xref: /linux/arch/powerpc/kernel/traps.c (revision 4f58e6dceb0e44ca8f21568ed81e1df24e55964c)
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/extable.h>
29 #include <linux/module.h>	/* print_modules */
30 #include <linux/prctl.h>
31 #include <linux/delay.h>
32 #include <linux/kprobes.h>
33 #include <linux/kexec.h>
34 #include <linux/backlight.h>
35 #include <linux/bug.h>
36 #include <linux/kdebug.h>
37 #include <linux/debugfs.h>
38 #include <linux/ratelimit.h>
39 #include <linux/context_tracking.h>
40 
41 #include <asm/emulated_ops.h>
42 #include <asm/pgtable.h>
43 #include <asm/uaccess.h>
44 #include <asm/io.h>
45 #include <asm/machdep.h>
46 #include <asm/rtas.h>
47 #include <asm/pmc.h>
48 #include <asm/reg.h>
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 #include <asm/tm.h>
56 #endif
57 #include <asm/kexec.h>
58 #include <asm/ppc-opcode.h>
59 #include <asm/rio.h>
60 #include <asm/fadump.h>
61 #include <asm/switch_to.h>
62 #include <asm/tm.h>
63 #include <asm/debug.h>
64 #include <asm/asm-prototypes.h>
65 #include <asm/hmi.h>
66 #include <sysdev/fsl_pci.h>
67 
68 #if defined(CONFIG_DEBUGGER) || defined(CONFIG_KEXEC)
69 int (*__debugger)(struct pt_regs *regs) __read_mostly;
70 int (*__debugger_ipi)(struct pt_regs *regs) __read_mostly;
71 int (*__debugger_bpt)(struct pt_regs *regs) __read_mostly;
72 int (*__debugger_sstep)(struct pt_regs *regs) __read_mostly;
73 int (*__debugger_iabr_match)(struct pt_regs *regs) __read_mostly;
74 int (*__debugger_break_match)(struct pt_regs *regs) __read_mostly;
75 int (*__debugger_fault_handler)(struct pt_regs *regs) __read_mostly;
76 
77 EXPORT_SYMBOL(__debugger);
78 EXPORT_SYMBOL(__debugger_ipi);
79 EXPORT_SYMBOL(__debugger_bpt);
80 EXPORT_SYMBOL(__debugger_sstep);
81 EXPORT_SYMBOL(__debugger_iabr_match);
82 EXPORT_SYMBOL(__debugger_break_match);
83 EXPORT_SYMBOL(__debugger_fault_handler);
84 #endif
85 
86 /* Transactional Memory trap debug */
87 #ifdef TM_DEBUG_SW
88 #define TM_DEBUG(x...) printk(KERN_INFO x)
89 #else
90 #define TM_DEBUG(x...) do { } while(0)
91 #endif
92 
93 /*
94  * Trap & Exception support
95  */
96 
97 #ifdef CONFIG_PMAC_BACKLIGHT
98 static void pmac_backlight_unblank(void)
99 {
100 	mutex_lock(&pmac_backlight_mutex);
101 	if (pmac_backlight) {
102 		struct backlight_properties *props;
103 
104 		props = &pmac_backlight->props;
105 		props->brightness = props->max_brightness;
106 		props->power = FB_BLANK_UNBLANK;
107 		backlight_update_status(pmac_backlight);
108 	}
109 	mutex_unlock(&pmac_backlight_mutex);
110 }
111 #else
112 static inline void pmac_backlight_unblank(void) { }
113 #endif
114 
115 static arch_spinlock_t die_lock = __ARCH_SPIN_LOCK_UNLOCKED;
116 static int die_owner = -1;
117 static unsigned int die_nest_count;
118 static int die_counter;
119 
120 static unsigned long oops_begin(struct pt_regs *regs)
121 {
122 	int cpu;
123 	unsigned long flags;
124 
125 	if (debugger(regs))
126 		return 1;
127 
128 	oops_enter();
129 
130 	/* racy, but better than risking deadlock. */
131 	raw_local_irq_save(flags);
132 	cpu = smp_processor_id();
133 	if (!arch_spin_trylock(&die_lock)) {
134 		if (cpu == die_owner)
135 			/* nested oops. should stop eventually */;
136 		else
137 			arch_spin_lock(&die_lock);
138 	}
139 	die_nest_count++;
140 	die_owner = cpu;
141 	console_verbose();
142 	bust_spinlocks(1);
143 	if (machine_is(powermac))
144 		pmac_backlight_unblank();
145 	return flags;
146 }
147 NOKPROBE_SYMBOL(oops_begin);
148 
149 static void oops_end(unsigned long flags, struct pt_regs *regs,
150 			       int signr)
151 {
152 	bust_spinlocks(0);
153 	die_owner = -1;
154 	add_taint(TAINT_DIE, LOCKDEP_NOW_UNRELIABLE);
155 	die_nest_count--;
156 	oops_exit();
157 	printk("\n");
158 	if (!die_nest_count)
159 		/* Nest count reaches zero, release the lock. */
160 		arch_spin_unlock(&die_lock);
161 	raw_local_irq_restore(flags);
162 
163 	crash_fadump(regs, "die oops");
164 
165 	/*
166 	 * A system reset (0x100) is a request to dump, so we always send
167 	 * it through the crashdump code.
168 	 */
169 	if (kexec_should_crash(current) || (TRAP(regs) == 0x100)) {
170 		crash_kexec(regs);
171 
172 		/*
173 		 * We aren't the primary crash CPU. We need to send it
174 		 * to a holding pattern to avoid it ending up in the panic
175 		 * code.
176 		 */
177 		crash_kexec_secondary(regs);
178 	}
179 
180 	if (!signr)
181 		return;
182 
183 	/*
184 	 * While our oops output is serialised by a spinlock, output
185 	 * from panic() called below can race and corrupt it. If we
186 	 * know we are going to panic, delay for 1 second so we have a
187 	 * chance to get clean backtraces from all CPUs that are oopsing.
188 	 */
189 	if (in_interrupt() || panic_on_oops || !current->pid ||
190 	    is_global_init(current)) {
191 		mdelay(MSEC_PER_SEC);
192 	}
193 
194 	if (in_interrupt())
195 		panic("Fatal exception in interrupt");
196 	if (panic_on_oops)
197 		panic("Fatal exception");
198 	do_exit(signr);
199 }
200 NOKPROBE_SYMBOL(oops_end);
201 
202 static int __die(const char *str, struct pt_regs *regs, long err)
203 {
204 	printk("Oops: %s, sig: %ld [#%d]\n", str, err, ++die_counter);
205 #ifdef CONFIG_PREEMPT
206 	printk("PREEMPT ");
207 #endif
208 #ifdef CONFIG_SMP
209 	printk("SMP NR_CPUS=%d ", NR_CPUS);
210 #endif
211 	if (debug_pagealloc_enabled())
212 		printk("DEBUG_PAGEALLOC ");
213 #ifdef CONFIG_NUMA
214 	printk("NUMA ");
215 #endif
216 	printk("%s\n", ppc_md.name ? ppc_md.name : "");
217 
218 	if (notify_die(DIE_OOPS, str, regs, err, 255, SIGSEGV) == NOTIFY_STOP)
219 		return 1;
220 
221 	print_modules();
222 	show_regs(regs);
223 
224 	return 0;
225 }
226 NOKPROBE_SYMBOL(__die);
227 
228 void die(const char *str, struct pt_regs *regs, long err)
229 {
230 	unsigned long flags = oops_begin(regs);
231 
232 	if (__die(str, regs, err))
233 		err = 0;
234 	oops_end(flags, regs, err);
235 }
236 
237 void user_single_step_siginfo(struct task_struct *tsk,
238 				struct pt_regs *regs, siginfo_t *info)
239 {
240 	memset(info, 0, sizeof(*info));
241 	info->si_signo = SIGTRAP;
242 	info->si_code = TRAP_TRACE;
243 	info->si_addr = (void __user *)regs->nip;
244 }
245 
246 void _exception(int signr, struct pt_regs *regs, int code, unsigned long addr)
247 {
248 	siginfo_t info;
249 	const char fmt32[] = KERN_INFO "%s[%d]: unhandled signal %d " \
250 			"at %08lx nip %08lx lr %08lx code %x\n";
251 	const char fmt64[] = KERN_INFO "%s[%d]: unhandled signal %d " \
252 			"at %016lx nip %016lx lr %016lx code %x\n";
253 
254 	if (!user_mode(regs)) {
255 		die("Exception in kernel mode", regs, signr);
256 		return;
257 	}
258 
259 	if (show_unhandled_signals && unhandled_signal(current, signr)) {
260 		printk_ratelimited(regs->msr & MSR_64BIT ? fmt64 : fmt32,
261 				   current->comm, current->pid, signr,
262 				   addr, regs->nip, regs->link, code);
263 	}
264 
265 	if (arch_irqs_disabled() && !arch_irq_disabled_regs(regs))
266 		local_irq_enable();
267 
268 	current->thread.trap_nr = code;
269 	memset(&info, 0, sizeof(info));
270 	info.si_signo = signr;
271 	info.si_code = code;
272 	info.si_addr = (void __user *) addr;
273 	force_sig_info(signr, &info, current);
274 }
275 
276 #ifdef CONFIG_PPC64
277 void system_reset_exception(struct pt_regs *regs)
278 {
279 	/* See if any machine dependent calls */
280 	if (ppc_md.system_reset_exception) {
281 		if (ppc_md.system_reset_exception(regs))
282 			return;
283 	}
284 
285 	die("System Reset", regs, SIGABRT);
286 
287 	/* Must die if the interrupt is not recoverable */
288 	if (!(regs->msr & MSR_RI))
289 		panic("Unrecoverable System Reset");
290 
291 	/* What should we do here? We could issue a shutdown or hard reset. */
292 }
293 
294 /*
295  * This function is called in real mode. Strictly no printk's please.
296  *
297  * regs->nip and regs->msr contains srr0 and ssr1.
