[PATCH] Add initalization of the RDTSCP auxilliary values
This patch adds initalization of the RDTSCP auxilliary values to CPU numbers
to time.c. If RDTSCP is available, the MSRs are written with the respective
values. It can be later used to initalize per-cpu timekeeping variables.
AK: Some cleanups. Move externs into headers and fix CPU hotplug.
Signed-off-by: Vojtech Pavlik <vojtech@suse.cz>
Signed-off-by: Andi Kleen <ak@suse.de>
diff --git a/arch/x86_64/kernel/smpboot.c b/arch/x86_64/kernel/smpboot.c
index 1555587..582896f 100644
--- a/arch/x86_64/kernel/smpboot.c
+++ b/arch/x86_64/kernel/smpboot.c
@@ -1181,6 +1181,8 @@
#endif
check_nmi_watchdog();
+
+ time_init_gtod();
}
#ifdef CONFIG_HOTPLUG_CPU
diff --git a/arch/x86_64/kernel/time.c b/arch/x86_64/kernel/time.c
index 7a9b182..97b9e46d 100644
--- a/arch/x86_64/kernel/time.c
+++ b/arch/x86_64/kernel/time.c
@@ -24,6 +24,8 @@
#include <linux/device.h>
#include <linux/sysdev.h>
#include <linux/bcd.h>
+#include <linux/notifier.h>
+#include <linux/cpu.h>
#include <linux/kallsyms.h>
#include <linux/acpi.h>
#ifdef CONFIG_ACPI
@@ -49,7 +51,7 @@
extern void i8254_timer_resume(void);
extern int using_apic_timer;
-static char *time_init_gtod(void);
+static char *timename = NULL;
DEFINE_SPINLOCK(rtc_lock);
EXPORT_SYMBOL(rtc_lock);
@@ -893,11 +895,21 @@
timer_interrupt, IRQF_DISABLED, CPU_MASK_NONE, "timer", NULL, NULL
};
+static int __cpuinit
+time_cpu_notifier(struct notifier_block *nb, unsigned long action, void *hcpu)
+{
+ unsigned cpu = (unsigned long) hcpu;
+ if (action == CPU_ONLINE &&
+ cpu_has(&cpu_data[cpu], X86_FEATURE_RDTSCP)) {
+ unsigned p;
+ p = smp_processor_id() | (cpu_to_node(smp_processor_id())<<12);
+ write_rdtscp_aux(p);
+ }
+ return NOTIFY_DONE;
+}
+
void __init time_init(void)
{
- char *timename;
- char *gtod;
-
if (nohpet)
vxtime.hpet_address = 0;
@@ -931,18 +943,19 @@
}
vxtime.mode = VXTIME_TSC;
- gtod = time_init_gtod();
-
- printk(KERN_INFO "time.c: Using %ld.%06ld MHz WALL %s GTOD %s timer.\n",
- vxtime_hz / 1000000, vxtime_hz % 1000000, timename, gtod);
- printk(KERN_INFO "time.c: Detected %d.%03d MHz processor.\n",
- cpu_khz / 1000, cpu_khz % 1000);
vxtime.quot = (USEC_PER_SEC << US_SCALE) / vxtime_hz;
vxtime.tsc_quot = (USEC_PER_MSEC << US_SCALE) / cpu_khz;
vxtime.last_tsc = get_cycles_sync();
setup_irq(0, &irq0);
set_cyc2ns_scale(cpu_khz);
+
+ hotcpu_notifier(time_cpu_notifier, 0);
+ time_cpu_notifier(NULL, CPU_ONLINE, (void *)(long)smp_processor_id());
+
+#ifndef CONFIG_SMP
+ time_init_gtod();
+#endif
}
/*
@@ -973,12 +986,13 @@
/*
* Decide what mode gettimeofday should use.
*/
-__init static char *time_init_gtod(void)
+void time_init_gtod(void)
{
char *timetype;
if (unsynchronized_tsc())
notsc = 1;
+
if (vxtime.hpet_address && notsc) {
timetype = hpet_use_timer ? "HPET" : "PIT/HPET";
if (hpet_use_timer)
@@ -1001,7 +1015,16 @@
timetype = hpet_use_timer ? "HPET/TSC" : "PIT/TSC";
vxtime.mode = VXTIME_TSC;
}
- return timetype;
+
+ printk(KERN_INFO "time.c: Using %ld.%06ld MHz WALL %s GTOD %s timer.\n",
+ vxtime_hz / 1000000, vxtime_hz % 1000000, timename, timetype);
+ printk(KERN_INFO "time.c: Detected %d.%03d MHz processor.\n",
+ cpu_khz / 1000, cpu_khz % 1000);
+ vxtime.quot = (USEC_PER_SEC << US_SCALE) / vxtime_hz;
+ vxtime.tsc_quot = (USEC_PER_MSEC << US_SCALE) / cpu_khz;
+ vxtime.last_tsc = get_cycles_sync();
+
+ set_cyc2ns_scale(cpu_khz);
}
__setup("report_lost_ticks", time_setup);
diff --git a/include/asm-x86_64/proto.h b/include/asm-x86_64/proto.h
index 038fe1f4..3b1c602 100644
--- a/include/asm-x86_64/proto.h
+++ b/include/asm-x86_64/proto.h
@@ -51,6 +51,7 @@
extern int sysctl_vsyscall;
extern int nohpet;
extern unsigned long vxtime_hz;
+extern void time_init_gtod(void);
extern int numa_setup(char *opt);
