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authorThomas Gleixner <tglx@linutronix.de>2009-05-20 09:02:28 +0200
committerThomas Gleixner <tglx@linutronix.de>2009-05-20 09:02:28 +0200
commit521c180874dae86f675d23c4eade4dba8b1f2cc8 (patch)
tree7509303da3a9a1b40a26f6811f321c89cd31737b /include/linux/bitops.h
parentf1a11e0576c7a73d759d05d776692b2b2d37172b (diff)
parent64d1304a64477629cb16b75491a77bafe6f86963 (diff)
Merge branch 'core/urgent' into core/futexes
Merge reason: this branch was on an pre -rc1 base, merge it up to -rc6+ to get the latest upstream fixes. Conflicts: kernel/futex.c Signed-off-by: Thomas Gleixner <tglx@linutronix.de>
Diffstat (limited to 'include/linux/bitops.h')
-rw-r--r--include/linux/bitops.h19
1 files changed, 19 insertions, 0 deletions
diff --git a/include/linux/bitops.h b/include/linux/bitops.h
index 61829139795..c05a29cb9bb 100644
--- a/include/linux/bitops.h
+++ b/include/linux/bitops.h
@@ -112,6 +112,25 @@ static inline unsigned fls_long(unsigned long l)
return fls64(l);
}
+/**
+ * __ffs64 - find first set bit in a 64 bit word
+ * @word: The 64 bit word
+ *
+ * On 64 bit arches this is a synomyn for __ffs
+ * The result is not defined if no bits are set, so check that @word
+ * is non-zero before calling this.
+ */
+static inline unsigned long __ffs64(u64 word)
+{
+#if BITS_PER_LONG == 32
+ if (((u32)word) == 0UL)
+ return __ffs((u32)(word >> 32)) + 32;
+#elif BITS_PER_LONG != 64
+#error BITS_PER_LONG not 32 or 64
+#endif
+ return __ffs((unsigned long)word);
+}
+
#ifdef __KERNEL__
#ifdef CONFIG_GENERIC_FIND_FIRST_BIT