[PATCH V4 22/26] arc/mm: Enable ARCH_HAS_VM_GET_PAGE_PROT

[Anshuman Khandual]

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: Vineet Gupta <vgupta@xxxxxxxxxx>
Cc: linux-snps-arc@xxxxxxxxxxxxxxxxxxx
Cc: linux-kernel@xxxxxxxxxxxxxxx
Signed-off-by: Anshuman Khandual <anshuman.khandual@xxxxxxx>
---
 arch/arc/Kconfig                          |  1 +
 arch/arc/include/asm/pgtable-bits-arcv2.h | 18 ------------------
 arch/arc/mm/mmap.c                        | 20 ++++++++++++++++++++
 3 files changed, 21 insertions(+), 18 deletions(-)

diff --git a/arch/arc/Kconfig b/arch/arc/Kconfig
index 9e3653253ef2..8be56a5d8a9b 100644
--- a/arch/arc/Kconfig
+++ b/arch/arc/Kconfig
@@ -13,6 +13,7 @@ config ARC
 	select ARCH_HAS_SETUP_DMA_OPS
 	select ARCH_HAS_SYNC_DMA_FOR_CPU
 	select ARCH_HAS_SYNC_DMA_FOR_DEVICE
+	select ARCH_HAS_VM_GET_PAGE_PROT
 	select ARCH_SUPPORTS_ATOMIC_RMW if ARC_HAS_LLSC
 	select ARCH_32BIT_OFF_T
 	select BUILDTIME_TABLE_SORT
diff --git a/arch/arc/include/asm/pgtable-bits-arcv2.h b/arch/arc/include/asm/pgtable-bits-arcv2.h
index 183d23bc1e00..b23be557403e 100644
--- a/arch/arc/include/asm/pgtable-bits-arcv2.h
+++ b/arch/arc/include/asm/pgtable-bits-arcv2.h
@@ -72,24 +72,6 @@
  *     This is to enable COW mechanism
  */
 	/* xwr */
-#define __P000  PAGE_U_NONE
-#define __P001  PAGE_U_R
-#define __P010  PAGE_U_R	/* Pvt-W => !W */
-#define __P011  PAGE_U_R	/* Pvt-W => !W */
-#define __P100  PAGE_U_X_R	/* X => R */
-#define __P101  PAGE_U_X_R
-#define __P110  PAGE_U_X_R	/* Pvt-W => !W and X => R */
-#define __P111  PAGE_U_X_R	/* Pvt-W => !W */
-
-#define __S000  PAGE_U_NONE
-#define __S001  PAGE_U_R
-#define __S010  PAGE_U_W_R	/* W => R */
-#define __S011  PAGE_U_W_R
-#define __S100  PAGE_U_X_R	/* X => R */
-#define __S101  PAGE_U_X_R
-#define __S110  PAGE_U_X_W_R	/* X => R */
-#define __S111  PAGE_U_X_W_R
-
 #ifndef __ASSEMBLY__
 
 #define pte_write(pte)		(pte_val(pte) & _PAGE_WRITE)
diff --git a/arch/arc/mm/mmap.c b/arch/arc/mm/mmap.c
index 722d26b94307..7dd50b66f266 100644
--- a/arch/arc/mm/mmap.c
+++ b/arch/arc/mm/mmap.c
@@ -74,3 +74,23 @@ arch_get_unmapped_area(struct file *filp, unsigned long addr,
 	info.align_offset = pgoff << PAGE_SHIFT;
 	return vm_unmapped_area(&info);
 }
+
+static pgprot_t protection_map[16] __ro_after_init = {
+	[VM_NONE]					= PAGE_U_NONE,
+	[VM_READ]					= PAGE_U_R,
+	[VM_WRITE]					= PAGE_U_R,
+	[VM_WRITE | VM_READ]				= PAGE_U_R,
+	[VM_EXEC]					= PAGE_U_X_R,
+	[VM_EXEC | VM_READ]				= PAGE_U_X_R,
+	[VM_EXEC | VM_WRITE]				= PAGE_U_X_R,
+	[VM_EXEC | VM_WRITE | VM_READ]			= PAGE_U_X_R,
+	[VM_SHARED]					= PAGE_U_NONE,
+	[VM_SHARED | VM_READ]				= PAGE_U_R,
+	[VM_SHARED | VM_WRITE]				= PAGE_U_W_R,
+	[VM_SHARED | VM_WRITE | VM_READ]		= PAGE_U_W_R,
+	[VM_SHARED | VM_EXEC]				= PAGE_U_X_R,
+	[VM_SHARED | VM_EXEC | VM_READ]			= PAGE_U_X_R,
+	[VM_SHARED | VM_EXEC | VM_WRITE]		= PAGE_U_X_W_R,
+	[VM_SHARED | VM_EXEC | VM_WRITE | VM_READ]	= PAGE_U_X_W_R
+};
+DECLARE_VM_GET_PAGE_PROT
-- 
2.25.1