298  */
299 long machine_check_early(struct pt_regs *regs)
300 {
301 	long handled = 0;
302 
303 	__this_cpu_inc(irq_stat.mce_exceptions);
304 
305 	add_taint(TAINT_MACHINE_CHECK, LOCKDEP_NOW_UNRELIABLE);
306 
307 	if (cur_cpu_spec && cur_cpu_spec->machine_check_early)
308 		handled = cur_cpu_spec->machine_check_early(regs);
309 	return handled;
310 }
311 
312 long hmi_exception_realmode(struct pt_regs *regs)
313 {
314 	__this_cpu_inc(irq_stat.hmi_exceptions);
315 
316 	wait_for_subcore_guest_exit();
317 
318 	if (ppc_md.hmi_exception_early)
319 		ppc_md.hmi_exception_early(regs);
320 
321 	wait_for_tb_resync();
322 
323 	return 0;
324 }
325 
326 #endif
327 
328 /*
329  * I/O accesses can cause machine checks on powermacs.
330  * Check if the NIP corresponds to the address of a sync
331  * instruction for which there is an entry in the exception
332  * table.
333  * Note that the 601 only takes a machine check on TEA
334  * (transfer error ack) signal assertion, and does not
335  * set any of the top 16 bits of SRR1.
336  *  -- paulus.
337  */
338 static inline int check_io_access(struct pt_regs *regs)
339 {
340 #ifdef CONFIG_PPC32
341 	unsigned long msr = regs->msr;
342 	const struct exception_table_entry *entry;
343 	unsigned int *nip = (unsigned int *)regs->nip;
344 
345 	if (((msr & 0xffff0000) == 0 || (msr & (0x80000 | 0x40000)))
346 	    && (entry = search_exception_tables(regs->nip)) != NULL) {
347 		/*
348 		 * Check that it's a sync instruction, or somewhere
349 		 * in the twi; isync; nop sequence that inb/inw/inl uses.
350 		 * As the address is in the exception table
351 		 * we should be able to read the instr there.
352 		 * For the debug message, we look at the preceding
353 		 * load or store.
354 		 */
355 		if (*nip == 0x60000000)		/* nop */
356 			nip -= 2;
357 		else if (*nip == 0x4c00012c)	/* isync */
358 			--nip;
359 		if (*nip == 0x7c0004ac || (*nip >> 26) == 3) {
360 			/* sync or twi */
361 			unsigned int rb;
362 
363 			--nip;
364 			rb = (*nip >> 11) & 0x1f;
365 			printk(KERN_DEBUG "%s bad port %lx at %p\n",
366 			       (*nip & 0x100)? "OUT to": "IN from",
367 			       regs->gpr[rb] - _IO_BASE, nip);
368 			regs->msr |= MSR_RI;
369 			regs->nip = entry->fixup;
370 			return 1;
371 		}
372 	}
373 #endif /* CONFIG_PPC32 */
374 	return 0;
375 }
376 
377 #ifdef CONFIG_PPC_ADV_DEBUG_REGS
378 /* On 4xx, the reason for the machine check or program exception
379    is in the ESR. */
380 #define get_reason(regs)	((regs)->dsisr)
381 #ifndef CONFIG_FSL_BOOKE
382 #define get_mc_reason(regs)	((regs)->dsisr)
383 #else
384 #define get_mc_reason(regs)	(mfspr(SPRN_MCSR))
385 #endif
386 #define REASON_FP		ESR_FP
387 #define REASON_ILLEGAL		(ESR_PIL | ESR_PUO)
388 #define REASON_PRIVILEGED	ESR_PPR
389 #define REASON_TRAP		ESR_PTR
390 
391 /* single-step stuff */
392 #define single_stepping(regs)	(current->thread.debug.dbcr0 & DBCR0_IC)
393 #define clear_single_step(regs)	(current->thread.debug.dbcr0 &= ~DBCR0_IC)
394 
395 #else
396 /* On non-4xx, the reason for the machine check or program
397    exception is in the MSR. */
398 #define get_reason(regs)	((regs)->msr)
399 #define get_mc_reason(regs)	((regs)->msr)
400 #define REASON_TM		0x200000
401 #define REASON_FP		0x100000
402 #define REASON_ILLEGAL		0x80000
403 #define REASON_PRIVILEGED	0x40000
404 #define REASON_TRAP		0x20000
405 
406 #define single_stepping(regs)	((regs)->msr & MSR_SE)
407 #define clear_single_step(regs)	((regs)->msr &= ~MSR_SE)
408 #endif
409 
410 #if defined(CONFIG_4xx)
411 int machine_check_4xx(struct pt_regs *regs)
412 {
413 	unsigned long reason = get_mc_reason(regs);
414 
415 	if (reason & ESR_IMCP) {
416 		printk("Instruction");
417 		mtspr(SPRN_ESR, reason & ~ESR_IMCP);
418 	} else
419 		printk("Data");
420 	printk(" machine check in kernel mode.\n");
421 
422 	return 0;
423 }
424 
425 int machine_check_440A(struct pt_regs *regs)
426 {
427 	unsigned long reason = get_mc_reason(regs);
428 
429 	printk("Machine check in kernel mode.\n");
430 	if (reason & ESR_IMCP){
431 		printk("Instruction Synchronous Machine Check exception\n");
432 		mtspr(SPRN_ESR, reason & ~ESR_IMCP);
433 	}
434 	else {
435 		u32 mcsr = mfspr(SPRN_MCSR);
436 		if (mcsr & MCSR_IB)
437 			printk("Instruction Read PLB Error\n");
438 		if (mcsr & MCSR_DRB)
439 			printk("Data Read PLB Error\n");
440 		if (mcsr & MCSR_DWB)
441 			printk("Data Write PLB Error\n");
442 		if (mcsr & MCSR_TLBP)
443 			printk("TLB Parity Error\n");
444 		if (mcsr & MCSR_ICP){
445 			flush_instruction_cache();
446 			printk("I-Cache Parity Error\n");
447 		}
448 		if (mcsr & MCSR_DCSP)
449 			printk("D-Cache Search Parity Error\n");
450 		if (mcsr & MCSR_DCFP)
451 			printk("D-Cache Flush Parity Error\n");
452 		if (mcsr & MCSR_IMPE)
453 			printk("Machine Check exception is imprecise\n");
454 
455 		/* Clear MCSR */
456 		mtspr(SPRN_MCSR, mcsr);
457 	}
458 	return 0;
459 }
460 
461 int machine_check_47x(struct pt_regs *regs)
462 {
463 	unsigned long reason = get_mc_reason(regs);
464 	u32 mcsr;
465 
466 	printk(KERN_ERR "Machine check in kernel mode.\n");
467 	if (reason & ESR_IMCP) {
468 		printk(KERN_ERR
469 		       "Instruction Synchronous Machine Check exception\n");
470 		mtspr(SPRN_ESR, reason & ~ESR_IMCP);
471 		return 0;
472 	}
473 	mcsr = mfspr(SPRN_MCSR);
474 	if (mcsr & MCSR_IB)
475 		printk(KERN_ERR "Instruction Read PLB Error\n");
476 	if (mcsr & MCSR_DRB)
477 		printk(KERN_ERR "Data Read PLB Error\n");
478 	if (mcsr & MCSR_DWB)
479 		printk(KERN_ERR "Data Write PLB Error\n");
480 	if (mcsr & MCSR_TLBP)
481 		printk(KERN_ERR "TLB Parity Error\n");
482 	if (mcsr & MCSR_ICP) {
483 		flush_instruction_cache();
484 		printk(KERN_ERR "I-Cache Parity Error\n");
485 	}
486 	if (mcsr & MCSR_DCSP)
487 		printk(KERN_ERR "D-Cache Search Parity Error\n");
488 	if (mcsr & PPC47x_MCSR_GPR)
489 		printk(KERN_ERR "GPR Parity Error\n");
490 	if (mcsr & PPC47x_MCSR_FPR)
491 		printk(KERN_ERR "FPR Parity Error\n");
492 	if (mcsr & PPC47x_MCSR_IPR)
493 		printk(KERN_ERR "Machine Check exception is imprecise\n");
494 
495 	/* Clear MCSR */
496 	mtspr(SPRN_MCSR, mcsr);
497 
498 	return 0;
499 }
500 #elif defined(CONFIG_E500)
501 int machine_check_e500mc(struct pt_regs *regs)
502 {
503 	unsigned long mcsr = mfspr(SPRN_MCSR);
504 	unsigned long reason = mcsr;
505 	int recoverable = 1;
506 
507 	if (reason & MCSR_LD) {
508 		recoverable = fsl_rio_mcheck_exception(regs);
509 		if (recoverable == 1)
510 			goto silent_out;
511 	}
512 
513 	printk("Machine check in kernel mode.\n");
514 	printk("Caused by (from MCSR=%lx): ", reason);
515 
516 	if (reason & MCSR_MCP)
517 		printk("Machine Check Signal\n");
518 
519 	if (reason & MCSR_ICPERR) {
520 		printk("Instruction Cache Parity Error\n");
521 
522 		/*
523 		 * This is recoverable by invalidating the i-cache.
524 		 */
525 		mtspr(SPRN_L1CSR1, mfspr(SPRN_L1CSR1) | L1CSR1_ICFI);
526 		while (mfspr(SPRN_L1CSR1) & L1CSR1_ICFI)
527 			;
528 
529 		/*
530 		 * This will generally be accompanied by an instruction
531 		 * fetch error report -- only treat MCSR_IF as fatal
532 		 * if it wasn't due to an L1 parity error.
533 		 */
534 		reason &= ~MCSR_IF;
535 	}
536 
537 	if (reason & MCSR_DCPERR_MC) {
538 		printk("Data Cache Parity Error\n");
539 
540 		/*
541 		 * In write shadow mode we auto-recover from the error, but it
542 		 * may still get logged and cause a machine check.  We should
543 		 * only treat the non-write shadow case as non-recoverable.
