54 lines
1.7 KiB
C
54 lines
1.7 KiB
C
|
/*
|
||
|
|
* 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;
|
||
|
|
}
|