From d0b2f91bede3bd5e3d24dd6803e56eee959c1797 Mon Sep 17 00:00:00 2001 From: =?UTF-8?q?Andr=C3=A9=20Fabian=20Silva=20Delgado?= Date: Thu, 20 Oct 2016 00:10:27 -0300 Subject: Linux-libre 4.8.2-gnu --- arch/s390/mm/pgtable.c | 302 +++++++++++++++++++++++++++++++++++++++---------- 1 file changed, 245 insertions(+), 57 deletions(-) (limited to 'arch/s390/mm/pgtable.c') diff --git a/arch/s390/mm/pgtable.c b/arch/s390/mm/pgtable.c index ebb4f8711..5f092015a 100644 --- a/arch/s390/mm/pgtable.c +++ b/arch/s390/mm/pgtable.c @@ -27,40 +27,37 @@ 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 && + atomic_inc(&mm->context.flush_count); + if (MACHINE_HAS_TLB_LC && 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); + 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 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) { + 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(addr, ptep); - atomic_sub(0x10000, &mm->context.attach_count); + atomic_dec(&mm->context.flush_count); return old; } @@ -70,7 +67,6 @@ static inline pgste_t pgste_get_lock(pte_t *ptep) #ifdef CONFIG_PGSTE unsigned long old; - preempt_disable(); asm( " lg %0,%2\n" "0: lgr %1,%0\n" @@ -93,7 +89,6 @@ static inline void pgste_set_unlock(pte_t *ptep, pgste_t pgste) : "=Q" (ptep[PTRS_PER_PTE]) : "d" (pgste_val(pgste)), "Q" (ptep[PTRS_PER_PTE]) : "cc", "memory"); - preempt_enable(); #endif } @@ -179,14 +174,17 @@ static inline pgste_t pgste_set_pte(pte_t *ptep, pgste_t pgste, pte_t entry) return pgste; } -static inline pgste_t pgste_ipte_notify(struct mm_struct *mm, - unsigned long addr, - pte_t *ptep, pgste_t pgste) +static inline pgste_t pgste_pte_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); + 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; @@ -199,7 +197,7 @@ static inline pgste_t ptep_xchg_start(struct mm_struct *mm, if (mm_has_pgste(mm)) { pgste = pgste_get_lock(ptep); - pgste = pgste_ipte_notify(mm, addr, ptep, pgste); + pgste = pgste_pte_notify(mm, addr, ptep, pgste); } return pgste; } @@ -230,9 +228,11 @@ pte_t ptep_xchg_direct(struct mm_struct *mm, unsigned long addr, pgste_t pgste; pte_t old; + preempt_disable(); pgste = ptep_xchg_start(mm, addr, ptep); old = ptep_flush_direct(mm, addr, ptep); ptep_xchg_commit(mm, addr, ptep, pgste, old, new); + preempt_enable(); return old; } EXPORT_SYMBOL(ptep_xchg_direct); @@ -243,9 +243,11 @@ pte_t ptep_xchg_lazy(struct mm_struct *mm, unsigned long addr, pgste_t pgste; pte_t old; + preempt_disable(); pgste = ptep_xchg_start(mm, addr, ptep); old = ptep_flush_lazy(mm, addr, ptep); ptep_xchg_commit(mm, addr, ptep, pgste, old, new); + preempt_enable(); return old; } EXPORT_SYMBOL(ptep_xchg_lazy); @@ -256,6 +258,7 @@ pte_t ptep_modify_prot_start(struct mm_struct *mm, unsigned long addr, pgste_t pgste; pte_t old; + preempt_disable(); pgste = ptep_xchg_start(mm, addr, ptep); old = ptep_flush_lazy(mm, addr, ptep); if (mm_has_pgste(mm)) { @@ -279,13 +282,13 @@ void ptep_modify_prot_commit(struct mm_struct *mm, unsigned long addr, } else { *ptep = pte; } + preempt_enable(); } 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; @@ -295,36 +298,34 @@ static inline pmd_t pmdp_flush_direct(struct mm_struct *mm, __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 && + atomic_inc(&mm->context.flush_count); + if (MACHINE_HAS_TLB_LC && 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); + 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) { - 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) { + 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 if (MACHINE_HAS_IDTE) __pmdp_idte(addr, pmdp); else __pmdp_csp(pmdp); - atomic_sub(0x10000, &mm->context.attach_count); + atomic_dec(&mm->context.flush_count); return old; } @@ -333,8 +334,10 @@ pmd_t pmdp_xchg_direct(struct