From cd774b9076845312caf76ad52523bd9219e89ae1 Mon Sep 17 00:00:00 2001 From: Martin Schwidefsky Date: Tue, 26 Jul 2016 17:02:31 +0200 Subject: [PATCH] s390/mm,kvm: use nodat PGSTE tag to optimize TLB flushing Signed-off-by: Martin Schwidefsky --- arch/s390/include/asm/pgtable.h | 1 + arch/s390/mm/pgtable.c | 47 +++++++++++++++++++++------------ 2 files changed, 31 insertions(+), 17 deletions(-) diff --git a/arch/s390/include/asm/pgtable.h b/arch/s390/include/asm/pgtable.h index b20b0f7170e8..bb59a0aa3249 100644 --- a/arch/s390/include/asm/pgtable.h +++ b/arch/s390/include/asm/pgtable.h @@ -376,6 +376,7 @@ static inline int is_module_addr(void *addr) /* Guest Page State used for virtualization */ #define _PGSTE_GPS_ZERO 0x0000000080000000UL +#define _PGSTE_GPS_NODAT 0x0000000040000000UL #define _PGSTE_GPS_USAGE_MASK 0x0000000003000000UL #define _PGSTE_GPS_USAGE_STABLE 0x0000000000000000UL #define _PGSTE_GPS_USAGE_UNUSED 0x0000000001000000UL diff --git a/arch/s390/mm/pgtable.c b/arch/s390/mm/pgtable.c index 3f1abc7b5fd2..8d018c76ee85 100644 --- a/arch/s390/mm/pgtable.c +++ b/arch/s390/mm/pgtable.c @@ -26,14 +26,14 @@ #include static inline void ptep_ipte_local(struct mm_struct *mm, unsigned long addr, - pte_t *ptep) + 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) + if (asce == 0UL || nodat) opt |= IPTE_NODAT; if (asce != -1UL) { asce = asce ? : mm->context.asce; @@ -46,14 +46,14 @@ static inline void ptep_ipte_local(struct mm_struct *mm, unsigned long addr, } static inline void ptep_ipte_global(struct mm_struct *mm, unsigned long addr, - pte_t *ptep) + 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) + if (asce == 0UL || nodat) opt |= IPTE_NODAT; if (asce != -1UL) { asce = asce ? : mm->context.asce; @@ -66,7 +66,8 @@ static inline void ptep_ipte_global(struct mm_struct *mm, unsigned long addr, } static inline pte_t ptep_flush_direct(struct mm_struct *mm, - unsigned long addr, pte_t *ptep) + unsigned long addr, pte_t *ptep, + int nodat) { pte_t old; @@ -76,15 +77,16 @@ static inline pte_t ptep_flush_direct(struct mm_struct *mm, 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); + ptep_ipte_local(mm, addr, ptep, nodat); else - ptep_ipte_global(mm, addr, ptep); + 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) + unsigned long addr, pte_t *ptep, + int nodat) { pte_t old; @@ -97,7 +99,7 @@ static inline pte_t ptep_flush_lazy(struct mm_struct *mm, pte_val(*ptep) |= _PAGE_INVALID; mm->context.flush_mm = 1; } else - ptep_ipte_global(mm, addr, ptep); + ptep_ipte_global(mm, addr, ptep, nodat); atomic_dec(&mm->context.flush_count); return old; } @@ -269,10 +271,12 @@ pte_t ptep_xchg_direct(struct mm_struct *mm, unsigned long addr, { pgste_t pgste; pte_t old; + int nodat; preempt_disable(); pgste = ptep_xchg_start(mm, addr, ptep); - old = ptep_flush_direct(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; @@ -284,10 +288,12 @@ pte_t ptep_xchg_lazy(struct mm_struct *mm, unsigned long addr, { pgste_t pgste; pte_t old; + int nodat; preempt_disable(); pgste = ptep_xchg_start(mm, addr, ptep); - old = ptep_flush_lazy(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; @@ -299,10 +305,12 @@ pte_t ptep_modify_prot_start(struct mm_struct *mm, unsigned long addr, { pgste_t pgste; pte_t old; + int nodat; preempt_disable(); pgste = ptep_xchg_start(mm, addr, ptep); - old = ptep_flush_lazy(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); @@ -557,7 +565,7 @@ int ptep_force_prot(struct mm_struct *mm, unsigned long addr, { pte_t entry; pgste_t pgste; - int pte_i, pte_p; + int pte_i, pte_p, nodat; pgste = pgste_get_lock(ptep); entry = *ptep; @@ -570,13 +578,14 @@ int ptep_force_prot(struct mm_struct *mm, unsigned long addr, 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); + 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); + ptep_flush_direct(mm, addr, ptep, nodat); pte_val(entry) &= ~_PAGE_INVALID; pte_val(entry) |= _PAGE_PROTECT; } @@ -616,10 +625,12 @@ int ptep_shadow_pte(struct mm_struct *mm, unsigned long saddr, 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 */ - ptep_flush_direct(mm, saddr, ptep); + 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); @@ -692,6 +703,7 @@ bool test_and_clear_guest_dirty(struct mm_struct *mm, unsigned long addr) pte_t *ptep; pte_t pte; bool dirty; + int nodat; pgd = pgd_offset(mm, addr); p4d = p4d_alloc(mm, pgd, addr); @@ -720,7 +732,8 @@ bool test_and_clear_guest_dirty(struct mm_struct *mm, unsigned long addr) pte = *ptep; if (dirty && (pte_val(pte) & _PAGE_PRESENT)) { pgste = pgste_pte_notify(mm, addr, ptep, pgste); - ptep_ipte_global(mm, addr, ptep); + 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 -- 2.39.5