diff options
Diffstat (limited to 'arch/x86/kernel/cpu/mshyperv.c')
| -rw-r--r-- | arch/x86/kernel/cpu/mshyperv.c | 153 |
1 files changed, 153 insertions, 0 deletions
diff --git a/arch/x86/kernel/cpu/mshyperv.c b/arch/x86/kernel/cpu/mshyperv.c new file mode 100644 index 000000000..939155ffd --- /dev/null +++ b/arch/x86/kernel/cpu/mshyperv.c @@ -0,0 +1,153 @@ +/* + * 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 <linux/hardirq.h> +#include <linux/efi.h> +#include <linux/interrupt.h> +#include <linux/irq.h> +#include <asm/processor.h> +#include <asm/hypervisor.h> +#include <asm/hyperv.h> +#include <asm/mshyperv.h> +#include <asm/desc.h> +#include <asm/idle.h> +#include <asm/irq_regs.h> +#include <asm/i8259.h> +#include <asm/apic.h> +#include <asm/timer.h> + +struct ms_hyperv_info ms_hyperv; +EXPORT_SYMBOL_GPL(ms_hyperv); + +#if IS_ENABLED(CONFIG_HYPERV) +static void (*vmbus_handler)(void); + +void hyperv_vector_handler(struct pt_regs *regs) +{ + struct pt_regs *old_regs = set_irq_regs(regs); + + irq_enter(); + exit_idle(); + + inc_irq_stat(irq_hv_callback_count); + if (vmbus_handler) + vmbus_handler(); + + irq_exit(); + set_irq_regs(old_regs); +} + +void hv_setup_vmbus_irq(void (*handler)(void)) +{ + vmbus_handler = handler; + /* + * Setup the IDT for hypervisor callback. Prevent reallocation + * at module reload. + */ + if (!test_bit(HYPERVISOR_CALLBACK_VECTOR, used_vectors)) + alloc_intr_gate(HYPERVISOR_CALLBACK_VECTOR, + hyperv_callback_vector); +} + +void hv_remove_vmbus_irq(void) +{ + /* We have no way to deallocate the interrupt gate */ + vmbus_handler = NULL; +} +EXPORT_SYMBOL_GPL(hv_setup_vmbus_irq); +EXPORT_SYMBOL_GPL(hv_remove_vmbus_irq); +#endif + +static uint32_t __init ms_hyperv_platform(void) +{ + u32 eax; + u32 hyp_signature[3]; + + if (!boot_cpu_has(X86_FEATURE_HYPERVISOR)) + return 0; + + cpuid(HYPERV_CPUID_VENDOR_AND_MAX_FUNCTIONS, + &eax, &hyp_signature[0], &hyp_signature[1], &hyp_signature[2]); + + if (eax >= HYPERV_CPUID_MIN && + eax <= HYPERV_CPUID_MAX && + !memcmp("Microsoft Hv", hyp_signature, 12)) + return HYPERV_CPUID_VENDOR_AND_MAX_FUNCTIONS; + + return 0; +} + +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), + .flags = CLOCK_SOURCE_IS_CONTINUOUS, +}; + +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); + +#ifdef CONFIG_X86_LOCAL_APIC + if (ms_hyperv.features & HV_X64_MSR_APIC_FREQUENCY_AVAILABLE) { + /* + * Get the APIC frequency. + */ + u64 hv_lapic_frequency; + + rdmsrl(HV_X64_MSR_APIC_FREQUENCY, hv_lapic_frequency); + hv_lapic_frequency = div_u64(hv_lapic_frequency, HZ); + lapic_timer_frequency = hv_lapic_frequency; + printk(KERN_INFO "HyperV: LAPIC Timer Frequency: %#x\n", + lapic_timer_frequency); + } +#endif + + if (ms_hyperv.features & HV_X64_MSR_TIME_REF_COUNT_AVAILABLE) + clocksource_register_hz(&hyperv_cs, NSEC_PER_SEC/100); + +#ifdef CONFIG_X86_IO_APIC + no_timer_check = 1; +#endif + +} + +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); |