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1// SPDX-License-Identifier: GPL-2.0
2/*
3 * Copyright IBM Corp. 2007, 2011
4 * Author(s): Martin Schwidefsky <schwidefsky@de.ibm.com>
5 */
6
7#include <linux/sched.h>
8#include <linux/kernel.h>
9#include <linux/errno.h>
10#include <linux/gfp.h>
11#include <linux/mm.h>
12#include <linux/swap.h>
13#include <linux/smp.h>
14#include <linux/spinlock.h>
15#include <linux/rcupdate.h>
16#include <linux/slab.h>
17#include <linux/swapops.h>
18#include <linux/sysctl.h>
19#include <linux/ksm.h>
20#include <linux/mman.h>
21
22#include <asm/tlb.h>
23#include <asm/tlbflush.h>
24#include <asm/mmu_context.h>
25#include <asm/page-states.h>
26
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
1/*
2 * Copyright IBM Corp. 2007, 2011
3 * Author(s): Martin Schwidefsky <schwidefsky@de.ibm.com>
4 */
5
6#include <linux/sched.h>
7#include <linux/kernel.h>
8#include <linux/errno.h>
9#include <linux/gfp.h>
10#include <linux/mm.h>
11#include <linux/swap.h>
12#include <linux/smp.h>
13#include <linux/spinlock.h>
14#include <linux/rcupdate.h>
15#include <linux/slab.h>
16#include <linux/swapops.h>
17#include <linux/sysctl.h>
18#include <linux/ksm.h>
19#include <linux/mman.h>
20
21#include <asm/pgtable.h>
22#include <asm/pgalloc.h>
23#include <asm/tlb.h>
24#include <asm/tlbflush.h>
25#include <asm/mmu_context.h>
26
27static inline pte_t ptep_flush_direct(struct mm_struct *mm,
28 unsigned long addr, pte_t *ptep)
29{
30 int active, count;
31 pte_t old;
32
33 old = *ptep;
34 if (unlikely(pte_val(old) & _PAGE_INVALID))
35 return old;
36 active = (mm == current->active_mm) ? 1 : 0;
37 count = atomic_add_return(0x10000, &mm->context.attach_count);
38 if (MACHINE_HAS_TLB_LC && (count & 0xffff) <= active &&
39 cpumask_equal(mm_cpumask(mm), cpumask_of(smp_processor_id())))
40 __ptep_ipte_local(addr, ptep);
41 else
42 __ptep_ipte(addr, ptep);
43 atomic_sub(0x10000, &mm->context.attach_count);
44 return old;
45}
46
47static inline pte_t ptep_flush_lazy(struct mm_struct *mm,
48 unsigned long addr, pte_t *ptep)
49{
50 int active, count;
51 pte_t old;
52
53 old = *ptep;
54 if (unlikely(pte_val(old) & _PAGE_INVALID))
55 return old;
56 active = (mm == current->active_mm) ? 1 : 0;
57 count = atomic_add_return(0x10000, &mm->context.attach_count);
58 if ((count & 0xffff) <= active) {
59 pte_val(*ptep) |= _PAGE_INVALID;
60 mm->context.flush_mm = 1;
61 } else
62 __ptep_ipte(addr, ptep);
63 atomic_sub(0x10000, &mm->context.attach_count);
64 return old;
65}
66
67static inline pgste_t pgste_get_lock(pte_t *ptep)
68{
69 unsigned long new = 0;
70#ifdef CONFIG_PGSTE
71 unsigned long old;
72
73 preempt_disable();
74 asm(
75 " lg %0,%2\n"
76 "0: lgr %1,%0\n"
77 " nihh %0,0xff7f\n" /* clear PCL bit in old */