544 		 */
545 		if (!(mfspr(SPRN_L1CSR2) & L1CSR2_DCWS))
546 			recoverable = 0;
547 	}
548 
549 	if (reason & MCSR_L2MMU_MHIT) {
550 		printk("Hit on multiple TLB entries\n");
551 		recoverable = 0;
552 	}
553 
554 	if (reason & MCSR_NMI)
555 		printk("Non-maskable interrupt\n");
556 
557 	if (reason & MCSR_IF) {
558 		printk("Instruction Fetch Error Report\n");
559 		recoverable = 0;
560 	}
561 
562 	if (reason & MCSR_LD) {
563 		printk("Load Error Report\n");
564 		recoverable = 0;
565 	}
566 
567 	if (reason & MCSR_ST) {
568 		printk("Store Error Report\n");
569 		recoverable = 0;
570 	}
571 
572 	if (reason & MCSR_LDG) {
573 		printk("Guarded Load Error Report\n");
574 		recoverable = 0;
575 	}
576 
577 	if (reason & MCSR_TLBSYNC)
578 		printk("Simultaneous tlbsync operations\n");
579 
580 	if (reason & MCSR_BSL2_ERR) {
581 		printk("Level 2 Cache Error\n");
582 		recoverable = 0;
583 	}
584 
585 	if (reason & MCSR_MAV) {
586 		u64 addr;
587 
588 		addr = mfspr(SPRN_MCAR);
589 		addr |= (u64)mfspr(SPRN_MCARU) << 32;
590 
591 		printk("Machine Check %s Address: %#llx\n",
592 		       reason & MCSR_MEA ? "Effective" : "Physical", addr);
593 	}
594 
595 silent_out:
596 	mtspr(SPRN_MCSR, mcsr);
597 	return mfspr(SPRN_MCSR) == 0 && recoverable;
598 }
599 
600 int machine_check_e500(struct pt_regs *regs)
601 {
602 	unsigned long reason = get_mc_reason(regs);
603 
604 	if (reason & MCSR_BUS_RBERR) {
605 		if (fsl_rio_mcheck_exception(regs))
606 			return 1;
607 		if (fsl_pci_mcheck_exception(regs))
608 			return 1;
609 	}
610 
611 	printk("Machine check in kernel mode.\n");
612 	printk("Caused by (from MCSR=%lx): ", reason);
613 
614 	if (reason & MCSR_MCP)
615 		printk("Machine Check Signal\n");
616 	if (reason & MCSR_ICPERR)
617 		printk("Instruction Cache Parity Error\n");
618 	if (reason & MCSR_DCP_PERR)
619 		printk("Data Cache Push Parity Error\n");
620 	if (reason & MCSR_DCPERR)
621 		printk("Data Cache Parity Error\n");
622 	if (reason & MCSR_BUS_IAERR)
623 		printk("Bus - Instruction Address Error\n");
624 	if (reason & MCSR_BUS_RAERR)
625 		printk("Bus - Read Address Error\n");
626 	if (reason & MCSR_BUS_WAERR)
627 		printk("Bus - Write Address Error\n");
628 	if (reason & MCSR_BUS_IBERR)
629 		printk("Bus - Instruction Data Error\n");
630 	if (reason & MCSR_BUS_RBERR)
631 		printk("Bus - Read Data Bus Error\n");
632 	if (reason & MCSR_BUS_WBERR)
633 		printk("Bus - Write Data Bus Error\n");
634 	if (reason & MCSR_BUS_IPERR)
635 		printk("Bus - Instruction Parity Error\n");
636 	if (reason & MCSR_BUS_RPERR)
637 		printk("Bus - Read Parity Error\n");
638 
639 	return 0;
640 }
641 
642 int machine_check_generic(struct pt_regs *regs)
643 {
644 	return 0;
645 }
646 #elif defined(CONFIG_E200)
647 int machine_check_e200(struct pt_regs *regs)
648 {
649 	unsigned long reason = get_mc_reason(regs);
650 
651 	printk("Machine check in kernel mode.\n");
652 	printk("Caused by (from MCSR=%lx): ", reason);
653 
654 	if (reason & MCSR_MCP)
655 		printk("Machine Check Signal\n");
656 	if (reason & MCSR_CP_PERR)
657 		printk("Cache Push Parity Error\n");
658 	if (reason & MCSR_CPERR)
659 		printk("Cache Parity Error\n");
660 	if (reason & MCSR_EXCP_ERR)
661 		printk("ISI, ITLB, or Bus Error on first instruction fetch for an exception handler\n");
662 	if (reason & MCSR_BUS_IRERR)
663 		printk("Bus - Read Bus Error on instruction fetch\n");
664 	if (reason & MCSR_BUS_DRERR)
665 		printk("Bus - Read Bus Error on data load\n");
666 	if (reason & MCSR_BUS_WRERR)
667 		printk("Bus - Write Bus Error on buffered store or cache line push\n");
668 
669 	return 0;
670 }
671 #else
672 int machine_check_generic(struct pt_regs *regs)
673 {
674 	unsigned long reason = get_mc_reason(regs);
675 
676 	printk("Machine check in kernel mode.\n");
677 	printk("Caused by (from SRR1=%lx): ", reason);
678 	switch (reason & 0x601F0000) {
679 	case 0x80000:
680 		printk("Machine check signal\n");
681 		break;
682 	case 0:		/* for 601 */
683 	case 0x40000:
684 	case 0x140000:	/* 7450 MSS error and TEA */
685 		printk("Transfer error ack signal\n");
686 		break;
687 	case 0x20000:
688 		printk("Data parity error signal\n");
689 		break;
690 	case 0x10000:
691 		printk("Address parity error signal\n");
692 		break;
693 	case 0x20000000:
694 		printk("L1 Data Cache error\n");
695 		break;
696 	case 0x40000000:
697 		printk("L1 Instruction Cache error\n");
698 		break;
699 	case 0x00100000:
700 		printk("L2 data cache parity error\n");
701 		break;
702 	default:
703 		printk("Unknown values in msr\n");
704 	}
705 	return 0;
706 }
707 #endif /* everything else */
708 
709 void machine_check_exception(struct pt_regs *regs)
710 {
711 	enum ctx_state prev_state = exception_enter();
712 	int recover = 0;
713 
714 	__this_cpu_inc(irq_stat.mce_exceptions);
715 
716 	/* See if any machine dependent calls. In theory, we would want
717 	 * to call the CPU first, and call the ppc_md. one if the CPU
718 	 * one returns a positive number. However there is existing code
719 	 * that assumes the board gets a first chance, so let's keep it
720 	 * that way for now and fix things later. --BenH.
721 	 */
722 	if (ppc_md.machine_check_exception)
723 		recover = ppc_md.machine_check_exception(regs);
724 	else if (cur_cpu_spec->machine_check)
725 		recover = cur_cpu_spec->machine_check(regs);
726 
727 	if (recover > 0)
728 		goto bail;
729 
730 #if defined(CONFIG_8xx) && defined(CONFIG_PCI)
731 	/* the qspan pci read routines can cause machine checks -- Cort
732 	 *
733 	 * yuck !!! that totally needs to go away ! There are better ways
734 	 * to deal with that than having a wart in the mcheck handler.
735 	 * -- BenH
736 	 */
737 	bad_page_fault(regs, regs->dar, SIGBUS);
738 	goto bail;
739 #endif
740 
741 	if (debugger_fault_handler(regs))
742 		goto bail;
743 
744 	if (check_io_access(regs))
745 		goto bail;
746 
747 	die("Machine check", regs, SIGBUS);
748 
749 	/* Must die if the interrupt is not recoverable */
750 	if (!(regs->msr & MSR_RI))
751 		panic("Unrecoverable Machine check");
752 
753 bail:
754 	exception_exit(prev_state);
755 }
756 
757 void SMIException(struct pt_regs *regs)
758 {
759 	die("System Management Interrupt", regs, SIGABRT);
760 }
761 
762 void handle_hmi_exception(struct pt_regs *regs)
763 {
764 	struct pt_regs *old_regs;
765 
766 	old_regs = set_irq_regs(regs);
767 	irq_enter();
768 
769 	if (ppc_md.handle_hmi_exception)
770 		ppc_md.handle_hmi_exception(regs);
771 
772 	irq_exit();
773 	set_irq_regs(old_regs);
774 }
775 
776 void unknown_exception(struct pt_regs *regs)
777 {
778 	enum ctx_state prev_state = exception_enter();
779 
780 	printk("Bad trap at PC: %lx, SR: %lx, vector=%lx\n",
781 	       regs->nip, regs->msr, regs->trap);
782 
783 	_exception(SIGTRAP, regs, 0, 0);
784 
785 	exception_exit(prev_state);
786 }
787 
788 void instruction_breakpoint_exception(struct pt_regs *regs)
789 {
790 	enum ctx_state prev_state = exception_enter();
791 
792 	if (notify_die(DIE_IABR_MATCH, "iabr_match", regs, 5,
793 					5, SIGTRAP) == NOTIFY_STOP)
794 		goto bail;
795 	if (debugger_iabr_match(regs))
796 		goto bail;
797 	_exception(SIGTRAP, regs, TRAP_BRKPT, regs->nip);
798 
799 bail:
800 	exception_exit(prev_state);
801 }
802 
803 void RunModeException(struct pt_regs *regs)
804 {
805 	_exception(SIGTRAP, regs, 0, 0);
806 }
807 
808 void single_step_exception(struct pt_regs *regs)
809 {
810 	enum ctx_state prev_state = exception_enter();
811 
812 	clear_single_step(regs);
813 
814 	if (notify_die(DIE_SSTEP, "single_step", regs, 5,
815 					5, SIGTRAP) == NOTIFY_STOP)
816 		goto bail;
817 	if (debugger_sstep(regs))
818 		goto bail;
819 
820 	_exception(SIGTRAP, regs, TRAP_TRACE, regs->nip);
821 
822 bail:
823 	exception_exit(prev_state);
824 }
825 NOKPROBE_SYMBOL(single_step_exception);
826 
827 /*
828  * After we have successfully emulated an instruction, we have to
829  * check if the instruction was being single-stepped, and if so,
830  * pretend we got a single-step exception.  This was pointed out
831  * by Kumar Gala.  -- paulus
832  */
833 static void emulate_single_step(struct pt_regs *regs)
834 {
835 	if (single_stepping(regs))
836 		single_step_exception(regs);
837 }
838 
839 static inline int __parse_fpscr(unsigned long fpscr)
840 {
841 	int ret = 0;
842 
843 	/* Invalid operation */
844 	if ((fpscr & FPSCR_VE) && (fpscr & FPSCR_VX))
845 		ret = FPE_FLTINV;
846 
847 	/* Overflow */
848 	else if ((fpscr & FPSCR_OE) && (fpscr & FPSCR_OX))
849 		ret = FPE_FLTOVF;
850 
851 	/* Underflow */
852 	else if ((fpscr & FPSCR_UE) && (fpscr & FPSCR_UX))
853 		ret = FPE_FLTUND;
854 
855 	/* Divide by zero */
856 	else if ((fpscr & FPSCR_ZE) && (fpscr & FPSCR_ZX))
857 		ret = FPE_FLTDIV;
858 
859 	/* Inexact result */
860 	else if ((fpscr & FPSCR_XE) && (fpscr & FPSCR_XX))
861 		ret = FPE_FLTRES;
862 
863 	return ret;
864 }
865 
866 static void parse_fpe(struct pt_regs *regs)
867 {
868 	int code = 0;
869 
870 	flush_fp_to_thread(current);
871 
872 	code = __parse_fpscr(current->thread.fp_state.fpscr);
873 
874 	_exception(SIGFPE, regs, code, regs->nip);
875 }
876 
877 /*
878  * Illegal instruction emulation support.  Originally written to
879  * provide the PVR to user applications using the mfspr rd, PVR.
