generic-ipi: Add smp_call_function_any()

Andrew points out that acpi-cpufreq uses cpumask_any, when it really
would prefer to use the same CPU if possible (to avoid an IPI).  In
general, this seems a good idea to offer.

[ tglx: Documented selection preference and Inlined the UP case to
  	avoid the copy of smp_call_function_single() and the extra
  	EXPORT ]

Signed-off-by: Rusty Russell <rusty@rustcorp.com.au>
Cc: Ingo Molnar <mingo@elte.hu>
Cc: Venkatesh Pallipadi <venkatesh.pallipadi@intel.com>
Cc: Len Brown <len.brown@intel.com>
Cc: Zhao Yakui <yakui.zhao@intel.com>
Cc: Dave Jones <davej@redhat.com>
Cc: Thomas Gleixner <tglx@linutronix.de>
Cc: Mike Galbraith <efault@gmx.de>
Cc: "Zhang, Yanmin" <yanmin_zhang@linux.intel.com>
Signed-off-by: Andrew Morton <akpm@linux-foundation.org>
Signed-off-by: Thomas Gleixner <tglx@linutronix.de>

1 files changed, 10 insertions, 1 deletions

diff --git a/include/linux/smp.h b/include/linux/smp.h
index 39c64bae776d..7a0570e6a596 100644
--- a/include/linux/smp.h
+++ b/include/linux/smp.h
@@ -76,6 +76,9 @@ void smp_call_function_many(const struct cpumask *mask,
 void __smp_call_function_single(int cpuid, struct call_single_data *data,
 				int wait);
 
+int smp_call_function_any(const struct cpumask *mask,
+			  void (*func)(void *info), void *info, int wait);
+
 /*
  * Generic and arch helpers
  */
@@ -137,9 +140,15 @@ static inline void smp_send_reschedule(int cpu) { }
 #define smp_prepare_boot_cpu()			do {} while (0)
 #define smp_call_function_many(mask, func, info, wait) \
 			(up_smp_call_function(func, info))
-static inline void init_call_single_data(void)
+static inline void init_call_single_data(void) { }
+
+static inline int
+smp_call_function_any(const struct cpumask *mask, void (*func)(void *info),
+		      void *info, int wait)
 {
+	return smp_call_function_single(0, func, info, wait);
 }
+
 #endif /* !SMP */
 
 /*