Merge branch 'for-linus' of git://git.kernel.org/pub/scm/linux/kernel/git/x86/linux-2.6-x86

* 'for-linus' of git://git.kernel.org/pub/scm/linux/kernel/git/x86/linux-2.6-x86:
  x86: fix 64-bit asm NOPS for CONFIG_GENERIC_CPU
  x86: fix call to set_cyc2ns_scale() from time_cpufreq_notifier()
  revert "x86: tsc prevent time going backwards"

2 files changed, 6 insertions, 40 deletions

diff --git a/arch/x86/kernel/tsc_32.c b/arch/x86/kernel/tsc_32.c
index d7498b34c8e9..c2241e04ea5f 100644
--- a/arch/x86/kernel/tsc_32.c
+++ b/arch/x86/kernel/tsc_32.c
@@ -256,9 +256,7 @@ time_cpufreq_notifier(struct notifier_block *nb, unsigned long val, void *data)
                                                 ref_freq, freq->new);
                         if (!(freq->flags & CPUFREQ_CONST_LOOPS)) {
                                 tsc_khz = cpu_khz;
-                                preempt_disable();
-                                set_cyc2ns_scale(cpu_khz, smp_processor_id());
-                                preempt_enable();
+                                set_cyc2ns_scale(cpu_khz, freq->cpu);
                                 /*
                                  * TSC based sched_clock turns
                                  * to junk w/ cpufreq
@@ -287,27 +285,14 @@ core_initcall(cpufreq_tsc);
 /* clock source code */
 
 static unsigned long current_tsc_khz = 0;
-static struct clocksource clocksource_tsc;
 
-/*
- * We compare the TSC to the cycle_last value in the clocksource
- * structure to avoid a nasty time-warp issue. This can be observed in
- * a very small window right after one CPU updated cycle_last under
- * xtime lock and the other CPU reads a TSC value which is smaller
- * than the cycle_last reference value due to a TSC which is slighty
- * behind. This delta is nowhere else observable, but in that case it
- * results in a forward time jump in the range of hours due to the
- * unsigned delta calculation of the time keeping core code, which is
- * necessary to support wrapping clocksources like pm timer.
- */
 static cycle_t read_tsc(void)
 {
         cycle_t ret;
 
         rdtscll(ret);
 
-        return ret >= clocksource_tsc.cycle_last ?
-                ret : clocksource_tsc.cycle_last;
+        return ret;
 }
 
 static struct clocksource clocksource_tsc = {
diff --git a/arch/x86/kernel/tsc_64.c b/arch/x86/kernel/tsc_64.c
index 01fc9f0c39e2..d3bebaaad842 100644
--- a/arch/x86/kernel/tsc_64.c
+++ b/arch/x86/kernel/tsc_64.c
@@ -11,7 +11,6 @@
 #include <asm/hpet.h>
 #include <asm/timex.h>
 #include <asm/timer.h>
-#include <asm/vgtod.h>
 
 static int notsc __initdata = 0;
 
@@ -149,9 +148,7 @@ static int time_cpufreq_notifier(struct notifier_block *nb, unsigned long val,
                         mark_tsc_unstable("cpufreq changes");
         }
 
-        preempt_disable();
-        set_cyc2ns_scale(tsc_khz_ref, smp_processor_id());
-        preempt_enable();
+        set_cyc2ns_scale(tsc_khz_ref, freq->cpu);
 
         return 0;
 }
@@ -291,34 +288,18 @@ int __init notsc_setup(char *s)
 
 __setup("notsc", notsc_setup);
 
-static struct clocksource clocksource_tsc;
 
-/*
- * We compare the TSC to the cycle_last value in the clocksource
- * structure to avoid a nasty time-warp. This can be observed in a
- * very small window right after one CPU updated cycle_last under
- * xtime/vsyscall_gtod lock and the other CPU reads a TSC value which
- * is smaller than the cycle_last reference value due to a TSC which
- * is slighty behind. This delta is nowhere else observable, but in
- * that case it results in a forward time jump in the range of hours
- * due to the unsigned delta calculation of the time keeping core
- * code, which is necessary to support wrapping clocksources like pm
- * timer.
- */
+/* clock source code: */
 static cycle_t read_tsc(void)
 {
         cycle_t ret = (cycle_t)get_cycles();
-
-        return ret >= clocksource_tsc.cycle_last ?
-                ret : clocksource_tsc.cycle_last;
+        return ret;
 }
 
 static cycle_t __vsyscall_fn vread_tsc(void)
 {
         cycle_t ret = (cycle_t)vget_cycles();
-
-        return ret >= __vsyscall_gtod_data.clock.cycle_last ?
-                ret : __vsyscall_gtod_data.clock.cycle_last;
+        return ret;
 }
 
 static struct clocksource clocksource_tsc = {