xref: /linux/arch/powerpc/kernel/traps.c (revision 092e0e7e520a1fca03e13c9f2d157432a8657ff2)
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 
38 #include <asm/emulated_ops.h>
39 #include <asm/pgtable.h>
40 #include <asm/uaccess.h>
41 #include <asm/system.h>
42 #include <asm/io.h>
43 #include <asm/machdep.h>
44 #include <asm/rtas.h>
45 #include <asm/pmc.h>
46 #ifdef CONFIG_PPC32
47 #include <asm/reg.h>
48 #endif
49 #ifdef CONFIG_PMAC_BACKLIGHT
50 #include <asm/backlight.h>
51 #endif
52 #ifdef CONFIG_PPC64
53 #include <asm/firmware.h>
54 #include <asm/processor.h>
55 #endif
56 #include <asm/kexec.h>
57 #include <asm/ppc-opcode.h>
58 
59 #if defined(CONFIG_DEBUGGER) || defined(CONFIG_KEXEC)
60 int (*__debugger)(struct pt_regs *regs) __read_mostly;
61 int (*__debugger_ipi)(struct pt_regs *regs) __read_mostly;
62 int (*__debugger_bpt)(struct pt_regs *regs) __read_mostly;
63 int (*__debugger_sstep)(struct pt_regs *regs) __read_mostly;
64 int (*__debugger_iabr_match)(struct pt_regs *regs) __read_mostly;
65 int (*__debugger_dabr_match)(struct pt_regs *regs) __read_mostly;
66 int (*__debugger_fault_handler)(struct pt_regs *regs) __read_mostly;
67 
68 EXPORT_SYMBOL(__debugger);
69 EXPORT_SYMBOL(__debugger_ipi);
70 EXPORT_SYMBOL(__debugger_bpt);
71 EXPORT_SYMBOL(__debugger_sstep);
72 EXPORT_SYMBOL(__debugger_iabr_match);
73 EXPORT_SYMBOL(__debugger_dabr_match);
74 EXPORT_SYMBOL(__debugger_fault_handler);
75 #endif
76 
77 /*
78  * Trap & Exception support
79  */
80 
81 #ifdef CONFIG_PMAC_BACKLIGHT
82 static void pmac_backlight_unblank(void)
83 {
84 	mutex_lock(&pmac_backlight_mutex);
85 	if (pmac_backlight) {
86 		struct backlight_properties *props;
87 
88 		props = &pmac_backlight->props;
89 		props->brightness = props->max_brightness;
90 		props->power = FB_BLANK_UNBLANK;
91 		backlight_update_status(pmac_backlight);
92 	}
93 	mutex_unlock(&pmac_backlight_mutex);
94 }
95 #else
96 static inline void pmac_backlight_unblank(void) { }
97 #endif
98 
99 int die(const char *str, struct pt_regs *regs, long err)
100 {
101 	static struct {
102 		raw_spinlock_t lock;
103 		u32 lock_owner;
104 		int lock_owner_depth;
105 	} die = {
106 		.lock =			__RAW_SPIN_LOCK_UNLOCKED(die.lock),
107 		.lock_owner =		-1,
108 		.lock_owner_depth =	0
109 	};
110 	static int die_counter;
111 	unsigned long flags;
112 
113 	if (debugger(regs))
114 		return 1;
115 
116 	oops_enter();
117 
118 	if (die.lock_owner != raw_smp_processor_id()) {
119 		console_verbose();
120 		raw_spin_lock_irqsave(&die.lock, flags);
121 		die.lock_owner = smp_processor_id();
122 		die.lock_owner_depth = 0;
123 		bust_spinlocks(1);
124 		if (machine_is(powermac))
125 			pmac_backlight_unblank();
126 	} else {
127 		local_save_flags(flags);
128 	}
129 
130 	if (++die.lock_owner_depth < 3) {
131 		printk("Oops: %s, sig: %ld [#%d]\n", str, err, ++die_counter);
132 #ifdef CONFIG_PREEMPT
133 		printk("PREEMPT ");
134 #endif
135 #ifdef CONFIG_SMP
136 		printk("SMP NR_CPUS=%d ", NR_CPUS);
137 #endif
138 #ifdef CONFIG_DEBUG_PAGEALLOC
139 		printk("DEBUG_PAGEALLOC ");
140 #endif
141 #ifdef CONFIG_NUMA
142 		printk("NUMA ");
143 #endif
144 		printk("%s\n", ppc_md.name ? ppc_md.name : "");
145 
146 		sysfs_printk_last_file();
147 		if (notify_die(DIE_OOPS, str, regs, err, 255,
148 			       SIGSEGV) == NOTIFY_STOP)
149 			return 1;
150 
151 		print_modules();
152 		show_regs(regs);
153 	} else {
154 		printk("Recursive die() failure, output suppressed\n");
155 	}
156 
157 	bust_spinlocks(0);
158 	die.lock_owner = -1;
159 	add_taint(TAINT_DIE);
160 	raw_spin_unlock_irqrestore(&die.lock, flags);
161 
162 	if (kexec_should_crash(current) ||
163 		kexec_sr_activated(smp_processor_id()))
164 		crash_kexec(regs);
165 	crash_kexec_secondary(regs);
166 
167 	if (in_interrupt())
168 		panic("Fatal exception in interrupt");
169 
170 	if (panic_on_oops)
171 		panic("Fatal exception");
172 
173 	oops_exit();
174 	do_exit(err);
175 
176 	return 0;
177 }
178 
179 void user_single_step_siginfo(struct task_struct *tsk,
180 				struct pt_regs *regs, siginfo_t *info)
181 {
182 	memset(info, 0, sizeof(*info));
183 	info->si_signo = SIGTRAP;
184 	info->si_code = TRAP_TRACE;
185 	info->si_addr = (void __user *)regs->nip;
186 }
187 
188 void _exception(int signr, struct pt_regs *regs, int code, unsigned long addr)
189 {
190 	siginfo_t info;
191 	const char fmt32[] = KERN_INFO "%s[%d]: unhandled signal %d " \
192 			"at %08lx nip %08lx lr %08lx code %x\n";
193 	const char fmt64[] = KERN_INFO "%s[%d]: unhandled signal %d " \
194 			"at %016lx nip %016lx lr %016lx code %x\n";
195 
196 	if (!user_mode(regs)) {
197 		if (die("Exception in kernel mode", regs, signr))
198 			return;
199 	} else if (show_unhandled_signals &&
200 		    unhandled_signal(current, signr) &&
201 		    printk_ratelimit()) {
202 			printk(regs->msr & MSR_SF ? fmt64 : fmt32,
203 				current->comm, current->pid, signr,
204 				addr, regs->nip, regs->link, code);
205 		}
206 
207 	memset(&info, 0, sizeof(info));
208 	info.si_signo = signr;
209 	info.si_code = code;
210 	info.si_addr = (void __user *) addr;
211 	force_sig_info(signr, &info, current);
212 }
213 
214 #ifdef CONFIG_PPC64
215 void system_reset_exception(struct pt_regs *regs)
216 {
217 	/* See if any machine dependent calls */
218 	if (ppc_md.system_reset_exception) {
219 		if (ppc_md.system_reset_exception(regs))
220 			return;
221 	}
222 
223 #ifdef CONFIG_KEXEC
224 	cpu_set(smp_processor_id(), cpus_in_sr);
225 #endif
226 
227 	die("System Reset", regs, SIGABRT);
228 
229 	/*
230 	 * Some CPUs when released from the debugger will execute this path.
