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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// SPDX-License-Identifier: GPL-2.0
2/*
3 * Copyright IBM Corp. 2007, 2011
4 * Author(s): Martin Schwidefsky <schwidefsky@de.ibm.com>
5 */
6
7#include <linux/sched.h>
8#include <linux/kernel.h>
9#include <linux/errno.h>
10#include <linux/gfp.h>
11#include <linux/mm.h>
12#include <linux/swap.h>
13#include <linux/smp.h>
14#include <linux/spinlock.h>
15#include <linux/rcupdate.h>
16#include <linux/slab.h>
17#include <linux/swapops.h>
18#include <linux/sysctl.h>
19#include <linux/ksm.h>
20#include <linux/mman.h>
21
22#include <asm/tlb.h>
23#include <asm/tlbflush.h>
24#include <asm/mmu_context.h>
25#include <asm/page-states.h>
26
27static inline void ptep_ipte_local(struct mm_struct *mm, unsigned long addr,
28 pte_t *ptep, int nodat)
29{
30 unsigned long opt, asce;
31
32 if (MACHINE_HAS_TLB_GUEST) {
33 opt = 0;
34 asce = READ_ONCE(mm->context.gmap_asce);
35 if (asce == 0UL || nodat)
36 opt |= IPTE_NODAT;
37 if (asce != -1UL) {
38 asce = asce ? : mm->context.asce;
39 opt |= IPTE_GUEST_ASCE;
40 }
41 __ptep_ipte(addr, ptep, opt, asce, IPTE_LOCAL);
42 } else {
43 __ptep_ipte(addr, ptep, 0, 0, IPTE_LOCAL);
44 }
45}
46
47static inline void ptep_ipte_global(struct mm_struct *mm, unsigned long addr,
48 pte_t *ptep, int nodat)
49{
50 unsigned long opt, asce;
51
52 if (MACHINE_HAS_TLB_GUEST) {
53 opt = 0;
54 asce = READ_ONCE(mm->context.gmap_asce);
55 if (asce == 0UL || nodat)
56 opt |= IPTE_NODAT;
57 if (asce != -1UL) {
58 asce = asce ? : mm->context.asce;
59 opt |= IPTE_GUEST_ASCE;
60 }
61 __ptep_ipte(addr, ptep, opt, asce, IPTE_GLOBAL);
62 } else {
63 __ptep_ipte(addr, ptep, 0, 0, IPTE_GLOBAL);
64 }
65}
66
67static inline pte_t ptep_flush_direct(struct mm_struct *mm,
68 unsigned long addr, pte_t *ptep,
69 int nodat)
70{
71 pte_t old;
72
73 old = *ptep;
74 if (unlikely(pte_val(old) & _PAGE_INVALID))
75 return old;
76 atomic_inc(&mm->context.flush_count);
77 if (MACHINE_HAS_TLB_LC &&
78 cpumask_equal(mm_cpumask(mm), cpumask_of(smp_processor_id())))
79 ptep_ipte_local(mm, addr, ptep, nodat);
80 else
81 ptep_ipte_global(mm, addr, ptep, nodat);
82 atomic_dec(&mm->context.flush_count);
83 return old;
84}
85
86static inline pte_t ptep_flush_lazy(struct mm_struct *mm,
87 unsigned long addr, pte_t *ptep,
88 int nodat)
89{
90 pte_t old;
91
92 old = *ptep;
93 if (unlikely(pte_val(old) & _PAGE_INVALID))
94 return old;
95 atomic_inc(&mm->context.flush_count);
96 if (cpumask_equal(&mm->context.cpu_attach_mask,
97 cpumask_of(smp_processor_id()))) {
98 pte_val(*ptep) |= _PAGE_INVALID;
99 mm->context.flush_mm = 1;
100 } else
101 ptep_ipte_global(mm, addr, ptep, nodat);
102 atomic_dec(&mm->context.flush_count);
103 return old;
104}
105
106static inline pgste_t pgste_get_lock(pte_t *ptep)
107{
108 unsigned long new = 0;
109#ifdef CONFIG_PGSTE
110 unsigned long old;
111
112 asm(
113 " lg %0,%2\n"
114 "0: lgr %1,%0\n"
115 " nihh %0,0xff7f\n" /* clear PCL bit in old */
116 " oihh %1,0x0080\n" /* set PCL bit in new */
117 " csg %0,%1,%2\n"
118 " jl 0b\n"
119 : "=&d" (old), "=&d" (new), "=Q" (ptep[PTRS_PER_PTE])
120 : "Q" (ptep[PTRS_PER_PTE]) : "cc", "memory");
121#endif
122 return __pgste(new);
123}
124
125static inline void pgste_set_unlock(pte_t *ptep, pgste_t pgste)
126{
127#ifdef CONFIG_PGSTE
128 asm(
129 " nihh %1,0xff7f\n" /* clear PCL bit */
130 " stg %1,%0\n"
131 : "=Q" (ptep[PTRS_PER_PTE])
132 : "d" (pgste_val(pgste)), "Q" (ptep[PTRS_PER_PTE])
133 : "cc", "memory");
134#endif
135}
136
137static inline pgste_t pgste_get(pte_t *ptep)
138{
139 unsigned long pgste = 0;
140#ifdef CONFIG_PGSTE
141 pgste = *(unsigned long *)(ptep + PTRS_PER_PTE);
142#endif
143 return __pgste(pgste);
144}
145
146static inline void pgste_set(pte_t *ptep, pgste_t pgste)
147{
148#ifdef CONFIG_PGSTE
149 *(pgste_t *)(ptep + PTRS_PER_PTE) = pgste;
150#endif
151}
152
153static inline pgste_t pgste_update_all(pte_t pte, pgste_t pgste,
154 struct mm_struct *mm)
155{
156#ifdef CONFIG_PGSTE
157 unsigned long address, bits, skey;
158
159 if (!mm_uses_skeys(mm) || pte_val(pte) & _PAGE_INVALID)
160 return pgste;
161 address = pte_val(pte) & PAGE_MASK;
162 skey = (unsigned long) page_get_storage_key(address);
163 bits = skey & (_PAGE_CHANGED | _PAGE_REFERENCED);
164 /* Transfer page changed & referenced bit to guest bits in pgste */
165 pgste_val(pgste) |= bits << 48; /* GR bit & GC bit */
166 /* Copy page access key and fetch protection bit to pgste */
167 pgste_val(pgste) &= ~(PGSTE_ACC_BITS | PGSTE_FP_BIT);
168 pgste_val(pgste) |= (skey & (_PAGE_ACC_BITS | _PAGE_FP_BIT)) << 56;
169#endif
170 return pgste;
171
172}
173
174static inline void pgste_set_key(pte_t *ptep, pgste_t pgste, pte_t entry,
175 struct mm_struct *mm)
176{
177#ifdef CONFIG_PGSTE
178 unsigned long address;
179 unsigned long nkey;
180
181 if (!mm_uses_skeys(mm) || pte_val(entry) & _PAGE_INVALID)
182 return;
183 VM_BUG_ON(!(pte_val(*ptep) & _PAGE_INVALID));
184 address = pte_val(entry) & PAGE_MASK;
185 /*
186 * Set page access key and fetch protection bit from pgste.
