1 files changed, 75 insertions, 15 deletions

diff --git a/drivers/net/ethernet/sfc/nic.c b/drivers/net/ethernet/sfc/nic.c
index 0ad790cc473c..f9f5df8b51fe 100644
--- a/drivers/net/ethernet/sfc/nic.c
+++ b/drivers/net/ethernet/sfc/nic.c
@@ -591,12 +591,22 @@ void efx_nic_init_rx(struct efx_rx_queue *rx_queue)
         struct efx_nic *efx = rx_queue->efx;
         bool is_b0 = efx_nic_rev(efx) >= EFX_REV_FALCON_B0;
         bool iscsi_digest_en = is_b0;
+        bool jumbo_en;
+
+        /* For kernel-mode queues in Falcon A1, the JUMBO flag enables
+         * DMA to continue after a PCIe page boundary (and scattering
+         * is not possible).  In Falcon B0 and Siena, it enables
+         * scatter.
+         */
+        jumbo_en = !is_b0 || efx->rx_scatter;
 
         netif_dbg(efx, hw, efx->net_dev,
                   "RX queue %d ring in special buffers %d-%d\n",
                   efx_rx_queue_index(rx_queue), rx_queue->rxd.index,
                   rx_queue->rxd.index + rx_queue->rxd.entries - 1);
 
+        rx_queue->scatter_n = 0;
+
         /* Pin RX descriptor ring */
         efx_init_special_buffer(efx, &rx_queue->rxd);
 
@@ -613,8 +623,7 @@ void efx_nic_init_rx(struct efx_rx_queue *rx_queue)
                               FRF_AZ_RX_DESCQ_SIZE,
                               __ffs(rx_queue->rxd.entries),
                               FRF_AZ_RX_DESCQ_TYPE, 0 /* kernel queue */ ,
-                              /* For >=B0 this is scatter so disable */
-                              FRF_AZ_RX_DESCQ_JUMBO, !is_b0,
+                              FRF_AZ_RX_DESCQ_JUMBO, jumbo_en,
                               FRF_AZ_RX_DESCQ_EN, 1);
         efx_writeo_table(efx, &rx_desc_ptr, efx->type->rxd_ptr_tbl_base,
                          efx_rx_queue_index(rx_queue));
@@ -968,13 +977,24 @@ static u16 efx_handle_rx_not_ok(struct efx_rx_queue *rx_queue,
                 EFX_RX_PKT_DISCARD : 0;
 }
 
-/* Handle receive events that are not in-order. */
-static void
+/* Handle receive events that are not in-order. Return true if this
+ * can be handled as a partial packet discard, false if it's more
+ * serious.
+ */
+static bool
 efx_handle_rx_bad_index(struct efx_rx_queue *rx_queue, unsigned index)
 {
+        struct efx_channel *channel = efx_rx_queue_channel(rx_queue);
         struct efx_nic *efx = rx_queue->efx;
         unsigned expected, dropped;
 
+        if (rx_queue->scatter_n &&
+            index == ((rx_queue->removed_count + rx_queue->scatter_n - 1) &
+                      rx_queue->ptr_mask)) {
+                ++channel->n_rx_nodesc_trunc;
+                return true;
+        }
+
         expected = rx_queue->removed_count & rx_queue->ptr_mask;
         dropped = (index - expected) & rx_queue->ptr_mask;
         netif_info(efx, rx_err, efx->net_dev,
@@ -983,6 +1003,7 @@ efx_handle_rx_bad_index(struct efx_rx_queue *rx_queue, unsigned index)
 
         efx_schedule_reset(efx, EFX_WORKAROUND_5676(efx) ?
                            RESET_TYPE_RX_RECOVERY : RESET_TYPE_DISABLE);
+        return false;
 }
 
 /* Handle a packet received event
@@ -998,7 +1019,7 @@ efx_handle_rx_event(struct efx_channel *channel, const efx_qword_t *event)
         unsigned int rx_ev_desc_ptr, rx_ev_byte_cnt;
         unsigned int rx_ev_hdr_type, rx_ev_mcast_pkt;
         unsigned expected_ptr;
-        bool rx_ev_pkt_ok;
+        bool rx_ev_pkt_ok, rx_ev_sop, rx_ev_cont;
         u16 flags;
         struct efx_rx_queue *rx_queue;
         struct efx_nic *efx = channel->efx;
@@ -1006,21 +1027,56 @@ efx_handle_rx_event(struct efx_channel *channel, const efx_qword_t *event)
         if (unlikely(ACCESS_ONCE(efx->reset_pending)))
                 return;
 
