+++ /dev/null
-From f24b5ff2bb0ef5ddbf058c64ef96bf2739be7a1a Mon Sep 17 00:00:00 2001
-From: Sasha Levin <sashal@kernel.org>
-Date: Tue, 16 Nov 2021 19:29:22 -0800
-Subject: net: annotate accesses to queue->trans_start
-
-From: Eric Dumazet <edumazet@google.com>
-
-[ Upstream commit 5337824f4dc4bb26f38fbbba4ffb425a92803f15 ]
-
-In following patches, dev_watchdog() will no longer stop all queues.
-It will read queue->trans_start locklessly.
-
-Signed-off-by: Eric Dumazet <edumazet@google.com>
-Signed-off-by: David S. Miller <davem@davemloft.net>
-Stable-dep-of: 78adb4bcf99e ("igc: Prevent garbled TX queue with XDP ZEROCOPY")
-Signed-off-by: Sasha Levin <sashal@kernel.org>
----
- drivers/net/ethernet/apm/xgene/xgene_enet_main.c | 2 +-
- drivers/net/ethernet/atheros/ag71xx.c | 2 +-
- drivers/net/ethernet/freescale/dpaa/dpaa_eth.c | 4 ++--
- drivers/net/ethernet/hisilicon/hns3/hns3_enet.c | 2 +-
- drivers/net/ethernet/ibm/ibmvnic.c | 2 +-
- drivers/net/ethernet/intel/igb/igb_main.c | 4 ++--
- .../ethernet/mellanox/mlx5/core/en/reporter_tx.c | 2 +-
- .../net/ethernet/stmicro/stmmac/stmmac_main.c | 6 +++---
- drivers/net/ethernet/ti/am65-cpsw-nuss.c | 2 +-
- drivers/net/wireless/marvell/mwifiex/init.c | 2 +-
- drivers/staging/rtl8192e/rtllib_softmac.c | 2 +-
- include/linux/netdevice.h | 16 +++++++++++++---
- net/sched/sch_generic.c | 8 ++++----
- 13 files changed, 32 insertions(+), 22 deletions(-)
-
-diff --git a/drivers/net/ethernet/apm/xgene/xgene_enet_main.c b/drivers/net/ethernet/apm/xgene/xgene_enet_main.c
-index 71151f675a498..292c2ce16672f 100644
---- a/drivers/net/ethernet/apm/xgene/xgene_enet_main.c
-+++ b/drivers/net/ethernet/apm/xgene/xgene_enet_main.c
-@@ -871,7 +871,7 @@ static void xgene_enet_timeout(struct net_device *ndev, unsigned int txqueue)
-
- for (i = 0; i < pdata->txq_cnt; i++) {
- txq = netdev_get_tx_queue(ndev, i);
-- txq->trans_start = jiffies;
-+ txq_trans_cond_update(txq);
- netif_tx_start_queue(txq);
- }
- }
-diff --git a/drivers/net/ethernet/atheros/ag71xx.c b/drivers/net/ethernet/atheros/ag71xx.c
-index 9d8b214c129d2..7e83319b26c14 100644
---- a/drivers/net/ethernet/atheros/ag71xx.c
-+++ b/drivers/net/ethernet/atheros/ag71xx.c
-@@ -766,7 +766,7 @@ static bool ag71xx_check_dma_stuck(struct ag71xx *ag)
- unsigned long timestamp;
- u32 rx_sm, tx_sm, rx_fd;
-
-- timestamp = netdev_get_tx_queue(ag->ndev, 0)->trans_start;
-+ timestamp = READ_ONCE(netdev_get_tx_queue(ag->ndev, 0)->trans_start);
- if (likely(time_before(jiffies, timestamp + HZ / 10)))
- return false;
-
-diff --git a/drivers/net/ethernet/freescale/dpaa/dpaa_eth.c b/drivers/net/ethernet/freescale/dpaa/dpaa_eth.c
-index fe5fc2b3406f9..5f5392e6d096a 100644
---- a/drivers/net/ethernet/freescale/dpaa/dpaa_eth.c
-+++ b/drivers/net/ethernet/freescale/dpaa/dpaa_eth.c
-@@ -2325,7 +2325,7 @@ dpaa_start_xmit(struct sk_buff *skb, struct net_device *net_dev)
