[PATCH] roundup_pow_of_two() 64-bit fix
fls() takes an integer, so roundup_pow_of_two() is busted for ulongs larger
than 2^32-1.
Fix this by implementing and using fls_long().
(Why does roundup_pow_of_two() return a long?)
(Why is roundup_pow_of_two() __attribute_const__ whereas long_log2() is
__attribute_pure__?)
(Why does long_log2() suck so much? Because we were missing fls_long()?)
Cc: Roland Dreier <rdreier@cisco.com>
Cc: "Chen, Kenneth W" <kenneth.w.chen@intel.com>
Cc: John Hawkes <hawkes@sgi.com>
Signed-off-by: Andrew Morton <akpm@osdl.org>
Signed-off-by: Linus Torvalds <torvalds@osdl.org>
diff --git a/include/linux/bitops.h b/include/linux/bitops.h
index 208650b..f17525a 100644
--- a/include/linux/bitops.h
+++ b/include/linux/bitops.h
@@ -175,4 +175,11 @@
return (word >> shift) | (word << (32 - shift));
}
+static inline unsigned fls_long(unsigned long l)
+{
+ if (sizeof(l) == 4)
+ return fls(l);
+ return fls64(l);
+}
+
#endif
diff --git a/include/linux/kernel.h b/include/linux/kernel.h
index bb6e7dd..03d6cfa 100644
--- a/include/linux/kernel.h
+++ b/include/linux/kernel.h
@@ -154,9 +154,10 @@
return r;
}
-static inline unsigned long __attribute_const__ roundup_pow_of_two(unsigned long x)
+static inline unsigned long
+__attribute_const__ roundup_pow_of_two(unsigned long x)
{
- return (1UL << fls(x - 1));
+ return 1UL << fls_long(x - 1);
}
extern int printk_ratelimit(void);