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authorJiang, Yunhong <yunhong.jiang@intel.com>2016-10-28 23:29:15 +0000
committerGerrit Code Review <gerrit@opnfv.org>2016-10-28 23:29:15 +0000
commitff067418f34c3670cbab67587d8ab0dc0c8f1acc (patch)
tree5991abe90fad967bfed0638d9d979777f70f3df3
parentf2e379228d244be691bee350da1cb3d820cb6dfb (diff)
parentab1366e1b48fa0b56752a3b56e7456c3c7ecb011 (diff)
Merge "Inform TSC deadline clockevent device about recalibration"
-rw-r--r--kernel/arch/x86/include/asm/apic.h2
-rw-r--r--kernel/arch/x86/kernel/apic/apic.c24
-rw-r--r--kernel/arch/x86/kernel/tsc.c4
3 files changed, 30 insertions, 0 deletions
diff --git a/kernel/arch/x86/include/asm/apic.h b/kernel/arch/x86/include/asm/apic.h
index a30316bf8..9686289d2 100644
--- a/kernel/arch/x86/include/asm/apic.h
+++ b/kernel/arch/x86/include/asm/apic.h
@@ -131,6 +131,7 @@ extern void init_apic_mappings(void);
void register_lapic_address(unsigned long address);
extern void setup_boot_APIC_clock(void);
extern void setup_secondary_APIC_clock(void);
+extern void lapic_update_tsc_freq(void);
extern int APIC_init_uniprocessor(void);
#ifdef CONFIG_X86_64
@@ -166,6 +167,7 @@ static inline void init_apic_mappings(void) { }
static inline void disable_local_APIC(void) { }
# define setup_boot_APIC_clock x86_init_noop
# define setup_secondary_APIC_clock x86_init_noop
+static inline void lapic_update_tsc_freq(void) { }
#endif /* !CONFIG_X86_LOCAL_APIC */
#ifdef CONFIG_X86_X2APIC
diff --git a/kernel/arch/x86/kernel/apic/apic.c b/kernel/arch/x86/kernel/apic/apic.c
index d2eee3e1b..58e7cdb25 100644
--- a/kernel/arch/x86/kernel/apic/apic.c
+++ b/kernel/arch/x86/kernel/apic/apic.c
@@ -564,6 +564,30 @@ static void setup_APIC_timer(void)
}
/*
+ * Install the updated TSC frequency from recalibration at the TSC
+ * deadline clockevent devices.
+ */
+static void __lapic_update_tsc_freq(void *info)
+{
+ struct clock_event_device *levt = this_cpu_ptr(&lapic_events);
+
+ if (!this_cpu_has(X86_FEATURE_TSC_DEADLINE_TIMER))
+ return;
+
+ clockevents_update_freq(levt, tsc_khz * (1000 / TSC_DIVISOR));
+}
+
+void lapic_update_tsc_freq(void)
+{
+ /*
+ * The clockevent device's ->mult and ->shift can both be
+ * changed. In order to avoid races, schedule the frequency
+ * update code on each CPU.
+ */
+ on_each_cpu(__lapic_update_tsc_freq, NULL, 0);
+}
+
+/*
* In this functions we calibrate APIC bus clocks to the external timer.
*
* We want to do the calibration only once since we want to have local timer
diff --git a/kernel/arch/x86/kernel/tsc.c b/kernel/arch/x86/kernel/tsc.c
index c7c4d9c51..eafe93888 100644
--- a/kernel/arch/x86/kernel/tsc.c
+++ b/kernel/arch/x86/kernel/tsc.c
@@ -22,6 +22,7 @@
#include <asm/nmi.h>
#include <asm/x86_init.h>
#include <asm/geode.h>
+#include <asm/apic.h>
unsigned int __read_mostly cpu_khz; /* TSC clocks / usec, not used here */
EXPORT_SYMBOL(cpu_khz);
@@ -1141,6 +1142,9 @@ static void tsc_refine_calibration_work(struct work_struct *work)
(unsigned long)tsc_khz / 1000,
(unsigned long)tsc_khz % 1000);
+ /* Inform the TSC deadline clockevent devices about the recalibration */
+ lapic_update_tsc_freq();
+
out:
clocksource_register_khz(&clocksource_tsc, tsc_khz);
}