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[mirror_ubuntu-bionic-kernel.git] / arch / s390 / mm / pgtable.c
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3610cce8 1/*
a53c8fab 2 * Copyright IBM Corp. 2007, 2011
3610cce8
MS		 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>
5a0e3ad6 9#include <linux/gfp.h>
3610cce8
MS		 10#include <linux/mm.h>
11#include <linux/swap.h>
12#include <linux/smp.h>
3610cce8 13#include <linux/spinlock.h>
80217147 14#include <linux/rcupdate.h>
e5992f2e 15#include <linux/slab.h>
b31288fa 16#include <linux/swapops.h>
0b46e0a3 17#include <linux/sysctl.h>
3ac8e380
DD		 18#include <linux/ksm.h>
19#include <linux/mman.h>
3610cce8 20
3610cce8
MS		 21#include <asm/pgtable.h>
22#include <asm/pgalloc.h>
23#include <asm/tlb.h>
24#include <asm/tlbflush.h>
6252d702 25#include <asm/mmu_context.h>
3610cce8 26
ebde765c
MS		 27static inline pte_t ptep_flush_direct(struct mm_struct *mm,
28 unsigned long addr, pte_t *ptep)
29{
ebde765c
MS		 30 pte_t old;
31
32 old = *ptep;
33 if (unlikely(pte_val(old) & _PAGE_INVALID))
34 return old;
64f31d58
MS		 35 atomic_inc(&mm->context.flush_count);
36 if (MACHINE_HAS_TLB_LC &&
ebde765c 37 cpumask_equal(mm_cpumask(mm), cpumask_of(smp_processor_id())))
34eeaf37 38 __ptep_ipte(addr, ptep, IPTE_LOCAL);
ebde765c 39 else
34eeaf37 40 __ptep_ipte(addr, ptep, IPTE_GLOBAL);
64f31d58 41 atomic_dec(&mm->context.flush_count);
ebde765c
MS		 42 return old;
43}
44
45static inline pte_t ptep_flush_lazy(struct mm_struct *mm,
46 unsigned long addr, pte_t *ptep)
47{
ebde765c
MS		 48 pte_t old;
49
50 old = *ptep;
51 if (unlikely(pte_val(old) & _PAGE_INVALID))
52 return old;
64f31d58
MS		 53 atomic_inc(&mm->context.flush_count);
54 if (cpumask_equal(&mm->context.cpu_attach_mask,
55 cpumask_of(smp_processor_id()))) {
ebde765c
MS		 56 pte_val(*ptep) |= _PAGE_INVALID;
57 mm->context.flush_mm = 1;
58 } else
34eeaf37 59 __ptep_ipte(addr, ptep, IPTE_GLOBAL);
64f31d58 60 atomic_dec(&mm->context.flush_count);
ebde765c
MS		 61 return old;
62}
63
1e133ab2
MS		 64static inline pgste_t pgste_get_lock(pte_t *ptep)
65{
66 unsigned long new = 0;
67#ifdef CONFIG_PGSTE
68 unsigned long old;
69
1e133ab2
MS		 70 asm(
71 " lg %0,%2\n"
72 "0: lgr %1,%0\n"
73 " nihh %0,0xff7f\n" /* clear PCL bit in old */
74 " oihh %1,0x0080\n" /* set PCL bit in new */
75 " csg %0,%1,%2\n"
76 " jl 0b\n"
77 : "=&d" (old), "=&d" (new), "=Q" (ptep[PTRS_PER_PTE])
78 : "Q" (ptep[PTRS_PER_PTE]) : "cc", "memory");
79#endif
80 return __pgste(new);
81}
82
83static inline void pgste_set_unlock(pte_t *ptep, pgste_t pgste)
84{
85#ifdef CONFIG_PGSTE
86 asm(
87 " nihh %1,0xff7f\n" /* clear PCL bit */
88 " stg %1,%0\n"
89 : "=Q" (ptep[PTRS_PER_PTE])
90 : "d" (pgste_val(pgste)), "Q" (ptep[PTRS_PER_PTE])
91 : "cc", "memory");
1e133ab2
MS		 92#endif
93}
94
95static inline pgste_t pgste_get(pte_t *ptep)
96{
97 unsigned long pgste = 0;
98#ifdef CONFIG_PGSTE
99 pgste = *(unsigned long *)(ptep + PTRS_PER_PTE);
100#endif
101 return __pgste(pgste);
102}
103
104static inline void pgste_set(pte_t *ptep, pgste_t pgste)
105{
106#ifdef CONFIG_PGSTE
107 *(pgste_t *)(ptep + PTRS_PER_PTE) = pgste;
108#endif
109}
110
ebde765c
