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)
6 *
7 *  Derived from "arch/i386/mm/fault.c"
8 *    Copyright (C) 1995  Linus Torvalds
9 */
10
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"
38
39#define __FAIL_ADDR_MASK -4096L
40#define __SUBCODE_MASK 0x0600
41#define __PF_RES_FIELD 0x8000000000000000ULL
42
43#define VM_FAULT_BADCONTEXT	0x010000
44#define VM_FAULT_BADMAP		0x020000
45#define VM_FAULT_BADACCESS	0x040000
46#define VM_FAULT_SIGNAL		0x080000
47#define VM_FAULT_PFAULT		0x100000
48
49static unsigned long store_indication __read_mostly;
50
51static int __init fault_init(void)
52{
53	if (test_facility(75))
54		store_indication = 0xc00;
55	return 0;
56}
57early_initcall(fault_init);
58
59static inline int notify_page_fault(struct pt_regs *regs)
60{
61	int ret = 0;
62
63	/* kprobe_running() needs smp_processor_id() */
64	if (kprobes_built_in() && !user_mode(regs)) {
65		preempt_disable();
66		if (kprobe_running() && kprobe_fault_handler(regs, 14))
67			ret = 1;
68		preempt_enable();
69	}
70	return ret;
71}
72
73
74/*
75 * Unlock any spinlocks which will prevent us from getting the
76 * message out.
77 */
78void bust_spinlocks(int yes)
79{
80	if (yes) {
81		oops_in_progress = 1;
82	} else {
83		int loglevel_save = console_loglevel;
84		console_unblank();
85		oops_in_progress = 0;
86		/*
87		 * OK, the message is on the console.  Now we call printk()
88		 * without oops_in_progress set so that printk will give klogd
89		 * a poke.  Hold onto your hats...
90		 */
91		console_loglevel = 15;
92		printk(" ");
93		console_loglevel = loglevel_save;
94	}
95}
96
97/*
98 * Returns the address space associated with the fault.
99 * Returns 0 for kernel space and 1 for user space.
100 */
101static inline int user_space_fault(struct pt_regs *regs)
102{
103	unsigned long trans_exc_code;
104
105	/*
106	 * The lowest two bits of the translation exception
107	 * identification indicate which paging table was used.
108	 */
109	trans_exc_code = regs->int_parm_long & 3;
110	if (trans_exc_code == 3) /* home space -> kernel */
111		return 0;
112	if (user_mode(regs))
113		return 1;
114	if (trans_exc_code == 2) /* secondary space -> set_fs */
115		return current->thread.mm_segment.ar4;
116	if (current->flags & PF_VCPU)
117		return 1;
118	return 0;
119}
120
121static int bad_address(void *p)
122{
123	unsigned long dummy;
124
125	return probe_kernel_address((unsigned long *)p, dummy);
126}
127
128static void dump_pagetable(unsigned long asce, unsigned long address)
129{
130	unsigned long *table = __va(asce & PAGE_MASK);
131
132	pr_alert("AS:%016lx ", asce);
133	switch (asce & _ASCE_TYPE_MASK) {
134	case _ASCE_TYPE_REGION1:
135		table = table + ((address >> 53) & 0x7ff);
136		if (bad_address(table))
137			goto bad;
138		pr_cont("R1:%016lx ", *table);
139		if (*table & _REGION_ENTRY_INVALID)
140			goto out;
141		table = (unsigned long *)(*table & _REGION_ENTRY_ORIGIN);
142		/* fallthrough */
143	case _ASCE_TYPE_REGION2:
144		table = table + ((address >> 42) & 0x7ff);
145		if (bad_address(table))
146			goto bad;
147		pr_cont("R2:%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_REGION3:
153		table = table + ((address >> 31) & 0x7ff);
154		if (bad_address(table))
155			goto bad;
