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https://git.kernel.org/pub/scm/linux/kernel/git/torvalds/linux.git
synced 2026-05-07 19:49:33 -04:00
Merge branch '1GbE' of git://git.kernel.org/pub/scm/linux/kernel/git/tnguy/net-queue
Tony Nguyen says:
====================
igc: TX timestamping fixes
This is the fixes part of the series intended to add support for using
the 4 timestamp registers present in i225/i226.
Moving the timestamp handling to be inline with the interrupt handling
has the advantage of improving the TX timestamping retrieval latency,
here are some numbers using ntpperf:
Before:
$ sudo ./ntpperf -i enp3s0 -m 10:22:22:22:22:21 -d 192.168.1.3 -s 172.18.0.0/16 -I -H -o -37
| responses | TX timestamp offset (ns)
rate clients | lost invalid basic xleave | min mean max stddev
1000 100 0.00% 0.00% 0.00% 100.00% -56 +9 +52 19
1500 150 0.00% 0.00% 0.00% 100.00% -40 +30 +75 22
2250 225 0.00% 0.00% 0.00% 100.00% -11 +29 +72 15
3375 337 0.00% 0.00% 0.00% 100.00% -18 +40 +88 22
5062 506 0.00% 0.00% 0.00% 100.00% -19 +23 +77 15
7593 759 0.00% 0.00% 0.00% 100.00% +7 +47 +5168 43
11389 1138 0.00% 0.00% 0.00% 100.00% -11 +41 +5240 39
17083 1708 0.00% 0.00% 0.00% 100.00% +19 +60 +5288 50
25624 2562 0.00% 0.00% 0.00% 100.00% +1 +56 +5368 58
38436 3843 0.00% 0.00% 0.00% 100.00% -84 +12 +8847 66
57654 5765 0.00% 0.00% 100.00% 0.00%
86481 8648 0.00% 0.00% 100.00% 0.00%
129721 12972 0.00% 0.00% 100.00% 0.00%
194581 16384 0.00% 0.00% 100.00% 0.00%
291871 16384 27.35% 0.00% 72.65% 0.00%
437806 16384 50.05% 0.00% 49.95% 0.00%
After:
$ sudo ./ntpperf -i enp3s0 -m 10:22:22:22:22:21 -d 192.168.1.3 -s 172.18.0.0/16 -I -H -o -37
| responses | TX timestamp offset (ns)
rate clients | lost invalid basic xleave | min mean max stddev
1000 100 0.00% 0.00% 0.00% 100.00% -44 +0 +61 19
1500 150 0.00% 0.00% 0.00% 100.00% -6 +39 +81 16
2250 225 0.00% 0.00% 0.00% 100.00% -22 +25 +69 15
3375 337 0.00% 0.00% 0.00% 100.00% -28 +15 +56 14
5062 506 0.00% 0.00% 0.00% 100.00% +7 +78 +143 27
7593 759 0.00% 0.00% 0.00% 100.00% -54 +24 +144 47
11389 1138 0.00% 0.00% 0.00% 100.00% -90 -33 +28 21
17083 1708 0.00% 0.00% 0.00% 100.00% -50 -2 +35 14
25624 2562 0.00% 0.00% 0.00% 100.00% -62 +7 +66 23
38436 3843 0.00% 0.00% 0.00% 100.00% -33 +30 +5395 36
57654 5765 0.00% 0.00% 100.00% 0.00%
86481 8648 0.00% 0.00% 100.00% 0.00%
129721 12972 0.00% 0.00% 100.00% 0.00%
194581 16384 19.50% 0.00% 80.50% 0.00%
291871 16384 35.81% 0.00% 64.19% 0.00%
437806 16384 55.40% 0.00% 44.60% 0.00%
During this series, and to show that as is always the case, things are
never easy as they should be, a hardware issue was found, and it took
some time to find the workaround(s). The bug and workaround are better
explained in patch 4/4.
Note: the workaround has a simpler alternative, but it would involve
adding support for the other timestamp registers, and only using the
TXSTMP{H/L}_0 as a way to clear the interrupt. But I feel bad about
throwing this kind of resources away. Didn't test this extensively but
it should work.
Also, as Marc Kleine-Budde suggested, after some consensus is reached
on this series, most parts of it will be proposed for igb.