880  * Return non-zero if we can't emulate, or -EFAULT if the associated
881  * memory access caused an access fault.  Return zero on success.
882  *
883  * There are a couple of ways to do this, either "decode" the instruction
884  * or directly match lots of bits.  In this case, matching lots of
885  * bits is faster and easier.
886  *
887  */
888 static int emulate_string_inst(struct pt_regs *regs, u32 instword)
889 {
890 	u8 rT = (instword >> 21) & 0x1f;
891 	u8 rA = (instword >> 16) & 0x1f;
892 	u8 NB_RB = (instword >> 11) & 0x1f;
893 	u32 num_bytes;
894 	unsigned long EA;
895 	int pos = 0;
896 
897 	/* Early out if we are an invalid form of lswx */
898 	if ((instword & PPC_INST_STRING_MASK) == PPC_INST_LSWX)
899 		if ((rT == rA) || (rT == NB_RB))
900 			return -EINVAL;
901 
902 	EA = (rA == 0) ? 0 : regs->gpr[rA];
903 
904 	switch (instword & PPC_INST_STRING_MASK) {
905 		case PPC_INST_LSWX:
906 		case PPC_INST_STSWX:
907 			EA += NB_RB;
908 			num_bytes = regs->xer & 0x7f;
909 			break;
910 		case PPC_INST_LSWI:
911 		case PPC_INST_STSWI:
912 			num_bytes = (NB_RB == 0) ? 32 : NB_RB;
913 			break;
914 		default:
915 			return -EINVAL;
916 	}
917 
918 	while (num_bytes != 0)
919 	{
920 		u8 val;
921 		u32 shift = 8 * (3 - (pos & 0x3));
922 
923 		/* if process is 32-bit, clear upper 32 bits of EA */
924 		if ((regs->msr & MSR_64BIT) == 0)
925 			EA &= 0xFFFFFFFF;
926 
927 		switch ((instword & PPC_INST_STRING_MASK)) {
928 			case PPC_INST_LSWX:
929 			case PPC_INST_LSWI:
930 				if (get_user(val, (u8 __user *)EA))
931 					return -EFAULT;
932 				/* first time updating this reg,
933 				 * zero it out */
934 				if (pos == 0)
935 					regs->gpr[rT] = 0;
936 				regs->gpr[rT] |= val << shift;
937 				break;
938 			case PPC_INST_STSWI:
939 			case PPC_INST_STSWX:
940 				val = regs->gpr[rT] >> shift;
941 				if (put_user(val, (u8 __user *)EA))
942 					return -EFAULT;
943 				break;
944 		}
945 		/* move EA to next address */
946 		EA += 1;
947 		num_bytes--;
948 
949 		/* manage our position within the register */
950 		if (++pos == 4) {
951 			pos = 0;
952 			if (++rT == 32)
953 				rT = 0;
954 		}
955 	}
956 
957 	return 0;
958 }
959 
960 static int emulate_popcntb_inst(struct pt_regs *regs, u32 instword)
961 {
962 	u32 ra,rs;
963 	unsigned long tmp;
964 
965 	ra = (instword >> 16) & 0x1f;
966 	rs = (instword >> 21) & 0x1f;
967 
968 	tmp = regs->gpr[rs];
969 	tmp = tmp - ((tmp >> 1) & 0x5555555555555555ULL);
970 	tmp = (tmp & 0x3333333333333333ULL) + ((tmp >> 2) & 0x3333333333333333ULL);
971 	tmp = (tmp + (tmp >> 4)) & 0x0f0f0f0f0f0f0f0fULL;
972 	regs->gpr[ra] = tmp;
973 
974 	return 0;
975 }
976 
977 static int emulate_isel(struct pt_regs *regs, u32 instword)
978 {
979 	u8 rT = (instword >> 21) & 0x1f;
980 	u8 rA = (instword >> 16) & 0x1f;
981 	u8 rB = (instword >> 11) & 0x1f;
982 	u8 BC = (instword >> 6) & 0x1f;
983 	u8 bit;
984 	unsigned long tmp;
985 
986 	tmp = (rA == 0) ? 0 : regs->gpr[rA];
987 	bit = (regs->ccr >> (31 - BC)) & 0x1;
988 
989 	regs->gpr[rT] = bit ? tmp : regs->gpr[rB];
990 
991 	return 0;
992 }
993 
994 #ifdef CONFIG_PPC_TRANSACTIONAL_MEM
995 static inline bool tm_abort_check(struct pt_regs *regs, int cause)
996 {
997         /* If we're emulating a load/store in an active transaction, we cannot
998          * emulate it as the kernel operates in transaction suspended context.
999          * We need to abort the transaction.  This creates a persistent TM
1000          * abort so tell the user what caused it with a new code.
1001 	 */
1002 	if (MSR_TM_TRANSACTIONAL(regs->msr)) {
1003 		tm_enable();
1004 		tm_abort(cause);
1005 		return true;
1006 	}
1007 	return false;
1008 }
1009 #else
1010 static inline bool tm_abort_check(struct pt_regs *regs, int reason)
1011 {
1012 	return false;
1013 }
1014 #endif
1015 
1016 static int emulate_instruction(struct pt_regs *regs)
1017 {
1018 	u32 instword;
1019 	u32 rd;
1020 
1021 	if (!user_mode(regs))
1022 		return -EINVAL;
1023 	CHECK_FULL_REGS(regs);
1024 
1025 	if (get_user(instword, (u32 __user *)(regs->nip)))
1026 		return -EFAULT;
1027 
1028 	/* Emulate the mfspr rD, PVR. */
1029 	if ((instword & PPC_INST_MFSPR_PVR_MASK) == PPC_INST_MFSPR_PVR) {
1030 		PPC_WARN_EMULATED(mfpvr, regs);
1031 		rd = (instword >> 21) & 0x1f;
1032 		regs->gpr[rd] = mfspr(SPRN_PVR);
1033 		return 0;
1034 	}
1035 
1036 	/* Emulating the dcba insn is just a no-op.  */
1037 	if ((instword & PPC_INST_DCBA_MASK) == PPC_INST_DCBA) {
1038 		PPC_WARN_EMULATED(dcba, regs);
1039 		return 0;
1040 	}
1041 
1042 	/* Emulate the mcrxr insn.  */
1043 	if ((instword & PPC_INST_MCRXR_MASK) == PPC_INST_MCRXR) {
1044 		int shift = (instword >> 21) & 0x1c;
1045 		unsigned long msk = 0xf0000000UL >> shift;
1046 
1047 		PPC_WARN_EMULATED(mcrxr, regs);
1048 		regs->ccr = (regs->ccr & ~msk) | ((regs->xer >> shift) & msk);
1049 		regs->xer &= ~0xf0000000UL;
1050 		return 0;
1051 	}
1052 
1053 	/* Emulate load/store string insn. */
1054 	if ((instword & PPC_INST_STRING_GEN_MASK) == PPC_INST_STRING) {
1055 		if (tm_abort_check(regs,
1056 				   TM_CAUSE_EMULATE | TM_CAUSE_PERSISTENT))
1057 			return -EINVAL;
1058 		PPC_WARN_EMULATED(string, regs);
1059 		return emulate_string_inst(regs, instword);
1060 	}
1061 
1062 	/* Emulate the popcntb (Population Count Bytes) instruction. */
1063 	if ((instword & PPC_INST_POPCNTB_MASK) == PPC_INST_POPCNTB) {
1064 		PPC_WARN_EMULATED(popcntb, regs);
1065 		return emulate_popcntb_inst(regs, instword);
1066 	}
1067 
1068 	/* Emulate isel (Integer Select) instruction */
1069 	if ((instword & PPC_INST_ISEL_MASK) == PPC_INST_ISEL) {
1070 		PPC_WARN_EMULATED(isel, regs);
1071 		return emulate_isel(regs, instword);
1072 	}
1073 
1074 	/* Emulate sync instruction variants */
1075 	if ((instword & PPC_INST_SYNC_MASK) == PPC_INST_SYNC) {
1076 		PPC_WARN_EMULATED(sync, regs);
1077 		asm volatile("sync");
1078 		return 0;
1079 	}
1080 
1081 #ifdef CONFIG_PPC64
1082 	/* Emulate the mfspr rD, DSCR. */
1083 	if ((((instword & PPC_INST_MFSPR_DSCR_USER_MASK) ==
1084 		PPC_INST_MFSPR_DSCR_USER) ||
1085 	     ((instword & PPC_INST_MFSPR_DSCR_MASK) ==