MS		 111static inline pgste_t pgste_update_all(pte_t pte, pgste_t pgste,
112 struct mm_struct *mm)
113{
114#ifdef CONFIG_PGSTE
115 unsigned long address, bits, skey;
116
117 if (!mm_use_skey(mm) || pte_val(pte) & _PAGE_INVALID)
118 return pgste;
119 address = pte_val(pte) & PAGE_MASK;
120 skey = (unsigned long) page_get_storage_key(address);
121 bits = skey & (_PAGE_CHANGED | _PAGE_REFERENCED);
122 /* Transfer page changed & referenced bit to guest bits in pgste */
123 pgste_val(pgste) |= bits << 48; /* GR bit & GC bit */
124 /* Copy page access key and fetch protection bit to pgste */
125 pgste_val(pgste) &= ~(PGSTE_ACC_BITS | PGSTE_FP_BIT);
126 pgste_val(pgste) |= (skey & (_PAGE_ACC_BITS | _PAGE_FP_BIT)) << 56;
127#endif
128 return pgste;
129
130}
131
132static inline void pgste_set_key(pte_t *ptep, pgste_t pgste, pte_t entry,
133 struct mm_struct *mm)
134{
135#ifdef CONFIG_PGSTE
136 unsigned long address;
137 unsigned long nkey;
138
139 if (!mm_use_skey(mm) || pte_val(entry) & _PAGE_INVALID)
140 return;
141 VM_BUG_ON(!(pte_val(*ptep) & _PAGE_INVALID));
142 address = pte_val(entry) & PAGE_MASK;
143 /*
144 * Set page access key and fetch protection bit from pgste.
145 * The guest C/R information is still in the PGSTE, set real
146 * key C/R to 0.
147 */
148 nkey = (pgste_val(pgste) & (PGSTE_ACC_BITS | PGSTE_FP_BIT)) >> 56;
149 nkey |= (pgste_val(pgste) & (PGSTE_GR_BIT | PGSTE_GC_BIT)) >> 48;
150 page_set_storage_key(address, nkey, 0);
151#endif
152}
153
154static inline pgste_t pgste_set_pte(pte_t *ptep, pgste_t pgste, pte_t entry)
155{
156#ifdef CONFIG_PGSTE
157 if ((pte_val(entry) & _PAGE_PRESENT) &&
158 (pte_val(entry) & _PAGE_WRITE) &&
159 !(pte_val(entry) & _PAGE_INVALID)) {
160 if (!MACHINE_HAS_ESOP) {
161 /*
162 * Without enhanced suppression-on-protection force
163 * the dirty bit on for all writable ptes.
164 */
165 pte_val(entry) |= _PAGE_DIRTY;
166 pte_val(entry) &= ~_PAGE_PROTECT;
167 }
168 if (!(pte_val(entry) & _PAGE_PROTECT))
169 /* This pte allows write access, set user-dirty */
170 pgste_val(pgste) |= PGSTE_UC_BIT;
171 }
172#endif
173 *ptep = entry;
174 return pgste;
175}
176
b2d73b2a
MS		 177static inline pgste_t pgste_pte_notify(struct mm_struct *mm,
178 unsigned long addr,
179 pte_t *ptep, pgste_t pgste)
ebde765c
MS		 180{
181#ifdef CONFIG_PGSTE
4be130a0
MS		 182 unsigned long bits;
183
184 bits = pgste_val(pgste) & (PGSTE_IN_BIT | PGSTE_VSIE_BIT);
185 if (bits) {
186 pgste_val(pgste) ^= bits;
187 ptep_notify(mm, addr, ptep, bits);
ebde765c
MS		 188 }
189#endif
190 return pgste;
191}
192
ebde765c
MS		 193static inline pgste_t ptep_xchg_start(struct mm_struct *mm,
194 unsigned long addr, pte_t *ptep)
195{
196 pgste_t pgste = __pgste(0);
197
198 if (mm_has_pgste(mm)) {
199 pgste = pgste_get_lock(ptep);
b2d73b2a 200 pgste = pgste_pte_notify(mm, addr, ptep, pgste);
ebde765c
MS		 201 }
202 return pgste;
203}
204
0d6da872 205static inline pte_t ptep_xchg_commit(struct mm_struct *mm,
ebde765c
MS		 206 unsigned long addr, pte_t *ptep,
207 pgste_t pgste, pte_t old, pte_t new)
208{
209 if (mm_has_pgste(mm)) {
210 if (pte_val(old) & _PAGE_INVALID)
211 pgste_set_key(ptep, pgste, new, mm);
212 if (pte_val(new) & _PAGE_INVALID) {
