1 // SPDX-License-Identifier: GPL-2.0
3 * Copyright IBM Corp. 2007, 2011
4 * Author(s): Martin Schwidefsky <schwidefsky@de.ibm.com>
7 #include <linux/sched.h>
8 #include <linux/kernel.h>
9 #include <linux/errno.h>
10 #include <linux/gfp.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>
22 #include <asm/pgtable.h>
23 #include <asm/pgalloc.h>
25 #include <asm/tlbflush.h>
26 #include <asm/mmu_context.h>
27 #include <asm/page-states.h>
29 static inline void ptep_ipte_local(struct mm_struct *mm, unsigned long addr,
30 pte_t *ptep, int nodat)
32 unsigned long opt, asce;
34 if (MACHINE_HAS_TLB_GUEST) {
36 asce = READ_ONCE(mm->context.gmap_asce);
37 if (asce == 0UL || nodat)
40 asce = asce ? : mm->context.asce;
41 opt |= IPTE_GUEST_ASCE;
43 __ptep_ipte(addr, ptep, opt, asce, IPTE_LOCAL);
45 __ptep_ipte(addr, ptep, 0, 0, IPTE_LOCAL);
49 static inline void ptep_ipte_global(struct mm_struct *mm, unsigned long addr,
50 pte_t *ptep, int nodat)
52 unsigned long opt, asce;
54 if (MACHINE_HAS_TLB_GUEST) {
56 asce = READ_ONCE(mm->context.gmap_asce);
57 if (asce == 0UL || nodat)
60 asce = asce ? : mm->context.asce;
61 opt |= IPTE_GUEST_ASCE;
63 __ptep_ipte(addr, ptep, opt, asce, IPTE_GLOBAL);
65 __ptep_ipte(addr, ptep, 0, 0, IPTE_GLOBAL);
69 static inline pte_t ptep_flush_direct(struct mm_struct *mm,
70 unsigned long addr, pte_t *ptep,
76 if (unlikely(pte_val(old) & _PAGE_INVALID))
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);
83 ptep_ipte_global(mm, addr, ptep, nodat);
84 atomic_dec(&mm->context.flush_count);
88 static inline pte_t ptep_flush_lazy(struct mm_struct *mm,
89 unsigned long addr, pte_t *ptep,
95 if (unlikely(pte_val(old) & _PAGE_INVALID))
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;
103 ptep_ipte_global(mm, addr, ptep, nodat);
104 atomic_dec(&mm->context.flush_count);
108 static inline pgste_t pgste_get_lock(pte_t *ptep)
110 unsigned long new = 0;
117 " nihh %0,0xff7f\n" /* clear PCL bit in old */
118 " oihh %1,0x0080\n" /* set PCL bit in new */
121 : "=&d" (old), "=&d" (new), "=Q" (ptep[PTRS_PER_PTE])
122 : "Q" (ptep[PTRS_PER_PTE]) : "cc", "memory");
127 static inline void pgste_set_unlock(pte_t *ptep, pgste_t pgste)
131 " nihh %1,0xff7f\n" /* clear PCL bit */
133 : "=Q" (ptep[PTRS_PER_PTE])
134 : "d" (pgste_val(pgste)), "Q" (ptep[PTRS_PER_PTE])
139 static inline pgste_t pgste_get(pte_t *ptep)
141 unsigned long pgste = 0;
143 pgste = *(unsigned long *)(ptep + PTRS_PER_PTE);
145 return __pgste(pgste);
148 static inline void pgste_set(pte_t *ptep, pgste_t pgste)
151 *(pgste_t *)(ptep + PTRS_PER_PTE) = pgste;
155 static inline pgste_t pgste_update_all(pte_t pte, pgste_t pgste,
156 struct mm_struct *mm)
159 unsigned long address, bits, skey;
161 if (!mm_uses_skeys(mm) || pte_val(pte) & _PAGE_INVALID)
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;
176 static inline void pgste_set_key(pte_t *ptep, pgste_t pgste, pte_t entry,
177 struct mm_struct *mm)
180 unsigned long address;
183 if (!mm_uses_skeys(mm) || pte_val(entry) & _PAGE_INVALID)
185 VM_BUG_ON(!(pte_val(*ptep) & _PAGE_INVALID));
186 address = pte_val(entry) & PAGE_MASK;
188 * Set page access key and fetch protection bit from pgste.