1086 		PPC_INST_MFSPR_DSCR)) &&
1087 			cpu_has_feature(CPU_FTR_DSCR)) {
1088 		PPC_WARN_EMULATED(mfdscr, regs);
1089 		rd = (instword >> 21) & 0x1f;
1090 		regs->gpr[rd] = mfspr(SPRN_DSCR);
1091 		return 0;
1092 	}
1093 	/* Emulate the mtspr DSCR, rD. */
1094 	if ((((instword & PPC_INST_MTSPR_DSCR_USER_MASK) ==
1095 		PPC_INST_MTSPR_DSCR_USER) ||
1096 	     ((instword & PPC_INST_MTSPR_DSCR_MASK) ==
1097 		PPC_INST_MTSPR_DSCR)) &&
1098 			cpu_has_feature(CPU_FTR_DSCR)) {
1099 		PPC_WARN_EMULATED(mtdscr, regs);
1100 		rd = (instword >> 21) & 0x1f;
1101 		current->thread.dscr = regs->gpr[rd];
1102 		current->thread.dscr_inherit = 1;
1103 		mtspr(SPRN_DSCR, current->thread.dscr);
1104 		return 0;
1105 	}
1106 #endif
1107 
1108 	return -EINVAL;
1109 }
1110 
1111 int is_valid_bugaddr(unsigned long addr)
1112 {
1113 	return is_kernel_addr(addr);
1114 }
1115 
1116 #ifdef CONFIG_MATH_EMULATION
1117 static int emulate_math(struct pt_regs *regs)
1118 {
1119 	int ret;
1120 	extern int do_mathemu(struct pt_regs *regs);
1121 
1122 	ret = do_mathemu(regs);
1123 	if (ret >= 0)
1124 		PPC_WARN_EMULATED(math, regs);
1125 
1126 	switch (ret) {
1127 	case 0:
1128 		emulate_single_step(regs);
1129 		return 0;
1130 	case 1: {
1131 			int code = 0;
1132 			code = __parse_fpscr(current->thread.fp_state.fpscr);
1133 			_exception(SIGFPE, regs, code, regs->nip);
1134 			return 0;
1135 		}
1136 	case -EFAULT:
1137 		_exception(SIGSEGV, regs, SEGV_MAPERR, regs->nip);
1138 		return 0;
1139 	}
1140 
1141 	return -1;
1142 }
1143 #else
1144 static inline int emulate_math(struct pt_regs *regs) { return -1; }
1145 #endif
1146 
1147 void program_check_exception(struct pt_regs *regs)
1148 {
1149 	enum ctx_state prev_state = exception_enter();
1150 	unsigned int reason = get_reason(regs);
1151 
1152 	/* We can now get here via a FP Unavailable exception if the core
1153 	 * has no FPU, in that case the reason flags will be 0 */
1154 
1155 	if (reason & REASON_FP) {
1156 		/* IEEE FP exception */
1157 		parse_fpe(regs);
1158 		goto bail;
1159 	}
1160 	if (reason & REASON_TRAP) {
1161 		unsigned long bugaddr;
1162 		/* Debugger is first in line to stop recursive faults in
1163 		 * rcu_lock, notify_die, or atomic_notifier_call_chain */
1164 		if (debugger_bpt(regs))
1165 			goto bail;
1166 
1167 		/* trap exception */
1168 		if (notify_die(DIE_BPT, "breakpoint", regs, 5, 5, SIGTRAP)
1169 				== NOTIFY_STOP)
1170 			goto bail;
1171 
1172 		bugaddr = regs->nip;
1173 		/*
1174 		 * Fixup bugaddr for BUG_ON() in real mode
1175 		 */
1176 		if (!is_kernel_addr(bugaddr) && !(regs->msr & MSR_IR))
1177 			bugaddr += PAGE_OFFSET;
1178 
1179 		if (!(regs->msr & MSR_PR) &&  /* not user-mode */
1180 		    report_bug(bugaddr, regs) == BUG_TRAP_TYPE_WARN) {
1181 			regs->nip += 4;
1182 			goto bail;
1183 		}
1184 		_exception(SIGTRAP, regs, TRAP_BRKPT, regs->nip);
1185 		goto bail;
1186 	}
1187 #ifdef CONFIG_PPC_TRANSACTIONAL_MEM
1188 	if (reason & REASON_TM) {
1189 		/* This is a TM "Bad Thing Exception" program check.
1190 		 * This occurs when:
1191 		 * -  An rfid/hrfid/mtmsrd attempts to cause an illegal
1192 		 *    transition in TM states.
1193 		 * -  A trechkpt is attempted when transactional.
1194 		 * -  A treclaim is attempted when non transactional.
1195 		 * -  A tend is illegally attempted.
1196 		 * -  writing a TM SPR when transactional.
1197 		 */
1198 		if (!user_mode(regs) &&
1199 		    report_bug(regs->nip, regs) == BUG_TRAP_TYPE_WARN) {
1200 			regs->nip += 4;
1201 			goto bail;
1202 		}
1203 		/* If usermode caused this, it's done something illegal and
1204 		 * gets a SIGILL slap on the wrist.  We call it an illegal
1205 		 * operand to distinguish from the instruction just being bad
1206 		 * (e.g. executing a 'tend' on a CPU without TM!); it's an
1207 		 * illegal /placement/ of a valid instruction.
1208 		 */
1209 		if (user_mode(regs)) {
1210 			_exception(SIGILL, regs, ILL_ILLOPN, regs->nip);
1211 			goto bail;
1212 		} else {
1213 			printk(KERN_EMERG "Unexpected TM Bad Thing exception "
1214 			       "at %lx (msr 0x%x)\n", regs->nip, reason);
1215 			die("Unrecoverable exception", regs, SIGABRT);
1216 		}
1217 	}
1218 #endif
1219 
1220 	/*
1221 	 * If we took the program check in the kernel skip down to sending a
1222 	 * SIGILL. The subsequent cases all relate to emulating instructions
1223 	 * which we should only do for userspace. We also do not want to enable
1224 	 * interrupts for kernel faults because that might lead to further
1225 	 * faults, and loose the context of the original exception.
1226 	 */
1227 	if (!user_mode(regs))
1228 		goto sigill;
1229 
1230 	/* We restore the interrupt state now */
1231 	if (!arch_irq_disabled_regs(regs))
1232 		local_irq_enable();
1233 
1234 	/* (reason & REASON_ILLEGAL) would be the obvious thing here,
1235 	 * but there seems to be a hardware bug on the 405GP (RevD)
1236 	 * that means ESR is sometimes set incorrectly - either to
1237 	 * ESR_DST (!?) or 0.  In the process of chasing this with the
1238 	 * hardware people - not sure if it can happen on any illegal
1239 	 * instruction or only on FP instructions, whether there is a
1240 	 * pattern to occurrences etc. -dgibson 31/Mar/2003
1241 	 */
1242 	if (!emulate_math(regs))
1243 		goto bail;
1244 
1245 	/* Try to emulate it if we should. */
1246 	if (reason & (REASON_ILLEGAL | REASON_PRIVILEGED)) {
1247 		switch (emulate_instruction(regs)) {
1248 		case 0:
1249 			regs->nip += 4;
1250 			emulate_single_step(regs);
1251 			goto bail;
1252 		case -EFAULT:
1253 			_exception(SIGSEGV, regs, SEGV_MAPERR, regs->nip);
1254 			goto bail;
1255 		}
1256 	}
1257 
1258 sigill:
1259 	if (reason & REASON_PRIVILEGED)
1260 		_exception(SIGILL, regs, ILL_PRVOPC, regs->nip);
1261 	else
1262 		_exception(SIGILL, regs, ILL_ILLOPC, regs->nip);
1263 
1264 bail:
1265 	exception_exit(prev_state);
1266 }
1267 NOKPROBE_SYMBOL(program_check_exception);
1268 
1269 /*
1270  * This occurs when running in hypervisor mode on POWER6 or later
1271  * and an illegal instruction is encountered.
