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authorVitaly Kuznetsov <vkuznets@redhat.com>2018-01-24 14:23:32 +0100
committerThomas Gleixner <tglx@linutronix.de>2018-01-30 23:55:32 +0100
commite2768eaa1ca4fbb7b778da5615cce3dd310352e6 (patch)
treec0c97a888218a8c23324aa1a5db08d1361972f0b /arch
parentx86/hyperv: Check for required priviliges in hyperv_init() (diff)
downloadlinux-e2768eaa1ca4fbb7b778da5615cce3dd310352e6.tar.xz
linux-e2768eaa1ca4fbb7b778da5615cce3dd310352e6.zip
x86/hyperv: Add a function to read both TSC and TSC page value simulateneously
This is going to be used from KVM code where both TSC and TSC page value are needed. Nothing is supposed to use the function when Hyper-V code is compiled out, just BUG(). Signed-off-by: Vitaly Kuznetsov <vkuznets@redhat.com> Signed-off-by: Thomas Gleixner <tglx@linutronix.de> Cc: Stephen Hemminger <sthemmin@microsoft.com> Cc: kvm@vger.kernel.org Cc: Radim Krčmář <rkrcmar@redhat.com> Cc: Haiyang Zhang <haiyangz@microsoft.com> Cc: "Michael Kelley (EOSG)" <Michael.H.Kelley@microsoft.com> Cc: Roman Kagan <rkagan@virtuozzo.com> Cc: Andy Lutomirski <luto@kernel.org> Cc: devel@linuxdriverproject.org Cc: Paolo Bonzini <pbonzini@redhat.com> Cc: "K. Y. Srinivasan" <kys@microsoft.com> Cc: Cathy Avery <cavery@redhat.com> Cc: Mohammed Gamal <mmorsy@redhat.com> Link: https://lkml.kernel.org/r/20180124132337.30138-3-vkuznets@redhat.com
Diffstat (limited to 'arch')
-rw-r--r--arch/x86/hyperv/hv_init.c1
-rw-r--r--arch/x86/include/asm/mshyperv.h23
2 files changed, 20 insertions, 4 deletions
diff --git a/arch/x86/hyperv/hv_init.c b/arch/x86/hyperv/hv_init.c
index 21f9d53d9f00..1a6c63f721bc 100644
--- a/arch/x86/hyperv/hv_init.c
+++ b/arch/x86/hyperv/hv_init.c
@@ -37,6 +37,7 @@ struct ms_hyperv_tsc_page *hv_get_tsc_page(void)
{
return tsc_pg;
}
+EXPORT_SYMBOL_GPL(hv_get_tsc_page);
static u64 read_hv_clock_tsc(struct clocksource *arg)
{
diff --git a/arch/x86/include/asm/mshyperv.h b/arch/x86/include/asm/mshyperv.h
index 8bf450b13d9f..6b1d4ea78270 100644
--- a/arch/x86/include/asm/mshyperv.h
+++ b/arch/x86/include/asm/mshyperv.h
@@ -325,9 +325,10 @@ static inline void hyperv_setup_mmu_ops(void) {}
#ifdef CONFIG_HYPERV_TSCPAGE
struct ms_hyperv_tsc_page *hv_get_tsc_page(void);
-static inline u64 hv_read_tsc_page(const struct ms_hyperv_tsc_page *tsc_pg)
+static inline u64 hv_read_tsc_page_tsc(const struct ms_hyperv_tsc_page *tsc_pg,
+ u64 *cur_tsc)
{
- u64 scale, offset, cur_tsc;
+ u64 scale, offset;
u32 sequence;
/*
@@ -358,7 +359,7 @@ static inline u64 hv_read_tsc_page(const struct ms_hyperv_tsc_page *tsc_pg)
scale = READ_ONCE(tsc_pg->tsc_scale);
offset = READ_ONCE(tsc_pg->tsc_offset);
- cur_tsc = rdtsc_ordered();
+ *cur_tsc = rdtsc_ordered();
/*
* Make sure we read sequence after we read all other values
@@ -368,7 +369,14 @@ static inline u64 hv_read_tsc_page(const struct ms_hyperv_tsc_page *tsc_pg)
} while (READ_ONCE(tsc_pg->tsc_sequence) != sequence);
- return mul_u64_u64_shr(cur_tsc, scale, 64) + offset;
+ return mul_u64_u64_shr(*cur_tsc, scale, 64) + offset;
+}
+
+static inline u64 hv_read_tsc_page(const struct ms_hyperv_tsc_page *tsc_pg)
+{
+ u64 cur_tsc;
+
+ return hv_read_tsc_page_tsc(tsc_pg, &cur_tsc);
}
#else
@@ -376,5 +384,12 @@ static inline struct ms_hyperv_tsc_page *hv_get_tsc_page(void)
{
return NULL;
}
+
+static inline u64 hv_read_tsc_page_tsc(const struct ms_hyperv_tsc_page *tsc_pg,
+ u64 *cur_tsc)
+{
+ BUG();
+ return U64_MAX;
+}
#endif
#endif