[PATCH v2 0/2] move __HAVE_ARCH_PTE_SPECIAL in Kconfig

[PATCH v2 0/2] move __HAVE_ARCH_PTE_SPECIAL in Kconfig

[Laurent Dufour]

The per architecture __HAVE_ARCH_PTE_SPECIAL is defined statically in the
per architecture header files. This doesn't allow to make other
configuration dependent on it.

The first patch of this series is replacing __HAVE_ARCH_PTE_SPECIAL by
CONFIG_ARCH_HAS_PTE_SPECIAL defined into the Kconfig files,
setting it automatically when architectures was already setting it in
header file.

The second patch is removing the odd define HAVE_PTE_SPECIAL which is a
duplicate of CONFIG_ARCH_HAS_PTE_SPECIAL.

There is no functional change introduced by this series.

Laurent Dufour (2):
  mm: introduce ARCH_HAS_PTE_SPECIAL
  mm: remove odd HAVE_PTE_SPECIAL

 .../features/vm/pte_special/arch-support.txt       |  2 +-
 arch/arc/Kconfig                                   |  1 +
 arch/arc/include/asm/pgtable.h                     |  2 --
 arch/arm/Kconfig                                   |  1 +
 arch/arm/include/asm/pgtable-3level.h              |  1 -
 arch/arm64/Kconfig                                 |  1 +
 arch/arm64/include/asm/pgtable.h                   |  2 --
 arch/powerpc/Kconfig                               |  1 +
 arch/powerpc/include/asm/book3s/64/pgtable.h       |  3 ---
 arch/powerpc/include/asm/pte-common.h              |  3 ---
 arch/riscv/Kconfig                                 |  1 +
 arch/s390/Kconfig                                  |  1 +
 arch/s390/include/asm/pgtable.h                    |  1 -
 arch/sh/Kconfig                                    |  1 +
 arch/sh/include/asm/pgtable.h                      |  2 --
 arch/sparc/Kconfig                                 |  1 +
 arch/sparc/include/asm/pgtable_64.h                |  3 ---
 arch/x86/Kconfig                                   |  1 +
 arch/x86/include/asm/pgtable_types.h               |  1 -
 include/linux/pfn_t.h                              |  4 ++--
 mm/Kconfig                                         |  3 +++
 mm/gup.c                                           |  4 ++--
 mm/memory.c                                        | 23 ++++++++++------------
 23 files changed, 27 insertions(+), 36 deletions(-)

-- 
2.7.4

[PATCH v2 0/2] move __HAVE_ARCH_PTE_SPECIAL in Kconfig

[Laurent Dufour]

The per architecture __HAVE_ARCH_PTE_SPECIAL is defined statically in the
per architecture header files. This doesn't allow to make other
configuration dependent on it.

The first patch of this series is replacing __HAVE_ARCH_PTE_SPECIAL by
CONFIG_ARCH_HAS_PTE_SPECIAL defined into the Kconfig files,
setting it automatically when architectures was already setting it in
header file.

The second patch is removing the odd define HAVE_PTE_SPECIAL which is a
duplicate of CONFIG_ARCH_HAS_PTE_SPECIAL.

There is no functional change introduced by this series.

Laurent Dufour (2):
  mm: introduce ARCH_HAS_PTE_SPECIAL
  mm: remove odd HAVE_PTE_SPECIAL

 .../features/vm/pte_special/arch-support.txt       |  2 +-
 arch/arc/Kconfig                                   |  1 +
 arch/arc/include/asm/pgtable.h                     |  2 --
 arch/arm/Kconfig                                   |  1 +
 arch/arm/include/asm/pgtable-3level.h              |  1 -
 arch/arm64/Kconfig                                 |  1 +
 arch/arm64/include/asm/pgtable.h                   |  2 --
 arch/powerpc/Kconfig                               |  1 +
 arch/powerpc/include/asm/book3s/64/pgtable.h       |  3 ---
 arch/powerpc/include/asm/pte-common.h              |  3 ---
 arch/riscv/Kconfig                                 |  1 +
 arch/s390/Kconfig                                  |  1 +
 arch/s390/include/asm/pgtable.h                    |  1 -
 arch/sh/Kconfig                                    |  1 +
 arch/sh/include/asm/pgtable.h                      |  2 --
 arch/sparc/Kconfig                                 |  1 +
 arch/sparc/include/asm/pgtable_64.h                |  3 ---
 arch/x86/Kconfig                                   |  1 +
 arch/x86/include/asm/pgtable_types.h               |  1 -
 include/linux/pfn_t.h                              |  4 ++--
 mm/Kconfig                                         |  3 +++
 mm/gup.c                                           |  4 ++--
 mm/memory.c                                        | 23 ++++++++++------------
 23 files changed, 27 insertions(+), 36 deletions(-)

-- 
2.7.4

[PATCH v2 0/2] move __HAVE_ARCH_PTE_SPECIAL in Kconfig

[Laurent Dufour]

The per architecture __HAVE_ARCH_PTE_SPECIAL is defined statically in the
per architecture header files. This doesn't allow to make other
configuration dependent on it.

The first patch of this series is replacing __HAVE_ARCH_PTE_SPECIAL by
CONFIG_ARCH_HAS_PTE_SPECIAL defined into the Kconfig files,
setting it automatically when architectures was already setting it in
header file.

The second patch is removing the odd define HAVE_PTE_SPECIAL which is a
duplicate of CONFIG_ARCH_HAS_PTE_SPECIAL.

There is no functional change introduced by this series.

Laurent Dufour (2):
  mm: introduce ARCH_HAS_PTE_SPECIAL
  mm: remove odd HAVE_PTE_SPECIAL

 .../features/vm/pte_special/arch-support.txt       |  2 +-
 arch/arc/Kconfig                                   |  1 +
 arch/arc/include/asm/pgtable.h                     |  2 --
 arch/arm/Kconfig                                   |  1 +
 arch/arm/include/asm/pgtable-3level.h              |  1 -
 arch/arm64/Kconfig                                 |  1 +
 arch/arm64/include/asm/pgtable.h                   |  2 --
 arch/powerpc/Kconfig                               |  1 +
 arch/powerpc/include/asm/book3s/64/pgtable.h       |  3 ---
 arch/powerpc/include/asm/pte-common.h              |  3 ---
 arch/riscv/Kconfig                                 |  1 +
 arch/s390/Kconfig                                  |  1 +
 arch/s390/include/asm/pgtable.h                    |  1 -
 arch/sh/Kconfig                                    |  1 +
 arch/sh/include/asm/pgtable.h                      |  2 --
 arch/sparc/Kconfig                                 |  1 +
 arch/sparc/include/asm/pgtable_64.h                |  3 ---
 arch/x86/Kconfig                                   |  1 +
 arch/x86/include/asm/pgtable_types.h               |  1 -
 include/linux/pfn_t.h                              |  4 ++--
 mm/Kconfig                                         |  3 +++
 mm/gup.c                                           |  4 ++--
 mm/memory.c                                        | 23 ++++++++++------------
 23 files changed, 27 insertions(+), 36 deletions(-)

-- 
2.7.4

[PATCH v2 0/2] move __HAVE_ARCH_PTE_SPECIAL in Kconfig

[Laurent Dufour]

The per architecture __HAVE_ARCH_PTE_SPECIAL is defined statically in the
per architecture header files. This doesn't allow to make other
configuration dependent on it.

The first patch of this series is replacing __HAVE_ARCH_PTE_SPECIAL by
CONFIG_ARCH_HAS_PTE_SPECIAL defined into the Kconfig files,
setting it automatically when architectures was already setting it in
header file.

The second patch is removing the odd define HAVE_PTE_SPECIAL which is a
duplicate of CONFIG_ARCH_HAS_PTE_SPECIAL.

There is no functional change introduced by this series.

Laurent Dufour (2):
  mm: introduce ARCH_HAS_PTE_SPECIAL
  mm: remove odd HAVE_PTE_SPECIAL

 .../features/vm/pte_special/arch-support.txt       |  2 +-
 arch/arc/Kconfig                                   |  1 +
 arch/arc/include/asm/pgtable.h                     |  2 --
 arch/arm/Kconfig                                   |  1 +
 arch/arm/include/asm/pgtable-3level.h              |  1 -
 arch/arm64/Kconfig                                 |  1 +
 arch/arm64/include/asm/pgtable.h                   |  2 --
 arch/powerpc/Kconfig                               |  1 +
 arch/powerpc/include/asm/book3s/64/pgtable.h       |  3 ---
 arch/powerpc/include/asm/pte-common.h              |  3 ---
 arch/riscv/Kconfig                                 |  1 +
 arch/s390/Kconfig                                  |  1 +
 arch/s390/include/asm/pgtable.h                    |  1 -
 arch/sh/Kconfig                                    |  1 +
 arch/sh/include/asm/pgtable.h                      |  2 --
 arch/sparc/Kconfig                                 |  1 +
 arch/sparc/include/asm/pgtable_64.h                |  3 ---
 arch/x86/Kconfig                                   |  1 +
 arch/x86/include/asm/pgtable_types.h               |  1 -
 include/linux/pfn_t.h                              |  4 ++--
 mm/Kconfig                                         |  3 +++
 mm/gup.c                                           |  4 ++--
 mm/memory.c                                        | 23 ++++++++++------------
 23 files changed, 27 insertions(+), 36 deletions(-)

-- 
2.7.4

[PATCH v2 0/2] move __HAVE_ARCH_PTE_SPECIAL in Kconfig

[Laurent Dufour]

The per architecture __HAVE_ARCH_PTE_SPECIAL is defined statically in the
per architecture header files. This doesn't allow to make other
configuration dependent on it.

The first patch of this series is replacing __HAVE_ARCH_PTE_SPECIAL by
CONFIG_ARCH_HAS_PTE_SPECIAL defined into the Kconfig files,
setting it automatically when architectures was already setting it in
header file.

The second patch is removing the odd define HAVE_PTE_SPECIAL which is a
duplicate of CONFIG_ARCH_HAS_PTE_SPECIAL.

There is no functional change introduced by this series.

Laurent Dufour (2):
  mm: introduce ARCH_HAS_PTE_SPECIAL
  mm: remove odd HAVE_PTE_SPECIAL

 .../features/vm/pte_special/arch-support.txt       |  2 +-
 arch/arc/Kconfig                                   |  1 +
 arch/arc/include/asm/pgtable.h                     |  2 --
 arch/arm/Kconfig                                   |  1 +
 arch/arm/include/asm/pgtable-3level.h              |  1 -
 arch/arm64/Kconfig                                 |  1 +
 arch/arm64/include/asm/pgtable.h                   |  2 --
 arch/powerpc/Kconfig                               |  1 +
 arch/powerpc/include/asm/book3s/64/pgtable.h       |  3 ---
 arch/powerpc/include/asm/pte-common.h              |  3 ---
 arch/riscv/Kconfig                                 |  1 +
 arch/s390/Kconfig                                  |  1 +
 arch/s390/include/asm/pgtable.h                    |  1 -
 arch/sh/Kconfig                                    |  1 +
 arch/sh/include/asm/pgtable.h                      |  2 --
 arch/sparc/Kconfig                                 |  1 +
 arch/sparc/include/asm/pgtable_64.h                |  3 ---
 arch/x86/Kconfig                                   |  1 +
 arch/x86/include/asm/pgtable_types.h               |  1 -
 include/linux/pfn_t.h                              |  4 ++--
 mm/Kconfig                                         |  3 +++
 mm/gup.c                                           |  4 ++--
 mm/memory.c                                        | 23 ++++++++++------------
 23 files changed, 27 insertions(+), 36 deletions(-)

-- 
2.7.4

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[PATCH v2 0/2] move __HAVE_ARCH_PTE_SPECIAL in Kconfig

[Laurent Dufour]

The per architecture __HAVE_ARCH_PTE_SPECIAL is defined statically in the
per architecture header files. This doesn't allow to make other
configuration dependent on it.

The first patch of this series is replacing __HAVE_ARCH_PTE_SPECIAL by
CONFIG_ARCH_HAS_PTE_SPECIAL defined into the Kconfig files,
setting it automatically when architectures was already setting it in
header file.

The second patch is removing the odd define HAVE_PTE_SPECIAL which is a
duplicate of CONFIG_ARCH_HAS_PTE_SPECIAL.

There is no functional change introduced by this series.

Laurent Dufour (2):
  mm: introduce ARCH_HAS_PTE_SPECIAL
  mm: remove odd HAVE_PTE_SPECIAL

 .../features/vm/pte_special/arch-support.txt       |  2 +-
 arch/arc/Kconfig                                   |  1 +
 arch/arc/include/asm/pgtable.h                     |  2 --
 arch/arm/Kconfig                                   |  1 +
 arch/arm/include/asm/pgtable-3level.h              |  1 -
 arch/arm64/Kconfig                                 |  1 +
 arch/arm64/include/asm/pgtable.h                   |  2 --
 arch/powerpc/Kconfig                               |  1 +
 arch/powerpc/include/asm/book3s/64/pgtable.h       |  3 ---
 arch/powerpc/include/asm/pte-common.h              |  3 ---
 arch/riscv/Kconfig                                 |  1 +
 arch/s390/Kconfig                                  |  1 +
 arch/s390/include/asm/pgtable.h                    |  1 -
 arch/sh/Kconfig                                    |  1 +
 arch/sh/include/asm/pgtable.h                      |  2 --
 arch/sparc/Kconfig                                 |  1 +
 arch/sparc/include/asm/pgtable_64.h                |  3 ---
 arch/x86/Kconfig                                   |  1 +
 arch/x86/include/asm/pgtable_types.h               |  1 -
 include/linux/pfn_t.h                              |  4 ++--
 mm/Kconfig                                         |  3 +++
 mm/gup.c                                           |  4 ++--
 mm/memory.c                                        | 23 ++++++++++------------
 23 files changed, 27 insertions(+), 36 deletions(-)

-- 
2.7.4

[PATCH v2 1/2] mm: introduce ARCH_HAS_PTE_SPECIAL

[Laurent Dufour]

Currently the PTE special supports is turned on in per architecture header
files. Most of the time, it is defined in arch/*/include/asm/pgtable.h
depending or not on some other per architecture static definition.

This patch introduce a new configuration variable to manage this directly
in the Kconfig files. It would later replace __HAVE_ARCH_PTE_SPECIAL.

Here notes for some architecture where the definition of
__HAVE_ARCH_PTE_SPECIAL is not obvious:

arm
 __HAVE_ARCH_PTE_SPECIAL which is currently defined in
arch/arm/include/asm/pgtable-3level.h which is included by
arch/arm/include/asm/pgtable.h when CONFIG_ARM_LPAE is set.
So select ARCH_HAS_PTE_SPECIAL if ARM_LPAE.

powerpc
__HAVE_ARCH_PTE_SPECIAL is defined in 2 files:
 - arch/powerpc/include/asm/book3s/64/pgtable.h
 - arch/powerpc/include/asm/pte-common.h
The first one is included if (PPC_BOOK3S & PPC64) while the second is
included in all the other cases.
So select ARCH_HAS_PTE_SPECIAL all the time.

sparc:
__HAVE_ARCH_PTE_SPECIAL is defined if defined(__sparc__) &&
defined(__arch64__) which are defined through the compiler in
sparc/Makefile if !SPARC32 which I assume to be if SPARC64.
So select ARCH_HAS_PTE_SPECIAL if SPARC64

There is no functional change introduced by this patch.

Suggested-by: Jerome Glisse <jglisse@redhat>
Reviewed-by: Jerome Glisse <jglisse@redhat>
Signed-off-by: Laurent Dufour <ldufour@linux.vnet.ibm.com>
---
 Documentation/features/vm/pte_special/arch-support.txt | 2 +-
 arch/arc/Kconfig                                       | 1 +
 arch/arc/include/asm/pgtable.h                         | 2 --
 arch/arm/Kconfig                                       | 1 +
 arch/arm/include/asm/pgtable-3level.h                  | 1 -
 arch/arm64/Kconfig                                     | 1 +
 arch/arm64/include/asm/pgtable.h                       | 2 --
 arch/powerpc/Kconfig                                   | 1 +
 arch/powerpc/include/asm/book3s/64/pgtable.h           | 3 ---
 arch/powerpc/include/asm/pte-common.h                  | 3 ---
 arch/riscv/Kconfig                                     | 1 +
 arch/s390/Kconfig                                      | 1 +
 arch/s390/include/asm/pgtable.h                        | 1 -
 arch/sh/Kconfig                                        | 1 +
 arch/sh/include/asm/pgtable.h                          | 2 --
 arch/sparc/Kconfig                                     | 1 +
 arch/sparc/include/asm/pgtable_64.h                    | 3 ---
 arch/x86/Kconfig                                       | 1 +
 arch/x86/include/asm/pgtable_types.h                   | 1 -
 include/linux/pfn_t.h                                  | 4 ++--
 mm/Kconfig                                             | 3 +++
 mm/gup.c                                               | 4 ++--
 mm/memory.c                                            | 2 +-
 23 files changed, 18 insertions(+), 24 deletions(-)

diff --git a/Documentation/features/vm/pte_special/arch-support.txt b/Documentation/features/vm/pte_special/arch-support.txt
index 055004f467d2..cd05924ea875 100644
--- a/Documentation/features/vm/pte_special/arch-support.txt
+++ b/Documentation/features/vm/pte_special/arch-support.txt
@@ -1,6 +1,6 @@
 #
 # Feature name:          pte_special
-#         Kconfig:       __HAVE_ARCH_PTE_SPECIAL
+#         Kconfig:       ARCH_HAS_PTE_SPECIAL
 #         description:   arch supports the pte_special()/pte_mkspecial() VM APIs
 #
     -----------------------
diff --git a/arch/arc/Kconfig b/arch/arc/Kconfig
index d76bf4a83740..8516e2b0239a 100644
--- a/arch/arc/Kconfig
+++ b/arch/arc/Kconfig
@@ -44,6 +44,7 @@ config ARC
 	select HAVE_GENERIC_DMA_COHERENT
 	select HAVE_KERNEL_GZIP
 	select HAVE_KERNEL_LZMA
+	select ARCH_HAS_PTE_SPECIAL
 
 config MIGHT_HAVE_PCI
 	bool
diff --git a/arch/arc/include/asm/pgtable.h b/arch/arc/include/asm/pgtable.h
index 08fe33830d4b..8ec5599a0957 100644
--- a/arch/arc/include/asm/pgtable.h
+++ b/arch/arc/include/asm/pgtable.h
@@ -320,8 +320,6 @@ PTE_BIT_FUNC(mkexec,	|= (_PAGE_EXECUTE));
 PTE_BIT_FUNC(mkspecial,	|= (_PAGE_SPECIAL));
 PTE_BIT_FUNC(mkhuge,	|= (_PAGE_HW_SZ));
 
-#define __HAVE_ARCH_PTE_SPECIAL
-
 static inline pte_t pte_modify(pte_t pte, pgprot_t newprot)
 {
 	return __pte((pte_val(pte) & _PAGE_CHG_MASK) | pgprot_val(newprot));
diff --git a/arch/arm/Kconfig b/arch/arm/Kconfig
index a7f8e7f4b88f..c088c851b235 100644
--- a/arch/arm/Kconfig
+++ b/arch/arm/Kconfig
@@ -8,6 +8,7 @@ config ARM
 	select ARCH_HAS_DEVMEM_IS_ALLOWED
 	select ARCH_HAS_ELF_RANDOMIZE
 	select ARCH_HAS_FORTIFY_SOURCE
+	select ARCH_HAS_PTE_SPECIAL if ARM_LPAE
 	select ARCH_HAS_SET_MEMORY
 	select ARCH_HAS_PHYS_TO_DMA
 	select ARCH_HAS_STRICT_KERNEL_RWX if MMU && !XIP_KERNEL
diff --git a/arch/arm/include/asm/pgtable-3level.h b/arch/arm/include/asm/pgtable-3level.h
index 2a4836087358..6d50a11d7793 100644
--- a/arch/arm/include/asm/pgtable-3level.h
+++ b/arch/arm/include/asm/pgtable-3level.h
@@ -219,7 +219,6 @@ static inline pte_t pte_mkspecial(pte_t pte)
 	pte_val(pte) |= L_PTE_SPECIAL;
 	return pte;
 }
-#define	__HAVE_ARCH_PTE_SPECIAL
 
 #define pmd_write(pmd)		(pmd_isclear((pmd), L_PMD_SECT_RDONLY))
 #define pmd_dirty(pmd)		(pmd_isset((pmd), L_PMD_SECT_DIRTY))
diff --git a/arch/arm64/Kconfig b/arch/arm64/Kconfig
index eb2cf4938f6d..9a3f1b1ab50c 100644
--- a/arch/arm64/Kconfig
+++ b/arch/arm64/Kconfig
@@ -17,6 +17,7 @@ config ARM64
 	select ARCH_HAS_GIGANTIC_PAGE if (MEMORY_ISOLATION && COMPACTION) || CMA
 	select ARCH_HAS_KCOV
 	select ARCH_HAS_MEMBARRIER_SYNC_CORE
+	select ARCH_HAS_PTE_SPECIAL
 	select ARCH_HAS_SET_MEMORY
 	select ARCH_HAS_SG_CHAIN
 	select ARCH_HAS_STRICT_KERNEL_RWX
diff --git a/arch/arm64/include/asm/pgtable.h b/arch/arm64/include/asm/pgtable.h
index 7e2c27e63cd8..b96c8a186908 100644
--- a/arch/arm64/include/asm/pgtable.h
+++ b/arch/arm64/include/asm/pgtable.h
@@ -306,8 +306,6 @@ static inline int pte_same(pte_t pte_a, pte_t pte_b)
 #define HPAGE_MASK		(~(HPAGE_SIZE - 1))
 #define HUGETLB_PAGE_ORDER	(HPAGE_SHIFT - PAGE_SHIFT)
 
-#define __HAVE_ARCH_PTE_SPECIAL
-
 static inline pte_t pgd_pte(pgd_t pgd)
 {
 	return __pte(pgd_val(pgd));
diff --git a/arch/powerpc/Kconfig b/arch/powerpc/Kconfig
index c32a181a7cbb..f7415fe25c07 100644
--- a/arch/powerpc/Kconfig
+++ b/arch/powerpc/Kconfig
@@ -141,6 +141,7 @@ config PPC
 	select ARCH_HAS_GCOV_PROFILE_ALL
 	select ARCH_HAS_PHYS_TO_DMA
 	select ARCH_HAS_PMEM_API                if PPC64
+	select ARCH_HAS_PTE_SPECIAL
 	select ARCH_HAS_MEMBARRIER_CALLBACKS
 	select ARCH_HAS_SCALED_CPUTIME		if VIRT_CPU_ACCOUNTING_NATIVE
 	select ARCH_HAS_SG_CHAIN
diff --git a/arch/powerpc/include/asm/book3s/64/pgtable.h b/arch/powerpc/include/asm/book3s/64/pgtable.h
index 47b5ffc8715d..b3ac8948b257 100644
--- a/arch/powerpc/include/asm/book3s/64/pgtable.h
+++ b/arch/powerpc/include/asm/book3s/64/pgtable.h
@@ -319,9 +319,6 @@ extern unsigned long pci_io_base;
 /* Advertise special mapping type for AGP */
 #define HAVE_PAGE_AGP
 
-/* Advertise support for _PAGE_SPECIAL */
-#define __HAVE_ARCH_PTE_SPECIAL
-
 #ifndef __ASSEMBLY__
 
 /*
diff --git a/arch/powerpc/include/asm/pte-common.h b/arch/powerpc/include/asm/pte-common.h
index c4a72c7a8c83..03dfddb1f49a 100644
--- a/arch/powerpc/include/asm/pte-common.h
+++ b/arch/powerpc/include/asm/pte-common.h
@@ -216,9 +216,6 @@ static inline bool pte_user(pte_t pte)
 #define PAGE_AGP		(PAGE_KERNEL_NC)
 #define HAVE_PAGE_AGP
 
-/* Advertise support for _PAGE_SPECIAL */
-#define __HAVE_ARCH_PTE_SPECIAL
-
 #ifndef _PAGE_READ
 /* if not defined, we should not find _PAGE_WRITE too */
 #define _PAGE_READ 0
diff --git a/arch/riscv/Kconfig b/arch/riscv/Kconfig
index 5287c1441d66..b01c183836e5 100644
--- a/arch/riscv/Kconfig
+++ b/arch/riscv/Kconfig
@@ -34,6 +34,7 @@ config RISCV
 	select THREAD_INFO_IN_TASK
 	select RISCV_TIMER
 	select GENERIC_IRQ_MULTI_HANDLER
+	select ARCH_HAS_PTE_SPECIAL
 
 config MMU
 	def_bool y
diff --git a/arch/s390/Kconfig b/arch/s390/Kconfig
index 32a0d5b958bf..5f1f4997e7e9 100644
--- a/arch/s390/Kconfig
+++ b/arch/s390/Kconfig
@@ -72,6 +72,7 @@ config S390
 	select ARCH_HAS_GCOV_PROFILE_ALL
 	select ARCH_HAS_GIGANTIC_PAGE if (MEMORY_ISOLATION && COMPACTION) || CMA
 	select ARCH_HAS_KCOV
+	select ARCH_HAS_PTE_SPECIAL
 	select ARCH_HAS_SET_MEMORY
 	select ARCH_HAS_SG_CHAIN
 	select ARCH_HAS_STRICT_KERNEL_RWX
diff --git a/arch/s390/include/asm/pgtable.h b/arch/s390/include/asm/pgtable.h
index 2d24d33bf188..9809694e1389 100644
--- a/arch/s390/include/asm/pgtable.h
+++ b/arch/s390/include/asm/pgtable.h
@@ -171,7 +171,6 @@ static inline int is_module_addr(void *addr)
 #define _PAGE_WRITE	0x020		/* SW pte write bit */
 #define _PAGE_SPECIAL	0x040		/* SW associated with special page */
 #define _PAGE_UNUSED	0x080		/* SW bit for pgste usage state */
-#define __HAVE_ARCH_PTE_SPECIAL
 
 #ifdef CONFIG_MEM_SOFT_DIRTY
 #define _PAGE_SOFT_DIRTY 0x002		/* SW pte soft dirty bit */
diff --git a/arch/sh/Kconfig b/arch/sh/Kconfig
index 97fe29316476..a6c75b6806d2 100644
--- a/arch/sh/Kconfig
+++ b/arch/sh/Kconfig
@@ -50,6 +50,7 @@ config SUPERH
 	select HAVE_ARCH_AUDITSYSCALL
 	select HAVE_FUTEX_CMPXCHG if FUTEX
 	select HAVE_NMI
+	select ARCH_HAS_PTE_SPECIAL
 	help
 	  The SuperH is a RISC processor targeted for use in embedded systems
 	  and consumer electronics; it was also used in the Sega Dreamcast
diff --git a/arch/sh/include/asm/pgtable.h b/arch/sh/include/asm/pgtable.h
index 89c513a982fc..f6abfe2bca93 100644
--- a/arch/sh/include/asm/pgtable.h
+++ b/arch/sh/include/asm/pgtable.h
@@ -156,8 +156,6 @@ extern void page_table_range_init(unsigned long start, unsigned long end,
 #define HAVE_ARCH_UNMAPPED_AREA
 #define HAVE_ARCH_UNMAPPED_AREA_TOPDOWN
 
-#define __HAVE_ARCH_PTE_SPECIAL
-
 #include <asm-generic/pgtable.h>
 
 #endif /* __ASM_SH_PGTABLE_H */
diff --git a/arch/sparc/Kconfig b/arch/sparc/Kconfig
index 8767e45f1b2b..6b5a4f05dcb2 100644
--- a/arch/sparc/Kconfig
+++ b/arch/sparc/Kconfig
@@ -86,6 +86,7 @@ config SPARC64
 	select ARCH_USE_QUEUED_SPINLOCKS
 	select GENERIC_TIME_VSYSCALL
 	select ARCH_CLOCKSOURCE_DATA
+	select ARCH_HAS_PTE_SPECIAL
 
 config ARCH_DEFCONFIG
 	string
diff --git a/arch/sparc/include/asm/pgtable_64.h b/arch/sparc/include/asm/pgtable_64.h
index 44d6ac47e035..1393a8ac596b 100644
--- a/arch/sparc/include/asm/pgtable_64.h
+++ b/arch/sparc/include/asm/pgtable_64.h
@@ -117,9 +117,6 @@ bool kern_addr_valid(unsigned long addr);
 #define _PAGE_PMD_HUGE    _AC(0x0100000000000000,UL) /* Huge page            */
 #define _PAGE_PUD_HUGE    _PAGE_PMD_HUGE
 
-/* Advertise support for _PAGE_SPECIAL */
-#define __HAVE_ARCH_PTE_SPECIAL
-
 /* SUN4U pte bits... */
 #define _PAGE_SZ4MB_4U	  _AC(0x6000000000000000,UL) /* 4MB Page             */
 #define _PAGE_SZ512K_4U	  _AC(0x4000000000000000,UL) /* 512K Page            */
diff --git a/arch/x86/Kconfig b/arch/x86/Kconfig
index bf4ddea48e61..3f5fb25486bf 100644
--- a/arch/x86/Kconfig
+++ b/arch/x86/Kconfig
@@ -56,6 +56,7 @@ config X86
 	select ARCH_HAS_KCOV			if X86_64
 	select ARCH_HAS_MEMBARRIER_SYNC_CORE
 	select ARCH_HAS_PMEM_API		if X86_64
+	select ARCH_HAS_PTE_SPECIAL
 	select ARCH_HAS_REFCOUNT
 	select ARCH_HAS_UACCESS_FLUSHCACHE	if X86_64
 	select ARCH_HAS_SET_MEMORY
diff --git a/arch/x86/include/asm/pgtable_types.h b/arch/x86/include/asm/pgtable_types.h
index acfe755562a6..3e195728d7d1 100644
--- a/arch/x86/include/asm/pgtable_types.h
+++ b/arch/x86/include/asm/pgtable_types.h
@@ -65,7 +65,6 @@
 #define _PAGE_PKEY_BIT2	(_AT(pteval_t, 0))
 #define _PAGE_PKEY_BIT3	(_AT(pteval_t, 0))
 #endif
-#define __HAVE_ARCH_PTE_SPECIAL
 
 #define _PAGE_PKEY_MASK (_PAGE_PKEY_BIT0 | \
 			 _PAGE_PKEY_BIT1 | \
diff --git a/include/linux/pfn_t.h b/include/linux/pfn_t.h
index a03c2642a87c..21713dc14ce2 100644
--- a/include/linux/pfn_t.h
+++ b/include/linux/pfn_t.h
@@ -122,7 +122,7 @@ pud_t pud_mkdevmap(pud_t pud);
 #endif
 #endif /* __HAVE_ARCH_PTE_DEVMAP */
 
-#ifdef __HAVE_ARCH_PTE_SPECIAL
+#ifdef CONFIG_ARCH_HAS_PTE_SPECIAL
 static inline bool pfn_t_special(pfn_t pfn)
 {
 	return (pfn.val & PFN_SPECIAL) = PFN_SPECIAL;
@@ -132,5 +132,5 @@ static inline bool pfn_t_special(pfn_t pfn)
 {
 	return false;
 }
-#endif /* __HAVE_ARCH_PTE_SPECIAL */
+#endif /* CONFIG_ARCH_HAS_PTE_SPECIAL */
 #endif /* _LINUX_PFN_T_H_ */
diff --git a/mm/Kconfig b/mm/Kconfig
index d5004d82a1d6..1ea3e4a6a123 100644
--- a/mm/Kconfig
+++ b/mm/Kconfig
@@ -752,3 +752,6 @@ config GUP_BENCHMARK
 	  performance of get_user_pages_fast().
 
