Bochs/bochs/iodev/virt_timer.cc

550 lines
19 KiB
C++
Raw Normal View History

////////////////////////////////////////////////////////////////////////
// $Id$
/////////////////////////////////////////////////////////////////////////
//
// Copyright (C) 2002-2021 The Bochs Project
//
// This library is free software; you can redistribute it and/or
// modify it under the terms of the GNU Lesser General Public
// License as published by the Free Software Foundation; either
// version 2 of the License, or (at your option) any later version.
//
// This library 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
// Lesser General Public License for more details.
//
// You should have received a copy of the GNU Lesser General Public
// License along with this library; if not, write to the Free Software
// Foundation, Inc., 51 Franklin St, Fifth Floor, Boston, MA 02110-1301 USA
////////////////////////////////////////////////////////////////////////
/////////////////////////////////////////////////////////////////////////
//
//Realtime Algorithm (with gettimeofday)
// HAVE:
// Real number of usec.
// Emulated number of usec.
// WANT:
// Number of ticks to use.
// Number of emulated usec to wait until next try.
//
// ticks=number of ticks needed to match total real usec.
// if(desired ticks > max ticks for elapsed real time)
// ticks = max ticks for elapsed real time.
// if(desired ticks > max ticks for elapsed emulated usec)
// ticks = max ticks for emulated usec.
// next wait ticks = number of ticks until next event.
// next wait real usec = (current ticks + next wait ticks) * usec per ticks
// next wait emulated usec = next wait real usec * emulated usec / real usec
// if(next wait emulated usec < minimum emulated usec for next wait ticks)
// next wait emulated usec = minimum emulated usec for next wait ticks.
// if(next wait emulated usec > max emulated usec wait)
// next wait emulated usec = max emulated usec wait.
//
// How to calculate elapsed real time:
// store an unused time value whenever no ticks are used in a given time.
// add this to the current elapsed time.
// How to calculate elapsed emulated time:
// same as above.
// Above can be done by not updating last_usec and last_sec.
//
// How to calculate emulated usec/real usec:
// Each time there are actual ticks:
// Alpha_product(old emulated usec, emulated usec);
// Alpha_product(old real usec, real usec);
// Divide resulting values.
//
/////////////////////////////////////////////////////////////////////////
#include "bochs.h"
#include "gui/siminterface.h"
#include "param_names.h"
#include "virt_timer.h"
2003-08-04 17:27:39 +04:00
//Important constant #defines:
#define USEC_PER_SECOND (1000000)
// define a macro to convert floating point numbers into 64-bit integers.
// In MSVC++ you can convert a 64-bit float into a 64-bit signed integer,
// but it will not convert a 64-bit float into a 64-bit unsigned integer.
// This macro works around that.
#define F2I(x) ((Bit64u)(Bit64s) (x))
#define I2F(x) ((double)(Bit64s) (x))
//CONFIGURATION #defines:
//MAINLINE Configuration (For realtime PIT):
//How much faster than real time we can go:
#define MAX_MULT (1.25)
//Minimum number of emulated useconds per second.
// Now calculated using BX_MIN_IPS, the minimum number of
// instructions per second.
#define MIN_USEC_PER_SECOND (((((Bit64u)USEC_PER_SECOND)*((Bit64u)BX_MIN_IPS))/((Bit64u)ips))+(Bit64u)1)
2003-08-04 17:27:39 +04:00
//DEBUG configuration:
//Debug with printf options.
#define DEBUG_REALTIME_WITH_PRINTF 0
#define GET_VIRT_REALTIME64_USEC() (bx_get_realtime64_usec())
2003-08-04 17:27:39 +04:00
//Set up Logging.
#define LOG_THIS bx_virt_timer.
//A single instance.
bx_virt_timer_c bx_virt_timer;
//USEC_ALPHA is multiplier for the past.
//USEC_ALPHA_B is 1-USEC_ALPHA, or multiplier for the present.
#define USEC_ALPHA ((double)(.8))
#define USEC_ALPHA_B ((double)(((double)1)-USEC_ALPHA))
#define USEC_ALPHA2 ((double)(.5))
#define USEC_ALPHA2_B ((double)(((double)1)-USEC_ALPHA2))
#define ALPHA_LOWER(old,new) ((Bit64u)((old<new)?((USEC_ALPHA*(I2F(old)))+(USEC_ALPHA_B*(I2F(new)))):((USEC_ALPHA2*(I2F(old)))+(USEC_ALPHA2_B*(I2F(new))))))
//Conversion between emulated useconds and optionally realtime ticks.
