* [PATCH] clocksource: Use GENMASK_ULL in definition of CLOCKSOURCE_MASK
@ 2017-04-11 19:17 Matthias Kaehlcke
2017-04-15 4:02 ` Dmitry Torokhov
0 siblings, 1 reply; 3+ messages in thread
From: Matthias Kaehlcke @ 2017-04-11 19:17 UTC (permalink / raw)
To: John Stultz, Thomas Gleixner
Cc: linux-kernel, Dmitry Torokhov, Grant Grundler, Greg Hackmann,
Michael Davidson, Matthias Kaehlcke
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>
---
include/linux/clocksource.h | 2 +-
1 file changed, 1 insertion(+), 1 deletion(-)
diff --git a/include/linux/clocksource.h b/include/linux/clocksource.h
index cfc75848a35d..06e604b9e9dc 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) (u64)GENMASK_ULL((bits) - 1, 0)
static inline u32 clocksource_freq2mult(u32 freq, u32 shift_constant, u64 from)
{
--
2.12.2.715.g7642488e1d-goog
^ permalink raw reply related [flat|nested] 3+ messages in thread* Re: [PATCH] clocksource: Use GENMASK_ULL in definition of CLOCKSOURCE_MASK
2017-04-11 19:17 [PATCH] clocksource: Use GENMASK_ULL in definition of CLOCKSOURCE_MASK Matthias Kaehlcke
@ 2017-04-15 4:02 ` Dmitry Torokhov
2017-04-17 16:57 ` Matthias Kaehlcke
0 siblings, 1 reply; 3+ messages in thread
From: Dmitry Torokhov @ 2017-04-15 4:02 UTC (permalink / raw)
To: Matthias Kaehlcke
Cc: John Stultz, Thomas Gleixner, linux-kernel@vger.kernel.org,
Dmitry Torokhov, Grant Grundler, Greg Hackmann, Michael Davidson
Hi Matthias,
On Tue, Apr 11, 2017 at 12:17 PM, Matthias Kaehlcke <mka@chromium.org> wrote:
> 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>
> ---
> include/linux/clocksource.h | 2 +-
> 1 file changed, 1 insertion(+), 1 deletion(-)
>
> diff --git a/include/linux/clocksource.h b/include/linux/clocksource.h
> index cfc75848a35d..06e604b9e9dc 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) (u64)GENMASK_ULL((bits) - 1, 0)
I do not think cast to u64 is needed for GENMASK_ULL.
>
> static inline u32 clocksource_freq2mult(u32 freq, u32 shift_constant, u64 from)
> {
> --
> 2.12.2.715.g7642488e1d-goog
>
Thanks,
Dmitry
^ permalink raw reply [flat|nested] 3+ messages in thread* Re: [PATCH] clocksource: Use GENMASK_ULL in definition of CLOCKSOURCE_MASK
2017-04-15 4:02 ` Dmitry Torokhov
@ 2017-04-17 16:57 ` Matthias Kaehlcke
0 siblings, 0 replies; 3+ messages in thread
From: Matthias Kaehlcke @ 2017-04-17 16:57 UTC (permalink / raw)
To: Dmitry Torokhov
Cc: John Stultz, Thomas Gleixner, linux-kernel@vger.kernel.org,
Grant Grundler, Greg Hackmann, Michael Davidson
Hi Dmitry,
El Fri, Apr 14, 2017 at 09:02:03PM -0700 Dmitry Torokhov ha dit:
> On Tue, Apr 11, 2017 at 12:17 PM, Matthias Kaehlcke <mka@chromium.org> wrote:
> > 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>
> > ---
> > include/linux/clocksource.h | 2 +-
> > 1 file changed, 1 insertion(+), 1 deletion(-)
> >
> > diff --git a/include/linux/clocksource.h b/include/linux/clocksource.h
> > index cfc75848a35d..06e604b9e9dc 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) (u64)GENMASK_ULL((bits) - 1, 0)
>
> I do not think cast to u64 is needed for GENMASK_ULL.
Indeed, it is not needed, I will update the patch
Thanks!
Matthias
^ permalink raw reply [flat|nested] 3+ messages in thread
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2017-04-11 19:17 [PATCH] clocksource: Use GENMASK_ULL in definition of CLOCKSOURCE_MASK Matthias Kaehlcke
2017-04-15 4:02 ` Dmitry Torokhov
2017-04-17 16:57 ` Matthias Kaehlcke
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