9 files changed, 83 insertions, 11 deletions

diff --git a/drivers/net/ethernet/sfc/ef10.c b/drivers/net/ethernet/sfc/ef10.c
index e9c546bdbdfe..c1b85edcb204 100644
--- a/drivers/net/ethernet/sfc/ef10.c
+++ b/drivers/net/ethernet/sfc/ef10.c
@@ -902,6 +902,7 @@ static int efx_ef10_try_update_nic_stats(struct efx_nic *efx)
                 return -EAGAIN;
 
         /* Update derived statistics */
+        efx_nic_fix_nodesc_drop_stat(efx, &stats[EF10_STAT_rx_nodesc_drops]);
         stats[EF10_STAT_rx_good_bytes] =
                 stats[EF10_STAT_rx_bytes] -
                 stats[EF10_STAT_rx_bytes_minus_good_bytes];
@@ -3423,6 +3424,7 @@ const struct efx_nic_type efx_hunt_a0_nic_type = {
         .describe_stats = efx_ef10_describe_stats,
         .update_stats = efx_ef10_update_stats,
         .start_stats = efx_mcdi_mac_start_stats,
+        .pull_stats = efx_mcdi_mac_pull_stats,
         .stop_stats = efx_mcdi_mac_stop_stats,
         .set_id_led = efx_mcdi_set_id_led,
         .push_irq_moderation = efx_ef10_push_irq_moderation,
diff --git a/drivers/net/ethernet/sfc/efx.c b/drivers/net/ethernet/sfc/efx.c
index 5e2454d07137..c734fba8c99c 100644
--- a/drivers/net/ethernet/sfc/efx.c
+++ b/drivers/net/ethernet/sfc/efx.c
@@ -1684,6 +1684,10 @@ static void efx_start_all(struct efx_nic *efx)
         }
 
         efx->type->start_stats(efx);
+        efx->type->pull_stats(efx);
+        spin_lock_bh(&efx->stats_lock);
+        efx->type->update_stats(efx, NULL, NULL);
+        spin_unlock_bh(&efx->stats_lock);
 }
 
 /* Flush all delayed work. Should only be called when no more delayed work
@@ -1711,6 +1715,13 @@ static void efx_stop_all(struct efx_nic *efx)
         if (!efx->port_enabled)
                 return;
 
+        /* update stats before we go down so we can accurately count
+         * rx_nodesc_drops
+         */
+        efx->type->pull_stats(efx);
+        spin_lock_bh(&efx->stats_lock);
+        efx->type->update_stats(efx, NULL, NULL);
+        spin_unlock_bh(&efx->stats_lock);
         efx->type->stop_stats(efx);
         efx_stop_port(efx);
 
diff --git a/drivers/net/ethernet/sfc/falcon.c b/drivers/net/ethernet/sfc/falcon.c
index ff5d322b9b49..4a9e05c82e2a 100644
--- a/drivers/net/ethernet/sfc/falcon.c
+++ b/drivers/net/ethernet/sfc/falcon.c
@@ -2593,6 +2593,14 @@ void falcon_start_nic_stats(struct efx_nic *efx)
         spin_unlock_bh(&efx->stats_lock);
 }
 
