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1// SPDX-License-Identifier: GPL-2.0
2/*
3 * Copyright IBM Corp. 2007, 2011
4 * Author(s): Martin Schwidefsky <schwidefsky@de.ibm.com>
5 */
6
7#include <linux/sched.h>
8#include <linux/kernel.h>
9#include <linux/errno.h>
10#include <linux/gfp.h>
11#include <linux/mm.h>
12#include <linux/swap.h>
13#include <linux/smp.h>
14#include <linux/spinlock.h>
15#include <linux/rcupdate.h>
16#include <linux/slab.h>
17#include <linux/swapops.h>
18#include <linux/sysctl.h>
19#include <linux/ksm.h>
20#include <linux/mman.h>
21
22#include <asm/tlb.h>
23#include <asm/tlbflush.h>
24#include <asm/mmu_context.h>
25#include <asm/page-states.h>
26
27pgprot_t pgprot_writecombine(pgprot_t prot)
28{
29 /*
30 * mio_wb_bit_mask may be set on a different CPU, but it is only set
31 * once at init and only read afterwards.
32 */
33 return __pgprot(pgprot_val(prot) | mio_wb_bit_mask);
34}
35EXPORT_SYMBOL_GPL(pgprot_writecombine);
36
37pgprot_t pgprot_writethrough(pgprot_t prot)
38{
39 /*
40 * mio_wb_bit_mask may be set on a different CPU, but it is only set
41 * once at init and only read afterwards.
42 */
43 return __pgprot(pgprot_val(prot) & ~mio_wb_bit_mask);
44}
45EXPORT_SYMBOL_GPL(pgprot_writethrough);
46
47static inline void ptep_ipte_local(struct mm_struct *mm, unsigned long addr,
48 pte_t *ptep, int nodat)
49{
50 unsigned long opt, asce;
51
52 if (MACHINE_HAS_TLB_GUEST) {
53 opt = 0;
54 asce = READ_ONCE(mm->context.gmap_asce);
55 if (asce == 0UL || nodat)
56 opt |= IPTE_NODAT;
57 if (asce != -1UL) {
58 asce = asce ? : mm->context.asce;
59 opt |= IPTE_GUEST_ASCE;
60 }
61 __ptep_ipte(addr, ptep, opt, asce, IPTE_LOCAL);
62 } else {
63 __ptep_ipte(addr, ptep, 0, 0, IPTE_LOCAL);
64 }
65}
66
67static inline void ptep_ipte_global(struct mm_struct *mm, unsigned long addr,
68 pte_t *ptep, int nodat)
69{
70 unsigned long opt, asce;
71
72 if (MACHINE_HAS_TLB_GUEST) {
73 opt = 0;
74 asce = READ_ONCE(mm->context.gmap_asce);
75 if (asce == 0UL || nodat)
76 opt |= IPTE_NODAT;
77 if (asce != -1UL) {
78 asce = asce ? : mm->context.asce;
79 opt |= IPTE_GUEST_ASCE;
80 }
81 __ptep_ipte(addr, ptep, opt, asce, IPTE_GLOBAL);
82 } else {
83 __ptep_ipte(addr, ptep, 0, 0, IPTE_GLOBAL);
84 }
85}
86
87static inline pte_t ptep_flush_direct(struct mm_struct *mm,
88 unsigned long addr, pte_t *ptep,
89 int nodat)
90{
91 pte_t old;
92
93 old = *ptep;
94 if (unlikely(pte_val(old) & _PAGE_INVALID))
95 return old;
96 atomic_inc(&mm->context.flush_count);
97 if (MACHINE_HAS_TLB_LC &&
98 cpumask_equal(mm_cpumask(mm), cpumask_of(smp_processor_id())))
99 ptep_ipte_local(mm, addr, ptep, nodat);
100 else
101 ptep_ipte_global(mm, addr, ptep, nodat);
102 atomic_dec(&mm->context.flush_count);
103 return old;
104}
105
106static inline pte_t ptep_flush_lazy(struct mm_struct *mm,
107 unsigned long addr, pte_t *ptep,
108 int nodat)
109{
110 pte_t old;
111
112 old = *ptep;
113 if (unlikely(pte_val(old) & _PAGE_INVALID))
114 return old;
115 atomic_inc(&mm->context.flush_count);
116 if (cpumask_equal(&mm->context.cpu_attach_mask,
117 cpumask_of(smp_processor_id()))) {
118 set_pte(ptep, set_pte_bit(*ptep, __pgprot(_PAGE_INVALID)));
119 mm->context.flush_mm = 1;
120 } else
121 ptep_ipte_global(mm, addr, ptep, nodat);
122 atomic_dec(&mm->context.flush_count);
123 return old;
124}
125
126static inline pgste_t pgste_get_lock(pte_t *ptep)
127{
128 unsigned long new = 0;
129#ifdef CONFIG_PGSTE
130 unsigned long old;
131
132 asm(
133 " lg %0,%2\n"
134 "0: lgr %1,%0\n"
135 " nihh %0,0xff7f\n" /* clear PCL bit in old */
136 " oihh %1,0x0080\n" /* set PCL bit in new */
137 " csg %0,%1,%2\n"
138 " jl 0b\n"
139 : "=&d" (old), "=&d" (new), "=Q" (ptep[PTRS_PER_PTE])
140 : "Q" (ptep[PTRS_PER_PTE]) : "cc", "memory");
141#endif
142 return __pgste(new);
143}
144
145static inline void pgste_set_unlock(pte_t *ptep, pgste_t pgste)
146{
147#ifdef CONFIG_PGSTE
148 asm(
149 " nihh %1,0xff7f\n" /* clear PCL bit */
150 " stg %1,%0\n"
151 : "=Q" (ptep[PTRS_PER_PTE])
152 : "d" (pgste_val(pgste)), "Q" (ptep[PTRS_PER_PTE])
153 : "cc", "memory");
154#endif
155}
156
157static inline pgste_t pgste_get(pte_t *ptep)
158{
159 unsigned long pgste = 0;
160#ifdef CONFIG_PGSTE
161 pgste = *(unsigned long *)(ptep + PTRS_PER_PTE);
162#endif
163 return __pgste(pgste);
164}
165
166static inline void pgste_set(pte_t *ptep, pgste_t pgste)
167{
168#ifdef CONFIG_PGSTE
169 *(pgste_t *)(ptep + PTRS_PER_PTE) = pgste;
170#endif
171}
172
173static inline pgste_t pgste_update_all(pte_t pte, pgste_t pgste,
174 struct mm_struct *mm)
175{
176#ifdef CONFIG_PGSTE
177 unsigned long address, bits, skey;
178
179 if (!mm_uses_skeys(mm) || pte_val(pte) & _PAGE_INVALID)
180 return pgste;
181 address = pte_val(pte) & PAGE_MASK;
182 skey = (unsigned long) page_get_storage_key(address);
183 bits = skey & (_PAGE_CHANGED | _PAGE_REFERENCED);
184 /* Transfer page changed & referenced bit to guest bits in pgste */
185 pgste_val(pgste) |= bits << 48; /* GR bit & GC bit */
186 /* Copy page access key and fetch protection bit to pgste */
187 pgste_val(pgste) &= ~(PGSTE_ACC_BITS | PGSTE_FP_BIT);
188 pgste_val(pgste) |= (skey & (_PAGE_ACC_BITS | _PAGE_FP_BIT)) << 56;
189#endif
190 return pgste;
191
192}
193
194static inline void pgste_set_key(pte_t *ptep, pgste_t pgste, pte_t entry,
195 struct mm_struct *mm)
196{
197#ifdef CONFIG_PGSTE
198 unsigned long address;
199 unsigned long nkey;
200
201 if (!mm_uses_skeys(mm) || pte_val(entry) & _PAGE_INVALID)
202 return;
203 VM_BUG_ON(!(pte_val(*ptep) & _PAGE_INVALID));
204 address = pte_val(entry) & PAGE_MASK;
205 /*
206 * Set page access key and fetch protection bit from pgste.
207 * The guest C/R information is still in the PGSTE, set real
208 * key C/R to 0.
209 */
210 nkey = (pgste_val(pgste) & (PGSTE_ACC_BITS | PGSTE_FP_BIT)) >> 56;
211 nkey |= (pgste_val(pgste) & (PGSTE_GR_BIT | PGSTE_GC_BIT)) >> 48;
212 page_set_storage_key(address, nkey, 0);
213#endif
214}
215
216static inline pgste_t pgste_set_pte(pte_t *ptep, pgste_t pgste, pte_t entry)
217{
218#ifdef CONFIG_PGSTE
219 if ((pte_val(entry) & _PAGE_PRESENT) &&
220 (pte_val(entry) & _PAGE_WRITE) &&
221 !(pte_val(entry) & _PAGE_INVALID)) {
222 if (!MACHINE_HAS_ESOP) {
223 /*
224 * Without enhanced suppression-on-protection force
225 * the dirty bit on for all writable ptes.
