[PATCH 1/4] kernel.h: Implement DIV_ROUND_CLOSEST_ULL

Javi Merino
2015-03-20T11:14:40Z

We have grown a number of different implementations of
DIV_ROUND_CLOSEST_ULL throughout the kernel. Move the i915 one to
kernel.h so that it can be reused.

Cc: Daniel Vetter <daniel.vetter@intel.com>
Cc: Jani Nikula <jani.nikula@linux.intel.com>
Cc: David Airlie <airlied@linux.ie>
Cc: Darrick J. Wong <djwong@us.ibm.com>
Cc: Guenter Roeck <linux@roeck-us.net>
Cc: Andrew Morton <akpm@linux-foundation.org>
Signed-off-by: Javi Merino <javi.merino@arm.com>
---
drivers/gpu/drm/i915/intel_drv.h | 4 +---
include/linux/kernel.h | 11 +++++++++++
2 files changed, 12 insertions(+), 3 deletions(-)

diff --git a/drivers/gpu/drm/i915/intel_drv.h b/drivers/gpu/drm/i915/intel_drv.h
index eef79ccd0b7c..346e28fdd7dd 100644
--- a/drivers/gpu/drm/i915/intel_drv.h
+++ b/drivers/gpu/drm/i915/intel_drv.h
@@ -28,6 +28,7 @@
#include <linux/async.h>
#include <linux/i2c.h>
#include <linux/hdmi.h>
+#include <linux/kernel.h>
#include <drm/i915_drm.h>
#include "i915_drv.h"
#include <drm/drm_crtc.h>
@@ -36,9 +37,6 @@
#include <drm/drm_dp_mst_helper.h>
#include <drm/drm_rect.h>

-#define DIV_ROUND_CLOSEST_ULL(ll, d) \
-({ unsigned long long _tmp = (ll)+(d)/2; do_div(_tmp, d); _tmp; })
-
/**
* _wait_for - magic (register) wait macro
*
diff --git a/include/linux/kernel.h b/include/linux/kernel.h
index d6d630d31ef3..f7d744e9d275 100644
--- a/include/linux/kernel.h
+++ b/include/linux/kernel.h
@@ -103,6 +103,17 @@
(((__x) - ((__d) / 2)) / (__d)); \
} \
)
+/*
+ * Same as above but for u64 dividends. divisor must be a 32-bit
+ * number.
+ */
+#define DIV_ROUND_CLOSEST_ULL(x, divisor)( \
+{ \
+ unsigned long long _tmp = (x) + (divisor) / 2; \
+ do_div(_tmp, divisor); \
+ _tmp; \
+} \
+)

/*
* Multiplies an integer by a fraction, while avoiding unnecessary
--
1.9.1