posix-timers: Introduce clock_posix_cpu

The CLOCK_DISPATCH() macro is a horrible magic. We call common
functions if a function pointer is not set. That's just backwards.

To support dynamic file decriptor based clocks we need to cleanup that
dispatch logic.

Create a k_clock struct clock_posix_cpu which has all the
posix-cpu-timer functions filled in. After the cleanup the functions
can be made static.

Signed-off-by: Thomas Gleixner <tglx@linutronix.de>
Acked-by: John Stultz <johnstul@us.ibm.com>
Tested-by: Richard Cochran <richard.cochran@omicron.at>
LKML-Reference: <20110201134417.841974553@linutronix.de>

include/linux/posix-timers.h

@@ -85,6 +85,8 @@ struct k_clock {
 			   struct itimerspec * cur_setting);
 };
 
+extern struct k_clock clock_posix_cpu;
+
 void register_posix_clock(const clockid_t clock_id, struct k_clock *new_clock);
 
 /* error handlers for timer_create, nanosleep and settime */

kernel/posix-cpu-timers.c

@@ -1604,6 +1604,18 @@ static long thread_cpu_nsleep_restart(struct restart_block *restart_block)
 	return -EINVAL;
 }
 
+struct k_clock clock_posix_cpu = {
+	.clock_getres	= posix_cpu_clock_getres,
+	.clock_set	= posix_cpu_clock_set,
+	.clock_get	= posix_cpu_clock_get,
+	.timer_create	= posix_cpu_timer_create,
+	.nsleep		= posix_cpu_nsleep,
+	.nsleep_restart	= posix_cpu_nsleep_restart,
+	.timer_set	= posix_cpu_timer_set,
+	.timer_del	= posix_cpu_timer_del,
+	.timer_get	= posix_cpu_timer_get,
+};
+
 static __init int init_posix_cpu_timers(void)
 {
 	struct k_clock process = {