213 pgste = pgste_update_all(old, pgste, mm);
214 if ((pgste_val(pgste) & _PGSTE_GPS_USAGE_MASK) ==
215 _PGSTE_GPS_USAGE_UNUSED)
216 pte_val(old) |= _PAGE_UNUSED;
217 }
218 pgste = pgste_set_pte(ptep, pgste, new);
219 pgste_set_unlock(ptep, pgste);
220 } else {
221 *ptep = new;
222 }
0d6da872 223 return old;
ebde765c
MS		 224}
225
226pte_t ptep_xchg_direct(struct mm_struct *mm, unsigned long addr,
227 pte_t *ptep, pte_t new)
228{
229 pgste_t pgste;
230 pte_t old;
231
a9809407 232 preempt_disable();
ebde765c
MS		 233 pgste = ptep_xchg_start(mm, addr, ptep);
234 old = ptep_flush_direct(mm, addr, ptep);
0d6da872 235 old = ptep_xchg_commit(mm, addr, ptep, pgste, old, new);
a9809407 236 preempt_enable();
ebde765c
MS		 237 return old;
238}
239EXPORT_SYMBOL(ptep_xchg_direct);
240
241pte_t ptep_xchg_lazy(struct mm_struct *mm, unsigned long addr,
242 pte_t *ptep, pte_t new)
243{
244 pgste_t pgste;
245 pte_t old;
246
a9809407 247 preempt_disable();
ebde765c
MS		 248 pgste = ptep_xchg_start(mm, addr, ptep);
249 old = ptep_flush_lazy(mm, addr, ptep);
0d6da872 250 old = ptep_xchg_commit(mm, addr, ptep, pgste, old, new);
a9809407 251 preempt_enable();
ebde765c
MS		 252 return old;
253}
254EXPORT_SYMBOL(ptep_xchg_lazy);
255
256pte_t ptep_modify_prot_start(struct mm_struct *mm, unsigned long addr,
257 pte_t *ptep)
258{
259 pgste_t pgste;
260 pte_t old;
261
a9809407 262 preempt_disable();
ebde765c
MS		 263 pgste = ptep_xchg_start(mm, addr, ptep);
264 old = ptep_flush_lazy(mm, addr, ptep);
265 if (mm_has_pgste(mm)) {
266 pgste = pgste_update_all(old, pgste, mm);
267 pgste_set(ptep, pgste);
268 }
269 return old;
270}
271EXPORT_SYMBOL(ptep_modify_prot_start);
272
273void ptep_modify_prot_commit(struct mm_struct *mm, unsigned long addr,
274 pte_t *ptep, pte_t pte)
275{
276 pgste_t pgste;
277
57d7f939
MS		 278 if (!MACHINE_HAS_NX)
279 pte_val(pte) &= ~_PAGE_NOEXEC;
ebde765c
MS		 280 if (mm_has_pgste(mm)) {
281 pgste = pgste_get(ptep);
282 pgste_set_key(ptep, pgste, pte, mm);
283 pgste = pgste_set_pte(ptep, pgste, pte);
284 pgste_set_unlock(ptep, pgste);
285 } else {
286 *ptep = pte;
287 }
a9809407 288 preempt_enable();
ebde765c
MS		 289}
290EXPORT_SYMBOL(ptep_modify_prot_commit);
291
227be799
MS		 292static inline pmd_t pmdp_flush_direct(struct mm_struct *mm,
293 unsigned long addr, pmd_t *pmdp)
294{
227be799
MS		 295 pmd_t old;
296
297 old = *pmdp;
298 if (pmd_val(old) & _SEGMENT_ENTRY_INVALID)
299 return old;
300 if (!MACHINE_HAS_IDTE) {
301 __pmdp_csp(pmdp);
302 return old;
303 }
64f31d58
MS		 304 atomic_inc(&mm->context.flush_count);
305 if (MACHINE_HAS_TLB_LC &&
227be799 306 cpumask_equal(mm_cpumask(mm), cpumask_of(smp_processor_id())))
47e4d851 307 __pmdp_idte(addr, pmdp, IDTE_LOCAL);
227be799 308 else
47e4d851 309 __pmdp_idte(addr, pmdp, IDTE_GLOBAL);
64f31d58 310 atomic_dec(&mm->context.flush_count);
227be799
MS		 311 return old;
312}
313
314static inline pmd_t pmdp_flush_lazy(struct mm_struct *mm,
315 unsigned long addr, pmd_t *pmdp)
316{
227be799
MS		 317 pmd_t old;
318
319 old = *pmdp;
320 if (pmd_val(old) & _SEGMENT_ENTRY_INVALID)
321 return old;
64f31d58
MS		 322 atomic_inc(&mm->context.flush_count);
323 if (cpumask_equal(&mm->context.cpu_attach_mask,