 	  See tools/testing/selftests/vm/gup_benchmark.c
+
+config ARCH_HAS_PTE_SPECIAL
+	bool
diff --git a/mm/gup.c b/mm/gup.c
index f296df6cf666..b044a3d14dc5 100644
--- a/mm/gup.c
+++ b/mm/gup.c
@@ -1351,7 +1351,7 @@ static void undo_dev_pagemap(int *nr, int nr_start, struct page **pages)
 	}
 }
 
-#ifdef __HAVE_ARCH_PTE_SPECIAL
+#ifdef CONFIG_ARCH_HAS_PTE_SPECIAL
 static int gup_pte_range(pmd_t pmd, unsigned long addr, unsigned long end,
 			 int write, struct page **pages, int *nr)
 {
@@ -1427,7 +1427,7 @@ static int gup_pte_range(pmd_t pmd, unsigned long addr, unsigned long end,
 {
 	return 0;
 }
-#endif /* __HAVE_ARCH_PTE_SPECIAL */
+#endif /* CONFIG_ARCH_HAS_PTE_SPECIAL */
 
 #if defined(__HAVE_ARCH_PTE_DEVMAP) && defined(CONFIG_TRANSPARENT_HUGEPAGE)
 static int __gup_device_huge(unsigned long pfn, unsigned long addr,
diff --git a/mm/memory.c b/mm/memory.c
index a1f990e33e38..96910c625daa 100644
--- a/mm/memory.c
+++ b/mm/memory.c
@@ -817,7 +817,7 @@ static void print_bad_pte(struct vm_area_struct *vma, unsigned long addr,
  * PFNMAP mappings in order to support COWable mappings.
  *
  */
-#ifdef __HAVE_ARCH_PTE_SPECIAL
+#ifdef CONFIG_ARCH_HAS_PTE_SPECIAL
 # define HAVE_PTE_SPECIAL 1
 #else
 # define HAVE_PTE_SPECIAL 0
-- 
2.7.4

[PATCH v2 1/2] mm: introduce ARCH_HAS_PTE_SPECIAL

[Laurent Dufour]

Currently the PTE special supports is turned on in per architecture header
files. Most of the time, it is defined in arch/*/include/asm/pgtable.h
depending or not on some other per architecture static definition.

This patch introduce a new configuration variable to manage this directly
in the Kconfig files. It would later replace __HAVE_ARCH_PTE_SPECIAL.

Here notes for some architecture where the definition of
__HAVE_ARCH_PTE_SPECIAL is not obvious:

arm
 __HAVE_ARCH_PTE_SPECIAL which is currently defined in
arch/arm/include/asm/pgtable-3level.h which is included by
arch/arm/include/asm/pgtable.h when CONFIG_ARM_LPAE is set.
So select ARCH_HAS_PTE_SPECIAL if ARM_LPAE.

powerpc
__HAVE_ARCH_PTE_SPECIAL is defined in 2 files:
 - arch/powerpc/include/asm/book3s/64/pgtable.h
 - arch/powerpc/include/asm/pte-common.h
The first one is included if (PPC_BOOK3S & PPC64) while the second is
included in all the other cases.
So select ARCH_HAS_PTE_SPECIAL all the time.

sparc:
__HAVE_ARCH_PTE_SPECIAL is defined if defined(__sparc__) &&
defined(__arch64__) which are defined through the compiler in
sparc/Makefile if !SPARC32 which I assume to be if SPARC64.
So select ARCH_HAS_PTE_SPECIAL if SPARC64

There is no functional change introduced by this patch.

Suggested-by: Jerome Glisse <jglisse@redhat>
Reviewed-by: Jerome Glisse <jglisse@redhat>
Signed-off-by: Laurent Dufour <ldufour@linux.vnet.ibm.com>
---
 Documentation/features/vm/pte_special/arch-support.txt | 2 +-
 arch/arc/Kconfig                                       | 1 +
 arch/arc/include/asm/pgtable.h                         | 2 --
 arch/arm/Kconfig                                       | 1 +
 arch/arm/include/asm/pgtable-3level.h                  | 1 -
 arch/arm64/Kconfig                                     | 1 +
 arch/arm64/include/asm/pgtable.h                       | 2 --
 arch/powerpc/Kconfig                                   | 1 +
 arch/powerpc/include/asm/book3s/64/pgtable.h           | 3 ---
 arch/powerpc/include/asm/pte-common.h                  | 3 ---
 arch/riscv/Kconfig                                     | 1 +
 arch/s390/Kconfig                                      | 1 +
 arch/s390/include/asm/pgtable.h                        | 1 -
 arch/sh/Kconfig                                        | 1 +
 arch/sh/include/asm/pgtable.h                          | 2 --
 arch/sparc/Kconfig                                     | 1 +
 arch/sparc/include/asm/pgtable_64.h                    | 3 ---
 arch/x86/Kconfig                                       | 1 +
 arch/x86/include/asm/pgtable_types.h                   | 1 -
 include/linux/pfn_t.h                                  | 4 ++--
 mm/Kconfig                                             | 3 +++
 mm/gup.c                                               | 4 ++--
 mm/memory.c                                            | 2 +-
 23 files changed, 18 insertions(+), 24 deletions(-)

diff --git a/Documentation/features/vm/pte_special/arch-support.txt b/Documentation/features/vm/pte_special/arch-support.txt
index 055004f467d2..cd05924ea875 100644
--- a/Documentation/features/vm/pte_special/arch-support.txt
+++ b/Documentation/features/vm/pte_special/arch-support.txt
@@ -1,6 +1,6 @@
 #
 # Feature name:          pte_special
-#         Kconfig:       __HAVE_ARCH_PTE_SPECIAL
+#         Kconfig:       ARCH_HAS_PTE_SPECIAL
 #         description:   arch supports the pte_special()/pte_mkspecial() VM APIs
 #
     -----------------------
diff --git a/arch/arc/Kconfig b/arch/arc/Kconfig
index d76bf4a83740..8516e2b0239a 100644
--- a/arch/arc/Kconfig
+++ b/arch/arc/Kconfig
@@ -44,6 +44,7 @@ config ARC
 	select HAVE_GENERIC_DMA_COHERENT
 	select HAVE_KERNEL_GZIP
 	select HAVE_KERNEL_LZMA
+	select ARCH_HAS_PTE_SPECIAL
 
 config MIGHT_HAVE_PCI
 	bool
diff --git a/arch/arc/include/asm/pgtable.h b/arch/arc/include/asm/pgtable.h
index 08fe33830d4b..8ec5599a0957 100644
--- a/arch/arc/include/asm/pgtable.h
+++ b/arch/arc/include/asm/pgtable.h
@@ -320,8 +320,6 @@ PTE_BIT_FUNC(mkexec,	|= (_PAGE_EXECUTE));
 PTE_BIT_FUNC(mkspecial,	|= (_PAGE_SPECIAL));
 PTE_BIT_FUNC(mkhuge,	|= (_PAGE_HW_SZ));
 
-#define __HAVE_ARCH_PTE_SPECIAL
-
 static inline pte_t pte_modify(pte_t pte, pgprot_t newprot)
 {
 	return __pte((pte_val(pte) & _PAGE_CHG_MASK) | pgprot_val(newprot));
diff --git a/arch/arm/Kconfig b/arch/arm/Kconfig
index a7f8e7f4b88f..c088c851b235 100644
--- a/arch/arm/Kconfig
+++ b/arch/arm/Kconfig
@@ -8,6 +8,7 @@ config ARM
 	select ARCH_HAS_DEVMEM_IS_ALLOWED
 	select ARCH_HAS_ELF_RANDOMIZE
 	select ARCH_HAS_FORTIFY_SOURCE
+	select ARCH_HAS_PTE_SPECIAL if ARM_LPAE
 	select ARCH_HAS_SET_MEMORY
 	select ARCH_HAS_PHYS_TO_DMA
 	select ARCH_HAS_STRICT_KERNEL_RWX if MMU && !XIP_KERNEL
diff --git a/arch/arm/include/asm/pgtable-3level.h b/arch/arm/include/asm/pgtable-3level.h
index 2a4836087358..6d50a11d7793 100644
--- a/arch/arm/include/asm/pgtable-3level.h
+++ b/arch/arm/include/asm/pgtable-3level.h
@@ -219,7 +219,6 @@ static inline pte_t pte_mkspecial(pte_t pte)
 	pte_val(pte) |= L_PTE_SPECIAL;
 	return pte;
 }
-#define	__HAVE_ARCH_PTE_SPECIAL
 
 #define pmd_write(pmd)		(pmd_isclear((pmd), L_PMD_SECT_RDONLY))
 #define pmd_dirty(pmd)		(pmd_isset((pmd), L_PMD_SECT_DIRTY))
diff --git a/arch/arm64/Kconfig b/arch/arm64/Kconfig
index eb2cf4938f6d..9a3f1b1ab50c 100644
--- a/arch/arm64/Kconfig
+++ b/arch/arm64/Kconfig
@@ -17,6 +17,7 @@ config ARM64
 	select ARCH_HAS_GIGANTIC_PAGE if (MEMORY_ISOLATION && COMPACTION) || CMA
 	select ARCH_HAS_KCOV
 	select ARCH_HAS_MEMBARRIER_SYNC_CORE
+	select ARCH_HAS_PTE_SPECIAL
 	select ARCH_HAS_SET_MEMORY
 	select ARCH_HAS_SG_CHAIN
 	select ARCH_HAS_STRICT_KERNEL_RWX
diff --git a/arch/arm64/include/asm/pgtable.h b/arch/arm64/include/asm/pgtable.h
index 7e2c27e63cd8..b96c8a186908 100644
--- a/arch/arm64/include/asm/pgtable.h
+++ b/arch/arm64/include/asm/pgtable.h
@@ -306,8 +306,6 @@ static inline int pte_same(pte_t pte_a, pte_t pte_b)
 #define HPAGE_MASK		(~(HPAGE_SIZE - 1))
 #define HUGETLB_PAGE_ORDER	(HPAGE_SHIFT - PAGE_SHIFT)
 
-#define __HAVE_ARCH_PTE_SPECIAL
-
 static inline pte_t pgd_pte(pgd_t pgd)
 {
 	return __pte(pgd_val(pgd));
diff --git a/arch/powerpc/Kconfig b/arch/powerpc/Kconfig
index c32a181a7cbb..f7415fe25c07 100644
--- a/arch/powerpc/Kconfig
+++ b/arch/powerpc/Kconfig
@@ -141,6 +141,7 @@ config PPC
 	select ARCH_HAS_GCOV_PROFILE_ALL
 	select ARCH_HAS_PHYS_TO_DMA
 	select ARCH_HAS_PMEM_API                if PPC64
+	select ARCH_HAS_PTE_SPECIAL
 	select ARCH_HAS_MEMBARRIER_CALLBACKS
 	select ARCH_HAS_SCALED_CPUTIME		if VIRT_CPU_ACCOUNTING_NATIVE
 	select ARCH_HAS_SG_CHAIN
diff --git a/arch/powerpc/include/asm/book3s/64/pgtable.h b/arch/powerpc/include/asm/book3s/64/pgtable.h
index 47b5ffc8715d..b3ac8948b257 100644
--- a/arch/powerpc/include/asm/book3s/64/pgtable.h
+++ b/arch/powerpc/include/asm/book3s/64/pgtable.h
@@ -319,9 +319,6 @@ extern unsigned long pci_io_base;
 /* Advertise special mapping type for AGP */
 #define HAVE_PAGE_AGP
 
-/* Advertise support for _PAGE_SPECIAL */
-#define __HAVE_ARCH_PTE_SPECIAL
-
 #ifndef __ASSEMBLY__
 
 /*
diff --git a/arch/powerpc/include/asm/pte-common.h b/arch/powerpc/include/asm/pte-common.h
index c4a72c7a8c83..03dfddb1f49a 100644
--- a/arch/powerpc/include/asm/pte-common.h
+++ b/arch/powerpc/include/asm/pte-common.h
@@ -216,9 +216,6 @@ static inline bool pte_user(pte_t pte)
 #define PAGE_AGP		(PAGE_KERNEL_NC)
 #define HAVE_PAGE_AGP
 
-/* Advertise support for _PAGE_SPECIAL */
-#define __HAVE_ARCH_PTE_SPECIAL
-
 #ifndef _PAGE_READ
 /* if not defined, we should not find _PAGE_WRITE too */
 #define _PAGE_READ 0
diff --git a/arch/riscv/Kconfig b/arch/riscv/Kconfig
index 5287c1441d66..b01c183836e5 100644
--- a/arch/riscv/Kconfig
+++ b/arch/riscv/Kconfig
@@ -34,6 +34,7 @@ config RISCV
 	select THREAD_INFO_IN_TASK
 	select RISCV_TIMER
 	select GENERIC_IRQ_MULTI_HANDLER
+	select ARCH_HAS_PTE_SPECIAL
 
 config MMU
 	def_bool y
diff --git a/arch/s390/Kconfig b/arch/s390/Kconfig
index 32a0d5b958bf..5f1f4997e7e9 100644
--- a/arch/s390/Kconfig
+++ b/arch/s390/Kconfig
@@ -72,6 +72,7 @@ config S390
 	select ARCH_HAS_GCOV_PROFILE_ALL
 	select ARCH_HAS_GIGANTIC_PAGE if (MEMORY_ISOLATION && COMPACTION) || CMA
 	select ARCH_HAS_KCOV
+	select ARCH_HAS_PTE_SPECIAL
 	select ARCH_HAS_SET_MEMORY
 	select ARCH_HAS_SG_CHAIN
 	select ARCH_HAS_STRICT_KERNEL_RWX
diff --git a/arch/s390/include/asm/pgtable.h b/arch/s390/include/asm/pgtable.h
index 2d24d33bf188..9809694e1389 100644
--- a/arch/s390/include/asm/pgtable.h
+++ b/arch/s390/include/asm/pgtable.h
@@ -171,7 +171,6 @@ static inline int is_module_addr(void *addr)
 #define _PAGE_WRITE	0x020		/* SW pte write bit */
 #define _PAGE_SPECIAL	0x040		/* SW associated with special page */
 #define _PAGE_UNUSED	0x080		/* SW bit for pgste usage state */
-#define __HAVE_ARCH_PTE_SPECIAL
 
 #ifdef CONFIG_MEM_SOFT_DIRTY
 #define _PAGE_SOFT_DIRTY 0x002		/* SW pte soft dirty bit */
diff --git a/arch/sh/Kconfig b/arch/sh/Kconfig
index 97fe29316476..a6c75b6806d2 100644
--- a/arch/sh/Kconfig
+++ b/arch/sh/Kconfig
@@ -50,6 +50,7 @@ config SUPERH
 	select HAVE_ARCH_AUDITSYSCALL
 	select HAVE_FUTEX_CMPXCHG if FUTEX
 	select HAVE_NMI
+	select ARCH_HAS_PTE_SPECIAL
 	help
 	  The SuperH is a RISC processor targeted for use in embedded systems
 	  and consumer electronics; it was also used in the Sega Dreamcast
diff --git a/arch/sh/include/asm/pgtable.h b/arch/sh/include/asm/pgtable.h
index 89c513a982fc..f6abfe2bca93 100644
--- a/arch/sh/include/asm/pgtable.h
+++ b/arch/sh/include/asm/pgtable.h
@@ -156,8 +156,6 @@ extern void page_table_range_init(unsigned long start, unsigned long end,
 #define HAVE_ARCH_UNMAPPED_AREA
 #define HAVE_ARCH_UNMAPPED_AREA_TOPDOWN
 
-#define __HAVE_ARCH_PTE_SPECIAL
-
 #include <asm-generic/pgtable.h>
 
 #endif /* __ASM_SH_PGTABLE_H */
diff --git a/arch/sparc/Kconfig b/arch/sparc/Kconfig
index 8767e45f1b2b..6b5a4f05dcb2 100644
--- a/arch/sparc/Kconfig
+++ b/arch/sparc/Kconfig
@@ -86,6 +86,7 @@ config SPARC64
 	select ARCH_USE_QUEUED_SPINLOCKS
 	select GENERIC_TIME_VSYSCALL
 	select ARCH_CLOCKSOURCE_DATA
+	select ARCH_HAS_PTE_SPECIAL
 
 config ARCH_DEFCONFIG
 	string
diff --git a/arch/sparc/include/asm/pgtable_64.h b/arch/sparc/include/asm/pgtable_64.h
index 44d6ac47e035..1393a8ac596b 100644
--- a/arch/sparc/include/asm/pgtable_64.h
+++ b/arch/sparc/include/asm/pgtable_64.h
@@ -117,9 +117,6 @@ bool kern_addr_valid(unsigned long addr);
 #define _PAGE_PMD_HUGE    _AC(0x0100000000000000,UL) /* Huge page            */
 #define _PAGE_PUD_HUGE    _PAGE_PMD_HUGE
 
-/* Advertise support for _PAGE_SPECIAL */
-#define __HAVE_ARCH_PTE_SPECIAL
-
 /* SUN4U pte bits... */
 #define _PAGE_SZ4MB_4U	  _AC(0x6000000000000000,UL) /* 4MB Page             */
 #define _PAGE_SZ512K_4U	  _AC(0x4000000000000000,UL) /* 512K Page            */
diff --git a/arch/x86/Kconfig b/arch/x86/Kconfig
index bf4ddea48e61..3f5fb25486bf 100644
--- a/arch/x86/Kconfig
+++ b/arch/x86/Kconfig
@@ -56,6 +56,7 @@ config X86
 	select ARCH_HAS_KCOV			if X86_64
 	select ARCH_HAS_MEMBARRIER_SYNC_CORE
 	select ARCH_HAS_PMEM_API		if X86_64
+	select ARCH_HAS_PTE_SPECIAL
 	select ARCH_HAS_REFCOUNT
 	select ARCH_HAS_UACCESS_FLUSHCACHE	if X86_64
 	select ARCH_HAS_SET_MEMORY
diff --git a/arch/x86/include/asm/pgtable_types.h b/arch/x86/include/asm/pgtable_types.h
index acfe755562a6..3e195728d7d1 100644
--- a/arch/x86/include/asm/pgtable_types.h
+++ b/arch/x86/include/asm/pgtable_types.h
@@ -65,7 +65,6 @@
 #define _PAGE_PKEY_BIT2	(_AT(pteval_t, 0))
 #define _PAGE_PKEY_BIT3	(_AT(pteval_t, 0))
 #endif
-#define __HAVE_ARCH_PTE_SPECIAL
 
 #define _PAGE_PKEY_MASK (_PAGE_PKEY_BIT0 | \
 			 _PAGE_PKEY_BIT1 | \
diff --git a/include/linux/pfn_t.h b/include/linux/pfn_t.h
index a03c2642a87c..21713dc14ce2 100644
--- a/include/linux/pfn_t.h
+++ b/include/linux/pfn_t.h
@@ -122,7 +122,7 @@ pud_t pud_mkdevmap(pud_t pud);
 #endif
 #endif /* __HAVE_ARCH_PTE_DEVMAP */
 
-#ifdef __HAVE_ARCH_PTE_SPECIAL
+#ifdef CONFIG_ARCH_HAS_PTE_SPECIAL
 static inline bool pfn_t_special(pfn_t pfn)
 {
 	return (pfn.val & PFN_SPECIAL) == PFN_SPECIAL;
@@ -132,5 +132,5 @@ static inline bool pfn_t_special(pfn_t pfn)
 {
 	return false;
 }
-#endif /* __HAVE_ARCH_PTE_SPECIAL */
+#endif /* CONFIG_ARCH_HAS_PTE_SPECIAL */
 #endif /* _LINUX_PFN_T_H_ */
diff --git a/mm/Kconfig b/mm/Kconfig
index d5004d82a1d6..1ea3e4a6a123 100644
--- a/mm/Kconfig
+++ b/mm/Kconfig
@@ -752,3 +752,6 @@ config GUP_BENCHMARK
 	  performance of get_user_pages_fast().
 
 	  See tools/testing/selftests/vm/gup_benchmark.c
+
+config ARCH_HAS_PTE_SPECIAL
+	bool
diff --git a/mm/gup.c b/mm/gup.c
index f296df6cf666..b044a3d14dc5 100644
--- a/mm/gup.c
+++ b/mm/gup.c
@@ -1351,7 +1351,7 @@ static void undo_dev_pagemap(int *nr, int nr_start, struct page **pages)
 	}
 }
 
-#ifdef __HAVE_ARCH_PTE_SPECIAL
+#ifdef CONFIG_ARCH_HAS_PTE_SPECIAL
 static int gup_pte_range(pmd_t pmd, unsigned long addr, unsigned long end,
 			 int write, struct page **pages, int *nr)
 {
@@ -1427,7 +1427,7 @@ static int gup_pte_range(pmd_t pmd, unsigned long addr, unsigned long end,
 {
 	return 0;
 }
-#endif /* __HAVE_ARCH_PTE_SPECIAL */
+#endif /* CONFIG_ARCH_HAS_PTE_SPECIAL */
 
 #if defined(__HAVE_ARCH_PTE_DEVMAP) && defined(CONFIG_TRANSPARENT_HUGEPAGE)
 static int __gup_device_huge(unsigned long pfn, unsigned long addr,
diff --git a/mm/memory.c b/mm/memory.c
index a1f990e33e38..96910c625daa 100644
--- a/mm/memory.c
+++ b/mm/memory.c
@@ -817,7 +817,7 @@ static void print_bad_pte(struct vm_area_struct *vma, unsigned long addr,
  * PFNMAP mappings in order to support COWable mappings.
  *
  */
-#ifdef __HAVE_ARCH_PTE_SPECIAL
+#ifdef CONFIG_ARCH_HAS_PTE_SPECIAL
 # define HAVE_PTE_SPECIAL 1
 #else
 # define HAVE_PTE_SPECIAL 0
-- 
2.7.4

[PATCH v2 1/2] mm: introduce ARCH_HAS_PTE_SPECIAL

[Laurent Dufour]

Currently the PTE special supports is turned on in per architecture header
files. Most of the time, it is defined in arch/*/include/asm/pgtable.h
depending or not on some other per architecture static definition.

This patch introduce a new configuration variable to manage this directly
in the Kconfig files. It would later replace __HAVE_ARCH_PTE_SPECIAL.

Here notes for some architecture where the definition of
__HAVE_ARCH_PTE_SPECIAL is not obvious:

arm
 __HAVE_ARCH_PTE_SPECIAL which is currently defined in
arch/arm/include/asm/pgtable-3level.h which is included by
arch/arm/include/asm/pgtable.h when CONFIG_ARM_LPAE is set.
So select ARCH_HAS_PTE_SPECIAL if ARM_LPAE.

powerpc
__HAVE_ARCH_PTE_SPECIAL is defined in 2 files:
 - arch/powerpc/include/asm/book3s/64/pgtable.h
 - arch/powerpc/include/asm/pte-common.h
The first one is included if (PPC_BOOK3S & PPC64) while the second is
included in all the other cases.
So select ARCH_HAS_PTE_SPECIAL all the time.

sparc:
__HAVE_ARCH_PTE_SPECIAL is defined if defined(__sparc__) &&
defined(__arch64__) which are defined through the compiler in
sparc/Makefile if !SPARC32 which I assume to be if SPARC64.
So select ARCH_HAS_PTE_SPECIAL if SPARC64

There is no functional change introduced by this patch.