mm_struct *mm, unsigned long addr, { pmd_t old; + preempt_disable(); old = pmdp_flush_direct(mm, addr, pmdp); *pmdp = new; + preempt_enable(); return old; } EXPORT_SYMBOL(pmdp_xchg_direct); @@ -344,12 +347,53 @@ pmd_t pmdp_xchg_lazy(struct mm_struct *mm, unsigned long addr, { 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 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; + if (!MACHINE_HAS_IDTE) { + /* + * Invalid bit position is the same for pmd and pud, so we can + * re-use _pmd_csp() here + */ + __pmdp_csp((pmd_t *) pudp); + 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(addr, pudp); + else + __pudp_idte(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) @@ -398,20 +442,108 @@ void ptep_set_pte_at(struct mm_struct *mm, unsigned long addr, 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; + + 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 */ + if (prot == PROT_NONE && !pte_i) { + ptep_flush_direct(mm, addr, ptep); + pgste = pgste_update_all(entry, pgste, mm); + pte_val(entry) |= _PAGE_INVALID; + } + if (prot == PROT_READ && !pte_p) { + ptep_flush_direct(mm, addr, ptep); + 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; + + 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) @@ -434,6 +566,7 @@ void ptep_zap_unused(struct mm_struct *mm, unsigned long addr, pte_t pte; /* Zap unused and logically-zero pages */ + preempt_disable(); pgste = pgste_get_lock(ptep); pgstev = pgste_val(pgste); pte = *ptep; @@ -446,6 +579,7 @@ void ptep_zap_unused(struct mm_struct *mm, unsigned long addr, 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) @@ -454,6 +588,7 @@ void ptep_zap_key(struct mm_struct *mm, unsigned long addr, pte_t *ptep) pgste_t pgste; /* Clear storage key */ + preempt_disable(); pgste = pgste_get_lock(ptep); pgste_val(pgste) &= ~(PGSTE_ACC_BITS | PGSTE_FP_BIT | PGSTE_GR_BIT | PGSTE_GC_BIT); @@ -461,6 +596,7 @@ void ptep_zap_key(struct mm_struct *mm, unsigned long addr, pte_t *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(); } /* @@ -483,7 +619,7 @@ bool test_and_clear_guest_dirty(struct mm_struct *mm, unsigned long addr) pgste_val(pgste) &= ~PGSTE_UC_BIT; pte = *ptep; if (dirty && (pte_val(pte) & _PAGE_PRESENT)) { - pgste = pgste_ipte_notify(mm, addr, ptep, pgste); + pgste = pgste_pte_notify(mm, addr, ptep, pgste); __ptep_ipte(addr, ptep); if (MACHINE_HAS_ESOP || !(pte_val(pte) & _PAGE_WRITE)) pte_val(pte) |= _PAGE_PROTECT; @@ -506,12 +642,9 @@ int set_guest_storage_key(struct mm_struct *mm, unsigned long addr, 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); + if (unlikely(!ptep)) return -EFAULT; - } new = old = pgste_get_lock(ptep); pgste_val(new) &= ~(PGSTE_GR_BIT | PGSTE_GC_BIT | @@ -538,45 +671,100 @@ int set_guest_storage_key(struct mm_struct *mm, unsigned long addr, pgste_set_unlock(ptep, new); pte_unmap_unlock(ptep, ptl); - up_read(&mm->mmap_sem); return 0; } EXPORT_SYMBOL(set_guest_storage_key); -unsigned long get_guest_storage_key(struct mm_struct *mm, unsigned long addr) +/** + * 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) { - unsigned char key; spinlock_t *ptl; - pgste_t pgste; + pgste_t old, new; pte_t *ptep; + int cc = 0; - down_read(&mm->mmap_sem); ptep = get_locked_pte(mm, addr, &ptl); - if (unlikely(!ptep)) { - up_read(&mm->mmap_sem); + if (unlikely(!ptep)) 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); + new = old = pgste_get_lock(ptep); + /* Reset guest reference bit only */ + pgste_val(new) &= ~PGSTE_GR_BIT; - /* 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; + 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 0; +} +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); - up_read(&mm->mmap_sem); - return key; + return 0; } EXPORT_SYMBOL(get_guest_storage_key); #endif -- cgit v1.2.3