summaryrefslogtreecommitdiffstats
path: root/include
diff options
context:
space:
mode:
authorSascha Hauer <s.hauer@pengutronix.de>2014-07-10 09:12:02 +0200
committerSascha Hauer <s.hauer@pengutronix.de>2014-07-17 07:45:55 +0200
commit77bd64d1fd37704bbd9e78b10b3847381299889a (patch)
treee571abe5c7b58001d575df8609c0776aebc7f7f2 /include
parent36d837d791c52f28565325d30494118de65986ce (diff)
downloadbarebox-77bd64d1fd37704bbd9e78b10b3847381299889a.tar.gz
barebox-77bd64d1fd37704bbd9e78b10b3847381299889a.tar.xz
include: Add round_up/round_down macros from kernel
Yes, we already have roundup/rounddown. Unlike these macros round_up/round_down are optimized to (and only work with) power-of-2 arguments. It's a poor name, but kernel code needs it, so add it to barebox aswell. Signed-off-by: Sascha Hauer <s.hauer@pengutronix.de>
Diffstat (limited to 'include')
-rw-r--r--include/linux/kernel.h13
1 files changed, 13 insertions, 0 deletions
diff --git a/include/linux/kernel.h b/include/linux/kernel.h
index 4322f01580..b90d8f7e04 100644
--- a/include/linux/kernel.h
+++ b/include/linux/kernel.h
@@ -5,6 +5,19 @@
#include <linux/barebox-wrapper.h>
/*
+ * This looks more complex than it should be. But we need to
+ * get the type for the ~ right in round_down (it needs to be
+ * as wide as the result!), and we want to evaluate the macro
+ * arguments just once each.
+ *
+ * NOTE these functions only round to power-of-2 arguments. Use
+ * roundup/rounddown for non power-of-2-arguments.
+ */
+#define __round_mask(x, y) ((__typeof__(x))((y)-1))
+#define round_up(x, y) ((((x)-1) | __round_mask(x, y))+1)
+#define round_down(x, y) ((x) & ~__round_mask(x, y))
+
+/*
* min()/max()/clamp() macros that also do
* strict type-checking.. See the
* "unnecessary" pointer comparison.