NetBSD-5.0.2/sys/arch/powerpc/ibm4xx/clock.c
/* $NetBSD: clock.c,v 1.21 2008/01/09 06:50:36 simonb Exp $ */
/* $OpenBSD: clock.c,v 1.3 1997/10/13 13:42:53 pefo Exp $ */
/*
* Copyright (C) 1995, 1996 Wolfgang Solfrank.
* Copyright (C) 1995, 1996 TooLs GmbH.
* All rights reserved.
*
* Redistribution and use in source and binary forms, with or without
* modification, are permitted provided that the following conditions
* are met:
* 1. Redistributions of source code must retain the above copyright
* notice, this list of conditions and the following disclaimer.
* 2. Redistributions in binary form must reproduce the above copyright
* notice, this list of conditions and the following disclaimer in the
* documentation and/or other materials provided with the distribution.
* 3. All advertising materials mentioning features or use of this software
* must display the following acknowledgement:
* This product includes software developed by TooLs GmbH.
* 4. The name of TooLs GmbH may not be used to endorse or promote products
* derived from this software without specific prior written permission.
*
* THIS SOFTWARE IS PROVIDED BY TOOLS GMBH ``AS IS'' AND ANY EXPRESS OR
* IMPLIED WARRANTIES, INCLUDING, BUT NOT LIMITED TO, THE IMPLIED WARRANTIES
* OF MERCHANTABILITY AND FITNESS FOR A PARTICULAR PURPOSE ARE DISCLAIMED.
* IN NO EVENT SHALL TOOLS GMBH BE LIABLE FOR ANY DIRECT, INDIRECT, INCIDENTAL,
* SPECIAL, EXEMPLARY, OR CONSEQUENTIAL DAMAGES (INCLUDING, BUT NOT LIMITED TO,
* PROCUREMENT OF SUBSTITUTE GOODS OR SERVICES; LOSS OF USE, DATA, OR PROFITS;
* OR BUSINESS INTERRUPTION) HOWEVER CAUSED AND ON ANY THEORY OF LIABILITY,
* WHETHER IN CONTRACT, STRICT LIABILITY, OR TORT (INCLUDING NEGLIGENCE OR
* OTHERWISE) ARISING IN ANY WAY OUT OF THE USE OF THIS SOFTWARE, EVEN IF
* ADVISED OF THE POSSIBILITY OF SUCH DAMAGE.
*/
#include <sys/cdefs.h>
__KERNEL_RCSID(0, "$NetBSD: clock.c,v 1.21 2008/01/09 06:50:36 simonb Exp $");
#include <sys/param.h>
#include <sys/kernel.h>
#include <sys/systm.h>
#include <sys/timetc.h>
#include <uvm/uvm_extern.h>
#include <prop/proplib.h>
#include <machine/cpu.h>
#include <powerpc/spr.h>
/*
* Initially we assume a processor with a bus frequency of 12.5 MHz.
*/
static u_long ticks_per_sec;
static u_long ns_per_tick;
static long ticks_per_intr;
static volatile u_long lasttb, lasttb2;
static u_long ticksmissed;
static volatile int tickspending;
static void init_ppc4xx_tc(void);
static u_int get_ppc4xx_timecount(struct timecounter *);
static struct timecounter ppc4xx_timecounter = {
get_ppc4xx_timecount, /* get_timecount */
0, /* no poll_pps */
~0u, /* counter_mask */
0, /* frequency */
"ppc_timebase", /* name */
100, /* quality */
NULL, /* tc_priv */
NULL /* tc_next */
};
void decr_intr(struct clockframe *); /* called from trap_subr.S */
void stat_intr(struct clockframe *); /* called from trap_subr.S */
#ifdef FAST_STAT_CLOCK
/* Stat clock runs at ~ 1.5 kHz */
#define PERIOD_POWER 17
#define TCR_PERIOD TCR_FP_2_17
#else
/* Stat clock runs at ~ 95Hz */
#define PERIOD_POWER 21
#define TCR_PERIOD TCR_FP_2_21
#endif
void
stat_intr(struct clockframe *frame)
{
mtspr(SPR_TSR, TSR_FIS); /* Clear TSR[FIS] */
uvmexp.intrs++;
curcpu()->ci_ev_statclock.ev_count++;
/* Nobody can interrupt us, but see if we're allowed to run. */
if (! (curcpu()->ci_cpl & mask_statclock))
statclock(frame);
}
void
decr_intr(struct clockframe *frame)
{
int pri;
long tbtick, xticks;
int nticks;
/*
* Check whether we are initialized.
