f28fd84c68
- add ioapic support - currently, all irq will forwarded to the boot processor git-svn-id: http://svn.lfbs.rwth-aachen.de/svn/scc/trunk/MetalSVM@293 315a16e6-25f9-4109-90ae-ca3045a26c18
109 lines
2.7 KiB
C
109 lines
2.7 KiB
C
/*
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* Copyright 2010 Stefan Lankes, Chair for Operating Systems,
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* RWTH Aachen University
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*
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* Licensed under the Apache License, Version 2.0 (the "License");
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* you may not use this file except in compliance with the License.
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* You may obtain a copy of the License at
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*
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* http://www.apache.org/licenses/LICENSE-2.0
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*
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* Unless required by applicable law or agreed to in writing, software
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* distributed under the License is distributed on an "AS IS" BASIS,
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* WITHOUT WARRANTIES OR CONDITIONS OF ANY KIND, either express or implied.
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* See the License for the specific language governing permissions and
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* limitations under the License.
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*
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* This file is part of MetalSVM.
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*/
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#include <metalsvm/stdio.h>
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#include <metalsvm/string.h>
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#include <metalsvm/tasks.h>
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#include <metalsvm/time.h>
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#include <metalsvm/processor.h>
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#include <asm/irq.h>
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#include <asm/irqflags.h>
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#include <asm/gdt.h>
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#include <asm/tss.h>
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#include <asm/vga.h>
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/*
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* This will keep track of how many ticks the system
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* has been running for
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*/
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static volatile uint64_t timer_ticks = 0;
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uint64_t get_clock_tick(void)
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{
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return timer_ticks;
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}
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/*
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* Handles the timer. In this case, it's very simple: We
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* increment the 'timer_ticks' variable every time the
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* timer fires.
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*/
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static void timer_handler(struct state *s)
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{
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/* Increment our 'tick counter' */
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timer_ticks++;
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/*
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* Every TIMER_FREQ clocks (approximately 1 second), we will
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* display a message on the screen
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*/
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/*if (timer_ticks % TIMER_FREQ == 0) {
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vga_puts("One second has passed\n");
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}*/
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}
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/*
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* This will continuously loop until the given time has
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* been reached
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*/
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void timer_wait(unsigned int ticks)
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{
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uint64_t eticks = timer_ticks + ticks;
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while (timer_ticks < eticks)
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reschedule();
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}
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#define LATCH(f) ((CLOCK_TICK_RATE + f/2) / f)
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/*
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* Sets up the system clock by installing the timer handler
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* into IRQ0
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*/
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int timer_init(void)
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{
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uint64_t start;
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/*
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* Installs 'timer_handler' for the PIC and APIC timer,
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* only one handler will be later used.
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*/
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irq_install_handler(0, timer_handler);
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irq_install_handler(123-32, timer_handler);
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/*
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* The Rock Creek processor doesn't posseess an tradional PIC.
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* Therefore, we have not to configure the PIC timer.
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*/
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#ifndef CONFIG_ROCKCREEK
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outportb(0x43, 0x34);
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/* before we write to 0x40, we wait some time */
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start = rdtsc();
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while(rdtsc() - start < 1000000)
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;
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outportb(0x40, LATCH(TIMER_FREQ) & 0xFF); /* low byte */
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/* before we write to 0x40, we wait some time */
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start = rdtsc();
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while(rdtsc() - start < 1000000)
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;
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outportb(0x40, LATCH(TIMER_FREQ) >> 8); /* high byte */
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#endif
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return 0;
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}
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