xref: /linux/arch/powerpc/kernel/traps.c (revision a33f32244d8550da8b4a26e277ce07d5c6d158b5)
1 /*
2  *  Copyright (C) 1995-1996  Gary Thomas (gdt@linuxppc.org)
3  *
4  *  This program is free software; you can redistribute it and/or
5  *  modify it under the terms of the GNU General Public License
6  *  as published by the Free Software Foundation; either version
7  *  2 of the License, or (at your option) any later version.
8  *
9  *  Modified by Cort Dougan (cort@cs.nmt.edu)
10  *  and Paul Mackerras (paulus@samba.org)
11  */
12 
13 /*
14  * This file handles the architecture-dependent parts of hardware exceptions
15  */
16 
17 #include <linux/errno.h>
18 #include <linux/sched.h>
19 #include <linux/kernel.h>
20 #include <linux/mm.h>
21 #include <linux/stddef.h>
22 #include <linux/unistd.h>
23 #include <linux/ptrace.h>
24 #include <linux/user.h>
25 #include <linux/interrupt.h>
26 #include <linux/init.h>
27 #include <linux/module.h>
28 #include <linux/prctl.h>
29 #include <linux/delay.h>
30 #include <linux/kprobes.h>
31 #include <linux/kexec.h>
32 #include <linux/backlight.h>
33 #include <linux/bug.h>
34 #include <linux/kdebug.h>
35 #include <linux/debugfs.h>
36 
37 #include <asm/emulated_ops.h>
38 #include <asm/pgtable.h>
39 #include <asm/uaccess.h>
40 #include <asm/system.h>
41 #include <asm/io.h>
42 #include <asm/machdep.h>
43 #include <asm/rtas.h>
44 #include <asm/pmc.h>
45 #ifdef CONFIG_PPC32
46 #include <asm/reg.h>
47 #endif
48 #ifdef CONFIG_PMAC_BACKLIGHT
49 #include <asm/backlight.h>
50 #endif
51 #ifdef CONFIG_PPC64
52 #include <asm/firmware.h>
53 #include <asm/processor.h>
54 #endif
55 #include <asm/kexec.h>
56 #include <asm/ppc-opcode.h>
57 #ifdef CONFIG_FSL_BOOKE
58 #include <asm/dbell.h>
59 #endif
60 
61 #if defined(CONFIG_DEBUGGER) || defined(CONFIG_KEXEC)
62 int (*__debugger)(struct pt_regs *regs) __read_mostly;
63 int (*__debugger_ipi)(struct pt_regs *regs) __read_mostly;
64 int (*__debugger_bpt)(struct pt_regs *regs) __read_mostly;
65 int (*__debugger_sstep)(struct pt_regs *regs) __read_mostly;
66 int (*__debugger_iabr_match)(struct pt_regs *regs) __read_mostly;
67 int (*__debugger_dabr_match)(struct pt_regs *regs) __read_mostly;
68 int (*__debugger_fault_handler)(struct pt_regs *regs) __read_mostly;
69 
70 EXPORT_SYMBOL(__debugger);
71 EXPORT_SYMBOL(__debugger_ipi);
72 EXPORT_SYMBOL(__debugger_bpt);
73 EXPORT_SYMBOL(__debugger_sstep);
74 EXPORT_SYMBOL(__debugger_iabr_match);
75 EXPORT_SYMBOL(__debugger_dabr_match);
76 EXPORT_SYMBOL(__debugger_fault_handler);
77 #endif
78 
79 /*
80  * Trap & Exception support
81  */
82 
83 #ifdef CONFIG_PMAC_BACKLIGHT
84 static void pmac_backlight_unblank(void)
85 {
86 	mutex_lock(&pmac_backlight_mutex);
87 	if (pmac_backlight) {
88 		struct backlight_properties *props;
89 
90 		props = &pmac_backlight->props;
91 		props->brightness = props->max_brightness;
92 		props->power = FB_BLANK_UNBLANK;
93 		backlight_update_status(pmac_backlight);
94 	}
95 	mutex_unlock(&pmac_backlight_mutex);
96 }
97 #else
98 static inline void pmac_backlight_unblank(void) { }
99 #endif
100 
101 int die(const char *str, struct pt_regs *regs, long err)
102 {
103 	static struct {
104 		raw_spinlock_t lock;
105 		u32 lock_owner;
106 		int lock_owner_depth;
107 	} die = {
108 		.lock =			__RAW_SPIN_LOCK_UNLOCKED(die.lock),
109 		.lock_owner =		-1,
110 		.lock_owner_depth =	0
111 	};
112 	static int die_counter;
113 	unsigned long flags;
114 
115 	if (debugger(regs))
116 		return 1;
117 
118 	oops_enter();
119 
120 	if (die.lock_owner != raw_smp_processor_id()) {
121 		console_verbose();
122 		raw_spin_lock_irqsave(&die.lock, flags);
123 		die.lock_owner = smp_processor_id();
124 		die.lock_owner_depth = 0;
125 		bust_spinlocks(1);
126 		if (machine_is(powermac))
127 			pmac_backlight_unblank();
128 	} else {
129 		local_save_flags(flags);
130 	}
131 
132 	if (++die.lock_owner_depth < 3) {
133 		printk("Oops: %s, sig: %ld [#%d]\n", str, err, ++die_counter);
134 #ifdef CONFIG_PREEMPT
135 		printk("PREEMPT ");
136 #endif
137 #ifdef CONFIG_SMP
138 		printk("SMP NR_CPUS=%d ", NR_CPUS);
139 #endif
140 #ifdef CONFIG_DEBUG_PAGEALLOC
141 		printk("DEBUG_PAGEALLOC ");
142 #endif
143 #ifdef CONFIG_NUMA
144 		printk("NUMA ");
145 #endif
146 		printk("%s\n", ppc_md.name ? ppc_md.name : "");
147 
148 		sysfs_printk_last_file();
149 		if (notify_die(DIE_OOPS, str, regs, err, 255,
150 			       SIGSEGV) == NOTIFY_STOP)
151 			return 1;
152 
153 		print_modules();
154 		show_regs(regs);
155 	} else {
156 		printk("Recursive die() failure, output suppressed\n");
157 	}
158 
159 	bust_spinlocks(0);
160 	die.lock_owner = -1;
161 	add_taint(TAINT_DIE);
162 	raw_spin_unlock_irqrestore(&die.lock, flags);
163 
164 	if (kexec_should_crash(current) ||
165 		kexec_sr_activated(smp_processor_id()))
166 		crash_kexec(regs);
167 	crash_kexec_secondary(regs);
168 
169 	if (in_interrupt())
170 		panic("Fatal exception in interrupt");
171 
172 	if (panic_on_oops)
173 		panic("Fatal exception");
174 
175 	oops_exit();
176 	do_exit(err);
177 
178 	return 0;
179 }
180 
181 void user_single_step_siginfo(struct task_struct *tsk,
182 				struct pt_regs *regs, siginfo_t *info)
183 {
184 	memset(info, 0, sizeof(*info));
185 	info->si_signo = SIGTRAP;
186 	info->si_code = TRAP_TRACE;
187 	info->si_addr = (void __user *)regs->nip;
188 }
189 
190 void _exception(int signr, struct pt_regs *regs, int code, unsigned long addr)
191 {
192 	siginfo_t info;
193 	const char fmt32[] = KERN_INFO "%s[%d]: unhandled signal %d " \
194 			"at %08lx nip %08lx lr %08lx code %x\n";
195 	const char fmt64[] = KERN_INFO "%s[%d]: unhandled signal %d " \
196 			"at %016lx nip %016lx lr %016lx code %x\n";
197 
198 	if (!user_mode(regs)) {
199 		if (die("Exception in kernel mode", regs, signr))
200 			return;
201 	} else if (show_unhandled_signals &&
202 		    unhandled_signal(current, signr) &&
203 		    printk_ratelimit()) {
204 			printk(regs->msr & MSR_SF ? fmt64 : fmt32,
205 				current->comm, current->pid, signr,
206 				addr, regs->nip, regs->link, code);
207 		}
208 
209 	memset(&info, 0, sizeof(info));
210 	info.si_signo = signr;
211 	info.si_code = code;
212 	info.si_addr = (void __user *) addr;
213 	force_sig_info(signr, &info, current);
214 }
215 
216 #ifdef CONFIG_PPC64
217 void system_reset_exception(struct pt_regs *regs)
218 {
219 	/* See if any machine dependent calls */
220 	if (ppc_md.system_reset_exception) {
221 		if (ppc_md.system_reset_exception(regs))
222 			return;
223 	}
224 
225 #ifdef CONFIG_KEXEC
226 	cpu_set(smp_processor_id(), cpus_in_sr);
227 #endif
228 
229 	die("System Reset", regs, SIGABRT);
230 
231 	/*
232 	 * Some CPUs when released from the debugger will execute this path.