231 	 * These CPUs entered the debugger via a soft-reset. If the CPU was
232 	 * hung before entering the debugger it will return to the hung
233 	 * state when exiting this function.  This causes a problem in
234 	 * kdump since the hung CPU(s) will not respond to the IPI sent
235 	 * from kdump. To prevent the problem we call crash_kexec_secondary()
236 	 * here. If a kdump had not been initiated or we exit the debugger
237 	 * with the "exit and recover" command (x) crash_kexec_secondary()
238 	 * will return after 5ms and the CPU returns to its previous state.
239 	 */
240 	crash_kexec_secondary(regs);
241 
242 	/* Must die if the interrupt is not recoverable */
243 	if (!(regs->msr & MSR_RI))
244 		panic("Unrecoverable System Reset");
245 
246 	/* What should we do here? We could issue a shutdown or hard reset. */
247 }
248 #endif
249 
250 /*
251  * I/O accesses can cause machine checks on powermacs.
252  * Check if the NIP corresponds to the address of a sync
253  * instruction for which there is an entry in the exception
254  * table.
255  * Note that the 601 only takes a machine check on TEA
256  * (transfer error ack) signal assertion, and does not
257  * set any of the top 16 bits of SRR1.
258  *  -- paulus.
259  */
260 static inline int check_io_access(struct pt_regs *regs)
261 {
262 #ifdef CONFIG_PPC32
263 	unsigned long msr = regs->msr;
264 	const struct exception_table_entry *entry;
265 	unsigned int *nip = (unsigned int *)regs->nip;
266 
267 	if (((msr & 0xffff0000) == 0 || (msr & (0x80000 | 0x40000)))
268 	    && (entry = search_exception_tables(regs->nip)) != NULL) {
269 		/*
270 		 * Check that it's a sync instruction, or somewhere
271 		 * in the twi; isync; nop sequence that inb/inw/inl uses.
272 		 * As the address is in the exception table
273 		 * we should be able to read the instr there.
274 		 * For the debug message, we look at the preceding
275 		 * load or store.
276 		 */
277 		if (*nip == 0x60000000)		/* nop */
278 			nip -= 2;
279 		else if (*nip == 0x4c00012c)	/* isync */
280 			--nip;
281 		if (*nip == 0x7c0004ac || (*nip >> 26) == 3) {
282 			/* sync or twi */
283 			unsigned int rb;
284 
285 			--nip;
286 			rb = (*nip >> 11) & 0x1f;
287 			printk(KERN_DEBUG "%s bad port %lx at %p\n",
288 			       (*nip & 0x100)? "OUT to": "IN from",
289 			       regs->gpr[rb] - _IO_BASE, nip);
290 			regs->msr |= MSR_RI;
291 			regs->nip = entry->fixup;
292 			return 1;
293 		}
294 	}
295 #endif /* CONFIG_PPC32 */
296 	return 0;
297 }
298 
299 #ifdef CONFIG_PPC_ADV_DEBUG_REGS
300 /* On 4xx, the reason for the machine check or program exception
301    is in the ESR. */
302 #define get_reason(regs)	((regs)->dsisr)
303 #ifndef CONFIG_FSL_BOOKE
304 #define get_mc_reason(regs)	((regs)->dsisr)
305 #else
306 #define get_mc_reason(regs)	(mfspr(SPRN_MCSR))
307 #endif
308 #define REASON_FP		ESR_FP
309 #define REASON_ILLEGAL		(ESR_PIL | ESR_PUO)
310 #define REASON_PRIVILEGED	ESR_PPR
311 #define REASON_TRAP		ESR_PTR
312 
313 /* single-step stuff */
314 #define single_stepping(regs)	(current->thread.dbcr0 & DBCR0_IC)
315 #define clear_single_step(regs)	(current->thread.dbcr0 &= ~DBCR0_IC)
316 
317 #else
318 /* On non-4xx, the reason for the machine check or program
319    exception is in the MSR. */
320 #define get_reason(regs)	((regs)->msr)
321 #define get_mc_reason(regs)	((regs)->msr)
322 #define REASON_FP		0x100000
323 #define REASON_ILLEGAL		0x80000
324 #define REASON_PRIVILEGED	0x40000
325 #define REASON_TRAP		0x20000
326 
327 #define single_stepping(regs)	((regs)->msr & MSR_SE)
328 #define clear_single_step(regs)	((regs)->msr &= ~MSR_SE)
329 #endif
330 
331 #if defined(CONFIG_4xx)
332 int machine_check_4xx(struct pt_regs *regs)
333 {
334 	unsigned long reason = get_mc_reason(regs);
335 
336 	if (reason & ESR_IMCP) {
337 		printk("Instruction");
338 		mtspr(SPRN_ESR, reason & ~ESR_IMCP);
339 	} else
340 		printk("Data");
341 	printk(" machine check in kernel mode.\n");
342 
343 	return 0;
344 }
345 
346 int machine_check_440A(struct pt_regs *regs)
347 {
348 	unsigned long reason = get_mc_reason(regs);
349 
350 	printk("Machine check in kernel mode.\n");
351 	if (reason & ESR_IMCP){
352 		printk("Instruction Synchronous Machine Check exception\n");
353 		mtspr(SPRN_ESR, reason & ~ESR_IMCP);
354 	}
355 	else {
356 		u32 mcsr = mfspr(SPRN_MCSR);
357 		if (mcsr & MCSR_IB)
358 			printk("Instruction Read PLB Error\n");
359 		if (mcsr & MCSR_DRB)
360 			printk("Data Read PLB Error\n");
361 		if (mcsr & MCSR_DWB)
362 			printk("Data Write PLB Error\n");
363 		if (mcsr & MCSR_TLBP)
364 			printk("TLB Parity Error\n");
365 		if (mcsr & MCSR_ICP){
366 			flush_instruction_cache();
367 			printk("I-Cache Parity Error\n");
368 		}
369 		if (mcsr & MCSR_DCSP)
370 			printk("D-Cache Search Parity Error\n");
371 		if (mcsr & MCSR_DCFP)
372 			printk("D-Cache Flush Parity Error\n");
373 		if (mcsr & MCSR_IMPE)
374 			printk("Machine Check exception is imprecise\n");
375 
376 		/* Clear MCSR */
377 		mtspr(SPRN_MCSR, mcsr);
378 	}
379 	return 0;
380 }
381 
382 int machine_check_47x(struct pt_regs *regs)
383 {
384 	unsigned long reason = get_mc_reason(regs);
385 	u32 mcsr;
386 
387 	printk(KERN_ERR "Machine check in kernel mode.\n");
388 	if (reason & ESR_IMCP) {
389 		printk(KERN_ERR
390 		       "Instruction Synchronous Machine Check exception\n");
391 		mtspr(SPRN_ESR, reason & ~ESR_IMCP);
392 		return 0;
393 	}
394 	mcsr = mfspr(SPRN_MCSR);
395 	if (mcsr & MCSR_IB)
396 		printk(KERN_ERR "Instruction Read PLB Error\n");
397 	if (mcsr & MCSR_DRB)
398 		printk(KERN_ERR "Data Read PLB Error\n");
399 	if (mcsr & MCSR_DWB)
400 		printk(KERN_ERR "Data Write PLB Error\n");
401 	if (mcsr & MCSR_TLBP)
402 		printk(KERN_ERR "TLB Parity Error\n");
403 	if (mcsr & MCSR_ICP) {
404 		flush_instruction_cache();
405 		printk(KERN_ERR "I-Cache Parity Error\n");
406 	}
407 	if (mcsr & MCSR_DCSP)
408 		printk(KERN_ERR "D-Cache Search Parity Error\n");
409 	if (mcsr & PPC47x_MCSR_GPR)
410 		printk(KERN_ERR "GPR Parity Error\n");
411 	if (mcsr & PPC47x_MCSR_FPR)
412 		printk(KERN_ERR "FPR Parity Error\n");
413 	if (mcsr & PPC47x_MCSR_IPR)
414 		printk(KERN_ERR "Machine Check exception is imprecise\n");
415 
416 	/* Clear MCSR */
417 	mtspr(SPRN_MCSR, mcsr);
418 
419 	return 0;
420 }
421 #elif defined(CONFIG_E500)
422 int machine_check_e500mc(struct pt_regs *regs)
423 {
424 	unsigned long mcsr = mfspr(SPRN_MCSR);
425 	unsigned long reason = mcsr;
426 	int recoverable = 1;
427 
428 	printk("Machine check in kernel mode.\n");
429 	printk("Caused by (from MCSR=%lx): ", reason);
430 
431 	if (reason & MCSR_MCP)
432 		printk("Machine Check Signal\n");
433 
434 	if (reason & MCSR_ICPERR) {
435 		printk("Instruction Cache Parity Error\n");
436 
437 		/*
438 		 * This is recoverable by invalidating the i-cache.
