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ARM: Realview/Versatile: separate out common sched_clock()

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Provide a common sched_clock() implementation for Versatile and
Realview.

Signed-off-by: Russell King <rmk+kernel@arm.linux.org.uk>
This commit is contained in:
Russell King 2010-01-14 20:07:35 +00:00
parent 6be4826e37
commit f5fc00826d
4 changed files with 55 additions and 38 deletions
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16
arch/arm/mach-realview/core.c
View File

@ -53,8 +53,6 @@
#include "core.h"
#define REALVIEW_REFCOUNTER (__io_address(REALVIEW_SYS_BASE) + REALVIEW_SYS_24MHz_OFFSET)
/* used by entry-macro.S and platsmp.c */
void __iomem *gic_cpu_base_addr;
@ -77,20 +75,6 @@ void __init realview_adjust_zones(int node, unsigned long *size,
}
#endif
/*
* This is the RealView sched_clock implementation. This has
* a resolution of 41.7ns, and a maximum value of about 179s.
*/
unsigned long long sched_clock(void)
{
unsigned long long v;
v = (unsigned long long)readl(REALVIEW_REFCOUNTER) * 125;
do_div(v, 3);
return v;
}
#define REALVIEW_FLASHCTRL (__io_address(REALVIEW_SYS_BASE) + REALVIEW_SYS_FLASH_OFFSET)

22
arch/arm/mach-versatile/core.c
View File

@ -28,7 +28,6 @@
#include <linux/amba/clcd.h>
#include <linux/amba/pl061.h>
#include <linux/amba/mmci.h>
#include <linux/cnt32_to_63.h>
#include <linux/io.h>
#include <asm/clkdev.h>
@ -227,27 +226,6 @@ void __init versatile_map_io(void)
iotable_init(versatile_io_desc, ARRAY_SIZE(versatile_io_desc));
}
#define VERSATILE_REFCOUNTER (__io_address(VERSATILE_SYS_BASE) + VERSATILE_SYS_24MHz_OFFSET)
/*
* This is the Versatile sched_clock implementation. This has
* a resolution of 41.7ns, and a maximum value of about 35583 days.
*
* The return value is guaranteed to be monotonic in that range as
* long as there is always less than 89 seconds between successive
* calls to this function.
*/
unsigned long long sched_clock(void)
{
unsigned long long v = cnt32_to_63(readl(VERSATILE_REFCOUNTER));
/* the <<1 gets rid of the cnt_32_to_63 top bit saving on a bic insn */
v *= 125<<1;
do_div(v, 3<<1);
return v;
}
#define VERSATILE_FLASHCTRL (__io_address(VERSATILE_SYS_BASE) + VERSATILE_SYS_FLASH_OFFSET)

2
arch/arm/plat-versatile/Makefile
View File

@ -1,2 +1,4 @@
obj-y := clock.o
obj-$(CONFIG_ARM_TIMER_SP804) += timer-sp.o
obj-$(CONFIG_ARCH_REALVIEW) += sched-clock.o
obj-$(CONFIG_ARCH_VERSATILE) += sched-clock.o

53
arch/arm/plat-versatile/sched-clock.c Normal file
View File

@ -0,0 +1,53 @@
/*
* linux/arch/arm/plat-versatile/sched-clock.c
*
* Copyright (C) 1999 - 2003 ARM Limited
* Copyright (C) 2000 Deep Blue Solutions Ltd
*
* This program is free software; you can redistribute it and/or modify
* it under the terms of the GNU General Public License as published by
* the Free Software Foundation; either version 2 of the License, or
* (at your option) any later version.
*
* This program is distributed in the hope that it will be useful,
* but WITHOUT ANY WARRANTY; without even the implied warranty of
* MERCHANTABILITY or FITNESS FOR A PARTICULAR PURPOSE. See the
* GNU General Public License for more details.
*
* You should have received a copy of the GNU General Public License
* along with this program; if not, write to the Free Software
* Foundation, Inc., 59 Temple Place, Suite 330, Boston, MA 02111-1307 USA
*/
#include <linux/cnt32_to_63.h>
#include <linux/io.h>
#include <asm/div64.h>
#include <mach/hardware.h>
#include <mach/platform.h>
#ifdef VERSATILE_SYS_BASE
#define REFCOUNTER (__io_address(VERSATILE_SYS_BASE) + VERSATILE_SYS_24MHz_OFFSET)
#endif
#ifdef REALVIEW_SYS_BASE
#define REFCOUNTER (__io_address(REALVIEW_SYS_BASE) + REALVIEW_SYS_24MHz_OFFSET)
#endif
/*
* This is the Realview and Versatile sched_clock implementation. This
* has a resolution of 41.7ns, and a maximum value of about 35583 days.
*
* The return value is guaranteed to be monotonic in that range as
* long as there is always less than 89 seconds between successive
* calls to this function.
*/
unsigned long long sched_clock(void)
{
unsigned long long v = cnt32_to_63(readl(REFCOUNTER));
/* the <<1 gets rid of the cnt_32_to_63 top bit saving on a bic insn */
v *= 125<<1;
do_div(v, 3<<1);
return v;
}