1272  */
1273 void emulation_assist_interrupt(struct pt_regs *regs)
1274 {
1275 	regs->msr |= REASON_ILLEGAL;
1276 	program_check_exception(regs);
1277 }
1278 NOKPROBE_SYMBOL(emulation_assist_interrupt);
1279 
1280 void alignment_exception(struct pt_regs *regs)
1281 {
1282 	enum ctx_state prev_state = exception_enter();
1283 	int sig, code, fixed = 0;
1284 
1285 	/* We restore the interrupt state now */
1286 	if (!arch_irq_disabled_regs(regs))
1287 		local_irq_enable();
1288 
1289 	if (tm_abort_check(regs, TM_CAUSE_ALIGNMENT | TM_CAUSE_PERSISTENT))
1290 		goto bail;
1291 
1292 	/* we don't implement logging of alignment exceptions */
1293 	if (!(current->thread.align_ctl & PR_UNALIGN_SIGBUS))
1294 		fixed = fix_alignment(regs);
1295 
1296 	if (fixed == 1) {
1297 		regs->nip += 4;	/* skip over emulated instruction */
1298 		emulate_single_step(regs);
1299 		goto bail;
1300 	}
1301 
1302 	/* Operand address was bad */
1303 	if (fixed == -EFAULT) {
1304 		sig = SIGSEGV;
1305 		code = SEGV_ACCERR;
1306 	} else {
1307 		sig = SIGBUS;
1308 		code = BUS_ADRALN;
1309 	}
1310 	if (user_mode(regs))
1311 		_exception(sig, regs, code, regs->dar);
1312 	else
1313 		bad_page_fault(regs, regs->dar, sig);
1314 
1315 bail:
1316 	exception_exit(prev_state);
1317 }
1318 
1319 void slb_miss_bad_addr(struct pt_regs *regs)
1320 {
1321 	enum ctx_state prev_state = exception_enter();
1322 
1323 	if (user_mode(regs))
1324 		_exception(SIGSEGV, regs, SEGV_BNDERR, regs->dar);
1325 	else
1326 		bad_page_fault(regs, regs->dar, SIGSEGV);
1327 
1328 	exception_exit(prev_state);
1329 }
1330 
1331 void StackOverflow(struct pt_regs *regs)
1332 {
1333 	printk(KERN_CRIT "Kernel stack overflow in process %p, r1=%lx\n",
1334 	       current, regs->gpr[1]);
1335 	debugger(regs);
1336 	show_regs(regs);
1337 	panic("kernel stack overflow");
1338 }
1339 
1340 void nonrecoverable_exception(struct pt_regs *regs)
1341 {
1342 	printk(KERN_ERR "Non-recoverable exception at PC=%lx MSR=%lx\n",
1343 	       regs->nip, regs->msr);
1344 	debugger(regs);
1345 	die("nonrecoverable exception", regs, SIGKILL);
1346 }
1347 
1348 void kernel_fp_unavailable_exception(struct pt_regs *regs)
1349 {
1350 	enum ctx_state prev_state = exception_enter();
1351 
1352 	printk(KERN_EMERG "Unrecoverable FP Unavailable Exception "
1353 			  "%lx at %lx\n", regs->trap, regs->nip);
1354 	die("Unrecoverable FP Unavailable Exception", regs, SIGABRT);
1355 
1356 	exception_exit(prev_state);
1357 }
1358 
1359 void altivec_unavailable_exception(struct pt_regs *regs)
1360 {
1361 	enum ctx_state prev_state = exception_enter();
1362 
1363 	if (user_mode(regs)) {
1364 		/* A user program has executed an altivec instruction,
1365 		   but this kernel doesn't support altivec. */
1366 		_exception(SIGILL, regs, ILL_ILLOPC, regs->nip);
1367 		goto bail;
1368 	}
1369 
1370 	printk(KERN_EMERG "Unrecoverable VMX/Altivec Unavailable Exception "
1371 			"%lx at %lx\n", regs->trap, regs->nip);
1372 	die("Unrecoverable VMX/Altivec Unavailable Exception", regs, SIGABRT);
1373 
1374 bail:
1375 	exception_exit(prev_state);
1376 }
1377 
1378 void vsx_unavailable_exception(struct pt_regs *regs)
1379 {
1380 	if (user_mode(regs)) {
1381 		/* A user program has executed an vsx instruction,
1382 		   but this kernel doesn't support vsx. */
1383 		_exception(SIGILL, regs, ILL_ILLOPC, regs->nip);
1384 		return;
1385 	}
1386 
1387 	printk(KERN_EMERG "Unrecoverable VSX Unavailable Exception "
1388 			"%lx at %lx\n", regs->trap, regs->nip);
1389 	die("Unrecoverable VSX Unavailable Exception", regs, SIGABRT);
1390 }
1391 
1392 #ifdef CONFIG_PPC64
1393 static void tm_unavailable(struct pt_regs *regs)
1394 {
1395 #ifdef CONFIG_PPC_TRANSACTIONAL_MEM
1396 	if (user_mode(regs)) {
1397 		current->thread.load_tm++;
1398 		regs->msr |= MSR_TM;
1399 		tm_enable();
1400 		tm_restore_sprs(&current->thread);
1401 		return;
1402 	}
1403 #endif
1404 	pr_emerg("Unrecoverable TM Unavailable Exception "
1405 			"%lx at %lx\n", regs->trap, regs->nip);
1406 	die("Unrecoverable TM Unavailable Exception", regs, SIGABRT);
1407 }
1408 
1409 void facility_unavailable_exception(struct pt_regs *regs)
1410 {
1411 	static char *facility_strings[] = {
1412 		[FSCR_FP_LG] = "FPU",
1413 		[FSCR_VECVSX_LG] = "VMX/VSX",
1414 		[FSCR_DSCR_LG] = "DSCR",
1415 		[FSCR_PM_LG] = "PMU SPRs",
1416 		[FSCR_BHRB_LG] = "BHRB",
1417 		[FSCR_TM_LG] = "TM",
1418 		[FSCR_EBB_LG] = "EBB",
1419 		[FSCR_TAR_LG] = "TAR",
1420 		[FSCR_LM_LG] = "LM",
1421 	};
1422 	char *facility = "unknown";
1423 	u64 value;
1424 	u32 instword, rd;
1425 	u8 status;
1426 	bool hv;
1427 
1428 	hv = (regs->trap == 0xf80);
1429 	if (hv)
1430 		value = mfspr(SPRN_HFSCR);
1431 	else
1432 		value = mfspr(SPRN_FSCR);
1433 
1434 	status = value >> 56;
1435 	if (status == FSCR_DSCR_LG) {
1436 		/*
1437 		 * User is accessing the DSCR register using the problem
1438 		 * state only SPR number (0x03) either through a mfspr or
1439 		 * a mtspr instruction. If it is a write attempt through
1440 		 * a mtspr, then we set the inherit bit. This also allows
1441 		 * the user to write or read the register directly in the
1442 		 * future by setting via the FSCR DSCR bit. But in case it
1443 		 * is a read DSCR attempt through a mfspr instruction, we
1444 		 * just emulate the instruction instead. This code path will
1445 		 * always emulate all the mfspr instructions till the user
1446 		 * has attempted at least one mtspr instruction. This way it
1447 		 * preserves the same behaviour when the user is accessing
1448 		 * the DSCR through privilege level only SPR number (0x11)
1449 		 * which is emulated through illegal instruction exception.
1450 		 * We always leave HFSCR DSCR set.
1451 		 */
1452 		if (get_user(instword, (u32 __user *)(regs->nip))) {
1453 			pr_err("Failed to fetch the user instruction\n");
1454 			return;
1455 		}
1456 
1457 		/* Write into DSCR (mtspr 0x03, RS) */
1458 		if ((instword & PPC_INST_MTSPR_DSCR_USER_MASK)
1459 				== PPC_INST_MTSPR_DSCR_USER) {
1460 			rd = (instword >> 21) & 0x1f;
1461 			current->thread.dscr = regs->gpr[rd];
1462 			current->thread.dscr_inherit = 1;
1463 			current->thread.fscr |= FSCR_DSCR;
1464 			mtspr(SPRN_FSCR, current->thread.fscr);
1465 		}
1466 
1467 		/* Read from DSCR (mfspr RT, 0x03) */
1468 		if ((instword & PPC_INST_MFSPR_DSCR_USER_MASK)
1469 				== PPC_INST_MFSPR_DSCR_USER) {
1470 			if (emulate_instruction(regs)) {
1471 				pr_err("DSCR based mfspr emulation failed\n");
1472 				return;
1473 			}
1474 			regs->nip += 4;
1475 			emulate_single_step(regs);
1476 		}
1477 		return;
1478 	} else if ((status == FSCR_LM_LG) && cpu_has_feature(CPU_FTR_ARCH_300)) {
1479 		/*
1480 		 * This process has touched LM, so turn it on forever
1481 		 * for this process
1482 		 */
1483 		current->thread.fscr |= FSCR_LM;
1484 		mtspr(SPRN_FSCR, current->thread.fscr);
1485 		return;
1486 	}
1487 
1488 	if (status == FSCR_TM_LG) {
1489 		/*
1490 		 * If we're here then the hardware is TM aware because it
1491 		 * generated an exception with FSRM_TM set.
1492 		 *
1493 		 * If cpu_has_feature(CPU_FTR_TM) is false, then either firmware
1494 		 * told us not to do TM, or the kernel is not built with TM
1495 		 * support.
1496 		 *
1497 		 * If both of those things are true, then userspace can spam the
1498 		 * console by triggering the printk() below just by continually
1499 		 * doing tbegin (or any TM instruction). So in that case just
1500 		 * send the process a SIGILL immediately.
1501 		 */
1502 		if (!cpu_has_feature(CPU_FTR_TM))
1503 			goto out;
1504 
1505 		tm_unavailable(regs);
1506 		return;
1507 	}
1508 
1509 	if ((status < ARRAY_SIZE(facility_strings)) &&
1510 	    facility_strings[status])
1511 		facility = facility_strings[status];
1512 
1513 	/* We restore the interrupt state now */
1514 	if (!arch_irq_disabled_regs(regs))
1515 		local_irq_enable();
1516 
1517 	pr_err_ratelimited(
1518 		"%sFacility '%s' unavailable, exception at 0x%lx, MSR=%lx\n",
1519 		hv ? "Hypervisor " : "", facility, regs->nip, regs->msr);
1520 
1521 out:
1522 	if (user_mode(regs)) {
1523 		_exception(SIGILL, regs, ILL_ILLOPC, regs->nip);
1524 		return;
1525 	}
1526 
1527 	die("Unexpected facility unavailable exception", regs, SIGABRT);
1528 }
1529 #endif
1530 
1531 #ifdef CONFIG_PPC_TRANSACTIONAL_MEM
1532 
1533 void fp_unavailable_tm(struct pt_regs *regs)
1534 {
1535 	/* Note:  This does not handle any kind of FP laziness. */
1536 
1537 	TM_DEBUG("FP Unavailable trap whilst transactional at 0x%lx, MSR=%lx\n",
1538 		 regs->nip, regs->msr);
1539 
1540         /* We can only have got here if the task started using FP after
1541          * beginning the transaction.  So, the transactional regs are just a
1542          * copy of the checkpointed ones.  But, we still need to recheckpoint
1543          * as we're enabling FP for the process; it will return, abort the
1544          * transaction, and probably retry but now with FP enabled.  So the
1545          * checkpointed FP registers need to be loaded.
1546 	 */
1547 	tm_reclaim_current(TM_CAUSE_FAC_UNAV);
1548 	/* Reclaim didn't save out any FPRs to transact_fprs. */
1549 
1550 	/* Enable FP for the task: */
1551 	regs->msr |= (MSR_FP | current->thread.fpexc_mode);
1552 
1553 	/* This loads and recheckpoints the FP registers from
1554 	 * thread.fpr[].  They will remain in registers after the
1555 	 * checkpoint so we don't need to reload them after.
1556 	 * If VMX is in use, the VRs now hold checkpointed values,
1557 	 * so we don't want to load the VRs from the thread_struct.
1558 	 */
1559 	tm_recheckpoint(&current->thread, MSR_FP);
1560 
1561 	/* If VMX is in use, get the transactional values back */
1562 	if (regs->msr & MSR_VEC) {
1563 		msr_check_and_set(MSR_VEC);
1564 		load_vr_state(&current->thread.vr_state);
1565 		/* At this point all the VSX state is loaded, so enable it */
1566 		regs->msr |= MSR_VSX;
1567 	}
1568 }
1569 
1570 void altivec_unavailable_tm(struct pt_regs *regs)
1571 {
1572 	/* See the comments in fp_unavailable_tm().  This function operates
1573 	 * the same way.
