v4.19.13 snapshot.
diff --git a/arch/s390/mm/pgtable.c b/arch/s390/mm/pgtable.c
new file mode 100644
index 0000000..f2cc7da
--- /dev/null
+++ b/arch/s390/mm/pgtable.c
@@ -0,0 +1,1111 @@
+// SPDX-License-Identifier: GPL-2.0
+/*
+ * Copyright IBM Corp. 2007, 2011
+ * Author(s): Martin Schwidefsky <schwidefsky@de.ibm.com>
+ */
+
+#include <linux/sched.h>
+#include <linux/kernel.h>
+#include <linux/errno.h>
+#include <linux/gfp.h>
+#include <linux/mm.h>
+#include <linux/swap.h>
+#include <linux/smp.h>
+#include <linux/spinlock.h>
+#include <linux/rcupdate.h>
+#include <linux/slab.h>
+#include <linux/swapops.h>
+#include <linux/sysctl.h>
+#include <linux/ksm.h>
+#include <linux/mman.h>
+
+#include <asm/pgtable.h>
+#include <asm/pgalloc.h>
+#include <asm/tlb.h>
+#include <asm/tlbflush.h>
+#include <asm/mmu_context.h>
+#include <asm/page-states.h>
+
+static inline void ptep_ipte_local(struct mm_struct *mm, unsigned long addr,
+ pte_t *ptep, int nodat)
+{
+ unsigned long opt, asce;
+
+ if (MACHINE_HAS_TLB_GUEST) {
+ opt = 0;
+ asce = READ_ONCE(mm->context.gmap_asce);
+ if (asce == 0UL || nodat)
+ opt |= IPTE_NODAT;
+ if (asce != -1UL) {
+ asce = asce ? : mm->context.asce;
+ opt |= IPTE_GUEST_ASCE;
+ }
+ __ptep_ipte(addr, ptep, opt, asce, IPTE_LOCAL);
+ } else {
+ __ptep_ipte(addr, ptep, 0, 0, IPTE_LOCAL);
+ }
+}
+
+static inline void ptep_ipte_global(struct mm_struct *mm, unsigned long addr,
+ pte_t *ptep, int nodat)
+{
+ unsigned long opt, asce;
+
+ if (MACHINE_HAS_TLB_GUEST) {
+ opt = 0;
+ asce = READ_ONCE(mm->context.gmap_asce);
+ if (asce == 0UL || nodat)
+ opt |= IPTE_NODAT;
+ if (asce != -1UL) {
+ asce = asce ? : mm->context.asce;
+ opt |= IPTE_GUEST_ASCE;
+ }
+ __ptep_ipte(addr, ptep, opt, asce, IPTE_GLOBAL);
+ } else {
+ __ptep_ipte(addr, ptep, 0, 0, IPTE_GLOBAL);
+ }
+}
+
+static inline pte_t ptep_flush_direct(struct mm_struct *mm,
+ unsigned long addr, pte_t *ptep,
+ int nodat)
+{
+ pte_t old;
+
+ old = *ptep;
+ if (unlikely(pte_val(old) & _PAGE_INVALID))
+ return old;
+ atomic_inc(&mm->context.flush_count);
+ if (MACHINE_HAS_TLB_LC &&
+ cpumask_equal(mm_cpumask(mm), cpumask_of(smp_processor_id())))
+ ptep_ipte_local(mm, addr, ptep, nodat);
+ else
+ ptep_ipte_global(mm, addr, ptep, nodat);
+ atomic_dec(&mm->context.flush_count);
+ return old;
+}
+
+static inline pte_t ptep_flush_lazy(struct mm_struct *mm,
+ unsigned long addr, pte_t *ptep,
+ int nodat)
+{
+ pte_t old;
+
+ old = *ptep;
+ if (unlikely(pte_val(old) & _PAGE_INVALID))
+ return old;
+ atomic_inc(&mm->context.flush_count);
+ if (cpumask_equal(&mm->context.cpu_attach_mask,
+ cpumask_of(smp_processor_id()))) {
+ pte_val(*ptep) |= _PAGE_INVALID;
+ mm->context.flush_mm = 1;
+ } else
+ ptep_ipte_global(mm, addr, ptep, nodat);
+ atomic_dec(&mm->context.flush_count);
+ return old;
