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1/*
2 * arch/powerpc/kernel/traps.c
3 *
4 * Copyright (C) 1995-1996 Gary Thomas (gdt@linuxppc.org)
5 *
6 * This program is free software; you can redistribute it and/or
7 * modify it under the terms of the GNU General Public License
8 * as published by the Free Software Foundation; either version
9 * 2 of the License, or (at your option) any later version.
10 *
11 * Modified by Cort Dougan (cort@cs.nmt.edu)
12 * and Paul Mackerras (paulus@samba.org)
13 */
14
15/*
16 * This file handles the architecture-dependent parts of hardware exceptions
17 */
18
19#include <linux/config.h>
20#include <linux/errno.h>
21#include <linux/sched.h>
22#include <linux/kernel.h>
23#include <linux/mm.h>
24#include <linux/stddef.h>
25#include <linux/unistd.h>
26#include <linux/ptrace.h>
27#include <linux/slab.h>
28#include <linux/user.h>
29#include <linux/a.out.h>
30#include <linux/interrupt.h>
31#include <linux/config.h>
32#include <linux/init.h>
33#include <linux/module.h>
34#include <linux/prctl.h>
35#include <linux/delay.h>
36#include <linux/kprobes.h>
37#include <asm/kdebug.h>
38
39#include <asm/pgtable.h>
40#include <asm/uaccess.h>
41#include <asm/system.h>
42#include <asm/io.h>
43#include <asm/reg.h>
44#include <asm/xmon.h>
45#ifdef CONFIG_PMAC_BACKLIGHT
46#include <asm/backlight.h>
47#endif
48#include <asm/perfmon.h>
49
50#ifdef CONFIG_DEBUGGER
51int (*__debugger)(struct pt_regs *regs);
52int (*__debugger_ipi)(struct pt_regs *regs);
53int (*__debugger_bpt)(struct pt_regs *regs);
54int (*__debugger_sstep)(struct pt_regs *regs);
55int (*__debugger_iabr_match)(struct pt_regs *regs);
56int (*__debugger_dabr_match)(struct pt_regs *regs);
57int (*__debugger_fault_handler)(struct pt_regs *regs);
58
59EXPORT_SYMBOL(__debugger);
60EXPORT_SYMBOL(__debugger_ipi);
61EXPORT_SYMBOL(__debugger_bpt);
62EXPORT_SYMBOL(__debugger_sstep);
63EXPORT_SYMBOL(__debugger_iabr_match);
64EXPORT_SYMBOL(__debugger_dabr_match);
65EXPORT_SYMBOL(__debugger_fault_handler);
66#endif
67
68struct notifier_block *powerpc_die_chain;
69static DEFINE_SPINLOCK(die_notifier_lock);
70
71int register_die_notifier(struct notifier_block *nb)
72{
73 int err = 0;
74 unsigned long flags;
75
76 spin_lock_irqsave(&die_notifier_lock, flags);
77 err = notifier_chain_register(&powerpc_die_chain, nb);
78 spin_unlock_irqrestore(&die_notifier_lock, flags);
79 return err;
80}
81
82/*
83 * Trap & Exception support
84 */
85
86static DEFINE_SPINLOCK(die_lock);
87
88int die(const char *str, struct pt_regs *regs, long err)
89{
90 static int die_counter;
91 int nl = 0;
92
93 if (debugger(regs))
94 return 1;
95
96 console_verbose();
97 spin_lock_irq(&die_lock);
98 bust_spinlocks(1);
99#ifdef CONFIG_PMAC_BACKLIGHT
100 if (_machine == _MACH_Pmac) {
101 set_backlight_enable(1);
102 set_backlight_level(BACKLIGHT_MAX);
103 }
104#endif
105 printk("Oops: %s, sig: %ld [#%d]\n", str, err, ++die_counter);
106#ifdef CONFIG_PREEMPT
107 printk("PREEMPT ");
108 nl = 1;
109#endif
110#ifdef CONFIG_SMP
111 printk("SMP NR_CPUS=%d ", NR_CPUS);
112 nl = 1;
113#endif
114#ifdef CONFIG_DEBUG_PAGEALLOC
115 printk("DEBUG_PAGEALLOC ");
116 nl = 1;
117#endif
118#ifdef CONFIG_NUMA
119 printk("NUMA ");
120 nl = 1;
121#endif
122#ifdef CONFIG_PPC64
123 switch (systemcfg->platform) {
124 case PLATFORM_PSERIES:
125 printk("PSERIES ");
126 nl = 1;
127 break;
128 case PLATFORM_PSERIES_LPAR:
129 printk("PSERIES LPAR ");
130 nl = 1;
131 break;
132 case PLATFORM_ISERIES_LPAR:
133 printk("ISERIES LPAR ");
134 nl = 1;
135 break;
136 case PLATFORM_POWERMAC:
137 printk("POWERMAC ");
138 nl = 1;
139 break;
140 case PLATFORM_BPA:
141 printk("BPA ");
142 nl = 1;
143 break;
144 }
145#endif
146 if (nl)
147 printk("\n");
148 print_modules();
149 show_regs(regs);
150 bust_spinlocks(0);
151 spin_unlock_irq(&die_lock);
152
153 if (in_interrupt())
154 panic("Fatal exception in interrupt");
155
156 if (panic_on_oops) {
157 panic("Fatal exception");
158 }
159 do_exit(err);
160
161 return 0;
162}
163
164void _exception(int signr, struct pt_regs *regs, int code, unsigned long addr)
165{
166 siginfo_t info;
167
168 if (!user_mode(regs)) {
169 if (die("Exception in kernel mode", regs, signr))
170 return;
171 }
172
173 memset(&info, 0, sizeof(info));
174 info.si_signo = signr;
175 info.si_code = code;
176 info.si_addr = (void __user *) addr;
177 force_sig_info(signr, &info, current);
178
179 /*
180 * Init gets no signals that it doesn't have a handler for.
