xref: /linux/arch/powerpc/kernel/traps.c (revision d39d0ed196aa1685bb24771e92f78633c66ac9cb)
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 #elif defined(CONFIG_E200)
542 int machine_check_e200(struct pt_regs *regs)
543 {
544 	unsigned long reason = get_mc_reason(regs);
545 
546 	printk("Machine check in kernel mode.\n");
547 	printk("Caused by (from MCSR=%lx): ", reason);
548 
549 	if (reason & MCSR_MCP)
550 		printk("Machine Check Signal\n");
551 	if (reason & MCSR_CP_PERR)
552 		printk("Cache Push Parity Error\n");
553 	if (reason & MCSR_CPERR)
554 		printk("Cache Parity Error\n");
555 	if (reason & MCSR_EXCP_ERR)
556 		printk("ISI, ITLB, or Bus Error on first instruction fetch for an exception handler\n");
557 	if (reason & MCSR_BUS_IRERR)
558 		printk("Bus - Read Bus Error on instruction fetch\n");
559 	if (reason & MCSR_BUS_DRERR)
560 		printk("Bus - Read Bus Error on data load\n");
561 	if (reason & MCSR_BUS_WRERR)
562 		printk("Bus - Write Bus Error on buffered store or cache line push\n");
563 
564 	return 0;
565 }
566 #else
567 int machine_check_generic(struct pt_regs *regs)
568 {
569 	unsigned long reason = get_mc_reason(regs);
570 
571 	printk("Machine check in kernel mode.\n");
572 	printk("Caused by (from SRR1=%lx): ", reason);
573 	switch (reason & 0x601F0000) {
574 	case 0x80000:
575 		printk("Machine check signal\n");
576 		break;
577 	case 0:		/* for 601 */
578 	case 0x40000:
579 	case 0x140000:	/* 7450 MSS error and TEA */
580 		printk("Transfer error ack signal\n");
581 		break;
582 	case 0x20000:
583 		printk("Data parity error signal\n");
584 		break;
585 	case 0x10000:
586 		printk("Address parity error signal\n");
587 		break;
588 	case 0x20000000:
589 		printk("L1 Data Cache error\n");
590 		break;
591 	case 0x40000000:
592 		printk("L1 Instruction Cache error\n");
593 		break;
594 	case 0x00100000:
595 		printk("L2 data cache parity error\n");
596 		break;
597 	default:
598 		printk("Unknown values in msr\n");
599 	}
600 	return 0;
601 }
602 #endif /* everything else */
603 
604 void machine_check_exception(struct pt_regs *regs)
605 {
606 	int recover = 0;
607 
608 	__get_cpu_var(irq_stat).mce_exceptions++;
609 
610 	/* See if any machine dependent calls. In theory, we would want
611 	 * to call the CPU first, and call the ppc_md. one if the CPU
612 	 * one returns a positive number. However there is existing code
613 	 * that assumes the board gets a first chance, so let's keep it
614 	 * that way for now and fix things later. --BenH.
615 	 */
616 	if (ppc_md.machine_check_exception)
617 		recover = ppc_md.machine_check_exception(regs);
618 	else if (cur_cpu_spec->machine_check)
619 		recover = cur_cpu_spec->machine_check(regs);
620 
621 	if (recover > 0)
622 		return;
623 
624 	if (user_mode(regs)) {
625 		regs->msr |= MSR_RI;
626 		_exception(SIGBUS, regs, BUS_ADRERR, regs->nip);
627 		return;
628 	}
629 
630 #if defined(CONFIG_8xx) && defined(CONFIG_PCI)
631 	/* the qspan pci read routines can cause machine checks -- Cort
632 	 *
633 	 * yuck !!! that totally needs to go away ! There are better ways
634 	 * to deal with that than having a wart in the mcheck handler.
