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