324 cpumask_of(smp_processor_id()))) {
227be799
MS		 325 pmd_val(*pmdp) |= _SEGMENT_ENTRY_INVALID;
326 mm->context.flush_mm = 1;
327 } else if (MACHINE_HAS_IDTE)
47e4d851 328 __pmdp_idte(addr, pmdp, IDTE_GLOBAL);
227be799
MS		 329 else
330 __pmdp_csp(pmdp);
64f31d58 331 atomic_dec(&mm->context.flush_count);
227be799
MS		 332 return old;
333}
334
335pmd_t pmdp_xchg_direct(struct mm_struct *mm, unsigned long addr,
336 pmd_t *pmdp, pmd_t new)
337{
338 pmd_t old;
339
a9809407 340 preempt_disable();
227be799
MS		 341 old = pmdp_flush_direct(mm, addr, pmdp);
342 *pmdp = new;
a9809407 343 preempt_enable();
227be799
MS		 344 return old;
345}
346EXPORT_SYMBOL(pmdp_xchg_direct);
347
348pmd_t pmdp_xchg_lazy(struct mm_struct *mm, unsigned long addr,
349 pmd_t *pmdp, pmd_t new)
350{
351 pmd_t old;
352
a9809407 353 preempt_disable();
227be799
MS		 354 old = pmdp_flush_lazy(mm, addr, pmdp);
355 *pmdp = new;
a9809407 356 preempt_enable();
227be799
MS		 357 return old;
358}
359EXPORT_SYMBOL(pmdp_xchg_lazy);
360
d08de8e2
GS		 361static inline pud_t pudp_flush_direct(struct mm_struct *mm,
362 unsigned long addr, pud_t *pudp)
363{
364 pud_t old;
365
366 old = *pudp;
367 if (pud_val(old) & _REGION_ENTRY_INVALID)
368 return old;
369 if (!MACHINE_HAS_IDTE) {
370 /*
371 * Invalid bit position is the same for pmd and pud, so we can
372 * re-use _pmd_csp() here
373 */
374 __pmdp_csp((pmd_t *) pudp);
375 return old;
376 }
377 atomic_inc(&mm->context.flush_count);
378 if (MACHINE_HAS_TLB_LC &&
379 cpumask_equal(mm_cpumask(mm), cpumask_of(smp_processor_id())))
47e4d851 380 __pudp_idte(addr, pudp, IDTE_LOCAL);
d08de8e2 381 else
47e4d851 382 __pudp_idte(addr, pudp, IDTE_GLOBAL);
d08de8e2
GS		 383 atomic_dec(&mm->context.flush_count);
384 return old;
385}
386
387pud_t pudp_xchg_direct(struct mm_struct *mm, unsigned long addr,
388 pud_t *pudp, pud_t new)
389{
390 pud_t old;
391
392 preempt_disable();
393 old = pudp_flush_direct(mm, addr, pudp);
394 *pudp = new;
395 preempt_enable();
396 return old;
397}
398EXPORT_SYMBOL(pudp_xchg_direct);
399
75077afb 400#ifdef CONFIG_TRANSPARENT_HUGEPAGE
6b0b50b0
AK		 401void pgtable_trans_huge_deposit(struct mm_struct *mm, pmd_t *pmdp,
402 pgtable_t pgtable)
9501d09f
GS		 403{
404 struct list_head *lh = (struct list_head *) pgtable;
405
ec66ad66 406 assert_spin_locked(pmd_lockptr(mm, pmdp));
9501d09f
GS		 407
408 /* FIFO */
c389a250 409 if (!pmd_huge_pte(mm, pmdp))
9501d09f
GS		 410 INIT_LIST_HEAD(lh);
411 else
c389a250
KS		 412 list_add(lh, (struct list_head *) pmd_huge_pte(mm, pmdp));
413 pmd_huge_pte(mm, pmdp) = pgtable;
9501d09f
GS		 414}
415
6b0b50b0 416pgtable_t pgtable_trans_huge_withdraw(struct mm_struct *mm, pmd_t *pmdp)
9501d09f
GS		 417{
418 struct list_head *lh;
419 pgtable_t pgtable;
420 pte_t *ptep;
421
ec66ad66 422 assert_spin_locked(pmd_lockptr(mm, pmdp));
9501d09f
GS		 423
424 /* FIFO */
c389a250 425 pgtable = pmd_huge_pte(mm, pmdp);
9501d09f
GS		 426 lh = (struct list_head *) pgtable;
427 if (list_empty(lh))
c389a250 428 pmd_huge_pte(mm, pmdp) = NULL;
9501d09f 429 else {
c389a250 430 pmd_huge_pte(mm, pmdp) = (pgtable_t) lh->next;
9501d09f
GS		 431 list_del(lh);
432 }
433 ptep = (pte_t *) pgtable;
