x86/hyperv: Implement hv_get_tsc_page()
To use Hyper-V TSC page clocksource from vDSO we need to make tsc_pg
available. Implement hv_get_tsc_page() and add CONFIG_HYPERV_TSCPAGE to
make #ifdef-s simple.
Signed-off-by: Vitaly Kuznetsov <vkuznets@redhat.com>
Cc: Stephen Hemminger <sthemmin@microsoft.com>
Cc: Haiyang Zhang <haiyangz@microsoft.com>
Cc: Dexuan Cui <decui@microsoft.com>
Cc: Andy Lutomirski <luto@amacapital.net>
Cc: devel@linuxdriverproject.org
Cc: "K. Y. Srinivasan" <kys@microsoft.com>
Cc: virtualization@lists.linux-foundation.org
Link: http://lkml.kernel.org/r/20170303132142.25595-2-vkuznets@redhat.com
Signed-off-by: Thomas Gleixner <tglx@linutronix.de>
diff --git a/arch/x86/hyperv/hv_init.c b/arch/x86/hyperv/hv_init.c
index 8bef70e..bb1ea58 100644
--- a/arch/x86/hyperv/hv_init.c
+++ b/arch/x86/hyperv/hv_init.c
@@ -27,10 +27,15 @@
#include <linux/clockchips.h>
-#ifdef CONFIG_X86_64
+#ifdef CONFIG_HYPERV_TSCPAGE
static struct ms_hyperv_tsc_page *tsc_pg;
+struct ms_hyperv_tsc_page *hv_get_tsc_page(void)
+{
+ return tsc_pg;
+}
+
static u64 read_hv_clock_tsc(struct clocksource *arg)
{
u64 current_tick;
@@ -139,7 +144,7 @@
/*
* Register Hyper-V specific clocksource.
*/
-#ifdef CONFIG_X86_64
+#ifdef CONFIG_HYPERV_TSCPAGE
if (ms_hyperv.features & HV_X64_MSR_REFERENCE_TSC_AVAILABLE) {
union hv_x64_msr_hypercall_contents tsc_msr;
diff --git a/arch/x86/include/asm/mshyperv.h b/arch/x86/include/asm/mshyperv.h
index 7c9c895..d324dce 100644
--- a/arch/x86/include/asm/mshyperv.h
+++ b/arch/x86/include/asm/mshyperv.h
@@ -176,4 +176,12 @@
bool hv_is_hypercall_page_setup(void);
void hyperv_cleanup(void);
#endif
+#ifdef CONFIG_HYPERV_TSCPAGE
+struct ms_hyperv_tsc_page *hv_get_tsc_page(void);
+#else
+static inline struct ms_hyperv_tsc_page *hv_get_tsc_page(void)
+{
+ return NULL;
+}
+#endif
#endif
diff --git a/drivers/hv/Kconfig b/drivers/hv/Kconfig
index 0403b51..c29cd53 100644
--- a/drivers/hv/Kconfig
+++ b/drivers/hv/Kconfig
@@ -7,6 +7,9 @@
Select this option to run Linux as a Hyper-V client operating
system.
+config HYPERV_TSCPAGE
+ def_bool HYPERV && X86_64
+
config HYPERV_UTILS
tristate "Microsoft Hyper-V Utilities driver"
depends on HYPERV && CONNECTOR && NLS