sched: Extract the basic add/sub preempt_count modifiers

Rewrite the preempt_count macros in order to extract the 3 basic
preempt_count value modifiers:

  __preempt_count_add()
  __preempt_count_sub()

and the new:

  __preempt_count_dec_and_test()

And since we're at it anyway, replace the unconventional
$op_preempt_count names with the more conventional preempt_count_$op.

Since these basic operators are equivalent to the previous _notrace()
variants, do away with the _notrace() versions.

Signed-off-by: Peter Zijlstra <peterz@infradead.org>
Link: http://lkml.kernel.org/n/tip-ewbpdbupy9xpsjhg960zwbv8@git.kernel.org
Signed-off-by: Ingo Molnar <mingo@kernel.org>
diff --git a/include/linux/hardirq.h b/include/linux/hardirq.h
index 1e04106..d9cf963 100644
--- a/include/linux/hardirq.h
+++ b/include/linux/hardirq.h
@@ -33,7 +33,7 @@
 #define __irq_enter()					\
 	do {						\
 		account_irq_enter_time(current);	\
-		add_preempt_count(HARDIRQ_OFFSET);	\
+		preempt_count_add(HARDIRQ_OFFSET);	\
 		trace_hardirq_enter();			\
 	} while (0)
 
@@ -49,7 +49,7 @@
 	do {						\
 		trace_hardirq_exit();			\
 		account_irq_exit_time(current);		\
-		sub_preempt_count(HARDIRQ_OFFSET);	\
+		preempt_count_sub(HARDIRQ_OFFSET);	\
 	} while (0)
 
 /*
@@ -62,7 +62,7 @@
 		lockdep_off();					\
 		ftrace_nmi_enter();				\
 		BUG_ON(in_nmi());				\
-		add_preempt_count(NMI_OFFSET + HARDIRQ_OFFSET);	\
+		preempt_count_add(NMI_OFFSET + HARDIRQ_OFFSET);	\
 		rcu_nmi_enter();				\
 		trace_hardirq_enter();				\
 	} while (0)
@@ -72,7 +72,7 @@
 		trace_hardirq_exit();				\
 		rcu_nmi_exit();					\
 		BUG_ON(!in_nmi());				\
-		sub_preempt_count(NMI_OFFSET + HARDIRQ_OFFSET);	\
+		preempt_count_sub(NMI_OFFSET + HARDIRQ_OFFSET);	\
 		ftrace_nmi_exit();				\
 		lockdep_on();					\
 	} while (0)