From 72c9ac4e1f4faf1f4e7252319ab8af2517891ae5 Mon Sep 17 00:00:00 2001 From: "Lendacky, Thomas" Date: Wed, 30 Sep 2015 08:53:10 -0500 Subject: amd-xgbe: Add receive buffer unavailable statistic Add a statistic that tracks how many times an interrupt is generated for a receive buffer not being available to the hardware which prevents the hardware from being able to DMA the received data. Signed-off-by: Tom Lendacky Signed-off-by: David S. Miller --- drivers/net/ethernet/amd/xgbe/xgbe-drv.c | 3 +++ 1 file changed, 3 insertions(+) (limited to 'drivers/net/ethernet/amd/xgbe/xgbe-drv.c') diff --git a/drivers/net/ethernet/amd/xgbe/xgbe-drv.c b/drivers/net/ethernet/amd/xgbe/xgbe-drv.c index aae9d5ecd182..24212d256a01 100644 --- a/drivers/net/ethernet/amd/xgbe/xgbe-drv.c +++ b/drivers/net/ethernet/amd/xgbe/xgbe-drv.c @@ -360,6 +360,9 @@ static irqreturn_t xgbe_isr(int irq, void *data) } } + if (XGMAC_GET_BITS(dma_ch_isr, DMA_CH_SR, RBU)) + pdata->ext_stats.rx_buffer_unavailable++; + /* Restart the device on a Fatal Bus Error */ if (XGMAC_GET_BITS(dma_ch_isr, DMA_CH_SR, FBE)) schedule_work(&pdata->restart_work); -- cgit v1.2.3 From afb43e8a0af18fa959e9ef09abfa969c3c83f4ef Mon Sep 17 00:00:00 2001 From: "Lendacky, Thomas" Date: Wed, 30 Sep 2015 08:53:16 -0500 Subject: amd-xgbe: Use device workqueue instead of system workqueue The driver creates, flushes and destroys a device workqueue but queues work to the system workqueue. Switch from using the system workqueue to the device workqueue. Signed-off-by: Tom Lendacky Signed-off-by: David S. Miller --- drivers/net/ethernet/amd/xgbe/xgbe-drv.c | 11 ++++++----- 1 file changed, 6 insertions(+), 5 deletions(-) (limited to 'drivers/net/ethernet/amd/xgbe/xgbe-drv.c') diff --git a/drivers/net/ethernet/amd/xgbe/xgbe-drv.c b/drivers/net/ethernet/amd/xgbe/xgbe-drv.c index 24212d256a01..14bad8c44c87 100644 --- a/drivers/net/ethernet/amd/xgbe/xgbe-drv.c +++ b/drivers/net/ethernet/amd/xgbe/xgbe-drv.c @@ -365,7 +365,7 @@ static irqreturn_t xgbe_isr(int irq, void *data) /* Restart the device on a Fatal Bus Error */ if (XGMAC_GET_BITS(dma_ch_isr, DMA_CH_SR, FBE)) - schedule_work(&pdata->restart_work); + queue_work(pdata->dev_workqueue, &pdata->restart_work); /* Clear all interrupt signals */ XGMAC_DMA_IOWRITE(channel, DMA_CH_SR, dma_ch_isr); @@ -387,7 +387,8 @@ static irqreturn_t xgbe_isr(int irq, void *data) /* Read Tx Timestamp to clear interrupt */ pdata->tx_tstamp = hw_if->get_tx_tstamp(pdata); - schedule_work(&pdata->tx_tstamp_work); + queue_work(pdata->dev_workqueue, + &pdata->tx_tstamp_work); } } } @@ -453,7 +454,7 @@ static void xgbe_service_timer(unsigned long data) { struct xgbe_prv_data *pdata = (struct xgbe_prv_data *)data; - schedule_work(&pdata->service_work); + queue_work(pdata->dev_workqueue, &pdata->service_work); mod_timer(&pdata->service_timer, jiffies + HZ); } @@ -894,7 +895,7 @@ static int xgbe_start(struct xgbe_prv_data *pdata) netif_tx_start_all_queues(netdev); xgbe_start_timers(pdata); - schedule_work(&pdata->service_work); + queue_work(pdata->dev_workqueue, &pdata->service_work); DBGPR("<--xgbe_start\n"); @@ -1536,7 +1537,7 @@ static void xgbe_tx_timeout(struct net_device *netdev) struct xgbe_prv_data *pdata = netdev_priv(netdev); netdev_warn(netdev, "tx timeout, device restarting\n"); - schedule_work(&pdata->restart_work); + queue_work(pdata->dev_workqueue, &pdata->restart_work); } static struct rtnl_link_stats64 *xgbe_get_stats64(struct net_device *netdev, -- cgit v1.2.3 From 96aec911482246a319bf457f39fa848ce436c8fd Mon Sep 17 00:00:00 2001 From: "Lendacky, Thomas" Date: Wed, 14 Oct 2015 12:37:32 -0500 Subject: amd-xgbe: Use system workqueue for device restart A previous patch switched from using the system workqueue to the device workqueue for various operations. During a device restart the device workqueue is flushed so the restart cannot use this workqueue or else a deadlock results. Move the device restart back to using the system workqueue. Signed-off-by: Tom Lendacky Signed-off-by: David S. Miller --- drivers/net/ethernet/amd/xgbe/xgbe-drv.c | 4 ++-- 1 file changed, 2 insertions(+), 2 deletions(-) (limited to 'drivers/net/ethernet/amd/xgbe/xgbe-drv.c') diff --git a/drivers/net/ethernet/amd/xgbe/xgbe-drv.c b/drivers/net/ethernet/amd/xgbe/xgbe-drv.c index 14bad8c44c87..49f796aaad4f 100644 --- a/drivers/net/ethernet/amd/xgbe/xgbe-drv.c +++ b/drivers/net/ethernet/amd/xgbe/xgbe-drv.c @@ -365,7 +365,7 @@ static irqreturn_t xgbe_isr(int irq, void *data) /* Restart the device on a Fatal Bus Error */ if (XGMAC_GET_BITS(dma_ch_isr, DMA_CH_SR, FBE)) - queue_work(pdata->dev_workqueue, &pdata->restart_work); + schedule_work(&pdata->restart_work); /* Clear all interrupt signals */ XGMAC_DMA_IOWRITE(channel, DMA_CH_SR, dma_ch_isr); @@ -1537,7 +1537,7 @@ static void xgbe_tx_timeout(struct net_device *netdev) struct xgbe_prv_data *pdata = netdev_priv(netdev); netdev_warn(netdev, "tx timeout, device restarting\n"); - queue_work(pdata->dev_workqueue, &pdata->restart_work); + schedule_work(&pdata->restart_work); } static struct rtnl_link_stats64 *xgbe_get_stats64(struct net_device *netdev, -- cgit v1.2.3 From 20a41fba679d665cdae2808e2b9cae97c073351f Mon Sep 17 00:00:00 2001 From: "Lendacky, Thomas" Date: Wed, 21 Oct 2015 15:37:05 -0500 Subject: amd-xgbe: Use wmb before updating current descriptor count The code currently uses the lightweight dma_wmb barrier before updating the current descriptor count. Under heavy load, the Tx cleanup routine was seeing the updated current descriptor count before the updated descriptor information. As a result, the Tx descriptor was being cleaned up before it was used because it was not "owned" by the hardware yet, resulting in a Tx queue hang. Using the wmb barrier insures that the descriptor is updated before the descriptor counter preventing the Tx queue hang. For extra insurance, the Tx cleanup routine is changed to grab the current decriptor count on entry and uses that initial value in the processing loop rather than trying to chase the current value. Signed-off-by: Tom Lendacky Tested-by: Christoffer Dall Signed-off-by: David S. Miller --- drivers/net/ethernet/amd/xgbe/xgbe-dev.c | 2 +- drivers/net/ethernet/amd/xgbe/xgbe-drv.c | 4 +++- 2 files changed, 4 insertions(+), 2 deletions(-) (limited to 'drivers/net/ethernet/amd/xgbe/xgbe-drv.c') diff --git a/drivers/net/ethernet/amd/xgbe/xgbe-dev.c b/drivers/net/ethernet/amd/xgbe/xgbe-dev.c