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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/pgtable.h>
23#include <asm/pgalloc.h>
24#include <asm/tlb.h>
25#include <asm/tlbflush.h>
26#include <asm/mmu_context.h>
27#include <asm/page-states.h>
28
29static inline void ptep_ipte_local(struct mm_struct *mm, unsigned long addr,
30 pte_t *ptep, int nodat)
31{
32 unsigned long opt, asce;
33
34 if (MACHINE_HAS_TLB_GUEST) {
35 opt = 0;
36 asce = READ_ONCE(mm->context.gmap_asce);
37 if (asce == 0UL || nodat)
38 opt |= IPTE_NODAT;
39 if (asce != -1UL) {
40 asce = asce ? : mm->context.asce;
41 opt |= IPTE_GUEST_ASCE;
42 }
43 __ptep_ipte(addr, ptep, opt, asce, IPTE_LOCAL);
44 } else {
45 __ptep_ipte(addr, ptep, 0, 0, IPTE_LOCAL);
46 }
47}
48
49static inline void ptep_ipte_global(struct mm_struct *mm, unsigned long addr,
50 pte_t *ptep, int nodat)
51{
52 unsigned long opt, asce;
53
54 if (MACHINE_HAS_TLB_GUEST) {
55 opt = 0;
56 asce = READ_ONCE(mm->context.gmap_asce);
57 if (asce == 0UL || nodat)
58 opt |= IPTE_NODAT;
59 if (asce != -1UL) {
60 asce = asce ? : mm->context.asce;
61 opt |= IPTE_GUEST_ASCE;
62 }
63 __ptep_ipte(addr, ptep, opt, asce, IPTE_GLOBAL);
64 } else {
65 __ptep_ipte(addr, ptep, 0, 0, IPTE_GLOBAL);
66 }
67}
68
69static inline pte_t ptep_flush_direct(struct mm_struct *mm,
70 unsigned long addr, pte_t *ptep,
71 int nodat)
72{
73 pte_t old;
74
75 old = *ptep;
76 if (unlikely(pte_val(old) & _PAGE_INVALID))
77 return old;
78 atomic_inc(&mm->context.flush_count);
79 if (MACHINE_HAS_TLB_LC &&
80 cpumask_equal(mm_cpumask(mm), cpumask_of(smp_processor_id())))
81 ptep_ipte_local(mm, addr, ptep, nodat);
82 else
83 ptep_ipte_global(mm, addr, ptep, nodat);
84 atomic_dec(&mm->context.flush_count);
85 return old;
86}
87
88static inline pte_t ptep_flush_lazy(struct mm_struct *mm,
89 unsigned long addr, pte_t *ptep,
90 int nodat)
91{
92 pte_t old;
93
94 old = *ptep;
95 if (unlikely(pte_val(old) & _PAGE_INVALID))
96 return old;
97 atomic_inc(&mm->context.flush_count);
98 if (cpumask_equal(&mm->context.cpu_attach_mask,
99 cpumask_of(smp_processor_id()))) {
100 pte_val(*ptep) |= _PAGE_INVALID;
101 mm->context.flush_mm = 1;
102 } else
103 ptep_ipte_global(mm, addr, ptep, nodat);
104 atomic_dec(&mm->context.flush_count);
105 return old;
106}
107
108static inline pgste_t pgste_get_lock(pte_t *ptep)
109{
110 unsigned long new = 0;
111#ifdef CONFIG_PGSTE
112 unsigned long old;
113
114 asm(
115 " lg %0,%2\n"
116 "0: lgr %1,%0\n"
117 " nihh %0,0xff7f\n" /* clear PCL bit in old */
118 " oihh %1,0x0080\n" /* set PCL bit in new */
119 " csg %0,%1,%2\n"
120 " jl 0b\n"
121 : "=&d" (old), "=&d" (new), "=Q" (ptep[PTRS_PER_PTE])
122 : "Q" (ptep[PTRS_PER_PTE]) : "cc", "memory");
123#endif
124 return __pgste(new);
125}
126
127static inline void pgste_set_unlock(pte_t *ptep, pgste_t pgste)
128{
129#ifdef CONFIG_PGSTE
130 asm(
131 " nihh %1,0xff7f\n" /* clear PCL bit */
132 " stg %1,%0\n"
133 : "=Q" (ptep[PTRS_PER_PTE])
134 : "d" (pgste_val(pgste)), "Q" (ptep[PTRS_PER_PTE])
135 : "cc", "memory");
136#endif
137}
138
139static inline pgste_t pgste_get(pte_t *ptep)
140{
141 unsigned long pgste = 0;
142#ifdef CONFIG_PGSTE
143 pgste = *(unsigned long *)(ptep + PTRS_PER_PTE);
144#endif
145 return __pgste(pgste);
146}
147
148static inline void pgste_set(pte_t *ptep, pgste_t pgste)
149{
150#ifdef CONFIG_PGSTE
151 *(pgste_t *)(ptep + PTRS_PER_PTE) = pgste;
152#endif
153}
154
155static inline pgste_t pgste_update_all(pte_t pte, pgste_t pgste,
156 struct mm_struct *mm)
157{
158#ifdef CONFIG_PGSTE
159 unsigned long address, bits, skey;
160
161 if (!mm_uses_skeys(mm) || pte_val(pte) & _PAGE_INVALID)
162 return pgste;
163 address = pte_val(pte) & PAGE_MASK;
164 skey = (unsigned long) page_get_storage_key(address);
165 bits = skey & (_PAGE_CHANGED | _PAGE_REFERENCED);
166 /* Transfer page changed & referenced bit to guest bits in pgste */
167 pgste_val(pgste) |= bits << 48; /* GR bit & GC bit */
168 /* Copy page access key and fetch protection bit to pgste */
169 pgste_val(pgste) &= ~(PGSTE_ACC_BITS | PGSTE_FP_BIT);
170 pgste_val(pgste) |= (skey & (_PAGE_ACC_BITS | _PAGE_FP_BIT)) << 56;
171#endif
172 return pgste;
173
174}
175
176static inline void pgste_set_key(pte_t *ptep, pgste_t pgste, pte_t entry,
177 struct mm_struct *mm)
178{
179#ifdef CONFIG_PGSTE
180 unsigned long address;
181 unsigned long nkey;
182
183 if (!mm_uses_skeys(mm) || pte_val(entry) & _PAGE_INVALID)
184 return;
185 VM_BUG_ON(!(pte_val(*ptep) & _PAGE_INVALID));
186 address = pte_val(entry) & PAGE_MASK;
187 /*
188 * Set page access key and fetch protection bit from pgste.
189 * The guest C/R information is still in the PGSTE, set real
190 * key C/R to 0.
191 */
192 nkey = (pgste_val(pgste) & (PGSTE_ACC_BITS | PGSTE_FP_BIT)) >> 56;
193 nkey |= (pgste_val(pgste) & (PGSTE_GR_BIT | PGSTE_GC_BIT)) >> 48;
194 page_set_storage_key(address, nkey, 0);
195#endif
196}
197
198static inline pgste_t pgste_set_pte(pte_t *ptep, pgste_t pgste, pte_t entry)
199{
200#ifdef CONFIG_PGSTE
201 if ((pte_val(entry) & _PAGE_PRESENT) &&
202 (pte_val(entry) & _PAGE_WRITE) &&
203 !(pte_val(entry) & _PAGE_INVALID)) {
204 if (!MACHINE_HAS_ESOP) {
205 /*
206 * Without enhanced suppression-on-protection force
207 * the dirty bit on for all writable ptes.
