Merge tag 'locks-v3.16-2' of git://git.samba.org/jlayton/linux
[linux/fpc-iii.git] / arch / s390 / mm / fault.c
blob3f3b35403d0a4100bd0bd0bdee424f693ad93670
1 /*
2 * S390 version
3 * Copyright IBM Corp. 1999
4 * Author(s): Hartmut Penner (hp@de.ibm.com)
5 * Ulrich Weigand (uweigand@de.ibm.com)
7 * Derived from "arch/i386/mm/fault.c"
8 * Copyright (C) 1995 Linus Torvalds
9 */
11 #include <linux/kernel_stat.h>
12 #include <linux/perf_event.h>
13 #include <linux/signal.h>
14 #include <linux/sched.h>
15 #include <linux/kernel.h>
16 #include <linux/errno.h>
17 #include <linux/string.h>
18 #include <linux/types.h>
19 #include <linux/ptrace.h>
20 #include <linux/mman.h>
21 #include <linux/mm.h>
22 #include <linux/compat.h>
23 #include <linux/smp.h>
24 #include <linux/kdebug.h>
25 #include <linux/init.h>
26 #include <linux/console.h>
27 #include <linux/module.h>
28 #include <linux/hardirq.h>
29 #include <linux/kprobes.h>
30 #include <linux/uaccess.h>
31 #include <linux/hugetlb.h>
32 #include <asm/asm-offsets.h>
33 #include <asm/pgtable.h>
34 #include <asm/irq.h>
35 #include <asm/mmu_context.h>
36 #include <asm/facility.h>
37 #include "../kernel/entry.h"
39 #ifndef CONFIG_64BIT
40 #define __FAIL_ADDR_MASK 0x7ffff000
41 #define __SUBCODE_MASK 0x0200
42 #define __PF_RES_FIELD 0ULL
43 #else /* CONFIG_64BIT */
44 #define __FAIL_ADDR_MASK -4096L
45 #define __SUBCODE_MASK 0x0600
46 #define __PF_RES_FIELD 0x8000000000000000ULL
47 #endif /* CONFIG_64BIT */
49 #define VM_FAULT_BADCONTEXT 0x010000
50 #define VM_FAULT_BADMAP 0x020000
51 #define VM_FAULT_BADACCESS 0x040000
52 #define VM_FAULT_SIGNAL 0x080000
53 #define VM_FAULT_PFAULT 0x100000
55 static unsigned long store_indication __read_mostly;
57 #ifdef CONFIG_64BIT
58 static int __init fault_init(void)
60 if (test_facility(75))
61 store_indication = 0xc00;
62 return 0;
64 early_initcall(fault_init);
65 #endif
67 static inline int notify_page_fault(struct pt_regs *regs)
69 int ret = 0;
71 /* kprobe_running() needs smp_processor_id() */
72 if (kprobes_built_in() && !user_mode(regs)) {
73 preempt_disable();
74 if (kprobe_running() && kprobe_fault_handler(regs, 14))
75 ret = 1;
76 preempt_enable();
78 return ret;
83 * Unlock any spinlocks which will prevent us from getting the
84 * message out.
86 void bust_spinlocks(int yes)
88 if (yes) {
89 oops_in_progress = 1;
90 } else {
91 int loglevel_save = console_loglevel;
92 console_unblank();
93 oops_in_progress = 0;
95 * OK, the message is on the console. Now we call printk()
96 * without oops_in_progress set so that printk will give klogd
97 * a poke. Hold onto your hats...
99 console_loglevel = 15;
100 printk(" ");
101 console_loglevel = loglevel_save;
106 * Returns the address space associated with the fault.
107 * Returns 0 for kernel space and 1 for user space.
109 static inline int user_space_fault(struct pt_regs *regs)
111 unsigned long trans_exc_code;
114 * The lowest two bits of the translation exception
115 * identification indicate which paging table was used.
