| /* |
| * 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> |
| |
| static inline pte_t ptep_flush_direct(struct mm_struct *mm, |
| unsigned long addr, pte_t *ptep) |
| { |
| int active, count; |
| pte_t old; |
| |
| old = *ptep; |
| if (unlikely(pte_val(old) & _PAGE_INVALID)) |
| return old; |
| active = (mm == current->active_mm) ? 1 : 0; |
| count = atomic_add_return(0x10000, &mm->context.attach_count); |
| if (MACHINE_HAS_TLB_LC && (count & 0xffff) <= active && |
| cpumask_equal(mm_cpumask(mm), cpumask_of(smp_processor_id()))) |
| __ptep_ipte_local(addr, ptep); |
| else |
| __ptep_ipte(addr, ptep); |
| atomic_sub(0x10000, &mm->context.attach_count); |
| return old; |
| } |
| |
| static inline pte_t ptep_flush_lazy(struct mm_struct *mm, |
| unsigned long addr, pte_t *ptep) |
| { |
| int active, count; |
| pte_t old; |
| |
| old = *ptep; |
| if (unlikely(pte_val(old) & _PAGE_INVALID)) |
| return old; |
| active = (mm == current->active_mm) ? 1 : 0; |
| count = atomic_add_return(0x10000, &mm->context.attach_count); |
| if ((count & 0xffff) <= active) { |
| pte_val(*ptep) |= _PAGE_INVALID; |
| mm->context.flush_mm = 1; |
| } else |
| __ptep_ipte(addr, ptep); |
| atomic_sub(0x10000, &mm->context.attach_count); |
| return old; |
| } |
| |
| static inline pgste_t pgste_get_lock(pte_t *ptep) |
| { |
| unsigned long new = 0; |
| #ifdef CONFIG_PGSTE |
| unsigned long old; |
| |
| preempt_disable(); |
| 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"); |
| preempt_enable(); |
| #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_ipte_notify(struct mm_struct *mm, |
| unsigned long addr, |
| 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); |
| } |
| #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_ipte_notify(mm, addr, ptep, pgste); |
| } |
| return pgste; |
| } |
| |
| static inline void 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; |
| } |
| } |
| |
| pte_t ptep_xchg_direct(struct mm_struct *mm, unsigned long addr, |
| pte_t *ptep, pte_t new) |
| { |
| pgste_t pgste; |
| pte_t old; |
| |
| pgste = ptep_xchg_start(mm, addr, ptep); |
| old = ptep_flush_direct(mm, addr, ptep); |
| ptep_xchg_commit(mm, addr, ptep, pgste, old, new); |
| 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; |
| |
| pgste = ptep_xchg_start(mm, addr, ptep); |
| old = ptep_flush_lazy(mm, addr, ptep); |
| ptep_xchg_commit(mm, addr, ptep, pgste, old, new); |
| 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; |
| |
| pgste = ptep_xchg_start(mm, addr, ptep); |
| old = ptep_flush_lazy(mm, addr, ptep); |
| 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 (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; |
| } |
| } |
| EXPORT_SYMBOL(ptep_modify_prot_commit); |
| |
| static inline pmd_t pmdp_flush_direct(struct mm_struct *mm, |
| unsigned long addr, pmd_t *pmdp) |
| { |
| int active, count; |
| pmd_t old; |
| |
| old = *pmdp; |
| if (pmd_val(old) & _SEGMENT_ENTRY_INVALID) |
| return old; |
| if (!MACHINE_HAS_IDTE) { |
| __pmdp_csp(pmdp); |
| return old; |
| } |
| active = (mm == current->active_mm) ? 1 : 0; |
| count = atomic_add_return(0x10000, &mm->context.attach_count); |
| if (MACHINE_HAS_TLB_LC && (count & 0xffff) <= active && |
| cpumask_equal(mm_cpumask(mm), cpumask_of(smp_processor_id()))) |
| __pmdp_idte_local(addr, pmdp); |
| else |
| __pmdp_idte(addr, pmdp); |
| atomic_sub(0x10000, &mm->context.attach_count); |
| return old; |
| } |
| |
