct pt_regs *regs)
829 {
830 	if (single_stepping(regs))
831 		single_step_exception(regs);
832 }
833 
834 static inline int __parse_fpscr(unsigned long fpscr)
835 {
836 	int ret = 0;
837 
838 	/* Invalid operation */
839 	if ((fpscr & FPSCR_VE) && (fpscr & FPSCR_VX))
840 		ret = FPE_FLTINV;
841 
842 	/* Overflow */
843 	else if ((fpscr & FPSCR_OE) && (fpscr & FPSCR_OX))
844 		ret = FPE_FLTOVF;
845 
846 	/* Underflow */
847 	else if ((fpscr & FPSCR_UE) && (fpscr & FPSCR_UX))
848 		ret = FPE_FLTUND;
849 
850 	/* Divide by zero */
851 	else if ((fpscr & FPSCR_ZE) && (fpscr & FPSCR_ZX))
852 		ret = FPE_FLTDIV;
853 
854 	/* Inexact result */
855 	else if ((fpscr & FPSCR_XE) && (fpscr & FPSCR_XX))
856 		ret = FPE_FLTRES;
857 
858 	return ret;
859 }
860 
861 static void parse_fpe(struct pt_regs *regs)
862 {
863 	int code = 0;
864 
865 	flush_fp_to_thread(current);
866 
867 	code = __parse_fpscr(current->thread.fp_state.fpscr);
868 
869 	_exception(SIGFPE, regs, code, regs->nip);
870 }
871 
872 /*
873  * Illegal instruction emulation support.  Originally written to
874  * provide the PVR to user applications using the mfspr rd, PVR.
875  * Return non-zero if we can't emulate, or -EFAULT if the associated
876  * memory access caused an access fault.  Return zero on success.
877  *
878  * There are a couple of ways to do this, either "decode" the instruction
879  * or directly match lots of bits.  In this case, matching lots of
880  * bits is faster and easier.
881  *
882  */
883 static int emulate_string_inst(struct pt_regs *regs, u32 instword)
884 {
885 	u8 rT = (instword >> 21) & 0x1f;
886 	u8 rA = (instword >> 16) & 0x1f;
887 	u8 NB_RB = (instword >> 11) & 0x1f;
888 	u32 num_bytes;
889 	unsigned long EA;
890 	int pos = 0;
891 
892 	/* Early out if we are an invalid form of lswx */
893 	if ((instword & PPC_INST_STRING_MASK) == PPC_INST_LSWX)
894 		if ((rT == rA) || (rT == NB_RB))
895 			return -EINVAL;
896 
897 	EA = (rA == 0) ? 0 : regs->gpr[rA];
898 
899 	switch (instword & PPC_INST_STRING_MASK) {
900 		case PPC_INST_LSWX:
901 		case PPC_INST_STSWX:
902 			EA += NB_RB;
903 			num_bytes = regs->xer & 0x7f;
904 			break;
905 		case PPC_INST_LSWI:
906 		case PPC_INST_STSWI:
907 			num_bytes = (NB_RB == 0) ? 32 : NB_RB;
908 			break;
909 		default:
910 			return -EINVAL;
911 	}
912 
913 	while (num_bytes != 0)
914 	{
915 		u8 val;
916 		u32 shift = 8 * (3 - (pos & 0x3));
917 
918 		/* if process is 32-bit, clear upper 32 bits of EA */
919 		if ((regs->msr & MSR_64BIT) == 0)
920 			EA &= 0xFFFFFFFF;
921 
922 		switch ((instword & PPC_INST_STRING_MASK)) {
923 			case PPC_INST_LSWX:
924 			case PPC_INST_LSWI:
925 				if (get_user(val, (u8 __user *)EA))
926 					return -EFAULT;
927 				/* first time updating this reg,
928 				 * zero it out */
929 				if (pos == 0)
930 					regs->gpr[rT] = 0;
931 				regs->gpr[rT] |= val << shift;
932 				break;
933 			case PPC_INST_STSWI:
934 			case PPC_INST_STSWX:
935 				val = regs->gpr[rT] >> shift;
936 				if (put_user(val, (u8 __user *)EA))
937 					return -EFAULT;
938 				break;
939 		}
940 		/* move EA to next address */
941 		EA += 1;
942 		num_bytes--;
943 
944 		/* manage our position within the register */
945 		if (++pos == 4) {
946 			pos = 0;
947 			if (++rT == 32)
948 				rT = 0;
949 		}
950 	}
951 
952 	return 0;
953 }
954 
955 static int emulate_popcntb_inst(struct pt_regs *regs, u32 instword)
956 {
957 	u32 ra,rs;
958 	unsigned long tmp;
959 
960 	ra = (instword >> 16) & 0x1f;
961 	rs = (instword >> 21) & 0x1f;
962 
963 	tmp = regs->gpr[rs];
964 	tmp = tmp - ((tmp >> 1) & 0x5555555555555555ULL);
965 	tmp = (tmp & 0x3333333333333333ULL) + ((tmp >> 2) & 0x3333333333333333ULL);
966 	tmp = (tmp + (tmp >> 4)) & 0x0f0f0f0f0f0f0f0fULL;
967 	regs->gpr[ra] = tmp;
968 
969 	return 0;
970 }
971 
972 static int emulate_isel(struct pt_regs *regs, u32 instword)
973 {
974 	u8 rT = (instword >> 21) & 0x1f;
975 	u8 rA = (instword >> 16) & 0x1f;
976 	u8 rB = (instword >> 11) & 0x1f;
977 	u8 BC = (instword >> 6) & 0x1f;
978 	u8 bit;
979 	unsigned long tmp;
980 
981 	tmp = (rA == 0) ? 0 : regs->gpr[rA];
982 	bit = (regs->ccr >> (31 - BC)) & 0x1;
983 
984 	regs->gpr[rT] = bit ? tmp : regs->gpr[rB];
985 
986 	return 0;
987 }
988 
989 #ifdef CONFIG_PPC_TRANSACTIONAL_MEM
990 static inline bool tm_abort_check(struct pt_regs *regs, int cause)
991 {
992         /* If we're emulating a load/store in an active transaction, we cannot
993          * emulate it as the kernel operates in transaction suspended context.