Suggested-by: Jerome Glisse <jglisse at redhat>
Reviewed-by: Jerome Glisse <jglisse at redhat>
Signed-off-by: Laurent Dufour <ldufour at linux.vnet.ibm.com>
---
 Documentation/features/vm/pte_special/arch-support.txt | 2 +-
 arch/arc/Kconfig                                       | 1 +
 arch/arc/include/asm/pgtable.h                         | 2 --
 arch/arm/Kconfig                                       | 1 +
 arch/arm/include/asm/pgtable-3level.h                  | 1 -
 arch/arm64/Kconfig                                     | 1 +
 arch/arm64/include/asm/pgtable.h                       | 2 --
 arch/powerpc/Kconfig                                   | 1 +
 arch/powerpc/include/asm/book3s/64/pgtable.h           | 3 ---
 arch/powerpc/include/asm/pte-common.h                  | 3 ---
 arch/riscv/Kconfig                                     | 1 +
 arch/s390/Kconfig                                      | 1 +
 arch/s390/include/asm/pgtable.h                        | 1 -
 arch/sh/Kconfig                                        | 1 +
 arch/sh/include/asm/pgtable.h                          | 2 --
 arch/sparc/Kconfig                                     | 1 +
 arch/sparc/include/asm/pgtable_64.h                    | 3 ---
 arch/x86/Kconfig                                       | 1 +
 arch/x86/include/asm/pgtable_types.h                   | 1 -
 include/linux/pfn_t.h                                  | 4 ++--
 mm/Kconfig                                             | 3 +++
 mm/gup.c                                               | 4 ++--
 mm/memory.c                                            | 2 +-
 23 files changed, 18 insertions(+), 24 deletions(-)

diff --git a/Documentation/features/vm/pte_special/arch-support.txt b/Documentation/features/vm/pte_special/arch-support.txt
index 055004f467d2..cd05924ea875 100644
--- a/Documentation/features/vm/pte_special/arch-support.txt
+++ b/Documentation/features/vm/pte_special/arch-support.txt
@@ -1,6 +1,6 @@
 #
 # Feature name:          pte_special
-#         Kconfig:       __HAVE_ARCH_PTE_SPECIAL
+#         Kconfig:       ARCH_HAS_PTE_SPECIAL
 #         description:   arch supports the pte_special()/pte_mkspecial() VM APIs
 #
     -----------------------
diff --git a/arch/arc/Kconfig b/arch/arc/Kconfig
index d76bf4a83740..8516e2b0239a 100644
--- a/arch/arc/Kconfig
+++ b/arch/arc/Kconfig
@@ -44,6 +44,7 @@ config ARC
 	select HAVE_GENERIC_DMA_COHERENT
 	select HAVE_KERNEL_GZIP
 	select HAVE_KERNEL_LZMA
+	select ARCH_HAS_PTE_SPECIAL
 
 config MIGHT_HAVE_PCI
 	bool
diff --git a/arch/arc/include/asm/pgtable.h b/arch/arc/include/asm/pgtable.h
index 08fe33830d4b..8ec5599a0957 100644
--- a/arch/arc/include/asm/pgtable.h
+++ b/arch/arc/include/asm/pgtable.h
@@ -320,8 +320,6 @@ PTE_BIT_FUNC(mkexec,	|= (_PAGE_EXECUTE));
 PTE_BIT_FUNC(mkspecial,	|= (_PAGE_SPECIAL));
 PTE_BIT_FUNC(mkhuge,	|= (_PAGE_HW_SZ));
 
-#define __HAVE_ARCH_PTE_SPECIAL
-
 static inline pte_t pte_modify(pte_t pte, pgprot_t newprot)
 {
 	return __pte((pte_val(pte) & _PAGE_CHG_MASK) | pgprot_val(newprot));
diff --git a/arch/arm/Kconfig b/arch/arm/Kconfig
index a7f8e7f4b88f..c088c851b235 100644
--- a/arch/arm/Kconfig
+++ b/arch/arm/Kconfig
@@ -8,6 +8,7 @@ config ARM
 	select ARCH_HAS_DEVMEM_IS_ALLOWED
 	select ARCH_HAS_ELF_RANDOMIZE
 	select ARCH_HAS_FORTIFY_SOURCE
+	select ARCH_HAS_PTE_SPECIAL if ARM_LPAE
 	select ARCH_HAS_SET_MEMORY
 	select ARCH_HAS_PHYS_TO_DMA
 	select ARCH_HAS_STRICT_KERNEL_RWX if MMU && !XIP_KERNEL
diff --git a/arch/arm/include/asm/pgtable-3level.h b/arch/arm/include/asm/pgtable-3level.h
index 2a4836087358..6d50a11d7793 100644
--- a/arch/arm/include/asm/pgtable-3level.h
+++ b/arch/arm/include/asm/pgtable-3level.h
@@ -219,7 +219,6 @@ static inline pte_t pte_mkspecial(pte_t pte)
 	pte_val(pte) |= L_PTE_SPECIAL;
 	return pte;
 }
-#define	__HAVE_ARCH_PTE_SPECIAL
 
 #define pmd_write(pmd)		(pmd_isclear((pmd), L_PMD_SECT_RDONLY))
 #define pmd_dirty(pmd)		(pmd_isset((pmd), L_PMD_SECT_DIRTY))
diff --git a/arch/arm64/Kconfig b/arch/arm64/Kconfig
index eb2cf4938f6d..9a3f1b1ab50c 100644
--- a/arch/arm64/Kconfig
+++ b/arch/arm64/Kconfig
@@ -17,6 +17,7 @@ config ARM64
 	select ARCH_HAS_GIGANTIC_PAGE if (MEMORY_ISOLATION && COMPACTION) || CMA
 	select ARCH_HAS_KCOV
 	select ARCH_HAS_MEMBARRIER_SYNC_CORE
+	select ARCH_HAS_PTE_SPECIAL
 	select ARCH_HAS_SET_MEMORY
 	select ARCH_HAS_SG_CHAIN
 	select ARCH_HAS_STRICT_KERNEL_RWX
diff --git a/arch/arm64/include/asm/pgtable.h b/arch/arm64/include/asm/pgtable.h
index 7e2c27e63cd8..b96c8a186908 100644
--- a/arch/arm64/include/asm/pgtable.h
+++ b/arch/arm64/include/asm/pgtable.h
@@ -306,8 +306,6 @@ static inline int pte_same(pte_t pte_a, pte_t pte_b)
 #define HPAGE_MASK		(~(HPAGE_SIZE - 1))
 #define HUGETLB_PAGE_ORDER	(HPAGE_SHIFT - PAGE_SHIFT)
 
-#define __HAVE_ARCH_PTE_SPECIAL
-
 static inline pte_t pgd_pte(pgd_t pgd)
 {
 	return __pte(pgd_val(pgd));
diff --git a/arch/powerpc/Kconfig b/arch/powerpc/Kconfig
index c32a181a7cbb..f7415fe25c07 100644
--- a/arch/powerpc/Kconfig
+++ b/arch/powerpc/Kconfig
@@ -141,6 +141,7 @@ config PPC
 	select ARCH_HAS_GCOV_PROFILE_ALL
 	select ARCH_HAS_PHYS_TO_DMA
 	select ARCH_HAS_PMEM_API                if PPC64
+	select ARCH_HAS_PTE_SPECIAL
 	select ARCH_HAS_MEMBARRIER_CALLBACKS
 	select ARCH_HAS_SCALED_CPUTIME		if VIRT_CPU_ACCOUNTING_NATIVE
 	select ARCH_HAS_SG_CHAIN
diff --git a/arch/powerpc/include/asm/book3s/64/pgtable.h b/arch/powerpc/include/asm/book3s/64/pgtable.h
index 47b5ffc8715d..b3ac8948b257 100644
--- a/arch/powerpc/include/asm/book3s/64/pgtable.h
+++ b/arch/powerpc/include/asm/book3s/64/pgtable.h
@@ -319,9 +319,6 @@ extern unsigned long pci_io_base;
 /* Advertise special mapping type for AGP */
 #define HAVE_PAGE_AGP
 
-/* Advertise support for _PAGE_SPECIAL */
-#define __HAVE_ARCH_PTE_SPECIAL
-
 #ifndef __ASSEMBLY__
 
 /*
diff --git a/arch/powerpc/include/asm/pte-common.h b/arch/powerpc/include/asm/pte-common.h
index c4a72c7a8c83..03dfddb1f49a 100644
--- a/arch/powerpc/include/asm/pte-common.h
+++ b/arch/powerpc/include/asm/pte-common.h
@@ -216,9 +216,6 @@ static inline bool pte_user(pte_t pte)
 #define PAGE_AGP		(PAGE_KERNEL_NC)
 #define HAVE_PAGE_AGP
 
-/* Advertise support for _PAGE_SPECIAL */
-#define __HAVE_ARCH_PTE_SPECIAL
-
 #ifndef _PAGE_READ
 /* if not defined, we should not find _PAGE_WRITE too */
 #define _PAGE_READ 0
diff --git a/arch/riscv/Kconfig b/arch/riscv/Kconfig
index 5287c1441d66..b01c183836e5 100644
--- a/arch/riscv/Kconfig
+++ b/arch/riscv/Kconfig
@@ -34,6 +34,7 @@ config RISCV
 	select THREAD_INFO_IN_TASK
 	select RISCV_TIMER
 	select GENERIC_IRQ_MULTI_HANDLER
+	select ARCH_HAS_PTE_SPECIAL
 
 config MMU
 	def_bool y
diff --git a/arch/s390/Kconfig b/arch/s390/Kconfig
index 32a0d5b958bf..5f1f4997e7e9 100644
--- a/arch/s390/Kconfig
+++ b/arch/s390/Kconfig
@@ -72,6 +72,7 @@ config S390
 	select ARCH_HAS_GCOV_PROFILE_ALL
 	select ARCH_HAS_GIGANTIC_PAGE if (MEMORY_ISOLATION && COMPACTION) || CMA
 	select ARCH_HAS_KCOV
+	select ARCH_HAS_PTE_SPECIAL
 	select ARCH_HAS_SET_MEMORY
 	select ARCH_HAS_SG_CHAIN
 	select ARCH_HAS_STRICT_KERNEL_RWX
diff --git a/arch/s390/include/asm/pgtable.h b/arch/s390/include/asm/pgtable.h
index 2d24d33bf188..9809694e1389 100644
--- a/arch/s390/include/asm/pgtable.h
+++ b/arch/s390/include/asm/pgtable.h
@@ -171,7 +171,6 @@ static inline int is_module_addr(void *addr)
 #define _PAGE_WRITE	0x020		/* SW pte write bit */
 #define _PAGE_SPECIAL	0x040		/* SW associated with special page */
 #define _PAGE_UNUSED	0x080		/* SW bit for pgste usage state */
-#define __HAVE_ARCH_PTE_SPECIAL
 
 #ifdef CONFIG_MEM_SOFT_DIRTY
 #define _PAGE_SOFT_DIRTY 0x002		/* SW pte soft dirty bit */
diff --git a/arch/sh/Kconfig b/arch/sh/Kconfig
index 97fe29316476..a6c75b6806d2 100644
--- a/arch/sh/Kconfig
+++ b/arch/sh/Kconfig
@@ -50,6 +50,7 @@ config SUPERH
 	select HAVE_ARCH_AUDITSYSCALL
 	select HAVE_FUTEX_CMPXCHG if FUTEX
 	select HAVE_NMI
+	select ARCH_HAS_PTE_SPECIAL
 	help
 	  The SuperH is a RISC processor targeted for use in embedded systems
 	  and consumer electronics; it was also used in the Sega Dreamcast
diff --git a/arch/sh/include/asm/pgtable.h b/arch/sh/include/asm/pgtable.h
index 89c513a982fc..f6abfe2bca93 100644
--- a/arch/sh/include/asm/pgtable.h
+++ b/arch/sh/include/asm/pgtable.h
@@ -156,8 +156,6 @@ extern void page_table_range_init(unsigned long start, unsigned long end,
 #define HAVE_ARCH_UNMAPPED_AREA
 #define HAVE_ARCH_UNMAPPED_AREA_TOPDOWN
 
-#define __HAVE_ARCH_PTE_SPECIAL
-
 #include <asm-generic/pgtable.h>
 
 #endif /* __ASM_SH_PGTABLE_H */
diff --git a/arch/sparc/Kconfig b/arch/sparc/Kconfig
index 8767e45f1b2b..6b5a4f05dcb2 100644
--- a/arch/sparc/Kconfig
+++ b/arch/sparc/Kconfig
@@ -86,6 +86,7 @@ config SPARC64
 	select ARCH_USE_QUEUED_SPINLOCKS
 	select GENERIC_TIME_VSYSCALL
 	select ARCH_CLOCKSOURCE_DATA
+	select ARCH_HAS_PTE_SPECIAL
 
 config ARCH_DEFCONFIG
 	string
diff --git a/arch/sparc/include/asm/pgtable_64.h b/arch/sparc/include/asm/pgtable_64.h
index 44d6ac47e035..1393a8ac596b 100644
--- a/arch/sparc/include/asm/pgtable_64.h
+++ b/arch/sparc/include/asm/pgtable_64.h
@@ -117,9 +117,6 @@ bool kern_addr_valid(unsigned long addr);
 #define _PAGE_PMD_HUGE    _AC(0x0100000000000000,UL) /* Huge page            */
 #define _PAGE_PUD_HUGE    _PAGE_PMD_HUGE
 
-/* Advertise support for _PAGE_SPECIAL */
-#define __HAVE_ARCH_PTE_SPECIAL
-
 /* SUN4U pte bits... */
 #define _PAGE_SZ4MB_4U	  _AC(0x6000000000000000,UL) /* 4MB Page             */
 #define _PAGE_SZ512K_4U	  _AC(0x4000000000000000,UL) /* 512K Page            */
diff --git a/arch/x86/Kconfig b/arch/x86/Kconfig
index bf4ddea48e61..3f5fb25486bf 100644
--- a/arch/x86/Kconfig
+++ b/arch/x86/Kconfig
@@ -56,6 +56,7 @@ config X86
 	select ARCH_HAS_KCOV			if X86_64
 	select ARCH_HAS_MEMBARRIER_SYNC_CORE
 	select ARCH_HAS_PMEM_API		if X86_64
+	select ARCH_HAS_PTE_SPECIAL
 	select ARCH_HAS_REFCOUNT
 	select ARCH_HAS_UACCESS_FLUSHCACHE	if X86_64
 	select ARCH_HAS_SET_MEMORY
diff --git a/arch/x86/include/asm/pgtable_types.h b/arch/x86/include/asm/pgtable_types.h
index acfe755562a6..3e195728d7d1 100644
--- a/arch/x86/include/asm/pgtable_types.h
+++ b/arch/x86/include/asm/pgtable_types.h
@@ -65,7 +65,6 @@
 #define _PAGE_PKEY_BIT2	(_AT(pteval_t, 0))
 #define _PAGE_PKEY_BIT3	(_AT(pteval_t, 0))
 #endif
-#define __HAVE_ARCH_PTE_SPECIAL
 
 #define _PAGE_PKEY_MASK (_PAGE_PKEY_BIT0 | \
 			 _PAGE_PKEY_BIT1 | \
diff --git a/include/linux/pfn_t.h b/include/linux/pfn_t.h
index a03c2642a87c..21713dc14ce2 100644
--- a/include/linux/pfn_t.h
+++ b/include/linux/pfn_t.h
@@ -122,7 +122,7 @@ pud_t pud_mkdevmap(pud_t pud);
 #endif
 #endif /* __HAVE_ARCH_PTE_DEVMAP */
 
-#ifdef __HAVE_ARCH_PTE_SPECIAL
+#ifdef CONFIG_ARCH_HAS_PTE_SPECIAL
 static inline bool pfn_t_special(pfn_t pfn)
 {
 	return (pfn.val & PFN_SPECIAL) == PFN_SPECIAL;
@@ -132,5 +132,5 @@ static inline bool pfn_t_special(pfn_t pfn)
 {
 	return false;
 }
-#endif /* __HAVE_ARCH_PTE_SPECIAL */
+#endif /* CONFIG_ARCH_HAS_PTE_SPECIAL */
 #endif /* _LINUX_PFN_T_H_ */
diff --git a/mm/Kconfig b/mm/Kconfig
index d5004d82a1d6..1ea3e4a6a123 100644
--- a/mm/Kconfig
+++ b/mm/Kconfig
@@ -752,3 +752,6 @@ config GUP_BENCHMARK
 	  performance of get_user_pages_fast().
 
 	  See tools/testing/selftests/vm/gup_benchmark.c
+
+config ARCH_HAS_PTE_SPECIAL
+	bool
diff --git a/mm/gup.c b/mm/gup.c
index f296df6cf666..b044a3d14dc5 100644
--- a/mm/gup.c
+++ b/mm/gup.c
@@ -1351,7 +1351,7 @@ static void undo_dev_pagemap(int *nr, int nr_start, struct page **pages)
 	}
 }
 
-#ifdef __HAVE_ARCH_PTE_SPECIAL
+#ifdef CONFIG_ARCH_HAS_PTE_SPECIAL
 static int gup_pte_range(pmd_t pmd, unsigned long addr, unsigned long end,
 			 int write, struct page **pages, int *nr)
 {
@@ -1427,7 +1427,7 @@ static int gup_pte_range(pmd_t pmd, unsigned long addr, unsigned long end,
 {
 	return 0;
 }
-#endif /* __HAVE_ARCH_PTE_SPECIAL */
+#endif /* CONFIG_ARCH_HAS_PTE_SPECIAL */
 
 #if defined(__HAVE_ARCH_PTE_DEVMAP) && defined(CONFIG_TRANSPARENT_HUGEPAGE)
 static int __gup_device_huge(unsigned long pfn, unsigned long addr,
diff --git a/mm/memory.c b/mm/memory.c
index a1f990e33e38..96910c625daa 100644
--- a/mm/memory.c
+++ b/mm/memory.c
@@ -817,7 +817,7 @@ static void print_bad_pte(struct vm_area_struct *vma, unsigned long addr,
  * PFNMAP mappings in order to support COWable mappings.
  *
  */
-#ifdef __HAVE_ARCH_PTE_SPECIAL
+#ifdef CONFIG_ARCH_HAS_PTE_SPECIAL
 # define HAVE_PTE_SPECIAL 1
 #else
 # define HAVE_PTE_SPECIAL 0
-- 
2.7.4

[PATCH v2 1/2] mm: introduce ARCH_HAS_PTE_SPECIAL

[Laurent Dufour]

Currently the PTE special supports is turned on in per architecture header
files. Most of the time, it is defined in arch/*/include/asm/pgtable.h
depending or not on some other per architecture static definition.

This patch introduce a new configuration variable to manage this directly
in the Kconfig files. It would later replace __HAVE_ARCH_PTE_SPECIAL.

Here notes for some architecture where the definition of
__HAVE_ARCH_PTE_SPECIAL is not obvious:

arm
 __HAVE_ARCH_PTE_SPECIAL which is currently defined in
arch/arm/include/asm/pgtable-3level.h which is included by
arch/arm/include/asm/pgtable.h when CONFIG_ARM_LPAE is set.
So select ARCH_HAS_PTE_SPECIAL if ARM_LPAE.

powerpc
__HAVE_ARCH_PTE_SPECIAL is defined in 2 files:
 - arch/powerpc/include/asm/book3s/64/pgtable.h
 - arch/powerpc/include/asm/pte-common.h
The first one is included if (PPC_BOOK3S & PPC64) while the second is
included in all the other cases.
So select ARCH_HAS_PTE_SPECIAL all the time.

sparc:
__HAVE_ARCH_PTE_SPECIAL is defined if defined(__sparc__) &&
defined(__arch64__) which are defined through the compiler in
sparc/Makefile if !SPARC32 which I assume to be if SPARC64.
So select ARCH_HAS_PTE_SPECIAL if SPARC64

There is no functional change introduced by this patch.

Suggested-by: Jerome Glisse <jglisse@redhat>
Reviewed-by: Jerome Glisse <jglisse@redhat>
Signed-off-by: Laurent Dufour <ldufour@linux.vnet.ibm.com>
---
 Documentation/features/vm/pte_special/arch-support.txt | 2 +-
 arch/arc/Kconfig                                       | 1 +
 arch/arc/include/asm/pgtable.h                         | 2 --
 arch/arm/Kconfig                                       | 1 +
 arch/arm/include/asm/pgtable-3level.h                  | 1 -
 arch/arm64/Kconfig                                     | 1 +
 arch/arm64/include/asm/pgtable.h                       | 2 --
 arch/powerpc/Kconfig                                   | 1 +
 arch/powerpc/include/asm/book3s/64/pgtable.h           | 3 ---
 arch/powerpc/include/asm/pte-common.h                  | 3 ---
 arch/riscv/Kconfig                                     | 1 +
 arch/s390/Kconfig                                      | 1 +
 arch/s390/include/asm/pgtable.h                        | 1 -
 arch/sh/Kconfig                                        | 1 +
 arch/sh/include/asm/pgtable.h                          | 2 --
 arch/sparc/Kconfig                                     | 1 +
 arch/sparc/include/asm/pgtable_64.h                    | 3 ---
 arch/x86/Kconfig                                       | 1 +
 arch/x86/include/asm/pgtable_types.h                   | 1 -
 include/linux/pfn_t.h                                  | 4 ++--
 mm/Kconfig                                             | 3 +++
 mm/gup.c                                               | 4 ++--
 mm/memory.c                                            | 2 +-
 23 files changed, 18 insertions(+), 24 deletions(-)

diff --git a/Documentation/features/vm/pte_special/arch-support.txt b/Documentation/features/vm/pte_special/arch-support.txt
index 055004f467d2..cd05924ea875 100644
--- a/Documentation/features/vm/pte_special/arch-support.txt
+++ b/Documentation/features/vm/pte_special/arch-support.txt
@@ -1,6 +1,6 @@
 #
 # Feature name:          pte_special
-#         Kconfig:       __HAVE_ARCH_PTE_SPECIAL
+#         Kconfig:       ARCH_HAS_PTE_SPECIAL
 #         description:   arch supports the pte_special()/pte_mkspecial() VM APIs
 #
     -----------------------
diff --git a/arch/arc/Kconfig b/arch/arc/Kconfig
index d76bf4a83740..8516e2b0239a 100644
--- a/arch/arc/Kconfig
+++ b/arch/arc/Kconfig
@@ -44,6 +44,7 @@ config ARC
 	select HAVE_GENERIC_DMA_COHERENT
 	select HAVE_KERNEL_GZIP
 	select HAVE_KERNEL_LZMA
+	select ARCH_HAS_PTE_SPECIAL
 
 config MIGHT_HAVE_PCI
 	bool
diff --git a/arch/arc/include/asm/pgtable.h b/arch/arc/include/asm/pgtable.h
index 08fe33830d4b..8ec5599a0957 100644
--- a/arch/arc/include/asm/pgtable.h
+++ b/arch/arc/include/asm/pgtable.h
@@ -320,8 +320,6 @@ PTE_BIT_FUNC(mkexec,	|= (_PAGE_EXECUTE));
 PTE_BIT_FUNC(mkspecial,	|= (_PAGE_SPECIAL));
 PTE_BIT_FUNC(mkhuge,	|= (_PAGE_HW_SZ));
 
-#define __HAVE_ARCH_PTE_SPECIAL
-
 static inline pte_t pte_modify(pte_t pte, pgprot_t newprot)
 {
 	return __pte((pte_val(pte) & _PAGE_CHG_MASK) | pgprot_val(newprot));
diff --git a/arch/arm/Kconfig b/arch/arm/Kconfig
index a7f8e7f4b88f..c088c851b235 100644
--- a/arch/arm/Kconfig
+++ b/arch/arm/Kconfig
@@ -8,6 +8,7 @@ config ARM
 	select ARCH_HAS_DEVMEM_IS_ALLOWED
 	select ARCH_HAS_ELF_RANDOMIZE
 	select ARCH_HAS_FORTIFY_SOURCE
+	select ARCH_HAS_PTE_SPECIAL if ARM_LPAE
 	select ARCH_HAS_SET_MEMORY
 	select ARCH_HAS_PHYS_TO_DMA
 	select ARCH_HAS_STRICT_KERNEL_RWX if MMU && !XIP_KERNEL
diff --git a/arch/arm/include/asm/pgtable-3level.h b/arch/arm/include/asm/pgtable-3level.h
index 2a4836087358..6d50a11d7793 100644
--- a/arch/arm/include/asm/pgtable-3level.h
+++ b/arch/arm/include/asm/pgtable-3level.h
@@ -219,7 +219,6 @@ static inline pte_t pte_mkspecial(pte_t pte)
 	pte_val(pte) |= L_PTE_SPECIAL;
 	return pte;
 }
-#define	__HAVE_ARCH_PTE_SPECIAL
 
 #define pmd_write(pmd)		(pmd_isclear((pmd), L_PMD_SECT_RDONLY))
 #define pmd_dirty(pmd)		(pmd_isset((pmd), L_PMD_SECT_DIRTY))
diff --git a/arch/arm64/Kconfig b/arch/arm64/Kconfig
index eb2cf4938f6d..9a3f1b1ab50c 100644
--- a/arch/arm64/Kconfig
+++ b/arch/arm64/Kconfig
@@ -17,6 +17,7 @@ config ARM64
 	select ARCH_HAS_GIGANTIC_PAGE if (MEMORY_ISOLATION && COMPACTION) || CMA
 	select ARCH_HAS_KCOV
 	select ARCH_HAS_MEMBARRIER_SYNC_CORE
+	select ARCH_HAS_PTE_SPECIAL
 	select ARCH_HAS_SET_MEMORY
 	select ARCH_HAS_SG_CHAIN
 	select ARCH_HAS_STRICT_KERNEL_RWX
diff --git a/arch/arm64/include/asm/pgtable.h b/arch/arm64/include/asm/pgtable.h
index 7e2c27e63cd8..b96c8a186908 100644
--- a/arch/arm64/include/asm/pgtable.h
+++ b/arch/arm64/include/asm/pgtable.h
@@ -306,8 +306,6 @@ static inline int pte_same(pte_t pte_a, pte_t pte_b)
 #define HPAGE_MASK		(~(HPAGE_SIZE - 1))
 #define HUGETLB_PAGE_ORDER	(HPAGE_SHIFT - PAGE_SHIFT)
 
-#define __HAVE_ARCH_PTE_SPECIAL
-
 static inline pte_t pgd_pte(pgd_t pgd)
 {
 	return __pte(pgd_val(pgd));
diff --git a/arch/powerpc/Kconfig b/arch/powerpc/Kconfig
index c32a181a7cbb..f7415fe25c07 100644
--- a/arch/powerpc/Kconfig
+++ b/arch/powerpc/Kconfig
@@ -141,6 +141,7 @@ config PPC
 	select ARCH_HAS_GCOV_PROFILE_ALL
 	select ARCH_HAS_PHYS_TO_DMA
 	select ARCH_HAS_PMEM_API                if PPC64
+	select ARCH_HAS_PTE_SPECIAL
 	select ARCH_HAS_MEMBARRIER_CALLBACKS
 	select ARCH_HAS_SCALED_CPUTIME		if VIRT_CPU_ACCOUNTING_NATIVE
 	select ARCH_HAS_SG_CHAIN
diff --git a/arch/powerpc/include/asm/book3s/64/pgtable.h b/arch/powerpc/include/asm/book3s/64/pgtable.h
index 47b5ffc8715d..b3ac8948b257 100644
--- a/arch/powerpc/include/asm/book3s/64/pgtable.h
+++ b/arch/powerpc/include/asm/book3s/64/pgtable.h
@@ -319,9 +319,6 @@ extern unsigned long pci_io_base;
 /* Advertise special mapping type for AGP */
 #define HAVE_PAGE_AGP
 
-/* Advertise support for _PAGE_SPECIAL */
-#define __HAVE_ARCH_PTE_SPECIAL
-
 #ifndef __ASSEMBLY__
 
 /*
diff --git a/arch/powerpc/include/asm/pte-common.h b/arch/powerpc/include/asm/pte-common.h
index c4a72c7a8c83..03dfddb1f49a 100644
--- a/arch/powerpc/include/asm/pte-common.h
+++ b/arch/powerpc/include/asm/pte-common.h
@@ -216,9 +216,6 @@ static inline bool pte_user(pte_t pte)
 #define PAGE_AGP		(PAGE_KERNEL_NC)
 #define HAVE_PAGE_AGP
 
-/* Advertise support for _PAGE_SPECIAL */
-#define __HAVE_ARCH_PTE_SPECIAL
-
 #ifndef _PAGE_READ
 /* if not defined, we should not find _PAGE_WRITE too */
 #define _PAGE_READ 0
diff --git a/arch/riscv/Kconfig b/arch/riscv/Kconfig
index 5287c1441d66..b01c183836e5 100644
--- a/arch/riscv/Kconfig
+++ b/arch/riscv/Kconfig
@@ -34,6 +34,7 @@ config RISCV
 	select THREAD_INFO_IN_TASK
 	select RISCV_TIMER
 	select GENERIC_IRQ_MULTI_HANDLER
+	select ARCH_HAS_PTE_SPECIAL
 
 config MMU
 	def_bool y
diff --git a/arch/s390/Kconfig b/arch/s390/Kconfig
index 32a0d5b958bf..5f1f4997e7e9 100644
--- a/arch/s390/Kconfig
+++ b/arch/s390/Kconfig
@@ -72,6 +72,7 @@ config S390
 	select ARCH_HAS_GCOV_PROFILE_ALL
 	select ARCH_HAS_GIGANTIC_PAGE if (MEMORY_ISOLATION && COMPACTION) || CMA
 	select ARCH_HAS_KCOV
+	select ARCH_HAS_PTE_SPECIAL
 	select ARCH_HAS_SET_MEMORY
 	select ARCH_HAS_SG_CHAIN
 	select ARCH_HAS_STRICT_KERNEL_RWX
diff --git a/arch/s390/include/asm/pgtable.h b/arch/s390/include/asm/pgtable.h
index 2d24d33bf188..9809694e1389 100644
--- a/arch/s390/include/asm/pgtable.h
+++ b/arch/s390/include/asm/pgtable.h
@@ -171,7 +171,6 @@ static inline int is_module_addr(void *addr)
 #define _PAGE_WRITE	0x020		/* SW pte write bit */
 #define _PAGE_SPECIAL	0x040		/* SW associated with special page */
 #define _PAGE_UNUSED	0x080		/* SW bit for pgste usage state */
-#define __HAVE_ARCH_PTE_SPECIAL
 
