mm: switch to 'define pmd_write' instead of __HAVE_ARCH_PMD_WRITE

In response to compile breakage introduced by a series that added the
pud_write helper to x86, Stephen notes:

    did you consider using the other paradigm:

    In arch include files:
    #define pud_write       pud_write
    static inline int pud_write(pud_t pud)
     .....

    Then in include/asm-generic/pgtable.h:

    #ifndef pud_write
    tatic inline int pud_write(pud_t pud)
    {
            ....
    }
    #endif

    If you had, then the powerpc code would have worked ... ;-) and many
    of the other interfaces in include/asm-generic/pgtable.h are
    protected that way ...

Given that some architecture already define pmd_write() as a macro, it's
a net reduction to drop the definition of __HAVE_ARCH_PMD_WRITE.

Link: http://lkml.kernel.org/r/151129126721.37405.13339850900081557813.stgit@dwillia2-desk3.amr.corp.intel.com
Signed-off-by: Dan Williams <dan.j.williams@intel.com>
Suggested-by: Stephen Rothwell <sfr@canb.auug.org.au>
Cc: Benjamin Herrenschmidt <benh@kernel.crashing.org>
Cc: "Aneesh Kumar K.V" <aneesh.kumar@linux.vnet.ibm.com>
Cc: Oliver OHalloran <oliveroh@au1.ibm.com>
Cc: Chris Metcalf <cmetcalf@mellanox.com>
Cc: Russell King <linux@armlinux.org.uk>
Cc: Ralf Baechle <ralf@linux-mips.org>
Cc: "H. Peter Anvin" <hpa@zytor.com>
Cc: Arnd Bergmann <arnd@arndb.de>
Signed-off-by: Andrew Morton <akpm@linux-foundation.org>
Signed-off-by: Linus Torvalds <torvalds@linux-foundation.org>

1 files changed, 0 insertions, 1 deletions

diff --git a/arch/tile/include/asm/pgtable.h b/arch/tile/include/asm/pgtable.h
index 2a26cc4fefc2..adfa21b18488 100644
--- a/arch/tile/include/asm/pgtable.h
+++ b/arch/tile/include/asm/pgtable.h
@@ -475,7 +475,6 @@ static inline void pmd_clear(pmd_t *pmdp)
 #define pmd_mkdirty(pmd)        pte_pmd(pte_mkdirty(pmd_pte(pmd)))
 #define pmd_huge_page(pmd)      pte_huge(pmd_pte(pmd))
 #define pmd_mkhuge(pmd)         pte_pmd(pte_mkhuge(pmd_pte(pmd)))
-#define __HAVE_ARCH_PMD_WRITE
 
 #define pfn_pmd(pfn, pgprot)    pte_pmd(pfn_pte((pfn), (pgprot)))
 #define pmd_pfn(pmd)            pte_pfn(pmd_pte(pmd))