208 */
209 pte_val(entry) |= _PAGE_DIRTY;
210 pte_val(entry) &= ~_PAGE_PROTECT;
211 }
212 if (!(pte_val(entry) & _PAGE_PROTECT))
213 /* This pte allows write access, set user-dirty */
214 pgste_val(pgste) |= PGSTE_UC_BIT;
215 }
216#endif
217 *ptep = entry;
218 return pgste;
219}
220
221static inline pgste_t pgste_pte_notify(struct mm_struct *mm,
222 unsigned long addr,
223 pte_t *ptep, pgste_t pgste)
224{
225#ifdef CONFIG_PGSTE
226 unsigned long bits;
227
228 bits = pgste_val(pgste) & (PGSTE_IN_BIT | PGSTE_VSIE_BIT);
229 if (bits) {
230 pgste_val(pgste) ^= bits;
231 ptep_notify(mm, addr, ptep, bits);
232 }
233#endif
234 return pgste;
235}
236
237static inline pgste_t ptep_xchg_start(struct mm_struct *mm,
238 unsigned long addr, pte_t *ptep)
239{
240 pgste_t pgste = __pgste(0);
241
242 if (mm_has_pgste(mm)) {
243 pgste = pgste_get_lock(ptep);
244 pgste = pgste_pte_notify(mm, addr, ptep, pgste);
245 }
246 return pgste;
247}
248
249static inline pte_t ptep_xchg_commit(struct mm_struct *mm,
250 unsigned long addr, pte_t *ptep,
251 pgste_t pgste, pte_t old, pte_t new)
252{
253 if (mm_has_pgste(mm)) {
254 if (pte_val(old) & _PAGE_INVALID)
255 pgste_set_key(ptep, pgste, new, mm);
256 if (pte_val(new) & _PAGE_INVALID) {
257 pgste = pgste_update_all(old, pgste, mm);
258 if ((pgste_val(pgste) & _PGSTE_GPS_USAGE_MASK) ==
259 _PGSTE_GPS_USAGE_UNUSED)
260 pte_val(old) |= _PAGE_UNUSED;
261 }
262 pgste = pgste_set_pte(ptep, pgste, new);
263 pgste_set_unlock(ptep, pgste);
264 } else {
265 *ptep = new;
266 }
267 return old;
268}
269
270pte_t ptep_xchg_direct(struct mm_struct *mm, unsigned long addr,
271 pte_t *ptep, pte_t new)
272{
273 pgste_t pgste;
274 pte_t old;
275 int nodat;
276
277 preempt_disable();
278 pgste = ptep_xchg_start(mm, addr, ptep);
279 nodat = !!(pgste_val(pgste) & _PGSTE_GPS_NODAT);
280 old = ptep_flush_direct(mm, addr, ptep, nodat);
281 old = ptep_xchg_commit(mm, addr, ptep, pgste, old, new);
282 preempt_enable();
283 return old;
284}
285EXPORT_SYMBOL(ptep_xchg_direct);
286
287pte_t ptep_xchg_lazy(struct mm_struct *mm, unsigned long addr,
288 pte_t *ptep, pte_t new)
289{
290 pgste_t pgste;
291 pte_t old;
292 int nodat;
293
294 preempt_disable();
295 pgste = ptep_xchg_start(mm, addr, ptep);
296 nodat = !!(pgste_val(pgste) & _PGSTE_GPS_NODAT);
297 old = ptep_flush_lazy(mm, addr, ptep, nodat);
298 old = ptep_xchg_commit(mm, addr, ptep, pgste, old, new);
299 preempt_enable();
300 return old;
301}
302EXPORT_SYMBOL(ptep_xchg_lazy);
303
304pte_t ptep_modify_prot_start(struct vm_area_struct *vma, unsigned long addr,
305 pte_t *ptep)
306{
307 pgste_t pgste;
308 pte_t old;
309 int nodat;
310 struct mm_struct *mm = vma->vm_mm;
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 if (mm_has_pgste(mm)) {
317 pgste = pgste_update_all(old, pgste, mm);
318 pgste_set(ptep, pgste);
319 }
320 return old;
321}
322
323void ptep_modify_prot_commit(struct vm_area_struct *vma, unsigned long addr,
324 pte_t *ptep, pte_t old_pte, pte_t pte)
325{
326 pgste_t pgste;
327 struct mm_struct *mm = vma->vm_mm;
328
329 if (!MACHINE_HAS_NX)
330 pte_val(pte) &= ~_PAGE_NOEXEC;
331 if (mm_has_pgste(mm)) {
332 pgste = pgste_get(ptep);
333 pgste_set_key(ptep, pgste, pte, mm);
334 pgste = pgste_set_pte(ptep, pgste, pte);
335 pgste_set_unlock(ptep, pgste);
336 } else {
337 *ptep = pte;
338 }
339 preempt_enable();
340}
341
342static inline void pmdp_idte_local(struct mm_struct *mm,
343 unsigned long addr, pmd_t *pmdp)
344{
345 if (MACHINE_HAS_TLB_GUEST)
346 __pmdp_idte(addr, pmdp, IDTE_NODAT | IDTE_GUEST_ASCE,
347 mm->context.asce, IDTE_LOCAL);
348 else
349 __pmdp_idte(addr, pmdp, 0, 0, IDTE_LOCAL);
350 if (mm_has_pgste(mm) && mm->context.allow_gmap_hpage_1m)
351 gmap_pmdp_idte_local(mm, addr);
352}
353
354static inline void pmdp_idte_global(struct mm_struct *mm,
355 unsigned long addr, pmd_t *pmdp)
356{
357 if (MACHINE_HAS_TLB_GUEST) {
358 __pmdp_idte(addr, pmdp, IDTE_NODAT | IDTE_GUEST_ASCE,
359 mm->context.asce, IDTE_GLOBAL);
360 if (mm_has_pgste(mm) && mm->context.allow_gmap_hpage_1m)
361 gmap_pmdp_idte_global(mm, addr);
362 } else if (MACHINE_HAS_IDTE) {
363 __pmdp_idte(addr, pmdp, 0, 0, IDTE_GLOBAL);
364 if (mm_has_pgste(mm) && mm->context.allow_gmap_hpage_1m)
365 gmap_pmdp_idte_global(mm, addr);
366 } else {
367 __pmdp_csp(pmdp);
368 if (mm_has_pgste(mm) && mm->context.allow_gmap_hpage_1m)
369 gmap_pmdp_csp(mm, addr);
370 }
371}
372
373static inline pmd_t pmdp_flush_direct(struct mm_struct *mm,
374 unsigned long addr, pmd_t *pmdp)
375{
376 pmd_t old;
377
378 old = *pmdp;
379 if (pmd_val(old) & _SEGMENT_ENTRY_INVALID)
380 return old;
381 atomic_inc(&mm->context.flush_count);
382 if (MACHINE_HAS_TLB_LC &&
383 cpumask_equal(mm_cpumask(mm), cpumask_of(smp_processor_id())))
384 pmdp_idte_local(mm, addr, pmdp);
385 else
386 pmdp_idte_global(mm, addr, pmdp);
387 atomic_dec(&mm->context.flush_count);
388 return old;
389}
390
391static inline pmd_t pmdp_flush_lazy(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 (cpumask_equal(&mm->context.cpu_attach_mask,
401 cpumask_of(smp_processor_id()))) {
402 pmd_val(*pmdp) |= _SEGMENT_ENTRY_INVALID;
403 mm->context.flush_mm = 1;
404 if (mm_has_pgste(mm))
405 gmap_pmdp_invalidate(mm, addr);
406 } else {
407 pmdp_idte_global(mm, addr, pmdp);
408 }
409 atomic_dec(&mm->context.flush_count);
410 return old;
411}
412
413#ifdef CONFIG_PGSTE
414static pmd_t *pmd_alloc_map(struct mm_struct *mm, unsigned long addr)
415{
416 pgd_t *pgd;
417 p4d_t *p4d;
418 pud_t *pud;
419 pmd_t *pmd;
420
421 pgd = pgd_offset(mm, addr);
422 p4d = p4d_alloc(mm, pgd, addr);
423 if (!p4d)
424 return NULL;
425 pud = pud_alloc(mm, p4d, addr);
426 if (!pud)
427 return NULL;
428 pmd = pmd_alloc(mm, pud, addr);
429 return pmd;
430}
431#endif
432
433pmd_t pmdp_xchg_direct(struct mm_struct *mm, unsigned long addr,
434 pmd_t *pmdp, pmd_t new)
435{
436 pmd_t old;
437
438 preempt_disable();
439 old = pmdp_flush_direct(mm, addr, pmdp);
440 *pmdp = new;
441 preempt_enable();
442 return old;
443}
444EXPORT_SYMBOL(pmdp_xchg_direct);
445