439 		 */
440 		mtspr(SPRN_L1CSR1, mfspr(SPRN_L1CSR1) | L1CSR1_ICFI);
441 		while (mfspr(SPRN_L1CSR1) & L1CSR1_ICFI)
442 			;
443 
444 		/*
445 		 * This will generally be accompanied by an instruction
446 		 * fetch error report -- only treat MCSR_IF as fatal
447 		 * if it wasn't due to an L1 parity error.
448 		 */
449 		reason &= ~MCSR_IF;
450 	}
451 
452 	if (reason & MCSR_DCPERR_MC) {
453 		printk("Data Cache Parity Error\n");
454 		recoverable = 0;
455 	}
456 
457 	if (reason & MCSR_L2MMU_MHIT) {
458 		printk("Hit on multiple TLB entries\n");
459 		recoverable = 0;
460 	}
461 
462 	if (reason & MCSR_NMI)
463 		printk("Non-maskable interrupt\n");
464 
465 	if (reason & MCSR_IF) {
466 		printk("Instruction Fetch Error Report\n");
467 		recoverable = 0;
468 	}
469 
470 	if (reason & MCSR_LD) {
471 		printk("Load Error Report\n");
472 		recoverable = 0;
473 	}
474 
475 	if (reason & MCSR_ST) {
476 		printk("Store Error Report\n");
477 		recoverable = 0;
478 	}
479 
480 	if (reason & MCSR_LDG) {
481 		printk("Guarded Load Error Report\n");
482 		recoverable = 0;
483 	}
484 
485 	if (reason & MCSR_TLBSYNC)
486 		printk("Simultaneous tlbsync operations\n");
487 
488 	if (reason & MCSR_BSL2_ERR) {
489 		printk("Level 2 Cache Error\n");
490 		recoverable = 0;
491 	}
492 
493 	if (reason & MCSR_MAV) {
494 		u64 addr;
495 
496 		addr = mfspr(SPRN_MCAR);
497 		addr |= (u64)mfspr(SPRN_MCARU) << 32;
498 
499 		printk("Machine Check %s Address: %#llx\n",
500 		       reason & MCSR_MEA ? "Effective" : "Physical", addr);
501 	}
502 
503 	mtspr(SPRN_MCSR, mcsr);
504 	return mfspr(SPRN_MCSR) == 0 && recoverable;
505 }
506 
507 int machine_check_e500(struct pt_regs *regs)
508 {
509 	unsigned long reason = get_mc_reason(regs);
510 
511 	printk("Machine check in kernel mode.\n");
512 	printk("Caused by (from MCSR=%lx): ", reason);
513 
514 	if (reason & MCSR_MCP)
515 		printk("Machine Check Signal\n");
516 	if (reason & MCSR_ICPERR)
517 		printk("Instruction Cache Parity Error\n");
518 	if (reason & MCSR_DCP_PERR)
519 		printk("Data Cache Push Parity Error\n");
520 	if (reason & MCSR_DCPERR)
521 		printk("Data Cache Parity Error\n");
522 	if (reason & MCSR_BUS_IAERR)
523 		printk("Bus - Instruction Address Error\n");
524 	if (reason & MCSR_BUS_RAERR)
525 		printk("Bus - Read Address Error\n");
526 	if (reason & MCSR_BUS_WAERR)
527 		printk("Bus - Write Address Error\n");
528 	if (reason & MCSR_BUS_IBERR)
529 		printk("Bus - Instruction Data Error\n");
530 	if (reason & MCSR_BUS_RBERR)
531 		printk("Bus - Read Data Bus Error\n");
532 	if (reason & MCSR_BUS_WBERR)
533 		printk("Bus - Read Data Bus Error\n");
534 	if (reason & MCSR_BUS_IPERR)
535 		printk("Bus - Instruction Parity Error\n");
536 	if (reason & MCSR_BUS_RPERR)
537 		printk("Bus - Read Parity Error\n");
538 
539 	return 0;
540 }
541 
542 int machine_check_generic(struct pt_regs *regs)
543 {
544 	return 0;
545 }
546 #elif defined(CONFIG_E200)
547 int machine_check_e200(struct pt_regs *regs)
548 {
549 	unsigned long reason = get_mc_reason(regs);
550 
551 	printk("Machine check in kernel mode.\n");
552 	printk("Caused by (from MCSR=%lx): ", reason);
553 
554 	if (reason & MCSR_MCP)
555 		printk("Machine Check Signal\n");
556 	if (reason & MCSR_CP_PERR)
557 		printk("Cache Push Parity Error\n");
558 	if (reason & MCSR_CPERR)
559 		printk("Cache Parity Error\n");
560 	if (reason & MCSR_EXCP_ERR)
561 		printk("ISI, ITLB, or Bus Error on first instruction fetch for an exception handler\n");
562 	if (reason & MCSR_BUS_IRERR)
563 		printk("Bus - Read Bus Error on instruction fetch\n");
564 	if (reason & MCSR_BUS_DRERR)
565 		printk("Bus - Read Bus Error on data load\n");
566 	if (reason & MCSR_BUS_WRERR)
567 		printk("Bus - Write Bus Error on buffered store or cache line push\n");
568 
569 	return 0;
570 }
571 #else
572 int machine_check_generic(struct pt_regs *regs)
573 {
574 	unsigned long reason = get_mc_reason(regs);
575 
576 	printk("Machine check in kernel mode.\n");
577 	printk("Caused by (from SRR1=%lx): ", reason);
578 	switch (reason & 0x601F0000) {
579 	case 0x80000:
580 		printk("Machine check signal\n");
581 		break;
582 	case 0:		/* for 601 */
583 	case 0x40000:
584 	case 0x140000:	/* 7450 MSS error and TEA */
585 		printk("Transfer error ack signal\n");
586 		break;
587 	case 0x20000:
588 		printk("Data parity error signal\n");
589 		break;
590 	case 0x10000:
591 		printk("Address parity error signal\n");
592 		break;
593 	case 0x20000000:
594 		printk("L1 Data Cache error\n");
595 		break;
596 	case 0x40000000:
597 		printk("L1 Instruction Cache error\n");
598 		break;
599 	case 0x00100000:
600 		printk("L2 data cache parity error\n");
601 		break;
602 	default:
603 		printk("Unknown values in msr\n");
604 	}
605 	return 0;
606 }
607 #endif /* everything else */
608 
609 void machine_check_exception(struct pt_regs *regs)
610 {
611 	int recover = 0;
612 
613 	__get_cpu_var(irq_stat).mce_exceptions++;
614 
615 	/* See if any machine dependent calls. In theory, we would want
616 	 * to call the CPU first, and call the ppc_md. one if the CPU
617 	 * one returns a positive number. However there is existing code
618 	 * that assumes the board gets a first chance, so let's keep it
619 	 * that way for now and fix things later. --BenH.
