[PATCH V3 20/30] xtensa/mm: Enable ARCH_HAS_VM_GET_PAGE_PROT

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

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: Chris Zankel <chris@zankel.net>
Cc: Guo Ren <guoren@kernel.org>
Cc: linux-xtensa@linux-xtensa.org
Cc: linux-csky@vger.kernel.org
Cc: linux-kernel@vger.kernel.org
Signed-off-by: Anshuman Khandual <anshuman.khandual@arm.com>
---
 arch/xtensa/Kconfig               |  1 +
 arch/xtensa/include/asm/pgtable.h | 19 -----------------
 arch/xtensa/mm/init.c             | 35 +++++++++++++++++++++++++++++++
 3 files changed, 36 insertions(+), 19 deletions(-)

diff --git a/arch/xtensa/Kconfig b/arch/xtensa/Kconfig
index 8ac599aa6d99..1608f7517546 100644
--- a/arch/xtensa/Kconfig
+++ b/arch/xtensa/Kconfig
@@ -9,6 +9,7 @@ config XTENSA
 	select ARCH_HAS_DMA_SET_UNCACHED if MMU
 	select ARCH_HAS_STRNCPY_FROM_USER if !KASAN
 	select ARCH_HAS_STRNLEN_USER
+	select ARCH_HAS_VM_GET_PAGE_PROT
 	select ARCH_USE_MEMTEST
 	select ARCH_USE_QUEUED_RWLOCKS
 	select ARCH_USE_QUEUED_SPINLOCKS
diff --git a/arch/xtensa/include/asm/pgtable.h b/arch/xtensa/include/asm/pgtable.h
index bd5aeb795567..509f765281d8 100644
--- a/arch/xtensa/include/asm/pgtable.h
+++ b/arch/xtensa/include/asm/pgtable.h
@@ -198,26 +198,7 @@
  * the MMU can't do page protection for execute, and considers that the same as
  * read.  Also, write permissions may imply read permissions.
  * What follows is the closest we can get by reasonable means..
- * See linux/mm/mmap.c for protection_map[] array that uses these definitions.
  */
-#define __P000	PAGE_NONE		/* private --- */
-#define __P001	PAGE_READONLY		/* private --r */
-#define __P010	PAGE_COPY		/* private -w- */
-#define __P011	PAGE_COPY		/* private -wr */
-#define __P100	PAGE_READONLY_EXEC	/* private x-- */
-#define __P101	PAGE_READONLY_EXEC	/* private x-r */
-#define __P110	PAGE_COPY_EXEC		/* private xw- */
-#define __P111	PAGE_COPY_EXEC		/* private xwr */
-
-#define __S000	PAGE_NONE		/* shared  --- */
-#define __S001	PAGE_READONLY		/* shared  --r */
-#define __S010	PAGE_SHARED		/* shared  -w- */
-#define __S011	PAGE_SHARED		/* shared  -wr */
-#define __S100	PAGE_READONLY_EXEC	/* shared  x-- */
-#define __S101	PAGE_READONLY_EXEC	/* shared  x-r */
-#define __S110	PAGE_SHARED_EXEC	/* shared  xw- */
-#define __S111	PAGE_SHARED_EXEC	/* shared  xwr */
-
 #ifndef __ASSEMBLY__
 
 #define pte_ERROR(e) \
diff --git a/arch/xtensa/mm/init.c b/arch/xtensa/mm/init.c
index 6a32b2cf2718..5f090749e9e0 100644
--- a/arch/xtensa/mm/init.c
+++ b/arch/xtensa/mm/init.c
@@ -216,3 +216,38 @@ static int __init parse_memmap_opt(char *str)
 	return 0;
 }
 early_param("memmap", parse_memmap_opt);
+
+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_NONE;
+	case VM_READ:
+		return PAGE_READONLY;
+	case VM_WRITE:
+	case VM_WRITE | VM_READ:
+		return PAGE_COPY;
+	case VM_EXEC:
+	case VM_EXEC | VM_READ:
+		return PAGE_READONLY_EXEC;
+	case VM_EXEC | VM_WRITE:
+	case VM_EXEC | VM_WRITE | VM_READ:
+		return PAGE_COPY_EXEC;
+	case VM_SHARED:
+		return PAGE_NONE;
+	case VM_SHARED | VM_READ:
+		return PAGE_READONLY;
+	case VM_SHARED | VM_WRITE:
+	case VM_SHARED | VM_WRITE | VM_READ:
+		return PAGE_SHARED;
+	case VM_SHARED | VM_EXEC:
+	case VM_SHARED | VM_EXEC | VM_READ:
+		return PAGE_READONLY_EXEC;
+	case VM_SHARED | VM_EXEC | VM_WRITE:
+	case VM_SHARED | VM_EXEC | VM_WRITE | VM_READ:
+		return PAGE_SHARED_EXEC;
+	default:
+		BUILD_BUG();
+	}
+}
+EXPORT_SYMBOL(vm_get_page_prot);
-- 
2.25.1