Let r4600 PRID detection match only legacy CPUs, cleanups.

Signed-off-by: Thiemo Seufer <ths@networkno.de>
Signed-off-by: Ralf Baechle <ralf@linux-mips.org>
diff --git a/arch/mips/mm/pg-r4k.c b/arch/mips/mm/pg-r4k.c
index 75d9ebf..c9e6ee2 100644
--- a/arch/mips/mm/pg-r4k.c
+++ b/arch/mips/mm/pg-r4k.c
@@ -25,7 +25,10 @@
 #include <asm/cpu.h>
 #include <asm/war.h>
 
-#define half_scache_line_size()		(cpu_scache_line_size() >> 1)
+#define half_scache_line_size()	(cpu_scache_line_size() >> 1)
+#define cpu_is_r4600_v1_x()	((read_c0_prid() & 0xfffffff0) == 0x00002010)
+#define cpu_is_r4600_v2_x()	((read_c0_prid() & 0xfffffff0) == 0x00002020)
+
 
 /*
  * Maximum sizes:
@@ -198,14 +201,14 @@
 	if (store_offset & (cpu_dcache_line_size() - 1))
 		return;
 
-	if (R4600_V1_HIT_CACHEOP_WAR && ((read_c0_prid() & 0xfff0) == 0x2010)) {
+	if (R4600_V1_HIT_CACHEOP_WAR && cpu_is_r4600_v1_x()) {
 		build_nop();
 		build_nop();
 		build_nop();
 		build_nop();
 	}
 
-	if (R4600_V2_HIT_CACHEOP_WAR && ((read_c0_prid() & 0xfff0) == 0x2020))
+	if (R4600_V2_HIT_CACHEOP_WAR && cpu_is_r4600_v2_x())
 		build_insn_word(0x8c200000);	/* lw      $zero, ($at) */
 
 	mi.c_format.opcode     = cache_op;
@@ -361,7 +364,7 @@
 
 	build_addiu_a2_a0(PAGE_SIZE - (cpu_has_prefetch ? pref_offset_clear : 0));
 
-	if (R4600_V2_HIT_CACHEOP_WAR && ((read_c0_prid() & 0xfff0) == 0x2020))
+	if (R4600_V2_HIT_CACHEOP_WAR && cpu_is_r4600_v2_x())
 		build_insn_word(0x3c01a000);	/* lui     $at, 0xa000  */
 
 dest = label();
@@ -417,7 +420,7 @@
 
 	build_addiu_a2_a0(PAGE_SIZE - (cpu_has_prefetch ? pref_offset_copy : 0));
 
-	if (R4600_V2_HIT_CACHEOP_WAR && ((read_c0_prid() & 0xfff0) == 0x2020))
+	if (R4600_V2_HIT_CACHEOP_WAR && cpu_is_r4600_v2_x())
 		build_insn_word(0x3c01a000);	/* lui     $at, 0xa000  */
 
 dest = label();