78 " oihh %1,0x0080\n" /* set PCL bit in new */
79 " csg %0,%1,%2\n"
80 " jl 0b\n"
81 : "=&d" (old), "=&d" (new), "=Q" (ptep[PTRS_PER_PTE])
82 : "Q" (ptep[PTRS_PER_PTE]) : "cc", "memory");
83#endif
84 return __pgste(new);
85}
86
87static inline void pgste_set_unlock(pte_t *ptep, pgste_t pgste)
88{
89#ifdef CONFIG_PGSTE
90 asm(
91 " nihh %1,0xff7f\n" /* clear PCL bit */
92 " stg %1,%0\n"
93 : "=Q" (ptep[PTRS_PER_PTE])
94 : "d" (pgste_val(pgste)), "Q" (ptep[PTRS_PER_PTE])
95 : "cc", "memory");
96 preempt_enable();
97#endif
98}
99
100static inline pgste_t pgste_get(pte_t *ptep)
101{
102 unsigned long pgste = 0;
103#ifdef CONFIG_PGSTE
104 pgste = *(unsigned long *)(ptep + PTRS_PER_PTE);
105#endif
106 return __pgste(pgste);
107}
108
109static inline void pgste_set(pte_t *ptep, pgste_t pgste)
110{
111#ifdef CONFIG_PGSTE
112 *(pgste_t *)(ptep + PTRS_PER_PTE) = pgste;
113#endif
114}
115
116static inline pgste_t pgste_update_all(pte_t pte, pgste_t pgste,
117 struct mm_struct *mm)
118{
119#ifdef CONFIG_PGSTE
120 unsigned long address, bits, skey;
121
122 if (!mm_use_skey(mm) || pte_val(pte) & _PAGE_INVALID)
123 return pgste;
124 address = pte_val(pte) & PAGE_MASK;
125 skey = (unsigned long) page_get_storage_key(address);
126 bits = skey & (_PAGE_CHANGED | _PAGE_REFERENCED);
127 /* Transfer page changed & referenced bit to guest bits in pgste */
128 pgste_val(pgste) |= bits << 48; /* GR bit & GC bit */
129 /* Copy page access key and fetch protection bit to pgste */
130 pgste_val(pgste) &= ~(PGSTE_ACC_BITS | PGSTE_FP_BIT);
131 pgste_val(pgste) |= (skey & (_PAGE_ACC_BITS | _PAGE_FP_BIT)) << 56;
132#endif
133 return pgste;
134
135}
136
137static inline void pgste_set_key(pte_t *ptep, pgste_t pgste, pte_t entry,
138 struct mm_struct *mm)
139{
140#ifdef CONFIG_PGSTE
141 unsigned long address;
142 unsigned long nkey;
143
144 if (!mm_use_skey(mm) || pte_val(entry) & _PAGE_INVALID)
145 return;
146 VM_BUG_ON(!(pte_val(*ptep) & _PAGE_INVALID));
147 address = pte_val(entry) & PAGE_MASK;
148 /*
149 * Set page access key and fetch protection bit from pgste.
150 * The guest C/R information is still in the PGSTE, set real
151 * key C/R to 0.
152 */
153 nkey = (pgste_val(pgste) & (PGSTE_ACC_BITS | PGSTE_FP_BIT)) >> 56;
154 nkey |= (pgste_val(pgste) & (PGSTE_GR_BIT | PGSTE_GC_BIT)) >> 48;
155 page_set_storage_key(address, nkey, 0);
156#endif
157}
158
159static inline pgste_t pgste_set_pte(pte_t *ptep, pgste_t pgste, pte_t entry)
160{
161#ifdef CONFIG_PGSTE
162 if ((pte_val(entry) & _PAGE_PRESENT) &&
163 (pte_val(entry) & _PAGE_WRITE) &&
164 !(pte_val(entry) & _PAGE_INVALID)) {
165 if (!MACHINE_HAS_ESOP) {
166 /*
167 * Without enhanced suppression-on-protection force
168 * the dirty bit on for all writable ptes.
