* [PATCH 1/2] bitops: use find_first_zero_bit() instead of find_next_zero_bit(addr, size, 0)
2010-11-26 16:28 [PATCH 0/2] little-endian bitops bugfixes Akinobu Mita
@ 2010-11-26 16:28 ` Akinobu Mita
2010-11-26 16:28 ` [PATCH 2/2] bitops: introduce CONFIG_GENERIC_FIND_LE_BIT Akinobu Mita
1 sibling, 0 replies; 4+ messages in thread
From: Akinobu Mita @ 2010-11-26 16:28 UTC (permalink / raw)
To: linux-kernel, linux-arch, Andrew Morton; +Cc: Akinobu Mita, Arnd Bergmann
The little-endian bitops patch series introduced inefficiency to some
little-endian architectures.
include/asm-generic/bitops/le.h defines find_first_zero_le_bit() like this:
#define find_first_zero_le_bit(addr, size) \
find_next_zero_le_bit((addr), (size), 0)
All little-endian architectures include le.h and little-endian bitops
are just aliases for their native endian bitops. So above macro definision
is converted to:
#define find_first_zero_le_bit(addr, size) \
find_next_zero_bit(addr, size, 0)
This is inefficient for some architectures which have faster
find_first_zero_bit() than find_next_zero_bit(addr, size, 0).
Fix it by aliasing find_first_zero_bit() to find_first_zero_le_bit()
on little-endian architectures.
Signed-off-by: Akinobu Mita <akinobu.mita@gmail.com>
Cc: Arnd Bergmann <arnd@arndb.de>
---
include/asm-generic/bitops/le.h | 8 +++++---
1 files changed, 5 insertions(+), 3 deletions(-)
diff --git a/include/asm-generic/bitops/le.h b/include/asm-generic/bitops/le.h
index 6ad46ce..17a7119 100644
--- a/include/asm-generic/bitops/le.h
+++ b/include/asm-generic/bitops/le.h
@@ -12,6 +12,8 @@
find_next_zero_bit(addr, size, offset)
#define find_next_le_bit(addr, size, offset) \
find_next_bit(addr, size, offset)
+#define find_first_zero_le_bit(addr, size) \
+ find_first_zero_bit(addr, size)
#elif defined(__BIG_ENDIAN)
@@ -22,6 +24,9 @@ extern unsigned long find_next_zero_le_bit(const unsigned long *addr,
extern unsigned long find_next_le_bit(const unsigned long *addr,
unsigned long size, unsigned long offset);
+#define find_first_zero_le_bit(addr, size) \
+ find_next_zero_le_bit((addr), (size), 0)
+
#else
#error "Please fix <asm/byteorder.h>"
#endif
@@ -43,7 +48,4 @@ extern unsigned long find_next_le_bit(const unsigned long *addr,
#define __test_and_clear_le_bit(nr, addr) \
__test_and_clear_bit((nr) ^ BITOP_LE_SWIZZLE, (addr))
-#define find_first_zero_le_bit(addr, size) \
- find_next_zero_le_bit((addr), (size), 0)
-
#endif /* _ASM_GENERIC_BITOPS_LE_H_ */
--
1.7.3.2
^ permalink raw reply related [flat|nested] 4+ messages in thread
* [PATCH 2/2] bitops: introduce CONFIG_GENERIC_FIND_LE_BIT
2010-11-26 16:28 [PATCH 0/2] little-endian bitops bugfixes Akinobu Mita
2010-11-26 16:28 ` [PATCH 1/2] bitops: use find_first_zero_bit() instead of find_next_zero_bit(addr, size, 0) Akinobu Mita
@ 2010-11-26 16:28 ` Akinobu Mita
2010-11-26 16:28 ` Akinobu Mita
1 sibling, 1 reply; 4+ messages in thread
From: Akinobu Mita @ 2010-11-26 16:28 UTC (permalink / raw)
To: linux-kernel, linux-arch, Andrew Morton
Cc: Akinobu Mita, Greg Ungerer, Arnd Bergmann
The little-endian bitops patch series broke the build on m68knommu.
lib/find_next_bit.c:190: error: conflicting types for 'find_next_zero_le_bit'
/home/mita/scm/linux-2.6/arch/m68k/include/asm/bitops_no.h:286: error: previous
definition of 'find_next_zero_le_bit' was here
Because m68knommu selects CONFIG_GENERIC_FIND_NEXT_BIT, it redefines
find_next_zero_le_bit() in lib/find_next_bit.c.
