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authorDave Jones <davej@redhat.com>2005-05-31 19:03:46 -0700
committerDave Jones <davej@redhat.com>2005-05-31 19:03:46 -0700
commitc5d28fb297efaa97c4b90e36f9dff3066e7f2778 (patch)
treeb0636983104860fa15d9054d29ec9e8b912642cd /arch/i386/kernel/timers
parent91350ed49bf3613e243c2e216228cd4ae8f32516 (diff)
[CPUFREQ] Recalibrate cpu_khz [2/2]
Some cpufreq drivers (at that time, only powernow-k7) need to recalibrate the cpu_khz at runtime. Signed-off-by: Bruno Ducrot <ducrot@poupinou.org> Signed-off-by: Andrew Morton <akpm@osdl.org> Signed-off-by: Dave Jones <davej@redhat.com>
Diffstat (limited to 'arch/i386/kernel/timers')
-rw-r--r--arch/i386/kernel/timers/common.c6
-rw-r--r--arch/i386/kernel/timers/timer_tsc.c20
2 files changed, 24 insertions, 2 deletions
diff --git a/arch/i386/kernel/timers/common.c b/arch/i386/kernel/timers/common.c
index f7f90005e22..8e201219f52 100644
--- a/arch/i386/kernel/timers/common.c
+++ b/arch/i386/kernel/timers/common.c
@@ -6,6 +6,7 @@
#include <linux/timex.h>
#include <linux/errno.h>
#include <linux/jiffies.h>
+#include <linux/module.h>
#include <asm/io.h>
#include <asm/timer.h>
@@ -24,7 +25,7 @@
#define CALIBRATE_TIME (5 * 1000020/HZ)
-unsigned long __init calibrate_tsc(void)
+unsigned long calibrate_tsc(void)
{
mach_prepare_counter();
@@ -139,7 +140,7 @@ bad_calibration:
#endif
/* calculate cpu_khz */
-void __init init_cpu_khz(void)
+void init_cpu_khz(void)
{
if (cpu_has_tsc) {
unsigned long tsc_quotient = calibrate_tsc();
@@ -158,3 +159,4 @@ void __init init_cpu_khz(void)
}
}
}
+
diff --git a/arch/i386/kernel/timers/timer_tsc.c b/arch/i386/kernel/timers/timer_tsc.c
index 7926d967be0..180444d8782 100644
--- a/arch/i386/kernel/timers/timer_tsc.c
+++ b/arch/i386/kernel/timers/timer_tsc.c
@@ -320,6 +320,26 @@ core_initcall(cpufreq_tsc);
static inline void cpufreq_delayed_get(void) { return; }
#endif
+int recalibrate_cpu_khz(void)
+{
+#ifndef CONFIG_SMP
+ unsigned long cpu_khz_old = cpu_khz;
+
+ if (cpu_has_tsc) {
+ init_cpu_khz();
+ cpu_data[0].loops_per_jiffy =
+ cpufreq_scale(cpu_data[0].loops_per_jiffy,
+ cpu_khz_old,
+ cpu_khz);
+ return 0;
+ } else
+ return -ENODEV;
+#else
+ return -ENODEV;
+#endif
+}
+EXPORT_SYMBOL(recalibrate_cpu_khz);
+
static void mark_offset_tsc(void)
{
unsigned long lost,delay;