169 */
170 pte_val(entry) |= _PAGE_DIRTY;
171 pte_val(entry) &= ~_PAGE_PROTECT;
172 }
173 if (!(pte_val(entry) & _PAGE_PROTECT))
174 /* This pte allows write access, set user-dirty */
175 pgste_val(pgste) |= PGSTE_UC_BIT;
176 }
177#endif
178 *ptep = entry;
179 return pgste;
180}
181
182static inline pgste_t pgste_ipte_notify(struct mm_struct *mm,
183 unsigned long addr,
184 pte_t *ptep, pgste_t pgste)
185{
186#ifdef CONFIG_PGSTE
187 if (pgste_val(pgste) & PGSTE_IN_BIT) {
188 pgste_val(pgste) &= ~PGSTE_IN_BIT;
189 ptep_notify(mm, addr, ptep);
190 }
191#endif
192 return pgste;
193}
194
195static inline pgste_t ptep_xchg_start(struct mm_struct *mm,
196 unsigned long addr, pte_t *ptep)
197{
198 pgste_t pgste = __pgste(0);
199
200 if (mm_has_pgste(mm)) {
201 pgste = pgste_get_lock(ptep);
202 pgste = pgste_ipte_notify(mm, addr, ptep, pgste);
203 }
204 return pgste;
205}
206
207static inline void ptep_xchg_commit(struct mm_struct *mm,
208 unsigned long addr, pte_t *ptep,
209 pgste_t pgste, pte_t old, pte_t new)
210{
211 if (mm_has_pgste(mm)) {
212 if (pte_val(old) & _PAGE_INVALID)
213 pgste_set_key(ptep, pgste, new, mm);
214 if (pte_val(new) & _PAGE_INVALID) {
215 pgste = pgste_update_all(old, pgste, mm);
216 if ((pgste_val(pgste) & _PGSTE_GPS_USAGE_MASK) ==
217 _PGSTE_GPS_USAGE_UNUSED)
218 pte_val(old) |= _PAGE_UNUSED;
219 }
220 pgste = pgste_set_pte(ptep, pgste, new);
221 pgste_set_unlock(ptep, pgste);
222 } else {
223 *ptep = new;
224 }
225}
226
227pte_t ptep_xchg_direct(struct mm_struct *mm, unsigned long addr,
228 pte_t *ptep, pte_t new)
229{
230 pgste_t pgste;
231 pte_t old;
232
233 pgste = ptep_xchg_start(mm, addr, ptep);
234 old = ptep_flush_direct(mm, addr, ptep);
235 ptep_xchg_commit(mm, addr, ptep, pgste, old, new);
236 return old;
237}
238EXPORT_SYMBOL(ptep_xchg_direct);
239
240pte_t ptep_xchg_lazy(struct mm_struct *mm, unsigned long addr,
241 pte_t *ptep, pte_t new)
242{
243 pgste_t pgste;
244 pte_t old;
245
246 pgste = ptep_xchg_start(mm, addr, ptep);
247 old = ptep_flush_lazy(mm, addr, ptep);
248 ptep_xchg_commit(mm, addr, ptep, pgste, old, new);
249 return old;
250}
251EXPORT_SYMBOL(ptep_xchg_lazy);
252
253pte_t ptep_modify_prot_start(struct mm_struct *mm, unsigned long addr,
254 pte_t *ptep)
255{
256 pgste_t pgste;
257 pte_t old;
258
259 pgste = ptep_xchg_start(mm, addr, ptep);
260 old = ptep_flush_lazy(mm, addr, ptep);
261 if (mm_has_pgste(mm)) {
262 pgste = pgste_update_all(old, pgste, mm);
263 pgste_set(ptep, pgste);
264 }
265 return old;
266}
267EXPORT_SYMBOL(ptep_modify_prot_start);
268
269void ptep_modify_prot_commit(struct mm_struct *mm, unsigned long addr,
270 pte_t *ptep, pte_t pte)
271{
272 pgste_t pgste;
273
274 if (mm_has_pgste(mm)) {
275 pgste = pgste_get(ptep);
276 pgste_set_key(ptep, pgste, pte, mm);
277 pgste = pgste_set_pte(ptep, pgste, pte);