226 */
227 entry = set_pte_bit(entry, __pgprot(_PAGE_DIRTY));
228 entry = clear_pte_bit(entry, __pgprot(_PAGE_PROTECT));
229 }
230 if (!(pte_val(entry) & _PAGE_PROTECT))
231 /* This pte allows write access, set user-dirty */
232 pgste_val(pgste) |= PGSTE_UC_BIT;
233 }
234#endif
235 set_pte(ptep, entry);
236 return pgste;
237}
238
239static inline pgste_t pgste_pte_notify(struct mm_struct *mm,
240 unsigned long addr,
241 pte_t *ptep, pgste_t pgste)
242{
243#ifdef CONFIG_PGSTE
244 unsigned long bits;
245
246 bits = pgste_val(pgste) & (PGSTE_IN_BIT | PGSTE_VSIE_BIT);
247 if (bits) {
248 pgste_val(pgste) ^= bits;
249 ptep_notify(mm, addr, ptep, bits);
250 }
251#endif
252 return pgste;
253}
254
255static inline pgste_t ptep_xchg_start(struct mm_struct *mm,
256 unsigned long addr, pte_t *ptep)
257{
258 pgste_t pgste = __pgste(0);
259
260 if (mm_has_pgste(mm)) {
261 pgste = pgste_get_lock(ptep);
262 pgste = pgste_pte_notify(mm, addr, ptep, pgste);
263 }
264 return pgste;
265}
266
267static inline pte_t ptep_xchg_commit(struct mm_struct *mm,
268 unsigned long addr, pte_t *ptep,
269 pgste_t pgste, pte_t old, pte_t new)
270{
271 if (mm_has_pgste(mm)) {
272 if (pte_val(old) & _PAGE_INVALID)
273 pgste_set_key(ptep, pgste, new, mm);
274 if (pte_val(new) & _PAGE_INVALID) {
275 pgste = pgste_update_all(old, pgste, mm);
276 if ((pgste_val(pgste) & _PGSTE_GPS_USAGE_MASK) ==
277 _PGSTE_GPS_USAGE_UNUSED)
278 old = set_pte_bit(old, __pgprot(_PAGE_UNUSED));
279 }
280 pgste = pgste_set_pte(ptep, pgste, new);
281 pgste_set_unlock(ptep, pgste);
282 } else {
283 set_pte(ptep, new);
284 }
285 return old;
286}
287
288pte_t ptep_xchg_direct(struct mm_struct *mm, unsigned long addr,
289 pte_t *ptep, pte_t new)
290{
291 pgste_t pgste;
292 pte_t old;
293 int nodat;
294
295 preempt_disable();
296 pgste = ptep_xchg_start(mm, addr, ptep);
297 nodat = !!(pgste_val(pgste) & _PGSTE_GPS_NODAT);
298 old = ptep_flush_direct(mm, addr, ptep, nodat);
299 old = ptep_xchg_commit(mm, addr, ptep, pgste, old, new);
300 preempt_enable();
301 return old;
302}
303EXPORT_SYMBOL(ptep_xchg_direct);
304
305pte_t ptep_xchg_lazy(struct mm_struct *mm, unsigned long addr,
306 pte_t *ptep, pte_t new)
307{
308 pgste_t pgste;
309 pte_t old;
310 int nodat;
311
312 preempt_disable();
313 pgste = ptep_xchg_start(mm, addr, ptep);
314 nodat = !!(pgste_val(pgste) & _PGSTE_GPS_NODAT);
315 old = ptep_flush_lazy(mm, addr, ptep, nodat);
316 old = ptep_xchg_commit(mm, addr, ptep, pgste, old, new);
317 preempt_enable();
318 return old;
319}
320EXPORT_SYMBOL(ptep_xchg_lazy);
321
322pte_t ptep_modify_prot_start(struct vm_area_struct *vma, unsigned long addr,
323 pte_t *ptep)
324{
325 pgste_t pgste;
326 pte_t old;
327 int nodat;
328 struct mm_struct *mm = vma->vm_mm;
329
330 preempt_disable();
331 pgste = ptep_xchg_start(mm, addr, ptep);
332 nodat = !!(pgste_val(pgste) & _PGSTE_GPS_NODAT);
333 old = ptep_flush_lazy(mm, addr, ptep, nodat);
334 if (mm_has_pgste(mm)) {
335 pgste = pgste_update_all(old, pgste, mm);
336 pgste_set(ptep, pgste);
337 }
338 return old;
339}
340
341void ptep_modify_prot_commit(struct vm_area_struct *vma, unsigned long addr,
342 pte_t *ptep, pte_t old_pte, pte_t pte)
343{
344 pgste_t pgste;
345 struct mm_struct *mm = vma->vm_mm;
346
347 if (!MACHINE_HAS_NX)
348 pte = clear_pte_bit(pte, __pgprot(_PAGE_NOEXEC));
349 if (mm_has_pgste(mm)) {
350 pgste = pgste_get(ptep);
351 pgste_set_key(ptep, pgste, pte, mm);
352 pgste = pgste_set_pte(ptep, pgste, pte);
353 pgste_set_unlock(ptep, pgste);
354 } else {
355 set_pte(ptep, pte);
356 }
357 preempt_enable();
358}
359
360static inline void pmdp_idte_local(struct mm_struct *mm,
361 unsigned long addr, pmd_t *pmdp)
362{
363 if (MACHINE_HAS_TLB_GUEST)
364 __pmdp_idte(addr, pmdp, IDTE_NODAT | IDTE_GUEST_ASCE,
365 mm->context.asce, IDTE_LOCAL);
366 else
367 __pmdp_idte(addr, pmdp, 0, 0, IDTE_LOCAL);
368 if (mm_has_pgste(mm) && mm->context.allow_gmap_hpage_1m)
369 gmap_pmdp_idte_local(mm, addr);
370}
371
372static inline void pmdp_idte_global(struct mm_struct *mm,
373 unsigned long addr, pmd_t *pmdp)
374{
375 if (MACHINE_HAS_TLB_GUEST) {
376 __pmdp_idte(addr, pmdp, IDTE_NODAT | IDTE_GUEST_ASCE,
377 mm->context.asce, IDTE_GLOBAL);
378 if (mm_has_pgste(mm) && mm->context.allow_gmap_hpage_1m)
379 gmap_pmdp_idte_global(mm, addr);
380 } else if (MACHINE_HAS_IDTE) {
381 __pmdp_idte(addr, pmdp, 0, 0, IDTE_GLOBAL);
382 if (mm_has_pgste(mm) && mm->context.allow_gmap_hpage_1m)
383 gmap_pmdp_idte_global(mm, addr);
384 } else {
385 __pmdp_csp(pmdp);
386 if (mm_has_pgste(mm) && mm->context.allow_gmap_hpage_1m)
387 gmap_pmdp_csp(mm, addr);
388 }
389}
390
391static inline pmd_t pmdp_flush_direct(struct mm_struct *mm,
392 unsigned long addr, pmd_t *pmdp)
393{
394 pmd_t old;
395
396 old = *pmdp;
397 if (pmd_val(old) & _SEGMENT_ENTRY_INVALID)
398 return old;
399 atomic_inc(&mm->context.flush_count);
400 if (MACHINE_HAS_TLB_LC &&
401 cpumask_equal(mm_cpumask(mm), cpumask_of(smp_processor_id())))
402 pmdp_idte_local(mm, addr, pmdp);
403 else
404 pmdp_idte_global(mm, addr, pmdp);
405 atomic_dec(&mm->context.flush_count);
406 return old;
407}
408
409static inline pmd_t pmdp_flush_lazy(struct mm_struct *mm,
410 unsigned long addr, pmd_t *pmdp)
411{
412 pmd_t old;
413
414 old = *pmdp;
415 if (pmd_val(old) & _SEGMENT_ENTRY_INVALID)
416 return old;
417 atomic_inc(&mm->context.flush_count);
418 if (cpumask_equal(&mm->context.cpu_attach_mask,
419 cpumask_of(smp_processor_id()))) {
420 set_pmd(pmdp, set_pmd_bit(*pmdp, __pgprot(_SEGMENT_ENTRY_INVALID)));
421 mm->context.flush_mm = 1;
422 if (mm_has_pgste(mm))
423 gmap_pmdp_invalidate(mm, addr);
424 } else {
425 pmdp_idte_global(mm, addr, pmdp);
426 }
427 atomic_dec(&mm->context.flush_count);
428 return old;
429}
430
431#ifdef CONFIG_PGSTE
432static int pmd_lookup(struct mm_struct *mm, unsigned long addr, pmd_t **pmdp)
433{
434 struct vm_area_struct *vma;
435 pgd_t *pgd;
436 p4d_t *p4d;
437 pud_t *pud;
438
439 /* We need a valid VMA, otherwise this is clearly a fault. */
440 vma = vma_lookup(mm, addr);
441 if (!vma)
442 return -EFAULT;
443
444 pgd = pgd_offset(mm, addr);
445 if (!pgd_present(*pgd))
446 return -ENOENT;
447
448 p4d = p4d_offset(pgd, addr);
449 if (!p4d_present(*p4d))
450 return -ENOENT;
451
452 pud = pud_offset(p4d, addr);
453 if (!pud_present(*pud))
454 return -ENOENT;
455
456 /* Large PUDs are not supported yet. */
457 if (pud_large(*pud))
458 return -EFAULT;
459
460 *pmdp = pmd_offset(pud, addr);
461 return 0;
462}
463#endif
464
465pmd_t pmdp_xchg_direct(struct mm_struct *mm, unsigned long addr,
466 pmd_t *pmdp, pmd_t new)
467{
468 pmd_t old;
469
470 preempt_disable();
471 old = pmdp_flush_direct(mm, addr, pmdp);
472 set_pmd(pmdp, new);
473 preempt_enable();
474 return old;
475}
476EXPORT_SYMBOL(pmdp_xchg_direct);
477
478pmd_t pmdp_xchg_lazy(struct mm_struct *mm, unsigned long addr,
479 pmd_t *pmdp, pmd_t new)
480{
481 pmd_t old;
482
483 preempt_disable();
484 old = pmdp_flush_lazy(mm, addr, pmdp);
485 set_pmd(pmdp, new);
486 preempt_enable();
487 return old;
488}
489EXPORT_SYMBOL(pmdp_xchg_lazy);