e5098611 434 pte_val(*ptep) = _PAGE_INVALID;
9501d09f 435 ptep++;
e5098611 436 pte_val(*ptep) = _PAGE_INVALID;
9501d09f
GS		 437 return pgtable;
438}
75077afb 439#endif /* CONFIG_TRANSPARENT_HUGEPAGE */
1e133ab2
MS		 440
441#ifdef CONFIG_PGSTE
442void ptep_set_pte_at(struct mm_struct *mm, unsigned long addr,
443 pte_t *ptep, pte_t entry)
444{
445 pgste_t pgste;
446
447 /* the mm_has_pgste() check is done in set_pte_at() */
a9809407 448 preempt_disable();
1e133ab2
MS		 449 pgste = pgste_get_lock(ptep);
450 pgste_val(pgste) &= ~_PGSTE_GPS_ZERO;
451 pgste_set_key(ptep, pgste, entry, mm);
452 pgste = pgste_set_pte(ptep, pgste, entry);
453 pgste_set_unlock(ptep, pgste);
a9809407 454 preempt_enable();
1e133ab2
MS		 455}
456
457void ptep_set_notify(struct mm_struct *mm, unsigned long addr, pte_t *ptep)
458{
459 pgste_t pgste;
460
a9809407 461 preempt_disable();
1e133ab2
MS		 462 pgste = pgste_get_lock(ptep);
463 pgste_val(pgste) |= PGSTE_IN_BIT;
464 pgste_set_unlock(ptep, pgste);
a9809407 465 preempt_enable();
1e133ab2
MS		 466}
467
b2d73b2a
MS		 468/**
469 * ptep_force_prot - change access rights of a locked pte
470 * @mm: pointer to the process mm_struct
471 * @addr: virtual address in the guest address space
472 * @ptep: pointer to the page table entry
473 * @prot: indicates guest access rights: PROT_NONE, PROT_READ or PROT_WRITE
4be130a0 474 * @bit: pgste bit to set (e.g. for notification)
b2d73b2a
MS		 475 *
476 * Returns 0 if the access rights were changed and -EAGAIN if the current
477 * and requested access rights are incompatible.
478 */
479int ptep_force_prot(struct mm_struct *mm, unsigned long addr,
4be130a0 480 pte_t *ptep, int prot, unsigned long bit)
b2d73b2a
MS		 481{
482 pte_t entry;
483 pgste_t pgste;
484 int pte_i, pte_p;
485
486 pgste = pgste_get_lock(ptep);
487 entry = *ptep;
488 /* Check pte entry after all locks have been acquired */
489 pte_i = pte_val(entry) & _PAGE_INVALID;
490 pte_p = pte_val(entry) & _PAGE_PROTECT;
491 if ((pte_i && (prot != PROT_NONE)) ||
492 (pte_p && (prot & PROT_WRITE))) {
493 pgste_set_unlock(ptep, pgste);
494 return -EAGAIN;
495 }
4be130a0 496 /* Change access rights and set pgste bit */
b2d73b2a
MS		 497 if (prot == PROT_NONE && !pte_i) {
498 ptep_flush_direct(mm, addr, ptep);
499 pgste = pgste_update_all(entry, pgste, mm);
500 pte_val(entry) |= _PAGE_INVALID;
501 }
502 if (prot == PROT_READ && !pte_p) {
503 ptep_flush_direct(mm, addr, ptep);
504 pte_val(entry) &= ~_PAGE_INVALID;
505 pte_val(entry) |= _PAGE_PROTECT;
506 }
4be130a0 507 pgste_val(pgste) |= bit;
b2d73b2a
MS		 508 pgste = pgste_set_pte(ptep, pgste, entry);
509 pgste_set_unlock(ptep, pgste);
510 return 0;
511}
512
4be130a0 513int ptep_shadow_pte(struct mm_struct *mm, unsigned long saddr,
a9d23e71 514 pte_t *sptep, pte_t *tptep, pte_t pte)
4be130a0
MS		 515{
516 pgste_t spgste, tpgste;
517 pte_t spte, tpte;
518 int rc = -EAGAIN;
519
a9d23e71
DH		 520 if (!(pte_val(*tptep) & _PAGE_INVALID))
521 return 0; /* already shadowed */
4be130a0
MS		 522 spgste = pgste_get_lock(sptep);
523 spte = *sptep;
524 if (!(pte_val(spte) & _PAGE_INVALID) &&
a9d23e71
DH		 525 !((pte_val(spte) & _PAGE_PROTECT) &&
526 !(pte_val(pte) & _PAGE_PROTECT))) {
