| /* |
| * 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_use_skey(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_use_skey(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); |
| } |
| |
| 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); |
| else if (MACHINE_HAS_IDTE) |
| __pmdp_idte(addr, pmdp, 0, 0, IDTE_GLOBAL); |
| else |
| __pmdp_csp(pmdp); |
| } |
| |
| 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; |
| } else { |
| pmdp_idte_global(mm, addr, pmdp); |
| } |
| atomic_dec(&mm->context.flush_count); |
| return old; |
| } |
| |
| 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 test_and_clear_guest_dirty(struct mm_struct *mm, unsigned long addr) |
| { |
| spinlock_t *ptl; |
| pgd_t *pgd; |
| p4d_t *p4d; |
| pud_t *pud; |
| pmd_t *pmd; |
| pgste_t pgste; |
| pte_t *ptep; |
| pte_t pte; |
| bool dirty; |
| int nodat; |
| |
| pgd = pgd_offset(mm, addr); |
| p4d = p4d_alloc(mm, pgd, addr); |
| if (!p4d) |
| return false; |
| pud = pud_alloc(mm, p4d, addr); |
| if (!pud) |
| return false; |
| pmd = pmd_alloc(mm, pud, addr); |
| if (!pmd) |
| return false; |
| /* We can't run guests backed by huge pages, but userspace can |
| * still set them up and then try to migrate them without any |
| * migration support. |
| */ |
| if (pmd_large(*pmd)) |
| return true; |
| |
| ptep = pte_alloc_map_lock(mm, pmd, addr, &ptl); |
| if (unlikely(!ptep)) |
| return false; |
| |
| 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); |
| |
| spin_unlock(ptl); |
| return dirty; |
| } |
| EXPORT_SYMBOL_GPL(test_and_clear_guest_dirty); |
| |
| int set_guest_storage_key(struct mm_struct *mm, unsigned long addr, |
| unsigned char key, bool nq) |
| { |
| unsigned long keyul; |
| spinlock_t *ptl; |
| pgste_t old, new; |
| pte_t *ptep; |
| |
| ptep = get_locked_pte(mm, 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 address, bits, skey; |
| |
| address = pte_val(*ptep) & PAGE_MASK; |
| skey = (unsigned long) page_get_storage_key(address); |
| bits = skey & (_PAGE_CHANGED | _PAGE_REFERENCED); |
| skey = key & (_PAGE_ACC_BITS | _PAGE_FP_BIT); |
| /* Set storage key ACC and FP */ |
| page_set_storage_key(address, 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; |
| pgste_t old, new; |
| pte_t *ptep; |
| int cc = 0; |
| |
| ptep = get_locked_pte(mm, 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)) { |
| cc = page_reset_referenced(pte_val(*ptep) & PAGE_MASK); |
| /* 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) |
| { |
| spinlock_t *ptl; |
| pgste_t pgste; |
| pte_t *ptep; |
| |
| ptep = get_locked_pte(mm, addr, &ptl); |
| if (unlikely(!ptep)) |
| return -EFAULT; |
| |
| pgste = pgste_get_lock(ptep); |
| *key = (pgste_val(pgste) & (PGSTE_ACC_BITS | PGSTE_FP_BIT)) >> 56; |
| if (!(pte_val(*ptep) & _PAGE_INVALID)) |
| *key = page_get_storage_key(pte_val(*ptep) & PAGE_MASK); |
| /* 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 |