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a2a47c6c KS |
1 | /* |
2 | * HyperV Detection code. | |
3 | * | |
4 | * Copyright (C) 2010, Novell, Inc. | |
5 | * Author : K. Y. Srinivasan <ksrinivasan@novell.com> | |
6 | * | |
7 | * This program is free software; you can redistribute it and/or modify | |
8 | * it under the terms of the GNU General Public License as published by | |
9fa02317 | 9 | * the Free Software Foundation; version 2 of the License. |
a2a47c6c KS |
10 | * |
11 | */ | |
12 | ||
13 | #include <linux/types.h> | |
6f4151c8 S |
14 | #include <linux/time.h> |
15 | #include <linux/clocksource.h> | |
3998d095 | 16 | #include <linux/module.h> |
bc2b0331 S |
17 | #include <linux/hardirq.h> |
18 | #include <linux/interrupt.h> | |
a2a47c6c | 19 | #include <asm/processor.h> |
e08cae41 | 20 | #include <asm/hypervisor.h> |
a2a47c6c KS |
21 | #include <asm/hyperv.h> |
22 | #include <asm/mshyperv.h> | |
bc2b0331 S |
23 | #include <asm/desc.h> |
24 | #include <asm/idle.h> | |
25 | #include <asm/irq_regs.h> | |
a2a47c6c | 26 | |
e08cae41 | 27 | struct ms_hyperv_info ms_hyperv; |
9279aa55 | 28 | EXPORT_SYMBOL_GPL(ms_hyperv); |
a2a47c6c | 29 | |
e08cae41 | 30 | static bool __init ms_hyperv_platform(void) |
a2a47c6c | 31 | { |
e08cae41 PA |
32 | u32 eax; |
33 | u32 hyp_signature[3]; | |
a2a47c6c | 34 | |
e08cae41 PA |
35 | if (!boot_cpu_has(X86_FEATURE_HYPERVISOR)) |
36 | return false; | |
a2a47c6c | 37 | |
db34bbb7 S |
38 | /* |
39 | * Xen emulates Hyper-V to support enlightened Windows. | |
40 | * Check to see first if we are on a Xen Hypervisor. | |
41 | */ | |
42 | if (xen_cpuid_base()) | |
43 | return false; | |
44 | ||
e08cae41 PA |
45 | cpuid(HYPERV_CPUID_VENDOR_AND_MAX_FUNCTIONS, |
46 | &eax, &hyp_signature[0], &hyp_signature[1], &hyp_signature[2]); | |
a2a47c6c | 47 | |
e08cae41 PA |
48 | return eax >= HYPERV_CPUID_MIN && |
49 | eax <= HYPERV_CPUID_MAX && | |
50 | !memcmp("Microsoft Hv", hyp_signature, 12); | |
a2a47c6c KS |
51 | } |
52 | ||
6f4151c8 S |
53 | static cycle_t read_hv_clock(struct clocksource *arg) |
54 | { | |
55 | cycle_t current_tick; | |
56 | /* | |
57 | * Read the partition counter to get the current tick count. This count | |
58 | * is set to 0 when the partition is created and is incremented in | |
59 | * 100 nanosecond units. | |
60 | */ | |
61 | rdmsrl(HV_X64_MSR_TIME_REF_COUNT, current_tick); | |
62 | return current_tick; | |
63 | } | |
64 | ||
65 | static struct clocksource hyperv_cs = { | |
66 | .name = "hyperv_clocksource", | |
67 | .rating = 400, /* use this when running on Hyperv*/ | |
68 | .read = read_hv_clock, | |
69 | .mask = CLOCKSOURCE_MASK(64), | |
70 | }; | |
71 | ||
e08cae41 | 72 | static void __init ms_hyperv_init_platform(void) |
a2a47c6c | 73 | { |
a2a47c6c | 74 | /* |
e08cae41 | 75 | * Extract the features and hints |
a2a47c6c | 76 | */ |
e08cae41 PA |
77 | ms_hyperv.features = cpuid_eax(HYPERV_CPUID_FEATURES); |
78 | ms_hyperv.hints = cpuid_eax(HYPERV_CPUID_ENLIGHTMENT_INFO); | |
a2a47c6c | 79 | |
e08cae41 PA |
80 | printk(KERN_INFO "HyperV: features 0x%x, hints 0x%x\n", |
81 | ms_hyperv.features, ms_hyperv.hints); | |
6f4151c8 | 82 | |
32068f65 OH |
83 | if (ms_hyperv.features & HV_X64_MSR_TIME_REF_COUNT_AVAILABLE) |
84 | clocksource_register_hz(&hyperv_cs, NSEC_PER_SEC/100); | |
bc2b0331 S |
85 | #if IS_ENABLED(CONFIG_HYPERV) |
86 | /* | |
87 | * Setup the IDT for hypervisor callback. | |
88 | */ | |
89 | alloc_intr_gate(HYPERVISOR_CALLBACK_VECTOR, hyperv_callback_vector); | |
90 | #endif | |
a2a47c6c | 91 | } |
e08cae41 PA |
92 | |
93 | const __refconst struct hypervisor_x86 x86_hyper_ms_hyperv = { | |
94 | .name = "Microsoft HyperV", | |
95 | .detect = ms_hyperv_platform, | |
96 | .init_platform = ms_hyperv_init_platform, | |
97 | }; | |
96f6e775 | 98 | EXPORT_SYMBOL(x86_hyper_ms_hyperv); |
bc2b0331 S |
99 | |
100 | #if IS_ENABLED(CONFIG_HYPERV) | |
101 | static int vmbus_irq = -1; | |
102 | static irq_handler_t vmbus_isr; | |
103 | ||
104 | void hv_register_vmbus_handler(int irq, irq_handler_t handler) | |
105 | { | |
106 | vmbus_irq = irq; | |
107 | vmbus_isr = handler; | |
108 | } | |
109 | ||
110 | void hyperv_vector_handler(struct pt_regs *regs) | |
111 | { | |
112 | struct pt_regs *old_regs = set_irq_regs(regs); | |
113 | struct irq_desc *desc; | |
114 | ||
115 | irq_enter(); | |
116 | exit_idle(); | |
117 | ||
118 | desc = irq_to_desc(vmbus_irq); | |
119 | ||
120 | if (desc) | |
121 | generic_handle_irq_desc(vmbus_irq, desc); | |
122 | ||
123 | irq_exit(); | |
124 | set_irq_regs(old_regs); | |
125 | } | |
126 | #else | |
127 | void hv_register_vmbus_handler(int irq, irq_handler_t handler) | |
128 | { | |
129 | } | |
130 | #endif | |
131 | EXPORT_SYMBOL_GPL(hv_register_vmbus_handler); |