- txq = netdev_get_tx_queue(net_dev, queue_mapping);
-
- /* LLTX requires to do our own update of trans_start */
-- txq->trans_start = jiffies;
-+ txq_trans_cond_update(txq);
-
- if (priv->tx_tstamp && skb_shinfo(skb)->tx_flags & SKBTX_HW_TSTAMP) {
- fd.cmd |= cpu_to_be32(FM_FD_CMD_UPD);
-@@ -2531,7 +2531,7 @@ static int dpaa_xdp_xmit_frame(struct net_device *net_dev,
-
- /* Bump the trans_start */
- txq = netdev_get_tx_queue(net_dev, smp_processor_id());
-- txq->trans_start = jiffies;
-+ txq_trans_cond_update(txq);
-
- err = dpaa_xmit(priv, percpu_stats, smp_processor_id(), &fd);
- if (err) {
-diff --git a/drivers/net/ethernet/hisilicon/hns3/hns3_enet.c b/drivers/net/ethernet/hisilicon/hns3/hns3_enet.c
-index 2acf50ed6025a..90314a4adcfd9 100644
---- a/drivers/net/ethernet/hisilicon/hns3/hns3_enet.c
-+++ b/drivers/net/ethernet/hisilicon/hns3/hns3_enet.c
-@@ -2645,7 +2645,7 @@ static bool hns3_get_tx_timeo_queue_info(struct net_device *ndev)
- unsigned long trans_start;
-
- q = netdev_get_tx_queue(ndev, i);
-- trans_start = q->trans_start;
-+ trans_start = READ_ONCE(q->trans_start);
- if (netif_xmit_stopped(q) &&
- time_after(jiffies,
- (trans_start + ndev->watchdog_timeo))) {
-diff --git a/drivers/net/ethernet/ibm/ibmvnic.c b/drivers/net/ethernet/ibm/ibmvnic.c
-index 450b4fd9aa7f7..ad45158651ddf 100644
---- a/drivers/net/ethernet/ibm/ibmvnic.c
-+++ b/drivers/net/ethernet/ibm/ibmvnic.c
-@@ -1910,7 +1910,7 @@ static netdev_tx_t ibmvnic_xmit(struct sk_buff *skb, struct net_device *netdev)
-
- tx_packets++;
- tx_bytes += skb->len;
-- txq->trans_start = jiffies;
-+ txq_trans_cond_update(txq);
- ret = NETDEV_TX_OK;
- goto out;
-
-diff --git a/drivers/net/ethernet/intel/igb/igb_main.c b/drivers/net/ethernet/intel/igb/igb_main.c
-index 3d380dfff7783..606ac667b8ec6 100644
---- a/drivers/net/ethernet/intel/igb/igb_main.c
-+++ b/drivers/net/ethernet/intel/igb/igb_main.c
-@@ -2933,7 +2933,7 @@ static int igb_xdp_xmit_back(struct igb_adapter *adapter, struct xdp_buff *xdp)
- nq = txring_txq(tx_ring);
- __netif_tx_lock(nq, cpu);
- /* Avoid transmit queue timeout since we share it with the slow path */
-- nq->trans_start = jiffies;
-+ txq_trans_cond_update(nq);
- ret = igb_xmit_xdp_ring(adapter, tx_ring, xdpf);
- __netif_tx_unlock(nq);
-
-@@ -2967,7 +2967,7 @@ static int igb_xdp_xmit(struct net_device *dev, int n,
- __netif_tx_lock(nq, cpu);
-
- /* Avoid transmit queue timeout since we share it with the slow path */
-- nq->trans_start = jiffies;
-+ txq_trans_cond_update(nq);
-
- for (i = 0; i < n; i++) {
- struct xdp_frame *xdpf = frames[i];
-diff --git a/drivers/net/ethernet/mellanox/mlx5/core/en/reporter_tx.c b/drivers/net/ethernet/mellanox/mlx5/core/en/reporter_tx.c
-index 8024599994642..f7fc3c2fa100e 100644
---- a/drivers/net/ethernet/mellanox/mlx5/core/en/reporter_tx.c
-+++ b/drivers/net/ethernet/mellanox/mlx5/core/en/reporter_tx.c
