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authorFabio Estevam <fabio.estevam@freescale.com>2015-11-05 12:43:23 -0200
committerTom Rini <trini@konsulko.com>2015-11-05 10:51:57 -0500
commit77c8554e4d7db8d04f03ee92d186bd87f74e3773 (patch)
tree709b900ed22641760b41ca9880679eab2b36c2eb /include/asm-generic/bitops/fls.h
parentf598e7a99eda286d4c0883e440b5f81c8ac050f3 (diff)
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include: Add generic bitops headers
Use the generic bitops header files from the kernel. Imported from kernel 4.2.3. Signed-off-by: Fabio Estevam <fabio.estevam@freescale.com>
Diffstat (limited to 'include/asm-generic/bitops/fls.h')
-rw-r--r--include/asm-generic/bitops/fls.h41
1 files changed, 41 insertions, 0 deletions
diff --git a/include/asm-generic/bitops/fls.h b/include/asm-generic/bitops/fls.h
new file mode 100644
index 0000000..0576d1f
--- /dev/null
+++ b/include/asm-generic/bitops/fls.h
@@ -0,0 +1,41 @@
+#ifndef _ASM_GENERIC_BITOPS_FLS_H_
+#define _ASM_GENERIC_BITOPS_FLS_H_
+
+/**
+ * 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 __always_inline int 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;
+}
+
+#endif /* _ASM_GENERIC_BITOPS_FLS_H_ */