bitops: introduce CONFIG_GENERIC_FIND_BIT_LE

This introduces CONFIG_GENERIC_FIND_BIT_LE to tell whether to use generic
implementation of find_*_bit_le() in lib/find_next_bit.c or not.

For now we select CONFIG_GENERIC_FIND_BIT_LE for all architectures which
enable CONFIG_GENERIC_FIND_NEXT_BIT.

But m68knommu wants to define own faster find_next_zero_bit_le() and
continues using generic find_next_{,zero_}bit().
(CONFIG_GENERIC_FIND_NEXT_BIT and !CONFIG_GENERIC_FIND_BIT_LE)

Signed-off-by: Akinobu Mita <akinobu.mita@gmail.com>
Cc: Greg Ungerer <gerg@uclinux.org>
Cc: Arnd Bergmann <arnd@arndb.de>
Signed-off-by: Andrew Morton <akpm@linux-foundation.org>
Signed-off-by: Linus Torvalds <torvalds@linux-foundation.org>

14 files changed, 48 insertions, 0 deletions

diff --git a/arch/frv/Kconfig b/arch/frv/Kconfig
index 747499a..f6037b2 100644
--- a/arch/frv/Kconfig
+++ b/arch/frv/Kconfig
@@ -22,6 +22,10 @@ config GENERIC_FIND_NEXT_BIT
 	bool
 	default y
 
+config GENERIC_FIND_BIT_LE
+	bool
+	default y
+
 config GENERIC_HWEIGHT
 	bool
 	default y
diff --git a/arch/h8300/Kconfig b/arch/h8300/Kconfig
index 6df692d..9624db1 100644
--- a/arch/h8300/Kconfig
+++ b/arch/h8300/Kconfig
@@ -45,6 +45,10 @@ config GENERIC_FIND_NEXT_BIT
 	bool
 	default y
 
+config GENERIC_FIND_BIT_LE
+	bool
+	default y
+
 config GENERIC_HWEIGHT
 	bool
 	default y
diff --git a/arch/m32r/Kconfig b/arch/m32r/Kconfig
index ef4c1e4..62afe23 100644
--- a/arch/m32r/Kconfig
+++ b/arch/m32r/Kconfig
@@ -260,6 +260,10 @@ config GENERIC_FIND_NEXT_BIT
 	bool
 	default y
 
+config GENERIC_FIND_BIT_LE
+	bool
+	default y
+
 config GENERIC_HWEIGHT
 	bool
 	default y
diff --git a/arch/m68knommu/Kconfig b/arch/m68knommu/Kconfig
index b5424cf..5795f58 100644
--- a/arch/m68knommu/Kconfig
+++ b/arch/m68knommu/Kconfig
@@ -42,6 +42,10 @@ config GENERIC_FIND_NEXT_BIT
 	bool
 	default y
 
+config GENERIC_FIND_BIT_LE
+	bool
+	default y
+
 config GENERIC_GPIO
 	bool
 	default n
diff --git a/arch/microblaze/Kconfig b/arch/microblaze/Kconfig
index 922c419..5f0cf0e 100644
--- a/arch/microblaze/Kconfig
+++ b/arch/microblaze/Kconfig
@@ -37,6 +37,9 @@ config ARCH_HAS_ILOG2_U64
 config GENERIC_FIND_NEXT_BIT
 	def_bool y
 
+config GENERIC_FIND_BIT_LE
+	def_bool y
+
 config GENERIC_HWEIGHT
 	def_bool y
 
diff --git a/arch/mips/Kconfig b/arch/mips/Kconfig
index d889835..6e9811d 100644
--- a/arch/mips/Kconfig
+++ b/arch/mips/Kconfig
@@ -777,6 +777,10 @@ config GENERIC_FIND_NEXT_BIT
 	bool
 	default y
 
+config GENERIC_FIND_BIT_LE
+	bool
+	default y
+
 config GENERIC_HWEIGHT
 	bool
 	default y
diff --git a/arch/parisc/Kconfig b/arch/parisc/Kconfig
index fafdf30..9b1f427 100644
--- a/arch/parisc/Kconfig
+++ b/arch/parisc/Kconfig
@@ -52,6 +52,10 @@ config GENERIC_FIND_NEXT_BIT
 	bool
 	default y
 
+config GENERIC_FIND_BIT_LE
+	bool
+	default y
+
 config GENERIC_BUG
 	bool
 	default y
diff --git a/arch/powerpc/Kconfig b/arch/powerpc/Kconfig
index 71ba047..ce9ff55 100644
--- a/arch/powerpc/Kconfig
+++ b/arch/powerpc/Kconfig
@@ -95,6 +95,10 @@ config GENERIC_FIND_NEXT_BIT
 	bool
 	default y
 
+config GENERIC_FIND_BIT_LE
+	bool
+	default y
+
 config GENERIC_GPIO
 	bool
 	help
diff --git a/arch/sh/Kconfig b/arch/sh/Kconfig
index 2d264fa..1fbf0c7 100644
--- a/arch/sh/Kconfig
+++ b/arch/sh/Kconfig
@@ -75,6 +75,9 @@ config GENERIC_CSUM
 config GENERIC_FIND_NEXT_BIT
 	def_bool y
 
+config GENERIC_FIND_BIT_LE
+	def_bool y
+
 config GENERIC_HWEIGHT
 	def_bool y
 
diff --git a/arch/sparc/Kconfig b/arch/sparc/Kconfig
index e48f471..f766e6b 100644
--- a/arch/sparc/Kconfig
+++ b/arch/sparc/Kconfig
@@ -192,6 +192,10 @@ config GENERIC_FIND_NEXT_BIT
 	bool
 	default y
 
+config GENERIC_FIND_BIT_LE
+	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..7283919 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_BIT_LE
+	def_bool y
+
 config GENERIC_HWEIGHT
 	def_bool y
 
diff --git a/lib/Kconfig b/lib/Kconfig
index 3a55a43..23fa7a3 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_BIT_LE
+	bool
+
 config GENERIC_FIND_LAST_BIT
 	bool
 	default y
diff --git a/lib/Makefile b/lib/Makefile
index 8c9de02..d7872b5 100644
--- a/lib/Makefile
+++ b/lib/Makefile
@@ -40,6 +40,7 @@ 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-$(CONFIG_GENERIC_FIND_BIT_LE) += find_next_bit.o
 obj-$(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 7667c3d..b0a8767 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_BIT_LE
 
 /* include/linux/byteorder does not support "unsigned long" type */
 static inline unsigned long ext2_swabp(const unsigned long * x)
@@ -273,4 +274,6 @@ found_middle_swap:
 	return result + __ffs(ext2_swab(tmp));
 }
 EXPORT_SYMBOL(find_next_bit_le);
+
+#endif /* CONFIG_GENERIC_FIND_BIT_LE */
 #endif /* __BIG_ENDIAN */