620 	 */
621 	if (ppc_md.machine_check_exception)
622 		recover = ppc_md.machine_check_exception(regs);
623 	else if (cur_cpu_spec->machine_check)
624 		recover = cur_cpu_spec->machine_check(regs);
625 
626 	if (recover > 0)
627 		return;
628 
629 	if (user_mode(regs)) {
630 		regs->msr |= MSR_RI;
631 		_exception(SIGBUS, regs, BUS_ADRERR, regs->nip);
632 		return;
633 	}
634 
635 #if defined(CONFIG_8xx) && defined(CONFIG_PCI)
636 	/* the qspan pci read routines can cause machine checks -- Cort
637 	 *
638 	 * yuck !!! that totally needs to go away ! There are better ways
639 	 * to deal with that than having a wart in the mcheck handler.
640 	 * -- BenH
641 	 */
642 	bad_page_fault(regs, regs->dar, SIGBUS);
643 	return;
644 #endif
645 
646 	if (debugger_fault_handler(regs)) {
647 		regs->msr |= MSR_RI;
648 		return;
649 	}
650 
651 	if (check_io_access(regs))
652 		return;
653 
654 	if (debugger_fault_handler(regs))
655 		return;
656 	die("Machine check", regs, SIGBUS);
657 
658 	/* Must die if the interrupt is not recoverable */
659 	if (!(regs->msr & MSR_RI))
660 		panic("Unrecoverable Machine check");
661 }
662 
663 void SMIException(struct pt_regs *regs)
664 {
665 	die("System Management Interrupt", regs, SIGABRT);
666 }
667 
668 void unknown_exception(struct pt_regs *regs)
669 {
670 	printk("Bad trap at PC: %lx, SR: %lx, vector=%lx\n",
671 	       regs->nip, regs->msr, regs->trap);
672 
673 	_exception(SIGTRAP, regs, 0, 0);
674 }
675 
676 void instruction_breakpoint_exception(struct pt_regs *regs)
677 {
678 	if (notify_die(DIE_IABR_MATCH, "iabr_match", regs, 5,
679 					5, SIGTRAP) == NOTIFY_STOP)
680 		return;
681 	if (debugger_iabr_match(regs))
682 		return;
683 	_exception(SIGTRAP, regs, TRAP_BRKPT, regs->nip);
684 }
685 
686 void RunModeException(struct pt_regs *regs)
687 {
688 	_exception(SIGTRAP, regs, 0, 0);
689 }
690 
691 void __kprobes single_step_exception(struct pt_regs *regs)
692 {
693 	clear_single_step(regs);
694 
695 	if (notify_die(DIE_SSTEP, "single_step", regs, 5,
696 					5, SIGTRAP) == NOTIFY_STOP)
697 		return;
698 	if (debugger_sstep(regs))
699 		return;
700 
701 	_exception(SIGTRAP, regs, TRAP_TRACE, regs->nip);
702 }
703 
704 /*
705  * After we have successfully emulated an instruction, we have to
706  * check if the instruction was being single-stepped, and if so,
707  * pretend we got a single-step exception.  This was pointed out
708  * by Kumar Gala.  -- paulus
709  */
710 static void emulate_single_step(struct pt_regs *regs)
711 {
712 	if (single_stepping(regs))
713 		single_step_exception(regs);
714 }
715 
716 static inline int __parse_fpscr(unsigned long fpscr)
717 {
718 	int ret = 0;
719 
720 	/* Invalid operation */
721 	if ((fpscr & FPSCR_VE) && (fpscr & FPSCR_VX))
722 		ret = FPE_FLTINV;
723 
724 	/* Overflow */
725 	else if ((fpscr & FPSCR_OE) && (fpscr & FPSCR_OX))
726 		ret = FPE_FLTOVF;
727 
728 	/* Underflow */
729 	else if ((fpscr & FPSCR_UE) && (fpscr & FPSCR_UX))
730 		ret = FPE_FLTUND;
731 
732 	/* Divide by zero */
733 	else if ((fpscr & FPSCR_ZE) && (fpscr & FPSCR_ZX))
734 		ret = FPE_FLTDIV;
735 
736 	/* Inexact result */
737 	else if ((fpscr & FPSCR_XE) && (fpscr & FPSCR_XX))
738 		ret = FPE_FLTRES;
739 
740 	return ret;
741 }
742 
743 static void parse_fpe(struct pt_regs *regs)
744 {
745 	int code = 0;
746 
747 	flush_fp_to_thread(current);
748 
749 	code = __parse_fpscr(current->thread.fpscr.val);
750 
751 	_exception(SIGFPE, regs, code, regs->nip);
752 }
753 
754 /*
755  * Illegal instruction emulation support.  Originally written to
756  * provide the PVR to user applications using the mfspr rd, PVR.
757  * Return non-zero if we can't emulate, or -EFAULT if the associated
758  * memory access caused an access fault.  Return zero on success.
759  *
760  * There are a couple of ways to do this, either "decode" the instruction
761  * or directly match lots of bits.  In this case, matching lots of
762  * bits is faster and easier.
763  *
764  */
765 static int emulate_string_inst(struct pt_regs *regs, u32 instword)
766 {
767 	u8 rT = (instword >> 21) & 0x1f;
768 	u8 rA = (instword >> 16) & 0x1f;
769 	u8 NB_RB = (instword >> 11) & 0x1f;
770 	u32 num_bytes;
771 	unsigned long EA;
772 	int pos = 0;
773 
774 	/* Early out if we are an invalid form of lswx */
775 	if ((instword & PPC_INST_STRING_MASK) == PPC_INST_LSWX)
776 		if ((rT == rA) || (rT == NB_RB))
777 			return -EINVAL;
778 
779 	EA = (rA == 0) ? 0 : regs->gpr[rA];
780 
781 	switch (instword & PPC_INST_STRING_MASK) {
782 		case PPC_INST_LSWX:
783 		case PPC_INST_STSWX:
784 			EA += NB_RB;
785 			num_bytes = regs->xer & 0x7f;
786 			break;
787 		case PPC_INST_LSWI:
788 		case PPC_INST_STSWI:
789 			num_bytes = (NB_RB == 0) ? 32 : NB_RB;
790 			break;
791 		default:
792 			return -EINVAL;
793 	}
794 
795 	while (num_bytes != 0)
796 	{
797 		u8 val;
798 		u32 shift = 8 * (3 - (pos & 0x3));
799 
800 		switch ((instword & PPC_INST_STRING_MASK)) {
801 			case PPC_INST_LSWX:
802 			case PPC_INST_LSWI:
803 				if (get_user(val, (u8 __user *)EA))
804 					return -EFAULT;
805 				/* first time updating this reg,
806 				 * zero it out */
807 				if (pos == 0)
808 					regs->gpr[rT] = 0;
809 				regs->gpr[rT] |= val << shift;
810 				break;
811 			case PPC_INST_STSWI:
812 			case PPC_INST_STSWX:
813 				val = regs->gpr[rT] >> shift;
814 				if (put_user(val, (u8 __user *)EA))
815 					return -EFAULT;
816 				break;
817 		}
818 		/* move EA to next address */
819 		EA += 1;
820 		num_bytes--;
821 
822 		/* manage our position within the register */
823 		if (++pos == 4) {
824 			pos = 0;
825 			if (++rT == 32)
826 				rT = 0;
827 		}
828 	}
829 
830 	return 0;
831 }
832 
833 static int emulate_popcntb_inst(struct pt_regs *regs, u32 instword)
834 {
835 	u32 ra,rs;
836 	unsigned long tmp;