| static inline pmd_t pmdp_flush_lazy(struct mm_struct *mm, |
| unsigned long addr, pmd_t *pmdp) |
| { |
| int active, count; |
| pmd_t old; |
| |
| old = *pmdp; |
| if (pmd_val(old) & _SEGMENT_ENTRY_INVALID) |
| return old; |
| active = (mm == current->active_mm) ? 1 : 0; |
| count = atomic_add_return(0x10000, &mm->context.attach_count); |
| if ((count & 0xffff) <= active) { |
| pmd_val(*pmdp) |= _SEGMENT_ENTRY_INVALID; |
| mm->context.flush_mm = 1; |
| } else if (MACHINE_HAS_IDTE) |
| __pmdp_idte(addr, pmdp); |
| else |
| __pmdp_csp(pmdp); |
| atomic_sub(0x10000, &mm->context.attach_count); |
| return old; |
| } |
| |
| pmd_t pmdp_xchg_direct(struct mm_struct *mm, unsigned long addr, |
| pmd_t *pmdp, pmd_t new) |
| { |
| pmd_t old; |
| |
| old = pmdp_flush_direct(mm, addr, pmdp); |
| *pmdp = new; |
| 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; |
| |
| old = pmdp_flush_lazy(mm, addr, pmdp); |
| *pmdp = new; |
| return old; |
| } |
| EXPORT_SYMBOL(pmdp_xchg_lazy); |
| |
| #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() */ |
| 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); |
| } |
| |
| void ptep_set_notify(struct mm_struct *mm, unsigned long addr, pte_t *ptep) |
| { |
| pgste_t pgste; |
| |
| pgste = pgste_get_lock(ptep); |
| pgste_val(pgste) |= PGSTE_IN_BIT; |
| 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 */ |
| 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); |
| } |
| |
| void ptep_zap_key(struct mm_struct *mm, unsigned long addr, pte_t *ptep) |
| { |
| unsigned long ptev; |
| pgste_t pgste; |
| |
| /* Clear storage key */ |
| pgste = pgste_get_lock(ptep); |
| pgste_val(pgste) &= ~(PGSTE_ACC_BITS | PGSTE_FP_BIT | |
| 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); |
| } |
| |
| /* |
| * 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; |
| pgste_t pgste; |
| pte_t *ptep; |
| pte_t pte; |
| bool dirty; |
| |
| ptep = get_locked_pte(mm, 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_ipte_notify(mm, addr, ptep, pgste); |
| __ptep_ipte(addr, ptep); |
| 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; |
| |
| down_read(&mm->mmap_sem); |
| ptep = get_locked_pte(mm, addr, &ptl); |
| if (unlikely(!ptep)) { |
| up_read(&mm->mmap_sem); |
| 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); |
| up_read(&mm->mmap_sem); |
| return 0; |
| } |
| EXPORT_SYMBOL(set_guest_storage_key); |
| |
| unsigned char get_guest_storage_key(struct mm_struct *mm, unsigned long addr) |
| { |
| unsigned char key; |
| spinlock_t *ptl; |
| pgste_t pgste; |
| pte_t *ptep; |
| |
| down_read(&mm->mmap_sem); |
| ptep = get_locked_pte(mm, addr, &ptl); |
| if (unlikely(!ptep)) { |
| up_read(&mm->mmap_sem); |
| return -EFAULT; |
| } |
| pgste = pgste_get_lock(ptep); |
| |
| if (pte_val(*ptep) & _PAGE_INVALID) { |
| key = (pgste_val(pgste) & PGSTE_ACC_BITS) >> 56; |
| key |= (pgste_val(pgste) & PGSTE_FP_BIT) >> 56; |
| key |= (pgste_val(pgste) & PGSTE_GR_BIT) >> 48; |
| key |= (pgste_val(pgste) & PGSTE_GC_BIT) >> 48; |
| } else { |
| key = page_get_storage_key(pte_val(*ptep) & PAGE_MASK); |
| |
| /* Reflect guest's logical view, not physical */ |
| if (pgste_val(pgste) & PGSTE_GR_BIT) |
| key |= _PAGE_REFERENCED; |
| if (pgste_val(pgste) & PGSTE_GC_BIT) |
| key |= _PAGE_CHANGED; |
| } |
| |
| pgste_set_unlock(ptep, pgste); |
| pte_unmap_unlock(ptep, ptl); |
| up_read(&mm->mmap_sem); |
| return key; |
| } |
| EXPORT_SYMBOL(get_guest_storage_key); |
| #endif |