156		pr_cont("R3:%016lx ", *table);
157		if (*table & (_REGION_ENTRY_INVALID | _REGION3_ENTRY_LARGE))
158			goto out;
159		table = (unsigned long *)(*table & _REGION_ENTRY_ORIGIN);
160		/* fallthrough */
161	case _ASCE_TYPE_SEGMENT:
162		table = table + ((address >> 20) & 0x7ff);
163		if (bad_address(table))
164			goto bad;
165		pr_cont("S:%016lx ", *table);
166		if (*table & (_SEGMENT_ENTRY_INVALID | _SEGMENT_ENTRY_LARGE))
167			goto out;
168		table = (unsigned long *)(*table & _SEGMENT_ENTRY_ORIGIN);
169	}
170	table = table + ((address >> 12) & 0xff);
171	if (bad_address(table))
172		goto bad;
173	pr_cont("P:%016lx ", *table);
174out:
175	pr_cont("\n");
176	return;
177bad:
178	pr_cont("BAD\n");
179}
180
181static void dump_fault_info(struct pt_regs *regs)
182{
183	unsigned long asce;
184
185	pr_alert("Fault in ");
186	switch (regs->int_parm_long & 3) {
187	case 3:
188		pr_cont("home space ");
189		break;
190	case 2:
191		pr_cont("secondary space ");
192		break;
193	case 1:
194		pr_cont("access register ");
195		break;
196	case 0:
197		pr_cont("primary space ");
198		break;
199	}
200	pr_cont("mode while using ");
201	if (!user_space_fault(regs)) {
202		asce = S390_lowcore.kernel_asce;
203		pr_cont("kernel ");
204	}
205#ifdef CONFIG_PGSTE
206	else if ((current->flags & PF_VCPU) && S390_lowcore.gmap) {
207		struct gmap *gmap = (struct gmap *)S390_lowcore.gmap;
208		asce = gmap->asce;
209		pr_cont("gmap ");
210	}
211#endif
212	else {
213		asce = S390_lowcore.user_asce;
214		pr_cont("user ");
215	}
216	pr_cont("ASCE.\n");
217	dump_pagetable(asce, regs->int_parm_long & __FAIL_ADDR_MASK);
218}
219
220static inline void report_user_fault(struct pt_regs *regs, long signr)
221{
222	if ((task_pid_nr(current) > 1) && !show_unhandled_signals)
223		return;
224	if (!unhandled_signal(current, signr))
225		return;
226	if (!printk_ratelimit())
227		return;
228	printk(KERN_ALERT "User process fault: interruption code %04x ilc:%d ",
229	       regs->int_code & 0xffff, regs->int_code >> 17);
230	print_vma_addr(KERN_CONT "in ", regs->psw.addr & PSW_ADDR_INSN);
231	printk(KERN_CONT "\n");
232	printk(KERN_ALERT "failing address: %016lx TEID: %016lx\n",
233	       regs->int_parm_long & __FAIL_ADDR_MASK, regs->int_parm_long);
234	dump_fault_info(regs);
235	show_regs(regs);
236}
237
238/*
239 * Send SIGSEGV to task.  This is an external routine
240 * to keep the stack usage of do_page_fault small.
241 */
242static noinline void do_sigsegv(struct pt_regs *regs, int si_code)
243{
244	struct siginfo si;
245
246	report_user_fault(regs, SIGSEGV);
247	si.si_signo = SIGSEGV;
248	si.si_code = si_code;
249	si.si_addr = (void __user *)(regs->int_parm_long & __FAIL_ADDR_MASK);
250	force_sig_info(SIGSEGV, &si, current);
251}
252
253static noinline void do_no_context(struct pt_regs *regs)
254{
255	const struct exception_table_entry *fixup;
256	unsigned long address;
257
258	/* Are we prepared to handle this kernel fault?  */
259	fixup = search_exception_tables(regs->psw.addr & PSW_ADDR_INSN);
260	if (fixup) {
261		regs->psw.addr = extable_fixup(fixup) | PSW_ADDR_AMODE;
262		return;
263	}
264
265	/*
266	 * Oops. The kernel tried to access some bad page. We'll have to
267	 * terminate things with extreme prejudice.
