arc/mm: enable ARCH_HAS_VM_GET_PAGE_PROT

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.

Link: https://lkml.kernel.org/r/[email protected]
Signed-off-by: Anshuman Khandual <[email protected]>
Cc: Vineet Gupta <[email protected]>
Cc: Arnd Bergmann <[email protected]>
Cc: Brian Cain <[email protected]>
Cc: Catalin Marinas <[email protected]>
Cc: Christophe Leroy <[email protected]>
Cc: Christoph Hellwig <[email protected]>
Cc: Christoph Hellwig <[email protected]>
Cc: Chris Zankel <[email protected]>
Cc: "David S. Miller" <[email protected]>
Cc: Dinh Nguyen <[email protected]>
Cc: Geert Uytterhoeven <[email protected]>
Cc: Guo Ren <[email protected]>
Cc: Heiko Carstens <[email protected]>
Cc: Huacai Chen <[email protected]>
Cc: Ingo Molnar <[email protected]>
Cc: "James E.J. Bottomley" <[email protected]>
Cc: Jeff Dike <[email protected]>
Cc: Jonas Bonn <[email protected]>
Cc: Michael Ellerman <[email protected]>
Cc: Michal Simek <[email protected]>
Cc: Nicholas Piggin <[email protected]>
Cc: Palmer Dabbelt <[email protected]>
Cc: Paul Mackerras <[email protected]>
Cc: Paul Walmsley <[email protected]>
Cc: Richard Henderson <[email protected]>
Cc: Rich Felker <[email protected]>
Cc: Russell King <[email protected]>
Cc: Sam Ravnborg <[email protected]>
Cc: Stafford Horne <[email protected]>
Cc: Thomas Bogendoerfer <[email protected]>
Cc: Thomas Gleixner <[email protected]>
Cc: Vasily Gorbik <[email protected]>
Cc: WANG Xuerui <[email protected]>
Cc: Will Deacon <[email protected]>
Cc: Yoshinori Sato <[email protected]>
Signed-off-by: Andrew Morton <[email protected]>

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

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)

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 const pgprot_t protection_map[16] = {
+	[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