278 pgste_set_unlock(ptep, pgste);
279 } else {
280 *ptep = pte;
281 }
282}
283EXPORT_SYMBOL(ptep_modify_prot_commit);
284
285static inline pmd_t pmdp_flush_direct(struct mm_struct *mm,
286 unsigned long addr, pmd_t *pmdp)
287{
288 int active, count;
289 pmd_t old;
290
291 old = *pmdp;
292 if (pmd_val(old) & _SEGMENT_ENTRY_INVALID)
293 return old;
294 if (!MACHINE_HAS_IDTE) {
295 __pmdp_csp(pmdp);
296 return old;
297 }
298 active = (mm == current->active_mm) ? 1 : 0;
299 count = atomic_add_return(0x10000, &mm->context.attach_count);
300 if (MACHINE_HAS_TLB_LC && (count & 0xffff) <= active &&
301 cpumask_equal(mm_cpumask(mm), cpumask_of(smp_processor_id())))
302 __pmdp_idte_local(addr, pmdp);
303 else
304 __pmdp_idte(addr, pmdp);
305 atomic_sub(0x10000, &mm->context.attach_count);
306 return old;
307}
308
309static inline pmd_t pmdp_flush_lazy(struct mm_struct *mm,
310 unsigned long addr, pmd_t *pmdp)
311{
312 int active, count;
313 pmd_t old;
314
315 old = *pmdp;
316 if (pmd_val(old) & _SEGMENT_ENTRY_INVALID)
317 return old;
318 active = (mm == current->active_mm) ? 1 : 0;
319 count = atomic_add_return(0x10000, &mm->context.attach_count);
320 if ((count & 0xffff) <= active) {
321 pmd_val(*pmdp) |= _SEGMENT_ENTRY_INVALID;
322 mm->context.flush_mm = 1;
323 } else if (MACHINE_HAS_IDTE)
324 __pmdp_idte(addr, pmdp);
325 else
326 __pmdp_csp(pmdp);
327 atomic_sub(0x10000, &mm->context.attach_count);
328 return old;
329}
330
331pmd_t pmdp_xchg_direct(struct mm_struct *mm, unsigned long addr,
332 pmd_t *pmdp, pmd_t new)
333{
334 pmd_t old;
335
336 old = pmdp_flush_direct(mm, addr, pmdp);
337 *pmdp = new;
338 return old;
339}
340EXPORT_SYMBOL(pmdp_xchg_direct);
341
342pmd_t pmdp_xchg_lazy(struct mm_struct *mm, unsigned long addr,
343 pmd_t *pmdp, pmd_t new)
344{
345 pmd_t old;
346
347 old = pmdp_flush_lazy(mm, addr, pmdp);
348 *pmdp = new;
349 return old;
350}
351EXPORT_SYMBOL(pmdp_xchg_lazy);
352
353#ifdef CONFIG_TRANSPARENT_HUGEPAGE
354void pgtable_trans_huge_deposit(struct mm_struct *mm, pmd_t *pmdp,
355 pgtable_t pgtable)
356{
357 struct list_head *lh = (struct list_head *) pgtable;
358
359 assert_spin_locked(pmd_lockptr(mm, pmdp));
360
361 /* FIFO */
362 if (!pmd_huge_pte(mm, pmdp))
363 INIT_LIST_HEAD(lh);
364 else
365 list_add(lh, (struct list_head *) pmd_huge_pte(mm, pmdp));
366 pmd_huge_pte(mm, pmdp) = pgtable;
367}
368
369pgtable_t pgtable_trans_huge_withdraw(struct mm_struct *mm, pmd_t *pmdp)
370{
371 struct list_head *lh;
372 pgtable_t pgtable;
373 pte_t *ptep;
374
375 assert_spin_locked(pmd_lockptr(mm, pmdp));
376
377 /* FIFO */
378 pgtable = pmd_huge_pte(mm, pmdp);
379 lh = (struct list_head *) pgtable;
380 if (list_empty(lh))
381 pmd_huge_pte(mm, pmdp) = NULL;
382 else {
383 pmd_huge_pte(mm, pmdp) = (pgtable_t) lh->next;
384 list_del(lh);
385 }
386 ptep = (pte_t *) pgtable;
387 pte_val(*ptep) = _PAGE_INVALID;
