s390/hugetlb: use direct TLB flushing for hugetlbfs pages

huge_ptep_get_and_clear() is either missing a TLB invalidation or
an mm->context.attach_count check. Since the attach_count logic was
introduced with normal ptes in mind, let's just use direct TLB
flushing for hugetlbfs pages.

Signed-off-by: Gerald Schaefer <gerald.schaefer@de.ibm.com>
Signed-off-by: Martin Schwidefsky <schwidefsky@de.ibm.com>

diff --git a/arch/s390/include/asm/hugetlb.h b/arch/s390/include/asm/hugetlb.h
index 799ed0f..2d6e6e3 100644 (file)
--- a/arch/s390/include/asm/hugetlb.h
+++ b/arch/s390/include/asm/hugetlb.h
@@ -66,16 +66,6 @@ static inline pte_t huge_ptep_get(pte_t *ptep)
        return pte;
 }
 
-static inline pte_t huge_ptep_get_and_clear(struct mm_struct *mm,
-                                           unsigned long addr, pte_t *ptep)
-{
-       pte_t pte = huge_ptep_get(ptep);
-
-       mm->context.flush_mm = 1;
-       pmd_clear((pmd_t *) ptep);
-       return pte;
-}
-
 static inline void __pmd_csp(pmd_t *pmdp)
 {
        register unsigned long reg2 asm("2") = pmd_val(*pmdp);
@@ -117,6 +107,15 @@ static inline void huge_ptep_invalidate(struct mm_struct *mm,
                __pmd_csp(pmdp);
 }
 
+static inline pte_t huge_ptep_get_and_clear(struct mm_struct *mm,
+                                           unsigned long addr, pte_t *ptep)
+{
+       pte_t pte = huge_ptep_get(ptep);
+
+       huge_ptep_invalidate(mm, addr, ptep);
+       return pte;
+}
+
 #define huge_ptep_set_access_flags(__vma, __addr, __ptep, __entry, __dirty) \
 ({                                                                         \
        int __changed = !pte_same(huge_ptep_get(__ptep), __entry);          \
@@ -131,10 +130,7 @@ static inline void huge_ptep_invalidate(struct mm_struct *mm,
 ({                                                                     \
        pte_t __pte = huge_ptep_get(__ptep);                            \
        if (pte_write(__pte)) {                                         \
-               (__mm)->context.flush_mm = 1;                           \
-               if (atomic_read(&(__mm)->context.attach_count) > 1 ||   \
-                   (__mm) != current->active_mm)                       \
-                       huge_ptep_invalidate(__mm, __addr, __ptep);     \
+               huge_ptep_invalidate(__mm, __addr, __ptep);             \
                set_huge_pte_at(__mm, __addr, __ptep,                   \
                                huge_pte_wrprotect(__pte));             \
        }                                                               \