181 * That's all very well, but if it has caused a synchronous
182 * exception and we ignore the resulting signal, it will just
183 * generate the same exception over and over again and we get
184 * nowhere. Better to kill it and let the kernel panic.
185 */
186 if (current->pid == 1) {
187 __sighandler_t handler;
188
189 spin_lock_irq(&current->sighand->siglock);
190 handler = current->sighand->action[signr-1].sa.sa_handler;
191 spin_unlock_irq(&current->sighand->siglock);
192 if (handler == SIG_DFL) {
193 /* init has generated a synchronous exception
194 and it doesn't have a handler for the signal */
195 printk(KERN_CRIT "init has generated signal %d "
196 "but has no handler for it\n", signr);
197 do_exit(signr);
198 }
199 }
200}
201
202#ifdef CONFIG_PPC64
203void system_reset_exception(struct pt_regs *regs)
204{
205 /* See if any machine dependent calls */
206 if (ppc_md.system_reset_exception)
207 ppc_md.system_reset_exception(regs);
208
209 die("System Reset", regs, SIGABRT);
210
211 /* Must die if the interrupt is not recoverable */
212 if (!(regs->msr & MSR_RI))
213 panic("Unrecoverable System Reset");
214
215 /* What should we do here? We could issue a shutdown or hard reset. */
216}
217#endif
218
219/*
220 * I/O accesses can cause machine checks on powermacs.
221 * Check if the NIP corresponds to the address of a sync
222 * instruction for which there is an entry in the exception
223 * table.
224 * Note that the 601 only takes a machine check on TEA
225 * (transfer error ack) signal assertion, and does not
226 * set any of the top 16 bits of SRR1.
227 * -- paulus.
228 */
229static inline int check_io_access(struct pt_regs *regs)
230{
231#ifdef CONFIG_PPC_PMAC
232 unsigned long msr = regs->msr;
233 const struct exception_table_entry *entry;
234 unsigned int *nip = (unsigned int *)regs->nip;
235
236 if (((msr & 0xffff0000) == 0 || (msr & (0x80000 | 0x40000)))
237 && (entry = search_exception_tables(regs->nip)) != NULL) {
238 /*
239 * Check that it's a sync instruction, or somewhere
240 * in the twi; isync; nop sequence that inb/inw/inl uses.
241 * As the address is in the exception table
242 * we should be able to read the instr there.
243 * For the debug message, we look at the preceding
244 * load or store.
