159 строки
3.1 KiB
C
159 строки
3.1 KiB
C
// SPDX-License-Identifier: GPL-2.0-or-later
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/*
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* Virtual PTP 1588 clock for use with KVM guests
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*
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* Copyright (C) 2017 Red Hat Inc.
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*/
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#include <linux/device.h>
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#include <linux/err.h>
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#include <linux/init.h>
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#include <linux/kernel.h>
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#include <linux/slab.h>
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#include <linux/module.h>
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#include <linux/ptp_kvm.h>
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#include <uapi/linux/kvm_para.h>
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#include <asm/kvm_para.h>
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#include <uapi/asm/kvm_para.h>
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#include <linux/ptp_clock_kernel.h>
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struct kvm_ptp_clock {
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struct ptp_clock *ptp_clock;
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struct ptp_clock_info caps;
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};
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static DEFINE_SPINLOCK(kvm_ptp_lock);
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static int ptp_kvm_get_time_fn(ktime_t *device_time,
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struct system_counterval_t *system_counter,
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void *ctx)
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{
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long ret;
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u64 cycle;
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struct timespec64 tspec;
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struct clocksource *cs;
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spin_lock(&kvm_ptp_lock);
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preempt_disable_notrace();
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ret = kvm_arch_ptp_get_crosststamp(&cycle, &tspec, &cs);
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if (ret) {
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spin_unlock(&kvm_ptp_lock);
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preempt_enable_notrace();
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return ret;
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}
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preempt_enable_notrace();
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system_counter->cycles = cycle;
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system_counter->cs = cs;
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*device_time = timespec64_to_ktime(tspec);
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spin_unlock(&kvm_ptp_lock);
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return 0;
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}
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static int ptp_kvm_getcrosststamp(struct ptp_clock_info *ptp,
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struct system_device_crosststamp *xtstamp)
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{
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return get_device_system_crosststamp(ptp_kvm_get_time_fn, NULL,
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NULL, xtstamp);
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}
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/*
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* PTP clock operations
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*/
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static int ptp_kvm_adjfine(struct ptp_clock_info *ptp, long delta)
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{
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return -EOPNOTSUPP;
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}
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static int ptp_kvm_adjtime(struct ptp_clock_info *ptp, s64 delta)
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{
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return -EOPNOTSUPP;
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}
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static int ptp_kvm_settime(struct ptp_clock_info *ptp,
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const struct timespec64 *ts)
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{
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return -EOPNOTSUPP;
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}
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static int ptp_kvm_gettime(struct ptp_clock_info *ptp, struct timespec64 *ts)
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{
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long ret;
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struct timespec64 tspec;
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spin_lock(&kvm_ptp_lock);
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ret = kvm_arch_ptp_get_clock(&tspec);
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if (ret) {
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spin_unlock(&kvm_ptp_lock);
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return ret;
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}
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spin_unlock(&kvm_ptp_lock);
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memcpy(ts, &tspec, sizeof(struct timespec64));
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return 0;
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}
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static int ptp_kvm_enable(struct ptp_clock_info *ptp,
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struct ptp_clock_request *rq, int on)
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{
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return -EOPNOTSUPP;
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}
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static const struct ptp_clock_info ptp_kvm_caps = {
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.owner = THIS_MODULE,
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.name = "KVM virtual PTP",
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.max_adj = 0,
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.n_ext_ts = 0,
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.n_pins = 0,
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.pps = 0,
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.adjfine = ptp_kvm_adjfine,
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.adjtime = ptp_kvm_adjtime,
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.gettime64 = ptp_kvm_gettime,
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.settime64 = ptp_kvm_settime,
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.enable = ptp_kvm_enable,
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.getcrosststamp = ptp_kvm_getcrosststamp,
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};
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/* module operations */
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static struct kvm_ptp_clock kvm_ptp_clock;
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static void __exit ptp_kvm_exit(void)
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{
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ptp_clock_unregister(kvm_ptp_clock.ptp_clock);
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}
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static int __init ptp_kvm_init(void)
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{
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long ret;
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ret = kvm_arch_ptp_init();
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if (ret) {
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if (ret != -EOPNOTSUPP)
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pr_err("fail to initialize ptp_kvm");
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return ret;
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}
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kvm_ptp_clock.caps = ptp_kvm_caps;
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kvm_ptp_clock.ptp_clock = ptp_clock_register(&kvm_ptp_clock.caps, NULL);
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return PTR_ERR_OR_ZERO(kvm_ptp_clock.ptp_clock);
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}
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module_init(ptp_kvm_init);
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module_exit(ptp_kvm_exit);
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MODULE_AUTHOR("Marcelo Tosatti <mtosatti@redhat.com>");
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MODULE_DESCRIPTION("PTP clock using KVMCLOCK");
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MODULE_LICENSE("GPL");
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