#define TICKS_TO_USEC(a) (((a)*usec_per_second)/ticks_per_second)
#define USEC_TO_TICKS(a) (((a)*ticks_per_second)/usec_per_second)
2003-08-04 17:27:39 +04:00
bx_virt_timer_c::bx_virt_timer_c()
2003-08-04 17:27:39 +04:00
{
2013-12-29 16:56:52 +04:00
put("virt_timer", "VTIMER");
2003-08-04 17:27:39 +04:00
setup();
2003-08-04 17:27:39 +04:00
}
const Bit64u bx_virt_timer_c::NullTimerInterval = BX_MAX_VIRTUAL_TIME;
void bx_virt_timer_c::nullTimer(void* this_ptr)
{
2003-08-04 17:27:39 +04:00
UNUSED(this_ptr);
}
void bx_virt_timer_c::periodic(Bit64u time_passed, bool mode)
{
2003-08-04 17:27:39 +04:00
//Assert that we haven't skipped any events.
BX_ASSERT (time_passed <= s[mode].timers_next_event_time);
2003-08-04 17:27:39 +04:00
BX_ASSERT(!in_timer_handler);
//Update time variables.
s[mode].timers_next_event_time -= time_passed;
s[mode].current_timers_time += time_passed;
2003-08-04 17:27:39 +04:00
//If no events are occurring, just pass the time and we're done.
if (time_passed < s[mode].timers_next_event_time) return;
2006-05-27 18:02:34 +04:00
2003-08-04 17:27:39 +04:00
//Starting timer handler calls.
in_timer_handler = 1;
//Otherwise, cause any events to occur that should.
unsigned i;
for (i=0;i<numTimers;i++) {
if (timer[i].inUse && timer[i].active) {
if (timer[i].realtime != mode) continue;
2003-08-04 17:27:39 +04:00
//Assert that we haven't skipped any timers.
BX_ASSERT(s[mode].current_timers_time <= timer[i].timeToFire);
if (timer[i].timeToFire == s[mode].current_timers_time) {
if (timer[i].continuous) {
timer[i].timeToFire += timer[i].period;
} else {
timer[i].active = 0;
}
//This function MUST return, or the timer mechanism
// will be broken.
timer[i].funct(timer[i].this_ptr);
2003-08-04 17:27:39 +04:00
}
}
}
//Finished timer handler calls.
in_timer_handler = 0;
//Use a second FOR loop so that a timer function call can
// change the behavior of another timer.
//s[mode].timers_next_event_time normally contains a cycle count, not a cycle time.
2003-08-04 17:27:39 +04:00
// here we use it as a temporary variable that IS a cycle time,
// but then convert it back to a cycle count afterwards.
s[mode].timers_next_event_time = s[mode].current_timers_time + BX_MAX_VIRTUAL_TIME;
for (i=0;i<numTimers;i++) {
if (timer[i].inUse && timer[i].active && (timer[i].realtime == mode) &&
((timer[i].timeToFire)<s[mode].timers_next_event_time)) {
s[mode].timers_next_event_time = timer[i].timeToFire;
2003-08-04 17:27:39 +04:00
}
}
s[mode].timers_next_event_time -= s[mode].current_timers_time;
next_event_time_update(mode);
2003-08-04 17:27:39 +04:00
//FIXME
}
//Get the current virtual time.
// This may return the same value on subsequent calls.
Bit64u bx_virt_timer_c::time_usec(bool mode)
{
//Update the time here only if we're not in a timer handler.
//If we're in a timer handler we're up-to-date, and otherwise
// this prevents call stack loops.
if (!in_timer_handler) {
timer_handler(mode);
2003-08-04 17:27:39 +04:00
}
return s[mode].current_timers_time;
2003-08-04 17:27:39 +04:00
}
//Get the current virtual time.
// This will return a monotonically increasing value.
// MUST NOT be called from within a timer interrupt.