1574 	 */
1575 
1576 	TM_DEBUG("Vector Unavailable trap whilst transactional at 0x%lx,"
1577 		 "MSR=%lx\n",
1578 		 regs->nip, regs->msr);
1579 	tm_reclaim_current(TM_CAUSE_FAC_UNAV);
1580 	regs->msr |= MSR_VEC;
1581 	tm_recheckpoint(&current->thread, MSR_VEC);
1582 	current->thread.used_vr = 1;
1583 
1584 	if (regs->msr & MSR_FP) {
1585 		msr_check_and_set(MSR_FP);
1586 		load_fp_state(&current->thread.fp_state);
1587 		regs->msr |= MSR_VSX;
1588 	}
1589 }
1590 
1591 void vsx_unavailable_tm(struct pt_regs *regs)
1592 {
1593 	unsigned long orig_msr = regs->msr;
1594 
1595 	/* See the comments in fp_unavailable_tm().  This works similarly,
1596 	 * though we're loading both FP and VEC registers in here.
1597 	 *
1598 	 * If FP isn't in use, load FP regs.  If VEC isn't in use, load VEC
1599 	 * regs.  Either way, set MSR_VSX.
1600 	 */
1601 
1602 	TM_DEBUG("VSX Unavailable trap whilst transactional at 0x%lx,"
1603 		 "MSR=%lx\n",
1604 		 regs->nip, regs->msr);
1605 
1606 	current->thread.used_vsr = 1;
1607 
1608 	/* If FP and VMX are already loaded, we have all the state we need */
1609 	if ((orig_msr & (MSR_FP | MSR_VEC)) == (MSR_FP | MSR_VEC)) {
1610 		regs->msr |= MSR_VSX;
1611 		return;
1612 	}
1613 
1614 	/* This reclaims FP and/or VR regs if they're already enabled */
1615 	tm_reclaim_current(TM_CAUSE_FAC_UNAV);
1616 
1617 	regs->msr |= MSR_VEC | MSR_FP | current->thread.fpexc_mode |
1618 		MSR_VSX;
1619 
1620 	/* This loads & recheckpoints FP and VRs; but we have
1621 	 * to be sure not to overwrite previously-valid state.
1622 	 */
1623 	tm_recheckpoint(&current->thread, regs->msr & ~orig_msr);
1624 
1625 	msr_check_and_set(orig_msr & (MSR_FP | MSR_VEC));
1626 
1627 	if (orig_msr & MSR_FP)
1628 		load_fp_state(&current->thread.fp_state);
1629 	if (orig_msr & MSR_VEC)
1630 		load_vr_state(&current->thread.vr_state);
1631 }
1632 #endif /* CONFIG_PPC_TRANSACTIONAL_MEM */
1633 
1634 void performance_monitor_exception(struct pt_regs *regs)
1635 {
1636 	__this_cpu_inc(irq_stat.pmu_irqs);
1637 
1638 	perf_irq(regs);
1639 }
1640 
1641 #ifdef CONFIG_8xx
1642 void SoftwareEmulation(struct pt_regs *regs)
1643 {
1644 	CHECK_FULL_REGS(regs);
1645 
1646 	if (!user_mode(regs)) {
1647 		debugger(regs);
1648 		die("Kernel Mode Unimplemented Instruction or SW FPU Emulation",
1649 			regs, SIGFPE);
1650 	}
1651 
1652 	if (!emulate_math(regs))
1653 		return;
1654 
1655 	_exception(SIGILL, regs, ILL_ILLOPC, regs->nip);
1656 }
1657 #endif /* CONFIG_8xx */
1658 
1659 #ifdef CONFIG_PPC_ADV_DEBUG_REGS
1660 static void handle_debug(struct pt_regs *regs, unsigned long debug_status)
1661 {
1662 	int changed = 0;
1663 	/*
1664 	 * Determine the cause of the debug event, clear the
1665 	 * event flags and send a trap to the handler. Torez
1666 	 */
1667 	if (debug_status & (DBSR_DAC1R | DBSR_DAC1W)) {
1668 		dbcr_dac(current) &= ~(DBCR_DAC1R | DBCR_DAC1W);
1669 #ifdef CONFIG_PPC_ADV_DEBUG_DAC_RANGE
1670 		current->thread.debug.dbcr2 &= ~DBCR2_DAC12MODE;
1671 #endif
1672 		do_send_trap(regs, mfspr(SPRN_DAC1), debug_status, TRAP_HWBKPT,
1673 			     5);
1674 		changed |= 0x01;
1675 	}  else if (debug_status & (DBSR_DAC2R | DBSR_DAC2W)) {
1676 		dbcr_dac(current) &= ~(DBCR_DAC2R | DBCR_DAC2W);
1677 		do_send_trap(regs, mfspr(SPRN_DAC2), debug_status, TRAP_HWBKPT,
1678 			     6);
1679 		changed |= 0x01;
1680 	}  else if (debug_status & DBSR_IAC1) {
1681 		current->thread.debug.dbcr0 &= ~DBCR0_IAC1;
1682 		dbcr_iac_range(current) &= ~DBCR_IAC12MODE;
1683 		do_send_trap(regs, mfspr(SPRN_IAC1), debug_status, TRAP_HWBKPT,
1684 			     1);
1685 		changed |= 0x01;
1686 	}  else if (debug_status & DBSR_IAC2) {
1687 		current->thread.debug.dbcr0 &= ~DBCR0_IAC2;
1688 		do_send_trap(regs, mfspr(SPRN_IAC2), debug_status, TRAP_HWBKPT,
1689 			     2);
1690 		changed |= 0x01;
1691 	}  else if (debug_status & DBSR_IAC3) {
1692 		current->thread.debug.dbcr0 &= ~DBCR0_IAC3;
1693 		dbcr_iac_range(current) &= ~DBCR_IAC34MODE;
1694 		do_send_trap(regs, mfspr(SPRN_IAC3), debug_status, TRAP_HWBKPT,
1695 			     3);
1696 		changed |= 0x01;
1697 	}  else if (debug_status & DBSR_IAC4) {
1698 		current->thread.debug.dbcr0 &= ~DBCR0_IAC4;
1699 		do_send_trap(regs, mfspr(SPRN_IAC4), debug_status, TRAP_HWBKPT,
1700 			     4);
1701 		changed |= 0x01;
1702 	}
1703 	/*
1704 	 * At the point this routine was called, the MSR(DE) was turned off.
1705 	 * Check all other debug flags and see if that bit needs to be turned
1706 	 * back on or not.
1707 	 */
1708 	if (DBCR_ACTIVE_EVENTS(current->thread.debug.dbcr0,
1709 			       current->thread.debug.dbcr1))
1710 		regs->msr |= MSR_DE;
1711 	else
1712 		/* Make sure the IDM flag is off */
1713 		current->thread.debug.dbcr0 &= ~DBCR0_IDM;
1714 
1715 	if (changed & 0x01)
1716 		mtspr(SPRN_DBCR0, current->thread.debug.dbcr0);
1717 }
1718 
1719 void DebugException(struct pt_regs *regs, unsigned long debug_status)
1720 {
1721 	current->thread.debug.dbsr = debug_status;
1722 
1723 	/* Hack alert: On BookE, Branch Taken stops on the branch itself, while
1724 	 * on server, it stops on the target of the branch. In order to simulate
1725 	 * the server behaviour, we thus restart right away with a single step
1726 	 * instead of stopping here when hitting a BT
1727 	 */
1728 	if (debug_status & DBSR_BT) {
1729 		regs->msr &= ~MSR_DE;
1730 
1731 		/* Disable BT */
1732 		mtspr(SPRN_DBCR0, mfspr(SPRN_DBCR0) & ~DBCR0_BT);
1733 		/* Clear the BT event */
1734 		mtspr(SPRN_DBSR, DBSR_BT);
1735 
1736 		/* Do the single step trick only when coming from userspace */
1737 		if (user_mode(regs)) {
1738 			current->thread.debug.dbcr0 &= ~DBCR0_BT;
1739 			current->thread.debug.dbcr0 |= DBCR0_IDM | DBCR0_IC;
1740 			regs->msr |= MSR_DE;
1741 			return;
1742 		}
1743 
1744 		if (notify_die(DIE_SSTEP, "block_step", regs, 5,
1745 			       5, SIGTRAP) == NOTIFY_STOP) {
1746 			return;
1747 		}
1748 		if (debugger_sstep(regs))
1749 			return;
1750 	} else if (debug_status & DBSR_IC) { 	/* Instruction complete */
1751 		regs->msr &= ~MSR_DE;
1752 
1753 		/* Disable instruction completion */
1754 		mtspr(SPRN_DBCR0, mfspr(SPRN_DBCR0) & ~DBCR0_IC);
1755 		/* Clear the instruction completion event */
1756 		mtspr(SPRN_DBSR, DBSR_IC);
1757 
1758 		if (notify_die(DIE_SSTEP, "single_step", regs, 5,
1759 			       5, SIGTRAP) == NOTIFY_STOP) {
1760 			return;
1761 		}
1762 
1763 		if (debugger_sstep(regs))
1764 			return;
1765 
1766 		if (user_mode(regs)) {
1767 			current->thread.debug.dbcr0 &= ~DBCR0_IC;
1768 			if (DBCR_ACTIVE_EVENTS(current->thread.debug.dbcr0,
1769 					       current->thread.debug.dbcr1))
1770 				regs->msr |= MSR_DE;
1771 			else
1772 				/* Make sure the IDM bit is off */
1773 				current->thread.debug.dbcr0 &= ~DBCR0_IDM;
1774 		}
1775 
1776 		_exception(SIGTRAP, regs, TRAP_TRACE, regs->nip);
1777 	} else
1778 		handle_debug(regs, debug_status);
1779 }
1780 NOKPROBE_SYMBOL(DebugException);
1781 #endif /* CONFIG_PPC_ADV_DEBUG_REGS */
1782 
1783 #if !defined(CONFIG_TAU_INT)
1784 void TAUException(struct pt_regs *regs)
1785 {
1786 	printk("TAU trap at PC: %lx, MSR: %lx, vector=%lx    %s\n",
1787 	       regs->nip, regs->msr, regs->trap, print_tainted());
1788 }
1789 #endif /* CONFIG_INT_TAU */
1790 
1791 #ifdef CONFIG_ALTIVEC
1792 void altivec_assist_exception(struct pt_regs *regs)
