sparc/mm: enable ARCH_HAS_VM_GET_PAGE_PROT

This defines and exports a platform specific custom vm_get_page_prot() via
subscribing ARCH_HAS_VM_GET_PAGE_PROT.  It localizes
arch_vm_get_page_prot() as sparc_vm_get_page_prot() and moves near
vm_get_page_prot().

Link: https://lkml.kernel.org/r/20220414062125.609297-5-anshuman.khandual@arm.comSigned-off-by: NAnshuman Khandual <anshuman.khandual@arm.com>
Acked-by: NDavid S. Miller <davem@davemloft.net>
Reviewed-by: NKhalid Aziz <khalid.aziz@oracle.com>
Reviewed-by: NChristophe Leroy <christophe.leroy@csgroup.eu>
Cc: Khalid Aziz <khalid.aziz@oracle.com>
Cc: Catalin Marinas <catalin.marinas@arm.com>
Cc: Christoph Hellwig <hch@infradead.org>
Cc: Ingo Molnar <mingo@redhat.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: NAndrew Morton <akpm@linux-foundation.org>

arch/sparc/Kconfig

@@ -84,6 +84,7 @@ config SPARC64
 	select PERF_USE_VMALLOC
 	select ARCH_HAVE_NMI_SAFE_CMPXCHG
 	select HAVE_C_RECORDMCOUNT
+	select ARCH_HAS_VM_GET_PAGE_PROT
 	select HAVE_ARCH_AUDITSYSCALL
 	select ARCH_SUPPORTS_ATOMIC_RMW
 	select ARCH_SUPPORTS_DEBUG_PAGEALLOC

arch/sparc/include/asm/mman.h

@@ -46,12 +46,6 @@ static inline unsigned long sparc_calc_vm_prot_bits(unsigned long prot)
 	}
 }
 
-#define arch_vm_get_page_prot(vm_flags) sparc_vm_get_page_prot(vm_flags)
-static inline pgprot_t sparc_vm_get_page_prot(unsigned long vm_flags)
-{
-	return (vm_flags & VM_SPARC_ADI) ? __pgprot(_PAGE_MCD_4V) : __pgprot(0);
-}
-
 #define arch_validate_prot(prot, addr) sparc_validate_prot(prot, addr)
 static inline int sparc_validate_prot(unsigned long prot, unsigned long addr)
 {

arch/sparc/mm/init_64.c

@@ -3184,3 +3184,15 @@ void copy_highpage(struct page *to, struct page *from)
 	}
 }
 EXPORT_SYMBOL(copy_highpage);
+
+pgprot_t vm_get_page_prot(unsigned long vm_flags)
+{
+	unsigned long prot = pgprot_val(protection_map[vm_flags &
+					(VM_READ|VM_WRITE|VM_EXEC|VM_SHARED)]);
+
+	if (vm_flags & VM_SPARC_ADI)
+		prot |= _PAGE_MCD_4V;
+
+	return __pgprot(prot);
+}
+EXPORT_SYMBOL(vm_get_page_prot);