[PATCH resend RFC 7/9] s390/mm: no need for pte_alloc_map_lock() if we know the pmd is present

David Hildenbrand
2021-09-09T16:24:06Z

pte_map_lock() is sufficient.

Signed-off-by: David Hildenbrand <david@redhat.com>
---
arch/s390/mm/pgtable.c | 15 +++------------
1 file changed, 3 insertions(+), 12 deletions(-)

diff --git a/arch/s390/mm/pgtable.c b/arch/s390/mm/pgtable.c
index 5fb409ff7842..4e77b8ebdcc5 100644
--- a/arch/s390/mm/pgtable.c
+++ b/arch/s390/mm/pgtable.c
@@ -814,10 +814,7 @@ int set_guest_storage_key(struct mm_struct *mm, unsigned long addr,
}
spin_unlock(ptl);

- ptep = pte_alloc_map_lock(mm, pmdp, addr, &ptl);
- if (unlikely(!ptep))
- return -EFAULT;
-
+ ptep = pte_offset_map_lock(mm, pmdp, addr, &ptl);
new = old = pgste_get_lock(ptep);
pgste_val(new) &= ~(PGSTE_GR_BIT | PGSTE_GC_BIT |
PGSTE_ACC_BITS | PGSTE_FP_BIT);
@@ -912,10 +909,7 @@ int reset_guest_reference_bit(struct mm_struct *mm, unsigned long addr)
}
spin_unlock(ptl);

- ptep = pte_alloc_map_lock(mm, pmdp, addr, &ptl);
- if (unlikely(!ptep))
- return -EFAULT;
-
+ ptep = pte_offset_map_lock(mm, pmdp, addr, &ptl);
new = old = pgste_get_lock(ptep);
/* Reset guest reference bit only */
pgste_val(new) &= ~PGSTE_GR_BIT;
@@ -977,10 +971,7 @@ int get_guest_storage_key(struct mm_struct *mm, unsigned long addr,
}
spin_unlock(ptl);

- ptep = pte_alloc_map_lock(mm, pmdp, addr, &ptl);
- if (unlikely(!ptep))
- return -EFAULT;
-
+ ptep = pte_offset_map_lock(mm, pmdp, addr, &ptl);
pgste = pgste_get_lock(ptep);
*key = (pgste_val(pgste) & (PGSTE_ACC_BITS | PGSTE_FP_BIT)) >> 56;
paddr = pte_val(*ptep) & PAGE_MASK;
--
2.31.1