Bit64u bx_virt_timer_c::time_usec_sequential(bool mode)
{
2003-08-04 17:27:39 +04:00
//Can't prevent call stack loops here, so this
// MUST NOT be called from within a timer handler.
BX_ASSERT(s[mode].timers_next_event_time>0);
2003-08-04 17:27:39 +04:00
BX_ASSERT(!in_timer_handler);
if (s[mode].last_sequential_time >= s[mode].current_timers_time) {
periodic(1, mode);
s[mode].last_sequential_time = s[mode].current_timers_time;
2003-08-04 17:27:39 +04:00
}
return s[mode].current_timers_time;
2003-08-04 17:27:39 +04:00
}
//Register a timer handler to go off after a given interval.
//Register a timer handler to go off with a periodic interval.
2006-05-27 18:02:34 +04:00
int bx_virt_timer_c::register_timer(void *this_ptr, bx_timer_handler_t handler,
Bit32u useconds, bool continuous,
bool active, bool realtime,
const char *id)
{
2003-08-04 17:27:39 +04:00
//We don't like starting with a zero period timer.
BX_ASSERT((!active) || (useconds>0));
//Search for an unused timer.
unsigned int i;
for (i=0; i < numTimers; i++) {
if ((timer[i].inUse == 0) || (i == numTimers))
2003-08-04 17:27:39 +04:00
break;
2006-05-27 19:54:49 +04:00
}
2003-08-04 17:27:39 +04:00
// If we didn't find a free slot, increment the bound, numTimers.
if (i == numTimers)
2003-08-04 17:27:39 +04:00
numTimers++; // One new timer installed.
BX_ASSERT(numTimers<BX_MAX_VIRTUAL_TIMERS);
timer[i].inUse = 1;
timer[i].period = useconds;
timer[i].timeToFire = s[realtime].current_timers_time + (Bit64u)useconds;
2003-08-04 17:27:39 +04:00
timer[i].active = active;
timer[i].realtime = realtime;
2003-08-04 17:27:39 +04:00
timer[i].continuous = continuous;
timer[i].funct = handler;
timer[i].this_ptr = this_ptr;
strncpy(timer[i].id, id, BxMaxTimerIDLen);
timer[i].id[BxMaxTimerIDLen-1]=0; //I like null terminated strings.
if (realtime) {
BX_DEBUG(("Timer #%d ('%s') using realtime synchronisation mode", i, timer[i].id));
} else {
BX_DEBUG(("Timer #%d ('%s') using standard mode", i, timer[i].id));
}
if (useconds < s[realtime].timers_next_event_time) {
s[realtime].timers_next_event_time = useconds;
next_event_time_update(realtime);
2003-08-04 17:27:39 +04:00
//FIXME
}
return i;
}
//unregister a previously registered timer.
bool bx_virt_timer_c::unregisterTimer(unsigned timerID)
{
2003-08-04 17:27:39 +04:00
BX_ASSERT(timerID < BX_MAX_VIRTUAL_TIMERS);
if (timer[timerID].active) {
BX_PANIC(("unregisterTimer: timer '%s' is still active!", timer[timerID].id));
return(0); // Fail.
}
2003-08-04 17:27:39 +04:00
//No need to prevent doing this to unused timers.
timer[timerID].inUse = 0;
2006-05-27 18:02:34 +04:00
if (timerID == (numTimers-1)) numTimers--;
return 1;
2003-08-04 17:27:39 +04:00
}
void bx_virt_timer_c::start_timers(void)
{
2003-08-04 17:27:39 +04:00
//FIXME
}
//activate a deactivated but registered timer.
void bx_virt_timer_c::activate_timer(unsigned timer_index, Bit32u useconds,
bool continuous)
{
2003-08-04 17:27:39 +04:00
BX_ASSERT(timer_index < BX_MAX_VIRTUAL_TIMERS);
BX_ASSERT(timer[timer_index].inUse);
BX_ASSERT(useconds>0);
bool realtime = timer[timer_index].realtime;
timer[timer_index].period = useconds;
timer[timer_index].timeToFire = s[realtime].current_timers_time + (Bit64u)useconds;
timer[timer_index].active = 1;
timer[timer_index].continuous = continuous;
2003-08-04 17:27:39 +04:00
if (useconds < s[realtime].timers_next_event_time) {
s[realtime].timers_next_event_time = useconds;
next_event_time_update(realtime);
2003-08-04 17:27:39 +04:00
//FIXME
}
}
//deactivate (but don't unregister) a currently registered timer.