117 trans_exc_code = regs->int_parm_long & 3;
118 if (trans_exc_code == 3) /* home space -> kernel */
119 return 0;
120 if (user_mode(regs))
121 return 1;
122 if (trans_exc_code == 2) /* secondary space -> set_fs */
123 return current->thread.mm_segment.ar4;
124 if (current->flags & PF_VCPU)
125 return 1;
126 return 0;
129 static int bad_address(void *p)
131 unsigned long dummy;
133 return probe_kernel_address((unsigned long *)p, dummy);
136 #ifdef CONFIG_64BIT
137 static void dump_pagetable(unsigned long asce, unsigned long address)
139 unsigned long *table = __va(asce & PAGE_MASK);
141 pr_alert("AS:%016lx ", asce);
142 switch (asce & _ASCE_TYPE_MASK) {
143 case _ASCE_TYPE_REGION1:
144 table = table + ((address >> 53) & 0x7ff);
145 if (bad_address(table))
146 goto bad;
147 pr_cont("R1:%016lx ", *table);
148 if (*table & _REGION_ENTRY_INVALID)
149 goto out;
150 table = (unsigned long *)(*table & _REGION_ENTRY_ORIGIN);
151 /* fallthrough */
152 case _ASCE_TYPE_REGION2:
153 table = table + ((address >> 42) & 0x7ff);
154 if (bad_address(table))
155 goto bad;
156 pr_cont("R2:%016lx ", *table);
157 if (*table & _REGION_ENTRY_INVALID)
158 goto out;
159 table = (unsigned long *)(*table & _REGION_ENTRY_ORIGIN);
160 /* fallthrough */
161 case _ASCE_TYPE_REGION3:
162 table = table + ((address >> 31) & 0x7ff);
163 if (bad_address(table))
164 goto bad;
165 pr_cont("R3:%016lx ", *table);
166 if (*table & (_REGION_ENTRY_INVALID | _REGION3_ENTRY_LARGE))
167 goto out;
168 table = (unsigned long *)(*table & _REGION_ENTRY_ORIGIN);
169 /* fallthrough */
170 case _ASCE_TYPE_SEGMENT:
171 table = table + ((address >> 20) & 0x7ff);
172 if (bad_address(table))
173 goto bad;
174 pr_cont(KERN_CONT "S:%016lx ", *table);
175 if (*table & (_SEGMENT_ENTRY_INVALID | _SEGMENT_ENTRY_LARGE))
176 goto out;
177 table = (unsigned long *)(*table & _SEGMENT_ENTRY_ORIGIN);
179 table = table + ((address >> 12) & 0xff);
180 if (bad_address(table))
181 goto bad;
182 pr_cont("P:%016lx ", *table);
183 out:
184 pr_cont("\n");
185 return;
186 bad:
187 pr_cont("BAD\n");
190 #else /* CONFIG_64BIT */
192 static void dump_pagetable(unsigned long asce, unsigned long address)
194 unsigned long *table = __va(asce & PAGE_MASK);
196 pr_alert("AS:%08lx ", asce);
197 table = table + ((address >> 20) & 0x7ff);
198 if (bad_address(table))
199 goto bad;
200 pr_cont("S:%08lx ", *table);
201 if (*table & _SEGMENT_ENTRY_INVALID)
202 goto out;
203 table = (unsigned long *)(*table & _SEGMENT_ENTRY_ORIGIN);
204 table = table + ((address >> 12) & 0xff);
205 if (bad_address(table))
206 goto bad;
207 pr_cont("P:%08lx ", *table);
208 out:
209 pr_cont("\n");
210 return;
211 bad:
212 pr_cont("BAD\n");
215 #endif /* CONFIG_64BIT */
217 static void dump_fault_info(struct pt_regs *regs)
219 unsigned long asce;
221 pr_alert("Fault in ");
222 switch (regs->int_parm_long & 3) {
223 case 3:
224 pr_cont("home space ");
225 break;
226 case 2:
227 pr_cont("secondary space ");
228 break;
229 case 1:
230 pr_cont("access register ");
231 break;
232 case 0:
233 pr_cont("primary space ");
234 break;
236 pr_cont("mode while using ");
237 if (!user_space_fault(regs)) {
238 asce = S390_lowcore.kernel_asce;
239 pr_cont("kernel ");
241 #ifdef CONFIG_PGSTE
242 else if ((current->flags & PF_VCPU) && S390_lowcore.gmap) {
243 struct gmap *gmap = (struct gmap *)S390_lowcore.gmap;
244 asce = gmap->asce;
245 pr_cont("gmap ");
247 #endif
248 else {
249 asce = S390_lowcore.user_asce;
250 pr_cont("user ");
252 pr_cont("ASCE.\n");
253 dump_pagetable(asce, regs->int_parm_long & __FAIL_ADDR_MASK);
256 static inline void report_user_fault(struct pt_regs *regs, long signr)
258 if ((task_pid_nr(current) > 1) && !show_unhandled_signals)
259 return;
260 if (!unhandled_signal(current, signr))
261 return;
262 if (!printk_ratelimit())
263 return;
264 printk(KERN_ALERT "User process fault: interruption code 0x%X ",
265 regs->int_code);
266 print_vma_addr(KERN_CONT "in ", regs->psw.addr & PSW_ADDR_INSN);
267 printk(KERN_CONT "\n");
268 printk(KERN_ALERT "failing address: %016lx TEID: %016lx\n",
269 regs->int_parm_long & __FAIL_ADDR_MASK, regs->int_parm_long);
270 dump_fault_info(regs);
271 show_regs(regs);
275 * Send SIGSEGV to task. This is an external routine
276 * to keep the stack usage of do_page_fault small.