994          * We need to abort the transaction.  This creates a persistent TM
995          * abort so tell the user what caused it with a new code.
996 	 */
997 	if (MSR_TM_TRANSACTIONAL(regs->msr)) {
998 		tm_enable();
999 		tm_abort(cause);
1000 		return true;
1001 	}
1002 	return false;
1003 }
1004 #else
1005 static inline bool tm_abort_check(struct pt_regs *regs, int reason)
1006 {
1007 	return false;
1008 }
1009 #endif
1010 
1011 static int emulate_instruction(struct pt_regs *regs)
1012 {
1013 	u32 instword;
1014 	u32 rd;
1015 
1016 	if (!user_mode(regs))
1017 		return -EINVAL;
1018 	CHECK_FULL_REGS(regs);
1019 
1020 	if (get_user(instword, (u32 __user *)(regs->nip)))
1021 		return -EFAULT;
1022 
1023 	/* Emulate the mfspr rD, PVR. */
1024 	if ((instword & PPC_INST_MFSPR_PVR_MASK) == PPC_INST_MFSPR_PVR) {
1025 		PPC_WARN_EMULATED(mfpvr, regs);
1026 		rd = (instword >> 21) & 0x1f;
1027 		regs->gpr[rd] = mfspr(SPRN_PVR);
1028 		return 0;
1029 	}
1030 
1031 	/* Emulating the dcba insn is just a no-op.  */
1032 	if ((instword & PPC_INST_DCBA_MASK) == PPC_INST_DCBA) {
1033 		PPC_WARN_EMULATED(dcba, regs);
1034 		return 0;
1035 	}
1036 
1037 	/* Emulate the mcrxr insn.  */
1038 	if ((instword & PPC_INST_MCRXR_MASK) == PPC_INST_MCRXR) {
1039 		int shift = (instword >> 21) & 0x1c;
1040 		unsigned long msk = 0xf0000000UL >> shift;
1041 
1042 		PPC_WARN_EMULATED(mcrxr, regs);
1043 		regs->ccr = (regs->ccr & ~msk) | ((regs->xer >> shift) & msk);
1044 		regs->xer &= ~0xf0000000UL;
1045 		return 0;
1046 	}
1047 
1048 	/* Emulate load/store string insn. */
1049 	if ((instword & PPC_INST_STRING_GEN_MASK) == PPC_INST_STRING) {
1050 		if (tm_abort_check(regs,
1051 				   TM_CAUSE_EMULATE | TM_CAUSE_PERSISTENT))
1052 			return -EINVAL;
1053 		PPC_WARN_EMULATED(string, regs);
1054 		return emulate_string_inst(regs, instword);
1055 	}
1056 
1057 	/* Emulate the popcntb (Population Count Bytes) instruction. */
1058 	if ((instword & PPC_INST_POPCNTB_MASK) == PPC_INST_POPCNTB) {
1059 		PPC_WARN_EMULATED(popcntb, regs);
1060 		return emulate_popcntb_inst(regs, instword);
1061 	}
1062 
1063 	/* Emulate isel (Integer Select) instruction */
1064 	if ((instword & PPC_INST_ISEL_MASK) == PPC_INST_ISEL) {
1065 		PPC_WARN_EMULATED(isel, regs);
1066 		return emulate_isel(regs, instword);
1067 	}
1068 
1069 	/* Emulate sync instruction variants */
1070 	if ((instword & PPC_INST_SYNC_MASK) == PPC_INST_SYNC) {
1071 		PPC_WARN_EMULATED(sync, regs);
1072 		asm volatile("sync");
1073 		return 0;
1074 	}
1075 
1076 #ifdef CONFIG_PPC64
1077 	/* Emulate the mfspr rD, DSCR. */
1078 	if ((((instword & PPC_INST_MFSPR_DSCR_USER_MASK) ==
1079 		PPC_INST_MFSPR_DSCR_USER) ||
1080 	     ((instword & PPC_INST_MFSPR_DSCR_MASK) ==
1081 		PPC_INST_MFSPR_DSCR)) &&
1082 			cpu_has_feature(CPU_FTR_DSCR)) {
1083 		PPC_WARN_EMULATED(mfdscr, regs);
1084 		rd = (instword >> 21) & 0x1f;
1085 		regs->gpr[rd] = mfspr(SPRN_DSCR);
1086 		return 0;
1087 	}
1088 	/* Emulate the mtspr DSCR, rD. */
1089 	if ((((instword & PPC_INST_MTSPR_DSCR_USER_MASK) ==
1090 		PPC_INST_MTSPR_DSCR_USER) ||
1091 	     ((instword & PPC_INST_MTSPR_DSCR_MASK) ==
1092 		PPC_INST_MTSPR_DSCR)) &&
1093 			cpu_has_feature(CPU_FTR_DSCR)) {
1094 		PPC_WARN_EMULATED(mtdscr, regs);
1095 		rd = (instword >> 21) & 0x1f;
1096 		current->thread.dscr = regs->gpr[rd];
1097 		current->thread.dscr_inherit = 1;
1098 		mtspr(SPRN_DSCR, current->thread.dscr);
1099 		return 0;
1100 	}
1101 #endif
1102 
1103 	return -EINVAL;
1104 }
1105 
1106 int is_valid_bugaddr(unsigned long addr)
1107 {
1108 	return is_kernel_addr(addr);
1109 }
1110 
1111 #ifdef CONFIG_MATH_EMULATION
1112 static int emulate_math(struct pt_regs *regs)
1113 {
1114 	int ret;
1115 	extern int do_mathemu(struct pt_regs *regs);
1116 
1117 	ret = do_mathemu(regs);
1118 	if (ret >= 0)
1119 		PPC_WARN_EMULATED(math, regs);
1120 
1121 	switch (ret) {
1122 	case 0:
1123 		emulate_single_step(regs);
1124 		return 0;
1125 	case 1: {
1126 			int code = 0;
1127 			code = __parse_fpscr(current->thread.fp_state.fpscr);
1128 			_exception(SIGFPE, regs, code, regs->nip);
1129 			return 0;
1130 		}
1131 	case -EFAULT:
1132 		_exception(SIGSEGV, regs, SEGV_MAPERR, regs->nip);
1133 		return 0;
1134 	}
1135 
1136 	return -1;
1137 }
1138 #else
1139 static inline int emulate_math(struct pt_regs *regs) { return -1; }
1140 #endif
1141 
