diff --git a/arch/s390/include/asm/page-states.h b/arch/s390/include/asm/page-states.h
new file mode 100644
index 0000000000000000000000000000000000000000..42267a2fe29e74763ae08b2f5d782c54d1ecc615
--- /dev/null
+++ b/arch/s390/include/asm/page-states.h
@@ -0,0 +1,19 @@
+/*
+ * Copyright IBM Corp. 2017
+ * Author(s): Claudio Imbrenda <imbrenda@linux.vnet.ibm.com>
+ */
+
+#ifndef PAGE_STATES_H
+#define PAGE_STATES_H
+
+#define ESSA_GET_STATE 0
+#define ESSA_SET_STABLE 1
+#define ESSA_SET_UNUSED 2
+#define ESSA_SET_VOLATILE 3
+#define ESSA_SET_POT_VOLATILE 4
+#define ESSA_SET_STABLE_RESIDENT 5
+#define ESSA_SET_STABLE_IF_RESIDENT 6
+
+#define ESSA_MAX ESSA_SET_STABLE_IF_RESIDENT
+
+#endif
diff --git a/arch/s390/include/asm/pgtable.h b/arch/s390/include/asm/pgtable.h
index 93e37b12e88237766821369e19827e5e2d844a1b..bdabbbb3e925ebcfee6059cbb10279a9761e3c08 100644
--- a/arch/s390/include/asm/pgtable.h
+++ b/arch/s390/include/asm/pgtable.h
@@ -372,10 +372,12 @@ static inline int is_module_addr(void *addr)
#define PGSTE_VSIE_BIT 0x0000200000000000UL /* ref'd in a shadow table */
/* Guest Page State used for virtualization */
-#define _PGSTE_GPS_ZERO 0x0000000080000000UL
-#define _PGSTE_GPS_USAGE_MASK 0x0000000003000000UL
-#define _PGSTE_GPS_USAGE_STABLE 0x0000000000000000UL
-#define _PGSTE_GPS_USAGE_UNUSED 0x0000000001000000UL
+#define _PGSTE_GPS_ZERO 0x0000000080000000UL
+#define _PGSTE_GPS_USAGE_MASK 0x0000000003000000UL
+#define _PGSTE_GPS_USAGE_STABLE 0x0000000000000000UL
+#define _PGSTE_GPS_USAGE_UNUSED 0x0000000001000000UL
+#define _PGSTE_GPS_USAGE_POT_VOLATILE 0x0000000002000000UL
+#define _PGSTE_GPS_USAGE_VOLATILE _PGSTE_GPS_USAGE_MASK
/*
* A user page table pointer has the space-switch-event bit, the
@@ -1041,6 +1043,12 @@ int reset_guest_reference_bit(struct mm_struct *mm, unsigned long addr);
int get_guest_storage_key(struct mm_struct *mm, unsigned long addr,
unsigned char *key);
+int set_pgste_bits(struct mm_struct *mm, unsigned long addr,
+ unsigned long bits, unsigned long value);
+int get_pgste(struct mm_struct *mm, unsigned long hva, unsigned long *pgstep);
+int pgste_perform_essa(struct mm_struct *mm, unsigned long hva, int orc,
+ unsigned long *oldpte, unsigned long *oldpgste);
+
/*
* Certain architectures need to do special things when PTEs
* within a page table are directly modified. Thus, the following
diff --git a/arch/s390/mm/page-states.c b/arch/s390/mm/page-states.c
index 3330ea124eec32af519f0a496a471b3732cb2101..69a7b01ae746f02c3ab6dea4bf158e8fe04efd41 100644
--- a/arch/s390/mm/page-states.c
+++ b/arch/s390/mm/page-states.c
@@ -13,8 +13,7 @@
#include <linux/gfp.h>
#include <linux/init.h>
-#define ESSA_SET_STABLE 1
-#define ESSA_SET_UNUSED 2
+#include <asm/page-states.h>
static int cmma_flag = 1;
diff --git a/arch/s390/mm/pgtable.c b/arch/s390/mm/pgtable.c
index 463e5ef02304bb99c352c8468c7cf0ce57f0ba4e..947b66a5cdba730573a4f0f4bd299a6d7b7b52bd 100644
--- a/arch/s390/mm/pgtable.c
+++ b/arch/s390/mm/pgtable.c
@@ -23,6 +23,7 @@
#include <asm/tlb.h>
#include <asm/tlbflush.h>
#include <asm/mmu_context.h>
+#include <asm/page-states.h>
static inline pte_t ptep_flush_direct(struct mm_struct *mm,
unsigned long addr, pte_t *ptep)
@@ -787,4 +788,156 @@ int get_guest_storage_key(struct mm_struct *mm, unsigned long addr,
return 0;
}
EXPORT_SYMBOL(get_guest_storage_key);
+
+/**
+ * pgste_perform_essa - perform ESSA actions on the PGSTE.
+ * @mm: the memory context. It must have PGSTEs, no check is performed here!
+ * @hva: the host virtual address of the page whose PGSTE is to be processed
+ * @orc: the specific action to perform, see the ESSA_SET_* macros.
+ * @oldpte: the PTE will be saved there if the pointer is not NULL.
+ * @oldpgste: the old PGSTE will be saved there if the pointer is not NULL.
+ *
+ * Return: 1 if the page is to be added to the CBRL, otherwise 0,
+ * or < 0 in case of error. -EINVAL is returned for invalid values
+ * of orc, -EFAULT for invalid addresses.
