#include <linux/sched.h>
#include <linux/clocksource.h>
#include <linux/workqueue.h>
+#include <linux/delay.h>
#include <linux/cpufreq.h>
#include <linux/jiffies.h>
#include <linux/init.h>
#include "mach_timer.h"
-static int tsc_disabled;
+/* native_sched_clock() is called before tsc_init(), so
+ we must start with the TSC soft disabled to prevent
+ erroneous rdtsc usage on !cpu_has_tsc processors */
+static int tsc_disabled = -1;
/*
* On some systems the TSC frequency does not
/* clock source code */
-static unsigned long current_tsc_khz;
static struct clocksource clocksource_tsc;
/*
void __init tsc_init(void)
{
int cpu;
+ u64 lpj;
- if (!cpu_has_tsc || tsc_disabled) {
- /* Disable the TSC in case of !cpu_has_tsc */
- tsc_disabled = 1;
+ if (!cpu_has_tsc || tsc_disabled > 0)
return;
- }
cpu_khz = calculate_cpu_khz();
tsc_khz = cpu_khz;
if (!cpu_khz) {
mark_tsc_unstable("could not calculate TSC khz");
- /*
- * We need to disable the TSC completely in this case
- * to prevent sched_clock() from using it.
- */
- tsc_disabled = 1;
return;
}
+ lpj = ((u64)tsc_khz * 1000);
+ do_div(lpj, HZ);
+ lpj_fine = lpj;
+
+ /* now allow native_sched_clock() to use rdtsc */
+ tsc_disabled = 0;
+
printk("Detected %lu.%03lu MHz processor.\n",
(unsigned long)cpu_khz / 1000,
(unsigned long)cpu_khz % 1000);
unsynchronized_tsc();
check_geode_tsc_reliable();
- current_tsc_khz = tsc_khz;
- clocksource_tsc.mult = clocksource_khz2mult(current_tsc_khz,
- clocksource_tsc.shift);
+ clocksource_tsc.mult = clocksource_khz2mult(tsc_khz,
+ clocksource_tsc.shift);
/* lower the rating if we already know its unstable: */
if (check_tsc_unstable()) {
clocksource_tsc.rating = 0;