490
491static inline void pudp_idte_local(struct mm_struct *mm,
492 unsigned long addr, pud_t *pudp)
493{
494 if (MACHINE_HAS_TLB_GUEST)
495 __pudp_idte(addr, pudp, IDTE_NODAT | IDTE_GUEST_ASCE,
496 mm->context.asce, IDTE_LOCAL);
497 else
498 __pudp_idte(addr, pudp, 0, 0, IDTE_LOCAL);
499}
500
501static inline void pudp_idte_global(struct mm_struct *mm,
502 unsigned long addr, pud_t *pudp)
503{
504 if (MACHINE_HAS_TLB_GUEST)
505 __pudp_idte(addr, pudp, IDTE_NODAT | IDTE_GUEST_ASCE,
506 mm->context.asce, IDTE_GLOBAL);
507 else if (MACHINE_HAS_IDTE)
508 __pudp_idte(addr, pudp, 0, 0, IDTE_GLOBAL);
509 else
510 /*
511 * Invalid bit position is the same for pmd and pud, so we can
512 * re-use _pmd_csp() here
513 */
514 __pmdp_csp((pmd_t *) pudp);
515}
516
517static inline pud_t pudp_flush_direct(struct mm_struct *mm,
518 unsigned long addr, pud_t *pudp)
519{
520 pud_t old;
521
522 old = *pudp;
523 if (pud_val(old) & _REGION_ENTRY_INVALID)
524 return old;
525 atomic_inc(&mm->context.flush_count);
526 if (MACHINE_HAS_TLB_LC &&
527 cpumask_equal(mm_cpumask(mm), cpumask_of(smp_processor_id())))
528 pudp_idte_local(mm, addr, pudp);
529 else
530 pudp_idte_global(mm, addr, pudp);
531 atomic_dec(&mm->context.flush_count);
532 return old;
533}
534
535pud_t pudp_xchg_direct(struct mm_struct *mm, unsigned long addr,
536 pud_t *pudp, pud_t new)
537{
538 pud_t old;
539
540 preempt_disable();
541 old = pudp_flush_direct(mm, addr, pudp);
542 set_pud(pudp, new);
543 preempt_enable();
544 return old;
545}
546EXPORT_SYMBOL(pudp_xchg_direct);
547
548#ifdef CONFIG_TRANSPARENT_HUGEPAGE
549void pgtable_trans_huge_deposit(struct mm_struct *mm, pmd_t *pmdp,
550 pgtable_t pgtable)
551{
552 struct list_head *lh = (struct list_head *) pgtable;
553
554 assert_spin_locked(pmd_lockptr(mm, pmdp));
555
556 /* FIFO */
557 if (!pmd_huge_pte(mm, pmdp))
558 INIT_LIST_HEAD(lh);
559 else
560 list_add(lh, (struct list_head *) pmd_huge_pte(mm, pmdp));
561 pmd_huge_pte(mm, pmdp) = pgtable;
562}
563
564pgtable_t pgtable_trans_huge_withdraw(struct mm_struct *mm, pmd_t *pmdp)
565{
566 struct list_head *lh;
567 pgtable_t pgtable;
568 pte_t *ptep;
569
570 assert_spin_locked(pmd_lockptr(mm, pmdp));
571
572 /* FIFO */
573 pgtable = pmd_huge_pte(mm, pmdp);
574 lh = (struct list_head *) pgtable;
575 if (list_empty(lh))
576 pmd_huge_pte(mm, pmdp) = NULL;
577 else {
578 pmd_huge_pte(mm, pmdp) = (pgtable_t) lh->next;
579 list_del(lh);
580 }
581 ptep = (pte_t *) pgtable;
582 set_pte(ptep, __pte(_PAGE_INVALID));
583 ptep++;
584 set_pte(ptep, __pte(_PAGE_INVALID));
585 return pgtable;
586}
587#endif /* CONFIG_TRANSPARENT_HUGEPAGE */
588
589#ifdef CONFIG_PGSTE
590void ptep_set_pte_at(struct mm_struct *mm, unsigned long addr,
591 pte_t *ptep, pte_t entry)
592{
593 pgste_t pgste;
594
595 /* the mm_has_pgste() check is done in set_pte_at() */
596 preempt_disable();
597 pgste = pgste_get_lock(ptep);
598 pgste_val(pgste) &= ~_PGSTE_GPS_ZERO;
599 pgste_set_key(ptep, pgste, entry, mm);
600 pgste = pgste_set_pte(ptep, pgste, entry);
601 pgste_set_unlock(ptep, pgste);
602 preempt_enable();
603}
604
605void ptep_set_notify(struct mm_struct *mm, unsigned long addr, pte_t *ptep)
606{
607 pgste_t pgste;
608
609 preempt_disable();
610 pgste = pgste_get_lock(ptep);
611 pgste_val(pgste) |= PGSTE_IN_BIT;
612 pgste_set_unlock(ptep, pgste);
613 preempt_enable();
614}
615
616/**
617 * ptep_force_prot - change access rights of a locked pte
618 * @mm: pointer to the process mm_struct
619 * @addr: virtual address in the guest address space
620 * @ptep: pointer to the page table entry
621 * @prot: indicates guest access rights: PROT_NONE, PROT_READ or PROT_WRITE
622 * @bit: pgste bit to set (e.g. for notification)
623 *
624 * Returns 0 if the access rights were changed and -EAGAIN if the current
625 * and requested access rights are incompatible.
626 */
627int ptep_force_prot(struct mm_struct *mm, unsigned long addr,
628 pte_t *ptep, int prot, unsigned long bit)
629{
630 pte_t entry;
631 pgste_t pgste;
632 int pte_i, pte_p, nodat;
633
634 pgste = pgste_get_lock(ptep);
635 entry = *ptep;
636 /* Check pte entry after all locks have been acquired */
637 pte_i = pte_val(entry) & _PAGE_INVALID;
638 pte_p = pte_val(entry) & _PAGE_PROTECT;
639 if ((pte_i && (prot != PROT_NONE)) ||
640 (pte_p && (prot & PROT_WRITE))) {
641 pgste_set_unlock(ptep, pgste);
642 return -EAGAIN;
643 }
644 /* Change access rights and set pgste bit */
645 nodat = !!(pgste_val(pgste) & _PGSTE_GPS_NODAT);
646 if (prot == PROT_NONE && !pte_i) {
647 ptep_flush_direct(mm, addr, ptep, nodat);
648 pgste = pgste_update_all(entry, pgste, mm);
649 entry = set_pte_bit(entry, __pgprot(_PAGE_INVALID));
650 }
651 if (prot == PROT_READ && !pte_p) {
652 ptep_flush_direct(mm, addr, ptep, nodat);
653 entry = clear_pte_bit(entry, __pgprot(_PAGE_INVALID));
654 entry = set_pte_bit(entry, __pgprot(_PAGE_PROTECT));
655 }
656 pgste_val(pgste) |= bit;
657 pgste = pgste_set_pte(ptep, pgste, entry);
658 pgste_set_unlock(ptep, pgste);
659 return 0;
660}
661
662int ptep_shadow_pte(struct mm_struct *mm, unsigned long saddr,
663 pte_t *sptep, pte_t *tptep, pte_t pte)
664{
665 pgste_t spgste, tpgste;
666 pte_t spte, tpte;
667 int rc = -EAGAIN;
668
669 if (!(pte_val(*tptep) & _PAGE_INVALID))
670 return 0; /* already shadowed */
671 spgste = pgste_get_lock(sptep);
672 spte = *sptep;
673 if (!(pte_val(spte) & _PAGE_INVALID) &&
674 !((pte_val(spte) & _PAGE_PROTECT) &&
675 !(pte_val(pte) & _PAGE_PROTECT))) {
676 pgste_val(spgste) |= PGSTE_VSIE_BIT;
677 tpgste = pgste_get_lock(tptep);
678 tpte = __pte((pte_val(spte) & PAGE_MASK) |
679 (pte_val(pte) & _PAGE_PROTECT));
680 /* don't touch the storage key - it belongs to parent pgste */
681 tpgste = pgste_set_pte(tptep, tpgste, tpte);
682 pgste_set_unlock(tptep, tpgste);
683 rc = 1;
684 }
685 pgste_set_unlock(sptep, spgste);
686 return rc;
687}
688
689void ptep_unshadow_pte(struct mm_struct *mm, unsigned long saddr, pte_t *ptep)
690{
691 pgste_t pgste;
692 int nodat;
693
694 pgste = pgste_get_lock(ptep);
695 /* notifier is called by the caller */
696 nodat = !!(pgste_val(pgste) & _PGSTE_GPS_NODAT);
697 ptep_flush_direct(mm, saddr, ptep, nodat);
698 /* don't touch the storage key - it belongs to parent pgste */
699 pgste = pgste_set_pte(ptep, pgste, __pte(_PAGE_INVALID));
700 pgste_set_unlock(ptep, pgste);
701}
702
703static void ptep_zap_swap_entry(struct mm_struct *mm, swp_entry_t entry)
704{
705 if (!non_swap_entry(entry))
706 dec_mm_counter(mm, MM_SWAPENTS);
707 else if (is_migration_entry(entry)) {
708 struct page *page = pfn_swap_entry_to_page(entry);
709
710 dec_mm_counter(mm, mm_counter(page));
711 }
712 free_swap_and_cache(entry);
713}
714
715void ptep_zap_unused(struct mm_struct *mm, unsigned long addr,
716 pte_t *ptep, int reset)
717{
718 unsigned long pgstev;
719 pgste_t pgste;
720 pte_t pte;
721
722 /* Zap unused and logically-zero pages */
723 preempt_disable();
724 pgste = pgste_get_lock(ptep);
725 pgstev = pgste_val(pgste);
726 pte = *ptep;
727 if (!reset && pte_swap(pte) &&