 #ifdef CONFIG_MEM_SOFT_DIRTY
 #define _PAGE_SOFT_DIRTY 0x002		/* SW pte soft dirty bit */
diff --git a/arch/sh/Kconfig b/arch/sh/Kconfig
index 97fe29316476..a6c75b6806d2 100644
--- a/arch/sh/Kconfig
+++ b/arch/sh/Kconfig
@@ -50,6 +50,7 @@ config SUPERH
 	select HAVE_ARCH_AUDITSYSCALL
 	select HAVE_FUTEX_CMPXCHG if FUTEX
 	select HAVE_NMI
+	select ARCH_HAS_PTE_SPECIAL
 	help
 	  The SuperH is a RISC processor targeted for use in embedded systems
 	  and consumer electronics; it was also used in the Sega Dreamcast
diff --git a/arch/sh/include/asm/pgtable.h b/arch/sh/include/asm/pgtable.h
index 89c513a982fc..f6abfe2bca93 100644
--- a/arch/sh/include/asm/pgtable.h
+++ b/arch/sh/include/asm/pgtable.h
@@ -156,8 +156,6 @@ extern void page_table_range_init(unsigned long start, unsigned long end,
 #define HAVE_ARCH_UNMAPPED_AREA
 #define HAVE_ARCH_UNMAPPED_AREA_TOPDOWN
 
-#define __HAVE_ARCH_PTE_SPECIAL
-
 #include <asm-generic/pgtable.h>
 
 #endif /* __ASM_SH_PGTABLE_H */
diff --git a/arch/sparc/Kconfig b/arch/sparc/Kconfig
index 8767e45f1b2b..6b5a4f05dcb2 100644
--- a/arch/sparc/Kconfig
+++ b/arch/sparc/Kconfig
@@ -86,6 +86,7 @@ config SPARC64
 	select ARCH_USE_QUEUED_SPINLOCKS
 	select GENERIC_TIME_VSYSCALL
 	select ARCH_CLOCKSOURCE_DATA
+	select ARCH_HAS_PTE_SPECIAL
 
 config ARCH_DEFCONFIG
 	string
diff --git a/arch/sparc/include/asm/pgtable_64.h b/arch/sparc/include/asm/pgtable_64.h
index 44d6ac47e035..1393a8ac596b 100644
--- a/arch/sparc/include/asm/pgtable_64.h
+++ b/arch/sparc/include/asm/pgtable_64.h
@@ -117,9 +117,6 @@ bool kern_addr_valid(unsigned long addr);
 #define _PAGE_PMD_HUGE    _AC(0x0100000000000000,UL) /* Huge page            */
 #define _PAGE_PUD_HUGE    _PAGE_PMD_HUGE
 
-/* Advertise support for _PAGE_SPECIAL */
-#define __HAVE_ARCH_PTE_SPECIAL
-
 /* SUN4U pte bits... */
 #define _PAGE_SZ4MB_4U	  _AC(0x6000000000000000,UL) /* 4MB Page             */
 #define _PAGE_SZ512K_4U	  _AC(0x4000000000000000,UL) /* 512K Page            */
diff --git a/arch/x86/Kconfig b/arch/x86/Kconfig
index bf4ddea48e61..3f5fb25486bf 100644
--- a/arch/x86/Kconfig
+++ b/arch/x86/Kconfig
@@ -56,6 +56,7 @@ config X86
 	select ARCH_HAS_KCOV			if X86_64
 	select ARCH_HAS_MEMBARRIER_SYNC_CORE
 	select ARCH_HAS_PMEM_API		if X86_64
+	select ARCH_HAS_PTE_SPECIAL
 	select ARCH_HAS_REFCOUNT
 	select ARCH_HAS_UACCESS_FLUSHCACHE	if X86_64
 	select ARCH_HAS_SET_MEMORY
diff --git a/arch/x86/include/asm/pgtable_types.h b/arch/x86/include/asm/pgtable_types.h
index acfe755562a6..3e195728d7d1 100644
--- a/arch/x86/include/asm/pgtable_types.h
+++ b/arch/x86/include/asm/pgtable_types.h
@@ -65,7 +65,6 @@
 #define _PAGE_PKEY_BIT2	(_AT(pteval_t, 0))
 #define _PAGE_PKEY_BIT3	(_AT(pteval_t, 0))
 #endif
-#define __HAVE_ARCH_PTE_SPECIAL
 
 #define _PAGE_PKEY_MASK (_PAGE_PKEY_BIT0 | \
 			 _PAGE_PKEY_BIT1 | \
diff --git a/include/linux/pfn_t.h b/include/linux/pfn_t.h
index a03c2642a87c..21713dc14ce2 100644
--- a/include/linux/pfn_t.h
+++ b/include/linux/pfn_t.h
@@ -122,7 +122,7 @@ pud_t pud_mkdevmap(pud_t pud);
 #endif
 #endif /* __HAVE_ARCH_PTE_DEVMAP */
 
-#ifdef __HAVE_ARCH_PTE_SPECIAL
+#ifdef CONFIG_ARCH_HAS_PTE_SPECIAL
 static inline bool pfn_t_special(pfn_t pfn)
 {
 	return (pfn.val & PFN_SPECIAL) == PFN_SPECIAL;
@@ -132,5 +132,5 @@ static inline bool pfn_t_special(pfn_t pfn)
 {
 	return false;
 }
-#endif /* __HAVE_ARCH_PTE_SPECIAL */
+#endif /* CONFIG_ARCH_HAS_PTE_SPECIAL */
 #endif /* _LINUX_PFN_T_H_ */
diff --git a/mm/Kconfig b/mm/Kconfig
index d5004d82a1d6..1ea3e4a6a123 100644
--- a/mm/Kconfig
+++ b/mm/Kconfig
@@ -752,3 +752,6 @@ config GUP_BENCHMARK
 	  performance of get_user_pages_fast().
 
 	  See tools/testing/selftests/vm/gup_benchmark.c
+
+config ARCH_HAS_PTE_SPECIAL
+	bool
diff --git a/mm/gup.c b/mm/gup.c
index f296df6cf666..b044a3d14dc5 100644
--- a/mm/gup.c
+++ b/mm/gup.c
@@ -1351,7 +1351,7 @@ static void undo_dev_pagemap(int *nr, int nr_start, struct page **pages)
 	}
 }
 
-#ifdef __HAVE_ARCH_PTE_SPECIAL
+#ifdef CONFIG_ARCH_HAS_PTE_SPECIAL
 static int gup_pte_range(pmd_t pmd, unsigned long addr, unsigned long end,
 			 int write, struct page **pages, int *nr)
 {
@@ -1427,7 +1427,7 @@ static int gup_pte_range(pmd_t pmd, unsigned long addr, unsigned long end,
 {
 	return 0;
 }
-#endif /* __HAVE_ARCH_PTE_SPECIAL */
+#endif /* CONFIG_ARCH_HAS_PTE_SPECIAL */
 
 #if defined(__HAVE_ARCH_PTE_DEVMAP) && defined(CONFIG_TRANSPARENT_HUGEPAGE)
 static int __gup_device_huge(unsigned long pfn, unsigned long addr,
diff --git a/mm/memory.c b/mm/memory.c
index a1f990e33e38..96910c625daa 100644
--- a/mm/memory.c
+++ b/mm/memory.c
@@ -817,7 +817,7 @@ static void print_bad_pte(struct vm_area_struct *vma, unsigned long addr,
  * PFNMAP mappings in order to support COWable mappings.
  *
  */
-#ifdef __HAVE_ARCH_PTE_SPECIAL
+#ifdef CONFIG_ARCH_HAS_PTE_SPECIAL
 # define HAVE_PTE_SPECIAL 1
 #else
 # define HAVE_PTE_SPECIAL 0
-- 
2.7.4

[PATCH v2 1/2] mm: introduce ARCH_HAS_PTE_SPECIAL

[Laurent Dufour]

Currently the PTE special supports is turned on in per architecture header
files. Most of the time, it is defined in arch/*/include/asm/pgtable.h
depending or not on some other per architecture static definition.

This patch introduce a new configuration variable to manage this directly
in the Kconfig files. It would later replace __HAVE_ARCH_PTE_SPECIAL.

Here notes for some architecture where the definition of
__HAVE_ARCH_PTE_SPECIAL is not obvious:

arm
 __HAVE_ARCH_PTE_SPECIAL which is currently defined in
arch/arm/include/asm/pgtable-3level.h which is included by
arch/arm/include/asm/pgtable.h when CONFIG_ARM_LPAE is set.
So select ARCH_HAS_PTE_SPECIAL if ARM_LPAE.

powerpc
__HAVE_ARCH_PTE_SPECIAL is defined in 2 files:
 - arch/powerpc/include/asm/book3s/64/pgtable.h
 - arch/powerpc/include/asm/pte-common.h
The first one is included if (PPC_BOOK3S & PPC64) while the second is
included in all the other cases.
So select ARCH_HAS_PTE_SPECIAL all the time.

sparc:
__HAVE_ARCH_PTE_SPECIAL is defined if defined(__sparc__) &&
defined(__arch64__) which are defined through the compiler in
sparc/Makefile if !SPARC32 which I assume to be if SPARC64.
So select ARCH_HAS_PTE_SPECIAL if SPARC64

There is no functional change introduced by this patch.

Suggested-by: Jerome Glisse <jglisse@redhat>
Reviewed-by: Jerome Glisse <jglisse@redhat>
Signed-off-by: Laurent Dufour <ldufour@linux.vnet.ibm.com>
---
 Documentation/features/vm/pte_special/arch-support.txt | 2 +-
 arch/arc/Kconfig                                       | 1 +
 arch/arc/include/asm/pgtable.h                         | 2 --
 arch/arm/Kconfig                                       | 1 +
 arch/arm/include/asm/pgtable-3level.h                  | 1 -
 arch/arm64/Kconfig                                     | 1 +
 arch/arm64/include/asm/pgtable.h                       | 2 --
 arch/powerpc/Kconfig                                   | 1 +
 arch/powerpc/include/asm/book3s/64/pgtable.h           | 3 ---
 arch/powerpc/include/asm/pte-common.h                  | 3 ---
 arch/riscv/Kconfig                                     | 1 +
 arch/s390/Kconfig                                      | 1 +
 arch/s390/include/asm/pgtable.h                        | 1 -
 arch/sh/Kconfig                                        | 1 +
 arch/sh/include/asm/pgtable.h                          | 2 --
 arch/sparc/Kconfig                                     | 1 +
 arch/sparc/include/asm/pgtable_64.h                    | 3 ---
 arch/x86/Kconfig                                       | 1 +
 arch/x86/include/asm/pgtable_types.h                   | 1 -
 include/linux/pfn_t.h                                  | 4 ++--
 mm/Kconfig                                             | 3 +++
 mm/gup.c                                               | 4 ++--
 mm/memory.c                                            | 2 +-
 23 files changed, 18 insertions(+), 24 deletions(-)

diff --git a/Documentation/features/vm/pte_special/arch-support.txt b/Documentation/features/vm/pte_special/arch-support.txt
index 055004f467d2..cd05924ea875 100644
--- a/Documentation/features/vm/pte_special/arch-support.txt
+++ b/Documentation/features/vm/pte_special/arch-support.txt
@@ -1,6 +1,6 @@
 #
 # Feature name:          pte_special
-#         Kconfig:       __HAVE_ARCH_PTE_SPECIAL
+#         Kconfig:       ARCH_HAS_PTE_SPECIAL
 #         description:   arch supports the pte_special()/pte_mkspecial() VM APIs
 #
     -----------------------
diff --git a/arch/arc/Kconfig b/arch/arc/Kconfig
index d76bf4a83740..8516e2b0239a 100644
--- a/arch/arc/Kconfig
+++ b/arch/arc/Kconfig
@@ -44,6 +44,7 @@ config ARC
 	select HAVE_GENERIC_DMA_COHERENT
 	select HAVE_KERNEL_GZIP
 	select HAVE_KERNEL_LZMA
+	select ARCH_HAS_PTE_SPECIAL
 
 config MIGHT_HAVE_PCI
 	bool
diff --git a/arch/arc/include/asm/pgtable.h b/arch/arc/include/asm/pgtable.h
index 08fe33830d4b..8ec5599a0957 100644
--- a/arch/arc/include/asm/pgtable.h
+++ b/arch/arc/include/asm/pgtable.h
@@ -320,8 +320,6 @@ PTE_BIT_FUNC(mkexec,	|= (_PAGE_EXECUTE));
 PTE_BIT_FUNC(mkspecial,	|= (_PAGE_SPECIAL));
 PTE_BIT_FUNC(mkhuge,	|= (_PAGE_HW_SZ));
 
-#define __HAVE_ARCH_PTE_SPECIAL
-
 static inline pte_t pte_modify(pte_t pte, pgprot_t newprot)
 {
 	return __pte((pte_val(pte) & _PAGE_CHG_MASK) | pgprot_val(newprot));
diff --git a/arch/arm/Kconfig b/arch/arm/Kconfig
index a7f8e7f4b88f..c088c851b235 100644
--- a/arch/arm/Kconfig
+++ b/arch/arm/Kconfig
@@ -8,6 +8,7 @@ config ARM
 	select ARCH_HAS_DEVMEM_IS_ALLOWED
 	select ARCH_HAS_ELF_RANDOMIZE
 	select ARCH_HAS_FORTIFY_SOURCE
+	select ARCH_HAS_PTE_SPECIAL if ARM_LPAE
 	select ARCH_HAS_SET_MEMORY
 	select ARCH_HAS_PHYS_TO_DMA
 	select ARCH_HAS_STRICT_KERNEL_RWX if MMU && !XIP_KERNEL
diff --git a/arch/arm/include/asm/pgtable-3level.h b/arch/arm/include/asm/pgtable-3level.h
index 2a4836087358..6d50a11d7793 100644
--- a/arch/arm/include/asm/pgtable-3level.h
+++ b/arch/arm/include/asm/pgtable-3level.h
@@ -219,7 +219,6 @@ static inline pte_t pte_mkspecial(pte_t pte)
 	pte_val(pte) |= L_PTE_SPECIAL;
 	return pte;
 }
-#define	__HAVE_ARCH_PTE_SPECIAL
 
 #define pmd_write(pmd)		(pmd_isclear((pmd), L_PMD_SECT_RDONLY))
 #define pmd_dirty(pmd)		(pmd_isset((pmd), L_PMD_SECT_DIRTY))
diff --git a/arch/arm64/Kconfig b/arch/arm64/Kconfig
index eb2cf4938f6d..9a3f1b1ab50c 100644
--- a/arch/arm64/Kconfig
+++ b/arch/arm64/Kconfig
@@ -17,6 +17,7 @@ config ARM64
 	select ARCH_HAS_GIGANTIC_PAGE if (MEMORY_ISOLATION && COMPACTION) || CMA
 	select ARCH_HAS_KCOV
 	select ARCH_HAS_MEMBARRIER_SYNC_CORE
+	select ARCH_HAS_PTE_SPECIAL
 	select ARCH_HAS_SET_MEMORY
 	select ARCH_HAS_SG_CHAIN
 	select ARCH_HAS_STRICT_KERNEL_RWX
diff --git a/arch/arm64/include/asm/pgtable.h b/arch/arm64/include/asm/pgtable.h
index 7e2c27e63cd8..b96c8a186908 100644
--- a/arch/arm64/include/asm/pgtable.h
+++ b/arch/arm64/include/asm/pgtable.h
@@ -306,8 +306,6 @@ static inline int pte_same(pte_t pte_a, pte_t pte_b)
 #define HPAGE_MASK		(~(HPAGE_SIZE - 1))
 #define HUGETLB_PAGE_ORDER	(HPAGE_SHIFT - PAGE_SHIFT)
 
-#define __HAVE_ARCH_PTE_SPECIAL
-
 static inline pte_t pgd_pte(pgd_t pgd)
 {
 	return __pte(pgd_val(pgd));
diff --git a/arch/powerpc/Kconfig b/arch/powerpc/Kconfig
index c32a181a7cbb..f7415fe25c07 100644
--- a/arch/powerpc/Kconfig
+++ b/arch/powerpc/Kconfig
@@ -141,6 +141,7 @@ config PPC
 	select ARCH_HAS_GCOV_PROFILE_ALL
 	select ARCH_HAS_PHYS_TO_DMA
 	select ARCH_HAS_PMEM_API                if PPC64
+	select ARCH_HAS_PTE_SPECIAL
 	select ARCH_HAS_MEMBARRIER_CALLBACKS
 	select ARCH_HAS_SCALED_CPUTIME		if VIRT_CPU_ACCOUNTING_NATIVE
 	select ARCH_HAS_SG_CHAIN
diff --git a/arch/powerpc/include/asm/book3s/64/pgtable.h b/arch/powerpc/include/asm/book3s/64/pgtable.h
index 47b5ffc8715d..b3ac8948b257 100644
--- a/arch/powerpc/include/asm/book3s/64/pgtable.h
+++ b/arch/powerpc/include/asm/book3s/64/pgtable.h
@@ -319,9 +319,6 @@ extern unsigned long pci_io_base;
 /* Advertise special mapping type for AGP */
 #define HAVE_PAGE_AGP
 
-/* Advertise support for _PAGE_SPECIAL */
-#define __HAVE_ARCH_PTE_SPECIAL
-
 #ifndef __ASSEMBLY__
 
 /*
diff --git a/arch/powerpc/include/asm/pte-common.h b/arch/powerpc/include/asm/pte-common.h
index c4a72c7a8c83..03dfddb1f49a 100644
--- a/arch/powerpc/include/asm/pte-common.h
+++ b/arch/powerpc/include/asm/pte-common.h
@@ -216,9 +216,6 @@ static inline bool pte_user(pte_t pte)
 #define PAGE_AGP		(PAGE_KERNEL_NC)
 #define HAVE_PAGE_AGP
 
-/* Advertise support for _PAGE_SPECIAL */
-#define __HAVE_ARCH_PTE_SPECIAL
-
 #ifndef _PAGE_READ
 /* if not defined, we should not find _PAGE_WRITE too */
 #define _PAGE_READ 0
diff --git a/arch/riscv/Kconfig b/arch/riscv/Kconfig
index 5287c1441d66..b01c183836e5 100644
--- a/arch/riscv/Kconfig
+++ b/arch/riscv/Kconfig
@@ -34,6 +34,7 @@ config RISCV
 	select THREAD_INFO_IN_TASK
 	select RISCV_TIMER
 	select GENERIC_IRQ_MULTI_HANDLER
+	select ARCH_HAS_PTE_SPECIAL
 
 config MMU
 	def_bool y
diff --git a/arch/s390/Kconfig b/arch/s390/Kconfig
index 32a0d5b958bf..5f1f4997e7e9 100644
--- a/arch/s390/Kconfig
+++ b/arch/s390/Kconfig
@@ -72,6 +72,7 @@ config S390
 	select ARCH_HAS_GCOV_PROFILE_ALL
 	select ARCH_HAS_GIGANTIC_PAGE if (MEMORY_ISOLATION && COMPACTION) || CMA
 	select ARCH_HAS_KCOV
+	select ARCH_HAS_PTE_SPECIAL
 	select ARCH_HAS_SET_MEMORY
 	select ARCH_HAS_SG_CHAIN
 	select ARCH_HAS_STRICT_KERNEL_RWX
diff --git a/arch/s390/include/asm/pgtable.h b/arch/s390/include/asm/pgtable.h
index 2d24d33bf188..9809694e1389 100644
--- a/arch/s390/include/asm/pgtable.h
+++ b/arch/s390/include/asm/pgtable.h
@@ -171,7 +171,6 @@ static inline int is_module_addr(void *addr)
 #define _PAGE_WRITE	0x020		/* SW pte write bit */
 #define _PAGE_SPECIAL	0x040		/* SW associated with special page */
 #define _PAGE_UNUSED	0x080		/* SW bit for pgste usage state */
-#define __HAVE_ARCH_PTE_SPECIAL
 
 #ifdef CONFIG_MEM_SOFT_DIRTY
 #define _PAGE_SOFT_DIRTY 0x002		/* SW pte soft dirty bit */
diff --git a/arch/sh/Kconfig b/arch/sh/Kconfig
index 97fe29316476..a6c75b6806d2 100644
--- a/arch/sh/Kconfig
+++ b/arch/sh/Kconfig
@@ -50,6 +50,7 @@ config SUPERH
 	select HAVE_ARCH_AUDITSYSCALL
 	select HAVE_FUTEX_CMPXCHG if FUTEX
 	select HAVE_NMI
+	select ARCH_HAS_PTE_SPECIAL
 	help
 	  The SuperH is a RISC processor targeted for use in embedded systems
 	  and consumer electronics; it was also used in the Sega Dreamcast
diff --git a/arch/sh/include/asm/pgtable.h b/arch/sh/include/asm/pgtable.h
index 89c513a982fc..f6abfe2bca93 100644
--- a/arch/sh/include/asm/pgtable.h
+++ b/arch/sh/include/asm/pgtable.h
@@ -156,8 +156,6 @@ extern void page_table_range_init(unsigned long start, unsigned long end,
 #define HAVE_ARCH_UNMAPPED_AREA
 #define HAVE_ARCH_UNMAPPED_AREA_TOPDOWN
 
-#define __HAVE_ARCH_PTE_SPECIAL
-
 #include <asm-generic/pgtable.h>
 
 #endif /* __ASM_SH_PGTABLE_H */
diff --git a/arch/sparc/Kconfig b/arch/sparc/Kconfig
index 8767e45f1b2b..6b5a4f05dcb2 100644
--- a/arch/sparc/Kconfig
+++ b/arch/sparc/Kconfig
@@ -86,6 +86,7 @@ config SPARC64
 	select ARCH_USE_QUEUED_SPINLOCKS
 	select GENERIC_TIME_VSYSCALL
 	select ARCH_CLOCKSOURCE_DATA
+	select ARCH_HAS_PTE_SPECIAL
 
 config ARCH_DEFCONFIG
 	string
diff --git a/arch/sparc/include/asm/pgtable_64.h b/arch/sparc/include/asm/pgtable_64.h
index 44d6ac47e035..1393a8ac596b 100644
--- a/arch/sparc/include/asm/pgtable_64.h
+++ b/arch/sparc/include/asm/pgtable_64.h
@@ -117,9 +117,6 @@ bool kern_addr_valid(unsigned long addr);
 #define _PAGE_PMD_HUGE    _AC(0x0100000000000000,UL) /* Huge page            */
 #define _PAGE_PUD_HUGE    _PAGE_PMD_HUGE
 
-/* Advertise support for _PAGE_SPECIAL */
-#define __HAVE_ARCH_PTE_SPECIAL
-
 /* SUN4U pte bits... */
 #define _PAGE_SZ4MB_4U	  _AC(0x6000000000000000,UL) /* 4MB Page             */
 #define _PAGE_SZ512K_4U	  _AC(0x4000000000000000,UL) /* 512K Page            */
diff --git a/arch/x86/Kconfig b/arch/x86/Kconfig
index bf4ddea48e61..3f5fb25486bf 100644
--- a/arch/x86/Kconfig
+++ b/arch/x86/Kconfig
@@ -56,6 +56,7 @@ config X86
 	select ARCH_HAS_KCOV			if X86_64
 	select ARCH_HAS_MEMBARRIER_SYNC_CORE
 	select ARCH_HAS_PMEM_API		if X86_64
+	select ARCH_HAS_PTE_SPECIAL
 	select ARCH_HAS_REFCOUNT
 	select ARCH_HAS_UACCESS_FLUSHCACHE	if X86_64
 	select ARCH_HAS_SET_MEMORY
diff --git a/arch/x86/include/asm/pgtable_types.h b/arch/x86/include/asm/pgtable_types.h
index acfe755562a6..3e195728d7d1 100644
--- a/arch/x86/include/asm/pgtable_types.h
+++ b/arch/x86/include/asm/pgtable_types.h
@@ -65,7 +65,6 @@
 #define _PAGE_PKEY_BIT2	(_AT(pteval_t, 0))
 #define _PAGE_PKEY_BIT3	(_AT(pteval_t, 0))
 #endif
-#define __HAVE_ARCH_PTE_SPECIAL
 
 #define _PAGE_PKEY_MASK (_PAGE_PKEY_BIT0 | \
 			 _PAGE_PKEY_BIT1 | \
diff --git a/include/linux/pfn_t.h b/include/linux/pfn_t.h
index a03c2642a87c..21713dc14ce2 100644
--- a/include/linux/pfn_t.h
+++ b/include/linux/pfn_t.h
@@ -122,7 +122,7 @@ pud_t pud_mkdevmap(pud_t pud);
 #endif
 #endif /* __HAVE_ARCH_PTE_DEVMAP */
 
-#ifdef __HAVE_ARCH_PTE_SPECIAL
+#ifdef CONFIG_ARCH_HAS_PTE_SPECIAL
 static inline bool pfn_t_special(pfn_t pfn)
 {
 	return (pfn.val & PFN_SPECIAL) == PFN_SPECIAL;
@@ -132,5 +132,5 @@ static inline bool pfn_t_special(pfn_t pfn)
 {
 	return false;
 }
-#endif /* __HAVE_ARCH_PTE_SPECIAL */
+#endif /* CONFIG_ARCH_HAS_PTE_SPECIAL */
 #endif /* _LINUX_PFN_T_H_ */
diff --git a/mm/Kconfig b/mm/Kconfig
index d5004d82a1d6..1ea3e4a6a123 100644
--- a/mm/Kconfig
+++ b/mm/Kconfig
@@ -752,3 +752,6 @@ config GUP_BENCHMARK
 	  performance of get_user_pages_fast().
 
 	  See tools/testing/selftests/vm/gup_benchmark.c
+
+config ARCH_HAS_PTE_SPECIAL
+	bool
diff --git a/mm/gup.c b/mm/gup.c
index f296df6cf666..b044a3d14dc5 100644
--- a/mm/gup.c
+++ b/mm/gup.c
@@ -1351,7 +1351,7 @@ static void undo_dev_pagemap(int *nr, int nr_start, struct page **pages)
 	}
 }
 
-#ifdef __HAVE_ARCH_PTE_SPECIAL
+#ifdef CONFIG_ARCH_HAS_PTE_SPECIAL
 static int gup_pte_range(pmd_t pmd, unsigned long addr, unsigned long end,
 			 int write, struct page **pages, int *nr)
 {
@@ -1427,7 +1427,7 @@ static int gup_pte_range(pmd_t pmd, unsigned long addr, unsigned long end,
 {
 	return 0;
 }
-#endif /* __HAVE_ARCH_PTE_SPECIAL */
+#endif /* CONFIG_ARCH_HAS_PTE_SPECIAL */
 
 #if defined(__HAVE_ARCH_PTE_DEVMAP) && defined(CONFIG_TRANSPARENT_HUGEPAGE)
 static int __gup_device_huge(unsigned long pfn, unsigned long addr,
diff --git a/mm/memory.c b/mm/memory.c
index a1f990e33e38..96910c625daa 100644
--- a/mm/memory.c
+++ b/mm/memory.c
@@ -817,7 +817,7 @@ static void print_bad_pte(struct vm_area_struct *vma, unsigned long addr,
  * PFNMAP mappings in order to support COWable mappings.
  *
  */
-#ifdef __HAVE_ARCH_PTE_SPECIAL
+#ifdef CONFIG_ARCH_HAS_PTE_SPECIAL
 # define HAVE_PTE_SPECIAL 1
 #else
 # define HAVE_PTE_SPECIAL 0
-- 
2.7.4

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[PATCH v2 1/2] mm: introduce ARCH_HAS_PTE_SPECIAL

[Laurent Dufour]

Currently the PTE special supports is turned on in per architecture header
files. Most of the time, it is defined in arch/*/include/asm/pgtable.h
depending or not on some other per architecture static definition.

This patch introduce a new configuration variable to manage this directly
in the Kconfig files. It would later replace __HAVE_ARCH_PTE_SPECIAL.