446pmd_t pmdp_xchg_lazy(struct mm_struct *mm, unsigned long addr,
447 pmd_t *pmdp, pmd_t new)
448{
449 pmd_t old;
450
451 preempt_disable();
452 old = pmdp_flush_lazy(mm, addr, pmdp);
453 *pmdp = new;
454 preempt_enable();
455 return old;
456}
457EXPORT_SYMBOL(pmdp_xchg_lazy);
458
459static inline void pudp_idte_local(struct mm_struct *mm,
460 unsigned long addr, pud_t *pudp)
461{
462 if (MACHINE_HAS_TLB_GUEST)
463 __pudp_idte(addr, pudp, IDTE_NODAT | IDTE_GUEST_ASCE,
464 mm->context.asce, IDTE_LOCAL);
465 else
466 __pudp_idte(addr, pudp, 0, 0, IDTE_LOCAL);
467}
468
469static inline void pudp_idte_global(struct mm_struct *mm,
470 unsigned long addr, pud_t *pudp)
471{
472 if (MACHINE_HAS_TLB_GUEST)
473 __pudp_idte(addr, pudp, IDTE_NODAT | IDTE_GUEST_ASCE,
474 mm->context.asce, IDTE_GLOBAL);
475 else if (MACHINE_HAS_IDTE)
476 __pudp_idte(addr, pudp, 0, 0, IDTE_GLOBAL);
477 else
478 /*
479 * Invalid bit position is the same for pmd and pud, so we can
480 * re-use _pmd_csp() here
481 */
482 __pmdp_csp((pmd_t *) pudp);
483}
484
485static inline pud_t pudp_flush_direct(struct mm_struct *mm,
486 unsigned long addr, pud_t *pudp)
487{
488 pud_t old;
489
490 old = *pudp;
491 if (pud_val(old) & _REGION_ENTRY_INVALID)
492 return old;
493 atomic_inc(&mm->context.flush_count);
494 if (MACHINE_HAS_TLB_LC &&
495 cpumask_equal(mm_cpumask(mm), cpumask_of(smp_processor_id())))
496 pudp_idte_local(mm, addr, pudp);
497 else
498 pudp_idte_global(mm, addr, pudp);
499 atomic_dec(&mm->context.flush_count);
500 return old;
501}
502
503pud_t pudp_xchg_direct(struct mm_struct *mm, unsigned long addr,
504 pud_t *pudp, pud_t new)
505{
506 pud_t old;
507
508 preempt_disable();
509 old = pudp_flush_direct(mm, addr, pudp);
510 *pudp = new;
511 preempt_enable();
512 return old;
513}
514EXPORT_SYMBOL(pudp_xchg_direct);
515
516#ifdef CONFIG_TRANSPARENT_HUGEPAGE
517void pgtable_trans_huge_deposit(struct mm_struct *mm, pmd_t *pmdp,
518 pgtable_t pgtable)
519{
520 struct list_head *lh = (struct list_head *) pgtable;
521
522 assert_spin_locked(pmd_lockptr(mm, pmdp));
523
524 /* FIFO */
525 if (!pmd_huge_pte(mm, pmdp))
526 INIT_LIST_HEAD(lh);
527 else
528 list_add(lh, (struct list_head *) pmd_huge_pte(mm, pmdp));
529 pmd_huge_pte(mm, pmdp) = pgtable;
530}
531
532pgtable_t pgtable_trans_huge_withdraw(struct mm_struct *mm, pmd_t *pmdp)
533{
534 struct list_head *lh;
535 pgtable_t pgtable;
536 pte_t *ptep;
537
538 assert_spin_locked(pmd_lockptr(mm, pmdp));
539
540 /* FIFO */
541 pgtable = pmd_huge_pte(mm, pmdp);
542 lh = (struct list_head *) pgtable;
543 if (list_empty(lh))
544 pmd_huge_pte(mm, pmdp) = NULL;
545 else {
546 pmd_huge_pte(mm, pmdp) = (pgtable_t) lh->next;
547 list_del(lh);
548 }
549 ptep = (pte_t *) pgtable;
550 pte_val(*ptep) = _PAGE_INVALID;
551 ptep++;
552 pte_val(*ptep) = _PAGE_INVALID;
553 return pgtable;
554}
555#endif /* CONFIG_TRANSPARENT_HUGEPAGE */
556
557#ifdef CONFIG_PGSTE
558void ptep_set_pte_at(struct mm_struct *mm, unsigned long addr,
559 pte_t *ptep, pte_t entry)
560{
561 pgste_t pgste;
562
563 /* the mm_has_pgste() check is done in set_pte_at() */
564 preempt_disable();
565 pgste = pgste_get_lock(ptep);
566 pgste_val(pgste) &= ~_PGSTE_GPS_ZERO;
567 pgste_set_key(ptep, pgste, entry, mm);
568 pgste = pgste_set_pte(ptep, pgste, entry);
569 pgste_set_unlock(ptep, pgste);
570 preempt_enable();
571}
572
573void ptep_set_notify(struct mm_struct *mm, unsigned long addr, pte_t *ptep)
574{
575 pgste_t pgste;
576
577 preempt_disable();
578 pgste = pgste_get_lock(ptep);
579 pgste_val(pgste) |= PGSTE_IN_BIT;
580 pgste_set_unlock(ptep, pgste);
581 preempt_enable();
582}
583
584/**
585 * ptep_force_prot - change access rights of a locked pte
586 * @mm: pointer to the process mm_struct
587 * @addr: virtual address in the guest address space
588 * @ptep: pointer to the page table entry
589 * @prot: indicates guest access rights: PROT_NONE, PROT_READ or PROT_WRITE
590 * @bit: pgste bit to set (e.g. for notification)
591 *
592 * Returns 0 if the access rights were changed and -EAGAIN if the current
593 * and requested access rights are incompatible.
594 */
595int ptep_force_prot(struct mm_struct *mm, unsigned long addr,
596 pte_t *ptep, int prot, unsigned long bit)
597{
598 pte_t entry;
599 pgste_t pgste;
600 int pte_i, pte_p, nodat;
601
602 pgste = pgste_get_lock(ptep);
603 entry = *ptep;
604 /* Check pte entry after all locks have been acquired */
605 pte_i = pte_val(entry) & _PAGE_INVALID;
606 pte_p = pte_val(entry) & _PAGE_PROTECT;
607 if ((pte_i && (prot != PROT_NONE)) ||
608 (pte_p && (prot & PROT_WRITE))) {
609 pgste_set_unlock(ptep, pgste);
610 return -EAGAIN;
611 }
612 /* Change access rights and set pgste bit */
613 nodat = !!(pgste_val(pgste) & _PGSTE_GPS_NODAT);
614 if (prot == PROT_NONE && !pte_i) {
615 ptep_flush_direct(mm, addr, ptep, nodat);
616 pgste = pgste_update_all(entry, pgste, mm);
617 pte_val(entry) |= _PAGE_INVALID;
618 }
619 if (prot == PROT_READ && !pte_p) {
620 ptep_flush_direct(mm, addr, ptep, nodat);
621 pte_val(entry) &= ~_PAGE_INVALID;
622 pte_val(entry) |= _PAGE_PROTECT;
623 }
624 pgste_val(pgste) |= bit;
625 pgste = pgste_set_pte(ptep, pgste, entry);
626 pgste_set_unlock(ptep, pgste);
627 return 0;
628}
629
630int ptep_shadow_pte(struct mm_struct *mm, unsigned long saddr,
631 pte_t *sptep, pte_t *tptep, pte_t pte)
632{
633 pgste_t spgste, tpgste;
634 pte_t spte, tpte;
635 int rc = -EAGAIN;
636
637 if (!(pte_val(*tptep) & _PAGE_INVALID))
638 return 0; /* already shadowed */
639 spgste = pgste_get_lock(sptep);
640 spte = *sptep;
641 if (!(pte_val(spte) & _PAGE_INVALID) &&
642 !((pte_val(spte) & _PAGE_PROTECT) &&
643 !(pte_val(pte) & _PAGE_PROTECT))) {
644 pgste_val(spgste) |= PGSTE_VSIE_BIT;
645 tpgste = pgste_get_lock(tptep);
646 pte_val(tpte) = (pte_val(spte) & PAGE_MASK) |
647 (pte_val(pte) & _PAGE_PROTECT);
648 /* don't touch the storage key - it belongs to parent pgste */
649 tpgste = pgste_set_pte(tptep, tpgste, tpte);
650 pgste_set_unlock(tptep, tpgste);
651 rc = 1;
652 }
653 pgste_set_unlock(sptep, spgste);
654 return rc;
