freebsd-dev/sys/powerpc/aim/clock.c
Alexander Motin fdc5dd2d2f MFcalloutng:
Switch eventtimers(9) from using struct bintime to sbintime_t.
Even before this not a single driver really supported full dynamic range of
struct bintime even in theory, not speaking about practical inexpediency.
This change legitimates the status quo and cleans up the code.
2013-02-28 13:46:03 +00:00

272 lines
7.1 KiB
C

/*-
* 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.
*
* $NetBSD: clock.c,v 1.9 2000/01/19 02:52:19 msaitoh Exp $
*/
/*
* Copyright (C) 2001 Benno Rice.
* 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.
*
* THIS SOFTWARE IS PROVIDED BY Benno Rice ``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>
__FBSDID("$FreeBSD$");
#include <sys/param.h>
#include <sys/systm.h>
#include <sys/kernel.h>
#include <sys/bus.h>
#include <sys/interrupt.h>
#include <sys/pcpu.h>
#include <sys/sysctl.h>
#include <sys/timeet.h>
#include <sys/timetc.h>
#include <dev/ofw/openfirm.h>
#include <machine/clock.h>
#include <machine/cpu.h>
#include <machine/intr_machdep.h>
#include <machine/md_var.h>
#include <machine/smp.h>
/*
* Initially we assume a processor with a bus frequency of 12.5 MHz.
*/
static int initialized = 0;
static u_long ns_per_tick = 80;
static u_long ticks_per_sec = 12500000;
static u_long *decr_counts[MAXCPU];
static int decr_et_start(struct eventtimer *et,
sbintime_t first, sbintime_t period);
static int decr_et_stop(struct eventtimer *et);
static timecounter_get_t decr_get_timecount;
struct decr_state {
int mode; /* 0 - off, 1 - periodic, 2 - one-shot. */
int32_t div; /* Periodic divisor. */
};
static DPCPU_DEFINE(struct decr_state, decr_state);
static struct eventtimer decr_et;
static struct timecounter decr_tc = {
decr_get_timecount, /* get_timecount */
0, /* no poll_pps */
~0u, /* counter_mask */
0, /* frequency */
"timebase" /* name */
};
/*
* Decrementer interrupt handler.
*/
void
decr_intr(struct trapframe *frame)
{
struct decr_state *s = DPCPU_PTR(decr_state);
int nticks = 0;
int32_t val;
if (!initialized)
return;
(*decr_counts[curcpu])++;
if (s->mode == 1) {
/*
* Based on the actual time delay since the last decrementer
* reload, we arrange for earlier interrupt next time.
*/
__asm ("mfdec %0" : "=r"(val));
while (val < 0) {
val += s->div;
nticks++;
}
mtdec(val);
} else if (s->mode == 2) {
nticks = 1;
decr_et_stop(NULL);
}
while (nticks-- > 0) {
if (decr_et.et_active)
decr_et.et_event_cb(&decr_et, decr_et.et_arg);
}
}
/*
* BSP early initialization.
*/
void
decr_init(void)
{
struct cpuref cpu;
char buf[32];
/*
* Check the BSP's timebase frequency. Sometimes we can't find the BSP, so fall
* back to the first CPU in this case.
*/
if (platform_smp_get_bsp(&cpu) != 0)
platform_smp_first_cpu(&cpu);
ticks_per_sec = platform_timebase_freq(&cpu);
ns_per_tick = 1000000000 / ticks_per_sec;
set_cputicker(mftb, ticks_per_sec, 0);
snprintf(buf, sizeof(buf), "cpu%d:decrementer", curcpu);
intrcnt_add(buf, &decr_counts[curcpu]);
decr_et_stop(NULL);
initialized = 1;
}
#ifdef SMP
/*
* AP early initialization.
*/
void
decr_ap_init(void)
{
char buf[32];
snprintf(buf, sizeof(buf), "cpu%d:decrementer", curcpu);
intrcnt_add(buf, &decr_counts[curcpu]);
decr_et_stop(NULL);
}
#endif
/*
* Final initialization.
*/
void
decr_tc_init(void)
{
decr_tc.tc_frequency = ticks_per_sec;
tc_init(&decr_tc);
decr_et.et_name = "decrementer";
decr_et.et_flags = ET_FLAGS_PERIODIC | ET_FLAGS_ONESHOT |
ET_FLAGS_PERCPU;
decr_et.et_quality = 1000;
decr_et.et_frequency = ticks_per_sec;
decr_et.et_min_period = (0x00000002LLU << 32) / ticks_per_sec;
decr_et.et_max_period = (0x7fffffffLLU << 32) / ticks_per_sec;
decr_et.et_start = decr_et_start;
decr_et.et_stop = decr_et_stop;
decr_et.et_priv = NULL;
et_register(&decr_et);
}
/*
* Event timer start method.
*/
static int
decr_et_start(struct eventtimer *et,
sbintime_t first, sbintime_t period)
{
struct decr_state *s = DPCPU_PTR(decr_state);
uint32_t fdiv;
if (period != 0) {
s->mode = 1;
s->div = (decr_et.et_frequency * period) >> 32;
} else {
s->mode = 2;
s->div = 0;
}
if (first != 0) {
fdiv = (decr_et.et_frequency * first) >> 32;
} else
fdiv = s->div;
mtdec(fdiv);
return (0);
}
/*
* Event timer stop method.
*/
static int
decr_et_stop(struct eventtimer *et)
{
struct decr_state *s = DPCPU_PTR(decr_state);
s->mode = 0;
s->div = 0x7fffffff;
mtdec(s->div);
return (0);
}
/*
* Timecounter get method.
*/
static unsigned
decr_get_timecount(struct timecounter *tc)
{
register_t tb;
__asm __volatile("mftb %0" : "=r"(tb));
return (tb);
}
/*
* Wait for about n microseconds (at least!).
*/
void
DELAY(int n)
{
u_quad_t tb, ttb;
tb = mftb();
ttb = tb + (n * 1000 + ns_per_tick - 1) / ns_per_tick;
while (tb < ttb)
tb = mftb();
}