635 	 * -- BenH
636 	 */
637 	bad_page_fault(regs, regs->dar, SIGBUS);
638 	return;
639 #endif
640 
641 	if (debugger_fault_handler(regs)) {
642 		regs->msr |= MSR_RI;
643 		return;
644 	}
645 
646 	if (check_io_access(regs))
647 		return;
648 
649 	if (debugger_fault_handler(regs))
650 		return;
651 	die("Machine check", regs, SIGBUS);
652 
653 	/* Must die if the interrupt is not recoverable */
654 	if (!(regs->msr & MSR_RI))
655 		panic("Unrecoverable Machine check");
656 }
657 
658 void SMIException(struct pt_regs *regs)
659 {
660 	die("System Management Interrupt", regs, SIGABRT);
661 }
662 
663 void unknown_exception(struct pt_regs *regs)
664 {
665 	printk("Bad trap at PC: %lx, SR: %lx, vector=%lx\n",
666 	       regs->nip, regs->msr, regs->trap);
667 
668 	_exception(SIGTRAP, regs, 0, 0);
669 }
670 
671 void instruction_breakpoint_exception(struct pt_regs *regs)
672 {
673 	if (notify_die(DIE_IABR_MATCH, "iabr_match", regs, 5,
674 					5, SIGTRAP) == NOTIFY_STOP)
675 		return;
676 	if (debugger_iabr_match(regs))
677 		return;
678 	_exception(SIGTRAP, regs, TRAP_BRKPT, regs->nip);
679 }
680 
681 void RunModeException(struct pt_regs *regs)
682 {
683 	_exception(SIGTRAP, regs, 0, 0);
684 }
685 
686 void __kprobes single_step_exception(struct pt_regs *regs)
687 {
688 	clear_single_step(regs);
689 
690 	if (notify_die(DIE_SSTEP, "single_step", regs, 5,
691 					5, SIGTRAP) == NOTIFY_STOP)
692 		return;
693 	if (debugger_sstep(regs))
694 		return;
695 
696 	_exception(SIGTRAP, regs, TRAP_TRACE, regs->nip);
697 }
698 
699 /*
700  * After we have successfully emulated an instruction, we have to
701  * check if the instruction was being single-stepped, and if so,
702  * pretend we got a single-step exception.  This was pointed out
703  * by Kumar Gala.  -- paulus
704  */
705 static void emulate_single_step(struct pt_regs *regs)
706 {
707 	if (single_stepping(regs))
708 		single_step_exception(regs);
709 }
710 
711 static inline int __parse_fpscr(unsigned long fpscr)
712 {
713 	int ret = 0;
714 
715 	/* Invalid operation */
716 	if ((fpscr & FPSCR_VE) && (fpscr & FPSCR_VX))
717 		ret = FPE_FLTINV;
718 
719 	/* Overflow */
720 	else if ((fpscr & FPSCR_OE) && (fpscr & FPSCR_OX))
721 		ret = FPE_FLTOVF;
722 
723 	/* Underflow */
724 	else if ((fpscr & FPSCR_UE) && (fpscr & FPSCR_UX))
725 		ret = FPE_FLTUND;
726 
727 	/* Divide by zero */
728 	else if ((fpscr & FPSCR_ZE) && (fpscr & FPSCR_ZX))
729 		ret = FPE_FLTDIV;
730 
731 	/* Inexact result */
732 	else if ((fpscr & FPSCR_XE) && (fpscr & FPSCR_XX))
733 		ret = FPE_FLTRES;
734 
735 	return ret;
736 }
737 
738 static void parse_fpe(struct pt_regs *regs)
739 {
740 	int code = 0;
741 
742 	flush_fp_to_thread(current);
743 
744 	code = __parse_fpscr(current->thread.fpscr.val);
745 
746 	_exception(SIGFPE, regs, code, regs->nip);
747 }
748 
749 /*
750  * Illegal instruction emulation support.  Originally written to
751  * provide the PVR to user applications using the mfspr rd, PVR.
752  * Return non-zero if we can't emulate, or -EFAULT if the associated
753  * memory access caused an access fault.  Return zero on success.
754  *
755  * There are a couple of ways to do this, either "decode" the instruction
756  * or directly match lots of bits.  In this case, matching lots of
757  * bits is faster and easier.
758  *
759  */
760 static int emulate_string_inst(struct pt_regs *regs, u32 instword)
761 {
762 	u8 rT = (instword >> 21) & 0x1f;
763 	u8 rA = (instword >> 16) & 0x1f;
764 	u8 NB_RB = (instword >> 11) & 0x1f;
765 	u32 num_bytes;
766 	unsigned long EA;
767 	int pos = 0;
768 
769 	/* Early out if we are an invalid form of lswx */
770 	if ((instword & PPC_INST_STRING_MASK) == PPC_INST_LSWX)
771 		if ((rT == rA) || (rT == NB_RB))
772 			return -EINVAL;
773 
774 	EA = (rA == 0) ? 0 : regs->gpr[rA];
775 
776 	switch (instword & PPC_INST_STRING_MASK) {
777 		case PPC_INST_LSWX:
778 		case PPC_INST_STSWX:
779 			EA += NB_RB;
780 			num_bytes = regs->xer & 0x7f;
781 			break;
782 		case PPC_INST_LSWI:
783 		case PPC_INST_STSWI:
784 			num_bytes = (NB_RB == 0) ? 32 : NB_RB;
785 			break;
786 		default:
787 			return -EINVAL;
788 	}
789 
790 	while (num_bytes != 0)