187 * The guest C/R information is still in the PGSTE, set real
188 * key C/R to 0.
189 */
190 nkey = (pgste_val(pgste) & (PGSTE_ACC_BITS | PGSTE_FP_BIT)) >> 56;
191 nkey |= (pgste_val(pgste) & (PGSTE_GR_BIT | PGSTE_GC_BIT)) >> 48;
192 page_set_storage_key(address, nkey, 0);
193#endif
194}
195
196static inline pgste_t pgste_set_pte(pte_t *ptep, pgste_t pgste, pte_t entry)
197{
198#ifdef CONFIG_PGSTE
199 if ((pte_val(entry) & _PAGE_PRESENT) &&
200 (pte_val(entry) & _PAGE_WRITE) &&
201 !(pte_val(entry) & _PAGE_INVALID)) {
202 if (!MACHINE_HAS_ESOP) {
203 /*
204 * Without enhanced suppression-on-protection force
205 * the dirty bit on for all writable ptes.
206 */
207 pte_val(entry) |= _PAGE_DIRTY;
208 pte_val(entry) &= ~_PAGE_PROTECT;
209 }
210 if (!(pte_val(entry) & _PAGE_PROTECT))
211 /* This pte allows write access, set user-dirty */
212 pgste_val(pgste) |= PGSTE_UC_BIT;
213 }
214#endif
215 *ptep = entry;
216 return pgste;
217}
218
219static inline pgste_t pgste_pte_notify(struct mm_struct *mm,
220 unsigned long addr,
221 pte_t *ptep, pgste_t pgste)
222{
223#ifdef CONFIG_PGSTE
224 unsigned long bits;
225
226 bits = pgste_val(pgste) & (PGSTE_IN_BIT | PGSTE_VSIE_BIT);
227 if (bits) {
228 pgste_val(pgste) ^= bits;
229 ptep_notify(mm, addr, ptep, bits);
230 }
231#endif
232 return pgste;
233}
234
235static inline pgste_t ptep_xchg_start(struct mm_struct *mm,
236 unsigned long addr, pte_t *ptep)
237{
238 pgste_t pgste = __pgste(0);
239
240 if (mm_has_pgste(mm)) {
241 pgste = pgste_get_lock(ptep);
242 pgste = pgste_pte_notify(mm, addr, ptep, pgste);
243 }
244 return pgste;
245}
246
247static inline pte_t ptep_xchg_commit(struct mm_struct *mm,
248 unsigned long addr, pte_t *ptep,
249 pgste_t pgste, pte_t old, pte_t new)
250{
251 if (mm_has_pgste(mm)) {
252 if (pte_val(old) & _PAGE_INVALID)
253 pgste_set_key(ptep, pgste, new, mm);
254 if (pte_val(new) & _PAGE_INVALID) {
255 pgste = pgste_update_all(old, pgste, mm);
256 if ((pgste_val(pgste) & _PGSTE_GPS_USAGE_MASK) ==
257 _PGSTE_GPS_USAGE_UNUSED)
258 pte_val(old) |= _PAGE_UNUSED;
259 }
260 pgste = pgste_set_pte(ptep, pgste, new);
261 pgste_set_unlock(ptep, pgste);
262 } else {
263 *ptep = new;
264 }
265 return old;
266}
267
268pte_t ptep_xchg_direct(struct mm_struct *mm, unsigned long addr,
269 pte_t *ptep, pte_t new)
270{
271 pgste_t pgste;
272 pte_t old;
273 int nodat;
274
275 preempt_disable();
276 pgste = ptep_xchg_start(mm, addr, ptep);
277 nodat = !!(pgste_val(pgste) & _PGSTE_GPS_NODAT);
278 old = ptep_flush_direct(mm, addr, ptep, nodat);
279 old = ptep_xchg_commit(mm, addr, ptep, pgste, old, new);
280 preempt_enable();
281 return old;
282}
283EXPORT_SYMBOL(ptep_xchg_direct);
284
285pte_t ptep_xchg_lazy(struct mm_struct *mm, unsigned long addr,
286 pte_t *ptep, pte_t new)
287{
288 pgste_t pgste;
289 pte_t old;
290 int nodat;
291
292 preempt_disable();
293 pgste = ptep_xchg_start(mm, addr, ptep);
294 nodat = !!(pgste_val(pgste) & _PGSTE_GPS_NODAT);
295 old = ptep_flush_lazy(mm, addr, ptep, nodat);
296 old = ptep_xchg_commit(mm, addr, ptep, pgste, old, new);
297 preempt_enable();
298 return old;
299}
300EXPORT_SYMBOL(ptep_xchg_lazy);
301
302pte_t ptep_modify_prot_start(struct vm_area_struct *vma, unsigned long addr,
303 pte_t *ptep)
304{
305 pgste_t pgste;
306 pte_t old;
307 int nodat;
308 struct mm_struct *mm = vma->vm_mm;
309
310 preempt_disable();
311 pgste = ptep_xchg_start(mm, addr, ptep);
312 nodat = !!(pgste_val(pgste) & _PGSTE_GPS_NODAT);
313 old = ptep_flush_lazy(mm, addr, ptep, nodat);
314 if (mm_has_pgste(mm)) {
315 pgste = pgste_update_all(old, pgste, mm);
316 pgste_set(ptep, pgste);
317 }
318 return old;
319}
320
321void ptep_modify_prot_commit(struct vm_area_struct *vma, unsigned long addr,
