[PATCH V4 15/26] nios2/mm: Enable ARCH_HAS_VM_GET_PAGE_PROT

[Anshuman Khandual <anshuman.khandual@arm.com>]

This enables ARCH_HAS_VM_GET_PAGE_PROT on the platform and exports standard
vm_get_page_prot() implementation via DECLARE_VM_GET_PAGE_PROT, which looks
up a private and static protection_map[] array. Subsequently all __SXXX and
__PXXX macros can be dropped which are no longer needed.

Cc: Dinh Nguyen <dinguyen@kernel.org>
Cc: linux-kernel@vger.kernel.org
Signed-off-by: Anshuman Khandual <anshuman.khandual@arm.com>
---
 arch/nios2/Kconfig               |  1 +
 arch/nios2/include/asm/pgtable.h | 16 ----------------
 arch/nios2/mm/init.c             | 20 ++++++++++++++++++++
 3 files changed, 21 insertions(+), 16 deletions(-)

diff --git a/arch/nios2/Kconfig b/arch/nios2/Kconfig
index 4167f1eb4cd8..e0459dffd218 100644
--- a/arch/nios2/Kconfig
+++ b/arch/nios2/Kconfig
@@ -6,6 +6,7 @@ config NIOS2
 	select ARCH_HAS_SYNC_DMA_FOR_CPU
 	select ARCH_HAS_SYNC_DMA_FOR_DEVICE
 	select ARCH_HAS_DMA_SET_UNCACHED
+	select ARCH_HAS_VM_GET_PAGE_PROT
 	select ARCH_NO_SWAP
 	select COMMON_CLK
 	select TIMER_OF
diff --git a/arch/nios2/include/asm/pgtable.h b/arch/nios2/include/asm/pgtable.h
index 262d0609268c..470516d4555e 100644
--- a/arch/nios2/include/asm/pgtable.h
+++ b/arch/nios2/include/asm/pgtable.h
@@ -40,24 +40,8 @@ struct mm_struct;
  */
 
 /* Remove W bit on private pages for COW support */
-#define __P000	MKP(0, 0, 0)
-#define __P001	MKP(0, 0, 1)
-#define __P010	MKP(0, 0, 0)	/* COW */
-#define __P011	MKP(0, 0, 1)	/* COW */
-#define __P100	MKP(1, 0, 0)
-#define __P101	MKP(1, 0, 1)
-#define __P110	MKP(1, 0, 0)	/* COW */
-#define __P111	MKP(1, 0, 1)	/* COW */
 
 /* Shared pages can have exact HW mapping */
-#define __S000	MKP(0, 0, 0)
-#define __S001	MKP(0, 0, 1)
-#define __S010	MKP(0, 1, 0)
-#define __S011	MKP(0, 1, 1)
-#define __S100	MKP(1, 0, 0)
-#define __S101	MKP(1, 0, 1)
-#define __S110	MKP(1, 1, 0)
-#define __S111	MKP(1, 1, 1)
 
 /* Used all over the kernel */
 #define PAGE_KERNEL __pgprot(_PAGE_PRESENT | _PAGE_CACHED | _PAGE_READ | \
diff --git a/arch/nios2/mm/init.c b/arch/nios2/mm/init.c
index 613fcaa5988a..9a3dd4c80d70 100644
--- a/arch/nios2/mm/init.c
+++ b/arch/nios2/mm/init.c
@@ -124,3 +124,23 @@ const char *arch_vma_name(struct vm_area_struct *vma)
 {
 	return (vma->vm_start == KUSER_BASE) ? "[kuser]" : NULL;
 }
+
+static pgprot_t protection_map[16] __ro_after_init = {
+	[VM_NONE]					= MKP(0, 0, 0),
+	[VM_READ]					= MKP(0, 0, 1),
+	[VM_WRITE]					= MKP(0, 0, 0),
+	[VM_WRITE | VM_READ]				= MKP(0, 0, 1),
+	[VM_EXEC]					= MKP(1, 0, 0),
+	[VM_EXEC | VM_READ]				= MKP(1, 0, 1),
+	[VM_EXEC | VM_WRITE]				= MKP(1, 0, 0),
+	[VM_EXEC | VM_WRITE | VM_READ]			= MKP(1, 0, 1),
+	[VM_SHARED]					= MKP(0, 0, 0),
+	[VM_SHARED | VM_READ]				= MKP(0, 0, 1),
+	[VM_SHARED | VM_WRITE]				= MKP(0, 1, 0),
+	[VM_SHARED | VM_WRITE | VM_READ]		= MKP(0, 1, 1),
+	[VM_SHARED | VM_EXEC]				= MKP(1, 0, 0),
+	[VM_SHARED | VM_EXEC | VM_READ]			= MKP(1, 0, 1),
+	[VM_SHARED | VM_EXEC | VM_WRITE]		= MKP(1, 1, 0),
+	[VM_SHARED | VM_EXEC | VM_WRITE | VM_READ]	= MKP(1, 1, 1)
+};
+DECLARE_VM_GET_PAGE_PROT
-- 
2.25.1