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			153 lines
		
	
	
	
		
			3.7 KiB
		
	
	
	
		
			C
		
	
	
	
	
	
			
		
		
	
	
			153 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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| 
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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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| 
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| struct ms_hyperv_info ms_hyperv;
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| EXPORT_SYMBOL_GPL(ms_hyperv);
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| 
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| #if IS_ENABLED(CONFIG_HYPERV)
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| static void (*vmbus_handler)(void);
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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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| 
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| 	irq_enter();
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| 	exit_idle();
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| 
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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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| 
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| 	irq_exit();
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| 	set_irq_regs(old_regs);
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| }
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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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| 
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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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| 
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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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| 
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| 	if (!boot_cpu_has(X86_FEATURE_HYPERVISOR))
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| 		return 0;
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| 
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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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| 
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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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| 
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| 	return 0;
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| }
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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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| 
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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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| 
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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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| 
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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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| 
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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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| 
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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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| 
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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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| #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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| }
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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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