791 	{
792 		u8 val;
793 		u32 shift = 8 * (3 - (pos & 0x3));
794 
795 		switch ((instword & PPC_INST_STRING_MASK)) {
796 			case PPC_INST_LSWX:
797 			case PPC_INST_LSWI:
798 				if (get_user(val, (u8 __user *)EA))
799 					return -EFAULT;
800 				/* first time updating this reg,
801 				 * zero it out */
802 				if (pos == 0)
803 					regs->gpr[rT] = 0;
804 				regs->gpr[rT] |= val << shift;
805 				break;
806 			case PPC_INST_STSWI:
807 			case PPC_INST_STSWX:
808 				val = regs->gpr[rT] >> shift;
809 				if (put_user(val, (u8 __user *)EA))
810 					return -EFAULT;
811 				break;
812 		}
813 		/* move EA to next address */
814 		EA += 1;
815 		num_bytes--;
816 
817 		/* manage our position within the register */
818 		if (++pos == 4) {
819 			pos = 0;
820 			if (++rT == 32)
821 				rT = 0;
822 		}
823 	}
824 
825 	return 0;
826 }
827 
828 static int emulate_popcntb_inst(struct pt_regs *regs, u32 instword)
829 {
830 	u32 ra,rs;
831 	unsigned long tmp;
832 
833 	ra = (instword >> 16) & 0x1f;
834 	rs = (instword >> 21) & 0x1f;
835 
836 	tmp = regs->gpr[rs];
837 	tmp = tmp - ((tmp >> 1) & 0x5555555555555555ULL);
838 	tmp = (tmp & 0x3333333333333333ULL) + ((tmp >> 2) & 0x3333333333333333ULL);
839 	tmp = (tmp + (tmp >> 4)) & 0x0f0f0f0f0f0f0f0fULL;
840 	regs->gpr[ra] = tmp;
841 
842 	return 0;
843 }
844 
845 static int emulate_isel(struct pt_regs *regs, u32 instword)
846 {
847 	u8 rT = (instword >> 21) & 0x1f;
848 	u8 rA = (instword >> 16) & 0x1f;
849 	u8 rB = (instword >> 11) & 0x1f;
850 	u8 BC = (instword >> 6) & 0x1f;
851 	u8 bit;
852 	unsigned long tmp;
853 
854 	tmp = (rA == 0) ? 0 : regs->gpr[rA];
855 	bit = (regs->ccr >> (31 - BC)) & 0x1;
856 
857 	regs->gpr[rT] = bit ? tmp : regs->gpr[rB];
858 
859 	return 0;
860 }
861 
862 static int emulate_instruction(struct pt_regs *regs)
863 {
864 	u32 instword;
865 	u32 rd;
866 
867 	if (!user_mode(regs) || (regs->msr & MSR_LE))
868 		return -EINVAL;
869 	CHECK_FULL_REGS(regs);
870 
871 	if (get_user(instword, (u32 __user *)(regs->nip)))
872 		return -EFAULT;
873 
874 	/* Emulate the mfspr rD, PVR. */
875 	if ((instword & PPC_INST_MFSPR_PVR_MASK) == PPC_INST_MFSPR_PVR) {
876 		PPC_WARN_EMULATED(mfpvr, regs);
877 		rd = (instword >> 21) & 0x1f;
878 		regs->gpr[rd] = mfspr(SPRN_PVR);
879 		return 0;
880 	}
881 
882 	/* Emulating the dcba insn is just a no-op.  */
883 	if ((instword & PPC_INST_DCBA_MASK) == PPC_INST_DCBA) {
884 		PPC_WARN_EMULATED(dcba, regs);
885 		return 0;
886 	}
887 
888 	/* Emulate the mcrxr insn.  */
889 	if ((instword & PPC_INST_MCRXR_MASK) == PPC_INST_MCRXR) {
890 		int shift = (instword >> 21) & 0x1c;
891 		unsigned long msk = 0xf0000000UL >> shift;
892 
893 		PPC_WARN_EMULATED(mcrxr, regs);
894 		regs->ccr = (regs->ccr & ~msk) | ((regs->xer >> shift) & msk);
895 		regs->xer &= ~0xf0000000UL;
896 		return 0;
897 	}
898 
899 	/* Emulate load/store string insn. */
900 	if ((instword & PPC_INST_STRING_GEN_MASK) == PPC_INST_STRING) {
901 		PPC_WARN_EMULATED(string, regs);
902 		return emulate_string_inst(regs, instword);
903 	}
904 
905 	/* Emulate the popcntb (Population Count Bytes) instruction. */
906 	if ((instword & PPC_INST_POPCNTB_MASK) == PPC_INST_POPCNTB) {
907 		PPC_WARN_EMULATED(popcntb, regs);
908 		return emulate_popcntb_inst(regs, instword);
909 	}
910 
911 	/* Emulate isel (Integer Select) instruction */
912 	if ((instword & PPC_INST_ISEL_MASK) == PPC_INST_ISEL) {
913 		PPC_WARN_EMULATED(isel, regs);
914 		return emulate_isel(regs, instword);
915 	}
916 
917 	return -EINVAL;
918 }
919 
920 int is_valid_bugaddr(unsigned long addr)
921 {
922 	return is_kernel_addr(addr);
923 }
924 
925 void __kprobes program_check_exception(struct pt_regs *regs)
926 {
927 	unsigned int reason = get_reason(regs);
928 	extern int do_mathemu(struct pt_regs *regs);
929 
930 	/* We can now get here via a FP Unavailable exception if the core
931 	 * has no FPU, in that case the reason flags will be 0 */
932 
933 	if (reason & REASON_FP) {
934 		/* IEEE FP exception */
935 		parse_fpe(regs);
936 		return;
937 	}
938 	if (reason & REASON_TRAP) {
939 		/* Debugger is first in line to stop recursive faults in
940 		 * rcu_lock, notify_die, or atomic_notifier_call_chain */
