[MIPS] Enable support for the userlocal hardware register
Which will cut down the cost of RDHWR $29 which is used to obtain the
TLS pointer and so far being emulated in software down to a single cycle
operation.
Signed-off-by: Ralf Baechle <ralf@linux-mips.org>
diff --git a/arch/mips/kernel/syscall.c b/arch/mips/kernel/syscall.c
index 9dd5a2d..b947c61 100644
--- a/arch/mips/kernel/syscall.c
+++ b/arch/mips/kernel/syscall.c
@@ -272,9 +272,8 @@
struct thread_info *ti = task_thread_info(current);
ti->tp_value = addr;
-
- /* If some future MIPS implementation has this register in hardware,
- * we will need to update it here (and in context switches). */
+ if (cpu_has_userlocal)
+ write_c0_userlocal(addr);
return 0;
}
