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

Anshuman Khandual
2022-02-28T10:54:00Z

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