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path: root/drivers/clocksource/hyperv_timer.c
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2019-08-23clocksource/drivers/hyperv: Enable TSC page clocksource on 32bitVitaly Kuznetsov1-11/+0
There is no particular reason to not enable TSC page clocksource on 32-bit. mul_u64_u64_shr() is available and despite the increased computational complexity (compared to 64bit) TSC page is still a huge win compared to MSR-based clocksource. In-kernel reads: MSR based clocksource: 3361 cycles TSC page clocksource: 49 cycles Reads from userspace (utilizing vDSO in case of TSC page): MSR based clocksource: 5664 cycles TSC page clocksource: 131 cycles Enabling TSC page on 32bits allows to get rid of CONFIG_HYPERV_TSCPAGE as it is now not any different from CONFIG_HYPERV_TIMER. Signed-off-by: Vitaly Kuznetsov <[email protected]> Signed-off-by: Thomas Gleixner <[email protected]> Reviewed-by: Michael Kelley <[email protected]> Link: https://lkml.kernel.org/r/[email protected]
2019-08-23clocksource/drivers/hyperv: Add Hyper-V specific sched clock functionTianyu Lan1-10/+12
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 <[email protected]> Signed-off-by: Thomas Gleixner <[email protected]> Reviewed-by: Michael Kelley <[email protected]> Link: https://lkml.kernel.org/r/[email protected]
2019-08-23clocksource/drivers/hyperv: Allocate Hyper-V TSC page staticallyTianyu Lan1-8/+4
Prepare to add Hyper-V sched clock callback and move Hyper-V Reference TSC initialization much earlier in the boot process. Earlier initialization is needed so that it happens while the timestamp value is still 0 and no discontinuity in the timestamp will occur when pv_ops.time.sched_clock calculates its offset. The earlier initialization requires that the Hyper-V TSC page be allocated statically instead of with vmalloc(), so fixup the references to the TSC page and the method of getting its physical address. Signed-off-by: Tianyu Lan <[email protected]> Signed-off-by: Thomas Gleixner <[email protected]> Acked-by: Daniel Lezcano <[email protected]> Link: https://lkml.kernel.org/r/[email protected]
2019-07-03clocksource/drivers: Continue making Hyper-V clocksource ISA agnosticMichael Kelley1-0/+139
Continue consolidating Hyper-V clock and timer code into an ISA independent Hyper-V clocksource driver. Move the existing clocksource code under drivers/hv and arch/x86 to the new clocksource driver while separating out the ISA dependencies. Update Hyper-V initialization to call initialization and cleanup routines since the Hyper-V synthetic clock is not independently enumerated in ACPI. Update Hyper-V clocksource users in KVM and VDSO to get definitions from the new include file. No behavior is changed and no new functionality is added. Suggested-by: Marc Zyngier <[email protected]> Signed-off-by: Michael Kelley <[email protected]> Signed-off-by: Thomas Gleixner <[email protected]> Reviewed-by: Vitaly Kuznetsov <[email protected]> Cc: "[email protected]" <[email protected]> Cc: "[email protected]" <[email protected]> Cc: "[email protected]" <[email protected]> Cc: "[email protected]" <[email protected]> Cc: "[email protected]" <[email protected]> Cc: "[email protected]" <[email protected]> Cc: "[email protected]" <[email protected]> Cc: "[email protected]" <[email protected]> Cc: "[email protected]" <[email protected]> Cc: "[email protected]" <[email protected]> Cc: "[email protected]" <[email protected]> Cc: Sunil Muthuswamy <[email protected]> Cc: KY Srinivasan <[email protected]> Cc: "[email protected]" <[email protected]> Cc: "[email protected]" <[email protected]> Cc: "[email protected]" <[email protected]> Cc: "[email protected]" <[email protected]> Cc: "[email protected]" <[email protected]> Cc: "[email protected]" <[email protected]> Cc: "[email protected]" <[email protected]> Cc: "[email protected]" <[email protected]> Cc: "[email protected]" <[email protected]> Cc: "[email protected]" <[email protected]> Cc: "[email protected]" <[email protected]> Cc: "[email protected]" <[email protected]> Cc: "[email protected]" <[email protected]> Cc: "[email protected]" <[email protected]> Cc: "[email protected]" <[email protected]> Cc: "[email protected]" <[email protected]> Cc: "[email protected]" <[email protected]> Cc: "[email protected]" <[email protected]> Cc: "[email protected]" <[email protected]> Cc: "[email protected]" <[email protected]> Link: https://lkml.kernel.org/r/[email protected]
2019-07-03clocksource/drivers: Make Hyper-V clocksource ISA agnosticMichael Kelley1-0/+200
Hyper-V clock/timer code and data structures are currently mixed in with other code in the ISA independent drivers/hv directory as well as the ISA dependent Hyper-V code under arch/x86. Consolidate this code and data structures into a Hyper-V clocksource driver to better follow the Linux model. In doing so, separate out the ISA dependent portions so the new clocksource driver works for x86 and for the in-process Hyper-V on ARM64 code. To start, move the existing clockevents code to create the new clocksource driver. Update the VMbus driver to call initialization and cleanup routines since the Hyper-V synthetic timers are not independently enumerated in ACPI. No behavior is changed and no new functionality is added. Suggested-by: Marc Zyngier <[email protected]> Signed-off-by: Michael Kelley <[email protected]> Signed-off-by: Thomas Gleixner <[email protected]> Reviewed-by: Vitaly Kuznetsov <[email protected]> Cc: "[email protected]" <[email protected]> Cc: "[email protected]" <[email protected]> Cc: "[email protected]" <[email protected]> Cc: "[email protected]" <[email protected]> Cc: "[email protected]" <[email protected]> Cc: "[email protected]" <[email protected]> Cc: "[email protected]" <[email protected]> Cc: "[email protected]" <[email protected]> Cc: "[email protected]" <[email protected]> Cc: "[email protected]" <[email protected]> Cc: "[email protected]" <[email protected]> Cc: Sunil Muthuswamy <[email protected]> Cc: KY Srinivasan <[email protected]> Cc: "[email protected]" <[email protected]> Cc: "[email protected]" <[email protected]> Cc: "[email protected]" <[email protected]> Cc: "[email protected]" <[email protected]> Cc: "[email protected]" <[email protected]> Cc: "[email protected]" <[email protected]> Cc: "[email protected]" <[email protected]> Cc: "[email protected]" <[email protected]> Cc: "[email protected]" <[email protected]> Cc: "[email protected]" <[email protected]> Cc: "[email protected]" <[email protected]> Cc: "[email protected]" <[email protected]> Cc: "[email protected]" <[email protected]> Cc: "[email protected]" <[email protected]> Cc: "[email protected]" <[email protected]> Cc: "[email protected]" <[email protected]> Cc: "[email protected]" <[email protected]> Cc: "[email protected]" <[email protected]> Cc: "[email protected]" <[email protected]> Cc: "[email protected]" <[email protected]> Link: https://lkml.kernel.org/r/[email protected]
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