322 pte_t *ptep, pte_t old_pte, pte_t pte)
323{
324 pgste_t pgste;
325 struct mm_struct *mm = vma->vm_mm;
326
327 if (!MACHINE_HAS_NX)
328 pte_val(pte) &= ~_PAGE_NOEXEC;
329 if (mm_has_pgste(mm)) {
330 pgste = pgste_get(ptep);
331 pgste_set_key(ptep, pgste, pte, mm);
332 pgste = pgste_set_pte(ptep, pgste, pte);
333 pgste_set_unlock(ptep, pgste);
334 } else {
335 *ptep = pte;
336 }
337 preempt_enable();
338}
339
340static inline void pmdp_idte_local(struct mm_struct *mm,
341 unsigned long addr, pmd_t *pmdp)
342{
343 if (MACHINE_HAS_TLB_GUEST)
344 __pmdp_idte(addr, pmdp, IDTE_NODAT | IDTE_GUEST_ASCE,
345 mm->context.asce, IDTE_LOCAL);
346 else
347 __pmdp_idte(addr, pmdp, 0, 0, IDTE_LOCAL);
348 if (mm_has_pgste(mm) && mm->context.allow_gmap_hpage_1m)
349 gmap_pmdp_idte_local(mm, addr);
350}
351
352static inline void pmdp_idte_global(struct mm_struct *mm,
353 unsigned long addr, pmd_t *pmdp)
354{
355 if (MACHINE_HAS_TLB_GUEST) {
356 __pmdp_idte(addr, pmdp, IDTE_NODAT | IDTE_GUEST_ASCE,
357 mm->context.asce, IDTE_GLOBAL);
358 if (mm_has_pgste(mm) && mm->context.allow_gmap_hpage_1m)
359 gmap_pmdp_idte_global(mm, addr);
360 } else if (MACHINE_HAS_IDTE) {
361 __pmdp_idte(addr, pmdp, 0, 0, IDTE_GLOBAL);
362 if (mm_has_pgste(mm) && mm->context.allow_gmap_hpage_1m)
363 gmap_pmdp_idte_global(mm, addr);
364 } else {
365 __pmdp_csp(pmdp);
366 if (mm_has_pgste(mm) && mm->context.allow_gmap_hpage_1m)
367 gmap_pmdp_csp(mm, addr);
368 }
369}
370
371static inline pmd_t pmdp_flush_direct(struct mm_struct *mm,
372 unsigned long addr, pmd_t *pmdp)
373{
374 pmd_t old;
375
376 old = *pmdp;
377 if (pmd_val(old) & _SEGMENT_ENTRY_INVALID)
378 return old;
379 atomic_inc(&mm->context.flush_count);
380 if (MACHINE_HAS_TLB_LC &&
381 cpumask_equal(mm_cpumask(mm), cpumask_of(smp_processor_id())))
382 pmdp_idte_local(mm, addr, pmdp);
383 else
384 pmdp_idte_global(mm, addr, pmdp);
385 atomic_dec(&mm->context.flush_count);
386 return old;
387}
388
389static inline pmd_t pmdp_flush_lazy(struct mm_struct *mm,
390 unsigned long addr, pmd_t *pmdp)
391{
392 pmd_t old;
393
394 old = *pmdp;
395 if (pmd_val(old) & _SEGMENT_ENTRY_INVALID)
396 return old;
397 atomic_inc(&mm->context.flush_count);
398 if (cpumask_equal(&mm->context.cpu_attach_mask,
399 cpumask_of(smp_processor_id()))) {
400 pmd_val(*pmdp) |= _SEGMENT_ENTRY_INVALID;
401 mm->context.flush_mm = 1;
402 if (mm_has_pgste(mm))
403 gmap_pmdp_invalidate(mm, addr);
404 } else {
405 pmdp_idte_global(mm, addr, pmdp);
406 }
407 atomic_dec(&mm->context.flush_count);
408 return old;
409}
410
411#ifdef CONFIG_PGSTE
412static pmd_t *pmd_alloc_map(struct mm_struct *mm, unsigned long addr)
413{
414 pgd_t *pgd;
415 p4d_t *p4d;
416 pud_t *pud;
417 pmd_t *pmd;
418
419 pgd = pgd_offset(mm, addr);
420 p4d = p4d_alloc(mm, pgd, addr);
421 if (!p4d)
422 return NULL;
423 pud = pud_alloc(mm, p4d, addr);
424 if (!pud)
425 return NULL;
426 pmd = pmd_alloc(mm, pud, addr);
427 return pmd;
428}
429#endif
430
431pmd_t pmdp_xchg_direct(struct mm_struct *mm, unsigned long addr,
432 pmd_t *pmdp, pmd_t new)
433{
434 pmd_t old;
435
436 preempt_disable();
437 old = pmdp_flush_direct(mm, addr, pmdp);
438 *pmdp = new;
439 preempt_enable();
440 return old;
441}
442EXPORT_SYMBOL(pmdp_xchg_direct);
443
444pmd_t pmdp_xchg_lazy(struct mm_struct *mm, unsigned long addr,
445 pmd_t *pmdp, pmd_t new)
446{
447 pmd_t old;
448
449 preempt_disable();
450 old = pmdp_flush_lazy(mm, addr, pmdp);
451 *pmdp = new;
452 preempt_enable();
453 return old;
454}
455EXPORT_SYMBOL(pmdp_xchg_lazy);
456
457static inline void pudp_idte_local(struct mm_struct *mm,
458 unsigned long addr, pud_t *pudp)
459{
460 if (MACHINE_HAS_TLB_GUEST)