268	 */
269	address = regs->int_parm_long & __FAIL_ADDR_MASK;
270	if (!user_space_fault(regs))
271		printk(KERN_ALERT "Unable to handle kernel pointer dereference"
272		       " in virtual kernel address space\n");
273	else
274		printk(KERN_ALERT "Unable to handle kernel paging request"
275		       " in virtual user address space\n");
276	printk(KERN_ALERT "failing address: %016lx TEID: %016lx\n",
277	       regs->int_parm_long & __FAIL_ADDR_MASK, regs->int_parm_long);
278	dump_fault_info(regs);
279	die(regs, "Oops");
280	do_exit(SIGKILL);
281}
282
283static noinline void do_low_address(struct pt_regs *regs)
284{
285	/* Low-address protection hit in kernel mode means
286	   NULL pointer write access in kernel mode.  */
287	if (regs->psw.mask & PSW_MASK_PSTATE) {
288		/* Low-address protection hit in user mode 'cannot happen'. */
289		die (regs, "Low-address protection");
290		do_exit(SIGKILL);
291	}
292
293	do_no_context(regs);
294}
295
296static noinline void do_sigbus(struct pt_regs *regs)
297{
298	struct task_struct *tsk = current;
299	struct siginfo si;
300
301	/*
302	 * Send a sigbus, regardless of whether we were in kernel
303	 * or user mode.
304	 */
305	si.si_signo = SIGBUS;
306	si.si_errno = 0;
307	si.si_code = BUS_ADRERR;
308	si.si_addr = (void __user *)(regs->int_parm_long & __FAIL_ADDR_MASK);
309	force_sig_info(SIGBUS, &si, tsk);
310}
311
312static noinline void do_fault_error(struct pt_regs *regs, int fault)
313{
314	int si_code;
315
316	switch (fault) {
317	case VM_FAULT_BADACCESS:
318	case VM_FAULT_BADMAP:
319		/* Bad memory access. Check if it is kernel or user space. */
320		if (user_mode(regs)) {
321			/* User mode accesses just cause a SIGSEGV */
322			si_code = (fault == VM_FAULT_BADMAP) ?
323				SEGV_MAPERR : SEGV_ACCERR;
324			do_sigsegv(regs, si_code);
325			return;
326		}
327	case VM_FAULT_BADCONTEXT:
328	case VM_FAULT_PFAULT:
329		do_no_context(regs);
330		break;
331	case VM_FAULT_SIGNAL:
332		if (!user_mode(regs))
333			do_no_context(regs);
334		break;
335	default: /* fault & VM_FAULT_ERROR */
336		if (fault & VM_FAULT_OOM) {
337			if (!user_mode(regs))
338				do_no_context(regs);
339			else
340				pagefault_out_of_memory();
341		} else if (fault & VM_FAULT_SIGSEGV) {
342			/* Kernel mode? Handle exceptions or die */
343			if (!user_mode(regs))
344				do_no_context(regs);
345			else
346				do_sigsegv(regs, SEGV_MAPERR);
347		} else if (fault & VM_FAULT_SIGBUS) {
348			/* Kernel mode? Handle exceptions or die */
349			if (!user_mode(regs))
350				do_no_context(regs);
351			else
352				do_sigbus(regs);
353		} else
354			BUG();
355		break;
356	}
357}
358
359/*
360 * This routine handles page faults.  It determines the address,
361 * and the problem, and then passes it off to one of the appropriate
362 * routines.
363 *
364 * interruption code (int_code):
365 *   04       Protection           ->  Write-Protection  (suprression)
366 *   10       Segment translation  ->  Not present       (nullification)
367 *   11       Page translation     ->  Not present       (nullification)
368 *   3b       Region third trans.  ->  Not present       (nullification)
369 */
370static inline int do_exception(struct pt_regs *regs, int access)
371{
372#ifdef CONFIG_PGSTE
373	struct gmap *gmap;
374#endif
375	struct task_struct *tsk;
376	struct mm_struct *mm;
377	struct vm_area_struct *vma;
378	unsigned long trans_exc_code;
379	unsigned long address;
380	unsigned int flags;
381	int fault;
382
383	tsk = current;
384	/*
385	 * The instruction that caused the program check has
386	 * been nullified. Don't signal single step via SIGTRAP.
387	 */
388	clear_pt_regs_flag(regs, PIF_PER_TRAP);
389
390	if (notify_page_fault(regs))
391		return 0;
392
393	mm = tsk->mm;
394	trans_exc_code = regs->int_parm_long;
395
396	/*
397	 * Verify that the fault happened in user space, that
398	 * we are not in an interrupt and that there is a
399	 * user context.
