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Release 4.11 drivers/ptp/ptp_kvm.c

Directory: drivers/ptp
/*
 * Virtual PTP 1588 clock for use with KVM guests
 *
 * Copyright (C) 2017 Red Hat Inc.
 *
 *  This program is free software; you can redistribute it and/or modify
 *  it under the terms of the GNU General Public License as published by
 *  the Free Software Foundation; either version 2 of the License, or
 *  (at your option) any later version.
 *
 *  This program is distributed in the hope that it will be useful,
 *  but WITHOUT ANY WARRANTY; without even the implied warranty of
 *  MERCHANTABILITY or FITNESS FOR A PARTICULAR PURPOSE.  See the
 *  GNU General Public License for more details.
 *
 */
#include <linux/device.h>
#include <linux/err.h>
#include <linux/init.h>
#include <linux/kernel.h>
#include <linux/module.h>
#include <uapi/linux/kvm_para.h>
#include <asm/kvm_para.h>
#include <asm/pvclock.h>
#include <asm/kvmclock.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;
};


DEFINE_SPINLOCK(kvm_ptp_lock);


static struct pvclock_vsyscall_time_info *hv_clock;


static struct kvm_clock_pairing clock_pair;

static phys_addr_t clock_pair_gpa;


static int ptp_kvm_get_time_fn(ktime_t *device_time, struct system_counterval_t *system_counter, void *ctx) { unsigned long ret; struct timespec64 tspec; unsigned version; int cpu; struct pvclock_vcpu_time_info *src; spin_lock(&kvm_ptp_lock); preempt_disable_notrace(); cpu = smp_processor_id(); src = &hv_clock[cpu].pvti; do { /* * We are using a TSC value read in the hosts * kvm_hc_clock_pairing handling. * So any changes to tsc_to_system_mul * and tsc_shift or any other pvclock * data invalidate that measurement. */ version = pvclock_read_begin(src); ret = kvm_hypercall2(KVM_HC_CLOCK_PAIRING, clock_pair_gpa, KVM_CLOCK_PAIRING_WALLCLOCK); if (ret != 0) { pr_err_ratelimited("clock pairing hypercall ret %lu\n", ret); spin_unlock(&kvm_ptp_lock); preempt_enable_notrace(); return -EOPNOTSUPP; } tspec.tv_sec = clock_pair.sec; tspec.tv_nsec = clock_pair.nsec; ret = __pvclock_read_cycles(src, clock_pair.tsc); } while (pvclock_read_retry(src, version)); preempt_enable_notrace(); system_counter->cycles = ret; system_counter->cs = &kvm_clock; *device_time = timespec64_to_ktime(tspec); spin_unlock(&kvm_ptp_lock); return 0; }

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Marcelo Tosatti182100.00%1100.00%
Total182100.00%1100.00%


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); }

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Marcelo Tosatti28100.00%1100.00%
Total28100.00%1100.00%

/* * PTP clock operations */
static int ptp_kvm_adjfreq(struct ptp_clock_info *ptp, s32 ppb) { return -EOPNOTSUPP; }

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Marcelo Tosatti18100.00%1100.00%
Total18100.00%1100.00%


static int ptp_kvm_adjtime(struct ptp_clock_info *ptp, s64 delta) { return -EOPNOTSUPP; }

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Marcelo Tosatti18100.00%1100.00%
Total18100.00%1100.00%


static int ptp_kvm_settime(struct ptp_clock_info *ptp, const struct timespec64 *ts) { return -EOPNOTSUPP; }

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Marcelo Tosatti21100.00%1100.00%
Total21100.00%1100.00%


static int ptp_kvm_gettime(struct ptp_clock_info *ptp, struct timespec64 *ts) { unsigned long ret; struct timespec64 tspec; spin_lock(&kvm_ptp_lock); ret = kvm_hypercall2(KVM_HC_CLOCK_PAIRING, clock_pair_gpa, KVM_CLOCK_PAIRING_WALLCLOCK); if (ret != 0) { pr_err_ratelimited("clock offset hypercall ret %lu\n", ret); spin_unlock(&kvm_ptp_lock); return -EOPNOTSUPP; } tspec.tv_sec = clock_pair.sec; tspec.tv_nsec = clock_pair.nsec; spin_unlock(&kvm_ptp_lock); memcpy(ts, &tspec, sizeof(struct timespec64)); return 0; }

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Marcelo Tosatti105100.00%1100.00%
Total105100.00%1100.00%


static int ptp_kvm_enable(struct ptp_clock_info *ptp, struct ptp_clock_request *rq, int on) { return -EOPNOTSUPP; }

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Marcelo Tosatti23100.00%1100.00%
Total23100.00%1100.00%

static 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, .adjfreq = ptp_kvm_adjfreq, .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); }

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Marcelo Tosatti16100.00%1100.00%
Total16100.00%1100.00%


static int __init ptp_kvm_init(void) { long ret; clock_pair_gpa = slow_virt_to_phys(&clock_pair); hv_clock = pvclock_pvti_cpu0_va(); if (!hv_clock) return -ENODEV; ret = kvm_hypercall2(KVM_HC_CLOCK_PAIRING, clock_pair_gpa, KVM_CLOCK_PAIRING_WALLCLOCK); if (ret == -KVM_ENOSYS || ret == -KVM_EOPNOTSUPP) return -ENODEV; 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); }

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Marcelo Tosatti5865.17%133.33%
Radim Krčmář3033.71%133.33%
Fengguang Wu11.12%133.33%
Total89100.00%3100.00%

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");

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PersonTokensPropCommitsCommitProp
Marcelo Tosatti63695.35%133.33%
Radim Krčmář304.50%133.33%
Fengguang Wu10.15%133.33%
Total667100.00%3100.00%
Directory: drivers/ptp
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