461 __pudp_idte(addr, pudp, IDTE_NODAT | IDTE_GUEST_ASCE,
462 mm->context.asce, IDTE_LOCAL);
463 else
464 __pudp_idte(addr, pudp, 0, 0, IDTE_LOCAL);
465}
466
467static inline void pudp_idte_global(struct mm_struct *mm,
468 unsigned long addr, pud_t *pudp)
469{
470 if (MACHINE_HAS_TLB_GUEST)
471 __pudp_idte(addr, pudp, IDTE_NODAT | IDTE_GUEST_ASCE,
472 mm->context.asce, IDTE_GLOBAL);
473 else if (MACHINE_HAS_IDTE)
474 __pudp_idte(addr, pudp, 0, 0, IDTE_GLOBAL);
475 else
476 /*
477 * Invalid bit position is the same for pmd and pud, so we can
478 * re-use _pmd_csp() here
479 */
480 __pmdp_csp((pmd_t *) pudp);
481}
482
483static inline pud_t pudp_flush_direct(struct mm_struct *mm,
484 unsigned long addr, pud_t *pudp)
485{
486 pud_t old;
487
488 old = *pudp;
489 if (pud_val(old) & _REGION_ENTRY_INVALID)
490 return old;
491 atomic_inc(&mm->context.flush_count);
492 if (MACHINE_HAS_TLB_LC &&
493 cpumask_equal(mm_cpumask(mm), cpumask_of(smp_processor_id())))
494 pudp_idte_local(mm, addr, pudp);
495 else
496 pudp_idte_global(mm, addr, pudp);
497 atomic_dec(&mm->context.flush_count);
498 return old;
499}
500
501pud_t pudp_xchg_direct(struct mm_struct *mm, unsigned long addr,
502 pud_t *pudp, pud_t new)
503{
504 pud_t old;
505
506 preempt_disable();
507 old = pudp_flush_direct(mm, addr, pudp);
508 *pudp = new;
509 preempt_enable();
510 return old;
511}
512EXPORT_SYMBOL(pudp_xchg_direct);
513
514#ifdef CONFIG_TRANSPARENT_HUGEPAGE
515void pgtable_trans_huge_deposit(struct mm_struct *mm, pmd_t *pmdp,
516 pgtable_t pgtable)
517{
518 struct list_head *lh = (struct list_head *) pgtable;
519
520 assert_spin_locked(pmd_lockptr(mm, pmdp));
521
522 /* FIFO */
523 if (!pmd_huge_pte(mm, pmdp))
524 INIT_LIST_HEAD(lh);
525 else
526 list_add(lh, (struct list_head *) pmd_huge_pte(mm, pmdp));
527 pmd_huge_pte(mm, pmdp) = pgtable;
528}
529
530pgtable_t pgtable_trans_huge_withdraw(struct mm_struct *mm, pmd_t *pmdp)
531{
532 struct list_head *lh;
533 pgtable_t pgtable;
534 pte_t *ptep;
535
536 assert_spin_locked(pmd_lockptr(mm, pmdp));
537
538 /* FIFO */
539 pgtable = pmd_huge_pte(mm, pmdp);
540 lh = (struct list_head *) pgtable;
541 if (list_empty(lh))
542 pmd_huge_pte(mm, pmdp) = NULL;
543 else {
544 pmd_huge_pte(mm, pmdp) = (pgtable_t) lh->next;
545 list_del(lh);
546 }
547 ptep = (pte_t *) pgtable;
548 pte_val(*ptep) = _PAGE_INVALID;
549 ptep++;
550 pte_val(*ptep) = _PAGE_INVALID;
551 return pgtable;
552}
553#endif /* CONFIG_TRANSPARENT_HUGEPAGE */
554
555#ifdef CONFIG_PGSTE
556void ptep_set_pte_at(struct mm_struct *mm, unsigned long addr,
557 pte_t *ptep, pte_t entry)
558{
559 pgste_t pgste;
560
561 /* the mm_has_pgste() check is done in set_pte_at() */
562 preempt_disable();
563 pgste = pgste_get_lock(ptep);
564 pgste_val(pgste) &= ~_PGSTE_GPS_ZERO;
565 pgste_set_key(ptep, pgste, entry, mm);
566 pgste = pgste_set_pte(ptep, pgste, entry);
567 pgste_set_unlock(ptep, pgste);
568 preempt_enable();
569}
570
571void ptep_set_notify(struct mm_struct *mm, unsigned long addr, pte_t *ptep)
572{
573 pgste_t pgste;
574
575 preempt_disable();
576 pgste = pgste_get_lock(ptep);
577 pgste_val(pgste) |= PGSTE_IN_BIT;
578 pgste_set_unlock(ptep, pgste);
579 preempt_enable();
580}
581
582/**
583 * ptep_force_prot - change access rights of a locked pte
584 * @mm: pointer to the process mm_struct
585 * @addr: virtual address in the guest address space
586 * @ptep: pointer to the page table entry
587 * @prot: indicates guest access rights: PROT_NONE, PROT_READ or PROT_WRITE
588 * @bit: pgste bit to set (e.g. for notification)
589 *
590 * Returns 0 if the access rights were changed and -EAGAIN if the current
591 * and requested access rights are incompatible.