233 	 * These CPUs entered the debugger via a soft-reset. If the CPU was
234 	 * hung before entering the debugger it will return to the hung
235 	 * state when exiting this function.  This causes a problem in
236 	 * kdump since the hung CPU(s) will not respond to the IPI sent
237 	 * from kdump. To prevent the problem we call crash_kexec_secondary()
238 	 * here. If a kdump had not been initiated or we exit the debugger
239 	 * with the "exit and recover" command (x) crash_kexec_secondary()
240 	 * will return after 5ms and the CPU returns to its previous state.
241 	 */
242 	crash_kexec_secondary(regs);
243 
244 	/* Must die if the interrupt is not recoverable */
245 	if (!(regs->msr & MSR_RI))
246 		panic("Unrecoverable System Reset");
247 
248 	/* What should we do here? We could issue a shutdown or hard reset. */
249 }
250 #endif
251 
252 /*
253  * I/O accesses can cause machine checks on powermacs.
254  * Check if the NIP corresponds to the address of a sync
255  * instruction for which there is an entry in the exception
256  * table.
257  * Note that the 601 only takes a machine check on TEA
258  * (transfer error ack) signal assertion, and does not
259  * set any of the top 16 bits of SRR1.
260  *  -- paulus.
261  */
262 static inline int check_io_access(struct pt_regs *regs)
263 {
264 #ifdef CONFIG_PPC32
265 	unsigned long msr = regs->msr;
266 	const struct exception_table_entry *entry;
267 	unsigned int *nip = (unsigned int *)regs->nip;
268 
269 	if (((msr & 0xffff0000) == 0 || (msr & (0x80000 | 0x40000)))
270 	    && (entry = search_exception_tables(regs->nip)) != NULL) {
271 		/*
272 		 * Check that it's a sync instruction, or somewhere
273 		 * in the twi; isync; nop sequence that inb/inw/inl uses.
274 		 * As the address is in the exception table
275 		 * we should be able to read the instr there.
276 		 * For the debug message, we look at the preceding
277 		 * load or store.
278 		 */
279 		if (*nip == 0x60000000)		/* nop */
280 			nip -= 2;
281 		else if (*nip == 0x4c00012c)	/* isync */
282 			--nip;
283 		if (*nip == 0x7c0004ac || (*nip >> 26) == 3) {
284 			/* sync or twi */
285 			unsigned int rb;
286 
287 			--nip;
288 			rb = (*nip >> 11) & 0x1f;
289 			printk(KERN_DEBUG "%s bad port %lx at %p\n",
290 			       (*nip & 0x100)? "OUT to": "IN from",
291 			       regs->gpr[rb] - _IO_BASE, nip);
292 			regs->msr |= MSR_RI;
293 			regs->nip = entry->fixup;
294 			return 1;
295 		}
296 	}
297 #endif /* CONFIG_PPC32 */
298 	return 0;
299 }
300 
301 #ifdef CONFIG_PPC_ADV_DEBUG_REGS
302 /* On 4xx, the reason for the machine check or program exception
303    is in the ESR. */
304 #define get_reason(regs)	((regs)->dsisr)
305 #ifndef CONFIG_FSL_BOOKE
306 #define get_mc_reason(regs)	((regs)->dsisr)
307 #else
308 #define get_mc_reason(regs)	(mfspr(SPRN_MCSR) & MCSR_MASK)
309 #endif
310 #define REASON_FP		ESR_FP
311 #define REASON_ILLEGAL		(ESR_PIL | ESR_PUO)
312 #define REASON_PRIVILEGED	ESR_PPR
313 #define REASON_TRAP		ESR_PTR
314 
315 /* single-step stuff */
316 #define single_stepping(regs)	(current->thread.dbcr0 & DBCR0_IC)
317 #define clear_single_step(regs)	(current->thread.dbcr0 &= ~DBCR0_IC)
318 
319 #else
320 /* On non-4xx, the reason for the machine check or program
321    exception is in the MSR. */
322 #define get_reason(regs)	((regs)->msr)
323 #define get_mc_reason(regs)	((regs)->msr)
324 #define REASON_FP		0x100000
325 #define REASON_ILLEGAL		0x80000
326 #define REASON_PRIVILEGED	0x40000
327 #define REASON_TRAP		0x20000
328 
329 #define single_stepping(regs)	((regs)->msr & MSR_SE)
330 #define clear_single_step(regs)	((regs)->msr &= ~MSR_SE)
331 #endif
332 
333 #if defined(CONFIG_4xx)
334 int machine_check_4xx(struct pt_regs *regs)
335 {
336 	unsigned long reason = get_mc_reason(regs);
337 
338 	if (reason & ESR_IMCP) {
339 		printk("Instruction");
340 		mtspr(SPRN_ESR, reason & ~ESR_IMCP);
341 	} else
342 		printk("Data");
343 	printk(" machine check in kernel mode.\n");
344 
345 	return 0;
346 }
347 
348 int machine_check_440A(struct pt_regs *regs)
349 {
350 	unsigned long reason = get_mc_reason(regs);
351 
352 	printk("Machine check in kernel mode.\n");
353 	if (reason & ESR_IMCP){
354 		printk("Instruction Synchronous Machine Check exception\n");
355 		mtspr(SPRN_ESR, reason & ~ESR_IMCP);
356 	}
357 	else {
358 		u32 mcsr = mfspr(SPRN_MCSR);
359 		if (mcsr & MCSR_IB)
360 			printk("Instruction Read PLB Error\n");
361 		if (mcsr & MCSR_DRB)
362 			printk("Data Read PLB Error\n");
363 		if (mcsr & MCSR_DWB)
364 			printk("Data Write PLB Error\n");
365 		if (mcsr & MCSR_TLBP)
366 			printk("TLB Parity Error\n");
367 		if (mcsr & MCSR_ICP){