941 		if (debugger_bpt(regs))
942 			return;
943 
944 		/* trap exception */
945 		if (notify_die(DIE_BPT, "breakpoint", regs, 5, 5, SIGTRAP)
946 				== NOTIFY_STOP)
947 			return;
948 
949 		if (!(regs->msr & MSR_PR) &&  /* not user-mode */
950 		    report_bug(regs->nip, regs) == BUG_TRAP_TYPE_WARN) {
951 			regs->nip += 4;
952 			return;
953 		}
954 		_exception(SIGTRAP, regs, TRAP_BRKPT, regs->nip);
955 		return;
956 	}
957 
958 	local_irq_enable();
959 
960 #ifdef CONFIG_MATH_EMULATION
961 	/* (reason & REASON_ILLEGAL) would be the obvious thing here,
962 	 * but there seems to be a hardware bug on the 405GP (RevD)
963 	 * that means ESR is sometimes set incorrectly - either to
964 	 * ESR_DST (!?) or 0.  In the process of chasing this with the
965 	 * hardware people - not sure if it can happen on any illegal
966 	 * instruction or only on FP instructions, whether there is a
967 	 * pattern to occurences etc. -dgibson 31/Mar/2003 */
968 	switch (do_mathemu(regs)) {
969 	case 0:
970 		emulate_single_step(regs);
971 		return;
972 	case 1: {
973 			int code = 0;
974 			code = __parse_fpscr(current->thread.fpscr.val);
975 			_exception(SIGFPE, regs, code, regs->nip);
976 			return;
977 		}
978 	case -EFAULT:
979 		_exception(SIGSEGV, regs, SEGV_MAPERR, regs->nip);
980 		return;
981 	}
982 	/* fall through on any other errors */
983 #endif /* CONFIG_MATH_EMULATION */
984 
985 	/* Try to emulate it if we should. */
986 	if (reason & (REASON_ILLEGAL | REASON_PRIVILEGED)) {
987 		switch (emulate_instruction(regs)) {
988 		case 0:
989 			regs->nip += 4;
990 			emulate_single_step(regs);
991 			return;
992 		case -EFAULT:
993 			_exception(SIGSEGV, regs, SEGV_MAPERR, regs->nip);
994 			return;
995 		}
996 	}
997 
998 	if (reason & REASON_PRIVILEGED)
999 		_exception(SIGILL, regs, ILL_PRVOPC, regs->nip);
1000 	else
1001 		_exception(SIGILL, regs, ILL_ILLOPC, regs->nip);
1002 }
1003 
1004 void alignment_exception(struct pt_regs *regs)
1005 {
1006 	int sig, code, fixed = 0;
1007 
1008 	/* we don't implement logging of alignment exceptions */
1009 	if (!(current->thread.align_ctl & PR_UNALIGN_SIGBUS))
1010 		fixed = fix_alignment(regs);
1011 
1012 	if (fixed == 1) {
1013 		regs->nip += 4;	/* skip over emulated instruction */
1014 		emulate_single_step(regs);
1015 		return;
1016 	}
1017 
1018 	/* Operand address was bad */
1019 	if (fixed == -EFAULT) {
1020 		sig = SIGSEGV;
1021 		code = SEGV_ACCERR;
1022 	} else {
1023 		sig = SIGBUS;
1024 		code = BUS_ADRALN;
1025 	}
1026 	if (user_mode(regs))
1027 		_exception(sig, regs, code, regs->dar);
1028 	else
1029 		bad_page_fault(regs, regs->dar, sig);
1030 }
1031 
1032 void StackOverflow(struct pt_regs *regs)
1033 {
1034 	printk(KERN_CRIT "Kernel stack overflow in process %p, r1=%lx\n",
1035 	       current, regs->gpr[1]);
1036 	debugger(regs);
1037 	show_regs(regs);
1038 	panic("kernel stack overflow");
1039 }
1040 
1041 void nonrecoverable_exception(struct pt_regs *regs)
1042 {
1043 	printk(KERN_ERR "Non-recoverable exception at PC=%lx MSR=%lx\n",
1044 	       regs->nip, regs->msr);
1045 	debugger(regs);
1046 	die("nonrecoverable exception", regs, SIGKILL);
1047 }
1048 
1049 void trace_syscall(struct pt_regs *regs)
1050 {
1051 	printk("Task: %p(%d), PC: %08lX/%08lX, Syscall: %3ld, Result: %s%ld    %s\n",
1052 	       current, task_pid_nr(current), regs->nip, regs->link, regs->gpr[0],
1053 	       regs->ccr&0x10000000?"Error=":"", regs->gpr[3], print_tainted());
1054 }
1055 
1056 void kernel_fp_unavailable_exception(struct pt_regs *regs)
1057 {
1058 	printk(KERN_EMERG "Unrecoverable FP Unavailable Exception "
1059 			  "%lx at %lx\n", regs->trap, regs->nip);
1060 	die("Unrecoverable FP Unavailable Exception", regs, SIGABRT);
1061 }
1062 
1063 void altivec_unavailable_exception(struct pt_regs *regs)
1064 {
1065 	if (user_mode(regs)) {
1066 		/* A user program has executed an altivec instruction,
1067 		   but this kernel doesn't support altivec. */
1068 		_exception(SIGILL, regs, ILL_ILLOPC, regs->nip);
1069 		return;
1070 	}
1071 
1072 	printk(KERN_EMERG "Unrecoverable VMX/Altivec Unavailable Exception "
1073 			"%lx at %lx\n", regs->trap, regs->nip);
