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Diffstat (limited to 'arch')
-rw-r--r--arch/i386/kernel/tsc.c50
1 files changed, 17 insertions, 33 deletions
diff --git a/arch/i386/kernel/tsc.c b/arch/i386/kernel/tsc.c
index a3765499178..b4b2be21d1c 100644
--- a/arch/i386/kernel/tsc.c
+++ b/arch/i386/kernel/tsc.c
@@ -60,12 +60,6 @@ static inline int check_tsc_unstable(void)
return tsc_unstable;
}
-void mark_tsc_unstable(void)
-{
- tsc_unstable = 1;
-}
-EXPORT_SYMBOL_GPL(mark_tsc_unstable);
-
/* Accellerators for sched_clock()
* convert from cycles(64bits) => nanoseconds (64bits)
* basic equation:
@@ -295,7 +289,6 @@ core_initcall(cpufreq_tsc);
/* clock source code */
static unsigned long current_tsc_khz = 0;
-static int tsc_update_callback(void);
static cycle_t read_tsc(void)
{
@@ -313,37 +306,28 @@ static struct clocksource clocksource_tsc = {
.mask = CLOCKSOURCE_MASK(64),
.mult = 0, /* to be set */
.shift = 22,
- .update_callback = tsc_update_callback,
.flags = CLOCK_SOURCE_IS_CONTINUOUS |
CLOCK_SOURCE_MUST_VERIFY,
};
-static int tsc_update_callback(void)
+void mark_tsc_unstable(void)
{
- int change = 0;
-
- /* check to see if we should switch to the safe clocksource: */
- if (clocksource_tsc.rating != 0 && check_tsc_unstable()) {
- clocksource_change_rating(&clocksource_tsc, 0);
- change = 1;
- }
-
- /* only update if tsc_khz has changed: */
- if (current_tsc_khz != tsc_khz) {
- current_tsc_khz = tsc_khz;
- clocksource_tsc.mult = clocksource_khz2mult(current_tsc_khz,
- clocksource_tsc.shift);
- change = 1;
+ if (!tsc_unstable) {
+ tsc_unstable = 1;
+ /* Can be called before registration */
+ if (clocksource_tsc.mult)
+ clocksource_change_rating(&clocksource_tsc, 0);
+ else
+ clocksource_tsc.rating = 0;
}
-
- return change;
}
+EXPORT_SYMBOL_GPL(mark_tsc_unstable);
static int __init dmi_mark_tsc_unstable(struct dmi_system_id *d)
{
printk(KERN_NOTICE "%s detected: marking TSC unstable.\n",
d->ident);
- mark_tsc_unstable();
+ tsc_unstable = 1;
return 0;
}
@@ -415,11 +399,12 @@ __cpuinit int unsynchronized_tsc(void)
* Intel systems are normally all synchronized.
* Exceptions must mark TSC as unstable:
*/
- if (boot_cpu_data.x86_vendor == X86_VENDOR_INTEL)
- return 0;
-
- /* assume multi socket systems are not synchronized: */
- return num_possible_cpus() > 1;
+ if (boot_cpu_data.x86_vendor != X86_VENDOR_INTEL) {
+ /* assume multi socket systems are not synchronized: */
+ if (num_possible_cpus() > 1)
+ tsc_unstable = 1;
+ }
+ return tsc_unstable;
}
static int __init init_tsc_clocksource(void)
@@ -429,8 +414,7 @@ static int __init init_tsc_clocksource(void)
/* check blacklist */
dmi_check_system(bad_tsc_dmi_table);
- if (unsynchronized_tsc()) /* mark unstable if unsynced */
- mark_tsc_unstable();
+ unsynchronized_tsc();
current_tsc_khz = tsc_khz;
clocksource_tsc.mult = clocksource_khz2mult(current_tsc_khz,
clocksource_tsc.shift);