368 			flush_instruction_cache();
369 			printk("I-Cache Parity Error\n");
370 		}
371 		if (mcsr & MCSR_DCSP)
372 			printk("D-Cache Search Parity Error\n");
373 		if (mcsr & MCSR_DCFP)
374 			printk("D-Cache Flush Parity Error\n");
375 		if (mcsr & MCSR_IMPE)
376 			printk("Machine Check exception is imprecise\n");
377 
378 		/* Clear MCSR */
379 		mtspr(SPRN_MCSR, mcsr);
380 	}
381 	return 0;
382 }
383 #elif defined(CONFIG_E500)
384 int machine_check_e500(struct pt_regs *regs)
385 {
386 	unsigned long reason = get_mc_reason(regs);
387 
388 	printk("Machine check in kernel mode.\n");
389 	printk("Caused by (from MCSR=%lx): ", reason);
390 
391 	if (reason & MCSR_MCP)
392 		printk("Machine Check Signal\n");
393 	if (reason & MCSR_ICPERR)
394 		printk("Instruction Cache Parity Error\n");
395 	if (reason & MCSR_DCP_PERR)
396 		printk("Data Cache Push Parity Error\n");
397 	if (reason & MCSR_DCPERR)
398 		printk("Data Cache Parity Error\n");
399 	if (reason & MCSR_BUS_IAERR)
400 		printk("Bus - Instruction Address Error\n");
401 	if (reason & MCSR_BUS_RAERR)
402 		printk("Bus - Read Address Error\n");
403 	if (reason & MCSR_BUS_WAERR)
404 		printk("Bus - Write Address Error\n");
405 	if (reason & MCSR_BUS_IBERR)
406 		printk("Bus - Instruction Data Error\n");
407 	if (reason & MCSR_BUS_RBERR)
408 		printk("Bus - Read Data Bus Error\n");
409 	if (reason & MCSR_BUS_WBERR)
410 		printk("Bus - Read Data Bus Error\n");
411 	if (reason & MCSR_BUS_IPERR)
412 		printk("Bus - Instruction Parity Error\n");
413 	if (reason & MCSR_BUS_RPERR)
414 		printk("Bus - Read Parity Error\n");
415 
416 	return 0;
417 }
418 #elif defined(CONFIG_E200)
419 int machine_check_e200(struct pt_regs *regs)
420 {
421 	unsigned long reason = get_mc_reason(regs);
422 
423 	printk("Machine check in kernel mode.\n");
424 	printk("Caused by (from MCSR=%lx): ", reason);
425 
426 	if (reason & MCSR_MCP)
427 		printk("Machine Check Signal\n");
428 	if (reason & MCSR_CP_PERR)
429 		printk("Cache Push Parity Error\n");
430 	if (reason & MCSR_CPERR)
431 		printk("Cache Parity Error\n");
432 	if (reason & MCSR_EXCP_ERR)
433 		printk("ISI, ITLB, or Bus Error on first instruction fetch for an exception handler\n");
434 	if (reason & MCSR_BUS_IRERR)
435 		printk("Bus - Read Bus Error on instruction fetch\n");
436 	if (reason & MCSR_BUS_DRERR)
437 		printk("Bus - Read Bus Error on data load\n");
438 	if (reason & MCSR_BUS_WRERR)
439 		printk("Bus - Write Bus Error on buffered store or cache line push\n");
440 
441 	return 0;
442 }
443 #else
444 int machine_check_generic(struct pt_regs *regs)
445 {
446 	unsigned long reason = get_mc_reason(regs);
447 
448 	printk("Machine check in kernel mode.\n");
449 	printk("Caused by (from SRR1=%lx): ", reason);
450 	switch (reason & 0x601F0000) {
451 	case 0x80000:
452 		printk("Machine check signal\n");
453 		break;
454 	case 0:		/* for 601 */
455 	case 0x40000:
456 	case 0x140000:	/* 7450 MSS error and TEA */
457 		printk("Transfer error ack signal\n");
458 		break;
459 	case 0x20000:
460 		printk("Data parity error signal\n");
461 		break;
462 	case 0x10000:
463 		printk("Address parity error signal\n");
464 		break;
465 	case 0x20000000:
466 		printk("L1 Data Cache error\n");
467 		break;
468 	case 0x40000000:
469 		printk("L1 Instruction Cache error\n");
470 		break;
471 	case 0x00100000:
472 		printk("L2 data cache parity error\n");
473 		break;
474 	default:
475 		printk("Unknown values in msr\n");
476 	}
477 	return 0;
478 }
479 #endif /* everything else */
480 
481 void machine_check_exception(struct pt_regs *regs)
482 {
483 	int recover = 0;
484 
485 	__get_cpu_var(irq_stat).mce_exceptions++;
486 
487 	/* See if any machine dependent calls. In theory, we would want
488 	 * to call the CPU first, and call the ppc_md. one if the CPU
489 	 * one returns a positive number. However there is existing code
490 	 * that assumes the board gets a first chance, so let's keep it
491 	 * that way for now and fix things later. --BenH.
492 	 */
493 	if (ppc_md.machine_check_exception)
494 		recover = ppc_md.machine_check_exception(regs);
495 	else if (cur_cpu_spec->machine_check)
496 		recover = cur_cpu_spec->machine_check(regs);
497 
498 	if (recover > 0)
499 		return;
500 
501 	if (user_mode(regs)) {
502 		regs->msr |= MSR_RI;
503 		_exception(SIGBUS, regs, BUS_ADRERR, regs->nip);
504 		return;
505 	}
506 
507 #if defined(CONFIG_8xx) && defined(CONFIG_PCI)
508 	/* the qspan pci read routines can cause machine checks -- Cort
509 	 *
510 	 * yuck !!! that totally needs to go away ! There are better ways
511 	 * to deal with that than having a wart in the mcheck handler.
