59 строки
1.7 KiB
C
59 строки
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/io.h>
|
|
#include <linux/sched.h>
|
|
|
|
#include <asm/sched_clock.h>
|
|
#include <plat/sched_clock.h>
|
|
|
|
static DEFINE_CLOCK_DATA(cd);
|
|
static void __iomem *ctr;
|
|
|
|
/*
|
|
* Constants generated by clocks_calc_mult_shift(m, s, 24MHz, NSEC_PER_SEC, 60).
|
|
* This gives a resolution of about 41ns and a wrap period of about 178s.
|
|
*/
|
|
#define SC_MULT 2796202667u
|
|
#define SC_SHIFT 26
|
|
|
|
unsigned long long notrace sched_clock(void)
|
|
{
|
|
if (ctr) {
|
|
u32 cyc = readl(ctr);
|
|
return cyc_to_fixed_sched_clock(&cd, cyc, (u32)~0,
|
|
SC_MULT, SC_SHIFT);
|
|
} else
|
|
return 0;
|
|
}
|
|
|
|
static void notrace versatile_update_sched_clock(void)
|
|
{
|
|
u32 cyc = readl(ctr);
|
|
update_sched_clock(&cd, cyc, (u32)~0);
|
|
}
|
|
|
|
void __init versatile_sched_clock_init(void __iomem *reg, unsigned long rate)
|
|
{
|
|
ctr = reg;
|
|
init_fixed_sched_clock(&cd, versatile_update_sched_clock,
|
|
32, rate, SC_MULT, SC_SHIFT);
|
|
}
|