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authorThomas Chou <thomas@wytron.com.tw>2010-03-20 07:05:46 +0800
committerScott McNutt <smcnutt@psyent.com>2010-04-02 12:28:40 -0400
commit3bef253f0802c6292b8e2acc0089894019e99e62 (patch)
tree4117b2da164130ffc4ee38b35f472e853142427c /include/asm-nios2/bitops/ffs.h
parentd8b73dffa9866d6de3c05c8a2d07ecd4bc0d5d7e (diff)
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nios2: use bitops from linux-2.6 asm-generic
These are needed to use ubi/ubifs. Signed-off-by: Thomas Chou <thomas@wytron.com.tw> Signed-off-by: Scott McNutt <smcnutt@psyent.com>
Diffstat (limited to 'include/asm-nios2/bitops/ffs.h')
-rw-r--r--include/asm-nios2/bitops/ffs.h41
1 files changed, 41 insertions, 0 deletions
diff --git a/include/asm-nios2/bitops/ffs.h b/include/asm-nios2/bitops/ffs.h
new file mode 100644
index 0000000..fbbb43a
--- /dev/null
+++ b/include/asm-nios2/bitops/ffs.h
@@ -0,0 +1,41 @@
+#ifndef _ASM_GENERIC_BITOPS_FFS_H_
+#define _ASM_GENERIC_BITOPS_FFS_H_
+
+/**
+ * ffs - find first bit set
+ * @x: the word to search
+ *
+ * This is defined the same way as
+ * the libc and compiler builtin ffs routines, therefore
+ * differs in spirit from the above ffz (man ffs).
+ */
+static inline int ffs(int x)
+{
+ int r = 1;
+
+ if (!x)
+ return 0;
+ if (!(x & 0xffff)) {
+ x >>= 16;
+ r += 16;
+ }
+ if (!(x & 0xff)) {
+ x >>= 8;
+ r += 8;
+ }
+ if (!(x & 0xf)) {
+ x >>= 4;
+ r += 4;
+ }
+ if (!(x & 3)) {
+ x >>= 2;
+ r += 2;
+ }
+ if (!(x & 1)) {
+ x >>= 1;
+ r += 1;
+ }
+ return r;
+}
+
+#endif /* _ASM_GENERIC_BITOPS_FFS_H_ */