728 ((pgstev & _PGSTE_GPS_USAGE_MASK) == _PGSTE_GPS_USAGE_UNUSED ||
729 (pgstev & _PGSTE_GPS_ZERO))) {
730 ptep_zap_swap_entry(mm, pte_to_swp_entry(pte));
731 pte_clear(mm, addr, ptep);
732 }
733 if (reset)
734 pgste_val(pgste) &= ~_PGSTE_GPS_USAGE_MASK;
735 pgste_set_unlock(ptep, pgste);
736 preempt_enable();
737}
738
739void ptep_zap_key(struct mm_struct *mm, unsigned long addr, pte_t *ptep)
740{
741 unsigned long ptev;
742 pgste_t pgste;
743
744 /* Clear storage key ACC and F, but set R/C */
745 preempt_disable();
746 pgste = pgste_get_lock(ptep);
747 pgste_val(pgste) &= ~(PGSTE_ACC_BITS | PGSTE_FP_BIT);
748 pgste_val(pgste) |= PGSTE_GR_BIT | PGSTE_GC_BIT;
749 ptev = pte_val(*ptep);
750 if (!(ptev & _PAGE_INVALID) && (ptev & _PAGE_WRITE))
751 page_set_storage_key(ptev & PAGE_MASK, PAGE_DEFAULT_KEY, 0);
752 pgste_set_unlock(ptep, pgste);
753 preempt_enable();
754}
755
756/*
757 * Test and reset if a guest page is dirty
758 */
759bool ptep_test_and_clear_uc(struct mm_struct *mm, unsigned long addr,
760 pte_t *ptep)
761{
762 pgste_t pgste;
763 pte_t pte;
764 bool dirty;
765 int nodat;
766
767 pgste = pgste_get_lock(ptep);
768 dirty = !!(pgste_val(pgste) & PGSTE_UC_BIT);
769 pgste_val(pgste) &= ~PGSTE_UC_BIT;
770 pte = *ptep;
771 if (dirty && (pte_val(pte) & _PAGE_PRESENT)) {
772 pgste = pgste_pte_notify(mm, addr, ptep, pgste);
773 nodat = !!(pgste_val(pgste) & _PGSTE_GPS_NODAT);
774 ptep_ipte_global(mm, addr, ptep, nodat);
775 if (MACHINE_HAS_ESOP || !(pte_val(pte) & _PAGE_WRITE))
776 pte = set_pte_bit(pte, __pgprot(_PAGE_PROTECT));
777 else
778 pte = set_pte_bit(pte, __pgprot(_PAGE_INVALID));
779 set_pte(ptep, pte);
780 }
781 pgste_set_unlock(ptep, pgste);
782 return dirty;
783}
784EXPORT_SYMBOL_GPL(ptep_test_and_clear_uc);
785
786int set_guest_storage_key(struct mm_struct *mm, unsigned long addr,
787 unsigned char key, bool nq)
788{
789 unsigned long keyul, paddr;
790 spinlock_t *ptl;
791 pgste_t old, new;
792 pmd_t *pmdp;
793 pte_t *ptep;
794
795 /*
796 * If we don't have a PTE table and if there is no huge page mapped,
797 * we can ignore attempts to set the key to 0, because it already is 0.
798 */
799 switch (pmd_lookup(mm, addr, &pmdp)) {
800 case -ENOENT:
801 return key ? -EFAULT : 0;
802 case 0:
803 break;
804 default:
805 return -EFAULT;
806 }
807
808 ptl = pmd_lock(mm, pmdp);
809 if (!pmd_present(*pmdp)) {
810 spin_unlock(ptl);
811 return key ? -EFAULT : 0;
812 }
813
814 if (pmd_large(*pmdp)) {
815 paddr = pmd_val(*pmdp) & HPAGE_MASK;
816 paddr |= addr & ~HPAGE_MASK;
817 /*
818 * Huge pmds need quiescing operations, they are
819 * always mapped.
820 */
821 page_set_storage_key(paddr, key, 1);
822 spin_unlock(ptl);
823 return 0;
824 }
825 spin_unlock(ptl);
826
827 ptep = pte_offset_map_lock(mm, pmdp, addr, &ptl);
828 new = old = pgste_get_lock(ptep);
829 pgste_val(new) &= ~(PGSTE_GR_BIT | PGSTE_GC_BIT |
830 PGSTE_ACC_BITS | PGSTE_FP_BIT);
831 keyul = (unsigned long) key;
832 pgste_val(new) |= (keyul & (_PAGE_CHANGED | _PAGE_REFERENCED)) << 48;
833 pgste_val(new) |= (keyul & (_PAGE_ACC_BITS | _PAGE_FP_BIT)) << 56;
834 if (!(pte_val(*ptep) & _PAGE_INVALID)) {
835 unsigned long bits, skey;
836
837 paddr = pte_val(*ptep) & PAGE_MASK;
838 skey = (unsigned long) page_get_storage_key(paddr);
839 bits = skey & (_PAGE_CHANGED | _PAGE_REFERENCED);
840 skey = key & (_PAGE_ACC_BITS | _PAGE_FP_BIT);
841 /* Set storage key ACC and FP */
842 page_set_storage_key(paddr, skey, !nq);
843 /* Merge host changed & referenced into pgste */
844 pgste_val(new) |= bits << 52;
845 }
846 /* changing the guest storage key is considered a change of the page */
847 if ((pgste_val(new) ^ pgste_val(old)) &
848 (PGSTE_ACC_BITS | PGSTE_FP_BIT | PGSTE_GR_BIT | PGSTE_GC_BIT))
849 pgste_val(new) |= PGSTE_UC_BIT;
850
851 pgste_set_unlock(ptep, new);
852 pte_unmap_unlock(ptep, ptl);
853 return 0;
854}
855EXPORT_SYMBOL(set_guest_storage_key);
856
857/*
858 * Conditionally set a guest storage key (handling csske).
859 * oldkey will be updated when either mr or mc is set and a pointer is given.
860 *
861 * Returns 0 if a guests storage key update wasn't necessary, 1 if the guest
862 * storage key was updated and -EFAULT on access errors.
863 */
864int cond_set_guest_storage_key(struct mm_struct *mm, unsigned long addr,
865 unsigned char key, unsigned char *oldkey,
866 bool nq, bool mr, bool mc)
867{
868 unsigned char tmp, mask = _PAGE_ACC_BITS | _PAGE_FP_BIT;
869 int rc;
870
871 /* we can drop the pgste lock between getting and setting the key */
872 if (mr | mc) {
873 rc = get_guest_storage_key(current->mm, addr, &tmp);
874 if (rc)
875 return rc;
876 if (oldkey)
877 *oldkey = tmp;
878 if (!mr)
879 mask |= _PAGE_REFERENCED;
880 if (!mc)
881 mask |= _PAGE_CHANGED;
882 if (!((tmp ^ key) & mask))
883 return 0;
884 }
885 rc = set_guest_storage_key(current->mm, addr, key, nq);
886 return rc < 0 ? rc : 1;
887}
888EXPORT_SYMBOL(cond_set_guest_storage_key);
889
890/*
891 * Reset a guest reference bit (rrbe), returning the reference and changed bit.
892 *
893 * Returns < 0 in case of error, otherwise the cc to be reported to the guest.
894 */
895int reset_guest_reference_bit(struct mm_struct *mm, unsigned long addr)
896{
897 spinlock_t *ptl;
898 unsigned long paddr;
899 pgste_t old, new;
900 pmd_t *pmdp;
901 pte_t *ptep;
902 int cc = 0;
903
904 /*
905 * If we don't have a PTE table and if there is no huge page mapped,
906 * the storage key is 0 and there is nothing for us to do.
907 */
908 switch (pmd_lookup(mm, addr, &pmdp)) {
909 case -ENOENT:
910 return 0;
911 case 0:
912 break;
913 default:
914 return -EFAULT;
915 }
916
917 ptl = pmd_lock(mm, pmdp);
918 if (!pmd_present(*pmdp)) {
919 spin_unlock(ptl);
920 return 0;
921 }
922
923 if (pmd_large(*pmdp)) {
924 paddr = pmd_val(*pmdp) & HPAGE_MASK;
925 paddr |= addr & ~HPAGE_MASK;
926 cc = page_reset_referenced(paddr);
927 spin_unlock(ptl);
928 return cc;
929 }
930 spin_unlock(ptl);
931
932 ptep = pte_offset_map_lock(mm, pmdp, addr, &ptl);
933 new = old = pgste_get_lock(ptep);
934 /* Reset guest reference bit only */
935 pgste_val(new) &= ~PGSTE_GR_BIT;
936
937 if (!(pte_val(*ptep) & _PAGE_INVALID)) {
938 paddr = pte_val(*ptep) & PAGE_MASK;
939 cc = page_reset_referenced(paddr);
940 /* Merge real referenced bit into host-set */
941 pgste_val(new) |= ((unsigned long) cc << 53) & PGSTE_HR_BIT;
942 }
943 /* Reflect guest's logical view, not physical */
944 cc |= (pgste_val(old) & (PGSTE_GR_BIT | PGSTE_GC_BIT)) >> 49;
945 /* Changing the guest storage key is considered a change of the page */
946 if ((pgste_val(new) ^ pgste_val(old)) & PGSTE_GR_BIT)
947 pgste_val(new) |= PGSTE_UC_BIT;
948
949 pgste_set_unlock(ptep, new);
950 pte_unmap_unlock(ptep, ptl);
951 return cc;
952}
953EXPORT_SYMBOL(reset_guest_reference_bit);
954
955int get_guest_storage_key(struct mm_struct *mm, unsigned long addr,
956 unsigned char *key)
957{
958 unsigned long paddr;
959 spinlock_t *ptl;
960 pgste_t pgste;
961 pmd_t *pmdp;
962 pte_t *ptep;
963
964 /*
965 * If we don't have a PTE table and if there is no huge page mapped,
966 * the storage key is 0.
