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
ptep_ipte_local(struct mm_struct * mm,unsigned long addr,pte_t * ptep,int nodat)29 static 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
ptep_ipte_global(struct mm_struct * mm,unsigned long addr,pte_t * ptep,int nodat)49 static 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
ptep_flush_direct(struct mm_struct * mm,unsigned long addr,pte_t * ptep,int nodat)69 static 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
ptep_flush_lazy(struct mm_struct * mm,unsigned long addr,pte_t * ptep,int nodat)88 static 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
pgste_get_lock(pte_t * ptep)108 static 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
pgste_set_unlock(pte_t * ptep,pgste_t pgste)127 static 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
pgste_get(pte_t * ptep)139 static 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
pgste_set(pte_t * ptep,pgste_t pgste)148 static 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
pgste_update_all(pte_t pte,pgste_t pgste,struct mm_struct * mm)155 static 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
pgste_set_key(pte_t * ptep,pgste_t pgste,pte_t entry,struct mm_struct * mm)176 static 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
pgste_set_pte(pte_t * ptep,pgste_t pgste,pte_t entry)198 static 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
pgste_pte_notify(struct mm_struct * mm,unsigned long addr,pte_t * ptep,pgste_t pgste)221 static 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
ptep_xchg_start(struct mm_struct * mm,unsigned long addr,pte_t * ptep)237 static 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
ptep_xchg_commit(struct mm_struct * mm,unsigned long addr,pte_t * ptep,pgste_t pgste,pte_t old,pte_t new)249 static 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
ptep_xchg_direct(struct mm_struct * mm,unsigned long addr,pte_t * ptep,pte_t new)270 pte_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 }
285 EXPORT_SYMBOL(ptep_xchg_direct);
286
ptep_xchg_lazy(struct mm_struct * mm,unsigned long addr,pte_t * ptep,pte_t new)287 pte_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 }
302 EXPORT_SYMBOL(ptep_xchg_lazy);
303
ptep_modify_prot_start(struct vm_area_struct * vma,unsigned long addr,pte_t * ptep)304 pte_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
ptep_modify_prot_commit(struct vm_area_struct * vma,unsigned long addr,pte_t * ptep,pte_t old_pte,pte_t pte)323 void 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
pmdp_idte_local(struct mm_struct * mm,unsigned long addr,pmd_t * pmdp)342 static 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
pmdp_idte_global(struct mm_struct * mm,unsigned long addr,pmd_t * pmdp)354 static 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
pmdp_flush_direct(struct mm_struct * mm,unsigned long addr,pmd_t * pmdp)373 static 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
pmdp_flush_lazy(struct mm_struct * mm,unsigned long addr,pmd_t * pmdp)391 static 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
pmd_alloc_map(struct mm_struct * mm,unsigned long addr)414 static 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
pmdp_xchg_direct(struct mm_struct * mm,unsigned long addr,pmd_t * pmdp,pmd_t new)433 pmd_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 }
444 EXPORT_SYMBOL(pmdp_xchg_direct);
445
pmdp_xchg_lazy(struct mm_struct * mm,unsigned long addr,pmd_t * pmdp,pmd_t new)446 pmd_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 }
457 EXPORT_SYMBOL(pmdp_xchg_lazy);
458
pudp_idte_local(struct mm_struct * mm,unsigned long addr,pud_t * pudp)459 static 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
pudp_idte_global(struct mm_struct * mm,unsigned long addr,pud_t * pudp)469 static 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
pudp_flush_direct(struct mm_struct * mm,unsigned long addr,pud_t * pudp)485 static 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
pudp_xchg_direct(struct mm_struct * mm,unsigned long addr,pud_t * pudp,pud_t new)503 pud_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 }
514 EXPORT_SYMBOL(pudp_xchg_direct);
515
516 #ifdef CONFIG_TRANSPARENT_HUGEPAGE
pgtable_trans_huge_deposit(struct mm_struct * mm,pmd_t * pmdp,pgtable_t pgtable)517 void 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
pgtable_trans_huge_withdraw(struct mm_struct * mm,pmd_t * pmdp)532 pgtable_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
