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Message-Id: <1432832996-12129-1-git-send-email-hofrat@osadl.org>
Date: Thu, 28 May 2015 19:09:55 +0200
From: Nicholas Mc Guire <hofrat@...dl.org>
To: Michal Marek <mmarek@...e.cz>
Cc: Masahiro Yamada <yamada.m@...panasonic.com>,
Sam Ravnborg <sam@...nborg.org>,
Thomas Gleixner <tglx@...utronix.de>,
"H. Peter Alvin" <hpa@...or.com>, Joe Perches <joe@...ches.com>,
John Stultz <john.stultz@...aro.org>,
Andrew Hunter <ahh@...gle.com>, Paul Turner <pjt@...gle.com>,
linux-kernel@...r.kernel.org, Nicholas Mc Guire <hofrat@...dl.org>
Subject: [PATCH 1/2] time: refactor usecs_to_jiffies
Refactor the usecs_to_jiffies conditional code part in time.c and
jiffies.h putting it into conditional functions rather than #ifdefs
to improve readability. This is analogous to the msecs_to_jiffies()
cleanup commit ca42aaf0c861 ("time: Refactor msecs_to_jiffies")
Patch was build tested for:
arm - imx_v6_v7_defconfig, vexpress_defconfig
cris - etrax-100lx_v2_defconfig
ia64 - generic_defconfig
(though with lots of build warnings both with and without patch)
m68k - multi_defconfig
mips32 - ar7_defconfig,
mips64 - loongson3_defconfig
powerpc - 44x/virtex5_defconfig
powerpc64 - ppc64_defconfig
s390 - failed to build for all defconfigs with toolchain from kernel.org
(cc1: error: unrecognized command line option '-mtune=zEC12')
sh - se7780_defconfig,
sparc32 - sparc32_defconfig
sparc64 - sparc64_defconfig
x86 64 - x86_64_defconfig,
patch is against 4.1-rc5 (localversion-next is -next-20150527)
Link: http://lkml.org/lkml/2015/5/18/273
Signed-off-by: Nicholas Mc Guire <hofrat@...dl.org>
---
Verification of const folding
config: x86_64_defconfig + CONFIG_DRM_GMA500=m, CONFIG_DRM_GMA3600=y
drivers/gpu/drm/gma500/intel_gmbus.c
204 gpio->algo.timeout = usecs_to_jiffies(2200);
-> reduced to load instruction
config: x86_64_defconfig + CONFIG_INFINIBAND=m, CONFIG_INFINIBAND_QIB=m
drivers/infiniband/hw/qib/qib_qp.c
809 qp->timeout = attr->timeout;
810 qp->timeout_jiffies =
811 usecs_to_jiffies((4096UL * (1UL << qp->timeout)) /
812 1000UL);
-> call __usecs_to_jiffies
include/linux/jiffies.h | 27 ++++++++++++++++++++++++++-
kernel/time/time.c | 13 +++----------
:2 files changed, 29 insertions(+), 11 deletions(-)
diff --git a/include/linux/jiffies.h b/include/linux/jiffies.h
index 3bde5eb..cf6eaaf 100644
--- a/include/linux/jiffies.h
+++ b/include/linux/jiffies.h
@@ -362,7 +362,32 @@ static inline unsigned long msecs_to_jiffies(const unsigned int m)
}
}
-extern unsigned long usecs_to_jiffies(const unsigned int u);
+extern unsigned long __usecs_to_jiffies(const unsigned int u);
+#if HZ <= USEC_PER_SEC && !(USEC_PER_SEC % HZ)
+static inline unsigned long _usecs_to_jiffies(const unsigned int u)
+{
+ return (u + (USEC_PER_SEC / HZ) - 1) / (USEC_PER_SEC / HZ);
+}
+#elif HZ > USEC_PER_SEC && !(HZ % USEC_PER_SEC)
+static inline unsigned long _usecs_to_jiffies(const unsigned int u)
+{
+ return u * (HZ / USEC_PER_SEC);
+}
+static inline unsigned long _usecs_to_jiffies(const unsigned int u)
+{
+#else
+static inline unsigned long _usecs_to_jiffies(const unsigned int u)
+{
+ return (USEC_TO_HZ_MUL32 * u + USEC_TO_HZ_ADJ32)
+ >> USEC_TO_HZ_SHR32;
+}
+#endif
+
+static inline unsigned long usecs_to_jiffies(const unsigned int u)
+{
+ return __usecs_to_jiffies(u);
+}
+
extern unsigned long timespec_to_jiffies(const struct timespec *value);
extern void jiffies_to_timespec(const unsigned long jiffies,
struct timespec *value);
diff --git a/kernel/time/time.c b/kernel/time/time.c
index 972e3bb..85d5bb1 100644
--- a/kernel/time/time.c
+++ b/kernel/time/time.c
@@ -522,20 +522,13 @@ unsigned long __msecs_to_jiffies(const unsigned int m)
}
EXPORT_SYMBOL(__msecs_to_jiffies);
-unsigned long usecs_to_jiffies(const unsigned int u)
+unsigned long __usecs_to_jiffies(const unsigned int u)
{
if (u > jiffies_to_usecs(MAX_JIFFY_OFFSET))
return MAX_JIFFY_OFFSET;
-#if HZ <= USEC_PER_SEC && !(USEC_PER_SEC % HZ)
- return (u + (USEC_PER_SEC / HZ) - 1) / (USEC_PER_SEC / HZ);
-#elif HZ > USEC_PER_SEC && !(HZ % USEC_PER_SEC)
- return u * (HZ / USEC_PER_SEC);
-#else
- return (USEC_TO_HZ_MUL32 * u + USEC_TO_HZ_ADJ32)
- >> USEC_TO_HZ_SHR32;
-#endif
+ return _usecs_to_jiffies(u);
}
-EXPORT_SYMBOL(usecs_to_jiffies);
+EXPORT_SYMBOL(__usecs_to_jiffies);
/*
* The TICK_NSEC - 1 rounds up the value to the next resolution. Note
--
1.7.10.4
--
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