1 files changed, 159 insertions, 0 deletions
diff --git a/include/linux/bitops.h b/include/linux/bitops.h
new file mode 100644
index 0000000..cb3c3ef
--- /dev/null
+++ b/include/linux/bitops.h
@@ -0,0 +1,159 @@
+#ifndef _LINUX_BITOPS_H
+#define _LINUX_BITOPS_H
+#include <asm/types.h>
+
+/*
+ * ffs: find first bit set. 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 generic_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;
+}
+
+/*
+ * fls: find last bit set.
+ */
+
+static __inline__ int generic_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;
+}
+
+/*
+ * Include this here because some architectures need generic_ffs/fls in
+ * scope
+ */
+#include <asm/bitops.h>
+
+static __inline__ int get_bitmask_order(unsigned int count)
+{
+	int order;
+	
+	order = fls(count);
+	return order;	/* We could be slightly more clever with -1 here... */
+}
+
+/*
+ * hweightN: returns the hamming weight (i.e. the number
+ * of bits set) of a N-bit word
+ */
+
+static inline unsigned int generic_hweight32(unsigned int w)
+{
+        unsigned int res = (w & 0x55555555) + ((w >> 1) & 0x55555555);
+        res = (res & 0x33333333) + ((res >> 2) & 0x33333333);
+        res = (res & 0x0F0F0F0F) + ((res >> 4) & 0x0F0F0F0F);
+        res = (res & 0x00FF00FF) + ((res >> 8) & 0x00FF00FF);
+        return (res & 0x0000FFFF) + ((res >> 16) & 0x0000FFFF);
+}
+
+static inline unsigned int generic_hweight16(unsigned int w)
+{
+        unsigned int res = (w & 0x5555) + ((w >> 1) & 0x5555);
+        res = (res & 0x3333) + ((res >> 2) & 0x3333);
+        res = (res & 0x0F0F) + ((res >> 4) & 0x0F0F);
+        return (res & 0x00FF) + ((res >> 8) & 0x00FF);
+}
+
+static inline unsigned int generic_hweight8(unsigned int w)
+{
+        unsigned int res = (w & 0x55) + ((w >> 1) & 0x55);
+        res = (res & 0x33) + ((res >> 2) & 0x33);
+        return (res & 0x0F) + ((res >> 4) & 0x0F);
+}
+
+static inline unsigned long generic_hweight64(__u64 w)
+{
+#if BITS_PER_LONG < 64
+	return generic_hweight32((unsigned int)(w >> 32)) +
+				generic_hweight32((unsigned int)w);
+#else
+	u64 res;
+	res = (w & 0x5555555555555555ul) + ((w >> 1) & 0x5555555555555555ul);
+	res = (res & 0x3333333333333333ul) + ((res >> 2) & 0x3333333333333333ul);
+	res = (res & 0x0F0F0F0F0F0F0F0Ful) + ((res >> 4) & 0x0F0F0F0F0F0F0F0Ful);
+	res = (res & 0x00FF00FF00FF00FFul) + ((res >> 8) & 0x00FF00FF00FF00FFul);
+	res = (res & 0x0000FFFF0000FFFFul) + ((res >> 16) & 0x0000FFFF0000FFFFul);
+	return (res & 0x00000000FFFFFFFFul) + ((res >> 32) & 0x00000000FFFFFFFFul);
+#endif
+}
+
+static inline unsigned long hweight_long(unsigned long w)
+{
+	return sizeof(w) == 4 ? generic_hweight32(w) : generic_hweight64(w);
+}
+
+/*
+ * rol32 - rotate a 32-bit value left
+ *
+ * @word: value to rotate
+ * @shift: bits to roll
+ */
+static inline __u32 rol32(__u32 word, unsigned int shift)
+{
+	return (word << shift) | (word >> (32 - shift));
+}
+
+/*
+ * ror32 - rotate a 32-bit value right
+ *
+ * @word: value to rotate
+ * @shift: bits to roll
+ */
+static inline __u32 ror32(__u32 word, unsigned int shift)
+{
+	return (word >> shift) | (word << (32 - shift));
+}
+
+#endif