[src/trunk]: src/sys/external/bsd/drm2/include/linux Make Linux usecs_to_jiff...

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

details:   https://anonhg.NetBSD.org/src/rev/9f97ccd4fe81
branches:  trunk
changeset: 797736:9f97ccd4fe81
user:      riastradh <riastradh%NetBSD.org@localhost>
date:      Sat Jul 26 06:20:25 2014 +0000

description:
Make Linux usecs_to_jiffies work with hz up to 2000.

diffstat:

 sys/external/bsd/drm2/include/linux/jiffies.h |  16 ++++++++++++++--
 1 files changed, 14 insertions(+), 2 deletions(-)

diffs (30 lines):

diff -r 20a369f3d711 -r 9f97ccd4fe81 sys/external/bsd/drm2/include/linux/jiffies.h
--- a/sys/external/bsd/drm2/include/linux/jiffies.h     Sat Jul 26 06:12:30 2014 +0000
+++ b/sys/external/bsd/drm2/include/linux/jiffies.h     Sat Jul 26 06:20:25 2014 +0000
@@ -1,4 +1,4 @@
-/*     $NetBSD: jiffies.h,v 1.4 2014/07/16 20:59:58 riastradh Exp $    */
+/*     $NetBSD: jiffies.h,v 1.5 2014/07/26 06:20:25 riastradh Exp $    */
 
 /*-
  * Copyright (c) 2013 The NetBSD Foundation, Inc.
@@ -56,7 +56,19 @@
 static inline unsigned int
 usecs_to_jiffies(unsigned int usec)
 {
-       return mstohz((usec + (1000 / hz) - 1) / (1000 / hz));
+       if (hz <= 100)
+               return mstohz(roundup(usec, (1000 / hz)));
+
+       /*
+        * Avoid integer overflow on 32-bit platforms.  The cutoff is
+        * kinda arbitrary; for hz <= 2000, 0x200000 is safe, but both
+        * values could wiggle around a little.
+        */
+       KASSERT(hz <= 2000);
+       if (usec <= 0x200000)
+               return ((usec * hz) / 1000000);
+       else
+               return ((usec / 1000000) * hz);
 }
 
 static inline unsigned int