MIPS-cavium-octeon-rewrite-the-sched_clock-based-on-.patch

From 4bf235ddf271eeb96f0fd08f2dbeef26495ebd10 Mon Sep 17 00:00:00 2001
From: Wu Zhangjin <wuzhangjin@gmail.com>
Date: Mon, 1 Feb 2010 18:58:13 +0800
Subject: [PATCH] MIPS: cavium-octeon: rewrite the sched_clock() based on mips_sched_clock()

commit 4bf235ddf271eeb96f0fd08f2dbeef26495ebd10 in tip.

The commit "MIPS: add a common mips_sched_clock()" have abstracted the
solution of the 64bit calculation's overflow problem into a common
mips_sched_clock() function in arch/mips/include/asm/time.h, This patch
just rewrites the sched_clock() for cavium-octeon on it.

Signed-off-by: Wu Zhangjin <wuzhangjin@gmail.com>

diff --git a/arch/mips/cavium-octeon/csrc-octeon.c b/arch/mips/cavium-octeon/csrc-octeon.c
index 0bf4bbe..53b1c32 100644
--- a/arch/mips/cavium-octeon/csrc-octeon.c
+++ b/arch/mips/cavium-octeon/csrc-octeon.c
@@ -52,34 +52,9 @@ static struct clocksource clocksource_mips = {
 
 unsigned long long notrace sched_clock(void)
 {
-	/* 64-bit arithmatic can overflow, so use 128-bit.  */
-#if (__GNUC__ < 4) || ((__GNUC__ == 4) && (__GNUC_MINOR__ <= 3))
-	u64 t1, t2, t3;
-	unsigned long long rv;
-	u64 mult = clocksource_mips.mult;
-	u64 shift = clocksource_mips.shift;
 	u64 cnt = read_c0_cvmcount();
 
-	asm (
-		"dmultu\t%[cnt],%[mult]\n\t"
-		"nor\t%[t1],$0,%[shift]\n\t"
-		"mfhi\t%[t2]\n\t"
-		"mflo\t%[t3]\n\t"
-		"dsll\t%[t2],%[t2],1\n\t"
-		"dsrlv\t%[rv],%[t3],%[shift]\n\t"
-		"dsllv\t%[t1],%[t2],%[t1]\n\t"
-		"or\t%[rv],%[t1],%[rv]\n\t"
-		: [rv] "=&r" (rv), [t1] "=&r" (t1), [t2] "=&r" (t2), [t3] "=&r" (t3)
-		: [cnt] "r" (cnt), [mult] "r" (mult), [shift] "r" (shift)
-		: "hi", "lo");
-	return rv;
-#else
-	/* GCC > 4.3 do it the easy way.  */
-	unsigned int __attribute__((mode(TI))) t;
-	t = read_c0_cvmcount();
-	t = t * clocksource_mips.mult;
-	return (unsigned long long)(t >> clocksource_mips.shift);
-#endif
+	return mips_sched_clock(&clocksource_mips, cnt);
 }
 
 void __init plat_time_init(void)
-- 
1.7.1.1