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Commit a13cff31 authored by Dominik Dingel's avatar Dominik Dingel Committed by Martin Schwidefsky
Browse files

s390/mm: recfactor global pgste updates 



Replace the s390 specific page table walker for the pgste updates
with a call to the common code walk_page_range function.
There are now two pte modification functions, one for the reset
of the CMMA state and another one for the initialization of the
storage keys.

Signed-off-by: default avatarDominik Dingel <dingel@linux.vnet.ibm.com>
Signed-off-by: default avatarMartin Schwidefsky <schwidefsky@de.ibm.com>
parent e43b49a0

arch/s390/include/asm/pgalloc.h

+0 −2
Original line number Diff line number Diff line
@@ -22,8 +22,6 @@ unsigned long *page_table_alloc(struct mm_struct *); 
void page_table_free(struct mm_struct *, unsigned long *);

void page_table_free_rcu(struct mmu_gather *, unsigned long *, unsigned long);



void page_table_reset_pgste(struct mm_struct *, unsigned long, unsigned long,

			    bool init_skey);

int set_guest_storage_key(struct mm_struct *mm, unsigned long addr,

			  unsigned long key, bool nq);

arch/s390/include/asm/pgtable.h

+1 −0
Original line number Diff line number Diff line
@@ -1747,6 +1747,7 @@ extern int vmem_add_mapping(unsigned long start, unsigned long size); 
extern int vmem_remove_mapping(unsigned long start, unsigned long size);

extern int s390_enable_sie(void);

extern void s390_enable_skey(void);

extern void s390_reset_cmma(struct mm_struct *mm);



/*

 * No page table caches to initialise

arch/s390/kvm/kvm-s390.c

+1 −1
Original line number Diff line number Diff line
@@ -271,7 +271,7 @@ static int kvm_s390_mem_control(struct kvm *kvm, struct kvm_device_attr *attr) 
	case KVM_S390_VM_MEM_CLR_CMMA:

		mutex_lock(&kvm->lock);

		idx = srcu_read_lock(&kvm->srcu);

		page_table_reset_pgste(kvm->arch.gmap->mm, 0, TASK_SIZE, false);

		s390_reset_cmma(kvm->arch.gmap->mm);

		srcu_read_unlock(&kvm->srcu, idx);

		mutex_unlock(&kvm->lock);

		ret = 0;

arch/s390/mm/pgtable.c

+54 −99
Original line number Diff line number Diff line
@@ -834,99 +834,6 @@ static inline void page_table_free_pgste(unsigned long *table) 
	__free_page(page);

}



static inline unsigned long page_table_reset_pte(struct mm_struct *mm, pmd_t *pmd,

			unsigned long addr, unsigned long end, bool init_skey)

{

	pte_t *start_pte, *pte;

	spinlock_t *ptl;

	pgste_t pgste;



	start_pte = pte_offset_map_lock(mm, pmd, addr, &ptl);

	pte = start_pte;

	do {

		pgste = pgste_get_lock(pte);

		pgste_val(pgste) &= ~_PGSTE_GPS_USAGE_MASK;

		if (init_skey) {

			unsigned long address;



			pgste_val(pgste) &= ~(PGSTE_ACC_BITS | PGSTE_FP_BIT |

					      PGSTE_GR_BIT | PGSTE_GC_BIT);



			/* skip invalid and not writable pages */

			if (pte_val(*pte) & _PAGE_INVALID ||

			    !(pte_val(*pte) & _PAGE_WRITE)) {

				pgste_set_unlock(pte, pgste);

				continue;

			}



			address = pte_val(*pte) & PAGE_MASK;

			page_set_storage_key(address, PAGE_DEFAULT_KEY, 1);

		}

		pgste_set_unlock(pte, pgste);

	} while (pte++, addr += PAGE_SIZE, addr != end);

	pte_unmap_unlock(start_pte, ptl);



	return addr;

}



static inline unsigned long page_table_reset_pmd(struct mm_struct *mm, pud_t *pud,

			unsigned long addr, unsigned long end, bool init_skey)

{

	unsigned long next;

	pmd_t *pmd;



	pmd = pmd_offset(pud, addr);

	do {

		next = pmd_addr_end(addr, end);

		if (pmd_none_or_clear_bad(pmd))

			continue;

		next = page_table_reset_pte(mm, pmd, addr, next, init_skey);

