lkml.org 
[lkml]   [2020]   [Mar]   [20]   [last100]   RSS Feed
Views: [wrap][no wrap]   [headers]  [forward] 
 
Messages in this thread
Patch in this message
/
From
Subject[PATCH net-next v3 06/11] net: ethernet: ti: cpts: move tx timestamp processing to ptp worker only
Date
Now the tx timestamp processing happens from different contexts - softirq
and thread/PTP worker. Enabling IRQ will add one more hard_irq context.
This makes over all defered TX timestamp processing and locking
overcomplicated. Move tx timestamp processing to PTP worker always instead.

napi_rx->cpts_tx_timestamp
if ptp_packet then
push to txq
ptp_schedule_worker()

do_aux_work->cpts_overflow_check
cpts_process_events()

Signed-off-by: Grygorii Strashko <grygorii.strashko@ti.com>
---
drivers/net/ethernet/ti/cpts.c | 165 +++++++++++++++++++--------------
1 file changed, 94 insertions(+), 71 deletions(-)

diff --git a/drivers/net/ethernet/ti/cpts.c b/drivers/net/ethernet/ti/cpts.c
index f7ce482ad09c..10061e17d7b4 100644
--- a/drivers/net/ethernet/ti/cpts.c
+++ b/drivers/net/ethernet/ti/cpts.c
@@ -21,6 +21,8 @@
#include "cpts.h"

#define CPTS_SKB_TX_WORK_TIMEOUT 1 /* jiffies */
+#define CPTS_SKB_RX_TX_TMO 100 /*ms */
+#define CPTS_EVENT_RX_TX_TIMEOUT (100) /* ms */

struct cpts_skb_cb_data {
u32 skb_mtype_seqid;
@@ -92,46 +94,6 @@ static void cpts_purge_txq(struct cpts *cpts)
dev_dbg(cpts->dev, "txq cleaned up %d\n", removed);
}

-static bool cpts_match_tx_ts(struct cpts *cpts, struct cpts_event *event)
-{
- struct sk_buff *skb, *tmp;
- bool found = false;
- u32 mtype_seqid;
-
- mtype_seqid = event->high &
- ((MESSAGE_TYPE_MASK << MESSAGE_TYPE_SHIFT) |
- (SEQUENCE_ID_MASK << SEQUENCE_ID_SHIFT) |
- (EVENT_TYPE_MASK << EVENT_TYPE_SHIFT));
-
- /* 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;
- struct cpts_skb_cb_data *skb_cb =
- (struct cpts_skb_cb_data *)skb->cb;
-
- if (mtype_seqid == skb_cb->skb_mtype_seqid) {
- memset(&ssh, 0, sizeof(ssh));
- ssh.hwtstamp = ns_to_ktime(event->timestamp);
- 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_seqid %08x\n",
- mtype_seqid);
- break;
- }
-
- if (time_after(jiffies, skb_cb->tmo)) {
- /* timeout any expired skbs over 1s */
- dev_dbg(cpts->dev, "expiring tx timestamp from txq\n");
- __skb_unlink(skb, &cpts->txq);
- dev_consume_skb_any(skb);
- }
- }
-
- return found;
-}
-
/*
* Returns zero if matching event type was found.
*/
@@ -151,7 +113,6 @@ static int cpts_fifo_read(struct cpts *cpts, int match)
}

event = list_first_entry(&cpts->pool, struct cpts_event, list);
- event->tmo = jiffies + 2;
event->high = hi;
event->low = lo;
event->timestamp = timecounter_cyc2time(&cpts->tc, event->low);
@@ -169,14 +130,10 @@ static int cpts_fifo_read(struct cpts *cpts, int match)
}
break;
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;
- }
- /* fall through */
case CPTS_EV_RX:
+ event->tmo = jiffies +
+ msecs_to_jiffies(CPTS_EVENT_RX_TX_TIMEOUT);
+
list_del_init(&event->list);
list_add_tail(&event->list, &cpts->events);
break;
@@ -297,6 +254,84 @@ static int cpts_ptp_enable(struct ptp_clock_info *ptp,
return -EOPNOTSUPP;
}