512 	 * -- BenH
513 	 */
514 	bad_page_fault(regs, regs->dar, SIGBUS);
515 	return;
516 #endif
517 
518 	if (debugger_fault_handler(regs)) {
519 		regs->msr |= MSR_RI;
520 		return;
521 	}
522 
523 	if (check_io_access(regs))
524 		return;
525 
526 	if (debugger_fault_handler(regs))
527 		return;
528 	die("Machine check", regs, SIGBUS);
529 
530 	/* Must die if the interrupt is not recoverable */
531 	if (!(regs->msr & MSR_RI))
532 		panic("Unrecoverable Machine check");
533 }
534 
535 void SMIException(struct pt_regs *regs)
536 {
537 	die("System Management Interrupt", regs, SIGABRT);
538 }
539 
540 void unknown_exception(struct pt_regs *regs)
541 {
542 	printk("Bad trap at PC: %lx, SR: %lx, vector=%lx\n",
543 	       regs->nip, regs->msr, regs->trap);
544 
545 	_exception(SIGTRAP, regs, 0, 0);
546 }
547 
548 void instruction_breakpoint_exception(struct pt_regs *regs)
549 {
550 	if (notify_die(DIE_IABR_MATCH, "iabr_match", regs, 5,
551 					5, SIGTRAP) == NOTIFY_STOP)
552 		return;
553 	if (debugger_iabr_match(regs))
554 		return;
555 	_exception(SIGTRAP, regs, TRAP_BRKPT, regs->nip);
556 }
557 
558 void RunModeException(struct pt_regs *regs)
559 {
560 	_exception(SIGTRAP, regs, 0, 0);
561 }
562 
563 void __kprobes single_step_exception(struct pt_regs *regs)
564 {
565 	regs->msr &= ~(MSR_SE | MSR_BE);  /* Turn off 'trace' bits */
566 
567 	if (notify_die(DIE_SSTEP, "single_step", regs, 5,
568 					5, SIGTRAP) == NOTIFY_STOP)
569 		return;
570 	if (debugger_sstep(regs))
571 		return;
572 
573 	_exception(SIGTRAP, regs, TRAP_TRACE, regs->nip);
574 }
575 
576 /*
577  * After we have successfully emulated an instruction, we have to
578  * check if the instruction was being single-stepped, and if so,
579  * pretend we got a single-step exception.  This was pointed out
580  * by Kumar Gala.  -- paulus
581  */
582 static void emulate_single_step(struct pt_regs *regs)
583 {
584 	if (single_stepping(regs)) {
585 		clear_single_step(regs);
586 		_exception(SIGTRAP, regs, TRAP_TRACE, 0);
587 	}
588 }
589 
590 static inline int __parse_fpscr(unsigned long fpscr)
591 {
592 	int ret = 0;
593 
594 	/* Invalid operation */
595 	if ((fpscr & FPSCR_VE) && (fpscr & FPSCR_VX))
596 		ret = FPE_FLTINV;
597 
598 	/* Overflow */
599 	else if ((fpscr & FPSCR_OE) && (fpscr & FPSCR_OX))
600 		ret = FPE_FLTOVF;
601 
602 	/* Underflow */
603 	else if ((fpscr & FPSCR_UE) && (fpscr & FPSCR_UX))
604 		ret = FPE_FLTUND;
605 
606 	/* Divide by zero */
607 	else if ((fpscr & FPSCR_ZE) && (fpscr & FPSCR_ZX))
608 		ret = FPE_FLTDIV;
609 
610 	/* Inexact result */
611 	else if ((fpscr & FPSCR_XE) && (fpscr & FPSCR_XX))
612 		ret = FPE_FLTRES;
613 
614 	return ret;
615 }
616 
617 static void parse_fpe(struct pt_regs *regs)
618 {
619 	int code = 0;
620 
621 	flush_fp_to_thread(current);
622 
623 	code = __parse_fpscr(current->thread.fpscr.val);
624 
625 	_exception(SIGFPE, regs, code, regs->nip);
626 }
627 
628 /*
629  * Illegal instruction emulation support.  Originally written to
630  * provide the PVR to user applications using the mfspr rd, PVR.
631  * Return non-zero if we can't emulate, or -EFAULT if the associated
632  * memory access caused an access fault.  Return zero on success.
633  *
634  * There are a couple of ways to do this, either "decode" the instruction
635  * or directly match lots of bits.  In this case, matching lots of
636  * bits is faster and easier.
637  *
638  */
639 static int emulate_string_inst(struct pt_regs *regs, u32 instword)
640 {
641 	u8 rT = (instword >> 21) & 0x1f;
642 	u8 rA = (instword >> 16) & 0x1f;
643 	u8 NB_RB = (instword >> 11) & 0x1f;
644 	u32 num_bytes;
645 	unsigned long EA;
646 	int pos = 0;
647 
648 	/* Early out if we are an invalid form of lswx */
649 	if ((instword & PPC_INST_STRING_MASK) == PPC_INST_LSWX)
650 		if ((rT == rA) || (rT == NB_RB))
651 			return -EINVAL;
652 
653 	EA = (rA == 0) ? 0 : regs->gpr[rA];
654 
655 	switch (instword & PPC_INST_STRING_MASK) {
656 		case PPC_INST_LSWX:
657 		case PPC_INST_STSWX:
658 			EA += NB_RB;
659 			num_bytes = regs->xer & 0x7f;
660 			break;
661 		case PPC_INST_LSWI:
662 		case PPC_INST_STSWI:
663 			num_bytes = (NB_RB == 0) ? 32 : NB_RB;
664 			break;
665 		default:
666 			return -EINVAL;
667 	}
668 
669 	while (num_bytes != 0)
670 	{
671 		u8 val;
672 		u32 shift = 8 * (3 - (pos & 0x3));
673 
674 		switch ((instword & PPC_INST_STRING_MASK)) {
675 			case PPC_INST_LSWX:
676 			case PPC_INST_LSWI:
677 				if (get_user(val, (u8 __user *)EA))
678 					return -EFAULT;
679 				/* first time updating this reg,
680 				 * zero it out */
681 				if (pos == 0)
682 					regs->gpr[rT] = 0;
683 				regs->gpr[rT] |= val << shift;
684 				break;
685 			case PPC_INST_STSWI:
686 			case PPC_INST_STSWX:
687 				val = regs->gpr[rT] >> shift;
688 				if (put_user(val, (u8 __user *)EA))
689 					return -EFAULT;
690 				break;
691 		}
692 		/* move EA to next address */
693 		EA += 1;
694 		num_bytes--;
695 
696 		/* manage our position within the register */
697 		if (++pos == 4) {
698 			pos = 0;
699 			if (++rT == 32)
700 				rT = 0;
701 		}
702 	}
703 
704 	return 0;
705 }
706 
707 static int emulate_popcntb_inst(struct pt_regs *regs, u32 instword)
708 {
709 	u32 ra,rs;
710 	unsigned long tmp;
711 
712 	ra = (instword >> 16) & 0x1f;
713 	rs = (instword >> 21) & 0x1f;
714 
715 	tmp = regs->gpr[rs];
716 	tmp = tmp - ((tmp >> 1) & 0x5555555555555555ULL);
717 	tmp = (tmp & 0x3333333333333333ULL) + ((tmp >> 2) & 0x3333333333333333ULL);
718 	tmp = (tmp + (tmp >> 4)) & 0x0f0f0f0f0f0f0f0fULL;
719 	regs->gpr[ra] = tmp;