1074 	die("Unrecoverable VMX/Altivec Unavailable Exception", regs, SIGABRT);
1075 }
1076 
1077 void vsx_unavailable_exception(struct pt_regs *regs)
1078 {
1079 	if (user_mode(regs)) {
1080 		/* A user program has executed an vsx instruction,
1081 		   but this kernel doesn't support vsx. */
1082 		_exception(SIGILL, regs, ILL_ILLOPC, regs->nip);
1083 		return;
1084 	}
1085 
1086 	printk(KERN_EMERG "Unrecoverable VSX Unavailable Exception "
1087 			"%lx at %lx\n", regs->trap, regs->nip);
1088 	die("Unrecoverable VSX Unavailable Exception", regs, SIGABRT);
1089 }
1090 
1091 void performance_monitor_exception(struct pt_regs *regs)
1092 {
1093 	__get_cpu_var(irq_stat).pmu_irqs++;
1094 
1095 	perf_irq(regs);
1096 }
1097 
1098 #ifdef CONFIG_8xx
1099 void SoftwareEmulation(struct pt_regs *regs)
1100 {
1101 	extern int do_mathemu(struct pt_regs *);
1102 	extern int Soft_emulate_8xx(struct pt_regs *);
1103 #if defined(CONFIG_MATH_EMULATION) || defined(CONFIG_8XX_MINIMAL_FPEMU)
1104 	int errcode;
1105 #endif
1106 
1107 	CHECK_FULL_REGS(regs);
1108 
1109 	if (!user_mode(regs)) {
1110 		debugger(regs);
1111 		die("Kernel Mode Software FPU Emulation", regs, SIGFPE);
1112 	}
1113 
1114 #ifdef CONFIG_MATH_EMULATION
1115 	errcode = do_mathemu(regs);
1116 	if (errcode >= 0)
1117 		PPC_WARN_EMULATED(math, regs);
1118 
1119 	switch (errcode) {
1120 	case 0:
1121 		emulate_single_step(regs);
1122 		return;
1123 	case 1: {
1124 			int code = 0;
1125 			code = __parse_fpscr(current->thread.fpscr.val);
1126 			_exception(SIGFPE, regs, code, regs->nip);
1127 			return;
1128 		}
1129 	case -EFAULT:
1130 		_exception(SIGSEGV, regs, SEGV_MAPERR, regs->nip);
1131 		return;
1132 	default:
1133 		_exception(SIGILL, regs, ILL_ILLOPC, regs->nip);
1134 		return;
1135 	}
1136 
1137 #elif defined(CONFIG_8XX_MINIMAL_FPEMU)
1138 	errcode = Soft_emulate_8xx(regs);
1139 	if (errcode >= 0)
1140 		PPC_WARN_EMULATED(8xx, regs);
1141 
1142 	switch (errcode) {
1143 	case 0:
1144 		emulate_single_step(regs);
1145 		return;
1146 	case 1:
1147 		_exception(SIGILL, regs, ILL_ILLOPC, regs->nip);
1148 		return;
1149 	case -EFAULT:
1150 		_exception(SIGSEGV, regs, SEGV_MAPERR, regs->nip);
1151 		return;
1152 	}
1153 #else
1154 	_exception(SIGILL, regs, ILL_ILLOPC, regs->nip);
1155 #endif
1156 }
1157 #endif /* CONFIG_8xx */
1158 
1159 #ifdef CONFIG_PPC_ADV_DEBUG_REGS
1160 static void handle_debug(struct pt_regs *regs, unsigned long debug_status)
1161 {
1162 	int changed = 0;
1163 	/*
1164 	 * Determine the cause of the debug event, clear the
1165 	 * event flags and send a trap to the handler. Torez
1166 	 */
1167 	if (debug_status & (DBSR_DAC1R | DBSR_DAC1W)) {
1168 		dbcr_dac(current) &= ~(DBCR_DAC1R | DBCR_DAC1W);
1169 #ifdef CONFIG_PPC_ADV_DEBUG_DAC_RANGE
1170 		current->thread.dbcr2 &= ~DBCR2_DAC12MODE;
1171 #endif
1172 		do_send_trap(regs, mfspr(SPRN_DAC1), debug_status, TRAP_HWBKPT,
1173 			     5);
1174 		changed |= 0x01;
1175 	}  else if (debug_status & (DBSR_DAC2R | DBSR_DAC2W)) {
1176 		dbcr_dac(current) &= ~(DBCR_DAC2R | DBCR_DAC2W);
1177 		do_send_trap(regs, mfspr(SPRN_DAC2), debug_status, TRAP_HWBKPT,
1178 			     6);
1179 		changed |= 0x01;
1180 	}  else if (debug_status & DBSR_IAC1) {
1181 		current->thread.dbcr0 &= ~DBCR0_IAC1;
1182 		dbcr_iac_range(current) &= ~DBCR_IAC12MODE;
1183 		do_send_trap(regs, mfspr(SPRN_IAC1), debug_status, TRAP_HWBKPT,
1184 			     1);
1185 		changed |= 0x01;
1186 	}  else if (debug_status & DBSR_IAC2) {
1187 		current->thread.dbcr0 &= ~DBCR0_IAC2;
1188 		do_send_trap(regs, mfspr(SPRN_IAC2), debug_status, TRAP_HWBKPT,
1189 			     2);
1190 		changed |= 0x01;
1191 	}  else if (debug_status & DBSR_IAC3) {
1192 		current->thread.dbcr0 &= ~DBCR0_IAC3;
1193 		dbcr_iac_range(current) &= ~DBCR_IAC34MODE;
1194 		do_send_trap(regs, mfspr(SPRN_IAC3), debug_status, TRAP_HWBKPT,
1195 			     3);
1196 		changed |= 0x01;
1197 	}  else if (debug_status & DBSR_IAC4) {
1198 		current->thread.dbcr0 &= ~DBCR0_IAC4;
1199 		do_send_trap(regs, mfspr(SPRN_IAC4), debug_status, TRAP_HWBKPT,
1200 			     4);
1201 		changed |= 0x01;
1202 	}
1203 	/*
1204 	 * At the point this routine was called, the MSR(DE) was turned off.