This introduces CONFIG_GENERIC_FIND_NEXT_BIT to tell whether to use generic
implementation of find_*_le_bit() in lib/find_next_bit.c or not. It will not
be selected by m68knommu to fix build failure.
Signed-off-by: Akinobu Mita <akinobu.mita@gmail.com>
Cc: Greg Ungerer <gerg@uclinux.org>
Cc: Arnd Bergmann <arnd@arndb.de>
---
arch/frv/Kconfig | 4 ++++
arch/h8300/Kconfig | 4 ++++
arch/m32r/Kconfig | 4 ++++
arch/microblaze/Kconfig | 3 +++
arch/mips/Kconfig | 4 ++++
arch/parisc/Kconfig | 4 ++++
arch/powerpc/Kconfig | 4 ++++
arch/sh/Kconfig | 3 +++
arch/sparc/Kconfig | 4 ++++
arch/xtensa/Kconfig | 3 +++
lib/Kconfig | 3 +++
lib/Makefile | 1 +
lib/find_next_bit.c | 3 +++
13 files changed, 44 insertions(+), 0 deletions(-)
diff --git a/arch/frv/Kconfig b/arch/frv/Kconfig
index f6bcb03..77deacd 100644
--- a/arch/frv/Kconfig
+++ b/arch/frv/Kconfig
@@ -21,6 +21,10 @@ config GENERIC_FIND_NEXT_BIT
bool
default y
+config GENERIC_FIND_LE_BIT
+ bool
+ default y
+
config GENERIC_HWEIGHT
bool
default y
diff --git a/arch/h8300/Kconfig b/arch/h8300/Kconfig
index 65f897d8..02de073 100644
--- a/arch/h8300/Kconfig
+++ b/arch/h8300/Kconfig
@@ -43,6 +43,10 @@ config GENERIC_FIND_NEXT_BIT
bool
default y
+config GENERIC_FIND_LE_BIT
+ bool
+ default y
+
config GENERIC_HWEIGHT
bool
default y
diff --git a/arch/m32r/Kconfig b/arch/m32r/Kconfig
index 5c291d6..df2e01a 100644
--- a/arch/m32r/Kconfig
+++ b/arch/m32r/Kconfig
@@ -265,6 +265,10 @@ config GENERIC_FIND_NEXT_BIT
bool
default y
+config GENERIC_FIND_LE_BIT
+ bool
+ default y
+
config GENERIC_HWEIGHT
bool
default y
diff --git a/arch/microblaze/Kconfig b/arch/microblaze/Kconfig
index 387d5ff..5f29d63 100644
--- a/arch/microblaze/Kconfig
+++ b/arch/microblaze/Kconfig
@@ -34,6 +34,9 @@ config ARCH_HAS_ILOG2_U64
config GENERIC_FIND_NEXT_BIT
def_bool y
+config GENERIC_FIND_LE_BIT
+ def_bool y
+
config GENERIC_HWEIGHT
def_bool y
diff --git a/arch/mips/Kconfig b/arch/mips/Kconfig
index 67a2fa2..0ca01a2 100644
--- a/arch/mips/Kconfig
+++ b/arch/mips/Kconfig
@@ -753,6 +753,10 @@ config GENERIC_FIND_NEXT_BIT
bool
default y
+config GENERIC_FIND_LE_BIT
+ bool
+ default y
+
config GENERIC_HWEIGHT
bool
default y
diff --git a/arch/parisc/Kconfig b/arch/parisc/Kconfig
index 0888675..ca59250 100644
--- a/arch/parisc/Kconfig
+++ b/arch/parisc/Kconfig
@@ -48,6 +48,10 @@ config GENERIC_FIND_NEXT_BIT
bool
default y
+config GENERIC_FIND_LE_BIT
+ bool
+ default y
+
config GENERIC_BUG
bool
default y
diff --git a/arch/powerpc/Kconfig b/arch/powerpc/Kconfig
index e625e9e..ac44ad9 100644
--- a/arch/powerpc/Kconfig