720 
721 	return 0;
722 }
723 
724 static int emulate_isel(struct pt_regs *regs, u32 instword)
725 {
726 	u8 rT = (instword >> 21) & 0x1f;
727 	u8 rA = (instword >> 16) & 0x1f;
728 	u8 rB = (instword >> 11) & 0x1f;
729 	u8 BC = (instword >> 6) & 0x1f;
730 	u8 bit;
731 	unsigned long tmp;
732 
733 	tmp = (rA == 0) ? 0 : regs->gpr[rA];
734 	bit = (regs->ccr >> (31 - BC)) & 0x1;
735 
736 	regs->gpr[rT] = bit ? tmp : regs->gpr[rB];
737 
738 	return 0;
739 }
740 
741 static int emulate_instruction(struct pt_regs *regs)
742 {
743 	u32 instword;
744 	u32 rd;
745 
746 	if (!user_mode(regs) || (regs->msr & MSR_LE))
747 		return -EINVAL;
748 	CHECK_FULL_REGS(regs);
749 
750 	if (get_user(instword, (u32 __user *)(regs->nip)))
751 		return -EFAULT;
752 
753 	/* Emulate the mfspr rD, PVR. */
754 	if ((instword & PPC_INST_MFSPR_PVR_MASK) == PPC_INST_MFSPR_PVR) {
755 		PPC_WARN_EMULATED(mfpvr, regs);
756 		rd = (instword >> 21) & 0x1f;
757 		regs->gpr[rd] = mfspr(SPRN_PVR);
758 		return 0;
759 	}
760 
761 	/* Emulating the dcba insn is just a no-op.  */
762 	if ((instword & PPC_INST_DCBA_MASK) == PPC_INST_DCBA) {
763 		PPC_WARN_EMULATED(dcba, regs);
764 		return 0;
765 	}
766 
767 	/* Emulate the mcrxr insn.  */
768 	if ((instword & PPC_INST_MCRXR_MASK) == PPC_INST_MCRXR) {
769 		int shift = (instword >> 21) & 0x1c;
770 		unsigned long msk = 0xf0000000UL >> shift;
771 
772 		PPC_WARN_EMULATED(mcrxr, regs);
773 		regs->ccr = (regs->ccr & ~msk) | ((regs->xer >> shift) & msk);
774 		regs->xer &= ~0xf0000000UL;
775 		return 0;
776 	}
777 
778 	/* Emulate load/store string insn. */
779 	if ((instword & PPC_INST_STRING_GEN_MASK) == PPC_INST_STRING) {
780 		PPC_WARN_EMULATED(string, regs);
781 		return emulate_string_inst(regs, instword);
782 	}
783 
784 	/* Emulate the popcntb (Population Count Bytes) instruction. */
785 	if ((instword & PPC_INST_POPCNTB_MASK) == PPC_INST_POPCNTB) {
786 		PPC_WARN_EMULATED(popcntb, regs);
787 		return emulate_popcntb_inst(regs, instword);
788 	}
789 
790 	/* Emulate isel (Integer Select) instruction */
791 	if ((instword & PPC_INST_ISEL_MASK) == PPC_INST_ISEL) {
792 		PPC_WARN_EMULATED(isel, regs);
793 		return emulate_isel(regs, instword);
794 	}
795 
796 	return -EINVAL;
797 }
798 
799 int is_valid_bugaddr(unsigned long addr)
800 {
801 	return is_kernel_addr(addr);
802 }
803 
804 void __kprobes program_check_exception(struct pt_regs *regs)
805 {
806 	unsigned int reason = get_reason(regs);
807 	extern int do_mathemu(struct pt_regs *regs);
808 
809 	/* We can now get here via a FP Unavailable exception if the core
810 	 * has no FPU, in that case the reason flags will be 0 */
811 
812 	if (reason & REASON_FP) {
813 		/* IEEE FP exception */
814 		parse_fpe(regs);
815 		return;
816 	}
817 	if (reason & REASON_TRAP) {
818 		/* trap exception */
819 		if (notify_die(DIE_BPT, "breakpoint", regs, 5, 5, SIGTRAP)
820 				== NOTIFY_STOP)
821 			return;
822 		if (debugger_bpt(regs))
823 			return;
824 
825 		if (!(regs->msr & MSR_PR) &&  /* not user-mode */
826 		    report_bug(regs->nip, regs) == BUG_TRAP_TYPE_WARN) {
827 			regs->nip += 4;
828 			return;
829 		}
830 		_exception(SIGTRAP, regs, TRAP_BRKPT, regs->nip);
831 		return;
832 	}
833 
834 	local_irq_enable();
835 
836 #ifdef CONFIG_MATH_EMULATION
837 	/* (reason & REASON_ILLEGAL) would be the obvious thing here,
838 	 * but there seems to be a hardware bug on the 405GP (RevD)
839 	 * that means ESR is sometimes set incorrectly - either to
840 	 * ESR_DST (!?) or 0.  In the process of chasing this with the
841 	 * hardware people - not sure if it can happen on any illegal
842 	 * instruction or only on FP instructions, whether there is a
843 	 * pattern to occurences etc. -dgibson 31/Mar/2003 */
844 	switch (do_mathemu(regs)) {
845 	case 0:
846 		emulate_single_step(regs);
847 		return;
848 	case 1: {
849 			int code = 0;
850 			code = __parse_fpscr(current->thread.fpscr.val);
851 			_exception(SIGFPE, regs, code, regs->nip);
852 			return;
853 		}
854 	case -EFAULT:
855 		_exception(SIGSEGV, regs, SEGV_MAPERR, regs->nip);
856 		return;
857 	}
858 	/* fall through on any other errors */
859 #endif /* CONFIG_MATH_EMULATION */
860 
861 	/* Try to emulate it if we should. */
862 	if (reason & (REASON_ILLEGAL | REASON_PRIVILEGED)) {
863 		switch (emulate_instruction(regs)) {
864 		case 0:
865 			regs->nip += 4;
866 			emulate_single_step(regs);
867 			return;
868 		case -EFAULT:
869 			_exception(SIGSEGV, regs, SEGV_MAPERR, regs->nip);
870 			return;
871 		}
872 	}
873 
874 	if (reason & REASON_PRIVILEGED)
875 		_exception(SIGILL, regs, ILL_PRVOPC, regs->nip);
876 	else
877 		_exception(SIGILL, regs, ILL_ILLOPC, regs->nip);
878 }
879 
880 void alignment_exception(struct pt_regs *regs)
881 {
882 	int sig, code, fixed = 0;
883 
884 	/* we don't implement logging of alignment exceptions */
885 	if (!(current->thread.align_ctl & PR_UNALIGN_SIGBUS))
886 		fixed = fix_alignment(regs);
887 
888 	if (fixed == 1) {
889 		regs->nip += 4;	/* skip over emulated instruction */
890 		emulate_single_step(regs);
891 		return;
892 	}
893 
894 	/* Operand address was bad */
895 	if (fixed == -EFAULT) {
896 		sig = SIGSEGV;
897 		code = SEGV_ACCERR;
898 	} else {
899 		sig = SIGBUS;
900 		code = BUS_ADRALN;
901 	}
902 	if (user_mode(regs))
903 		_exception(sig, regs, code, regs->dar);
904 	else
905 		bad_page_fault(regs, regs->dar, sig);
906 }
907 
908 void StackOverflow(struct pt_regs *regs)
909 {
910 	printk(KERN_CRIT "Kernel stack overflow in process %p, r1=%lx\n",
911 	       current, regs->gpr[1]);
