linux-kernel - [PATCH 1/3] cpu topology: remove stale arch_provides_topology_pointers and define_siblings_show

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Date:	Sat, 27 Jul 2013 11:00:49 +0800
From:	Hanjun Guo <hanjun.guo@...aro.org>
To:	Greg Kroah-Hartman <gregkh@...uxfoundation.org>,
	Thomas Gleixner <tglx@...utronix.de>,
	Chris Metcalf <cmetcalf@...era.com>
Cc:	patches@...aro.org, linaro-kernel@...ts.linaro.org,
	Mike Travis <travis@....com>,
	Rusty Russell <rusty@...tcorp.com.au>,
	Ingo Molnar <mingo@...hat.com>,
	"H. Peter Anvin" <hpa@...or.com>, linux-kernel@...r.kernel.org,
	x86@...nel.org, linaro-acpi@...ts.linaro.org,
	Al Stone <al.stone@...aro.org>,
	Graeme Gregory <graeme.gregory@...aro.org>,
	Naresh Bhat <naresh.bhat@...aro.org>,
	Tomasz Nowicki <tomasz.nowicki@...aro.org>,
	Hanjun Guo <hanjun.guo@...aro.org>
Subject: [PATCH 1/3] cpu topology: remove stale arch_provides_topology_pointers and define_siblings_show_map/list()

arch_provides_topology_pointers was introduced in commit 23ca4bba3 (x86:
cleanup early per cpu variables/accesses v4) to indicate pointers to the
topology cpumask_t maps are valid to avoid copying data on to/off of the
stack.

But later in commit fbd59a8d (cpumask: Use topology_core_cpumask()/
topology_thread_cpumask()), the pointers to the topology struct cpumask maps
are always valid.

After that commit, the only difference is that there is a redundant
"unsigned int cpu = dev->id;" if arch_provides_topology_pointers defined, but
dev->id is type 'u32' which devolves to 'unsigned int' on all supported arches.
So this arch_provides_topology_pointers define is pointless and only cause
obfuscation now, remove it.

Tested on x86 machine, topology information in sys/devices/system/cpu/
cpuX/topology/ is the same after appling this patch set.

Signed-off-by: Hanjun Guo <hanjun.guo@...aro.org>
---
 drivers/base/topology.c |   20 --------------------
 1 file changed, 20 deletions(-)

diff --git a/drivers/base/topology.c b/drivers/base/topology.c
index 2f5919e..94ffee3 100644
--- a/drivers/base/topology.c
+++ b/drivers/base/topology.c
@@ -62,25 +62,6 @@ static ssize_t show_cpumap(int type, const struct cpumask *mask, char *buf)
 }
 #endif
 
-#ifdef arch_provides_topology_pointers
-#define define_siblings_show_map(name)					\
-static ssize_t show_##name(struct device *dev,				\
-			   struct device_attribute *attr, char *buf)	\
-{									\
-	unsigned int cpu = dev->id;					\
-	return show_cpumap(0, topology_##name(cpu), buf);		\
-}
-
-#define define_siblings_show_list(name)					\
-static ssize_t show_##name##_list(struct device *dev,			\
-				  struct device_attribute *attr,	\
-				  char *buf)				\
-{									\
-	unsigned int cpu = dev->id;					\
-	return show_cpumap(1, topology_##name(cpu), buf);		\
-}
-
-#else
 #define define_siblings_show_map(name)					\
 static ssize_t show_##name(struct device *dev,				\
 			   struct device_attribute *attr, char *buf)	\
@@ -95,7 +76,6 @@ static ssize_t show_##name##_list(struct device *dev,			\
 {									\
 	return show_cpumap(1, topology_##name(dev->id), buf);		\
 }
-#endif
 
 #define define_siblings_show_func(name)		\
 	define_siblings_show_map(name); define_siblings_show_list(name)
-- 
1.7.9.5

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