[PATCH v2 1/4] kernel.h: Implement DIV_ROUND_CLOSEST_ULL

[Javi Merino <javi.merino@arm.com>]

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: Jani Nikula <jani.nikula@linux.intel.com>
Cc: David Airlie <airlied@linux.ie>
Cc: Guenter Roeck <linux@roeck-us.net>
Cc: Andrew Morton <akpm@linux-foundation.org>
Acked-by: Daniel Vetter <daniel.vetter@ffwll.ch>
Signed-off-by: Javi Merino <javi.merino@arm.com>
---
 drivers/gpu/drm/i915/intel_drv.h   |  3 ---
 drivers/gpu/drm/i915/intel_panel.c |  1 +
 include/linux/kernel.h             | 12 ++++++++++++
 3 files changed, 13 insertions(+), 3 deletions(-)

diff --git a/drivers/gpu/drm/i915/intel_drv.h b/drivers/gpu/drm/i915/intel_drv.h
index eef79ccd0b7c..ba243db35840 100644
--- a/drivers/gpu/drm/i915/intel_drv.h
+++ b/drivers/gpu/drm/i915/intel_drv.h
@@ -36,9 +36,6 @@
 #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/drivers/gpu/drm/i915/intel_panel.c b/drivers/gpu/drm/i915/intel_panel.c
index d8686ce89160..08532d4ffe0a 100644
--- a/drivers/gpu/drm/i915/intel_panel.c
+++ b/drivers/gpu/drm/i915/intel_panel.c
@@ -30,6 +30,7 @@
 
 #define pr_fmt(fmt) KBUILD_MODNAME ": " fmt
 
+#include <linux/kernel.h>
 #include <linux/moduleparam.h>
 #include "intel_drv.h"
 
diff --git a/include/linux/kernel.h b/include/linux/kernel.h
index d6d630d31ef3..3a5b48e52a9e 100644
--- a/include/linux/kernel.h
+++ b/include/linux/kernel.h
@@ -103,6 +103,18 @@
 		(((__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)(		\
+{							\
+	typeof(divisor) __d = divisor;			\
+	unsigned long long _tmp = (x) + (__d) / 2;	\
+	do_div(_tmp, __d);				\
+	_tmp;						\
+}							\
+)
 
 /*
  * Multiplies an integer by a fraction, while avoiding unnecessary
-- 
1.9.1