655}
656
657void ptep_unshadow_pte(struct mm_struct *mm, unsigned long saddr, pte_t *ptep)
658{
659 pgste_t pgste;
660 int nodat;
661
662 pgste = pgste_get_lock(ptep);
663 /* notifier is called by the caller */
664 nodat = !!(pgste_val(pgste) & _PGSTE_GPS_NODAT);
665 ptep_flush_direct(mm, saddr, ptep, nodat);
666 /* don't touch the storage key - it belongs to parent pgste */
667 pgste = pgste_set_pte(ptep, pgste, __pte(_PAGE_INVALID));
668 pgste_set_unlock(ptep, pgste);
669}
670
671static void ptep_zap_swap_entry(struct mm_struct *mm, swp_entry_t entry)
672{
673 if (!non_swap_entry(entry))
674 dec_mm_counter(mm, MM_SWAPENTS);
675 else if (is_migration_entry(entry)) {
676 struct page *page = migration_entry_to_page(entry);
677
678 dec_mm_counter(mm, mm_counter(page));
679 }
680 free_swap_and_cache(entry);
681}
682
683void ptep_zap_unused(struct mm_struct *mm, unsigned long addr,
684 pte_t *ptep, int reset)
685{
686 unsigned long pgstev;
687 pgste_t pgste;
688 pte_t pte;
689
690 /* Zap unused and logically-zero pages */
691 preempt_disable();
692 pgste = pgste_get_lock(ptep);
693 pgstev = pgste_val(pgste);
694 pte = *ptep;
695 if (!reset && pte_swap(pte) &&
696 ((pgstev & _PGSTE_GPS_USAGE_MASK) == _PGSTE_GPS_USAGE_UNUSED ||
697 (pgstev & _PGSTE_GPS_ZERO))) {
698 ptep_zap_swap_entry(mm, pte_to_swp_entry(pte));
699 pte_clear(mm, addr, ptep);
700 }
701 if (reset)
702 pgste_val(pgste) &= ~_PGSTE_GPS_USAGE_MASK;
703 pgste_set_unlock(ptep, pgste);
704 preempt_enable();
705}
706
707void ptep_zap_key(struct mm_struct *mm, unsigned long addr, pte_t *ptep)
708{
709 unsigned long ptev;
710 pgste_t pgste;
711
712 /* Clear storage key ACC and F, but set R/C */
713 preempt_disable();
714 pgste = pgste_get_lock(ptep);
715 pgste_val(pgste) &= ~(PGSTE_ACC_BITS | PGSTE_FP_BIT);
716 pgste_val(pgste) |= PGSTE_GR_BIT | PGSTE_GC_BIT;
717 ptev = pte_val(*ptep);
718 if (!(ptev & _PAGE_INVALID) && (ptev & _PAGE_WRITE))
719 page_set_storage_key(ptev & PAGE_MASK, PAGE_DEFAULT_KEY, 1);
720 pgste_set_unlock(ptep, pgste);
721 preempt_enable();
722}
723
724/*
725 * Test and reset if a guest page is dirty
726 */
727bool ptep_test_and_clear_uc(struct mm_struct *mm, unsigned long addr,
728 pte_t *ptep)
729{
730 pgste_t pgste;
731 pte_t pte;
732 bool dirty;
733 int nodat;
734
735 pgste = pgste_get_lock(ptep);
736 dirty = !!(pgste_val(pgste) & PGSTE_UC_BIT);
737 pgste_val(pgste) &= ~PGSTE_UC_BIT;
738 pte = *ptep;
739 if (dirty && (pte_val(pte) & _PAGE_PRESENT)) {
740 pgste = pgste_pte_notify(mm, addr, ptep, pgste);
741 nodat = !!(pgste_val(pgste) & _PGSTE_GPS_NODAT);
742 ptep_ipte_global(mm, addr, ptep, nodat);
743 if (MACHINE_HAS_ESOP || !(pte_val(pte) & _PAGE_WRITE))
744 pte_val(pte) |= _PAGE_PROTECT;
745 else
746 pte_val(pte) |= _PAGE_INVALID;
747 *ptep = pte;
748 }
749 pgste_set_unlock(ptep, pgste);
750 return dirty;
751}
752EXPORT_SYMBOL_GPL(ptep_test_and_clear_uc);
753
754int set_guest_storage_key(struct mm_struct *mm, unsigned long addr,
755 unsigned char key, bool nq)
756{
757 unsigned long keyul, paddr;
758 spinlock_t *ptl;
759 pgste_t old, new;
760 pmd_t *pmdp;
761 pte_t *ptep;
762
763 pmdp = pmd_alloc_map(mm, addr);
764 if (unlikely(!pmdp))
765 return -EFAULT;
766
767 ptl = pmd_lock(mm, pmdp);
768 if (!pmd_present(*pmdp)) {
769 spin_unlock(ptl);
770 return -EFAULT;
771 }
772
773 if (pmd_large(*pmdp)) {
774 paddr = pmd_val(*pmdp) & HPAGE_MASK;
775 paddr |= addr & ~HPAGE_MASK;
776 /*
777 * Huge pmds need quiescing operations, they are
778 * always mapped.
779 */
780 page_set_storage_key(paddr, key, 1);
781 spin_unlock(ptl);
782 return 0;
783 }
784 spin_unlock(ptl);
785
786 ptep = pte_alloc_map_lock(mm, pmdp, addr, &ptl);
787 if (unlikely(!ptep))
788 return -EFAULT;
789
790 new = old = pgste_get_lock(ptep);
791 pgste_val(new) &= ~(PGSTE_GR_BIT | PGSTE_GC_BIT |
792 PGSTE_ACC_BITS | PGSTE_FP_BIT);
793 keyul = (unsigned long) key;
794 pgste_val(new) |= (keyul & (_PAGE_CHANGED | _PAGE_REFERENCED)) << 48;
795 pgste_val(new) |= (keyul & (_PAGE_ACC_BITS | _PAGE_FP_BIT)) << 56;
796 if (!(pte_val(*ptep) & _PAGE_INVALID)) {
797 unsigned long bits, skey;
798
799 paddr = pte_val(*ptep) & PAGE_MASK;
800 skey = (unsigned long) page_get_storage_key(paddr);
801 bits = skey & (_PAGE_CHANGED | _PAGE_REFERENCED);
802 skey = key & (_PAGE_ACC_BITS | _PAGE_FP_BIT);
803 /* Set storage key ACC and FP */
804 page_set_storage_key(paddr, skey, !nq);
805 /* Merge host changed & referenced into pgste */
806 pgste_val(new) |= bits << 52;
807 }
808 /* changing the guest storage key is considered a change of the page */
809 if ((pgste_val(new) ^ pgste_val(old)) &
810 (PGSTE_ACC_BITS | PGSTE_FP_BIT | PGSTE_GR_BIT | PGSTE_GC_BIT))
811 pgste_val(new) |= PGSTE_UC_BIT;
812
813 pgste_set_unlock(ptep, new);
814 pte_unmap_unlock(ptep, ptl);
815 return 0;
816}
817EXPORT_SYMBOL(set_guest_storage_key);
818
819/**
820 * Conditionally set a guest storage key (handling csske).
821 * oldkey will be updated when either mr or mc is set and a pointer is given.
822 *
823 * Returns 0 if a guests storage key update wasn't necessary, 1 if the guest
824 * storage key was updated and -EFAULT on access errors.
825 */
826int cond_set_guest_storage_key(struct mm_struct *mm, unsigned long addr,
827 unsigned char key, unsigned char *oldkey,
828 bool nq, bool mr, bool mc)
829{
830 unsigned char tmp, mask = _PAGE_ACC_BITS | _PAGE_FP_BIT;
831 int rc;
832
833 /* we can drop the pgste lock between getting and setting the key */
834 if (mr | mc) {
835 rc = get_guest_storage_key(current->mm, addr, &tmp);
836 if (rc)
837 return rc;
838 if (oldkey)
839 *oldkey = tmp;
840 if (!mr)
841 mask |= _PAGE_REFERENCED;
842 if (!mc)
843 mask |= _PAGE_CHANGED;
844 if (!((tmp ^ key) & mask))
845 return 0;
846 }
847 rc = set_guest_storage_key(current->mm, addr, key, nq);
848 return rc < 0 ? rc : 1;
849}
850EXPORT_SYMBOL(cond_set_guest_storage_key);
851
852/**
853 * Reset a guest reference bit (rrbe), returning the reference and changed bit.
854 *
855 * Returns < 0 in case of error, otherwise the cc to be reported to the guest.
