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/* $Id$
*
* Copytight (C) 1999 Ralf Baechle (ralf@gnu.org)
* Copytight (C) 1999 Silicon Graphics, Inc.
*/
#include <linux/init.h>
#include <linux/kernel.h>
#include <linux/sched.h>
#include <linux/interrupt.h>
#include <linux/kernel_stat.h>
#include <linux/param.h>
#include <linux/timex.h>
#include <linux/mm.h>
#include <asm/pgtable.h>
#include <asm/sgialib.h>
#include <asm/sn/arch.h>
#include <asm/sn/addrs.h>
#include <asm/sn/sn0/ip27.h>
#include <asm/sn/sn0/hub.h>
/* This is a hack; we really need to figure these values out dynamically
*
* Since 800 ns works very well with various HUB frequencies, such as
* 360, 380, 390 and 400 MHZ, we use 800 ns rtc cycle time.
*
* Ralf: which clock rate is used to feed the counter?
*/
#define NSEC_PER_CYCLE 800
#define NSEC_PER_SEC 1000000000
#define CYCLES_PER_SEC (NSEC_PER_SEC/NSEC_PER_CYCLE)
#define CYCLES_PER_JIFFY (CYCLES_PER_SEC/HZ)
static unsigned long ct_cur; /* What counter should be at next timer irq */
extern rwlock_t xtime_lock;
void rt_timer_interrupt(struct pt_regs *regs)
{
int irq = 7; /* XXX Assign number */
write_lock(&xtime_lock);
again:
LOCAL_HUB_S(PI_RT_PEND_A, 0); /* Ack */
ct_cur += CYCLES_PER_JIFFY;
LOCAL_HUB_S(PI_RT_COMPARE_A, ct_cur);
if (LOCAL_HUB_L(PI_RT_COUNT) >= ct_cur)
goto again;
kstat.irqs[0][irq]++;
do_timer(regs);
write_unlock(&xtime_lock);
}
void do_gettimeofday(struct timeval *tv)
{
unsigned long flags;
read_lock_irqsave(&xtime_lock, flags);
*tv = xtime;
read_unlock_irqrestore(&xtime_lock, flags);
}
void do_settimeofday(struct timeval *tv)
{
write_lock_irq(&xtime_lock);
xtime = *tv;
time_state = TIME_BAD;
time_maxerror = MAXPHASE;
time_esterror = MAXPHASE;
write_unlock_irq(&xtime_lock);
}
/* Includes for ioc3_init(). */
#include <linux/init.h>
#include <asm/sn/types.h>
#include <asm/sn/sn0/addrs.h>
#include <asm/sn/sn0/hubni.h>
#include <asm/sn/sn0/hubio.h>
#include <asm/sn/klconfig.h>
#include <asm/ioc3.h>
#include <asm/pci/bridge.h>
extern void ioc3_eth_init(void);
void __init time_init(void)
{
unsigned int cpufreq;
char *cpufreqstr;
/* Is this timesource good enough? Ok to assume that all CPUs have
this clockrate? Are they 100% synchronously clocked? */
cpufreqstr = ArcGetEnvironmentVariable("cpufreq");
if (cpufreqstr == NULL)
panic("Cannot detect CPU clock rate");
cpufreq = simple_strtoul(cpufreqstr, NULL, 10);
printk("PROM says CPU clock is %dMHz\n", cpufreq);
/* We didn't flush the TLB earlier since the ARC firmware depends on
it. So do it now. */
flush_tlb_all();
/* Don't worry about second CPU, it's disabled. */
LOCAL_HUB_S(PI_RT_EN_A, 1);
LOCAL_HUB_S(PI_PROF_EN_A, 0);
ct_cur = CYCLES_PER_JIFFY;
LOCAL_HUB_S(PI_RT_COMPARE_A, ct_cur);
LOCAL_HUB_S(PI_RT_COUNT, 0);
LOCAL_HUB_S(PI_RT_PEND_A, 0);
set_cp0_status(SRB_TIMOCLK, SRB_TIMOCLK);
}
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