forked from Minki/linux
152 lines
3.7 KiB
C
152 lines
3.7 KiB
C
/*
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* HyperV Detection code.
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*
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* Copyright (C) 2010, Novell, Inc.
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* Author : K. Y. Srinivasan <ksrinivasan@novell.com>
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*
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* This program is free software; you can redistribute it and/or modify
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* it under the terms of the GNU General Public License as published by
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* the Free Software Foundation; version 2 of the License.
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*
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*/
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#include <linux/types.h>
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#include <linux/time.h>
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#include <linux/clocksource.h>
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#include <linux/module.h>
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#include <linux/hardirq.h>
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#include <linux/efi.h>
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#include <linux/interrupt.h>
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#include <linux/irq.h>
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#include <asm/processor.h>
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#include <asm/hypervisor.h>
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#include <asm/hyperv.h>
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#include <asm/mshyperv.h>
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#include <asm/desc.h>
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#include <asm/idle.h>
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#include <asm/irq_regs.h>
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#include <asm/i8259.h>
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#include <asm/apic.h>
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#include <asm/timer.h>
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struct ms_hyperv_info ms_hyperv;
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EXPORT_SYMBOL_GPL(ms_hyperv);
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#if IS_ENABLED(CONFIG_HYPERV)
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static void (*vmbus_handler)(void);
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void hyperv_vector_handler(struct pt_regs *regs)
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{
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struct pt_regs *old_regs = set_irq_regs(regs);
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entering_irq();
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inc_irq_stat(irq_hv_callback_count);
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if (vmbus_handler)
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vmbus_handler();
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exiting_irq();
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set_irq_regs(old_regs);
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}
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void hv_setup_vmbus_irq(void (*handler)(void))
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{
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vmbus_handler = handler;
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/*
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* Setup the IDT for hypervisor callback. Prevent reallocation
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* at module reload.
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*/
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if (!test_bit(HYPERVISOR_CALLBACK_VECTOR, used_vectors))
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alloc_intr_gate(HYPERVISOR_CALLBACK_VECTOR,
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hyperv_callback_vector);
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}
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void hv_remove_vmbus_irq(void)
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{
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/* We have no way to deallocate the interrupt gate */
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vmbus_handler = NULL;
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}
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EXPORT_SYMBOL_GPL(hv_setup_vmbus_irq);
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EXPORT_SYMBOL_GPL(hv_remove_vmbus_irq);
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#endif
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static uint32_t __init ms_hyperv_platform(void)
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{
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u32 eax;
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u32 hyp_signature[3];
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if (!boot_cpu_has(X86_FEATURE_HYPERVISOR))
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return 0;
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cpuid(HYPERV_CPUID_VENDOR_AND_MAX_FUNCTIONS,
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&eax, &hyp_signature[0], &hyp_signature[1], &hyp_signature[2]);
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if (eax >= HYPERV_CPUID_MIN &&
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eax <= HYPERV_CPUID_MAX &&
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!memcmp("Microsoft Hv", hyp_signature, 12))
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return HYPERV_CPUID_VENDOR_AND_MAX_FUNCTIONS;
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return 0;
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}
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static cycle_t read_hv_clock(struct clocksource *arg)
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{
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cycle_t current_tick;
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/*
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* Read the partition counter to get the current tick count. This count
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* is set to 0 when the partition is created and is incremented in
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* 100 nanosecond units.
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*/
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rdmsrl(HV_X64_MSR_TIME_REF_COUNT, current_tick);
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return current_tick;
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}
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static struct clocksource hyperv_cs = {
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.name = "hyperv_clocksource",
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.rating = 400, /* use this when running on Hyperv*/
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.read = read_hv_clock,
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.mask = CLOCKSOURCE_MASK(64),
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.flags = CLOCK_SOURCE_IS_CONTINUOUS,
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};
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static void __init ms_hyperv_init_platform(void)
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{
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/*
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* Extract the features and hints
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*/
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ms_hyperv.features = cpuid_eax(HYPERV_CPUID_FEATURES);
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ms_hyperv.hints = cpuid_eax(HYPERV_CPUID_ENLIGHTMENT_INFO);
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printk(KERN_INFO "HyperV: features 0x%x, hints 0x%x\n",
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ms_hyperv.features, ms_hyperv.hints);
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#ifdef CONFIG_X86_LOCAL_APIC
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if (ms_hyperv.features & HV_X64_MSR_APIC_FREQUENCY_AVAILABLE) {
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/*
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* Get the APIC frequency.
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*/
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u64 hv_lapic_frequency;
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rdmsrl(HV_X64_MSR_APIC_FREQUENCY, hv_lapic_frequency);
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hv_lapic_frequency = div_u64(hv_lapic_frequency, HZ);
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lapic_timer_frequency = hv_lapic_frequency;
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printk(KERN_INFO "HyperV: LAPIC Timer Frequency: %#x\n",
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lapic_timer_frequency);
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}
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#endif
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if (ms_hyperv.features & HV_X64_MSR_TIME_REF_COUNT_AVAILABLE)
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clocksource_register_hz(&hyperv_cs, NSEC_PER_SEC/100);
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#ifdef CONFIG_X86_IO_APIC
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no_timer_check = 1;
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#endif
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}
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const __refconst struct hypervisor_x86 x86_hyper_ms_hyperv = {
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.name = "Microsoft HyperV",
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.detect = ms_hyperv_platform,
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.init_platform = ms_hyperv_init_platform,
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};
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EXPORT_SYMBOL(x86_hyper_ms_hyperv);
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