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- replace some mysterious magic numbers in CPU clock measurement code

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with some more meaningful expressions
- compare counter values in 100ms rather than 2ms
- check CPU_MIPS_DOUBLE_COUNT in mips_cpu_flags explicitly
This commit is contained in:
tsutsui 2008-08-03 00:20:18 +00:00
parent 2d4879d193
commit 8485799843
1 changed files with 21 additions and 15 deletions
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36
sys/arch/sgimips/dev/crime.c
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@ -1,4 +1,4 @@
/* $NetBSD: crime.c,v 1.29 2008/05/26 15:59:30 tsutsui Exp $ */
/* $NetBSD: crime.c,v 1.30 2008/08/03 00:20:18 tsutsui Exp $ */
/*
* Copyright (c) 2004 Christopher SEKIYA
@ -38,7 +38,7 @@
*/
#include <sys/cdefs.h>
__KERNEL_RCSID(0, "$NetBSD: crime.c,v 1.29 2008/05/26 15:59:30 tsutsui Exp $");
__KERNEL_RCSID(0, "$NetBSD: crime.c,v 1.30 2008/08/03 00:20:18 tsutsui Exp $");
#include <sys/param.h>
#include <sys/device.h>
@ -101,8 +101,8 @@ crime_attach(struct device *parent, struct device *self, void *aux)
{
struct mainbus_attach_args *ma = aux;
u_int64_t crm_id;
u_int64_t baseline;
u_int32_t cps;
u_int64_t baseline, endline;
u_int32_t startctr, endctr, cps;
crm_iot = SGIMIPS_BUS_SPACE_CRIME;
@ -145,19 +145,25 @@ crime_attach(struct device *parent, struct device *self, void *aux)
bus_space_write_8(crm_iot, crm_ioh, CRIME_WATCHDOG, 0);
bus_space_write_8(crm_iot, crm_ioh, CRIME_CONTROL, 0);
baseline = bus_space_read_8(crm_iot, crm_ioh, CRIME_TIME) & CRIME_TIME_MASK;
cps = mips3_cp0_count_read();
#define CRIME_TIMER_FREQ 66666666 /* crime clock is 66.7MHz */
while (((bus_space_read_8(crm_iot, crm_ioh, CRIME_TIME) & CRIME_TIME_MASK)
- baseline) < 50 * 1000000 / 15)
continue;
cps = mips3_cp0_count_read() - cps;
cps = cps / 5;
baseline = bus_space_read_8(crm_iot, crm_ioh, CRIME_TIME)
& CRIME_TIME_MASK;
startctr = mips3_cp0_count_read();
/* Counter on R4k/R4400/R4600/R5k counts at half the CPU frequency */
curcpu()->ci_cpu_freq = cps * 2 * hz;
curcpu()->ci_cycles_per_hz = curcpu()->ci_cpu_freq / (2 * hz);
curcpu()->ci_divisor_delay = curcpu()->ci_cpu_freq / (2 * 1000000);
/* read both cp0 and crime counters for 100ms */
do {
endline = bus_space_read_8(crm_iot, crm_ioh, CRIME_TIME)
& CRIME_TIME_MASK;
endctr = mips3_cp0_count_read();
} while (endline - baseline < (CRIME_TIMER_FREQ / 10));
cps = (endctr - startctr) * 10;
curcpu()->ci_cpu_freq = cps;
if (mips_cpu_flags & CPU_MIPS_DOUBLE_COUNT)
curcpu()->ci_cpu_freq *= 2;
curcpu()->ci_cycles_per_hz = (cps + (hz / 2)) / hz;
curcpu()->ci_divisor_delay = (cps + (1000000 / 2)) / 1000000;
/* Turn on memory error and crime error interrupts.
All others turned on as devices are registered. */