245 */
246 if (*nip == 0x60000000) /* nop */
247 nip -= 2;
248 else if (*nip == 0x4c00012c) /* isync */
249 --nip;
250 if (*nip == 0x7c0004ac || (*nip >> 26) == 3) {
251 /* sync or twi */
252 unsigned int rb;
253
254 --nip;
255 rb = (*nip >> 11) & 0x1f;
256 printk(KERN_DEBUG "%s bad port %lx at %p\n",
257 (*nip & 0x100)? "OUT to": "IN from",
258 regs->gpr[rb] - _IO_BASE, nip);
259 regs->msr |= MSR_RI;
260 regs->nip = entry->fixup;
261 return 1;
262 }
263 }
264#endif /* CONFIG_PPC_PMAC */
265 return 0;
266}
267
268#if defined(CONFIG_4xx) || defined(CONFIG_BOOKE)
269/* On 4xx, the reason for the machine check or program exception
270 is in the ESR. */
271#define get_reason(regs) ((regs)->dsisr)
272#ifndef CONFIG_FSL_BOOKE
273#define get_mc_reason(regs) ((regs)->dsisr)
274#else
275#define get_mc_reason(regs) (mfspr(SPRN_MCSR))
276#endif
277#define REASON_FP ESR_FP
278#define REASON_ILLEGAL (ESR_PIL | ESR_PUO)
279#define REASON_PRIVILEGED ESR_PPR
280#define REASON_TRAP ESR_PTR
281
282/* single-step stuff */
283#define single_stepping(regs) (current->thread.dbcr0 & DBCR0_IC)
284#define clear_single_step(regs) (current->thread.dbcr0 &= ~DBCR0_IC)
285
286#else
287/* On non-4xx, the reason for the machine check or program
288 exception is in the MSR. */
289#define get_reason(regs) ((regs)->msr)
290#define get_mc_reason(regs) ((regs)->msr)
291#define REASON_FP 0x100000
292#define REASON_ILLEGAL 0x80000
293#define REASON_PRIVILEGED 0x40000
294#define REASON_TRAP 0x20000
295
296#define single_stepping(regs) ((regs)->msr & MSR_SE)
297#define clear_single_step(regs) ((regs)->msr &= ~MSR_SE)
298#endif
299
300/*
301 * This is "fall-back" implementation for configurations
302 * which don't provide platform-specific machine check info
303 */
304void __attribute__ ((weak))
305platform_machine_check(struct pt_regs *regs)
306{
307}
308
309void MachineCheckException(struct pt_regs *regs)
310{
311#ifdef CONFIG_PPC64
312 int recover = 0;
313
314 /* See if any machine dependent calls */
315 if (ppc_md.machine_check_exception)
316 recover = ppc_md.machine_check_exception(regs);
317
318 if (recover)
319 return;
320#else
321 unsigned long reason = get_mc_reason(regs);
322
323 if (user_mode(regs)) {
324 regs->msr |= MSR_RI;
325 _exception(SIGBUS, regs, BUS_ADRERR, regs->nip);
326 return;
327 }
328
329#if defined(CONFIG_8xx) && defined(CONFIG_PCI)
330 /* the qspan pci read routines can cause machine checks -- Cort */
331 bad_page_fault(regs, regs->dar, SIGBUS);
332 return;
333#endif
334
335 if (debugger_fault_handler(regs)) {
336 regs->msr |= MSR_RI;
337 return;
338 }
339
340 if (check_io_access(regs))
341 return;
342
343#if defined(CONFIG_4xx) && !defined(CONFIG_440A)
344 if (reason & ESR_IMCP) {
345 printk("Instruction");
346 mtspr(SPRN_ESR, reason & ~ESR_IMCP);
347 } else
348 printk("Data");
349 printk(" machine check in kernel mode.\n");
350#elif defined(CONFIG_440A)
351 printk("Machine check in kernel mode.\n");
352 if (reason & ESR_IMCP){
353 printk("Instruction Synchronous Machine Check exception\n");
354 mtspr(SPRN_ESR, reason & ~ESR_IMCP);
355 }
356 else {
357 u32 mcsr = mfspr(SPRN_MCSR);
358 if (mcsr & MCSR_IB)
359 printk("Instruction Read PLB Error\n");
360 if (mcsr & MCSR_DRB)
361 printk("Data Read PLB Error\n");
362 if (mcsr & MCSR_DWB)
363 printk("Data Write PLB Error\n");
364 if (mcsr & MCSR_TLBP)
365 printk("TLB Parity Error\n");
366 if (mcsr & MCSR_ICP){
367 flush_instruction_cache();
368 printk("I-Cache Parity Error\n");
369 }
370 if (mcsr & MCSR_DCSP)
371 printk("D-Cache Search Parity Error\n");
372 if (mcsr & MCSR_DCFP)
373 printk("D-Cache Flush Parity Error\n");
374 if (mcsr & MCSR_IMPE)
375 printk("Machine Check exception is imprecise\n");
376
377 /* Clear MCSR */
378 mtspr(SPRN_MCSR, mcsr);
379 }
380#elif defined (CONFIG_E500)
381 printk("Machine check in kernel mode.\n");
382 printk("Caused by (from MCSR=%lx): ", reason);
383
384 if (reason & MCSR_MCP)
385 printk("Machine Check Signal\n");
386 if (reason & MCSR_ICPERR)
387 printk("Instruction Cache Parity Error\n");
388 if (reason & MCSR_DCP_PERR)
389 printk("Data Cache Push Parity Error\n");
390 if (reason & MCSR_DCPERR)
391 printk("Data Cache Parity Error\n");
392 if (reason & MCSR_GL_CI)
393 printk("Guarded Load or Cache-Inhibited stwcx.\n");
