[PATCH 8/11] Add a CPU KHZ calibration function to paravirt-ops

From: Zachary Amsden
Date: Mon Feb 05 2007 - 22:55:57 EST


Provide a paravirtualized way to get the CPU clock frequency; this allows much
of the code in tsc.c to be shared between all paravirt implementations.

Subject: Add a CPU KHZ calibration function to paravirt-ops
Signed-off-by: Zachary Amsden <zach@xxxxxxxxxx>

diff -r a08f195aa92a arch/i386/kernel/vmi.c
--- a/arch/i386/kernel/vmi.c Fri Feb 02 16:30:59 2007 -0800
+++ b/arch/i386/kernel/vmi.c Fri Feb 02 16:31:45 2007 -0800
@@ -881,6 +881,7 @@ static int __init activate_vmi(void)
paravirt_ops.setup_secondary_clock = vmi_timer_setup_secondary_alarm;
#endif
paravirt_ops.get_scheduled_cycles = vmi_get_sched_cycles;
+ paravirt_ops.get_cpu_khz = vmi_cpu_khz;
}

/*
diff -r a08f195aa92a arch/i386/kernel/vmitime.c
--- a/arch/i386/kernel/vmitime.c Fri Feb 02 16:30:59 2007 -0800
+++ b/arch/i386/kernel/vmitime.c Fri Feb 02 16:30:59 2007 -0800
@@ -175,6 +175,15 @@ unsigned long long vmi_get_sched_cycles(
return read_available_cycles();
}

+unsigned long vmi_cpu_khz(void)
+{
+ unsigned long long khz;
+
+ khz = vmi_timer_ops.get_cycle_frequency();
+ (void)do_div(khz, 1000);
+ return khz;
+}
+
void __init vmi_time_init(void)
{
unsigned long long cycles_per_sec, cycles_per_msec;
@@ -204,7 +213,6 @@ void __init vmi_time_init(void)
(void)do_div(cycles_per_alarm, alarm_hz);
cycles_per_msec = cycles_per_sec;
(void)do_div(cycles_per_msec, 1000);
- cpu_khz = cycles_per_msec;

printk(KERN_WARNING "VMI timer cycles/sec = %llu ; cycles/jiffy = %llu ;"
"cycles/alarm = %llu\n", cycles_per_sec, cycles_per_jiffy,
diff -r a08f195aa92a include/asm-i386/vmi_time.h
--- a/include/asm-i386/vmi_time.h Fri Feb 02 16:30:59 2007 -0800
+++ b/include/asm-i386/vmi_time.h Fri Feb 02 16:31:24 2007 -0800
@@ -50,6 +50,7 @@ extern unsigned long vmi_get_wallclock(v
extern unsigned long vmi_get_wallclock(void);
extern int vmi_set_wallclock(unsigned long now);
extern unsigned long long vmi_get_sched_cycles(void);
+extern unsigned long vmi_cpu_khz(void);

#ifdef CONFIG_X86_LOCAL_APIC
extern void __init vmi_timer_setup_boot_alarm(void);
-
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