From 999f129289ab1599e7cdc08804a9b5ec4e1418f4 Mon Sep 17 00:00:00 2001 From: Grygorii Strashko Date: Fri, 28 Jul 2017 17:30:03 -0500 Subject: net: ethernet: ti: cpts: convert to use ptp auxiliary worker There could be significant delay in CPTS work schedule under high system load and on -RT which could cause CPTS misbehavior due to internal counter overflow. Usage of own kthread_worker allows to avoid such kind of issues and makes it possible to tune priority of CPTS kthread_worker thread on -RT (thread name "cpts"). Hence, the CPTS driver is converted to use PTP auxiliary worker as PHC subsystem implements such functionality in a generic way now. Signed-off-by: Grygorii Strashko Signed-off-by: David S. Miller --- drivers/net/ethernet/ti/cpts.c | 27 +++++++++++++-------------- drivers/net/ethernet/ti/cpts.h | 1 - 2 files changed, 13 insertions(+), 15 deletions(-) (limited to 'drivers/net/ethernet/ti') diff --git a/drivers/net/ethernet/ti/cpts.c b/drivers/net/ethernet/ti/cpts.c index 32279d21c836..3ed438ef9e1e 100644 --- a/drivers/net/ethernet/ti/cpts.c +++ b/drivers/net/ethernet/ti/cpts.c @@ -224,6 +224,17 @@ static int cpts_ptp_enable(struct ptp_clock_info *ptp, return -EOPNOTSUPP; } +static long cpts_overflow_check(struct ptp_clock_info *ptp) +{ + struct cpts *cpts = container_of(ptp, struct cpts, info); + unsigned long delay = cpts->ov_check_period; + struct timespec64 ts; + + cpts_ptp_gettime(&cpts->info, &ts); + pr_debug("cpts overflow check at %lld.%09lu\n", ts.tv_sec, ts.tv_nsec); + return (long)delay; +} + static struct ptp_clock_info cpts_info = { .owner = THIS_MODULE, .name = "CTPS timer", @@ -236,18 +247,9 @@ static struct ptp_clock_info cpts_info = { .gettime64 = cpts_ptp_gettime, .settime64 = cpts_ptp_settime, .enable = cpts_ptp_enable, + .do_aux_work = cpts_overflow_check, }; -static void cpts_overflow_check(struct work_struct *work) -{ - struct timespec64 ts; - struct cpts *cpts = container_of(work, struct cpts, overflow_work.work); - - cpts_ptp_gettime(&cpts->info, &ts); - pr_debug("cpts overflow check at %lld.%09lu\n", ts.tv_sec, ts.tv_nsec); - schedule_delayed_work(&cpts->overflow_work, cpts->ov_check_period); -} - static int cpts_match(struct sk_buff *skb, unsigned int ptp_class, u16 ts_seqid, u8 ts_msgtype) { @@ -378,7 +380,7 @@ int cpts_register(struct cpts *cpts) } cpts->phc_index = ptp_clock_index(cpts->clock); - schedule_delayed_work(&cpts->overflow_work, cpts->ov_check_period); + ptp_schedule_worker(cpts->clock, cpts->ov_check_period); return 0; err_ptp: @@ -392,8 +394,6 @@ void cpts_unregister(struct cpts *cpts) if (WARN_ON(!cpts->clock)) return; - cancel_delayed_work_sync(&cpts->overflow_work); - ptp_clock_unregister(cpts->clock); cpts->clock = NULL; @@ -476,7 +476,6 @@ struct cpts *cpts_create(struct device *dev, void __iomem *regs, cpts->dev = dev; cpts->reg = (struct cpsw_cpts __iomem *)regs; spin_lock_init(&cpts->lock); - INIT_DELAYED_WORK(&cpts->overflow_work, cpts_overflow_check); ret = cpts_of_parse(cpts, node); if (ret) diff --git a/drivers/net/ethernet/ti/cpts.h b/drivers/net/ethernet/ti/cpts.h index 01ea82ba9cdc..586edd9c7de0 100644 --- a/drivers/net/ethernet/ti/cpts.h +++ b/drivers/net/ethernet/ti/cpts.h @@ -119,7 +119,6 @@ struct cpts { u32 cc_mult; /* for the nominal frequency */ struct cyclecounter cc; struct timecounter tc; - struct delayed_work overflow_work; int phc_index; struct clk *refclk; struct list_head events; -- cgit v1.2.3 From 0d5f54fec0a18eea5e4ac005646fd2bc2118636c Mon Sep 17 00:00:00 2001 From: Grygorii Strashko Date: Fri, 