394 if (reason & MCSR_BUS_IAERR)
395 printk("Bus - Instruction Address Error\n");
396 if (reason & MCSR_BUS_RAERR)
397 printk("Bus - Read Address Error\n");
398 if (reason & MCSR_BUS_WAERR)
399 printk("Bus - Write Address Error\n");
400 if (reason & MCSR_BUS_IBERR)
401 printk("Bus - Instruction Data Error\n");
402 if (reason & MCSR_BUS_RBERR)
403 printk("Bus - Read Data Bus Error\n");
404 if (reason & MCSR_BUS_WBERR)
405 printk("Bus - Read Data Bus Error\n");
406 if (reason & MCSR_BUS_IPERR)
407 printk("Bus - Instruction Parity Error\n");
408 if (reason & MCSR_BUS_RPERR)
409 printk("Bus - Read Parity Error\n");
410#elif defined (CONFIG_E200)
411 printk("Machine check in kernel mode.\n");
412 printk("Caused by (from MCSR=%lx): ", reason);
413
414 if (reason & MCSR_MCP)
415 printk("Machine Check Signal\n");
416 if (reason & MCSR_CP_PERR)
417 printk("Cache Push Parity Error\n");
418 if (reason & MCSR_CPERR)
419 printk("Cache Parity Error\n");
420 if (reason & MCSR_EXCP_ERR)
421 printk("ISI, ITLB, or Bus Error on first instruction fetch for an exception handler\n");
422 if (reason & MCSR_BUS_IRERR)
423 printk("Bus - Read Bus Error on instruction fetch\n");
424 if (reason & MCSR_BUS_DRERR)
425 printk("Bus - Read Bus Error on data load\n");
426 if (reason & MCSR_BUS_WRERR)
427 printk("Bus - Write Bus Error on buffered store or cache line push\n");
428#else /* !CONFIG_4xx && !CONFIG_E500 && !CONFIG_E200 */
429 printk("Machine check in kernel mode.\n");
430 printk("Caused by (from SRR1=%lx): ", reason);
431 switch (reason & 0x601F0000) {
432 case 0x80000:
433 printk("Machine check signal\n");
434 break;
435 case 0: /* for 601 */
436 case 0x40000:
437 case 0x140000: /* 7450 MSS error and TEA */
438 printk("Transfer error ack signal\n");
439 break;
440 case 0x20000:
441 printk("Data parity error signal\n");
442 break;
443 case 0x10000:
444 printk("Address parity error signal\n");
445 break;
446 case 0x20000000:
447 printk("L1 Data Cache error\n");
448 break;
449 case 0x40000000:
450 printk("L1 Instruction Cache error\n");
451 break;
452 case 0x00100000:
453 printk("L2 data cache parity error\n");
454 break;
455 default:
456 printk("Unknown values in msr\n");
457 }
458#endif /* CONFIG_4xx */
459
460 /*
461 * Optional platform-provided routine to print out
462 * additional info, e.g. bus error registers.
463 */
464 platform_machine_check(regs);
465#endif /* CONFIG_PPC64 */
466
467 if (debugger_fault_handler(regs))
468 return;
469 die("Machine check", regs, SIGBUS);
470
471 /* Must die if the interrupt is not recoverable */
472 if (!(regs->msr & MSR_RI))
473 panic("Unrecoverable Machine check");
474}
475
476void SMIException(struct pt_regs *regs)
477{
478 die("System Management Interrupt", regs, SIGABRT);
479}
480
481void UnknownException(struct pt_regs *regs)
482{
483 printk("Bad trap at PC: %lx, SR: %lx, vector=%lx\n",
484 regs->nip, regs->msr, regs->trap);
485
486 _exception(SIGTRAP, regs, 0, 0);
487}
488
489void InstructionBreakpoint(struct pt_regs *regs)
490{
491 if (notify_die(DIE_IABR_MATCH, "iabr_match", regs, 5,
492 5, SIGTRAP) == NOTIFY_STOP)
493 return;
494 if (debugger_iabr_match(regs))
495 return;
496 _exception(SIGTRAP, regs, TRAP_BRKPT, regs->nip);
497}
498
499void RunModeException(struct pt_regs *regs)
500{
501 _exception(SIGTRAP, regs, 0, 0);
502}
503
504void SingleStepException(struct pt_regs *regs)
505{
506 regs->msr &= ~(MSR_SE | MSR_BE); /* Turn off 'trace' bits */
507
508 if (notify_die(DIE_SSTEP, "single_step", regs, 5,
509 5, SIGTRAP) == NOTIFY_STOP)
510 return;
511 if (debugger_sstep(regs))
512 return;
513
514 _exception(SIGTRAP, regs, TRAP_TRACE, regs->nip);
515}
516
517/*
518 * After we have successfully emulated an instruction, we have to
519 * check if the instruction was being single-stepped, and if so,
520 * pretend we got a single-step exception. This was pointed out
521 * by Kumar Gala. -- paulus
522 */
523static void emulate_single_step(struct pt_regs *regs)
524{
525 if (single_stepping(regs)) {
526 clear_single_step(regs);
527 _exception(SIGTRAP, regs, TRAP_TRACE, 0);
528 }
529}
530
531/* Illegal instruction emulation support. Originally written to
532 * provide the PVR to user applications using the mfspr rd, PVR.
