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-rw-r--r--sys/compat/linuxkpi/common/include/linux/jhash.h145
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diff --git a/sys/compat/linuxkpi/common/include/linux/jhash.h b/sys/compat/linuxkpi/common/include/linux/jhash.h
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+++ b/sys/compat/linuxkpi/common/include/linux/jhash.h
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+#ifndef _LINUX_JHASH_H_
+#define _LINUX_JHASH_H_
+
+/* jhash.h: Jenkins hash support.
+ *
+ * Copyright (C) 1996 Bob Jenkins (bob_jenkins@burtleburtle.net)
+ *
+ * http://burtleburtle.net/bob/hash/
+ *
+ * These are the credits from Bob's sources:
+ *
+ * lookup2.c, by Bob Jenkins, December 1996, Public Domain.
+ * hash(), hash2(), hash3, and mix() are externally useful functions.
+ * Routines to test the hash are included if SELF_TEST is defined.
+ * You can use this free for any purpose. It has no warranty.
+ *
+ * Copyright (C) 2003 David S. Miller (davem@redhat.com)
+ *
+ * I've modified Bob's hash to be useful in the Linux kernel, and
+ * any bugs present are surely my fault. -DaveM
+ *
+ * $FreeBSD$
+ */
+
+/* NOTE: Arguments are modified. */
+#define __jhash_mix(a, b, c) \
+{ \
+ a -= b; a -= c; a ^= (c>>13); \
+ b -= c; b -= a; b ^= (a<<8); \
+ c -= a; c -= b; c ^= (b>>13); \
+ a -= b; a -= c; a ^= (c>>12); \
+ b -= c; b -= a; b ^= (a<<16); \
+ c -= a; c -= b; c ^= (b>>5); \
+ a -= b; a -= c; a ^= (c>>3); \
+ b -= c; b -= a; b ^= (a<<10); \
+ c -= a; c -= b; c ^= (b>>15); \
+}
+
+/* The golden ration: an arbitrary value */
+#define JHASH_GOLDEN_RATIO 0x9e3779b9
+
+/* The most generic version, hashes an arbitrary sequence
+ * of bytes. No alignment or length assumptions are made about
+ * the input key.
+ */
+static inline u32 jhash(const void *key, u32 length, u32 initval)
+{
+ u32 a, b, c, len;
+ const u8 *k = key;
+
+ len = length;
+ a = b = JHASH_GOLDEN_RATIO;
+ c = initval;
+
+ while (len >= 12) {
+ a += (k[0] +((u32)k[1]<<8) +((u32)k[2]<<16) +((u32)k[3]<<24));
+ b += (k[4] +((u32)k[5]<<8) +((u32)k[6]<<16) +((u32)k[7]<<24));
+ c += (k[8] +((u32)k[9]<<8) +((u32)k[10]<<16)+((u32)k[11]<<24));
+
+ __jhash_mix(a,b,c);
+
+ k += 12;
+ len -= 12;
+ }
+
+ c += length;
+ switch (len) {
+ case 11: c += ((u32)k[10]<<24);
+ case 10: c += ((u32)k[9]<<16);
+ case 9 : c += ((u32)k[8]<<8);
+ case 8 : b += ((u32)k[7]<<24);
+ case 7 : b += ((u32)k[6]<<16);
+ case 6 : b += ((u32)k[5]<<8);
+ case 5 : b += k[4];
+ case 4 : a += ((u32)k[3]<<24);
+ case 3 : a += ((u32)k[2]<<16);
+ case 2 : a += ((u32)k[1]<<8);
+ case 1 : a += k[0];
+ };
+
+ __jhash_mix(a,b,c);
+
+ return c;
+}
+
+/* A special optimized version that handles 1 or more of u32s.
+ * The length parameter here is the number of u32s in the key.
+ */
+static inline u32 jhash2(const u32 *k, u32 length, u32 initval)
+{
+ u32 a, b, c, len;
+
+ a = b = JHASH_GOLDEN_RATIO;
+ c = initval;
+ len = length;
+
+ while (len >= 3) {
+ a += k[0];
+ b += k[1];
+ c += k[2];
+ __jhash_mix(a, b, c);
+ k += 3; len -= 3;
+ }
+
+ c += length * 4;
+
+ switch (len) {
+ case 2 : b += k[1];
+ case 1 : a += k[0];
+ };
+
+ __jhash_mix(a,b,c);
+
+ return c;
+}
+
+
+/* A special ultra-optimized versions that knows they are hashing exactly
+ * 3, 2 or 1 word(s).
+ *
+ * NOTE: In partilar the "c += length; __jhash_mix(a,b,c);" normally
+ * done at the end is not done here.
+ */
+static inline u32 jhash_3words(u32 a, u32 b, u32 c, u32 initval)
+{
+ a += JHASH_GOLDEN_RATIO;
+ b += JHASH_GOLDEN_RATIO;
+ c += initval;
+
+ __jhash_mix(a, b, c);
+
+ return c;
+}
+
+static inline u32 jhash_2words(u32 a, u32 b, u32 initval)
+{
+ return jhash_3words(a, b, 0, initval);
+}
+
+static inline u32 jhash_1word(u32 a, u32 initval)
+{
+ return jhash_3words(a, 0, 0, initval);
+}
+
+#endif /* _LINUX_JHASH_H_ */