[RFC V1 14/31] s390/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: Heiko Carstens <hca@linux.ibm.com>
Cc: Vasily Gorbik <gor@linux.ibm.com>
Cc: linux-s390@vger.kernel.org
Cc: linux-kernel@vger.kernel.org
Signed-off-by: Anshuman Khandual <anshuman.khandual@arm.com>
---
 arch/s390/Kconfig               |  1 +
 arch/s390/include/asm/pgtable.h | 17 --------------
 arch/s390/mm/mmap.c             | 41 +++++++++++++++++++++++++++++++++
 3 files changed, 42 insertions(+), 17 deletions(-)

diff --git a/arch/s390/Kconfig b/arch/s390/Kconfig
index 9750f92380f5..83d1e0e3c762 100644
--- a/arch/s390/Kconfig
+++ b/arch/s390/Kconfig
@@ -78,6 +78,7 @@ config S390
 	select ARCH_HAS_SYSCALL_WRAPPER
 	select ARCH_HAS_UBSAN_SANITIZE_ALL
 	select ARCH_HAS_VDSO_DATA
+	select ARCH_HAS_VM_GET_PAGE_PROT
 	select ARCH_HAVE_NMI_SAFE_CMPXCHG
 	select ARCH_INLINE_READ_LOCK
 	select ARCH_INLINE_READ_LOCK_BH
diff --git a/arch/s390/include/asm/pgtable.h b/arch/s390/include/asm/pgtable.h
index 008a6c856fa4..3893ef64b439 100644
--- a/arch/s390/include/asm/pgtable.h
+++ b/arch/s390/include/asm/pgtable.h
@@ -422,23 +422,6 @@ static inline int is_module_addr(void *addr)
  * implies read permission.
  */
          /*xwr*/
-#define __P000	PAGE_NONE
-#define __P001	PAGE_RO
-#define __P010	PAGE_RO
-#define __P011	PAGE_RO
-#define __P100	PAGE_RX
-#define __P101	PAGE_RX
-#define __P110	PAGE_RX
-#define __P111	PAGE_RX
-
-#define __S000	PAGE_NONE
-#define __S001	PAGE_RO
-#define __S010	PAGE_RW
-#define __S011	PAGE_RW
-#define __S100	PAGE_RX
-#define __S101	PAGE_RX
-#define __S110	PAGE_RWX
-#define __S111	PAGE_RWX
 
 /*
  * Segment entry (large page) protection definitions.
diff --git a/arch/s390/mm/mmap.c b/arch/s390/mm/mmap.c
index e54f928503c5..5b15469eef7a 100644
--- a/arch/s390/mm/mmap.c
+++ b/arch/s390/mm/mmap.c
@@ -188,3 +188,44 @@ void arch_pick_mmap_layout(struct mm_struct *mm, struct rlimit *rlim_stack)
 		mm->get_unmapped_area = arch_get_unmapped_area_topdown;
 	}
 }
+
+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_RO;
+	case VM_WRITE:
+		return PAGE_RO;
+	case VM_READ | VM_WRITE:
+		return PAGE_RO;
+	case VM_EXEC:
+		return PAGE_RX;
+	case VM_EXEC | VM_READ:
+		return PAGE_RX;
+	case VM_EXEC | VM_WRITE:
+		return PAGE_RX;
+	case VM_EXEC | VM_READ | VM_WRITE:
+		return PAGE_RX;
+	case VM_SHARED:
+		return PAGE_NONE;
+	case VM_SHARED | VM_READ:
+		return PAGE_RO;
+	case VM_SHARED | VM_WRITE:
+		return PAGE_RW;
+	case VM_SHARED | VM_READ | VM_WRITE:
+		return PAGE_RW;
+	case VM_SHARED | VM_EXEC:
+		return PAGE_RX;
+	case VM_SHARED | VM_EXEC | VM_READ:
+		return PAGE_RX;
+	case VM_SHARED | VM_EXEC | VM_WRITE:
+		return PAGE_RWX;
+	case VM_SHARED | VM_EXEC | VM_READ | VM_WRITE:
+		return PAGE_RWX;
+	default:
+		BUILD_BUG();
+	}
+}
+EXPORT_SYMBOL(vm_get_page_prot);
-- 
2.25.1