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authorK. Y. Srinivasan <kys@microsoft.com>2015-08-05 00:52:42 -0700
committerGreg Kroah-Hartman <gregkh@linuxfoundation.org>2015-08-05 11:44:29 -0700
commitca9357bd26c2f8e7b909321eedd651f52cc30d04 (patch)
treef9417defaed1252c6bc0442285314ee9ca777258 /arch/x86/include/uapi/asm
parentbc609cb47fb2e74654e23cef0a1d4db38b6570a3 (diff)
Drivers: hv: vmbus: Implement a clocksource based on the TSC page
The current Hyper-V clock source is based on the per-partition reference counter and this counter is being accessed via s synthetic MSR - HV_X64_MSR_TIME_REF_COUNT. Hyper-V has a more efficient way of computing the per-partition reference counter value that does not involve reading a synthetic MSR. We implement a time source based on this mechanism. Tested-by: Vivek Yadav <vyadav@microsoft.com> Signed-off-by: K. Y. Srinivasan <kys@microsoft.com> Signed-off-by: Greg Kroah-Hartman <gregkh@linuxfoundation.org>
Diffstat (limited to 'arch/x86/include/uapi/asm')
-rw-r--r--arch/x86/include/uapi/asm/hyperv.h2
1 files changed, 2 insertions, 0 deletions
diff --git a/arch/x86/include/uapi/asm/hyperv.h b/arch/x86/include/uapi/asm/hyperv.h
index f36d56bd7632..f0412c50c47b 100644
--- a/arch/x86/include/uapi/asm/hyperv.h
+++ b/arch/x86/include/uapi/asm/hyperv.h
@@ -27,6 +27,8 @@
#define HV_X64_MSR_VP_RUNTIME_AVAILABLE (1 << 0)
/* Partition Reference Counter (HV_X64_MSR_TIME_REF_COUNT) available*/
#define HV_X64_MSR_TIME_REF_COUNT_AVAILABLE (1 << 1)
+/* Partition reference TSC MSR is available */
+#define HV_X64_MSR_REFERENCE_TSC_AVAILABLE (1 << 9)
/* A partition's reference time stamp counter (TSC) page */
#define HV_X64_MSR_REFERENCE_TSC 0x40000021