68 lines
1.6 KiB
ReStructuredText
68 lines
1.6 KiB
ReStructuredText
.. _timer-hld:
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Timer
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#####
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Because ACRN is a flexible, lightweight reference hypervisor, we provide
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limited timer management services:
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- Only the lapic tsc-deadline timer is supported as the clock source.
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- A timer can only be added on the logical CPU for a process or thread. Timer
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scheduling or timer migrating is not supported.
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How It Works
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************
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When the system boots, we check that the hardware supports lapic
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tsc-deadline timer by checking CPUID.01H:ECX.TSC_Deadline[bit 24]. If
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support is missing, we output an error message and panic the hypervisor.
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If supported, we register the timer interrupt callback that raises a
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timer softirq on each logical CPU and sets the lapic timer mode to
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tsc-deadline timer mode by writing the local APIC LVT register.
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Data Structures and APIs
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************************
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Interfaces Design
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=================
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.. doxygenfunction:: initialize_timer
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:project: Project ACRN
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.. doxygenfunction:: timer_expired
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:project: Project ACRN
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.. doxygenfunction:: add_timer
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:project: Project ACRN
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.. doxygenfunction:: del_timer
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:project: Project ACRN
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.. doxygenfunction:: timer_init
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:project: Project ACRN
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.. doxygenfunction:: calibrate_tsc
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:project: Project ACRN
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.. doxygenfunction:: us_to_ticks
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:project: Project ACRN
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.. doxygenfunction:: ticks_to_us
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:project: Project ACRN
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.. doxygenfunction:: ticks_to_ms
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:project: Project ACRN
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.. doxygenfunction:: rdtsc
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:project: Project ACRN
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.. doxygenfunction:: get_tsc_khz
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:project: Project ACRN
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.. doxygenfunction:: timer_is_started
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:project: Project ACRN
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.. doxygenfunction:: udelay
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:project: Project ACRN
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