Here notes for some architecture where the definition of
__HAVE_ARCH_PTE_SPECIAL is not obvious:

arm
 __HAVE_ARCH_PTE_SPECIAL which is currently defined in
arch/arm/include/asm/pgtable-3level.h which is included by
arch/arm/include/asm/pgtable.h when CONFIG_ARM_LPAE is set.
So select ARCH_HAS_PTE_SPECIAL if ARM_LPAE.

powerpc
__HAVE_ARCH_PTE_SPECIAL is defined in 2 files:
 - arch/powerpc/include/asm/book3s/64/pgtable.h
 - arch/powerpc/include/asm/pte-common.h
The first one is included if (PPC_BOOK3S & PPC64) while the second is
included in all the other cases.
So select ARCH_HAS_PTE_SPECIAL all the time.

sparc:
__HAVE_ARCH_PTE_SPECIAL is defined if defined(__sparc__) &&
defined(__arch64__) which are defined through the compiler in
sparc/Makefile if !SPARC32 which I assume to be if SPARC64.
So select ARCH_HAS_PTE_SPECIAL if SPARC64

There is no functional change introduced by this patch.

Suggested-by: Jerome Glisse <jglisse@redhat>
Reviewed-by: Jerome Glisse <jglisse@redhat>
Signed-off-by: Laurent Dufour <ldufour@linux.vnet.ibm.com>
---
 Documentation/features/vm/pte_special/arch-support.txt | 2 +-
 arch/arc/Kconfig                                       | 1 +
 arch/arc/include/asm/pgtable.h                         | 2 --
 arch/arm/Kconfig                                       | 1 +
 arch/arm/include/asm/pgtable-3level.h                  | 1 -
 arch/arm64/Kconfig                                     | 1 +
 arch/arm64/include/asm/pgtable.h                       | 2 --
 arch/powerpc/Kconfig                                   | 1 +
 arch/powerpc/include/asm/book3s/64/pgtable.h           | 3 ---
 arch/powerpc/include/asm/pte-common.h                  | 3 ---
 arch/riscv/Kconfig                                     | 1 +
 arch/s390/Kconfig                                      | 1 +
 arch/s390/include/asm/pgtable.h                        | 1 -
 arch/sh/Kconfig                                        | 1 +
 arch/sh/include/asm/pgtable.h                          | 2 --
 arch/sparc/Kconfig                                     | 1 +
 arch/sparc/include/asm/pgtable_64.h                    | 3 ---
 arch/x86/Kconfig                                       | 1 +
 arch/x86/include/asm/pgtable_types.h                   | 1 -
 include/linux/pfn_t.h                                  | 4 ++--
 mm/Kconfig                                             | 3 +++
 mm/gup.c                                               | 4 ++--
 mm/memory.c                                            | 2 +-
 23 files changed, 18 insertions(+), 24 deletions(-)

diff --git a/Documentation/features/vm/pte_special/arch-support.txt b/Documentation/features/vm/pte_special/arch-support.txt
index 055004f467d2..cd05924ea875 100644
--- a/Documentation/features/vm/pte_special/arch-support.txt
+++ b/Documentation/features/vm/pte_special/arch-support.txt
@@ -1,6 +1,6 @@
 #
 # Feature name:          pte_special
-#         Kconfig:       __HAVE_ARCH_PTE_SPECIAL
+#         Kconfig:       ARCH_HAS_PTE_SPECIAL
 #         description:   arch supports the pte_special()/pte_mkspecial() VM APIs
 #
     -----------------------
diff --git a/arch/arc/Kconfig b/arch/arc/Kconfig
index d76bf4a83740..8516e2b0239a 100644
--- a/arch/arc/Kconfig
+++ b/arch/arc/Kconfig
@@ -44,6 +44,7 @@ config ARC
 	select HAVE_GENERIC_DMA_COHERENT
 	select HAVE_KERNEL_GZIP
 	select HAVE_KERNEL_LZMA
+	select ARCH_HAS_PTE_SPECIAL
 
 config MIGHT_HAVE_PCI
 	bool
diff --git a/arch/arc/include/asm/pgtable.h b/arch/arc/include/asm/pgtable.h
index 08fe33830d4b..8ec5599a0957 100644
--- a/arch/arc/include/asm/pgtable.h
+++ b/arch/arc/include/asm/pgtable.h
@@ -320,8 +320,6 @@ PTE_BIT_FUNC(mkexec,	|= (_PAGE_EXECUTE));
 PTE_BIT_FUNC(mkspecial,	|= (_PAGE_SPECIAL));
 PTE_BIT_FUNC(mkhuge,	|= (_PAGE_HW_SZ));
 
-#define __HAVE_ARCH_PTE_SPECIAL
-
 static inline pte_t pte_modify(pte_t pte, pgprot_t newprot)
 {
 	return __pte((pte_val(pte) & _PAGE_CHG_MASK) | pgprot_val(newprot));
diff --git a/arch/arm/Kconfig b/arch/arm/Kconfig
index a7f8e7f4b88f..c088c851b235 100644
--- a/arch/arm/Kconfig
+++ b/arch/arm/Kconfig
@@ -8,6 +8,7 @@ config ARM
 	select ARCH_HAS_DEVMEM_IS_ALLOWED
 	select ARCH_HAS_ELF_RANDOMIZE
 	select ARCH_HAS_FORTIFY_SOURCE
+	select ARCH_HAS_PTE_SPECIAL if ARM_LPAE
 	select ARCH_HAS_SET_MEMORY
 	select ARCH_HAS_PHYS_TO_DMA
 	select ARCH_HAS_STRICT_KERNEL_RWX if MMU && !XIP_KERNEL
diff --git a/arch/arm/include/asm/pgtable-3level.h b/arch/arm/include/asm/pgtable-3level.h
index 2a4836087358..6d50a11d7793 100644
--- a/arch/arm/include/asm/pgtable-3level.h
+++ b/arch/arm/include/asm/pgtable-3level.h
@@ -219,7 +219,6 @@ static inline pte_t pte_mkspecial(pte_t pte)
 	pte_val(pte) |= L_PTE_SPECIAL;
 	return pte;
 }
-#define	__HAVE_ARCH_PTE_SPECIAL
 
 #define pmd_write(pmd)		(pmd_isclear((pmd), L_PMD_SECT_RDONLY))
 #define pmd_dirty(pmd)		(pmd_isset((pmd), L_PMD_SECT_DIRTY))
diff --git a/arch/arm64/Kconfig b/arch/arm64/Kconfig
index eb2cf4938f6d..9a3f1b1ab50c 100644
--- a/arch/arm64/Kconfig
+++ b/arch/arm64/Kconfig
@@ -17,6 +17,7 @@ config ARM64
 	select ARCH_HAS_GIGANTIC_PAGE if (MEMORY_ISOLATION && COMPACTION) || CMA
 	select ARCH_HAS_KCOV
 	select ARCH_HAS_MEMBARRIER_SYNC_CORE
+	select ARCH_HAS_PTE_SPECIAL
 	select ARCH_HAS_SET_MEMORY
 	select ARCH_HAS_SG_CHAIN
 	select ARCH_HAS_STRICT_KERNEL_RWX
diff --git a/arch/arm64/include/asm/pgtable.h b/arch/arm64/include/asm/pgtable.h
index 7e2c27e63cd8..b96c8a186908 100644
--- a/arch/arm64/include/asm/pgtable.h
+++ b/arch/arm64/include/asm/pgtable.h
@@ -306,8 +306,6 @@ static inline int pte_same(pte_t pte_a, pte_t pte_b)
 #define HPAGE_MASK		(~(HPAGE_SIZE - 1))
 #define HUGETLB_PAGE_ORDER	(HPAGE_SHIFT - PAGE_SHIFT)
 
-#define __HAVE_ARCH_PTE_SPECIAL
-
 static inline pte_t pgd_pte(pgd_t pgd)
 {
 	return __pte(pgd_val(pgd));
diff --git a/arch/powerpc/Kconfig b/arch/powerpc/Kconfig
index c32a181a7cbb..f7415fe25c07 100644
--- a/arch/powerpc/Kconfig
+++ b/arch/powerpc/Kconfig
@@ -141,6 +141,7 @@ config PPC
 	select ARCH_HAS_GCOV_PROFILE_ALL
 	select ARCH_HAS_PHYS_TO_DMA
 	select ARCH_HAS_PMEM_API                if PPC64
+	select ARCH_HAS_PTE_SPECIAL
 	select ARCH_HAS_MEMBARRIER_CALLBACKS
 	select ARCH_HAS_SCALED_CPUTIME		if VIRT_CPU_ACCOUNTING_NATIVE
 	select ARCH_HAS_SG_CHAIN
diff --git a/arch/powerpc/include/asm/book3s/64/pgtable.h b/arch/powerpc/include/asm/book3s/64/pgtable.h
index 47b5ffc8715d..b3ac8948b257 100644
--- a/arch/powerpc/include/asm/book3s/64/pgtable.h
+++ b/arch/powerpc/include/asm/book3s/64/pgtable.h
@@ -319,9 +319,6 @@ extern unsigned long pci_io_base;
 /* Advertise special mapping type for AGP */
 #define HAVE_PAGE_AGP
 
-/* Advertise support for _PAGE_SPECIAL */
-#define __HAVE_ARCH_PTE_SPECIAL
-
 #ifndef __ASSEMBLY__
 
 /*
diff --git a/arch/powerpc/include/asm/pte-common.h b/arch/powerpc/include/asm/pte-common.h
index c4a72c7a8c83..03dfddb1f49a 100644
--- a/arch/powerpc/include/asm/pte-common.h
+++ b/arch/powerpc/include/asm/pte-common.h
@@ -216,9 +216,6 @@ static inline bool pte_user(pte_t pte)
 #define PAGE_AGP		(PAGE_KERNEL_NC)
 #define HAVE_PAGE_AGP
 
-/* Advertise support for _PAGE_SPECIAL */
-#define __HAVE_ARCH_PTE_SPECIAL
-
 #ifndef _PAGE_READ
 /* if not defined, we should not find _PAGE_WRITE too */
 #define _PAGE_READ 0
diff --git a/arch/riscv/Kconfig b/arch/riscv/Kconfig
index 5287c1441d66..b01c183836e5 100644
--- a/arch/riscv/Kconfig
+++ b/arch/riscv/Kconfig
@@ -34,6 +34,7 @@ config RISCV
 	select THREAD_INFO_IN_TASK
 	select RISCV_TIMER
 	select GENERIC_IRQ_MULTI_HANDLER
+	select ARCH_HAS_PTE_SPECIAL
 
 config MMU
 	def_bool y
diff --git a/arch/s390/Kconfig b/arch/s390/Kconfig
index 32a0d5b958bf..5f1f4997e7e9 100644
--- a/arch/s390/Kconfig
+++ b/arch/s390/Kconfig
@@ -72,6 +72,7 @@ config S390
 	select ARCH_HAS_GCOV_PROFILE_ALL
 	select ARCH_HAS_GIGANTIC_PAGE if (MEMORY_ISOLATION && COMPACTION) || CMA
 	select ARCH_HAS_KCOV
+	select ARCH_HAS_PTE_SPECIAL
 	select ARCH_HAS_SET_MEMORY
 	select ARCH_HAS_SG_CHAIN
 	select ARCH_HAS_STRICT_KERNEL_RWX
diff --git a/arch/s390/include/asm/pgtable.h b/arch/s390/include/asm/pgtable.h
index 2d24d33bf188..9809694e1389 100644
--- a/arch/s390/include/asm/pgtable.h
+++ b/arch/s390/include/asm/pgtable.h
@@ -171,7 +171,6 @@ static inline int is_module_addr(void *addr)
 #define _PAGE_WRITE	0x020		/* SW pte write bit */
 #define _PAGE_SPECIAL	0x040		/* SW associated with special page */
 #define _PAGE_UNUSED	0x080		/* SW bit for pgste usage state */
-#define __HAVE_ARCH_PTE_SPECIAL
 
 #ifdef CONFIG_MEM_SOFT_DIRTY
 #define _PAGE_SOFT_DIRTY 0x002		/* SW pte soft dirty bit */
diff --git a/arch/sh/Kconfig b/arch/sh/Kconfig
index 97fe29316476..a6c75b6806d2 100644
--- a/arch/sh/Kconfig
+++ b/arch/sh/Kconfig
@@ -50,6 +50,7 @@ config SUPERH
 	select HAVE_ARCH_AUDITSYSCALL
 	select HAVE_FUTEX_CMPXCHG if FUTEX
 	select HAVE_NMI
+	select ARCH_HAS_PTE_SPECIAL
 	help
 	  The SuperH is a RISC processor targeted for use in embedded systems
 	  and consumer electronics; it was also used in the Sega Dreamcast
diff --git a/arch/sh/include/asm/pgtable.h b/arch/sh/include/asm/pgtable.h
index 89c513a982fc..f6abfe2bca93 100644
--- a/arch/sh/include/asm/pgtable.h
+++ b/arch/sh/include/asm/pgtable.h
@@ -156,8 +156,6 @@ extern void page_table_range_init(unsigned long start, unsigned long end,
 #define HAVE_ARCH_UNMAPPED_AREA
 #define HAVE_ARCH_UNMAPPED_AREA_TOPDOWN
 
-#define __HAVE_ARCH_PTE_SPECIAL
-
 #include <asm-generic/pgtable.h>
 
 #endif /* __ASM_SH_PGTABLE_H */
diff --git a/arch/sparc/Kconfig b/arch/sparc/Kconfig
index 8767e45f1b2b..6b5a4f05dcb2 100644
--- a/arch/sparc/Kconfig
+++ b/arch/sparc/Kconfig
@@ -86,6 +86,7 @@ config SPARC64
 	select ARCH_USE_QUEUED_SPINLOCKS
 	select GENERIC_TIME_VSYSCALL
 	select ARCH_CLOCKSOURCE_DATA
+	select ARCH_HAS_PTE_SPECIAL
 
 config ARCH_DEFCONFIG
 	string
diff --git a/arch/sparc/include/asm/pgtable_64.h b/arch/sparc/include/asm/pgtable_64.h
index 44d6ac47e035..1393a8ac596b 100644
--- a/arch/sparc/include/asm/pgtable_64.h
+++ b/arch/sparc/include/asm/pgtable_64.h
@@ -117,9 +117,6 @@ bool kern_addr_valid(unsigned long addr);
 #define _PAGE_PMD_HUGE    _AC(0x0100000000000000,UL) /* Huge page            */
 #define _PAGE_PUD_HUGE    _PAGE_PMD_HUGE
 
-/* Advertise support for _PAGE_SPECIAL */
-#define __HAVE_ARCH_PTE_SPECIAL
-
 /* SUN4U pte bits... */
 #define _PAGE_SZ4MB_4U	  _AC(0x6000000000000000,UL) /* 4MB Page             */
 #define _PAGE_SZ512K_4U	  _AC(0x4000000000000000,UL) /* 512K Page            */
diff --git a/arch/x86/Kconfig b/arch/x86/Kconfig
index bf4ddea48e61..3f5fb25486bf 100644
--- a/arch/x86/Kconfig
+++ b/arch/x86/Kconfig
@@ -56,6 +56,7 @@ config X86
 	select ARCH_HAS_KCOV			if X86_64
 	select ARCH_HAS_MEMBARRIER_SYNC_CORE
 	select ARCH_HAS_PMEM_API		if X86_64
+	select ARCH_HAS_PTE_SPECIAL
 	select ARCH_HAS_REFCOUNT
 	select ARCH_HAS_UACCESS_FLUSHCACHE	if X86_64
 	select ARCH_HAS_SET_MEMORY
diff --git a/arch/x86/include/asm/pgtable_types.h b/arch/x86/include/asm/pgtable_types.h
index acfe755562a6..3e195728d7d1 100644
--- a/arch/x86/include/asm/pgtable_types.h
+++ b/arch/x86/include/asm/pgtable_types.h
@@ -65,7 +65,6 @@
 #define _PAGE_PKEY_BIT2	(_AT(pteval_t, 0))
 #define _PAGE_PKEY_BIT3	(_AT(pteval_t, 0))
 #endif
-#define __HAVE_ARCH_PTE_SPECIAL
 
 #define _PAGE_PKEY_MASK (_PAGE_PKEY_BIT0 | \
 			 _PAGE_PKEY_BIT1 | \
diff --git a/include/linux/pfn_t.h b/include/linux/pfn_t.h
index a03c2642a87c..21713dc14ce2 100644
--- a/include/linux/pfn_t.h
+++ b/include/linux/pfn_t.h
@@ -122,7 +122,7 @@ pud_t pud_mkdevmap(pud_t pud);
 #endif
 #endif /* __HAVE_ARCH_PTE_DEVMAP */
 
-#ifdef __HAVE_ARCH_PTE_SPECIAL
+#ifdef CONFIG_ARCH_HAS_PTE_SPECIAL
 static inline bool pfn_t_special(pfn_t pfn)
 {
 	return (pfn.val & PFN_SPECIAL) == PFN_SPECIAL;
@@ -132,5 +132,5 @@ static inline bool pfn_t_special(pfn_t pfn)
 {
 	return false;
 }
-#endif /* __HAVE_ARCH_PTE_SPECIAL */
+#endif /* CONFIG_ARCH_HAS_PTE_SPECIAL */
 #endif /* _LINUX_PFN_T_H_ */
diff --git a/mm/Kconfig b/mm/Kconfig
index d5004d82a1d6..1ea3e4a6a123 100644
--- a/mm/Kconfig
+++ b/mm/Kconfig
@@ -752,3 +752,6 @@ config GUP_BENCHMARK
 	  performance of get_user_pages_fast().
 
 	  See tools/testing/selftests/vm/gup_benchmark.c
+
+config ARCH_HAS_PTE_SPECIAL
+	bool
diff --git a/mm/gup.c b/mm/gup.c
index f296df6cf666..b044a3d14dc5 100644
--- a/mm/gup.c
+++ b/mm/gup.c
@@ -1351,7 +1351,7 @@ static void undo_dev_pagemap(int *nr, int nr_start, struct page **pages)
 	}
 }
 
-#ifdef __HAVE_ARCH_PTE_SPECIAL
+#ifdef CONFIG_ARCH_HAS_PTE_SPECIAL
 static int gup_pte_range(pmd_t pmd, unsigned long addr, unsigned long end,
 			 int write, struct page **pages, int *nr)
 {
@@ -1427,7 +1427,7 @@ static int gup_pte_range(pmd_t pmd, unsigned long addr, unsigned long end,
 {
 	return 0;
 }
-#endif /* __HAVE_ARCH_PTE_SPECIAL */
+#endif /* CONFIG_ARCH_HAS_PTE_SPECIAL */
 
 #if defined(__HAVE_ARCH_PTE_DEVMAP) && defined(CONFIG_TRANSPARENT_HUGEPAGE)
 static int __gup_device_huge(unsigned long pfn, unsigned long addr,
diff --git a/mm/memory.c b/mm/memory.c
index a1f990e33e38..96910c625daa 100644
--- a/mm/memory.c
+++ b/mm/memory.c
@@ -817,7 +817,7 @@ static void print_bad_pte(struct vm_area_struct *vma, unsigned long addr,
  * PFNMAP mappings in order to support COWable mappings.
  *
  */
-#ifdef __HAVE_ARCH_PTE_SPECIAL
+#ifdef CONFIG_ARCH_HAS_PTE_SPECIAL
 # define HAVE_PTE_SPECIAL 1
 #else
 # define HAVE_PTE_SPECIAL 0
-- 
2.7.4

Re: [PATCH v2 1/2] mm: introduce ARCH_HAS_PTE_SPECIAL

[Matthew Wilcox]

On Tue, Apr 10, 2018 at 05:25:50PM +0200, Laurent Dufour wrote:
>  arch/powerpc/include/asm/pte-common.h                  | 3 ---
>  arch/riscv/Kconfig                                     | 1 +
>  arch/s390/Kconfig                                      | 1 +

You forgot to delete __HAVE_ARCH_PTE_SPECIAL from
arch/riscv/include/asm/pgtable-bits.h

[PATCH v2 1/2] mm: introduce ARCH_HAS_PTE_SPECIAL

[Matthew Wilcox]

On Tue, Apr 10, 2018 at 05:25:50PM +0200, Laurent Dufour wrote:
>  arch/powerpc/include/asm/pte-common.h                  | 3 ---
>  arch/riscv/Kconfig                                     | 1 +
>  arch/s390/Kconfig                                      | 1 +

You forgot to delete __HAVE_ARCH_PTE_SPECIAL from
arch/riscv/include/asm/pgtable-bits.h

[PATCH v2 1/2] mm: introduce ARCH_HAS_PTE_SPECIAL

[Matthew Wilcox]

On Tue, Apr 10, 2018@05:25:50PM +0200, Laurent Dufour wrote:
>  arch/powerpc/include/asm/pte-common.h                  | 3 ---
>  arch/riscv/Kconfig                                     | 1 +
>  arch/s390/Kconfig                                      | 1 +

You forgot to delete __HAVE_ARCH_PTE_SPECIAL from
arch/riscv/include/asm/pgtable-bits.h

[PATCH v2 1/2] mm: introduce ARCH_HAS_PTE_SPECIAL

[Matthew Wilcox]

On Tue, Apr 10, 2018 at 05:25:50PM +0200, Laurent Dufour wrote:
>  arch/powerpc/include/asm/pte-common.h                  | 3 ---
>  arch/riscv/Kconfig                                     | 1 +
>  arch/s390/Kconfig                                      | 1 +

You forgot to delete __HAVE_ARCH_PTE_SPECIAL from
arch/riscv/include/asm/pgtable-bits.h

Re: [PATCH v2 1/2] mm: introduce ARCH_HAS_PTE_SPECIAL

[Matthew Wilcox]

On Tue, Apr 10, 2018 at 05:25:50PM +0200, Laurent Dufour wrote:
>  arch/powerpc/include/asm/pte-common.h                  | 3 ---
>  arch/riscv/Kconfig                                     | 1 +
>  arch/s390/Kconfig                                      | 1 +

You forgot to delete __HAVE_ARCH_PTE_SPECIAL from
arch/riscv/include/asm/pgtable-bits.h
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Re: [PATCH v2 1/2] mm: introduce ARCH_HAS_PTE_SPECIAL

[Matthew Wilcox]

On Tue, Apr 10, 2018 at 05:25:50PM +0200, Laurent Dufour wrote:
>  arch/powerpc/include/asm/pte-common.h                  | 3 ---
>  arch/riscv/Kconfig                                     | 1 +
>  arch/s390/Kconfig                                      | 1 +

You forgot to delete __HAVE_ARCH_PTE_SPECIAL from
arch/riscv/include/asm/pgtable-bits.h

Re: [PATCH v2 1/2] mm: introduce ARCH_HAS_PTE_SPECIAL

[Laurent Dufour]

On 10/04/2018 18:09, Matthew Wilcox wrote:
> On Tue, Apr 10, 2018 at 05:25:50PM +0200, Laurent Dufour wrote:
>>  arch/powerpc/include/asm/pte-common.h                  | 3 ---
>>  arch/riscv/Kconfig                                     | 1 +
>>  arch/s390/Kconfig                                      | 1 +
> 
> You forgot to delete __HAVE_ARCH_PTE_SPECIAL from
> arch/riscv/include/asm/pgtable-bits.h

Damned !
Thanks for catching it.

[PATCH v2 1/2] mm: introduce ARCH_HAS_PTE_SPECIAL

[Laurent Dufour]

On 10/04/2018 18:09, Matthew Wilcox wrote:
> On Tue, Apr 10, 2018 at 05:25:50PM +0200, Laurent Dufour wrote:
>>  arch/powerpc/include/asm/pte-common.h                  | 3 ---
>>  arch/riscv/Kconfig                                     | 1 +
>>  arch/s390/Kconfig                                      | 1 +
> 
> You forgot to delete __HAVE_ARCH_PTE_SPECIAL from
> arch/riscv/include/asm/pgtable-bits.h

Damned !
Thanks for catching it.

[PATCH v2 1/2] mm: introduce ARCH_HAS_PTE_SPECIAL

[Laurent Dufour]

On 10/04/2018 18:09, Matthew Wilcox wrote:
> On Tue, Apr 10, 2018@05:25:50PM +0200, Laurent Dufour wrote:
>>  arch/powerpc/include/asm/pte-common.h                  | 3 ---
>>  arch/riscv/Kconfig                                     | 1 +
>>  arch/s390/Kconfig                                      | 1 +
> 
> You forgot to delete __HAVE_ARCH_PTE_SPECIAL from
> arch/riscv/include/asm/pgtable-bits.h

Damned !
Thanks for catching it.

[PATCH v2 1/2] mm: introduce ARCH_HAS_PTE_SPECIAL

[Laurent Dufour]

On 10/04/2018 18:09, Matthew Wilcox wrote:
> On Tue, Apr 10, 2018 at 05:25:50PM +0200, Laurent Dufour wrote:
>>  arch/powerpc/include/asm/pte-common.h                  | 3 ---
>>  arch/riscv/Kconfig                                     | 1 +
>>  arch/s390/Kconfig                                      | 1 +
> 
> You forgot to delete __HAVE_ARCH_PTE_SPECIAL from
> arch/riscv/include/asm/pgtable-bits.h

Damned !
Thanks for catching it.

Re: [PATCH v2 1/2] mm: introduce ARCH_HAS_PTE_SPECIAL

[Laurent Dufour]

On 10/04/2018 18:09, Matthew Wilcox wrote:
> On Tue, Apr 10, 2018 at 05:25:50PM +0200, Laurent Dufour wrote:
>>  arch/powerpc/include/asm/pte-common.h                  | 3 ---
>>  arch/riscv/Kconfig                                     | 1 +
>>  arch/s390/Kconfig                                      | 1 +
> 
> You forgot to delete __HAVE_ARCH_PTE_SPECIAL from
> arch/riscv/include/asm/pgtable-bits.h

Damned !
Thanks for catching it.

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Re: [PATCH v2 1/2] mm: introduce ARCH_HAS_PTE_SPECIAL

[Laurent Dufour]

On 10/04/2018 18:09, Matthew Wilcox wrote:
> On Tue, Apr 10, 2018 at 05:25:50PM +0200, Laurent Dufour wrote:
>>  arch/powerpc/include/asm/pte-common.h                  | 3 ---
>>  arch/riscv/Kconfig                                     | 1 +
>>  arch/s390/Kconfig                                      | 1 +
> 
> You forgot to delete __HAVE_ARCH_PTE_SPECIAL from
> arch/riscv/include/asm/pgtable-bits.h

Damned !
Thanks for catching it.

Re: [PATCH v2 1/2] mm: introduce ARCH_HAS_PTE_SPECIAL

[David Rientjes]

On Tue, 10 Apr 2018, Laurent Dufour wrote:

> > On Tue, Apr 10, 2018 at 05:25:50PM +0200, Laurent Dufour wrote:
> >>  arch/powerpc/include/asm/pte-common.h                  | 3 ---
> >>  arch/riscv/Kconfig                                     | 1 +
> >>  arch/s390/Kconfig                                      | 1 +
> > 
> > You forgot to delete __HAVE_ARCH_PTE_SPECIAL from
> > arch/riscv/include/asm/pgtable-bits.h
> 
> Damned !
> Thanks for catching it.
> 

Squashing the two patches together at least allowed it to be caught 
easily.  After it's fixed, feel free to add

	Acked-by: David Rientjes <rientjes@google.com>

Thanks for doing this!

[PATCH v2 1/2] mm: introduce ARCH_HAS_PTE_SPECIAL

[David Rientjes]

On Tue, 10 Apr 2018, Laurent Dufour wrote:

> > On Tue, Apr 10, 2018 at 05:25:50PM +0200, Laurent Dufour wrote:
> >>  arch/powerpc/include/asm/pte-common.h                  | 3 ---
> >>  arch/riscv/Kconfig                                     | 1 +
> >>  arch/s390/Kconfig                                      | 1 +
> > 
> > You forgot to delete __HAVE_ARCH_PTE_SPECIAL from
> > arch/riscv/include/asm/pgtable-bits.h
> 
> Damned !
> Thanks for catching it.
> 

Squashing the two patches together at least allowed it to be caught 
easily.  After it's fixed, feel free to add

	Acked-by: David Rientjes <rientjes@google.com>

Thanks for doing this!

