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authorLinus Torvalds <torvalds@linux-foundation.org>2011-10-28 05:08:40 -0700
committerLinus Torvalds <torvalds@linux-foundation.org>2011-10-28 05:08:40 -0700
commitcc21fe518a971bb2b0ab8370ec46ea21e84c57ab (patch)
tree5d701b2c3ca84a7848c240a325621868d9592da7 /arch/x86
parenta93f3e9f424ffb82b4983d2ebf8667ef20255015 (diff)
parent6f4151c89b7d036c755d8cf74729e09b76fa6676 (diff)
downloadlinux-cc21fe518a971bb2b0ab8370ec46ea21e84c57ab.tar.bz2
Merge branch 'x86-hyperv-for-linus' of git://git.kernel.org/pub/scm/linux/kernel/git/tip/tip
* 'x86-hyperv-for-linus' of git://git.kernel.org/pub/scm/linux/kernel/git/tip/tip: x86: Hyper-V: Integrate the clocksource with Hyper-V detection code Fix up conflicts in drivers/staging/hv/Makefile manually (some of the hv code has moved out of staging to drivers/hv/)
Diffstat (limited to 'arch/x86')
-rw-r--r--arch/x86/kernel/cpu/mshyperv.c23
1 files changed, 23 insertions, 0 deletions
diff --git a/arch/x86/kernel/cpu/mshyperv.c b/arch/x86/kernel/cpu/mshyperv.c
index d944bf6c50e9..0a630dd4b620 100644
--- a/arch/x86/kernel/cpu/mshyperv.c
+++ b/arch/x86/kernel/cpu/mshyperv.c
@@ -11,6 +11,8 @@
*/
#include <linux/types.h>
+#include <linux/time.h>
+#include <linux/clocksource.h>
#include <linux/module.h>
#include <asm/processor.h>
#include <asm/hypervisor.h>
@@ -36,6 +38,25 @@ static bool __init ms_hyperv_platform(void)
!memcmp("Microsoft Hv", hyp_signature, 12);
}
+static cycle_t read_hv_clock(struct clocksource *arg)
+{
+ cycle_t current_tick;
+ /*
+ * Read the partition counter to get the current tick count. This count
+ * is set to 0 when the partition is created and is incremented in
+ * 100 nanosecond units.
+ */
+ rdmsrl(HV_X64_MSR_TIME_REF_COUNT, current_tick);
+ return current_tick;
+}
+
+static struct clocksource hyperv_cs = {
+ .name = "hyperv_clocksource",
+ .rating = 400, /* use this when running on Hyperv*/
+ .read = read_hv_clock,
+ .mask = CLOCKSOURCE_MASK(64),
+};
+
static void __init ms_hyperv_init_platform(void)
{
/*
@@ -46,6 +67,8 @@ static void __init ms_hyperv_init_platform(void)
printk(KERN_INFO "HyperV: features 0x%x, hints 0x%x\n",
ms_hyperv.features, ms_hyperv.hints);
+
+ clocksource_register_hz(&hyperv_cs, NSEC_PER_SEC/100);
}
const __refconst struct hypervisor_x86 x86_hyper_ms_hyperv = {