967 */
968 *key = 0;
969
970 switch (pmd_lookup(mm, addr, &pmdp)) {
971 case -ENOENT:
972 return 0;
973 case 0:
974 break;
975 default:
976 return -EFAULT;
977 }
978
979 ptl = pmd_lock(mm, pmdp);
980 if (!pmd_present(*pmdp)) {
981 spin_unlock(ptl);
982 return 0;
983 }
984
985 if (pmd_large(*pmdp)) {
986 paddr = pmd_val(*pmdp) & HPAGE_MASK;
987 paddr |= addr & ~HPAGE_MASK;
988 *key = page_get_storage_key(paddr);
989 spin_unlock(ptl);
990 return 0;
991 }
992 spin_unlock(ptl);
993
994 ptep = pte_offset_map_lock(mm, pmdp, addr, &ptl);
995 pgste = pgste_get_lock(ptep);
996 *key = (pgste_val(pgste) & (PGSTE_ACC_BITS | PGSTE_FP_BIT)) >> 56;
997 paddr = pte_val(*ptep) & PAGE_MASK;
998 if (!(pte_val(*ptep) & _PAGE_INVALID))
999 *key = page_get_storage_key(paddr);
1000 /* Reflect guest's logical view, not physical */
1001 *key |= (pgste_val(pgste) & (PGSTE_GR_BIT | PGSTE_GC_BIT)) >> 48;
1002 pgste_set_unlock(ptep, pgste);
1003 pte_unmap_unlock(ptep, ptl);
1004 return 0;
1005}
1006EXPORT_SYMBOL(get_guest_storage_key);
1007
1008/**
1009 * pgste_perform_essa - perform ESSA actions on the PGSTE.
1010 * @mm: the memory context. It must have PGSTEs, no check is performed here!
1011 * @hva: the host virtual address of the page whose PGSTE is to be processed
1012 * @orc: the specific action to perform, see the ESSA_SET_* macros.
1013 * @oldpte: the PTE will be saved there if the pointer is not NULL.
1014 * @oldpgste: the old PGSTE will be saved there if the pointer is not NULL.
1015 *
1016 * Return: 1 if the page is to be added to the CBRL, otherwise 0,
1017 * or < 0 in case of error. -EINVAL is returned for invalid values
1018 * of orc, -EFAULT for invalid addresses.
1019 */
1020int pgste_perform_essa(struct mm_struct *mm, unsigned long hva, int orc,
1021 unsigned long *oldpte, unsigned long *oldpgste)
1022{
1023 struct vm_area_struct *vma;
1024 unsigned long pgstev;
1025 spinlock_t *ptl;
1026 pgste_t pgste;
1027 pte_t *ptep;
1028 int res = 0;
1029
1030 WARN_ON_ONCE(orc > ESSA_MAX);
1031 if (unlikely(orc > ESSA_MAX))
1032 return -EINVAL;
1033
1034 vma = vma_lookup(mm, hva);
1035 if (!vma || is_vm_hugetlb_page(vma))
1036 return -EFAULT;
1037 ptep = get_locked_pte(mm, hva, &ptl);
1038 if (unlikely(!ptep))
1039 return -EFAULT;
1040 pgste = pgste_get_lock(ptep);
1041 pgstev = pgste_val(pgste);
1042 if (oldpte)
1043 *oldpte = pte_val(*ptep);
1044 if (oldpgste)
1045 *oldpgste = pgstev;
1046
1047 switch (orc) {
1048 case ESSA_GET_STATE:
1049 break;
1050 case ESSA_SET_STABLE:
1051 pgstev &= ~(_PGSTE_GPS_USAGE_MASK | _PGSTE_GPS_NODAT);
1052 pgstev |= _PGSTE_GPS_USAGE_STABLE;
1053 break;
1054 case ESSA_SET_UNUSED:
1055 pgstev &= ~_PGSTE_GPS_USAGE_MASK;
1056 pgstev |= _PGSTE_GPS_USAGE_UNUSED;
1057 if (pte_val(*ptep) & _PAGE_INVALID)
1058 res = 1;
1059 break;
1060 case ESSA_SET_VOLATILE:
1061 pgstev &= ~_PGSTE_GPS_USAGE_MASK;
1062 pgstev |= _PGSTE_GPS_USAGE_VOLATILE;
1063 if (pte_val(*ptep) & _PAGE_INVALID)
1064 res = 1;
1065 break;
1066 case ESSA_SET_POT_VOLATILE:
1067 pgstev &= ~_PGSTE_GPS_USAGE_MASK;
1068 if (!(pte_val(*ptep) & _PAGE_INVALID)) {
1069 pgstev |= _PGSTE_GPS_USAGE_POT_VOLATILE;
1070 break;
1071 }
1072 if (pgstev & _PGSTE_GPS_ZERO) {
1073 pgstev |= _PGSTE_GPS_USAGE_VOLATILE;
1074 break;
1075 }
1076 if (!(pgstev & PGSTE_GC_BIT)) {
1077 pgstev |= _PGSTE_GPS_USAGE_VOLATILE;
1078 res = 1;
1079 break;
1080 }
1081 break;
1082 case ESSA_SET_STABLE_RESIDENT:
1083 pgstev &= ~_PGSTE_GPS_USAGE_MASK;
1084 pgstev |= _PGSTE_GPS_USAGE_STABLE;
1085 /*
1086 * Since the resident state can go away any time after this
1087 * call, we will not make this page resident. We can revisit
1088 * this decision if a guest will ever start using this.
1089 */
1090 break;
1091 case ESSA_SET_STABLE_IF_RESIDENT:
1092 if (!(pte_val(*ptep) & _PAGE_INVALID)) {
1093 pgstev &= ~_PGSTE_GPS_USAGE_MASK;
1094 pgstev |= _PGSTE_GPS_USAGE_STABLE;
1095 }
1096 break;
1097 case ESSA_SET_STABLE_NODAT:
1098 pgstev &= ~_PGSTE_GPS_USAGE_MASK;
1099 pgstev |= _PGSTE_GPS_USAGE_STABLE | _PGSTE_GPS_NODAT;
1100 break;
1101 default:
1102 /* we should never get here! */
1103 break;
1104 }
1105 /* If we are discarding a page, set it to logical zero */
1106 if (res)
1107 pgstev |= _PGSTE_GPS_ZERO;
1108
1109 pgste_val(pgste) = pgstev;
1110 pgste_set_unlock(ptep, pgste);
1111 pte_unmap_unlock(ptep, ptl);
1112 return res;
1113}
1114EXPORT_SYMBOL(pgste_perform_essa);
1115
1116/**
1117 * set_pgste_bits - set specific PGSTE bits.
1118 * @mm: the memory context. It must have PGSTEs, no check is performed here!
1119 * @hva: the host virtual address of the page whose PGSTE is to be processed
1120 * @bits: a bitmask representing the bits that will be touched
1121 * @value: the values of the bits to be written. Only the bits in the mask
1122 * will be written.
1123 *
1124 * Return: 0 on success, < 0 in case of error.
1125 */
1126int set_pgste_bits(struct mm_struct *mm, unsigned long hva,
1127 unsigned long bits, unsigned long value)
1128{
1129 struct vm_area_struct *vma;
1130 spinlock_t *ptl;
1131 pgste_t new;
1132 pte_t *ptep;
1133
1134 vma = vma_lookup(mm, hva);
1135 if (!vma || is_vm_hugetlb_page(vma))
1136 return -EFAULT;
1137 ptep = get_locked_pte(mm, hva, &ptl);
1138 if (unlikely(!ptep))
1139 return -EFAULT;
1140 new = pgste_get_lock(ptep);
1141
1142 pgste_val(new) &= ~bits;
1143 pgste_val(new) |= value & bits;
1144
1145 pgste_set_unlock(ptep, new);
1146 pte_unmap_unlock(ptep, ptl);
1147 return 0;
1148}
1149EXPORT_SYMBOL(set_pgste_bits);
1150
1151/**
1152 * get_pgste - get the current PGSTE for the given address.
1153 * @mm: the memory context. It must have PGSTEs, no check is performed here!
1154 * @hva: the host virtual address of the page whose PGSTE is to be processed
1155 * @pgstep: will be written with the current PGSTE for the given address.
1156 *
1157 * Return: 0 on success, < 0 in case of error.