+++ b/arch/powerpc/Kconfig
@@ -104,6 +104,10 @@ config GENERIC_FIND_NEXT_BIT
bool
default y
+config GENERIC_FIND_LE_BIT
+ bool
+ default y
+
config GENERIC_GPIO
bool
help
diff --git a/arch/sh/Kconfig b/arch/sh/Kconfig
index 7f217b3..0438776 100644
--- a/arch/sh/Kconfig
+++ b/arch/sh/Kconfig
@@ -72,6 +72,9 @@ config GENERIC_CSUM
config GENERIC_FIND_NEXT_BIT
def_bool y
+config GENERIC_FIND_LE_BIT
+ def_bool y
+
config GENERIC_HWEIGHT
def_bool y
diff --git a/arch/sparc/Kconfig b/arch/sparc/Kconfig
index 45d9c87..af40adf 100644
--- a/arch/sparc/Kconfig
+++ b/arch/sparc/Kconfig
@@ -194,6 +194,10 @@ config GENERIC_FIND_NEXT_BIT
bool
default y
+config GENERIC_FIND_LE_BIT
+ bool
+ default y
+
config GENERIC_HWEIGHT
bool
default y if !ULTRA_HAS_POPULATION_COUNT
diff --git a/arch/xtensa/Kconfig b/arch/xtensa/Kconfig
index d373d15..d20d434 100644
--- a/arch/xtensa/Kconfig
+++ b/arch/xtensa/Kconfig
@@ -21,6 +21,9 @@ config RWSEM_XCHGADD_ALGORITHM
config GENERIC_FIND_NEXT_BIT
def_bool y
+config GENERIC_FIND_LE_BIT
+ def_bool y
+
config GENERIC_HWEIGHT
def_bool y
diff --git a/lib/Kconfig b/lib/Kconfig
index fa9bf2c..2e5df8e 100644
--- a/lib/Kconfig
+++ b/lib/Kconfig
@@ -22,6 +22,9 @@ config GENERIC_FIND_FIRST_BIT
config GENERIC_FIND_NEXT_BIT
bool
+config GENERIC_FIND_LE_BIT
+ bool
+
config GENERIC_FIND_LAST_BIT
bool
default y
diff --git a/lib/Makefile b/lib/Makefile
index e6a3763..a3265d6 100644
--- a/lib/Makefile
+++ b/lib/Makefile
@@ -38,6 +38,7 @@ lib-$(CONFIG_RWSEM_GENERIC_SPINLOCK) += rwsem-spinlock.o
lib-$(CONFIG_RWSEM_XCHGADD_ALGORITHM) += rwsem.o
lib-$(CONFIG_GENERIC_FIND_FIRST_BIT) += find_next_bit.o
lib-$(CONFIG_GENERIC_FIND_NEXT_BIT) += find_next_bit.o
+lib-$(CONFIG_GENERIC_FIND_LE_BIT) += find_next_bit.o
obj-$(CONFIG_GENERIC_FIND_LAST_BIT) += find_last_bit.o
CFLAGS_hweight.o = $(subst $(quote),,$(CONFIG_ARCH_HWEIGHT_CFLAGS))
diff --git a/lib/find_next_bit.c b/lib/find_next_bit.c
index eb8934b..b7047d1 100644
--- a/lib/find_next_bit.c
+++ b/lib/find_next_bit.c
@@ -160,6 +160,7 @@ EXPORT_SYMBOL(find_first_zero_bit);
#endif /* CONFIG_GENERIC_FIND_FIRST_BIT */
#ifdef __BIG_ENDIAN
+#ifdef CONFIG_GENERIC_FIND_LE_BIT
/* include/linux/byteorder does not support "unsigned long" type */
static inline unsigned long ext2_swabp(const unsigned long * x)
@@ -271,4 +272,6 @@ found_middle_swap:
return result + __ffs(ext2_swab(tmp));
}
EXPORT_SYMBOL(find_next_le_bit);
+
+#endif /* CONFIG_GENERIC_FIND_LE_BIT */
#endif /* __BIG_ENDIAN */
--
1.7.3.2
^ permalink raw reply related [flat|nested] 4+ messages in thread