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c942fddf | 1 | // SPDX-License-Identifier: GPL-2.0-or-later |
a0e136d4 MT |
2 | /* |
3 | * Virtual PTP 1588 clock for use with KVM guests | |
4 | * | |
5 | * Copyright (C) 2017 Red Hat Inc. | |
a0e136d4 MT |
6 | */ |
7 | #include <linux/device.h> | |
8 | #include <linux/err.h> | |
9 | #include <linux/init.h> | |
10 | #include <linux/kernel.h> | |
a8cf291b | 11 | #include <linux/slab.h> |
a0e136d4 | 12 | #include <linux/module.h> |
a8cf291b | 13 | #include <linux/ptp_kvm.h> |
a0e136d4 MT |
14 | #include <uapi/linux/kvm_para.h> |
15 | #include <asm/kvm_para.h> | |
a0e136d4 MT |
16 | #include <uapi/asm/kvm_para.h> |
17 | ||
18 | #include <linux/ptp_clock_kernel.h> | |
19 | ||
20 | struct kvm_ptp_clock { | |
21 | struct ptp_clock *ptp_clock; | |
22 | struct ptp_clock_info caps; | |
23 | }; | |
24 | ||
0673f976 | 25 | static DEFINE_SPINLOCK(kvm_ptp_lock); |
a0e136d4 | 26 | |
a0e136d4 MT |
27 | static int ptp_kvm_get_time_fn(ktime_t *device_time, |
28 | struct system_counterval_t *system_counter, | |
29 | void *ctx) | |
30 | { | |
a8cf291b JW |
31 | long ret; |
32 | u64 cycle; | |
a0e136d4 | 33 | struct timespec64 tspec; |
a8cf291b | 34 | struct clocksource *cs; |
a0e136d4 MT |
35 | |
36 | spin_lock(&kvm_ptp_lock); | |
37 | ||
38 | preempt_disable_notrace(); | |
a8cf291b JW |
39 | ret = kvm_arch_ptp_get_crosststamp(&cycle, &tspec, &cs); |
40 | if (ret) { | |
41 | spin_unlock(&kvm_ptp_lock); | |
42 | preempt_enable_notrace(); | |
43 | return ret; | |
44 | } | |
a0e136d4 MT |
45 | |
46 | preempt_enable_notrace(); | |
47 | ||
a8cf291b JW |
48 | system_counter->cycles = cycle; |
49 | system_counter->cs = cs; | |
a0e136d4 MT |
50 | |
51 | *device_time = timespec64_to_ktime(tspec); | |
52 | ||
53 | spin_unlock(&kvm_ptp_lock); | |
54 | ||
55 | return 0; | |
56 | } | |
57 | ||
58 | static int ptp_kvm_getcrosststamp(struct ptp_clock_info *ptp, | |
59 | struct system_device_crosststamp *xtstamp) | |
60 | { | |
61 | return get_device_system_crosststamp(ptp_kvm_get_time_fn, NULL, | |
62 | NULL, xtstamp); | |
63 | } | |
64 | ||
65 | /* | |
66 | * PTP clock operations | |
67 | */ | |
68 | ||
73aa29a2 | 69 | static int ptp_kvm_adjfine(struct ptp_clock_info *ptp, long delta) |
a0e136d4 MT |
70 | { |
71 | return -EOPNOTSUPP; | |
72 | } | |
73 | ||
74 | static int ptp_kvm_adjtime(struct ptp_clock_info *ptp, s64 delta) | |
75 | { | |
76 | return -EOPNOTSUPP; | |
77 | } | |
78 | ||
79 | static int ptp_kvm_settime(struct ptp_clock_info *ptp, | |
80 | const struct timespec64 *ts) | |
81 | { | |
82 | return -EOPNOTSUPP; | |
83 | } | |
84 | ||
85 | static int ptp_kvm_gettime(struct ptp_clock_info *ptp, struct timespec64 *ts) | |
86 | { | |
a8cf291b | 87 | long ret; |
a0e136d4 MT |
88 | struct timespec64 tspec; |
89 | ||
90 | spin_lock(&kvm_ptp_lock); | |
91 | ||
a8cf291b JW |
92 | ret = kvm_arch_ptp_get_clock(&tspec); |
93 | if (ret) { | |
a0e136d4 | 94 | spin_unlock(&kvm_ptp_lock); |
a8cf291b | 95 | return ret; |
a0e136d4 MT |
96 | } |
97 | ||
a0e136d4 MT |
98 | spin_unlock(&kvm_ptp_lock); |
99 | ||
100 | memcpy(ts, &tspec, sizeof(struct timespec64)); | |
101 | ||
102 | return 0; | |
103 | } | |
104 | ||
105 | static int ptp_kvm_enable(struct ptp_clock_info *ptp, | |
106 | struct ptp_clock_request *rq, int on) | |
107 | { | |
108 | return -EOPNOTSUPP; | |
109 | } | |
110 | ||
7d47e9a2 | 111 | static const struct ptp_clock_info ptp_kvm_caps = { |
a0e136d4 MT |
112 | .owner = THIS_MODULE, |
113 | .name = "KVM virtual PTP", | |
114 | .max_adj = 0, | |
115 | .n_ext_ts = 0, | |
116 | .n_pins = 0, | |
117 | .pps = 0, | |
73aa29a2 | 118 | .adjfine = ptp_kvm_adjfine, |
a0e136d4 MT |
119 | .adjtime = ptp_kvm_adjtime, |
120 | .gettime64 = ptp_kvm_gettime, | |
121 | .settime64 = ptp_kvm_settime, | |
122 | .enable = ptp_kvm_enable, | |
123 | .getcrosststamp = ptp_kvm_getcrosststamp, | |
124 | }; | |
125 | ||
126 | /* module operations */ | |
127 | ||
128 | static struct kvm_ptp_clock kvm_ptp_clock; | |
129 | ||
130 | static void __exit ptp_kvm_exit(void) | |
131 | { | |
132 | ptp_clock_unregister(kvm_ptp_clock.ptp_clock); | |
6365ba64 | 133 | kvm_arch_ptp_exit(); |
a0e136d4 MT |
134 | } |
135 | ||
136 | static int __init ptp_kvm_init(void) | |
137 | { | |
4306f200 RK |
138 | long ret; |
139 | ||
a8cf291b JW |
140 | ret = kvm_arch_ptp_init(); |
141 | if (ret) { | |
a86ed2cf JH |
142 | if (ret != -EOPNOTSUPP) |
143 | pr_err("fail to initialize ptp_kvm"); | |
a8cf291b JW |
144 | return ret; |
145 | } | |
4306f200 | 146 | |
a0e136d4 MT |
147 | kvm_ptp_clock.caps = ptp_kvm_caps; |
148 | ||
149 | kvm_ptp_clock.ptp_clock = ptp_clock_register(&kvm_ptp_clock.caps, NULL); | |
150 | ||
49e190ec | 151 | return PTR_ERR_OR_ZERO(kvm_ptp_clock.ptp_clock); |
a0e136d4 MT |
152 | } |
153 | ||
154 | module_init(ptp_kvm_init); | |
155 | module_exit(ptp_kvm_exit); | |
156 | ||
157 | MODULE_AUTHOR("Marcelo Tosatti <mtosatti@redhat.com>"); | |
158 | MODULE_DESCRIPTION("PTP clock using KVMCLOCK"); | |
159 | MODULE_LICENSE("GPL"); |