2006-05-27 18:02:34 +04:00
void bx_virt_timer_c::deactivate_timer(unsigned timer_index)
{
2003-08-04 17:27:39 +04:00
BX_ASSERT(timer_index < BX_MAX_VIRTUAL_TIMERS);
//No need to prevent doing this to unused/inactive timers.
timer[timer_index].active = 0;
}
void bx_virt_timer_c::advance_virtual_time(Bit64u time_passed, bool mode)
{
BX_ASSERT(time_passed <= s[mode].virtual_next_event_time);
2003-08-04 17:27:39 +04:00
s[mode].current_virtual_time += time_passed;
s[mode].virtual_next_event_time -= time_passed;
2003-08-04 17:27:39 +04:00
if (s[mode].current_virtual_time > s[mode].current_timers_time) {
periodic(s[mode].current_virtual_time - s[mode].current_timers_time, mode);
2003-08-04 17:27:39 +04:00
}
}
//Called when next_event_time changes.
void bx_virt_timer_c::next_event_time_update(bool mode)
{
s[mode].virtual_next_event_time = s[mode].timers_next_event_time + s[mode].current_timers_time - s[mode].current_virtual_time;
if (init_done) {
bx_pc_system.deactivate_timer(s[mode].system_timer_id);
BX_ASSERT(s[mode].virtual_next_event_time);
bx_pc_system.activate_timer(s[mode].system_timer_id,
(Bit32u)BX_MIN(0x7FFFFFFF,BX_MAX(1,TICKS_TO_USEC(s[mode].virtual_next_event_time))),
0);
2003-08-04 17:27:39 +04:00
}
}
void bx_virt_timer_c::setup(void)
{
numTimers = 0;
in_timer_handler = 0;
for (unsigned i = 0; i < 2; i++) {
s[i].current_timers_time = 0;
s[i].timers_next_event_time = BX_MAX_VIRTUAL_TIME;
s[i].last_sequential_time = 0;
s[i].virtual_next_event_time = BX_MAX_VIRTUAL_TIME;
s[i].current_virtual_time = 0;
}
init_done = 0;
}
void bx_virt_timer_c::init(void)
{
// Local copy of IPS value to avoid reading it frequently in timer handler
ips = SIM->get_param_num(BXPN_IPS)->get();
register_timer(this, nullTimer, (Bit32u)NullTimerInterval, 1, 1, 0, "Null Timer #1");
register_timer(this, nullTimer, (Bit32u)NullTimerInterval, 1, 1, 1, "Null Timer #2");
2003-08-04 17:27:39 +04:00
s[0].system_timer_id = bx_pc_system.register_timer(this, pc_system_timer_handler_0,
(Bit32u)s[0].virtual_next_event_time, 0, 1, "Virtual Timer #0");
s[1].system_timer_id = bx_pc_system.register_timer(this, pc_system_timer_handler_1,
(Bit32u)s[1].virtual_next_event_time, 0, 1, "Virtual Timer #1");
2003-08-04 17:27:39 +04:00
//Real time variables:
2004-02-07 01:28:00 +03:00
#if BX_HAVE_REALTIME_USEC
last_real_time = GET_VIRT_REALTIME64_USEC();
2004-02-07 01:28:00 +03:00
#endif
total_real_usec = 0;
last_realtime_delta = 0;
real_time_delay = 0;
2003-08-04 17:27:39 +04:00
//System time variables:
2006-05-27 18:02:34 +04:00
last_usec = 0;
2003-08-04 17:27:39 +04:00
usec_per_second = USEC_PER_SECOND;
stored_delta = 0;
last_system_usec = 0;
em_last_realtime = 0;
2003-08-04 17:27:39 +04:00
//Virtual timer variables:
total_ticks = 0;
last_realtime_ticks = 0;
2003-08-04 17:27:39 +04:00
ticks_per_second = USEC_PER_SECOND;
init_done = 1;
}
2006-05-27 19:54:49 +04:00
void bx_virt_timer_c::register_state(void)
{
unsigned i;
char name[4];
bx_list_c *list = new bx_list_c(SIM->get_bochs_root(), "virt_timer", "Virtual Timer State");