189 * The guest C/R information is still in the PGSTE, set real
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);
198 static inline pgste_t pgste_set_pte(pte_t *ptep, pgste_t pgste, pte_t entry)
201 if ((pte_val(entry) & _PAGE_PRESENT) &&
202 (pte_val(entry) & _PAGE_WRITE) &&
203 !(pte_val(entry) & _PAGE_INVALID)) {
204 if (!MACHINE_HAS_ESOP) {
206 * Without enhanced suppression-on-protection force
207 * the dirty bit on for all writable ptes.
209 pte_val(entry) |= _PAGE_DIRTY;
210 pte_val(entry) &= ~_PAGE_PROTECT;
212 if (!(pte_val(entry) & _PAGE_PROTECT))
213 /* This pte allows write access, set user-dirty */
214 pgste_val(pgste) |= PGSTE_UC_BIT;
221 static inline pgste_t pgste_pte_notify(struct mm_struct *mm,
223 pte_t *ptep, pgste_t pgste)
228 bits = pgste_val(pgste) & (PGSTE_IN_BIT | PGSTE_VSIE_BIT);
230 pgste_val(pgste) ^= bits;
231 ptep_notify(mm, addr, ptep, bits);
237 static inline pgste_t ptep_xchg_start(struct mm_struct *mm,
238 unsigned long addr, pte_t *ptep)
240 pgste_t pgste = __pgste(0);
242 if (mm_has_pgste(mm)) {
243 pgste = pgste_get_lock(ptep);
244 pgste = pgste_pte_notify(mm, addr, ptep, pgste);
249 static inline pte_t ptep_xchg_commit(struct mm_struct *mm,
250 unsigned long addr, pte_t *ptep,
251 pgste_t pgste, pte_t old, pte_t new)
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;
262 pgste = pgste_set_pte(ptep, pgste, new);
263 pgste_set_unlock(ptep, pgste);
270 pte_t ptep_xchg_direct(struct mm_struct *mm, unsigned long addr,
271 pte_t *ptep, pte_t new)
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);
285 EXPORT_SYMBOL(ptep_xchg_direct);
287 pte_t ptep_xchg_lazy(struct mm_struct *mm, unsigned long addr,
288 pte_t *ptep, pte_t new)
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);
302 EXPORT_SYMBOL(ptep_xchg_lazy);
304 pte_t ptep_modify_prot_start(struct mm_struct *mm, unsigned long addr,
312 pgste = ptep_xchg_start(mm, addr, ptep);
313 nodat = !!(pgste_val(pgste) & _PGSTE_GPS_NODAT);
314 old = ptep_flush_lazy(mm, addr, ptep, nodat);
315 if (mm_has_pgste(mm)) {
316 pgste = pgste_update_all(old, pgste, mm);
317 pgste_set(ptep, pgste);
321 EXPORT_SYMBOL(ptep_modify_prot_start);
323 void ptep_modify_prot_commit(struct mm_struct *mm, unsigned long addr,
324 pte_t *ptep, pte_t pte)
329 pte_val(pte) &= ~_PAGE_NOEXEC;
330 if (mm_has_pgste(mm)) {
331 pgste = pgste_get(ptep);
332 pgste_set_key(ptep, pgste, pte, mm);
333 pgste = pgste_set_pte(ptep, pgste, pte);
334 pgste_set_unlock(ptep, pgste);
340 EXPORT_SYMBOL(ptep_modify_prot_commit);
342 static inline void pmdp_idte_local(struct mm_struct *mm,
343 unsigned long addr, pmd_t *pmdp)
345 if (MACHINE_HAS_TLB_GUEST)
346 __pmdp_idte(addr, pmdp, IDTE_NODAT | IDTE_GUEST_ASCE,
347 mm->context.asce, IDTE_LOCAL);
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);
354 static inline void pmdp_idte_global(struct mm_struct *mm,
355 unsigned long addr, pmd_t *pmdp)
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);
368 if (mm_has_pgste(mm) && mm->context.allow_gmap_hpage_1m)
369 gmap_pmdp_csp(mm, addr);
373 static inline pmd_t pmdp_flush_direct(struct mm_struct *mm,
374 unsigned long addr, pmd_t *pmdp)
379 if (pmd_val(old) & _SEGMENT_ENTRY_INVALID)
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);
386 pmdp_idte_global(mm, addr, pmdp);