533 * Return non-zero if we can't emulate, or -EFAULT if the associated
534 * memory access caused an access fault. Return zero on success.
535 *
536 * There are a couple of ways to do this, either "decode" the instruction
537 * or directly match lots of bits. In this case, matching lots of
538 * bits is faster and easier.
539 *
540 */
541#define INST_MFSPR_PVR 0x7c1f42a6
542#define INST_MFSPR_PVR_MASK 0xfc1fffff
543
544#define INST_DCBA 0x7c0005ec
545#define INST_DCBA_MASK 0x7c0007fe
546
547#define INST_MCRXR 0x7c000400
548#define INST_MCRXR_MASK 0x7c0007fe
549
550#define INST_STRING 0x7c00042a
551#define INST_STRING_MASK 0x7c0007fe
552#define INST_STRING_GEN_MASK 0x7c00067e
553#define INST_LSWI 0x7c0004aa
554#define INST_LSWX 0x7c00042a
555#define INST_STSWI 0x7c0005aa
556#define INST_STSWX 0x7c00052a
557
558static int emulate_string_inst(struct pt_regs *regs, u32 instword)
559{
560 u8 rT = (instword >> 21) & 0x1f;
561 u8 rA = (instword >> 16) & 0x1f;
562 u8 NB_RB = (instword >> 11) & 0x1f;
563 u32 num_bytes;
564 unsigned long EA;
565 int pos = 0;
566
567 /* Early out if we are an invalid form of lswx */
568 if ((instword & INST_STRING_MASK) == INST_LSWX)
569 if ((rT == rA) || (rT == NB_RB))
570 return -EINVAL;
571
572 EA = (rA == 0) ? 0 : regs->gpr[rA];
573
574 switch (instword & INST_STRING_MASK) {
575 case INST_LSWX:
576 case INST_STSWX:
577 EA += NB_RB;
578 num_bytes = regs->xer & 0x7f;
579 break;
580 case INST_LSWI:
581 case INST_STSWI:
582 num_bytes = (NB_RB == 0) ? 32 : NB_RB;
583 break;
584 default:
585 return -EINVAL;
586 }
587
588 while (num_bytes != 0)
589 {
590 u8 val;
591 u32 shift = 8 * (3 - (pos & 0x3));
592
593 switch ((instword & INST_STRING_MASK)) {
594 case INST_LSWX:
595 case INST_LSWI:
596 if (get_user(val, (u8 __user *)EA))
597 return -EFAULT;
598 /* first time updating this reg,
599 * zero it out */
600 if (pos == 0)
601 regs->gpr[rT] = 0;
602 regs->gpr[rT] |= val << shift;
603 break;
604 case INST_STSWI:
605 case INST_STSWX:
606 val = regs->gpr[rT] >> shift;
607 if (put_user(val, (u8 __user *)EA))
608 return -EFAULT;
609 break;
610 }
611 /* move EA to next address */
612 EA += 1;
613 num_bytes--;
614
615 /* manage our position within the register */
616 if (++pos == 4) {
617 pos = 0;
618 if (++rT == 32)
619 rT = 0;
620 }
621 }
622
623 return 0;
624}
625
626static int emulate_instruction(struct pt_regs *regs)
627{
628 u32 instword;
629 u32 rd;
630
631 if (!user_mode(regs))
632 return -EINVAL;
633 CHECK_FULL_REGS(regs);
634
635 if (get_user(instword, (u32 __user *)(regs->nip)))
636 return -EFAULT;
637
638 /* Emulate the mfspr rD, PVR. */
639 if ((instword & INST_MFSPR_PVR_MASK) == INST_MFSPR_PVR) {
640 rd = (instword >> 21) & 0x1f;
641 regs->gpr[rd] = mfspr(SPRN_PVR);
642 return 0;
643 }
644
645 /* Emulating the dcba insn is just a no-op. */
646 if ((instword & INST_DCBA_MASK) == INST_DCBA)
647 return 0;
648
649 /* Emulate the mcrxr insn. */
650 if ((instword & INST_MCRXR_MASK) == INST_MCRXR) {
651 int shift = (instword >> 21) & 0x1c;
652 unsigned long msk = 0xf0000000UL >> shift;
653
654 regs->ccr = (regs->ccr & ~msk) | ((regs->xer >> shift) & msk);
655 regs->xer &= ~0xf0000000UL;
656 return 0;
657 }
658
659 /* Emulate load/store string insn. */
660 if ((instword & INST_STRING_GEN_MASK) == INST_STRING)
661 return emulate_string_inst(regs, instword);
662
663 return -EINVAL;
664}
665
666/*
667 * Look through the list of trap instructions that are used for BUG(),
668 * BUG_ON() and WARN_ON() and see if we hit one. At this point we know
669 * that the exception was caused by a trap instruction of some kind.
