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295 lines
6.9 KiB
295 lines
6.9 KiB
// SPDX-License-Identifier: GPL-2.0-or-later |
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/* |
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* PTP virtual clock driver |
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* |
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* Copyright 2021 NXP |
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*/ |
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#include <linux/slab.h> |
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#include <linux/hashtable.h> |
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#include "ptp_private.h" |
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#define PTP_VCLOCK_CC_SHIFT 31 |
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#define PTP_VCLOCK_CC_MULT (1 << PTP_VCLOCK_CC_SHIFT) |
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#define PTP_VCLOCK_FADJ_SHIFT 9 |
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#define PTP_VCLOCK_FADJ_DENOMINATOR 15625ULL |
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#define PTP_VCLOCK_REFRESH_INTERVAL (HZ * 2) |
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/* protects vclock_hash addition/deletion */ |
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static DEFINE_SPINLOCK(vclock_hash_lock); |
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static DEFINE_READ_MOSTLY_HASHTABLE(vclock_hash, 8); |
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static void ptp_vclock_hash_add(struct ptp_vclock *vclock) |
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{ |
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spin_lock(&vclock_hash_lock); |
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hlist_add_head_rcu(&vclock->vclock_hash_node, |
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&vclock_hash[vclock->clock->index % HASH_SIZE(vclock_hash)]); |
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spin_unlock(&vclock_hash_lock); |
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} |
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static void ptp_vclock_hash_del(struct ptp_vclock *vclock) |
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{ |
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spin_lock(&vclock_hash_lock); |
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hlist_del_init_rcu(&vclock->vclock_hash_node); |
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spin_unlock(&vclock_hash_lock); |
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synchronize_rcu(); |
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} |
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static int ptp_vclock_adjfine(struct ptp_clock_info *ptp, long scaled_ppm) |
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{ |
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struct ptp_vclock *vclock = info_to_vclock(ptp); |
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unsigned long flags; |
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s64 adj; |
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adj = (s64)scaled_ppm << PTP_VCLOCK_FADJ_SHIFT; |
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adj = div_s64(adj, PTP_VCLOCK_FADJ_DENOMINATOR); |
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spin_lock_irqsave(&vclock->lock, flags); |
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timecounter_read(&vclock->tc); |
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vclock->cc.mult = PTP_VCLOCK_CC_MULT + adj; |
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spin_unlock_irqrestore(&vclock->lock, flags); |
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return 0; |
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} |
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static int ptp_vclock_adjtime(struct ptp_clock_info *ptp, s64 delta) |
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{ |
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struct ptp_vclock *vclock = info_to_vclock(ptp); |
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unsigned long flags; |
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spin_lock_irqsave(&vclock->lock, flags); |
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timecounter_adjtime(&vclock->tc, delta); |
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spin_unlock_irqrestore(&vclock->lock, flags); |
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return 0; |
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} |
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static int ptp_vclock_gettime(struct ptp_clock_info *ptp, |
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struct timespec64 *ts) |
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{ |
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struct ptp_vclock *vclock = info_to_vclock(ptp); |
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unsigned long flags; |
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u64 ns; |
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spin_lock_irqsave(&vclock->lock, flags); |
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ns = timecounter_read(&vclock->tc); |
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spin_unlock_irqrestore(&vclock->lock, flags); |
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*ts = ns_to_timespec64(ns); |
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return 0; |
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} |
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static int ptp_vclock_gettimex(struct ptp_clock_info *ptp, |
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struct timespec64 *ts, |
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struct ptp_system_timestamp *sts) |
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{ |
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struct ptp_vclock *vclock = info_to_vclock(ptp); |
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struct ptp_clock *pptp = vclock->pclock; |
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struct timespec64 pts; |
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unsigned long flags; |
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int err; |
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u64 ns; |
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err = pptp->info->getcyclesx64(pptp->info, &pts, sts); |
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if (err) |
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return err; |
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spin_lock_irqsave(&vclock->lock, flags); |
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ns = timecounter_cyc2time(&vclock->tc, timespec64_to_ns(&pts)); |
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spin_unlock_irqrestore(&vclock->lock, flags); |
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*ts = ns_to_timespec64(ns); |
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return 0; |
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} |
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static int ptp_vclock_settime(struct ptp_clock_info *ptp, |
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const struct timespec64 *ts) |
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{ |
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struct ptp_vclock *vclock = info_to_vclock(ptp); |
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u64 ns = timespec64_to_ns(ts); |
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unsigned long flags; |
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spin_lock_irqsave(&vclock->lock, flags); |
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timecounter_init(&vclock->tc, &vclock->cc, ns); |
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spin_unlock_irqrestore(&vclock->lock, flags); |
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return 0; |
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} |
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static int ptp_vclock_getcrosststamp(struct ptp_clock_info *ptp, |
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struct system_device_crosststamp *xtstamp) |
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{ |
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struct ptp_vclock *vclock = info_to_vclock(ptp); |
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struct ptp_clock *pptp = vclock->pclock; |
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unsigned long flags; |
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int err; |
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u64 ns; |
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err = pptp->info->getcrosscycles(pptp->info, xtstamp); |
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if (err) |
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return err; |
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spin_lock_irqsave(&vclock->lock, flags); |
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ns = timecounter_cyc2time(&vclock->tc, ktime_to_ns(xtstamp->device)); |
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spin_unlock_irqrestore(&vclock->lock, flags); |
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xtstamp->device = ns_to_ktime(ns); |
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return 0; |
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} |
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static long ptp_vclock_refresh(struct ptp_clock_info *ptp) |