1142 void __kprobes program_check_exception(struct pt_regs *regs)
1143 {
1144 	enum ctx_state prev_state = exception_enter();
1145 	unsigned int reason = get_reason(regs);
1146 
1147 	/* We can now get here via a FP Unavailable exception if the core
1148 	 * has no FPU, in that case the reason flags will be 0 */
1149 
1150 	if (reason & REASON_FP) {
1151 		/* IEEE FP exception */
1152 		parse_fpe(regs);
1153 		goto bail;
1154 	}
1155 	if (reason & REASON_TRAP) {
1156 		unsigned long bugaddr;
1157 		/* Debugger is first in line to stop recursive faults in
1158 		 * rcu_lock, notify_die, or atomic_notifier_call_chain */
1159 		if (debugger_bpt(regs))
1160 			goto bail;
1161 
1162 		/* trap exception */
1163 		if (notify_die(DIE_BPT, "breakpoint", regs, 5, 5, SIGTRAP)
1164 				== NOTIFY_STOP)
1165 			goto bail;
1166 
1167 		bugaddr = regs->nip;
1168 		/*
1169 		 * Fixup bugaddr for BUG_ON() in real mode
1170 		 */
1171 		if (!is_kernel_addr(bugaddr) && !(regs->msr & MSR_IR))
1172 			bugaddr += PAGE_OFFSET;
1173 
1174 		if (!(regs->msr & MSR_PR) &&  /* not user-mode */
1175 		    report_bug(bugaddr, regs) == BUG_TRAP_TYPE_WARN) {
1176 			regs->nip += 4;
1177 			goto bail;
1178 		}
1179 		_exception(SIGTRAP, regs, TRAP_BRKPT, regs->nip);
1180 		goto bail;
1181 	}
1182 #ifdef CONFIG_PPC_TRANSACTIONAL_MEM
1183 	if (reason & REASON_TM) {
1184 		/* This is a TM "Bad Thing Exception" program check.
1185 		 * This occurs when:
1186 		 * -  An rfid/hrfid/mtmsrd attempts to cause an illegal
1187 		 *    transition in TM states.
1188 		 * -  A trechkpt is attempted when transactional.
1189 		 * -  A treclaim is attempted when non transactional.
1190 		 * -  A tend is illegally attempted.
1191 		 * -  writing a TM SPR when transactional.
1192 		 */
1193 		if (!user_mode(regs) &&
1194 		    report_bug(regs->nip, regs) == BUG_TRAP_TYPE_WARN) {
1195 			regs->nip += 4;
1196 			goto bail;
1197 		}
1198 		/* If usermode caused this, it's done something illegal and
1199 		 * gets a SIGILL slap on the wrist.  We call it an illegal
1200 		 * operand to distinguish from the instruction just being bad
1201 		 * (e.g. executing a 'tend' on a CPU without TM!); it's an
1202 		 * illegal /placement/ of a valid instruction.
1203 		 */
1204 		if (user_mode(regs)) {
1205 			_exception(SIGILL, regs, ILL_ILLOPN, regs->nip);
1206 			goto bail;
1207 		} else {
1208 			printk(KERN_EMERG "Unexpected TM Bad Thing exception "
1209 			       "at %lx (msr 0x%x)\n", regs->nip, reason);
1210 			die("Unrecoverable exception", regs, SIGABRT);
1211 		}
1212 	}
1213 #endif
1214 
1215 	/*
1216 	 * If we took the program check in the kernel skip down to sending a
1217 	 * SIGILL. The subsequent cases all relate to emulating instructions
1218 	 * which we should only do for userspace. We also do not want to enable
1219 	 * interrupts for kernel faults because that might lead to further
1220 	 * faults, and loose the context of the original exception.
1221 	 */
1222 	if (!user_mode(regs))
1223 		goto sigill;
1224 
1225 	/* We restore the interrupt state now */
1226 	if (!arch_irq_disabled_regs(regs))
1227 		local_irq_enable();
1228 
1229 	/* (reason & REASON_ILLEGAL) would be the obvious thing here,
1230 	 * but there seems to be a hardware bug on the 405GP (RevD)
1231 	 * that means ESR is sometimes set incorrectly - either to
1232 	 * ESR_DST (!?) or 0.  In the process of chasing this with the
1233 	 * hardware people - not sure if it can happen on any illegal
1234 	 * instruction or only on FP instructions, whether there is a
1235 	 * pattern to occurrences etc. -dgibson 31/Mar/2003
1236 	 */
1237 	if (!emulate_math(regs))
1238 		goto bail;
1239 
1240 	/* Try to emulate it if we should. */
1241 	if (reason & (REASON_ILLEGAL | REASON_PRIVILEGED)) {
1242 		switch (emulate_instruction(regs)) {
1243 		case 0:
1244 			regs->nip += 4;
1245 			emulate_single_step(regs);
1246 			goto bail;
1247 		case -EFAULT:
1248 			_exception(SIGSEGV, regs, SEGV_MAPERR, regs->nip);
1249 			goto bail;
1250 		}
1251 	}
1252 
1253 sigill:
1254 	if (reason & REASON_PRIVILEGED)
1255 		_exception(SIGILL, regs, ILL_PRVOPC, regs->nip);
1256 	else
1257 		_exception(SIGILL, regs, ILL_ILLOPC, regs->nip);
1258 
1259 bail:
1260 	exception_exit(prev_state);
1261 }
1262 
1263 /*
1264  * This occurs when running in hypervisor mode on POWER6 or later
1265  * and an illegal instruction is encountered.