+}
+
+static inline pgste_t pgste_get_lock(pte_t *ptep)
+{
+ unsigned long new = 0;
+#ifdef CONFIG_PGSTE
+ unsigned long old;
+
+ asm(
+ " lg %0,%2\n"
+ "0: lgr %1,%0\n"
+ " nihh %0,0xff7f\n" /* clear PCL bit in old */
+ " oihh %1,0x0080\n" /* set PCL bit in new */
+ " csg %0,%1,%2\n"
+ " jl 0b\n"
+ : "=&d" (old), "=&d" (new), "=Q" (ptep[PTRS_PER_PTE])
+ : "Q" (ptep[PTRS_PER_PTE]) : "cc", "memory");
+#endif
+ return __pgste(new);
+}
+
+static inline void pgste_set_unlock(pte_t *ptep, pgste_t pgste)
+{
+#ifdef CONFIG_PGSTE
+ asm(
+ " nihh %1,0xff7f\n" /* clear PCL bit */
+ " stg %1,%0\n"
+ : "=Q" (ptep[PTRS_PER_PTE])
+ : "d" (pgste_val(pgste)), "Q" (ptep[PTRS_PER_PTE])
+ : "cc", "memory");
+#endif
+}
+
+static inline pgste_t pgste_get(pte_t *ptep)
+{
+ unsigned long pgste = 0;
+#ifdef CONFIG_PGSTE
+ pgste = *(unsigned long *)(ptep + PTRS_PER_PTE);
+#endif
+ return __pgste(pgste);
+}
+
+static inline void pgste_set(pte_t *ptep, pgste_t pgste)
+{
+#ifdef CONFIG_PGSTE
+ *(pgste_t *)(ptep + PTRS_PER_PTE) = pgste;
+#endif
+}
+
+static inline pgste_t pgste_update_all(pte_t pte, pgste_t pgste,
+ struct mm_struct *mm)
+{
+#ifdef CONFIG_PGSTE
+ unsigned long address, bits, skey;
+
+ if (!mm_uses_skeys(mm) || pte_val(pte) & _PAGE_INVALID)
+ return pgste;
+ address = pte_val(pte) & PAGE_MASK;
+ skey = (unsigned long) page_get_storage_key(address);
+ bits = skey & (_PAGE_CHANGED | _PAGE_REFERENCED);
+ /* Transfer page changed & referenced bit to guest bits in pgste */
+ pgste_val(pgste) |= bits << 48; /* GR bit & GC bit */
+ /* Copy page access key and fetch protection bit to pgste */
+ pgste_val(pgste) &= ~(PGSTE_ACC_BITS | PGSTE_FP_BIT);
+ pgste_val(pgste) |= (skey & (_PAGE_ACC_BITS | _PAGE_FP_BIT)) << 56;
+#endif
+ return pgste;
+
+}
+
+static inline void pgste_set_key(pte_t *ptep, pgste_t pgste, pte_t entry,
+ struct mm_struct *mm)
+{
+#ifdef CONFIG_PGSTE
+ unsigned long address;
+ unsigned long nkey;
+
+ if (!mm_uses_skeys(mm) || pte_val(entry) & _PAGE_INVALID)
+ return;
+ VM_BUG_ON(!(pte_val(*ptep) & _PAGE_INVALID));
+ address = pte_val(entry) & PAGE_MASK;
+ /*
+ * Set page access key and fetch protection bit from pgste.
+ * The guest C/R information is still in the PGSTE, set real
+ * key C/R to 0.
+ */
+ nkey = (pgste_val(pgste) & (PGSTE_ACC_BITS | PGSTE_FP_BIT)) >> 56;
+ nkey |= (pgste_val(pgste) & (PGSTE_GR_BIT | PGSTE_GC_BIT)) >> 48;
+ page_set_storage_key(address, nkey, 0);
+#endif
+}
+
+static inline pgste_t pgste_set_pte(pte_t *ptep, pgste_t pgste, pte_t entry)
+{
+#ifdef CONFIG_PGSTE
+ if ((pte_val(entry) & _PAGE_PRESENT) &&
+ (pte_val(entry) & _PAGE_WRITE) &&
+ !(pte_val(entry) & _PAGE_INVALID)) {
+ if (!MACHINE_HAS_ESOP) {
+ /*
+ * Without enhanced suppression-on-protection force
+ * the dirty bit on for all writable ptes.