837 
838 	ra = (instword >> 16) & 0x1f;
839 	rs = (instword >> 21) & 0x1f;
840 
841 	tmp = regs->gpr[rs];
842 	tmp = tmp - ((tmp >> 1) & 0x5555555555555555ULL);
843 	tmp = (tmp & 0x3333333333333333ULL) + ((tmp >> 2) & 0x3333333333333333ULL);
844 	tmp = (tmp + (tmp >> 4)) & 0x0f0f0f0f0f0f0f0fULL;
845 	regs->gpr[ra] = tmp;
846 
847 	return 0;
848 }
849 
850 static int emulate_isel(struct pt_regs *regs, u32 instword)
851 {
852 	u8 rT = (instword >> 21) & 0x1f;
853 	u8 rA = (instword >> 16) & 0x1f;
854 	u8 rB = (instword >> 11) & 0x1f;
855 	u8 BC = (instword >> 6) & 0x1f;
856 	u8 bit;
857 	unsigned long tmp;
858 
859 	tmp = (rA == 0) ? 0 : regs->gpr[rA];
860 	bit = (regs->ccr >> (31 - BC)) & 0x1;
861 
862 	regs->gpr[rT] = bit ? tmp : regs->gpr[rB];
863 
864 	return 0;
865 }
866 
867 static int emulate_instruction(struct pt_regs *regs)
868 {
869 	u32 instword;
870 	u32 rd;
871 
872 	if (!user_mode(regs) || (regs->msr & MSR_LE))
873 		return -EINVAL;
874 	CHECK_FULL_REGS(regs);
875 
876 	if (get_user(instword, (u32 __user *)(regs->nip)))
877 		return -EFAULT;
878 
879 	/* Emulate the mfspr rD, PVR. */
880 	if ((instword & PPC_INST_MFSPR_PVR_MASK) == PPC_INST_MFSPR_PVR) {
881 		PPC_WARN_EMULATED(mfpvr, regs);
882 		rd = (instword >> 21) & 0x1f;
883 		regs->gpr[rd] = mfspr(SPRN_PVR);
884 		return 0;
885 	}
886 
887 	/* Emulating the dcba insn is just a no-op.  */
888 	if ((instword & PPC_INST_DCBA_MASK) == PPC_INST_DCBA) {
889 		PPC_WARN_EMULATED(dcba, regs);
890 		return 0;
891 	}
892 
893 	/* Emulate the mcrxr insn.  */
894 	if ((instword & PPC_INST_MCRXR_MASK) == PPC_INST_MCRXR) {
895 		int shift = (instword >> 21) & 0x1c;
896 		unsigned long msk = 0xf0000000UL >> shift;
897 
898 		PPC_WARN_EMULATED(mcrxr, regs);
899 		regs->ccr = (regs->ccr & ~msk) | ((regs->xer >> shift) & msk);
900 		regs->xer &= ~0xf0000000UL;
901 		return 0;
902 	}
903 
904 	/* Emulate load/store string insn. */
905 	if ((instword & PPC_INST_STRING_GEN_MASK) == PPC_INST_STRING) {
906 		PPC_WARN_EMULATED(string, regs);
907 		return emulate_string_inst(regs, instword);
908 	}
909 
910 	/* Emulate the popcntb (Population Count Bytes) instruction. */
911 	if ((instword & PPC_INST_POPCNTB_MASK) == PPC_INST_POPCNTB) {
912 		PPC_WARN_EMULATED(popcntb, regs);
913 		return emulate_popcntb_inst(regs, instword);
914 	}
915 
916 	/* Emulate isel (Integer Select) instruction */
917 	if ((instword & PPC_INST_ISEL_MASK) == PPC_INST_ISEL) {
918 		PPC_WARN_EMULATED(isel, regs);
919 		return emulate_isel(regs, instword);
920 	}
921 
922 	return -EINVAL;
923 }
924 
925 int is_valid_bugaddr(unsigned long addr)
926 {
927 	return is_kernel_addr(addr);
928 }
929 
930 void __kprobes program_check_exception(struct pt_regs *regs)
931 {
932 	unsigned int reason = get_reason(regs);
933 	extern int do_mathemu(struct pt_regs *regs);
934 
935 	/* We can now get here via a FP Unavailable exception if the core
936 	 * has no FPU, in that case the reason flags will be 0 */
937 
938 	if (reason & REASON_FP) {
939 		/* IEEE FP exception */
940 		parse_fpe(regs);
941 		return;
942 	}
943 	if (reason & REASON_TRAP) {
944 		/* Debugger is first in line to stop recursive faults in
945 		 * rcu_lock, notify_die, or atomic_notifier_call_chain */
946 		if (debugger_bpt(regs))
947 			return;
948 
949 		/* trap exception */
950 		if (notify_die(DIE_BPT, "breakpoint", regs, 5, 5, SIGTRAP)
951 				== NOTIFY_STOP)
952 			return;
953 
954 		if (!(regs->msr & MSR_PR) &&  /* not user-mode */
955 		    report_bug(regs->nip, regs) == BUG_TRAP_TYPE_WARN) {
956 			regs->nip += 4;
957 			return;
958 		}
959 		_exception(SIGTRAP, regs, TRAP_BRKPT, regs->nip);
960 		return;
961 	}
962 
963 	local_irq_enable();
964 
965 #ifdef CONFIG_MATH_EMULATION
966 	/* (reason & REASON_ILLEGAL) would be the obvious thing here,
967 	 * but there seems to be a hardware bug on the 405GP (RevD)
968 	 * that means ESR is sometimes set incorrectly - either to
969 	 * ESR_DST (!?) or 0.  In the process of chasing this with the
970 	 * hardware people - not sure if it can happen on any illegal
971 	 * instruction or only on FP instructions, whether there is a
972 	 * pattern to occurences etc. -dgibson 31/Mar/2003 */
973 	switch (do_mathemu(regs)) {
974 	case 0:
975 		emulate_single_step(regs);
976 		return;
977 	case 1: {
978 			int code = 0;
979 			code = __parse_fpscr(current->thread.fpscr.val);
980 			_exception(SIGFPE, regs, code, regs->nip);
981 			return;
982 		}
983 	case -EFAULT:
984 		_exception(SIGSEGV, regs, SEGV_MAPERR, regs->nip);
985 		return;
986 	}
987 	/* fall through on any other errors */
988 #endif /* CONFIG_MATH_EMULATION */
989 
990 	/* Try to emulate it if we should. */
991 	if (reason & (REASON_ILLEGAL | REASON_PRIVILEGED)) {
992 		switch (emulate_instruction(regs)) {
993 		case 0:
994 			regs->nip += 4;
995 			emulate_single_step(regs);
996 			return;
997 		case -EFAULT:
998 			_exception(SIGSEGV, regs, SEGV_MAPERR, regs->nip);
999 			return;
1000 		}
1001 	}
1002 
1003 	if (reason & REASON_PRIVILEGED)
1004 		_exception(SIGILL, regs, ILL_PRVOPC, regs->nip);
1005 	else
1006 		_exception(SIGILL, regs, ILL_ILLOPC, regs->nip);
1007 }
1008 
1009 void alignment_exception(struct pt_regs *regs)
1010 {
1011 	int sig, code, fixed = 0;
1012 
1013 	/* we don't implement logging of alignment exceptions */
1014 	if (!(current->thread.align_ctl & PR_UNALIGN_SIGBUS))
1015 		fixed = fix_alignment(regs);
1016 
1017 	if (fixed == 1) {
1018 		regs->nip += 4;	/* skip over emulated instruction */
1019 		emulate_single_step(regs);
1020 		return;
1021 	}
1022 
1023 	/* Operand address was bad */
1024 	if (fixed == -EFAULT) {
1025 		sig = SIGSEGV;
1026 		code = SEGV_ACCERR;
1027 	} else {
1028 		sig = SIGBUS;
1029 		code = BUS_ADRALN;
1030 	}
1031 	if (user_mode(regs))
