locking/csd-lock: make CSD lock debug tunables writable in /sys

Currently the CSD lock tunables can only be set at boot time in the
kernel commandline, but the way these variables are used means there
is really no reason not to tune them at runtime through /sys.

Make the CSD lock debug tunables tunable through /sys.

Signed-off-by: Rik van Riel <riel@surriel.com>
Signed-off-by: Paul E. McKenney <paulmck@kernel.org>

Author: rikvanriel

kernel/smp.c

@@ -170,9 +170,9 @@ static DEFINE_PER_CPU(smp_call_func_t, cur_csd_func);
 static DEFINE_PER_CPU(void *, cur_csd_info);
 
 static ulong csd_lock_timeout = 5000;  /* CSD lock timeout in milliseconds. */
-module_param(csd_lock_timeout, ulong, 0444);
+module_param(csd_lock_timeout, ulong, 0644);
 static int panic_on_ipistall;  /* CSD panic timeout in milliseconds, 300000 for five minutes. */
-module_param(panic_on_ipistall, int, 0444);
+module_param(panic_on_ipistall, int, 0644);
 
 static atomic_t csd_bug_count = ATOMIC_INIT(0);