+ */
+ pte_val(entry) |= _PAGE_DIRTY;
+ pte_val(entry) &= ~_PAGE_PROTECT;
+ }
+ if (!(pte_val(entry) & _PAGE_PROTECT))
+ /* This pte allows write access, set user-dirty */
+ pgste_val(pgste) |= PGSTE_UC_BIT;
+ }
+#endif
+ *ptep = entry;
+ return pgste;
+}
+
+static inline pgste_t pgste_pte_notify(struct mm_struct *mm,
+ unsigned long addr,
+ pte_t *ptep, pgste_t pgste)
+{
+#ifdef CONFIG_PGSTE
+ 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;
+}
+
+static inline pgste_t ptep_xchg_start(struct mm_struct *mm,
+ unsigned long addr, pte_t *ptep)
+{
+ pgste_t pgste = __pgste(0);
+
+ if (mm_has_pgste(mm)) {
+ pgste = pgste_get_lock(ptep);
+ pgste = pgste_pte_notify(mm, addr, ptep, pgste);
+ }
+ return pgste;
+}
+
+static inline pte_t ptep_xchg_commit(struct mm_struct *mm,
+ unsigned long addr, pte_t *ptep,
+ pgste_t pgste, pte_t old, pte_t new)
+{
+ if (mm_has_pgste(mm)) {
+ if (pte_val(old) & _PAGE_INVALID)
+ pgste_set_key(ptep, pgste, new, mm);
+ if (pte_val(new) & _PAGE_INVALID) {
+ pgste = pgste_update_all(old, pgste, mm);
+ if ((pgste_val(pgste) & _PGSTE_GPS_USAGE_MASK) ==
+ _PGSTE_GPS_USAGE_UNUSED)
+ pte_val(old) |= _PAGE_UNUSED;
+ }
+ pgste = pgste_set_pte(ptep, pgste, new);
+ pgste_set_unlock(ptep, pgste);
+ } else {
+ *ptep = new;
+ }
+ return old;
+}
+
+pte_t ptep_xchg_direct(struct mm_struct *mm, unsigned long addr,
+ pte_t *ptep, pte_t new)
+{
+ pgste_t pgste;
+ pte_t old;
+ int nodat;
+
+ preempt_disable();
+ pgste = ptep_xchg_start(mm, addr, ptep);
+ nodat = !!(pgste_val(pgste) & _PGSTE_GPS_NODAT);
+ old = ptep_flush_direct(mm, addr, ptep, nodat);
+ old = ptep_xchg_commit(mm, addr, ptep, pgste, old, new);
+ preempt_enable();
+ return old;
+}
+EXPORT_SYMBOL(ptep_xchg_direct);
+
+pte_t ptep_xchg_lazy(struct mm_struct *mm, unsigned long addr,
+ pte_t *ptep, pte_t new)
+{
+ pgste_t pgste;
+ pte_t old;
+ int nodat;
+
+ preempt_disable();
+ pgste = ptep_xchg_start(mm, addr, ptep);
+ nodat = !!(pgste_val(pgste) & _PGSTE_GPS_NODAT);
+ old = ptep_flush_lazy(mm, addr, ptep, nodat);
+ old = ptep_xchg_commit(mm, addr, ptep, pgste, old, new);
+ preempt_enable();
+ return old;
+}
+EXPORT_SYMBOL(ptep_xchg_lazy);
+
+pte_t ptep_modify_prot_start(struct mm_struct *mm, unsigned long addr,
+ pte_t *ptep)
+{
+ pgste_t pgste;
+ pte_t old;
+ int nodat;
+
+ preempt_disable();
+ pgste = ptep_xchg_start(mm, addr, ptep);
+ nodat = !!(pgste_val(pgste) & _PGSTE_GPS_NODAT);
+ old = ptep_flush_lazy(mm, addr, ptep, nodat);
+ if (mm_has_pgste(mm)) {
+ pgste = pgste_update_all(old, pgste, mm);
+ pgste_set(ptep, pgste);
+ }
+ return old;
+}
+EXPORT_SYMBOL(ptep_modify_prot_start);
+
+void ptep_modify_prot_commit(struct mm_struct *mm, unsigned long addr,
+ pte_t *ptep, pte_t pte)
+{
+ pgste_t pgste;
+
+ if (!MACHINE_HAS_NX)
+ pte_val(pte) &= ~_PAGE_NOEXEC;
+ if (mm_has_pgste(mm)) {
+ pgste = pgste_get(ptep);
+ pgste_set_key(ptep, pgste, pte, mm);
+ pgste = pgste_set_pte(ptep, pgste, pte);
+ pgste_set_unlock(ptep, pgste);
+ } else {
+ *ptep = pte;
+ }
+ preempt_enable();
+}
+EXPORT_SYMBOL(ptep_modify_prot_commit);
+
+static inline void pmdp_idte_local(struct mm_struct *mm,
+ unsigned long addr, pmd_t *pmdp)
+{
+ if (MACHINE_HAS_TLB_GUEST)