1205 	 * Check all other debug flags and see if that bit needs to be turned
1206 	 * back on or not.
1207 	 */
1208 	if (DBCR_ACTIVE_EVENTS(current->thread.dbcr0, current->thread.dbcr1))
1209 		regs->msr |= MSR_DE;
1210 	else
1211 		/* Make sure the IDM flag is off */
1212 		current->thread.dbcr0 &= ~DBCR0_IDM;
1213 
1214 	if (changed & 0x01)
1215 		mtspr(SPRN_DBCR0, current->thread.dbcr0);
1216 }
1217 
1218 void __kprobes DebugException(struct pt_regs *regs, unsigned long debug_status)
1219 {
1220 	current->thread.dbsr = debug_status;
1221 
1222 	/* Hack alert: On BookE, Branch Taken stops on the branch itself, while
1223 	 * on server, it stops on the target of the branch. In order to simulate
1224 	 * the server behaviour, we thus restart right away with a single step
1225 	 * instead of stopping here when hitting a BT
1226 	 */
1227 	if (debug_status & DBSR_BT) {
1228 		regs->msr &= ~MSR_DE;
1229 
1230 		/* Disable BT */
1231 		mtspr(SPRN_DBCR0, mfspr(SPRN_DBCR0) & ~DBCR0_BT);
1232 		/* Clear the BT event */
1233 		mtspr(SPRN_DBSR, DBSR_BT);
1234 
1235 		/* Do the single step trick only when coming from userspace */
1236 		if (user_mode(regs)) {
1237 			current->thread.dbcr0 &= ~DBCR0_BT;
1238 			current->thread.dbcr0 |= DBCR0_IDM | DBCR0_IC;
1239 			regs->msr |= MSR_DE;
1240 			return;
1241 		}
1242 
1243 		if (notify_die(DIE_SSTEP, "block_step", regs, 5,
1244 			       5, SIGTRAP) == NOTIFY_STOP) {
1245 			return;
1246 		}
1247 		if (debugger_sstep(regs))
1248 			return;
1249 	} else if (debug_status & DBSR_IC) { 	/* Instruction complete */
1250 		regs->msr &= ~MSR_DE;
1251 
1252 		/* Disable instruction completion */
1253 		mtspr(SPRN_DBCR0, mfspr(SPRN_DBCR0) & ~DBCR0_IC);
1254 		/* Clear the instruction completion event */
1255 		mtspr(SPRN_DBSR, DBSR_IC);
1256 
1257 		if (notify_die(DIE_SSTEP, "single_step", regs, 5,
1258 			       5, SIGTRAP) == NOTIFY_STOP) {
1259 			return;
1260 		}
1261 
1262 		if (debugger_sstep(regs))
1263 			return;
1264 
1265 		if (user_mode(regs)) {
1266 			current->thread.dbcr0 &= ~DBCR0_IC;
1267 #ifdef CONFIG_PPC_ADV_DEBUG_REGS
1268 			if (DBCR_ACTIVE_EVENTS(current->thread.dbcr0,
1269 					       current->thread.dbcr1))
1270 				regs->msr |= MSR_DE;
1271 			else
1272 				/* Make sure the IDM bit is off */
1273 				current->thread.dbcr0 &= ~DBCR0_IDM;
1274 #endif
1275 		}
1276 
1277 		_exception(SIGTRAP, regs, TRAP_TRACE, regs->nip);
1278 	} else
1279 		handle_debug(regs, debug_status);
1280 }
1281 #endif /* CONFIG_PPC_ADV_DEBUG_REGS */
1282 
1283 #if !defined(CONFIG_TAU_INT)
1284 void TAUException(struct pt_regs *regs)
1285 {
1286 	printk("TAU trap at PC: %lx, MSR: %lx, vector=%lx    %s\n",
1287 	       regs->nip, regs->msr, regs->trap, print_tainted());
1288 }
1289 #endif /* CONFIG_INT_TAU */
1290 
1291 #ifdef CONFIG_ALTIVEC
1292 void altivec_assist_exception(struct pt_regs *regs)
1293 {
1294 	int err;
1295 
1296 	if (!user_mode(regs)) {
1297 		printk(KERN_EMERG "VMX/Altivec assist exception in kernel mode"
1298 		       " at %lx\n", regs->nip);
1299 		die("Kernel VMX/Altivec assist exception", regs, SIGILL);
1300 	}
1301 
1302 	flush_altivec_to_thread(current);
1303 
1304 	PPC_WARN_EMULATED(altivec, regs);
1305 	err = emulate_altivec(regs);
1306 	if (err == 0) {
1307 		regs->nip += 4;		/* skip emulated instruction */
1308 		emulate_single_step(regs);
1309 		return;
1310 	}
1311 
1312 	if (err == -EFAULT) {
1313 		/* got an error reading the instruction */
1314 		_exception(SIGSEGV, regs, SEGV_ACCERR, regs->nip);
1315 	} else {
1316 		/* didn't recognize the instruction */
1317 		/* XXX quick hack for now: set the non-Java bit in the VSCR */
1318 		if (printk_ratelimit())
1319 			printk(KERN_ERR "Unrecognized altivec instruction "
1320 			       "in %s at %lx\n", current->comm, regs->nip);