4be130a0
MS		 527 pgste_val(spgste) |= PGSTE_VSIE_BIT;
528 tpgste = pgste_get_lock(tptep);
529 pte_val(tpte) = (pte_val(spte) & PAGE_MASK) |
a9d23e71 530 (pte_val(pte) & _PAGE_PROTECT);
4be130a0
MS		 531 /* don't touch the storage key - it belongs to parent pgste */
532 tpgste = pgste_set_pte(tptep, tpgste, tpte);
533 pgste_set_unlock(tptep, tpgste);
a9d23e71 534 rc = 1;
4be130a0
MS		 535 }
536 pgste_set_unlock(sptep, spgste);
537 return rc;
538}
539
540void ptep_unshadow_pte(struct mm_struct *mm, unsigned long saddr, pte_t *ptep)
541{
542 pgste_t pgste;
543
544 pgste = pgste_get_lock(ptep);
545 /* notifier is called by the caller */
546 ptep_flush_direct(mm, saddr, ptep);
547 /* don't touch the storage key - it belongs to parent pgste */
548 pgste = pgste_set_pte(ptep, pgste, __pte(_PAGE_INVALID));
549 pgste_set_unlock(ptep, pgste);
550}
551
1e133ab2
MS		 552static void ptep_zap_swap_entry(struct mm_struct *mm, swp_entry_t entry)
553{
554 if (!non_swap_entry(entry))
555 dec_mm_counter(mm, MM_SWAPENTS);
556 else if (is_migration_entry(entry)) {
557 struct page *page = migration_entry_to_page(entry);
558
559 dec_mm_counter(mm, mm_counter(page));
560 }
561 free_swap_and_cache(entry);
562}
563
564void ptep_zap_unused(struct mm_struct *mm, unsigned long addr,
565 pte_t *ptep, int reset)
566{
567 unsigned long pgstev;
568 pgste_t pgste;
569 pte_t pte;
570
571 /* Zap unused and logically-zero pages */
a9809407 572 preempt_disable();
1e133ab2
MS		 573 pgste = pgste_get_lock(ptep);
574 pgstev = pgste_val(pgste);
575 pte = *ptep;
1c343f7b 576 if (!reset && pte_swap(pte) &&
1e133ab2
MS		 577 ((pgstev & _PGSTE_GPS_USAGE_MASK) == _PGSTE_GPS_USAGE_UNUSED ||
578 (pgstev & _PGSTE_GPS_ZERO))) {
579 ptep_zap_swap_entry(mm, pte_to_swp_entry(pte));
580 pte_clear(mm, addr, ptep);
581 }
582 if (reset)
583 pgste_val(pgste) &= ~_PGSTE_GPS_USAGE_MASK;
584 pgste_set_unlock(ptep, pgste);
a9809407 585 preempt_enable();
1e133ab2
MS		 586}
587
588void ptep_zap_key(struct mm_struct *mm, unsigned long addr, pte_t *ptep)
589{
590 unsigned long ptev;
591 pgste_t pgste;
592
593 /* Clear storage key */
a9809407 594 preempt_disable();
1e133ab2
MS		 595 pgste = pgste_get_lock(ptep);
596 pgste_val(pgste) &= ~(PGSTE_ACC_BITS | PGSTE_FP_BIT |
597 PGSTE_GR_BIT | PGSTE_GC_BIT);
598 ptev = pte_val(*ptep);
599 if (!(ptev & _PAGE_INVALID) && (ptev & _PAGE_WRITE))
600 page_set_storage_key(ptev & PAGE_MASK, PAGE_DEFAULT_KEY, 1);
601 pgste_set_unlock(ptep, pgste);
a9809407 602 preempt_enable();
1e133ab2
MS		 603}
604
605/*
606 * Test and reset if a guest page is dirty
607 */
608bool test_and_clear_guest_dirty(struct mm_struct *mm, unsigned long addr)
609{
610 spinlock_t *ptl;
2e4d8800
JF		 611 pgd_t *pgd;
612 pud_t *pud;
613 pmd_t *pmd;
1e133ab2
MS		 614 pgste_t pgste;
615 pte_t *ptep;
616 pte_t pte;
617 bool dirty;
618
2e4d8800
JF		 619 pgd = pgd_offset(mm, addr);
620 pud = pud_alloc(mm, pgd, addr);
621 if (!pud)
622 return false;
623 pmd = pmd_alloc(mm, pud, addr);
624 if (!pmd)
625 return false;
626 /* We can't run guests backed by huge pages, but userspace can
627 * still set them up and then try to migrate them without any
628 * migration support.