278 static noinline void do_sigsegv(struct pt_regs *regs, int si_code)
280 struct siginfo si;
282 report_user_fault(regs, SIGSEGV);
283 si.si_signo = SIGSEGV;
284 si.si_code = si_code;
285 si.si_addr = (void __user *)(regs->int_parm_long & __FAIL_ADDR_MASK);
286 force_sig_info(SIGSEGV, &si, current);
289 static noinline void do_no_context(struct pt_regs *regs)
291 const struct exception_table_entry *fixup;
292 unsigned long address;
294 /* Are we prepared to handle this kernel fault? */
295 fixup = search_exception_tables(regs->psw.addr & PSW_ADDR_INSN);
296 if (fixup) {
297 regs->psw.addr = extable_fixup(fixup) | PSW_ADDR_AMODE;
298 return;
302 * Oops. The kernel tried to access some bad page. We'll have to
303 * terminate things with extreme prejudice.
305 address = regs->int_parm_long & __FAIL_ADDR_MASK;
306 if (!user_space_fault(regs))
307 printk(KERN_ALERT "Unable to handle kernel pointer dereference"
308 " in virtual kernel address space\n");
309 else
310 printk(KERN_ALERT "Unable to handle kernel paging request"
311 " in virtual user address space\n");
312 printk(KERN_ALERT "failing address: %016lx TEID: %016lx\n",
313 regs->int_parm_long & __FAIL_ADDR_MASK, regs->int_parm_long);
314 dump_fault_info(regs);
315 die(regs, "Oops");
316 do_exit(SIGKILL);
319 static noinline void do_low_address(struct pt_regs *regs)
321 /* Low-address protection hit in kernel mode means
322 NULL pointer write access in kernel mode. */
323 if (regs->psw.mask & PSW_MASK_PSTATE) {
324 /* Low-address protection hit in user mode 'cannot happen'. */
325 die (regs, "Low-address protection");
326 do_exit(SIGKILL);
329 do_no_context(regs);
332 static noinline void do_sigbus(struct pt_regs *regs)
334 struct task_struct *tsk = current;
335 struct siginfo si;
338 * Send a sigbus, regardless of whether we were in kernel
339 * or user mode.
341 si.si_signo = SIGBUS;
342 si.si_errno = 0;
343 si.si_code = BUS_ADRERR;
344 si.si_addr = (void __user *)(regs->int_parm_long & __FAIL_ADDR_MASK);
345 force_sig_info(SIGBUS, &si, tsk);
348 static noinline void do_fault_error(struct pt_regs *regs, int fault)
350 int si_code;
352 switch (fault) {
353 case VM_FAULT_BADACCESS:
354 case VM_FAULT_BADMAP:
355 /* Bad memory access. Check if it is kernel or user space. */
356 if (user_mode(regs)) {
357 /* User mode accesses just cause a SIGSEGV */
358 si_code = (fault == VM_FAULT_BADMAP) ?
359 SEGV_MAPERR : SEGV_ACCERR;
360 do_sigsegv(regs, si_code);
361 return;
363 case VM_FAULT_BADCONTEXT:
364 case VM_FAULT_PFAULT:
365 do_no_context(regs);
366 break;
367 case VM_FAULT_SIGNAL:
368 if (!user_mode(regs))
369 do_no_context(regs);
370 break;
371 default: /* fault & VM_FAULT_ERROR */
372 if (fault & VM_FAULT_OOM) {
373 if (!user_mode(regs))
374 do_no_context(regs);
375 else
376 pagefault_out_of_memory();
377 } else if (fault & VM_FAULT_SIGBUS) {
378 /* Kernel mode? Handle exceptions or die */
379 if (!user_mode(regs))
380 do_no_context(regs);
381 else
382 do_sigbus(regs);
383 } else
384 BUG();
385 break;
390 * This routine handles page faults. It determines the address,
391 * and the problem, and then passes it off to one of the appropriate
392 * routines.