bx_list_c *vtimers = new bx_list_c(list, "timer");
for (i = 0; i < numTimers; i++) {
sprintf(name, "%u", i);
bx_list_c *bxtimer = new bx_list_c(vtimers, name);
BXRS_PARAM_BOOL(bxtimer, inUse, timer[i].inUse);
BXRS_DEC_PARAM_FIELD(bxtimer, period, timer[i].period);
BXRS_DEC_PARAM_FIELD(bxtimer, timeToFire, timer[i].timeToFire);
BXRS_PARAM_BOOL(bxtimer, active, timer[i].active);
BXRS_PARAM_BOOL(bxtimer, continuous, timer[i].continuous);
BXRS_PARAM_BOOL(bxtimer, realtime, timer[i].realtime);
}
bx_list_c *sys = new bx_list_c(list, "s");
for (i = 0; i < 2; i++) {
sprintf(name, "%u", i);
bx_list_c *snum = new bx_list_c(sys, name);
BXRS_DEC_PARAM_FIELD(snum, current_timers_time, s[i].current_timers_time);
BXRS_DEC_PARAM_FIELD(snum, timers_next_event_time, s[i].timers_next_event_time);
BXRS_DEC_PARAM_FIELD(snum, last_sequential_time, s[i].last_sequential_time);
BXRS_DEC_PARAM_FIELD(snum, virtual_next_event_time, s[i].virtual_next_event_time);
BXRS_DEC_PARAM_FIELD(snum, current_virtual_time, s[i].current_virtual_time);
2006-05-27 19:54:49 +04:00
}
BXRS_DEC_PARAM_SIMPLE(list, last_real_time);
BXRS_DEC_PARAM_SIMPLE(list, total_real_usec);
BXRS_DEC_PARAM_SIMPLE(list, last_realtime_delta);
BXRS_DEC_PARAM_SIMPLE(list, last_usec);
BXRS_DEC_PARAM_SIMPLE(list, usec_per_second);
BXRS_DEC_PARAM_SIMPLE(list, stored_delta);
BXRS_DEC_PARAM_SIMPLE(list, last_system_usec);
BXRS_DEC_PARAM_SIMPLE(list, em_last_realtime);
BXRS_DEC_PARAM_SIMPLE(list, total_ticks);
BXRS_DEC_PARAM_SIMPLE(list, last_realtime_ticks);
BXRS_DEC_PARAM_SIMPLE(list, ticks_per_second);
2006-05-27 19:54:49 +04:00
}
void bx_virt_timer_c::timer_handler(bool mode)
{
if (!mode) {
2003-08-04 17:27:39 +04:00
Bit64u temp_final_time = bx_pc_system.time_usec();
temp_final_time -= s[0].current_virtual_time;
while (temp_final_time) {
if ((temp_final_time)>(s[0].virtual_next_event_time)) {
temp_final_time -= s[0].virtual_next_event_time;
advance_virtual_time(s[0].virtual_next_event_time, 0);
2003-08-04 17:27:39 +04:00
} else {
advance_virtual_time(temp_final_time, 0);
temp_final_time -= temp_final_time;
2003-08-04 17:27:39 +04:00
}
}
bx_pc_system.activate_timer(s[0].system_timer_id,
(Bit32u)BX_MIN(0x7FFFFFFF,(s[0].virtual_next_event_time>2)?(s[0].virtual_next_event_time-2):1),
0);
2003-08-04 17:27:39 +04:00
return;
}
Bit64u usec_delta = bx_pc_system.time_usec()-last_usec;
if (usec_delta) {
#if BX_HAVE_REALTIME_USEC
Bit64u ticks_delta = 0;
Bit64u real_time_delta = GET_VIRT_REALTIME64_USEC() - last_real_time - real_time_delay;
2003-08-04 17:27:39 +04:00
Bit64u real_time_total = real_time_delta + total_real_usec;
Bit64u system_time_delta = (Bit64u)usec_delta + (Bit64u)stored_delta;
if (real_time_delta) {
2003-08-04 17:27:39 +04:00
last_realtime_delta = real_time_delta;
last_realtime_ticks = total_ticks;
}
ticks_per_second = USEC_PER_SECOND;
//Start out with the number of ticks we would like
// to have to line up with real time.
ticks_delta = real_time_total - total_ticks;
if (real_time_total < total_ticks) {
2003-08-04 17:27:39 +04:00
//This slows us down if we're already ahead.