912 	debugger(regs);
913 	show_regs(regs);
914 	panic("kernel stack overflow");
915 }
916 
917 void nonrecoverable_exception(struct pt_regs *regs)
918 {
919 	printk(KERN_ERR "Non-recoverable exception at PC=%lx MSR=%lx\n",
920 	       regs->nip, regs->msr);
921 	debugger(regs);
922 	die("nonrecoverable exception", regs, SIGKILL);
923 }
924 
925 void trace_syscall(struct pt_regs *regs)
926 {
927 	printk("Task: %p(%d), PC: %08lX/%08lX, Syscall: %3ld, Result: %s%ld    %s\n",
928 	       current, task_pid_nr(current), regs->nip, regs->link, regs->gpr[0],
929 	       regs->ccr&0x10000000?"Error=":"", regs->gpr[3], print_tainted());
930 }
931 
932 void kernel_fp_unavailable_exception(struct pt_regs *regs)
933 {
934 	printk(KERN_EMERG "Unrecoverable FP Unavailable Exception "
935 			  "%lx at %lx\n", regs->trap, regs->nip);
936 	die("Unrecoverable FP Unavailable Exception", regs, SIGABRT);
937 }
938 
939 void altivec_unavailable_exception(struct pt_regs *regs)
940 {
941 	if (user_mode(regs)) {
942 		/* A user program has executed an altivec instruction,
943 		   but this kernel doesn't support altivec. */
944 		_exception(SIGILL, regs, ILL_ILLOPC, regs->nip);
945 		return;
946 	}
947 
948 	printk(KERN_EMERG "Unrecoverable VMX/Altivec Unavailable Exception "
949 			"%lx at %lx\n", regs->trap, regs->nip);
950 	die("Unrecoverable VMX/Altivec Unavailable Exception", regs, SIGABRT);
951 }
952 
953 void vsx_unavailable_exception(struct pt_regs *regs)
954 {
955 	if (user_mode(regs)) {
956 		/* A user program has executed an vsx instruction,
957 		   but this kernel doesn't support vsx. */
958 		_exception(SIGILL, regs, ILL_ILLOPC, regs->nip);
959 		return;
960 	}
961 
962 	printk(KERN_EMERG "Unrecoverable VSX Unavailable Exception "
963 			"%lx at %lx\n", regs->trap, regs->nip);
964 	die("Unrecoverable VSX Unavailable Exception", regs, SIGABRT);
965 }
966 
967 void performance_monitor_exception(struct pt_regs *regs)
968 {
969 	__get_cpu_var(irq_stat).pmu_irqs++;
970 
971 	perf_irq(regs);
972 }
973 
974 #ifdef CONFIG_8xx
975 void SoftwareEmulation(struct pt_regs *regs)
976 {
977 	extern int do_mathemu(struct pt_regs *);
978 	extern int Soft_emulate_8xx(struct pt_regs *);
979 #if defined(CONFIG_MATH_EMULATION) || defined(CONFIG_8XX_MINIMAL_FPEMU)
980 	int errcode;
981 #endif
982 
983 	CHECK_FULL_REGS(regs);
984 
985 	if (!user_mode(regs)) {
986 		debugger(regs);
987 		die("Kernel Mode Software FPU Emulation", regs, SIGFPE);
988 	}
989 
990 #ifdef CONFIG_MATH_EMULATION
991 	errcode = do_mathemu(regs);
992 	if (errcode >= 0)
993 		PPC_WARN_EMULATED(math, regs);
994 
995 	switch (errcode) {
996 	case 0:
997 		emulate_single_step(regs);
998 		return;
999 	case 1: {
1000 			int code = 0;
1001 			code = __parse_fpscr(current->thread.fpscr.val);
1002 			_exception(SIGFPE, regs, code, regs->nip);
1003 			return;
1004 		}
1005 	case -EFAULT:
1006 		_exception(SIGSEGV, regs, SEGV_MAPERR, regs->nip);
1007 		return;
1008 	default:
1009 		_exception(SIGILL, regs, ILL_ILLOPC, regs->nip);
1010 		return;
1011 	}
1012 
1013 #elif defined(CONFIG_8XX_MINIMAL_FPEMU)
1014 	errcode = Soft_emulate_8xx(regs);
1015 	if (errcode >= 0)
1016 		PPC_WARN_EMULATED(8xx, regs);
1017 
1018 	switch (errcode) {
1019 	case 0:
1020 		emulate_single_step(regs);
1021 		return;
1022 	case 1:
1023 		_exception(SIGILL, regs, ILL_ILLOPC, regs->nip);
1024 		return;
1025 	case -EFAULT:
1026 		_exception(SIGSEGV, regs, SEGV_MAPERR, regs->nip);
1027 		return;
1028 	}
1029 #else
1030 	_exception(SIGILL, regs, ILL_ILLOPC, regs->nip);
1031 #endif
1032 }
1033 #endif /* CONFIG_8xx */
1034 
1035 #ifdef CONFIG_PPC_ADV_DEBUG_REGS
1036 static void handle_debug(struct pt_regs *regs, unsigned long debug_status)
1037 {
1038 	int changed = 0;
1039 	/*
1040 	 * Determine the cause of the debug event, clear the
1041 	 * event flags and send a trap to the handler. Torez
1042 	 */
1043 	if (debug_status & (DBSR_DAC1R | DBSR_DAC1W)) {
1044 		dbcr_dac(current) &= ~(DBCR_DAC1R | DBCR_DAC1W);
1045 #ifdef CONFIG_PPC_ADV_DEBUG_DAC_RANGE
1046 		current->thread.dbcr2 &= ~DBCR2_DAC12MODE;
1047 #endif
1048 		do_send_trap(regs, mfspr(SPRN_DAC1), debug_status, TRAP_HWBKPT,
1049 			     5);
1050 		changed |= 0x01;
1051 	}  else if (debug_status & (DBSR_DAC2R | DBSR_DAC2W)) {
1052 		dbcr_dac(current) &= ~(DBCR_DAC2R | DBCR_DAC2W);
1053 		do_send_trap(regs, mfspr(SPRN_DAC2), debug_status, TRAP_HWBKPT,
1054 			     6);
1055 		changed |= 0x01;
1056 	}  else if (debug_status & DBSR_IAC1) {
1057 		current->thread.dbcr0 &= ~DBCR0_IAC1;
1058 		dbcr_iac_range(current) &= ~DBCR_IAC12MODE;
1059 		do_send_trap(regs, mfspr(SPRN_IAC1), debug_status, TRAP_HWBKPT,
1060 			     1);
1061 		changed |= 0x01;
1062 	}  else if (debug_status & DBSR_IAC2) {
1063 		current->thread.dbcr0 &= ~DBCR0_IAC2;
1064 		do_send_trap(regs, mfspr(SPRN_IAC2), debug_status, TRAP_HWBKPT,
1065 			     2);
1066 		changed |= 0x01;
1067 	}  else if (debug_status & DBSR_IAC3) {
1068 		current->thread.dbcr0 &= ~DBCR0_IAC3;
1069 		dbcr_iac_range(current) &= ~DBCR_IAC34MODE;
1070 		do_send_trap(regs, mfspr(SPRN_IAC3), debug_status, TRAP_HWBKPT,
1071 			     3);
1072 		changed |= 0x01;
1073 	}  else if (debug_status & DBSR_IAC4) {
1074 		current->thread.dbcr0 &= ~DBCR0_IAC4;
1075 		do_send_trap(regs, mfspr(SPRN_IAC4), debug_status, TRAP_HWBKPT,
1076 			     4);
1077 		changed |= 0x01;
1078 	}
1079 	/*
1080 	 * At the point this routine was called, the MSR(DE) was turned off.
1081 	 * Check all other debug flags and see if that bit needs to be turned
1082 	 * back on or not.
