MIPS: Allow CPU specific overriding of CP0 hwrena impl bits.

Some CPUs have implementation dependent rdhwr registers.  Allow them
to be enabled on a per CPU basis.

Signed-off-by: David Daney <ddaney@caviumnetworks.com>
Signed-off-by: Ralf Baechle <ralf@linux-mips.org>

2 files changed, 5 insertions, 1 deletions

diff --git a/arch/mips/include/asm/cpu-features.h b/arch/mips/include/asm/cpu-features.h
index 1cba4b2ffd1e..8ab1d12ba7f4 100644
--- a/arch/mips/include/asm/cpu-features.h
+++ b/arch/mips/include/asm/cpu-features.h
@@ -234,4 +234,8 @@
 #define cpu_scache_line_size()  cpu_data[0].scache.linesz
 #endif
 
+#ifndef cpu_hwrena_impl_bits
+#define cpu_hwrena_impl_bits            0
+#endif
+
 #endif /* __ASM_CPU_FEATURES_H */
diff --git a/arch/mips/kernel/traps.c b/arch/mips/kernel/traps.c
index e83da174b533..f54871797ab9 100644
--- a/arch/mips/kernel/traps.c
+++ b/arch/mips/kernel/traps.c
@@ -1502,7 +1502,7 @@ void __cpuinit per_cpu_trap_init(void)
                          status_set);
 
         if (cpu_has_mips_r2) {
-                unsigned int enable = 0x0000000f;
+                unsigned int enable = 0x0000000f | cpu_hwrena_impl_bits;
 
                 if (!noulri && cpu_has_userlocal)
                         enable |= (1 << 29);