#include <asm/time.h>
#include <asm/delay.h>
#include <asm/hypervisor.h>
+#include <asm/nmi.h>
+#include <asm/x86_init.h>
unsigned int __read_mostly cpu_khz; /* TSC clocks / usec, not used here */
EXPORT_SYMBOL(cpu_khz);
* unstable. We do this because unlike Time Of Day,
* the scheduler clock tolerates small errors and it's
* very important for it to be as fast as the platform
- * can achive it. )
+ * can achieve it. )
*/
if (unlikely(tsc_disabled)) {
/* No locking but a rare wrong value is not a big deal: */
__setup("notsc", notsc_setup);
+static int no_sched_irq_time;
+
static int __init tsc_setup(char *str)
{
if (!strcmp(str, "reliable"))
tsc_clocksource_reliable = 1;
+ if (!strncmp(str, "noirqtime", 9))
+ no_sched_irq_time = 1;
return 1;
}
{
u64 tsc1, tsc2, delta, ref1, ref2;
unsigned long tsc_pit_min = ULONG_MAX, tsc_ref_min = ULONG_MAX;
- unsigned long flags, latch, ms, fast_calibrate, hv_tsc_khz;
+ unsigned long flags, latch, ms, fast_calibrate;
int hpet = is_hpet_enabled(), i, loopmin;
- hv_tsc_khz = get_hypervisor_tsc_freq();
- if (hv_tsc_khz) {
- printk(KERN_INFO "TSC: Frequency read from the hypervisor\n");
- return hv_tsc_khz;
- }
-
local_irq_save(flags);
fast_calibrate = quick_pit_calibrate();
local_irq_restore(flags);
unsigned long cpu_khz_old = cpu_khz;
if (cpu_has_tsc) {
- tsc_khz = calibrate_tsc();
+ tsc_khz = x86_platform.calibrate_tsc();
cpu_khz = tsc_khz;
cpu_data(0).loops_per_jiffy =
cpufreq_scale(cpu_data(0).loops_per_jiffy,
local_irq_restore(flags);
}
+static unsigned long long cyc2ns_suspend;
+
+void save_sched_clock_state(void)
+{
+ if (!sched_clock_stable)
+ return;
+
+ cyc2ns_suspend = sched_clock();
+}
+
+/*
+ * Even on processors with invariant TSC, TSC gets reset in some the
+ * ACPI system sleep states. And in some systems BIOS seem to reinit TSC to
+ * arbitrary value (still sync'd across cpu's) during resume from such sleep
+ * states. To cope up with this, recompute the cyc2ns_offset for each cpu so
+ * that sched_clock() continues from the point where it was left off during
+ * suspend.
+ */
+void restore_sched_clock_state(void)
+{
+ unsigned long long offset;
+ unsigned long flags;
+ int cpu;
+
+ if (!sched_clock_stable)
+ return;
+
+ local_irq_save(flags);
+
+ __get_cpu_var(cyc2ns_offset) = 0;
+ offset = cyc2ns_suspend - sched_clock();
+
+ for_each_possible_cpu(cpu)
+ per_cpu(cyc2ns_offset, cpu) = offset;
+
+ local_irq_restore(flags);
+}
+
#ifdef CONFIG_CPU_FREQ
/* Frequency scaling support. Adjust the TSC based timer when the cpu frequency
if ((val == CPUFREQ_PRECHANGE && freq->old < freq->new) ||
(val == CPUFREQ_POSTCHANGE && freq->old > freq->new) ||
(val == CPUFREQ_RESUMECHANGE)) {
- *lpj = cpufreq_scale(loops_per_jiffy_ref, ref_freq, freq->new);
+ *lpj = cpufreq_scale(loops_per_jiffy_ref, ref_freq, freq->new);
tsc_khz = cpufreq_scale(tsc_khz_ref, ref_freq, freq->new);
if (!(freq->flags & CPUFREQ_CONST_LOOPS))
}
#endif
+static void resume_tsc(struct clocksource *cs)
+{
+ clocksource_tsc.cycle_last = 0;
+}
+
static struct clocksource clocksource_tsc = {
.name = "tsc",
.rating = 300,
.read = read_tsc,
+ .resume = resume_tsc,
.mask = CLOCKSOURCE_MASK(64),
- .shift = 22,
.flags = CLOCK_SOURCE_IS_CONTINUOUS |
CLOCK_SOURCE_MUST_VERIFY,
#ifdef CONFIG_X86_64
{
if (!tsc_unstable) {
tsc_unstable = 1;
- printk("Marking TSC unstable due to %s\n", reason);
+ sched_clock_stable = 0;
+ disable_sched_clock_irqtime();
+ printk(KERN_INFO "Marking TSC unstable due to %s\n", reason);
/* Change only the rating, when not registered */
if (clocksource_tsc.mult)
- clocksource_change_rating(&clocksource_tsc, 0);
- else
+ clocksource_mark_unstable(&clocksource_tsc);
+ else {
+ clocksource_tsc.flags |= CLOCK_SOURCE_UNSTABLE;
clocksource_tsc.rating = 0;
+ }
}
}
unsigned long res_low, res_high;
rdmsr_safe(MSR_GEODE_BUSCONT_CONF0, &res_low, &res_high);
- /* Geode_LX - the OLPC CPU has a possibly a very reliable TSC */
+ /* Geode_LX - the OLPC CPU has a very reliable TSC */
if (res_low & RTSC_SUSP)
tsc_clocksource_reliable = 1;
#endif
static void __init init_tsc_clocksource(void)
{
- clocksource_tsc.mult = clocksource_khz2mult(tsc_khz,
- clocksource_tsc.shift);
if (tsc_clocksource_reliable)
clocksource_tsc.flags &= ~CLOCK_SOURCE_MUST_VERIFY;
/* lower the rating if we already know its unstable: */
clocksource_tsc.rating = 0;
clocksource_tsc.flags &= ~CLOCK_SOURCE_IS_CONTINUOUS;
}
- clocksource_register(&clocksource_tsc);
+ clocksource_register_khz(&clocksource_tsc, tsc_khz);
}
void __init tsc_init(void)
u64 lpj;
int cpu;
+ x86_init.timers.tsc_pre_init();
+
if (!cpu_has_tsc)
return;
- tsc_khz = calibrate_tsc();
+ tsc_khz = x86_platform.calibrate_tsc();
cpu_khz = tsc_khz;
if (!tsc_khz) {
return;
}
-#ifdef CONFIG_X86_64
- if (cpu_has(&boot_cpu_data, X86_FEATURE_CONSTANT_TSC) &&
- (boot_cpu_data.x86_vendor == X86_VENDOR_AMD))
- cpu_khz = calibrate_cpu();
-#endif
-
printk("Detected %lu.%03lu MHz processor.\n",
(unsigned long)cpu_khz / 1000,
(unsigned long)cpu_khz % 1000);
/* now allow native_sched_clock() to use rdtsc */
tsc_disabled = 0;
+ if (!no_sched_irq_time)
+ enable_sched_clock_irqtime();
+
lpj = ((u64)tsc_khz * 1000);
do_div(lpj, HZ);
lpj_fine = lpj;
git.openpandora.org / pandora-kernel.git / blobdiff