ptep_set_pte_at(struct mm_struct * mm,unsigned long addr,pte_t * ptep,pte_t entry)558 void 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
ptep_set_notify(struct mm_struct * mm,unsigned long addr,pte_t * ptep)573 void 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 */
ptep_force_prot(struct mm_struct * mm,unsigned long addr,pte_t * ptep,int prot,unsigned long bit)595 int 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
ptep_shadow_pte(struct mm_struct * mm,unsigned long saddr,pte_t * sptep,pte_t * tptep,pte_t pte)630 int 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
ptep_unshadow_pte(struct mm_struct * mm,unsigned long saddr,pte_t * ptep)657 void 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
ptep_zap_swap_entry(struct mm_struct * mm,swp_entry_t entry)671 static 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
ptep_zap_unused(struct mm_struct * mm,unsigned long addr,pte_t * ptep,int reset)683 void 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 | _PGSTE_GPS_NODAT);
703 pgste_set_unlock(ptep, pgste);
704 preempt_enable();
705 }
706
ptep_zap_key(struct mm_struct * mm,unsigned long addr,pte_t * ptep)707 void 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, 0);
720 pgste_set_unlock(ptep, pgste);
721 preempt_enable();
722 }
723
724 /*
725 * Test and reset if a guest page is dirty
726 */
ptep_test_and_clear_uc(struct mm_struct * mm,unsigned long addr,pte_t * ptep)727 bool 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 }
752 EXPORT_SYMBOL_GPL(ptep_test_and_clear_uc);
753
set_guest_storage_key(struct mm_struct * mm,unsigned long addr,unsigned char key,bool nq)754 int 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 }
817 EXPORT_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 */
cond_set_guest_storage_key(struct mm_struct * mm,unsigned long addr,unsigned char key,unsigned char * oldkey,bool nq,bool mr,bool mc)826 int 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 }
850 EXPORT_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 */
reset_guest_reference_bit(struct mm_struct * mm,unsigned long addr)857 int 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 }
909 EXPORT_SYMBOL(reset_guest_reference_bit);
910
get_guest_storage_key(struct mm_struct * mm,unsigned long addr,unsigned char * key)911 int 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 }
956 EXPORT_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 */
pgste_perform_essa(struct mm_struct * mm,unsigned long hva,int orc,unsigned long * oldpte,unsigned long * oldpgste)970 int pgste_perform_essa(struct mm_struct *mm, unsigned long hva, int orc,
971 unsigned long *oldpte, unsigned long *oldpgste)
972 {
973 struct vm_area_struct *vma;
974 unsigned long pgstev;
975 spinlock_t *ptl;
976 pgste_t pgste;
977 pte_t *ptep;
978 int res = 0;
979
980 WARN_ON_ONCE(orc > ESSA_MAX);
981 if (unlikely(orc > ESSA_MAX))
982 return -EINVAL;
983
984 vma = find_vma(mm, hva);
985 if (!vma || hva < vma->vm_start || is_vm_hugetlb_page(vma))
986 return -EFAULT;
987 ptep = get_locked_pte(mm, hva, &ptl);
988 if (unlikely(!ptep))
989 return -EFAULT;
990 pgste = pgste_get_lock(ptep);
991 pgstev = pgste_val(pgste);
992 if (oldpte)
993 *oldpte = pte_val(*ptep);
994 if (oldpgste)
995 *oldpgste = pgstev;
996
997 switch (orc) {
998 case ESSA_GET_STATE:
999 break;
1000 case ESSA_SET_STABLE:
1001 pgstev &= ~(_PGSTE_GPS_USAGE_MASK | _PGSTE_GPS_NODAT);
1002 pgstev |= _PGSTE_GPS_USAGE_STABLE;
1003 break;
1004 case ESSA_SET_UNUSED:
1005 pgstev &= ~_PGSTE_GPS_USAGE_MASK;
1006 pgstev |= _PGSTE_GPS_USAGE_UNUSED;
1007 if (pte_val(*ptep) & _PAGE_INVALID)
1008 res = 1;
1009 break;
1010 case ESSA_SET_VOLATILE:
1011 pgstev &= ~_PGSTE_GPS_USAGE_MASK;
1012 pgstev |= _PGSTE_GPS_USAGE_VOLATILE;
1013 if (pte_val(*ptep) & _PAGE_INVALID)
1014 res = 1;
1015 break;
1016 case ESSA_SET_POT_VOLATILE:
1017 pgstev &= ~_PGSTE_GPS_USAGE_MASK;
1018 if (!(pte_val(*ptep) & _PAGE_INVALID)) {
1019 pgstev |= _PGSTE_GPS_USAGE_POT_VOLATILE;
1020 break;
1021 }
1022 if (pgstev & _PGSTE_GPS_ZERO) {
1023 pgstev |= _PGSTE_GPS_USAGE_VOLATILE;
1024 break;
1025 }
1026 if (!(pgstev & PGSTE_GC_BIT)) {
1027 pgstev |= _PGSTE_GPS_USAGE_VOLATILE;
1028 res = 1;
1029 break;
1030 }
1031 break;
1032 case ESSA_SET_STABLE_RESIDENT:
1033 pgstev &= ~_PGSTE_GPS_USAGE_MASK;
1034 pgstev |= _PGSTE_GPS_USAGE_STABLE;
1035 /*
1036 * Since the resident state can go away any time after this
1037 * call, we will not make this page resident. We can revisit
1038 * this decision if a guest will ever start using this.
