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1// SPDX-License-Identifier: GPL-2.0-or-later2/*3 * Virtual PTP 1588 clock for use with KVM guests4 *5 * Copyright (C) 2017 Red Hat Inc.6 */7#include <linux/device.h>8#include <linux/err.h>9#include <linux/init.h>10#include <linux/kernel.h>11#include <linux/slab.h>12#include <linux/module.h>13#include <linux/ptp_kvm.h>14#include <uapi/linux/kvm_para.h>15#include <asm/kvm_para.h>16#include <uapi/asm/kvm_para.h>17 18#include <linux/ptp_clock_kernel.h>19 20struct kvm_ptp_clock {21 struct ptp_clock *ptp_clock;22 struct ptp_clock_info caps;23};24 25static DEFINE_SPINLOCK(kvm_ptp_lock);26 27static int ptp_kvm_get_time_fn(ktime_t *device_time,28 struct system_counterval_t *system_counter,29 void *ctx)30{31 enum clocksource_ids cs_id;32 struct timespec64 tspec;33 u64 cycle;34 int ret;35 36 spin_lock(&kvm_ptp_lock);37 38 preempt_disable_notrace();39 ret = kvm_arch_ptp_get_crosststamp(&cycle, &tspec, &cs_id);40 if (ret) {41 spin_unlock(&kvm_ptp_lock);42 preempt_enable_notrace();43 return ret;44 }45 46 preempt_enable_notrace();47 48 system_counter->cycles = cycle;49 system_counter->cs_id = cs_id;50 51 *device_time = timespec64_to_ktime(tspec);52 53 spin_unlock(&kvm_ptp_lock);54 55 return 0;56}57 58static 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 operations67 */68 69static int ptp_kvm_adjfine(struct ptp_clock_info *ptp, long delta)70{71 return -EOPNOTSUPP;72}73 74static int ptp_kvm_adjtime(struct ptp_clock_info *ptp, s64 delta)75{76 return -EOPNOTSUPP;77}78 79static int ptp_kvm_settime(struct ptp_clock_info *ptp,80 const struct timespec64 *ts)81{82 return -EOPNOTSUPP;83}84 85static int ptp_kvm_gettime(struct ptp_clock_info *ptp, struct timespec64 *ts)86{87 long ret;88 struct timespec64 tspec;89 90 spin_lock(&kvm_ptp_lock);91 92 ret = kvm_arch_ptp_get_clock(&tspec);93 if (ret) {94 spin_unlock(&kvm_ptp_lock);95 return ret;96 }97 98 spin_unlock(&kvm_ptp_lock);99 100 memcpy(ts, &tspec, sizeof(struct timespec64));101 102 return 0;103}104 105static int ptp_kvm_enable(struct ptp_clock_info *ptp,106 struct ptp_clock_request *rq, int on)107{108 return -EOPNOTSUPP;109}110 111static const struct ptp_clock_info ptp_kvm_caps = {112 .owner = THIS_MODULE,113 .name = "KVM virtual PTP",114 .max_adj = 0,115 .n_ext_ts = 0,116 .n_pins = 0,117 .pps = 0,118 .adjfine = ptp_kvm_adjfine,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 128static struct kvm_ptp_clock kvm_ptp_clock;129 130static void __exit ptp_kvm_exit(void)131{132 ptp_clock_unregister(kvm_ptp_clock.ptp_clock);133 kvm_arch_ptp_exit();134}135 136static int __init ptp_kvm_init(void)137{138 long ret;139 140 ret = kvm_arch_ptp_init();141 if (ret) {142 if (ret != -EOPNOTSUPP)143 pr_err("fail to initialize ptp_kvm");144 return ret;145 }146 147 kvm_ptp_clock.caps = ptp_kvm_caps;148 149 kvm_ptp_clock.ptp_clock = ptp_clock_register(&kvm_ptp_clock.caps, NULL);150 151 return PTR_ERR_OR_ZERO(kvm_ptp_clock.ptp_clock);152}153 154module_init(ptp_kvm_init);155module_exit(ptp_kvm_exit);156 157MODULE_AUTHOR("Marcelo Tosatti <mtosatti@redhat.com>");158MODULE_DESCRIPTION("PTP clock using KVMCLOCK");159MODULE_LICENSE("GPL");160