400	 */
401	fault = VM_FAULT_BADCONTEXT;
402	if (unlikely(!user_space_fault(regs) || in_atomic() || !mm))
403		goto out;
404
405	address = trans_exc_code & __FAIL_ADDR_MASK;
406	perf_sw_event(PERF_COUNT_SW_PAGE_FAULTS, 1, regs, address);
407	flags = FAULT_FLAG_ALLOW_RETRY | FAULT_FLAG_KILLABLE;
408	if (user_mode(regs))
409		flags |= FAULT_FLAG_USER;
410	if (access == VM_WRITE || (trans_exc_code & store_indication) == 0x400)
411		flags |= FAULT_FLAG_WRITE;
412	down_read(&mm->mmap_sem);
413
414#ifdef CONFIG_PGSTE
415	gmap = (current->flags & PF_VCPU) ?
416		(struct gmap *) S390_lowcore.gmap : NULL;
417	if (gmap) {
418		current->thread.gmap_addr = address;
419		address = __gmap_translate(gmap, address);
420		if (address == -EFAULT) {
421			fault = VM_FAULT_BADMAP;
422			goto out_up;
423		}
424		if (gmap->pfault_enabled)
425			flags |= FAULT_FLAG_RETRY_NOWAIT;
426	}
427#endif
428
429retry:
430	fault = VM_FAULT_BADMAP;
431	vma = find_vma(mm, address);
432	if (!vma)
433		goto out_up;
434
435	if (unlikely(vma->vm_start > address)) {
436		if (!(vma->vm_flags & VM_GROWSDOWN))
437			goto out_up;
438		if (expand_stack(vma, address))
439			goto out_up;
440	}
441
442	/*
443	 * Ok, we have a good vm_area for this memory access, so
444	 * we can handle it..
445	 */
446	fault = VM_FAULT_BADACCESS;
447	if (unlikely(!(vma->vm_flags & access)))
448		goto out_up;
449
450	if (is_vm_hugetlb_page(vma))
451		address &= HPAGE_MASK;
452	/*
453	 * If for any reason at all we couldn't handle the fault,
454	 * make sure we exit gracefully rather than endlessly redo
455	 * the fault.
456	 */
457	fault = handle_mm_fault(mm, vma, address, flags);
458	/* No reason to continue if interrupted by SIGKILL. */
459	if ((fault & VM_FAULT_RETRY) && fatal_signal_pending(current)) {
460		fault = VM_FAULT_SIGNAL;
461		goto out;
462	}
463	if (unlikely(fault & VM_FAULT_ERROR))
464		goto out_up;
465
466	/*
467	 * Major/minor page fault accounting is only done on the
468	 * initial attempt. If we go through a retry, it is extremely
469	 * likely that the page will be found in page cache at that point.
470	 */
471	if (flags & FAULT_FLAG_ALLOW_RETRY) {
472		if (fault & VM_FAULT_MAJOR) {
473			tsk->maj_flt++;
474			perf_sw_event(PERF_COUNT_SW_PAGE_FAULTS_MAJ, 1,
475				      regs, address);
476		} else {
477			tsk->min_flt++;
478			perf_sw_event(PERF_COUNT_SW_PAGE_FAULTS_MIN, 1,
479				      regs, address);
480		}
481		if (fault & VM_FAULT_RETRY) {
482#ifdef CONFIG_PGSTE
483			if (gmap && (flags & FAULT_FLAG_RETRY_NOWAIT)) {
484				/* FAULT_FLAG_RETRY_NOWAIT has been set,
485				 * mmap_sem has not been released */
486				current->thread.gmap_pfault = 1;
487				fault = VM_FAULT_PFAULT;
488				goto out_up;
489			}
490#endif
491			/* Clear FAULT_FLAG_ALLOW_RETRY to avoid any risk
492			 * of starvation. */
493			flags &= ~(FAULT_FLAG_ALLOW_RETRY |
494				   FAULT_FLAG_RETRY_NOWAIT);
495			flags |= FAULT_FLAG_TRIED;
496			down_read(&mm->mmap_sem);
497			goto retry;
498		}
499	}
500#ifdef CONFIG_PGSTE
501	if (gmap) {
502		address =  __gmap_link(gmap, current->thread.gmap_addr,
503				       address);
504		if (address == -EFAULT) {
505			fault = VM_FAULT_BADMAP;
506			goto out_up;
507		}
508		if (address == -ENOMEM) {
509			fault = VM_FAULT_OOM;
510			goto out_up;
511		}
512	}
513#endif
514	fault = 0;
515out_up:
516	up_read(&mm->mmap_sem);
517out:
518	return fault;
519}
520
521void do_protection_exception(struct pt_regs *regs)
522{
523	unsigned long trans_exc_code;
524	int fault;
525
526	trans_exc_code = regs->int_parm_long;
527	/*
528	 * Protection exceptions are suppressing, decrement psw address.