*/
if (!ticks_per_intr)
return;
tbtick = mftbl();
mtspr(SPR_TSR, TSR_PIS); /* Clear TSR[PIS] */
xticks = tbtick - lasttb2; /* Number of TLB cycles since last exception */
for (nticks = 0; xticks > ticks_per_intr; nticks++)
xticks -= ticks_per_intr;
lasttb2 = tbtick - xticks;
uvmexp.intrs++;
curcpu()->ci_ev_clock.ev_count++;
pri = splclock();
if (pri & mask_clock) {
tickspending += nticks;
ticksmissed += nticks;
} else {
nticks += tickspending;
tickspending = 0;
/*
* lasttb is used during microtime. Set it to the virtual
* start of this tick interval.
*/
lasttb = lasttb2;
/*
* Reenable interrupts
*/
__asm volatile ("wrteei 1");
/*
* Do standard timer interrupt stuff.
* Do softclock stuff only on the last iteration.
*/
frame->pri = pri | mask_clock;
while (--nticks > 0)
hardclock(frame);
frame->pri = pri;
hardclock(frame);
}
splx(pri);
}
void
cpu_initclocks(void)
{
/* Initialized in powerpc/ibm4xx/cpu.c */
evcnt_attach_static(&curcpu()->ci_ev_clock);
evcnt_attach_static(&curcpu()->ci_ev_statclock);
ticks_per_intr = ticks_per_sec / hz;
stathz = profhz = ticks_per_sec / (1 << PERIOD_POWER);
printf("Setting PIT to %ld/%d = %ld\n", ticks_per_sec, hz,
ticks_per_intr);
lasttb2 = lasttb = mftbl();
mtspr(SPR_PIT, ticks_per_intr);
/* Enable PIT & FIT(2^17c = 0.655ms) interrupts and auto-reload */
mtspr(SPR_TCR, TCR_PIE | TCR_ARE | TCR_FIE | TCR_PERIOD);
init_ppc4xx_tc();
}
void
calc_delayconst(void)
{
prop_number_t freq;
freq = prop_dictionary_get(board_properties, "processor-frequency");
KASSERT(freq != NULL);
ticks_per_sec = (u_long) prop_number_integer_value(freq);
ns_per_tick = 1000000000 / ticks_per_sec;
}
static u_int
get_ppc4xx_timecount(struct timecounter *tc)
{
u_long tb;
int msr;
__asm volatile ("mfmsr %0; wrteei 0" : "=r"(msr) :);
tb = mftbl();
__asm volatile ("mtmsr %0" :: "r"(msr));
return tb;
}
/*
* Wait for about n microseconds (at least!).
*/
void
delay(unsigned int n)
{
u_quad_t tb;
u_long tbh, tbl, scratch;
tb = mftb();
/* use 1000ULL to force 64 bit math to avoid 32 bit overflows */
tb += (n * 1000ULL + ns_per_tick - 1) / ns_per_tick;
tbh = tb >> 32;
tbl = tb;
__asm volatile (
#ifdef PPC_IBM403
"1: mftbhi %0 \n"
#else
"1: mftbu %0 \n"
#endif
" cmplw %0,%1 \n"
" blt 1b \n"
" bgt 2f \n"
#ifdef PPC_IBM403
" mftblo %0 \n"
#else
" mftb %0 \n"
#endif
" cmplw %0,%2 \n"
" blt 1b \n"
"2: \n"
: "=&r"(scratch) : "r"(tbh), "r"(tbl) : "cr0");
}
/*
* Nothing to do.
*/
void
setstatclockrate(int arg)
{
/* Do nothing */
}
static void
init_ppc4xx_tc(void)
{
/* from machdep initialization */
ppc4xx_timecounter.tc_frequency = ticks_per_sec;
tc_init(&ppc4xx_timecounter);
}