[PATCH] x86-64: fix cpu MHz reporting on constant_tsc cpus

This patch fixes the reporting of cpu_mhz in /proc/cpuinfo on CPUs with
a constant TSC rate and a kernel with disabled cpufreq.

Signed-off-by: Mark Langsdorf <mark.langsdorf@amd.com>
Signed-off-by: Joerg Roedel <joerg.roedel@amd.com>
Signed-off-by: Andi Kleen <ak@suse.de>

 arch/x86_64/kernel/apic.c     |    2 -
 arch/x86_64/kernel/time.c     |   58 +++++++++++++++++++++++++++++++++++++++---
 arch/x86_64/kernel/tsc.c      |   12 +++++---
 arch/x86_64/kernel/tsc_sync.c |    2 -
 include/asm-x86_64/proto.h    |    1
 5 files changed, 65 insertions(+), 10 deletions(-)

1 files changed, 7 insertions, 5 deletions

diff --git a/arch/x86_64/kernel/tsc.c b/arch/x86_64/kernel/tsc.c
index 1a0edbbffaa0..5c84992c676d 100644
--- a/arch/x86_64/kernel/tsc.c
+++ b/arch/x86_64/kernel/tsc.c
@@ -13,6 +13,8 @@ static int notsc __initdata = 0;
 
 unsigned int cpu_khz;           /* TSC clocks / usec, not used here */
 EXPORT_SYMBOL(cpu_khz);
+unsigned int tsc_khz;
+EXPORT_SYMBOL(tsc_khz);
 
 static unsigned int cyc2ns_scale __read_mostly;
 
@@ -77,7 +79,7 @@ static void handle_cpufreq_delayed_get(struct work_struct *v)
 static unsigned int  ref_freq = 0;
 static unsigned long loops_per_jiffy_ref = 0;
 
-static unsigned long cpu_khz_ref = 0;
+static unsigned long tsc_khz_ref = 0;
 
 static int time_cpufreq_notifier(struct notifier_block *nb, unsigned long val,
                                  void *data)
@@ -99,7 +101,7 @@ static int time_cpufreq_notifier(struct notifier_block *nb, unsigned long val,
         if (!ref_freq) {
                 ref_freq = freq->old;
                 loops_per_jiffy_ref = *lpj;
-                cpu_khz_ref = cpu_khz;
+                tsc_khz_ref = tsc_khz;
         }
         if ((val == CPUFREQ_PRECHANGE  && freq->old < freq->new) ||
                 (val == CPUFREQ_POSTCHANGE && freq->old > freq->new) ||
@@ -107,12 +109,12 @@ static int time_cpufreq_notifier(struct notifier_block *nb, unsigned long val,
                 *lpj =
                 cpufreq_scale(loops_per_jiffy_ref, ref_freq, freq->new);
 
-                cpu_khz = cpufreq_scale(cpu_khz_ref, ref_freq, freq->new);
+                tsc_khz = cpufreq_scale(tsc_khz_ref, ref_freq, freq->new);
                 if (!(freq->flags & CPUFREQ_CONST_LOOPS))
                         mark_tsc_unstable();
         }
 
-        set_cyc2ns_scale(cpu_khz_ref);
+        set_cyc2ns_scale(tsc_khz_ref);
 
         return 0;
 }
@@ -213,7 +215,7 @@ EXPORT_SYMBOL_GPL(mark_tsc_unstable);
 void __init init_tsc_clocksource(void)
 {
         if (!notsc) {
-                clocksource_tsc.mult = clocksource_khz2mult(cpu_khz,
+                clocksource_tsc.mult = clocksource_khz2mult(tsc_khz,
                                                         clocksource_tsc.shift);
                 if (check_tsc_unstable())
                         clocksource_tsc.rating = 0;