Donate to e Foundation | Murena handsets with /e/OS | Own a part of Murena! Learn more

Commit 65eef335 authored by Dominik Dingel's avatar Dominik Dingel Committed by Christian Borntraeger
Browse files

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: default avatarDominik Dingel <dingel@linux.vnet.ibm.com>
Acked-by: default avatarMartin Schwidefsky <schwidefsky@de.ibm.com>
Signed-off-by: default avatarChristian Borntraeger <borntraeger@de.ibm.com>
parent 0f689a33

arch/s390/include/asm/mmu.h

+2 −0
Original line number Diff line number Diff line
@@ -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)						      \

arch/s390/include/asm/mmu_context.h

+1 −0
Original line number Diff line number Diff line
@@ -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;

arch/s390/include/asm/pgtable.h

+27 −14
Original line number Diff line number Diff line
@@ -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;