s390/mm: enable ARCH_HAS_VM_GET_PAGE_PROT

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.

Link: https://lkml.kernel.org/r/20220711070600.2378316-19-anshuman.khandual@arm.comSigned-off-by: Anshuman Khandual <anshuman.khandual@arm.com>
Cc: Heiko Carstens <hca@linux.ibm.com>
Cc: Vasily Gorbik <gor@linux.ibm.com>
Cc: Arnd Bergmann <arnd@arndb.de>
Cc: Brian Cain <bcain@quicinc.com>
Cc: Catalin Marinas <catalin.marinas@arm.com>
Cc: Christophe Leroy <christophe.leroy@csgroup.eu>
Cc: Christoph Hellwig <hch@infradead.org>
Cc: Christoph Hellwig <hch@lst.de>
Cc: Chris Zankel <chris@zankel.net>
Cc: "David S. Miller" <davem@davemloft.net>
Cc: Dinh Nguyen <dinguyen@kernel.org>
Cc: Geert Uytterhoeven <geert@linux-m68k.org>
Cc: Guo Ren <guoren@kernel.org>
Cc: Huacai Chen <chenhuacai@kernel.org>
Cc: Ingo Molnar <mingo@redhat.com>
Cc: "James E.J. Bottomley" <James.Bottomley@HansenPartnership.com>
Cc: Jeff Dike <jdike@addtoit.com>
Cc: Jonas Bonn <jonas@southpole.se>
Cc: Michael Ellerman <mpe@ellerman.id.au>
Cc: Michal Simek <monstr@monstr.eu>
Cc: Nicholas Piggin <npiggin@gmail.com>
Cc: Palmer Dabbelt <palmer@dabbelt.com>
Cc: Paul Mackerras <paulus@samba.org>
Cc: Paul Walmsley <paul.walmsley@sifive.com>
Cc: Richard Henderson <rth@twiddle.net>
Cc: Rich Felker <dalias@libc.org>
Cc: Russell King <linux@armlinux.org.uk>
Cc: Sam Ravnborg <sam@ravnborg.org>
Cc: Stafford Horne <shorne@gmail.com>
Cc: Thomas Bogendoerfer <tsbogend@alpha.franken.de>
Cc: Thomas Gleixner <tglx@linutronix.de>
Cc: Vineet Gupta <vgupta@kernel.org>
Cc: WANG Xuerui <kernel@xen0n.name>
Cc: Will Deacon <will@kernel.org>
Cc: Yoshinori Sato <ysato@users.sourceforge.jp>
Signed-off-by: Andrew Morton <akpm@linux-foundation.org>

arch/s390/Kconfig

@@ -81,6 +81,7 @@ 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

arch/s390/include/asm/pgtable.h

@@ -424,23 +424,6 @@ 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.

arch/s390/mm/mmap.c

@@ -188,3 +188,23 @@ void arch_pick_mmap_layout(struct mm_struct *mm, struct rlimit *rlim_stack)
 		mm->get_unmapped_area = arch_get_unmapped_area_topdown;
 	}
 }
+
+static const pgprot_t protection_map[16] = {
+	[VM_NONE]					= PAGE_NONE,
+	[VM_READ]					= PAGE_RO,
+	[VM_WRITE]					= PAGE_RO,
+	[VM_WRITE | VM_READ]				= PAGE_RO,
+	[VM_EXEC]					= PAGE_RX,
+	[VM_EXEC | VM_READ]				= PAGE_RX,
+	[VM_EXEC | VM_WRITE]				= PAGE_RX,
+	[VM_EXEC | VM_WRITE | VM_READ]			= PAGE_RX,
+	[VM_SHARED]					= PAGE_NONE,
+	[VM_SHARED | VM_READ]				= PAGE_RO,
+	[VM_SHARED | VM_WRITE]				= PAGE_RW,
+	[VM_SHARED | VM_WRITE | VM_READ]		= PAGE_RW,
+	[VM_SHARED | VM_EXEC]				= PAGE_RX,
+	[VM_SHARED | VM_EXEC | VM_READ]			= PAGE_RX,
+	[VM_SHARED | VM_EXEC | VM_WRITE]		= PAGE_RWX,
+	[VM_SHARED | VM_EXEC | VM_WRITE | VM_READ]	= PAGE_RWX
+};
+DECLARE_VM_GET_PAGE_PROT