* '1GbE' of git://git.kernel.org/pub/scm/linux/kernel/git/tnguy/net-queue:
igc: Work around HW bug causing missing timestamps
igc: Retrieve TX timestamp during interrupt handling
igc: Check if hardware TX timestamping is enabled earlier
igc: Fix race condition in PTP tx code
====================
Link: https://lore.kernel.org/r/20230622165244.2202786-1-anthony.l.nguyen@intel.com
Signed-off-by: Jakub Kicinski <kuba@kernel.org>
This commit is contained in:
Jakub Kicinski
@@ -228,7 +228,10 @@ struct igc_adapter {
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struct ptp_clock *ptp_clock;
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struct ptp_clock_info ptp_caps;
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struct work_struct ptp_tx_work;
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/* Access to ptp_tx_skb and ptp_tx_start are protected by the
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* ptp_tx_lock.
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*/
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spinlock_t ptp_tx_lock;
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struct sk_buff *ptp_tx_skb;
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struct hwtstamp_config tstamp_config;
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unsigned long ptp_tx_start;
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@@ -401,7 +404,6 @@ enum igc_state_t {
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__IGC_TESTING,
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__IGC_RESETTING,
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__IGC_DOWN,
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__IGC_PTP_TX_IN_PROGRESS,
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};
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enum igc_tx_flags {
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@@ -578,6 +580,7 @@ enum igc_ring_flags_t {
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IGC_RING_FLAG_TX_CTX_IDX,
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IGC_RING_FLAG_TX_DETECT_HANG,
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IGC_RING_FLAG_AF_XDP_ZC,
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IGC_RING_FLAG_TX_HWTSTAMP,
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};
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#define ring_uses_large_buffer(ring) \
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@@ -634,6 +637,7 @@ int igc_ptp_set_ts_config(struct net_device *netdev, struct ifreq *ifr);
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int igc_ptp_get_ts_config(struct net_device *netdev, struct ifreq *ifr);
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void igc_ptp_tx_hang(struct igc_adapter *adapter);
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void igc_ptp_read(struct igc_adapter *adapter, struct timespec64 *ts);
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void igc_ptp_tx_tstamp_event(struct igc_adapter *adapter);
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#define igc_rx_pg_size(_ring) (PAGE_SIZE << igc_rx_pg_order(_ring))
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@@ -1585,14 +1585,16 @@ static netdev_tx_t igc_xmit_frame_ring(struct sk_buff *skb,
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}
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}
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if (unlikely(skb_shinfo(skb)->tx_flags & SKBTX_HW_TSTAMP)) {
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if (unlikely(test_bit(IGC_RING_FLAG_TX_HWTSTAMP, &tx_ring->flags) &&
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skb_shinfo(skb)->tx_flags & SKBTX_HW_TSTAMP)) {
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/* FIXME: add support for retrieving timestamps from
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* the other timer registers before skipping the
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* timestamping request.
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*/
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if (adapter->tstamp_config.tx_type == HWTSTAMP_TX_ON &&
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!test_and_set_bit_lock(__IGC_PTP_TX_IN_PROGRESS,
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&adapter->state)) {
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unsigned long flags;
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spin_lock_irqsave(&adapter->ptp_tx_lock, flags);
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if (!adapter->ptp_tx_skb) {
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skb_shinfo(skb)->tx_flags |= SKBTX_IN_PROGRESS;
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tx_flags |= IGC_TX_FLAGS_TSTAMP;
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@@ -1601,6 +1603,8 @@ static netdev_tx_t igc_xmit_frame_ring(struct sk_buff *skb,
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} else {
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adapter->tx_hwtstamp_skipped++;
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}
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spin_unlock_irqrestore(&adapter->ptp_tx_lock, flags);
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}
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if (skb_vlan_tag_present(skb)) {
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@@ -5219,7 +5223,7 @@ static void igc_tsync_interrupt(struct igc_adapter *adapter)
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if (tsicr & IGC_TSICR_TXTS) {
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/* retrieve hardware timestamp */
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schedule_work(&adapter->ptp_tx_work);
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igc_ptp_tx_tstamp_event(adapter);
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ack |= IGC_TSICR_TXTS;
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}
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@@ -536,9 +536,34 @@ static void igc_ptp_enable_rx_timestamp(struct igc_adapter *adapter)
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wr32(IGC_TSYNCRXCTL, val);
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}
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static void igc_ptp_clear_tx_tstamp(struct igc_adapter *adapter)
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{
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unsigned long flags;
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spin_lock_irqsave(&adapter->ptp_tx_lock, flags);
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dev_kfree_skb_any(adapter->ptp_tx_skb);
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adapter->ptp_tx_skb = NULL;
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spin_unlock_irqrestore(&adapter->ptp_tx_lock, flags);
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}
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static void igc_ptp_disable_tx_timestamp(struct igc_adapter *adapter)
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{
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struct igc_hw *hw = &adapter->hw;
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int i;
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/* Clear the flags first to avoid new packets to be enqueued
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* for TX timestamping.