index a4473d8ff4fa..e9ab8b9f3b9c 100644 --- a/drivers/net/ethernet/amd/xgbe/xgbe-dev.c +++ b/drivers/net/ethernet/amd/xgbe/xgbe-dev.c @@ -1595,7 +1595,7 @@ static void xgbe_dev_xmit(struct xgbe_channel *channel) packet->rdesc_count, 1); /* Make sure ownership is written to the descriptor */ - dma_wmb(); + wmb(); ring->cur = cur_index + 1; if (!packet->skb->xmit_more || diff --git a/drivers/net/ethernet/amd/xgbe/xgbe-drv.c b/drivers/net/ethernet/amd/xgbe/xgbe-drv.c index aae9d5ecd182..d2b77d985441 100644 --- a/drivers/net/ethernet/amd/xgbe/xgbe-drv.c +++ b/drivers/net/ethernet/amd/xgbe/xgbe-drv.c @@ -1807,6 +1807,7 @@ static int xgbe_tx_poll(struct xgbe_channel *channel) struct netdev_queue *txq; int processed = 0; unsigned int tx_packets = 0, tx_bytes = 0; + unsigned int cur; DBGPR("-->xgbe_tx_poll\n"); @@ -1814,10 +1815,11 @@ static int xgbe_tx_poll(struct xgbe_channel *channel) if (!ring) return 0; + cur = ring->cur; txq = netdev_get_tx_queue(netdev, channel->queue_index); while ((processed < XGBE_TX_DESC_MAX_PROC) && - (ring->dirty != ring->cur)) { + (ring->dirty != cur)) { rdata = XGBE_GET_DESC_DATA(ring, ring->dirty); rdesc = rdata->rdesc; -- cgit v1.2.3 From 20986ed826cbb36bb8f2d77f872e3c52d8d30647 Mon Sep 17 00:00:00 2001 From: "Lendacky, Thomas" Date: Mon, 26 Oct 2015 17:13:54 -0500 Subject: amd-xgbe: Fix race between access of desc and desc index During Tx cleanup it's still possible for the descriptor data to be read ahead of the descriptor index. A memory barrier is required between the read of the descriptor index and the start of the Tx cleanup loop. This allows a change to a lighter-weight barrier in the Tx transmit routine just before updating the current descriptor index. Since the memory barrier does result in extra overhead on arm64, keep the previous change to not chase the current descriptor value. This prevents the execution of the barrier for each loop performed. Suggested-by: Alexander Duyck Signed-off-by: Tom Lendacky Signed-off-by: David S. Miller --- drivers/net/ethernet/amd/xgbe/xgbe-dev.c | 2 +- drivers/net/ethernet/amd/xgbe/xgbe-drv.c | 4 ++++ 2 files changed, 5 insertions(+), 1 deletion(-) (limited to 'drivers/net/ethernet/amd/xgbe/xgbe-drv.c') diff --git a/drivers/net/ethernet/amd/xgbe/xgbe-dev.c b/drivers/net/ethernet/amd/xgbe/xgbe-dev.c index e9ab8b9f3b9c..f672dba345f7 100644 --- a/drivers/net/ethernet/amd/xgbe/xgbe-dev.c +++ b/drivers/net/ethernet/amd/xgbe/xgbe-dev.c @@ -1595,7 +1595,7 @@ static void xgbe_dev_xmit(struct xgbe_channel *channel) packet->rdesc_count, 1); /* Make sure ownership is written to the descriptor */ - wmb(); + smp_wmb(); ring->cur = cur_index + 1; if (!packet->skb->xmit_more || diff --git a/drivers/net/ethernet/amd/xgbe/xgbe-drv.c b/drivers/net/ethernet/amd/xgbe/xgbe-drv.c index d2b77d985441..dde0486667e0 100644 --- a/drivers/net/ethernet/amd/xgbe/xgbe-drv.c +++ b/drivers/net/ethernet/amd/xgbe/xgbe-drv.c @@ -1816,6 +1816,10 @@ static int xgbe_tx_poll(struct xgbe_channel *channel) return 0; cur = ring->cur; + + /* Be sure we get ring->cur before accessing descriptor data */ + smp_rmb(); + txq = netdev_get_tx_queue(netdev, channel->queue_index); while ((processed < XGBE_TX_DESC_MAX_PROC) && -- cgit v1.2.3