mm/special: create generic fallbacks for pte_special() and pte_mkspecial()

Currently there are many platforms that dont enable ARCH_HAS_PTE_SPECIAL
but required to define quite similar fallback stubs for special page
table entry helpers such as pte_special() and pte_mkspecial(), as they
get build in generic MM without a config check.  This creates two
generic fallback stub definitions for these helpers, eliminating much
code duplication.

mips platform has a special case where pte_special() and pte_mkspecial()
visibility is wider than what ARCH_HAS_PTE_SPECIAL enablement requires.
This restricts those symbol visibility in order to avoid redefinitions
which is now exposed through this new generic stubs and subsequent build
failure.  arm platform set_pte_at() definition needs to be moved into a
C file just to prevent a build failure.

[anshuman.khandual@arm.com: use defined(CONFIG_ARCH_HAS_PTE_SPECIAL) in mips per Thomas]
  Link: http://lkml.kernel.org/r/1583851924-21603-1-git-send-email-anshuman.khandual@arm.com
Signed-off-by: Anshuman Khandual <anshuman.khandual@arm.com>
Signed-off-by: Andrew Morton <akpm@linux-foundation.org>
Acked-by: Guo Ren <guoren@kernel.org>			[csky]
Acked-by: Geert Uytterhoeven <geert@linux-m68k.org>	[m68k]
Acked-by: Stafford Horne <shorne@gmail.com>		[openrisc]
Acked-by: Helge Deller <deller@gmx.de>			[parisc]
Cc: Richard Henderson <rth@twiddle.net>
Cc: Ivan Kokshaysky <ink@jurassic.park.msu.ru>
Cc: Matt Turner <mattst88@gmail.com>
Cc: Russell King <linux@armlinux.org.uk>
Cc: Brian Cain <bcain@codeaurora.org>
Cc: Tony Luck <tony.luck@intel.com>
Cc: Fenghua Yu <fenghua.yu@intel.com>
Cc: Sam Creasey <sammy@sammy.net>
Cc: Michal Simek <monstr@monstr.eu>
Cc: Ralf Baechle <ralf@linux-mips.org>
Cc: Paul Burton <paulburton@kernel.org>
Cc: Nick Hu <nickhu@andestech.com>
Cc: Greentime Hu <green.hu@gmail.com>
Cc: Vincent Chen <deanbo422@gmail.com>
Cc: Ley Foon Tan <ley.foon.tan@intel.com>
Cc: Jonas Bonn <jonas@southpole.se>
Cc: Stefan Kristiansson <stefan.kristiansson@saunalahti.fi>
Cc: "James E.J. Bottomley" <James.Bottomley@HansenPartnership.com>
Cc: "David S. Miller" <davem@davemloft.net>
Cc: Jeff Dike <jdike@addtoit.com>
Cc: Richard Weinberger <richard@nod.at>
Cc: Anton Ivanov <anton.ivanov@cambridgegreys.com>
Cc: Guan Xuetao <gxt@pku.edu.cn>
Cc: Chris Zankel <chris@zankel.net>
Cc: Max Filippov <jcmvbkbc@gmail.com>
Cc: Thomas Bogendoerfer <tsbogend@alpha.franken.de>
Link: http://lkml.kernel.org/r/1583802551-15406-1-git-send-email-anshuman.khandual@arm.com
Signed-off-by: Linus Torvalds <torvalds@linux-foundation.org>

1 files changed, 0 insertions, 2 deletions

diff --git a/arch/ia64/include/asm/pgtable.h b/arch/ia64/include/asm/pgtable.h
index d602e7c622db..0e7b645b76c6 100644
--- a/arch/ia64/include/asm/pgtable.h
+++ b/arch/ia64/include/asm/pgtable.h
@@ -298,7 +298,6 @@ extern unsigned long VMALLOC_END;
 #define pte_exec(pte)		((pte_val(pte) & _PAGE_AR_RX) != 0)
 #define pte_dirty(pte)		((pte_val(pte) & _PAGE_D) != 0)
 #define pte_young(pte)		((pte_val(pte) & _PAGE_A) != 0)
-#define pte_special(pte)	0
 
 /*
  * Note: we convert AR_RWX to AR_RX and AR_RW to AR_R by clearing the 2nd bit in the
@@ -311,7 +310,6 @@ extern unsigned long VMALLOC_END;
 #define pte_mkclean(pte)	(__pte(pte_val(pte) & ~_PAGE_D))
 #define pte_mkdirty(pte)	(__pte(pte_val(pte) | _PAGE_D))
 #define pte_mkhuge(pte)		(__pte(pte_val(pte)))
-#define pte_mkspecial(pte)	(pte)
 
 /*
  * Because ia64's Icache and Dcache is not coherent (on a cpu), we need to