projects / linux-2.6-block.git / blame
| Commit | Line | Data |
|---|---|---|
| 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> |
| a2a47c6c | 17 | #include <asm/processor.h> |
| e08cae41 | 18 | #include <asm/hypervisor.h> |
| a2a47c6c KS |
19 | #include <asm/hyperv.h> |
| 20 | #include <asm/mshyperv.h> | |
| 21 | ||
| e08cae41 | 22 | struct ms_hyperv_info ms_hyperv; |
| 9279aa55 | 23 | EXPORT_SYMBOL_GPL(ms_hyperv); |
| a2a47c6c | 24 | |
| e08cae41 | 25 | static bool __init ms_hyperv_platform(void) |
| a2a47c6c | 26 | { |
| e08cae41 PA |
27 | u32 eax; |
| 28 | u32 hyp_signature[3]; | |
| a2a47c6c | 29 | |
| e08cae41 PA |
30 | if (!boot_cpu_has(X86_FEATURE_HYPERVISOR)) |
| 31 | return false; | |
| a2a47c6c | 32 | |
| db34bbb7 S |
33 | /* |
| 34 | * Xen emulates Hyper-V to support enlightened Windows. | |
| 35 | * Check to see first if we are on a Xen Hypervisor. | |
| 36 | */ | |
| 37 | if (xen_cpuid_base()) | |
| 38 | return false; | |
| 39 | ||
| e08cae41 PA |
40 | cpuid(HYPERV_CPUID_VENDOR_AND_MAX_FUNCTIONS, |
| 41 | &eax, &hyp_signature[0], &hyp_signature[1], &hyp_signature[2]); | |
| a2a47c6c | 42 | |
| e08cae41 PA |
43 | return eax >= HYPERV_CPUID_MIN && |
| 44 | eax <= HYPERV_CPUID_MAX && | |
| 45 | !memcmp("Microsoft Hv", hyp_signature, 12); | |
| a2a47c6c KS |
46 | } |
| 47 | ||
| 6f4151c8 S |
48 | static cycle_t read_hv_clock(struct clocksource *arg) |
| 49 | { | |
| 50 | cycle_t current_tick; | |
| 51 | /* | |
| 52 | * Read the partition counter to get the current tick count. This count | |
| 53 | * is set to 0 when the partition is created and is incremented in | |
| 54 | * 100 nanosecond units. | |
| 55 | */ | |
| 56 | rdmsrl(HV_X64_MSR_TIME_REF_COUNT, current_tick); | |
| 57 | return current_tick; | |
| 58 | } | |
| 59 | ||
| 60 | static struct clocksource hyperv_cs = { | |
| 61 | .name = "hyperv_clocksource", | |
| 62 | .rating = 400, /* use this when running on Hyperv*/ | |
| 63 | .read = read_hv_clock, | |
| 64 | .mask = CLOCKSOURCE_MASK(64), | |
| 65 | }; | |
| 66 | ||
| e08cae41 | 67 | static void __init ms_hyperv_init_platform(void) |
| a2a47c6c | 68 | { |
| a2a47c6c | 69 | /* |
| e08cae41 | 70 | * Extract the features and hints |
| a2a47c6c | 71 | */ |
| e08cae41 PA |
72 | ms_hyperv.features = cpuid_eax(HYPERV_CPUID_FEATURES); |
| 73 | ms_hyperv.hints = cpuid_eax(HYPERV_CPUID_ENLIGHTMENT_INFO); | |
| a2a47c6c | 74 | |
| e08cae41 PA |
75 | printk(KERN_INFO "HyperV: features 0x%x, hints 0x%x\n", |
| 76 | ms_hyperv.features, ms_hyperv.hints); | |
| 6f4151c8 | 77 | |
| 32068f65 OH |
78 | if (ms_hyperv.features & HV_X64_MSR_TIME_REF_COUNT_AVAILABLE) |
| 79 | clocksource_register_hz(&hyperv_cs, NSEC_PER_SEC/100); | |
| a2a47c6c | 80 | } |
| e08cae41 PA |
81 | |
| 82 | const __refconst struct hypervisor_x86 x86_hyper_ms_hyperv = { | |
| 83 | .name = "Microsoft HyperV", | |
| 84 | .detect = ms_hyperv_platform, | |
| 85 | .init_platform = ms_hyperv_init_platform, | |
| 86 | }; | |
| 96f6e775 | 87 | EXPORT_SYMBOL(x86_hyper_ms_hyperv); |