1158 */
1159int get_pgste(struct mm_struct *mm, unsigned long hva, unsigned long *pgstep)
1160{
1161 struct vm_area_struct *vma;
1162 spinlock_t *ptl;
1163 pte_t *ptep;
1164
1165 vma = vma_lookup(mm, hva);
1166 if (!vma || is_vm_hugetlb_page(vma))
1167 return -EFAULT;
1168 ptep = get_locked_pte(mm, hva, &ptl);
1169 if (unlikely(!ptep))
1170 return -EFAULT;
1171 *pgstep = pgste_val(pgste_get(ptep));
1172 pte_unmap_unlock(ptep, ptl);
1173 return 0;
1174}
1175EXPORT_SYMBOL(get_pgste);
1176#endif
1/*
2 * Copyright IBM Corp. 2007,2009
3 * Author(s): Martin Schwidefsky <schwidefsky@de.ibm.com>
4 */
5
6#include <linux/sched.h>
7#include <linux/kernel.h>
8#include <linux/errno.h>
9#include <linux/gfp.h>
10#include <linux/mm.h>
11#include <linux/swap.h>
12#include <linux/smp.h>
13#include <linux/highmem.h>
14#include <linux/pagemap.h>
15#include <linux/spinlock.h>
16#include <linux/module.h>
17#include <linux/quicklist.h>
18#include <linux/rcupdate.h>
19#include <linux/slab.h>
20
21#include <asm/system.h>
22#include <asm/pgtable.h>
23#include <asm/pgalloc.h>
24#include <asm/tlb.h>
25#include <asm/tlbflush.h>
26#include <asm/mmu_context.h>
27
28#ifndef CONFIG_64BIT
29#define ALLOC_ORDER 1
30#define FRAG_MASK 0x0f
31#else
32#define ALLOC_ORDER 2
33#define FRAG_MASK 0x03
34#endif
35
36unsigned long VMALLOC_START = VMALLOC_END - VMALLOC_SIZE;
37EXPORT_SYMBOL(VMALLOC_START);
38
39static int __init parse_vmalloc(char *arg)
40{
41 if (!arg)
42 return -EINVAL;
43 VMALLOC_START = (VMALLOC_END - memparse(arg, &arg)) & PAGE_MASK;
44 return 0;
45}
46early_param("vmalloc", parse_vmalloc);
47
48unsigned long *crst_table_alloc(struct mm_struct *mm)
49{
50 struct page *page = alloc_pages(GFP_KERNEL, ALLOC_ORDER);
51
52 if (!page)
53 return NULL;
54 return (unsigned long *) page_to_phys(page);
55}
56
57void crst_table_free(struct mm_struct *mm, unsigned long *table)
58{
59 free_pages((unsigned long) table, ALLOC_ORDER);
60}
61
62#ifdef CONFIG_64BIT
63int crst_table_upgrade(struct mm_struct *mm, unsigned long limit)
64{
65 unsigned long *table, *pgd;
66 unsigned long entry;
67
68 BUG_ON(limit > (1UL << 53));
69repeat:
70 table = crst_table_alloc(mm);
71 if (!table)
72 return -ENOMEM;
73 spin_lock_bh(&mm->page_table_lock);
74 if (mm->context.asce_limit < limit) {
75 pgd = (unsigned long *) mm->pgd;
76 if (mm->context.asce_limit <= (1UL << 31)) {
77 entry = _REGION3_ENTRY_EMPTY;
78 mm->context.asce_limit = 1UL << 42;
79 mm->context.asce_bits = _ASCE_TABLE_LENGTH |
80 _ASCE_USER_BITS |
81 _ASCE_TYPE_REGION3;
82 } else {
83 entry = _REGION2_ENTRY_EMPTY;
84 mm->context.asce_limit = 1UL << 53;
85 mm->context.asce_bits = _ASCE_TABLE_LENGTH |
86 _ASCE_USER_BITS |
87 _ASCE_TYPE_REGION2;
88 }
89 crst_table_init(table, entry);
90 pgd_populate(mm, (pgd_t *) table, (pud_t *) pgd);
91 mm->pgd = (pgd_t *) table;
92 mm->task_size = mm->context.asce_limit;
93 table = NULL;
94 }
95 spin_unlock_bh(&mm->page_table_lock);
96 if (table)
97 crst_table_free(mm, table);
98 if (mm->context.asce_limit < limit)
99 goto repeat;
100 update_mm(mm, current);
101 return 0;
102}
103
104void crst_table_downgrade(struct mm_struct *mm, unsigned long limit)
105{
106 pgd_t *pgd;
107
108 if (mm->context.asce_limit <= limit)
109 return;
110 __tlb_flush_mm(mm);
111 while (mm->context.asce_limit > limit) {
112 pgd = mm->pgd;
113 switch (pgd_val(*pgd) & _REGION_ENTRY_TYPE_MASK) {
114 case _REGION_ENTRY_TYPE_R2:
115 mm->context.asce_limit = 1UL << 42;
116 mm->context.asce_bits = _ASCE_TABLE_LENGTH |
117 _ASCE_USER_BITS |
118 _ASCE_TYPE_REGION3;
119 break;
120 case _REGION_ENTRY_TYPE_R3:
121 mm->context.asce_limit = 1UL << 31;
122 mm->context.asce_bits = _ASCE_TABLE_LENGTH |
123 _ASCE_USER_BITS |
124 _ASCE_TYPE_SEGMENT;
125 break;
126 default:
127 BUG();
128 }
129 mm->pgd = (pgd_t *) (pgd_val(*pgd) & _REGION_ENTRY_ORIGIN);
130 mm->task_size = mm->context.asce_limit;
131 crst_table_free(mm, (unsigned long *) pgd);
132 }
133 update_mm(mm, current);
134}
135#endif
136
137#ifdef CONFIG_PGSTE
138
139/**
140 * gmap_alloc - allocate a guest address space
141 * @mm: pointer to the parent mm_struct
142 *
143 * Returns a guest address space structure.
144 */
145struct gmap *gmap_alloc(struct mm_struct *mm)
146{
147 struct gmap *gmap;
148 struct page *page;
149 unsigned long *table;
150
151 gmap = kzalloc(sizeof(struct gmap), GFP_KERNEL);
152 if (!gmap)
153 goto out;
154 INIT_LIST_HEAD(&gmap->crst_list);
155 gmap->mm = mm;
156 page = alloc_pages(GFP_KERNEL, ALLOC_ORDER);
157 if (!page)
158 goto out_free;
159 list_add(&page->lru, &gmap->crst_list);
160 table = (unsigned long *) page_to_phys(page);
161 crst_table_init(table, _REGION1_ENTRY_EMPTY);
162 gmap->table = table;
163 gmap->asce = _ASCE_TYPE_REGION1 | _ASCE_TABLE_LENGTH |
164 _ASCE_USER_BITS | __pa(table);
165 list_add(&gmap->list, &mm->context.gmap_list);
166 return gmap;
167
168out_free:
169 kfree(gmap);
170out:
171 return NULL;
172}
173EXPORT_SYMBOL_GPL(gmap_alloc);
174
175static int gmap_unlink_segment(struct gmap *gmap, unsigned long *table)
176{
177 struct gmap_pgtable *mp;
178 struct gmap_rmap *rmap;
179 struct page *page;
180
181 if (*table & _SEGMENT_ENTRY_INV)
182 return 0;
183 page = pfn_to_page(*table >> PAGE_SHIFT);
184 mp = (struct gmap_pgtable *) page->index;
185 list_for_each_entry(rmap, &mp->mapper, list) {
186 if (rmap->entry != table)
187 continue;
188 list_del(&rmap->list);
189 kfree(rmap);
190 break;
191 }
192 *table = _SEGMENT_ENTRY_INV | _SEGMENT_ENTRY_RO | mp->vmaddr;
193 return 1;
194}
195
196static void gmap_flush_tlb(struct gmap *gmap)
197{
198 if (MACHINE_HAS_IDTE)
199 __tlb_flush_idte((unsigned long) gmap->table |
200 _ASCE_TYPE_REGION1);
201 else
202 __tlb_flush_global();
203}
204
205/**
206 * gmap_free - free a guest address space
207 * @gmap: pointer to the guest address space structure
208 */
209void gmap_free(struct gmap *gmap)
210{
211 struct page *page, *next;
212 unsigned long *table;
213 int i;
214
215
216 /* Flush tlb. */
217 if (MACHINE_HAS_IDTE)
218 __tlb_flush_idte((unsigned long) gmap->table |
219 _ASCE_TYPE_REGION1);
220 else
221 __tlb_flush_global();
222
223 /* Free all segment & region tables. */
224 down_read(&gmap->mm->mmap_sem);
225 list_for_each_entry_safe(page, next, &gmap->crst_list, lru) {
226 table = (unsigned long *) page_to_phys(page);
227 if ((*table & _REGION_ENTRY_TYPE_MASK) == 0)
228 /* Remove gmap rmap structures for segment table. */
229 for (i = 0; i < PTRS_PER_PMD; i++, table++)
230 gmap_unlink_segment(gmap, table);
231 __free_pages(page, ALLOC_ORDER);
232 }
233 up_read(&gmap->mm->mmap_sem);
234 list_del(&gmap->list);
235 kfree(gmap);
236}
237EXPORT_SYMBOL_GPL(gmap_free);
238
239/**
240 * gmap_enable - switch primary space to the guest address space
241 * @gmap: pointer to the guest address space structure
242 */
243void gmap_enable(struct gmap *gmap)
244{
245 S390_lowcore.gmap = (unsigned long) gmap;
246}
247EXPORT_SYMBOL_GPL(gmap_enable);
248
249/**
250 * gmap_disable - switch back to the standard primary address space
251 * @gmap: pointer to the guest address space structure
252 */
253void gmap_disable(struct gmap *gmap)
254{
255 S390_lowcore.gmap = 0UL;
256}
257EXPORT_SYMBOL_GPL(gmap_disable);
258
259static int gmap_alloc_table(struct gmap *gmap,
260 unsigned long *table, unsigned long init)
261{
262 struct page *page;
263 unsigned long *new;
264
265 page = alloc_pages(GFP_KERNEL, ALLOC_ORDER);
266 if (!page)
267 return -ENOMEM;
268 new = (unsigned long *) page_to_phys(page);
269 crst_table_init(new, init);
270 down_read(&gmap->mm->mmap_sem);
271 if (*table & _REGION_ENTRY_INV) {
272 list_add(&page->lru, &gmap->crst_list);
273 *table = (unsigned long) new | _REGION_ENTRY_LENGTH |
274 (*table & _REGION_ENTRY_TYPE_MASK);
275 } else
276 __free_pages(page, ALLOC_ORDER);
277 up_read(&gmap->mm->mmap_sem);
278 return 0;
279}
280
281/**
282 * gmap_unmap_segment - unmap segment from the guest address space
283 * @gmap: pointer to the guest address space structure
284 * @addr: address in the guest address space
285 * @len: length of the memory area to unmap
286 *
287 * Returns 0 if the unmap succeded, -EINVAL if not.