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*/
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for (i = 0; i < adapter->num_tx_queues; i++) {
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struct igc_ring *tx_ring = adapter->tx_ring[i];
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clear_bit(IGC_RING_FLAG_TX_HWTSTAMP, &tx_ring->flags);
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}
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/* Now we can clean the pending TX timestamp requests. */
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igc_ptp_clear_tx_tstamp(adapter);
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wr32(IGC_TSYNCTXCTL, 0);
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}
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@@ -546,12 +571,23 @@ static void igc_ptp_disable_tx_timestamp(struct igc_adapter *adapter)
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static void igc_ptp_enable_tx_timestamp(struct igc_adapter *adapter)
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{
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struct igc_hw *hw = &adapter->hw;
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int i;
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wr32(IGC_TSYNCTXCTL, IGC_TSYNCTXCTL_ENABLED | IGC_TSYNCTXCTL_TXSYNSIG);
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/* Read TXSTMP registers to discard any timestamp previously stored. */
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rd32(IGC_TXSTMPL);
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rd32(IGC_TXSTMPH);
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/* The hardware is ready to accept TX timestamp requests,
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* notify the transmit path.
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*/
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for (i = 0; i < adapter->num_tx_queues; i++) {
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struct igc_ring *tx_ring = adapter->tx_ring[i];
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set_bit(IGC_RING_FLAG_TX_HWTSTAMP, &tx_ring->flags);
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}
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}
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/**
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@@ -603,6 +639,7 @@ static int igc_ptp_set_timestamp_mode(struct igc_adapter *adapter,
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return 0;
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}
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/* Requires adapter->ptp_tx_lock held by caller. */
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static void igc_ptp_tx_timeout(struct igc_adapter *adapter)
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{
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struct igc_hw *hw = &adapter->hw;
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@@ -610,7 +647,6 @@ static void igc_ptp_tx_timeout(struct igc_adapter *adapter)
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dev_kfree_skb_any(adapter->ptp_tx_skb);
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adapter->ptp_tx_skb = NULL;
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adapter->tx_hwtstamp_timeouts++;
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clear_bit_unlock(__IGC_PTP_TX_IN_PROGRESS, &adapter->state);
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/* Clear the tx valid bit in TSYNCTXCTL register to enable interrupt. */
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rd32(IGC_TXSTMPH);
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netdev_warn(adapter->netdev, "Tx timestamp timeout\n");
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@@ -618,20 +654,20 @@ static void igc_ptp_tx_timeout(struct igc_adapter *adapter)
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void igc_ptp_tx_hang(struct igc_adapter *adapter)
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{
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bool timeout = time_is_before_jiffies(adapter->ptp_tx_start +
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IGC_PTP_TX_TIMEOUT);
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unsigned long flags;
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if (!test_bit(__IGC_PTP_TX_IN_PROGRESS, &adapter->state))
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return;
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spin_lock_irqsave(&adapter->ptp_tx_lock, flags);
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/* If we haven't received a timestamp within the timeout, it is
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* reasonable to assume that it will never occur, so we can unlock the
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* timestamp bit when this occurs.
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*/
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if (timeout) {
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cancel_work_sync(&adapter->ptp_tx_work);
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igc_ptp_tx_timeout(adapter);
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}
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if (!adapter->ptp_tx_skb)
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goto unlock;
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if (time_is_after_jiffies(adapter->ptp_tx_start + IGC_PTP_TX_TIMEOUT))
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goto unlock;
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igc_ptp_tx_timeout(adapter);
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unlock:
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spin_unlock_irqrestore(&adapter->ptp_tx_lock, flags);
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}
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/**
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@@ -641,20 +677,57 @@ void igc_ptp_tx_hang(struct igc_adapter *adapter)
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* If we were asked to do hardware stamping and such a time stamp is
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* available, then it must have been for this skb here because we only
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* allow only one such packet into the queue.
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*
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* Context: Expects adapter->ptp_tx_lock to be held by caller.
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*/
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static void igc_ptp_tx_hwtstamp(struct igc_adapter *adapter)
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{
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struct sk_buff *skb = adapter->ptp_tx_skb;
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struct skb_shared_hwtstamps shhwtstamps;
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struct igc_hw *hw = &adapter->hw;
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u32 tsynctxctl;
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int adjust = 0;
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u64 regval;
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if (WARN_ON_ONCE(!skb))
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return;
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regval = rd32(IGC_TXSTMPL);
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regval |= (u64)rd32(IGC_TXSTMPH) << 32;
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tsynctxctl = rd32(IGC_TSYNCTXCTL);
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tsynctxctl &= IGC_TSYNCTXCTL_TXTT_0;
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if (tsynctxctl) {
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regval = rd32(IGC_TXSTMPL);
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regval |= (u64)rd32(IGC_TXSTMPH) << 32;
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} else {
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/* There's a bug in the hardware that could cause
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* missing interrupts for TX timestamping. The issue
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* is that for new interrupts to be triggered, the
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* IGC_TXSTMPH_0 register must be read.
