[PATCH V3 18/30] arc/mm: Enable ARCH_HAS_VM_GET_PAGE_PROT

Anshuman Khandual
2022-02-28T10:53:28Z

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: 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 | 17 ----------
arch/arc/mm/mmap.c | 41 +++++++++++++++++++++++
3 files changed, 42 insertions(+), 17 deletions(-)

diff --git a/arch/arc/Kconfig b/arch/arc/Kconfig
index 3c2a4753d09b..78ff0644b343 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..798308f4dbad 100644
--- a/arch/arc/include/asm/pgtable-bits-arcv2.h
+++ b/arch/arc/include/asm/pgtable-bits-arcv2.h
@@ -72,23 +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__

diff --git a/arch/arc/mm/mmap.c b/arch/arc/mm/mmap.c
index 722d26b94307..d286894d7359 100644
--- a/arch/arc/mm/mmap.c
+++ b/arch/arc/mm/mmap.c
@@ -74,3 +74,44 @@ arch_get_unmapped_area(struct file *filp, unsigned long addr,
info.align_offset = pgoff << PAGE_SHIFT;
return vm_unmapped_area(&info);
}
+
+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_U_NONE;
+ case VM_READ:
+ /* Pvt-W => !W */
+ case VM_WRITE:
+ /* Pvt-W => !W */
+ case VM_WRITE | VM_READ:
+ return PAGE_U_R;
+ /* X => R */
+ case VM_EXEC:
+ case VM_EXEC | VM_READ:
+ /* Pvt-W => !W and X => R */
+ case VM_EXEC | VM_WRITE:
+ /* Pvt-W => !W */
+ case VM_EXEC | VM_WRITE | VM_READ:
+ return PAGE_U_X_R;
+ case VM_SHARED:
+ return PAGE_U_NONE;
+ case VM_SHARED | VM_READ:
+ return PAGE_U_R;
+ /* W => R */
+ case VM_SHARED | VM_WRITE:
+ case VM_SHARED | VM_WRITE | VM_READ:
+ return PAGE_U_W_R;
+ /* X => R */
+ case VM_SHARED | VM_EXEC:
+ case VM_SHARED | VM_EXEC | VM_READ:
+ return PAGE_U_X_R;
+ /* X => R */
+ case VM_SHARED | VM_EXEC | VM_WRITE:
+ case VM_SHARED | VM_EXEC | VM_WRITE | VM_READ:
+ return PAGE_U_X_W_R;
+ default:
+ BUILD_BUG();
+ }
+}
+EXPORT_SYMBOL(vm_get_page_prot);
--
2.25.1