+/* We don't acutally pull stats on falcon. Wait 10ms so that
+ * they arrive when we call this just after start_stats
+ */
+void falcon_pull_nic_stats(struct efx_nic *efx)
+{
+        msleep(10);
+}
+
 void falcon_stop_nic_stats(struct efx_nic *efx)
 {
         struct falcon_nic_data *nic_data = efx->nic_data;
@@ -2672,6 +2680,7 @@ const struct efx_nic_type falcon_a1_nic_type = {
         .describe_stats = falcon_describe_nic_stats,
         .update_stats = falcon_update_nic_stats,
         .start_stats = falcon_start_nic_stats,
+        .pull_stats = falcon_pull_nic_stats,
         .stop_stats = falcon_stop_nic_stats,
         .set_id_led = falcon_set_id_led,
         .push_irq_moderation = falcon_push_irq_moderation,
@@ -2765,6 +2774,7 @@ const struct efx_nic_type falcon_b0_nic_type = {
         .describe_stats = falcon_describe_nic_stats,
         .update_stats = falcon_update_nic_stats,
         .start_stats = falcon_start_nic_stats,
+        .pull_stats = falcon_pull_nic_stats,
         .stop_stats = falcon_stop_nic_stats,
         .set_id_led = falcon_set_id_led,
         .push_irq_moderation = falcon_push_irq_moderation,
diff --git a/drivers/net/ethernet/sfc/mcdi.h b/drivers/net/ethernet/sfc/mcdi.h
index 15816cacb548..d861628b7ee6 100644
--- a/drivers/net/ethernet/sfc/mcdi.h
+++ b/drivers/net/ethernet/sfc/mcdi.h
@@ -301,6 +301,7 @@ int efx_mcdi_set_mac(struct efx_nic *efx);
 #define EFX_MC_STATS_GENERATION_INVALID ((__force __le64)(-1))
 void efx_mcdi_mac_start_stats(struct efx_nic *efx);
 void efx_mcdi_mac_stop_stats(struct efx_nic *efx);
+void efx_mcdi_mac_pull_stats(struct efx_nic *efx);
 bool efx_mcdi_mac_check_fault(struct efx_nic *efx);
 enum reset_type efx_mcdi_map_reset_reason(enum reset_type reason);
 int efx_mcdi_reset(struct efx_nic *efx, enum reset_type method);
diff --git a/drivers/net/ethernet/sfc/mcdi_port.c b/drivers/net/ethernet/sfc/mcdi_port.c
index 7b6be61d549f..7288aefc2877 100644
--- a/drivers/net/ethernet/sfc/mcdi_port.c
+++ b/drivers/net/ethernet/sfc/mcdi_port.c
@@ -927,12 +927,23 @@ bool efx_mcdi_mac_check_fault(struct efx_nic *efx)
         return MCDI_DWORD(outbuf, GET_LINK_OUT_MAC_FAULT) != 0;
 }
 
-static int efx_mcdi_mac_stats(struct efx_nic *efx, dma_addr_t dma_addr,
-                              u32 dma_len, int enable, int clear)
+enum efx_stats_action {
+        EFX_STATS_ENABLE,
+        EFX_STATS_DISABLE,
+        EFX_STATS_PULL,
+};
+
+static int efx_mcdi_mac_stats(struct efx_nic *efx,
+                              enum efx_stats_action action, int clear)
 {
         MCDI_DECLARE_BUF(inbuf, MC_CMD_MAC_STATS_IN_LEN);
         int rc;
-        int period = enable ? 1000 : 0;
+        int change = action == EFX_STATS_PULL ? 0 : 1;
+        int enable = action == EFX_STATS_ENABLE ? 1 : 0;
+        int period = action == EFX_STATS_ENABLE ? 1000 : 0;
+        dma_addr_t dma_addr = efx->stats_buffer.dma_addr;
+        u32 dma_len = action != EFX_STATS_DISABLE ?
+                MC_CMD_MAC_NSTATS * sizeof(u64) : 0;
 
         BUILD_BUG_ON(MC_CMD_MAC_STATS_OUT_DMA_LEN != 0);
 
@@ -940,8 +951,8 @@ static int efx_mcdi_mac_stats(struct efx_nic *efx, dma_addr_t dma_addr,
         MCDI_POPULATE_DWORD_7(inbuf, MAC_STATS_IN_CMD,
                               MAC_STATS_IN_DMA, !!enable,
                               MAC_STATS_IN_CLEAR, clear,
-                              MAC_STATS_IN_PERIODIC_CHANGE, 1,
-                              MAC_STATS_IN_PERIODIC_ENABLE, !!enable,
+                              MAC_STATS_IN_PERIODIC_CHANGE, change,
+                              MAC_STATS_IN_PERIODIC_ENABLE, enable,
                               MAC_STATS_IN_PERIODIC_CLEAR, 0,
                               MAC_STATS_IN_PERIODIC_NOEVENT, 1,
                               MAC_STATS_IN_PERIOD_MS, period);
@@ -955,8 +966,8 @@ static int efx_mcdi_mac_stats(struct efx_nic *efx, dma_addr_t dma_addr,
         return 0;
 
