[PATCH 5.14 418/849] gve: Recover from queue stall due to missed IRQ

Greg Kroah-Hartman
2021-11-15T22:59:19Z

From: John Fraker <jfraker@google.com>

[ Upstream commit 87a7f321bb6a45e54b7d6c90d032ee5636a6ad97 ]

Don't always reset the driver on a TX timeout. Attempt to
recover by kicking the queue in case an IRQ was missed.

Fixes: 9e5f7d26a4c08 ("gve: Add workqueue and reset support")
Signed-off-by: John Fraker <jfraker@google.com>
Signed-off-by: David Awogbemila <awogbemila@google.com>
Signed-off-by: David S. Miller <davem@davemloft.net>
Signed-off-by: Sasha Levin <sashal@kernel.org>
---
drivers/net/ethernet/google/gve/gve.h | 4 +-
drivers/net/ethernet/google/gve/gve_adminq.h | 1 +
drivers/net/ethernet/google/gve/gve_main.c | 48 +++++++++++++++++++-
3 files changed, 51 insertions(+), 2 deletions(-)

diff --git a/drivers/net/ethernet/google/gve/gve.h b/drivers/net/ethernet/google/gve/gve.h
index 2f93ed4705905..c1d4042671f9f 100644
--- a/drivers/net/ethernet/google/gve/gve.h
+++ b/drivers/net/ethernet/google/gve/gve.h
@@ -30,7 +30,7 @@
#define GVE_MIN_MSIX 3

/* Numbers of gve tx/rx stats in stats report. */
-#define GVE_TX_STATS_REPORT_NUM 5
+#define GVE_TX_STATS_REPORT_NUM 6
#define GVE_RX_STATS_REPORT_NUM 2

/* Interval to schedule a stats report update, 20000ms. */
@@ -413,7 +413,9 @@ struct gve_tx_ring {
u32 q_num ____cacheline_aligned; /* queue idx */
u32 stop_queue; /* count of queue stops */
u32 wake_queue; /* count of queue wakes */
+ u32 queue_timeout; /* count of queue timeouts */
u32 ntfy_id; /* notification block index */
+ u32 last_kick_msec; /* Last time the queue was kicked */
dma_addr_t bus; /* dma address of the descr ring */
dma_addr_t q_resources_bus; /* dma address of the queue resources */
dma_addr_t complq_bus_dqo; /* dma address of the dqo.compl_ring */
diff --git a/drivers/net/ethernet/google/gve/gve_adminq.h b/drivers/net/ethernet/google/gve/gve_adminq.h
index 47c3d8f313fcf..3953f6f7a4273 100644
--- a/drivers/net/ethernet/google/gve/gve_adminq.h
+++ b/drivers/net/ethernet/google/gve/gve_adminq.h
@@ -270,6 +270,7 @@ enum gve_stat_names {
TX_LAST_COMPLETION_PROCESSED = 5,
RX_NEXT_EXPECTED_SEQUENCE = 6,
RX_BUFFERS_POSTED = 7,
+ TX_TIMEOUT_CNT = 8,
// stats from NIC
RX_QUEUE_DROP_CNT = 65,
RX_NO_BUFFERS_POSTED = 66,
diff --git a/drivers/net/ethernet/google/gve/gve_main.c b/drivers/net/ethernet/google/gve/gve_main.c
index bf8a4a7c43f78..8c996e72748d2 100644
--- a/drivers/net/ethernet/google/gve/gve_main.c
+++ b/drivers/net/ethernet/google/gve/gve_main.c
@@ -24,6 +24,9 @@
#define GVE_VERSION "1.0.0"
#define GVE_VERSION_PREFIX "GVE-"

+// Minimum amount of time between queue kicks in msec (10 seconds)
+#define MIN_TX_TIMEOUT_GAP (1000 * 10)
+
const char gve_version_str[] = GVE_VERSION;
static const char gve_version_prefix[] = GVE_VERSION_PREFIX;

@@ -1116,9 +1119,47 @@ static void gve_turnup(struct gve_priv *priv)

static void gve_tx_timeout(struct net_device *dev, unsigned int txqueue)
{
- struct gve_priv *priv = netdev_priv(dev);
+ struct gve_notify_block *block;
+ struct gve_tx_ring *tx = NULL;
+ struct gve_priv *priv;
+ u32 last_nic_done;
+ u32 current_time;
+ u32 ntfy_idx;
+
+ netdev_info(dev, "Timeout on tx queue, %d", txqueue);
+ priv = netdev_priv(dev);
+ if (txqueue > priv->tx_cfg.num_queues)
+ goto reset;
+
+ ntfy_idx = gve_tx_idx_to_ntfy(priv, txqueue);
+ if (ntfy_idx > priv->num_ntfy_blks)
+ goto reset;
+
+ block = &priv->ntfy_blocks[ntfy_idx];
+ tx = block->tx;

+ current_time = jiffies_to_msecs(jiffies);
+ if (tx->last_kick_msec + MIN_TX_TIMEOUT_GAP > current_time)
+ goto reset;
+
+ /* Check to see if there are missed completions, which will allow us to
+ * kick the queue.
+ */
+ last_nic_done = gve_tx_load_event_counter(priv, tx);
+ if (last_nic_done - tx->done) {
+ netdev_info(dev, "Kicking queue %d", txqueue);
+ iowrite32be(GVE_IRQ_MASK, gve_irq_doorbell(priv, block));
+ napi_schedule(&block->napi);
+ tx->last_kick_msec = current_time;
+ goto out;
+ } // Else reset.
+
+reset:
gve_schedule_reset(priv);
+
+out:
+ if (tx)
+ tx->queue_timeout++;
priv->tx_timeo_cnt++;
}

@@ -1247,6 +1288,11 @@ void gve_handle_report_stats(struct gve_priv *priv)
.value = cpu_to_be64(last_completion),
.queue_id = cpu_to_be32(idx),
};
+ stats[stats_idx++] = (struct stats) {
+ .stat_name = cpu_to_be32(TX_TIMEOUT_CNT),
+ .value = cpu_to_be64(priv->tx[idx].queue_timeout),
+ .queue_id = cpu_to_be32(idx),
+ };
}
}
/* rx stats */
--
2.33.0