From 59e3f562b87b1d6ffb44f84ad84820a4cc915bbe Mon Sep 17 00:00:00 2001
From: Jason Chen CJ <jason.cj.chen@intel.com>
Date: Fri, 14 Dec 2018 13:34:42 +0800
Subject: [PATCH] remove check_tsc

there is no need to clear CR4.TSD as there is no user mode
in ACRN hypervisor.

Tracked-On: #1842
Signed-off-by: Jason Chen CJ <jason.cj.chen@intel.com>
---
 doc/developer-guides/hld/hv-timer.rst | 3 ---
 hypervisor/arch/x86/cpu.c             | 3 ---
 hypervisor/arch/x86/timer.c           | 9 ---------
 hypervisor/include/arch/x86/timer.h   | 5 -----
 4 files changed, 20 deletions(-)

diff --git a/doc/developer-guides/hld/hv-timer.rst b/doc/developer-guides/hld/hv-timer.rst
index ce157bc72..8a4f07735 100644
--- a/doc/developer-guides/hld/hv-timer.rst
+++ b/doc/developer-guides/hld/hv-timer.rst
@@ -42,9 +42,6 @@ Interfaces Design
 .. doxygenfunction:: timer_init
    :project: Project ACRN
 
-.. doxygenfunction:: check_tsc
-   :project: Project ACRN
-
 .. doxygenfunction:: calibrate_tsc
    :project: Project ACRN
 
diff --git a/hypervisor/arch/x86/cpu.c b/hypervisor/arch/x86/cpu.c
index eeaf3f594..65b18a4b1 100644
--- a/hypervisor/arch/x86/cpu.c
+++ b/hypervisor/arch/x86/cpu.c
@@ -429,9 +429,6 @@ void init_cpu_post(uint16_t pcpu_id)
 
 	enable_smap();
 
-	/* Make sure rdtsc is enabled */
-	check_tsc();
-
 	cpu_xsave_init();
 
 	if (pcpu_id == BOOT_CPU_ID) {
diff --git a/hypervisor/arch/x86/timer.c b/hypervisor/arch/x86/timer.c
index 548914575..1696f0cb6 100644
--- a/hypervisor/arch/x86/timer.c
+++ b/hypervisor/arch/x86/timer.c
@@ -189,15 +189,6 @@ void timer_init(void)
 	}
 }
 
-void check_tsc(void)
-{
-	uint64_t temp64;
-
-	/* Ensure time-stamp timer is turned on for each CPU */
-	CPU_CR_READ(cr4, &temp64);
-	CPU_CR_WRITE(cr4, (temp64 & ~CR4_TSD));
-}
-
 static uint64_t pit_calibrate_tsc(uint32_t cal_ms_arg)
 {
 #define PIT_TICK_RATE	1193182U
diff --git a/hypervisor/include/arch/x86/timer.h b/hypervisor/include/arch/x86/timer.h
index e90179776..fd3daabb0 100644
--- a/hypervisor/include/arch/x86/timer.h
+++ b/hypervisor/include/arch/x86/timer.h
@@ -116,11 +116,6 @@ void del_timer(struct hv_timer *timer);
  */
 void timer_init(void);
 
-/**
- * @brief Check tsc to make sure rdtsc is enabled.
- */
-void check_tsc(void);
-
 /**
  * @brief Calibrate tsc.
  *