+ __pmdp_idte(addr, pmdp, IDTE_NODAT | IDTE_GUEST_ASCE,
+ mm->context.asce, IDTE_LOCAL);
+ else
+ __pmdp_idte(addr, pmdp, 0, 0, IDTE_LOCAL);
+ if (mm_has_pgste(mm) && mm->context.allow_gmap_hpage_1m)
+ gmap_pmdp_idte_local(mm, addr);
+}
+
+static inline void pmdp_idte_global(struct mm_struct *mm,
+ unsigned long addr, pmd_t *pmdp)
+{
+ if (MACHINE_HAS_TLB_GUEST) {
+ __pmdp_idte(addr, pmdp, IDTE_NODAT | IDTE_GUEST_ASCE,
+ mm->context.asce, IDTE_GLOBAL);
+ if (mm_has_pgste(mm) && mm->context.allow_gmap_hpage_1m)
+ gmap_pmdp_idte_global(mm, addr);
+ } else if (MACHINE_HAS_IDTE) {
+ __pmdp_idte(addr, pmdp, 0, 0, IDTE_GLOBAL);
+ if (mm_has_pgste(mm) && mm->context.allow_gmap_hpage_1m)
+ gmap_pmdp_idte_global(mm, addr);
+ } else {
+ __pmdp_csp(pmdp);
+ if (mm_has_pgste(mm) && mm->context.allow_gmap_hpage_1m)
+ gmap_pmdp_csp(mm, addr);
+ }
+}
+
+static inline pmd_t pmdp_flush_direct(struct mm_struct *mm,
+ unsigned long addr, pmd_t *pmdp)
+{
+ pmd_t old;
+
+ old = *pmdp;
+ if (pmd_val(old) & _SEGMENT_ENTRY_INVALID)
+ return old;
+ atomic_inc(&mm->context.flush_count);
+ if (MACHINE_HAS_TLB_LC &&
+ cpumask_equal(mm_cpumask(mm), cpumask_of(smp_processor_id())))
+ pmdp_idte_local(mm, addr, pmdp);
+ else
+ pmdp_idte_global(mm, addr, pmdp);
+ atomic_dec(&mm->context.flush_count);
+ return old;
+}
+
+static inline pmd_t pmdp_flush_lazy(struct mm_struct *mm,
+ unsigned long addr, pmd_t *pmdp)
+{
+ pmd_t old;
+
+ old = *pmdp;
+ if (pmd_val(old) & _SEGMENT_ENTRY_INVALID)
+ return old;
+ atomic_inc(&mm->context.flush_count);
+ if (cpumask_equal(&mm->context.cpu_attach_mask,
+ cpumask_of(smp_processor_id()))) {
+ pmd_val(*pmdp) |= _SEGMENT_ENTRY_INVALID;
+ mm->context.flush_mm = 1;
+ if (mm_has_pgste(mm))
+ gmap_pmdp_invalidate(mm, addr);
+ } else {
+ pmdp_idte_global(mm, addr, pmdp);
+ }
+ atomic_dec(&mm->context.flush_count);
+ return old;
+}
+
+static pmd_t *pmd_alloc_map(struct mm_struct *mm, unsigned long addr)
+{
+ pgd_t *pgd;
+ p4d_t *p4d;
+ pud_t *pud;
+ pmd_t *pmd;
+
+ pgd = pgd_offset(mm, addr);
+ p4d = p4d_alloc(mm, pgd, addr);
+ if (!p4d)
+ return NULL;
+ pud = pud_alloc(mm, p4d, addr);
+ if (!pud)
+ return NULL;
+ pmd = pmd_alloc(mm, pud, addr);
+ return pmd;
+}
+
+pmd_t pmdp_xchg_direct(struct mm_struct *mm, unsigned long addr,
+ pmd_t *pmdp, pmd_t new)
+{
+ pmd_t old;
+
+ preempt_disable();
+ old = pmdp_flush_direct(mm, addr, pmdp);
+ *pmdp = new;
+ preempt_enable();
+ return old;
+}
+EXPORT_SYMBOL(pmdp_xchg_direct);
+
+pmd_t pmdp_xchg_lazy(struct mm_struct *mm, unsigned long addr,
+ pmd_t *pmdp, pmd_t new)
+{
+ pmd_t old;
+
+ preempt_disable();
+ old = pmdp_flush_lazy(mm, addr, pmdp);
+ *pmdp = new;
+ preempt_enable();
+ return old;
+}
+EXPORT_SYMBOL(pmdp_xchg_lazy);
+
+static inline void pudp_idte_local(struct mm_struct *mm,
+ unsigned long addr, pud_t *pudp)
+{
+ if (MACHINE_HAS_TLB_GUEST)
+ __pudp_idte(addr, pudp, IDTE_NODAT | IDTE_GUEST_ASCE,
+ mm->context.asce, IDTE_LOCAL);
+ else
+ __pudp_idte(addr, pudp, 0, 0, IDTE_LOCAL);
+}
+
+static inline void pudp_idte_global(struct mm_struct *mm,
+ unsigned long addr, pud_t *pudp)
+{
+ if (MACHINE_HAS_TLB_GUEST)
+ __pudp_idte(addr, pudp, IDTE_NODAT | IDTE_GUEST_ASCE,
+ mm->context.asce, IDTE_GLOBAL);
