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158 lines
3.1 KiB
158 lines
3.1 KiB
// 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_adjfreq(struct ptp_clock_info *ptp, s32 ppb) |
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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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.adjfreq = ptp_kvm_adjfreq, |
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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 <[email protected]>"); |
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MODULE_DESCRIPTION("PTP clock using KVMCLOCK"); |
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MODULE_LICENSE("GPL");
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