From e2768eaa1ca4fbb7b778da5615cce3dd310352e6 Mon Sep 17 00:00:00 2001 From: Vitaly Kuznetsov Date: Wed, 24 Jan 2018 14:23:32 +0100 Subject: [PATCH] x86/hyperv: Add a function to read both TSC and TSC page value simulateneously MIME-Version: 1.0 Content-Type: text/plain; charset=utf8 Content-Transfer-Encoding: 8bit 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 Signed-off-by: Thomas Gleixner Cc: Stephen Hemminger Cc: kvm@vger.kernel.org Cc: Radim Krčmář Cc: Haiyang Zhang Cc: "Michael Kelley (EOSG)" Cc: Roman Kagan Cc: Andy Lutomirski Cc: devel@linuxdriverproject.org Cc: Paolo Bonzini Cc: "K. Y. Srinivasan" Cc: Cathy Avery Cc: Mohammed Gamal Link: https://lkml.kernel.org/r/20180124132337.30138-3-vkuznets@redhat.com --- arch/x86/hyperv/hv_init.c | 1 + arch/x86/include/asm/mshyperv.h | 23 +++++++++++++++++++---- 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 -- 2.11.0