mm/hugetlb: add more arch-defined huge_pte functions

Commit abf09bed3cce ("s390/mm: implement software dirty bits")
introduced another difference in the pte layout vs.  the pmd layout on
s390, thoroughly breaking the s390 support for hugetlbfs.  This requires
replacing some more pte_xxx functions in mm/hugetlbfs.c with a
huge_pte_xxx version.

This patch introduces those huge_pte_xxx functions and their generic
implementation in asm-generic/hugetlb.h, which will now be included on
all architectures supporting hugetlbfs apart from s390.  This change
will be a no-op for those architectures.

[akpm@linux-foundation.org: fix warning]
Signed-off-by: Gerald Schaefer <gerald.schaefer@de.ibm.com>
Cc: Mel Gorman <mgorman@suse.de>
Cc: Hugh Dickins <hughd@google.com>
Cc: Hillf Danton <dhillf@gmail.com>
Acked-by: Michal Hocko <mhocko@suse.cz>	[for !s390 parts]
Cc: Tony Luck <tony.luck@intel.com>
Cc: Fenghua Yu <fenghua.yu@intel.com>
Cc: Ralf Baechle <ralf@linux-mips.org>
Cc: Benjamin Herrenschmidt <benh@kernel.crashing.org>
Cc: Paul Mackerras <paulus@samba.org>
Cc: Paul Mundt <lethal@linux-sh.org>
Cc: "David S. Miller" <davem@davemloft.net>
Cc: Chris Metcalf <cmetcalf@tilera.com>
Cc: Thomas Gleixner <tglx@linutronix.de>
Cc: Ingo Molnar <mingo@redhat.com>
Cc: "H. Peter Anvin" <hpa@zytor.com>
Cc: Martin Schwidefsky <schwidefsky@de.ibm.com>
Cc: Heiko Carstens <heiko.carstens@de.ibm.com>
Signed-off-by: Andrew Morton <akpm@linux-foundation.org>
Signed-off-by: Linus Torvalds <torvalds@linux-foundation.org>

1 files changed, 55 insertions, 1 deletions

diff --git a/arch/s390/include/asm/hugetlb.h b/arch/s390/include/asm/hugetlb.h
index 593753ee07f3..bd90359d6d22 100644
--- a/arch/s390/include/asm/hugetlb.h
+++ b/arch/s390/include/asm/hugetlb.h
@@ -114,7 +114,7 @@ static inline pte_t huge_ptep_get_and_clear(struct mm_struct *mm,
 #define huge_ptep_set_wrprotect(__mm, __addr, __ptep)                   \
 ({                                                                      \
         pte_t __pte = huge_ptep_get(__ptep);                            \
-        if (pte_write(__pte)) {                                         \
+        if (huge_pte_write(__pte)) {                                    \
                 huge_ptep_invalidate(__mm, __addr, __ptep);             \
                 set_huge_pte_at(__mm, __addr, __ptep,                   \
                                 huge_pte_wrprotect(__pte));             \
@@ -127,4 +127,58 @@ static inline void huge_ptep_clear_flush(struct vm_area_struct *vma,
         huge_ptep_invalidate(vma->vm_mm, address, ptep);
 }
 
+static inline pte_t mk_huge_pte(struct page *page, pgprot_t pgprot)
+{
+        pte_t pte;
+        pmd_t pmd;
+
+        pmd = mk_pmd_phys(page_to_phys(page), pgprot);
+        pte_val(pte) = pmd_val(pmd);
+        return pte;
+}
+
+static inline int huge_pte_write(pte_t pte)
+{
+        pmd_t pmd;
+
+        pmd_val(pmd) = pte_val(pte);
+        return pmd_write(pmd);
+}
+
+static inline int huge_pte_dirty(pte_t pte)
+{
+        /* No dirty bit in the segment table entry. */
+        return 0;
+}
+
+static inline pte_t huge_pte_mkwrite(pte_t pte)
+{
+        pmd_t pmd;
+
+        pmd_val(pmd) = pte_val(pte);
+        pte_val(pte) = pmd_val(pmd_mkwrite(pmd));
+        return pte;
+}
+
+static inline pte_t huge_pte_mkdirty(pte_t pte)
+{
+        /* No dirty bit in the segment table entry. */
+        return pte;
+}
+
+static inline pte_t huge_pte_modify(pte_t pte, pgprot_t newprot)
+{
+        pmd_t pmd;
+
+        pmd_val(pmd) = pte_val(pte);
+        pte_val(pte) = pmd_val(pmd_modify(pmd, newprot));
+        return pte;
+}
+
+static inline void huge_pte_clear(struct mm_struct *mm, unsigned long addr,
+                                  pte_t *ptep)
+{
+        pmd_clear((pmd_t *) ptep);
+}
+
 #endif /* _ASM_S390_HUGETLB_H */