mirror of
https://gitlab.com/sortix/sortix.git
synced 2023-02-13 20:55:38 -05:00
135 lines
4.1 KiB
C++
135 lines
4.1 KiB
C++
/*******************************************************************************
|
|
|
|
Copyright(C) Jonas 'Sortie' Termansen 2011, 2012, 2013.
|
|
|
|
This file is part of Sortix.
|
|
|
|
Sortix is free software: you can redistribute it and/or modify it under the
|
|
terms of the GNU General Public License as published by the Free Software
|
|
Foundation, either version 3 of the License, or (at your option) any later
|
|
version.
|
|
|
|
Sortix 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 General Public License for more
|
|
details.
|
|
|
|
You should have received a copy of the GNU General Public License along with
|
|
Sortix. If not, see <http://www.gnu.org/licenses/>.
|
|
|
|
x86-family/time.cpp
|
|
Retrieving the current time.
|
|
|
|
*******************************************************************************/
|
|
|
|
#include <sys/types.h>
|
|
|
|
#include <timespec.h>
|
|
|
|
#include <sortix/timespec.h>
|
|
|
|
#include <sortix/kernel/clock.h>
|
|
#include <sortix/kernel/cpu.h>
|
|
#include <sortix/kernel/interrupt.h>
|
|
#include <sortix/kernel/kernel.h>
|
|
#include <sortix/kernel/process.h>
|
|
#include <sortix/kernel/scheduler.h>
|
|
#include <sortix/kernel/time.h>
|
|
|
|
namespace Sortix {
|
|
namespace Time {
|
|
|
|
static uint16_t DivisorOfFrequency(long frequency)
|
|
{
|
|
// The value we send to the PIT is the value to divide it's input clock
|
|
// (1193180 Hz) by, to get our required frequency. Note that the divisor
|
|
// must be small enough to fit into 16 bits.
|
|
return 1193180 / frequency;
|
|
}
|
|
|
|
static long FrequencyOfDivisor(uint16_t divisor)
|
|
{
|
|
return 1193180 / divisor;
|
|
}
|
|
|
|
static long RealFrequencyOfFrequency(long frequency)
|
|
{
|
|
return FrequencyOfDivisor(DivisorOfFrequency(frequency));
|
|
}
|
|
|
|
static struct timespec PeriodOfFrequency(long frequency)
|
|
{
|
|
long period_ns = 1000000000L / frequency;
|
|
return timespec_make(0, period_ns);
|
|
}
|
|
|
|
static void RequestIRQ0(uint16_t divisor)
|
|
{
|
|
CPU::OutPortB(0x43, 0x36);
|
|
CPU::OutPortB(0x40, divisor >> 0 & 0xFF);
|
|
CPU::OutPortB(0x40, divisor >> 8 & 0xFF);
|
|
}
|
|
|
|
extern Clock* realtime_clock;
|
|
extern Clock* uptime_clock;
|
|
|
|
static struct timespec tick_period;
|
|
static long tick_frequency;
|
|
static uint16_t tick_divisor;
|
|
|
|
static void OnIRQ0(CPU::InterruptRegisters* regs, void* /*user*/)
|
|
{
|
|
OnTick(tick_period, !regs->InUserspace());
|
|
Scheduler::Switch(regs);
|
|
|
|
// TODO: There is a horrible bug that causes Sortix to only receive
|
|
// one IRQ0 on my laptop, but it works in virtual machines. But
|
|
// re-requesting an addtional time seems to work. Hacky and ugly.
|
|
// TODO: Confirm whether this still happens and whether it is trigged by
|
|
// another bug in my system.
|
|
static bool did_ugly_irq0_hack = false;
|
|
if ( !did_ugly_irq0_hack )
|
|
RequestIRQ0(tick_divisor),
|
|
did_ugly_irq0_hack = true;
|
|
}
|
|
|
|
void CPUInit()
|
|
{
|
|
// Estimate the rate that interrupts will be coming at.
|
|
long desired_frequency = 100/*Hz*/;
|
|
tick_frequency = RealFrequencyOfFrequency(desired_frequency);
|
|
tick_divisor = DivisorOfFrequency(tick_frequency);
|
|
tick_period = PeriodOfFrequency(tick_frequency);
|
|
|
|
// Initialize the clocks on this system.
|
|
realtime_clock->SetCallableFromInterrupts(true);
|
|
uptime_clock->SetCallableFromInterrupts(true);
|
|
struct timespec nul_time = timespec_nul();
|
|
realtime_clock->Set(&nul_time, &tick_period);
|
|
uptime_clock->Set(&nul_time, &tick_period);
|
|
}
|
|
|
|
void InitializeProcessClocks(Process* process)
|
|
{
|
|
struct timespec nul_time = timespec_nul();
|
|
process->execute_clock.SetCallableFromInterrupts(true);
|
|
process->execute_clock.Set(&nul_time, &tick_period);
|
|
process->system_clock.SetCallableFromInterrupts(true);
|
|
process->system_clock.Set(&nul_time, &tick_period);
|
|
process->child_execute_clock.Set(&nul_time, &tick_period);
|
|
process->child_execute_clock.SetCallableFromInterrupts(true);
|
|
process->child_system_clock.Set(&nul_time, &tick_period);
|
|
process->child_system_clock.SetCallableFromInterrupts(true);
|
|
}
|
|
|
|
void Start()
|
|
{
|
|
// Handle timer interrupts if they arrive.
|
|
Interrupt::RegisterHandler(Interrupt::IRQ0, &OnIRQ0, NULL);
|
|
|
|
// Request a timer interrupt now that we can handle them safely.
|
|
RequestIRQ0(tick_divisor);
|
|
}
|
|
|
|
} // namespace Time
|
|
} // namespace Sortix
|