592 */
593int ptep_force_prot(struct mm_struct *mm, unsigned long addr,
594 pte_t *ptep, int prot, unsigned long bit)
595{
596 pte_t entry;
597 pgste_t pgste;
598 int pte_i, pte_p, nodat;
599
600 pgste = pgste_get_lock(ptep);
601 entry = *ptep;
602 /* Check pte entry after all locks have been acquired */
603 pte_i = pte_val(entry) & _PAGE_INVALID;
604 pte_p = pte_val(entry) & _PAGE_PROTECT;
605 if ((pte_i && (prot != PROT_NONE)) ||
606 (pte_p && (prot & PROT_WRITE))) {
607 pgste_set_unlock(ptep, pgste);
608 return -EAGAIN;
609 }
610 /* Change access rights and set pgste bit */
611 nodat = !!(pgste_val(pgste) & _PGSTE_GPS_NODAT);
612 if (prot == PROT_NONE && !pte_i) {
613 ptep_flush_direct(mm, addr, ptep, nodat);
614 pgste = pgste_update_all(entry, pgste, mm);
615 pte_val(entry) |= _PAGE_INVALID;
616 }
617 if (prot == PROT_READ && !pte_p) {
618 ptep_flush_direct(mm, addr, ptep, nodat);
619 pte_val(entry) &= ~_PAGE_INVALID;
620 pte_val(entry) |= _PAGE_PROTECT;
621 }
622 pgste_val(pgste) |= bit;
623 pgste = pgste_set_pte(ptep, pgste, entry);
624 pgste_set_unlock(ptep, pgste);
625 return 0;
626}
627
628int ptep_shadow_pte(struct mm_struct *mm, unsigned long saddr,
629 pte_t *sptep, pte_t *tptep, pte_t pte)
630{
631 pgste_t spgste, tpgste;
632 pte_t spte, tpte;
633 int rc = -EAGAIN;
634
635 if (!(pte_val(*tptep) & _PAGE_INVALID))
636 return 0; /* already shadowed */
637 spgste = pgste_get_lock(sptep);
638 spte = *sptep;
639 if (!(pte_val(spte) & _PAGE_INVALID) &&
640 !((pte_val(spte) & _PAGE_PROTECT) &&
641 !(pte_val(pte) & _PAGE_PROTECT))) {
642 pgste_val(spgste) |= PGSTE_VSIE_BIT;
643 tpgste = pgste_get_lock(tptep);
644 pte_val(tpte) = (pte_val(spte) & PAGE_MASK) |
645 (pte_val(pte) & _PAGE_PROTECT);
646 /* don't touch the storage key - it belongs to parent pgste */
647 tpgste = pgste_set_pte(tptep, tpgste, tpte);
648 pgste_set_unlock(tptep, tpgste);
649 rc = 1;
650 }
651 pgste_set_unlock(sptep, spgste);
652 return rc;
653}
654
655void ptep_unshadow_pte(struct mm_struct *mm, unsigned long saddr, pte_t *ptep)
656{
657 pgste_t pgste;
658 int nodat;
659
660 pgste = pgste_get_lock(ptep);
661 /* notifier is called by the caller */
662 nodat = !!(pgste_val(pgste) & _PGSTE_GPS_NODAT);
663 ptep_flush_direct(mm, saddr, ptep, nodat);
664 /* don't touch the storage key - it belongs to parent pgste */
665 pgste = pgste_set_pte(ptep, pgste, __pte(_PAGE_INVALID));
666 pgste_set_unlock(ptep, pgste);
667}
668
669static void ptep_zap_swap_entry(struct mm_struct *mm, swp_entry_t entry)
670{
671 if (!non_swap_entry(entry))
672 dec_mm_counter(mm, MM_SWAPENTS);
673 else if (is_migration_entry(entry)) {
674 struct page *page = migration_entry_to_page(entry);
675
676 dec_mm_counter(mm, mm_counter(page));
677 }
678 free_swap_and_cache(entry);
679}
680
681void ptep_zap_unused(struct mm_struct *mm, unsigned long addr,
682 pte_t *ptep, int reset)
683{
684 unsigned long pgstev;
685 pgste_t pgste;
686 pte_t pte;
687
688 /* Zap unused and logically-zero pages */
689 preempt_disable();
690 pgste = pgste_get_lock(ptep);
691 pgstev = pgste_val(pgste);
692 pte = *ptep;
693 if (!reset && pte_swap(pte) &&
694 ((pgstev & _PGSTE_GPS_USAGE_MASK) == _PGSTE_GPS_USAGE_UNUSED ||
695 (pgstev & _PGSTE_GPS_ZERO))) {
696 ptep_zap_swap_entry(mm, pte_to_swp_entry(pte));
697 pte_clear(mm, addr, ptep);
698 }
699 if (reset)
700 pgste_val(pgste) &= ~_PGSTE_GPS_USAGE_MASK;
701 pgste_set_unlock(ptep, pgste);
702 preempt_enable();
703}
704
705void ptep_zap_key(struct mm_struct *mm, unsigned long addr, pte_t *ptep)
706{
707 unsigned long ptev;
708 pgste_t pgste;
709
710 /* Clear storage key ACC and F, but set R/C */
711 preempt_disable();
712 pgste = pgste_get_lock(ptep);
713 pgste_val(pgste) &= ~(PGSTE_ACC_BITS | PGSTE_FP_BIT);
714 pgste_val(pgste) |= PGSTE_GR_BIT | PGSTE_GC_BIT;
715 ptev = pte_val(*ptep);
716 if (!(ptev & _PAGE_INVALID) && (ptev & _PAGE_WRITE))
717 page_set_storage_key(ptev & PAGE_MASK, PAGE_DEFAULT_KEY, 1);