387 atomic_dec(&mm->context.flush_count);
391 static inline pmd_t pmdp_flush_lazy(struct mm_struct *mm,
392 unsigned long addr, pmd_t *pmdp)
397 if (pmd_val(old) & _SEGMENT_ENTRY_INVALID)
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);
407 pmdp_idte_global(mm, addr, pmdp);
409 atomic_dec(&mm->context.flush_count);
413 static pmd_t *pmd_alloc_map(struct mm_struct *mm, unsigned long addr)
420 pgd = pgd_offset(mm, addr);
421 p4d = p4d_alloc(mm, pgd, addr);
424 pud = pud_alloc(mm, p4d, addr);
427 pmd = pmd_alloc(mm, pud, addr);
431 pmd_t pmdp_xchg_direct(struct mm_struct *mm, unsigned long addr,
432 pmd_t *pmdp, pmd_t new)
437 old = pmdp_flush_direct(mm, addr, pmdp);
442 EXPORT_SYMBOL(pmdp_xchg_direct);
444 pmd_t pmdp_xchg_lazy(struct mm_struct *mm, unsigned long addr,
445 pmd_t *pmdp, pmd_t new)
450 old = pmdp_flush_lazy(mm, addr, pmdp);
455 EXPORT_SYMBOL(pmdp_xchg_lazy);
457 static inline void pudp_idte_local(struct mm_struct *mm,
458 unsigned long addr, pud_t *pudp)
460 if (MACHINE_HAS_TLB_GUEST)
461 __pudp_idte(addr, pudp, IDTE_NODAT | IDTE_GUEST_ASCE,
462 mm->context.asce, IDTE_LOCAL);
464 __pudp_idte(addr, pudp, 0, 0, IDTE_LOCAL);
467 static inline void pudp_idte_global(struct mm_struct *mm,
468 unsigned long addr, pud_t *pudp)
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);
477 * Invalid bit position is the same for pmd and pud, so we can
478 * re-use _pmd_csp() here
480 __pmdp_csp((pmd_t *) pudp);
483 static inline pud_t pudp_flush_direct(struct mm_struct *mm,
484 unsigned long addr, pud_t *pudp)
489 if (pud_val(old) & _REGION_ENTRY_INVALID)
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);
496 pudp_idte_global(mm, addr, pudp);
497 atomic_dec(&mm->context.flush_count);
501 pud_t pudp_xchg_direct(struct mm_struct *mm, unsigned long addr,
502 pud_t *pudp, pud_t new)
507 old = pudp_flush_direct(mm, addr, pudp);
512 EXPORT_SYMBOL(pudp_xchg_direct);
514 #ifdef CONFIG_TRANSPARENT_HUGEPAGE
515 void pgtable_trans_huge_deposit(struct mm_struct *mm, pmd_t *pmdp,
518 struct list_head *lh = (struct list_head *) pgtable;
520 assert_spin_locked(pmd_lockptr(mm, pmdp));
523 if (!pmd_huge_pte(mm, pmdp))
526 list_add(lh, (struct list_head *) pmd_huge_pte(mm, pmdp));
527 pmd_huge_pte(mm, pmdp) = pgtable;
530 pgtable_t pgtable_trans_huge_withdraw(struct mm_struct *mm, pmd_t *pmdp)
532 struct list_head *lh;
536 assert_spin_locked(pmd_lockptr(mm, pmdp));
539 pgtable = pmd_huge_pte(mm, pmdp);
540 lh = (struct list_head *) pgtable;
542 pmd_huge_pte(mm, pmdp) = NULL;
544 pmd_huge_pte(mm, pmdp) = (pgtable_t) lh->next;
547 ptep = (pte_t *) pgtable;
548 pte_val(*ptep) = _PAGE_INVALID;
550 pte_val(*ptep) = _PAGE_INVALID;
553 #endif /* CONFIG_TRANSPARENT_HUGEPAGE */
556 void ptep_set_pte_at(struct mm_struct *mm, unsigned long addr,
557 pte_t *ptep, pte_t entry)
561 /* the mm_has_pgste() check is done in set_pte_at() */
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);
571 void ptep_set_notify(struct mm_struct *mm, unsigned long addr, pte_t *ptep)
576 pgste = pgste_get_lock(ptep);
577 pgste_val(pgste) |= PGSTE_IN_BIT;
578 pgste_set_unlock(ptep, pgste);
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)
590 * Returns 0 if the access rights were changed and -EAGAIN if the current
591 * and requested access rights are incompatible.