1266  */
1267 void __kprobes emulation_assist_interrupt(struct pt_regs *regs)
1268 {
1269 	regs->msr |= REASON_ILLEGAL;
1270 	program_check_exception(regs);
1271 }
1272 
1273 void alignment_exception(struct pt_regs *regs)
1274 {
1275 	enum ctx_state prev_state = exception_enter();
1276 	int sig, code, fixed = 0;
1277 
1278 	/* We restore the interrupt state now */
1279 	if (!arch_irq_disabled_regs(regs))
1280 		local_irq_enable();
1281 
1282 	if (tm_abort_check(regs, TM_CAUSE_ALIGNMENT | TM_CAUSE_PERSISTENT))
1283 		goto bail;
1284 
1285 	/* we don't implement logging of alignment exceptions */
1286 	if (!(current->thread.align_ctl & PR_UNALIGN_SIGBUS))
1287 		fixed = fix_alignment(regs);
1288 
1289 	if (fixed == 1) {
1290 		regs->nip += 4;	/* skip over emulated instruction */
1291 		emulate_single_step(regs);
1292 		goto bail;
1293 	}
1294 
1295 	/* Operand address was bad */
1296 	if (fixed == -EFAULT) {
1297 		sig = SIGSEGV;
1298 		code = SEGV_ACCERR;
1299 	} else {
1300 		sig = SIGBUS;
1301 		code = BUS_ADRALN;
1302 	}
1303 	if (user_mode(regs))
1304 		_exception(sig, regs, code, regs->dar);
1305 	else
1306 		bad_page_fault(regs, regs->dar, sig);
1307 
1308 bail:
1309 	exception_exit(prev_state);
1310 }
1311 
1312 void StackOverflow(struct pt_regs *regs)
1313 {
1314 	printk(KERN_CRIT "Kernel stack overflow in process %p, r1=%lx\n",
1315 	       current, regs->gpr[1]);
1316 	debugger(regs);
1317 	show_regs(regs);
1318 	panic("kernel stack overflow");
1319 }
1320 
1321 void nonrecoverable_exception(struct pt_regs *regs)
1322 {
1323 	printk(KERN_ERR "Non-recoverable exception at PC=%lx MSR=%lx\n",
1324 	       regs->nip, regs->msr);
1325 	debugger(regs);
1326 	die("nonrecoverable exception", regs, SIGKILL);
1327 }
1328 
1329 void kernel_fp_unavailable_exception(struct pt_regs *regs)
1330 {
1331 	enum ctx_state prev_state = exception_enter();
1332 
1333 	printk(KERN_EMERG "Unrecoverable FP Unavailable Exception "
1334 			  "%lx at %lx\n", regs->trap, regs->nip);
1335 	die("Unrecoverable FP Unavailable Exception", regs, SIGABRT);
1336 
1337 	exception_exit(prev_state);
1338 }
1339 
1340 void altivec_unavailable_exception(struct pt_regs *regs)
1341 {
1342 	enum ctx_state prev_state = exception_enter();
1343 
1344 	if (user_mode(regs)) {
1345 		/* A user program has executed an altivec instruction,
1346 		   but this kernel doesn't support altivec. */
1347 		_exception(SIGILL, regs, ILL_ILLOPC, regs->nip);
1348 		goto bail;
1349 	}
1350 
1351 	printk(KERN_EMERG "Unrecoverable VMX/Altivec Unavailable Exception "
1352 			"%lx at %lx\n", regs->trap, regs->nip);
1353 	die("Unrecoverable VMX/Altivec Unavailable Exception", regs, SIGABRT);
1354 
1355 bail:
1356 	exception_exit(prev_state);
1357 }
1358 
1359 void vsx_unavailable_exception(struct pt_regs *regs)
1360 {
1361 	if (user_mode(regs)) {
1362 		/* A user program has executed an vsx instruction,
1363 		   but this kernel doesn't support vsx. */
1364 		_exception(SIGILL, regs, ILL_ILLOPC, regs->nip);
1365 		return;
1366 	}
1367 
1368 	printk(KERN_EMERG "Unrecoverable VSX Unavailable Exception "
1369 			"%lx at %lx\n", regs->trap, regs->nip);
1370 	die("Unrecoverable VSX Unavailable Exception", regs, SIGABRT);
1371 }
1372 
1373 #ifdef CONFIG_PPC64
1374 void facility_unavailable_exception(struct pt_regs *regs)
1375 {
1376 	static char *facility_strings[] = {
1377 		[FSCR_FP_LG] = "FPU",
1378 		[FSCR_VECVSX_LG] = "VMX/VSX",
1379 		[FSCR_DSCR_LG] = "DSCR",
1380 		[FSCR_PM_LG] = "PMU SPRs",
1381 		[FSCR_BHRB_LG] = "BHRB",
1382 		[FSCR_TM_LG] = "TM",
1383 		[FSCR_EBB_LG] = "EBB",
1384 		[FSCR_TAR_LG] = "TAR",
1385 		[FSCR_LM_LG] = "LM",
1386 	};
1387 	char *facility = "unknown";
1388 	u64 value;
1389 	u32 instword, rd;
1390 	u8 status;
1391 	bool hv;
1392 
1393 	hv = (regs->trap == 0xf80);
1394 	if (hv)
1395 		value = mfspr(SPRN_HFSCR);
1396 	else
1397 		value = mfspr(SPRN_FSCR);
1398 
1399 	status = value >> 56;
1400 	if (status == FSCR_DSCR_LG) {
1401 		/*
1402 		 * User is accessing the DSCR register using the problem
1403 		 * state only SPR number (0x03) either through a mfspr or
1404 		 * a mtspr instruction. If it is a write attempt through
1405 		 * a mtspr, then we set the inherit bit. This also allows
1406 		 * the user to write or read the register directly in the
1407 		 * future by setting via the FSCR DSCR bit. But in case it
1408 		 * is a read DSCR attempt through a mfspr instruction, we
1409 		 * just emulate the instruction instead. This code path will
1410 		 * always emulate all the mfspr instructions till the user
1411 		 * has attempted at least one mtspr instruction. This way it
1412 		 * preserves the same behaviour when the user is accessing
1413 		 * the DSCR through privilege level only SPR number (0x11)
1414 		 * which is emulated through illegal instruction exception.
1415 		 * We always leave HFSCR DSCR set.
