From: Dominik Dingel Date: Tue, 14 Jan 2014 14:02:11 +0000 (+0100) Subject: KVM: s390: Adding skey bit to mmu context X-Git-Url: https://git.stricted.de/?a=commitdiff_plain;h=65eef33550f68e9a7f7d2dc64da94fb6cb85be2c;p=GitHub%2FLineageOS%2FG12%2Fandroid_kernel_amlogic_linux-4.9.git KVM: s390: Adding skey bit to mmu context For lazy storage key handling, we need a mechanism to track if the process ever issued a storage key operation. This patch adds the basic infrastructure for making the storage key handling optional, but still leaves it enabled for now by default. Signed-off-by: Dominik Dingel Acked-by: Martin Schwidefsky Signed-off-by: Christian Borntraeger --- diff --git a/arch/s390/include/asm/mmu.h b/arch/s390/include/asm/mmu.h index f77695a82f64..a5e656260a70 100644 --- a/arch/s390/include/asm/mmu.h +++ b/arch/s390/include/asm/mmu.h @@ -16,6 +16,8 @@ typedef struct { unsigned long vdso_base; /* The mmu context has extended page tables. */ unsigned int has_pgste:1; + /* The mmu context uses storage keys. */ + unsigned int use_skey:1; } mm_context_t; #define INIT_MM_CONTEXT(name) \ diff --git a/arch/s390/include/asm/mmu_context.h b/arch/s390/include/asm/mmu_context.h index 71be346d0e3c..05925ead0748 100644 --- a/arch/s390/include/asm/mmu_context.h +++ b/arch/s390/include/asm/mmu_context.h @@ -23,6 +23,7 @@ static inline int init_new_context(struct task_struct *tsk, mm->context.asce_bits |= _ASCE_TYPE_REGION3; #endif mm->context.has_pgste = 0; + mm->context.use_skey = 1; mm->context.asce_limit = STACK_TOP_MAX; crst_table_init((unsigned long *) mm->pgd, pgd_entry_type(mm)); return 0; diff --git a/arch/s390/include/asm/pgtable.h b/arch/s390/include/asm/pgtable.h index 12f75313e086..e88e9f6b07cc 100644 --- a/arch/s390/include/asm/pgtable.h +++ b/arch/s390/include/asm/pgtable.h @@ -466,6 +466,16 @@ static inline int mm_has_pgste(struct mm_struct *mm) #endif return 0; } + +static inline int mm_use_skey(struct mm_struct *mm) +{ +#ifdef CONFIG_PGSTE + if (mm->context.use_skey) + return 1; +#endif + return 0; +} + /* * pgd/pmd/pte query functions */ @@ -699,12 +709,13 @@ static inline void pgste_set(pte_t *ptep, pgste_t pgste) #endif } -static inline pgste_t pgste_update_all(pte_t *ptep, pgste_t pgste) +static inline pgste_t pgste_update_all(pte_t *ptep, pgste_t pgste, + struct mm_struct *mm) { #ifdef CONFIG_PGSTE unsigned long address, bits, skey; - if (pte_val(*ptep) & _PAGE_INVALID) + if (!mm_use_skey(mm) || pte_val(*ptep) & _PAGE_INVALID) return pgste; address = pte_val(*ptep) & PAGE_MASK; skey = (unsigned long) page_get_storage_key(address); @@ -729,10 +740,11 @@ static inline pgste_t pgste_update_all(pte_t *ptep, pgste_t pgste) } -static inline pgste_t pgste_update_young(pte_t *ptep, pgste_t pgste) +static inline pgste_t pgste_update_young(pte_t *ptep, pgste_t pgste, + struct mm_struct *mm) { #ifdef CONFIG_PGSTE - if (pte_val(*ptep) & _PAGE_INVALID) + if (!mm_use_skey(mm) || pte_val(*ptep) & _PAGE_INVALID) return pgste; /* Get referenced bit from storage key */ if (page_reset_referenced(pte_val(*ptep) & PAGE_MASK)) @@ -741,13 +753,14 @@ static inline pgste_t pgste_update_young(pte_t *ptep, pgste_t pgste) return pgste; } -static inline void pgste_set_key(pte_t *ptep, pgste_t pgste, pte_t entry) +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 (pte_val(entry) & _PAGE_INVALID) + 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; @@ -870,7 +883,7 @@ static inline void set_pte_at(struct mm_struct *mm, unsigned long addr, if (mm_has_pgste(mm)) { pgste = pgste_get_lock(ptep); pgste_val(pgste) &= ~_PGSTE_GPS_ZERO; - pgste_set_key(ptep, pgste, entry); + pgste_set_key(ptep, pgste, entry, mm); pgste_set_pte(ptep, entry); pgste_set_unlock(ptep, pgste); } else { @@ -1028,7 +1041,7 @@ static inline int ptep_test_and_clear_user_dirty(struct mm_struct *mm, if (mm_has_pgste(mm)) { pgste = pgste_get_lock(ptep); - pgste = pgste_update_all(ptep, pgste); + pgste = pgste_update_all(ptep, pgste, mm); dirty = !!(pgste_val(pgste) & PGSTE_HC_BIT); pgste_val(pgste) &= ~PGSTE_HC_BIT; pgste_set_unlock(ptep, pgste); @@ -1048,7 +1061,7 @@ static inline int ptep_test_and_clear_user_young(struct mm_struct *mm, if (mm_has_pgste(mm)) { pgste = pgste_get_lock(ptep); - pgste = pgste_update_young(ptep, pgste); + pgste = pgste_update_young(ptep, pgste, mm); young = !!(pgste_val(pgste) & PGSTE_HR_BIT); pgste_val(pgste) &= ~PGSTE_HR_BIT; pgste_set_unlock(ptep, pgste); @@ -1182,7 +1195,7 @@ static inline pte_t ptep_get_and_clear(struct mm_struct *mm, pte_val(*ptep) = _PAGE_INVALID; if (mm_has_pgste(mm)) { - pgste = pgste_update_all(&pte, pgste); + pgste = pgste_update_all(&pte, pgste, mm); pgste_set_unlock(ptep, pgste); } return pte; @@ -1205,7 +1218,7 @@ static inline pte_t ptep_modify_prot_start(struct mm_struct *mm, ptep_flush_lazy(mm, address, ptep); if (mm_has_pgste(mm)) { - pgste = pgste_update_all(&pte, pgste); + pgste = pgste_update_all(&pte, pgste, mm); pgste_set(ptep, pgste); } return pte; @@ -1219,7 +1232,7 @@ static inline void ptep_modify_prot_commit(struct mm_struct *mm, if (mm_has_pgste(mm)) { pgste = pgste_get(ptep); - pgste_set_key(ptep, pgste, pte); + pgste_set_key(ptep, pgste, pte, mm); pgste_set_pte(ptep, pte); pgste_set_unlock(ptep, pgste); } else @@ -1246,7 +1259,7 @@ static inline pte_t ptep_clear_flush(struct vm_area_struct *vma, if ((pgste_val(pgste) & _PGSTE_GPS_USAGE_MASK) == _PGSTE_GPS_USAGE_UNUSED) pte_val(pte) |= _PAGE_UNUSED; - pgste = pgste_update_all(&pte, pgste); + pgste = pgste_update_all(&pte, pgste, vma->vm_mm); pgste_set_unlock(ptep, pgste); } return pte; @@ -1278,7 +1291,7 @@ static inline pte_t ptep_get_and_clear_full(struct mm_struct *mm, pte_val(*ptep) = _PAGE_INVALID; if (!full && mm_has_pgste(mm)) { - pgste = pgste_update_all(&pte, pgste); + pgste = pgste_update_all(&pte, pgste, mm); pgste_set_unlock(ptep, pgste); } return pte;