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authorIngo Molnar <mingo@elte.hu>2009-04-29 14:46:59 +0200
committerIngo Molnar <mingo@elte.hu>2009-04-29 14:47:05 +0200
commite7fd5d4b3d240f42c30a9e3d20a4689c4d3a795a (patch)
tree4ba588631dd8189a818a91c9e3976526071178b6 /include/linux/bitops.h
parent1130b0296184bc21806225fd06d533515a99d2db (diff)
parent56a50adda49b2020156616c4eb15353e0f9ad7de (diff)
Merge branch 'linus' into perfcounters/core
Merge reason: This brach was on -rc1, refresh it to almost-rc4 to pick up the latest upstream fixes. Signed-off-by: Ingo Molnar <mingo@elte.hu>
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 61829139795a..c05a29cb9bb2 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