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*
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* To avoid discarding a valid timestamp that just
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* happened at the "wrong" time, we need to confirm
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* that there was no timestamp captured, we do that by
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* assuming that no two timestamps in sequence have
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* the same nanosecond value.
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*
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* So, we read the "low" register, read the "high"
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* register (to latch a new timestamp) and read the
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* "low" register again, if "old" and "new" versions
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* of the "low" register are different, a valid
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* timestamp was captured, we can read the "high"
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* register again.
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*/
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u32 txstmpl_old, txstmpl_new;
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txstmpl_old = rd32(IGC_TXSTMPL);
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rd32(IGC_TXSTMPH);
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txstmpl_new = rd32(IGC_TXSTMPL);
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if (txstmpl_old == txstmpl_new)
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return;
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regval = txstmpl_new;
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regval |= (u64)rd32(IGC_TXSTMPH) << 32;
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}
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if (igc_ptp_systim_to_hwtstamp(adapter, &shhwtstamps, regval))
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return;
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@@ -676,13 +749,7 @@ static void igc_ptp_tx_hwtstamp(struct igc_adapter *adapter)
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shhwtstamps.hwtstamp =
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ktime_add_ns(shhwtstamps.hwtstamp, adjust);
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/* Clear the lock early before calling skb_tstamp_tx so that
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* applications are not woken up before the lock bit is clear. We use
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* a copy of the skb pointer to ensure other threads can't change it
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* while we're notifying the stack.
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*/
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adapter->ptp_tx_skb = NULL;
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clear_bit_unlock(__IGC_PTP_TX_IN_PROGRESS, &adapter->state);
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/* Notify the stack and free the skb after we've unlocked */
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skb_tstamp_tx(skb, &shhwtstamps);
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@@ -690,27 +757,25 @@ static void igc_ptp_tx_hwtstamp(struct igc_adapter *adapter)
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}
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/**
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* igc_ptp_tx_work
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* @work: pointer to work struct
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* igc_ptp_tx_tstamp_event
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* @adapter: board private structure
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*
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* This work function polls the TSYNCTXCTL valid bit to determine when a
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* timestamp has been taken for the current stored skb.
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* Called when a TX timestamp interrupt happens to retrieve the
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* timestamp and send it up to the socket.
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*/
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static void igc_ptp_tx_work(struct work_struct *work)
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void igc_ptp_tx_tstamp_event(struct igc_adapter *adapter)
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{
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struct igc_adapter *adapter = container_of(work, struct igc_adapter,
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ptp_tx_work);
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struct igc_hw *hw = &adapter->hw;
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u32 tsynctxctl;
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unsigned long flags;
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if (!test_bit(__IGC_PTP_TX_IN_PROGRESS, &adapter->state))
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return;
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spin_lock_irqsave(&adapter->ptp_tx_lock, flags);
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tsynctxctl = rd32(IGC_TSYNCTXCTL);
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if (WARN_ON_ONCE(!(tsynctxctl & IGC_TSYNCTXCTL_TXTT_0)))
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return;
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if (!adapter->ptp_tx_skb)
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goto unlock;
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igc_ptp_tx_hwtstamp(adapter);
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unlock:
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spin_unlock_irqrestore(&adapter->ptp_tx_lock, flags);
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}
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/**
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@@ -959,8 +1024,8 @@ void igc_ptp_init(struct igc_adapter *adapter)
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return;
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}
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spin_lock_init(&adapter->ptp_tx_lock);
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spin_lock_init(&adapter->tmreg_lock);
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INIT_WORK(&adapter->ptp_tx_work, igc_ptp_tx_work);
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adapter->tstamp_config.rx_filter = HWTSTAMP_FILTER_NONE;
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adapter->tstamp_config.tx_type = HWTSTAMP_TX_OFF;
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@@ -1020,10 +1085,7 @@ void igc_ptp_suspend(struct igc_adapter *adapter)
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if (!(adapter->ptp_flags & IGC_PTP_ENABLED))
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return;
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cancel_work_sync(&adapter->ptp_tx_work);
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dev_kfree_skb_any(adapter->ptp_tx_skb);
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adapter->ptp_tx_skb = NULL;
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clear_bit_unlock(__IGC_PTP_TX_IN_PROGRESS, &adapter->state);
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igc_ptp_clear_tx_tstamp(adapter);
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if (pci_device_is_present(adapter->pdev)) {
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igc_ptp_time_save(adapter);
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Block a user