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{ |
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struct ptp_vclock *vclock = info_to_vclock(ptp); |
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struct timespec64 ts; |
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ptp_vclock_gettime(&vclock->info, &ts); |
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return PTP_VCLOCK_REFRESH_INTERVAL; |
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} |
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static const struct ptp_clock_info ptp_vclock_info = { |
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.owner = THIS_MODULE, |
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.name = "ptp virtual clock", |
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.max_adj = 500000000, |
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.adjfine = ptp_vclock_adjfine, |
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.adjtime = ptp_vclock_adjtime, |
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.settime64 = ptp_vclock_settime, |
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.do_aux_work = ptp_vclock_refresh, |
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}; |
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static u64 ptp_vclock_read(const struct cyclecounter *cc) |
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{ |
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struct ptp_vclock *vclock = cc_to_vclock(cc); |
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struct ptp_clock *ptp = vclock->pclock; |
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struct timespec64 ts = {}; |
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ptp->info->getcycles64(ptp->info, &ts); |
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return timespec64_to_ns(&ts); |
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} |
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static const struct cyclecounter ptp_vclock_cc = { |
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.read = ptp_vclock_read, |
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.mask = CYCLECOUNTER_MASK(32), |
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.mult = PTP_VCLOCK_CC_MULT, |
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.shift = PTP_VCLOCK_CC_SHIFT, |
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}; |
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struct ptp_vclock *ptp_vclock_register(struct ptp_clock *pclock) |
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{ |
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struct ptp_vclock *vclock; |
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vclock = kzalloc(sizeof(*vclock), GFP_KERNEL); |
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if (!vclock) |
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return NULL; |
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vclock->pclock = pclock; |
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vclock->info = ptp_vclock_info; |
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if (pclock->info->getcyclesx64) |
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vclock->info.gettimex64 = ptp_vclock_gettimex; |
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else |
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vclock->info.gettime64 = ptp_vclock_gettime; |
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if (pclock->info->getcrosscycles) |
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vclock->info.getcrosststamp = ptp_vclock_getcrosststamp; |
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vclock->cc = ptp_vclock_cc; |
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snprintf(vclock->info.name, PTP_CLOCK_NAME_LEN, "ptp%d_virt", |
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pclock->index); |
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INIT_HLIST_NODE(&vclock->vclock_hash_node); |
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spin_lock_init(&vclock->lock); |
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vclock->clock = ptp_clock_register(&vclock->info, &pclock->dev); |
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if (IS_ERR_OR_NULL(vclock->clock)) { |
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kfree(vclock); |
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return NULL; |
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} |
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timecounter_init(&vclock->tc, &vclock->cc, 0); |
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ptp_schedule_worker(vclock->clock, PTP_VCLOCK_REFRESH_INTERVAL); |
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ptp_vclock_hash_add(vclock); |
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return vclock; |
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} |
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void ptp_vclock_unregister(struct ptp_vclock *vclock) |
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{ |
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ptp_vclock_hash_del(vclock); |
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ptp_clock_unregister(vclock->clock); |
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kfree(vclock); |
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} |
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#if IS_BUILTIN(CONFIG_PTP_1588_CLOCK) |
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int ptp_get_vclocks_index(int pclock_index, int **vclock_index) |
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{ |
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char name[PTP_CLOCK_NAME_LEN] = ""; |
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struct ptp_clock *ptp; |
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struct device *dev; |
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int num = 0; |
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if (pclock_index < 0) |
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return num; |
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snprintf(name, PTP_CLOCK_NAME_LEN, "ptp%d", pclock_index); |
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dev = class_find_device_by_name(ptp_class, name); |
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if (!dev) |
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return num; |
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ptp = dev_get_drvdata(dev); |
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if (mutex_lock_interruptible(&ptp->n_vclocks_mux)) { |
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put_device(dev); |
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return num; |
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} |
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*vclock_index = kzalloc(sizeof(int) * ptp->n_vclocks, GFP_KERNEL); |
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if (!(*vclock_index)) |
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goto out; |
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memcpy(*vclock_index, ptp->vclock_index, sizeof(int) * ptp->n_vclocks); |
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num = ptp->n_vclocks; |
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out: |
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mutex_unlock(&ptp->n_vclocks_mux); |
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put_device(dev); |
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return num; |
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} |
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EXPORT_SYMBOL(ptp_get_vclocks_index); |
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ktime_t ptp_convert_timestamp(const ktime_t *hwtstamp, int vclock_index) |
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{ |
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unsigned int hash = vclock_index % HASH_SIZE(vclock_hash); |
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struct ptp_vclock *vclock; |
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unsigned long flags; |
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u64 ns; |
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u64 vclock_ns = 0; |
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ns = ktime_to_ns(*hwtstamp); |
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rcu_read_lock(); |
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hlist_for_each_entry_rcu(vclock, &vclock_hash[hash], vclock_hash_node) { |
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if (vclock->clock->index != vclock_index) |
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continue; |
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spin_lock_irqsave(&vclock->lock, flags); |
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vclock_ns = timecounter_cyc2time(&vclock->tc, ns); |
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spin_unlock_irqrestore(&vclock->lock, flags); |
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break; |
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} |
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rcu_read_unlock(); |
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return ns_to_ktime(vclock_ns); |
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} |
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EXPORT_SYMBOL(ptp_convert_timestamp); |
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#endif
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