+static bool cpts_match_tx_ts(struct cpts *cpts, struct cpts_event *event)
+{
+ struct sk_buff_head txq_list;
+ struct sk_buff *skb, *tmp;
+ unsigned long flags;
+ bool found = false;
+ u32 mtype_seqid;
+
+ mtype_seqid = event->high &
+ ((MESSAGE_TYPE_MASK << MESSAGE_TYPE_SHIFT) |
+ (SEQUENCE_ID_MASK << SEQUENCE_ID_SHIFT) |
+ (EVENT_TYPE_MASK << EVENT_TYPE_SHIFT));
+
+ __skb_queue_head_init(&txq_list);
+
+ spin_lock_irqsave(&cpts->txq.lock, flags);
+ skb_queue_splice_init(&cpts->txq, &txq_list);
+ spin_unlock_irqrestore(&cpts->txq.lock, flags);
+
+ skb_queue_walk_safe(&txq_list, skb, tmp) {
+ struct skb_shared_hwtstamps ssh;
+ struct cpts_skb_cb_data *skb_cb =
+ (struct cpts_skb_cb_data *)skb->cb;
+
+ if (mtype_seqid == skb_cb->skb_mtype_seqid) {
+ memset(&ssh, 0, sizeof(ssh));
+ ssh.hwtstamp = ns_to_ktime(event->timestamp);
+ skb_tstamp_tx(skb, &ssh);
+ found = true;
+ __skb_unlink(skb, &txq_list);
+ dev_consume_skb_any(skb);
+ dev_dbg(cpts->dev, "match tx timestamp mtype_seqid %08x\n",
+ mtype_seqid);
+ break;
+ }
+
+ if (time_after(jiffies, skb_cb->tmo)) {
+ /* timeout any expired skbs over 1s */
+ dev_dbg(cpts->dev, "expiring tx timestamp from txq\n");
+ __skb_unlink(skb, &txq_list);
+ dev_consume_skb_any(skb);
+ }
+ }
+
+ spin_lock_irqsave(&cpts->txq.lock, flags);
+ skb_queue_splice(&txq_list, &cpts->txq);
+ spin_unlock_irqrestore(&cpts->txq.lock, flags);
+
+ return found;
+}
+
+static void cpts_process_events(struct cpts *cpts)
+{
+ struct list_head *this, *next;
+ struct cpts_event *event;
+ LIST_HEAD(events_free);
+ unsigned long flags;
+ LIST_HEAD(events);
+
+ spin_lock_irqsave(&cpts->lock, flags);
+ list_splice_init(&cpts->events, &events);
+ spin_unlock_irqrestore(&cpts->lock, flags);
+
+ list_for_each_safe(this, next, &events) {
+ event = list_entry(this, struct cpts_event, list);
+ if (cpts_match_tx_ts(cpts, event) ||
+ time_after(jiffies, event->tmo)) {
+ list_del_init(&event->list);
+ list_add(&event->list, &events_free);
+ }
+ }
+
+ spin_lock_irqsave(&cpts->lock, flags);
+ list_splice_tail(&events, &cpts->events);
+ list_splice_tail(&events_free, &cpts->pool);
+ spin_unlock_irqrestore(&cpts->lock, flags);
+}
+
static long cpts_overflow_check(struct ptp_clock_info *ptp)
{
struct cpts *cpts = container_of(ptp, struct cpts, info);
@@ -305,17 +340,20 @@ static long cpts_overflow_check(struct ptp_clock_info *ptp)
u64 ns;

spin_lock_irqsave(&cpts->lock, flags);
-
cpts_update_cur_time(cpts, -1, NULL);
+ spin_unlock_irqrestore(&cpts->lock, flags);

ns = timecounter_read(&cpts->tc);

+ cpts_process_events(cpts);
+
+ spin_lock_irqsave(&cpts->txq.lock, flags);
if (!skb_queue_empty(&cpts->txq)) {
cpts_purge_txq(cpts);
if (!skb_queue_empty(&cpts->txq))
delay = CPTS_SKB_TX_WORK_TIMEOUT;
}
- spin_unlock_irqrestore(&cpts->lock, flags);
+ spin_unlock_irqrestore(&cpts->txq.lock, flags);

dev_dbg(cpts->dev, "cpts overflow check at %lld\n", ns);
return (long)delay;
@@ -409,19 +447,6 @@ static u64 cpts_find_ts(struct cpts *cpts, struct sk_buff *skb,
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;
@@ -455,9 +480,7 @@ EXPORT_SYMBOL_GPL(cpts_rx_timestamp);
void cpts_tx_timestamp(struct cpts *cpts, struct sk_buff *skb)
{
struct cpts_skb_cb_data *skb_cb = (struct cpts_skb_cb_data *)skb->cb;
- struct skb_shared_hwtstamps ssh;
int ret;
- u64 ns;

if (!(skb_shinfo(skb)->tx_flags & SKBTX_IN_PROGRESS))
return;
@@ -471,12 +494,12 @@ void cpts_tx_timestamp(struct cpts *cpts, struct sk_buff *skb)
dev_dbg(cpts->dev, "%s mtype seqid %08x\n",
__func__, skb_cb->skb_mtype_seqid);

- ns = cpts_find_ts(cpts, skb, CPTS_EV_TX, skb_cb->skb_mtype_seqid);
- if (!ns)
- return;
- memset(&ssh, 0, sizeof(ssh));
- ssh.hwtstamp = ns_to_ktime(ns);
- skb_tstamp_tx(skb, &ssh);
+ /* Always defer TX TS processing to PTP worker */
+ skb_get(skb);
+ /* get the timestamp for timeouts */
+ skb_cb->tmo = jiffies + msecs_to_jiffies(CPTS_SKB_RX_TX_TMO);
+ skb_queue_tail(&cpts->txq, skb);
+ ptp_schedule_worker(cpts->clock, 0);
}
EXPORT_SYMBOL_GPL(cpts_tx_timestamp);

--
2.17.1
\
 
 \ /
  Last update: 2020-03-20 20:43    [W:0.082 / U:11.656 seconds]
©2003-2020 Jasper Spaans|hosted at Digital Ocean and TransIP|Read the blog|Advertise on this site