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

Anshuman Khandual
2022-06-24T04:48:50Z

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@kernel.org>
Cc: linux-snps-arc@lists.infradead.org
Cc: linux-kernel@vger.kernel.org
Signed-off-by: Anshuman Khandual <anshuman.khandual@arm.com>
---
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