394 * interruption code (int_code):
395 * 04 Protection -> Write-Protection (suprression)
396 * 10 Segment translation -> Not present (nullification)
397 * 11 Page translation -> Not present (nullification)
398 * 3b Region third trans. -> Not present (nullification)
400 static inline int do_exception(struct pt_regs *regs, int access)
402 #ifdef CONFIG_PGSTE
403 struct gmap *gmap;
404 #endif
405 struct task_struct *tsk;
406 struct mm_struct *mm;
407 struct vm_area_struct *vma;
408 unsigned long trans_exc_code;
409 unsigned long address;
410 unsigned int flags;
411 int fault;
413 tsk = current;
415 * The instruction that caused the program check has
416 * been nullified. Don't signal single step via SIGTRAP.
418 clear_pt_regs_flag(regs, PIF_PER_TRAP);
420 if (notify_page_fault(regs))
421 return 0;
423 mm = tsk->mm;
424 trans_exc_code = regs->int_parm_long;
427 * Verify that the fault happened in user space, that
428 * we are not in an interrupt and that there is a
429 * user context.
431 fault = VM_FAULT_BADCONTEXT;
432 if (unlikely(!user_space_fault(regs) || in_atomic() || !mm))
433 goto out;
435 address = trans_exc_code & __FAIL_ADDR_MASK;
436 perf_sw_event(PERF_COUNT_SW_PAGE_FAULTS, 1, regs, address);
437 flags = FAULT_FLAG_ALLOW_RETRY | FAULT_FLAG_KILLABLE;
438 if (user_mode(regs))
439 flags |= FAULT_FLAG_USER;
440 if (access == VM_WRITE || (trans_exc_code & store_indication) == 0x400)
441 flags |= FAULT_FLAG_WRITE;
442 down_read(&mm->mmap_sem);
444 #ifdef CONFIG_PGSTE
445 gmap = (struct gmap *)
446 ((current->flags & PF_VCPU) ? S390_lowcore.gmap : 0);
447 if (gmap) {
448 address = __gmap_fault(address, gmap);
449 if (address == -EFAULT) {
450 fault = VM_FAULT_BADMAP;
451 goto out_up;
453 if (address == -ENOMEM) {
454 fault = VM_FAULT_OOM;
455 goto out_up;
457 if (gmap->pfault_enabled)
458 flags |= FAULT_FLAG_RETRY_NOWAIT;
460 #endif
462 retry:
463 fault = VM_FAULT_BADMAP;
464 vma = find_vma(mm, address);
465 if (!vma)
466 goto out_up;
468 if (unlikely(vma->vm_start > address)) {
469 if (!(vma->vm_flags & VM_GROWSDOWN))
470 goto out_up;
471 if (expand_stack(vma, address))
472 goto out_up;
476 * Ok, we have a good vm_area for this memory access, so
477 * we can handle it..
479 fault = VM_FAULT_BADACCESS;
480 if (unlikely(!(vma->vm_flags & access)))
481 goto out_up;
483 if (is_vm_hugetlb_page(vma))
484 address &= HPAGE_MASK;
486 * If for any reason at all we couldn't handle the fault,
487 * make sure we exit gracefully rather than endlessly redo
488 * the fault.
490 fault = handle_mm_fault(mm, vma, address, flags);
491 /* No reason to continue if interrupted by SIGKILL. */
492 if ((fault & VM_FAULT_RETRY) && fatal_signal_pending(current)) {
493 fault = VM_FAULT_SIGNAL;
494 goto out;
496 if (unlikely(fault & VM_FAULT_ERROR))
497 goto out_up;
500 * Major/minor page fault accounting is only done on the
501 * initial attempt. If we go through a retry, it is extremely
502 * likely that the page will be found in page cache at that point.
