Merge git://git.kernel.org/pub/scm/linux/kernel/git/torvalds/linux-2.6

[cascardo/linux.git] / arch / i386 / kernel / tsc.c

diff --git a/arch/i386/kernel/tsc.c b/arch/i386/kernel/tsc.c
index 3082a41..f64b81f 100644 (file)
--- a/arch/i386/kernel/tsc.c
+++ b/arch/i386/kernel/tsc.c
@@ -14,16 +14,18 @@
 #include <asm/delay.h>
 #include <asm/tsc.h>
 #include <asm/io.h>
+#include <asm/timer.h>
 
 #include "mach_timer.h"
 
+static int tsc_enabled;
+
 /*
  * On some systems the TSC frequency does not
  * change with the cpu frequency. So we need
  * an extra value to store the TSC freq
  */
 unsigned int tsc_khz;
-unsigned long long (*custom_sched_clock)(void);
 
 int tsc_disable;
 
@@ -102,24 +104,21 @@ 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:
         */
-       if (unlikely(tsc_disable))
+       if (unlikely(!tsc_enabled))
                /* No locking but a rare wrong value is not a big deal: */
                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;
@@ -186,34 +185,6 @@ int recalibrate_cpu_khz(void)
 
 EXPORT_SYMBOL(recalibrate_cpu_khz);
 
-void __init tsc_init(void)
-{
-       if (!cpu_has_tsc || tsc_disable)
-               goto out_no_tsc;
-
-       cpu_khz = calculate_cpu_khz();
-       tsc_khz = cpu_khz;
-
-       if (!cpu_khz)
-               goto out_no_tsc;
-
-       printk("Detected %lu.%03lu MHz processor.\n",
-                               (unsigned long)cpu_khz / 1000,
-                               (unsigned long)cpu_khz % 1000);
-
-       set_cyc2ns_scale(cpu_khz);
-       use_tsc_delay();
-       return;
-
-out_no_tsc:
-       /*
-        * Set the tsc_disable flag if there's no TSC support, this
-        * makes it a fast flag for the kernel to see whether it
-        * should be using the TSC.
-        */
-       tsc_disable = 1;
-}
-
 #ifdef CONFIG_CPU_FREQ
 
 /*
@@ -229,13 +200,10 @@ time_cpufreq_notifier(struct notifier_block *nb, unsigned long val, void *data)
 {
        struct cpufreq_freqs *freq = data;
 
-       if (val != CPUFREQ_RESUMECHANGE && val != CPUFREQ_SUSPENDCHANGE)
-               write_seqlock_irq(&xtime_lock);
-
        if (!ref_freq) {
                if (!freq->old){
                        ref_freq = freq->new;
-                       goto end;
+                       return 0;
                }
                ref_freq = freq->old;
                loops_per_jiffy_ref = cpu_data[freq->cpu].loops_per_jiffy;
@@ -262,13 +230,10 @@ time_cpufreq_notifier(struct notifier_block *nb, unsigned long val, void *data)
                                 * TSC based sched_clock turns
                                 * to junk w/ cpufreq
                                 */
-                               mark_tsc_unstable();
+                               mark_tsc_unstable("cpufreq changes");
                        }
                }
        }
-end:
-       if (val != CPUFREQ_RESUMECHANGE && val != CPUFREQ_SUSPENDCHANGE)
-               write_sequnlock_irq(&xtime_lock);
 
        return 0;
 }
@@ -310,10 +275,12 @@ static struct clocksource clocksource_tsc = {
                                  CLOCK_SOURCE_MUST_VERIFY,
 };
 
-void mark_tsc_unstable(void)
+void mark_tsc_unstable(char *reason)
 {
        if (!tsc_unstable) {
                tsc_unstable = 1;
+               tsc_enabled = 0;
+               printk("Marking TSC unstable due to: %s.\n", reason);
                /* Can be called before registration */
                if (clocksource_tsc.mult)
                        clocksource_change_rating(&clocksource_tsc, 0);
@@ -383,28 +350,49 @@ static void __init check_geode_tsc_reliable(void)
 static inline void check_geode_tsc_reliable(void) { }
 #endif
 
-static int __init init_tsc_clocksource(void)
+
+void __init tsc_init(void)
 {
+       if (!cpu_has_tsc || tsc_disable)
+               goto out_no_tsc;
+
+       cpu_khz = calculate_cpu_khz();
+       tsc_khz = cpu_khz;
+
+       if (!cpu_khz)
+               goto out_no_tsc;
+
+       printk("Detected %lu.%03lu MHz processor.\n",
+                               (unsigned long)cpu_khz / 1000,
+                               (unsigned long)cpu_khz % 1000);
+
+       set_cyc2ns_scale(cpu_khz);
+       use_tsc_delay();
 
-       if (cpu_has_tsc && tsc_khz && !tsc_disable) {
-               /* check blacklist */
-               dmi_check_system(bad_tsc_dmi_table);
+       /* Check and install the TSC clocksource */
+       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,
+       unsynchronized_tsc();
+       check_geode_tsc_reliable();
+       current_tsc_khz = tsc_khz;
+       clocksource_tsc.mult = clocksource_khz2mult(current_tsc_khz,
                                                        clocksource_tsc.shift);
-               /* lower the rating if we already know its unstable: */
-               if (check_tsc_unstable()) {
-                       clocksource_tsc.rating = 0;
-                       clocksource_tsc.flags &= ~CLOCK_SOURCE_IS_CONTINUOUS;
-               }
+       /* lower the rating if we already know its unstable: */
+       if (check_tsc_unstable()) {
+               clocksource_tsc.rating = 0;
+               clocksource_tsc.flags &= ~CLOCK_SOURCE_IS_CONTINUOUS;
+       } else
+               tsc_enabled = 1;
 
-               return clocksource_register(&clocksource_tsc);
-       }
+       clocksource_register(&clocksource_tsc);
 
-       return 0;
-}
+       return;
 
-module_init(init_tsc_clocksource);
+out_no_tsc:
+       /*
+        * Set the tsc_disable flag if there's no TSC support, this
+        * makes it a fast flag for the kernel to see whether it
+        * should be using the TSC.
+        */
+       tsc_disable = 1;
+}