[PATCH v2 1/2] mm: introduce ARCH_HAS_PTE_SPECIAL

[David Rientjes]

On Tue, 10 Apr 2018, Laurent Dufour wrote:

> > On Tue, Apr 10, 2018@05:25:50PM +0200, Laurent Dufour wrote:
> >>  arch/powerpc/include/asm/pte-common.h                  | 3 ---
> >>  arch/riscv/Kconfig                                     | 1 +
> >>  arch/s390/Kconfig                                      | 1 +
> > 
> > You forgot to delete __HAVE_ARCH_PTE_SPECIAL from
> > arch/riscv/include/asm/pgtable-bits.h
> 
> Damned !
> Thanks for catching it.
> 

Squashing the two patches together at least allowed it to be caught 
easily.  After it's fixed, feel free to add

	Acked-by: David Rientjes <rientjes at google.com>

Thanks for doing this!

[PATCH v2 1/2] mm: introduce ARCH_HAS_PTE_SPECIAL

[David Rientjes]

On Tue, 10 Apr 2018, Laurent Dufour wrote:

> > On Tue, Apr 10, 2018 at 05:25:50PM +0200, Laurent Dufour wrote:
> >>  arch/powerpc/include/asm/pte-common.h                  | 3 ---
> >>  arch/riscv/Kconfig                                     | 1 +
> >>  arch/s390/Kconfig                                      | 1 +
> > 
> > You forgot to delete __HAVE_ARCH_PTE_SPECIAL from
> > arch/riscv/include/asm/pgtable-bits.h
> 
> Damned !
> Thanks for catching it.
> 

Squashing the two patches together at least allowed it to be caught 
easily.  After it's fixed, feel free to add

	Acked-by: David Rientjes <rientjes@google.com>

Thanks for doing this!

Re: [PATCH v2 1/2] mm: introduce ARCH_HAS_PTE_SPECIAL

[David Rientjes]

On Tue, 10 Apr 2018, Laurent Dufour wrote:

> > On Tue, Apr 10, 2018 at 05:25:50PM +0200, Laurent Dufour wrote:
> >>  arch/powerpc/include/asm/pte-common.h                  | 3 ---
> >>  arch/riscv/Kconfig                                     | 1 +
> >>  arch/s390/Kconfig                                      | 1 +
> > 
> > You forgot to delete __HAVE_ARCH_PTE_SPECIAL from
> > arch/riscv/include/asm/pgtable-bits.h
> 
> Damned !
> Thanks for catching it.
> 

Squashing the two patches together at least allowed it to be caught 
easily.  After it's fixed, feel free to add

	Acked-by: David Rientjes <rientjes@google.com>

Thanks for doing this!
--
To unsubscribe from this list: send the line "unsubscribe linux-doc" in
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Re: [PATCH v2 1/2] mm: introduce ARCH_HAS_PTE_SPECIAL

[David Rientjes]

On Tue, 10 Apr 2018, Laurent Dufour wrote:

> > On Tue, Apr 10, 2018 at 05:25:50PM +0200, Laurent Dufour wrote:
> >>  arch/powerpc/include/asm/pte-common.h                  | 3 ---
> >>  arch/riscv/Kconfig                                     | 1 +
> >>  arch/s390/Kconfig                                      | 1 +
> > 
> > You forgot to delete __HAVE_ARCH_PTE_SPECIAL from
> > arch/riscv/include/asm/pgtable-bits.h
> 
> Damned !
> Thanks for catching it.
> 

Squashing the two patches together at least allowed it to be caught 
easily.  After it's fixed, feel free to add

	Acked-by: David Rientjes <rientjes@google.com>

Thanks for doing this!

Re: [PATCH v2 1/2] mm: introduce ARCH_HAS_PTE_SPECIAL

[Palmer Dabbelt]

On Tue, 10 Apr 2018 09:09:32 PDT (-0700), willy@infradead.org wrote:
> On Tue, Apr 10, 2018 at 05:25:50PM +0200, Laurent Dufour wrote:
>>  arch/powerpc/include/asm/pte-common.h                  | 3 ---
>>  arch/riscv/Kconfig                                     | 1 +
>>  arch/s390/Kconfig                                      | 1 +
>
> You forgot to delete __HAVE_ARCH_PTE_SPECIAL from
> arch/riscv/include/asm/pgtable-bits.h

Thanks -- I was looking for that but couldn't find it and assumed I'd just 
misunderstood something.

[PATCH v2 1/2] mm: introduce ARCH_HAS_PTE_SPECIAL

[Palmer Dabbelt]

On Tue, 10 Apr 2018 09:09:32 PDT (-0700), willy at infradead.org wrote:
> On Tue, Apr 10, 2018 at 05:25:50PM +0200, Laurent Dufour wrote:
>>  arch/powerpc/include/asm/pte-common.h                  | 3 ---
>>  arch/riscv/Kconfig                                     | 1 +
>>  arch/s390/Kconfig                                      | 1 +
>
> You forgot to delete __HAVE_ARCH_PTE_SPECIAL from
> arch/riscv/include/asm/pgtable-bits.h

Thanks -- I was looking for that but couldn't find it and assumed I'd just 
misunderstood something.

[PATCH v2 1/2] mm: introduce ARCH_HAS_PTE_SPECIAL

[Palmer Dabbelt]

On Tue, 10 Apr 2018 09:09:32 PDT (-0700), willy@infradead.org wrote:
> On Tue, Apr 10, 2018@05:25:50PM +0200, Laurent Dufour wrote:
>>  arch/powerpc/include/asm/pte-common.h                  | 3 ---
>>  arch/riscv/Kconfig                                     | 1 +
>>  arch/s390/Kconfig                                      | 1 +
>
> You forgot to delete __HAVE_ARCH_PTE_SPECIAL from
> arch/riscv/include/asm/pgtable-bits.h

Thanks -- I was looking for that but couldn't find it and assumed I'd just 
misunderstood something.

[PATCH v2 1/2] mm: introduce ARCH_HAS_PTE_SPECIAL

[Palmer Dabbelt]

On Tue, 10 Apr 2018 09:09:32 PDT (-0700), willy at infradead.org wrote:
> On Tue, Apr 10, 2018 at 05:25:50PM +0200, Laurent Dufour wrote:
>>  arch/powerpc/include/asm/pte-common.h                  | 3 ---
>>  arch/riscv/Kconfig                                     | 1 +
>>  arch/s390/Kconfig                                      | 1 +
>
> You forgot to delete __HAVE_ARCH_PTE_SPECIAL from
> arch/riscv/include/asm/pgtable-bits.h

Thanks -- I was looking for that but couldn't find it and assumed I'd just 
misunderstood something.

Re: [PATCH v2 1/2] mm: introduce ARCH_HAS_PTE_SPECIAL

[Palmer Dabbelt]

On Tue, 10 Apr 2018 09:09:32 PDT (-0700), willy@infradead.org wrote:
> On Tue, Apr 10, 2018 at 05:25:50PM +0200, Laurent Dufour wrote:
>>  arch/powerpc/include/asm/pte-common.h                  | 3 ---
>>  arch/riscv/Kconfig                                     | 1 +
>>  arch/s390/Kconfig                                      | 1 +
>
> You forgot to delete __HAVE_ARCH_PTE_SPECIAL from
> arch/riscv/include/asm/pgtable-bits.h

Thanks -- I was looking for that but couldn't find it and assumed I'd just 
misunderstood something.
--
To unsubscribe from this list: send the line "unsubscribe linux-doc" in
the body of a message to majordomo@vger.kernel.org
More majordomo info at  http://vger.kernel.org/majordomo-info.html

Re: [PATCH v2 1/2] mm: introduce ARCH_HAS_PTE_SPECIAL

[Palmer Dabbelt]

On Tue, 10 Apr 2018 09:09:32 PDT (-0700), willy@infradead.org wrote:
> On Tue, Apr 10, 2018 at 05:25:50PM +0200, Laurent Dufour wrote:
>>  arch/powerpc/include/asm/pte-common.h                  | 3 ---
>>  arch/riscv/Kconfig                                     | 1 +
>>  arch/s390/Kconfig                                      | 1 +
>
> You forgot to delete __HAVE_ARCH_PTE_SPECIAL from
> arch/riscv/include/asm/pgtable-bits.h

Thanks -- I was looking for that but couldn't find it and assumed I'd just 
misunderstood something.

[PATCH v2 2/2] mm: remove odd HAVE_PTE_SPECIAL

[Laurent Dufour]

Remove the additional define HAVE_PTE_SPECIAL and rely directly on
CONFIG_ARCH_HAS_PTE_SPECIAL.

There is no functional change introduced by this patch

Signed-off-by: Laurent Dufour <ldufour@linux.vnet.ibm.com>
---
 mm/memory.c | 23 ++++++++++-------------
 1 file changed, 10 insertions(+), 13 deletions(-)

diff --git a/mm/memory.c b/mm/memory.c
index 96910c625daa..53b6344a90d2 100644
--- a/mm/memory.c
+++ b/mm/memory.c
@@ -817,19 +817,13 @@ static void print_bad_pte(struct vm_area_struct *vma, unsigned long addr,
  * PFNMAP mappings in order to support COWable mappings.
  *
  */
-#ifdef CONFIG_ARCH_HAS_PTE_SPECIAL
-# define HAVE_PTE_SPECIAL 1
-#else
-# define HAVE_PTE_SPECIAL 0
-#endif
 struct page *_vm_normal_page(struct vm_area_struct *vma, unsigned long addr,
 			     pte_t pte, bool with_public_device)
 {
 	unsigned long pfn = pte_pfn(pte);
 
-	if (HAVE_PTE_SPECIAL) {
-		if (likely(!pte_special(pte)))
-			goto check_pfn;
+#ifdef CONFIG_ARCH_HAS_PTE_SPECIAL
+	if (unlikely(pte_special(pte))) {
 		if (vma->vm_ops && vma->vm_ops->find_special_page)
 			return vma->vm_ops->find_special_page(vma, addr);
 		if (vma->vm_flags & (VM_PFNMAP | VM_MIXEDMAP))
@@ -862,7 +856,7 @@ struct page *_vm_normal_page(struct vm_area_struct *vma, unsigned long addr,
 		return NULL;
 	}
 
-	/* !HAVE_PTE_SPECIAL case follows: */
+#else	/* CONFIG_ARCH_HAS_PTE_SPECIAL */
 
 	if (unlikely(vma->vm_flags & (VM_PFNMAP|VM_MIXEDMAP))) {
 		if (vma->vm_flags & VM_MIXEDMAP) {
@@ -881,7 +875,8 @@ struct page *_vm_normal_page(struct vm_area_struct *vma, unsigned long addr,
 
 	if (is_zero_pfn(pfn))
 		return NULL;
-check_pfn:
+#endif /* CONFIG_ARCH_HAS_PTE_SPECIAL */
+
 	if (unlikely(pfn > highest_memmap_pfn)) {
 		print_bad_pte(vma, addr, pte, NULL);
 		return NULL;
@@ -891,7 +886,7 @@ struct page *_vm_normal_page(struct vm_area_struct *vma, unsigned long addr,
 	 * NOTE! We still have PageReserved() pages in the page tables.
 	 * eg. VDSO mappings can cause them to exist.
 	 */
-out:
+out: __maybe_unused
 	return pfn_to_page(pfn);
 }
 
@@ -904,7 +899,7 @@ struct page *vm_normal_page_pmd(struct vm_area_struct *vma, unsigned long addr,
 	/*
 	 * There is no pmd_special() but there may be special pmds, e.g.
 	 * in a direct-access (dax) mapping, so let's just replicate the
-	 * !HAVE_PTE_SPECIAL case from vm_normal_page() here.
+	 * !CONFIG_ARCH_HAS_PTE_SPECIAL case from vm_normal_page() here.
 	 */
 	if (unlikely(vma->vm_flags & (VM_PFNMAP|VM_MIXEDMAP))) {
 		if (vma->vm_flags & VM_MIXEDMAP) {
@@ -1926,6 +1921,7 @@ static int __vm_insert_mixed(struct vm_area_struct *vma, unsigned long addr,
 
 	track_pfn_insert(vma, &pgprot, pfn);
 
+#ifndef CONFIG_ARCH_HAS_PTE_SPECIAL
 	/*
 	 * If we don't have pte special, then we have to use the pfn_valid()
 	 * based VM_MIXEDMAP scheme (see vm_normal_page), and thus we *must*
@@ -1933,7 +1929,7 @@ static int __vm_insert_mixed(struct vm_area_struct *vma, unsigned long addr,
 	 * than insert_pfn).  If a zero_pfn were inserted into a VM_MIXEDMAP
 	 * without pte special, it would there be refcounted as a normal page.
 	 */
-	if (!HAVE_PTE_SPECIAL && !pfn_t_devmap(pfn) && pfn_t_valid(pfn)) {
+	if (!pfn_t_devmap(pfn) && pfn_t_valid(pfn)) {
 		struct page *page;
 
 		/*
@@ -1944,6 +1940,7 @@ static int __vm_insert_mixed(struct vm_area_struct *vma, unsigned long addr,
 		page = pfn_to_page(pfn_t_to_pfn(pfn));
 		return insert_page(vma, addr, page, pgprot);
 	}
+#endif
 	return insert_pfn(vma, addr, pfn, pgprot, mkwrite);
 }
 
-- 
2.7.4

[PATCH v2 2/2] mm: remove odd HAVE_PTE_SPECIAL

[Laurent Dufour]

Remove the additional define HAVE_PTE_SPECIAL and rely directly on
CONFIG_ARCH_HAS_PTE_SPECIAL.

There is no functional change introduced by this patch

Signed-off-by: Laurent Dufour <ldufour@linux.vnet.ibm.com>
---
 mm/memory.c | 23 ++++++++++-------------
 1 file changed, 10 insertions(+), 13 deletions(-)

diff --git a/mm/memory.c b/mm/memory.c
index 96910c625daa..53b6344a90d2 100644
--- a/mm/memory.c
+++ b/mm/memory.c
@@ -817,19 +817,13 @@ static void print_bad_pte(struct vm_area_struct *vma, unsigned long addr,
  * PFNMAP mappings in order to support COWable mappings.
  *
  */
-#ifdef CONFIG_ARCH_HAS_PTE_SPECIAL
-# define HAVE_PTE_SPECIAL 1
-#else
-# define HAVE_PTE_SPECIAL 0
-#endif
 struct page *_vm_normal_page(struct vm_area_struct *vma, unsigned long addr,
 			     pte_t pte, bool with_public_device)
 {
 	unsigned long pfn = pte_pfn(pte);
 
-	if (HAVE_PTE_SPECIAL) {
-		if (likely(!pte_special(pte)))
-			goto check_pfn;
+#ifdef CONFIG_ARCH_HAS_PTE_SPECIAL
+	if (unlikely(pte_special(pte))) {
 		if (vma->vm_ops && vma->vm_ops->find_special_page)
 			return vma->vm_ops->find_special_page(vma, addr);
 		if (vma->vm_flags & (VM_PFNMAP | VM_MIXEDMAP))
@@ -862,7 +856,7 @@ struct page *_vm_normal_page(struct vm_area_struct *vma, unsigned long addr,
 		return NULL;
 	}
 
-	/* !HAVE_PTE_SPECIAL case follows: */
+#else	/* CONFIG_ARCH_HAS_PTE_SPECIAL */
 
 	if (unlikely(vma->vm_flags & (VM_PFNMAP|VM_MIXEDMAP))) {
 		if (vma->vm_flags & VM_MIXEDMAP) {
@@ -881,7 +875,8 @@ struct page *_vm_normal_page(struct vm_area_struct *vma, unsigned long addr,
 
 	if (is_zero_pfn(pfn))
 		return NULL;
-check_pfn:
+#endif /* CONFIG_ARCH_HAS_PTE_SPECIAL */
+
 	if (unlikely(pfn > highest_memmap_pfn)) {
 		print_bad_pte(vma, addr, pte, NULL);
 		return NULL;
@@ -891,7 +886,7 @@ struct page *_vm_normal_page(struct vm_area_struct *vma, unsigned long addr,
 	 * NOTE! We still have PageReserved() pages in the page tables.
 	 * eg. VDSO mappings can cause them to exist.
 	 */
-out:
+out: __maybe_unused
 	return pfn_to_page(pfn);
 }
 
@@ -904,7 +899,7 @@ struct page *vm_normal_page_pmd(struct vm_area_struct *vma, unsigned long addr,
 	/*
 	 * There is no pmd_special() but there may be special pmds, e.g.
 	 * in a direct-access (dax) mapping, so let's just replicate the
-	 * !HAVE_PTE_SPECIAL case from vm_normal_page() here.
+	 * !CONFIG_ARCH_HAS_PTE_SPECIAL case from vm_normal_page() here.
 	 */
 	if (unlikely(vma->vm_flags & (VM_PFNMAP|VM_MIXEDMAP))) {
 		if (vma->vm_flags & VM_MIXEDMAP) {
@@ -1926,6 +1921,7 @@ static int __vm_insert_mixed(struct vm_area_struct *vma, unsigned long addr,
 
 	track_pfn_insert(vma, &pgprot, pfn);
 
+#ifndef CONFIG_ARCH_HAS_PTE_SPECIAL
 	/*
 	 * If we don't have pte special, then we have to use the pfn_valid()
 	 * based VM_MIXEDMAP scheme (see vm_normal_page), and thus we *must*
@@ -1933,7 +1929,7 @@ static int __vm_insert_mixed(struct vm_area_struct *vma, unsigned long addr,
 	 * than insert_pfn).  If a zero_pfn were inserted into a VM_MIXEDMAP
 	 * without pte special, it would there be refcounted as a normal page.
 	 */
-	if (!HAVE_PTE_SPECIAL && !pfn_t_devmap(pfn) && pfn_t_valid(pfn)) {
+	if (!pfn_t_devmap(pfn) && pfn_t_valid(pfn)) {
 		struct page *page;
 
 		/*
@@ -1944,6 +1940,7 @@ static int __vm_insert_mixed(struct vm_area_struct *vma, unsigned long addr,
 		page = pfn_to_page(pfn_t_to_pfn(pfn));
 		return insert_page(vma, addr, page, pgprot);
 	}
+#endif
 	return insert_pfn(vma, addr, pfn, pgprot, mkwrite);
 }
 
-- 
2.7.4

[PATCH v2 2/2] mm: remove odd HAVE_PTE_SPECIAL

[Laurent Dufour]

Remove the additional define HAVE_PTE_SPECIAL and rely directly on
CONFIG_ARCH_HAS_PTE_SPECIAL.

There is no functional change introduced by this patch

Signed-off-by: Laurent Dufour <ldufour at linux.vnet.ibm.com>
---
 mm/memory.c | 23 ++++++++++-------------
 1 file changed, 10 insertions(+), 13 deletions(-)

diff --git a/mm/memory.c b/mm/memory.c
index 96910c625daa..53b6344a90d2 100644
--- a/mm/memory.c
+++ b/mm/memory.c
@@ -817,19 +817,13 @@ static void print_bad_pte(struct vm_area_struct *vma, unsigned long addr,
  * PFNMAP mappings in order to support COWable mappings.
  *
  */
-#ifdef CONFIG_ARCH_HAS_PTE_SPECIAL
-# define HAVE_PTE_SPECIAL 1
-#else
-# define HAVE_PTE_SPECIAL 0
-#endif
 struct page *_vm_normal_page(struct vm_area_struct *vma, unsigned long addr,
 			     pte_t pte, bool with_public_device)
 {
 	unsigned long pfn = pte_pfn(pte);
 
-	if (HAVE_PTE_SPECIAL) {
-		if (likely(!pte_special(pte)))
-			goto check_pfn;
+#ifdef CONFIG_ARCH_HAS_PTE_SPECIAL
+	if (unlikely(pte_special(pte))) {
 		if (vma->vm_ops && vma->vm_ops->find_special_page)
 			return vma->vm_ops->find_special_page(vma, addr);
 		if (vma->vm_flags & (VM_PFNMAP | VM_MIXEDMAP))
@@ -862,7 +856,7 @@ struct page *_vm_normal_page(struct vm_area_struct *vma, unsigned long addr,
 		return NULL;
 	}
 
-	/* !HAVE_PTE_SPECIAL case follows: */
+#else	/* CONFIG_ARCH_HAS_PTE_SPECIAL */
 
 	if (unlikely(vma->vm_flags & (VM_PFNMAP|VM_MIXEDMAP))) {
 		if (vma->vm_flags & VM_MIXEDMAP) {
@@ -881,7 +875,8 @@ struct page *_vm_normal_page(struct vm_area_struct *vma, unsigned long addr,
 
 	if (is_zero_pfn(pfn))
 		return NULL;
-check_pfn:
+#endif /* CONFIG_ARCH_HAS_PTE_SPECIAL */
+
 	if (unlikely(pfn > highest_memmap_pfn)) {
 		print_bad_pte(vma, addr, pte, NULL);
 		return NULL;
@@ -891,7 +886,7 @@ struct page *_vm_normal_page(struct vm_area_struct *vma, unsigned long addr,
 	 * NOTE! We still have PageReserved() pages in the page tables.
 	 * eg. VDSO mappings can cause them to exist.
 	 */
-out:
+out: __maybe_unused
 	return pfn_to_page(pfn);
 }
 
@@ -904,7 +899,7 @@ struct page *vm_normal_page_pmd(struct vm_area_struct *vma, unsigned long addr,
 	/*
 	 * There is no pmd_special() but there may be special pmds, e.g.
 	 * in a direct-access (dax) mapping, so let's just replicate the
-	 * !HAVE_PTE_SPECIAL case from vm_normal_page() here.
+	 * !CONFIG_ARCH_HAS_PTE_SPECIAL case from vm_normal_page() here.
 	 */
 	if (unlikely(vma->vm_flags & (VM_PFNMAP|VM_MIXEDMAP))) {
 		if (vma->vm_flags & VM_MIXEDMAP) {
@@ -1926,6 +1921,7 @@ static int __vm_insert_mixed(struct vm_area_struct *vma, unsigned long addr,
 
 	track_pfn_insert(vma, &pgprot, pfn);
 
+#ifndef CONFIG_ARCH_HAS_PTE_SPECIAL
 	/*
 	 * If we don't have pte special, then we have to use the pfn_valid()
 	 * based VM_MIXEDMAP scheme (see vm_normal_page), and thus we *must*
@@ -1933,7 +1929,7 @@ static int __vm_insert_mixed(struct vm_area_struct *vma, unsigned long addr,
 	 * than insert_pfn).  If a zero_pfn were inserted into a VM_MIXEDMAP
 	 * without pte special, it would there be refcounted as a normal page.
 	 */
-	if (!HAVE_PTE_SPECIAL && !pfn_t_devmap(pfn) && pfn_t_valid(pfn)) {
+	if (!pfn_t_devmap(pfn) && pfn_t_valid(pfn)) {
 		struct page *page;
 
 		/*
@@ -1944,6 +1940,7 @@ static int __vm_insert_mixed(struct vm_area_struct *vma, unsigned long addr,
 		page = pfn_to_page(pfn_t_to_pfn(pfn));
 		return insert_page(vma, addr, page, pgprot);
 	}
+#endif
 	return insert_pfn(vma, addr, pfn, pgprot, mkwrite);
 }
 
-- 
2.7.4

[PATCH v2 2/2] mm: remove odd HAVE_PTE_SPECIAL

[Laurent Dufour]

Remove the additional define HAVE_PTE_SPECIAL and rely directly on
CONFIG_ARCH_HAS_PTE_SPECIAL.

There is no functional change introduced by this patch

Signed-off-by: Laurent Dufour <ldufour@linux.vnet.ibm.com>
---
 mm/memory.c | 23 ++++++++++-------------
 1 file changed, 10 insertions(+), 13 deletions(-)

diff --git a/mm/memory.c b/mm/memory.c
index 96910c625daa..53b6344a90d2 100644
--- a/mm/memory.c
+++ b/mm/memory.c
@@ -817,19 +817,13 @@ static void print_bad_pte(struct vm_area_struct *vma, unsigned long addr,
  * PFNMAP mappings in order to support COWable mappings.
  *
  */
-#ifdef CONFIG_ARCH_HAS_PTE_SPECIAL
-# define HAVE_PTE_SPECIAL 1
-#else
-# define HAVE_PTE_SPECIAL 0
-#endif
 struct page *_vm_normal_page(struct vm_area_struct *vma, unsigned long addr,
 			     pte_t pte, bool with_public_device)
 {
 	unsigned long pfn = pte_pfn(pte);
 
-	if (HAVE_PTE_SPECIAL) {
-		if (likely(!pte_special(pte)))
-			goto check_pfn;
+#ifdef CONFIG_ARCH_HAS_PTE_SPECIAL
+	if (unlikely(pte_special(pte))) {
 		if (vma->vm_ops && vma->vm_ops->find_special_page)
 			return vma->vm_ops->find_special_page(vma, addr);
 		if (vma->vm_flags & (VM_PFNMAP | VM_MIXEDMAP))
@@ -862,7 +856,7 @@ struct page *_vm_normal_page(struct vm_area_struct *vma, unsigned long addr,
 		return NULL;
 	}
 
-	/* !HAVE_PTE_SPECIAL case follows: */
+#else	/* CONFIG_ARCH_HAS_PTE_SPECIAL */
 
 	if (unlikely(vma->vm_flags & (VM_PFNMAP|VM_MIXEDMAP))) {
 		if (vma->vm_flags & VM_MIXEDMAP) {
@@ -881,7 +875,8 @@ struct page *_vm_normal_page(struct vm_area_struct *vma, unsigned long addr,
 
 	if (is_zero_pfn(pfn))
 		return NULL;
-check_pfn:
+#endif /* CONFIG_ARCH_HAS_PTE_SPECIAL */
+
 	if (unlikely(pfn > highest_memmap_pfn)) {
 		print_bad_pte(vma, addr, pte, NULL);
 		return NULL;
@@ -891,7 +886,7 @@ struct page *_vm_normal_page(struct vm_area_struct *vma, unsigned long addr,
 	 * NOTE! We still have PageReserved() pages in the page tables.
 	 * eg. VDSO mappings can cause them to exist.
 	 */
-out:
+out: __maybe_unused
 	return pfn_to_page(pfn);
 }
 
@@ -904,7 +899,7 @@ struct page *vm_normal_page_pmd(struct vm_area_struct *vma, unsigned long addr,
 	/*
 	 * There is no pmd_special() but there may be special pmds, e.g.
 	 * in a direct-access (dax) mapping, so let's just replicate the
-	 * !HAVE_PTE_SPECIAL case from vm_normal_page() here.
+	 * !CONFIG_ARCH_HAS_PTE_SPECIAL case from vm_normal_page() here.
 	 */
 	if (unlikely(vma->vm_flags & (VM_PFNMAP|VM_MIXEDMAP))) {
 		if (vma->vm_flags & VM_MIXEDMAP) {
@@ -1926,6 +1921,7 @@ static int __vm_insert_mixed(struct vm_area_struct *vma, unsigned long addr,
 
 	track_pfn_insert(vma, &pgprot, pfn);
 
+#ifndef CONFIG_ARCH_HAS_PTE_SPECIAL
 	/*
 	 * If we don't have pte special, then we have to use the pfn_valid()
 	 * based VM_MIXEDMAP scheme (see vm_normal_page), and thus we *must*
@@ -1933,7 +1929,7 @@ static int __vm_insert_mixed(struct vm_area_struct *vma, unsigned long addr,
 	 * than insert_pfn).  If a zero_pfn were inserted into a VM_MIXEDMAP
 	 * without pte special, it would there be refcounted as a normal page.
 	 */
-	if (!HAVE_PTE_SPECIAL && !pfn_t_devmap(pfn) && pfn_t_valid(pfn)) {
+	if (!pfn_t_devmap(pfn) && pfn_t_valid(pfn)) {
 		struct page *page;
 
 		/*
@@ -1944,6 +1940,7 @@ static int __vm_insert_mixed(struct vm_area_struct *vma, unsigned long addr,
 		page = pfn_to_page(pfn_t_to_pfn(pfn));
 		return insert_page(vma, addr, page, pgprot);
 	}
+#endif
 	return insert_pfn(vma, addr, pfn, pgprot, mkwrite);
 }
 
-- 
2.7.4

[PATCH v2 2/2] mm: remove odd HAVE_PTE_SPECIAL

[Laurent Dufour]

Remove the additional define HAVE_PTE_SPECIAL and rely directly on
CONFIG_ARCH_HAS_PTE_SPECIAL.

