[U-Boot] [PATCH 2/4]: Define ffs/fls for all architectures

Simon Kagstrom
2009-08-18T09:13:08Z

Define ffs/fls for all architectures

UBIFS requires fls(), which is not defined for arm (and some other
architectures) and this patch adds it. The implementation is taken from
Linux and is generic. ffs() is also defined for those that miss it.

v2: Unify code style (empty line between ffs/fls)

Signed-off-by: Simon Kagstrom <simon.kagstrom@netinsight.net>
---
include/asm-arm/bitops.h | 4 ++++
include/asm-avr32/bitops.h | 4 ++++
include/asm-i386/bitops.h | 2 ++
include/asm-m68k/bitops.h | 2 ++
include/asm-microblaze/bitops.h | 2 ++
include/asm-mips/bitops.h | 2 ++
include/asm-nios/bitops.h | 5 ++++-
include/asm-nios2/bitops.h | 5 ++++-
include/asm-sh/bitops.h | 2 ++
include/asm-sparc/bitops.h | 4 ++++
include/linux/bitops.h | 37 +++++++++++++++++++++++++++++++++++++
11 files changed, 67 insertions(+), 2 deletions(-)

diff --git a/include/asm-arm/bitops.h b/include/asm-arm/bitops.h
index 4b8bab2..e98dd56 100644
--- a/include/asm-arm/bitops.h
+++ b/include/asm-arm/bitops.h
@@ -17,6 +17,8 @@

#ifdef __KERNEL__

+#include <asm/types.h>
+
#define smp_mb__before_clear_bit() do { } while (0)
#define smp_mb__after_clear_bit() do { } while (0)

@@ -117,6 +119,8 @@ static inline unsigned long ffz(unsigned long word)

#define ffs(x) generic_ffs(x)

+#define fls(x) generic_fls(x)
+
/*
* hweightN: returns the hamming weight (i.e. the number
* of bits set) of a N-bit word
diff --git a/include/asm-avr32/bitops.h b/include/asm-avr32/bitops.h
index b1cf2fb..5fa20e2 100644
--- a/include/asm-avr32/bitops.h
+++ b/include/asm-avr32/bitops.h
@@ -26,4 +26,8 @@

#define __clear_bit(nr, addr) generic_clear_bit(nr, addr)

+#define ffs(x) generic_ffs(x)
+
+#define fls(x) generic_fls(x)
+
#endif /* __ASM_AVR32_BITOPS_H */
diff --git a/include/asm-i386/bitops.h b/include/asm-i386/bitops.h
index b768e20..71c2256 100644
--- a/include/asm-i386/bitops.h
+++ b/include/asm-i386/bitops.h
@@ -350,6 +350,8 @@ static __inline__ int ffs(int x)
return r+1;
}

+#define fls(x) generic_fls(x)
+
/**
* hweightN - returns the hamming weight of a N-bit word
* @x: the word to weigh
diff --git a/include/asm-m68k/bitops.h b/include/asm-m68k/bitops.h
index fb472e6..a38a62a 100644
--- a/include/asm-m68k/bitops.h
+++ b/include/asm-m68k/bitops.h
@@ -56,6 +56,8 @@ extern __inline__ int ffs(int x)
}
#define __ffs(x) (ffs(x) - 1)

+#define fls(x) generic_fls(x)
+
#endif /* __KERNEL__ */

#endif /* _M68K_BITOPS_H */
diff --git a/include/asm-microblaze/bitops.h b/include/asm-microblaze/bitops.h
index 04ea020..e277ab8 100644
--- a/include/asm-microblaze/bitops.h
+++ b/include/asm-microblaze/bitops.h
@@ -266,6 +266,8 @@ found_middle:

#define ffs(x) generic_ffs(x)

+#define fls(x) generic_fls(x)
+
/*
* hweightN: returns the hamming weight (i.e. the number
* of bits set) of a N-bit word
diff --git a/include/asm-mips/bitops.h b/include/asm-mips/bitops.h
index 659ac9d..76b9baa 100644
--- a/include/asm-mips/bitops.h
+++ b/include/asm-mips/bitops.h
@@ -716,6 +716,8 @@ static __inline__ unsigned long ffz(unsigned long word)

