[PATCH 08/16] debug_vm_pgtable/set_pmd: Don't use set_pmd_at to update an existing pmd entry

[Aneesh Kumar K.V]

set_pmd_at() should not be used to set a pte entry at locations that
already holds a valid pte entry. Architectures like ppc64 don't do TLB
invalidate in set_pmd_at() and hence expect it to be used to set locations
that are not a valid PTE.

Signed-off-by: Aneesh Kumar K.V <aneesh.ku...@linux.ibm.com>
---
 mm/debug_vm_pgtable.c | 5 +----
 1 file changed, 1 insertion(+), 4 deletions(-)

diff --git a/mm/debug_vm_pgtable.c b/mm/debug_vm_pgtable.c
index cd609a212dd4..60bf876081b8 100644
--- a/mm/debug_vm_pgtable.c
+++ b/mm/debug_vm_pgtable.c
@@ -164,8 +164,6 @@ static void __init pmd_advanced_tests(struct mm_struct *mm,
        pmd = READ_ONCE(*pmdp);
        WARN_ON(pmd_write(pmd));
 
-       pmd = pmd_mkhuge(pfn_pmd(pfn, prot));
-       set_pmd_at(mm, vaddr, pmdp, pmd);
        pmdp_huge_get_and_clear(mm, vaddr, pmdp);
        pmd = READ_ONCE(*pmdp);
        WARN_ON(!pmd_none(pmd));
@@ -180,12 +178,11 @@ static void __init pmd_advanced_tests(struct mm_struct 
*mm,
        pmd = READ_ONCE(*pmdp);
        WARN_ON(!(pmd_write(pmd) && pmd_dirty(pmd)));
 
-       pmd = pmd_mkhuge(pfn_pmd(pfn, prot));
-       set_pmd_at(mm, vaddr, pmdp, pmd);
        pmdp_huge_get_and_clear_full(vma, vaddr, pmdp, 1);
        pmd = READ_ONCE(*pmdp);
        WARN_ON(!pmd_none(pmd));
 
+       pmd = pmd_mkhuge(pfn_pmd(pfn, prot));
        pmd = pmd_mkyoung(pmd);
        set_pmd_at(mm, vaddr, pmdp, pmd);
        pmdp_test_and_clear_young(vma, vaddr, pmdp);
-- 
2.26.2