670 * Returns 1 if we should continue (i.e. it was a WARN_ON) or 0
671 * otherwise.
672 */
673extern struct bug_entry __start___bug_table[], __stop___bug_table[];
674
675#ifndef CONFIG_MODULES
676#define module_find_bug(x) NULL
677#endif
678
679struct bug_entry *find_bug(unsigned long bugaddr)
680{
681 struct bug_entry *bug;
682
683 for (bug = __start___bug_table; bug < __stop___bug_table; ++bug)
684 if (bugaddr == bug->bug_addr)
685 return bug;
686 return module_find_bug(bugaddr);
687}
688
689int check_bug_trap(struct pt_regs *regs)
690{
691 struct bug_entry *bug;
692 unsigned long addr;
693
694 if (regs->msr & MSR_PR)
695 return 0; /* not in kernel */
696 addr = regs->nip; /* address of trap instruction */
697 if (addr < PAGE_OFFSET)
698 return 0;
699 bug = find_bug(regs->nip);
700 if (bug == NULL)
701 return 0;
702 if (bug->line & BUG_WARNING_TRAP) {
703 /* this is a WARN_ON rather than BUG/BUG_ON */
704#ifdef CONFIG_XMON
705 xmon_printf(KERN_ERR "Badness in %s at %s:%d\n",
706 bug->function, bug->file,
707 bug->line & ~BUG_WARNING_TRAP);
708#endif /* CONFIG_XMON */
709 printk(KERN_ERR "Badness in %s at %s:%d\n",
710 bug->function, bug->file,
711 bug->line & ~BUG_WARNING_TRAP);
712 dump_stack();
713 return 1;
714 }
715#ifdef CONFIG_XMON
716 xmon_printf(KERN_CRIT "kernel BUG in %s at %s:%d!\n",
717 bug->function, bug->file, bug->line);
718 xmon(regs);
719#endif /* CONFIG_XMON */
720 printk(KERN_CRIT "kernel BUG in %s at %s:%d!\n",
721 bug->function, bug->file, bug->line);
722
723 return 0;
724}
725
726void ProgramCheckException(struct pt_regs *regs)
727{
728 unsigned int reason = get_reason(regs);
729 extern int do_mathemu(struct pt_regs *regs);
730
731#ifdef CONFIG_MATH_EMULATION
732 /* (reason & REASON_ILLEGAL) would be the obvious thing here,
733 * but there seems to be a hardware bug on the 405GP (RevD)
734 * that means ESR is sometimes set incorrectly - either to
735 * ESR_DST (!?) or 0. In the process of chasing this with the
736 * hardware people - not sure if it can happen on any illegal
737 * instruction or only on FP instructions, whether there is a
738 * pattern to occurences etc. -dgibson 31/Mar/2003 */
739 if (!(reason & REASON_TRAP) && do_mathemu(regs) == 0) {
740 emulate_single_step(regs);
741 return;
742 }
743#endif /* CONFIG_MATH_EMULATION */
744
745 if (reason & REASON_FP) {
746 /* IEEE FP exception */
747 int code = 0;
748 u32 fpscr;
749
750 /* We must make sure the FP state is consistent with
751 * our MSR_FP in regs
752 */
753 preempt_disable();
754 if (regs->msr & MSR_FP)
755 giveup_fpu(current);
756 preempt_enable();
757
758 fpscr = current->thread.fpscr;
759 fpscr &= fpscr << 22; /* mask summary bits with enables */
760 if (fpscr & FPSCR_VX)
761 code = FPE_FLTINV;
762 else if (fpscr & FPSCR_OX)
763 code = FPE_FLTOVF;
764 else if (fpscr & FPSCR_UX)
765 code = FPE_FLTUND;
766 else if (fpscr & FPSCR_ZX)
767 code = FPE_FLTDIV;
768 else if (fpscr & FPSCR_XX)
769 code = FPE_FLTRES;
770 _exception(SIGFPE, regs, code, regs->nip);
771 return;
772 }
773
774 if (reason & REASON_TRAP) {
775 /* trap exception */
776 if (debugger_bpt(regs))
777 return;
778 if (check_bug_trap(regs)) {
779 regs->nip += 4;
780 return;
781 }
782 _exception(SIGTRAP, regs, TRAP_BRKPT, 0);
783 return;
784 }
785
786 /* Try to emulate it if we should. */
787 if (reason & (REASON_ILLEGAL | REASON_PRIVILEGED)) {
788 switch (emulate_instruction(regs)) {
789 case 0:
790 regs->nip += 4;
791 emulate_single_step(regs);
792 return;
793 case -EFAULT:
794 _exception(SIGSEGV, regs, SEGV_MAPERR, regs->nip);
795 return;
796 }
797 }
798
799 if (reason & REASON_PRIVILEGED)
800 _exception(SIGILL, regs, ILL_PRVOPC, regs->nip);
801 else
802 _exception(SIGILL, regs, ILL_ILLOPC, regs->nip);
803}
804
805void AlignmentException(struct pt_regs *regs)
806{
807 int fixed;
808
809 fixed = fix_alignment(regs);
810
811 if (fixed == 1) {
812 regs->nip += 4; /* skip over emulated instruction */
813 emulate_single_step(regs);
814 return;
815 }
816
817 /* Operand address was bad */
818 if (fixed == -EFAULT) {
819 if (user_mode(regs))
820 _exception(SIGSEGV, regs, SEGV_ACCERR, regs->dar);
821 else
822 /* Search exception table */
823 bad_page_fault(regs, regs->dar, SIGSEGV);
824 return;
825 }
826 _exception(SIGBUS, regs, BUS_ADRALN, regs->dar);
827}
828
829void StackOverflow(struct pt_regs *regs)
830{
831 printk(KERN_CRIT "Kernel stack overflow in process %p, r1=%lx\n",
832 current, regs->gpr[1]);
833 debugger(regs);
834 show_regs(regs);
835 panic("kernel stack overflow");
836}
837
838void nonrecoverable_exception(struct pt_regs *regs)
839{
840 printk(KERN_ERR "Non-recoverable exception at PC=%lx MSR=%lx\n",
841 regs->nip, regs->msr);
842 debugger(regs);
843 die("nonrecoverable exception", regs, SIGKILL);
844}
845
846void trace_syscall(struct pt_regs *regs)
847{
848 printk("Task: %p(%d), PC: %08lX/%08lX, Syscall: %3ld, Result: %s%ld %s\n",
849 current, current->pid, regs->nip, regs->link, regs->gpr[0],
850 regs->ccr&0x10000000?"Error=":"", regs->gpr[3], print_tainted());
851}
852
853#ifdef CONFIG_8xx
854void SoftwareEmulation(struct pt_regs *regs)
855{
856 extern int do_mathemu(struct pt_regs *);
857 extern int Soft_emulate_8xx(struct pt_regs *);
858 int errcode;
859
860 CHECK_FULL_REGS(regs);
861
862 if (!user_mode(regs)) {
863 debugger(regs);
864 die("Kernel Mode Software FPU Emulation", regs, SIGFPE);
865 }
866
867#ifdef CONFIG_MATH_EMULATION
868 errcode = do_mathemu(regs);
869#else
870 errcode = Soft_emulate_8xx(regs);
871#endif
872 if (errcode) {
873 if (errcode > 0)
874 _exception(SIGFPE, regs, 0, 0);
875 else if (errcode == -EFAULT)
876 _exception(SIGSEGV, regs, 0, 0);
877 else
878 _exception(SIGILL, regs, ILL_ILLOPC, regs->nip);
879 } else
880 emulate_single_step(regs);
881}
882#endif /* CONFIG_8xx */
883
884#if defined(CONFIG_40x) || defined(CONFIG_BOOKE)
885
886void DebugException(struct pt_regs *regs, unsigned long debug_status)
887{
888 if (debug_status & DBSR_IC) { /* instruction completion */
889 regs->msr &= ~MSR_DE;
890 if (user_mode(regs)) {
891 current->thread.dbcr0 &= ~DBCR0_IC;
892 } else {
893 /* Disable instruction completion */
894 mtspr(SPRN_DBCR0, mfspr(SPRN_DBCR0) & ~DBCR0_IC);
895 /* Clear the instruction completion event */
896 mtspr(SPRN_DBSR, DBSR_IC);
897 if (debugger_sstep(regs))
898 return;
899 }
900 _exception(SIGTRAP, regs, TRAP_TRACE, 0);
901 }
902}
903#endif /* CONFIG_4xx || CONFIG_BOOKE */
904
905#if !defined(CONFIG_TAU_INT)
906void TAUException(struct pt_regs *regs)
907{
908 printk("TAU trap at PC: %lx, MSR: %lx, vector=%lx %s\n",
909 regs->nip, regs->msr, regs->trap, print_tainted());
910}
911#endif /* CONFIG_INT_TAU */
912
913void AltivecUnavailException(struct pt_regs *regs)
914{
915 static int kernel_altivec_count;
916
917#ifndef CONFIG_ALTIVEC
918 if (user_mode(regs)) {
919 /* A user program has executed an altivec instruction,
920 but this kernel doesn't support altivec. */
921 _exception(SIGILL, regs, ILL_ILLOPC, regs->nip);
922 return;
923 }
924#endif