1416 		 */
1417 		if (get_user(instword, (u32 __user *)(regs->nip))) {
1418 			pr_err("Failed to fetch the user instruction\n");
1419 			return;
1420 		}
1421 
1422 		/* Write into DSCR (mtspr 0x03, RS) */
1423 		if ((instword & PPC_INST_MTSPR_DSCR_USER_MASK)
1424 				== PPC_INST_MTSPR_DSCR_USER) {
1425 			rd = (instword >> 21) & 0x1f;
1426 			current->thread.dscr = regs->gpr[rd];
1427 			current->thread.dscr_inherit = 1;
1428 			current->thread.fscr |= FSCR_DSCR;
1429 			mtspr(SPRN_FSCR, current->thread.fscr);
1430 		}
1431 
1432 		/* Read from DSCR (mfspr RT, 0x03) */
1433 		if ((instword & PPC_INST_MFSPR_DSCR_USER_MASK)
1434 				== PPC_INST_MFSPR_DSCR_USER) {
1435 			if (emulate_instruction(regs)) {
1436 				pr_err("DSCR based mfspr emulation failed\n");
1437 				return;
1438 			}
1439 			regs->nip += 4;
1440 			emulate_single_step(regs);
1441 		}
1442 		return;
1443 	} else if ((status == FSCR_LM_LG) && cpu_has_feature(CPU_FTR_ARCH_300)) {
1444 		/*
1445 		 * This process has touched LM, so turn it on forever
1446 		 * for this process
1447 		 */
1448 		current->thread.fscr |= FSCR_LM;
1449 		mtspr(SPRN_FSCR, current->thread.fscr);
1450 		return;
1451 	}
1452 
1453 	if ((status < ARRAY_SIZE(facility_strings)) &&
1454 	    facility_strings[status])
1455 		facility = facility_strings[status];
1456 
1457 	/* We restore the interrupt state now */
1458 	if (!arch_irq_disabled_regs(regs))
1459 		local_irq_enable();
1460 
1461 	pr_err_ratelimited(
1462 		"%sFacility '%s' unavailable, exception at 0x%lx, MSR=%lx\n",
1463 		hv ? "Hypervisor " : "", facility, regs->nip, regs->msr);
1464 
1465 	if (user_mode(regs)) {
1466 		_exception(SIGILL, regs, ILL_ILLOPC, regs->nip);
1467 		return;
1468 	}
1469 
1470 	die("Unexpected facility unavailable exception", regs, SIGABRT);
1471 }
1472 #endif
1473 
1474 #ifdef CONFIG_PPC_TRANSACTIONAL_MEM
1475 
1476 void fp_unavailable_tm(struct pt_regs *regs)
1477 {
1478 	/* Note:  This does not handle any kind of FP laziness. */
1479 
1480 	TM_DEBUG("FP Unavailable trap whilst transactional at 0x%lx, MSR=%lx\n",
1481 		 regs->nip, regs->msr);
1482 
1483         /* We can only have got here if the task started using FP after
1484          * beginning the transaction.  So, the transactional regs are just a
1485          * copy of the checkpointed ones.  But, we still need to recheckpoint
1486          * as we're enabling FP for the process; it will return, abort the
1487          * transaction, and probably retry but now with FP enabled.  So the
1488          * checkpointed FP registers need to be loaded.
1489 	 */
1490 	tm_reclaim_current(TM_CAUSE_FAC_UNAV);
1491 	/* Reclaim didn't save out any FPRs to transact_fprs. */
1492 
1493 	/* Enable FP for the task: */
1494 	regs->msr |= (MSR_FP | current->thread.fpexc_mode);
1495 
1496 	/* This loads and recheckpoints the FP registers from
1497 	 * thread.fpr[].  They will remain in registers after the
1498 	 * checkpoint so we don't need to reload them after.
1499 	 * If VMX is in use, the VRs now hold checkpointed values,
1500 	 * so we don't want to load the VRs from the thread_struct.
1501 	 */
1502 	tm_recheckpoint(&current->thread, MSR_FP);
1503 
1504 	/* If VMX is in use, get the transactional values back */
1505 	if (regs->msr & MSR_VEC) {
1506 		do_load_up_transact_altivec(&current->thread);
1507 		/* At this point all the VSX state is loaded, so enable it */
1508 		regs->msr |= MSR_VSX;
1509 	}
1510 }
1511 
1512 void altivec_unavailable_tm(struct pt_regs *regs)
1513 {
1514 	/* See the comments in fp_unavailable_tm().  This function operates
1515 	 * the same way.
1516 	 */
1517 
1518 	TM_DEBUG("Vector Unavailable trap whilst transactional at 0x%lx,"
1519 		 "MSR=%lx\n",
1520 		 regs->nip, regs->msr);
1521 	tm_reclaim_current(TM_CAUSE_FAC_UNAV);
1522 	regs->msr |= MSR_VEC;
1523 	tm_recheckpoint(&current->thread, MSR_VEC);
1524 	current->thread.used_vr = 1;
1525 
1526 	if (regs->msr & MSR_FP) {
1527 		do_load_up_transact_fpu(&current->thread);
1528 		regs->msr |= MSR_VSX;
1529 	}
1530 }
1531 
1532 void vsx_unavailable_tm(struct pt_regs *regs)
1533 {
1534 	unsigned long orig_msr = regs->msr;
1535 
1536 	/* See the comments in fp_unavailable_tm().  This works similarly,
1537 	 * though we're loading both FP and VEC registers in here.
1538 	 *
1539 	 * If FP isn't in use, load FP regs.  If VEC isn't in use, load VEC
1540 	 * regs.  Either way, set MSR_VSX.
1541 	 */
1542 
1543 	TM_DEBUG("VSX Unavailable trap whilst transactional at 0x%lx,"
1544 		 "MSR=%lx\n",
1545 		 regs->nip, regs->msr);
1546 
1547 	current->thread.used_vsr = 1;
1548 
1549 	/* If FP and VMX are already loaded, we have all the state we need */
1550 	if ((orig_msr & (MSR_FP | MSR_VEC)) == (MSR_FP | MSR_VEC)) {
1551 		regs->msr |= MSR_VSX;
1552 		return;
1553 	}
1554 
1555 	/* This reclaims FP and/or VR regs if they're already enabled */
1556 	tm_reclaim_current(TM_CAUSE_FAC_UNAV);
1557 
1558 	regs->msr |= MSR_VEC | MSR_FP | current->thread.fpexc_mode |
1559 		MSR_VSX;
1560 
1561 	/* This loads & recheckpoints FP and VRs; but we have
1562 	 * to be sure not to overwrite previously-valid state.