// probably only an issue on startup, but it solves some problems.
ticks_delta = 0;
}
if (ticks_delta + total_ticks - last_realtime_ticks > (F2I(MAX_MULT * I2F(last_realtime_delta)))) {
2003-08-04 17:27:39 +04:00
//This keeps us from going too fast in relation to real time.
#if 0
ticks_delta = (F2I(MAX_MULT * I2F(last_realtime_delta))) + last_realtime_ticks - total_ticks;
#endif
ticks_per_second = F2I(MAX_MULT * I2F(USEC_PER_SECOND));
}
if (ticks_delta > system_time_delta * USEC_PER_SECOND / MIN_USEC_PER_SECOND) {
2003-08-04 17:27:39 +04:00
//This keeps us from having too few instructions between ticks.
ticks_delta = system_time_delta * USEC_PER_SECOND / MIN_USEC_PER_SECOND;
}
if (ticks_delta > s[1].virtual_next_event_time) {
2003-08-04 17:27:39 +04:00
//This keeps us from missing ticks.
ticks_delta = s[1].virtual_next_event_time;
2003-08-04 17:27:39 +04:00
}
if (ticks_delta) {
2003-08-04 17:27:39 +04:00
# if DEBUG_REALTIME_WITH_PRINTF
//Every second print some info.
if (((last_real_time + real_time_delta) / USEC_PER_SECOND) > (last_real_time / USEC_PER_SECOND)) {
Bit64u temp1, temp2, temp3, temp4;
temp1 = (Bit64u) total_real_usec;
temp2 = (total_real_usec);
temp3 = (Bit64u)total_ticks;
temp4 = (Bit64u)((total_real_usec) - total_ticks);
printf("useconds: " FMT_LL "u, ", temp1);
printf("expect ticks: " FMT_LL "u, ", temp2);
printf("ticks: " FMT_LL "u, ", temp3);
2014-12-18 20:52:40 +03:00
printf("diff: " FMT_LL "u\n", temp4);
2003-08-04 17:27:39 +04:00
}
# endif
last_real_time += real_time_delta;
total_real_usec += real_time_delta;
last_system_usec += system_time_delta;
stored_delta = 0;
total_ticks += ticks_delta;
} else {
stored_delta = system_time_delta;
}
2007-10-25 03:17:42 +04:00
Bit64u a = usec_per_second, b;
if (real_time_delta) {
2003-08-04 17:27:39 +04:00
//FIXME
Bit64u em_realtime_delta = last_system_usec + stored_delta - em_last_realtime;
b=((Bit64u)USEC_PER_SECOND * em_realtime_delta / real_time_delta);
em_last_realtime = last_system_usec + stored_delta;
} else {
b=a;
}
usec_per_second = ALPHA_LOWER(a,b);
#else
BX_ASSERT(0);
#endif
2004-02-07 01:28:00 +03:00
#if BX_HAVE_REALTIME_USEC
advance_virtual_time(ticks_delta, 1);
2004-02-07 01:28:00 +03:00
#endif
2003-08-04 17:27:39 +04:00
}
last_usec=last_usec + usec_delta;
bx_pc_system.deactivate_timer(s[1].system_timer_id);
BX_ASSERT(s[1].virtual_next_event_time);
bx_pc_system.activate_timer(s[1].system_timer_id,
(Bit32u)BX_MIN(0x7FFFFFFF,BX_MAX(1,TICKS_TO_USEC(s[1].virtual_next_event_time))),
0);
2003-08-04 17:27:39 +04:00
}
void bx_virt_timer_c::pc_system_timer_handler_0(void* this_ptr)
{
((bx_virt_timer_c *)this_ptr)->timer_handler(0);
}
void bx_virt_timer_c::pc_system_timer_handler_1(void* this_ptr)
{
((bx_virt_timer_c *)this_ptr)->timer_handler(1);
2003-08-04 17:27:39 +04:00
}
void bx_virt_timer_c::set_realtime_delay()
{
real_time_delay = GET_VIRT_REALTIME64_USEC() - last_real_time;
}