28 Jul 2017 17:30:04 -0500 Subject: net: ethernet: ti: cpts: fix tx timestamping timeout With the low speed Ethernet connection CPDMA notification about packet processing can be received before CPTS TX timestamp event, which is set when packet actually left CPSW while cpdma notification is sent when packet pushed in CPSW fifo. As result, when connection is slow and CPU is fast enough TX timestamping is not working properly. Fix it, by introducing TX SKB queue to store PTP SKBs for which Ethernet Transmit Event hasn't been received yet and then re-check this queue with new Ethernet Transmit Events by scheduling CPTS overflow work more often (every 1 jiffies) until TX SKB queue is not empty. Side effect of this change is: - User space tools require to take into account possible delay in TX timestamp processing (for example ptp4l works with tx_timestamp_timeout=400 under net traffic and tx_timestamp_timeout=25 in idle). Signed-off-by: Grygorii Strashko Signed-off-by: David S. Miller --- drivers/net/ethernet/ti/cpts.c | 84 +++++++++++++++++++++++++++++++++++++++++- drivers/net/ethernet/ti/cpts.h | 1 + 2 files changed, 83 insertions(+), 2 deletions(-) (limited to 'drivers/net/ethernet/ti') diff --git a/drivers/net/ethernet/ti/cpts.c b/drivers/net/ethernet/ti/cpts.c index 3ed438ef9e1e..95a0076773b3 100644 --- a/drivers/net/ethernet/ti/cpts.c +++ b/drivers/net/ethernet/ti/cpts.c @@ -31,9 +31,18 @@ #include "cpts.h" +#define CPTS_SKB_TX_WORK_TIMEOUT 1 /* jiffies */ + +struct cpts_skb_cb_data { + unsigned long tmo; +}; + #define cpts_read32(c, r) readl_relaxed(&c->reg->r) #define cpts_write32(c, v, r) writel_relaxed(v, &c->reg->r) +static int cpts_match(struct sk_buff *skb, unsigned int ptp_class, + u16 ts_seqid, u8 ts_msgtype); + static int event_expired(struct cpts_event *event) { return time_after(jiffies, event->tmo); @@ -77,6 +86,47 @@ static int cpts_purge_events(struct cpts *cpts) return removed ? 0 : -1; } +static bool cpts_match_tx_ts(struct cpts *cpts, struct cpts_event *event) +{ + struct sk_buff *skb, *tmp; + u16 seqid; + u8 mtype; + bool found = false; + + mtype = (event->high >> MESSAGE_TYPE_SHIFT) & MESSAGE_TYPE_MASK; + seqid = (event->high >> SEQUENCE_ID_SHIFT) & SEQUENCE_ID_MASK; + + /* no need to grab txq.lock as access is always done under cpts->lock */ + skb_queue_walk_safe(&cpts->txq, skb, tmp) { + struct skb_shared_hwtstamps ssh; + unsigned int class = ptp_classify_raw(skb); + struct cpts_skb_cb_data *skb_cb = + (struct cpts_skb_cb_data *)skb->cb; + + if (cpts_match(skb, class, seqid, mtype)) { + u64 ns = timecounter_cyc2time(&cpts->tc, event->low); + + memset(&ssh, 0, sizeof(ssh)); + ssh.hwtstamp = ns_to_ktime(ns); + skb_tstamp_tx(skb, &ssh); + found = true; + __skb_unlink(skb, &cpts->txq); + dev_consume_skb_any(skb); + dev_dbg(cpts->dev, "match tx timestamp mtype %u seqid %04x\n", + mtype, seqid); + } else if (time_after(jiffies, skb_cb->tmo)) { + /* timeout any expired skbs over 1s */ + dev_dbg(cpts->dev, + "expiring tx timestamp mtype %u seqid %04x\n", + mtype, seqid); + __skb_unlink(skb, &cpts->txq); + dev_consume_skb_any(skb); + } + } + + return found; +} + /* * Returns zero if matching event type was found. */ @@ -101,9 +151,15 @@ static int cpts_fifo_read(struct cpts *cpts, int match) event->low = lo; type = event_type(event); switch (type) { + case CPTS_EV_TX: + if (cpts_match_tx_ts(cpts, event)) { + /* if the new event matches an existing skb, + * then don't queue it + */ + break; + } case CPTS_EV_PUSH: case CPTS_EV_RX: - case CPTS_EV_TX: list_del_init(&event->list); list_add_tail(&event->list, &cpts->events); break; @@ -229,8 +285,15 @@ static long cpts_overflow_check(struct ptp_clock_info *ptp) struct cpts *cpts = container_of(ptp, struct cpts, info); unsigned long delay = cpts->ov_check_period; struct timespec64 ts; + unsigned long flags; + + spin_lock_irqsave(&cpts->lock, flags); + ts = ns_to_timespec64(timecounter_read(&cpts->tc)); + + if (!skb_queue_empty(&cpts->txq)) + delay = CPTS_SKB_TX_WORK_TIMEOUT; + spin_unlock_irqrestore(&cpts->lock, flags); - cpts_ptp_gettime(&cpts->info, &ts); pr_debug("cpts overflow check at %lld.%09lu\n", ts.tv_sec, ts.tv_nsec); return (long)delay; } @@ -319,6 +382,19 @@ static u64 cpts_find_ts(struct cpts *cpts, struct sk_buff *skb, int ev_type) break; } } + + if (ev_type == CPTS_EV_TX && !ns) { + struct cpts_skb_cb_data *skb_cb = + (struct cpts_skb_cb_data *)skb->cb; + /* Not found, add frame to queue for processing later. + * The periodic FIFO check will handle this. + */ + skb_get(skb); + /* get the timestamp for timeouts */ + skb_cb->tmo = jiffies + msecs_to_jiffies(100); + __skb_queue_tail(&cpts->txq, skb); + ptp_schedule_worker(cpts->clock, 0); + } spin_unlock_irqrestore(&cpts->lock, flags); return ns; @@ -360,6 +436,7 @@ int cpts_register(struct cpts *cpts) { int err, i; + skb_queue_head_init(&cpts->txq); INIT_LIST_HEAD(&cpts->events); INIT_LIST_HEAD(&cpts->pool); for (i = 0; i < CPTS_MAX_EVENTS; i++) @@ -400,6 +477,9 @@ void cpts_unregister(struct cpts *cpts) cpts_write32(cpts, 0, int_enable); cpts_write32(cpts, 0, control); + /* Drop all packet */ + skb_queue_purge(&cpts->txq); + clk_disable(cpts->refclk); } EXPORT_SYMBOL_GPL(cpts_unregister); diff --git a/drivers/net/ethernet/ti/cpts.h b/drivers/net/ethernet/ti/cpts.h index 586edd9c7de0..73d73faf0f38 100644 --- a/drivers/net/ethernet/ti/cpts.h +++ b/drivers/net/ethernet/ti/cpts.h @@ -125,6 +125,7 @@ struct cpts { struct list_head pool; struct cpts_event pool_data[CPTS_MAX_EVENTS]; unsigned long ov_check_period; + struct sk_buff_head txq; }; void cpts_rx_timestamp(struct cpts *cpts, struct sk_buff *skb); -- cgit v1.2.3 From a93439cce2c1d31469e8245c504dbb6d1bed8749 Mon Sep 17 00:00:00 2001 From: Grygorii Strashko Date: Fri, 28 Jul 2017 17:30:05 -0500 Subject: net: ethernet: ti: cpts: fix fifo read in cpts_find_ts Now the call chain cpts_find_ts() |- cpts_fifo_read(cpts, CPTS_EV_PUSH) will stop reading CPTS FIFO if PUSH event is found. But this is not expected and CPTS FIFI should be completely drained here. This is most probably copy-paste error and it has no negative impact as CPTS_EV_PUSH should not be present in FIFO without TS_PUSH request and cpts_systim_read() and cpts_find_ts() synchronized by spin_lock. Correct above by calling cpts_fifo_read() with -1 parameter, so it will read all CPTS event from FIFO. Signed-off-by: Grygorii Strashko Signed-off-by: David S. Miller --- drivers/net/ethernet/ti/cpts.c | 2 +- 1 file changed, 1 insertion(+), 1 deletion(-) (limited to 'drivers/net/ethernet/ti') diff --git a/drivers/net/ethernet/ti/cpts.c b/drivers/net/ethernet/ti/cpts.c index 95a0076773b3..c2121d214f08 100644 --- a/drivers/net/ethernet/ti/cpts.c +++ b/drivers/net/ethernet/ti/cpts.c @@ -364,7 +364,7 @@ static u64 cpts_find_ts(struct cpts *cpts, struct sk_buff *skb, int ev_type) return 0; spin_lock_irqsave(&cpts->lock, flags); - cpts_fifo_read(cpts, CPTS_EV_PUSH); + cpts_fifo_read(cpts, -1); list_for_each_safe(this, next, &cpts->events) { event = list_entry(this, struct cpts_event, list); if (event_expired(event)) { -- cgit v1.2.3