504 if (flags & FAULT_FLAG_ALLOW_RETRY) {
505 if (fault & VM_FAULT_MAJOR) {
506 tsk->maj_flt++;
507 perf_sw_event(PERF_COUNT_SW_PAGE_FAULTS_MAJ, 1,
508 regs, address);
509 } else {
510 tsk->min_flt++;
511 perf_sw_event(PERF_COUNT_SW_PAGE_FAULTS_MIN, 1,
512 regs, address);
514 if (fault & VM_FAULT_RETRY) {
515 #ifdef CONFIG_PGSTE
516 if (gmap && (flags & FAULT_FLAG_RETRY_NOWAIT)) {
517 /* FAULT_FLAG_RETRY_NOWAIT has been set,
518 * mmap_sem has not been released */
519 current->thread.gmap_pfault = 1;
520 fault = VM_FAULT_PFAULT;
521 goto out_up;
523 #endif
524 /* Clear FAULT_FLAG_ALLOW_RETRY to avoid any risk
525 * of starvation. */
526 flags &= ~(FAULT_FLAG_ALLOW_RETRY |
527 FAULT_FLAG_RETRY_NOWAIT);
528 flags |= FAULT_FLAG_TRIED;
529 down_read(&mm->mmap_sem);
530 goto retry;
533 fault = 0;
534 out_up:
535 up_read(&mm->mmap_sem);
536 out:
537 return fault;
540 void __kprobes do_protection_exception(struct pt_regs *regs)
542 unsigned long trans_exc_code;
543 int fault;
545 trans_exc_code = regs->int_parm_long;
547 * Protection exceptions are suppressing, decrement psw address.
548 * The exception to this rule are aborted transactions, for these
549 * the PSW already points to the correct location.
551 if (!(regs->int_code & 0x200))
552 regs->psw.addr = __rewind_psw(regs->psw, regs->int_code >> 16);
554 * Check for low-address protection. This needs to be treated
555 * as a special case because the translation exception code
556 * field is not guaranteed to contain valid data in this case.
558 if (unlikely(!(trans_exc_code & 4))) {
559 do_low_address(regs);
560 return;
562 fault = do_exception(regs, VM_WRITE);
563 if (unlikely(fault))
564 do_fault_error(regs, fault);
567 void __kprobes do_dat_exception(struct pt_regs *regs)
569 int access, fault;
571 access = VM_READ | VM_EXEC | VM_WRITE;
572 fault = do_exception(regs, access);
573 if (unlikely(fault))
574 do_fault_error(regs, fault);
577 #ifdef CONFIG_PFAULT
579 * 'pfault' pseudo page faults routines.
581 static int pfault_disable;
583 static int __init nopfault(char *str)
585 pfault_disable = 1;
586 return 1;
589 __setup("nopfault", nopfault);
591 struct pfault_refbk {
592 u16 refdiagc;
593 u16 reffcode;
594 u16 refdwlen;
595 u16 refversn;
596 u64 refgaddr;
597 u64 refselmk;
598 u64 refcmpmk;
599 u64 reserved;
600 } __attribute__ ((packed, aligned(8)));
602 int pfault_init(void)
604 struct pfault_refbk refbk = {
605 .refdiagc = 0x258,
606 .reffcode = 0,
607 .refdwlen = 5,
608 .refversn = 2,
609 .refgaddr = __LC_CURRENT_PID,
610 .refselmk = 1ULL << 48,
611 .refcmpmk = 1ULL << 48,
612 .reserved = __PF_RES_FIELD };
613 int rc;
615 if (pfault_disable)
616 return -1;
617 asm volatile(
618 " diag %1,%0,0x258\n"
619 "0: j 2f\n"
620 "1: la %0,8\n"
621 "2:\n"
622 EX_TABLE(0b,1b)
623 : "=d" (rc) : "a" (&refbk), "m" (refbk) : "cc");
624 return rc;
627 void pfault_fini(void)
629 struct pfault_refbk refbk = {
630 .refdiagc = 0x258,
631 .reffcode = 1,
632 .refdwlen = 5,
633 .refversn = 2,
636 if (pfault_disable)
637 return;
638 asm volatile(
639 " diag %0,0,0x258\n"
640 "0:\n"
641 EX_TABLE(0b,0b)
642 : : "a" (&refbk), "m" (refbk) : "cc");
645 static DEFINE_SPINLOCK(pfault_lock);
646 static LIST_HEAD(pfault_list);
648 static void pfault_interrupt(struct ext_code ext_code,
649 unsigned int param32, unsigned long param64)
651 struct task_struct *tsk;
652 __u16 subcode;
653 pid_t pid;
656 * Get the external interruption subcode & pfault
657 * initial/completion signal bit. VM stores this
658 * in the 'cpu address' field associated with the
659 * external interrupt.