629 */
630 if (pmd_large(*pmd))
631 return true;
632
633 ptep = pte_alloc_map_lock(mm, pmd, addr, &ptl);
1e133ab2
MS		 634 if (unlikely(!ptep))
635 return false;
636
637 pgste = pgste_get_lock(ptep);
638 dirty = !!(pgste_val(pgste) & PGSTE_UC_BIT);
639 pgste_val(pgste) &= ~PGSTE_UC_BIT;
640 pte = *ptep;
641 if (dirty && (pte_val(pte) & _PAGE_PRESENT)) {
b2d73b2a 642 pgste = pgste_pte_notify(mm, addr, ptep, pgste);
34eeaf37 643 __ptep_ipte(addr, ptep, IPTE_GLOBAL);
1e133ab2
MS		 644 if (MACHINE_HAS_ESOP || !(pte_val(pte) & _PAGE_WRITE))
645 pte_val(pte) |= _PAGE_PROTECT;
646 else
647 pte_val(pte) |= _PAGE_INVALID;
648 *ptep = pte;
649 }
650 pgste_set_unlock(ptep, pgste);
651
652 spin_unlock(ptl);
653 return dirty;
654}
655EXPORT_SYMBOL_GPL(test_and_clear_guest_dirty);
656
657int set_guest_storage_key(struct mm_struct *mm, unsigned long addr,
658 unsigned char key, bool nq)
659{
660 unsigned long keyul;
661 spinlock_t *ptl;
662 pgste_t old, new;
663 pte_t *ptep;
664
1e133ab2 665 ptep = get_locked_pte(mm, addr, &ptl);
d3ed1cee 666 if (unlikely(!ptep))
1e133ab2 667 return -EFAULT;
1e133ab2
MS		 668
669 new = old = pgste_get_lock(ptep);
670 pgste_val(new) &= ~(PGSTE_GR_BIT | PGSTE_GC_BIT |
671 PGSTE_ACC_BITS | PGSTE_FP_BIT);
672 keyul = (unsigned long) key;
673 pgste_val(new) |= (keyul & (_PAGE_CHANGED | _PAGE_REFERENCED)) << 48;
674 pgste_val(new) |= (keyul & (_PAGE_ACC_BITS | _PAGE_FP_BIT)) << 56;
675 if (!(pte_val(*ptep) & _PAGE_INVALID)) {
676 unsigned long address, bits, skey;
677
678 address = pte_val(*ptep) & PAGE_MASK;
679 skey = (unsigned long) page_get_storage_key(address);
680 bits = skey & (_PAGE_CHANGED | _PAGE_REFERENCED);
681 skey = key & (_PAGE_ACC_BITS | _PAGE_FP_BIT);
682 /* Set storage key ACC and FP */
683 page_set_storage_key(address, skey, !nq);
684 /* Merge host changed & referenced into pgste */
685 pgste_val(new) |= bits << 52;
686 }
687 /* changing the guest storage key is considered a change of the page */
688 if ((pgste_val(new) ^ pgste_val(old)) &
689 (PGSTE_ACC_BITS | PGSTE_FP_BIT | PGSTE_GR_BIT | PGSTE_GC_BIT))
690 pgste_val(new) |= PGSTE_UC_BIT;
691
692 pgste_set_unlock(ptep, new);
693 pte_unmap_unlock(ptep, ptl);
1e133ab2
MS		 694 return 0;
695}
696EXPORT_SYMBOL(set_guest_storage_key);
697
1824c723
DH		 698/**
699 * Conditionally set a guest storage key (handling csske).
700 * oldkey will be updated when either mr or mc is set and a pointer is given.