529	 * The exception to this rule are aborted transactions, for these
530	 * the PSW already points to the correct location.
531	 */
532	if (!(regs->int_code & 0x200))
533		regs->psw.addr = __rewind_psw(regs->psw, regs->int_code >> 16);
534	/*
535	 * Check for low-address protection.  This needs to be treated
536	 * as a special case because the translation exception code
537	 * field is not guaranteed to contain valid data in this case.
538	 */
539	if (unlikely(!(trans_exc_code & 4))) {
540		do_low_address(regs);
541		return;
542	}
543	fault = do_exception(regs, VM_WRITE);
544	if (unlikely(fault))
545		do_fault_error(regs, fault);
546}
547NOKPROBE_SYMBOL(do_protection_exception);
548
549void do_dat_exception(struct pt_regs *regs)
550{
551	int access, fault;
552
553	access = VM_READ | VM_EXEC | VM_WRITE;
554	fault = do_exception(regs, access);
555	if (unlikely(fault))
556		do_fault_error(regs, fault);
557}
558NOKPROBE_SYMBOL(do_dat_exception);
559
560#ifdef CONFIG_PFAULT
561/*
562 * 'pfault' pseudo page faults routines.
563 */
564static int pfault_disable;
565
566static int __init nopfault(char *str)
567{
568	pfault_disable = 1;
569	return 1;
570}
571
572__setup("nopfault", nopfault);
573
574struct pfault_refbk {
575	u16 refdiagc;
576	u16 reffcode;
577	u16 refdwlen;
578	u16 refversn;
579	u64 refgaddr;
580	u64 refselmk;
581	u64 refcmpmk;
582	u64 reserved;
583} __attribute__ ((packed, aligned(8)));
584
585int pfault_init(void)
586{
587	struct pfault_refbk refbk = {
588		.refdiagc = 0x258,
589		.reffcode = 0,
590		.refdwlen = 5,
591		.refversn = 2,
592		.refgaddr = __LC_CURRENT_PID,
593		.refselmk = 1ULL << 48,
594		.refcmpmk = 1ULL << 48,
595		.reserved = __PF_RES_FIELD };
596        int rc;
597
598	if (pfault_disable)
599		return -1;
600	asm volatile(
601		"	diag	%1,%0,0x258\n"
602		"0:	j	2f\n"
603		"1:	la	%0,8\n"
604		"2:\n"
605		EX_TABLE(0b,1b)
606		: "=d" (rc) : "a" (&refbk), "m" (refbk) : "cc");
607        return rc;
608}
609
610void pfault_fini(void)
611{
612	struct pfault_refbk refbk = {
613		.refdiagc = 0x258,
614		.reffcode = 1,
615		.refdwlen = 5,
616		.refversn = 2,
617	};
618
619	if (pfault_disable)
620		return;
621	asm volatile(
622		"	diag	%0,0,0x258\n"
623		"0:\n"
624		EX_TABLE(0b,0b)
625		: : "a" (&refbk), "m" (refbk) : "cc");
626}
627
628static DEFINE_SPINLOCK(pfault_lock);
629static LIST_HEAD(pfault_list);
630
631static void pfault_interrupt(struct ext_code ext_code,
632			     unsigned int param32, unsigned long param64)
633{
634	struct task_struct *tsk;
635	__u16 subcode;
636	pid_t pid;
637
638	/*
639	 * Get the external interruption subcode & pfault
640	 * initial/completion signal bit. VM stores this
641	 * in the 'cpu address' field associated with the
642         * external interrupt.