#define ffs(x) generic_ffs(x)

+#define fls(x) generic_fls(x)
+
/*
* hweightN - returns the hamming weight of a N-bit word
* @x: the word to weigh
diff --git a/include/asm-nios/bitops.h b/include/asm-nios/bitops.h
index 76c52c2..33714c4 100644
--- a/include/asm-nios/bitops.h
+++ b/include/asm-nios/bitops.h
@@ -32,7 +32,10 @@ extern void change_bit(unsigned long nr, volatile void *addr);
extern int test_and_set_bit(int nr, volatile void * a);
extern int test_and_change_bit(int nr, volatile void * addr);
extern int test_bit(int nr, volatile void * a);
-extern int ffs(int i);
+
+#define ffs(x) generic_ffs(x)
+
+#define fls(x) generic_fls(x)

#define __set_bit(nr, addr) generic_set_bit(nr, addr)

diff --git a/include/asm-nios2/bitops.h b/include/asm-nios2/bitops.h
index da04b40..1fac52c 100644
--- a/include/asm-nios2/bitops.h
+++ b/include/asm-nios2/bitops.h
@@ -32,7 +32,10 @@ extern void change_bit(unsigned long nr, volatile void *addr);
extern int test_and_set_bit(int nr, volatile void * a);
extern int test_and_change_bit(int nr, volatile void * addr);
extern int test_bit(int nr, volatile void * a);
-extern int ffs(int i);
+
+#define ffs(x) generic_ffs(x)
+
+#define fls(x) generic_fls(x)

#define __set_bit(nr, addr) generic_set_bit(nr, addr)

diff --git a/include/asm-sh/bitops.h b/include/asm-sh/bitops.h
index f102e7e..8021455 100644
--- a/include/asm-sh/bitops.h
+++ b/include/asm-sh/bitops.h
@@ -147,6 +147,8 @@ static inline int ffs (int x)
return r;
}

+#define fls(x) generic_fls(x)
+
#define __set_bit(nr, addr) generic_set_bit(nr, addr)

#define __clear_bit(nr, addr) generic_clear_bit(nr, addr)
diff --git a/include/asm-sparc/bitops.h b/include/asm-sparc/bitops.h
index b1bcb53..942029f 100644
--- a/include/asm-sparc/bitops.h
+++ b/include/asm-sparc/bitops.h
@@ -30,4 +30,8 @@

#define __clear_bit(nr, addr) generic_clear_bit(nr, addr)

+#define ffs(x) generic_ffs(x)
+
+#define fls(x) generic_fls(x)
+
#endif /* _SPARC_BITOPS_H */
diff --git a/include/linux/bitops.h b/include/linux/bitops.h
index 6bdaad7..fcbd91f 100644
--- a/include/linux/bitops.h
+++ b/include/linux/bitops.h
@@ -37,6 +37,43 @@ static inline int generic_ffs(int x)
return r;
}

+/**
+ * fls - find last (most-significant) bit set
+ * @x: the word to search
+ *
+ * This is defined the same way as ffs.
+ * Note fls(0) = 0, fls(1) = 1, fls(0x80000000) = 32.
+ */
+static inline int generic_fls(int x)
+{
+ int r = 32;
+
+ if (!x)
+ return 0;
+ if (!(x & 0xffff0000u)) {
+ x <<= 16;
+ r -= 16;
+ }
+ if (!(x & 0xff000000u)) {
+ x <<= 8;
+ r -= 8;
+ }
+ if (!(x & 0xf0000000u)) {
+ x <<= 4;
+ r -= 4;
+ }
+ if (!(x & 0xc0000000u)) {
+ x <<= 2;
+ r -= 2;
+ }
+ if (!(x & 0x80000000u)) {
+ x <<= 1;
+ r -= 1;
+ }
+ return r;
+}
+
+
/*
* hweightN: returns the hamming weight (i.e. the number
* of bits set) of a N-bit word
--
1.6.0.4