[PATCH 1/3] bitops: add ifdef CONFIG_GENERIC_FIND_BIT_LE guard

[PATCH 1/3] bitops: add ifdef CONFIG_GENERIC_FIND_BIT_LE guard

[Akinobu Mita]

Some architectures have optimized find_*_bit_le() as static inline
functions but other little-endian bitops are identical to the generic
version.

This adds #ifdef CONFIG_GENERIC_FIND_BIT_LE guard for find_*_bit_le()
in asm-generic/bitops/le.h so that those architectures can use this
header file.

Signed-off-by: Akinobu Mita <akinobu.mita@gmail.com>
Cc: Arnd Bergmann <arnd@arndb.de>
Cc: linux-arch@vger.kernel.org
Cc: Martin Schwidefsky <schwidefsky@de.ibm.com>
Cc: Heiko Carstens <heiko.carstens@de.ibm.com>
Cc: linux390@de.ibm.com
Cc: linux-s390@vger.kernel.org
Cc: Russell King <linux@arm.linux.org.uk>
Cc: linux-arm-kernel@lists.infradead.org
---
 include/asm-generic/bitops/le.h |    4 ++++
 1 files changed, 4 insertions(+), 0 deletions(-)

diff --git a/include/asm-generic/bitops/le.h b/include/asm-generic/bitops/le.h
index 946a21b..bd2253e 100644
--- a/include/asm-generic/bitops/le.h
+++ b/include/asm-generic/bitops/le.h
@@ -30,6 +30,8 @@ static inline unsigned long find_first_zero_bit_le(const void *addr,
 
 #define BITOP_LE_SWIZZLE	((BITS_PER_LONG-1) & ~0x7)
 
+#ifdef CONFIG_GENERIC_FIND_BIT_LE
+
 extern unsigned long find_next_zero_bit_le(const void *addr,
 		unsigned long size, unsigned long offset);
 extern unsigned long find_next_bit_le(const void *addr,
@@ -38,6 +40,8 @@ extern unsigned long find_next_bit_le(const void *addr,
 #define find_first_zero_bit_le(addr, size) \
 	find_next_zero_bit_le((addr), (size), 0)
 
+#endif /* CONFIG_GENERIC_FIND_BIT_LE */
+
 #else
 #error "Please fix <asm/byteorder.h>"
 #endif
-- 
1.7.4.4

[PATCH 2/3] arm: use asm-generic/bitops/le.h

[Akinobu Mita]

The previous change enables to use asm-generic/bitops/le.h on arm.

Signed-off-by: Akinobu Mita <akinobu.mita@gmail.com>
Cc: Russell King <linux@arm.linux.org.uk>
Cc: linux-arm-kernel@lists.infradead.org
---
 arch/arm/include/asm/bitops.h |   41 ++++-------------------------------------
 1 files changed, 4 insertions(+), 37 deletions(-)

diff --git a/arch/arm/include/asm/bitops.h b/arch/arm/include/asm/bitops.h
index ec2e0d4..4615e1b 100644
--- a/arch/arm/include/asm/bitops.h
+++ b/arch/arm/include/asm/bitops.h
@@ -203,8 +203,6 @@ extern int _find_next_bit_be(const unsigned long *p, int size, int offset);
 #define find_first_bit(p,sz)		_find_first_bit_le(p,sz)
 #define find_next_bit(p,sz,off)		_find_next_bit_le(p,sz,off)
 
-#define WORD_BITOFF_TO_LE(x)		((x))
-
 #else
 /*
  * These are the big endian, atomic definitions.
@@ -214,8 +212,6 @@ extern int _find_next_bit_be(const unsigned long *p, int size, int offset);
 #define find_first_bit(p,sz)		_find_first_bit_be(p,sz)
 #define find_next_bit(p,sz,off)		_find_next_bit_be(p,sz,off)
 
-#define WORD_BITOFF_TO_LE(x)		((x) ^ 0x18)
-
 #endif
 
 #if __LINUX_ARM_ARCH__ < 5
@@ -287,40 +283,9 @@ static inline int fls(int x)
 #include <asm-generic/bitops/hweight.h>
 #include <asm-generic/bitops/lock.h>
 
