perf_counter: Make set_perf_counter_pending() declaration common

At present, every architecture that supports perf_counters has to
declare set_perf_counter_pending() in its arch-specific headers.
This consolidates the declarations into a single declaration in one
common place, include/linux/perf_counter.h.  On powerpc, we continue
to provide a static inline definition of set_perf_counter_pending()
in the powerpc hw_irq.h.

Also, this removes from the x86 perf_counter.h the unused null
definitions of {test,clear}_perf_counter_pending.

Reported-by: Mike Frysinger <vapier.adi@gmail.com>
Signed-off-by: Paul Mackerras <paulus@samba.org>
Cc: Peter Zijlstra <a.p.zijlstra@chello.nl>
Cc: benh@kernel.crashing.org
LKML-Reference: <18998.13388.920691.523227@cargo.ozlabs.ibm.com>
Signed-off-by: Ingo Molnar <mingo@elte.hu>

arch/powerpc/include/asm/hw_irq.h

@@ -163,7 +163,6 @@ static inline unsigned long test_perf_counter_pending(void)
 	return 0;
 }
 
-static inline void set_perf_counter_pending(void) {}
 static inline void clear_perf_counter_pending(void) {}
 #endif /* CONFIG_PERF_COUNTERS */
 

arch/powerpc/include/asm/perf_counter.h

@@ -10,6 +10,8 @@
  */
 #include <linux/types.h>
 
+#include <asm/hw_irq.h>
+
 #define MAX_HWCOUNTERS		8
 #define MAX_EVENT_ALTERNATIVES	8
 #define MAX_LIMITED_HWCOUNTERS	2

arch/x86/include/asm/perf_counter.h

@@ -84,11 +84,6 @@ union cpuid10_edx {
 #define MSR_ARCH_PERFMON_FIXED_CTR2			0x30b
 #define X86_PMC_IDX_FIXED_BUS_CYCLES			(X86_PMC_IDX_FIXED + 2)
 
-extern void set_perf_counter_pending(void);
-
-#define clear_perf_counter_pending()	do { } while (0)
-#define test_perf_counter_pending()	(0)
-
 #ifdef CONFIG_PERF_COUNTERS
 extern void init_hw_perf_counters(void);
 extern void perf_counters_lapic_init(void);

include/linux/perf_counter.h

@@ -604,6 +604,7 @@ extern void perf_counter_task_tick(struct task_struct *task, int cpu);
 extern int perf_counter_init_task(struct task_struct *child);
 extern void perf_counter_exit_task(struct task_struct *child);
 extern void perf_counter_free_task(struct task_struct *task);
+extern void set_perf_counter_pending(void);
 extern void perf_counter_do_pending(void);
 extern void perf_counter_print_debug(void);
 extern void __perf_disable(void);