288 */
289int gmap_unmap_segment(struct gmap *gmap, unsigned long to, unsigned long len)
290{
291 unsigned long *table;
292 unsigned long off;
293 int flush;
294
295 if ((to | len) & (PMD_SIZE - 1))
296 return -EINVAL;
297 if (len == 0 || to + len < to)
298 return -EINVAL;
299
300 flush = 0;
301 down_read(&gmap->mm->mmap_sem);
302 for (off = 0; off < len; off += PMD_SIZE) {
303 /* Walk the guest addr space page table */
304 table = gmap->table + (((to + off) >> 53) & 0x7ff);
305 if (*table & _REGION_ENTRY_INV)
306 goto out;
307 table = (unsigned long *)(*table & _REGION_ENTRY_ORIGIN);
308 table = table + (((to + off) >> 42) & 0x7ff);
309 if (*table & _REGION_ENTRY_INV)
310 goto out;
311 table = (unsigned long *)(*table & _REGION_ENTRY_ORIGIN);
312 table = table + (((to + off) >> 31) & 0x7ff);
313 if (*table & _REGION_ENTRY_INV)
314 goto out;
315 table = (unsigned long *)(*table & _REGION_ENTRY_ORIGIN);
316 table = table + (((to + off) >> 20) & 0x7ff);
317
318 /* Clear segment table entry in guest address space. */
319 flush |= gmap_unlink_segment(gmap, table);
320 *table = _SEGMENT_ENTRY_INV;
321 }
322out:
323 up_read(&gmap->mm->mmap_sem);
324 if (flush)
325 gmap_flush_tlb(gmap);
326 return 0;
327}
328EXPORT_SYMBOL_GPL(gmap_unmap_segment);
329
330/**
331 * gmap_mmap_segment - map a segment to the guest address space
332 * @gmap: pointer to the guest address space structure
333 * @from: source address in the parent address space
334 * @to: target address in the guest address space
335 *
336 * Returns 0 if the mmap succeded, -EINVAL or -ENOMEM if not.
337 */
338int gmap_map_segment(struct gmap *gmap, unsigned long from,
339 unsigned long to, unsigned long len)
340{
341 unsigned long *table;
342 unsigned long off;
343 int flush;
344
345 if ((from | to | len) & (PMD_SIZE - 1))
346 return -EINVAL;
347 if (len == 0 || from + len > PGDIR_SIZE ||
348 from + len < from || to + len < to)
349 return -EINVAL;
350
351 flush = 0;
352 down_read(&gmap->mm->mmap_sem);
353 for (off = 0; off < len; off += PMD_SIZE) {
354 /* Walk the gmap address space page table */
355 table = gmap->table + (((to + off) >> 53) & 0x7ff);
356 if ((*table & _REGION_ENTRY_INV) &&
357 gmap_alloc_table(gmap, table, _REGION2_ENTRY_EMPTY))
358 goto out_unmap;
359 table = (unsigned long *)(*table & _REGION_ENTRY_ORIGIN);
360 table = table + (((to + off) >> 42) & 0x7ff);
361 if ((*table & _REGION_ENTRY_INV) &&
362 gmap_alloc_table(gmap, table, _REGION3_ENTRY_EMPTY))
363 goto out_unmap;
364 table = (unsigned long *)(*table & _REGION_ENTRY_ORIGIN);
365 table = table + (((to + off) >> 31) & 0x7ff);
366 if ((*table & _REGION_ENTRY_INV) &&
367 gmap_alloc_table(gmap, table, _SEGMENT_ENTRY_EMPTY))
368 goto out_unmap;
369 table = (unsigned long *) (*table & _REGION_ENTRY_ORIGIN);
370 table = table + (((to + off) >> 20) & 0x7ff);
371
372 /* Store 'from' address in an invalid segment table entry. */
373 flush |= gmap_unlink_segment(gmap, table);
374 *table = _SEGMENT_ENTRY_INV | _SEGMENT_ENTRY_RO | (from + off);
375 }
376 up_read(&gmap->mm->mmap_sem);
377 if (flush)
378 gmap_flush_tlb(gmap);
379 return 0;
380
381out_unmap:
382 up_read(&gmap->mm->mmap_sem);
383 gmap_unmap_segment(gmap, to, len);
384 return -ENOMEM;
385}
386EXPORT_SYMBOL_GPL(gmap_map_segment);
387
388unsigned long gmap_fault(unsigned long address, struct gmap *gmap)
389{
390 unsigned long *table, vmaddr, segment;
391 struct mm_struct *mm;
392 struct gmap_pgtable *mp;
393 struct gmap_rmap *rmap;
394 struct vm_area_struct *vma;
395 struct page *page;
396 pgd_t *pgd;
397 pud_t *pud;
398 pmd_t *pmd;
399
400 current->thread.gmap_addr = address;
401 mm = gmap->mm;
402 /* Walk the gmap address space page table */
403 table = gmap->table + ((address >> 53) & 0x7ff);
404 if (unlikely(*table & _REGION_ENTRY_INV))
405 return -EFAULT;
406 table = (unsigned long *)(*table & _REGION_ENTRY_ORIGIN);
407 table = table + ((address >> 42) & 0x7ff);
408 if (unlikely(*table & _REGION_ENTRY_INV))
409 return -EFAULT;
410 table = (unsigned long *)(*table & _REGION_ENTRY_ORIGIN);
411 table = table + ((address >> 31) & 0x7ff);
412 if (unlikely(*table & _REGION_ENTRY_INV))
413 return -EFAULT;
414 table = (unsigned long *)(*table & _REGION_ENTRY_ORIGIN);
415 table = table + ((address >> 20) & 0x7ff);
416
417 /* Convert the gmap address to an mm address. */
418 segment = *table;
419 if (likely(!(segment & _SEGMENT_ENTRY_INV))) {
420 page = pfn_to_page(segment >> PAGE_SHIFT);
421 mp = (struct gmap_pgtable *) page->index;
422 return mp->vmaddr | (address & ~PMD_MASK);
423 } else if (segment & _SEGMENT_ENTRY_RO) {
424 vmaddr = segment & _SEGMENT_ENTRY_ORIGIN;
425 vma = find_vma(mm, vmaddr);
426 if (!vma || vma->vm_start > vmaddr)
427 return -EFAULT;
428
429 /* Walk the parent mm page table */
430 pgd = pgd_offset(mm, vmaddr);
431 pud = pud_alloc(mm, pgd, vmaddr);
432 if (!pud)
433 return -ENOMEM;
434 pmd = pmd_alloc(mm, pud, vmaddr);
435 if (!pmd)
436 return -ENOMEM;
437 if (!pmd_present(*pmd) &&
438 __pte_alloc(mm, vma, pmd, vmaddr))
439 return -ENOMEM;
440 /* pmd now points to a valid segment table entry. */
441 rmap = kmalloc(sizeof(*rmap), GFP_KERNEL|__GFP_REPEAT);
442 if (!rmap)
443 return -ENOMEM;
444 /* Link gmap segment table entry location to page table. */
445 page = pmd_page(*pmd);
446 mp = (struct gmap_pgtable *) page->index;
447 rmap->entry = table;
448 list_add(&rmap->list, &mp->mapper);
449 /* Set gmap segment table entry to page table. */
450 *table = pmd_val(*pmd) & PAGE_MASK;
451 return vmaddr | (address & ~PMD_MASK);
452 }
453 return -EFAULT;
454
455}
456EXPORT_SYMBOL_GPL(gmap_fault);
457
458void gmap_unmap_notifier(struct mm_struct *mm, unsigned long *table)
459{
460 struct gmap_rmap *rmap, *next;
461 struct gmap_pgtable *mp;
462 struct page *page;
463 int flush;
464
465 flush = 0;
466 spin_lock(&mm->page_table_lock);
467 page = pfn_to_page(__pa(table) >> PAGE_SHIFT);
468 mp = (struct gmap_pgtable *) page->index;
469 list_for_each_entry_safe(rmap, next, &mp->mapper, list) {
470 *rmap->entry =
471 _SEGMENT_ENTRY_INV | _SEGMENT_ENTRY_RO | mp->vmaddr;
472 list_del(&rmap->list);
473 kfree(rmap);
474 flush = 1;
475 }
476 spin_unlock(&mm->page_table_lock);
477 if (flush)
478 __tlb_flush_global();
479}
480
481static inline unsigned long *page_table_alloc_pgste(struct mm_struct *mm,
482 unsigned long vmaddr)
483{
484 struct page *page;
485 unsigned long *table;
486 struct gmap_pgtable *mp;
487
488 page = alloc_page(GFP_KERNEL|__GFP_REPEAT);
489 if (!page)
490 return NULL;
491 mp = kmalloc(sizeof(*mp), GFP_KERNEL|__GFP_REPEAT);
492 if (!mp) {
493 __free_page(page);
494 return NULL;
495 }
496 pgtable_page_ctor(page);
497 mp->vmaddr = vmaddr & PMD_MASK;
498 INIT_LIST_HEAD(&mp->mapper);
499 page->index = (unsigned long) mp;
500 atomic_set(&page->_mapcount, 3);
501 table = (unsigned long *) page_to_phys(page);
502 clear_table(table, _PAGE_TYPE_EMPTY, PAGE_SIZE/2);
503 clear_table(table + PTRS_PER_PTE, 0, PAGE_SIZE/2);
504 return table;
505}
506
507static inline void page_table_free_pgste(unsigned long *table)
508{
509 struct page *page;
510 struct gmap_pgtable *mp;
511
512 page = pfn_to_page(__pa(table) >> PAGE_SHIFT);
513 mp = (struct gmap_pgtable *) page->index;
514 BUG_ON(!list_empty(&mp->mapper));
515 pgtable_page_ctor(page);
516 atomic_set(&page->_mapcount, -1);
517 kfree(mp);
518 __free_page(page);
519}
520
521#else /* CONFIG_PGSTE */
522
523static inline unsigned long *page_table_alloc_pgste(struct mm_struct *mm,
524 unsigned long vmaddr)
525{
526 return NULL;
527}
528
529static inline void page_table_free_pgste(unsigned long *table)
530{
531}
532
533static inline void gmap_unmap_notifier(struct mm_struct *mm,
534 unsigned long *table)
535{
536}
537
538#endif /* CONFIG_PGSTE */
539
540static inline unsigned int atomic_xor_bits(atomic_t *v, unsigned int bits)
541{
542 unsigned int old, new;
543
544 do {
545 old = atomic_read(v);
546 new = old ^ bits;
547 } while (atomic_cmpxchg(v, old, new) != old);
548 return new;
549}
550
551/*
552 * page table entry allocation/free routines.