+ else if (MACHINE_HAS_IDTE)
+ __pudp_idte(addr, pudp, 0, 0, IDTE_GLOBAL);
+ else
+ /*
+ * Invalid bit position is the same for pmd and pud, so we can
+ * re-use _pmd_csp() here
+ */
+ __pmdp_csp((pmd_t *) pudp);
+}
+
+static inline pud_t pudp_flush_direct(struct mm_struct *mm,
+ unsigned long addr, pud_t *pudp)
+{
+ pud_t old;
+
+ old = *pudp;
+ if (pud_val(old) & _REGION_ENTRY_INVALID)
+ return old;
+ atomic_inc(&mm->context.flush_count);
+ if (MACHINE_HAS_TLB_LC &&
+ cpumask_equal(mm_cpumask(mm), cpumask_of(smp_processor_id())))
+ pudp_idte_local(mm, addr, pudp);
+ else
+ pudp_idte_global(mm, addr, pudp);
+ atomic_dec(&mm->context.flush_count);
+ return old;
+}
+
+pud_t pudp_xchg_direct(struct mm_struct *mm, unsigned long addr,
+ pud_t *pudp, pud_t new)
+{
+ pud_t old;
+
+ preempt_disable();
+ old = pudp_flush_direct(mm, addr, pudp);
+ *pudp = new;
+ preempt_enable();
+ return old;
+}
+EXPORT_SYMBOL(pudp_xchg_direct);
+
+#ifdef CONFIG_TRANSPARENT_HUGEPAGE
+void pgtable_trans_huge_deposit(struct mm_struct *mm, pmd_t *pmdp,
+ pgtable_t pgtable)
+{
+ struct list_head *lh = (struct list_head *) pgtable;
+
+ assert_spin_locked(pmd_lockptr(mm, pmdp));
+
+ /* FIFO */
+ if (!pmd_huge_pte(mm, pmdp))
+ INIT_LIST_HEAD(lh);
+ else
+ list_add(lh, (struct list_head *) pmd_huge_pte(mm, pmdp));
+ pmd_huge_pte(mm, pmdp) = pgtable;
+}
+
+pgtable_t pgtable_trans_huge_withdraw(struct mm_struct *mm, pmd_t *pmdp)
+{
+ struct list_head *lh;
+ pgtable_t pgtable;
+ pte_t *ptep;
+
+ assert_spin_locked(pmd_lockptr(mm, pmdp));
+
+ /* FIFO */
+ pgtable = pmd_huge_pte(mm, pmdp);
+ lh = (struct list_head *) pgtable;
+ if (list_empty(lh))
+ pmd_huge_pte(mm, pmdp) = NULL;
+ else {
+ pmd_huge_pte(mm, pmdp) = (pgtable_t) lh->next;
+ list_del(lh);
+ }
+ ptep = (pte_t *) pgtable;
+ pte_val(*ptep) = _PAGE_INVALID;
+ ptep++;
+ pte_val(*ptep) = _PAGE_INVALID;
+ return pgtable;
+}
+#endif /* CONFIG_TRANSPARENT_HUGEPAGE */
+
+#ifdef CONFIG_PGSTE
+void ptep_set_pte_at(struct mm_struct *mm, unsigned long addr,
+ pte_t *ptep, pte_t entry)
+{
+ pgste_t pgste;
+
+ /* the mm_has_pgste() check is done in set_pte_at() */
+ preempt_disable();
+ pgste = pgste_get_lock(ptep);
+ pgste_val(pgste) &= ~_PGSTE_GPS_ZERO;
+ pgste_set_key(ptep, pgste, entry, mm);
+ pgste = pgste_set_pte(ptep, pgste, entry);
+ pgste_set_unlock(ptep, pgste);
+ preempt_enable();
+}
+
+void ptep_set_notify(struct mm_struct *mm, unsigned long addr, pte_t *ptep)
+{
+ pgste_t pgste;
+
+ preempt_disable();
+ pgste = pgste_get_lock(ptep);
+ pgste_val(pgste) |= PGSTE_IN_BIT;
+ pgste_set_unlock(ptep, pgste);
+ preempt_enable();
+}
+
+/**
+ * ptep_force_prot - change access rights of a locked pte
+ * @mm: pointer to the process mm_struct
+ * @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, unsigned long bit)
+{
+ pte_t entry;
+ pgste_t pgste;
+ int pte_i, pte_p, nodat;
+
+ pgste = pgste_get_lock(ptep);
+ entry = *ptep;
+ /* Check pte entry after all locks have been acquired */
+ pte_i = pte_val(entry) & _PAGE_INVALID;
+ pte_p = pte_val(entry) & _PAGE_PROTECT;
+ if ((pte_i && (prot != PROT_NONE)) ||
+ (pte_p && (prot & PROT_WRITE))) {
+ pgste_set_unlock(ptep, pgste);
+ return -EAGAIN;
+ }