There is no functional change introduced by this patch

Signed-off-by: Laurent Dufour <ldufour@linux.vnet.ibm.com>
---
 mm/memory.c | 23 ++++++++++-------------
 1 file changed, 10 insertions(+), 13 deletions(-)

diff --git a/mm/memory.c b/mm/memory.c
index 96910c625daa..53b6344a90d2 100644
--- a/mm/memory.c
+++ b/mm/memory.c
@@ -817,19 +817,13 @@ static void print_bad_pte(struct vm_area_struct *vma, unsigned long addr,
  * PFNMAP mappings in order to support COWable mappings.
  *
  */
-#ifdef CONFIG_ARCH_HAS_PTE_SPECIAL
-# define HAVE_PTE_SPECIAL 1
-#else
-# define HAVE_PTE_SPECIAL 0
-#endif
 struct page *_vm_normal_page(struct vm_area_struct *vma, unsigned long addr,
 			     pte_t pte, bool with_public_device)
 {
 	unsigned long pfn = pte_pfn(pte);
 
-	if (HAVE_PTE_SPECIAL) {
-		if (likely(!pte_special(pte)))
-			goto check_pfn;
+#ifdef CONFIG_ARCH_HAS_PTE_SPECIAL
+	if (unlikely(pte_special(pte))) {
 		if (vma->vm_ops && vma->vm_ops->find_special_page)
 			return vma->vm_ops->find_special_page(vma, addr);
 		if (vma->vm_flags & (VM_PFNMAP | VM_MIXEDMAP))
@@ -862,7 +856,7 @@ struct page *_vm_normal_page(struct vm_area_struct *vma, unsigned long addr,
 		return NULL;
 	}
 
-	/* !HAVE_PTE_SPECIAL case follows: */
+#else	/* CONFIG_ARCH_HAS_PTE_SPECIAL */
 
 	if (unlikely(vma->vm_flags & (VM_PFNMAP|VM_MIXEDMAP))) {
 		if (vma->vm_flags & VM_MIXEDMAP) {
@@ -881,7 +875,8 @@ struct page *_vm_normal_page(struct vm_area_struct *vma, unsigned long addr,
 
 	if (is_zero_pfn(pfn))
 		return NULL;
-check_pfn:
+#endif /* CONFIG_ARCH_HAS_PTE_SPECIAL */
+
 	if (unlikely(pfn > highest_memmap_pfn)) {
 		print_bad_pte(vma, addr, pte, NULL);
 		return NULL;
@@ -891,7 +886,7 @@ struct page *_vm_normal_page(struct vm_area_struct *vma, unsigned long addr,
 	 * NOTE! We still have PageReserved() pages in the page tables.
 	 * eg. VDSO mappings can cause them to exist.
 	 */
-out:
+out: __maybe_unused
 	return pfn_to_page(pfn);
 }
 
@@ -904,7 +899,7 @@ struct page *vm_normal_page_pmd(struct vm_area_struct *vma, unsigned long addr,
 	/*
 	 * There is no pmd_special() but there may be special pmds, e.g.
 	 * in a direct-access (dax) mapping, so let's just replicate the
-	 * !HAVE_PTE_SPECIAL case from vm_normal_page() here.
+	 * !CONFIG_ARCH_HAS_PTE_SPECIAL case from vm_normal_page() here.
 	 */
 	if (unlikely(vma->vm_flags & (VM_PFNMAP|VM_MIXEDMAP))) {
 		if (vma->vm_flags & VM_MIXEDMAP) {
@@ -1926,6 +1921,7 @@ static int __vm_insert_mixed(struct vm_area_struct *vma, unsigned long addr,
 
 	track_pfn_insert(vma, &pgprot, pfn);
 
+#ifndef CONFIG_ARCH_HAS_PTE_SPECIAL
 	/*
 	 * If we don't have pte special, then we have to use the pfn_valid()
 	 * based VM_MIXEDMAP scheme (see vm_normal_page), and thus we *must*
@@ -1933,7 +1929,7 @@ static int __vm_insert_mixed(struct vm_area_struct *vma, unsigned long addr,
 	 * than insert_pfn).  If a zero_pfn were inserted into a VM_MIXEDMAP
 	 * without pte special, it would there be refcounted as a normal page.
 	 */
-	if (!HAVE_PTE_SPECIAL && !pfn_t_devmap(pfn) && pfn_t_valid(pfn)) {
+	if (!pfn_t_devmap(pfn) && pfn_t_valid(pfn)) {
 		struct page *page;
 
 		/*
@@ -1944,6 +1940,7 @@ static int __vm_insert_mixed(struct vm_area_struct *vma, unsigned long addr,
 		page = pfn_to_page(pfn_t_to_pfn(pfn));
 		return insert_page(vma, addr, page, pgprot);
 	}
+#endif
 	return insert_pfn(vma, addr, pfn, pgprot, mkwrite);
 }
 
-- 
2.7.4

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[PATCH v2 2/2] mm: remove odd HAVE_PTE_SPECIAL

[Laurent Dufour]

Remove the additional define HAVE_PTE_SPECIAL and rely directly on
CONFIG_ARCH_HAS_PTE_SPECIAL.

There is no functional change introduced by this patch

Signed-off-by: Laurent Dufour <ldufour@linux.vnet.ibm.com>
---
 mm/memory.c | 23 ++++++++++-------------
 1 file changed, 10 insertions(+), 13 deletions(-)

diff --git a/mm/memory.c b/mm/memory.c
index 96910c625daa..53b6344a90d2 100644
--- a/mm/memory.c
+++ b/mm/memory.c
@@ -817,19 +817,13 @@ static void print_bad_pte(struct vm_area_struct *vma, unsigned long addr,
  * PFNMAP mappings in order to support COWable mappings.
  *
  */
-#ifdef CONFIG_ARCH_HAS_PTE_SPECIAL
-# define HAVE_PTE_SPECIAL 1
-#else
-# define HAVE_PTE_SPECIAL 0
-#endif
 struct page *_vm_normal_page(struct vm_area_struct *vma, unsigned long addr,
 			     pte_t pte, bool with_public_device)
 {
 	unsigned long pfn = pte_pfn(pte);
 
-	if (HAVE_PTE_SPECIAL) {
-		if (likely(!pte_special(pte)))
-			goto check_pfn;
+#ifdef CONFIG_ARCH_HAS_PTE_SPECIAL
+	if (unlikely(pte_special(pte))) {
 		if (vma->vm_ops && vma->vm_ops->find_special_page)
 			return vma->vm_ops->find_special_page(vma, addr);
 		if (vma->vm_flags & (VM_PFNMAP | VM_MIXEDMAP))
@@ -862,7 +856,7 @@ struct page *_vm_normal_page(struct vm_area_struct *vma, unsigned long addr,
 		return NULL;
 	}
 
-	/* !HAVE_PTE_SPECIAL case follows: */
+#else	/* CONFIG_ARCH_HAS_PTE_SPECIAL */
 
 	if (unlikely(vma->vm_flags & (VM_PFNMAP|VM_MIXEDMAP))) {
 		if (vma->vm_flags & VM_MIXEDMAP) {
@@ -881,7 +875,8 @@ struct page *_vm_normal_page(struct vm_area_struct *vma, unsigned long addr,
 
 	if (is_zero_pfn(pfn))
 		return NULL;
-check_pfn:
+#endif /* CONFIG_ARCH_HAS_PTE_SPECIAL */
+
 	if (unlikely(pfn > highest_memmap_pfn)) {
 		print_bad_pte(vma, addr, pte, NULL);
 		return NULL;
@@ -891,7 +886,7 @@ struct page *_vm_normal_page(struct vm_area_struct *vma, unsigned long addr,
 	 * NOTE! We still have PageReserved() pages in the page tables.
 	 * eg. VDSO mappings can cause them to exist.
 	 */
-out:
+out: __maybe_unused
 	return pfn_to_page(pfn);
 }
 
@@ -904,7 +899,7 @@ struct page *vm_normal_page_pmd(struct vm_area_struct *vma, unsigned long addr,
 	/*
 	 * There is no pmd_special() but there may be special pmds, e.g.
 	 * in a direct-access (dax) mapping, so let's just replicate the
-	 * !HAVE_PTE_SPECIAL case from vm_normal_page() here.
+	 * !CONFIG_ARCH_HAS_PTE_SPECIAL case from vm_normal_page() here.
 	 */
 	if (unlikely(vma->vm_flags & (VM_PFNMAP|VM_MIXEDMAP))) {
 		if (vma->vm_flags & VM_MIXEDMAP) {
@@ -1926,6 +1921,7 @@ static int __vm_insert_mixed(struct vm_area_struct *vma, unsigned long addr,
 
 	track_pfn_insert(vma, &pgprot, pfn);
 
+#ifndef CONFIG_ARCH_HAS_PTE_SPECIAL
 	/*
 	 * If we don't have pte special, then we have to use the pfn_valid()
 	 * based VM_MIXEDMAP scheme (see vm_normal_page), and thus we *must*
@@ -1933,7 +1929,7 @@ static int __vm_insert_mixed(struct vm_area_struct *vma, unsigned long addr,
 	 * than insert_pfn).  If a zero_pfn were inserted into a VM_MIXEDMAP
 	 * without pte special, it would there be refcounted as a normal page.
 	 */
-	if (!HAVE_PTE_SPECIAL && !pfn_t_devmap(pfn) && pfn_t_valid(pfn)) {
+	if (!pfn_t_devmap(pfn) && pfn_t_valid(pfn)) {
 		struct page *page;
 
 		/*
@@ -1944,6 +1940,7 @@ static int __vm_insert_mixed(struct vm_area_struct *vma, unsigned long addr,
 		page = pfn_to_page(pfn_t_to_pfn(pfn));
 		return insert_page(vma, addr, page, pgprot);
 	}
+#endif
 	return insert_pfn(vma, addr, pfn, pgprot, mkwrite);
 }
 
-- 
2.7.4

Re: [PATCH v2 2/2] mm: remove odd HAVE_PTE_SPECIAL

[Robin Murphy]

On 10/04/18 16:25, Laurent Dufour wrote:
> Remove the additional define HAVE_PTE_SPECIAL and rely directly on
> CONFIG_ARCH_HAS_PTE_SPECIAL.
> 
> There is no functional change introduced by this patch
> 
> Signed-off-by: Laurent Dufour <ldufour@linux.vnet.ibm.com>
> ---
>   mm/memory.c | 23 ++++++++++-------------
>   1 file changed, 10 insertions(+), 13 deletions(-)
> 
> diff --git a/mm/memory.c b/mm/memory.c
> index 96910c625daa..53b6344a90d2 100644
> --- a/mm/memory.c
> +++ b/mm/memory.c
> @@ -817,19 +817,13 @@ static void print_bad_pte(struct vm_area_struct *vma, unsigned long addr,
>    * PFNMAP mappings in order to support COWable mappings.
>    *
>    */
> -#ifdef CONFIG_ARCH_HAS_PTE_SPECIAL
> -# define HAVE_PTE_SPECIAL 1
> -#else
> -# define HAVE_PTE_SPECIAL 0
> -#endif
>   struct page *_vm_normal_page(struct vm_area_struct *vma, unsigned long addr,
>   			     pte_t pte, bool with_public_device)
>   {
>   	unsigned long pfn = pte_pfn(pte);
>   
> -	if (HAVE_PTE_SPECIAL) {
> -		if (likely(!pte_special(pte)))
> -			goto check_pfn;
> +#ifdef CONFIG_ARCH_HAS_PTE_SPECIAL

Nit: Couldn't you use IS_ENABLED(CONFIG_ARCH_HAS_PTE_SPECIAL) within the 
existing code structure to avoid having to add these #ifdefs?

Robin.

> +	if (unlikely(pte_special(pte))) {
>   		if (vma->vm_ops && vma->vm_ops->find_special_page)
>   			return vma->vm_ops->find_special_page(vma, addr);
>   		if (vma->vm_flags & (VM_PFNMAP | VM_MIXEDMAP))
> @@ -862,7 +856,7 @@ struct page *_vm_normal_page(struct vm_area_struct *vma, unsigned long addr,
>   		return NULL;
>   	}
>   
> -	/* !HAVE_PTE_SPECIAL case follows: */
> +#else	/* CONFIG_ARCH_HAS_PTE_SPECIAL */
>   
>   	if (unlikely(vma->vm_flags & (VM_PFNMAP|VM_MIXEDMAP))) {
>   		if (vma->vm_flags & VM_MIXEDMAP) {
> @@ -881,7 +875,8 @@ struct page *_vm_normal_page(struct vm_area_struct *vma, unsigned long addr,
>   
>   	if (is_zero_pfn(pfn))
>   		return NULL;
> -check_pfn:
> +#endif /* CONFIG_ARCH_HAS_PTE_SPECIAL */
> +
>   	if (unlikely(pfn > highest_memmap_pfn)) {
>   		print_bad_pte(vma, addr, pte, NULL);
>   		return NULL;
> @@ -891,7 +886,7 @@ struct page *_vm_normal_page(struct vm_area_struct *vma, unsigned long addr,
>   	 * NOTE! We still have PageReserved() pages in the page tables.
>   	 * eg. VDSO mappings can cause them to exist.
>   	 */
> -out:
> +out: __maybe_unused
>   	return pfn_to_page(pfn);
>   }
>   
> @@ -904,7 +899,7 @@ struct page *vm_normal_page_pmd(struct vm_area_struct *vma, unsigned long addr,
>   	/*
>   	 * There is no pmd_special() but there may be special pmds, e.g.
>   	 * in a direct-access (dax) mapping, so let's just replicate the
> -	 * !HAVE_PTE_SPECIAL case from vm_normal_page() here.
> +	 * !CONFIG_ARCH_HAS_PTE_SPECIAL case from vm_normal_page() here.
>   	 */
>   	if (unlikely(vma->vm_flags & (VM_PFNMAP|VM_MIXEDMAP))) {
>   		if (vma->vm_flags & VM_MIXEDMAP) {
> @@ -1926,6 +1921,7 @@ static int __vm_insert_mixed(struct vm_area_struct *vma, unsigned long addr,
>   
>   	track_pfn_insert(vma, &pgprot, pfn);
>   
> +#ifndef CONFIG_ARCH_HAS_PTE_SPECIAL
>   	/*
>   	 * If we don't have pte special, then we have to use the pfn_valid()
>   	 * based VM_MIXEDMAP scheme (see vm_normal_page), and thus we *must*
> @@ -1933,7 +1929,7 @@ static int __vm_insert_mixed(struct vm_area_struct *vma, unsigned long addr,
>   	 * than insert_pfn).  If a zero_pfn were inserted into a VM_MIXEDMAP
>   	 * without pte special, it would there be refcounted as a normal page.
>   	 */
> -	if (!HAVE_PTE_SPECIAL && !pfn_t_devmap(pfn) && pfn_t_valid(pfn)) {
> +	if (!pfn_t_devmap(pfn) && pfn_t_valid(pfn)) {
>   		struct page *page;
>   
>   		/*
> @@ -1944,6 +1940,7 @@ static int __vm_insert_mixed(struct vm_area_struct *vma, unsigned long addr,
>   		page = pfn_to_page(pfn_t_to_pfn(pfn));
>   		return insert_page(vma, addr, page, pgprot);
>   	}
> +#endif
>   	return insert_pfn(vma, addr, pfn, pgprot, mkwrite);
>   }
>   
> 

[PATCH v2 2/2] mm: remove odd HAVE_PTE_SPECIAL

[Robin Murphy]

On 10/04/18 16:25, Laurent Dufour wrote:
> Remove the additional define HAVE_PTE_SPECIAL and rely directly on
> CONFIG_ARCH_HAS_PTE_SPECIAL.
> 
> There is no functional change introduced by this patch
> 
> Signed-off-by: Laurent Dufour <ldufour@linux.vnet.ibm.com>
> ---
>   mm/memory.c | 23 ++++++++++-------------
>   1 file changed, 10 insertions(+), 13 deletions(-)
> 
> diff --git a/mm/memory.c b/mm/memory.c
> index 96910c625daa..53b6344a90d2 100644
> --- a/mm/memory.c
> +++ b/mm/memory.c
> @@ -817,19 +817,13 @@ static void print_bad_pte(struct vm_area_struct *vma, unsigned long addr,
>    * PFNMAP mappings in order to support COWable mappings.
>    *
>    */
> -#ifdef CONFIG_ARCH_HAS_PTE_SPECIAL
> -# define HAVE_PTE_SPECIAL 1
> -#else
> -# define HAVE_PTE_SPECIAL 0
> -#endif
>   struct page *_vm_normal_page(struct vm_area_struct *vma, unsigned long addr,
>   			     pte_t pte, bool with_public_device)
>   {
>   	unsigned long pfn = pte_pfn(pte);
>   
> -	if (HAVE_PTE_SPECIAL) {
> -		if (likely(!pte_special(pte)))
> -			goto check_pfn;
> +#ifdef CONFIG_ARCH_HAS_PTE_SPECIAL

Nit: Couldn't you use IS_ENABLED(CONFIG_ARCH_HAS_PTE_SPECIAL) within the 
existing code structure to avoid having to add these #ifdefs?

Robin.

> +	if (unlikely(pte_special(pte))) {
>   		if (vma->vm_ops && vma->vm_ops->find_special_page)
>   			return vma->vm_ops->find_special_page(vma, addr);
>   		if (vma->vm_flags & (VM_PFNMAP | VM_MIXEDMAP))
> @@ -862,7 +856,7 @@ struct page *_vm_normal_page(struct vm_area_struct *vma, unsigned long addr,
>   		return NULL;
>   	}
>   
> -	/* !HAVE_PTE_SPECIAL case follows: */
> +#else	/* CONFIG_ARCH_HAS_PTE_SPECIAL */
>   
>   	if (unlikely(vma->vm_flags & (VM_PFNMAP|VM_MIXEDMAP))) {
>   		if (vma->vm_flags & VM_MIXEDMAP) {
> @@ -881,7 +875,8 @@ struct page *_vm_normal_page(struct vm_area_struct *vma, unsigned long addr,
>   
>   	if (is_zero_pfn(pfn))
>   		return NULL;
> -check_pfn:
> +#endif /* CONFIG_ARCH_HAS_PTE_SPECIAL */
> +
>   	if (unlikely(pfn > highest_memmap_pfn)) {
>   		print_bad_pte(vma, addr, pte, NULL);
>   		return NULL;
> @@ -891,7 +886,7 @@ struct page *_vm_normal_page(struct vm_area_struct *vma, unsigned long addr,
>   	 * NOTE! We still have PageReserved() pages in the page tables.
>   	 * eg. VDSO mappings can cause them to exist.
>   	 */
> -out:
> +out: __maybe_unused
>   	return pfn_to_page(pfn);
>   }
>   
> @@ -904,7 +899,7 @@ struct page *vm_normal_page_pmd(struct vm_area_struct *vma, unsigned long addr,
>   	/*
>   	 * There is no pmd_special() but there may be special pmds, e.g.
>   	 * in a direct-access (dax) mapping, so let's just replicate the
> -	 * !HAVE_PTE_SPECIAL case from vm_normal_page() here.
> +	 * !CONFIG_ARCH_HAS_PTE_SPECIAL case from vm_normal_page() here.
>   	 */
>   	if (unlikely(vma->vm_flags & (VM_PFNMAP|VM_MIXEDMAP))) {
>   		if (vma->vm_flags & VM_MIXEDMAP) {
> @@ -1926,6 +1921,7 @@ static int __vm_insert_mixed(struct vm_area_struct *vma, unsigned long addr,
>   
>   	track_pfn_insert(vma, &pgprot, pfn);
>   
> +#ifndef CONFIG_ARCH_HAS_PTE_SPECIAL
>   	/*
>   	 * If we don't have pte special, then we have to use the pfn_valid()
>   	 * based VM_MIXEDMAP scheme (see vm_normal_page), and thus we *must*
> @@ -1933,7 +1929,7 @@ static int __vm_insert_mixed(struct vm_area_struct *vma, unsigned long addr,
>   	 * than insert_pfn).  If a zero_pfn were inserted into a VM_MIXEDMAP
>   	 * without pte special, it would there be refcounted as a normal page.
>   	 */
> -	if (!HAVE_PTE_SPECIAL && !pfn_t_devmap(pfn) && pfn_t_valid(pfn)) {
> +	if (!pfn_t_devmap(pfn) && pfn_t_valid(pfn)) {
>   		struct page *page;
>   
>   		/*
> @@ -1944,6 +1940,7 @@ static int __vm_insert_mixed(struct vm_area_struct *vma, unsigned long addr,
>   		page = pfn_to_page(pfn_t_to_pfn(pfn));
>   		return insert_page(vma, addr, page, pgprot);
>   	}
> +#endif
>   	return insert_pfn(vma, addr, pfn, pgprot, mkwrite);
>   }
>   
> 

[PATCH v2 2/2] mm: remove odd HAVE_PTE_SPECIAL

[Robin Murphy]

On 10/04/18 16:25, Laurent Dufour wrote:
> Remove the additional define HAVE_PTE_SPECIAL and rely directly on
> CONFIG_ARCH_HAS_PTE_SPECIAL.
> 
> There is no functional change introduced by this patch
> 
> Signed-off-by: Laurent Dufour <ldufour at linux.vnet.ibm.com>
> ---
>   mm/memory.c | 23 ++++++++++-------------
>   1 file changed, 10 insertions(+), 13 deletions(-)
> 
> diff --git a/mm/memory.c b/mm/memory.c
> index 96910c625daa..53b6344a90d2 100644
> --- a/mm/memory.c
> +++ b/mm/memory.c
> @@ -817,19 +817,13 @@ static void print_bad_pte(struct vm_area_struct *vma, unsigned long addr,
>    * PFNMAP mappings in order to support COWable mappings.
>    *
>    */
> -#ifdef CONFIG_ARCH_HAS_PTE_SPECIAL
> -# define HAVE_PTE_SPECIAL 1
> -#else
> -# define HAVE_PTE_SPECIAL 0
> -#endif
>   struct page *_vm_normal_page(struct vm_area_struct *vma, unsigned long addr,
>   			     pte_t pte, bool with_public_device)
>   {
>   	unsigned long pfn = pte_pfn(pte);
>   
> -	if (HAVE_PTE_SPECIAL) {
> -		if (likely(!pte_special(pte)))
> -			goto check_pfn;
> +#ifdef CONFIG_ARCH_HAS_PTE_SPECIAL

Nit: Couldn't you use IS_ENABLED(CONFIG_ARCH_HAS_PTE_SPECIAL) within the 
existing code structure to avoid having to add these #ifdefs?

Robin.

> +	if (unlikely(pte_special(pte))) {
>   		if (vma->vm_ops && vma->vm_ops->find_special_page)
>   			return vma->vm_ops->find_special_page(vma, addr);
>   		if (vma->vm_flags & (VM_PFNMAP | VM_MIXEDMAP))
> @@ -862,7 +856,7 @@ struct page *_vm_normal_page(struct vm_area_struct *vma, unsigned long addr,
>   		return NULL;
>   	}
>   
> -	/* !HAVE_PTE_SPECIAL case follows: */
> +#else	/* CONFIG_ARCH_HAS_PTE_SPECIAL */
>   
>   	if (unlikely(vma->vm_flags & (VM_PFNMAP|VM_MIXEDMAP))) {
>   		if (vma->vm_flags & VM_MIXEDMAP) {
> @@ -881,7 +875,8 @@ struct page *_vm_normal_page(struct vm_area_struct *vma, unsigned long addr,
>   
>   	if (is_zero_pfn(pfn))
>   		return NULL;
> -check_pfn:
> +#endif /* CONFIG_ARCH_HAS_PTE_SPECIAL */
> +
>   	if (unlikely(pfn > highest_memmap_pfn)) {
>   		print_bad_pte(vma, addr, pte, NULL);
>   		return NULL;
> @@ -891,7 +886,7 @@ struct page *_vm_normal_page(struct vm_area_struct *vma, unsigned long addr,
>   	 * NOTE! We still have PageReserved() pages in the page tables.
>   	 * eg. VDSO mappings can cause them to exist.
>   	 */
> -out:
> +out: __maybe_unused
>   	return pfn_to_page(pfn);
>   }
>   
> @@ -904,7 +899,7 @@ struct page *vm_normal_page_pmd(struct vm_area_struct *vma, unsigned long addr,
>   	/*
>   	 * There is no pmd_special() but there may be special pmds, e.g.
>   	 * in a direct-access (dax) mapping, so let's just replicate the
> -	 * !HAVE_PTE_SPECIAL case from vm_normal_page() here.
> +	 * !CONFIG_ARCH_HAS_PTE_SPECIAL case from vm_normal_page() here.
>   	 */
>   	if (unlikely(vma->vm_flags & (VM_PFNMAP|VM_MIXEDMAP))) {
>   		if (vma->vm_flags & VM_MIXEDMAP) {
> @@ -1926,6 +1921,7 @@ static int __vm_insert_mixed(struct vm_area_struct *vma, unsigned long addr,
>   
>   	track_pfn_insert(vma, &pgprot, pfn);
>   
> +#ifndef CONFIG_ARCH_HAS_PTE_SPECIAL
>   	/*
>   	 * If we don't have pte special, then we have to use the pfn_valid()
>   	 * based VM_MIXEDMAP scheme (see vm_normal_page), and thus we *must*
> @@ -1933,7 +1929,7 @@ static int __vm_insert_mixed(struct vm_area_struct *vma, unsigned long addr,
>   	 * than insert_pfn).  If a zero_pfn were inserted into a VM_MIXEDMAP
>   	 * without pte special, it would there be refcounted as a normal page.
>   	 */
> -	if (!HAVE_PTE_SPECIAL && !pfn_t_devmap(pfn) && pfn_t_valid(pfn)) {
> +	if (!pfn_t_devmap(pfn) && pfn_t_valid(pfn)) {
>   		struct page *page;
>   
>   		/*
> @@ -1944,6 +1940,7 @@ static int __vm_insert_mixed(struct vm_area_struct *vma, unsigned long addr,
>   		page = pfn_to_page(pfn_t_to_pfn(pfn));
>   		return insert_page(vma, addr, page, pgprot);
>   	}
> +#endif
>   	return insert_pfn(vma, addr, pfn, pgprot, mkwrite);
>   }
>   
> 

[PATCH v2 2/2] mm: remove odd HAVE_PTE_SPECIAL

[Robin Murphy]

On 10/04/18 16:25, Laurent Dufour wrote:
> Remove the additional define HAVE_PTE_SPECIAL and rely directly on
> CONFIG_ARCH_HAS_PTE_SPECIAL.
> 
> There is no functional change introduced by this patch
> 
> Signed-off-by: Laurent Dufour <ldufour@linux.vnet.ibm.com>
> ---
>   mm/memory.c | 23 ++++++++++-------------
>   1 file changed, 10 insertions(+), 13 deletions(-)
> 
> diff --git a/mm/memory.c b/mm/memory.c
> index 96910c625daa..53b6344a90d2 100644
> --- a/mm/memory.c
> +++ b/mm/memory.c
> @@ -817,19 +817,13 @@ static void print_bad_pte(struct vm_area_struct *vma, unsigned long addr,
>    * PFNMAP mappings in order to support COWable mappings.
>    *
>    */
> -#ifdef CONFIG_ARCH_HAS_PTE_SPECIAL
> -# define HAVE_PTE_SPECIAL 1
> -#else
> -# define HAVE_PTE_SPECIAL 0
> -#endif
>   struct page *_vm_normal_page(struct vm_area_struct *vma, unsigned long addr,
>   			     pte_t pte, bool with_public_device)
>   {
>   	unsigned long pfn = pte_pfn(pte);
>   
> -	if (HAVE_PTE_SPECIAL) {
> -		if (likely(!pte_special(pte)))
> -			goto check_pfn;
> +#ifdef CONFIG_ARCH_HAS_PTE_SPECIAL

Nit: Couldn't you use IS_ENABLED(CONFIG_ARCH_HAS_PTE_SPECIAL) within the 
existing code structure to avoid having to add these #ifdefs?

Robin.