925 /* The kernel has executed an altivec instruction without
926 first enabling altivec. Whinge but let it do it. */
927 if (++kernel_altivec_count < 10)
928 printk(KERN_ERR "AltiVec used in kernel (task=%p, pc=%lx)\n",
929 current, regs->nip);
930 regs->msr |= MSR_VEC;
931}
932
933#ifdef CONFIG_ALTIVEC
934void AltivecAssistException(struct pt_regs *regs)
935{
936 int err;
937
938 preempt_disable();
939 if (regs->msr & MSR_VEC)
940 giveup_altivec(current);
941 preempt_enable();
942 if (!user_mode(regs)) {
943 printk(KERN_EMERG "VMX/Altivec assist exception in kernel mode"
944 " at %lx\n", regs->nip);
945 die("Kernel Altivec assist exception", regs, SIGILL);
946 }
947
948 err = emulate_altivec(regs);
949 if (err == 0) {
950 regs->nip += 4; /* skip emulated instruction */
951 emulate_single_step(regs);
952 return;
953 }
954
955 if (err == -EFAULT) {
956 /* got an error reading the instruction */
957 _exception(SIGSEGV, regs, SEGV_ACCERR, regs->nip);
958 } else {
959 /* didn't recognize the instruction */
960 /* XXX quick hack for now: set the non-Java bit in the VSCR */
961 if (printk_ratelimit())
962 printk(KERN_ERR "Unrecognized altivec instruction "
963 "in %s at %lx\n", current->comm, regs->nip);
964 current->thread.vscr.u[3] |= 0x10000;
965 }
966}
967#endif /* CONFIG_ALTIVEC */
968
969#ifdef CONFIG_E500
970void PerformanceMonitorException(struct pt_regs *regs)
971{
972 perf_irq(regs);
973}
974#endif
975
976#ifdef CONFIG_FSL_BOOKE
977void CacheLockingException(struct pt_regs *regs, unsigned long address,
978 unsigned long error_code)
979{
980 /* We treat cache locking instructions from the user
981 * as priv ops, in the future we could try to do
982 * something smarter
983 */
984 if (error_code & (ESR_DLK|ESR_ILK))
985 _exception(SIGILL, regs, ILL_PRVOPC, regs->nip);
986 return;
987}
988#endif /* CONFIG_FSL_BOOKE */
989
990#ifdef CONFIG_SPE
991void SPEFloatingPointException(struct pt_regs *regs)
992{
993 unsigned long spefscr;
994 int fpexc_mode;
995 int code = 0;
996
997 spefscr = current->thread.spefscr;
998 fpexc_mode = current->thread.fpexc_mode;
999
1000 /* Hardware does not neccessarily set sticky
1001 * underflow/overflow/invalid flags */
1002 if ((spefscr & SPEFSCR_FOVF) && (fpexc_mode & PR_FP_EXC_OVF)) {
1003 code = FPE_FLTOVF;
1004 spefscr |= SPEFSCR_FOVFS;
1005 }
1006 else if ((spefscr & SPEFSCR_FUNF) && (fpexc_mode & PR_FP_EXC_UND)) {
1007 code = FPE_FLTUND;
1008 spefscr |= SPEFSCR_FUNFS;
1009 }
1010 else if ((spefscr & SPEFSCR_FDBZ) && (fpexc_mode & PR_FP_EXC_DIV))
1011 code = FPE_FLTDIV;
1012 else if ((spefscr & SPEFSCR_FINV) && (fpexc_mode & PR_FP_EXC_INV)) {
1013 code = FPE_FLTINV;
1014 spefscr |= SPEFSCR_FINVS;
1015 }
1016 else if ((spefscr & (SPEFSCR_FG | SPEFSCR_FX)) && (fpexc_mode & PR_FP_EXC_RES))
1017 code = FPE_FLTRES;
1018
1019 current->thread.spefscr = spefscr;
1020
1021 _exception(SIGFPE, regs, code, regs->nip);
1022 return;
1023}
1024#endif
1025
1026#ifdef CONFIG_BOOKE_WDT
1027/*
1028 * Default handler for a Watchdog exception,
1029 * spins until a reboot occurs
1030 */
1031void __attribute__ ((weak)) WatchdogHandler(struct pt_regs *regs)
1032{
1033 /* Generic WatchdogHandler, implement your own */
1034 mtspr(SPRN_TCR, mfspr(SPRN_TCR)&(~TCR_WIE));
1035 return;
1036}
1037
1038void WatchdogException(struct pt_regs *regs)
1039{
1040 printk (KERN_EMERG "PowerPC Book-E Watchdog Exception\n");
1041 WatchdogHandler(regs);
1042}
1043#endif
1044
1045void __init trap_init(void)
1046{
1047}
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