-static inline void __set_bit_le(int nr, void *addr)
-{
-	__set_bit(WORD_BITOFF_TO_LE(nr), addr);
-}
-
-static inline void __clear_bit_le(int nr, void *addr)
-{
-	__clear_bit(WORD_BITOFF_TO_LE(nr), addr);
-}
-
-static inline int __test_and_set_bit_le(int nr, void *addr)
-{
-	return __test_and_set_bit(WORD_BITOFF_TO_LE(nr), addr);
-}
+#include <asm-generic/bitops/le.h>
 
-static inline int test_and_set_bit_le(int nr, void *addr)
-{
-	return test_and_set_bit(WORD_BITOFF_TO_LE(nr), addr);
-}
-
-static inline int __test_and_clear_bit_le(int nr, void *addr)
-{
-	return __test_and_clear_bit(WORD_BITOFF_TO_LE(nr), addr);
-}
-
-static inline int test_and_clear_bit_le(int nr, void *addr)
-{
-	return test_and_clear_bit(WORD_BITOFF_TO_LE(nr), addr);
-}
-
-static inline int test_bit_le(int nr, const void *addr)
-{
-	return test_bit(WORD_BITOFF_TO_LE(nr), addr);
-}
+#ifdef __ARMEB__
 
 static inline int find_first_zero_bit_le(const void *p, unsigned size)
 {
@@ -337,6 +302,8 @@ static inline int find_next_bit_le(const void *p, int size, int offset)
 	return _find_next_bit_le(p, size, offset);
 }
 
+#endif
+
 /*
  * Ext2 is defined to use little-endian byte ordering.
  */
-- 
1.7.4.4

[PATCH 3/3] s390: use asm-generic/bitops/le.h

[Akinobu Mita]

The previous change enables to use asm-generic/bitops/le.h on s390.

Signed-off-by: Akinobu Mita <akinobu.mita@gmail.com>
Cc: Martin Schwidefsky <schwidefsky@de.ibm.com>
Cc: Heiko Carstens <heiko.carstens@de.ibm.com>
Cc: linux390@de.ibm.com
Cc: linux-s390@vger.kernel.org
---
 arch/s390/include/asm/bitops.h |   35 +----------------------------------
 1 files changed, 1 insertions(+), 34 deletions(-)

diff --git a/arch/s390/include/asm/bitops.h b/arch/s390/include/asm/bitops.h
index 38fab08..8a54b41 100644
--- a/arch/s390/include/asm/bitops.h
+++ b/arch/s390/include/asm/bitops.h
@@ -742,40 +742,7 @@ static inline int sched_find_first_bit(unsigned long *b)
  *    23 22 21 20 19 18 17 16 31 30 29 28 27 26 25 24
  */
 
-static inline void __set_bit_le(unsigned long nr, void *addr)
-{
-	__set_bit(nr ^ (__BITOPS_WORDSIZE - 8), addr);
-}
-
-static inline void __clear_bit_le(unsigned long nr, void *addr)
-{
-	__clear_bit(nr ^ (__BITOPS_WORDSIZE - 8), addr);
-}
-
-static inline int __test_and_set_bit_le(unsigned long nr, void *addr)
-{
-	return __test_and_set_bit(nr ^ (__BITOPS_WORDSIZE - 8), addr);
-}
-
-static inline int test_and_set_bit_le(unsigned long nr, void *addr)
-{
-	return test_and_set_bit(nr ^ (__BITOPS_WORDSIZE - 8), addr);
-}
-
-static inline int __test_and_clear_bit_le(unsigned long nr, void *addr)
-{
-	return __test_and_clear_bit(nr ^ (__BITOPS_WORDSIZE - 8), addr);
-}
-
-static inline int test_and_clear_bit_le(unsigned long nr, void *addr)
-{
-	return test_and_clear_bit(nr ^ (__BITOPS_WORDSIZE - 8), addr);
-}
-
-static inline int test_bit_le(unsigned long nr, const void *addr)
-{
-	return test_bit(nr ^ (__BITOPS_WORDSIZE - 8), addr);
-}
+#include <asm-generic/bitops/le.h>
 
 static inline int find_first_zero_bit_le(void *vaddr, unsigned int size)
 {
-- 
1.7.4.4

Re: [PATCH 1/3] bitops: add ifdef CONFIG_GENERIC_FIND_BIT_LE guard

[Arnd Bergmann]

