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freebsd/sys/dev/hyperv/vmbus/hv_et.c
Sepherosa Ziehau 1948628a54 hyperv/evttimer: Use an independent message slot so that it can work
Using the same message slot as the other types of the messages has
the side effect that the event timer message could be deferred to
the swi threads to run (lacking of trapframe and the original code
didn't even handle that, so the event timer was actually broken).

As of this commit we use an independent message slot for event timer,
so that we could handle all of event timer messages in the interrupt
handler directly.  Note, the message slot for event timer is still
bind to the same interrupt vector as the other types of messages.

Submitted by:	Jun Su <junsu microsoft com>
Reviewed by:	sephe
Discussed with: Jun Su <junsu microsoft com>, Dexuan Cui <decui microsoft com>
MFC after:	1 week
Sponsored by:	Microsoft OSTC
Differential Revision:	https://reviews.freebsd.org/D5696
2016-03-22 05:48:51 +00:00

132 lines
3.7 KiB
C

/*-
* Copyright (c) 2015 Microsoft Corp.
* 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 THE AUTHOR AND CONTRIBUTORS ``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 THE AUTHOR OR CONTRIBUTORS 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/proc.h>
#include <sys/systm.h>
#include <sys/smp.h>
#include <sys/time.h>
#include <sys/timeet.h>
#include "hv_vmbus_priv.h"
#define HV_TIMER_FREQUENCY (10 * 1000 * 1000LL) /* 100ns period */
#define HV_MAX_DELTA_TICKS 0xffffffffLL
#define HV_MIN_DELTA_TICKS 1LL
static struct eventtimer et;
static uint64_t periodticks[MAXCPU];
static inline uint64_t
sbintime2tick(sbintime_t time)
{
struct timespec val;
val = sbttots(time);
return val.tv_sec * HV_TIMER_FREQUENCY + val.tv_nsec / 100;
}
static int
hv_et_start(struct eventtimer *et, sbintime_t firsttime, sbintime_t periodtime)
{
union hv_timer_config timer_cfg;
uint64_t current;
timer_cfg.as_uint64 = 0;
timer_cfg.auto_enable = 1;
timer_cfg.sintx = HV_VMBUS_TIMER_SINT;
periodticks[curcpu] = sbintime2tick(periodtime);
if (firsttime == 0)
firsttime = periodtime;
current = rdmsr(HV_X64_MSR_TIME_REF_COUNT);
current += sbintime2tick(firsttime);
wrmsr(HV_X64_MSR_STIMER0_CONFIG, timer_cfg.as_uint64);
wrmsr(HV_X64_MSR_STIMER0_COUNT, current);
return (0);
}
static int
hv_et_stop(struct eventtimer *et)
{
wrmsr(HV_X64_MSR_STIMER0_CONFIG, 0);
wrmsr(HV_X64_MSR_STIMER0_COUNT, 0);
return (0);
}
void
hv_et_intr(struct trapframe *frame)
{
union hv_timer_config timer_cfg;
struct trapframe *oldframe;
struct thread *td;
if (periodticks[curcpu] != 0) {
uint64_t tick = sbintime2tick(periodticks[curcpu]);
timer_cfg.as_uint64 = rdmsr(HV_X64_MSR_STIMER0_CONFIG);
timer_cfg.enable = 0;
timer_cfg.auto_enable = 1;
timer_cfg.periodic = 1;
periodticks[curcpu] = 0;
wrmsr(HV_X64_MSR_STIMER0_CONFIG, timer_cfg.as_uint64);
wrmsr(HV_X64_MSR_STIMER0_COUNT, tick);
}
if (et.et_active) {
td = curthread;
td->td_intr_nesting_level++;
oldframe = td->td_intr_frame;
td->td_intr_frame = frame;
et.et_event_cb(&et, et.et_arg);
td->td_intr_frame = oldframe;
td->td_intr_nesting_level--;
}
}
void
hv_et_init(void)
{
et.et_name = "HyperV";
et.et_flags = ET_FLAGS_ONESHOT | ET_FLAGS_PERCPU | ET_FLAGS_PERIODIC;
et.et_quality = 1000;
et.et_frequency = HV_TIMER_FREQUENCY;
et.et_min_period = (1LL << 32) / HV_TIMER_FREQUENCY;
et.et_max_period = HV_MAX_DELTA_TICKS * ((1LL << 32) / HV_TIMER_FREQUENCY);
et.et_start = hv_et_start;
et.et_stop = hv_et_stop;
et.et_priv = &et;
et_register(&et);
}