 fail:
-        netif_err(efx, hw, efx->net_dev, "%s: %s failed rc=%d\n",
-                  __func__, enable ? "enable" : "disable", rc);
+        netif_err(efx, hw, efx->net_dev, "%s: action %d failed rc=%d\n",
+                  __func__, action, rc);
         return rc;
 }
 
@@ -966,13 +977,29 @@ void efx_mcdi_mac_start_stats(struct efx_nic *efx)
 
         dma_stats[MC_CMD_MAC_GENERATION_END] = EFX_MC_STATS_GENERATION_INVALID;
 
-        efx_mcdi_mac_stats(efx, efx->stats_buffer.dma_addr,
-                           MC_CMD_MAC_NSTATS * sizeof(u64), 1, 0);
+        efx_mcdi_mac_stats(efx, EFX_STATS_ENABLE, 0);
 }
 
 void efx_mcdi_mac_stop_stats(struct efx_nic *efx)
 {
-        efx_mcdi_mac_stats(efx, efx->stats_buffer.dma_addr, 0, 0, 0);
+        efx_mcdi_mac_stats(efx, EFX_STATS_DISABLE, 0);
+}
+
+#define EFX_MAC_STATS_WAIT_US 100
+#define EFX_MAC_STATS_WAIT_ATTEMPTS 10
+
+void efx_mcdi_mac_pull_stats(struct efx_nic *efx)
+{
+        __le64 *dma_stats = efx->stats_buffer.addr;
+        int attempts = EFX_MAC_STATS_WAIT_ATTEMPTS;
+
+        dma_stats[MC_CMD_MAC_GENERATION_END] = EFX_MC_STATS_GENERATION_INVALID;
+        efx_mcdi_mac_stats(efx, EFX_STATS_PULL, 0);
+
+        while (dma_stats[MC_CMD_MAC_GENERATION_END] ==
+                                EFX_MC_STATS_GENERATION_INVALID &&
+                        attempts-- != 0)
+                udelay(EFX_MAC_STATS_WAIT_US);
 }
 
 int efx_mcdi_port_probe(struct efx_nic *efx)
@@ -1003,7 +1030,7 @@ int efx_mcdi_port_probe(struct efx_nic *efx)
                   efx->stats_buffer.addr,
                   (u64)virt_to_phys(efx->stats_buffer.addr));
 
-        efx_mcdi_mac_stats(efx, efx->stats_buffer.dma_addr, 0, 0, 1);
+        efx_mcdi_mac_stats(efx, EFX_STATS_DISABLE, 1);
 
         return 0;
 }
diff --git a/drivers/net/ethernet/sfc/net_driver.h b/drivers/net/ethernet/sfc/net_driver.h
index d98b3f031ab5..f47bac78b92c 100644
--- a/drivers/net/ethernet/sfc/net_driver.h
+++ b/drivers/net/ethernet/sfc/net_driver.h
@@ -857,6 +857,9 @@ struct efx_nic {
         struct net_device *net_dev;
 
         struct efx_buffer stats_buffer;
+        u64 rx_nodesc_drops_total;
+        u64 rx_nodesc_drops_while_down;
+        bool rx_nodesc_drops_prev_state;
 
