/* * HyperV  Detection code. * * Copyright (C) 2010, Novell, Inc. * Author : K. Y. Srinivasan <ksrinivasan@novell.com> * * This program is free software; you can redistribute it and/or modify * it under the terms of the GNU General Public License as published by * the Free Software Foundation; version 2 of the License. * */ #include <linux/types.h>#include <linux/time.h>#include <linux/clocksource.h>#include <linux/module.h>#include <asm/processor.h>#include <asm/hypervisor.h>#include <asm/hyperv.h>#include <asm/mshyperv.h> struct ms_hyperv_info ms_hyperv;EXPORT_SYMBOL_GPL(ms_hyperv); static bool __init ms_hyperv_platform(void){	u32 eax;	u32 hyp_signature[3]; 	if (!boot_cpu_has(X86_FEATURE_HYPERVISOR))		return false; 	cpuid(HYPERV_CPUID_VENDOR_AND_MAX_FUNCTIONS,	      &eax, &hyp_signature[0], &hyp_signature[1], &hyp_signature[2]); 	return eax >= HYPERV_CPUID_MIN &&		eax <= HYPERV_CPUID_MAX &&		!memcmp("Microsoft Hv", hyp_signature, 12);} static cycle_t read_hv_clock(struct clocksource *arg){	cycle_t current_tick;	/*	 * Read the partition counter to get the current tick count. This count	 * is set to 0 when the partition is created and is incremented in	 * 100 nanosecond units.	 */	rdmsrl(HV_X64_MSR_TIME_REF_COUNT, current_tick);	return current_tick;} static struct clocksource hyperv_cs = {	.name		= "hyperv_clocksource",	.rating		= 400, /* use this when running on Hyperv*/	.read		= read_hv_clock,	.mask		= CLOCKSOURCE_MASK(64),}; static void __init ms_hyperv_init_platform(void){	/*	 * Extract the features and hints	 */	ms_hyperv.features = cpuid_eax(HYPERV_CPUID_FEATURES);	ms_hyperv.hints    = cpuid_eax(HYPERV_CPUID_ENLIGHTMENT_INFO); 	printk(KERN_INFO "HyperV: features 0x%x, hints 0x%x\n",	       ms_hyperv.features, ms_hyperv.hints); 	clocksource_register_hz(&hyperv_cs, NSEC_PER_SEC/100);} const __refconst struct hypervisor_x86 x86_hyper_ms_hyperv = {	.name			= "Microsoft HyperV",	.detect			= ms_hyperv_platform,	.init_platform		= ms_hyperv_init_platform,};EXPORT_SYMBOL(x86_hyper_ms_hyperv);