From: Dominik Dingel <dingel@xxxxxxxxxxxxxxxxxx>
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 <dingel@xxxxxxxxxxxxxxxxxx>
Acked-by: Martin Schwidefsky <schwidefsky@xxxxxxxxxx>
Signed-off-by: Christian Borntraeger <borntraeger@xxxxxxxxxx>
---
arch/s390/include/asm/mmu.h | 2 ++
arch/s390/include/asm/mmu_context.h | 1 +
arch/s390/include/asm/pgtable.h | 41 ++++++++++++++++++++++++-------------
3 files changed, 30 insertions(+), 14 deletions(-)
diff --git a/arch/s390/include/asm/mmu.h b/arch/s390/include/asm/mmu.h
index ff132ac..665cfb3 100644
--- a/arch/s390/include/asm/mmu.h
+++ b/arch/s390/include/asm/mmu.h
@@ -14,6 +14,8 @@ 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 38149b6..768e05a 100644
--- a/arch/s390/include/asm/mmu_context.h
+++ b/arch/s390/include/asm/mmu_context.h
@@ -22,6 +22,7 @@ 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 50a75d9..818ab0f 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);
@@ -1159,7 +1172,7 @@ 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;
@@ -1182,7 +1195,7 @@ 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;
@@ -1196,7 +1209,7 @@ 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
@@ -1223,7 +1236,7 @@ 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;
@@ -1255,7 +1268,7 @@ 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;
--
1.8.4.2
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