From: Matthias Kaehlcke <mka@chromium.org>
Date: Tue, 18 Apr 2017 23:30:37 +0000 (-0700)
Subject: clocksource: Use GENMASK_ULL in definition of CLOCKSOURCE_MASK
X-Git-Tag: v4.12-rc1~157^2~4
X-Git-Url: https://git.kernelconcepts.de/?p=karo-tx-linux.git;a=commitdiff_plain;h=0773cea37470f8e080c510fe720fc356cf35df3a

clocksource: Use GENMASK_ULL in definition of CLOCKSOURCE_MASK

Besides reusing existing code this removes the special case handling
for 64-bit masks, which causes clang to raise a shift count overflow
warning due to https://bugs.llvm.org//show_bug.cgi?id=10030.

Suggested-by: Dmitry Torokhov <dtor@chromium.org>
Signed-off-by: Matthias Kaehlcke <mka@chromium.org>
Cc: Grant Grundler <grundler@chromium.org>
Cc: Greg Hackmann <ghackmann@google.com>
Cc: Michael Davidson <md@google.com>
Cc: John Stultz <john.stultz@linaro.org>
Link: http://lkml.kernel.org/r/20170418233037.70990-1-mka@chromium.org
Signed-off-by: Thomas Gleixner <tglx@linutronix.de>
---

diff --git a/include/linux/clocksource.h b/include/linux/clocksource.h
index cfc75848a35d..f2b10d9ebd04 100644
--- a/include/linux/clocksource.h
+++ b/include/linux/clocksource.h
@@ -120,7 +120,7 @@ struct clocksource {
 #define CLOCK_SOURCE_RESELECT			0x100
 
 /* simplify initialization of mask field */
-#define CLOCKSOURCE_MASK(bits) (u64)((bits) < 64 ? ((1ULL<<(bits))-1) : -1)
+#define CLOCKSOURCE_MASK(bits) GENMASK_ULL((bits) - 1, 0)
 
 static inline u32 clocksource_freq2mult(u32 freq, u32 shift_constant, u64 from)
 {