856 */
857int reset_guest_reference_bit(struct mm_struct *mm, unsigned long addr)
858{
859 spinlock_t *ptl;
860 unsigned long paddr;
861 pgste_t old, new;
862 pmd_t *pmdp;
863 pte_t *ptep;
864 int cc = 0;
865
866 pmdp = pmd_alloc_map(mm, addr);
867 if (unlikely(!pmdp))
868 return -EFAULT;
869
870 ptl = pmd_lock(mm, pmdp);
871 if (!pmd_present(*pmdp)) {
872 spin_unlock(ptl);
873 return -EFAULT;
874 }
875
876 if (pmd_large(*pmdp)) {
877 paddr = pmd_val(*pmdp) & HPAGE_MASK;
878 paddr |= addr & ~HPAGE_MASK;
879 cc = page_reset_referenced(paddr);
880 spin_unlock(ptl);
881 return cc;
882 }
883 spin_unlock(ptl);
884
885 ptep = pte_alloc_map_lock(mm, pmdp, addr, &ptl);
886 if (unlikely(!ptep))
887 return -EFAULT;
888
889 new = old = pgste_get_lock(ptep);
890 /* Reset guest reference bit only */
891 pgste_val(new) &= ~PGSTE_GR_BIT;
892
893 if (!(pte_val(*ptep) & _PAGE_INVALID)) {
894 paddr = pte_val(*ptep) & PAGE_MASK;
895 cc = page_reset_referenced(paddr);
896 /* Merge real referenced bit into host-set */
897 pgste_val(new) |= ((unsigned long) cc << 53) & PGSTE_HR_BIT;
898 }
899 /* Reflect guest's logical view, not physical */
900 cc |= (pgste_val(old) & (PGSTE_GR_BIT | PGSTE_GC_BIT)) >> 49;
901 /* Changing the guest storage key is considered a change of the page */
902 if ((pgste_val(new) ^ pgste_val(old)) & PGSTE_GR_BIT)
903 pgste_val(new) |= PGSTE_UC_BIT;
904
905 pgste_set_unlock(ptep, new);
906 pte_unmap_unlock(ptep, ptl);
907 return cc;
908}
909EXPORT_SYMBOL(reset_guest_reference_bit);
910
911int get_guest_storage_key(struct mm_struct *mm, unsigned long addr,
912 unsigned char *key)
913{
914 unsigned long paddr;
915 spinlock_t *ptl;
916 pgste_t pgste;
917 pmd_t *pmdp;
918 pte_t *ptep;
919
920 pmdp = pmd_alloc_map(mm, addr);
921 if (unlikely(!pmdp))
922 return -EFAULT;
923
924 ptl = pmd_lock(mm, pmdp);
925 if (!pmd_present(*pmdp)) {
926 /* Not yet mapped memory has a zero key */
927 spin_unlock(ptl);
928 *key = 0;
929 return 0;
930 }
931
932 if (pmd_large(*pmdp)) {
933 paddr = pmd_val(*pmdp) & HPAGE_MASK;
934 paddr |= addr & ~HPAGE_MASK;
935 *key = page_get_storage_key(paddr);
936 spin_unlock(ptl);
937 return 0;
938 }
939 spin_unlock(ptl);
940
941 ptep = pte_alloc_map_lock(mm, pmdp, addr, &ptl);
942 if (unlikely(!ptep))
943 return -EFAULT;
944
945 pgste = pgste_get_lock(ptep);
946 *key = (pgste_val(pgste) & (PGSTE_ACC_BITS | PGSTE_FP_BIT)) >> 56;
947 paddr = pte_val(*ptep) & PAGE_MASK;
948 if (!(pte_val(*ptep) & _PAGE_INVALID))
949 *key = page_get_storage_key(paddr);
950 /* Reflect guest's logical view, not physical */
951 *key |= (pgste_val(pgste) & (PGSTE_GR_BIT | PGSTE_GC_BIT)) >> 48;
952 pgste_set_unlock(ptep, pgste);
953 pte_unmap_unlock(ptep, ptl);
954 return 0;
955}
956EXPORT_SYMBOL(get_guest_storage_key);
957
958/**
959 * pgste_perform_essa - perform ESSA actions on the PGSTE.
960 * @mm: the memory context. It must have PGSTEs, no check is performed here!
961 * @hva: the host virtual address of the page whose PGSTE is to be processed
962 * @orc: the specific action to perform, see the ESSA_SET_* macros.
963 * @oldpte: the PTE will be saved there if the pointer is not NULL.
964 * @oldpgste: the old PGSTE will be saved there if the pointer is not NULL.
965 *
966 * Return: 1 if the page is to be added to the CBRL, otherwise 0,
967 * or < 0 in case of error. -EINVAL is returned for invalid values
968 * of orc, -EFAULT for invalid addresses.
969 */
970int pgste_perform_essa(struct mm_struct *mm, unsigned long hva, int orc,
971 unsigned long *oldpte, unsigned long *oldpgste)
972{
973 unsigned long pgstev;
974 spinlock_t *ptl;
975 pgste_t pgste;
976 pte_t *ptep;
977 int res = 0;
978
979 WARN_ON_ONCE(orc > ESSA_MAX);
980 if (unlikely(orc > ESSA_MAX))
981 return -EINVAL;
982 ptep = get_locked_pte(mm, hva, &ptl);
983 if (unlikely(!ptep))
984 return -EFAULT;
985 pgste = pgste_get_lock(ptep);
986 pgstev = pgste_val(pgste);
987 if (oldpte)
988 *oldpte = pte_val(*ptep);
989 if (oldpgste)
990 *oldpgste = pgstev;
991
992 switch (orc) {
993 case ESSA_GET_STATE:
994 break;
995 case ESSA_SET_STABLE:
996 pgstev &= ~(_PGSTE_GPS_USAGE_MASK | _PGSTE_GPS_NODAT);
997 pgstev |= _PGSTE_GPS_USAGE_STABLE;
998 break;
999 case ESSA_SET_UNUSED:
1000 pgstev &= ~_PGSTE_GPS_USAGE_MASK;
1001 pgstev |= _PGSTE_GPS_USAGE_UNUSED;
1002 if (pte_val(*ptep) & _PAGE_INVALID)
1003 res = 1;
1004 break;
1005 case ESSA_SET_VOLATILE:
1006 pgstev &= ~_PGSTE_GPS_USAGE_MASK;
1007 pgstev |= _PGSTE_GPS_USAGE_VOLATILE;
1008 if (pte_val(*ptep) & _PAGE_INVALID)
1009 res = 1;
1010 break;
1011 case ESSA_SET_POT_VOLATILE:
1012 pgstev &= ~_PGSTE_GPS_USAGE_MASK;
1013 if (!(pte_val(*ptep) & _PAGE_INVALID)) {
1014 pgstev |= _PGSTE_GPS_USAGE_POT_VOLATILE;
1015 break;
1016 }
1017 if (pgstev & _PGSTE_GPS_ZERO) {
1018 pgstev |= _PGSTE_GPS_USAGE_VOLATILE;
1019 break;
1020 }
1021 if (!(pgstev & PGSTE_GC_BIT)) {
1022 pgstev |= _PGSTE_GPS_USAGE_VOLATILE;
1023 res = 1;
1024 break;
1025 }
1026 break;
1027 case ESSA_SET_STABLE_RESIDENT:
1028 pgstev &= ~_PGSTE_GPS_USAGE_MASK;
1029 pgstev |= _PGSTE_GPS_USAGE_STABLE;
1030 /*
1031 * Since the resident state can go away any time after this
1032 * call, we will not make this page resident. We can revisit
1033 * this decision if a guest will ever start using this.
1034 */
1035 break;
1036 case ESSA_SET_STABLE_IF_RESIDENT:
1037 if (!(pte_val(*ptep) & _PAGE_INVALID)) {
1038 pgstev &= ~_PGSTE_GPS_USAGE_MASK;
1039 pgstev |= _PGSTE_GPS_USAGE_STABLE;
1040 }
1041 break;
1042 case ESSA_SET_STABLE_NODAT:
1043 pgstev &= ~_PGSTE_GPS_USAGE_MASK;
1044 pgstev |= _PGSTE_GPS_USAGE_STABLE | _PGSTE_GPS_NODAT;
1045 break;
1046 default:
1047 /* we should never get here! */
1048 break;
1049 }
1050 /* If we are discarding a page, set it to logical zero */
1051 if (res)
1052 pgstev |= _PGSTE_GPS_ZERO;
1053
1054 pgste_val(pgste) = pgstev;
1055 pgste_set_unlock(ptep, pgste);
1056 pte_unmap_unlock(ptep, ptl);
1057 return res;
1058}
1059EXPORT_SYMBOL(pgste_perform_essa);
1060
1061/**
1062 * set_pgste_bits - set specific PGSTE bits.