1039 */
1040 break;
1041 case ESSA_SET_STABLE_IF_RESIDENT:
1042 if (!(pte_val(*ptep) & _PAGE_INVALID)) {
1043 pgstev &= ~_PGSTE_GPS_USAGE_MASK;
1044 pgstev |= _PGSTE_GPS_USAGE_STABLE;
1045 }
1046 break;
1047 case ESSA_SET_STABLE_NODAT:
1048 pgstev &= ~_PGSTE_GPS_USAGE_MASK;
1049 pgstev |= _PGSTE_GPS_USAGE_STABLE | _PGSTE_GPS_NODAT;
1050 break;
1051 default:
1052 /* we should never get here! */
1053 break;
1054 }
1055 /* If we are discarding a page, set it to logical zero */
1056 if (res)
1057 pgstev |= _PGSTE_GPS_ZERO;
1058
1059 pgste_val(pgste) = pgstev;
1060 pgste_set_unlock(ptep, pgste);
1061 pte_unmap_unlock(ptep, ptl);
1062 return res;
1063 }
1064 EXPORT_SYMBOL(pgste_perform_essa);
1065
1066 /**
1067 * set_pgste_bits - set specific PGSTE bits.
1068 * @mm: the memory context. It must have PGSTEs, no check is performed here!
1069 * @hva: the host virtual address of the page whose PGSTE is to be processed
1070 * @bits: a bitmask representing the bits that will be touched
1071 * @value: the values of the bits to be written. Only the bits in the mask
1072 * will be written.
1073 *
1074 * Return: 0 on success, < 0 in case of error.
1075 */
set_pgste_bits(struct mm_struct * mm,unsigned long hva,unsigned long bits,unsigned long value)1076 int set_pgste_bits(struct mm_struct *mm, unsigned long hva,
1077 unsigned long bits, unsigned long value)
1078 {
1079 struct vm_area_struct *vma;
1080 spinlock_t *ptl;
1081 pgste_t new;
1082 pte_t *ptep;
1083
1084 vma = find_vma(mm, hva);
1085 if (!vma || hva < vma->vm_start || is_vm_hugetlb_page(vma))
1086 return -EFAULT;
1087 ptep = get_locked_pte(mm, hva, &ptl);
1088 if (unlikely(!ptep))
1089 return -EFAULT;
1090 new = pgste_get_lock(ptep);
1091
1092 pgste_val(new) &= ~bits;
1093 pgste_val(new) |= value & bits;
1094
1095 pgste_set_unlock(ptep, new);
1096 pte_unmap_unlock(ptep, ptl);
1097 return 0;
1098 }
1099 EXPORT_SYMBOL(set_pgste_bits);
1100
1101 /**
1102 * get_pgste - get the current PGSTE for the given address.
1103 * @mm: the memory context. It must have PGSTEs, no check is performed here!
1104 * @hva: the host virtual address of the page whose PGSTE is to be processed
1105 * @pgstep: will be written with the current PGSTE for the given address.
1106 *
1107 * Return: 0 on success, < 0 in case of error.
1108 */
get_pgste(struct mm_struct * mm,unsigned long hva,unsigned long * pgstep)1109 int get_pgste(struct mm_struct *mm, unsigned long hva, unsigned long *pgstep)
1110 {
1111 struct vm_area_struct *vma;
1112 spinlock_t *ptl;
1113 pte_t *ptep;
1114
1115 vma = find_vma(mm, hva);
1116 if (!vma || hva < vma->vm_start || is_vm_hugetlb_page(vma))
1117 return -EFAULT;
1118 ptep = get_locked_pte(mm, hva, &ptl);
1119 if (unlikely(!ptep))
1120 return -EFAULT;
1121 *pgstep = pgste_val(pgste_get(ptep));
1122 pte_unmap_unlock(ptep, ptl);
1123 return 0;
1124 }
1125 EXPORT_SYMBOL(get_pgste);
1126 #endif
1127