powerpc/8xx: Use symbolic names for DSISR bits in DSI

Use symbolic names for DSISR bits in DSI
Signed-off-by: Christophe Leroy <christophe.leroy@c-s.fr>
Signed-off-by: Michael Ellerman <mpe@ellerman.id.au>

arch/powerpc/kernel/head_8xx.S

@@ -595,7 +595,7 @@ DARFixed:/* Return from dcbx instruction bug workaround */
 	mfspr	r5,SPRN_DSISR
 	stw	r5,_DSISR(r11)
 	mfspr	r4,SPRN_DAR
-	andis.	r10,r5,0x4000
+	andis.	r10,r5,DSISR_NOHPTE@h
 	beq+	1f
 	tlbie	r4
 dtlbie:

arch/powerpc/mm/fault.c

@@ -354,7 +354,7 @@ static void sanity_check_fault(bool is_write, unsigned long error_code) { }
 #else
 #define page_fault_is_write(__err)	((__err) & DSISR_ISSTORE)
 #if defined(CONFIG_PPC_8xx)
-#define page_fault_is_bad(__err)	((__err) & 0x10000000)
+#define page_fault_is_bad(__err)	((__err) & DSISR_NOEXEC_OR_G)
 #elif defined(CONFIG_PPC64)
 #define page_fault_is_bad(__err)	((__err) & DSISR_BAD_FAULT_64S)
 #else