388 ptep++;
389 pte_val(*ptep) = _PAGE_INVALID;
390 return pgtable;
391}
392#endif /* CONFIG_TRANSPARENT_HUGEPAGE */
393
394#ifdef CONFIG_PGSTE
395void ptep_set_pte_at(struct mm_struct *mm, unsigned long addr,
396 pte_t *ptep, pte_t entry)
397{
398 pgste_t pgste;
399
400 /* the mm_has_pgste() check is done in set_pte_at() */
401 pgste = pgste_get_lock(ptep);
402 pgste_val(pgste) &= ~_PGSTE_GPS_ZERO;
403 pgste_set_key(ptep, pgste, entry, mm);
404 pgste = pgste_set_pte(ptep, pgste, entry);
405 pgste_set_unlock(ptep, pgste);
406}
407
408void ptep_set_notify(struct mm_struct *mm, unsigned long addr, pte_t *ptep)
409{
410 pgste_t pgste;
411
412 pgste = pgste_get_lock(ptep);
413 pgste_val(pgste) |= PGSTE_IN_BIT;
414 pgste_set_unlock(ptep, pgste);
415}
416
417static void ptep_zap_swap_entry(struct mm_struct *mm, swp_entry_t entry)
418{
419 if (!non_swap_entry(entry))
420 dec_mm_counter(mm, MM_SWAPENTS);
421 else if (is_migration_entry(entry)) {
422 struct page *page = migration_entry_to_page(entry);
423
424 dec_mm_counter(mm, mm_counter(page));
425 }
426 free_swap_and_cache(entry);
427}
428
429void ptep_zap_unused(struct mm_struct *mm, unsigned long addr,
430 pte_t *ptep, int reset)
431{
432 unsigned long pgstev;
433 pgste_t pgste;
434 pte_t pte;
435
436 /* Zap unused and logically-zero pages */
437 pgste = pgste_get_lock(ptep);
438 pgstev = pgste_val(pgste);
439 pte = *ptep;
440 if (pte_swap(pte) &&
441 ((pgstev & _PGSTE_GPS_USAGE_MASK) == _PGSTE_GPS_USAGE_UNUSED ||
442 (pgstev & _PGSTE_GPS_ZERO))) {
443 ptep_zap_swap_entry(mm, pte_to_swp_entry(pte));
444 pte_clear(mm, addr, ptep);
445 }
446 if (reset)
447 pgste_val(pgste) &= ~_PGSTE_GPS_USAGE_MASK;
448 pgste_set_unlock(ptep, pgste);
449}
450
451void ptep_zap_key(struct mm_struct *mm, unsigned long addr, pte_t *ptep)
452{
453 unsigned long ptev;
454 pgste_t pgste;
455
456 /* Clear storage key */
457 pgste = pgste_get_lock(ptep);
458 pgste_val(pgste) &= ~(PGSTE_ACC_BITS | PGSTE_FP_BIT |
459 PGSTE_GR_BIT | PGSTE_GC_BIT);
460 ptev = pte_val(*ptep);
461 if (!(ptev & _PAGE_INVALID) && (ptev & _PAGE_WRITE))
462 page_set_storage_key(ptev & PAGE_MASK, PAGE_DEFAULT_KEY, 1);
463 pgste_set_unlock(ptep, pgste);
464}
465
466/*
467 * Test and reset if a guest page is dirty
468 */
469bool test_and_clear_guest_dirty(struct mm_struct *mm, unsigned long addr)
470{
471 spinlock_t *ptl;
472 pgste_t pgste;
473 pte_t *ptep;
474 pte_t pte;
475 bool dirty;
476
477 ptep = get_locked_pte(mm, addr, &ptl);
478 if (unlikely(!ptep))
479 return false;
480
481 pgste = pgste_get_lock(ptep);
482 dirty = !!(pgste_val(pgste) & PGSTE_UC_BIT);
483 pgste_val(pgste) &= ~PGSTE_UC_BIT;
484 pte = *ptep;
485 if (dirty && (pte_val(pte) & _PAGE_PRESENT)) {
486 pgste = pgste_ipte_notify(mm, addr, ptep, pgste);
487 __ptep_ipte(addr, ptep);
488 if (MACHINE_HAS_ESOP || !(pte_val(pte) & _PAGE_WRITE))
