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authorTianyu Lan <Tianyu.Lan@microsoft.com>2019-08-14 15:32:16 +0300
committerThomas Gleixner <tglx@linutronix.de>2019-08-23 17:59:54 +0300
commitbd00cd52d5be655a2f217e2ed74b91a71cb2b14f (patch)
tree90b8fe8d71a849f6066d1c2ba7500dba0fca9819 /include/asm-generic
parentadb87ff4f96c9700718e09c97a804124d5cd61ff (diff)
downloadlinux-bd00cd52d5be655a2f217e2ed74b91a71cb2b14f.tar.xz
clocksource/drivers/hyperv: Add Hyper-V specific sched clock function
Hyper-V guests use the default native_sched_clock() in pv_ops.time.sched_clock on x86. But native_sched_clock() directly uses the raw TSC value, which can be discontinuous in a Hyper-V VM. Add the generic hv_setup_sched_clock() to set the sched clock function appropriately. On x86, this sets pv_ops.time.sched_clock to read the Hyper-V reference TSC value that is scaled and adjusted to be continuous. Also move the Hyper-V reference TSC initialization much earlier in the boot process so no discontinuity is observed when pv_ops.time.sched_clock calculates its offset. [ tglx: Folded build fix ] Signed-off-by: Tianyu Lan <Tianyu.Lan@microsoft.com> Signed-off-by: Thomas Gleixner <tglx@linutronix.de> Reviewed-by: Michael Kelley <mikelley@microsoft.com> Link: https://lkml.kernel.org/r/20190814123216.32245-3-Tianyu.Lan@microsoft.com
Diffstat (limited to 'include/asm-generic')
-rw-r--r--include/asm-generic/mshyperv.h1
1 files changed, 1 insertions, 0 deletions
diff --git a/include/asm-generic/mshyperv.h b/include/asm-generic/mshyperv.h
index 0becb7d9704d..18d8e2d8210f 100644
--- a/include/asm-generic/mshyperv.h
+++ b/include/asm-generic/mshyperv.h
@@ -167,6 +167,7 @@ void hyperv_report_panic(struct pt_regs *regs, long err);
void hyperv_report_panic_msg(phys_addr_t pa, size_t size);
bool hv_is_hyperv_initialized(void);
void hyperv_cleanup(void);
+void hv_setup_sched_clock(void *sched_clock);
#else /* CONFIG_HYPERV */
static inline bool hv_is_hyperv_initialized(void) { return false; }
static inline void hyperv_cleanup(void) {}