MIPS: Allow UserLocal on MIPS_R1 processors

Some MIPS32R1 processors implement UserLocal (RDHWR $29) to accelerate
programs that make extensive use of thread-local storage.  Therefore,
setting up the HWRENA register should not depend on cpu_has_mips_r2.
Signed-off-by: Kevin Cernekee <cernekee@gmail.com>
Cc: linux-mips@linux-mips.org
Cc: linux-kernel@vger.kernel.org

arch/mips/kernel/traps.c

@@ -1481,6 +1481,7 @@ void __cpuinit per_cpu_trap_init(void)
 {
 	unsigned int cpu = smp_processor_id();
 	unsigned int status_set = ST0_CU0;
+	unsigned int hwrena = cpu_hwrena_impl_bits;
 #ifdef CONFIG_MIPS_MT_SMTC
 	int secondaryTC = 0;
 	int bootTC = (cpu == 0);
@@ -1513,14 +1514,14 @@ void __cpuinit per_cpu_trap_init(void)
 	change_c0_status(ST0_CU|ST0_MX|ST0_RE|ST0_FR|ST0_BEV|ST0_TS|ST0_KX|ST0_SX|ST0_UX,
 			 status_set);
 
-	if (cpu_has_mips_r2) {
-		unsigned int enable = 0x0000000f | cpu_hwrena_impl_bits;
+	if (cpu_has_mips_r2)
+		hwrena |= 0x0000000f;
 
 	if (!noulri && cpu_has_userlocal)
-			enable |= (1 << 29);
+		hwrena |= (1 << 29);
 
-		write_c0_hwrena(enable);
-	}
+	if (hwrena)
+		write_c0_hwrena(hwrena);
 
 #ifdef CONFIG_MIPS_MT_SMTC
 	if (!secondaryTC) {