[PATCH] generic-time: add macro to simplify/hide mask constants

[deliverable/linux.git] / include / linux / clocksource.h

diff --git a/include/linux/clocksource.h b/include/linux/clocksource.h
index 5f4a7f72f3ee4adc4729dfdedd71f227091d70a0..4bc94282c364ff7ef5e89aef3817cbe12bba6e95 100644 (file)
--- a/include/linux/clocksource.h
+++ b/include/linux/clocksource.h
@@ -65,6 +65,8 @@ struct clocksource {
        u64 interval_snsecs;
 };
 
+/* simplify initialization of mask field */
+#define CLOCKSOURCE_MASK(bits) (cycle_t)(bits<64 ? ((1ULL<<bits)-1) : -1)
 
 /**
  * clocksource_khz2mult - calculates mult from khz and shift