1321 		current->thread.vscr.u[3] |= 0x10000;
1322 	}
1323 }
1324 #endif /* CONFIG_ALTIVEC */
1325 
1326 #ifdef CONFIG_VSX
1327 void vsx_assist_exception(struct pt_regs *regs)
1328 {
1329 	if (!user_mode(regs)) {
1330 		printk(KERN_EMERG "VSX assist exception in kernel mode"
1331 		       " at %lx\n", regs->nip);
1332 		die("Kernel VSX assist exception", regs, SIGILL);
1333 	}
1334 
1335 	flush_vsx_to_thread(current);
1336 	printk(KERN_INFO "VSX assist not supported at %lx\n", regs->nip);
1337 	_exception(SIGILL, regs, ILL_ILLOPC, regs->nip);
1338 }
1339 #endif /* CONFIG_VSX */
1340 
1341 #ifdef CONFIG_FSL_BOOKE
1342 void CacheLockingException(struct pt_regs *regs, unsigned long address,
1343 			   unsigned long error_code)
1344 {
1345 	/* We treat cache locking instructions from the user
1346 	 * as priv ops, in the future we could try to do
1347 	 * something smarter
1348 	 */
1349 	if (error_code & (ESR_DLK|ESR_ILK))
1350 		_exception(SIGILL, regs, ILL_PRVOPC, regs->nip);
1351 	return;
1352 }
1353 #endif /* CONFIG_FSL_BOOKE */
1354 
1355 #ifdef CONFIG_SPE
1356 void SPEFloatingPointException(struct pt_regs *regs)
1357 {
1358 	extern int do_spe_mathemu(struct pt_regs *regs);
1359 	unsigned long spefscr;
1360 	int fpexc_mode;
1361 	int code = 0;
1362 	int err;
1363 
1364 	preempt_disable();
1365 	if (regs->msr & MSR_SPE)
1366 		giveup_spe(current);
1367 	preempt_enable();
1368 
1369 	spefscr = current->thread.spefscr;
1370 	fpexc_mode = current->thread.fpexc_mode;
1371 
1372 	if ((spefscr & SPEFSCR_FOVF) && (fpexc_mode & PR_FP_EXC_OVF)) {
1373 		code = FPE_FLTOVF;
1374 	}
1375 	else if ((spefscr & SPEFSCR_FUNF) && (fpexc_mode & PR_FP_EXC_UND)) {
1376 		code = FPE_FLTUND;
1377 	}
1378 	else if ((spefscr & SPEFSCR_FDBZ) && (fpexc_mode & PR_FP_EXC_DIV))
1379 		code = FPE_FLTDIV;
1380 	else if ((spefscr & SPEFSCR_FINV) && (fpexc_mode & PR_FP_EXC_INV)) {
1381 		code = FPE_FLTINV;
1382 	}
1383 	else if ((spefscr & (SPEFSCR_FG | SPEFSCR_FX)) && (fpexc_mode & PR_FP_EXC_RES))
1384 		code = FPE_FLTRES;
1385 
1386 	err = do_spe_mathemu(regs);
1387 	if (err == 0) {
1388 		regs->nip += 4;		/* skip emulated instruction */
1389 		emulate_single_step(regs);
1390 		return;
1391 	}
1392 
1393 	if (err == -EFAULT) {
1394 		/* got an error reading the instruction */
1395 		_exception(SIGSEGV, regs, SEGV_ACCERR, regs->nip);
1396 	} else if (err == -EINVAL) {
1397 		/* didn't recognize the instruction */
1398 		printk(KERN_ERR "unrecognized spe instruction "
1399 		       "in %s at %lx\n", current->comm, regs->nip);
1400 	} else {
1401 		_exception(SIGFPE, regs, code, regs->nip);
1402 	}
1403 
1404 	return;
1405 }
1406 
1407 void SPEFloatingPointRoundException(struct pt_regs *regs)
1408 {
1409 	extern int speround_handler(struct pt_regs *regs);
1410 	int err;
1411 
1412 	preempt_disable();
1413 	if (regs->msr & MSR_SPE)
1414 		giveup_spe(current);
1415 	preempt_enable();
1416 
1417 	regs->nip -= 4;
1418 	err = speround_handler(regs);
1419 	if (err == 0) {
1420 		regs->nip += 4;		/* skip emulated instruction */
1421 		emulate_single_step(regs);
1422 		return;
1423 	}
1424 
1425 	if (err == -EFAULT) {
1426 		/* got an error reading the instruction */
1427 		_exception(SIGSEGV, regs, SEGV_ACCERR, regs->nip);
1428 	} else if (err == -EINVAL) {
1429 		/* didn't recognize the instruction */
1430 		printk(KERN_ERR "unrecognized spe instruction "
1431 		       "in %s at %lx\n", current->comm, regs->nip);
1432 	} else {
1433 		_exception(SIGFPE, regs, 0, regs->nip);
1434 		return;
1435 	}
1436 }
1437 #endif
1438 
1439 /*
1440  * We enter here if we get an unrecoverable exception, that is, one
1441  * that happened at a point where the RI (recoverable interrupt) bit
1442  * in the MSR is 0.  This indicates that SRR0/1 are live, and that
1443  * we therefore lost state by taking this exception.