+ /* Change access rights and set pgste bit */
+ nodat = !!(pgste_val(pgste) & _PGSTE_GPS_NODAT);
+ if (prot == PROT_NONE && !pte_i) {
+ ptep_flush_direct(mm, addr, ptep, nodat);
+ pgste = pgste_update_all(entry, pgste, mm);
+ pte_val(entry) |= _PAGE_INVALID;
+ }
+ if (prot == PROT_READ && !pte_p) {
+ ptep_flush_direct(mm, addr, ptep, nodat);
+ pte_val(entry) &= ~_PAGE_INVALID;
+ pte_val(entry) |= _PAGE_PROTECT;
+ }
+ 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, pte_t pte)
+{
+ pgste_t spgste, tpgste;
+ pte_t spte, tpte;
+ int rc = -EAGAIN;
+
+ if (!(pte_val(*tptep) & _PAGE_INVALID))
+ return 0; /* already shadowed */
+ spgste = pgste_get_lock(sptep);
+ spte = *sptep;
+ if (!(pte_val(spte) & _PAGE_INVALID) &&
+ !((pte_val(spte) & _PAGE_PROTECT) &&
+ !(pte_val(pte) & _PAGE_PROTECT))) {
+ pgste_val(spgste) |= PGSTE_VSIE_BIT;
+ tpgste = pgste_get_lock(tptep);
+ pte_val(tpte) = (pte_val(spte) & PAGE_MASK) |
+ (pte_val(pte) & _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);
+ rc = 1;
+ }
+ pgste_set_unlock(sptep, spgste);
+ return rc;
+}
+
+void ptep_unshadow_pte(struct mm_struct *mm, unsigned long saddr, pte_t *ptep)
+{
+ pgste_t pgste;
+ int nodat;
+
+ pgste = pgste_get_lock(ptep);
+ /* notifier is called by the caller */
+ nodat = !!(pgste_val(pgste) & _PGSTE_GPS_NODAT);
+ ptep_flush_direct(mm, saddr, ptep, nodat);
+ /* 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))
+ dec_mm_counter(mm, MM_SWAPENTS);
+ else if (is_migration_entry(entry)) {
+ struct page *page = migration_entry_to_page(entry);
+
+ dec_mm_counter(mm, mm_counter(page));
+ }
+ free_swap_and_cache(entry);
+}
+
+void ptep_zap_unused(struct mm_struct *mm, unsigned long addr,
+ pte_t *ptep, int reset)
+{
+ unsigned long pgstev;
+ pgste_t pgste;
+ pte_t pte;
+
+ /* Zap unused and logically-zero pages */
+ preempt_disable();
+ pgste = pgste_get_lock(ptep);
+ pgstev = pgste_val(pgste);
+ pte = *ptep;
+ if (!reset && pte_swap(pte) &&
+ ((pgstev & _PGSTE_GPS_USAGE_MASK) == _PGSTE_GPS_USAGE_UNUSED ||
+ (pgstev & _PGSTE_GPS_ZERO))) {
+ ptep_zap_swap_entry(mm, pte_to_swp_entry(pte));
+ pte_clear(mm, addr, ptep);
+ }
+ if (reset)
+ pgste_val(pgste) &= ~_PGSTE_GPS_USAGE_MASK;
+ pgste_set_unlock(ptep, pgste);
+ preempt_enable();
+}
+
+void ptep_zap_key(struct mm_struct *mm, unsigned long addr, pte_t *ptep)
+{
+ unsigned long ptev;
+ pgste_t pgste;
+
+ /* Clear storage key ACC and F, but set R/C */
+ preempt_disable();
+ pgste = pgste_get_lock(ptep);
+ pgste_val(pgste) &= ~(PGSTE_ACC_BITS | PGSTE_FP_BIT);
+ pgste_val(pgste) |= PGSTE_GR_BIT | PGSTE_GC_BIT;
+ ptev = pte_val(*ptep);
+ if (!(ptev & _PAGE_INVALID) && (ptev & _PAGE_WRITE))
+ page_set_storage_key(ptev & PAGE_MASK, PAGE_DEFAULT_KEY, 1);
+ pgste_set_unlock(ptep, pgste);
+ preempt_enable();
+}
+
+/*
+ * Test and reset if a guest page is dirty
+ */
+bool ptep_test_and_clear_uc(struct mm_struct *mm, unsigned long addr,
+ pte_t *ptep)
+{
+ pgste_t pgste;
+ pte_t pte;
+ bool dirty;
+ int nodat;
+
+ pgste = pgste_get_lock(ptep);
+ dirty = !!(pgste_val(pgste) & PGSTE_UC_BIT);
+ pgste_val(pgste) &= ~PGSTE_UC_BIT;
+ pte = *ptep;
+ if (dirty && (pte_val(pte) & _PAGE_PRESENT)) {
+ pgste = pgste_pte_notify(mm, addr, ptep, pgste);
