These macros will be used in a later patch, where all usages are expected
to be optimized away without #ifdef CONFIG_TRANSPARENT_HUGEPAGE.  But to
detect unexpected usages, we convert the existing BUG() to BUILD_BUG().

[akpm@linux-foundation.org: fix build in mm/pgtable-generic.c]
Signed-off-by: NNaoya Horiguchi <n-horiguchi@ah.jp.nec.com>
Acked-by: NHillf Danton <dhillf@gmail.com>
Reviewed-by: NAndrea Arcangeli <aarcange@redhat.com>
Reviewed-by: NKAMEZAWA Hiroyuki <kamezawa.hiroyu@jp.fujitsu.com>
Acked-by: NDavid Rientjes <rientjes@google.com>
Cc: Daisuke Nishimura <nishimura@mxp.nes.nec.co.jp>
Signed-off-by: NAndrew Morton <akpm@linux-foundation.org>
Signed-off-by: NLinus Torvalds <torvalds@linux-foundation.org>

mips (and sparc32):

  In file included from arch/mips/include/asm/tlb.h:21,
                   from mm/pgtable-generic.c:9:
  include/asm-generic/tlb.h: In function `tlb_flush_mmu':
  include/asm-generic/tlb.h:76: error: implicit declaration of function `release_pages'
  include/asm-generic/tlb.h: In function `tlb_remove_page':
  include/asm-generic/tlb.h:105: error: implicit declaration of function `page_cache_release'

free_pages_and_swap_cache() and free_page_and_swap_cache() are macros
which call release_pages() and page_cache_release().  The obvious fix is
to include pagemap.h in swap.h, where those macros are defined.  But that
breaks sparc for weird reasons.

So fix it within mm/pgtable-generic.c instead.
Reported-by: NYoichi Yuasa <yuasa@linux-mips.org>
Cc: Geert Uytterhoeven <geert@linux-m68k.org>
Acked-by: NSam Ravnborg <sam@ravnborg.org>
Cc: Sergei Shtylyov <sshtylyov@mvista.com>
Signed-off-by: NAndrew Morton <akpm@linux-foundation.org>
Signed-off-by: NLinus Torvalds <torvalds@linux-foundation.org>

pmdp_get_and_clear/pmdp_clear_flush/pmdp_splitting_flush were trapped as
BUG() and they were defined only to diminish the risk of build issues on
not-x86 archs and to be consistent with the generic pte methods previously
defined in include/asm-generic/pgtable.h.

But they are causing more trouble than they were supposed to solve, so
it's simpler not to define them when THP is off.

This is also correcting the export of pmdp_splitting_flush which is
currently unused (x86 isn't using the generic implementation in
mm/pgtable-generic.c and no other arch needs that [yet]).
Signed-off-by: NAndrea Arcangeli <aarcange@redhat.com>
Sam Ravnborg <sam@ravnborg.org>
Cc: Stephen Rothwell <sfr@canb.auug.org.au>
Cc: "David S. Miller" <davem@davemloft.net>
Cc: Benjamin Herrenschmidt <benh@kernel.crashing.org>
Cc: "Luck, Tony" <tony.luck@intel.com>
Cc: James Bottomley <James.Bottomley@HansenPartnership.com>
Signed-off-by: NAndrew Morton <akpm@linux-foundation.org>
Signed-off-by: NLinus Torvalds <torvalds@linux-foundation.org>

Some are needed to build but not actually used on archs not supporting
transparent hugepages.  Others like pmdp_clear_flush are used by x86 too.
Signed-off-by: NAndrea Arcangeli <aarcange@redhat.com>
Acked-by: NRik van Riel <riel@redhat.com>
Acked-by: NMel Gorman <mel@csn.ul.ie>
Signed-off-by: NAndrew Morton <akpm@linux-foundation.org>
Signed-off-by: NLinus Torvalds <torvalds@linux-foundation.org>