1063 * @mm: the memory context. It must have PGSTEs, no check is performed here!
1064 * @hva: the host virtual address of the page whose PGSTE is to be processed
1065 * @bits: a bitmask representing the bits that will be touched
1066 * @value: the values of the bits to be written. Only the bits in the mask
1067 * will be written.
1068 *
1069 * Return: 0 on success, < 0 in case of error.
1070 */
1071int set_pgste_bits(struct mm_struct *mm, unsigned long hva,
1072 unsigned long bits, unsigned long value)
1073{
1074 spinlock_t *ptl;
1075 pgste_t new;
1076 pte_t *ptep;
1077
1078 ptep = get_locked_pte(mm, hva, &ptl);
1079 if (unlikely(!ptep))
1080 return -EFAULT;
1081 new = pgste_get_lock(ptep);
1082
1083 pgste_val(new) &= ~bits;
1084 pgste_val(new) |= value & bits;
1085
1086 pgste_set_unlock(ptep, new);
1087 pte_unmap_unlock(ptep, ptl);
1088 return 0;
1089}
1090EXPORT_SYMBOL(set_pgste_bits);
1091
1092/**
1093 * get_pgste - get the current PGSTE for the given address.
1094 * @mm: the memory context. It must have PGSTEs, no check is performed here!
1095 * @hva: the host virtual address of the page whose PGSTE is to be processed
1096 * @pgstep: will be written with the current PGSTE for the given address.
1097 *
1098 * Return: 0 on success, < 0 in case of error.
1099 */
1100int get_pgste(struct mm_struct *mm, unsigned long hva, unsigned long *pgstep)
1101{
1102 spinlock_t *ptl;
1103 pte_t *ptep;
1104
1105 ptep = get_locked_pte(mm, hva, &ptl);
1106 if (unlikely(!ptep))
1107 return -EFAULT;
1108 *pgstep = pgste_val(pgste_get(ptep));
1109 pte_unmap_unlock(ptep, ptl);
1110 return 0;
1111}
1112EXPORT_SYMBOL(get_pgste);
1113#endif
1/*
2 * Copyright IBM Corp. 2007, 2011
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/spinlock.h>
14#include <linux/rcupdate.h>
15#include <linux/slab.h>
16#include <linux/swapops.h>
17#include <linux/sysctl.h>
18#include <linux/ksm.h>
19#include <linux/mman.h>
20
21#include <asm/pgtable.h>
22#include <asm/pgalloc.h>
23#include <asm/tlb.h>
24#include <asm/tlbflush.h>
25#include <asm/mmu_context.h>
26
27static inline pte_t ptep_flush_direct(struct mm_struct *mm,
28 unsigned long addr, pte_t *ptep)
29{
30 int active, count;
31 pte_t old;
32
33 old = *ptep;
34 if (unlikely(pte_val(old) & _PAGE_INVALID))
35 return old;
36 active = (mm == current->active_mm) ? 1 : 0;
37 count = atomic_add_return(0x10000, &mm->context.attach_count);
38 if (MACHINE_HAS_TLB_LC && (count & 0xffff) <= active &&
39 cpumask_equal(mm_cpumask(mm), cpumask_of(smp_processor_id())))
40 __ptep_ipte_local(addr, ptep);
41 else
42 __ptep_ipte(addr, ptep);
43 atomic_sub(0x10000, &mm->context.attach_count);
44 return old;
45}
46
47static inline pte_t ptep_flush_lazy(struct mm_struct *mm,
48 unsigned long addr, pte_t *ptep)
49{
50 int active, count;
51 pte_t old;
52
53 old = *ptep;
54 if (unlikely(pte_val(old) & _PAGE_INVALID))
55 return old;
56 active = (mm == current->active_mm) ? 1 : 0;
57 count = atomic_add_return(0x10000, &mm->context.attach_count);
58 if ((count & 0xffff) <= active) {
59 pte_val(*ptep) |= _PAGE_INVALID;
60 mm->context.flush_mm = 1;
61 } else
62 __ptep_ipte(addr, ptep);
63 atomic_sub(0x10000, &mm->context.attach_count);
64 return old;
65}
66
67static inline pgste_t pgste_get_lock(pte_t *ptep)
68{
69 unsigned long new = 0;
70#ifdef CONFIG_PGSTE
71 unsigned long old;
72
73 preempt_disable();
74 asm(
75 " lg %0,%2\n"
76 "0: lgr %1,%0\n"
77 " nihh %0,0xff7f\n" /* clear PCL bit in old */
78 " oihh %1,0x0080\n" /* set PCL bit in new */
79 " csg %0,%1,%2\n"
80 " jl 0b\n"
81 : "=&d" (old), "=&d" (new), "=Q" (ptep[PTRS_PER_PTE])
82 : "Q" (ptep[PTRS_PER_PTE]) : "cc", "memory");
83#endif
84 return __pgste(new);
85}
86
87static inline void pgste_set_unlock(pte_t *ptep, pgste_t pgste)
88{
89#ifdef CONFIG_PGSTE
90 asm(
91 " nihh %1,0xff7f\n" /* clear PCL bit */
92 " stg %1,%0\n"
93 : "=Q" (ptep[PTRS_PER_PTE])
94 : "d" (pgste_val(pgste)), "Q" (ptep[PTRS_PER_PTE])
95 : "cc", "memory");
96 preempt_enable();
97#endif
98}
99
100static inline pgste_t pgste_get(pte_t *ptep)
101{
102 unsigned long pgste = 0;
103#ifdef CONFIG_PGSTE
104 pgste = *(unsigned long *)(ptep + PTRS_PER_PTE);
105#endif
106 return __pgste(pgste);
107}
108
109static inline void pgste_set(pte_t *ptep, pgste_t pgste)
110{
111#ifdef CONFIG_PGSTE
112 *(pgste_t *)(ptep + PTRS_PER_PTE) = pgste;
113#endif
114}
115
116static inline pgste_t pgste_update_all(pte_t pte, pgste_t pgste,
117 struct mm_struct *mm)
118{
119#ifdef CONFIG_PGSTE
120 unsigned long address, bits, skey;
121
122 if (!mm_use_skey(mm) || pte_val(pte) & _PAGE_INVALID)
123 return pgste;
124 address = pte_val(pte) & PAGE_MASK;
125 skey = (unsigned long) page_get_storage_key(address);
126 bits = skey & (_PAGE_CHANGED | _PAGE_REFERENCED);
127 /* Transfer page changed & referenced bit to guest bits in pgste */
128 pgste_val(pgste) |= bits << 48; /* GR bit & GC bit */
129 /* Copy page access key and fetch protection bit to pgste */
130 pgste_val(pgste) &= ~(PGSTE_ACC_BITS | PGSTE_FP_BIT);
131 pgste_val(pgste) |= (skey & (_PAGE_ACC_BITS | _PAGE_FP_BIT)) << 56;
132#endif
133 return pgste;
134
135}
136
137static inline void pgste_set_key(pte_t *ptep, pgste_t pgste, pte_t entry,
138 struct mm_struct *mm)
139{
140#ifdef CONFIG_PGSTE
141 unsigned long address;
142 unsigned long nkey;
143
144 if (!mm_use_skey(mm) || pte_val(entry) & _PAGE_INVALID)
145 return;
146 VM_BUG_ON(!(pte_val(*ptep) & _PAGE_INVALID));
147 address = pte_val(entry) & PAGE_MASK;
148 /*
149 * Set page access key and fetch protection bit from pgste.
150 * The guest C/R information is still in the PGSTE, set real
151 * key C/R to 0.
152 */
153 nkey = (pgste_val(pgste) & (PGSTE_ACC_BITS | PGSTE_FP_BIT)) >> 56;
154 nkey |= (pgste_val(pgste) & (PGSTE_GR_BIT | PGSTE_GC_BIT)) >> 48;
155 page_set_storage_key(address, nkey, 0);
156#endif
157}
158
159static inline pgste_t pgste_set_pte(pte_t *ptep, pgste_t pgste, pte_t entry)
160{
161#ifdef CONFIG_PGSTE
162 if ((pte_val(entry) & _PAGE_PRESENT) &&
163 (pte_val(entry) & _PAGE_WRITE) &&
164 !(pte_val(entry) & _PAGE_INVALID)) {
165 if (!MACHINE_HAS_ESOP) {
166 /*
167 * Without enhanced suppression-on-protection force
168 * the dirty bit on for all writable ptes.