-@@ -570,7 +570,7 @@ int mlx5e_reporter_tx_timeout(struct mlx5e_txqsq *sq)
- snprintf(err_str, sizeof(err_str),
- "TX timeout on queue: %d, SQ: 0x%x, CQ: 0x%x, SQ Cons: 0x%x SQ Prod: 0x%x, usecs since last trans: %u",
- sq->ch_ix, sq->sqn, sq->cq.mcq.cqn, sq->cc, sq->pc,
-- jiffies_to_usecs(jiffies - sq->txq->trans_start));
-+ jiffies_to_usecs(jiffies - READ_ONCE(sq->txq->trans_start)));
-
- mlx5e_health_report(priv, priv->tx_reporter, err_str, &err_ctx);
- return to_ctx.status;
-diff --git a/drivers/net/ethernet/stmicro/stmmac/stmmac_main.c b/drivers/net/ethernet/stmicro/stmmac/stmmac_main.c
-index a43628dd1f4c2..f2dd8c4deb44d 100644
---- a/drivers/net/ethernet/stmicro/stmmac/stmmac_main.c
-+++ b/drivers/net/ethernet/stmicro/stmmac/stmmac_main.c
-@@ -2416,7 +2416,7 @@ static bool stmmac_xdp_xmit_zc(struct stmmac_priv *priv, u32 queue, u32 budget)
- bool work_done = true;
-
- /* Avoids TX time-out as we are sharing with slow path */
-- nq->trans_start = jiffies;
-+ txq_trans_cond_update(nq->trans_start);
-
- budget = min(budget, stmmac_tx_avail(priv, queue));
-
-@@ -4731,7 +4731,7 @@ static int stmmac_xdp_xmit_back(struct stmmac_priv *priv,
-
- __netif_tx_lock(nq, cpu);
- /* Avoids TX time-out as we are sharing with slow path */
-- nq->trans_start = jiffies;
-+ txq_trans_cond_update(nq->trans_start);
-
- res = stmmac_xdp_xmit_xdpf(priv, queue, xdpf, false);
- if (res == STMMAC_XDP_TX)
-@@ -6374,7 +6374,7 @@ static int stmmac_xdp_xmit(struct net_device *dev, int num_frames,
-
- __netif_tx_lock(nq, cpu);
- /* Avoids TX time-out as we are sharing with slow path */
-- nq->trans_start = jiffies;
-+ txq_trans_cond_update(nq);
-
- for (i = 0; i < num_frames; i++) {
- int res;
-diff --git a/drivers/net/ethernet/ti/am65-cpsw-nuss.c b/drivers/net/ethernet/ti/am65-cpsw-nuss.c
-index daf0779261f3e..934d110ea351d 100644
---- a/drivers/net/ethernet/ti/am65-cpsw-nuss.c
-+++ b/drivers/net/ethernet/ti/am65-cpsw-nuss.c
-@@ -345,7 +345,7 @@ static void am65_cpsw_nuss_ndo_host_tx_timeout(struct net_device *ndev,
-
- netif_txq = netdev_get_tx_queue(ndev, txqueue);
- tx_chn = &common->tx_chns[txqueue];
-- trans_start = netif_txq->trans_start;
-+ trans_start = READ_ONCE(netif_txq->trans_start);
-
- netdev_err(ndev, "txq:%d DRV_XOFF:%d tmo:%u dql_avail:%d free_desc:%zu\n",
- txqueue,
-diff --git a/drivers/net/wireless/marvell/mwifiex/init.c b/drivers/net/wireless/marvell/mwifiex/init.c
-index f006a3d72b404..88c72d1827a00 100644
---- a/drivers/net/wireless/marvell/mwifiex/init.c
-+++ b/drivers/net/wireless/marvell/mwifiex/init.c
-@@ -332,7 +332,7 @@ void mwifiex_set_trans_start(struct net_device *dev)
- int i;
-
- for (i = 0; i < dev->num_tx_queues; i++)
-- netdev_get_tx_queue(dev, i)->trans_start = jiffies;
-+ txq_trans_cond_update(netdev_get_tx_queue(dev, i));
-
- netif_trans_update(dev);
- }
