[src/riastradh-drm2]: src/sys/external/bsd/drm2/include/linux Implement hash_...

[riastradh <riastradh%NetBSD.org@localhost>]

details:   https://anonhg.NetBSD.org/src/rev/647698ba6c02
branches:  riastradh-drm2
changeset: 788135:647698ba6c02
user:      riastradh <riastradh%NetBSD.org@localhost>
date:      Wed Jul 24 02:24:02 2013 +0000

description:
Implement hash_long in <linux/hash.h>.

Uses the same hash function as in Linux, implemented differently.

diffstat:

 sys/external/bsd/drm2/include/linux/hash.h |  13 ++++++++++++-
 1 files changed, 12 insertions(+), 1 deletions(-)

diffs (25 lines):

diff -r d95d07fac9ea -r 647698ba6c02 sys/external/bsd/drm2/include/linux/hash.h
--- a/sys/external/bsd/drm2/include/linux/hash.h        Wed Jul 24 02:23:48 2013 +0000
+++ b/sys/external/bsd/drm2/include/linux/hash.h        Wed Jul 24 02:24:02 2013 +0000
@@ -1,4 +1,4 @@
-/*     $NetBSD: hash.h,v 1.1.2.1 2013/07/24 00:33:12 riastradh Exp $   */
+/*     $NetBSD: hash.h,v 1.1.2.2 2013/07/24 02:24:02 riastradh Exp $   */
 
 /*-
  * Copyright (c) 2013 The NetBSD Foundation, Inc.
@@ -32,4 +32,15 @@
 #ifndef _LINUX_HASH_H_
 #define _LINUX_HASH_H_
 
+#include <machine/limits.h>
+
+static inline unsigned long
+hash_long(unsigned long value, unsigned int bits)
+{
+       const unsigned long factor = (sizeof(factor) > 4?
+           0x9e37fffffffc0001ull : 0x9e370001ul);
+
+       return ((value * factor) >> ((CHAR_BIT * sizeof(value)) - bits));
+}
+
 #endif  /* _LINUX_HASH_H_ */