643	 */
644	subcode = ext_code.subcode;
645	if ((subcode & 0xff00) != __SUBCODE_MASK)
646		return;
647	inc_irq_stat(IRQEXT_PFL);
648	/* Get the token (= pid of the affected task). */
649	pid = sizeof(void *) == 4 ? param32 : param64;
650	rcu_read_lock();
651	tsk = find_task_by_pid_ns(pid, &init_pid_ns);
652	if (tsk)
653		get_task_struct(tsk);
654	rcu_read_unlock();
655	if (!tsk)
656		return;
657	spin_lock(&pfault_lock);
658	if (subcode & 0x0080) {
659		/* signal bit is set -> a page has been swapped in by VM */
660		if (tsk->thread.pfault_wait == 1) {
661			/* Initial interrupt was faster than the completion
662			 * interrupt. pfault_wait is valid. Set pfault_wait
663			 * back to zero and wake up the process. This can
664			 * safely be done because the task is still sleeping
665			 * and can't produce new pfaults. */
666			tsk->thread.pfault_wait = 0;
667			list_del(&tsk->thread.list);
668			wake_up_process(tsk);
669			put_task_struct(tsk);
670		} else {
671			/* Completion interrupt was faster than initial
672			 * interrupt. Set pfault_wait to -1 so the initial
673			 * interrupt doesn't put the task to sleep.
674			 * If the task is not running, ignore the completion
675			 * interrupt since it must be a leftover of a PFAULT
676			 * CANCEL operation which didn't remove all pending
677			 * completion interrupts. */
678			if (tsk->state == TASK_RUNNING)
679				tsk->thread.pfault_wait = -1;
680		}
681	} else {
682		/* signal bit not set -> a real page is missing. */
683		if (WARN_ON_ONCE(tsk != current))
684			goto out;
685		if (tsk->thread.pfault_wait == 1) {
686			/* Already on the list with a reference: put to sleep */
687			__set_task_state(tsk, TASK_UNINTERRUPTIBLE);
688			set_tsk_need_resched(tsk);
689		} else if (tsk->thread.pfault_wait == -1) {
690			/* Completion interrupt was faster than the initial
691			 * interrupt (pfault_wait == -1). Set pfault_wait
692			 * back to zero and exit. */
693			tsk->thread.pfault_wait = 0;
694		} else {
695			/* Initial interrupt arrived before completion
696			 * interrupt. Let the task sleep.
697			 * An extra task reference is needed since a different
698			 * cpu may set the task state to TASK_RUNNING again
699			 * before the scheduler is reached. */
700			get_task_struct(tsk);
701			tsk->thread.pfault_wait = 1;
702			list_add(&tsk->thread.list, &pfault_list);
703			__set_task_state(tsk, TASK_UNINTERRUPTIBLE);
704			set_tsk_need_resched(tsk);
705		}
706	}
707out:
708	spin_unlock(&pfault_lock);
709	put_task_struct(tsk);
710}
711
712static int pfault_cpu_notify(struct notifier_block *self, unsigned long action,
713			     void *hcpu)
714{
715	struct thread_struct *thread, *next;
716	struct task_struct *tsk;
717
718	switch (action & ~CPU_TASKS_FROZEN) {
719	case CPU_DEAD:
720		spin_lock_irq(&pfault_lock);
721		list_for_each_entry_safe(thread, next, &pfault_list, list) {
722			thread->pfault_wait = 0;
723			list_del(&thread->list);
724			tsk = container_of(thread, struct task_struct, thread);
725			wake_up_process(tsk);
726			put_task_struct(tsk);
727		}
728		spin_unlock_irq(&pfault_lock);
729		break;
730	default:
731		break;
732	}
733	return NOTIFY_OK;
734}
735
736static int __init pfault_irq_init(void)
737{
738	int rc;
739
740	rc = register_external_irq(EXT_IRQ_CP_SERVICE, pfault_interrupt);
741	if (rc)
742		goto out_extint;
743	rc = pfault_init() == 0 ? 0 : -EOPNOTSUPP;
744	if (rc)
745		goto out_pfault;
746	irq_subclass_register(IRQ_SUBCLASS_SERVICE_SIGNAL);
747	hotcpu_notifier(pfault_cpu_notify, 0);
748	return 0;
749
750out_pfault:
751	unregister_external_irq(EXT_IRQ_CP_SERVICE, pfault_interrupt);
752out_extint:
753	pfault_disable = 1;
754	return rc;
755}
756early_initcall(pfault_irq_init);
757
758#endif /* CONFIG_PFAULT */
759