1563 	 */
1564 	tm_recheckpoint(&current->thread, regs->msr & ~orig_msr);
1565 
1566 	if (orig_msr & MSR_FP)
1567 		do_load_up_transact_fpu(&current->thread);
1568 	if (orig_msr & MSR_VEC)
1569 		do_load_up_transact_altivec(&current->thread);
1570 }
1571 #endif /* CONFIG_PPC_TRANSACTIONAL_MEM */
1572 
1573 void performance_monitor_exception(struct pt_regs *regs)
1574 {
1575 	__this_cpu_inc(irq_stat.pmu_irqs);
1576 
1577 	perf_irq(regs);
1578 }
1579 
1580 #ifdef CONFIG_8xx
1581 void SoftwareEmulation(struct pt_regs *regs)
1582 {
1583 	CHECK_FULL_REGS(regs);
1584 
1585 	if (!user_mode(regs)) {
1586 		debugger(regs);
1587 		die("Kernel Mode Unimplemented Instruction or SW FPU Emulation",
1588 			regs, SIGFPE);
1589 	}
1590 
1591 	if (!emulate_math(regs))
1592 		return;
1593 
1594 	_exception(SIGILL, regs, ILL_ILLOPC, regs->nip);
1595 }
1596 #endif /* CONFIG_8xx */
1597 
1598 #ifdef CONFIG_PPC_ADV_DEBUG_REGS
1599 static void handle_debug(struct pt_regs *regs, unsigned long debug_status)
1600 {
1601 	int changed = 0;
1602 	/*
1603 	 * Determine the cause of the debug event, clear the
1604 	 * event flags and send a trap to the handler. Torez
1605 	 */
1606 	if (debug_status & (DBSR_DAC1R | DBSR_DAC1W)) {
1607 		dbcr_dac(current) &= ~(DBCR_DAC1R | DBCR_DAC1W);
1608 #ifdef CONFIG_PPC_ADV_DEBUG_DAC_RANGE
1609 		current->thread.debug.dbcr2 &= ~DBCR2_DAC12MODE;
1610 #endif
1611 		do_send_trap(regs, mfspr(SPRN_DAC1), debug_status, TRAP_HWBKPT,
1612 			     5);
1613 		changed |= 0x01;
1614 	}  else if (debug_status & (DBSR_DAC2R | DBSR_DAC2W)) {
1615 		dbcr_dac(current) &= ~(DBCR_DAC2R | DBCR_DAC2W);
1616 		do_send_trap(regs, mfspr(SPRN_DAC2), debug_status, TRAP_HWBKPT,
1617 			     6);
1618 		changed |= 0x01;
1619 	}  else if (debug_status & DBSR_IAC1) {
1620 		current->thread.debug.dbcr0 &= ~DBCR0_IAC1;
1621 		dbcr_iac_range(current) &= ~DBCR_IAC12MODE;
1622 		do_send_trap(regs, mfspr(SPRN_IAC1), debug_status, TRAP_HWBKPT,
1623 			     1);
1624 		changed |= 0x01;
1625 	}  else if (debug_status & DBSR_IAC2) {
1626 		current->thread.debug.dbcr0 &= ~DBCR0_IAC2;
1627 		do_send_trap(regs, mfspr(SPRN_IAC2), debug_status, TRAP_HWBKPT,
1628 			     2);
1629 		changed |= 0x01;
1630 	}  else if (debug_status & DBSR_IAC3) {
1631 		current->thread.debug.dbcr0 &= ~DBCR0_IAC3;
1632 		dbcr_iac_range(current) &= ~DBCR_IAC34MODE;
1633 		do_send_trap(regs, mfspr(SPRN_IAC3), debug_status, TRAP_HWBKPT,
1634 			     3);
1635 		changed |= 0x01;
1636 	}  else if (debug_status & DBSR_IAC4) {
1637 		current->thread.debug.dbcr0 &= ~DBCR0_IAC4;
1638 		do_send_trap(regs, mfspr(SPRN_IAC4), debug_status, TRAP_HWBKPT,
1639 			     4);
1640 		changed |= 0x01;
1641 	}
1642 	/*
1643 	 * At the point this routine was called, the MSR(DE) was turned off.
1644 	 * Check all other debug flags and see if that bit needs to be turned
1645 	 * back on or not.
1646 	 */
1647 	if (DBCR_ACTIVE_EVENTS(current->thread.debug.dbcr0,
1648 			       current->thread.debug.dbcr1))
1649 		regs->msr |= MSR_DE;
1650 	else
1651 		/* Make sure the IDM flag is off */
1652 		current->thread.debug.dbcr0 &= ~DBCR0_IDM;
1653 
1654 	if (changed & 0x01)
1655 		mtspr(SPRN_DBCR0, current->thread.debug.dbcr0);
1656 }
1657 
1658 void __kprobes DebugException(struct pt_regs *regs, unsigned long debug_status)
1659 {
1660 	current->thread.debug.dbsr = debug_status;
1661 
1662 	/* Hack alert: On BookE, Branch Taken stops on the branch itself, while
1663 	 * on server, it stops on the target of the branch. In order to simulate
1664 	 * the server behaviour, we thus restart right away with a single step
1665 	 * instead of stopping here when hitting a BT
1666 	 */
1667 	if (debug_status & DBSR_BT) {
1668 		regs->msr &= ~MSR_DE;
1669 
1670 		/* Disable BT */
1671 		mtspr(SPRN_DBCR0, mfspr(SPRN_DBCR0) & ~DBCR0_BT);
1672 		/* Clear the BT event */
1673 		mtspr(SPRN_DBSR, DBSR_BT);
1674 
1675 		/* Do the single step trick only when coming from userspace */
1676 		if (user_mode(regs)) {
1677 			current->thread.debug.dbcr0 &= ~DBCR0_BT;
1678 			current->thread.debug.dbcr0 |= DBCR0_IDM | DBCR0_IC;
1679 			regs->msr |= MSR_DE;
1680 			return;
1681 		}
1682 
1683 		if (notify_die(DIE_SSTEP, "block_step", regs, 5,
1684 			       5, SIGTRAP) == NOTIFY_STOP) {
1685 			return;
1686 		}
1687 		if (debugger_sstep(regs))
1688 			return;
1689 	} else if (debug_status & DBSR_IC) { 	/* Instruction complete */
1690 		regs->msr &= ~MSR_DE;
1691 
1692 		/* Disable instruction completion */
1693 		mtspr(SPRN_DBCR0, mfspr(SPRN_DBCR0) & ~DBCR0_IC);
1694 		/* Clear the instruction completion event */
1695 		mtspr(SPRN_DBSR, DBSR_IC);
1696 
1697 		if (notify_die(DIE_SSTEP, "single_step", regs, 5,
1698 			       5, SIGTRAP) == NOTIFY_STOP) {
1699 			return;
1700 		}
1701 
1702 		if (debugger_sstep(regs))
1703 			return;
1704 
1705 		if (user_mode(regs)) {
1706 			current->thread.debug.dbcr0 &= ~DBCR0_IC;
1707 			if (DBCR_ACTIVE_EVENTS(current->thread.debug.dbcr0,