1032 		_exception(sig, regs, code, regs->dar);
1033 	else
1034 		bad_page_fault(regs, regs->dar, sig);
1035 }
1036 
1037 void StackOverflow(struct pt_regs *regs)
1038 {
1039 	printk(KERN_CRIT "Kernel stack overflow in process %p, r1=%lx\n",
1040 	       current, regs->gpr[1]);
1041 	debugger(regs);
1042 	show_regs(regs);
1043 	panic("kernel stack overflow");
1044 }
1045 
1046 void nonrecoverable_exception(struct pt_regs *regs)
1047 {
1048 	printk(KERN_ERR "Non-recoverable exception at PC=%lx MSR=%lx\n",
1049 	       regs->nip, regs->msr);
1050 	debugger(regs);
1051 	die("nonrecoverable exception", regs, SIGKILL);
1052 }
1053 
1054 void trace_syscall(struct pt_regs *regs)
1055 {
1056 	printk("Task: %p(%d), PC: %08lX/%08lX, Syscall: %3ld, Result: %s%ld    %s\n",
1057 	       current, task_pid_nr(current), regs->nip, regs->link, regs->gpr[0],
1058 	       regs->ccr&0x10000000?"Error=":"", regs->gpr[3], print_tainted());
1059 }
1060 
1061 void kernel_fp_unavailable_exception(struct pt_regs *regs)
1062 {
1063 	printk(KERN_EMERG "Unrecoverable FP Unavailable Exception "
1064 			  "%lx at %lx\n", regs->trap, regs->nip);
1065 	die("Unrecoverable FP Unavailable Exception", regs, SIGABRT);
1066 }
1067 
1068 void altivec_unavailable_exception(struct pt_regs *regs)
1069 {
1070 	if (user_mode(regs)) {
1071 		/* A user program has executed an altivec instruction,
1072 		   but this kernel doesn't support altivec. */
1073 		_exception(SIGILL, regs, ILL_ILLOPC, regs->nip);
1074 		return;
1075 	}
1076 
1077 	printk(KERN_EMERG "Unrecoverable VMX/Altivec Unavailable Exception "
1078 			"%lx at %lx\n", regs->trap, regs->nip);
1079 	die("Unrecoverable VMX/Altivec Unavailable Exception", regs, SIGABRT);
1080 }
1081 
1082 void vsx_unavailable_exception(struct pt_regs *regs)
1083 {
1084 	if (user_mode(regs)) {
1085 		/* A user program has executed an vsx instruction,
1086 		   but this kernel doesn't support vsx. */
1087 		_exception(SIGILL, regs, ILL_ILLOPC, regs->nip);
1088 		return;
1089 	}
1090 
1091 	printk(KERN_EMERG "Unrecoverable VSX Unavailable Exception "
1092 			"%lx at %lx\n", regs->trap, regs->nip);
1093 	die("Unrecoverable VSX Unavailable Exception", regs, SIGABRT);
1094 }
1095 
1096 void performance_monitor_exception(struct pt_regs *regs)
1097 {
1098 	__get_cpu_var(irq_stat).pmu_irqs++;
1099 
1100 	perf_irq(regs);
1101 }
1102 
1103 #ifdef CONFIG_8xx
1104 void SoftwareEmulation(struct pt_regs *regs)
1105 {
1106 	extern int do_mathemu(struct pt_regs *);
1107 	extern int Soft_emulate_8xx(struct pt_regs *);
1108 #if defined(CONFIG_MATH_EMULATION) || defined(CONFIG_8XX_MINIMAL_FPEMU)
1109 	int errcode;
1110 #endif
1111 
1112 	CHECK_FULL_REGS(regs);
1113 
1114 	if (!user_mode(regs)) {
1115 		debugger(regs);
1116 		die("Kernel Mode Software FPU Emulation", regs, SIGFPE);
1117 	}
1118 
1119 #ifdef CONFIG_MATH_EMULATION
1120 	errcode = do_mathemu(regs);
1121 	if (errcode >= 0)
1122 		PPC_WARN_EMULATED(math, regs);
1123 
1124 	switch (errcode) {
1125 	case 0:
1126 		emulate_single_step(regs);
1127 		return;
1128 	case 1: {
1129 			int code = 0;
1130 			code = __parse_fpscr(current->thread.fpscr.val);
1131 			_exception(SIGFPE, regs, code, regs->nip);
1132 			return;
1133 		}
1134 	case -EFAULT:
1135 		_exception(SIGSEGV, regs, SEGV_MAPERR, regs->nip);
1136 		return;
1137 	default:
1138 		_exception(SIGILL, regs, ILL_ILLOPC, regs->nip);
1139 		return;
1140 	}
1141 
1142 #elif defined(CONFIG_8XX_MINIMAL_FPEMU)
1143 	errcode = Soft_emulate_8xx(regs);
1144 	if (errcode >= 0)
1145 		PPC_WARN_EMULATED(8xx, regs);
1146 
1147 	switch (errcode) {
1148 	case 0:
1149 		emulate_single_step(regs);
1150 		return;
1151 	case 1:
1152 		_exception(SIGILL, regs, ILL_ILLOPC, regs->nip);
1153 		return;
1154 	case -EFAULT:
1155 		_exception(SIGSEGV, regs, SEGV_MAPERR, regs->nip);
1156 		return;
1157 	}
1158 #else
1159 	_exception(SIGILL, regs, ILL_ILLOPC, regs->nip);
1160 #endif
1161 }
1162 #endif /* CONFIG_8xx */
1163 
1164 #ifdef CONFIG_PPC_ADV_DEBUG_REGS
1165 static void handle_debug(struct pt_regs *regs, unsigned long debug_status)
1166 {
1167 	int changed = 0;
1168 	/*
1169 	 * Determine the cause of the debug event, clear the
1170 	 * event flags and send a trap to the handler. Torez
1171 	 */
1172 	if (debug_status & (DBSR_DAC1R | DBSR_DAC1W)) {
1173 		dbcr_dac(current) &= ~(DBCR_DAC1R | DBCR_DAC1W);
1174 #ifdef CONFIG_PPC_ADV_DEBUG_DAC_RANGE
1175 		current->thread.dbcr2 &= ~DBCR2_DAC12MODE;
1176 #endif
1177 		do_send_trap(regs, mfspr(SPRN_DAC1), debug_status, TRAP_HWBKPT,
1178 			     5);
1179 		changed |= 0x01;
1180 	}  else if (debug_status & (DBSR_DAC2R | DBSR_DAC2W)) {
1181 		dbcr_dac(current) &= ~(DBCR_DAC2R | DBCR_DAC2W);
1182 		do_send_trap(regs, mfspr(SPRN_DAC2), debug_status, TRAP_HWBKPT,
1183 			     6);
1184 		changed |= 0x01;
1185 	}  else if (debug_status & DBSR_IAC1) {
1186 		current->thread.dbcr0 &= ~DBCR0_IAC1;
1187 		dbcr_iac_range(current) &= ~DBCR_IAC12MODE;
1188 		do_send_trap(regs, mfspr(SPRN_IAC1), debug_status, TRAP_HWBKPT,
1189 			     1);
1190 		changed |= 0x01;
1191 	}  else if (debug_status & DBSR_IAC2) {
1192 		current->thread.dbcr0 &= ~DBCR0_IAC2;
1193 		do_send_trap(regs, mfspr(SPRN_IAC2), debug_status, TRAP_HWBKPT,
1194 			     2);
1195 		changed |= 0x01;
1196 	}  else if (debug_status & DBSR_IAC3) {
1197 		current->thread.dbcr0 &= ~DBCR0_IAC3;
1198 		dbcr_iac_range(current) &= ~DBCR_IAC34MODE;
1199 		do_send_trap(regs, mfspr(SPRN_IAC3), debug_status, TRAP_HWBKPT,
1200 			     3);
1201 		changed |= 0x01;
1202 	}  else if (debug_status & DBSR_IAC4) {
1203 		current->thread.dbcr0 &= ~DBCR0_IAC4;
1204 		do_send_trap(regs, mfspr(SPRN_IAC4), debug_status, TRAP_HWBKPT,
1205 			     4);
1206 		changed |= 0x01;
1207 	}
1208 	/*
1209 	 * At the point this routine was called, the MSR(DE) was turned off.