1444  */
1445 void unrecoverable_exception(struct pt_regs *regs)
1446 {
1447 	printk(KERN_EMERG "Unrecoverable exception %lx at %lx\n",
1448 	       regs->trap, regs->nip);
1449 	die("Unrecoverable exception", regs, SIGABRT);
1450 }
1451 
1452 #ifdef CONFIG_BOOKE_WDT
1453 /*
1454  * Default handler for a Watchdog exception,
1455  * spins until a reboot occurs
1456  */
1457 void __attribute__ ((weak)) WatchdogHandler(struct pt_regs *regs)
1458 {
1459 	/* Generic WatchdogHandler, implement your own */
1460 	mtspr(SPRN_TCR, mfspr(SPRN_TCR)&(~TCR_WIE));
1461 	return;
1462 }
1463 
1464 void WatchdogException(struct pt_regs *regs)
1465 {
1466 	printk (KERN_EMERG "PowerPC Book-E Watchdog Exception\n");
1467 	WatchdogHandler(regs);
1468 }
1469 #endif
1470 
1471 /*
1472  * We enter here if we discover during exception entry that we are
1473  * running in supervisor mode with a userspace value in the stack pointer.
1474  */
1475 void kernel_bad_stack(struct pt_regs *regs)
1476 {
1477 	printk(KERN_EMERG "Bad kernel stack pointer %lx at %lx\n",
1478 	       regs->gpr[1], regs->nip);
1479 	die("Bad kernel stack pointer", regs, SIGABRT);
1480 }
1481 
1482 void __init trap_init(void)
1483 {
1484 }
1485 
1486 
1487 #ifdef CONFIG_PPC_EMULATED_STATS
1488 
1489 #define WARN_EMULATED_SETUP(type)	.type = { .name = #type }
1490 
1491 struct ppc_emulated ppc_emulated = {
1492 #ifdef CONFIG_ALTIVEC
1493 	WARN_EMULATED_SETUP(altivec),
1494 #endif
1495 	WARN_EMULATED_SETUP(dcba),
1496 	WARN_EMULATED_SETUP(dcbz),
1497 	WARN_EMULATED_SETUP(fp_pair),
1498 	WARN_EMULATED_SETUP(isel),
1499 	WARN_EMULATED_SETUP(mcrxr),
1500 	WARN_EMULATED_SETUP(mfpvr),
1501 	WARN_EMULATED_SETUP(multiple),
1502 	WARN_EMULATED_SETUP(popcntb),
1503 	WARN_EMULATED_SETUP(spe),
1504 	WARN_EMULATED_SETUP(string),
1505 	WARN_EMULATED_SETUP(unaligned),
1506 #ifdef CONFIG_MATH_EMULATION
1507 	WARN_EMULATED_SETUP(math),
1508 #elif defined(CONFIG_8XX_MINIMAL_FPEMU)
1509 	WARN_EMULATED_SETUP(8xx),
1510 #endif
1511 #ifdef CONFIG_VSX
1512 	WARN_EMULATED_SETUP(vsx),
1513 #endif
1514 };
1515 
1516 u32 ppc_warn_emulated;
1517 
1518 void ppc_warn_emulated_print(const char *type)
1519 {
1520 	if (printk_ratelimit())
1521 		pr_warning("%s used emulated %s instruction\n", current->comm,
1522 			   type);
1523 }
1524 
1525 static int __init ppc_warn_emulated_init(void)
1526 {
1527 	struct dentry *dir, *d;
1528 	unsigned int i;
1529 	struct ppc_emulated_entry *entries = (void *)&ppc_emulated;
1530 
1531 	if (!powerpc_debugfs_root)
1532 		return -ENODEV;
1533 
1534 	dir = debugfs_create_dir("emulated_instructions",
1535 				 powerpc_debugfs_root);
1536 	if (!dir)
1537 		return -ENOMEM;
1538 
1539 	d = debugfs_create_u32("do_warn", S_IRUGO | S_IWUSR, dir,
1540 			       &ppc_warn_emulated);
1541 	if (!d)
1542 		goto fail;
1543 
1544 	for (i = 0; i < sizeof(ppc_emulated)/sizeof(*entries); i++) {
1545 		d = debugfs_create_u32(entries[i].name, S_IRUGO | S_IWUSR, dir,
1546 				       (u32 *)&entries[i].val.counter);
1547 		if (!d)
1548 			goto fail;
1549 	}
1550 
1551 	return 0;
1552 
1553 fail:
1554 	debugfs_remove_recursive(dir);
1555 	return -ENOMEM;
1556 }
1557 
1558 device_initcall(ppc_warn_emulated_init);
1559 
1560 #endif /* CONFIG_PPC_EMULATED_STATS */
1561