1708 					       current->thread.debug.dbcr1))
1709 				regs->msr |= MSR_DE;
1710 			else
1711 				/* Make sure the IDM bit is off */
1712 				current->thread.debug.dbcr0 &= ~DBCR0_IDM;
1713 		}
1714 
1715 		_exception(SIGTRAP, regs, TRAP_TRACE, regs->nip);
1716 	} else
1717 		handle_debug(regs, debug_status);
1718 }
1719 #endif /* CONFIG_PPC_ADV_DEBUG_REGS */
1720 
1721 #if !defined(CONFIG_TAU_INT)
1722 void TAUException(struct pt_regs *regs)
1723 {
1724 	printk("TAU trap at PC: %lx, MSR: %lx, vector=%lx    %s\n",
1725 	       regs->nip, regs->msr, regs->trap, print_tainted());
1726 }
1727 #endif /* CONFIG_INT_TAU */
1728 
1729 #ifdef CONFIG_ALTIVEC
1730 void altivec_assist_exception(struct pt_regs *regs)
1731 {
1732 	int err;
1733 
1734 	if (!user_mode(regs)) {
1735 		printk(KERN_EMERG "VMX/Altivec assist exception in kernel mode"
1736 		       " at %lx\n", regs->nip);
1737 		die("Kernel VMX/Altivec assist exception", regs, SIGILL);
1738 	}
1739 
1740 	flush_altivec_to_thread(current);
1741 
1742 	PPC_WARN_EMULATED(altivec, regs);
1743 	err = emulate_altivec(regs);
1744 	if (err == 0) {
1745 		regs->nip += 4;		/* skip emulated instruction */
1746 		emulate_single_step(regs);
1747 		return;
1748 	}
1749 
1750 	if (err == -EFAULT) {
1751 		/* got an error reading the instruction */
1752 		_exception(SIGSEGV, regs, SEGV_ACCERR, regs->nip);
1753 	} else {
1754 		/* didn't recognize the instruction */
1755 		/* XXX quick hack for now: set the non-Java bit in the VSCR */
1756 		printk_ratelimited(KERN_ERR "Unrecognized altivec instruction "
1757 				   "in %s at %lx\n", current->comm, regs->nip);
1758 		current->thread.vr_state.vscr.u[3] |= 0x10000;
1759 	}
1760 }
1761 #endif /* CONFIG_ALTIVEC */
1762 
1763 #ifdef CONFIG_FSL_BOOKE
1764 void CacheLockingException(struct pt_regs *regs, unsigned long address,
1765 			   unsigned long error_code)
1766 {
1767 	/* We treat cache locking instructions from the user
1768 	 * as priv ops, in the future we could try to do
1769 	 * something smarter
1770 	 */
1771 	if (error_code & (ESR_DLK|ESR_ILK))
1772 		_exception(SIGILL, regs, ILL_PRVOPC, regs->nip);
1773 	return;
1774 }
1775 #endif /* CONFIG_FSL_BOOKE */
1776 
1777 #ifdef CONFIG_SPE
1778 void SPEFloatingPointException(struct pt_regs *regs)
1779 {
1780 	extern int do_spe_mathemu(struct pt_regs *regs);
1781 	unsigned long spefscr;
1782 	int fpexc_mode;
1783 	int code = 0;
1784 	int err;
1785 
1786 	flush_spe_to_thread(current);
1787 
1788 	spefscr = current->thread.spefscr;
1789 	fpexc_mode = current->thread.fpexc_mode;
1790 
1791 	if ((spefscr & SPEFSCR_FOVF) && (fpexc_mode & PR_FP_EXC_OVF)) {
1792 		code = FPE_FLTOVF;
1793 	}
1794 	else if ((spefscr & SPEFSCR_FUNF) && (fpexc_mode & PR_FP_EXC_UND)) {
1795 		code = FPE_FLTUND;
1796 	}
1797 	else if ((spefscr & SPEFSCR_FDBZ) && (fpexc_mode & PR_FP_EXC_DIV))
1798 		code = FPE_FLTDIV;
1799 	else if ((spefscr & SPEFSCR_FINV) && (fpexc_mode & PR_FP_EXC_INV)) {
1800 		code = FPE_FLTINV;
1801 	}
1802 	else if ((spefscr & (SPEFSCR_FG | SPEFSCR_FX)) && (fpexc_mode & PR_FP_EXC_RES))
1803 		code = FPE_FLTRES;
1804 
1805 	err = do_spe_mathemu(regs);
1806 	if (err == 0) {
1807 		regs->nip += 4;		/* skip emulated instruction */
1808 		emulate_single_step(regs);
1809 		return;
1810 	}
1811 
1812 	if (err == -EFAULT) {
1813 		/* got an error reading the instruction */
1814 		_exception(SIGSEGV, regs, SEGV_ACCERR, regs->nip);
1815 	} else if (err == -EINVAL) {
1816 		/* didn't recognize the instruction */
1817 		printk(KERN_ERR "unrecognized spe instruction "
1818 		       "in %s at %lx\n", current->comm, regs->nip);
1819 	} else {
1820 		_exception(SIGFPE, regs, code, regs->nip);
1821 	}
1822 
1823 	return;
1824 }
1825 
1826 void SPEFloatingPointRoundException(struct pt_regs *regs)
1827 {
1828 	extern int speround_handler(struct pt_regs *regs);
1829 	int err;
1830 
1831 	preempt_disable();
1832 	if (regs->msr & MSR_SPE)
1833 		giveup_spe(current);
1834 	preempt_enable();
1835 
1836 	regs->nip -= 4;
1837 	err = speround_handler(regs);
1838 	if (err == 0) {
1839 		regs->nip += 4;		/* skip emulated instruction */
1840 		emulate_single_step(regs);
1841 		return;
1842 	}
1843 
1844 	if (err == -EFAULT) {
1845 		/* got an error reading the instruction */
1846 		_exception(SIGSEGV, regs, SEGV_ACCERR, regs->nip);
1847 	} else if (err == -EINVAL) {
1848 		/* didn't recognize the instruction */
1849 		printk(KERN_ERR "unrecognized spe instruction "
1850 		       "in %s at %lx\n", current->comm, regs->nip);
1851 	} else {
1852 		_exception(SIGFPE, regs, 0, regs->nip);
1853 		return;
1854 	}
1855 }
1856 #endif
1857 
1858 /*
1859  * We enter here if we get an unrecoverable exception, that is, one
1860  * that happened at a point where the RI (recoverable interrupt) bit
1861  * in the MSR is 0.  This indicates that SRR0/1 are live, and that
1862  * we therefore lost state by taking this exception.