701 *
702 * Returns 0 if a guests storage key update wasn't necessary, 1 if the guest
703 * storage key was updated and -EFAULT on access errors.
704 */
705int cond_set_guest_storage_key(struct mm_struct *mm, unsigned long addr,
706 unsigned char key, unsigned char *oldkey,
707 bool nq, bool mr, bool mc)
708{
709 unsigned char tmp, mask = _PAGE_ACC_BITS | _PAGE_FP_BIT;
710 int rc;
711
712 /* we can drop the pgste lock between getting and setting the key */
713 if (mr | mc) {
714 rc = get_guest_storage_key(current->mm, addr, &tmp);
715 if (rc)
716 return rc;
717 if (oldkey)
718 *oldkey = tmp;
719 if (!mr)
720 mask |= _PAGE_REFERENCED;
721 if (!mc)
722 mask |= _PAGE_CHANGED;
723 if (!((tmp ^ key) & mask))
724 return 0;
725 }
726 rc = set_guest_storage_key(current->mm, addr, key, nq);
727 return rc < 0 ? rc : 1;
728}
729EXPORT_SYMBOL(cond_set_guest_storage_key);
730
a7e19ab5
DH		 731/**
732 * Reset a guest reference bit (rrbe), returning the reference and changed bit.
733 *
734 * Returns < 0 in case of error, otherwise the cc to be reported to the guest.
735 */
736int reset_guest_reference_bit(struct mm_struct *mm, unsigned long addr)
1e133ab2 737{
1e133ab2 738 spinlock_t *ptl;
a7e19ab5 739 pgste_t old, new;
1e133ab2 740 pte_t *ptep;
a7e19ab5 741 int cc = 0;
1e133ab2 742
1e133ab2 743 ptep = get_locked_pte(mm, addr, &ptl);
a7e19ab5 744 if (unlikely(!ptep))
1e133ab2 745 return -EFAULT;
1e133ab2 746
a7e19ab5
DH		 747 new = old = pgste_get_lock(ptep);
748 /* Reset guest reference bit only */
749 pgste_val(new) &= ~PGSTE_GR_BIT;
1e133ab2 750
a7e19ab5
DH		 751 if (!(pte_val(*ptep) & _PAGE_INVALID)) {
752 cc = page_reset_referenced(pte_val(*ptep) & PAGE_MASK);
753 /* Merge real referenced bit into host-set */
754 pgste_val(new) |= ((unsigned long) cc << 53) & PGSTE_HR_BIT;
1e133ab2 755 }
a7e19ab5
DH		 756 /* Reflect guest's logical view, not physical */
757 cc |= (pgste_val(old) & (PGSTE_GR_BIT | PGSTE_GC_BIT)) >> 49;
758 /* Changing the guest storage key is considered a change of the page */
759 if ((pgste_val(new) ^ pgste_val(old)) & PGSTE_GR_BIT)
760 pgste_val(new) |= PGSTE_UC_BIT;
761
762 pgste_set_unlock(ptep, new);
763 pte_unmap_unlock(ptep, ptl);
4bead2a4 764 return cc;
a7e19ab5
DH		 765}
766EXPORT_SYMBOL(reset_guest_reference_bit);
767
154c8c19
DH		 768int get_guest_storage_key(struct mm_struct *mm, unsigned long addr,
769 unsigned char *key)
1e133ab2 770{
1e133ab2
MS		 771 spinlock_t *ptl;
772 pgste_t pgste;
773 pte_t *ptep;
1e133ab2 774
1e133ab2 775 ptep = get_locked_pte(mm, addr, &ptl);
d3ed1cee 776 if (unlikely(!ptep))
1e133ab2 777 return -EFAULT;
1e133ab2 778
d3ed1cee 779 pgste = pgste_get_lock(ptep);
154c8c19 780 *key = (pgste_val(pgste) & (PGSTE_ACC_BITS | PGSTE_FP_BIT)) >> 56;
8d6037a7 781 if (!(pte_val(*ptep) & _PAGE_INVALID))
154c8c19 782 *key = page_get_storage_key(pte_val(*ptep) & PAGE_MASK);
8d6037a7 783 /* Reflect guest's logical view, not physical */
154c8c19 784 *key |= (pgste_val(pgste) & (PGSTE_GR_BIT | PGSTE_GC_BIT)) >> 48;
1e133ab2
MS		 785 pgste_set_unlock(ptep, pgste);
786 pte_unmap_unlock(ptep, ptl);
154c8c19 787 return 0;
1e133ab2
MS		 788}
789EXPORT_SYMBOL(get_guest_storage_key);
790#endif
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