593 int ptep_force_prot(struct mm_struct *mm, unsigned long addr,
594 pte_t *ptep, int prot, unsigned long bit)
598 int pte_i, pte_p, nodat;
600 pgste = pgste_get_lock(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);
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;
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;
622 pgste_val(pgste) |= bit;
623 pgste = pgste_set_pte(ptep, pgste, entry);
624 pgste_set_unlock(ptep, pgste);
628 int ptep_shadow_pte(struct mm_struct *mm, unsigned long saddr,
629 pte_t *sptep, pte_t *tptep, pte_t pte)
631 pgste_t spgste, tpgste;
635 if (!(pte_val(*tptep) & _PAGE_INVALID))
636 return 0; /* already shadowed */
637 spgste = pgste_get_lock(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);
651 pgste_set_unlock(sptep, spgste);
655 void ptep_unshadow_pte(struct mm_struct *mm, unsigned long saddr, pte_t *ptep)
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);
669 static void ptep_zap_swap_entry(struct mm_struct *mm, swp_entry_t entry)
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);
676 dec_mm_counter(mm, mm_counter(page));
678 free_swap_and_cache(entry);
681 void ptep_zap_unused(struct mm_struct *mm, unsigned long addr,
682 pte_t *ptep, int reset)
684 unsigned long pgstev;
688 /* Zap unused and logically-zero pages */
690 pgste = pgste_get_lock(ptep);
691 pgstev = pgste_val(pgste);
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);
700 pgste_val(pgste) &= ~_PGSTE_GPS_USAGE_MASK;
701 pgste_set_unlock(ptep, pgste);
705 void ptep_zap_key(struct mm_struct *mm, unsigned long addr, pte_t *ptep)
710 /* Clear storage key ACC and F, but set R/C */
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);
723 * Test and reset if a guest page is dirty
725 bool ptep_test_and_clear_uc(struct mm_struct *mm, unsigned long addr,
733 pgste = pgste_get_lock(ptep);
734 dirty = !!(pgste_val(pgste) & PGSTE_UC_BIT);
735 pgste_val(pgste) &= ~PGSTE_UC_BIT;
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;
744 pte_val(pte) |= _PAGE_INVALID;
747 pgste_set_unlock(ptep, pgste);
750 EXPORT_SYMBOL_GPL(ptep_test_and_clear_uc);
752 int set_guest_storage_key(struct mm_struct *mm, unsigned long addr,
753 unsigned char key, bool nq)
755 unsigned long keyul, paddr;
761 pmdp = pmd_alloc_map(mm, addr);
765 ptl = pmd_lock(mm, pmdp);
766 if (!pmd_present(*pmdp)) {
771 if (pmd_large(*pmdp)) {
772 paddr = pmd_val(*pmdp) & HPAGE_MASK;
773 paddr |= addr & ~HPAGE_MASK;
775 * Huge pmds need quiescing operations, they are
778 page_set_storage_key(paddr, key, 1);
784 ptep = pte_alloc_map_lock(mm, pmdp, addr, &ptl);
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;
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;
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;
811 pgste_set_unlock(ptep, new);
812 pte_unmap_unlock(ptep, ptl);
815 EXPORT_SYMBOL(set_guest_storage_key);
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.
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.
824 int 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)
828 unsigned char tmp, mask = _PAGE_ACC_BITS | _PAGE_FP_BIT;
831 /* we can drop the pgste lock between getting and setting the key */
833 rc = get_guest_storage_key(current->mm, addr, &tmp);
839 mask |= _PAGE_REFERENCED;
841 mask |= _PAGE_CHANGED;
842 if (!((tmp ^ key) & mask))
845 rc = set_guest_storage_key(current->mm, addr, key, nq);
846 return rc < 0 ? rc : 1;
848 EXPORT_SYMBOL(cond_set_guest_storage_key);
851 * Reset a guest reference bit (rrbe), returning the reference and changed bit.
853 * Returns < 0 in case of error, otherwise the cc to be reported to the guest.