1863  */
1864 void unrecoverable_exception(struct pt_regs *regs)
1865 {
1866 	printk(KERN_EMERG "Unrecoverable exception %lx at %lx\n",
1867 	       regs->trap, regs->nip);
1868 	die("Unrecoverable exception", regs, SIGABRT);
1869 }
1870 
1871 #if defined(CONFIG_BOOKE_WDT) || defined(CONFIG_40x)
1872 /*
1873  * Default handler for a Watchdog exception,
1874  * spins until a reboot occurs
1875  */
1876 void __attribute__ ((weak)) WatchdogHandler(struct pt_regs *regs)
1877 {
1878 	/* Generic WatchdogHandler, implement your own */
1879 	mtspr(SPRN_TCR, mfspr(SPRN_TCR)&(~TCR_WIE));
1880 	return;
1881 }
1882 
1883 void WatchdogException(struct pt_regs *regs)
1884 {
1885 	printk (KERN_EMERG "PowerPC Book-E Watchdog Exception\n");
1886 	WatchdogHandler(regs);
1887 }
1888 #endif
1889 
1890 /*
1891  * We enter here if we discover during exception entry that we are
1892  * running in supervisor mode with a userspace value in the stack pointer.
1893  */
1894 void kernel_bad_stack(struct pt_regs *regs)
1895 {
1896 	printk(KERN_EMERG "Bad kernel stack pointer %lx at %lx\n",
1897 	       regs->gpr[1], regs->nip);
1898 	die("Bad kernel stack pointer", regs, SIGABRT);
1899 }
1900 
1901 void __init trap_init(void)
1902 {
1903 }
1904 
1905 
1906 #ifdef CONFIG_PPC_EMULATED_STATS
1907 
1908 #define WARN_EMULATED_SETUP(type)	.type = { .name = #type }
1909 
1910 struct ppc_emulated ppc_emulated = {
1911 #ifdef CONFIG_ALTIVEC
1912 	WARN_EMULATED_SETUP(altivec),
1913 #endif
1914 	WARN_EMULATED_SETUP(dcba),
1915 	WARN_EMULATED_SETUP(dcbz),
1916 	WARN_EMULATED_SETUP(fp_pair),
1917 	WARN_EMULATED_SETUP(isel),
1918 	WARN_EMULATED_SETUP(mcrxr),
1919 	WARN_EMULATED_SETUP(mfpvr),
1920 	WARN_EMULATED_SETUP(multiple),
1921 	WARN_EMULATED_SETUP(popcntb),
1922 	WARN_EMULATED_SETUP(spe),
1923 	WARN_EMULATED_SETUP(string),
1924 	WARN_EMULATED_SETUP(sync),
1925 	WARN_EMULATED_SETUP(unaligned),
1926 #ifdef CONFIG_MATH_EMULATION
1927 	WARN_EMULATED_SETUP(math),
1928 #endif
1929 #ifdef CONFIG_VSX
1930 	WARN_EMULATED_SETUP(vsx),
1931 #endif
1932 #ifdef CONFIG_PPC64
1933 	WARN_EMULATED_SETUP(mfdscr),
1934 	WARN_EMULATED_SETUP(mtdscr),
1935 	WARN_EMULATED_SETUP(lq_stq),
1936 #endif
1937 };
1938 
1939 u32 ppc_warn_emulated;
1940 
1941 void ppc_warn_emulated_print(const char *type)
1942 {
1943 	pr_warn_ratelimited("%s used emulated %s instruction\n", current->comm,
1944 			    type);
1945 }
1946 
1947 static int __init ppc_warn_emulated_init(void)
1948 {
1949 	struct dentry *dir, *d;
1950 	unsigned int i;
1951 	struct ppc_emulated_entry *entries = (void *)&ppc_emulated;
1952 
1953 	if (!powerpc_debugfs_root)
1954 		return -ENODEV;
1955 
1956 	dir = debugfs_create_dir("emulated_instructions",
1957 				 powerpc_debugfs_root);
1958 	if (!dir)
1959 		return -ENOMEM;
1960 
1961 	d = debugfs_create_u32("do_warn", S_IRUGO | S_IWUSR, dir,
1962 			       &ppc_warn_emulated);
1963 	if (!d)
1964 		goto fail;
1965 
1966 	for (i = 0; i < sizeof(ppc_emulated)/sizeof(*entries); i++) {
1967 		d = debugfs_create_u32(entries[i].name, S_IRUGO | S_IWUSR, dir,
1968 				       (u32 *)&entries[i].val.counter);
1969 		if (!d)
1970 			goto fail;
1971 	}
1972 
1973 	return 0;
1974 
1975 fail:
1976 	debugfs_remove_recursive(dir);
1977 	return -ENOMEM;
1978 }
1979 
1980 device_initcall(ppc_warn_emulated_init);
1981 
1982 #endif /* CONFIG_PPC_EMULATED_STATS */
1983