         unsigned int phy_type;
         const struct efx_phy_operations *phy_op;
@@ -960,6 +963,7 @@ struct efx_mtd_partition {
  * @update_stats: Update statistics not provided by event handling.
  *      Either argument may be %NULL.
  * @start_stats: Start the regular fetching of statistics
+ * @pull_stats: Pull stats from the NIC and wait until they arrive.
  * @stop_stats: Stop the regular fetching of statistics
  * @set_id_led: Set state of identifying LED or revert to automatic function
  * @push_irq_moderation: Apply interrupt moderation value
@@ -1078,6 +1082,7 @@ struct efx_nic_type {
         size_t (*update_stats)(struct efx_nic *efx, u64 *full_stats,
                                struct rtnl_link_stats64 *core_stats);
         void (*start_stats)(struct efx_nic *efx);
+        void (*pull_stats)(struct efx_nic *efx);
         void (*stop_stats)(struct efx_nic *efx);
         void (*set_id_led)(struct efx_nic *efx, enum efx_led_mode mode);
         void (*push_irq_moderation)(struct efx_channel *channel);
diff --git a/drivers/net/ethernet/sfc/nic.c b/drivers/net/ethernet/sfc/nic.c
index 9c90bf56090f..79226b19e3c4 100644
--- a/drivers/net/ethernet/sfc/nic.c
+++ b/drivers/net/ethernet/sfc/nic.c
@@ -519,3 +519,15 @@ void efx_nic_update_stats(const struct efx_hw_stat_desc *desc, size_t count,
                 }
         }
 }
+
+void efx_nic_fix_nodesc_drop_stat(struct efx_nic *efx, u64 *rx_nodesc_drops)
+{
+        /* if down, or this is the first update after coming up */
+        if (!(efx->net_dev->flags & IFF_UP) || !efx->rx_nodesc_drops_prev_state)
+                efx->rx_nodesc_drops_while_down +=
+                        *rx_nodesc_drops - efx->rx_nodesc_drops_total;
+        efx->rx_nodesc_drops_total = *rx_nodesc_drops;
+        efx->rx_nodesc_drops_prev_state = !!(efx->net_dev->flags & IFF_UP);
+        *rx_nodesc_drops -= efx->rx_nodesc_drops_while_down;
+}
+
diff --git a/drivers/net/ethernet/sfc/nic.h b/drivers/net/ethernet/sfc/nic.h
index fe71e81ee8bf..7ac9c000696f 100644
--- a/drivers/net/ethernet/sfc/nic.h
+++ b/drivers/net/ethernet/sfc/nic.h
@@ -775,6 +775,7 @@ size_t efx_nic_describe_stats(const struct efx_hw_stat_desc *desc, size_t count,
 void efx_nic_update_stats(const struct efx_hw_stat_desc *desc, size_t count,
                           const unsigned long *mask, u64 *stats,
                           const void *dma_buf, bool accumulate);
+void efx_nic_fix_nodesc_drop_stat(struct efx_nic *efx, u64 *stat);
 
 #define EFX_MAX_FLUSH_TIME 5000
 
diff --git a/drivers/net/ethernet/sfc/siena.c b/drivers/net/ethernet/sfc/siena.c
index d034bcd124ef..f2a7ad4c76aa 100644
--- a/drivers/net/ethernet/sfc/siena.c
+++ b/drivers/net/ethernet/sfc/siena.c
@@ -458,6 +458,8 @@ static int siena_try_update_nic_stats(struct efx_nic *efx)
                 return -EAGAIN;
 
         /* Update derived statistics */
+        efx_nic_fix_nodesc_drop_stat(efx,
+                                     &stats[SIENA_STAT_rx_nodesc_drop_cnt]);
         efx_update_diff_stat(&stats[SIENA_STAT_tx_good_bytes],
                              stats[SIENA_STAT_tx_bytes] -
                              stats[SIENA_STAT_tx_bad_bytes]);
@@ -878,6 +880,7 @@ const struct efx_nic_type siena_a0_nic_type = {
         .describe_stats = siena_describe_nic_stats,
         .update_stats = siena_update_nic_stats,
         .start_stats = efx_mcdi_mac_start_stats,
+        .pull_stats = efx_mcdi_mac_pull_stats,
         .stop_stats = efx_mcdi_mac_stop_stats,
         .set_id_led = efx_mcdi_set_id_led,
         .push_irq_moderation = siena_push_irq_moderation,