1793 {
1794 	int err;
1795 
1796 	if (!user_mode(regs)) {
1797 		printk(KERN_EMERG "VMX/Altivec assist exception in kernel mode"
1798 		       " at %lx\n", regs->nip);
1799 		die("Kernel VMX/Altivec assist exception", regs, SIGILL);
1800 	}
1801 
1802 	flush_altivec_to_thread(current);
1803 
1804 	PPC_WARN_EMULATED(altivec, regs);
1805 	err = emulate_altivec(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 {
1816 		/* didn't recognize the instruction */
1817 		/* XXX quick hack for now: set the non-Java bit in the VSCR */
1818 		printk_ratelimited(KERN_ERR "Unrecognized altivec instruction "
1819 				   "in %s at %lx\n", current->comm, regs->nip);
1820 		current->thread.vr_state.vscr.u[3] |= 0x10000;
1821 	}
1822 }
1823 #endif /* CONFIG_ALTIVEC */
1824 
1825 #ifdef CONFIG_FSL_BOOKE
1826 void CacheLockingException(struct pt_regs *regs, unsigned long address,
1827 			   unsigned long error_code)
1828 {
1829 	/* We treat cache locking instructions from the user
1830 	 * as priv ops, in the future we could try to do
1831 	 * something smarter
1832 	 */
1833 	if (error_code & (ESR_DLK|ESR_ILK))
1834 		_exception(SIGILL, regs, ILL_PRVOPC, regs->nip);
1835 	return;
1836 }
1837 #endif /* CONFIG_FSL_BOOKE */
1838 
1839 #ifdef CONFIG_SPE
1840 void SPEFloatingPointException(struct pt_regs *regs)
1841 {
1842 	extern int do_spe_mathemu(struct pt_regs *regs);
1843 	unsigned long spefscr;
1844 	int fpexc_mode;
1845 	int code = 0;
1846 	int err;
1847 
1848 	flush_spe_to_thread(current);
1849 
1850 	spefscr = current->thread.spefscr;
1851 	fpexc_mode = current->thread.fpexc_mode;
1852 
1853 	if ((spefscr & SPEFSCR_FOVF) && (fpexc_mode & PR_FP_EXC_OVF)) {
1854 		code = FPE_FLTOVF;
1855 	}
1856 	else if ((spefscr & SPEFSCR_FUNF) && (fpexc_mode & PR_FP_EXC_UND)) {
1857 		code = FPE_FLTUND;
1858 	}
1859 	else if ((spefscr & SPEFSCR_FDBZ) && (fpexc_mode & PR_FP_EXC_DIV))
1860 		code = FPE_FLTDIV;
1861 	else if ((spefscr & SPEFSCR_FINV) && (fpexc_mode & PR_FP_EXC_INV)) {
1862 		code = FPE_FLTINV;
1863 	}
1864 	else if ((spefscr & (SPEFSCR_FG | SPEFSCR_FX)) && (fpexc_mode & PR_FP_EXC_RES))
1865 		code = FPE_FLTRES;
1866 
1867 	err = do_spe_mathemu(regs);
1868 	if (err == 0) {
1869 		regs->nip += 4;		/* skip emulated instruction */
1870 		emulate_single_step(regs);
1871 		return;
1872 	}
1873 
1874 	if (err == -EFAULT) {
1875 		/* got an error reading the instruction */
1876 		_exception(SIGSEGV, regs, SEGV_ACCERR, regs->nip);
1877 	} else if (err == -EINVAL) {
1878 		/* didn't recognize the instruction */
1879 		printk(KERN_ERR "unrecognized spe instruction "
1880 		       "in %s at %lx\n", current->comm, regs->nip);
1881 	} else {
1882 		_exception(SIGFPE, regs, code, regs->nip);
1883 	}
1884 
1885 	return;
1886 }
1887 
1888 void SPEFloatingPointRoundException(struct pt_regs *regs)
1889 {
1890 	extern int speround_handler(struct pt_regs *regs);
1891 	int err;
1892 
1893 	preempt_disable();
1894 	if (regs->msr & MSR_SPE)
1895 		giveup_spe(current);
1896 	preempt_enable();
1897 
1898 	regs->nip -= 4;
1899 	err = speround_handler(regs);
1900 	if (err == 0) {
1901 		regs->nip += 4;		/* skip emulated instruction */
1902 		emulate_single_step(regs);
1903 		return;
1904 	}
1905 
1906 	if (err == -EFAULT) {
1907 		/* got an error reading the instruction */
1908 		_exception(SIGSEGV, regs, SEGV_ACCERR, regs->nip);
1909 	} else if (err == -EINVAL) {
1910 		/* didn't recognize the instruction */
1911 		printk(KERN_ERR "unrecognized spe instruction "
1912 		       "in %s at %lx\n", current->comm, regs->nip);
1913 	} else {
1914 		_exception(SIGFPE, regs, 0, regs->nip);
1915 		return;
1916 	}
1917 }
1918 #endif
1919 
1920 /*
1921  * We enter here if we get an unrecoverable exception, that is, one
1922  * that happened at a point where the RI (recoverable interrupt) bit
1923  * in the MSR is 0.  This indicates that SRR0/1 are live, and that
1924  * we therefore lost state by taking this exception.
1925  */
1926 void unrecoverable_exception(struct pt_regs *regs)
1927 {
1928 	printk(KERN_EMERG "Unrecoverable exception %lx at %lx\n",
1929 	       regs->trap, regs->nip);
1930 	die("Unrecoverable exception", regs, SIGABRT);
1931 }
1932 
1933 #if defined(CONFIG_BOOKE_WDT) || defined(CONFIG_40x)
1934 /*
1935  * Default handler for a Watchdog exception,
1936  * spins until a reboot occurs
1937  */
1938 void __attribute__ ((weak)) WatchdogHandler(struct pt_regs *regs)
1939 {
1940 	/* Generic WatchdogHandler, implement your own */
1941 	mtspr(SPRN_TCR, mfspr(SPRN_TCR)&(~TCR_WIE));
1942 	return;
1943 }
1944 
1945 void WatchdogException(struct pt_regs *regs)
1946 {
1947 	printk (KERN_EMERG "PowerPC Book-E Watchdog Exception\n");
1948 	WatchdogHandler(regs);
1949 }
1950 #endif
1951 
1952 /*
1953  * We enter here if we discover during exception entry that we are
1954  * running in supervisor mode with a userspace value in the stack pointer.
1955  */
1956 void kernel_bad_stack(struct pt_regs *regs)
1957 {
1958 	printk(KERN_EMERG "Bad kernel stack pointer %lx at %lx\n",
1959 	       regs->gpr[1], regs->nip);
1960 	die("Bad kernel stack pointer", regs, SIGABRT);
1961 }
1962 
1963 void __init trap_init(void)
1964 {
1965 }
1966 
1967 
1968 #ifdef CONFIG_PPC_EMULATED_STATS
1969 
1970 #define WARN_EMULATED_SETUP(type)	.type = { .name = #type }
1971 
1972 struct ppc_emulated ppc_emulated = {
1973 #ifdef CONFIG_ALTIVEC
1974 	WARN_EMULATED_SETUP(altivec),
1975 #endif
1976 	WARN_EMULATED_SETUP(dcba),
1977 	WARN_EMULATED_SETUP(dcbz),
1978 	WARN_EMULATED_SETUP(fp_pair),
1979 	WARN_EMULATED_SETUP(isel),
1980 	WARN_EMULATED_SETUP(mcrxr),
1981 	WARN_EMULATED_SETUP(mfpvr),
1982 	WARN_EMULATED_SETUP(multiple),
1983 	WARN_EMULATED_SETUP(popcntb),
1984 	WARN_EMULATED_SETUP(spe),
1985 	WARN_EMULATED_SETUP(string),
1986 	WARN_EMULATED_SETUP(sync),
1987 	WARN_EMULATED_SETUP(unaligned),
1988 #ifdef CONFIG_MATH_EMULATION
1989 	WARN_EMULATED_SETUP(math),
1990 #endif
1991 #ifdef CONFIG_VSX
1992 	WARN_EMULATED_SETUP(vsx),
1993 #endif
1994 #ifdef CONFIG_PPC64
1995 	WARN_EMULATED_SETUP(mfdscr),
1996 	WARN_EMULATED_SETUP(mtdscr),
1997 	WARN_EMULATED_SETUP(lq_stq),
1998 #endif
1999 };
2000 
2001 u32 ppc_warn_emulated;
2002 
2003 void ppc_warn_emulated_print(const char *type)
2004 {
2005 	pr_warn_ratelimited("%s used emulated %s instruction\n", current->comm,
2006 			    type);
2007 }
2008 
2009 static int __init ppc_warn_emulated_init(void)
2010 {
2011 	struct dentry *dir, *d;
2012 	unsigned int i;
2013 	struct ppc_emulated_entry *entries = (void *)&ppc_emulated;
2014 
2015 	if (!powerpc_debugfs_root)
2016 		return -ENODEV;
2017 
2018 	dir = debugfs_create_dir("emulated_instructions",
2019 				 powerpc_debugfs_root);
2020 	if (!dir)
2021 		return -ENOMEM;
2022 
2023 	d = debugfs_create_u32("do_warn", S_IRUGO | S_IWUSR, dir,
2024 			       &ppc_warn_emulated);
2025 	if (!d)
2026 		goto fail;
2027 
2028 	for (i = 0; i < sizeof(ppc_emulated)/sizeof(*entries); i++) {
2029 		d = debugfs_create_u32(entries[i].name, S_IRUGO | S_IWUSR, dir,
2030 				       (u32 *)&entries[i].val.counter);
2031 		if (!d)
2032 			goto fail;
2033 	}
2034 
2035 	return 0;
2036 
2037 fail:
2038 	debugfs_remove_recursive(dir);
2039 	return -ENOMEM;
2040 }
2041 
2042 device_initcall(ppc_warn_emulated_init);
2043 
2044 #endif /* CONFIG_PPC_EMULATED_STATS */
2045