855 int reset_guest_reference_bit(struct mm_struct *mm, unsigned long addr)
864 pmdp = pmd_alloc_map(mm, addr);
868 ptl = pmd_lock(mm, pmdp);
869 if (!pmd_present(*pmdp)) {
874 if (pmd_large(*pmdp)) {
875 paddr = pmd_val(*pmdp) & HPAGE_MASK;
876 paddr |= addr & ~HPAGE_MASK;
877 cc = page_reset_referenced(paddr);
883 ptep = pte_alloc_map_lock(mm, pmdp, addr, &ptl);
887 new = old = pgste_get_lock(ptep);
888 /* Reset guest reference bit only */
889 pgste_val(new) &= ~PGSTE_GR_BIT;
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;
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;
903 pgste_set_unlock(ptep, new);
904 pte_unmap_unlock(ptep, ptl);
907 EXPORT_SYMBOL(reset_guest_reference_bit);
909 int get_guest_storage_key(struct mm_struct *mm, unsigned long addr,
918 pmdp = pmd_alloc_map(mm, addr);
922 ptl = pmd_lock(mm, pmdp);
923 if (!pmd_present(*pmdp)) {
924 /* Not yet mapped memory has a zero key */
930 if (pmd_large(*pmdp)) {
931 paddr = pmd_val(*pmdp) & HPAGE_MASK;
932 paddr |= addr & ~HPAGE_MASK;
933 *key = page_get_storage_key(paddr);
939 ptep = pte_alloc_map_lock(mm, pmdp, addr, &ptl);
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);
954 EXPORT_SYMBOL(get_guest_storage_key);
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.
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.
968 int pgste_perform_essa(struct mm_struct *mm, unsigned long hva, int orc,
969 unsigned long *oldpte, unsigned long *oldpgste)
971 unsigned long pgstev;
977 WARN_ON_ONCE(orc > ESSA_MAX);
978 if (unlikely(orc > ESSA_MAX))
980 ptep = get_locked_pte(mm, hva, &ptl);
983 pgste = pgste_get_lock(ptep);
984 pgstev = pgste_val(pgste);
986 *oldpte = pte_val(*ptep);
993 case ESSA_SET_STABLE:
994 pgstev &= ~(_PGSTE_GPS_USAGE_MASK | _PGSTE_GPS_NODAT);
995 pgstev |= _PGSTE_GPS_USAGE_STABLE;
997 case ESSA_SET_UNUSED:
998 pgstev &= ~_PGSTE_GPS_USAGE_MASK;
999 pgstev |= _PGSTE_GPS_USAGE_UNUSED;
1000 if (pte_val(*ptep) & _PAGE_INVALID)
1003 case ESSA_SET_VOLATILE:
1004 pgstev &= ~_PGSTE_GPS_USAGE_MASK;
1005 pgstev |= _PGSTE_GPS_USAGE_VOLATILE;
1006 if (pte_val(*ptep) & _PAGE_INVALID)
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;
1015 if (pgstev & _PGSTE_GPS_ZERO) {
1016 pgstev |= _PGSTE_GPS_USAGE_VOLATILE;
1019 if (!(pgstev & PGSTE_GC_BIT)) {
1020 pgstev |= _PGSTE_GPS_USAGE_VOLATILE;
1025 case ESSA_SET_STABLE_RESIDENT:
1026 pgstev &= ~_PGSTE_GPS_USAGE_MASK;
1027 pgstev |= _PGSTE_GPS_USAGE_STABLE;
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.
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;
1040 case ESSA_SET_STABLE_NODAT:
1041 pgstev &= ~_PGSTE_GPS_USAGE_MASK;
1042 pgstev |= _PGSTE_GPS_USAGE_STABLE | _PGSTE_GPS_NODAT;
1045 /* we should never get here! */
1048 /* If we are discarding a page, set it to logical zero */
1050 pgstev |= _PGSTE_GPS_ZERO;
1052 pgste_val(pgste) = pgstev;
1053 pgste_set_unlock(ptep, pgste);
1054 pte_unmap_unlock(ptep, ptl);
1057 EXPORT_SYMBOL(pgste_perform_essa);
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
1067 * Return: 0 on success, < 0 in case of error.
1069 int set_pgste_bits(struct mm_struct *mm, unsigned long hva,
1070 unsigned long bits, unsigned long value)
1076 ptep = get_locked_pte(mm, hva, &ptl);
1077 if (unlikely(!ptep))
1079 new = pgste_get_lock(ptep);
1081 pgste_val(new) &= ~bits;
1082 pgste_val(new) |= value & bits;
1084 pgste_set_unlock(ptep, new);
1085 pte_unmap_unlock(ptep, ptl);
1088 EXPORT_SYMBOL(set_pgste_bits);
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.
1096 * Return: 0 on success, < 0 in case of error.
1098 int get_pgste(struct mm_struct *mm, unsigned long hva, unsigned long *pgstep)
1103 ptep = get_locked_pte(mm, hva, &ptl);
1104 if (unlikely(!ptep))
1106 *pgstep = pgste_val(pgste_get(ptep));
1107 pte_unmap_unlock(ptep, ptl);
1110 EXPORT_SYMBOL(get_pgste);