718 pgste_set_unlock(ptep, pgste);
719 preempt_enable();
720}
721
722/*
723 * Test and reset if a guest page is dirty
724 */
725bool ptep_test_and_clear_uc(struct mm_struct *mm, unsigned long addr,
726 pte_t *ptep)
727{
728 pgste_t pgste;
729 pte_t pte;
730 bool dirty;
731 int nodat;
732
733 pgste = pgste_get_lock(ptep);
734 dirty = !!(pgste_val(pgste) & PGSTE_UC_BIT);
735 pgste_val(pgste) &= ~PGSTE_UC_BIT;
736 pte = *ptep;
737 if (dirty && (pte_val(pte) & _PAGE_PRESENT)) {
738 pgste = pgste_pte_notify(mm, addr, ptep, pgste);
739 nodat = !!(pgste_val(pgste) & _PGSTE_GPS_NODAT);
740 ptep_ipte_global(mm, addr, ptep, nodat);
741 if (MACHINE_HAS_ESOP || !(pte_val(pte) & _PAGE_WRITE))
742 pte_val(pte) |= _PAGE_PROTECT;
743 else
744 pte_val(pte) |= _PAGE_INVALID;
745 *ptep = pte;
746 }
747 pgste_set_unlock(ptep, pgste);
748 return dirty;
749}
750EXPORT_SYMBOL_GPL(ptep_test_and_clear_uc);
751
752int set_guest_storage_key(struct mm_struct *mm, unsigned long addr,
753 unsigned char key, bool nq)
754{
755 unsigned long keyul, paddr;
756 spinlock_t *ptl;
757 pgste_t old, new;
758 pmd_t *pmdp;
759 pte_t *ptep;
760
761 pmdp = pmd_alloc_map(mm, addr);
762 if (unlikely(!pmdp))
763 return -EFAULT;
764
765 ptl = pmd_lock(mm, pmdp);
766 if (!pmd_present(*pmdp)) {
767 spin_unlock(ptl);
768 return -EFAULT;
769 }
770
771 if (pmd_large(*pmdp)) {
772 paddr = pmd_val(*pmdp) & HPAGE_MASK;
773 paddr |= addr & ~HPAGE_MASK;
774 /*
775 * Huge pmds need quiescing operations, they are
776 * always mapped.
777 */
778 page_set_storage_key(paddr, key, 1);
779 spin_unlock(ptl);
780 return 0;
781 }
782 spin_unlock(ptl);
783
784 ptep = pte_alloc_map_lock(mm, pmdp, addr, &ptl);
785 if (unlikely(!ptep))
786 return -EFAULT;
787
788 new = old = pgste_get_lock(ptep);
789 pgste_val(new) &= ~(PGSTE_GR_BIT | PGSTE_GC_BIT |
790 PGSTE_ACC_BITS | PGSTE_FP_BIT);
791 keyul = (unsigned long) key;
792 pgste_val(new) |= (keyul & (_PAGE_CHANGED | _PAGE_REFERENCED)) << 48;
793 pgste_val(new) |= (keyul & (_PAGE_ACC_BITS | _PAGE_FP_BIT)) << 56;
794 if (!(pte_val(*ptep) & _PAGE_INVALID)) {
795 unsigned long bits, skey;
796
797 paddr = pte_val(*ptep) & PAGE_MASK;
798 skey = (unsigned long) page_get_storage_key(paddr);
799 bits = skey & (_PAGE_CHANGED | _PAGE_REFERENCED);
800 skey = key & (_PAGE_ACC_BITS | _PAGE_FP_BIT);
801 /* Set storage key ACC and FP */
802 page_set_storage_key(paddr, skey, !nq);
803 /* Merge host changed & referenced into pgste */
804 pgste_val(new) |= bits << 52;
805 }
806 /* changing the guest storage key is considered a change of the page */
807 if ((pgste_val(new) ^ pgste_val(old)) &
808 (PGSTE_ACC_BITS | PGSTE_FP_BIT | PGSTE_GR_BIT | PGSTE_GC_BIT))
809 pgste_val(new) |= PGSTE_UC_BIT;
810
811 pgste_set_unlock(ptep, new);
812 pte_unmap_unlock(ptep, ptl);
813 return 0;
814}
815EXPORT_SYMBOL(set_guest_storage_key);
816
817/**
818 * Conditionally set a guest storage key (handling csske).
819 * oldkey will be updated when either mr or mc is set and a pointer is given.
820 *
821 * Returns 0 if a guests storage key update wasn't necessary, 1 if the guest
822 * storage key was updated and -EFAULT on access errors.
823 */
824int cond_set_guest_storage_key(struct mm_struct *mm, unsigned long addr,
825 unsigned char key, unsigned char *oldkey,
826 bool nq, bool mr, bool mc)
827{
828 unsigned char tmp, mask = _PAGE_ACC_BITS | _PAGE_FP_BIT;
829 int rc;
830
831 /* we can drop the pgste lock between getting and setting the key */
832 if (mr | mc) {
833 rc = get_guest_storage_key(current->mm, addr, &tmp);
834 if (rc)
835 return rc;
836 if (oldkey)
837 *oldkey = tmp;
838 if (!mr)
839 mask |= _PAGE_REFERENCED;
840 if (!mc)
841 mask |= _PAGE_CHANGED;
842 if (!((tmp ^ key) & mask))
843 return 0;
844 }
845 rc = set_guest_storage_key(current->mm, addr, key, nq);
846 return rc < 0 ? rc : 1;
847}
848EXPORT_SYMBOL(cond_set_guest_storage_key);
849
850/**
851 * Reset a guest reference bit (rrbe), returning the reference and changed bit.