1210 	 * Check all other debug flags and see if that bit needs to be turned
1211 	 * back on or not.
1212 	 */
1213 	if (DBCR_ACTIVE_EVENTS(current->thread.dbcr0, current->thread.dbcr1))
1214 		regs->msr |= MSR_DE;
1215 	else
1216 		/* Make sure the IDM flag is off */
1217 		current->thread.dbcr0 &= ~DBCR0_IDM;
1218 
1219 	if (changed & 0x01)
1220 		mtspr(SPRN_DBCR0, current->thread.dbcr0);
1221 }
1222 
1223 void __kprobes DebugException(struct pt_regs *regs, unsigned long debug_status)
1224 {
1225 	current->thread.dbsr = debug_status;
1226 
1227 	/* Hack alert: On BookE, Branch Taken stops on the branch itself, while
1228 	 * on server, it stops on the target of the branch. In order to simulate
1229 	 * the server behaviour, we thus restart right away with a single step
1230 	 * instead of stopping here when hitting a BT
1231 	 */
1232 	if (debug_status & DBSR_BT) {
1233 		regs->msr &= ~MSR_DE;
1234 
1235 		/* Disable BT */
1236 		mtspr(SPRN_DBCR0, mfspr(SPRN_DBCR0) & ~DBCR0_BT);
1237 		/* Clear the BT event */
1238 		mtspr(SPRN_DBSR, DBSR_BT);
1239 
1240 		/* Do the single step trick only when coming from userspace */
1241 		if (user_mode(regs)) {
1242 			current->thread.dbcr0 &= ~DBCR0_BT;
1243 			current->thread.dbcr0 |= DBCR0_IDM | DBCR0_IC;
1244 			regs->msr |= MSR_DE;
1245 			return;
1246 		}
1247 
1248 		if (notify_die(DIE_SSTEP, "block_step", regs, 5,
1249 			       5, SIGTRAP) == NOTIFY_STOP) {
1250 			return;
1251 		}
1252 		if (debugger_sstep(regs))
1253 			return;
1254 	} else if (debug_status & DBSR_IC) { 	/* Instruction complete */
1255 		regs->msr &= ~MSR_DE;
1256 
1257 		/* Disable instruction completion */
1258 		mtspr(SPRN_DBCR0, mfspr(SPRN_DBCR0) & ~DBCR0_IC);
1259 		/* Clear the instruction completion event */
1260 		mtspr(SPRN_DBSR, DBSR_IC);
1261 
1262 		if (notify_die(DIE_SSTEP, "single_step", regs, 5,
1263 			       5, SIGTRAP) == NOTIFY_STOP) {
1264 			return;
1265 		}
1266 
1267 		if (debugger_sstep(regs))
1268 			return;
1269 
1270 		if (user_mode(regs)) {
1271 			current->thread.dbcr0 &= ~DBCR0_IC;
1272 #ifdef CONFIG_PPC_ADV_DEBUG_REGS
1273 			if (DBCR_ACTIVE_EVENTS(current->thread.dbcr0,
1274 					       current->thread.dbcr1))
1275 				regs->msr |= MSR_DE;
1276 			else
1277 				/* Make sure the IDM bit is off */
1278 				current->thread.dbcr0 &= ~DBCR0_IDM;
1279 #endif
1280 		}
1281 
1282 		_exception(SIGTRAP, regs, TRAP_TRACE, regs->nip);
1283 	} else
1284 		handle_debug(regs, debug_status);
1285 }
1286 #endif /* CONFIG_PPC_ADV_DEBUG_REGS */
1287 
1288 #if !defined(CONFIG_TAU_INT)
1289 void TAUException(struct pt_regs *regs)
1290 {
1291 	printk("TAU trap at PC: %lx, MSR: %lx, vector=%lx    %s\n",
1292 	       regs->nip, regs->msr, regs->trap, print_tainted());
1293 }
1294 #endif /* CONFIG_INT_TAU */
1295 
1296 #ifdef CONFIG_ALTIVEC
1297 void altivec_assist_exception(struct pt_regs *regs)
1298 {
1299 	int err;
1300 
1301 	if (!user_mode(regs)) {
1302 		printk(KERN_EMERG "VMX/Altivec assist exception in kernel mode"
1303 		       " at %lx\n", regs->nip);
1304 		die("Kernel VMX/Altivec assist exception", regs, SIGILL);
1305 	}
1306 
1307 	flush_altivec_to_thread(current);
1308 
1309 	PPC_WARN_EMULATED(altivec, regs);
1310 	err = emulate_altivec(regs);
1311 	if (err == 0) {
1312 		regs->nip += 4;		/* skip emulated instruction */
1313 		emulate_single_step(regs);
1314 		return;
1315 	}
1316 
1317 	if (err == -EFAULT) {
1318 		/* got an error reading the instruction */
1319 		_exception(SIGSEGV, regs, SEGV_ACCERR, regs->nip);
1320 	} else {
1321 		/* didn't recognize the instruction */
1322 		/* XXX quick hack for now: set the non-Java bit in the VSCR */
1323 		if (printk_ratelimit())
1324 			printk(KERN_ERR "Unrecognized altivec instruction "
1325 			       "in %s at %lx\n", current->comm, regs->nip);
1326 		current->thread.vscr.u[3] |= 0x10000;
1327 	}
1328 }
1329 #endif /* CONFIG_ALTIVEC */
1330 
1331 #ifdef CONFIG_VSX
1332 void vsx_assist_exception(struct pt_regs *regs)
1333 {
1334 	if (!user_mode(regs)) {
1335 		printk(KERN_EMERG "VSX assist exception in kernel mode"
1336 		       " at %lx\n", regs->nip);
1337 		die("Kernel VSX assist exception", regs, SIGILL);
1338 	}
1339 
1340 	flush_vsx_to_thread(current);
1341 	printk(KERN_INFO "VSX assist not supported at %lx\n", regs->nip);
1342 	_exception(SIGILL, regs, ILL_ILLOPC, regs->nip);
1343 }
1344 #endif /* CONFIG_VSX */
1345 
1346 #ifdef CONFIG_FSL_BOOKE
1347 void CacheLockingException(struct pt_regs *regs, unsigned long address,
1348 			   unsigned long error_code)
1349 {
1350 	/* We treat cache locking instructions from the user
1351 	 * as priv ops, in the future we could try to do
1352 	 * something smarter
1353 	 */
1354 	if (error_code & (ESR_DLK|ESR_ILK))
1355 		_exception(SIGILL, regs, ILL_PRVOPC, regs->nip);
1356 	return;
1357 }
1358 #endif /* CONFIG_FSL_BOOKE */
1359 
1360 #ifdef CONFIG_SPE
1361 void SPEFloatingPointException(struct pt_regs *regs)
1362 {
1363 	extern int do_spe_mathemu(struct pt_regs *regs);
1364 	unsigned long spefscr;
1365 	int fpexc_mode;
1366 	int code = 0;
1367 	int err;
1368 
1369 	preempt_disable();
1370 	if (regs->msr & MSR_SPE)
1371 		giveup_spe(current);
1372 	preempt_enable();
1373 
1374 	spefscr = current->thread.spefscr;
1375 	fpexc_mode = current->thread.fpexc_mode;
1376 
1377 	if ((spefscr & SPEFSCR_FOVF) && (fpexc_mode & PR_FP_EXC_OVF)) {
1378 		code = FPE_FLTOVF;
1379 	}
1380 	else if ((spefscr & SPEFSCR_FUNF) && (fpexc_mode & PR_FP_EXC_UND)) {
