1 files changed, 51 insertions, 6 deletions

diff --git a/arch/s390/mm/pgtable.c b/arch/s390/mm/pgtable.c
index ab65fb11e058..5b02583fbf4c 100644
--- a/arch/s390/mm/pgtable.c
+++ b/arch/s390/mm/pgtable.c
@@ -184,9 +184,12 @@ static inline pgste_t pgste_pte_notify(struct mm_struct *mm,
 				       pte_t *ptep, pgste_t pgste)
 {
 #ifdef CONFIG_PGSTE
-	if (pgste_val(pgste) & PGSTE_IN_BIT) {
-		pgste_val(pgste) &= ~PGSTE_IN_BIT;
-		ptep_notify(mm, addr, ptep);
+	unsigned long bits;
+
+	bits = pgste_val(pgste) & (PGSTE_IN_BIT | PGSTE_VSIE_BIT);
+	if (bits) {
+		pgste_val(pgste) ^= bits;
+		ptep_notify(mm, addr, ptep, bits);
 	}
 #endif
 	return pgste;
@@ -420,12 +423,13 @@ void ptep_set_notify(struct mm_struct *mm, unsigned long addr, pte_t *ptep)
  * @addr: virtual address in the guest address space
  * @ptep: pointer to the page table entry
  * @prot: indicates guest access rights: PROT_NONE, PROT_READ or PROT_WRITE
+ * @bit: pgste bit to set (e.g. for notification)
  *
  * Returns 0 if the access rights were changed and -EAGAIN if the current
  * and requested access rights are incompatible.
  */
 int ptep_force_prot(struct mm_struct *mm, unsigned long addr,
-		    pte_t *ptep, int prot)
+		    pte_t *ptep, int prot, unsigned long bit)
 {
 	pte_t entry;
 	pgste_t pgste;
@@ -441,7 +445,7 @@ int ptep_force_prot(struct mm_struct *mm, unsigned long addr,
 		pgste_set_unlock(ptep, pgste);
 		return -EAGAIN;
 	}
-	/* Change access rights and set the pgste notification bit */
+	/* Change access rights and set pgste bit */
 	if (prot == PROT_NONE && !pte_i) {
 		ptep_flush_direct(mm, addr, ptep);
 		pgste = pgste_update_all(entry, pgste, mm);
@@ -452,12 +456,53 @@ int ptep_force_prot(struct mm_struct *mm, unsigned long addr,
 		pte_val(entry) &= ~_PAGE_INVALID;
 		pte_val(entry) |= _PAGE_PROTECT;
 	}
-	pgste_val(pgste) |= PGSTE_IN_BIT;
+	pgste_val(pgste) |= bit;
 	pgste = pgste_set_pte(ptep, pgste, entry);
 	pgste_set_unlock(ptep, pgste);
 	return 0;
 }
 
+int ptep_shadow_pte(struct mm_struct *mm, unsigned long saddr,
+		    pte_t *sptep, pte_t *tptep, int write)
+{
+	pgste_t spgste, tpgste;
+	pte_t spte, tpte;
+	int rc = -EAGAIN;
+
+	spgste = pgste_get_lock(sptep);
+	spte = *sptep;
+	if (!(pte_val(spte) & _PAGE_INVALID) &&
+	    !(pte_val(spte) & _PAGE_PROTECT)) {
+		rc = 0;
+		if (!(pte_val(*tptep) & _PAGE_INVALID))
+			/* Update existing mapping */
+			ptep_flush_direct(mm, saddr, tptep);
+		else
+			rc = 1;
+		pgste_val(spgste) |= PGSTE_VSIE_BIT;
+		tpgste = pgste_get_lock(tptep);
+		pte_val(tpte) = (pte_val(spte) & PAGE_MASK) |
+			(write ? 0 : _PAGE_PROTECT);
+		/* don't touch the storage key - it belongs to parent pgste */
+		tpgste = pgste_set_pte(tptep, tpgste, tpte);
+		pgste_set_unlock(tptep, tpgste);
+	}
+	pgste_set_unlock(sptep, spgste);
+	return rc;
+}
+
+void ptep_unshadow_pte(struct mm_struct *mm, unsigned long saddr, pte_t *ptep)
+{
+	pgste_t pgste;
+
+	pgste = pgste_get_lock(ptep);
+	/* notifier is called by the caller */
+	ptep_flush_direct(mm, saddr, ptep);
+	/* don't touch the storage key - it belongs to parent pgste */
+	pgste = pgste_set_pte(ptep, pgste, __pte(_PAGE_INVALID));
+	pgste_set_unlock(ptep, pgste);
+}
+
 static void ptep_zap_swap_entry(struct mm_struct *mm, swp_entry_t entry)
 {
 	if (!non_swap_entry(entry))