-        /* Basic packet information */
-        rx_ev_byte_cnt = EFX_QWORD_FIELD(*event, FSF_AZ_RX_EV_BYTE_CNT);
-        rx_ev_pkt_ok = EFX_QWORD_FIELD(*event, FSF_AZ_RX_EV_PKT_OK);
-        rx_ev_hdr_type = EFX_QWORD_FIELD(*event, FSF_AZ_RX_EV_HDR_TYPE);
-        WARN_ON(EFX_QWORD_FIELD(*event, FSF_AZ_RX_EV_JUMBO_CONT));
-        WARN_ON(EFX_QWORD_FIELD(*event, FSF_AZ_RX_EV_SOP) != 1);
+        rx_ev_cont = EFX_QWORD_FIELD(*event, FSF_AZ_RX_EV_JUMBO_CONT);
+        rx_ev_sop = EFX_QWORD_FIELD(*event, FSF_AZ_RX_EV_SOP);
         WARN_ON(EFX_QWORD_FIELD(*event, FSF_AZ_RX_EV_Q_LABEL) !=
                 channel->channel);
 
         rx_queue = efx_channel_get_rx_queue(channel);
 
         rx_ev_desc_ptr = EFX_QWORD_FIELD(*event, FSF_AZ_RX_EV_DESC_PTR);
-        expected_ptr = rx_queue->removed_count & rx_queue->ptr_mask;
-        if (unlikely(rx_ev_desc_ptr != expected_ptr))
-                efx_handle_rx_bad_index(rx_queue, rx_ev_desc_ptr);
+        expected_ptr = ((rx_queue->removed_count + rx_queue->scatter_n) &
+                        rx_queue->ptr_mask);
+
+        /* Check for partial drops and other errors */
+        if (unlikely(rx_ev_desc_ptr != expected_ptr) ||
+            unlikely(rx_ev_sop != (rx_queue->scatter_n == 0))) {
+                if (rx_ev_desc_ptr != expected_ptr &&
+                    !efx_handle_rx_bad_index(rx_queue, rx_ev_desc_ptr))
+                        return;
+
+                /* Discard all pending fragments */
+                if (rx_queue->scatter_n) {
+                        efx_rx_packet(
+                                rx_queue,
+                                rx_queue->removed_count & rx_queue->ptr_mask,
+                                rx_queue->scatter_n, 0, EFX_RX_PKT_DISCARD);
+                        rx_queue->removed_count += rx_queue->scatter_n;
+                        rx_queue->scatter_n = 0;
+                }
+
+                /* Return if there is no new fragment */
+                if (rx_ev_desc_ptr != expected_ptr)
+                        return;
+
+                /* Discard new fragment if not SOP */
+                if (!rx_ev_sop) {
+                        efx_rx_packet(
+                                rx_queue,
+                                rx_queue->removed_count & rx_queue->ptr_mask,
+                                1, 0, EFX_RX_PKT_DISCARD);
+                        ++rx_queue->removed_count;
+                        return;
+                }
+        }
+
+        ++rx_queue->scatter_n;
+        if (rx_ev_cont)
+                return;
+
+        rx_ev_byte_cnt = EFX_QWORD_FIELD(*event, FSF_AZ_RX_EV_BYTE_CNT);
+        rx_ev_pkt_ok = EFX_QWORD_FIELD(*event, FSF_AZ_RX_EV_PKT_OK);
+        rx_ev_hdr_type = EFX_QWORD_FIELD(*event, FSF_AZ_RX_EV_HDR_TYPE);
 
         if (likely(rx_ev_pkt_ok)) {
                 /* If packet is marked as OK and packet type is TCP/IP or
@@ -1048,7 +1104,11 @@ efx_handle_rx_event(struct efx_channel *channel, const efx_qword_t *event)
         channel->irq_mod_score += 2;
 
         /* Handle received packet */
-        efx_rx_packet(rx_queue, rx_ev_desc_ptr, rx_ev_byte_cnt, flags);
+        efx_rx_packet(rx_queue,
+                      rx_queue->removed_count & rx_queue->ptr_mask,
+                      rx_queue->scatter_n, rx_ev_byte_cnt, flags);
+        rx_queue->removed_count += rx_queue->scatter_n;
+        rx_queue->scatter_n = 0;
 }
 
 /* If this flush done event corresponds to a &struct efx_tx_queue, then