169 */
170 pte_val(entry) |= _PAGE_DIRTY;
171 pte_val(entry) &= ~_PAGE_PROTECT;
172 }
173 if (!(pte_val(entry) & _PAGE_PROTECT))
174 /* This pte allows write access, set user-dirty */
175 pgste_val(pgste) |= PGSTE_UC_BIT;
176 }
177#endif
178 *ptep = entry;
179 return pgste;
180}
181
182static inline pgste_t pgste_ipte_notify(struct mm_struct *mm,
183 unsigned long addr,
184 pte_t *ptep, pgste_t pgste)
185{
186#ifdef CONFIG_PGSTE
187 if (pgste_val(pgste) & PGSTE_IN_BIT) {
188 pgste_val(pgste) &= ~PGSTE_IN_BIT;
189 ptep_notify(mm, addr, ptep);
190 }
191#endif
192 return pgste;
193}
194
195static inline pgste_t ptep_xchg_start(struct mm_struct *mm,
196 unsigned long addr, pte_t *ptep)
197{
198 pgste_t pgste = __pgste(0);
199
200 if (mm_has_pgste(mm)) {
201 pgste = pgste_get_lock(ptep);
202 pgste = pgste_ipte_notify(mm, addr, ptep, pgste);
203 }
204 return pgste;
205}
206
207static inline void ptep_xchg_commit(struct mm_struct *mm,
208 unsigned long addr, pte_t *ptep,
209 pgste_t pgste, pte_t old, pte_t new)
210{
211 if (mm_has_pgste(mm)) {
212 if (pte_val(old) & _PAGE_INVALID)
213 pgste_set_key(ptep, pgste, new, mm);
214 if (pte_val(new) & _PAGE_INVALID) {
215 pgste = pgste_update_all(old, pgste, mm);
216 if ((pgste_val(pgste) & _PGSTE_GPS_USAGE_MASK) ==
217 _PGSTE_GPS_USAGE_UNUSED)
218 pte_val(old) |= _PAGE_UNUSED;
219 }
220 pgste = pgste_set_pte(ptep, pgste, new);
221 pgste_set_unlock(ptep, pgste);
222 } else {
223 *ptep = new;
224 }
225}
226
227pte_t ptep_xchg_direct(struct mm_struct *mm, unsigned long addr,
228 pte_t *ptep, pte_t new)
229{
230 pgste_t pgste;
231 pte_t old;
232
233 pgste = ptep_xchg_start(mm, addr, ptep);
234 old = ptep_flush_direct(mm, addr, ptep);
235 ptep_xchg_commit(mm, addr, ptep, pgste, old, new);
236 return old;
237}
238EXPORT_SYMBOL(ptep_xchg_direct);
239
240pte_t ptep_xchg_lazy(struct mm_struct *mm, unsigned long addr,
241 pte_t *ptep, pte_t new)
242{
243 pgste_t pgste;
244 pte_t old;
245
246 pgste = ptep_xchg_start(mm, addr, ptep);
247 old = ptep_flush_lazy(mm, addr, ptep);
248 ptep_xchg_commit(mm, addr, ptep, pgste, old, new);
249 return old;
250}
251EXPORT_SYMBOL(ptep_xchg_lazy);
252
253pte_t ptep_modify_prot_start(struct mm_struct *mm, unsigned long addr,
254 pte_t *ptep)
255{
256 pgste_t pgste;
257 pte_t old;
258
259 pgste = ptep_xchg_start(mm, addr, ptep);
260 old = ptep_flush_lazy(mm, addr, ptep);
261 if (mm_has_pgste(mm)) {
262 pgste = pgste_update_all(old, pgste, mm);
263 pgste_set(ptep, pgste);
264 }
265 return old;
266}
267EXPORT_SYMBOL(ptep_modify_prot_start);
268
269void ptep_modify_prot_commit(struct mm_struct *mm, unsigned long addr,
270 pte_t *ptep, pte_t pte)
271{
272 pgste_t pgste;
273
274 if (mm_has_pgste(mm)) {
275 pgste = pgste_get(ptep);
276 pgste_set_key(ptep, pgste, pte, mm);
277 pgste = pgste_set_pte(ptep, pgste, pte);
278 pgste_set_unlock(ptep, pgste);
279 } else {
280 *ptep = pte;
281 }
282}
283EXPORT_SYMBOL(ptep_modify_prot_commit);
284
285static inline pmd_t pmdp_flush_direct(struct mm_struct *mm,
286 unsigned long addr, pmd_t *pmdp)
287{
288 int active, count;
289 pmd_t old;
290
291 old = *pmdp;
292 if (pmd_val(old) & _SEGMENT_ENTRY_INVALID)
293 return old;
294 if (!MACHINE_HAS_IDTE) {
295 __pmdp_csp(pmdp);
296 return old;
297 }
298 active = (mm == current->active_mm) ? 1 : 0;
299 count = atomic_add_return(0x10000, &mm->context.attach_count);
300 if (MACHINE_HAS_TLB_LC && (count & 0xffff) <= active &&
301 cpumask_equal(mm_cpumask(mm), cpumask_of(smp_processor_id())))
302 __pmdp_idte_local(addr, pmdp);
303 else
304 __pmdp_idte(addr, pmdp);
305 atomic_sub(0x10000, &mm->context.attach_count);
306 return old;
307}
308
309static inline pmd_t pmdp_flush_lazy(struct mm_struct *mm,
310 unsigned long addr, pmd_t *pmdp)
311{
312 int active, count;
313 pmd_t old;
314
315 old = *pmdp;
316 if (pmd_val(old) & _SEGMENT_ENTRY_INVALID)
317 return old;
318 active = (mm == current->active_mm) ? 1 : 0;
319 count = atomic_add_return(0x10000, &mm->context.attach_count);
320 if ((count & 0xffff) <= active) {
321 pmd_val(*pmdp) |= _SEGMENT_ENTRY_INVALID;
322 mm->context.flush_mm = 1;
323 } else if (MACHINE_HAS_IDTE)
324 __pmdp_idte(addr, pmdp);
325 else
326 __pmdp_csp(pmdp);
327 atomic_sub(0x10000, &mm->context.attach_count);
328 return old;
329}
330
331pmd_t pmdp_xchg_direct(struct mm_struct *mm, unsigned long addr,
332 pmd_t *pmdp, pmd_t new)
333{
334 pmd_t old;
335
336 old = pmdp_flush_direct(mm, addr, pmdp);
337 *pmdp = new;
338 return old;
339}
340EXPORT_SYMBOL(pmdp_xchg_direct);
341
342pmd_t pmdp_xchg_lazy(struct mm_struct *mm, unsigned long addr,
343 pmd_t *pmdp, pmd_t new)
344{
345 pmd_t old;
346
347 old = pmdp_flush_lazy(mm, addr, pmdp);
348 *pmdp = new;
349 return old;
350}
351EXPORT_SYMBOL(pmdp_xchg_lazy);
352
353#ifdef CONFIG_TRANSPARENT_HUGEPAGE
354void pgtable_trans_huge_deposit(struct mm_struct *mm, pmd_t *pmdp,
355 pgtable_t pgtable)
356{
357 struct list_head *lh = (struct list_head *) pgtable;
358
359 assert_spin_locked(pmd_lockptr(mm, pmdp));
360
361 /* FIFO */
362 if (!pmd_huge_pte(mm, pmdp))
363 INIT_LIST_HEAD(lh);
364 else
365 list_add(lh, (struct list_head *) pmd_huge_pte(mm, pmdp));
366 pmd_huge_pte(mm, pmdp) = pgtable;
367}
368
369pgtable_t pgtable_trans_huge_withdraw(struct mm_struct *mm, pmd_t *pmdp)
370{
371 struct list_head *lh;
372 pgtable_t pgtable;
373 pte_t *ptep;
374
375 assert_spin_locked(pmd_lockptr(mm, pmdp));
376
377 /* FIFO */
378 pgtable = pmd_huge_pte(mm, pmdp);
379 lh = (struct list_head *) pgtable;
380 if (list_empty(lh))
381 pmd_huge_pte(mm, pmdp) = NULL;
382 else {
383 pmd_huge_pte(mm, pmdp) = (pgtable_t) lh->next;
384 list_del(lh);
385 }
386 ptep = (pte_t *) pgtable;
387 pte_val(*ptep) = _PAGE_INVALID;