-diff --git a/drivers/staging/rtl8192e/rtllib_softmac.c b/drivers/staging/rtl8192e/rtllib_softmac.c
-index ea8bc27fce494..b5a38f0a8d79b 100644
---- a/drivers/staging/rtl8192e/rtllib_softmac.c
-+++ b/drivers/staging/rtl8192e/rtllib_softmac.c
-@@ -2515,7 +2515,7 @@ void rtllib_stop_all_queues(struct rtllib_device *ieee)
- unsigned int i;
-
- for (i = 0; i < ieee->dev->num_tx_queues; i++)
-- netdev_get_tx_queue(ieee->dev, i)->trans_start = jiffies;
-+ txq_trans_cond_update(netdev_get_tx_queue(ieee->dev, i));
-
- netif_tx_stop_all_queues(ieee->dev);
- }
-diff --git a/include/linux/netdevice.h b/include/linux/netdevice.h
-index b5df2e59a51d3..f1dd4c102e9af 100644
---- a/include/linux/netdevice.h
-+++ b/include/linux/netdevice.h
-@@ -4473,10 +4473,21 @@ static inline void __netif_tx_unlock_bh(struct netdev_queue *txq)
- spin_unlock_bh(&txq->_xmit_lock);
- }
-
-+/*
-+ * txq->trans_start can be read locklessly from dev_watchdog()
-+ */
- static inline void txq_trans_update(struct netdev_queue *txq)
- {
- if (txq->xmit_lock_owner != -1)
-- txq->trans_start = jiffies;
-+ WRITE_ONCE(txq->trans_start, jiffies);
-+}
-+
-+static inline void txq_trans_cond_update(struct netdev_queue *txq)
-+{
-+ unsigned long now = jiffies;
-+
-+ if (READ_ONCE(txq->trans_start) != now)
-+ WRITE_ONCE(txq->trans_start, now);
- }
-
- /* legacy drivers only, netdev_start_xmit() sets txq->trans_start */
-@@ -4484,8 +4495,7 @@ static inline void netif_trans_update(struct net_device *dev)
- {
- struct netdev_queue *txq = netdev_get_tx_queue(dev, 0);
-
-- if (txq->trans_start != jiffies)
-- txq->trans_start = jiffies;
-+ txq_trans_cond_update(txq);
- }
-
- /**
-diff --git a/net/sched/sch_generic.c b/net/sched/sch_generic.c
-index 02299785209c1..76ed401af066b 100644
---- a/net/sched/sch_generic.c
-+++ b/net/sched/sch_generic.c
-@@ -434,9 +434,9 @@ unsigned long dev_trans_start(struct net_device *dev)
- dev = vlan_dev_real_dev(dev);
- else if (netif_is_macvlan(dev))
- dev = macvlan_dev_real_dev(dev);
-- res = netdev_get_tx_queue(dev, 0)->trans_start;
-+ res = READ_ONCE(netdev_get_tx_queue(dev, 0)->trans_start);
- for (i = 1; i < dev->num_tx_queues; i++) {
-- val = netdev_get_tx_queue(dev, i)->trans_start;
-+ val = READ_ONCE(netdev_get_tx_queue(dev, i)->trans_start);
- if (val && time_after(val, res))
- res = val;
- }
-@@ -462,7 +462,7 @@ static void dev_watchdog(struct timer_list *t)
- struct netdev_queue *txq;
-
- txq = netdev_get_tx_queue(dev, i);
-- trans_start = txq->trans_start;
-+ trans_start = READ_ONCE(txq->trans_start);
- if (netif_xmit_stopped(txq) &&
- time_after(jiffies, (trans_start +
- dev->watchdog_timeo))) {
-@@ -1172,7 +1172,7 @@ static void transition_one_qdisc(struct net_device *dev,
-
- rcu_assign_pointer(dev_queue->qdisc, new_qdisc);
- if (need_watchdog_p) {
-- dev_queue->trans_start = 0;
-+ WRITE_ONCE(dev_queue->trans_start, 0);
- *need_watchdog_p = 1;
- }
- }
---
-2.39.2
-