+ nodat = !!(pgste_val(pgste) & _PGSTE_GPS_NODAT);
+ ptep_ipte_global(mm, addr, ptep, nodat);
+ if (MACHINE_HAS_ESOP || !(pte_val(pte) & _PAGE_WRITE))
+ pte_val(pte) |= _PAGE_PROTECT;
+ else
+ pte_val(pte) |= _PAGE_INVALID;
+ *ptep = pte;
+ }
+ pgste_set_unlock(ptep, pgste);
+ return dirty;
+}
+EXPORT_SYMBOL_GPL(ptep_test_and_clear_uc);
+
+int set_guest_storage_key(struct mm_struct *mm, unsigned long addr,
+ unsigned char key, bool nq)
+{
+ unsigned long keyul, paddr;
+ spinlock_t *ptl;
+ pgste_t old, new;
+ pmd_t *pmdp;
+ pte_t *ptep;
+
+ pmdp = pmd_alloc_map(mm, addr);
+ if (unlikely(!pmdp))
+ return -EFAULT;
+
+ ptl = pmd_lock(mm, pmdp);
+ if (!pmd_present(*pmdp)) {
+ spin_unlock(ptl);
+ return -EFAULT;
+ }
+
+ if (pmd_large(*pmdp)) {
+ paddr = pmd_val(*pmdp) & HPAGE_MASK;
+ paddr |= addr & ~HPAGE_MASK;
+ /*
+ * Huge pmds need quiescing operations, they are
+ * always mapped.
+ */
+ page_set_storage_key(paddr, key, 1);
+ spin_unlock(ptl);
+ return 0;
+ }
+ spin_unlock(ptl);
+
+ ptep = pte_alloc_map_lock(mm, pmdp, addr, &ptl);
+ if (unlikely(!ptep))
+ return -EFAULT;
+
+ new = old = pgste_get_lock(ptep);
+ pgste_val(new) &= ~(PGSTE_GR_BIT | PGSTE_GC_BIT |
+ PGSTE_ACC_BITS | PGSTE_FP_BIT);
+ keyul = (unsigned long) key;
+ pgste_val(new) |= (keyul & (_PAGE_CHANGED | _PAGE_REFERENCED)) << 48;
+ pgste_val(new) |= (keyul & (_PAGE_ACC_BITS | _PAGE_FP_BIT)) << 56;
+ if (!(pte_val(*ptep) & _PAGE_INVALID)) {
+ unsigned long bits, skey;
+
+ paddr = pte_val(*ptep) & PAGE_MASK;
+ skey = (unsigned long) page_get_storage_key(paddr);
+ bits = skey & (_PAGE_CHANGED | _PAGE_REFERENCED);
+ skey = key & (_PAGE_ACC_BITS | _PAGE_FP_BIT);
+ /* Set storage key ACC and FP */
+ page_set_storage_key(paddr, skey, !nq);
+ /* Merge host changed & referenced into pgste */
+ pgste_val(new) |= bits << 52;
+ }
+ /* changing the guest storage key is considered a change of the page */
+ if ((pgste_val(new) ^ pgste_val(old)) &
+ (PGSTE_ACC_BITS | PGSTE_FP_BIT | PGSTE_GR_BIT | PGSTE_GC_BIT))
+ pgste_val(new) |= PGSTE_UC_BIT;
+
+ pgste_set_unlock(ptep, new);
+ pte_unmap_unlock(ptep, ptl);
+ return 0;
+}
+EXPORT_SYMBOL(set_guest_storage_key);
+
+/**
+ * Conditionally set a guest storage key (handling csske).
+ * oldkey will be updated when either mr or mc is set and a pointer is given.
+ *
+ * Returns 0 if a guests storage key update wasn't necessary, 1 if the guest
+ * storage key was updated and -EFAULT on access errors.
+ */
+int cond_set_guest_storage_key(struct mm_struct *mm, unsigned long addr,
+ unsigned char key, unsigned char *oldkey,
+ bool nq, bool mr, bool mc)
+{
+ unsigned char tmp, mask = _PAGE_ACC_BITS | _PAGE_FP_BIT;
+ int rc;
+
+ /* we can drop the pgste lock between getting and setting the key */
+ if (mr | mc) {
+ rc = get_guest_storage_key(current->mm, addr, &tmp);
+ if (rc)
+ return rc;
+ if (oldkey)
+ *oldkey = tmp;
+ if (!mr)
+ mask |= _PAGE_REFERENCED;
+ if (!mc)
+ mask |= _PAGE_CHANGED;
+ if (!((tmp ^ key) & mask))
+ return 0;
+ }
+ rc = set_guest_storage_key(current->mm, addr, key, nq);
+ return rc < 0 ? rc : 1;
+}
+EXPORT_SYMBOL(cond_set_guest_storage_key);
+
+/**
+ * Reset a guest reference bit (rrbe), returning the reference and changed bit.