388 ptep++;
389 pte_val(*ptep) = _PAGE_INVALID;
390 return pgtable;
391}
392#endif /* CONFIG_TRANSPARENT_HUGEPAGE */
393
394#ifdef CONFIG_PGSTE
395void ptep_set_pte_at(struct mm_struct *mm, unsigned long addr,
396 pte_t *ptep, pte_t entry)
397{
398 pgste_t pgste;
399
400 /* the mm_has_pgste() check is done in set_pte_at() */
401 pgste = pgste_get_lock(ptep);
402 pgste_val(pgste) &= ~_PGSTE_GPS_ZERO;
403 pgste_set_key(ptep, pgste, entry, mm);
404 pgste = pgste_set_pte(ptep, pgste, entry);
405 pgste_set_unlock(ptep, pgste);
406}
407
408void ptep_set_notify(struct mm_struct *mm, unsigned long addr, pte_t *ptep)
409{
410 pgste_t pgste;
411
412 pgste = pgste_get_lock(ptep);
413 pgste_val(pgste) |= PGSTE_IN_BIT;
414 pgste_set_unlock(ptep, pgste);
415}
416
417static void ptep_zap_swap_entry(struct mm_struct *mm, swp_entry_t entry)
418{
419 if (!non_swap_entry(entry))
420 dec_mm_counter(mm, MM_SWAPENTS);
421 else if (is_migration_entry(entry)) {
422 struct page *page = migration_entry_to_page(entry);
423
424 dec_mm_counter(mm, mm_counter(page));
425 }
426 free_swap_and_cache(entry);
427}
428
429void ptep_zap_unused(struct mm_struct *mm, unsigned long addr,
430 pte_t *ptep, int reset)
431{
432 unsigned long pgstev;
433 pgste_t pgste;
434 pte_t pte;
435
436 /* Zap unused and logically-zero pages */
437 pgste = pgste_get_lock(ptep);
438 pgstev = pgste_val(pgste);
439 pte = *ptep;
440 if (pte_swap(pte) &&
441 ((pgstev & _PGSTE_GPS_USAGE_MASK) == _PGSTE_GPS_USAGE_UNUSED ||
442 (pgstev & _PGSTE_GPS_ZERO))) {
443 ptep_zap_swap_entry(mm, pte_to_swp_entry(pte));
444 pte_clear(mm, addr, ptep);
445 }
446 if (reset)
447 pgste_val(pgste) &= ~_PGSTE_GPS_USAGE_MASK;
448 pgste_set_unlock(ptep, pgste);
449}
450
451void ptep_zap_key(struct mm_struct *mm, unsigned long addr, pte_t *ptep)
452{
453 unsigned long ptev;
454 pgste_t pgste;
455
456 /* Clear storage key */
457 pgste = pgste_get_lock(ptep);
458 pgste_val(pgste) &= ~(PGSTE_ACC_BITS | PGSTE_FP_BIT |
459 PGSTE_GR_BIT | PGSTE_GC_BIT);
460 ptev = pte_val(*ptep);
461 if (!(ptev & _PAGE_INVALID) && (ptev & _PAGE_WRITE))
462 page_set_storage_key(ptev & PAGE_MASK, PAGE_DEFAULT_KEY, 1);
463 pgste_set_unlock(ptep, pgste);
464}
465
466/*
467 * Test and reset if a guest page is dirty
468 */
469bool test_and_clear_guest_dirty(struct mm_struct *mm, unsigned long addr)
470{
471 spinlock_t *ptl;
472 pgste_t pgste;
473 pte_t *ptep;
474 pte_t pte;
475 bool dirty;
476
477 ptep = get_locked_pte(mm, addr, &ptl);
478 if (unlikely(!ptep))
479 return false;
480
481 pgste = pgste_get_lock(ptep);
482 dirty = !!(pgste_val(pgste) & PGSTE_UC_BIT);
483 pgste_val(pgste) &= ~PGSTE_UC_BIT;
484 pte = *ptep;
485 if (dirty && (pte_val(pte) & _PAGE_PRESENT)) {
486 pgste = pgste_ipte_notify(mm, addr, ptep, pgste);
487 __ptep_ipte(addr, ptep);
488 if (MACHINE_HAS_ESOP || !(pte_val(pte) & _PAGE_WRITE))
489 pte_val(pte) |= _PAGE_PROTECT;
490 else
491 pte_val(pte) |= _PAGE_INVALID;
492 *ptep = pte;
493 }
494 pgste_set_unlock(ptep, pgste);
495
496 spin_unlock(ptl);
497 return dirty;
498}
499EXPORT_SYMBOL_GPL(test_and_clear_guest_dirty);
500
501int set_guest_storage_key(struct mm_struct *mm, unsigned long addr,
502 unsigned char key, bool nq)
503{
504 unsigned long keyul;
505 spinlock_t *ptl;
506 pgste_t old, new;
507 pte_t *ptep;
508
509 down_read(&mm->mmap_sem);
510 ptep = get_locked_pte(mm, addr, &ptl);
511 if (unlikely(!ptep)) {
512 up_read(&mm->mmap_sem);
513 return -EFAULT;
514 }
515
516 new = old = pgste_get_lock(ptep);
517 pgste_val(new) &= ~(PGSTE_GR_BIT | PGSTE_GC_BIT |
518 PGSTE_ACC_BITS | PGSTE_FP_BIT);
519 keyul = (unsigned long) key;
520 pgste_val(new) |= (keyul & (_PAGE_CHANGED | _PAGE_REFERENCED)) << 48;
521 pgste_val(new) |= (keyul & (_PAGE_ACC_BITS | _PAGE_FP_BIT)) << 56;
522 if (!(pte_val(*ptep) & _PAGE_INVALID)) {
523 unsigned long address, bits, skey;
524
525 address = pte_val(*ptep) & PAGE_MASK;
526 skey = (unsigned long) page_get_storage_key(address);
527 bits = skey & (_PAGE_CHANGED | _PAGE_REFERENCED);
528 skey = key & (_PAGE_ACC_BITS | _PAGE_FP_BIT);
529 /* Set storage key ACC and FP */
530 page_set_storage_key(address, skey, !nq);
531 /* Merge host changed & referenced into pgste */
532 pgste_val(new) |= bits << 52;
533 }
534 /* changing the guest storage key is considered a change of the page */
535 if ((pgste_val(new) ^ pgste_val(old)) &
536 (PGSTE_ACC_BITS | PGSTE_FP_BIT | PGSTE_GR_BIT | PGSTE_GC_BIT))
537 pgste_val(new) |= PGSTE_UC_BIT;
538
539 pgste_set_unlock(ptep, new);
540 pte_unmap_unlock(ptep, ptl);
541 up_read(&mm->mmap_sem);
542 return 0;
543}
544EXPORT_SYMBOL(set_guest_storage_key);
545
546unsigned char get_guest_storage_key(struct mm_struct *mm, unsigned long addr)
547{
548 unsigned char key;
549 spinlock_t *ptl;
550 pgste_t pgste;
551 pte_t *ptep;
552
553 down_read(&mm->mmap_sem);
554 ptep = get_locked_pte(mm, addr, &ptl);
555 if (unlikely(!ptep)) {
556 up_read(&mm->mmap_sem);
557 return -EFAULT;
558 }
559 pgste = pgste_get_lock(ptep);
560
561 if (pte_val(*ptep) & _PAGE_INVALID) {
562 key = (pgste_val(pgste) & PGSTE_ACC_BITS) >> 56;
563 key |= (pgste_val(pgste) & PGSTE_FP_BIT) >> 56;
564 key |= (pgste_val(pgste) & PGSTE_GR_BIT) >> 48;
565 key |= (pgste_val(pgste) & PGSTE_GC_BIT) >> 48;
566 } else {
567 key = page_get_storage_key(pte_val(*ptep) & PAGE_MASK);
568
569 /* Reflect guest's logical view, not physical */
570 if (pgste_val(pgste) & PGSTE_GR_BIT)
571 key |= _PAGE_REFERENCED;
572 if (pgste_val(pgste) & PGSTE_GC_BIT)
573 key |= _PAGE_CHANGED;
574 }
575
576 pgste_set_unlock(ptep, pgste);
577 pte_unmap_unlock(ptep, ptl);
578 up_read(&mm->mmap_sem);
579 return key;
580}
581EXPORT_SYMBOL(get_guest_storage_key);
582#endif