852 *
853 * Returns < 0 in case of error, otherwise the cc to be reported to the guest.
854 */
855int reset_guest_reference_bit(struct mm_struct *mm, unsigned long addr)
856{
857 spinlock_t *ptl;
858 unsigned long paddr;
859 pgste_t old, new;
860 pmd_t *pmdp;
861 pte_t *ptep;
862 int cc = 0;
863
864 pmdp = pmd_alloc_map(mm, addr);
865 if (unlikely(!pmdp))
866 return -EFAULT;
867
868 ptl = pmd_lock(mm, pmdp);
869 if (!pmd_present(*pmdp)) {
870 spin_unlock(ptl);
871 return -EFAULT;
872 }
873
874 if (pmd_large(*pmdp)) {
875 paddr = pmd_val(*pmdp) & HPAGE_MASK;
876 paddr |= addr & ~HPAGE_MASK;
877 cc = page_reset_referenced(paddr);
878 spin_unlock(ptl);
879 return cc;
880 }
881 spin_unlock(ptl);
882
883 ptep = pte_alloc_map_lock(mm, pmdp, addr, &ptl);
884 if (unlikely(!ptep))
885 return -EFAULT;
886
887 new = old = pgste_get_lock(ptep);
888 /* Reset guest reference bit only */
889 pgste_val(new) &= ~PGSTE_GR_BIT;
890
891 if (!(pte_val(*ptep) & _PAGE_INVALID)) {
892 paddr = pte_val(*ptep) & PAGE_MASK;
893 cc = page_reset_referenced(paddr);
894 /* Merge real referenced bit into host-set */
895 pgste_val(new) |= ((unsigned long) cc << 53) & PGSTE_HR_BIT;
896 }
897 /* Reflect guest's logical view, not physical */
898 cc |= (pgste_val(old) & (PGSTE_GR_BIT | PGSTE_GC_BIT)) >> 49;
899 /* Changing the guest storage key is considered a change of the page */
900 if ((pgste_val(new) ^ pgste_val(old)) & PGSTE_GR_BIT)
901 pgste_val(new) |= PGSTE_UC_BIT;
902
903 pgste_set_unlock(ptep, new);
904 pte_unmap_unlock(ptep, ptl);
905 return cc;
906}
907EXPORT_SYMBOL(reset_guest_reference_bit);
908
909int get_guest_storage_key(struct mm_struct *mm, unsigned long addr,
910 unsigned char *key)
911{
912 unsigned long paddr;
913 spinlock_t *ptl;
914 pgste_t pgste;
915 pmd_t *pmdp;
916 pte_t *ptep;
917
918 pmdp = pmd_alloc_map(mm, addr);
919 if (unlikely(!pmdp))
920 return -EFAULT;
921
922 ptl = pmd_lock(mm, pmdp);
923 if (!pmd_present(*pmdp)) {
924 /* Not yet mapped memory has a zero key */
925 spin_unlock(ptl);
926 *key = 0;
927 return 0;
928 }
929
930 if (pmd_large(*pmdp)) {
931 paddr = pmd_val(*pmdp) & HPAGE_MASK;
932 paddr |= addr & ~HPAGE_MASK;
933 *key = page_get_storage_key(paddr);
934 spin_unlock(ptl);
935 return 0;
936 }
937 spin_unlock(ptl);
938
939 ptep = pte_alloc_map_lock(mm, pmdp, addr, &ptl);
940 if (unlikely(!ptep))
941 return -EFAULT;
942
943 pgste = pgste_get_lock(ptep);
944 *key = (pgste_val(pgste) & (PGSTE_ACC_BITS | PGSTE_FP_BIT)) >> 56;
945 paddr = pte_val(*ptep) & PAGE_MASK;
946 if (!(pte_val(*ptep) & _PAGE_INVALID))
947 *key = page_get_storage_key(paddr);
948 /* Reflect guest's logical view, not physical */
949 *key |= (pgste_val(pgste) & (PGSTE_GR_BIT | PGSTE_GC_BIT)) >> 48;
950 pgste_set_unlock(ptep, pgste);
951 pte_unmap_unlock(ptep, ptl);
952 return 0;
953}
954EXPORT_SYMBOL(get_guest_storage_key);
955
956/**
957 * pgste_perform_essa - perform ESSA actions on the PGSTE.
958 * @mm: the memory context. It must have PGSTEs, no check is performed here!
959 * @hva: the host virtual address of the page whose PGSTE is to be processed
960 * @orc: the specific action to perform, see the ESSA_SET_* macros.
961 * @oldpte: the PTE will be saved there if the pointer is not NULL.
962 * @oldpgste: the old PGSTE will be saved there if the pointer is not NULL.
963 *
964 * Return: 1 if the page is to be added to the CBRL, otherwise 0,
965 * or < 0 in case of error. -EINVAL is returned for invalid values
966 * of orc, -EFAULT for invalid addresses.
