1b56fdb33c
- as thre are still KERNEL and IDLE entries, time accounting for kernel and idle time works the same as for any other process - everytime we stop accounting for the currently running process, kernel or idle, we read the TSC counter and increment the p_cycles entry. - the process cycles inherently include some of the kernel cycles as we can stop accounting for the process only after we save its context and we start accounting just before we restore its context - this assumes that the system does not scale the CPU frequency which will be true for ... long time ;-)
146 lines
3.7 KiB
C
146 lines
3.7 KiB
C
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/* i386-specific clock functions. */
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#include <ibm/ports.h>
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#include <minix/portio.h>
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#include "../../kernel.h"
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#include "../../clock.h"
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#include "../../proc.h"
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#include <minix/u64.h>
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#ifdef CONFIG_APIC
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#include "apic.h"
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#endif
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#define CLOCK_ACK_BIT 0x80 /* PS/2 clock interrupt acknowledge bit */
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/* Clock parameters. */
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#define COUNTER_FREQ (2*TIMER_FREQ) /* counter frequency using square wave */
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#define LATCH_COUNT 0x00 /* cc00xxxx, c = channel, x = any */
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#define SQUARE_WAVE 0x36 /* ccaammmb, a = access, m = mode, b = BCD */
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/* 11x11, 11 = LSB then MSB, x11 = sq wave */
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#define TIMER_FREQ 1193182 /* clock frequency for timer in PC and AT */
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#define TIMER_COUNT(freq) (TIMER_FREQ/(freq)) /* initial value for counter*/
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/* FIXME make it cpu local! */
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PRIVATE u64_t tsc_ctr_switch; /* when did we switched time accounting */
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PRIVATE irq_hook_t pic_timer_hook; /* interrupt handler hook */
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/*===========================================================================*
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* init_8235A_timer *
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*===========================================================================*/
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PUBLIC int init_8253A_timer(unsigned freq)
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{
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/* Initialize channel 0 of the 8253A timer to, e.g., 60 Hz,
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* and register the CLOCK task's interrupt handler to be run
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* on every clock tick.
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*/
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outb(TIMER_MODE, SQUARE_WAVE); /* run continuously */
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outb(TIMER0, (TIMER_COUNT(freq) & 0xff)); /* timer low byte */
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outb(TIMER0, TIMER_COUNT(freq) >> 8); /* timer high byte */
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return OK;
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}
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/*===========================================================================*
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* stop_8235A_timer *
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*===========================================================================*/
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PUBLIC void stop_8253A_timer(void)
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{
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/* Reset the clock to the BIOS rate. (For rebooting.) */
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outb(TIMER_MODE, 0x36);
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outb(TIMER0, 0);
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outb(TIMER0, 0);
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}
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/*===========================================================================*
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* read_8235A_timer *
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*===========================================================================*/
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PRIVATE clock_t read_8253A_timer(void)
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{
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/* Read the counter of channel 0 of the 8253A timer. This counter
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* counts down at a rate of TIMER_FREQ and restarts at
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* TIMER_COUNT-1 when it reaches zero. A hardware interrupt
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* (clock tick) occurs when the counter gets to zero and restarts
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* its cycle.
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*/
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u32_t count;
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outb(TIMER_MODE, LATCH_COUNT);
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count = inb(TIMER0);
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count |= (inb(TIMER0) << 8);
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return count;
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}
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PUBLIC int arch_init_local_timer(unsigned freq)
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{
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#ifdef CONFIG_APIC
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/* if we know the address, lapic is enabled and we should use it */
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if (lapic_addr) {
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lapic_set_timer_periodic(freq);
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} else
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{
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BOOT_VERBOSE(kprintf("Initiating legacy i8253 timer\n"));
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#else
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{
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#endif
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init_8253A_timer(freq);
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}
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return 0;
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}
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PUBLIC void arch_stop_local_timer(void)
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{
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#ifdef CONFIG_APIC
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if (lapic_addr) {
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lapic_stop_timer();
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} else
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#endif
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{
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stop_8253A_timer();
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}
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}
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PUBLIC int arch_register_local_timer_handler(irq_handler_t handler)
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{
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#ifdef CONFIG_APIC
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if (lapic_addr) {
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/* Using APIC, it is configured in apic_idt_init() */
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BOOT_VERBOSE(kprintf("Using LAPIC timer as tick source\n"));
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} else
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#endif
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{
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/* Using PIC, Initialize the CLOCK's interrupt hook. */
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pic_timer_hook.proc_nr_e = NONE;
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pic_timer_hook.irq = CLOCK_IRQ;
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put_irq_handler(&pic_timer_hook, CLOCK_IRQ, handler);
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}
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return 0;
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}
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PUBLIC void cycles_accounting_init(void)
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{
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read_tsc_64(&tsc_ctr_switch);
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}
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PUBLIC void cycles_accounting_stop(struct proc * p)
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{
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u64_t tsc;
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read_tsc_64(&tsc);
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p->p_cycles = add64(p->p_cycles, sub64(tsc, tsc_ctr_switch));
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tsc_ctr_switch = tsc;
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}
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PUBLIC void cycles_accounting_stop_idle(void)
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{
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cycles_accounting_stop(proc_addr(IDLE));
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}
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