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7eff7ded02
Install the Hyper-V specific interrupt handler only when needed. This would permit us to get rid of the Xen check. Note that when the vmbus drivers invokes the call to register its handler, we are sure to be running on Hyper-V. Signed-off-by: K. Y. Srinivasan <kys@microsoft.com> Link: http://lkml.kernel.org/r/1366299886-6399-1-git-send-email-kys@microsoft.com Acked-by: Michael S. Tsirkin <mst@redhat.com> Signed-off-by: H. Peter Anvin <hpa@linux.intel.com>
123 lines
2.9 KiB
C
123 lines
2.9 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/interrupt.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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struct ms_hyperv_info ms_hyperv;
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EXPORT_SYMBOL_GPL(ms_hyperv);
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static bool __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 false;
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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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return 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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}
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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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};
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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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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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}
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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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#if IS_ENABLED(CONFIG_HYPERV)
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static int vmbus_irq = -1;
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static irq_handler_t vmbus_isr;
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void hv_register_vmbus_handler(int irq, irq_handler_t handler)
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{
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/*
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* Setup the IDT for hypervisor callback.
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*/
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alloc_intr_gate(HYPERVISOR_CALLBACK_VECTOR, hyperv_callback_vector);
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vmbus_irq = irq;
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vmbus_isr = handler;
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}
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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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struct irq_desc *desc;
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irq_enter();
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exit_idle();
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desc = irq_to_desc(vmbus_irq);
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if (desc)
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generic_handle_irq_desc(vmbus_irq, desc);
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irq_exit();
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set_irq_regs(old_regs);
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}
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#else
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void hv_register_vmbus_handler(int irq, irq_handler_t handler)
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{
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}
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#endif
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EXPORT_SYMBOL_GPL(hv_register_vmbus_handler);
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