> +	if (unlikely(pte_special(pte))) {
>   		if (vma->vm_ops && vma->vm_ops->find_special_page)
>   			return vma->vm_ops->find_special_page(vma, addr);
>   		if (vma->vm_flags & (VM_PFNMAP | VM_MIXEDMAP))
> @@ -862,7 +856,7 @@ struct page *_vm_normal_page(struct vm_area_struct *vma, unsigned long addr,
>   		return NULL;
>   	}
>   
> -	/* !HAVE_PTE_SPECIAL case follows: */
> +#else	/* CONFIG_ARCH_HAS_PTE_SPECIAL */
>   
>   	if (unlikely(vma->vm_flags & (VM_PFNMAP|VM_MIXEDMAP))) {
>   		if (vma->vm_flags & VM_MIXEDMAP) {
> @@ -881,7 +875,8 @@ struct page *_vm_normal_page(struct vm_area_struct *vma, unsigned long addr,
>   
>   	if (is_zero_pfn(pfn))
>   		return NULL;
> -check_pfn:
> +#endif /* CONFIG_ARCH_HAS_PTE_SPECIAL */
> +
>   	if (unlikely(pfn > highest_memmap_pfn)) {
>   		print_bad_pte(vma, addr, pte, NULL);
>   		return NULL;
> @@ -891,7 +886,7 @@ struct page *_vm_normal_page(struct vm_area_struct *vma, unsigned long addr,
>   	 * NOTE! We still have PageReserved() pages in the page tables.
>   	 * eg. VDSO mappings can cause them to exist.
>   	 */
> -out:
> +out: __maybe_unused
>   	return pfn_to_page(pfn);
>   }
>   
> @@ -904,7 +899,7 @@ struct page *vm_normal_page_pmd(struct vm_area_struct *vma, unsigned long addr,
>   	/*
>   	 * There is no pmd_special() but there may be special pmds, e.g.
>   	 * in a direct-access (dax) mapping, so let's just replicate the
> -	 * !HAVE_PTE_SPECIAL case from vm_normal_page() here.
> +	 * !CONFIG_ARCH_HAS_PTE_SPECIAL case from vm_normal_page() here.
>   	 */
>   	if (unlikely(vma->vm_flags & (VM_PFNMAP|VM_MIXEDMAP))) {
>   		if (vma->vm_flags & VM_MIXEDMAP) {
> @@ -1926,6 +1921,7 @@ static int __vm_insert_mixed(struct vm_area_struct *vma, unsigned long addr,
>   
>   	track_pfn_insert(vma, &pgprot, pfn);
>   
> +#ifndef CONFIG_ARCH_HAS_PTE_SPECIAL
>   	/*
>   	 * If we don't have pte special, then we have to use the pfn_valid()
>   	 * based VM_MIXEDMAP scheme (see vm_normal_page), and thus we *must*
> @@ -1933,7 +1929,7 @@ static int __vm_insert_mixed(struct vm_area_struct *vma, unsigned long addr,
>   	 * than insert_pfn).  If a zero_pfn were inserted into a VM_MIXEDMAP
>   	 * without pte special, it would there be refcounted as a normal page.
>   	 */
> -	if (!HAVE_PTE_SPECIAL && !pfn_t_devmap(pfn) && pfn_t_valid(pfn)) {
> +	if (!pfn_t_devmap(pfn) && pfn_t_valid(pfn)) {
>   		struct page *page;
>   
>   		/*
> @@ -1944,6 +1940,7 @@ static int __vm_insert_mixed(struct vm_area_struct *vma, unsigned long addr,
>   		page = pfn_to_page(pfn_t_to_pfn(pfn));
>   		return insert_page(vma, addr, page, pgprot);
>   	}
> +#endif
>   	return insert_pfn(vma, addr, pfn, pgprot, mkwrite);
>   }
>   
> 

Re: [PATCH v2 2/2] mm: remove odd HAVE_PTE_SPECIAL

[Robin Murphy]

On 10/04/18 16:25, Laurent Dufour wrote:
> Remove the additional define HAVE_PTE_SPECIAL and rely directly on
> CONFIG_ARCH_HAS_PTE_SPECIAL.
> 
> There is no functional change introduced by this patch
> 
> Signed-off-by: Laurent Dufour <ldufour@linux.vnet.ibm.com>
> ---
>   mm/memory.c | 23 ++++++++++-------------
>   1 file changed, 10 insertions(+), 13 deletions(-)
> 
> diff --git a/mm/memory.c b/mm/memory.c
> index 96910c625daa..53b6344a90d2 100644
> --- a/mm/memory.c
> +++ b/mm/memory.c
> @@ -817,19 +817,13 @@ static void print_bad_pte(struct vm_area_struct *vma, unsigned long addr,
>    * PFNMAP mappings in order to support COWable mappings.
>    *
>    */
> -#ifdef CONFIG_ARCH_HAS_PTE_SPECIAL
> -# define HAVE_PTE_SPECIAL 1
> -#else
> -# define HAVE_PTE_SPECIAL 0
> -#endif
>   struct page *_vm_normal_page(struct vm_area_struct *vma, unsigned long addr,
>   			     pte_t pte, bool with_public_device)
>   {
>   	unsigned long pfn = pte_pfn(pte);
>   
> -	if (HAVE_PTE_SPECIAL) {
> -		if (likely(!pte_special(pte)))
> -			goto check_pfn;
> +#ifdef CONFIG_ARCH_HAS_PTE_SPECIAL

Nit: Couldn't you use IS_ENABLED(CONFIG_ARCH_HAS_PTE_SPECIAL) within the 
existing code structure to avoid having to add these #ifdefs?

Robin.

> +	if (unlikely(pte_special(pte))) {
>   		if (vma->vm_ops && vma->vm_ops->find_special_page)
>   			return vma->vm_ops->find_special_page(vma, addr);
>   		if (vma->vm_flags & (VM_PFNMAP | VM_MIXEDMAP))
> @@ -862,7 +856,7 @@ struct page *_vm_normal_page(struct vm_area_struct *vma, unsigned long addr,
>   		return NULL;
>   	}
>   
> -	/* !HAVE_PTE_SPECIAL case follows: */
> +#else	/* CONFIG_ARCH_HAS_PTE_SPECIAL */
>   
>   	if (unlikely(vma->vm_flags & (VM_PFNMAP|VM_MIXEDMAP))) {
>   		if (vma->vm_flags & VM_MIXEDMAP) {
> @@ -881,7 +875,8 @@ struct page *_vm_normal_page(struct vm_area_struct *vma, unsigned long addr,
>   
>   	if (is_zero_pfn(pfn))
>   		return NULL;
> -check_pfn:
> +#endif /* CONFIG_ARCH_HAS_PTE_SPECIAL */
> +
>   	if (unlikely(pfn > highest_memmap_pfn)) {
>   		print_bad_pte(vma, addr, pte, NULL);
>   		return NULL;
> @@ -891,7 +886,7 @@ struct page *_vm_normal_page(struct vm_area_struct *vma, unsigned long addr,
>   	 * NOTE! We still have PageReserved() pages in the page tables.
>   	 * eg. VDSO mappings can cause them to exist.
>   	 */
> -out:
> +out: __maybe_unused
>   	return pfn_to_page(pfn);
>   }
>   
> @@ -904,7 +899,7 @@ struct page *vm_normal_page_pmd(struct vm_area_struct *vma, unsigned long addr,
>   	/*
>   	 * There is no pmd_special() but there may be special pmds, e.g.
>   	 * in a direct-access (dax) mapping, so let's just replicate the
> -	 * !HAVE_PTE_SPECIAL case from vm_normal_page() here.
> +	 * !CONFIG_ARCH_HAS_PTE_SPECIAL case from vm_normal_page() here.
>   	 */
>   	if (unlikely(vma->vm_flags & (VM_PFNMAP|VM_MIXEDMAP))) {
>   		if (vma->vm_flags & VM_MIXEDMAP) {
> @@ -1926,6 +1921,7 @@ static int __vm_insert_mixed(struct vm_area_struct *vma, unsigned long addr,
>   
>   	track_pfn_insert(vma, &pgprot, pfn);
>   
> +#ifndef CONFIG_ARCH_HAS_PTE_SPECIAL
>   	/*
>   	 * If we don't have pte special, then we have to use the pfn_valid()
>   	 * based VM_MIXEDMAP scheme (see vm_normal_page), and thus we *must*
> @@ -1933,7 +1929,7 @@ static int __vm_insert_mixed(struct vm_area_struct *vma, unsigned long addr,
>   	 * than insert_pfn).  If a zero_pfn were inserted into a VM_MIXEDMAP
>   	 * without pte special, it would there be refcounted as a normal page.
>   	 */
> -	if (!HAVE_PTE_SPECIAL && !pfn_t_devmap(pfn) && pfn_t_valid(pfn)) {
> +	if (!pfn_t_devmap(pfn) && pfn_t_valid(pfn)) {
>   		struct page *page;
>   
>   		/*
> @@ -1944,6 +1940,7 @@ static int __vm_insert_mixed(struct vm_area_struct *vma, unsigned long addr,
>   		page = pfn_to_page(pfn_t_to_pfn(pfn));
>   		return insert_page(vma, addr, page, pgprot);
>   	}
> +#endif
>   	return insert_pfn(vma, addr, pfn, pgprot, mkwrite);
>   }
>   
> 
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Re: [PATCH v2 2/2] mm: remove odd HAVE_PTE_SPECIAL

[Robin Murphy]

On 10/04/18 16:25, Laurent Dufour wrote:
> Remove the additional define HAVE_PTE_SPECIAL and rely directly on
> CONFIG_ARCH_HAS_PTE_SPECIAL.
> 
> There is no functional change introduced by this patch
> 
> Signed-off-by: Laurent Dufour <ldufour@linux.vnet.ibm.com>
> ---
>   mm/memory.c | 23 ++++++++++-------------
>   1 file changed, 10 insertions(+), 13 deletions(-)
> 
> diff --git a/mm/memory.c b/mm/memory.c
> index 96910c625daa..53b6344a90d2 100644
> --- a/mm/memory.c
> +++ b/mm/memory.c
> @@ -817,19 +817,13 @@ static void print_bad_pte(struct vm_area_struct *vma, unsigned long addr,
>    * PFNMAP mappings in order to support COWable mappings.
>    *
>    */
> -#ifdef CONFIG_ARCH_HAS_PTE_SPECIAL
> -# define HAVE_PTE_SPECIAL 1
> -#else
> -# define HAVE_PTE_SPECIAL 0
> -#endif
>   struct page *_vm_normal_page(struct vm_area_struct *vma, unsigned long addr,
>   			     pte_t pte, bool with_public_device)
>   {
>   	unsigned long pfn = pte_pfn(pte);
>   
> -	if (HAVE_PTE_SPECIAL) {
> -		if (likely(!pte_special(pte)))
> -			goto check_pfn;
> +#ifdef CONFIG_ARCH_HAS_PTE_SPECIAL

Nit: Couldn't you use IS_ENABLED(CONFIG_ARCH_HAS_PTE_SPECIAL) within the 
existing code structure to avoid having to add these #ifdefs?

Robin.

> +	if (unlikely(pte_special(pte))) {
>   		if (vma->vm_ops && vma->vm_ops->find_special_page)
>   			return vma->vm_ops->find_special_page(vma, addr);
>   		if (vma->vm_flags & (VM_PFNMAP | VM_MIXEDMAP))
> @@ -862,7 +856,7 @@ struct page *_vm_normal_page(struct vm_area_struct *vma, unsigned long addr,
>   		return NULL;
>   	}
>   
> -	/* !HAVE_PTE_SPECIAL case follows: */
> +#else	/* CONFIG_ARCH_HAS_PTE_SPECIAL */
>   
>   	if (unlikely(vma->vm_flags & (VM_PFNMAP|VM_MIXEDMAP))) {
>   		if (vma->vm_flags & VM_MIXEDMAP) {
> @@ -881,7 +875,8 @@ struct page *_vm_normal_page(struct vm_area_struct *vma, unsigned long addr,
>   
>   	if (is_zero_pfn(pfn))
>   		return NULL;
> -check_pfn:
> +#endif /* CONFIG_ARCH_HAS_PTE_SPECIAL */
> +
>   	if (unlikely(pfn > highest_memmap_pfn)) {
>   		print_bad_pte(vma, addr, pte, NULL);
>   		return NULL;
> @@ -891,7 +886,7 @@ struct page *_vm_normal_page(struct vm_area_struct *vma, unsigned long addr,
>   	 * NOTE! We still have PageReserved() pages in the page tables.
>   	 * eg. VDSO mappings can cause them to exist.
>   	 */
> -out:
> +out: __maybe_unused
>   	return pfn_to_page(pfn);
>   }
>   
> @@ -904,7 +899,7 @@ struct page *vm_normal_page_pmd(struct vm_area_struct *vma, unsigned long addr,
>   	/*
>   	 * There is no pmd_special() but there may be special pmds, e.g.
>   	 * in a direct-access (dax) mapping, so let's just replicate the
> -	 * !HAVE_PTE_SPECIAL case from vm_normal_page() here.
> +	 * !CONFIG_ARCH_HAS_PTE_SPECIAL case from vm_normal_page() here.
>   	 */
>   	if (unlikely(vma->vm_flags & (VM_PFNMAP|VM_MIXEDMAP))) {
>   		if (vma->vm_flags & VM_MIXEDMAP) {
> @@ -1926,6 +1921,7 @@ static int __vm_insert_mixed(struct vm_area_struct *vma, unsigned long addr,
>   
>   	track_pfn_insert(vma, &pgprot, pfn);
>   
> +#ifndef CONFIG_ARCH_HAS_PTE_SPECIAL
>   	/*
>   	 * If we don't have pte special, then we have to use the pfn_valid()
>   	 * based VM_MIXEDMAP scheme (see vm_normal_page), and thus we *must*
> @@ -1933,7 +1929,7 @@ static int __vm_insert_mixed(struct vm_area_struct *vma, unsigned long addr,
>   	 * than insert_pfn).  If a zero_pfn were inserted into a VM_MIXEDMAP
>   	 * without pte special, it would there be refcounted as a normal page.
>   	 */
> -	if (!HAVE_PTE_SPECIAL && !pfn_t_devmap(pfn) && pfn_t_valid(pfn)) {
> +	if (!pfn_t_devmap(pfn) && pfn_t_valid(pfn)) {
>   		struct page *page;
>   
>   		/*
> @@ -1944,6 +1940,7 @@ static int __vm_insert_mixed(struct vm_area_struct *vma, unsigned long addr,
>   		page = pfn_to_page(pfn_t_to_pfn(pfn));
>   		return insert_page(vma, addr, page, pgprot);
>   	}
> +#endif
>   	return insert_pfn(vma, addr, pfn, pgprot, mkwrite);
>   }
>   
> 

Re: [PATCH v2 2/2] mm: remove odd HAVE_PTE_SPECIAL

[Laurent Dufour]

On 10/04/2018 17:58, Robin Murphy wrote:
> On 10/04/18 16:25, Laurent Dufour wrote:
>> Remove the additional define HAVE_PTE_SPECIAL and rely directly on
>> CONFIG_ARCH_HAS_PTE_SPECIAL.
>>
>> There is no functional change introduced by this patch
>>
>> Signed-off-by: Laurent Dufour <ldufour@linux.vnet.ibm.com>
>> ---
>>   mm/memory.c | 23 ++++++++++-------------
>>   1 file changed, 10 insertions(+), 13 deletions(-)
>>
>> diff --git a/mm/memory.c b/mm/memory.c
>> index 96910c625daa..53b6344a90d2 100644
>> --- a/mm/memory.c
>> +++ b/mm/memory.c
>> @@ -817,19 +817,13 @@ static void print_bad_pte(struct vm_area_struct *vma,
>> unsigned long addr,
>>    * PFNMAP mappings in order to support COWable mappings.
>>    *
>>    */
>> -#ifdef CONFIG_ARCH_HAS_PTE_SPECIAL
>> -# define HAVE_PTE_SPECIAL 1
>> -#else
>> -# define HAVE_PTE_SPECIAL 0
>> -#endif
>>   struct page *_vm_normal_page(struct vm_area_struct *vma, unsigned long addr,
>>                    pte_t pte, bool with_public_device)
>>   {
>>       unsigned long pfn = pte_pfn(pte);
>>   -    if (HAVE_PTE_SPECIAL) {
>> -        if (likely(!pte_special(pte)))
>> -            goto check_pfn;
>> +#ifdef CONFIG_ARCH_HAS_PTE_SPECIAL
> 
> Nit: Couldn't you use IS_ENABLED(CONFIG_ARCH_HAS_PTE_SPECIAL) within the
> existing code structure to avoid having to add these #ifdefs?

I agree, that would be better. I didn't thought about this option..
Thanks for reporting this.

[PATCH v2 2/2] mm: remove odd HAVE_PTE_SPECIAL

[Laurent Dufour]

On 10/04/2018 17:58, Robin Murphy wrote:
> On 10/04/18 16:25, Laurent Dufour wrote:
>> Remove the additional define HAVE_PTE_SPECIAL and rely directly on
>> CONFIG_ARCH_HAS_PTE_SPECIAL.
>>
>> There is no functional change introduced by this patch
>>
>> Signed-off-by: Laurent Dufour <ldufour@linux.vnet.ibm.com>
>> ---
>> ? mm/memory.c | 23 ++++++++++-------------
>> ? 1 file changed, 10 insertions(+), 13 deletions(-)
>>
>> diff --git a/mm/memory.c b/mm/memory.c
>> index 96910c625daa..53b6344a90d2 100644
>> --- a/mm/memory.c
>> +++ b/mm/memory.c
>> @@ -817,19 +817,13 @@ static void print_bad_pte(struct vm_area_struct *vma,
>> unsigned long addr,
>> ?? * PFNMAP mappings in order to support COWable mappings.
>> ?? *
>> ?? */
>> -#ifdef CONFIG_ARCH_HAS_PTE_SPECIAL
>> -# define HAVE_PTE_SPECIAL 1
>> -#else
>> -# define HAVE_PTE_SPECIAL 0
>> -#endif
>> ? struct page *_vm_normal_page(struct vm_area_struct *vma, unsigned long addr,
>> ?????????????????? pte_t pte, bool with_public_device)
>> ? {
>> ????? unsigned long pfn = pte_pfn(pte);
>> ? -??? if (HAVE_PTE_SPECIAL) {
>> -??????? if (likely(!pte_special(pte)))
>> -??????????? goto check_pfn;
>> +#ifdef CONFIG_ARCH_HAS_PTE_SPECIAL
> 
> Nit: Couldn't you use IS_ENABLED(CONFIG_ARCH_HAS_PTE_SPECIAL) within the
> existing code structure to avoid having to add these #ifdefs?

I agree, that would be better. I didn't thought about this option..
Thanks for reporting this.

[PATCH v2 2/2] mm: remove odd HAVE_PTE_SPECIAL

[Laurent Dufour]

On 10/04/2018 17:58, Robin Murphy wrote:
> On 10/04/18 16:25, Laurent Dufour wrote:
>> Remove the additional define HAVE_PTE_SPECIAL and rely directly on
>> CONFIG_ARCH_HAS_PTE_SPECIAL.
>>
>> There is no functional change introduced by this patch
>>
>> Signed-off-by: Laurent Dufour <ldufour at linux.vnet.ibm.com>
>> ---
>> ? mm/memory.c | 23 ++++++++++-------------
>> ? 1 file changed, 10 insertions(+), 13 deletions(-)
>>
>> diff --git a/mm/memory.c b/mm/memory.c
>> index 96910c625daa..53b6344a90d2 100644
>> --- a/mm/memory.c
>> +++ b/mm/memory.c
>> @@ -817,19 +817,13 @@ static void print_bad_pte(struct vm_area_struct *vma,
>> unsigned long addr,
>> ?? * PFNMAP mappings in order to support COWable mappings.
>> ?? *
>> ?? */
>> -#ifdef CONFIG_ARCH_HAS_PTE_SPECIAL
>> -# define HAVE_PTE_SPECIAL 1
>> -#else
>> -# define HAVE_PTE_SPECIAL 0
>> -#endif
>> ? struct page *_vm_normal_page(struct vm_area_struct *vma, unsigned long addr,
>> ?????????????????? pte_t pte, bool with_public_device)
>> ? {
>> ????? unsigned long pfn = pte_pfn(pte);
>> ? -??? if (HAVE_PTE_SPECIAL) {
>> -??????? if (likely(!pte_special(pte)))
>> -??????????? goto check_pfn;
>> +#ifdef CONFIG_ARCH_HAS_PTE_SPECIAL
> 
> Nit: Couldn't you use IS_ENABLED(CONFIG_ARCH_HAS_PTE_SPECIAL) within the
> existing code structure to avoid having to add these #ifdefs?

I agree, that would be better. I didn't thought about this option..
Thanks for reporting this.

Re: [PATCH v2 2/2] mm: remove odd HAVE_PTE_SPECIAL

[Laurent Dufour]

On 10/04/2018 17:58, Robin Murphy wrote:
> On 10/04/18 16:25, Laurent Dufour wrote:
>> Remove the additional define HAVE_PTE_SPECIAL and rely directly on
>> CONFIG_ARCH_HAS_PTE_SPECIAL.
>>
>> There is no functional change introduced by this patch
>>
>> Signed-off-by: Laurent Dufour <ldufour@linux.vnet.ibm.com>
>> ---
>> A  mm/memory.c | 23 ++++++++++-------------
>> A  1 file changed, 10 insertions(+), 13 deletions(-)
>>
>> diff --git a/mm/memory.c b/mm/memory.c
>> index 96910c625daa..53b6344a90d2 100644
>> --- a/mm/memory.c
>> +++ b/mm/memory.c
>> @@ -817,19 +817,13 @@ static void print_bad_pte(struct vm_area_struct *vma,
>> unsigned long addr,
>> A A  * PFNMAP mappings in order to support COWable mappings.
>> A A  *
>> A A  */
>> -#ifdef CONFIG_ARCH_HAS_PTE_SPECIAL
>> -# define HAVE_PTE_SPECIAL 1
>> -#else
>> -# define HAVE_PTE_SPECIAL 0
>> -#endif
>> A  struct page *_vm_normal_page(struct vm_area_struct *vma, unsigned long addr,
>> A A A A A A A A A A A A A A A A A A  pte_t pte, bool with_public_device)
>> A  {
>> A A A A A  unsigned long pfn = pte_pfn(pte);
>> A  -A A A  if (HAVE_PTE_SPECIAL) {
>> -A A A A A A A  if (likely(!pte_special(pte)))
>> -A A A A A A A A A A A  goto check_pfn;
>> +#ifdef CONFIG_ARCH_HAS_PTE_SPECIAL
> 
> Nit: Couldn't you use IS_ENABLED(CONFIG_ARCH_HAS_PTE_SPECIAL) within the
> existing code structure to avoid having to add these #ifdefs?

I agree, that would be better. I didn't thought about this option..
Thanks for reporting this.

[PATCH v2 2/2] mm: remove odd HAVE_PTE_SPECIAL

[Laurent Dufour]

On 10/04/2018 17:58, Robin Murphy wrote:
> On 10/04/18 16:25, Laurent Dufour wrote:
>> Remove the additional define HAVE_PTE_SPECIAL and rely directly on
>> CONFIG_ARCH_HAS_PTE_SPECIAL.
>>
>> There is no functional change introduced by this patch
>>
>> Signed-off-by: Laurent Dufour <ldufour@linux.vnet.ibm.com>
>> ---
>> ? mm/memory.c | 23 ++++++++++-------------
>> ? 1 file changed, 10 insertions(+), 13 deletions(-)
>>
>> diff --git a/mm/memory.c b/mm/memory.c
>> index 96910c625daa..53b6344a90d2 100644
>> --- a/mm/memory.c
>> +++ b/mm/memory.c
>> @@ -817,19 +817,13 @@ static void print_bad_pte(struct vm_area_struct *vma,
>> unsigned long addr,
>> ?? * PFNMAP mappings in order to support COWable mappings.
>> ?? *
>> ?? */
>> -#ifdef CONFIG_ARCH_HAS_PTE_SPECIAL
>> -# define HAVE_PTE_SPECIAL 1
>> -#else
>> -# define HAVE_PTE_SPECIAL 0
>> -#endif
>> ? struct page *_vm_normal_page(struct vm_area_struct *vma, unsigned long addr,
>> ?????????????????? pte_t pte, bool with_public_device)
>> ? {
>> ????? unsigned long pfn = pte_pfn(pte);
>> ? -??? if (HAVE_PTE_SPECIAL) {
>> -??????? if (likely(!pte_special(pte)))
>> -??????????? goto check_pfn;
>> +#ifdef CONFIG_ARCH_HAS_PTE_SPECIAL
> 
> Nit: Couldn't you use IS_ENABLED(CONFIG_ARCH_HAS_PTE_SPECIAL) within the
> existing code structure to avoid having to add these #ifdefs?

I agree, that would be better. I didn't thought about this option..
Thanks for reporting this.

Re: [PATCH v2 2/2] mm: remove odd HAVE_PTE_SPECIAL

[Laurent Dufour]

On 10/04/2018 17:58, Robin Murphy wrote:
> On 10/04/18 16:25, Laurent Dufour wrote:
>> Remove the additional define HAVE_PTE_SPECIAL and rely directly on
>> CONFIG_ARCH_HAS_PTE_SPECIAL.
>>
>> There is no functional change introduced by this patch
>>
>> Signed-off-by: Laurent Dufour <ldufour@linux.vnet.ibm.com>
>> ---
>>   mm/memory.c | 23 ++++++++++-------------
>>   1 file changed, 10 insertions(+), 13 deletions(-)
>>
>> diff --git a/mm/memory.c b/mm/memory.c
>> index 96910c625daa..53b6344a90d2 100644
>> --- a/mm/memory.c
>> +++ b/mm/memory.c
>> @@ -817,19 +817,13 @@ static void print_bad_pte(struct vm_area_struct *vma,
>> unsigned long addr,
>>    * PFNMAP mappings in order to support COWable mappings.
>>    *
>>    */
>> -#ifdef CONFIG_ARCH_HAS_PTE_SPECIAL
>> -# define HAVE_PTE_SPECIAL 1
>> -#else
>> -# define HAVE_PTE_SPECIAL 0
>> -#endif
>>   struct page *_vm_normal_page(struct vm_area_struct *vma, unsigned long addr,
>>                    pte_t pte, bool with_public_device)
>>   {
>>       unsigned long pfn = pte_pfn(pte);
>>   -    if (HAVE_PTE_SPECIAL) {
>> -        if (likely(!pte_special(pte)))
>> -            goto check_pfn;
>> +#ifdef CONFIG_ARCH_HAS_PTE_SPECIAL
> 
> Nit: Couldn't you use IS_ENABLED(CONFIG_ARCH_HAS_PTE_SPECIAL) within the
> existing code structure to avoid having to add these #ifdefs?

I agree, that would be better. I didn't thought about this option..
Thanks for reporting this.

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Re: [PATCH v2 2/2] mm: remove odd HAVE_PTE_SPECIAL

[Laurent Dufour]

On 10/04/2018 17:58, Robin Murphy wrote:
> On 10/04/18 16:25, Laurent Dufour wrote:
>> Remove the additional define HAVE_PTE_SPECIAL and rely directly on
>> CONFIG_ARCH_HAS_PTE_SPECIAL.
>>
>> There is no functional change introduced by this patch
>>
>> Signed-off-by: Laurent Dufour <ldufour@linux.vnet.ibm.com>
>> ---
>>   mm/memory.c | 23 ++++++++++-------------
>>   1 file changed, 10 insertions(+), 13 deletions(-)
>>
>> diff --git a/mm/memory.c b/mm/memory.c
>> index 96910c625daa..53b6344a90d2 100644
>> --- a/mm/memory.c
>> +++ b/mm/memory.c
>> @@ -817,19 +817,13 @@ static void print_bad_pte(struct vm_area_struct *vma,
>> unsigned long addr,
>>    * PFNMAP mappings in order to support COWable mappings.
>>    *
>>    */
>> -#ifdef CONFIG_ARCH_HAS_PTE_SPECIAL
>> -# define HAVE_PTE_SPECIAL 1
>> -#else
>> -# define HAVE_PTE_SPECIAL 0
>> -#endif
>>   struct page *_vm_normal_page(struct vm_area_struct *vma, unsigned long addr,
>>                    pte_t pte, bool with_public_device)
>>   {
>>       unsigned long pfn = pte_pfn(pte);
>>   -    if (HAVE_PTE_SPECIAL) {
>> -        if (likely(!pte_special(pte)))
>> -            goto check_pfn;
>> +#ifdef CONFIG_ARCH_HAS_PTE_SPECIAL
> 
> Nit: Couldn't you use IS_ENABLED(CONFIG_ARCH_HAS_PTE_SPECIAL) within the
> existing code structure to avoid having to add these #ifdefs?

I agree, that would be better. I didn't thought about this option..
Thanks for reporting this.