1083 	 */
1084 	if (DBCR_ACTIVE_EVENTS(current->thread.dbcr0, current->thread.dbcr1))
1085 		regs->msr |= MSR_DE;
1086 	else
1087 		/* Make sure the IDM flag is off */
1088 		current->thread.dbcr0 &= ~DBCR0_IDM;
1089 
1090 	if (changed & 0x01)
1091 		mtspr(SPRN_DBCR0, current->thread.dbcr0);
1092 }
1093 
1094 void __kprobes DebugException(struct pt_regs *regs, unsigned long debug_status)
1095 {
1096 	current->thread.dbsr = debug_status;
1097 
1098 	/* Hack alert: On BookE, Branch Taken stops on the branch itself, while
1099 	 * on server, it stops on the target of the branch. In order to simulate
1100 	 * the server behaviour, we thus restart right away with a single step
1101 	 * instead of stopping here when hitting a BT
1102 	 */
1103 	if (debug_status & DBSR_BT) {
1104 		regs->msr &= ~MSR_DE;
1105 
1106 		/* Disable BT */
1107 		mtspr(SPRN_DBCR0, mfspr(SPRN_DBCR0) & ~DBCR0_BT);
1108 		/* Clear the BT event */
1109 		mtspr(SPRN_DBSR, DBSR_BT);
1110 
1111 		/* Do the single step trick only when coming from userspace */
1112 		if (user_mode(regs)) {
1113 			current->thread.dbcr0 &= ~DBCR0_BT;
1114 			current->thread.dbcr0 |= DBCR0_IDM | DBCR0_IC;
1115 			regs->msr |= MSR_DE;
1116 			return;
1117 		}
1118 
1119 		if (notify_die(DIE_SSTEP, "block_step", regs, 5,
1120 			       5, SIGTRAP) == NOTIFY_STOP) {
1121 			return;
1122 		}
1123 		if (debugger_sstep(regs))
1124 			return;
1125 	} else if (debug_status & DBSR_IC) { 	/* Instruction complete */
1126 		regs->msr &= ~MSR_DE;
1127 
1128 		/* Disable instruction completion */
1129 		mtspr(SPRN_DBCR0, mfspr(SPRN_DBCR0) & ~DBCR0_IC);
1130 		/* Clear the instruction completion event */
1131 		mtspr(SPRN_DBSR, DBSR_IC);
1132 
1133 		if (notify_die(DIE_SSTEP, "single_step", regs, 5,
1134 			       5, SIGTRAP) == NOTIFY_STOP) {
1135 			return;
1136 		}
1137 
1138 		if (debugger_sstep(regs))
1139 			return;
1140 
1141 		if (user_mode(regs)) {
1142 			current->thread.dbcr0 &= ~DBCR0_IC;
1143 #ifdef CONFIG_PPC_ADV_DEBUG_REGS
1144 			if (DBCR_ACTIVE_EVENTS(current->thread.dbcr0,
1145 					       current->thread.dbcr1))
1146 				regs->msr |= MSR_DE;
1147 			else
1148 				/* Make sure the IDM bit is off */
1149 				current->thread.dbcr0 &= ~DBCR0_IDM;
1150 #endif
1151 		}
1152 
1153 		_exception(SIGTRAP, regs, TRAP_TRACE, regs->nip);
1154 	} else
1155 		handle_debug(regs, debug_status);
1156 }
1157 #endif /* CONFIG_PPC_ADV_DEBUG_REGS */
1158 
1159 #if !defined(CONFIG_TAU_INT)
1160 void TAUException(struct pt_regs *regs)
1161 {
1162 	printk("TAU trap at PC: %lx, MSR: %lx, vector=%lx    %s\n",
1163 	       regs->nip, regs->msr, regs->trap, print_tainted());
1164 }
1165 #endif /* CONFIG_INT_TAU */
1166 
1167 #ifdef CONFIG_ALTIVEC
1168 void altivec_assist_exception(struct pt_regs *regs)
1169 {
1170 	int err;
1171 
1172 	if (!user_mode(regs)) {
1173 		printk(KERN_EMERG "VMX/Altivec assist exception in kernel mode"
1174 		       " at %lx\n", regs->nip);
1175 		die("Kernel VMX/Altivec assist exception", regs, SIGILL);
1176 	}
1177 
1178 	flush_altivec_to_thread(current);
1179 
1180 	PPC_WARN_EMULATED(altivec, regs);
1181 	err = emulate_altivec(regs);
1182 	if (err == 0) {
1183 		regs->nip += 4;		/* skip emulated instruction */
1184 		emulate_single_step(regs);
1185 		return;
1186 	}
1187 
1188 	if (err == -EFAULT) {
1189 		/* got an error reading the instruction */
1190 		_exception(SIGSEGV, regs, SEGV_ACCERR, regs->nip);
1191 	} else {
1192 		/* didn't recognize the instruction */
1193 		/* XXX quick hack for now: set the non-Java bit in the VSCR */
1194 		if (printk_ratelimit())
1195 			printk(KERN_ERR "Unrecognized altivec instruction "
1196 			       "in %s at %lx\n", current->comm, regs->nip);
1197 		current->thread.vscr.u[3] |= 0x10000;
1198 	}
1199 }
1200 #endif /* CONFIG_ALTIVEC */
1201 
1202 #ifdef CONFIG_VSX
1203 void vsx_assist_exception(struct pt_regs *regs)
1204 {
1205 	if (!user_mode(regs)) {
1206 		printk(KERN_EMERG "VSX assist exception in kernel mode"
1207 		       " at %lx\n", regs->nip);
1208 		die("Kernel VSX assist exception", regs, SIGILL);
1209 	}
1210 
1211 	flush_vsx_to_thread(current);
1212 	printk(KERN_INFO "VSX assist not supported at %lx\n", regs->nip);
1213 	_exception(SIGILL, regs, ILL_ILLOPC, regs->nip);
1214 }
1215 #endif /* CONFIG_VSX */
1216 
1217 #ifdef CONFIG_FSL_BOOKE
1218 
1219 void doorbell_exception(struct pt_regs *regs)
1220 {
1221 #ifdef CONFIG_SMP
1222 	int cpu = smp_processor_id();
1223 	int msg;
1224 
1225 	if (num_online_cpus() < 2)
1226 		return;
1227 
1228 	for (msg = 0; msg < 4; msg++)
1229 		if (test_and_clear_bit(msg, &dbell_smp_message[cpu]))
1230 			smp_message_recv(msg);
1231 #else
1232 	printk(KERN_WARNING "Received doorbell on non-smp system\n");
1233 #endif
1234 }
1235 
1236 void CacheLockingException(struct pt_regs *regs, unsigned long address,
1237 			   unsigned long error_code)
1238 {
1239 	/* We treat cache locking instructions from the user
1240 	 * as priv ops, in the future we could try to do
1241 	 * something smarter
1242 	 */
1243 	if (error_code & (ESR_DLK|ESR_ILK))
1244 		_exception(SIGILL, regs, ILL_PRVOPC, regs->nip);
1245 	return;
1246 }
1247 #endif /* CONFIG_FSL_BOOKE */
1248 
1249 #ifdef CONFIG_SPE
1250 void SPEFloatingPointException(struct pt_regs *regs)
1251 {
1252 	extern int do_spe_mathemu(struct pt_regs *regs);
1253 	unsigned long spefscr;
1254 	int fpexc_mode;
1255 	int code = 0;
1256 	int err;
1257 
1258 	preempt_disable();
1259 	if (regs->msr & MSR_SPE)
1260 		giveup_spe(current);
1261 	preempt_enable();
1262 
1263 	spefscr = current->thread.spefscr;
1264 	fpexc_mode = current->thread.fpexc_mode;
