diff options
| author | Martin Schwidefsky <schwidefsky@de.ibm.com> | 2016-03-08 11:53:35 +0100 |
|---|---|---|
| committer | Christian Borntraeger <borntraeger@de.ibm.com> | 2016-06-10 12:07:27 +0200 |
| commit | d3ed1ceeace311af9973d17a07a114bfaf0ca1b1 (patch) | |
| tree | 1e9a353c769d89bf8eee9489f931869dcaf0651a /arch/s390/mm | |
| parent | s390/mm: don't drop errors in get_guest_storage_key (diff) | |
| download | linux-d3ed1ceeace311af9973d17a07a114bfaf0ca1b1.tar.xz linux-d3ed1ceeace311af9973d17a07a114bfaf0ca1b1.zip | |
s390/mm: set and get guest storage key mmap locking
Move the mmap semaphore locking out of set_guest_storage_key
and get_guest_storage_key. This makes the two functions more
like the other ptep_xxx operations and allows to avoid repeated
semaphore operations if multiple keys are read or written.
Reviewed-by: David Hildenbrand <dahi@linux.vnet.ibm.com>
Reviewed-by: Christian Borntraeger <borntraeger@de.ibm.com>
Signed-off-by: Martin Schwidefsky <schwidefsky@de.ibm.com>
Signed-off-by: Christian Borntraeger <borntraeger@de.ibm.com>
Diffstat (limited to 'arch/s390/mm')
| -rw-r--r-- | arch/s390/mm/pgtable.c | 15 |
1 files changed, 3 insertions, 12 deletions
diff --git a/arch/s390/mm/pgtable.c b/arch/s390/mm/pgtable.c index 2a23ca96f9c2..7612a7c3a3a8 100644 --- a/arch/s390/mm/pgtable.c +++ b/arch/s390/mm/pgtable.c @@ -506,12 +506,9 @@ int set_guest_storage_key(struct mm_struct *mm, unsigned long addr, pgste_t old, new; pte_t *ptep; - down_read(&mm->mmap_sem); ptep = get_locked_pte(mm, addr, &ptl); - if (unlikely(!ptep)) { - up_read(&mm->mmap_sem); + if (unlikely(!ptep)) return -EFAULT; - } new = old = pgste_get_lock(ptep); pgste_val(new) &= ~(PGSTE_GR_BIT | PGSTE_GC_BIT | @@ -538,7 +535,6 @@ int set_guest_storage_key(struct mm_struct *mm, unsigned long addr, pgste_set_unlock(ptep, new); pte_unmap_unlock(ptep, ptl); - up_read(&mm->mmap_sem); return 0; } EXPORT_SYMBOL(set_guest_storage_key); @@ -550,14 +546,11 @@ unsigned long get_guest_storage_key(struct mm_struct *mm, unsigned long addr) pgste_t pgste; pte_t *ptep; - down_read(&mm->mmap_sem); ptep = get_locked_pte(mm, addr, &ptl); - if (unlikely(!ptep)) { - up_read(&mm->mmap_sem); + if (unlikely(!ptep)) return -EFAULT; - } - pgste = pgste_get_lock(ptep); + pgste = pgste_get_lock(ptep); if (pte_val(*ptep) & _PAGE_INVALID) { key = (pgste_val(pgste) & PGSTE_ACC_BITS) >> 56; key |= (pgste_val(pgste) & PGSTE_FP_BIT) >> 56; @@ -572,10 +565,8 @@ unsigned long get_guest_storage_key(struct mm_struct *mm, unsigned long addr) if (pgste_val(pgste) & PGSTE_GC_BIT) key |= _PAGE_CHANGED; } - pgste_set_unlock(ptep, pgste); pte_unmap_unlock(ptep, ptl); - up_read(&mm->mmap_sem); return key; } EXPORT_SYMBOL(get_guest_storage_key); |