553 */
554unsigned long *page_table_alloc(struct mm_struct *mm, unsigned long vmaddr)
555{
556 struct page *page;
557 unsigned long *table;
558 unsigned int mask, bit;
559
560 if (mm_has_pgste(mm))
561 return page_table_alloc_pgste(mm, vmaddr);
562 /* Allocate fragments of a 4K page as 1K/2K page table */
563 spin_lock_bh(&mm->context.list_lock);
564 mask = FRAG_MASK;
565 if (!list_empty(&mm->context.pgtable_list)) {
566 page = list_first_entry(&mm->context.pgtable_list,
567 struct page, lru);
568 table = (unsigned long *) page_to_phys(page);
569 mask = atomic_read(&page->_mapcount);
570 mask = mask | (mask >> 4);
571 }
572 if ((mask & FRAG_MASK) == FRAG_MASK) {
573 spin_unlock_bh(&mm->context.list_lock);
574 page = alloc_page(GFP_KERNEL|__GFP_REPEAT);
575 if (!page)
576 return NULL;
577 pgtable_page_ctor(page);
578 atomic_set(&page->_mapcount, 1);
579 table = (unsigned long *) page_to_phys(page);
580 clear_table(table, _PAGE_TYPE_EMPTY, PAGE_SIZE);
581 spin_lock_bh(&mm->context.list_lock);
582 list_add(&page->lru, &mm->context.pgtable_list);
583 } else {
584 for (bit = 1; mask & bit; bit <<= 1)
585 table += PTRS_PER_PTE;
586 mask = atomic_xor_bits(&page->_mapcount, bit);
587 if ((mask & FRAG_MASK) == FRAG_MASK)
588 list_del(&page->lru);
589 }
590 spin_unlock_bh(&mm->context.list_lock);
591 return table;
592}
593
594void page_table_free(struct mm_struct *mm, unsigned long *table)
595{
596 struct page *page;
597 unsigned int bit, mask;
598
599 if (mm_has_pgste(mm)) {
600 gmap_unmap_notifier(mm, table);
601 return page_table_free_pgste(table);
602 }
603 /* Free 1K/2K page table fragment of a 4K page */
604 page = pfn_to_page(__pa(table) >> PAGE_SHIFT);
605 bit = 1 << ((__pa(table) & ~PAGE_MASK)/(PTRS_PER_PTE*sizeof(pte_t)));
606 spin_lock_bh(&mm->context.list_lock);
607 if ((atomic_read(&page->_mapcount) & FRAG_MASK) != FRAG_MASK)
608 list_del(&page->lru);
609 mask = atomic_xor_bits(&page->_mapcount, bit);
610 if (mask & FRAG_MASK)
611 list_add(&page->lru, &mm->context.pgtable_list);
612 spin_unlock_bh(&mm->context.list_lock);
613 if (mask == 0) {
614 pgtable_page_dtor(page);
615 atomic_set(&page->_mapcount, -1);
616 __free_page(page);
617 }
618}
619
620#ifdef CONFIG_HAVE_RCU_TABLE_FREE
621
622static void __page_table_free_rcu(void *table, unsigned bit)
623{
624 struct page *page;
625
626 if (bit == FRAG_MASK)
627 return page_table_free_pgste(table);
628 /* Free 1K/2K page table fragment of a 4K page */
629 page = pfn_to_page(__pa(table) >> PAGE_SHIFT);
630 if (atomic_xor_bits(&page->_mapcount, bit) == 0) {
631 pgtable_page_dtor(page);
632 atomic_set(&page->_mapcount, -1);
633 __free_page(page);
634 }
635}
636
637void page_table_free_rcu(struct mmu_gather *tlb, unsigned long *table)
638{
639 struct mm_struct *mm;
640 struct page *page;
641 unsigned int bit, mask;
642
643 mm = tlb->mm;
644 if (mm_has_pgste(mm)) {
645 gmap_unmap_notifier(mm, table);
646 table = (unsigned long *) (__pa(table) | FRAG_MASK);
647 tlb_remove_table(tlb, table);
648 return;
649 }
650 bit = 1 << ((__pa(table) & ~PAGE_MASK) / (PTRS_PER_PTE*sizeof(pte_t)));
651 page = pfn_to_page(__pa(table) >> PAGE_SHIFT);
652 spin_lock_bh(&mm->context.list_lock);
653 if ((atomic_read(&page->_mapcount) & FRAG_MASK) != FRAG_MASK)
654 list_del(&page->lru);
655 mask = atomic_xor_bits(&page->_mapcount, bit | (bit << 4));
656 if (mask & FRAG_MASK)
657 list_add_tail(&page->lru, &mm->context.pgtable_list);
658 spin_unlock_bh(&mm->context.list_lock);
659 table = (unsigned long *) (__pa(table) | (bit << 4));
660 tlb_remove_table(tlb, table);
661}
662
663void __tlb_remove_table(void *_table)
664{
665 void *table = (void *)((unsigned long) _table & PAGE_MASK);
666 unsigned type = (unsigned long) _table & ~PAGE_MASK;
667
668 if (type)
669 __page_table_free_rcu(table, type);
670 else
671 free_pages((unsigned long) table, ALLOC_ORDER);
672}
673
674#endif
675
676/*
677 * switch on pgstes for its userspace process (for kvm)
678 */
679int s390_enable_sie(void)
680{
681 struct task_struct *tsk = current;
682 struct mm_struct *mm, *old_mm;
683
684 /* Do we have switched amode? If no, we cannot do sie */
685 if (user_mode == HOME_SPACE_MODE)
686 return -EINVAL;
687
688 /* Do we have pgstes? if yes, we are done */
689 if (mm_has_pgste(tsk->mm))
690 return 0;
691
692 /* lets check if we are allowed to replace the mm */
693 task_lock(tsk);
694 if (!tsk->mm || atomic_read(&tsk->mm->mm_users) > 1 ||
695#ifdef CONFIG_AIO
696 !hlist_empty(&tsk->mm->ioctx_list) ||
697#endif
698 tsk->mm != tsk->active_mm) {
699 task_unlock(tsk);
700 return -EINVAL;
701 }
702 task_unlock(tsk);
703
704 /* we copy the mm and let dup_mm create the page tables with_pgstes */
705 tsk->mm->context.alloc_pgste = 1;
706 mm = dup_mm(tsk);
707 tsk->mm->context.alloc_pgste = 0;
708 if (!mm)
709 return -ENOMEM;
710
711 /* Now lets check again if something happened */
712 task_lock(tsk);
713 if (!tsk->mm || atomic_read(&tsk->mm->mm_users) > 1 ||
714#ifdef CONFIG_AIO
715 !hlist_empty(&tsk->mm->ioctx_list) ||
716#endif
717 tsk->mm != tsk->active_mm) {
718 mmput(mm);
719 task_unlock(tsk);
720 return -EINVAL;
721 }
722
723 /* ok, we are alone. No ptrace, no threads, etc. */
724 old_mm = tsk->mm;
725 tsk->mm = tsk->active_mm = mm;
726 preempt_disable();
727 update_mm(mm, tsk);
728 atomic_inc(&mm->context.attach_count);
729 atomic_dec(&old_mm->context.attach_count);
730 cpumask_set_cpu(smp_processor_id(), mm_cpumask(mm));
731 preempt_enable();
732 task_unlock(tsk);
733 mmput(old_mm);
734 return 0;
735}
736EXPORT_SYMBOL_GPL(s390_enable_sie);
737
738#if defined(CONFIG_DEBUG_PAGEALLOC) && defined(CONFIG_HIBERNATION)
739bool kernel_page_present(struct page *page)
740{
741 unsigned long addr;
742 int cc;
743
744 addr = page_to_phys(page);
745 asm volatile(
746 " lra %1,0(%1)\n"
747 " ipm %0\n"
748 " srl %0,28"
749 : "=d" (cc), "+a" (addr) : : "cc");
750 return cc == 0;
751}
752#endif /* CONFIG_HIBERNATION && CONFIG_DEBUG_PAGEALLOC */