661 subcode = ext_code.subcode;
662 if ((subcode & 0xff00) != __SUBCODE_MASK)
663 return;
664 inc_irq_stat(IRQEXT_PFL);
665 /* Get the token (= pid of the affected task). */
666 pid = sizeof(void *) == 4 ? param32 : param64;
667 rcu_read_lock();
668 tsk = find_task_by_pid_ns(pid, &init_pid_ns);
669 if (tsk)
670 get_task_struct(tsk);
671 rcu_read_unlock();
672 if (!tsk)
673 return;
674 spin_lock(&pfault_lock);
675 if (subcode & 0x0080) {
676 /* signal bit is set -> a page has been swapped in by VM */
677 if (tsk->thread.pfault_wait == 1) {
678 /* Initial interrupt was faster than the completion
679 * interrupt. pfault_wait is valid. Set pfault_wait
680 * back to zero and wake up the process. This can
681 * safely be done because the task is still sleeping
682 * and can't produce new pfaults. */
683 tsk->thread.pfault_wait = 0;
684 list_del(&tsk->thread.list);
685 wake_up_process(tsk);
686 put_task_struct(tsk);
687 } else {
688 /* Completion interrupt was faster than initial
689 * interrupt. Set pfault_wait to -1 so the initial
690 * interrupt doesn't put the task to sleep.
691 * If the task is not running, ignore the completion
692 * interrupt since it must be a leftover of a PFAULT
693 * CANCEL operation which didn't remove all pending
694 * completion interrupts. */
695 if (tsk->state == TASK_RUNNING)
696 tsk->thread.pfault_wait = -1;
698 } else {
699 /* signal bit not set -> a real page is missing. */
700 if (WARN_ON_ONCE(tsk != current))
701 goto out;
702 if (tsk->thread.pfault_wait == 1) {
703 /* Already on the list with a reference: put to sleep */
704 __set_task_state(tsk, TASK_UNINTERRUPTIBLE);
705 set_tsk_need_resched(tsk);
706 } else if (tsk->thread.pfault_wait == -1) {
707 /* Completion interrupt was faster than the initial
708 * interrupt (pfault_wait == -1). Set pfault_wait
709 * back to zero and exit. */
710 tsk->thread.pfault_wait = 0;
711 } else {
712 /* Initial interrupt arrived before completion
713 * interrupt. Let the task sleep.
714 * An extra task reference is needed since a different
715 * cpu may set the task state to TASK_RUNNING again
716 * before the scheduler is reached. */
717 get_task_struct(tsk);
718 tsk->thread.pfault_wait = 1;
719 list_add(&tsk->thread.list, &pfault_list);
720 __set_task_state(tsk, TASK_UNINTERRUPTIBLE);
721 set_tsk_need_resched(tsk);
724 out:
725 spin_unlock(&pfault_lock);
726 put_task_struct(tsk);
729 static int pfault_cpu_notify(struct notifier_block *self, unsigned long action,
730 void *hcpu)
732 struct thread_struct *thread, *next;
733 struct task_struct *tsk;
735 switch (action & ~CPU_TASKS_FROZEN) {
736 case CPU_DEAD:
737 spin_lock_irq(&pfault_lock);
738 list_for_each_entry_safe(thread, next, &pfault_list, list) {
739 thread->pfault_wait = 0;
740 list_del(&thread->list);
741 tsk = container_of(thread, struct task_struct, thread);
742 wake_up_process(tsk);
743 put_task_struct(tsk);
745 spin_unlock_irq(&pfault_lock);
746 break;
747 default:
748 break;
750 return NOTIFY_OK;
753 static int __init pfault_irq_init(void)
755 int rc;
757 rc = register_external_irq(EXT_IRQ_CP_SERVICE, pfault_interrupt);
758 if (rc)
759 goto out_extint;
760 rc = pfault_init() == 0 ? 0 : -EOPNOTSUPP;
761 if (rc)
762 goto out_pfault;
763 irq_subclass_register(IRQ_SUBCLASS_SERVICE_SIGNAL);
764 hotcpu_notifier(pfault_cpu_notify, 0);
765 return 0;
767 out_pfault:
768 unregister_external_irq(EXT_IRQ_CP_SERVICE, pfault_interrupt);
769 out_extint:
770 pfault_disable = 1;
771 return rc;
773 early_initcall(pfault_irq_init);
775 #endif /* CONFIG_PFAULT */