	} while (pmd++, addr = next, addr != end);



	return addr;

}



static inline unsigned long page_table_reset_pud(struct mm_struct *mm, pgd_t *pgd,

			unsigned long addr, unsigned long end, bool init_skey)

{

	unsigned long next;

	pud_t *pud;



	pud = pud_offset(pgd, addr);

	do {

		next = pud_addr_end(addr, end);

		if (pud_none_or_clear_bad(pud))

			continue;

		next = page_table_reset_pmd(mm, pud, addr, next, init_skey);

	} while (pud++, addr = next, addr != end);



	return addr;

}



void page_table_reset_pgste(struct mm_struct *mm, unsigned long start,

			    unsigned long end, bool init_skey)

{

	unsigned long addr, next;

	pgd_t *pgd;



	down_write(&mm->mmap_sem);

	if (init_skey && mm_use_skey(mm))

		goto out_up;

	addr = start;

	pgd = pgd_offset(mm, addr);

	do {

		next = pgd_addr_end(addr, end);

		if (pgd_none_or_clear_bad(pgd))

			continue;

		next = page_table_reset_pud(mm, pgd, addr, next, init_skey);

	} while (pgd++, addr = next, addr != end);

	if (init_skey)

		current->mm->context.use_skey = 1;

out_up:

	up_write(&mm->mmap_sem);

}

EXPORT_SYMBOL(page_table_reset_pgste);



int set_guest_storage_key(struct mm_struct *mm, unsigned long addr,

			  unsigned long key, bool nq)

{
@@ -992,11 +899,6 @@ static inline unsigned long *page_table_alloc_pgste(struct mm_struct *mm) 
	return NULL;

}



void page_table_reset_pgste(struct mm_struct *mm, unsigned long start,

			    unsigned long end, bool init_skey)

{

}



static inline void page_table_free_pgste(unsigned long *table)

{

}
@@ -1347,12 +1249,65 @@ EXPORT_SYMBOL_GPL(s390_enable_sie); 
 * Enable storage key handling from now on and initialize the storage

 * keys with the default key.

 */

static int __s390_enable_skey(pte_t *pte, unsigned long addr,

			      unsigned long next, struct mm_walk *walk)

{

	unsigned long ptev;

	pgste_t pgste;



	pgste = pgste_get_lock(pte);

	/* Clear storage key */

	pgste_val(pgste) &= ~(PGSTE_ACC_BITS | PGSTE_FP_BIT |

			      PGSTE_GR_BIT | PGSTE_GC_BIT);

	ptev = pte_val(*pte);

	if (!(ptev & _PAGE_INVALID) && (ptev & _PAGE_WRITE))

		page_set_storage_key(ptev & PAGE_MASK, PAGE_DEFAULT_KEY, 1);

	pgste_set_unlock(pte, pgste);

	return 0;

}



void s390_enable_skey(void)

{

	page_table_reset_pgste(current->mm, 0, TASK_SIZE, true);

	struct mm_walk walk = { .pte_entry = __s390_enable_skey };

	struct mm_struct *mm = current->mm;



	down_write(&mm->mmap_sem);

	if (mm_use_skey(mm))

		goto out_up;

	walk.mm = mm;

	walk_page_range(0, TASK_SIZE, &walk);

	mm->context.use_skey = 1;



out_up:

	up_write(&mm->mmap_sem);

}

EXPORT_SYMBOL_GPL(s390_enable_skey);



/*

 * Reset CMMA state, make all pages stable again.

 */

static int __s390_reset_cmma(pte_t *pte, unsigned long addr,

			     unsigned long next, struct mm_walk *walk)

{

	pgste_t pgste;



	pgste = pgste_get_lock(pte);

	pgste_val(pgste) &= ~_PGSTE_GPS_USAGE_MASK;

	pgste_set_unlock(pte, pgste);

	return 0;

}



void s390_reset_cmma(struct mm_struct *mm)

{

	struct mm_walk walk = { .pte_entry = __s390_reset_cmma };



	down_write(&mm->mmap_sem);

	walk.mm = mm;

	walk_page_range(0, TASK_SIZE, &walk);

	up_write(&mm->mmap_sem);

}

EXPORT_SYMBOL_GPL(s390_reset_cmma);



/*

 * Test and reset if a guest page is dirty

 */