[RFC V1 16/31] alpha/mm: Enable ARCH_HAS_VM_GET_PAGE_PROT

[Anshuman Khandual]

This defines and exports a platform specific custom vm_get_page_prot() via
subscribing ARCH_HAS_VM_GET_PAGE_PROT. Subsequently all __SXXX and __PXXX
macros can be dropped which are no longer needed.

Cc: Richard Henderson <rth@xxxxxxxxxxx>
Cc: linux-alpha@xxxxxxxxxxxxxxx
Cc: linux-kernel@xxxxxxxxxxxxxxx
Signed-off-by: Anshuman Khandual <anshuman.khandual@xxxxxxx>
---
 arch/alpha/Kconfig               |  1 +
 arch/alpha/include/asm/pgtable.h | 17 -------------
 arch/alpha/mm/init.c             | 41 ++++++++++++++++++++++++++++++++
 3 files changed, 42 insertions(+), 17 deletions(-)

diff --git a/arch/alpha/Kconfig b/arch/alpha/Kconfig
index 4e87783c90ad..73e82fe5c770 100644
--- a/arch/alpha/Kconfig
+++ b/arch/alpha/Kconfig
@@ -2,6 +2,7 @@
 config ALPHA
 	bool
 	default y
+	select ARCH_HAS_VM_GET_PAGE_PROT
 	select ARCH_32BIT_USTAT_F_TINODE
 	select ARCH_MIGHT_HAVE_PC_PARPORT
 	select ARCH_MIGHT_HAVE_PC_SERIO
diff --git a/arch/alpha/include/asm/pgtable.h b/arch/alpha/include/asm/pgtable.h
index 02f0429f1068..9fb5e9d10bb6 100644
--- a/arch/alpha/include/asm/pgtable.h
+++ b/arch/alpha/include/asm/pgtable.h
@@ -116,23 +116,6 @@ struct vm_area_struct;
  * arch/alpha/mm/fault.c)
  */
 	/* xwr */
-#define __P000	_PAGE_P(_PAGE_FOE | _PAGE_FOW | _PAGE_FOR)
-#define __P001	_PAGE_P(_PAGE_FOE | _PAGE_FOW)
-#define __P010	_PAGE_P(_PAGE_FOE)
-#define __P011	_PAGE_P(_PAGE_FOE)
-#define __P100	_PAGE_P(_PAGE_FOW | _PAGE_FOR)
-#define __P101	_PAGE_P(_PAGE_FOW)
-#define __P110	_PAGE_P(0)
-#define __P111	_PAGE_P(0)
-
-#define __S000	_PAGE_S(_PAGE_FOE | _PAGE_FOW | _PAGE_FOR)
-#define __S001	_PAGE_S(_PAGE_FOE | _PAGE_FOW)
-#define __S010	_PAGE_S(_PAGE_FOE)
-#define __S011	_PAGE_S(_PAGE_FOE)
-#define __S100	_PAGE_S(_PAGE_FOW | _PAGE_FOR)
-#define __S101	_PAGE_S(_PAGE_FOW)
-#define __S110	_PAGE_S(0)
-#define __S111	_PAGE_S(0)
 
 /*
  * pgprot_noncached() is only for infiniband pci support, and a real
diff --git a/arch/alpha/mm/init.c b/arch/alpha/mm/init.c
index f6114d03357c..89e5e593194d 100644
--- a/arch/alpha/mm/init.c
+++ b/arch/alpha/mm/init.c
@@ -280,3 +280,44 @@ mem_init(void)
 	high_memory = (void *) __va(max_low_pfn * PAGE_SIZE);
 	memblock_free_all();
 }
+
+pgprot_t vm_get_page_prot(unsigned long vm_flags)
+{
+	switch (vm_flags & (VM_READ | VM_WRITE | VM_EXEC | VM_SHARED)) {
+	case VM_NONE:
+		return _PAGE_P(_PAGE_FOE|_PAGE_FOW|_PAGE_FOR);
+	case VM_READ:
+		return _PAGE_P(_PAGE_FOE|_PAGE_FOW);
+	case VM_WRITE:
+		return _PAGE_P(_PAGE_FOE);
+	case VM_READ | VM_WRITE:
+		return _PAGE_P(_PAGE_FOE);
+	case VM_EXEC:
+		return _PAGE_P(_PAGE_FOW|_PAGE_FOR);
+	case VM_EXEC | VM_READ:
+		return _PAGE_P(_PAGE_FOW);
+	case VM_EXEC | VM_WRITE:
+		return _PAGE_P(0);
+	case VM_EXEC | VM_READ | VM_WRITE:
+		return _PAGE_P(0);
+	case VM_SHARED:
+		return _PAGE_S(_PAGE_FOE|_PAGE_FOW|_PAGE_FOR);
+	case VM_SHARED | VM_READ:
+		return _PAGE_S(_PAGE_FOE|_PAGE_FOW);
+	case VM_SHARED | VM_WRITE:
+		return _PAGE_S(_PAGE_FOE);
+	case VM_SHARED | VM_READ | VM_WRITE:
+		return  _PAGE_S(_PAGE_FOE);
+	case VM_SHARED | VM_EXEC:
+		return _PAGE_S(_PAGE_FOW|_PAGE_FOR);
+	case VM_SHARED | VM_EXEC | VM_READ:
+		return _PAGE_S(_PAGE_FOW);
+	case VM_SHARED | VM_EXEC | VM_WRITE:
+		return _PAGE_S(0);
+	case VM_SHARED | VM_EXEC | VM_READ | VM_WRITE:
+		return _PAGE_S(0);
+	default:
+		BUILD_BUG();
+	}
+}
+EXPORT_SYMBOL(vm_get_page_prot);
-- 
2.25.1