1381 		code = FPE_FLTUND;
1382 	}
1383 	else if ((spefscr & SPEFSCR_FDBZ) && (fpexc_mode & PR_FP_EXC_DIV))
1384 		code = FPE_FLTDIV;
1385 	else if ((spefscr & SPEFSCR_FINV) && (fpexc_mode & PR_FP_EXC_INV)) {
1386 		code = FPE_FLTINV;
1387 	}
1388 	else if ((spefscr & (SPEFSCR_FG | SPEFSCR_FX)) && (fpexc_mode & PR_FP_EXC_RES))
1389 		code = FPE_FLTRES;
1390 
1391 	err = do_spe_mathemu(regs);
1392 	if (err == 0) {
1393 		regs->nip += 4;		/* skip emulated instruction */
1394 		emulate_single_step(regs);
1395 		return;
1396 	}
1397 
1398 	if (err == -EFAULT) {
1399 		/* got an error reading the instruction */
1400 		_exception(SIGSEGV, regs, SEGV_ACCERR, regs->nip);
1401 	} else if (err == -EINVAL) {
1402 		/* didn't recognize the instruction */
1403 		printk(KERN_ERR "unrecognized spe instruction "
1404 		       "in %s at %lx\n", current->comm, regs->nip);
1405 	} else {
1406 		_exception(SIGFPE, regs, code, regs->nip);
1407 	}
1408 
1409 	return;
1410 }
1411 
1412 void SPEFloatingPointRoundException(struct pt_regs *regs)
1413 {
1414 	extern int speround_handler(struct pt_regs *regs);
1415 	int err;
1416 
1417 	preempt_disable();
1418 	if (regs->msr & MSR_SPE)
1419 		giveup_spe(current);
1420 	preempt_enable();
1421 
1422 	regs->nip -= 4;
1423 	err = speround_handler(regs);
1424 	if (err == 0) {
1425 		regs->nip += 4;		/* skip emulated instruction */
1426 		emulate_single_step(regs);
1427 		return;
1428 	}
1429 
1430 	if (err == -EFAULT) {
1431 		/* got an error reading the instruction */
1432 		_exception(SIGSEGV, regs, SEGV_ACCERR, regs->nip);
1433 	} else if (err == -EINVAL) {
1434 		/* didn't recognize the instruction */
1435 		printk(KERN_ERR "unrecognized spe instruction "
1436 		       "in %s at %lx\n", current->comm, regs->nip);
1437 	} else {
1438 		_exception(SIGFPE, regs, 0, regs->nip);
1439 		return;
1440 	}
1441 }
1442 #endif
1443 
1444 /*
1445  * We enter here if we get an unrecoverable exception, that is, one
1446  * that happened at a point where the RI (recoverable interrupt) bit
1447  * in the MSR is 0.  This indicates that SRR0/1 are live, and that
1448  * we therefore lost state by taking this exception.
1449  */
1450 void unrecoverable_exception(struct pt_regs *regs)
1451 {
1452 	printk(KERN_EMERG "Unrecoverable exception %lx at %lx\n",
1453 	       regs->trap, regs->nip);
1454 	die("Unrecoverable exception", regs, SIGABRT);
1455 }
1456 
1457 #ifdef CONFIG_BOOKE_WDT
1458 /*
1459  * Default handler for a Watchdog exception,
1460  * spins until a reboot occurs
1461  */
1462 void __attribute__ ((weak)) WatchdogHandler(struct pt_regs *regs)
1463 {
1464 	/* Generic WatchdogHandler, implement your own */
1465 	mtspr(SPRN_TCR, mfspr(SPRN_TCR)&(~TCR_WIE));
1466 	return;
1467 }
1468 
1469 void WatchdogException(struct pt_regs *regs)
1470 {
1471 	printk (KERN_EMERG "PowerPC Book-E Watchdog Exception\n");
1472 	WatchdogHandler(regs);
1473 }
1474 #endif
1475 
1476 /*
1477  * We enter here if we discover during exception entry that we are
1478  * running in supervisor mode with a userspace value in the stack pointer.
1479  */
1480 void kernel_bad_stack(struct pt_regs *regs)
1481 {
1482 	printk(KERN_EMERG "Bad kernel stack pointer %lx at %lx\n",
1483 	       regs->gpr[1], regs->nip);
1484 	die("Bad kernel stack pointer", regs, SIGABRT);
1485 }
1486 
1487 void __init trap_init(void)
1488 {
1489 }
1490 
1491 
1492 #ifdef CONFIG_PPC_EMULATED_STATS
1493 
1494 #define WARN_EMULATED_SETUP(type)	.type = { .name = #type }
1495 
1496 struct ppc_emulated ppc_emulated = {
1497 #ifdef CONFIG_ALTIVEC
1498 	WARN_EMULATED_SETUP(altivec),
1499 #endif
1500 	WARN_EMULATED_SETUP(dcba),
1501 	WARN_EMULATED_SETUP(dcbz),
1502 	WARN_EMULATED_SETUP(fp_pair),
1503 	WARN_EMULATED_SETUP(isel),
1504 	WARN_EMULATED_SETUP(mcrxr),
1505 	WARN_EMULATED_SETUP(mfpvr),
1506 	WARN_EMULATED_SETUP(multiple),
1507 	WARN_EMULATED_SETUP(popcntb),
1508 	WARN_EMULATED_SETUP(spe),
1509 	WARN_EMULATED_SETUP(string),
1510 	WARN_EMULATED_SETUP(unaligned),
1511 #ifdef CONFIG_MATH_EMULATION
1512 	WARN_EMULATED_SETUP(math),
1513 #elif defined(CONFIG_8XX_MINIMAL_FPEMU)
1514 	WARN_EMULATED_SETUP(8xx),
1515 #endif
1516 #ifdef CONFIG_VSX
1517 	WARN_EMULATED_SETUP(vsx),
1518 #endif
1519 };
1520 
1521 u32 ppc_warn_emulated;
1522 
1523 void ppc_warn_emulated_print(const char *type)
1524 {
1525 	if (printk_ratelimit())
1526 		pr_warning("%s used emulated %s instruction\n", current->comm,
1527 			   type);
1528 }
1529 
1530 static int __init ppc_warn_emulated_init(void)
1531 {
1532 	struct dentry *dir, *d;
1533 	unsigned int i;
1534 	struct ppc_emulated_entry *entries = (void *)&ppc_emulated;
1535 
1536 	if (!powerpc_debugfs_root)
1537 		return -ENODEV;
1538 
1539 	dir = debugfs_create_dir("emulated_instructions",
1540 				 powerpc_debugfs_root);
1541 	if (!dir)
1542 		return -ENOMEM;
1543 
1544 	d = debugfs_create_u32("do_warn", S_IRUGO | S_IWUSR, dir,
1545 			       &ppc_warn_emulated);
1546 	if (!d)
1547 		goto fail;
1548 
1549 	for (i = 0; i < sizeof(ppc_emulated)/sizeof(*entries); i++) {
1550 		d = debugfs_create_u32(entries[i].name, S_IRUGO | S_IWUSR, dir,
1551 				       (u32 *)&entries[i].val.counter);
1552 		if (!d)
1553 			goto fail;
1554 	}
1555 
1556 	return 0;
1557 
1558 fail:
1559 	debugfs_remove_recursive(dir);
1560 	return -ENOMEM;
1561 }
1562 
1563 device_initcall(ppc_warn_emulated_init);
1564 
1565 #endif /* CONFIG_PPC_EMULATED_STATS */
1566