csky/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/20220711070600.2378316-18-anshuman.khandual@arm.comSigned-off-by: Anshuman Khandual <anshuman.khandual@arm.com>
Acked-by: Guo Ren <guoren@kernel.org>
Cc: Geert Uytterhoeven <geert@linux-m68k.org>
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: Heiko Carstens <hca@linux.ibm.com>
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: Vasily Gorbik <gor@linux.ibm.com>
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/csky/Kconfig

@@ -6,6 +6,7 @@ config CSKY
 	select ARCH_HAS_GCOV_PROFILE_ALL
 	select ARCH_HAS_SYNC_DMA_FOR_CPU
 	select ARCH_HAS_SYNC_DMA_FOR_DEVICE
+	select ARCH_HAS_VM_GET_PAGE_PROT
 	select ARCH_USE_BUILTIN_BSWAP
 	select ARCH_USE_QUEUED_RWLOCKS
 	select ARCH_WANT_FRAME_POINTERS if !CPU_CK610 && $(cc-option,-mbacktrace)

arch/csky/include/asm/pgtable.h

@@ -77,24 +77,6 @@
 #define MAX_SWAPFILES_CHECK() \
 		BUILD_BUG_ON(MAX_SWAPFILES_SHIFT != 5)
 
-#define __P000	PAGE_NONE
-#define __P001	PAGE_READ
-#define __P010	PAGE_READ
-#define __P011	PAGE_READ
-#define __P100	PAGE_READ
-#define __P101	PAGE_READ
-#define __P110	PAGE_READ
-#define __P111	PAGE_READ
-
-#define __S000	PAGE_NONE
-#define __S001	PAGE_READ
-#define __S010	PAGE_WRITE
-#define __S011	PAGE_WRITE
-#define __S100	PAGE_READ
-#define __S101	PAGE_READ
-#define __S110	PAGE_WRITE
-#define __S111	PAGE_WRITE
-
 extern unsigned long empty_zero_page[PAGE_SIZE / sizeof(unsigned long)];
 #define ZERO_PAGE(vaddr)	(virt_to_page(empty_zero_page))
 

arch/csky/mm/init.c

@@ -197,3 +197,23 @@ void __init fixaddr_init(void)
 	vaddr = __fix_to_virt(__end_of_fixed_addresses - 1) & PMD_MASK;
 	fixrange_init(vaddr, vaddr + PMD_SIZE, swapper_pg_dir);
 }
+
+static const pgprot_t protection_map[16] = {
+	[VM_NONE]					= PAGE_NONE,
+	[VM_READ]					= PAGE_READ,
+	[VM_WRITE]					= PAGE_READ,
+	[VM_WRITE | VM_READ]				= PAGE_READ,
+	[VM_EXEC]					= PAGE_READ,
+	[VM_EXEC | VM_READ]				= PAGE_READ,
+	[VM_EXEC | VM_WRITE]				= PAGE_READ,
+	[VM_EXEC | VM_WRITE | VM_READ]			= PAGE_READ,
+	[VM_SHARED]					= PAGE_NONE,
+	[VM_SHARED | VM_READ]				= PAGE_READ,
+	[VM_SHARED | VM_WRITE]				= PAGE_WRITE,
+	[VM_SHARED | VM_WRITE | VM_READ]		= PAGE_WRITE,
+	[VM_SHARED | VM_EXEC]				= PAGE_READ,
+	[VM_SHARED | VM_EXEC | VM_READ]			= PAGE_READ,
+	[VM_SHARED | VM_EXEC | VM_WRITE]		= PAGE_WRITE,
+	[VM_SHARED | VM_EXEC | VM_WRITE | VM_READ]	= PAGE_WRITE
+};
+DECLARE_VM_GET_PAGE_PROT