967 */
968int pgste_perform_essa(struct mm_struct *mm, unsigned long hva, int orc,
969 unsigned long *oldpte, unsigned long *oldpgste)
970{
971 unsigned long pgstev;
972 spinlock_t *ptl;
973 pgste_t pgste;
974 pte_t *ptep;
975 int res = 0;
976
977 WARN_ON_ONCE(orc > ESSA_MAX);
978 if (unlikely(orc > ESSA_MAX))
979 return -EINVAL;
980 ptep = get_locked_pte(mm, hva, &ptl);
981 if (unlikely(!ptep))
982 return -EFAULT;
983 pgste = pgste_get_lock(ptep);
984 pgstev = pgste_val(pgste);
985 if (oldpte)
986 *oldpte = pte_val(*ptep);
987 if (oldpgste)
988 *oldpgste = pgstev;
989
990 switch (orc) {
991 case ESSA_GET_STATE:
992 break;
993 case ESSA_SET_STABLE:
994 pgstev &= ~(_PGSTE_GPS_USAGE_MASK | _PGSTE_GPS_NODAT);
995 pgstev |= _PGSTE_GPS_USAGE_STABLE;
996 break;
997 case ESSA_SET_UNUSED:
998 pgstev &= ~_PGSTE_GPS_USAGE_MASK;
999 pgstev |= _PGSTE_GPS_USAGE_UNUSED;
1000 if (pte_val(*ptep) & _PAGE_INVALID)
1001 res = 1;
1002 break;
1003 case ESSA_SET_VOLATILE:
1004 pgstev &= ~_PGSTE_GPS_USAGE_MASK;
1005 pgstev |= _PGSTE_GPS_USAGE_VOLATILE;
1006 if (pte_val(*ptep) & _PAGE_INVALID)
1007 res = 1;
1008 break;
1009 case ESSA_SET_POT_VOLATILE:
1010 pgstev &= ~_PGSTE_GPS_USAGE_MASK;
1011 if (!(pte_val(*ptep) & _PAGE_INVALID)) {
1012 pgstev |= _PGSTE_GPS_USAGE_POT_VOLATILE;
1013 break;
1014 }
1015 if (pgstev & _PGSTE_GPS_ZERO) {
1016 pgstev |= _PGSTE_GPS_USAGE_VOLATILE;
1017 break;
1018 }
1019 if (!(pgstev & PGSTE_GC_BIT)) {
1020 pgstev |= _PGSTE_GPS_USAGE_VOLATILE;
1021 res = 1;
1022 break;
1023 }
1024 break;
1025 case ESSA_SET_STABLE_RESIDENT:
1026 pgstev &= ~_PGSTE_GPS_USAGE_MASK;
1027 pgstev |= _PGSTE_GPS_USAGE_STABLE;
1028 /*
1029 * Since the resident state can go away any time after this
1030 * call, we will not make this page resident. We can revisit
1031 * this decision if a guest will ever start using this.
1032 */
1033 break;
1034 case ESSA_SET_STABLE_IF_RESIDENT:
1035 if (!(pte_val(*ptep) & _PAGE_INVALID)) {
1036 pgstev &= ~_PGSTE_GPS_USAGE_MASK;
1037 pgstev |= _PGSTE_GPS_USAGE_STABLE;
1038 }
1039 break;
1040 case ESSA_SET_STABLE_NODAT:
1041 pgstev &= ~_PGSTE_GPS_USAGE_MASK;
1042 pgstev |= _PGSTE_GPS_USAGE_STABLE | _PGSTE_GPS_NODAT;
1043 break;
1044 default:
1045 /* we should never get here! */
1046 break;
1047 }
1048 /* If we are discarding a page, set it to logical zero */
1049 if (res)
1050 pgstev |= _PGSTE_GPS_ZERO;
1051
1052 pgste_val(pgste) = pgstev;
1053 pgste_set_unlock(ptep, pgste);
1054 pte_unmap_unlock(ptep, ptl);
1055 return res;
1056}
1057EXPORT_SYMBOL(pgste_perform_essa);
1058
1059/**
1060 * set_pgste_bits - set specific PGSTE bits.
1061 * @mm: the memory context. It must have PGSTEs, no check is performed here!
1062 * @hva: the host virtual address of the page whose PGSTE is to be processed
1063 * @bits: a bitmask representing the bits that will be touched
1064 * @value: the values of the bits to be written. Only the bits in the mask
1065 * will be written.
1066 *
1067 * Return: 0 on success, < 0 in case of error.
1068 */
1069int set_pgste_bits(struct mm_struct *mm, unsigned long hva,
1070 unsigned long bits, unsigned long value)
1071{
1072 spinlock_t *ptl;
1073 pgste_t new;
1074 pte_t *ptep;
1075
1076 ptep = get_locked_pte(mm, hva, &ptl);
1077 if (unlikely(!ptep))
1078 return -EFAULT;
1079 new = pgste_get_lock(ptep);
1080
1081 pgste_val(new) &= ~bits;
1082 pgste_val(new) |= value & bits;
1083
1084 pgste_set_unlock(ptep, new);
1085 pte_unmap_unlock(ptep, ptl);
1086 return 0;
1087}
1088EXPORT_SYMBOL(set_pgste_bits);
1089
1090/**
1091 * get_pgste - get the current PGSTE for the given address.
1092 * @mm: the memory context. It must have PGSTEs, no check is performed here!
1093 * @hva: the host virtual address of the page whose PGSTE is to be processed
1094 * @pgstep: will be written with the current PGSTE for the given address.
1095 *
1096 * Return: 0 on success, < 0 in case of error.
1097 */
1098int get_pgste(struct mm_struct *mm, unsigned long hva, unsigned long *pgstep)
1099{
1100 spinlock_t *ptl;
1101 pte_t *ptep;
1102
1103 ptep = get_locked_pte(mm, hva, &ptl);
1104 if (unlikely(!ptep))
1105 return -EFAULT;
1106 *pgstep = pgste_val(pgste_get(ptep));
1107 pte_unmap_unlock(ptep, ptl);
1108 return 0;
1109}
1110EXPORT_SYMBOL(get_pgste);
1111#endif