[PATCH] vmi: cpu cycles fix

[linux-2.6] / arch / i386 / kernel / tsc.c

diff --git a/arch/i386/kernel/tsc.c b/arch/i386/kernel/tsc.c
index 22931d24027c718e5b93d5e3ebaaf04ab0b3c278..59222a04234b929cb98b086caaad46f021b259df 100644 (file)
--- a/arch/i386/kernel/tsc.c
+++ b/arch/i386/kernel/tsc.c
@@ -14,6 +14,7 @@
 #include <asm/delay.h>
 #include <asm/tsc.h>
 #include <asm/io.h>
+#include <asm/timer.h>
 
 #include "mach_timer.h"
 
@@ -102,9 +103,6 @@ unsigned long long sched_clock(void)
 {
        unsigned long long this_offset;
 
-       if (unlikely(custom_sched_clock))
-               return (*custom_sched_clock)();
-
        /*
         * Fall back to jiffies if there's no TSC available:
         */
@@ -113,13 +111,13 @@ unsigned long long sched_clock(void)
                return (jiffies_64 - INITIAL_JIFFIES) * (1000000000 / HZ);
 
        /* read the Time Stamp Counter: */
-       rdtscll(this_offset);
+       get_scheduled_cycles(this_offset);
 
        /* return the value in ns */
        return cycles_2_ns(this_offset);
 }
 
-static unsigned long calculate_cpu_khz(void)
+unsigned long native_calculate_cpu_khz(void)
 {
        unsigned long long start, end;
        unsigned long count;
@@ -364,6 +362,25 @@ __cpuinit int unsynchronized_tsc(void)
        return tsc_unstable;
 }
 
+/*
+ * Geode_LX - the OLPC CPU has a possibly a very reliable TSC
+ */
+#ifdef CONFIG_MGEODE_LX
+/* RTSC counts during suspend */
+#define RTSC_SUSP 0x100
+
+static void __init check_geode_tsc_reliable(void)
+{
+       unsigned long val;
+
+       rdmsrl(MSR_GEODE_BUSCONT_CONF0, val);
+       if ((val & RTSC_SUSP))
+               clocksource_tsc.flags &= ~CLOCK_SOURCE_MUST_VERIFY;
+}
+#else
+static inline void check_geode_tsc_reliable(void) { }
+#endif
+
 static int __init init_tsc_clocksource(void)
 {
 
@@ -372,6 +389,7 @@ static int __init init_tsc_clocksource(void)
                dmi_check_system(bad_tsc_dmi_table);
 
                unsynchronized_tsc();
+               check_geode_tsc_reliable();
                current_tsc_khz = tsc_khz;
                clocksource_tsc.mult = clocksource_khz2mult(current_tsc_khz,
                                                        clocksource_tsc.shift);