[U-Boot] [PATCH 2/8]: Define ffs/fls for all architectures
Simon Kagstrom
simon.kagstrom at netinsight.net
Tue Jul 7 15:57:34 CEST 2009
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.
Signed-off-by: Simon Kagstrom <simon.kagstrom at netinsight.net>
---
include/asm-arm/bitops.h | 4 ++++
include/asm-avr32/bitops.h | 3 +++
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 | 4 +++-
include/asm-nios2/bitops.h | 4 +++-
include/asm-sh/bitops.h | 2 ++
include/asm-sparc/bitops.h | 3 +++
include/linux/bitops.h | 37 +++++++++++++++++++++++++++++++++++++
11 files changed, 63 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 bb272d8..75ba1c2 100644
--- a/include/asm-avr32/bitops.h
+++ b/include/asm-avr32/bitops.h
@@ -25,4 +25,7 @@
#define __set_bit(nr, addr) generic_set_bit(nr, addr)
#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 e113b55..9cf1b84 100644
--- a/include/asm-m68k/bitops.h
+++ b/include/asm-m68k/bitops.h
@@ -55,6 +55,8 @@ 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 db070f7..eb9df92 100644
--- a/include/asm-nios/bitops.h
+++ b/include/asm-nios/bitops.h
@@ -32,7 +32,9 @@ 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)
#define __clear_bit(nr, addr) generic_clear_bit(nr, addr)
diff --git a/include/asm-nios2/bitops.h b/include/asm-nios2/bitops.h
index 5f5e325..d51c238 100644
--- a/include/asm-nios2/bitops.h
+++ b/include/asm-nios2/bitops.h
@@ -32,7 +32,9 @@ 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)
#define __clear_bit(nr, addr) generic_clear_bit(nr, addr)
diff --git a/include/asm-sh/bitops.h b/include/asm-sh/bitops.h
index f83c493..327ec91 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 52a15cf..5202ed2 100644
--- a/include/asm-sparc/bitops.h
+++ b/include/asm-sparc/bitops.h
@@ -29,4 +29,7 @@
#define __set_bit(nr, addr) generic_set_bit(nr, addr)
#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
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