+ *
+ * Returns < 0 in case of error, otherwise the cc to be reported to the guest.
+ */
+int reset_guest_reference_bit(struct mm_struct *mm, unsigned long addr)
+{
+ spinlock_t *ptl;
+ unsigned long paddr;
+ pgste_t old, new;
+ pmd_t *pmdp;
+ pte_t *ptep;
+ int cc = 0;
+
+ pmdp = pmd_alloc_map(mm, addr);
+ if (unlikely(!pmdp))
+ return -EFAULT;
+
+ ptl = pmd_lock(mm, pmdp);
+ if (!pmd_present(*pmdp)) {
+ spin_unlock(ptl);
+ return -EFAULT;
+ }
+
+ if (pmd_large(*pmdp)) {
+ paddr = pmd_val(*pmdp) & HPAGE_MASK;
+ paddr |= addr & ~HPAGE_MASK;
+ cc = page_reset_referenced(paddr);
+ spin_unlock(ptl);
+ return cc;
+ }
+ spin_unlock(ptl);
+
+ ptep = pte_alloc_map_lock(mm, pmdp, addr, &ptl);
+ if (unlikely(!ptep))
+ return -EFAULT;
+
+ new = old = pgste_get_lock(ptep);
+ /* Reset guest reference bit only */
+ pgste_val(new) &= ~PGSTE_GR_BIT;
+
+ if (!(pte_val(*ptep) & _PAGE_INVALID)) {
+ paddr = pte_val(*ptep) & PAGE_MASK;
+ cc = page_reset_referenced(paddr);
+ /* Merge real referenced bit into host-set */
+ pgste_val(new) |= ((unsigned long) cc << 53) & PGSTE_HR_BIT;
+ }
+ /* Reflect guest's logical view, not physical */
+ cc |= (pgste_val(old) & (PGSTE_GR_BIT | PGSTE_GC_BIT)) >> 49;
+ /* Changing the guest storage key is considered a change of the page */
+ if ((pgste_val(new) ^ pgste_val(old)) & PGSTE_GR_BIT)
+ pgste_val(new) |= PGSTE_UC_BIT;
+
+ pgste_set_unlock(ptep, new);
+ pte_unmap_unlock(ptep, ptl);
+ return cc;
+}
+EXPORT_SYMBOL(reset_guest_reference_bit);
+
+int get_guest_storage_key(struct mm_struct *mm, unsigned long addr,
+ unsigned char *key)
+{
+ unsigned long paddr;
+ spinlock_t *ptl;
+ pgste_t pgste;
+ pmd_t *pmdp;
+ pte_t *ptep;
+
+ pmdp = pmd_alloc_map(mm, addr);
+ if (unlikely(!pmdp))
+ return -EFAULT;
+
+ ptl = pmd_lock(mm, pmdp);
+ if (!pmd_present(*pmdp)) {
+ /* Not yet mapped memory has a zero key */
+ spin_unlock(ptl);
+ *key = 0;
+ return 0;
+ }
+
+ if (pmd_large(*pmdp)) {
+ paddr = pmd_val(*pmdp) & HPAGE_MASK;
+ paddr |= addr & ~HPAGE_MASK;
+ *key = page_get_storage_key(paddr);
+ spin_unlock(ptl);
+ return 0;
+ }
+ spin_unlock(ptl);
+
+ ptep = pte_alloc_map_lock(mm, pmdp, addr, &ptl);
+ if (unlikely(!ptep))
+ return -EFAULT;
+
+ pgste = pgste_get_lock(ptep);
+ *key = (pgste_val(pgste) & (PGSTE_ACC_BITS | PGSTE_FP_BIT)) >> 56;
+ paddr = pte_val(*ptep) & PAGE_MASK;
+ if (!(pte_val(*ptep) & _PAGE_INVALID))
+ *key = page_get_storage_key(paddr);
+ /* Reflect guest's logical view, not physical */
+ *key |= (pgste_val(pgste) & (PGSTE_GR_BIT | PGSTE_GC_BIT)) >> 48;
+ pgste_set_unlock(ptep, pgste);
+ pte_unmap_unlock(ptep, ptl);
+ 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 | _PGSTE_GPS_NODAT);
+ 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;
+ case ESSA_SET_STABLE_NODAT:
+ pgstev &= ~_PGSTE_GPS_USAGE_MASK;
+ pgstev |= _PGSTE_GPS_USAGE_STABLE | _PGSTE_GPS_NODAT;
+ 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