+ */
+int pgste_perform_essa(struct mm_struct *mm, unsigned long hva, int orc,
+ unsigned long *oldpte, unsigned long *oldpgste)
+{
+ unsigned long pgstev;
+ spinlock_t *ptl;
+ pgste_t pgste;
+ pte_t *ptep;
+ int res = 0;
+
+ WARN_ON_ONCE(orc > ESSA_MAX);
+ if (unlikely(orc > ESSA_MAX))
+ return -EINVAL;
+ ptep = get_locked_pte(mm, hva, &ptl);
+ if (unlikely(!ptep))
+ return -EFAULT;
+ pgste = pgste_get_lock(ptep);
+ pgstev = pgste_val(pgste);
+ if (oldpte)
+ *oldpte = pte_val(*ptep);
+ if (oldpgste)
+ *oldpgste = pgstev;
+
+ switch (orc) {
+ case ESSA_GET_STATE:
+ break;
+ case ESSA_SET_STABLE:
+ pgstev &= ~_PGSTE_GPS_USAGE_MASK;
+ pgstev |= _PGSTE_GPS_USAGE_STABLE;
+ break;
+ case ESSA_SET_UNUSED:
+ pgstev &= ~_PGSTE_GPS_USAGE_MASK;
+ pgstev |= _PGSTE_GPS_USAGE_UNUSED;
+ if (pte_val(*ptep) & _PAGE_INVALID)
+ res = 1;
+ break;
+ case ESSA_SET_VOLATILE:
+ pgstev &= ~_PGSTE_GPS_USAGE_MASK;
+ pgstev |= _PGSTE_GPS_USAGE_VOLATILE;
+ if (pte_val(*ptep) & _PAGE_INVALID)
+ res = 1;
+ break;
+ case ESSA_SET_POT_VOLATILE:
+ pgstev &= ~_PGSTE_GPS_USAGE_MASK;
+ if (!(pte_val(*ptep) & _PAGE_INVALID)) {
+ pgstev |= _PGSTE_GPS_USAGE_POT_VOLATILE;
+ break;
+ }
+ if (pgstev & _PGSTE_GPS_ZERO) {
+ pgstev |= _PGSTE_GPS_USAGE_VOLATILE;
+ break;
+ }
+ if (!(pgstev & PGSTE_GC_BIT)) {
+ pgstev |= _PGSTE_GPS_USAGE_VOLATILE;
+ res = 1;
+ break;
+ }
+ break;
+ case ESSA_SET_STABLE_RESIDENT:
+ pgstev &= ~_PGSTE_GPS_USAGE_MASK;
+ pgstev |= _PGSTE_GPS_USAGE_STABLE;
+ /*
+ * Since the resident state can go away any time after this
+ * call, we will not make this page resident. We can revisit
+ * this decision if a guest will ever start using this.
+ */
+ break;
+ case ESSA_SET_STABLE_IF_RESIDENT:
+ if (!(pte_val(*ptep) & _PAGE_INVALID)) {
+ pgstev &= ~_PGSTE_GPS_USAGE_MASK;
+ pgstev |= _PGSTE_GPS_USAGE_STABLE;
+ }
+ break;
+ default:
+ /* we should never get here! */
+ break;
+ }
+ /* If we are discarding a page, set it to logical zero */
+ if (res)
+ pgstev |= _PGSTE_GPS_ZERO;
+
+ pgste_val(pgste) = pgstev;
+ pgste_set_unlock(ptep, pgste);
+ pte_unmap_unlock(ptep, ptl);
+ return res;
+}
+EXPORT_SYMBOL(pgste_perform_essa);
+
+/**
+ * set_pgste_bits - set specific PGSTE bits.
+ * @mm: the memory context. It must have PGSTEs, no check is performed here!
+ * @hva: the host virtual address of the page whose PGSTE is to be processed
+ * @bits: a bitmask representing the bits that will be touched
+ * @value: the values of the bits to be written. Only the bits in the mask
+ * will be written.
+ *
+ * Return: 0 on success, < 0 in case of error.
+ */
+int set_pgste_bits(struct mm_struct *mm, unsigned long hva,
+ unsigned long bits, unsigned long value)
+{
+ spinlock_t *ptl;
+ pgste_t new;
+ pte_t *ptep;
+
+ ptep = get_locked_pte(mm, hva, &ptl);
+ if (unlikely(!ptep))
+ return -EFAULT;
+ new = pgste_get_lock(ptep);
+
+ pgste_val(new) &= ~bits;
+ pgste_val(new) |= value & bits;
+
+ pgste_set_unlock(ptep, new);
+ pte_unmap_unlock(ptep, ptl);
+ return 0;
+}
+EXPORT_SYMBOL(set_pgste_bits);
+
+/**
+ * get_pgste - get the current PGSTE for the given address.
+ * @mm: the memory context. It must have PGSTEs, no check is performed here!
+ * @hva: the host virtual address of the page whose PGSTE is to be processed
+ * @pgstep: will be written with the current PGSTE for the given address.
+ *
+ * Return: 0 on success, < 0 in case of error.
+ */
+int get_pgste(struct mm_struct *mm, unsigned long hva, unsigned long *pgstep)
+{
+ spinlock_t *ptl;
+ pte_t *ptep;
+
+ ptep = get_locked_pte(mm, hva, &ptl);
+ if (unlikely(!ptep))
+ return -EFAULT;
+ *pgstep = pgste_val(pgste_get(ptep));
+ pte_unmap_unlock(ptep, ptl);
+ return 0;
+}
+EXPORT_SYMBOL(get_pgste);
#endif