mm/mmap: drop arch_vm_get_page_pgprot()

There are no platforms left which use arch_vm_get_page_prot(). Just drop
generic arch_vm_get_page_prot().

Link: https://lkml.kernel.org/r/20220414062125.609297-8-anshuman.khandual@arm.com
Cc: Andrew Morton <akpm@linux-foundation.org>
Cc: linux-mm@kvack.org
Cc: linux-kernel@vger.kernel.org
Reviewed-by: Christophe Leroy <christophe.leroy@csgroup.eu>
Reviewed-by: Catalin Marinas <catalin.marinas@arm.com>
Signed-off-by: Anshuman Khandual <anshuman.khandual@arm.com>
Cc: Christoph Hellwig <hch@infradead.org>
Cc: David S. Miller <davem@davemloft.net>
Cc: Ingo Molnar <mingo@redhat.com>
Cc: Khalid Aziz <khalid.aziz@oracle.com>
Cc: Michael Ellerman <mpe@ellerman.id.au>
Cc: Paul Mackerras <paulus@samba.org>
Cc: Thomas Gleixner <tglx@linutronix.de>
Cc: Will Deacon <will@kernel.org>
Signed-off-by: Andrew Morton <akpm@linux-foundation.org>

include/linux/mman.h

@@ -93,10 +93,6 @@ static inline void vm_unacct_memory(long pages)
 #define arch_calc_vm_flag_bits(flags) 0
 #endif
 
-#ifndef arch_vm_get_page_prot
-#define arch_vm_get_page_prot(vm_flags) __pgprot(0)
-#endif
-
 #ifndef arch_validate_prot
 /*
  * This is called from mprotect().  PROT_GROWSDOWN and PROT_GROWSUP have

mm/mmap.c

@@ -123,9 +123,7 @@ pgprot_t protection_map[16] __ro_after_init = {
 #ifndef CONFIG_ARCH_HAS_VM_GET_PAGE_PROT
 pgprot_t vm_get_page_prot(unsigned long vm_flags)
 {
-	return __pgprot(pgprot_val(protection_map[vm_flags &
-			(VM_READ|VM_WRITE|VM_EXEC|VM_SHARED)]) |
-			pgprot_val(arch_vm_get_page_prot(vm_flags)));
+	return protection_map[vm_flags & (VM_READ|VM_WRITE|VM_EXEC|VM_SHARED)];
 }
 EXPORT_SYMBOL(vm_get_page_prot);
 #endif	/* CONFIG_ARCH_HAS_VM_GET_PAGE_PROT */