1265 
1266 	if ((spefscr & SPEFSCR_FOVF) && (fpexc_mode & PR_FP_EXC_OVF)) {
1267 		code = FPE_FLTOVF;
1268 	}
1269 	else if ((spefscr & SPEFSCR_FUNF) && (fpexc_mode & PR_FP_EXC_UND)) {
1270 		code = FPE_FLTUND;
1271 	}
1272 	else if ((spefscr & SPEFSCR_FDBZ) && (fpexc_mode & PR_FP_EXC_DIV))
1273 		code = FPE_FLTDIV;
1274 	else if ((spefscr & SPEFSCR_FINV) && (fpexc_mode & PR_FP_EXC_INV)) {
1275 		code = FPE_FLTINV;
1276 	}
1277 	else if ((spefscr & (SPEFSCR_FG | SPEFSCR_FX)) && (fpexc_mode & PR_FP_EXC_RES))
1278 		code = FPE_FLTRES;
1279 
1280 	err = do_spe_mathemu(regs);
1281 	if (err == 0) {
1282 		regs->nip += 4;		/* skip emulated instruction */
1283 		emulate_single_step(regs);
1284 		return;
1285 	}
1286 
1287 	if (err == -EFAULT) {
1288 		/* got an error reading the instruction */
1289 		_exception(SIGSEGV, regs, SEGV_ACCERR, regs->nip);
1290 	} else if (err == -EINVAL) {
1291 		/* didn't recognize the instruction */
1292 		printk(KERN_ERR "unrecognized spe instruction "
1293 		       "in %s at %lx\n", current->comm, regs->nip);
1294 	} else {
1295 		_exception(SIGFPE, regs, code, regs->nip);
1296 	}
1297 
1298 	return;
1299 }
1300 
1301 void SPEFloatingPointRoundException(struct pt_regs *regs)
1302 {
1303 	extern int speround_handler(struct pt_regs *regs);
1304 	int err;
1305 
1306 	preempt_disable();
1307 	if (regs->msr & MSR_SPE)
1308 		giveup_spe(current);
1309 	preempt_enable();
1310 
1311 	regs->nip -= 4;
1312 	err = speround_handler(regs);
1313 	if (err == 0) {
1314 		regs->nip += 4;		/* skip emulated instruction */
1315 		emulate_single_step(regs);
1316 		return;
1317 	}
1318 
1319 	if (err == -EFAULT) {
1320 		/* got an error reading the instruction */
1321 		_exception(SIGSEGV, regs, SEGV_ACCERR, regs->nip);
1322 	} else if (err == -EINVAL) {
1323 		/* didn't recognize the instruction */
1324 		printk(KERN_ERR "unrecognized spe instruction "
1325 		       "in %s at %lx\n", current->comm, regs->nip);
1326 	} else {
1327 		_exception(SIGFPE, regs, 0, regs->nip);
1328 		return;
1329 	}
1330 }
1331 #endif
1332 
1333 /*
1334  * We enter here if we get an unrecoverable exception, that is, one
1335  * that happened at a point where the RI (recoverable interrupt) bit
1336  * in the MSR is 0.  This indicates that SRR0/1 are live, and that
1337  * we therefore lost state by taking this exception.
1338  */
1339 void unrecoverable_exception(struct pt_regs *regs)
1340 {
1341 	printk(KERN_EMERG "Unrecoverable exception %lx at %lx\n",
1342 	       regs->trap, regs->nip);
1343 	die("Unrecoverable exception", regs, SIGABRT);
1344 }
1345 
1346 #ifdef CONFIG_BOOKE_WDT
1347 /*
1348  * Default handler for a Watchdog exception,
1349  * spins until a reboot occurs
1350  */
1351 void __attribute__ ((weak)) WatchdogHandler(struct pt_regs *regs)
1352 {
1353 	/* Generic WatchdogHandler, implement your own */
1354 	mtspr(SPRN_TCR, mfspr(SPRN_TCR)&(~TCR_WIE));
1355 	return;
1356 }
1357 
1358 void WatchdogException(struct pt_regs *regs)
1359 {
1360 	printk (KERN_EMERG "PowerPC Book-E Watchdog Exception\n");
1361 	WatchdogHandler(regs);
1362 }
1363 #endif
1364 
1365 /*
1366  * We enter here if we discover during exception entry that we are
1367  * running in supervisor mode with a userspace value in the stack pointer.
1368  */
1369 void kernel_bad_stack(struct pt_regs *regs)
1370 {
1371 	printk(KERN_EMERG "Bad kernel stack pointer %lx at %lx\n",
1372 	       regs->gpr[1], regs->nip);
1373 	die("Bad kernel stack pointer", regs, SIGABRT);
1374 }
1375 
1376 void __init trap_init(void)
1377 {
1378 }
1379 
1380 
1381 #ifdef CONFIG_PPC_EMULATED_STATS
1382 
1383 #define WARN_EMULATED_SETUP(type)	.type = { .name = #type }
1384 
1385 struct ppc_emulated ppc_emulated = {
1386 #ifdef CONFIG_ALTIVEC
1387 	WARN_EMULATED_SETUP(altivec),
1388 #endif
1389 	WARN_EMULATED_SETUP(dcba),
1390 	WARN_EMULATED_SETUP(dcbz),
1391 	WARN_EMULATED_SETUP(fp_pair),
1392 	WARN_EMULATED_SETUP(isel),
1393 	WARN_EMULATED_SETUP(mcrxr),
1394 	WARN_EMULATED_SETUP(mfpvr),
1395 	WARN_EMULATED_SETUP(multiple),
1396 	WARN_EMULATED_SETUP(popcntb),
1397 	WARN_EMULATED_SETUP(spe),
1398 	WARN_EMULATED_SETUP(string),
1399 	WARN_EMULATED_SETUP(unaligned),
1400 #ifdef CONFIG_MATH_EMULATION
1401 	WARN_EMULATED_SETUP(math),
1402 #elif defined(CONFIG_8XX_MINIMAL_FPEMU)
1403 	WARN_EMULATED_SETUP(8xx),
1404 #endif
1405 #ifdef CONFIG_VSX
1406 	WARN_EMULATED_SETUP(vsx),
1407 #endif
1408 };
1409 
1410 u32 ppc_warn_emulated;
1411 
1412 void ppc_warn_emulated_print(const char *type)
1413 {
1414 	if (printk_ratelimit())
1415 		pr_warning("%s used emulated %s instruction\n", current->comm,
1416 			   type);
1417 }
1418 
1419 static int __init ppc_warn_emulated_init(void)
1420 {
1421 	struct dentry *dir, *d;
1422 	unsigned int i;
1423 	struct ppc_emulated_entry *entries = (void *)&ppc_emulated;
1424 
1425 	if (!powerpc_debugfs_root)
1426 		return -ENODEV;
1427 
1428 	dir = debugfs_create_dir("emulated_instructions",
1429 				 powerpc_debugfs_root);
1430 	if (!dir)
1431 		return -ENOMEM;
1432 
1433 	d = debugfs_create_u32("do_warn", S_IRUGO | S_IWUSR, dir,
1434 			       &ppc_warn_emulated);
1435 	if (!d)
1436 		goto fail;
1437 
1438 	for (i = 0; i < sizeof(ppc_emulated)/sizeof(*entries); i++) {
1439 		d = debugfs_create_u32(entries[i].name, S_IRUGO | S_IWUSR, dir,
1440 				       (u32 *)&entries[i].val.counter);
1441 		if (!d)
1442 			goto fail;
1443 	}
1444 
1445 	return 0;
1446 
1447 fail:
1448 	debugfs_remove_recursive(dir);
1449 	return -ENOMEM;
1450 }
1451 
1452 device_initcall(ppc_warn_emulated_init);
1453 
1454 #endif /* CONFIG_PPC_EMULATED_STATS */
1455