On Wednesday 20 April 2011, Akinobu Mita wrote:
> index 946a21b..bd2253e 100644
> --- a/include/asm-generic/bitops/le.h
> +++ b/include/asm-generic/bitops/le.h
> @@ -30,6 +30,8 @@ static inline unsigned long find_first_zero_bit_le(const void *addr,
>  
>  #define BITOP_LE_SWIZZLE       ((BITS_PER_LONG-1) & ~0x7)
>  
> +#ifdef CONFIG_GENERIC_FIND_BIT_LE
> +
>  extern unsigned long find_next_zero_bit_le(const void *addr,
>                 unsigned long size, unsigned long offset);
>  extern unsigned long find_next_bit_le(const void *addr,
> @@ -38,6 +40,8 @@ extern unsigned long find_next_bit_le(const void *addr,
>  #define find_first_zero_bit_le(addr, size) \
>         find_next_zero_bit_le((addr), (size), 0)
>  
> +#endif /* CONFIG_GENERIC_FIND_BIT_LE */
> +
>  #else
>  #error "Please fix <asm/byteorder.h>"
>  #endif

The style that we normally use in asm-generic is to test the macro itself
for existence, so in asm-generic, do:

#ifndef find_next_zero_bit_le
extern unsigned long find_next_zero_bit_le(const void *addr,
                 unsigned long size, unsigned long offset);
#endif

and in the architectures, write

static inline unsigned long find_next_zero_bit_le(const void *addr,
                 unsigned long size, unsigned long offset)
#define find_next_zero_bit_le find_next_zero_bit_le

I guess we can do the #ifdef separately for each of the three macros,
or choose one of them to use as a key.

	Arnd

Re: [PATCH 1/3] bitops: add ifdef CONFIG_GENERIC_FIND_BIT_LE guard

[Akinobu Mita]

2011/4/20 Arnd Bergmann <arnd@arndb.de>:
> On Wednesday 20 April 2011, Akinobu Mita wrote:
>> index 946a21b..bd2253e 100644
>> --- a/include/asm-generic/bitops/le.h
>> +++ b/include/asm-generic/bitops/le.h
>> @@ -30,6 +30,8 @@ static inline unsigned long find_first_zero_bit_le(const void *addr,
>>
>>  #define BITOP_LE_SWIZZLE       ((BITS_PER_LONG-1) & ~0x7)
>>
>> +#ifdef CONFIG_GENERIC_FIND_BIT_LE
>> +
>>  extern unsigned long find_next_zero_bit_le(const void *addr,
>>                 unsigned long size, unsigned long offset);
>>  extern unsigned long find_next_bit_le(const void *addr,
>> @@ -38,6 +40,8 @@ extern unsigned long find_next_bit_le(const void *addr,
>>  #define find_first_zero_bit_le(addr, size) \
>>         find_next_zero_bit_le((addr), (size), 0)
>>
>> +#endif /* CONFIG_GENERIC_FIND_BIT_LE */
>> +
>>  #else
>>  #error "Please fix <asm/byteorder.h>"
>>  #endif
>
> The style that we normally use in asm-generic is to test the macro itself
> for existence, so in asm-generic, do:
>
> #ifndef find_next_zero_bit_le
> extern unsigned long find_next_zero_bit_le(const void *addr,
>                 unsigned long size, unsigned long offset);
> #endif
>
> and in the architectures, write
>
> static inline unsigned long find_next_zero_bit_le(const void *addr,
>                 unsigned long size, unsigned long offset)
> #define find_next_zero_bit_le find_next_zero_bit_le
>
> I guess we can do the #ifdef separately for each of the three macros,
> or choose one of them to use as a key.

I see.

Should we also kill CONFIG_GENERIC_FIND_BIT_LE option comletely,
then add the #ifdef for each find_*() in lib/find_next_bit.c and always build
it unconditionally ?

Re: [PATCH 1/3] bitops: add ifdef CONFIG_GENERIC_FIND_BIT_LE guard

[Arnd Bergmann]

On Thursday 21 April 2011, Akinobu Mita wrote:
> Should we also kill CONFIG_GENERIC_FIND_BIT_LE option comletely,
> then add the #ifdef for each find_*() in lib/find_next_bit.c and always build
> it unconditionally ?

I think that would be more consistent. It's not a big difference anyway, so
do it only if you feel motivated. There are a lot of other things that could
be changed this way, I'd only change it while reworking other aspects in order
to avoid accidentally breaking things.

	Arnd