489 pte_val(pte) |= _PAGE_PROTECT;
490 else
491 pte_val(pte) |= _PAGE_INVALID;
492 *ptep = pte;
493 }
494 pgste_set_unlock(ptep, pgste);
495
496 spin_unlock(ptl);
497 return dirty;
498}
499EXPORT_SYMBOL_GPL(test_and_clear_guest_dirty);
500
501int set_guest_storage_key(struct mm_struct *mm, unsigned long addr,
502 unsigned char key, bool nq)
503{
504 unsigned long keyul;
505 spinlock_t *ptl;
506 pgste_t old, new;
507 pte_t *ptep;
508
509 down_read(&mm->mmap_sem);
510 ptep = get_locked_pte(mm, addr, &ptl);
511 if (unlikely(!ptep)) {
512 up_read(&mm->mmap_sem);
513 return -EFAULT;
514 }
515
516 new = old = pgste_get_lock(ptep);
517 pgste_val(new) &= ~(PGSTE_GR_BIT | PGSTE_GC_BIT |
518 PGSTE_ACC_BITS | PGSTE_FP_BIT);
519 keyul = (unsigned long) key;
520 pgste_val(new) |= (keyul & (_PAGE_CHANGED | _PAGE_REFERENCED)) << 48;
521 pgste_val(new) |= (keyul & (_PAGE_ACC_BITS | _PAGE_FP_BIT)) << 56;
522 if (!(pte_val(*ptep) & _PAGE_INVALID)) {
523 unsigned long address, bits, skey;
524
525 address = pte_val(*ptep) & PAGE_MASK;
526 skey = (unsigned long) page_get_storage_key(address);
527 bits = skey & (_PAGE_CHANGED | _PAGE_REFERENCED);
528 skey = key & (_PAGE_ACC_BITS | _PAGE_FP_BIT);
529 /* Set storage key ACC and FP */
530 page_set_storage_key(address, skey, !nq);
531 /* Merge host changed & referenced into pgste */
532 pgste_val(new) |= bits << 52;
533 }
534 /* changing the guest storage key is considered a change of the page */
535 if ((pgste_val(new) ^ pgste_val(old)) &
536 (PGSTE_ACC_BITS | PGSTE_FP_BIT | PGSTE_GR_BIT | PGSTE_GC_BIT))
537 pgste_val(new) |= PGSTE_UC_BIT;
538
539 pgste_set_unlock(ptep, new);
540 pte_unmap_unlock(ptep, ptl);
541 up_read(&mm->mmap_sem);
542 return 0;
543}
544EXPORT_SYMBOL(set_guest_storage_key);
545
546unsigned char get_guest_storage_key(struct mm_struct *mm, unsigned long addr)
547{
548 unsigned char key;
549 spinlock_t *ptl;
550 pgste_t pgste;
551 pte_t *ptep;
552
553 down_read(&mm->mmap_sem);
554 ptep = get_locked_pte(mm, addr, &ptl);
555 if (unlikely(!ptep)) {
556 up_read(&mm->mmap_sem);
557 return -EFAULT;
558 }
559 pgste = pgste_get_lock(ptep);
560
561 if (pte_val(*ptep) & _PAGE_INVALID) {
562 key = (pgste_val(pgste) & PGSTE_ACC_BITS) >> 56;
563 key |= (pgste_val(pgste) & PGSTE_FP_BIT) >> 56;
564 key |= (pgste_val(pgste) & PGSTE_GR_BIT) >> 48;
565 key |= (pgste_val(pgste) & PGSTE_GC_BIT) >> 48;
566 } else {
567 key = page_get_storage_key(pte_val(*ptep) & PAGE_MASK);
568
569 /* Reflect guest's logical view, not physical */
570 if (pgste_val(pgste) & PGSTE_GR_BIT)
571 key |= _PAGE_REFERENCED;
572 if (pgste_val(pgste) & PGSTE_GC_BIT)
573 key |= _PAGE_CHANGED;
574 }
575
576 pgste_set_unlock(ptep, pgste);
577 pte_unmap_unlock(ptep, ptl);
578 up_read(&mm->mmap_sem);
579 return key;
580}
581EXPORT_SYMBOL(get_guest_storage_key);
582#endif